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1

Explosives detection by nuclear quadrupole resonance (NQR)  

Microsoft Academic Search

Pure nuclear quadrupole resonance (NQR) of 14N nuclei is quite promising as a method for detecting explosives such as RDX and contraband narcotics such as cocaine and heroin in quantities of interest. Pure NQR is conducted without an external applied magnetic field, so potential concerns about damage to magnetically encoded data or exposure of personnel to large magnetic fields are

Allen N. Garroway; M. L. Buess; J. P. Yesinowski; J. B. Miller; Ronald A. Krauss

1994-01-01

2

Nuclear quadrupole resonance studies in semi-metallic structures  

NASA Technical Reports Server (NTRS)

Both experimental and theoretical studies are presented on spectrum analysis of nuclear quadrupole resonance of antimony and arsenic tellurides. Numerical solutions for secular equations of the quadrupole interaction energy are also discussed.

Murty, A. N.

1974-01-01

3

Extended Townes-Dailey Analysis of the Nuclear Quadrupole Coupling Tensor  

NASA Astrophysics Data System (ADS)

One simple way to understand nuclear quadrupole coupling constants is by invoking the model of Townes and Dailey. This model, involving the field gradients generated by p electrons, has usually been used to estimate the fractional ionic character of diatomic molecules from a single nuclear quadrupole coupling constant. We will extend the model to three dimensions for polyatomic molecules and use it to rationalize the perhaps unexpected nuclear quadrupole coupling tensor for molecules such as monobromogermylene (HGeBr) and compare this simple calculation with ab initio results. C. H. Townes, B. P. Dailey, J. Chem. Phys. 17, 782 (1949)

Novick, Stewart E.

2009-06-01

4

Density functional theory calculations of nuclear quadrupole coupling constants with calibrated 14N quadrupole moments  

NASA Astrophysics Data System (ADS)

Density functional calculations of the electric field gradient tensor at the nitrogen nucleus in 13 test molecules, containing 14 nitrogen sites, have been performed using the linear combination of Gaussian-type orbital Kohn-Sham density functional theory (LCGTO-KSDFT) approach. Local and gradient corrected functionals were used for all-electron calculations. All the molecular structures were optimized at their respective levels of theory with extended basis sets. Calibrated 14N nuclear quadrupole moments were obtained through a fitting procedure between calculated electric field gradients and experimental nuclear quadrupole coupling constants of the test set of molecules for each basis set and functional considered. With these calibrated 14N nuclear quadrupole moments, the nuclear quadrupole coupling constants of the following selected systems were determined: fluoromethylisonitrile, pyridine, pyrrole, imadazole, pyrazole, 1,8-bis(dimethyl-amino)naphthalene, cyclotetramethylenetetranitramine, cocaine and heroin.

Sicilia, E.; de Luca, G.; Chiodo, S.; Russo, N.; Calaminici, P.; Koster, A. M.; Jug, K.

5

Electronic configuration and nuclear quadrupole interaction in higher transition elements  

Microsoft Academic Search

Atomic self-consistent-field Hartree-Fock calculations were performed for several transition elements in several configurations, in particular for transition elements of the third period, in order to calculate for the outer d and p orbitals. Results are used to discuss possible mechanisms influencing the nuclear quadrupole interaction of compounds of transition elements. In particular, it is attempted to explain the large

Darci M. S. Esquivel; Diana Guenzburger; J. Danon

1979-01-01

6

Nuclear quadrupole moment of the {sup 99}Tc ground state  

SciTech Connect

By combining first-principles calculations and existing nuclear magnetic resonance (NMR) experiments, we determine the quadrupole moment of the 9/2{sup +} ground state of {sup 99}Tc to be (-)0.14(3)b. This confirms the value of -0.129(20)b, which is currently believed to be the most reliable experimental determination, and disagrees with two earlier experimental values. We supply ab initio calculated electric-field gradients for Tc in YTc{sub 2} and ZrTc{sub 2}. If this calculated information would be combined with yet to be performed Tc-NMR experiments in these compounds, the error bar on the {sup 99}Tc ground state quadrupole moment could be further reduced.

Errico, Leonardo [Departamento de Fisica and Instituto de Fisica La Plata (IFLP, CCT-La Plata, CONICET-UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Casilla de Coreo 67, 1900 La Plata (Argentina); Universidad Nacional del Noroeste Bonaerense (UNNOBA), Monteagudo 2772, 2700 Pergamino (Argentina); Darriba, German; Renteria, Mario [Departamento de Fisica and Instituto de Fisica La Plata (IFLP, CCT-La Plata, CONICET-UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Casilla de Coreo 67, 1900 La Plata (Argentina); Tang Zhengning [Bayerisches Geoinstitut, Universitaet Bayreuth, DE-95440 Bayreuth (Germany); Emmerich, Heike [Computational Materials Engineering (CME), Institute for Minerals Engineering (GHI), Center for Computational Engineering Science - CCES and Juelich-Aachen Research Alliance - JARA, RWTH Aachen University, DE-52064 Aachen (Germany); Cottenier, Stefaan [Computational Materials Engineering (CME), Institute for Minerals Engineering (GHI), Center for Computational Engineering Science - CCES and Juelich-Aachen Research Alliance - JARA, RWTH Aachen University, DE-52064 Aachen (Germany) and Instituut voor Kern-en Stralingsfysica and INPAC, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, BE-3001 Leuven (Belgium)

2008-05-15

7

Microscopic understanding for the simplicity of the quadrupole moments newly observed in Cd isotopes  

E-print Network

The simplicity in the nuclear quadrupole moments reported recently in $^{107-129}$Cd, i.e., a linear increase of the ${11/2}^-$ quadrupole moments, is investigated microscopically with the covariant density functional theory. Using the newly developed functional PC-PK1, the quadrupole moments as well as their linear increase tendency with the neutron number are excellently reproduced without any {\\it ad hoc} parameters. The core polarization is found to be very important and contributes almost half of the quadrupole moments. The simplicity of the linear increase is revealed to be due to the pairing correlation which smears out the abrupt changes induced by the single-particle shell structure.

P. W. Zhao; S. Q. Zhang; J. Meng

2013-11-13

8

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

NASA Technical Reports Server (NTRS)

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.

Murty, A. N.

1978-01-01

9

Low-frequency nuclear quadrupole resonance with a dc SQUID  

SciTech Connect

Conventional pure nuclear quadrupole resonance (NQR) is a technique well suited for the study of very large quadrupolar interactions. Numerous nuclear magnetic resonance (NMR) techniques have been developed for the study of smaller quadrupolar interactions. However, there are many nuclei which have quadrupolar interactions of intermediate strength. Quadrupolar interactions in this region have traditionally been difficult or unfeasible to detect. This work describes the development and application of a SQUID NQR technique which is capable of measuring intermediate strength quadrupolar interactions, in the range of a few hundred kilohertz to several megahertz. In this technique, a dc SQUID (Superconducting QUantum Interference Device) is used to monitor the longitudinal sample magnetization, as opposed to the transverse magnetization, as a rf field is swept in frequency. This allows the detection of low-frequency nuclear quadrupole resonances over a very wide frequency range with high sensitivity. The theory of this NQR technique is discussed and a description of the dc SQUID system is given. In the following chapters, the spectrometer is discussed along with its application to the study of samples containing half-odd-integer spin quadrupolar nuclei, in particular boron-11 and aluminum-27. The feasibility of applying this NQR technique in the study of samples containing integer spin nuclei is discussed in the last chapter. 140 refs., 46 figs., 6 tabs.

Chang, J.W.

1991-07-01

10

The two-frequency nuclear quadrupole resonance for explosives detection  

Microsoft Academic Search

The two-frequency nuclear quadrupole resonance (NQR) of14N nuclei is described for purposes of explosives detection. Two applications are known: two-frequency NQR for increasing the\\u000a signal intensity, two-frequency NQR for improved reliability of explosives detection. The two-frequency experiments were carried\\u000a out in hexahydro-1,3,5-trinitro-s-triazine C3H6N6O6 and sodium nitrite NaNO2 as a substitute for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocycine C4H8N8O8. The two-frequency sequences for NQR are proposed

G. V. Mozjoukhine

2000-01-01

11

New technologies: nuclear quadrupole resonance as an explosive and narcotic detection technique  

Microsoft Academic Search

Possibilities of detecting nuclear quadrupole resonance (NQR) signals in explosives and drugs are considered. Direct and indirect NQR techniques for searching substances are described and the potentialities of various experimental methods are compared.

Vadim S Grechishkin; Nikolai Ya Sinyavskii

1997-01-01

12

Nuclear electric quadrupole moment of 9Li using zero-field ?-detected NQR  

NASA Astrophysics Data System (ADS)

A ?-detected nuclear quadrupole resonance (NQR) spectrometer becomes a powerful tool to study changes in nuclear ground-state properties along isotopic chains when coupled to a laser excitation beamline to polarize the nuclei of interest. Recently, the ?-NQR technique in a zero magnetic field has been applied for the first time to measure the ratio of static nuclear quadrupole moments of 8, 9Li, Q9/Q8 = 0.966 75(9) denoted by Q8 for 8Li and Q9 for 9Li, respectively. This shows agreement with present literature values but with significantly improved precision. Based on the literature, the quadrupole moment for 8Li has been re-evaluated to be |Q8| = 32.6(5) mb. From this, the quadrupole moment for 9Li is calculated as |Q9| = 31.5(5) mb with the error being dominated by the error of Q8.

Voss, A.; Pearson, M. R.; Billowes, J.; Buchinger, F.; Chow, K. H.; Crawford, J. E.; Hossein, M. D.; Kiefl, R. F.; Levy, C. D. P.; MacFarlane, W. A.; Mané, E.; Morris, G. D.; Parolin, T. J.; Saadaoui, H.; Salman, Z.; Smadella, M.; Song, Q.; Wang, D.

2011-07-01

13

DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers  

DOEpatents

A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced.

Fan, Non Q. (San Diego, CA); Clarke, John (Berkeley, CA)

1993-01-01

14

DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers  

DOEpatents

A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced. 7 figures.

Fan, N.Q.; Clarke, J.

1993-10-19

15

Title: Quadrupole collective inertia in nuclear fission: cranking approximation  

E-print Network

Collective mass tensor derived from the cranking approximation to the adiabatic time-dependent Hartree-Fock-Bogoliubov (ATDHFB) approach is compared with that obtained in the Gaussian Overlap Approximation (GOA) to the generator coordinate method. Illustrative calculations are carried out for one-dimensional quadrupole fission pathways in 256Fm. It is shown that the collective mass exhibits strong variations with the quadrupole collective coordinate. These variations are related to the changes in the intrinsic shell structure. The differences between collective inertia obtained in cranking and perturbative cranking approximations to ATDHFB, and within GOA, are discussed.

A. Baran; J. A. Sheikh; J. Dobaczewski; W. Nazarewicz

2010-07-21

16

Subfemtotesla radio-frequency atomic magnetometer for detection of nuclear quadrupole resonance  

E-print Network

Subfemtotesla radio-frequency atomic magnetometer for detection of nuclear quadrupole resonance S 20 November 2006 A radio-frequency tunable atomic magnetometer is developed for detection of nuclearHz 14 N NQR frequency of ammonium nitrate. A potential application of the magnetometer is detection

Romalis, Mike

17

An effect of nuclear electric quadrupole moments in thermonuclear fusion plasmas  

NASA Technical Reports Server (NTRS)

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.

De, B. R.; Srnka, L. J.

1978-01-01

18

Quadrupole splitting and isomer shifts in Te oxides investigated using nuclear forward scattering  

NASA Astrophysics Data System (ADS)

Nuclear forward scattering by 125Te is a viable alternative to conventional 125Te Mössbauer spectroscopy avoiding all source related issues. Using reference compounds with known hyperfine parameters and Te oxides exhibiting stereochemically active lone pairs, we show that nuclear forward scattering by 125Te can be reliably used to extract quadrupole splitting energy and relative isomer shift. The rough correlation between Te-Ocoordination and quadrupole splitting energy as put forward by Takeda and Greenwood (J. Chem. Soc. Dalton, 2207, 1975), is corroborated by the presented results.

Klobes, Benedikt; Barrier, Nicolas; Vertruyen, Benedicte; Martin, Christine; Hermann, Raphaël P.

2014-04-01

19

Observation of nuclear quadrupole hyperfine structure in the infrared spectrum of hydrogen iodide using a tunable-diode laser  

NASA Technical Reports Server (NTRS)

Nuclear quadrupole hyperfine structure has been observed in the 1-0 vibration-rotation band of hydrogen iodide with a tunable-diode laser. The measured splittings agree well with microwave measurements of the HI molecule. Evidence for a slight change in the iodine nuclear quadrupole coupling constant from the ground to first excited vibrational state in hydrogen iodide was found.

Strow, L. L.

1980-01-01

20

Table of nuclear magnetic dipole and electric quadrupole moments  

SciTech Connect

The table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin, and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to late 2004. Many of the entries prior to 1988 follow those in Raghavan [At. Data Nucl. Data Tables 42 (1989) 189].

Stone, N.J. [Oxford Physics, Clarendon Laboratory, Oxford OX1 3PU (United Kingdom)]. E-mail: n.stone1@physics.oxford.ac.uk

2005-05-01

21

Narcotics and explosives detection by 14N pure nuclear quadrupole resonance  

Microsoft Academic Search

Pure nuclear quadrupole resonance (NQR) of 14N nuclei is quite promising as a method for detecting explosives such as RDX and contraband narcotics such as cocaine and heroin in quantities of interest. Pure NQR is conducted without an external applied magnetic field, so potential concerns about damage to magnetically encoded data or exposure of personnel to large magnetic fields are

Allen N. Garroway; M. L. Buess; J. P. Yesinowski; J. B. Miller

1994-01-01

22

Detection of RDX and TNT mine like targets by nuclear quadrupole resonance  

Microsoft Academic Search

Nuclear quadrupole resonance (NQR) is being researched in order to confirm the presence of explosives as part of landmine sensor suites for the UK MOD hand held and vehicle mounted detection applied research programs. A low power NQR system has been developed as a non-contacting, but short range, detection method for explosives typically found in landmines. The results of stand-off

Robert M. Deas; Ian A. Burch; Daniel M. Port

2002-01-01

23

Communication: Nuclear quadrupole moment-induced Cotton-Mouton effect in noble gas atoms  

SciTech Connect

New, high-sensitivity and high-resolution spectroscopic and imaging methods may be developed by exploiting nuclear magneto-optic effects. A first-principles electronic structure formulation of nuclear electric quadrupole moment-induced Cotton-Mouton effect (NQCME) is presented for closed-shell atoms. In NQCME, aligned quadrupole moments alter the index of refraction of the medium along with and perpendicular to the direction of nuclear alignment. The roles of basis-set convergence, electron correlation, and relativistic effects are investigated for three quadrupolar noble gas isotopes: {sup 21}Ne, {sup 83}Kr, and {sup 131}Xe. The magnitude of the resulting ellipticities is predicted to be 10{sup ?4}–10{sup ?6} rad/(M cm) for fully spin-polarized nuclei. These should be detectable in the Voigt setup. Particularly interesting is the case of {sup 131}Xe, in which a high degree of spin polarization can be achieved via spin-exchange optical hyperpolarization.

Fu, Li-juan; Vaara, Juha, E-mail: juha.vaara@iki.fi [NMR Research Group, Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland)] [NMR Research Group, Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland); Rizzo, Antonio [Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche (IPCF-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa (Italy)] [Istituto per i Processi Chimico-Fisici del Consiglio Nazionale delle Ricerche (IPCF-CNR), Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa (Italy)

2013-11-14

24

The Nuclear Quadrupole Interaction of 204mPb in Lead Oxides  

NASA Astrophysics Data System (ADS)

The nuclear quadrupole interaction of 204mPb in lead oxides has been measured by ? ? time differential perturbed angular correlation. Ab-initio calculations of the electric field gradients and X-ray diffraction allowed the assignment of the detected nuclear quadrupole interactions to the different Pb sites in the PbO phases litharge and massicote as well as in Pb3O4. The TDPAC probe 204mPb was produced with a 204Bi/204mPb-generator at the home laboratory at the University of Leipzig. The use of a high performance liquid chromatography system increased significantly the yield, the specific activity of 204mPb, and reduced the acidic concentration of the eluate.

Friedemann, S.; Heinrich, F.; Haas, H.; Tröger, W.

2004-12-01

25

Nuclear quadrupole resonance of explosives: Simultaneous detection of RDX and PETN in semtex  

Microsoft Academic Search

We have used nuclear quadrupole resonance (NQR) for the detection of14N in explosives and introduce a new method for the simultaneous detection of the explosives cyclotrimethylene trinitramine\\u000a (RDX) and pentaerythritol tetranitrate (PETN). We have developed an interleaved pulse sequence, which provides efficient excitation\\u000a of both RDX and PETN, to drive a solenoid coil that is doubly resonant at 3.41 and

R. I. Jenkinson; J. M. Bradley; G. N. Shilstone

2004-01-01

26

? -detected nuclear quadrupole resonance with a low-energy beam of 8Li+  

NASA Astrophysics Data System (ADS)

A nuclear quadrupole resonance (NQR) spectrum of Li8 has been observed in a single crystal of SrTiO3 using a beam of low-energy highly polarized radioactive Li+8 . The resonances were detected by monitoring the ? -decay anisotropy as a function of a small audio frequency magnetic field. These results demonstrate that low energy nuclear spin polarized Li8 can be used as a sensitive probe of the local magnetic and electronic environment in nanostructures and ultrathin films in zero static applied magnetic field.

Salman, Z.; Reynard, E. P.; Macfarlane, W. A.; Chow, K. H.; Chakhalian, J.; Kreitzman, S. R.; Daviel, S.; Levy, C. D. P.; Poutissou, R.; Kiefl, R. F.

2004-09-01

27

Nuclear quadrupole resonances in compact vapor cells: the crossover from the NMR to the NQR interaction regimes  

E-print Network

We present the first experimental study that maps the transformation of nuclear quadrupole resonances from the pure nuclear quadrupole regime to the quadrupole-perturbed Zeeman regime. The transformation presents an interesting quantum-mechanical problem, since the quantization axis changes from being aligned along the axis of the electric-field gradient tensor to being aligned along the magnetic field. We achieve large nuclear quadrupole shifts for I = 3/2 131-Xe by using a 1 mm^3 cubic cell with walls of different materials. When the magnetic and quadrupolar interactions are of comparable size, perturbation theory is not suitable for calculating the transition energies. Rather than use perturbation theory, we compare our data to theoretical calculations using a Liouvillian approach and find excellent agreement.

E. A. Donley; J. L. Long; T. C. Liebisch; E. R. Hodby; T. A. Fisher; J. Kitching

2008-10-21

28

Robinson-type nuclear quadrupole resonance spectrometer adapted to field-effect transistors  

NASA Astrophysics Data System (ADS)

A nuclear quadrupole resonance spectrometer, the Robinson circuit adapted with field-effect transistors, has operated satisfactorily up to 30 MHz with rf levels ranging from 40 mV to 2.6 V peak to peak across the sample coil. The S/N ratio of 14N in hexamethylenetetramin is 85 at room temperature and 150 at 77 K, with a sample volume of 6 cm3 and a time constant of 10 s. The spectrometer is also capable of measuring the spin-lattice relaxation time by the saturation method.

Lee, Jongmin; Choh, Sung Ho

1982-02-01

29

14N nuclear quadrupole resonance of p-nitrotoluene using a high-Tc rf SQUID  

NASA Astrophysics Data System (ADS)

Using a high-Tc radio-frequency superconducting quantum interference device (rf SQUID), we successfully detected nuclear quadrupole resonance (NQR) at about 887 kHz for 14N in p-nitrotoluene (PNT). A normal metal transformer made of copper wire was used to improve the sensitivity of the high-Tc rf SQUID and pulse-controlled rf switches and cross diodes were inserted in the transformer to reduce the influence of the strong excitation field. The preliminary results for NQR detection using the high-Tc SQUID had a similar signal-to-noise ratio to that of using a low noise preamplifier.

He, D. F.; Tachiki, M.; Itozaki, H.

2007-03-01

30

Sensing of chemical substances using SQUID-based nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

Using a high- Tc radio frequency superconducting quantum interference device (rf SQUID) with a normal metal transformer, we successfully detected the nuclear quadrupole resonance (NQR) at about 888 kHz of 14N in p-nitrotoluene (PNT) at room temperature. Only one coil was used as the resonator coil for the transmission and the pickup coil of the transformer. To reduce the influence of the strong excitation field, cross diodes and switches were inserted in the transformer. The signal-to-noise ratio of the NQR spectrum using high- Tc rf SQUID system was comparable to that of using a low noise preamplifier.

Tachiki, M.; He, D. F.; Itozaki, H.

2007-10-01

31

Simultaneous Application of ?-detected LMR and NMR Spectroscopy for Measurement of Nuclear Dipole and Quadrupole Moments  

NASA Astrophysics Data System (ADS)

We report the successful application of simultaneous ?-detected LMR (Level Mixing Resonance) and NMR (Nuclear Magnetic Resonance) techniques on ^12B implanted in a Mg single crystal. LMR experiments performed on ?-decaying nuclei allow determination of quadrupole frequency to magnetic moment ratio, and the addition of RF perturbation and subsequent determination of the NMR allows for extraction of each of the two individual moments. A major advantage of this technique is that projectile fragment alignment, which is readily produced in a projectile-fragmentation reaction, is transferred to nuclear polarization via the perturbing interaction in the non-cubic crystal. >From resonant change of the ?-decay asymmetry as a function of static magnetic field and applied RF we obtain information on nuclear structure and on initial alignment of the projectile fragments. This combined technique was then applied to neutron-rich ^18N spin-aligned projectile fragments, the results of which will be presented.

Rogers, W. F.; Neyens, G.; Coulier, N.; Teughels, S.; Vyvey, K.; Ternier, S.; Georgiev, G.; Coussement, R.; Lépine-Szily, A.

1997-10-01

32

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

NASA Astrophysics Data System (ADS)

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 ?-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.)

Pati, Ranjit

33

PHYSICAL REVIEW B VOLUME 48, NUMBER 13 1 OCTOBER 1993-1 Determination of the absolute sign of nuclear quadrupole interactions by laser radio-frequency  

E-print Network

PHYSICAL REVIEW B VOLUME 48, NUMBER 13 1 OCTOBER 1993-1 Determination of the absolute sign of nuclear quadrupole interactions by laser radio-frequency double-resonance experiments Tilo Blasberg the quadrupole moment of nuclear spins I > + with the electric-field-gradient (EFG) tensor leads to a splitting

Suter, Dieter

34

Time-reversal symmetry violation in molecules induced by nuclear magnetic quadrupole moments  

E-print Network

Recent measurements in paramagnetic molecules improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Time-reversal (T) and parity (P) symmetry violation in molecules may also come from their nuclei. We point out that nuclear T,P-odd effects are amplified in paramagnetic molecules containing deformed nuclei, where the primary effects arise from the T,P-odd nuclear magnetic quadrupole moment (MQM). We perform calculations of T,P-odd effects in the molecules TaN, ThO, ThF$^+$, HfF$^+$, YbF, HgF, and BaF induced by MQMs. We compare our results with those for the diamagnetic TlF molecule, where the T,P-odd effects are produced by the nuclear Schiff moment. We argue that measurements in molecules with MQMs may provide improved limits on the strength of T,P-odd nuclear forces, on the proton, neutron and quark EDMs, on quark chromo-EDMs, and on the QCD $\\theta$-term and CP-violating quark interactions.

V. V. Flambaum; D. DeMille; M. G. Kozlov

2014-06-25

35

Time-reversal symmetry violation in molecules induced by nuclear magnetic quadrupole moments  

E-print Network

Recent measurements in paramagnetic molecules improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Time-reversal (T) and parity (P) symmetry violation in molecules may also come from their nuclei. We point out that nuclear T,P-odd effects are amplified in paramagnetic molecules containing deformed nuclei, where the primary effects arise from the T,P-odd nuclear magnetic quadrupole moment (MQM). We perform calculations of T,P-odd effects in the molecules TaN, ThO, ThF$^+$, HfF$^+$, YbF, HgF, and BaF induced by MQMs. We compare our results with those for the diamagnetic TlF molecule, where the T,P-odd effects are produced by the nuclear Schiff moment. We argue that measurements in molecules with MQMs may provide improved limits on the strength of T,P-odd nuclear forces, on the proton, neutron and quark EDMs, on quark chromo-EDMs, and on the QCD $\\theta$-term and CP-violating quark interactions.

Flambaum, V V; Kozlov, M G

2014-01-01

36

Time-Reversal Symmetry Violation in Molecules Induced by Nuclear Magnetic Quadrupole Moments  

NASA Astrophysics Data System (ADS)

Recent measurements in paramagnetic molecules improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Time-reversal (T) and parity (P) symmetry violation in molecules may also come from their nuclei. We point out that nuclear T, P-odd effects are amplified in paramagnetic molecules containing deformed nuclei, where the primary effects arise from the T, P-odd nuclear magnetic quadrupole moment (MQM). We perform calculations of T, P-odd effects in the molecules TaN, ThO, ThF+, HfF+, YbF, HgF, and BaF induced by MQMs. We compare our results with those for the diamagnetic TlF molecule, where the T, P-odd effects are produced by the nuclear Schiff moment. We argue that measurements in molecules with MQMs may provide improved limits on the strength of T, P-odd nuclear forces, on the proton, neutron, and quark EDMs, on quark chromo-EDMs, and on the QCD ? term and CP-violating quark interactions.

Flambaum, V. V.; DeMille, D.; Kozlov, M. G.

2014-09-01

37

Time-reversal symmetry violation in molecules induced by nuclear magnetic quadrupole moments.  

PubMed

Recent measurements in paramagnetic molecules improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Time-reversal (T) and parity (P) symmetry violation in molecules may also come from their nuclei. We point out that nuclear T, P-odd effects are amplified in paramagnetic molecules containing deformed nuclei, where the primary effects arise from the T, P-odd nuclear magnetic quadrupole moment (MQM). We perform calculations of T, P-odd effects in the molecules TaN, ThO, ThF+, HfF+, YbF, HgF, and BaF induced by MQMs. We compare our results with those for the diamagnetic TlF molecule, where the T, P-odd effects are produced by the nuclear Schiff moment. We argue that measurements in molecules with MQMs may provide improved limits on the strength of T, P-odd nuclear forces, on the proton, neutron, and quark EDMs, on quark chromo-EDMs, and on the QCD ? term and CP-violating quark interactions. PMID:25238355

Flambaum, V V; DeMille, D; Kozlov, M G

2014-09-01

38

Crystallization of an amorphous solid studied by nuclear quadrupole double resonance  

NASA Astrophysics Data System (ADS)

Nuclear quadrupole double resonance (NQDR) is proposed as a method for quantitative observation of crystallization of amorphous solids. NQDR signals from amorphous and crystalline parts of a sample may be separated. The intensity I of the NQDR signal from the crystalline part of the sample is proportional to its mass. With increasing time the amorphous phase in the sample transforms to the crystal phase and the intensity I approaches its limiting value I0 corresponding to the complete transformation to the crystal phase. The ratio I/I0 is equal to the mass fraction of the crystalline part of the sample. The same experimental method can be used to determine the mass fraction of a given crystal polymorph in a mixture of crystal polymorphs. As an example we studied crystallization of amorphous nifedipine at 100 °C. The results of the NQDR study are compared to the published results of other studies.

Seliger, Janez; Žagar, Veselko

2013-06-01

39

Theoretical investigation of nuclear quadrupole interactions in DNA at first-principles level  

NASA Astrophysics Data System (ADS)

We have studied the nuclear quadrupole interactions (NQI) of the 14N, 17O and 2H nuclei in the nucleobases cytosine, adenine, guanine and thymine in the free state as well as when they are bonded to the sugar ring in DNA, simulated through a CH3 group attached to the nucleobases. The nucleobase uracil, which replaces thymine in RNA, has also been studied. Our results show that there are substantial indirect effects of the bonding with the sugar group in the nucleic acids on the NQI parameters e 2 qQ/h and ?. It is hoped that measurements of these NQI parameters in DNA will be available in the future to compare with our predictions. Our results provide the conclusion that for any property dependent on the electronic structures of the nucleic acids, the effects of the bonding between the nucleobases and the nucleic acid backbones have to be included.

Mahato, Dip N.; Dubey, Archana; Pink, R. H.; Scheicher, R. H.; Badu, S. R.; Nagamine, K.; Torikai, E.; Saha, H. P.; Chow, Lee; Huang, M. B.; Das, T. P.

2008-01-01

40

Theoretical investigation of nuclear quadrupole interactions in DNA at first-principles level  

NASA Astrophysics Data System (ADS)

We have studied the nuclear quadrupole interactions (NQI) of the 14N, 17O and 2H nuclei in the nucleobases cytosine, adenine, guanine and thymine in the free state as well as when they are bonded to the sugar ring in DNA, simulated through a CH3 group attached to the nucleobases. The nucleobase uracil, which replaces thymine in RNA, has also been studied. Our results show that there are substantial indirect effects of the bonding with the sugar group in the nucleic acids on the NQI parameters e 2 qQ/h and ?. It is hoped that measurements of these NQI parameters in DNA will be available in the future to compare with our predictions. Our results provide the conclusion that for any property dependent on the electronic structures of the nucleic acids, the effects of the bonding between the nucleobases and the nucleic acid backbones have to be included.

Mahato, Dip N.; Dubey, Archana; Pink, R. H.; Scheicher, R. H.; Badu, S. R.; Nagamine, K.; Torikai, E.; Saha, H. P.; Chow, Lee; Huang, M. B.; Das, T. P.

41

Role of spin state on the geometry and nuclear quadrupole resonance parameters in hemin complex.  

PubMed

Theoretical calculations of structural parameters, 57Fe, 14N and 17 O electric field gradient (EFG) tensors for full size-hemin group have been carried out using density functional theory. These calculations are intended to shed light on the difference between the geometry parameters, nuclear quadrupole coupling constants (QCC), and asymmetry parameters (eta Q) found in three spin states of hemin; doublet, quartet and sextet. The optimization results reveal a significant change for propionic groups and porphyrin plane in different spin states. It is found that all principal components of EFG tensor at the iron site are sensitive to electronic and geometry structures. A relationship between the EFG tensor at the 14N and 17 O sites and the spin state of hemin complex is also detected. PMID:18353527

Behzadi, Hadi; van der Spoel, David; Esrafili, Mehdi D; Parsafar, Gholam Abbas; Hadipour, Nasser L

2008-05-01

42

Multireference CI calculation of nuclear quadrupole coupling constants of CN + and CN -: rovibrational dependence  

NASA Astrophysics Data System (ADS)

The 14N quadrupole coupling constants of rovibrational levels of the X1? + and c1? + states of CN +, and the ground electronic state of CN - are calculated from molecular wavefunctions which explicitly describe nuclear displacement. From the electronic states considered, the excited 1? + state of CN + is predicted to exhibit the strongest N coupling, at least in the ground vibrational state. Compared to the vibrational dependence of the 14N QCC's, which is found to be significant in all cases, the rotational dependence is predicted to be unimportant. Special attention is paid to the assessment of adequacy of the expectation value approach to the evaluation of the electric field gradient tensor within the applied multireference configuration interaction formalism. Spectroscopic constants are derived from corresponding potential energy curves to testify to the quality of the correlated wave functions used.

Polák, R.; Fišer, J.

2002-07-01

43

Weak itinerant antiferromagnetism in PuIn3 explored using 115In nuclear quadrupole resonance.  

PubMed

The results of (115)In nuclear quadrupole resonance (NQR) measurements on PuIn3 are reported. Three of the four NQR lines of (115)In expected for nuclear spin I = 9/2 are observed. The equal spacing of these lines at 20 K yields the NQR frequency of ?Q = 10.45 MHz, and the asymmetry parameter of the electric field gradient ? = 0. The NQR line profile and the nuclear spin-lattice relaxation rate 1/T1 display an abrupt change at 14 K, which is associated with the onset of long-range antiferromagnetic order. The temperature dependences of the staggered magnetization MQ(T), extracted from the NQR spectra, and 1/T1 below TN = 14 K are well explained by the self-consistent renormalization (SCR) theory for spin fluctuations. In addition, the scaling between T1T and MQ(T)/MQ(0) is also consistent with the predictions of SCR theory, providing further evidence that PuIn3 is a weak itinerant antiferromagnet in which spin fluctuations around the antiferromagnetic wavevector play a major role in the system's behavior at finite temperatures. PMID:24334529

Chudo, H; Koutroulakis, G; Yasuoka, H; Bauer, E D; Tobash, P H; Mitchell, J N; Thompson, J D

2014-01-22

44

Nuclear quadrupole moment-induced Cotton-Mouton effect in molecules  

NASA Astrophysics Data System (ADS)

Nuclear magneto-optic effects could make important contributions to novel, high-sensitivity, and high-resolution spectroscopic and imaging methods that provide nuclear site-specific structural and dynamic information on molecular and materials systems. Here we present a first-principles electronic structure formulation of nuclear quadrupole moment-induced Cotton-Mouton effect in terms of response theory, as well as ab initio and density-functional theory calculations of this phenomenon for a series of molecular liquids: H2O, CH3NO2, CH3CH2OH, C6H6, C6H12 (cyclohexane), HI, XeF2, WF5Cl, and Pt(C2dtp)2. The roles of basis-set convergence, electron correlation, and relativistic effects are discussed. The estimated order of magnitude of the overall ellipticities induced to linearly polarized light is 10-3-10-7 rad/(M cm) for fully spin polarized nuclei. The cases with the largest presently obtained ellipticities should be detectable with modern instrumentation in the Voigt magneto-optic setup, particularly for the heavy nuclei.

Fu, Li-juan; Vaara, Juha

2014-01-01

45

Rabi and Larmor nuclear quadrupole double resonance of spin-1 nuclei.  

PubMed

We demonstrate the creation of two novel double-resonance conditions between spin-1 and spin-1/2 nuclei in a crystalline solid. Using a magnetic field oscillating at the spin-1/2 Larmor frequency, the nuclear quadrupole resonance (NQR) frequency is matched to the Rabi or Rabi plus Larmor frequency, as opposed to the Larmor frequency as is conventionally done. We derive expressions for the cross-polarization rate for all three conditions in terms of the relevant secular dipolar Hamiltonian, and demonstrate with these expressions how to measure the strength of the heterogenous dipolar coupling using only low magnetic fields. In addition, the combination of different resonance conditions permits the measurement of the spin-1/2 angular momentum vector using spin-1 NQR, opening up an alternate modality for the monitoring of low-field nuclear magnetic resonance. We use ammonium nitrate to explore these resonance conditions, and furthermore use the oscillating field to increase the signal-to-noise ratio per time by a factor of 3.5 for NQR detection of this substance. PMID:23231223

Prescott, D W; Malone, M W; Douglass, S P; Sauer, K L

2012-12-01

46

Temperature dependence of nuclear quadrupole coupling constant of ^7Li and ^93Nb in LiNbO_3^*  

NASA Astrophysics Data System (ADS)

It is well established that the ferroelectricity of LiNbO3 originates from the displacement of positive ions, lithium and niobium, relative to negative oxygen ions below T_c. The local structural environment of Li and Nb in the crystal is similar at room temperature. However, as the temperature increases they move opposite directions along the c-axis: Li ions move to the center of oxygen triangles while Nb move to the center of oxygen octahedra. The temperature dependence of the nuclear quadrupole coupling constant(QCC) of Li and Nb is quite different: the QCC of ^7Li increases while that of ^93Nb decreases as the temperature increases[1]. In order to understand this opposite tendency we calculated the electric field gradient(EFG) at the two sites due to the first and second nearest neighboring oxygen ions, by considering the effective charges. The calculated results turn out to be in good agreement with the temperature dependence of QCC for both cations in the crystal. * Supported by the National Research Laboratory Program(MOST). [1] H. J. Kim and S. H. Choh, J. Korean Phys. Soc. b28, 513 (1995).

Park, I.-W.; Choh, S. H.; Kim, H. J.; Kim, J. H.; Yoon, M.

2003-03-01

47

Noise-resilient multi-frequency surface sensor for nuclear quadrupole resonance.  

PubMed

A planar nuclear quadrupole resonance (NQR) sensor has been developed. The sensor is resilient to environmental noise and is capable of simultaneous independent multi-frequency operation. The device was constructed as an open multimodal birdcage structure, in which the higher modes, generally not used in magnetic resonance, are utilized for NQR detection. These modes have smooth distributions of the amplitudes of the corresponding radiofrequency magnetic fields everywhere along the sensor's surface. The phases of the fields, on the other hand, are cyclically shifted across the sensor's surface. Noise signals coming from distant sources, therefore, induce equal-magnitude cyclically phase-shifted currents in different parts of the sensor. When such cyclically phase-shifted currents arrive at the mode connection point, they destructively interfere with each other and are cancelled out. NQR signals of polycrystalline or disordered substances, however, are efficiently detected by these modes because they are insensitive to the phases of the excitation/detection. No blind spots exist along the sensor's surface. The sensor can be used for simultaneous detection of one or more substances in locations with environmental noise. PMID:18667343

Peshkovsky, A S; Cattena, C J; Cerioni, L M; Osán, T M; Forguez, J G; Peresson, W J; Pusiol, D J

2008-10-01

48

The temperature dependence of the nuclear quadrupole interaction of 44Ti(EC)44Sc in rutile  

NASA Astrophysics Data System (ADS)

The temperature dependence of the Nuclear Quadrupole Interaction on 44Sc in rutile was measured by Time Differential Perturbed Angular Correlation in the temperature range from 300 K to 945 K. Whereas \\upomega _Q = eQV_zz/4hbar with Vzz denoting the largest component of the electric field gradient tensor in magnitude increases with increasing temperature, the asymmetry parameter ? remains essentially constant. This observation fits into the systematic with other probes provided the sign of Vzz is negative.

Butz, T.; Vianden, R.

2013-05-01

49

A study of the semiconductor compound ?uAlO2 by the method of nuclear quadrupole resonance of Cu  

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

50

The nuclear quadrupole coupling constants of methanol in mixtures with CCl 4 by molecular dynamics and ab initio calculations  

Microsoft Academic Search

The deuterium nuclear quadrupole coupling constant (QCC) has recently been measured for the hydroxy-D in methanol-CCl4 mixtures of various compositions. The QCC which is strongly sensitive to the local environment of a molecule can also be calculated. For this purpose we have performed a series of molecular dynamics simulations (MD) of liquid mixtures of methanol and carbon tetrachloride and have

P. J. Merkling; M. D. Zeidler; P. A. Bopp

2000-01-01

51

Nuclear quadrupole hyperfine structure in the microwave spectrum of HCl–N2O: Electric field gradient perturbation of N2O by HCl  

Microsoft Academic Search

The microwave spectra of six isotopomers of HCl–N2O have been obtained in the 7–19 GHz region with a pulsed molecular beam, Fourier transform microwave spectrometer. The nuclear quadrupole hyperfine structure due to all quadrupolar nuclei is resolved and the spectra are analyzed using the Watson S-reduced Hamiltonian with the inclusion of nuclear quadrupole coupling interactions. The spectroscopic constants determined include

Helen O. Leung; Winn T. Cashion; Katharine K. Duncan; Christine L. Hagan; Sujin Joo

2004-01-01

52

Nuclear quadrupole hyperfine structure in the microwave spectrum of HCl-N2O: Electric field gradient perturbation of N2O by HCl  

Microsoft Academic Search

The microwave spectra of six isotopomers of HCl-N2O have been obtained in the 7-19 GHz region with a pulsed molecular beam, Fourier transform microwave spectrometer. The nuclear quadrupole hyperfine structure due to all quadrupolar nuclei is resolved and the spectra are analyzed using the Watson S-reduced Hamiltonian with the inclusion of nuclear quadrupole coupling interactions. The spectroscopic constants determined include

Helen O. Leung; Winn T. Cashion; Katharine K. Duncan; Christine L. Hagan; Sujin Joo

2004-01-01

53

Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz  

NASA Astrophysics Data System (ADS)

A spectrometer based on a dc superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux locked operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect 27Al NQR signals in ruby (Al2O3[Cr3+]) at 359 and 714 kHz.

TonThat, Dinh M.; Clarke, John

1996-08-01

54

The development of pure ?-NQR techniques for measurements of nuclear ground state quadrupole moments in lithium isotopes  

NASA Astrophysics Data System (ADS)

A ?-NQR spectrometer becomes a powerful tool to study changes in nuclear ground state properties along isotopic chains when coupled to a laser excitation beamline to polarise the nuclei of interest. Recently, the ?-NQR technique in a zero magnetic field has been applied for the first-time to measure ratios of static nuclear quadrupole moments of, Li. Preliminary results of the experiment determining the ratios Q9/Q8 and Q11/Q9 show agreement with present literature values with improved precision.

Voss, A.; Pearson, M. R.; Billowes, J.; Buchinger, F.; Chow, K. H.; Crawford, J. E.; Hossein, M. D.; Kiefl, R. F.; Levy, C. D. P.; MacFarlane, W. A.; Mané, E.; Morris, G. D.; Parolin, T. J.; Saadaoui, H.; Salman, Z.; Smadella, M.; Song, Q.; Wang, D.

2011-09-01

55

Nuclear Quadrupole Resonance Study of the Nitrogen Mustards and Local Anesthetics.  

NASA Astrophysics Data System (ADS)

The density matrix description of pulsed nitrogen -14 nuclear quadrupole resonance (NQR) spin-echoes is presented. The parallel between this problem, when formulated in terms of the fictitious spin- 1/2 operators, and that of spin - 1/2 NMR spin-echoes in liquids is discussed along with the complications which arise in multiple-pulse NQR experiments in powders due to the random orientation of the electric field gradient tensors. The equipment and procedures involved in searching for, detecting and identifying NQR resonances using pulsed techniques are described. The ('14)N NQR spectra of several nitrogen mustard compounds in the solid state are reported and analyzed in the framework of the Townes and Dailey theory. For the aniline derivatives, a correlation exists between l -(sigma), l being the nitrogen lone-pair electron density and (sigma) the average N-C sigma bond electron density, and the enhanced Hammett sigma constant (sigma)('-). An improved correlation is obtained between l-(sigma) and (sigma)(,R)('-), which emphasizes the importance of resonance effects in determining l-(sigma). The increase of hydrolysis and alkylation rates with increasing values of l-(sigma) is in agreement with the identification of the cyclic immonium ion as the intermediate in the hydrolysis and alkylation processes of the aromatic nitrogen mustards. A possible correlation is noted between the ('35)Cl NQR spectra for some of the mustards and measures of toxic and antitumor activity. ('14)N NQR spectra for several local anesthetics in the solid state are also reported and analyzed using the Townes and Dailey approach. The changes in the electron distributions at various nitrogen sites, produced by protonating the tertiary amino nitrogen, are discussed and shown to be in general agreement with expectations bases on the increased electrophilic character of the protonated amino group.

Buess, Michael Lee

56

Nuclear quadrupole resonance measurement of the anisotropic magnetic shielding and quadrupole coupling constants of 151Eu3+ and 153Eu3+ dilute in YAlO3 single crystal  

NASA Astrophysics Data System (ADS)

The nuclear quadrupole resonance spectra of Eu3+ in YAlO3 single crystal at ~ 10 K are reported. From the ratio of the quadrupole interaction parameters of 151Eu and 153Eu, the ratio of the quadrupole moments corrected for the pseudoquadrupole interaction is obtained Q153Q151=2.5812+/-0.0010. With low-magnetic-field studies the anisotropic magnetic shielding factors are measured. They are ?x=0.58, ?y=0.80, ?z=0.47 compared to an estimate of ?z=0.89 by Elliott. A measured value =39 Å-3 is obtained using Elliott's formulation and the experimental values of the anisotropic magnetic shielding factors.

Erickson, L. E.; Sharma, K. K.

1981-10-01

57

Nuclear collective motion with a coherent coupling interaction between quadrupole and octupole modes  

E-print Network

A collective Hamiltonian for the rotation-vibration motion of nuclei is considered, in which the axial quadrupole and octupole degrees of freedom are coupled through the centrifugal interaction. The potential of the system depends on the two deformation variables $\\beta_2$ and $\\beta_3$. The system is considered to oscillate between positive and negative $\\beta_3$-values, by rounding an infinite potential core in the $(\\beta_2,\\beta_3)$-plane with $\\beta_2>0$. By assuming a coherent contribution of the quadrupole and octupole oscillation modes in the collective motion, the energy spectrum is derived in an explicit analytic form, providing specific parity shift effects. On this basis several possible ways in the evolution of quadrupole-octupole collectivity are outlined. A particular application of the model to the energy levels and electric transition probabilities in alternating parity spectra of the nuclei $^{150}$Nd, $^{152}$Sm, $^{154}$Gd and $^{156}$Dy is presented.

Minkov, N; Drenska, S B; Scheid, W; Bonatsos, D; Lenis, D; Petrellis, D

2006-01-01

58

Nuclear collective motion with a coherent coupling interaction between quadrupole and octupole modes  

E-print Network

A collective Hamiltonian for the rotation-vibration motion of nuclei is considered, in which the axial quadrupole and octupole degrees of freedom are coupled through the centrifugal interaction. The potential of the system depends on the two deformation variables $\\beta_2$ and $\\beta_3$. The system is considered to oscillate between positive and negative $\\beta_3$-values, by rounding an infinite potential core in the $(\\beta_2,\\beta_3)$-plane with $\\beta_2>0$. By assuming a coherent contribution of the quadrupole and octupole oscillation modes in the collective motion, the energy spectrum is derived in an explicit analytic form, providing specific parity shift effects. On this basis several possible ways in the evolution of quadrupole-octupole collectivity are outlined. A particular application of the model to the energy levels and electric transition probabilities in alternating parity spectra of the nuclei $^{150}$Nd, $^{152}$Sm, $^{154}$Gd and $^{156}$Dy is presented.

N. Minkov; P. Yotov; S. Drenska; W. Scheid; D. Bonatsos; D. Lenis; D. Petrellis

2006-03-23

59

Nuclear quadrupole alignment of 176Lum and 177Lu in a lutetium single crystal at low temperatures and systematics of electric field gradients in pure hexagonal transition metals  

Microsoft Academic Search

The quadrupole frequencies for 176Lum and 177Lu nuclei in a Lu single crystal have been determined by nuclear orientation at temperatures down to 6 mK as -128(16) MHz and +294(37) MHz, respectively. From the observed gamma anisotropies several gamma-ray multipole mixing ratios could be derived. With the known ground-state quadrupole moment of Q=3.39(2) b for 177Lu the electric field gradient

H. Ernst; E. Hagn; E. Zech; G. Eska

1979-01-01

60

Structure and transport properties of stephanite (Ag5SbS4) according to antimony nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

Silver sulfo-antimonide Ag5SbS4 (stephanite) has been studied by nuclear quadrupole resonance (NQR) spectroscopy on antimony nuclei. The temperature dependences of the spectroscopic and relaxation parameters have been examined in the range of 4.2-395 K. A phase transition at 140 K and internal motions with an activation energy of 0.29 eV have been experimentally detected. The nature of the phase transition and diffusion of silver ions has been discussed in view of the reported data.

Orlova, A. Yu.; Gainov, R. R.; Dooglav, A. V.; Pen'kov, I. N.; Korolev, E. A.

2012-11-01

61

Reappraisal of nuclear quadrupole moments of atomic halogens via relativistic coupled cluster linear response theory for the ionization process.  

PubMed

The coupled cluster based linear response theory (CCLRT) with four-component relativistic spinors is employed to compute the electric field gradients (EFG) of (35)Cl, (79)Br, and (127)I nuclei. The EFGs resulting from these calculations are combined with experimental nuclear quadrupole coupling constants (NQCC) to determine the nuclear quadrupole moments (NQM), Q of the halide nuclei. Our estimated NQMs [(35)Cl = -81.12 mb, (79)Br = 307.98 mb, and (127)I = -688.22 mb] agree well with the new atomic values [(35)Cl = -81.1(1.2), (79)Br = 302(5), and (127)I = -680(10) mb] obtained via Fock space multireference coupled cluster method with the Dirac-Coulomb-Breit Hamiltonian. Although our estimated Q((79)Br) value deviates from the accepted reference value of 313(3) mb, it agrees well with the recently recommended value, Q((79)Br) = 308.7(20) mb. Good agreement with current reference data indicates the accuracy of the proposed value for these halogen nuclei and lends credence to the results obtained via CCLRT approach. The electron affinities yielded by this method with no extra cost are also in good agreement with experimental values, which bolster our belief that the NQMs values for halogen nuclei derived here are reliable. PMID:24171543

Chaudhuri, Rajat K; Chattopadhyay, Sudip; Mahapatra, Uttam Sinha

2013-11-27

62

Symmetry energy from the nuclear collective motion: constraints from dipole, quadrupole, monopole and spin-dipole resonances  

NASA Astrophysics Data System (ADS)

The experimental and theoretical studies of Giant Resonances, or more generally of the nuclear collective vibrations, are a well-established domain in which sophisticated techniques have been introduced and firm conclusions reached after an effort of several decades. From it, information on the nuclear equation of state can be extracted, albeit not far from usual nuclear densities. In this contribution, which complements other contributions appearing in this topical issue, we survey some of the constraints that have been extracted recently concerning the parameters of the nuclear symmetry energy. Isovector modes, in which neutrons and protons are in opposite phase, are a natural source of information and we illustrate the values of symmetry energy around saturation deduced from isovector dipole and isovector quadrupole states. The isotopic dependence of the isoscalar monopole energy has also been suggested to provide a connection to the symmetry energy: relevant theoretical arguments and experimental results are thoroughly discussed. Finally, we consider the case of the charge-exchange spin-dipole excitations in which the sum rule associated with the total strength gives in principle access to the neutron skin and thus, indirectly, to the symmetry energy.

Colò, G.; Garg, U.; Sagawa, H.

2014-02-01

63

Nuclear quadrupole hyperfine structure in the microwave spectrum of HCl-N2O: electric field gradient perturbation of N2O by HCl.  

PubMed

The microwave spectra of six isotopomers of HCl-N(2)O have been obtained in the 7-19 GHz region with a pulsed molecular beam, Fourier transform microwave spectrometer. The nuclear quadrupole hyperfine structure due to all quadrupolar nuclei is resolved and the spectra are analyzed using the Watson S-reduced Hamiltonian with the inclusion of nuclear quadrupole coupling interactions. The spectroscopic constants determined include rotational constants, quartic and sextic centrifugal distortion constants, and nuclear quadrupole coupling constants for each quadrupolar nucleus. Due to correlations of the structural parameters, the effective structure of the complex cannot be obtained by fitting to the spectroscopic constants of the six isotopomers. Instead, the parameters for each isotopomer are calculated from the A and C rotational constants and the chlorine nuclear quadrupole coupling constant along the a-axis, chi(aa). There are two possible structures; the one in which hydrogen of HCl interacts with the more electronegative oxygen of N(2)O is taken to represent the complex. The two subunits are approximately slipped parallel. For H (35)Cl-(14)N(2)O, the distance between the central nitrogen and chlorine is 3.5153 A and the N(2)O and HCl subunits form angles of 72.30 degrees and 119.44 degrees with this N-Cl axis, respectively. The chlorine and oxygen atoms occupy the opposite, obtuse vertices of the quadrilateral formed by O, central N, Cl, and H. Nuclear quadrupole coupling constants show that while the electric field gradient of the HCl subunit remains essentially unchanged upon complexation, there is electronic rearrangement about the two nitrogen nuclei in N(2)O. PMID:15260541

Leung, Helen O; Cashion, Winn T; Duncan, Katharine K; Hagan, Christine L; Joo, Sujin

2004-07-01

64

Nuclear energy and sustainability: Understanding ITER  

Microsoft Academic Search

Deregulation and new environmental requirements combined with the growing scarcity of fossil resources and the increasing world energy demand lead to a renewal of the debate on tomorrow's energies. Specifically, nuclear energy, which has undeniable assets, faces new constraints. On the one hand, nuclear energy is very competitive and harmless to greenhouse effect. From this point, it seems to be

Karine Fiore

2006-01-01

65

Nuclear quadrupole interaction studies of C15 RMn2 hydrides ( R=Y ,Gd,Tb,Dy)  

NASA Astrophysics Data System (ADS)

The nuclear electric quadrupole interaction (QI) of the probe nucleus I111n/C111d in the paramagnetic phase of the C15 rare earth (R) manganese hydrides (deuterides) RMn2H(D)x , with R=Y , Gd, Tb, and Dy, has been investigated by perturbed angular-correlation spectroscopy. The QI between the C111d quadrupole moment and the electric-field gradient (EFG) at the probe nucleus on the Mn site has been measured as a function of temperature in TbMn2H(D)x in the concentration range 0?x?4.3 and in RMn2H(D)x , R=Y ,Gd,Dy at the highest H content of xtilde 4.3 . The relative temperature dependence of the EFG in the parent compounds RMn2 is twice as strong as in isostructural RAl2 which can be related to differences in the Debye temperatures resulting from different radius ratios rR/rMn and rR/rAl [Joseph-Gschneidner postulate, Scr. Metall.2, 631 (1968)]. Hydrogenation of RMn2 increases the magnitude of the EFG by a factor of 2 between x=0 and x=4.3 but leaves the relative temperature dependence almost unchanged. Only at concentrations x>3.6 the temperature coefficient of the QI is significantly larger than in uncharged RMn2 . These results are compared with the much stronger concentration dependence and the anomalous temperature dependence of the QI of C111d in the C15 hydrides HfV2Hx . Evidence for an exceptionally high H mobility in TbMn2Hx is presented. The measurements provide information on structural changes and magnetic ordering temperatures at different H concentrations.

Forker, M.; Bedi, S. C.; Euler, H.

2008-09-01

66

Methods Using the Nuclear Quadrupole Interaction to Determine the Structure of Randomly Oriented Molecules  

NASA Astrophysics Data System (ADS)

In typical deuterated compounds, a deuteron feels an electric field gradient (EFG) which lies parallel to the bond in which the deuteron participates. In solids, the interaction between the quadrupole moment of the deuteron and the EFG splits the NMR spectrum. However, the size of the interaction depends on the orientation of the EFG with respect to the applied magnetic field, leaving a broad spectrum for unoriented powder samples. Advantage is taken of this orientation dependence to stimulate, with an H 1that is small compared to the linewidth, deuterons in molecules of a particular orientation in a powdered sample containing molecules of all orientations. The utility of this approach is demonstrated with two types of experiment. First, a "slow beat" measurement of the distance ( rDD= 1.673 ± 0.004 Å) between deuterons in deuterated ethylidyne, the structure resulting from the adsorption of ethylene on platinum, is performed. Then, a SEDOR measurement of the bond angle and distance between deuterons in a test compound, D 2O in gypsum, is performed. Also signal enhancement schemes involving the Carr-Purcell-Meiboom-Gill pulse sequence and a technique due to Haase and Conradi [J. Haase and M. S. Conradi, Chem. Phys. Lett.209, 287 (1993); J. Haase, M. S. Conradi, and E. Oldfield, J. Magn. Reson. A109, 210 (1994)] to aid the collection of SEDOR data are demonstrated.

Sakaie, Ken; Slichter, C. P.; Sinfelt, J. H.

67

Vibrationally induced nuclear quadrupole coupling in the v/sub 3/ = 1 state of /sup 189/OsO/sub 4/  

SciTech Connect

Electric nuclear quadrupole hyperfine structure arising from a quadrupolar nucleus at the center of tetrahedral molecules, such as /sup 189/OsO/sub 4/, is symmetry forbidden. However, through vibration--rotation distortion a small nuclear quadrupole coupling is induced. The hyperfine structure due to the vibrationally induced eqQ has been measured for a number of P- and R-branch transitions in the ..nu../sub 3/ fundamental of /sup 189/OsO/sub 4/, by using inverse Lamb dip spectroscopy. Microwave modulation sidebands of CO/sub 2/ laser lines have been used as the tunable infrared radiation. From the analysis of the observed hyperfine structure patterns, the values of the scalar and tensor coupling constants have been determined to be chi/sup V//sub s/ = -4.103 +- 0.048 MHz and chi/sup V//sub t/ = -3.090 +- 0.059 MHz.

Scappini, F.; Kreiner, W.A.; Frye, J.M.; Oka, T.

1987-11-15

68

Search for a Magnetic-Field Dependence of the Interaction of the Nuclear Quadrupole Moment with the Electric-Field Gradient  

Microsoft Academic Search

It is argued that the nuclear quadrupole–electric field gradient (EFG) interaction is, in principle, dependent on the presence of a magnetic fieldB. A rough estimate of the size of this effect yields 10?4in fields up to 10 T. However, if the site symmetry of the nucleus in question includes time-reversal symmetry, the linear dependence of the EFG onBvanishes. In diamagnetic

B. Filsinger; P. Gutsche; U. Haeberlen; N. Weiden

1997-01-01

69

Nuclear spins, magnetic moments, and quadrupole moments of Cu isotopes from N=28 to N=46: Probes for core polarization effects  

SciTech Connect

Measurements of the ground-state nuclear spins and magnetic and quadrupole moments of the copper isotopes from {sup 61}Cu up to {sup 75}Cu are reported. The experiments were performed at the CERN online isotope mass separator (ISOLDE) facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the N=28 and N=50 shell closures is reasonably reproduced by large-scale shell-model calculations starting from a {sup 56}Ni core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is, however, strongly reduced at N=40 due to the parity change between the pf and g orbits. No enhanced core polarization is seen beyond N=40. Deviations between measured and calculated moments are attributed to the softness of the {sup 56}Ni core and weakening of the Z=28 and N=28 shell gaps.

Vingerhoets, P.; Avgoulea, M.; Bissell, M. L.; De Rydt, M.; Neyens, G. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, B-3001 Leuven (Belgium); Flanagan, K. T. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, B-3001 Leuven (Belgium); IPN Orsay, F-91940 Orsay Cedex (France); Billowes, J.; Cheal, B.; Mane, E. [School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Blaum, K.; Schug, M. [Max-Planck-Institut fuer Kernphysik, D-69117 Heidelberg (Germany); Brown, B. A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824-1321 (United States); Forest, D. H.; Tungate, G. [School of Physics and Astronomy, The University of Birmingham, Birmingham B15 2TT (United Kingdom); Geppert, Ch.; Noertershaeuser, W. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Institut fuer Kernchemie, Johannes Gutenberg-Universitaet Mainz, D-55128 Mainz (Germany); Honma, M. [Center for Mathematical Sciences, University of Aizu, Tsuruga, Ikki-machi, Aizu-Wakamatsu, Fukushima 965-8580 (Japan); Kowalska, M. [Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Kraemer, J.; Krieger, A. [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet Mainz, D-55128 Mainz (Germany)

2010-12-15

70

First steps toward an understanding of «Cold» nuclear fusion  

Microsoft Academic Search

Summary  We point out that the first steps in understanding the recent results reported on cold nuclear fusion can be made by considering\\u000a the important role that the coherent interactions with the quantized e.m. field play in condensed matter. Indeed we find natural\\u000a mechanisms to decrease the Coulomb repulsion and to suppress the usual nuclear-fusion channels with respect to the transfer

T. Bressani; E. Del Giudice; G. Preparata

1989-01-01

71

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

72

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

NASA Technical Reports Server (NTRS)

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.

Norbury, John W.

1992-01-01

73

Phase diagram in bilayered-hydrate NaxCoO2·yH2O revealed by Co nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

We have performed Co nuclear quadrupole resonance (NQR) measurements in various bilayered-hydrate (BLH) NaxCoO2·yH2O compounds, showing superconducting (SC) and non-SC characteristics. A weak magnetic order was found in a BLH sample with a longer c-axis lattice parameter. We also found that the NQR frequency ?Q arising from the ±{7}/{2}?±{5}/{2} transition is related to the ground state of this system. A phase diagram is developed, in which the superconducting and magnetic-order temperature Tc and TM are plotted with respect to ?Q.

Ishida, K.; Ihara, Y.; Takeya, H.; Michioka, C.; Yoshimura, K.; Takada, K.; Sasaki, T.; Sakurai, H.; Takayama-Muromachi, E.

2006-05-01

74

A study of the spin-echo spin-locking effect in multi-pulse sequences in 14N nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

Experimental evidence of observing a rather unusual spin-locking spin echo (SLSE) effect in the fields of two multi-pulse sequences ( ?0) x - ( ? - ?x - 2 ? - ?x - 2 ? - ?- x - 2 ? - ?- x - ?) n and ( ?0) x - ( ? - ?x - 2 ? - ?y - ?) n in 14N nuclear quadrupole resonance is presented. It was demonstrated that the SLSE effect is observed only in the even pulse intervals of both sequences. All experiments were carried out at room temperature on a powder sample of NaNO 2. A theoretical description of the effect is given.

Mikhaltsevitch, V. T.

2005-12-01

75

Hyperfine and nuclear quadrupole tensors of nitrogen donors in the Q(A) site of bacterial reaction centers: correlation of the histidine N(?) tensors with hydrogen bond strength.  

PubMed

X- and Q-band pulsed EPR spectroscopy was applied to study the interaction of the QA site semiquinone (SQA) with nitrogens from the local protein environment in natural abundance (14)N and in (15)N uniformly labeled photosynthetic reaction centers of Rhodobacter sphaeroides. The hyperfine and nuclear quadrupole tensors for His-M219 N? and Ala-M260 peptide nitrogen (Np) were estimated through simultaneous simulation of the Q-band (15)N Davies ENDOR, X- and Q-band (14,15)N HYSCORE, and X-band (14)N three-pulse ESEEM spectra, with support from DFT calculations. The hyperfine coupling constants were found to be a((14)N) = 2.3 MHz, T = 0.3 MHz for His-M219 N? and a((14)N) = 2.6 MHz, T = 0.3 MHz for Ala-M260 Np. Despite that His-M219 N? is established as the stronger of the two H-bond donors, Ala-M260 Np is found to have the larger value of a((14)N). The nuclear quadrupole coupling constants were estimated as e(2)Qq/4h = 0.38 MHz, ? = 0.97 and e(2)Qq/4h = 0.74 MHz, ? = 0.59 for His-M219 N? and Ala-M260 Np, respectively. An analysis of the available data on nuclear quadrupole tensors for imidazole nitrogens found in semiquinone-binding proteins and copper complexes reveals these systems share similar electron occupancies of the protonated nitrogen orbitals. By applying the Townes-Dailey model, developed previously for copper complexes, to the semiquinones, we find the asymmetry parameter ? to be a sensitive probe of the histidine N?-semiquinone hydrogen bond strength. This is supported by a strong correlation observed between ? and the isotropic coupling constant a((14)N) and is consistent with previous computational works and our own semiquinone-histidine model calculations. The empirical relationship presented here for a((14)N) and ? will provide an important structural characterization tool in future studies of semiquinone-binding proteins. PMID:25026433

Taguchi, Alexander T; O'Malley, Patrick J; Wraight, Colin A; Dikanov, Sergei A

2014-08-01

76

Variable-Pitch Rectangular Cross-section Radiofrequency Coils for the Nitrogen-14 Nuclear Quadrupole Resonance Investigation of Sealed Medicines Packets  

PubMed Central

The performance of rectangular radio frequency (RF) coils capable of being used to detect nuclear quadrupole resonance (NQR) signals from blister packs of medicines has been compared. The performance of a fixed-pitch RF coil was compared with that from two variable-pitch coils, one based on a design in the literature and the other optimized to obtain the most homogeneous RF field over the whole volume of the coil. It has been shown from 14N NQR measurements with two medicines, the antibiotic ampicillin (as trihydrate) and the analgesic medicine Paracetamol, that the latter design gives NQR signal intensities almost independent of the distribution of the capsules or pills within the RF coil and is therefore more suitable for quantitative analysis. PMID:23057555

2012-01-01

77

Variable-pitch rectangular cross-section radiofrequency coils for the nitrogen-14 nuclear quadrupole resonance investigation of sealed medicines packets.  

PubMed

The performance of rectangular radio frequency (RF) coils capable of being used to detect nuclear quadrupole resonance (NQR) signals from blister packs of medicines has been compared. The performance of a fixed-pitch RF coil was compared with that from two variable-pitch coils, one based on a design in the literature and the other optimized to obtain the most homogeneous RF field over the whole volume of the coil. It has been shown from (14)N NQR measurements with two medicines, the antibiotic ampicillin (as trihydrate) and the analgesic medicine Paracetamol, that the latter design gives NQR signal intensities almost independent of the distribution of the capsules or pills within the RF coil and is therefore more suitable for quantitative analysis. PMID:23057555

Barras, Jamie; Katsura, Shota; Sato-Akaba, Hideo; Itozaki, Hideo; Kyriakidou, Georgia; Rowe, Michael D; Althoefer, Kaspar A; Smith, John A S

2012-11-01

78

Understanding the nature of nuclear power plant risk  

SciTech Connect

This paper describes the evolution of understanding of severe accident consequences from the non-mechanistic assumptions of WASH-740 to WASH-1400, NUREG-1150, SOARCA and today in the interpretation of the consequences of the accident at Fukushima. As opposed to the general perception, the radiological human health consequences to members of the Japanese public from the Fukushima accident will be small despite meltdowns at three reactors and loss of containment integrity. In contrast, the radiation-related societal impacts present a substantial additional economic burden on top of the monumental task of economic recovery from the nonnuclear aspects of the earthquake and tsunami damage. The Fukushima accident provides additional evidence that we have mis-characterized the risk of nuclear power plant accidents to ourselves and to the public. The human health risks are extremely small even to people living next door to a nuclear power plant. The principal risk associated with a nuclear power plant accident involves societal impacts: relocation of people, loss of land use, loss of contaminated products, decontamination costs and the need for replacement power. Although two of the three probabilistic safety goals of the NRC address societal risk, the associated quantitative health objectives in reality only address individual human health risk. This paper describes the types of analysis that would address compliance with the societal goals. (authors)

Denning, R. S. [Ohio State Univ., 201 West 19th Avenue, Columbus, OH 43210-1142 (United States)

2012-07-01

79

Nuclear Cardiology Objectives Understand the principles of myocardial perfusion and blood flow, factors  

E-print Network

Nuclear Cardiology Objectives Knowledge · Understand the principles of myocardial perfusion in nuclear imaging, including collimation, resolution, contrast, localization, noise, ECT, SPECT, PET, image. · Know the differences between the various radioisotopes used in nuclear cardiology, including

Ford, James

80

Nuclear Quadrupole Double Resonance Investigation of the Anomalous Temperature Coefficients of the Strong Hydrogen Bonds in Sodium and Potassium Deuterium Diacetate.  

NASA Astrophysics Data System (ADS)

This thesis was directed at learning more about the unusual electronic environment near hydrogen within strong hydrogen bonds. "Strong" hydrogen bonds are unique in that the hydrogen atom is symmetrically located, or nearly so, between two electronegative atoms; the bond energies are relatively large. In a "normal" hydrogen bond the hydrogen atom is bonded to, and thus physically closer to, a parent atom, and only weakly attracted to another electronegative atom; bond energies are typically small. To examine these bonds, deuterium was substituted for hydrogen and the electric quadrupole coupling constant (QCC) of deuterium was measured using field cycling nuclear magnetic resonance. The electric quadrupole moment of deuterium is sensitive to changes in the surrounding electric field gradient, and is thus a good probe of the immediate electronic structure. The results show that the temperature dependence of the QCC is opposite to, and much larger than, what one would normally expect to observe for deuterium. The QCC is found to decrease strongly with decreasing temperature. This project was the first to study in detail the temperature dependence of deuterium QCCs in strong hydrogen bonds. The magnitude of the deuterium QCCs for the diacetates was found to be strongly depressed relative to typical values for deuterium. These results parallel large shifts in the infrared vibrational frequencies observed in many molecules which contain strong hydrogen bonds. The asymmetry parameter, which is a measure of the departure from axial symmetry of the electric field gradient (EFG) at deuterium, was found to be unusually large for what are known to be linear, or nearly linear, three-center bonds. Based on ab initio Hartree-Fock calculations aimed at determining the EFG at H in the archetypal bifluoride ion, F-H-F^-, the electronic charge density is drastically depleted at H. It is believed that the large reduction in the charge density allows the deuterium EFG to be highly sensitive to the shape of the charge distribution on the atoms to which deuterium is bonded. If these atoms are at points of low crystallographic symmetry, the polarization of these adjacent atoms by other nearby atoms may cause the EFG to depart substantially from being axially symmetric. Also obtained from the molecular orbital calculations for bifluoride ion were the total electronic energy and the electric field gradient at H. From these calculations potential function models for the asymmetric stretch and the bend were constructed. An attempt was made to correlate the predictions made by these models for the temperature dependence of the deuteron quadrupole coupling constant in bifluoride ion with the experimentally observed results for the diacetates.

Shaw, Eric Max

81

Electronic Structure and Nuclear Quadrupole Interactions in Cocaine Hydrochloride(C_17H_21NO_4HCl)  

NASA Astrophysics Data System (ADS)

The electronic structure of C_17H_21NO_4HCl has been investigated using the Hartree-Fock-Roothaan variational procedure. The position of the hydrogen atom, associated with HCl, which is not available from structural data, has been determined through total energy optimization with two likely positions obtained, one at 1.06 A from the nitrogen atom and the other at 1.73 A from the latter and 1.35 A from chlorine, these positions indicating bonding of H with nitrogen and chlorine respectively. The former position is found to be significantly more stable(about 0.54 eV) compared to the latter and leads to quadrupole coupling constants and asymmetry parameters of -1.422 MHz and 0.281 for the ^14N nucleus and -8.609 MHz and 0.146 for ^35Cl. These results are in good agreement with the corresponding experimental magnitudes(J. P. Yesinowski, M. L. Buess, A. N. Garroway, M. Ziegeweid and A. Pines, Analytical Chemistry 67), 2256 (1995). of 1.1780 MHz, 0.2632 and 5.027 MHz, 0.2, demonstrating that the correct picture in this compound is one of hydrogen leaving the chlorine and getting attached to nitrogen, as suggested earlier^1.

Pati, Ranjit; Sahoo, N.; Das, T. P.; Ray, S. N.

1998-03-01

82

Bioactivity-integrated ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry for the identification of nuclear factor-?B inhibitors and ?2 adrenergic receptor agonists in Chinese medicinal preparation Chuanbeipipa dropping pills.  

PubMed

A simple and dual-target method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry combined with dual-bioactive [nuclear factor-?B (NF-?B) and ?2 -adrenergic receptor] luciferase reporter assay systems was developed to rapidly characterize the chemical structure of various bioactive compounds of TCM preparations. Chuanbeipipa dropping pills, a traditional Chinese medicine preparation used for the clinical therapy of chronic obstructive lung disease and cough caused by bronchial catarrh, was analyzed with this method. Potential anti-inflammatory and spasmolytic constituents were screened using NF-?B and ?2 -adrenergic receptor activity luciferase reporter assay systems and simultaneously identified according to the time-of-flight mass spectrometry data. One ?2-adrenergic receptor agonist (ephedrine) and two structural types of NF-?B inhibitors (platycosides derivatives and ursolic acid derivatives) were characterized. Platycodin D3 and E were considered new NF-?B inhibitors. Further cytokine and chemokine detection confirmed the anti-inflammatory effects of the potential NF-?B inhibitors. Compared with conventional fingerprints, activity-integrated fingerprints that contain both chemical and bioactive details offer a more comprehensive understanding of the chemical makeup of plant materials. This strategy clearly demonstrated that multiple bioactivity-integrated fingerprinting is a powerful tool for the improved screening and identification of potential multi-target lead compounds in complex herbal medicines. PMID:23483566

Dong, Linyi; Luo, Yi; Cheng, Binfeng; Zhang, Yaoshu; Zhang, Ning; Hou, Yuanyuan; Jiang, Min; Luo, Guoan; Bai, Gang

2013-08-01

83

Introduction A major goal in nuclear physics is to understand how  

E-print Network

Introduction A major goal in nuclear physics is to understand how nuclear binding, stability article 20 Nuclear Physics News, Vol. 13, No. 1, 2003 Ab Initio Calcula the accurate calculation of nuclear matrix ele- ments needed for some tests of the standard model

Mihaila, Bogdan

84

59Co Nuclear Quadrupole Resonance Studies of Superconducting and Nonsuperconducting Bilayer Water Intercalated Sodium Cobalt Oxides NaxCoO2\\cdotyH2O  

NASA Astrophysics Data System (ADS)

We report 59Co nuclear quadrupole resonance (NQR) studies of bilayer water intercalated sodium cobalt oxides NaxCoO2\\cdotyH2O (BLH) with the superconducting transition temperatures, 2 K < Tc ? 4.6 K, as well as a magnetic BLH sample without superconductivity. We obtained a magnetic phase diagram of Tc and the magnetic ordering temperature TM against the peak frequency ?3 of the 59Co NQR transition Iz = ± 5/2 ?ftrightarrow ± 7/2 and found a dome-shaped superconducting phase. The 59Co NQR spectrum of the nonsuperconducting BLH shows a broadening below TM without the critical divergence of 1/T1 or 1/T2, suggesting an unconventional magnetic ordering. The degree of enhancement of 1/T1T at low temperatures increases with the increase of ?3 though the optimal ?3 of approximately 12.30 MHz. In the NaxCoO2\\cdotyH2O system, the optimal-Tc superconductivity emerges close to the magnetic instability. Tc is suppressed near the phase boundary at ?3 ˜ 12.50 MHz, which is not a conventional magnetic quantum critical point.

Michioka, C.; Ohta, H.; Itoh, Y.; Yoshimura, K.

2006-06-01

85

Standard test method for analysis of isotopic composition of uranium in nuclear-grade fuel material by quadrupole inductively coupled plasma-mass spectrometry  

E-print Network

1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described i...

American Society for Testing and Materials. Philadelphia

2000-01-01

86

Centering of quadrupole family  

NASA Astrophysics Data System (ADS)

A procedure for finding the individual centers for a family of quadrupoles fed with a single power supply is described. The method is generalized for using the correctors adjacent to the quadrupoles. Theoretical background is presented as well as experimental data for the NSLS rings. The method accuracy is also discussed.

Pinayev, Igor

2007-01-01

87

Study of the extra-ionic electron distributions in semi-metallic structures by nuclear quadrupole resonance techniques  

NASA Technical Reports Server (NTRS)

A straightforward self-consistent method was developed to estimate solid state electrostatic potentials, fields and field gradients in ionic solids. The method is a direct practical application of basic electrostatics to solid state and also helps in the understanding of the principles of crystal structure. The necessary mathematical equations, derived from first principles, were presented and the systematic computational procedure developed to arrive at the solid state electrostatic field gradients values was given.

Murty, A. N.

1976-01-01

88

Sources of Nuclear Fuel, Understanding the Atom Series.  

ERIC Educational Resources Information Center

A brief outline of the historical landmarks in nuclear physics leading to the use of nuclear energy for peaceful purposes introduces this illustrated booklet. The distribution of known sources of uranium ores is mapped and some details about the geology of each geographical area given. Methods of prospective, mining, milling, refining, and fuel…

Singleton, Arthur L., Jr.

89

Nuclear Reactors for Space Power, Understanding the Atom Series.  

ERIC Educational Resources Information Center

The historical development of rocketry and nuclear technology includes a specific description of Systems for Nuclear Auxiliary Power (SNAP) programs. Solar cells and fuel cells are considered as alternative power supplies for space use. Construction and operation of space power plants must include considerations of the transfer of heat energy to…

Corliss, William R.

90

Toward understanding the structure of the vertebrate nuclear pore complex.  

PubMed

Nuclear pore complexes are large macromolecular assemblies that facilitate the nucleocytoplasmic exchange of macromolecules. Because of their intricate composition, membrane association, and sheer size, the integration of various, complementary structure determination approaches is a prerequisite for elucidating their structure. We have recently employed such an integrated strategy to analyze the scaffold structure of the cytoplasmic and nuclear rings of the human nuclear pore complex. In this extra view, we highlight two specific aspects of this work: the power of electron microscopy for bridging different resolution regimes and the importance of post-translational modifications for regulating nucleoporin interactions. We review recent technological developments and give a perspective toward future structure determination approaches. PMID:24699243

Beck, Martin; Glavy, Joseph S

2014-01-01

91

Toward Understanding the Microscopic Origin of Nuclear Clustering  

SciTech Connect

Open Quantum System (OQS) description of a many-body system involves interaction of Shell Model (SM) states through the particle continuum. In realistic nuclear applications, this interaction may lead to collective phenomena in the ensemble of SM states. We claim that the nuclear clustering is an emergent, near-threshold phenomenon, which cannot be elucidated within the Closed Quantum System (CQS) framework. We approach this problem by investigating the near-threshold behavior of Exceptional Points (EPs) in the realistic Continuum Shell Model (CSM). The consequences for the alpha-clustering phenomenon are discussed.

Okolowicz, J. [Institute of Nuclear Physics, Polish Academy of Sciences; Nazarewicz, Witold [UTK/ORNL/University of Warsaw; Ploszajczak, M. [Grand Accelerateur National d'Ions Lourds (GANIL)

2013-01-01

92

The Role of Nuclear Physics in Understanding the Cosmos and the Origin of Elements  

SciTech Connect

This popular lecture, given in the conference celebrating contributions of Akito Arima to physics on the occasion of his 80th anniversary, outlines the role of nuclear physics in understanding the origin of elements.

Balantekin, A. B. [Physics Department, University of Wisconsin, Madison WI 53706 (United States)

2011-05-06

93

Understanding Nuclear Receptor Form and Function Using Structural Biology  

PubMed Central

Nuclear receptors (NR) are a major transcription factor family whose members selectively bind small molecule lipophilic ligands and transduce those signals into specific changes in gene programs. For over two decades, structural biology efforts were directed exclusively on the individual ligand binding domains (LBDs) or DNA binding domains (DBDs) of NRs. These analyses revealed the basis for both ligand and DNA binding, and also revealed receptor conformations representing both the activated and repressed states. Additionally, crystallographic studies explained how NR LBD surfaces recognize discrete portions of transcriptional coregulators. The many structural snapshots of LBDs have also guided the development of synthetic ligands with therapeutic potential. Yet, the exclusive structural focus on isolated NR domains has made it difficult to conceptualize how all the NR polypeptide segments are coordinated physically and functionally in the context of receptor quaternary architectures. Newly emerged crystal structures of the PPAR?-RXR? heterodimer and HNF-4? homodimer have recently revealed the higher order organizations of these receptor complexes on DNA, as well as the complexity and uniqueness of their domain-domain interfaces. These emerging structural advances promise to better explain how signals in one domain can be allosterically transmitted to distal receptor domains, also providing much better frameworks for guiding future drug discovery efforts. PMID:24103914

Rastinejad, Fraydoon; Huang, Pengxiang; Chandra, Vikas; Khorasanizadeh, Sepideh

2013-01-01

94

High gradient superconducting quadrupoles  

SciTech Connect

Prototype superconducting quadrupoles with a 5 cm aperture and gradient of 16 kG/cm have been built and tested as candidate magnets for the final focus at SLC. The magnets are made from NbTi Tevatron style cable with 10 inner and 14 outer turns per quadrant. Quench performance and multipole data are presented. Design and data for a low current, high gradient quadrupole, similar in cross section but wound with a cable consisting of five insulated conductors are also discussed.

Lundy, R.A.; Brown, B.C.; Carson, J.A.; Fisk, H.E.; Hanft, R.H.; Mantsch, P.M.; McInturff, A.D.; Remsbottom, R.H.

1987-07-01

95

Nuclear quadrupole spin-lattice relaxation in Bi{sub 4}Ge{sub 3}O{sub 12} single crystals doped with atoms of d or f elements. Crystal field effects in compounds exhibiting anomalous magnetic properties  

SciTech Connect

The nuclear quadrupole spin-lattice relaxation was studied in the range 4.2-300 K for single crystals of Bi{sub 4}Ge{sub 3}O{sub 12} doped with minor amounts (the tenth fractions of mol%) of paramagnetic atoms of Cr, Nd, and Gd. Unusual spin dynamic features were recently found for these crystals at room temperature: a dramatic (up to 8-fold) increase in the effective nuclear quadrupole spin-spin relaxation time T{sub 2}* occurred upon doping the pure Bi{sub 4}Ge{sub 3}O{sub 12} sample. Unlike T{sub 2}*, the effective spin-lattice relaxation time T{sub 1}* at room temperature differs insignificantly for both doped and pure samples. But at lower temperatures, the samples exhibit considerably different behavior of the spin-lattice relaxation with temperature, which is caused by different contributions to the relaxation process of the dopant paramagnetic atoms. The distinctive maximum in the temperature dependence of the spin-lattice relaxation time for the Nd-doped crystal is shown to result from the crystal electric field effects.

Orlov, V. G., E-mail: orlov@mbslab.kiae.ru; Sergeev, G. S. [Russian Research Center 'Kurchatov Institute' (Russian Federation); Asaji, Tetsuo [Nihon University, Department of Chemistry, College of Humanities and Sciences (Japan); Kravchenko, E. A. [Russian Academy of Sciences, Institute of General and Inorganic Chemistry (Russian Federation); Kargin, Yu. F. [Russian Academy of Sciences, State Institute of Metallurgy and Material Science (Russian Federation)

2010-02-15

96

Three-Dimensional Nuclear Chart--Understanding Nuclear Physics and Nucleosynthesis in Stars  

ERIC Educational Resources Information Center

Three-dimensional (3D) nuclear charts were created using toy blocks, which represent the atomic masses per nucleon number and the total half-lives for each nucleus in the entire region of the nuclear mass. The bulk properties of the nuclei can be easily understood by using these charts. Subsequently, these charts were used in outreach activities…

Koura, Hiroyuki

2014-01-01

97

Progress in Understanding the Nuclear Equation of State at the Quark Level  

E-print Network

At the present time there is a lively debate within the nuclear community concerning the relevance of quark degrees of freedom in understanding nuclear structure. We outline the key issues and review the impressive progress made recently within the framework of the quark-meson coupling model. In particular, we explain in quite general terms how the modification of the internal structure of hadrons in-medium leads naturally to three- and four-body forces, or equivalently, to density dependent effective interactions.

AW Thomas; PAM Guichon

2007-01-31

98

Variable Permanent Magnet Quadrupole  

SciTech Connect

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 parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments.

Mihara, T.; Iwashita, Y.; /Kyoto U.; Kumada, M.; /NIRS, Chiba; Spencer, C.M.; /SLAC

2007-05-23

99

Three-dimensional nuclear chart—understanding nuclear physics and nucleosynthesis in stars  

NASA Astrophysics Data System (ADS)

Three-dimensional (3D) nuclear charts were created using toy blocks, which represent the atomic masses per nucleon number and the total half-lives for each nucleus in the entire region of the nuclear mass. The bulk properties of the nuclei can be easily understood by using these charts. Subsequently, these charts were used in outreach activities for the general public and high school students. As an example, an application for a lecture on nucleosynthesis in stars is introduced, and some explanations for the abundance of iron and the origin of uranium and heavy elements on the Earth are given with the 3D chart.

>Hiroyuki Koura,

2014-03-01

100

Nuclear hyperfine and quadrupole tensor characterization of the nitrogen hydrogen bond donors to the semiquinone of the QB site in bacterial reaction centers: a combined X- and S-band (14,15)N ESEEM and DFT study.  

PubMed

The secondary quinone anion radical QB(-) (SQB) in reaction centers of Rhodobacter sphaeroides interacts with N? of His-L190 and Np (peptide nitrogen) of Gly-L225 involved in hydrogen bonds to the QB carbonyls. In this work, S-band (?3.6 GHz) ESEEM was used with the aim of obtaining a complete characterization of the nuclear quadrupole interaction (nqi) tensors for both nitrogens by approaching the cancelation condition between the isotropic hyperfine coupling and (14)N Zeeman frequency at lower microwave frequencies than traditional X-band (9.5 GHz). By performing measurements at S-band, we found a dominating contribution of N? in the form of a zero-field nqi triplet at 0.55, 0.92, and 1.47 MHz, defining the quadrupole coupling constant K = e(2)qQ/4h = 0.4 MHz and associated asymmetry parameter ? = 0.69. Estimates of the hyperfine interaction (hfi) tensors for N? and Np were obtained from simulations of 1D and 2D (14,15)N X-band and three-pulse (14)N S-band spectra with all nuclear tensors defined in the SQB g-tensor coordinate system. From simulations, we conclude that the contribution of Np to the S-band spectrum is suppressed by its strong nqi and weak isotropic hfi comparable to the level of hyperfine anisotropy, despite the near-cancelation condition for Np at S-band. The excellent agreement between our EPR simulations and DFT calculations of the nitrogen hfi and nqi tensors to SQB is promising for the future application of powder ESEEM to full tensor characterizations. PMID:24437652

Taguchi, Alexander T; O'Malley, Patrick J; Wraight, Colin A; Dikanov, Sergei A

2014-02-13

101

Quadrupole shunt experiments at SPEAR  

SciTech Connect

As part of a program to align and stabilize the SPEAR storage ring, a switchable shunt resistor was installed on each quadrupole to bypass a small percentage of the magnet current. The impact of a quadrupole shunt is to move the electron beam orbit in proportion to the off-axis beam position at the quadrupole, and to shift the betatron tune. Initially, quadrupole shunts in SPEAR were used to position the electron beam in the center of the quadrupoles. This provided readback offsets for nearby beam position monitors, and helped to steer the photon beams with low-amplitude corrector currents. The shunt-induced tune shift measurements were then processed in MAD to derive a lattice model.

Corbett, W.J.; Hettel, R.O.; Nuhn, H.-D.

1996-05-01

102

Mapping Complexity Sources in Nuclear Power Plant Domains Understanding the sources of complexity in advanced Nuclear Power Plant (NPP) control rooms and their  

E-print Network

Mapping Complexity Sources in Nuclear Power Plant Domains Understanding the sources of complexity in advanced Nuclear Power Plant (NPP) control rooms and their effects on human reliability is critical of complexity leveraging network theory. INTRODUCTION The nuclear power industry in United States has declined

Cummings, Mary "Missy"

103

Relationship between magnetic fluctuations and superconductivity in Na x(H 3O) zCoO 2 · yH 2O revealed by a Co nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

Nuclear quadrupole frequency ( ?Q) and spin-lattice relaxation rate 1/ T1 of Co were measured on various bilayered hydrate (BLH) Na xCoO 2 · yH 2O ( y ? 1.3) with different values of superconducting (SC) and magnetic-transition temperatures, Tc and TM, together with non-SC monolayered hydrate (MLH) Na xCoO 2 · yH 2O ( y ? 0.7). In the temperature range above 70 K, 1/ T1T in all samples follows the similar temperature dependence as each other. In the BLH compounds, 1/ T1T is enhanced with decreasing temperature below 70 K, and the values of 1/ T1T at Tc are larger in the higher- ?3 sample, where ?3 is the peak frequency of the NQR spectrum arising from ±5/2 ? ±7/2 transitions. The magnetic ordering is indicated from the prominent divergence of 1/ T1T at TM and the presence of the internal field at the Co nuclear site in the samples with ?3 higher than 12.5 MHz. We analyze the temperature dependence of 1/ T1T in all samples on the basis of identical formula, and discuss the relationship between magnetic fluctuations and superconductivity in the BLH cobaltate.

Ishida, K.; Ihara, Y.; Takeya, H.; Michioka, C.; Yoshimura, K.; Takada, K.; Sasaki, T.; Sakurai, H.; Takayama-Muromachi, E.

2007-09-01

104

Dynamic use of geoscience information to develop scientific understanding for a nuclear waste repository  

SciTech Connect

The development and safety evaluation of a nuclear waste geologic repository require a proper scientific understanding of the site response. Such scientific understanding depends on information from a number of geoscience disciplines, including geology, geophysics, geochemistry, geomechanics and hydrogeology. The information comes in four stages: (1) general regional survey data base, (2) surface-based testing, (3) exploratory shaft testing, and (4) repository construction and evaluation. A discussion is given on the dynamic use of the information through the different stages. We point out the need for abstracting, deriving and updating a quantitative spatial and process model (QSPM) to develop a scientific understanding of site responses as a crucial element in the dynamic procedure. 2 figs.

Cook, N.G.W.; Tsang, C.F.

1990-01-01

105

Development of electrostatic quadrupoles for heavy ion fusion  

SciTech Connect

High-voltage electrostatic quadrupoles are used for focusing ion beams at low energies in the induction linac approach to heavy ion driven inertial confinement fusion for the production of electrical power. The transportable beam line charge density depends linearly on the operating voltage of the quadrupoles, so an experimental program was conducted to find the voltage breakdown dependence on the overall size of the quadrupoles which would then allow determination of the best geometry and operating voltage. The quadrupole electrodes are usually stainless steel cylinders with hemispherical end caps, mounted on stainless steel end plates. The end plates are precisely positioned with respect to each other and the vacuum chamber with alumina insulators with shielded triple points. It is advantageous for beam transport to employ an array of multiple beams for which a rather large number of interdigitated electrodes forms an array of quadrupoles. The tradeoffs between very large numbers of small channels and a smaller number of large channels, and the dependence of the choice on the voltage breakdown dependence is discussed. With present understanding, the optimum is about 100 beamlets focused with quadrupoles which have a beam aperture radius of about 2.3 cm and are operated with about 150 kV between electrodes.

Faltens, A.; Seidl, P. [Lawrence Berkeley National Lab., CA (United States)

1996-12-31

106

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

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. PMID:22283980

Latosi?ska, J N; Latosi?ska, M; Seliger, J; Žagar, V; Maurin, J K; Kazimierczuk, Z

2012-02-01

107

Impact hazard mitigation: understanding the effects of nuclear explosive outputs on comets and asteroids  

SciTech Connect

The NASA 2007 white paper ''Near-Earth Object Survey and Deflection Analysis of Alternatives'' affirms deflection as the safest and most effective means of potentially hazardous object (PHO) impact prevention. It also calls for further studies of object deflection. In principle, deflection of a PHO may be accomplished by using kinetic impactors, chemical explosives, gravity tractors, solar sails, or nuclear munitions. Of the sudden impulse options, nuclear munitions are by far the most efficient in terms of yield-per-unit-mass launched and are technically mature. However, there are still significant questions about the response of a comet or asteroid to a nuclear burst. Recent and ongoing observational and experimental work is revolutionizing our understanding of the physical and chemical properties of these bodies (e.g ., Ryan (2000) Fujiwara et al. (2006), and Jedicke et al. (2006)). The combination of this improved understanding of small solar-system bodies combined with current state-of-the-art modeling and simulation capabilities, which have also improved dramatically in recent years, allow for a science-based, comprehensive study of PHO mitigation techniques. Here we present an examination of the effects of radiation from a nuclear explosion on potentially hazardous asteroids and comets through Monte Carlo N-Particle code (MCNP) simulation techniques. MCNP is a general-purpose particle transport code commonly used to model neutron, photon, and electron transport for medical physics reactor design and safety, accelerator target and detector design, and a variety of other applications including modeling the propagation of epithermal neutrons through the Martian regolith (Prettyman 2002). It is a massively parallel code that can conduct simulations in 1-3 dimensions, complicated geometries, and with extremely powerful variance reduction techniques. It uses current nuclear cross section data, where available, and fills in the gaps with analytical models where data are not available. MCNP has undergone extensive verification and validation and is considered the gold-standard for particle transport. (Forrest B. Brown, et al., ''MCNP Version 5,'' Trans. Am. Nucl. Soc., 87, 273, November 2002.) Additionally, a new simulation capability using MCNP has become available to this collaboration. The first results of this new capability will also be presented.

Clement, Ralph R C [Los Alamos National Laboratory; Plesko, Catherine S [Los Alamos National Laboratory; Bradley, Paul A [Los Alamos National Laboratory; Conlon, Leann M [Los Alamos National Laboratory

2009-01-01

108

Sodium-23 and potassium-39 nuclear magnetic resonance relaxation in eye lens. Examples of quadrupole ion magnetic relaxation in a crowded protein environment.  

PubMed Central

Single and multiple quantum nuclear magnetic resonance (NMR) spectroscopic techniques were used to investigate the motional dynamics of sodium and potassium ions in concentrated protein solution, represented in this study by cortical and nuclear bovine lens tissue homogenates. Both ions displayed homogeneous biexponential magnetic relaxation behavior. Furthermore, the NMR relaxation behavior of these ions in lens homogenates was consistent either with a model that assumed the occurrence of two predominant ionic populations, "free" and "bound," in fast exchange with each other or with a model that assumed an asymmetric Gaussian distribution of correlation times. Regardless of the model employed, both ions were found to occur in a predominantly "free" or "unbound" rapidly reorienting state. The fraction of "bound" 23Na+, assuming a discrete two-site model, was approximately 0.006 and 0.017 for cortical and nuclear homogenates, respectively. Corresponding values for 39K+ were 0.003 and 0.007, respectively. Estimated values for the fraction of "bound" 23Na+ or 39K+ obtained from the distribution model (tau C greater than omega L-1) were less than or equal to 0.05 for all cases examined. The correlation times of the "bound" ions, derived using either a two-site or distribution model, yielded values that were at least one order of magnitude smaller than the reorientational motion of the constituent lens proteins. This observation implies that the apparent correlation time for ion binding is dominated by processes other than protein reorientational motion, most likely fast exchange between "free" and "bound" environments. The results of NMR visibility studies were consistent with the above findings, in agreement with other studies performed by non-NMR methods. These studies, in combination with those presented in the literature, suggest that the most likely role for sodium and potassium ions in the lens appears to be the regulation of cell volume by affecting the intralenticular water chemical potential. Images FIGURE 4 PMID:1600073

Stevens, A; Paschalis, P; Schleich, T

1992-01-01

109

Combined Panofsky Quadrupole & Corrector Dipole  

SciTech Connect

Two styles of Panofsky Quadrupoles with integral corrector dipole windings are in use in the electron beam line of the Free Electron Laser at Jefferson Lab. We combined steering and focusing functions into single magnets, adding hundreds of Gauss-cm dipole corrector capability to existing quadrupoles because space is at a premium along the beam line. Superposing a one part in 100 dipole corrector field on a 1 part in 1000, weak (600 to 1000 Gauss) quadrupole is possible because the parallel slab iron yoke of the Panofsky Quadrupole acts as a window frame style dipole yoke. The dipole field is formed when two electrically floating “current sources”, designed and made at JLab, add and subtract current from the two opposite quadrupole current sheet windings parallel to the dipole field direction. The current sources also drive auxiliary coils at the yoke’s inner corners that improve the dipole field. Magnet measurements yielded the control system field maps that characterize the two types of fields. Field analysis using TOSCA, construction and wiring details, magnet measurements and reference for the current source are presented.

George Biallas; Nathan Belcher; David Douglas; Tommy Hiatt; Kevin Jordan

2007-07-02

110

Microstructural Examination to Aid in Understanding Friction Bonding Fabrication Technique for Monolithic Nuclear Fuel  

SciTech Connect

Monolithic nuclear fuel is currently being developed for use in research reactors, and friction bonding (FB) is a technique being developed to help in this fuel’s fabrication. Since both FB and monolithic fuel are new concepts, research is needed to understand the impact of varying FB fabrication parameters on fuel plate characteristics. This thesis research provides insight into the FB process and its application to the monolithic fuel design by recognizing and understanding the microstructural effects of varying fabrication parameters (a) FB tool load, and (b) FB tool face alloy. These two fabrication parameters help drive material temperature during fabrication, and thus the material properties, bond strength, and possible formation of interface reaction layers. This study analyzed temperatures and tool loads measured during those FB processes and examined microstructural characteristics of materials and bonds in samples taken from the resulting fuel plates. This study shows that higher tool load increases aluminum plasticization and forging during FB, and that the tool face alloy helps determine the tool’s heat extraction efficacy. The study concludes that successful aluminum bonds can be attained in fuel plates using a wide range of FB tool loads. The range of tool loads yielding successful uranium-aluminum bonding was not established, but it was demonstrated that such bonding can be attained with FB tool load of 48,900 N (11,000 lbf) when using a FB tool faced with a tungsten alloy. This tool successfully performed FB, and with better results than tools faced with other materials. Results of this study correlate well with results reported for similar aluminum bonding techniques. This study’s results also provide support and validation for other nuclear fuel development studies and conclusions. Recommendations are offered for further research.

Karen L. Shropshire

2008-04-01

111

Experimental determination of linear optics including quadrupole rotations  

SciTech Connect

The measured response matrix giving the change in orbit at beam position monitors (BPMs) with changes in steering magnet excitation can be used to accurately determine many important parameters in a storage ring. Using the NSLS X-Ray Ring measured response matrix we have determined the gradients in all 56 quadrupole magnets; the calibration of the steering magnets and BPMs; the rotational mis-alignments of the quadrupoles, steering magnets, and BPMs about the electron beam direction; the longitudinal magnetic centers of the orbit steering magnets; and the transverse mis-alignments of the sextupoles. Random orbit measurement error of the BPMs propagated to give 0.04% rms error in determination of individual quadrupole gradients and 0.4 mrad rms error in the determination of quadrupole rotational alignment. Small variations of a few parts in a thousand in the quadrupole gradients within an individual family were resolved. The improved understanding of the X-Ray Ring has enabled us to better control the electron beam size.

Safranek, J.

1995-06-01

112

Quadrupole interactions in tetraoxoferrates (VI)  

NASA Astrophysics Data System (ADS)

An applicability of the point charge approach for calculations of quadrupole splittings in Mössbauer spectra of ferrates(VI) was studied. The reasonable correlation between calculated and experimental splittings was observed for the majority of ferrates excepting K3Na(FeO4)2. The comparison of ferrates and chromates was made using calculated nucleus independent coefficient.

Dedushenko, Sergey K.; Perfiliev, Yurii D.; Rusakov, Vyacheslav S.; Gapochka, Alexei M.

2013-05-01

113

Quadrupole magnets for the SSC  

SciTech Connect

At LBL, we have designed, constructed, and tested ten models (4-1meter, 6-5meter) of the Superconducting Super Collider (SSC) main-ring 5 meter focusing quadrupole magnet (211Tesla/meter). The results of this program are herein summarized.

Lietzke, A.; Barale, P.; Benjegerdes, R.; Caspi, S.; Cortella, J.; Dell'Orco, D.; Gilbert, W.; Green, M.I.; Mirk, K.; Peters, C.; Scanlan, R.; Taylor, C.E.; Wandesforde, A.

1992-08-01

114

LCLS Undulator Quadrupole Fiducialization Plan  

SciTech Connect

This note presents the fiducialization plan for the LCLS undulator quadrupoles. The note begins by summarizing the requirements for the fiducialization. A discussion of the measurement equipment is presented, followed by the methods used to perform the fiducialization and check the results. This is followed by the detailed fiducialization plan in which each step is enumerated. Finally, the measurement results and data storage formats are presented. The LCLS is made up of 33 assemblies consisting of an undulator, quadrupole, beam finder wire, and other components mounted on a girder. The components must be mounted in such a way that the beam passes down the axis of each component. In this note, we describe how the ideal beam axis is related to tooling balls on the quadrupole. This step, called fiducialization, is necessary because the ideal beam axis is determined magnetically, whereas tangible objects must be used to locate the quadrupole. The note begins with the list of fiducialization requirements. The laboratory in which the work will be performed and the relevant equipment is then briefly described. This is followed by a discussion of the methods used to perform the fiducialization and the methods used to check the results. A detailed fiducialization plan is presented in which all the steps of fiducialization are enumerated. A discussion of the resulting data files and directory structure concludes the note.

Wolf, Zachary; Levashov, Michael; Lundahl, Eric; Reese, Ed; LeCocq, Catherine; Ruland, Robert; /SLAC; ,

2010-11-24

115

Physical implications of the use of primitive and traceless electric quadrupole moments  

NASA Astrophysics Data System (ADS)

Theories of certain electromagnetic effects, such as chiral phenomena in fluids and crystals and gyrotropic birefringence in antiferromagnetic crystals, require the inclusion of electric quadrupole contributions for a full description of the effect. In a number of these theories the electric quadrupole moment is defined to be traceless, as indeed is the general practice for such moments in nuclear physics. It is shown that, when the traceless quadrupole moment is used in the derivation of the wave equation that describes light propagation through an optically active uniaxial medium, this equation and properties derived from it, in particular refractive index, depend in general on the arbitrary origin used to specify the quadrupole moment. This is physically unacceptable for an observable property of a substance. By contrast, this defect does not occur if the definition of the primitive quadrupole moment is adopted, namely qr r . beta

Gunning, M. J.; Raab, R. E.

116

Topology of the interactions pattern in pharmaceutically relevant polymorphs of methylxanthines (caffeine, theobromine, and theophiline): combined experimental ((1)h-(14)n nuclear quadrupole double resonance) and computational (DFT and hirshfeld-based) study.  

PubMed

Three anhydrous methylxanthines: caffeine (1,3,7-trimethylxanthine; 1,3,7-trimethyl-1H-purine-2,6-(3H,7H)-dione) and its two metabolites theophylline (1,3-dimethylxanthine; 1,3-dimethyl-7H-purine-2,6-dione) and theobromine (3,7-dimethyl-xanthine; 3,7-dimethyl-7H-purine-2,6-dione), which reveal multifaceted therapeutic potential, have been studied experimentally in solid state by (1)H-(14)N NMR-NQR (nuclear magnetic resonance-nuclear quadrupole resonance) double resonance (NQDR). For each compound the complete NQR spectrum consisting of 12 lines was recorded. The multiplicity of NQR lines indicates the presence of a stable ? form of anhydrous caffeine at 233 K and stable form II of anhydrous theobromine at 213 K. The assignment of signals detected in NQR experiment to particular nitrogen atoms was made on the basis of quantum chemistry calculations performed for monomer, cluster, and solid at the DFT/GGA/BLYP/DPD level. The shifts due to crystal packing interactions were evaluated, and the multiplets detected by NQR were assigned to N(9) in theobromine and N(1) and N(9) in caffeine. The ordering theobromine > theophylline > caffeine site and theophylline < theobromine < caffeine according to increasing electric field gradient (EFG) at the N(1) and N(7) sites, respectively, reflects the changes in biological activity profile of compounds from the methylxanthines series (different pharmacological effects). This difference is elucidated on the basis of the ability to form intra- and intermolecular interactions (hydrogen bonds and ?···? stacking interactions). The introduction of methyl groups to xanthine restricts the ability of nitrogen atoms to participate in strong hydrogen bonds; as a result, the dominating effect shifts from hydrogen bond (theobromine) to ?···? stacking (caffeine). Substantial differences in the intermolecular interactions in stable forms of methylxanthines differing in methylation (site or number) were analyzed within the Hirshfeld surface-based approach. The analysis of local environment of the nitrogen nucleus permitted drawing some conclusions on the nature of the interactions required for effective processes of recognition and binding of a given methylxanthine to A1-A2A receptor (target for caffeine in the brain). Although the interactions responsible for linking neighboring methylxanthines molecules in crystals and methylxanthines with targets in the human organism can differ significantly, the knowledge of the topology of interactions provides reliable preliminary information about the nature of this binding. PMID:25184363

Latosi?ska, Jolanta Natalia; Latosi?ska, Magdalena; Olejniczak, Grzegorz A; Seliger, Janez; Zagar, Veselko

2014-09-22

117

Understanding and Managing Aging of Spent Nuclear Fuel and Facility Components in Wet Storage  

SciTech Connect

Storage of nuclear fuel after it has been discharged from reactors has become the leading spent fuel management option. Many storage facilities are being required to operate longer than originally anticipated. Aging is a term that has emerged to focus attention on the consequences of extended operation on systems, structures, and components that comprise the storage facilities. The key to mitigation of age-related degradation in storage facilities is to implement effective strategies to understand and manage aging of the facility materials. A systematic approach to preclude serious effects of age-related degradation is addressed in this paper, directed principally to smaller facilities (test and research reactors). The first need is to assess the materials that comprise the facility and the environments that they are subject to. Access to historical data on facility design, fabrication, and operation can facilitate assessment of expected materials performance. Methods to assess the current condition of facility materials are summarized in the paper. Each facility needs an aging management plan to define the scope of the management program, involving identification of the materials that need specific actions to manage age-related degradation. For each material identified, one or more aging management programs are developed and become part of the plan Several national and international organizations have invested in development of comprehensive and systematic approaches to aging management. A method developed by the US Nuclear Regulatory Commission is recommended as a concise template to organize measures to effectively manage age-related degradation of storage facility materials, including the scope of inspection, surveillance, and maintenance that is needed to assure successful operation of the facility over its required life. Important to effective aging management is a staff that is alert for evidence of materials degradation and committed to carry out the aging management programs.

Johnson, A. Burton

2007-07-01

118

Electric quadrupole moment of the neutron-rich 33Al  

NASA Astrophysics Data System (ADS)

The nuclear electric quadrupole moment ( Q moment) of the neutron-rich nucleus 33Al ( I = 5/2 , T 1/2 = 41 ms) has been measured by the ? -ray detected nuclear quadrupole resonance ( ? -NQR) method for the first time. The 33Al nucleus is considered to be on the border of the island of inversion within which a significant intrusion of the pf orbits occurs across the N = 20 shell gap and the intrusion causes an anomalous enhancement of the Q moment. Polarized 33Al nuclei were produced from 36S (77.5MeV/ u beams through the fragmentation process and separated by LISE fragment separator at GANIL. The 33Al nuclei were implanted into a Al2O3 single-crystal plate and the ? -NQR spectrum was successfully obtained.

Nagatomo, T.; Shimada, K.; Asahi, K.; Balabanski, D. L.; Daugas, J. M.; Depuydt, M.; de Rydt, M.; Gaudefroy, L.; Grévy, S.; Hasama, Y.; Ichikawa, Y.; Kameda, D.; Morel, P.; Perrot, L.; Stödel, C.; Thomas, J. C.; Vanderheijden, W.; Vermeulen, N.; Vingerhoets, P.; Yoshimi, A.; Neyens, G.; Ueno, H.

2009-12-01

119

Sign-Selected Quadrupole Train  

SciTech Connect

The design of the Sign-Selected Quadrupole Train for E-815 (NuTeV) is set forth. The relevant physics requirements are explained. The optics of the beam are presented, along with an explanation of the proton dumping scheme. A discussion of rates and backgrounds follows, with special care given to backgrounds from scraping and obstructions. The relevant tolerances for beam construction are given and justified by simulations of the beamline. This leads to a discussion of the beam monitoring.

Bernstein, R.; NuTeV Collaboration

1994-05-03

120

Understanding the interplay of increased pressure, residual heat and geologic and geochemical environment on radionuclide migration from underground nuclear tests  

SciTech Connect

Understanding the processes that govern migration of radionuclides from underground nuclear tests is a problem of interest in many places in the world. Whether to gain understanding in the risks to human health, to guide water resources management decisions or as a surrogate for nuclear repository safety, there are a number of complex, coupled processes governing fate and form of radionuclides in the subsurface that need to be understood. These processes include the increased pore water pressure that is present after some underground nuclear tests, the residual heat signature from the nuclear detonation and the natural (i.e. pre-test) and altered (i.e. post-test) hydrogeologic and geochemical setting. We will focus on tests in saturated and unsaturated environments in Yucca Flat at the US Nevada Test Site. These tests all encompass a range of the aforementioned process interactions and provide insight into the broader context of understanding radionuclide migration from underground nuclear tests over a range of scale and environment.

Maxwell, R M; Detwiler, R L; Hu, Q; Tompson, A B

2008-01-14

121

Quadrupole mass spectrometer with a distorted analyzing field  

SciTech Connect

The purpose of this work is the mathematical modeling of the ion and field dynamics in a quadrupole mass spectrometer, designed for monitoring the composition of nuclear fuels, with a distorted analyzing field and the determination of its sensitivity on the distortion. The model takes into account ion trajectories in the analyzing field with distortions due to nonrectilinear field-specifying electrodes as well as edge distortion and the transmission coefficient of ions through the spectrometer.

Titov, V.V.

1987-02-01

122

Mathematical modeling and nuclear magnetic resonance techniques to understand electrochemically active biofilms .  

E-print Network

??The objective of this dissertation was to explore the electron transfer capabilities of electrochemically-active biofilms by employing mathematical modeling and nuclear magnetic resonance techniques. This… (more)

[No author

2012-01-01

123

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  

SciTech Connect

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 show 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.

Ki Deok Park; Guo, K.; Adebodun, F.; Chiu, M.L.; Sligar, S.G.; Oldfield, E. (Univ. of Illinois, Urbana (United States))

1991-03-05

124

a Nuclear Magnetic Resonance and a Nuclear Quadrupole Resonance Study of the Phases and Solid State Transformations in the Alkali Metal Hydroxides - Lithium-Hydroxide Sodium - Potassium-Hydroxide Rubidium-Hydroxide Cesium - and Cesium-Hydroxide - Water.  

NASA Astrophysics Data System (ADS)

The proton NMR lineshapes for all alkali metal hydroxides, except LiOH, have a weak doublet structure (most pronounced in KOH). This structure was explained by modelling the arrangement of hydrogen atoms with a 4 -spin planar zig-zag chain. The second moments of proton NMR recorded at 27 MHz and at 295 K are 8.8, 10.8, 6.5, 4.8 and 4.1 (gauss)('2) for LiOH, NaOH, KOH, RbOH and CsOH respectively. The phase diagram for NaOH and Na(,2)CO(,3) has been reviewed and appended using DTA results. The NMR of ('23)NaOH (QCC = 3.52 (+OR-) 0.06 MHz and (eta) < 0.04 at 295 K) has been measured from 77 K to 570 K. The temperature dependence of the NQR of ('23)NaOH, studied from 77 K to 550 K, shows a change in slope and a discontinuous change in NQR frequency of 6 (+OR-) 2 kHz on crossing from the orthorhombic to monoclinic phases. At 292 K, the sodium NQR frequency was 1.778 (+OR-) 0.001 MHz. The DTA and NQR results for ('23)NaOD show a phase transition at 160 K with an enthalpy change of 200 (+OR-) 75 J/mol. There is no corresponding transition in NaOH above 110 K. The deuterium NMR in NaOD was studied from 293 K to 570 K (QCC = 245 (+OR-) 2 kHz and (eta) = 0.05 (+OR-) 0.01 at 293 K). The decrease in deuterium QCC with increasing temperature was fitted to a librating molecule model and confirmed that the frequency of the OD('-) libration decreases in the monoclinic phase. The proton NMR linewidth in NaOH narrows from 10 gauss FWHM at 295 K to 1 gauss at 550 K due to proton conduction. The proton T(,1) (T(,1) = 300 sec. at 41 MHz and 293 K) decreases with increasing temperature and is extremely dependent on H(,2)O content. From the NMR of ('87)RbOH at 293 K, it was estimated that QCC = 9 (+OR-) 1 MHz. The ('133)Cs NMR in CsOH(.)H(,2)O was studied from 230 K to 470 K. At 293 K, QCC = 101 (+OR -) 2 kHz with (eta) = 0. The ('133)Cs NMR changes at the 232 K transition but varies smoothly through the 340 K transition in CsOH(.)H(,2)O. The unusual deuterium quadrupole coupling for the OD('-) ion in CsOD (QCC = 143 (+OR-) 2 kHz, (eta) = 0.66 (+OR-) 0.01 at 295 K) indicates that the OD('-) ion is orientationally disordered, with two equivalent deuterium sites in the orthorhombic phase. Below 247 K in CsOD (232 K in CsOH), the deuterium NMR suggests that the OD('-) ions are not orientationally disordered.

Amm, David Thomas

125

Quadrupole coupling and crystal-field shielding in CaF2:Eu3+:O2- under hydrostatic pressure  

Microsoft Academic Search

The nuclear quadrupole interactions in the 7F0 ground electronic state and the 5D0 excited state of the 151Eu3+ and 153Eu3+ ions have been investigated by optical means. The optically detected nuclear quadrupole resonance, excitation, and luminescence of the Eu3+-O2- C3v symmetry center have been studied at 4.2 K in single crystals of CaF2:Eu:O under hydrostatic pressure up to 7.5 kbar.

Andrzej P. Radlinski; A. J. Silversmith

1986-01-01

126

A Vibrating Wire System For Quadrupole Fiducialization  

SciTech Connect

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 step 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.

Wolf, Zachary

2010-12-13

127

Electrostatic quadrupoles for heavy-ion fusion  

SciTech Connect

Voltage-holding data for three quadrupole electrode sizes and inter-electrode spacings are reported. The dependence of the breakdown voltage on system size and its influence on the optimum quadrupole size for beam transport in a multiple beam array are discussed.

Seidl, P.; Faltens, A.

1993-05-01

128

How much nuclear physics do we need, to understand the neutrino nucleus cross section ?  

E-print Network

Over the past two decades, electron scattering experiments have clearly exposed the limits of the independent particle model description of atomic nuclei. I will briefly outline the dynamics leading to the appearance of strong correlation effects, and their impact on the electroweak nuclear cross sections in the impulse approximation regime.

Omar Benhar

2009-06-17

129

Application of Nuclear Microprobes towards Understanding Complex Ore Geo-electrochemistry  

NASA Astrophysics Data System (ADS)

We report on recent development on the CSIRO Nuclear Microprobe (NMP) towards catering for long exposure mapping required for large area scanning. A new data collection system based on Labview FPGA highly co-ordinated with beam transport sits at the heart of the upgrade. These upgrades are discussed and an example of the systems use for ?-Particle Induced X-ray Emission (PIXE) analysis in the area of complex ore geo-electrochemistry is briefly described.

Laird, J. S.; Szymanski, R.; Large, R.; Ryan, C. G.

2012-10-01

130

Research on Plants for the Understanding of Diseases of Nuclear and Mitochondrial Origin  

PubMed Central

Different model organisms, such as Escherichia coli, Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster, mouse, cultured human cell lines, among others, were used to study the mechanisms of several human diseases. Since human genes and proteins have been structurally and functionally conserved in plant organisms, the use of plants, especially Arabidopsis thaliana, as a model system to relate molecular defects to clinical disorders has recently increased. Here, we briefly review our current knowledge of human diseases of nuclear and mitochondrial origin and summarize the experimental findings of plant homologs implicated in each process. PMID:22690124

Spampinato, Claudia P.; Gomez-Casati, Diego F.

2012-01-01

131

Nonuniform radiation damage in permanent magnet quadrupoles  

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

132

Miniature quadrupole mass spectrometer array  

NASA Technical Reports Server (NTRS)

The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

1998-01-01

133

Miniature quadrupole mass spectrometer array  

NASA Technical Reports Server (NTRS)

The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

1997-01-01

134

Integrally formed radio frequency quadrupole  

DOEpatents

An improved radio frequency quadrupole (10) is provided having an elongate housing (11) with an elongate central axis (12) and top, bottom and two side walls (13a-d) symmetrically disposed about the axis, and vanes (14a-d) formed integrally with the walls (13a-d), the vanes (14a-d) each having a cross-section at right angles to the central axis (12) which tapers inwardly toward the axis to form electrode tips (15a-d) spaced from each other by predetermined distances. Each of the four walls (13a-d), and the vanes (14a-d) integral therewith, is a separate structural element having a central lengthwise plane (16) passing through the tip of the vane, the walls (13a-d) having flat mounting surfaces (17, 18) at right angles to and parallel to the control plane (16), respectively, which are butted together to position the walls and vane tips relative to each other.

Abbott, Steven R. (Concord, CA)

1989-01-01

135

Permanent magnet edge-field quadrupole  

DOEpatents

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.

Tatchyn, R.O.

1997-01-21

136

Permanent magnet edge-field quadrupole  

DOEpatents

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.

Tatchyn, Roman O. (Mountain View, CA)

1997-01-01

137

Use of First Order Reversal Curve Measurements to Understand Barkhausen Noise Emission in Nuclear Steel  

SciTech Connect

A prototypical ferritic/martensitic alloy, HT-9, of interest to the nuclear materials community was investigated for microstructure effects on Barkhausen noise emission and first-order reversal curve (FORC) analysis for three different heat-treated samples. It was observed that Barkhausen noise emission and reversible component of magnetization, computed from the FORC data, decreased with increasing measured mechanical hardness. The results are discussed in terms of the use of magnetic signatures for use in nondestructive interrogation of radiation damage and other microstructural changes in ferritic/martensitic alloys. FORC analysis is shown to be particularly useful for detailed characterization of defect density and pinning, which can be correlated to bulk non-destructive evaluation field measurements such as Barkhausen noise emission.

McCloy, John S.; Ramuhalli, Pradeep; Henager, Charles H.

2013-02-25

138

Use of first order reversal curve measurements to understand Barkhausen noise emission in nuclear steel  

NASA Astrophysics Data System (ADS)

A prototypical ferritic/martensitic alloy, HT-9, of interest to the nuclear materials community was investigated for microstructure effects on Barkhausen noise emission and first-order reversal curve (FORC) analysis for three different heat-treated samples. It was observed that Barkhausen noise emission and reversible component of magnetization, computed from the FORC data, decreased with increasing measured mechanical hardness. The results are discussed in terms of the use of magnetic signatures for use in nondestructive interrogation of radiation damage and other microstructural changes in ferritic/martensitic alloys. FORC analysis is shown to be particularly useful for detailed characterization of defect density and pinning, which can be correlated to bulk non-destructive evaluation field measurements such as Barkhausen noise emission.

McCloy, J. S.; Ramuhalli, Pradeep; Henager, Charles, Jr.

2013-01-01

139

Mechanistic understanding of irradiation-induced corrosion of zirconium alloys in nuclear power plants: Stimuli, status, and outlook  

SciTech Connect

Failures in the basic materials used in nuclear power plants continue to be costly and insidious, despite increasing industry vigilance to catch failures before they degrade safety. For instance, the overall costs to the US industry from materials problems could amount to as much as $10 billion annually. Moreover, estimates indicate that the cost of a pipe failure in a nuclear plant is one hundred times greater than the cost of a similar failure in a coal-fired plant. There are important practical stimuli and much scope for further understanding of the effects of irradiation on Zr-alloys (and other materials used in nuclear installations) by careful experimentation. Moreover, these studies need to address the effect of irradiation on all components of heterogeneous systems: the metal, the oxide and the environment, and especially those processes recurring at the interphases between these components. The present paper is aimed at providing specialists with some systematic information on the subject and with important considerations on the key items for further experimentation.

Johnson, A.B. Jr.; Ishigure, K.; Nechaev, A.F.; Reznichenko, E.A.; Cox, B.; Lemaignan, C.; Petrik, N.G.

1990-05-01

140

Toward Understanding the Effect of Nuclear Waste Glass Composition of Sulfur Solubility  

The concentration of sulfur in nuclear waste glass melter feed must be maintained below the point where salt accumulates on the melt surface. The allowable concentrations may range from 0.37 to over 2.05 weight percent (of SO3 on a calcined oxide basis) depending on the composition of the melter feed and processing conditions. If the amount of sulfur exceeds the melt tolerance level, a molten salt will accumulate, which may upset melter operations and potentially shorten the useful life of the melter. At the Hanford site, relatively conservative limits have been placed on sulfur loading in melter feed, which in turn significantly increases the amount of glass that will be produced. Crucible-scale sulfur solubility data and scaled melter sulfur tolerance data have been collected on simulated Hanford waste glasses over the last 15 years. These data were compiled and analyzed. A model was developed to predict the solubility of SO3 in glass based on 252 simulated Hanford low-activity waste (LAW) glass compositions. This model represents the data well, accounting for over 85% of the variation in data, and was well validated. The model was also found to accurately predict the tolerance for sulfur in melter feed for 13 scaled melter tests of simulated LAW glasses. The model can be used to help estimate glass volumes and make informed decisions on process options. The model also gives quantitative estimates of component concentration effects on sulfur solubility. The components that most increase sulfur solubility are Li2O > V2O5> CaO ? P2O5 > Na2O ? B2O3 > K2O. The components that most decrease sulfur solubility are Cl > Cr2O3 > Al2O3 > ZrO2 ? SnO2 > Others ? SiO2. The order of component effects is similar to previous literature data, in most cases.

Vienna, John D.; Kim, Dong-Sang; Muller, I. S.; Kruger, Albert A.; Piepel, Gregory F.

2014-02-13

141

Understanding Fuel Magnetization and Mix Using Secondary Nuclear Reactions in Magneto-Inertial Fusion  

NASA Astrophysics Data System (ADS)

Magnetizing the fuel in inertial confinement fusion relaxes ignition requirements by reducing thermal conductivity and changing the physics of burn product confinement. Diagnosing the level of fuel magnetization during burn is critical to understanding target performance in magneto-inertial fusion (MIF) implosions. In pure deuterium fusion plasma, 1.01 MeV tritons are emitted during deuterium-deuterium fusion and can undergo secondary deuterium-tritium reactions before exiting the fuel. Increasing the fuel magnetization elongates the path lengths through the fuel of some of the tritons, enhancing their probability of reaction. Based on this feature, a method to diagnose fuel magnetization using the ratio of overall deuterium-tritium to deuterium-deuterium neutron yields is developed. Analysis of anisotropies in the secondary neutron energy spectra further constrain the measurement. Secondary reactions also are shown to provide an upper bound for the volumetric fuel-pusher mix in MIF. The analysis is applied to recent MIF experiments [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014), 10.1103/PhysRevLett.113.155003] on the Z Pulsed Power Facility, indicating that significant magnetic confinement of charged burn products was achieved and suggesting a relatively low-mix environment. Both of these are essential features of future ignition-scale MIF designs.

Schmit, P. F.; Knapp, P. F.; Hansen, S. B.; Gomez, M. R.; Hahn, K. D.; Sinars, D. B.; Peterson, K. J.; Slutz, S. A.; Sefkow, A. B.; Awe, T. J.; Harding, E.; Jennings, C. A.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Geissel, M.; Harvey-Thompson, A. J.; Herrmann, M. C.; Hess, M. H.; Johns, O.; Lamppa, D. C.; Martin, M. R.; McBride, R. D.; Porter, J. L.; Robertson, G. K.; Rochau, G. A.; Rovang, D. C.; Ruiz, C. L.; Savage, M. E.; Smith, I. C.; Stygar, W. A.; Vesey, R. A.

2014-10-01

142

Professor Adam Sobiczewski: Seminal Contributions to Understanding and Predicting Nuclear Stability of the Heaviest Elements  

NASA Astrophysics Data System (ADS)

Throughout his long career Adam Sobiczewski has made major contributions to the interpretation and understanding of experimental results on the synthesis and decay properties of the heaviest nuclei and to the development of theoretical methods for predicting properties of as yet undiscovered nuclei. He led the way in using a dynamical approach to macroscopic-microscopic calculations of spontaneous fission half-lives of deformed nuclei in a multi-dimensional deformation space without adjustable parameters. Examination of the well-deformed even-even nuclei with Z=104--114 and N=142--176 showed that inclusion of higher order deformations greatly increased the N=162 shell correction. Nuclei in the region of the doubly magic deformed nucleus 270108 were predicted to be much more stable than previously believed and significant deviations from the old rule of rapidly decreasing spontaneous-fission half-lives with increasing Z should occur. The impact and influence of these results on experimental investigations and the interactions between theory and experiment will be discussed.

Hoffman, Darleane C.

2003-03-01

143

Understanding fuel magnetization and mix using secondary nuclear reactions in magneto-inertial fusion.  

PubMed

Magnetizing the fuel in inertial confinement fusion relaxes ignition requirements by reducing thermal conductivity and changing the physics of burn product confinement. Diagnosing the level of fuel magnetization during burn is critical to understanding target performance in magneto-inertial fusion (MIF) implosions. In pure deuterium fusion plasma, 1.01 MeV tritons are emitted during deuterium-deuterium fusion and can undergo secondary deuterium-tritium reactions before exiting the fuel. Increasing the fuel magnetization elongates the path lengths through the fuel of some of the tritons, enhancing their probability of reaction. Based on this feature, a method to diagnose fuel magnetization using the ratio of overall deuterium-tritium to deuterium-deuterium neutron yields is developed. Analysis of anisotropies in the secondary neutron energy spectra further constrain the measurement. Secondary reactions also are shown to provide an upper bound for the volumetric fuel-pusher mix in MIF. The analysis is applied to recent MIF experiments [M.?R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] on the Z Pulsed Power Facility, indicating that significant magnetic confinement of charged burn products was achieved and suggesting a relatively low-mix environment. Both of these are essential features of future ignition-scale MIF designs. PMID:25375715

Schmit, P F; Knapp, P F; Hansen, S B; Gomez, M R; Hahn, K D; Sinars, D B; Peterson, K J; Slutz, S A; Sefkow, A B; Awe, T J; Harding, E; Jennings, C A; Chandler, G A; Cooper, G W; Cuneo, M E; Geissel, M; Harvey-Thompson, A J; Herrmann, M C; Hess, M H; Johns, O; Lamppa, D C; Martin, M R; McBride, R D; Porter, J L; Robertson, G K; Rochau, G A; Rovang, D C; Ruiz, C L; Savage, M E; Smith, I C; Stygar, W A; Vesey, R A

2014-10-10

144

Understanding public responses to chemical, biological, radiological and nuclear incidents--driving factors, emerging themes and research gaps.  

PubMed

This paper discusses the management of public responses to incidents involving chemical, biological, radiological and nuclear materials (CBRN). Given the extraordinary technical and operational challenges of a response to a CBRN release including, but not limited to, hazard detection and identification, casualty decontamination and multi-agency co-ordination, it is not surprising that public psychological and behavioural responses to such incidents have received limited attention by scholars and practitioners alike. As a result, a lack of understanding about the role of the public in effective emergency response constitutes a major gap in research and practice. This limitation must be addressed as a CBRN release has the potential to have wide-reaching psychological and behavioural impacts which, in turn, impact upon public morbidity and mortality rates. This paper addresses a number of key issues: why public responses matter; how responses have been conceptualised by practitioners; what factors have been identified as influencing public responses to a CBRN release and similar extreme events, and what further analysis is needed in order to generate a better understanding of public responses to inform the management of public responses to a CBRN release. PMID:24856235

Krieger, Kristian; Amlôt, Richard; Rogers, M Brooke

2014-11-01

145

Detecting quadrupole interactions in ultracold Fermi gases  

E-print Network

We propose to detect quadrupole interactions of neutral ultra-cold atoms via their induced mean-field shift. We consider a Mott insulator state of spin-polarized atoms in a two-dimensional optical square lattice. The quadrupole moments of the atoms are aligned by an external magnetic field. As the alignment angle is varied, the mean-field shift shows a characteristic angular dependence, which constitutes the defining signature of the quadrupole interaction. For the $^{3}P_{2}$ states of Yb and Sr atoms, we find a frequency shift of the order of tens of Hertz, which can be realistically detected in experiment with current technology. We compare our results to the mean-field shift of a spin-polarized quasi-2D Fermi gas in continuum.

M. Lahrz; Mikhail Lemeshko; Klaus Sengstock; Christoph Becker; L. Mathey

2014-02-04

146

Microfluidic quadrupole and floating concentration gradient  

PubMed Central

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 center 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 – i.e. “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. PMID:21897375

Qasaimeh, Mohammad A.; Gervais, Thomas; Juncker, David

2014-01-01

147

44 CFR Appendix A to Part 353 - Memorandum of Understanding Between Federal Emergency Management Agency and Nuclear Regulatory...  

Code of Federal Regulations, 2012 CFR

...Preparedness Planning at Commercial Nuclear Power Plants). II. Authorities...results related to a specific nuclear power plant site. If the review...public living in the vicinity of a nuclear power plant. Because of the...

2012-10-01

148

44 CFR Appendix A to Part 353 - Memorandum of Understanding Between Federal Emergency Management Agency and Nuclear Regulatory...  

Code of Federal Regulations, 2013 CFR

...Preparedness Planning at Commercial Nuclear Power Plants). II. Authorities...results related to a specific nuclear power plant site. If the review...public living in the vicinity of a nuclear power plant. Because of the...

2013-10-01

149

44 CFR Appendix A to Part 353 - Memorandum of Understanding Between Federal Emergency Management Agency and Nuclear Regulatory...  

Code of Federal Regulations, 2011 CFR

...Preparedness Planning at Commercial Nuclear Power Plants). II. Authorities...results related to a specific nuclear power plant site. If the review...public living in the vicinity of a nuclear power plant. Because of the...

2011-10-01

150

44 CFR Appendix A to Part 353 - Memorandum of Understanding Between Federal Emergency Management Agency and Nuclear Regulatory...  

Code of Federal Regulations, 2010 CFR

...Preparedness Planning at Commercial Nuclear Power Plants). II. Authorities...results related to a specific nuclear power plant site. If the review...public living in the vicinity of a nuclear power plant. Because of the...

2010-10-01

151

Nuclear Magnetic Resonance  

NASA Astrophysics Data System (ADS)

Author's preface; 1. Introduction; 2. Basic theory; 3. Experimental methods; 4. Measurement of nuclear properties and general physical applications; 5. Nuclear magnetic resonance in liquids and gases; 6. Nuclear magnetic resonance in non-metallic solids; 7. Nuclear magnetic resonance in metals; 8. Quadrupole effects; Appendices 1-6; Glossary of symbols; Bibliography and author index; Subject index.

Andrew, E. R.

2009-06-01

152

High precision measurement of the 11Li and 9Li quadrupole moment ratio using zero-field ?-NQR  

NASA Astrophysics Data System (ADS)

The ratio of electric quadrupole moments of 11Li and 9Li was measured using the zero-field ?-detected nuclear quadrupole resonance technique at Triumf-Isac. The precision on the ratio Q11/Q9 = 1.0775(12) was improved by more than one order of magnitude and an absolute value for the quadrupole moment of 11Li was inferred. Systematic effects, as argued here, are not expected to contribute to the ratio on this scale. The zero-field spin-lattice relaxation time for 8Li implanted within SrTiO3 at 295?K in zero-field was found to be T1 = 1.73(2)?s. A comparison of the quadrupole moments of 9, 11Li and their ratio is made with the latest models, however, no conclusion may yet be drawn owing to the size of the theoretical uncertainties.

Voss, A.; Pearson, M. R.; Buchinger, F.; Crawford, J. E.; Kiefl, R. F.; Levy, C. D. P.; MacFarlane, W. A.; Mané, E.; Morris, G. D.; Shelbaya, O. T. J.; Song, Q.; Wang, D.

2014-01-01

153

Electric quadrupole and hexadecapole moments for ethyne  

NASA Astrophysics Data System (ADS)

We report an ab initio study of electric quadrupole and hexadecapole moments of ethyne (HC?CH). Large Gaussian basis sets are used to obtain SCF values close to the Hartree-Fock limit. Electron correlation corrections to the SCF values are calculated via SDQ-MP4, fourth-order Møller-Plesset perturbation theory with single, double and quadruple substitutions from the reference wavefunction. Our best values, obtained with a 4s3p3d2f/3s2p1d basis set, are 4.88 ea20 for the quadrupole and 55.8 ea40 for the hexadecapole moment at the experimental equilibrium geometry.

Maroulis, George

1991-02-01

154

Classical toy models for the monopole shift and the quadrupole shift.  

PubMed

The penetration of s- and p(1/2)-electrons into the atomic nucleus leads to a variety of observable effects. The presence of s-electrons inside the nucleus gives rise to the isotope shift in atomic spectroscopy, and to the isomer shift in Mössbauer spectroscopy. Both well-known phenomena are manifestations of the more general monopole shift. In a recent paper (Koch et al., Phys. Rev. A, 2010, 81, 032507), we discussed the existence of the formally analogous quadrupole shift: a tensor correction to the electric quadrupole interaction due to the penetration of relativistic p(1/2)-electrons into the nucleus. The quadrupole shift is predicted to be observable by high-accuracy molecular spectroscopy on a set of 4 molecules (the quadrupole anomaly). The simple physics behind all these related phenomena is easily obscured by an elaborate mathematical formalism that is required for their derivation: a multipole expansion in combination with perturbation theory, invoking quantum physics and ideally relativity. In the present paper, we take a totally different approach. We consider three classical 'toy models' that can be solved by elementary calculus, and that nevertheless contain all essential physics of the monopole and quadrupole shifts. We hope that this intuitive (yet exact) analysis will increase the understanding about multipole shift phenomena in a broader community. PMID:22782015

Rose, Katrin; Cottenier, Stefaan

2012-08-28

155

Chip-Scale Quadrupole Mass Filters for Portable Mass Spectrometry  

E-print Network

We report the design, fabrication, and characterization of a new class of chip-scale quadrupole mass filter (QMF). The devices are completely batch fabricated using a wafer-scale process that integrates the quadrupole ...

Cheung, Kerry

156

Hydrogen isotope analysis by quadrupole mass spectrometry  

Microsoft Academic Search

The analysis of isotopes of hydrogen (H, D, T) and helium (³He, He) and selected impurities using a quadrupole mass spectrometer (QMS) has been investigated as a method of measuring the purity of tritium gas for injection into the Tokamak Fusion Test Reactor (TFTR). A QMS was used at low resolution, m\\/..delta..m < 150, for quantifying impurities from m\\/q =

R. E. Ellefson; W. E. Moddeman; H. F. Dylla

1981-01-01

157

Electromagnetic launch by linear quadrupole field  

Microsoft Academic Search

This paper presents a novel electromagnetic launch concept based on a DC linear quadrupole field with no axial component. The proposed design enables contact-free power transfer to the launch vehicle while removing the need of switching power or AC induction. Passive damping windings are proposed to provide radial stability during launch. The 6-DOF dynamics of the launch vehicle, including the

Dengfeng Li; Rainer Meinke; Daniel Kirk; Hector Gutierrez

2008-01-01

158

Giant Quadrupole-Resonance in Ni Isotopes  

E-print Network

Inelastic scattering of 129 MeV alpha particles has been used to excite the giant quadrupole resonance in Ni-58, Ni-60, Ni-62, Ni-64. The resonance was found to exhaust 58 +/- 12%, 76 +/- 14%, 78 +/- 14%, and 90 +/-16% of the E2 energy-weighted sum...

Youngblood, David H.; Lui, YW; Garg, U.; Peterson, R. J.

1992-01-01

159

Occupation probabilities from quadrupole moments in the Sn region  

E-print Network

It is shown that a simple BCS model with a quadrupole-quadrupole interaction provides a consistent description of the measured quadrupole moments of a sequence of odd-mass Sn and Cd isotopes and allows the extraction of the neutron single-particle occupation probabilities.

N. B. de Takacsy

2014-03-10

160

Permanent Magnet Quadrupoles for CESR Phase-III Upgrade  

NASA Astrophysics Data System (ADS)

The CESR Phase-III upgrade plan includes very strong permanent magnet quadrupoles in front of the cryostat for the superconducting quadrupoles and physically as close as possible to the interaction point. Together with the superconducting quadrupoles, they provide tighter vertical focusing at the interaction point. The quadrupoles are built with Neodymium Iron Boron (NdFeB) material and operate inside the 15 kG solenoid field. Requirements on the field quality and stability of these quadrupoles are discussed and test results are presented.

Lou, W.; Hartill, D.; Rice, D.; Rubin, D.; Welch, J.

1997-05-01

161

Superconducting quadrupoles for the SLC final focus  

SciTech Connect

The final focus system of the SLC will be upgraded by replacing the final quadrupoles with higher gradient superconducting magnets positioned closer to the interaction point. The parameters of the new system have been chosen to be compatible with the experimental detectors with a minimum of changes to other final focus components. These parameter choices are discussed along with the expected improvement in SLC performance.

Erickson, R.; Fieguth, T.; Murray, J.J.

1987-01-01

162

Hydrogen isotope analysis by quadrupole mass spectrometry  

Microsoft Academic Search

The analysis of isotopes of hydrogen (H,D,T) and helium (³He,⁴He) and selected impurities using a quadrupole mass spectrometer (QMS) has been investigated as a method of measuring the purity of tritium gas for injection into the Tokamak Fusion Test Reactor (TFTR). A QMS was used at low resolution, m\\/Dm<150, for quantifying impurities from m\\/q = 2 to 44, and at

R. E. Ellefson; W. E. Moddeman; H. F. Dylla

1981-01-01

163

Muon cooling in a quadrupole magnet channel  

SciTech Connect

As discussed before,[1] a cooling channel using quadrupole magnets in a FODO transport channel can be used for initial cooling of muons. In the present note we discuss this possibility of a FODO focusing channel for cooling, and we present ICOOL simulations of muon cooling within a FODO channel. We explore a 1.5m cell-length cooling channel that could be used for the initial transverse cooling stage of a muon collider or neutrino factory.

Neuffer, David; /Fermilab; Poklonskiy, A.; /Michigan State U.

2007-10-01

164

15 T And Beyond - Dipoles and Quadrupoles  

SciTech Connect

Starting with the invention of the cyclotron by Lawrence, accelerator-based experiments have been the primary source of new discoveries in particle physics. In order to progress toward higher energy and luminosity, higher field magnets are required. R&D programs are underway to take advantage of new developments in superconducting materials, achieve better efficiency and simplify magnet fabrication while preserving accelerator-class field quality. A review of recent progress on high field dipole and quadrupole magnets is presented.

Sabbi, GianLuca

2008-05-19

165

The electric quadrupole moment of O2  

NASA Astrophysics Data System (ADS)

Room-temperature measurements of the Buckingham effect (electric-field-gradient-induced birefringence, EFGIB) for gaseous oxygen are presented. The traceless electric quadrupole moment of the oxygen molecule has been deduced from these data, with the assumption that the temperature-independent hyperpolarizability contribution to the EFGIB is negligibly small. The value obtained is ? = (-1.033 ± 0.027) × 10-40 C m2. This value is compared with the best available ab initio quantum computational values in the literature.

Couling, Vincent W.; Ntombela, Siyabonga S.

2014-10-01

166

Some interesting measurements with quadrupole mass spectrometers  

Microsoft Academic Search

Some measurements made with the NZ-850 type quadrupole mass spectrometer of the ATOMKI are reported. The analysis of gases\\u000a in operating rooms showed 1 ppm— 105 ppm concentration of narcotics. Purity control of gases regularly helps the radioactive pollution measurements and radio\\u000a carbon dating technique at our Institute. In an other application evidence of new possibilities is given which arise

S. Bohátka; I. Berecz; G. Langer

1980-01-01

167

Quadrupole transitions revealed by Borrmann spectroscopy.  

PubMed

The Borrmann effect-a dramatic increase in transparency to X-ray beams-is observed when X-rays satisfying Bragg's law diffract through a perfect crystal. The minimization of absorption seen in the Borrmann effect has been explained by noting that the electric field of the X-ray beam approaches zero amplitude at the crystal planes, thus avoiding the atoms. Here we show experimentally that under conditions of absorption suppression, the weaker electric quadrupole absorption transitions are effectively enhanced to such a degree that they can dominate the absorption spectrum. This effect can be exploited as an atomic spectroscopy technique; we show that quadrupole transitions give rise to additional structure at the L(1), L(2) and L(3) absorption edges of gadolinium in gadolinium gallium garnet, which mark the onset of excitations from 2s, 2p(1/2) and 2p(3/2) atomic core levels, respectively. Although the Borrmann effect served to underpin the development of the theory of X-ray diffraction, this is potentially the most important experimental application of the phenomenon since its first observation seven decades ago. Identifying quadrupole features in X-ray absorption spectroscopy is central to the interpretation of 'pre-edge' spectra, which are often taken to be indicators of local symmetry, valence and atomic environment. Quadrupolar absorption isolates states of different symmetries to that of the dominant dipole spectrum, and typically reveals orbitals that dominate the electronic ground-state properties of lanthanides and 3d transition metals, including magnetism. Results from our Borrmann spectroscopy technique feed into contemporary discussions regarding resonant X-ray diffraction and the nature of pre-edge lines identified by inelastic X-ray scattering. Furthermore, because the Borrmann effect has been observed in photonic materials, it seems likely that the quadrupole enhancement reported here will play an important role in modern optics. PMID:18615080

Pettifer, Robert F; Collins, Stephen P; Laundy, David

2008-07-10

168

Quadrupole Magnets for the SSC Collider  

SciTech Connect

A 40 mm bore 211 T/m quadrupole magnet has been designed and tested at LBL. There are 8 coils of 30 strand cable arranged in 2 layers in a cos 2{theta} distribution, supported by 18 mm thick collars, preassembled into 146 mm long packs, and rigidly aligned in a cold-iron yoke. The design, construction details, and test results are given for three 1 m models and the first 5 m model.

Taylor, C.E.; Barale, P.; Benjegerdes, R.; Caspi, S.; Dell'Orco, D.; Fritz, D.; Gilbert, W.; Lietzke, A.; Mirk, K.; Peters, C.; Scanlan, R.; Wandesforde, A.

1991-06-01

169

Deuteron electric quadrupole and octupole polarizabilities  

E-print Network

The direct transition-matrix approach to determination of the electric polarizabilities of quantum bound systems developed in my recent work is applied to study the electric multipole polarizabilities of a two-particle bound complex with a central interaction between the particles. Expressions for the electric quadrupole and octupole polarizabilities of the deuteron are derived and their values in the case of the S-wave separable interaction potential are calculated.

V. F. Kharchenko

2012-09-10

170

Well-proportioned universes suppress CMB quadrupole  

E-print Network

A widespread myth asserts that all small universe models suppress the CMB quadrupole. In actual fact, some models suppress the quadrupole while others elevate it, according to whether their low-order modes are weak or strong relative to their high-order modes. Elementary geometrical reasoning shows that a model's largest dimension determines the rough value ell_min at which the CMB power spectrum ell(ell + 1)C_ell/(2pi) effectively begins; for cosmologically relevant models, ell_min < 4. More surprisingly, elementary geometrical reasoning shows that further reduction of a model's smaller dimensions -- with its largest dimension held fixed -- serves to elevate modes in the neighborhood of ell_min relative to the high-ell portion of the spectrum, rather than suppressing them as one might naively expect. Thus among the models whose largest dimension is comparable to or less than the horizon diameter, the low-order C_ell tend to be relatively weak in well-proportioned spaces (spaces whose dimensions are approximately equal in all directions) but relatively strong in oddly-proportioned spaces (spaces that are significantly longer in some directions and shorter in others). We illustrate this principle in detail for the special cases of rectangular 3-tori and spherical spaces. We conclude that well-proportioned spaces make the best candidates for a topological explanation of the low CMB quadrupole observed by COBE and WMAP.

Jeffrey Weeks; Jean-Pierre Luminet; Alain Riazuelo; Roland Lehoucq

2003-12-11

171

A preliminary quadrupole asymmetry study of a ?=0.12 superconducting single spoke cavity  

NASA Astrophysics Data System (ADS)

An Accelerator Driven System (ADS) has been launched in China for nuclear waste transmutation. For the application of high intensity proton beam acceleration, the quadrupole asymmetry effect needs to be carefully evaluated for cavities. Single spoke cavities are the main accelerating structures in the low energy front-end. The single spoke cavity has small transverse electromagnetic field asymmetry, which may lead to transverse RF defocusing asymmetry and beam envelope asymmetry. A superconducting single spoke resonator (PKU-2 Spoke) of ?=0.12 and f=325 MHz with a racetrack-shaped inner conductor has been designed at Peking university. The study of its RF field quadrupole asymmetry and its effect on transverse momentum change has been performed. The quadrupole asymmetry study has also been performed on a ?=0.12 and f=325 MHz ring-shaped single spoke cavity. Our results show that the quadrupole asymmetry is very small for both the racetrack-shaped and the ring-shaped single spoke cavity.

Yang, Zi-Qin; Lu, Xiang-Yang; Yang, Liu; Luo, Xing; Zhou, Kui; Quan, Sheng-Wen

2014-10-01

172

Using density functional theory for analysis of quadrupole coupling constants and mössbauer isomer shifts of halogen compounds  

Microsoft Academic Search

Nuclear quadrupole coupling constants (QCC) for diatomic halides, their ions, and interhalogen compounds [1] are well-known tests in quantum chemical calculations of compounds. The theoretical and experimental values of the constants are generally compared in the framework of the Dailey-Townes approximation [2]. Our previous attempts to calculate QCC for heavy elements such as iodine, tin, and antimony in a series

O. K. Poleshchuk; J. N. Latosinska; V. G. Yakimov

2000-01-01

173

Photoassociation of a cold-atom-molecule pair: Long-range quadrupole-quadrupole interactions  

SciTech Connect

The general formalism of the multipolar expansion of electrostatic interactions is applied to the calculation of the potential energy between an excited atom (without fine structure) and a ground-state diatomic molecule at large mutual separations. Both partners exhibit a permanent quadrupole moment so that their mutual long-range interaction is dominated by a quadrupole-quadrupole term, which is attractive enough to bind trimers. Numerical results are given for an excited Cs(6{sup 2}P) atom and a ground-state Cs{sub 2} molecule. The prospects for achieving photoassociation of a cold-atom-dimer pair are thus discussed and found promising. The formalism can be generalized to the long-range interaction between molecules to investigate the formation of cold tetramers.

Lepers, M.; Dulieu, O. [Laboratoire Aime Cotton, CNRS, UPR3321, Batiment 505, Universite Paris-Sud, F-91405 Orsay Cedex (France); Kokoouline, V. [Laboratoire Aime Cotton, CNRS, UPR3321, Batiment 505, Universite Paris-Sud, F-91405 Orsay Cedex (France); Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States)

2010-10-15

174

Photoassociation of a cold-atom-molecule pair: Long-range quadrupole-quadrupole interactions  

NASA Astrophysics Data System (ADS)

The general formalism of the multipolar expansion of electrostatic interactions is applied to the calculation of the potential energy between an excited atom (without fine structure) and a ground-state diatomic molecule at large mutual separations. Both partners exhibit a permanent quadrupole moment so that their mutual long-range interaction is dominated by a quadrupole-quadrupole term, which is attractive enough to bind trimers. Numerical results are given for an excited Cs(62P) atom and a ground-state Cs2 molecule. The prospects for achieving photoassociation of a cold-atom-dimer pair are thus discussed and found promising. The formalism can be generalized to the long-range interaction between molecules to investigate the formation of cold tetramers.

Lepers, M.; Dulieu, O.; Kokoouline, V.

2010-10-01

175

75 FR 1416 - Final Memorandum of Understanding Between the U.S. Nuclear Regulatory Commission and the North...  

Federal Register 2010, 2011, 2012, 2013

...the North American Electric Reliability Corporation...and special nuclear materials in order to protect...nuclear facilities and materials in the USA. c. The...not limited to, the Electric Reliability Organization...facilitate the proper characterization of digital assets...

2010-01-11

176

Low-beam-loss design of a compact, high-current deuteron radio frequency quadrupole accelerator  

Microsoft Academic Search

A 201.5MHz, 50mA, 2.0MeV deuteron radio frequency quadrupole accelerator is proposed as the neutron generator for the neutron experiment facility project at Peking University, China. Based on better understanding of beam losses, some new optimization procedures concerning both longitudinal and transverse dynamics are adopted. Accordingly, the beam transmission efficiency is improved from 91.2% to 98.3% and the electrode length is

C. Zhang; Z. Y. Guo; A. Schempp; R. A. Jameson; J. E. Chen; J. X. Fang

2004-01-01

177

Nuclear deformation at finite temperature  

E-print Network

Deformation, a key concept in our understanding of heavy nuclei, is based on a mean-field description that breaks the rotational invariance of the nuclear many-body Hamiltonian. We present a method to analyze nuclear deformations at finite temperature in a framework that preserves rotational invariance. The auxiliary-field Monte-Carlo method is used to generate the statistical ensemble and calculate the probability distribution associated with the quadrupole operator. Applying the technique to nuclei in the rare-earth region, we identify model-independent signatures of deformation and find that deformation effects persist to higher temperatures than the spherical-to-deformed shape phase-transition temperature of mean-field theory.

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

2014-08-01

178

Magnetic mirror structure for testing shell-type quadrupole coils  

SciTech Connect

This paper presents magnetic and mechanical designs and analyses of the quadrupole mirror structure to test single shell-type quadrupole coils. Several quadrupole coils made of different Nb{sub 3}Sn strands, cable insulation and pole materials were tested using this structure at 4.5 and 1.9 K. The coils were instrumented with voltage taps, spot heaters, temperature sensors and strain gauges to study their mechanical and thermal properties and quench performance. The results of the quadrupole mirror model assembly and test are reported and discussed.

Andreev, N.; Barzi, E.; Bossert, R.; Chlachidze, G.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; Tartaglia, N.; Turrioni, D.; /Fermilab

2009-10-01

179

Noise reduction in negative-ion quadrupole mass spectrometry  

DOEpatents

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.

Chastagner, P.

1993-04-20

180

Noise reduction in negative-ion quadrupole mass spectrometry  

DOEpatents

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.

Chastagner, Philippe (3134 Natalie Cir., Augusta, GA 30909-2748)

1993-01-01

181

Thermogravimetric-quadrupole mass-spectrometric analysis of geochemical samples.  

NASA Technical Reports Server (NTRS)

Thermogravimetric-quadrupole mass-spectrometric-analysis techniques can be used to study a wide variety of problems involving decomposition processes and identification of released volatile components. A recording vacuum thermoanalyzer has been coupled with a quadrupole mass spectrometer. The rapid scan capabilities of the quadrupole mass spectrometer are used to identify the gaseous components released. The capability of the thermogravimetric-quadrupole mass spectrometer to provide analytical data for identification of the released volatile components, for determination of their sequence of release and for correlation of thermal-decomposition studies is illustrated by an analysis of the Orgueil carbonaceous chondrite.

Gibson, E. K., Jr.; Johnson, S. M.

1972-01-01

182

Ion energy in quadrupole mass spectrometry.  

PubMed

Application of an analytical solution of the Mathieu equation in conjunction with algebraic presentation of the Mathieu functions for description of the ion energy in a radiofrequency quadrupole field is discussed in this work. The analytical approach is used to express the ion energy averaged over the initial ion velocity distribution function, field phase and ion residence time. Comparisons with the approximate solutions for potential ion energy are presented with demonstration of their limits. Application of the method for different stability regions is discussed. PMID:14698555

Baranov, Vladimir

2004-01-01

183

Observation of Dipole-Quadrupole Interaction in an Ultracold Gas of Rydberg Atoms  

NASA Astrophysics Data System (ADS)

We observe the direct excitation of pairs of Cs atoms from the ground state to molecular states correlating asymptotically to n s n'f asymptotes. The molecular resonances are interpreted as originating from the dipole-quadrupole interaction between the n s n'f pair states and close-by n p n p asymptotes (22 ?n ?32 ). This interpretation is supported by Stark spectroscopy of the pair states and a detailed modeling of the interaction potentials. The dipole-quadrupole interaction mixes electronic states of opposite parity and, thus, requires a coupling between electronic and nuclear motion to conserve the total parity of the system. This non-Born-Oppenheimer coupling is facilitated by the near-degeneracy of even- and odd-L partial waves in the atom-atom scattering which have opposite parity.

Deiglmayr, Johannes; Saßmannshausen, Heiner; Pillet, Pierre; Merkt, Frédéric

2014-11-01

184

Magnetic dipole and electric quadrupole moments of the neutron-deficient bismuth isotopes  

NASA Astrophysics Data System (ADS)

The complete hyperfine structures of the A = 202, 203 and 204 bismuth isotopes have been observed in the 306.7 nm line using an extremely sensitive gas cell technique of laser spectroscopy. The magnetic moments, quadrupole moments and relative changes in the mean square charge radii have been extracted and have been used to study the bulk and valence nuclear behaviour around 208Pb. The trends of the quadrupole moments of the proton-particle, neutron-hole ground and isomeric systems are observed to be very nearly identical throughout the Z ? 82, N ? 126 region. Furthermore the correspondence between the behaviour of Qs and the behaviour of the ground state charge radii demonstrates that the global systematics of this region are closer than those of any other.

Campbell, P.; Behr, J. A.; Billowes, J.; Gwinner, G.; Sprouse, G. D.; Xu, F.

1996-02-01

185

Observation of dipole-quadrupole interaction in an ultracold gas of Rydberg atoms.  

PubMed

We observe the direct excitation of pairs of Cs atoms from the ground state to molecular states correlating asymptotically to nsn^{'}f asymptotes. The molecular resonances are interpreted as originating from the dipole-quadrupole interaction between the nsn^{'}f pair states and close-by npnp asymptotes (22?n?32). This interpretation is supported by Stark spectroscopy of the pair states and a detailed modeling of the interaction potentials. The dipole-quadrupole interaction mixes electronic states of opposite parity and, thus, requires a coupling between electronic and nuclear motion to conserve the total parity of the system. This non-Born-Oppenheimer coupling is facilitated by the near-degeneracy of even- and odd-L partial waves in the atom-atom scattering which have opposite parity. PMID:25415902

Deiglmayr, Johannes; Saßmannshausen, Heiner; Pillet, Pierre; Merkt, Frédéric

2014-11-01

186

The CMB Quadrupole in a Polarized Light  

E-print Network

The low quadrupole of the cosmic microwave background (CMB), measured by COBE and confirmed by WMAP, has generated much discussion recently. We point out that the well-known correlation between temperature and polarization anisotropies of the CMB further constrains the low multipole anisotropy data. This correlation originates from the fact that the low-multipole polarization signal is sourced by the CMB quadrupole as seen by free electrons during the relatively recent cosmic history. Consequently, the large-angle temperature anisotropy data make restrictive predictions for the large-angle polarization anisotropy, which depend primarily on the optical depth for electron scattering after cosmological recombination, tau. We show that if current cosmological models for the generation of large angle anisotropy are correct and the COBE/WMAP data are not significantly contaminated by non-CMB signals, then the observed C_te amplitude on the largest scales is discrepant at the 99.8% level with the observed C_tt for the concordance LCDM model with tau=0.10. Using tau=0.17, the preferred WMAP model-independent value, the discrepancy is at the level of 98.5%.

Olivier Doré; Gilbert P. Holder; Abraham Loeb

2003-09-10

187

SSC Quadrupole Magnet Performance at LBL  

SciTech Connect

Lawrence Berkeley Laboratory (LBL) contracted to design, construct, and test four short (1m) models and six full-size (5m) models of the Superconducting Super Collider (SSC) main-ring 5 meter focusing quadrupole magnet (211 Tesla/meter). The training performance of these magnets is summarized. Magnets were tested in a horizontal boiling helium (1 Atm) cryostat. The magnetic, strain-gage and training responses to two thermal cycles were measured. The quadrupole gradient, and relative multipole purity were determined from Fourier analysis of the rotating coil signals. Magnetic and strain-gage measurements were taken on-the-fly. The voltage-tap data was analyzed to determine quench-origin and propagation characteristics. Quench-training proceeded at 4.3K until a plateau was achieved or sub-cooling (2.5K) was used to accelerate the training process. The early short (1m) magnets were also trained at 1.8K (10kA) to help identify potential weak areas. The MIITs were calculated to compare various magnet protection methods. Except for modest training above the anticipated SSC operating point, the magnets performed very well and proved to be self-protecting. Some design flaws were identified and corrected. The last two 1 m models and all the 5m models have been reinstalled in cryostats at the SSC Laboratory, retested and used to achieve various milestones in their program.

Lietzke, A.F.; Barale, P.; Benjegerdes, r.; Caspi, S.; Cortella, J.; Dell'Orco, D.; Gilbert, W.; Green, M.I.; Mirk, K.; Peters, C.; Scalan, R.; Taylor, C.E.; Wandesforde, A.

1992-10-01

188

Mechanistic understanding of irradiation-induced corrosion of zirconium alloys in nuclear power plants: Stimuli, status, and outlook  

Microsoft Academic Search

Failures in the basic materials used in nuclear power plants continue to be costly and insidious, despite increasing industry vigilance to catch failures before they degrade safety. For instance, the overall costs to the US industry from materials problems could amount to as much as $10 billion annually. Moreover, estimates indicate that the cost of a pipe failure in a

A. B. Jr. Johnson; K. Ishigure; A. F. Nechaev; E. A. Reznichenko; B. Cox; C. Lemaignan; N. G. Petrik

1990-01-01

189

Diversion of Nuclear, Biological, and Chemical Weapons Expertise from the Former Soviet Union: Understanding an Evolving Problem.  

National Technical Information Service (NTIS)

Since the early 1990s, the United States has been concerned about the diversion of expertise and sensitive information from the nuclear, biological, and chemical (NBC) weapons complexes of the former Soviet Union (FSU). It has established a number of impo...

J. V. Parachini, D. E. Mosher, J. Baker, K. Crane, M. Chase

2005-01-01

190

Excitation of giant dipole and giant quadrupole states in nuclei  

Microsoft Academic Search

Calculations are presented for the excitation by protons of giant dipole (T = 1) and quadrupole (T = 0) states in nuclei. Two simple models are used for the transition densities and potentials in the dipole excitation. The usual deformed optical potential is applied to the quadrupole transitions. The strengths are determined by exhausting the linear energy-weighted sum rules. The

G. R. Satchler

1972-01-01

191

Electric quadrupole excitations in relativistic nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

Calculations are presented for electric quadrupole excitations in relativistic nucleus-nucleus collisions. The theoretical results are compared to an extensive data set and it is found that electric quadrupole effects provide substantial corrections to cross sections, especially for heavier nuclei.

Norbury, John W.

1989-01-01

192

40Ar\\/ 39Ar geochronology using a quadrupole mass spectrometer  

Microsoft Academic Search

Magnetic sector mass spectrometers dominate the field of 40Ar\\/39Ar geochronology. Recent advances in quadrupole mass spectrometer technology, especially improvements in resolution, have increased the performance of these instruments to the extent that they can be used for isotopic determinations. We describe a triple filter quadrupole mass spectrometer (Hiden HAL 3F Series Pulse Ion Counting Triple Filter QMS) linked to an

Björn Schneider; Klaudia Kuiper; Onno Postma; Jan Wijbrans

2009-01-01

193

Temperature dependent deuterium quadrupole coupling constants of short hydrogen bonds  

E-print Network

Temperature dependent deuterium quadrupole coupling constants of short hydrogen bonds Xingang Zhao January 2006 Abstract Very short hydrogen bonds universally show large positive dependences and intermode couplings. q 2006 Published by Elsevier B.V. Keywords: Hydrogen bonds; NMR; Deuterium quadrupole 1

Barsegov, Valeri

194

Fifth-order aberrations in magnetic quadrupole-octupole systems  

SciTech Connect

Explicit integral expressions are given for the fifth-order geometrical aberration coefficients in rectilinear magnetic quadrupole-octupole systems used for the transport of nonrelativistic charged particle beams. The numerical values of the fifth-order geometrical aberration coefficients for a rare earth cobalt (REC) quadrupole doublet are given as an example. 26 refs., 5 figs., 4 tabs.

Ling, K.M.

1990-01-01

195

UNDERSTANDING BELIEFS UNDERSTANDING BELIEFS  

E-print Network

UNDERSTANDING BELIEFS #12;UNDERSTANDING BELIEFS Nils J. Nilsson Stanford University nilsson@cs.stanford.edu http://ai.stanford.edu/nilsson August 21, 2013 #12;[Belief] ...that upon which a man is prepared to act. H. Auden2 So as not to distract the general reader unnecessarily, numbered notes containing

Pratt, Vaughan

196

Supersonic Quadrupole Noise Theory for High-Speed Helicopter Rotors  

NASA Technical Reports Server (NTRS)

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.

Farassat, F.; Brentner, Kenneth S.

1997-01-01

197

Roll measurement of Tevatron dipoles and quadrupoles  

SciTech Connect

In 2003 a simple digital level system was developed to allow for rapid roll measurements of all dipoles and quadrupoles in the Tevatron. The system uses a Mitutoyo digital level and a PC running MS WINDOWS XP and LAB VIEW to acquire data on the upstream and downstream roll of each magnet. The system is sufficiently simple that all 1,000 magnets in the Tevatron can be measured in less than 3 days. The data can be quickly processed allowing for correction of rolled magnets by the Fermilab alignment group. Data will be presented showing the state of the Tevatron in 2003 and the changes in rolls as measured in each shutdown since then.

Volk, J.T.; Elementi, L.; Gollwitzer, K.; Jostlein, H.; Nobrega, F.; Shiltsev, V.; Stefanski, R.

2006-09-01

198

An improved integrally formed radio frequency quadrupole  

DOEpatents

An improved radio frequency quadrupole is provided having an elongate housing with an elongate central axis and top, bottom and two side walls symmetrically disposed about the axis, and vanes formed integrally with the walls, the vanes each having a cross-section at right angles to the central axis which tapers inwardly toward the axis to form electrode tips spaced from each other by predetermined distances. Each of the four walls, and the vanes integral therewith, is a separate structural element having a central lengthwise plane passing through the tip of the vane, the walls having flat mounting surfaces at right angles to and parallel to the control plane, respectively, which are butted together to position the walls and vane tips relative to each other. 4 figs.

Abbott, S.R.

1987-10-05

199

Nuclear Quadrupole Resonance Studies of Charge Distributions in Molecular Solids  

Microsoft Academic Search

A detailed description of an NMR-NQR double resonance spectrometer designed and constructed in this laboratory is given, including some instruction on its use. ('14)N NQR data obtained by pulse methods for six classes of nitrogen-containing compounds are presented and analyzed in the framework of the Townes and Dailey theory. A study of the anti-cancer drugs cyclophosphamide, isophosphamide and triphosphamide suggests

Steven Garry Greenbaum

1982-01-01

200

Nondestructive testing of adhesive bonds by nuclear quadrupole resonance method  

NASA Technical Reports Server (NTRS)

Inert, strain sensitive tracer, cuprous oxide, added to polymeric adhesive ensures sufficiently large signal to noise ratio in NQR system output. Method is successful, provided that RF-transparent structural materials are used between modified adhesive and probe of NQR spectrometer.

Hewitt, R. R.

1971-01-01

201

Development of a nuclear quadrupole based technique for  

E-print Network

....................................................................... 6.2. Characterization method, x-ray diffraction................................. 6.2.1. Practical considerations for the x-ray experiment................. 6.3. Summary of the equation............................................. 8. Advantages and Disadvantages 1 3 4 10 10 12 12 14

Keren, Amit

202

A Graphical Approach to Radio Frequency Quadrupole Design  

E-print Network

The design of a radio frequency quadrupole, an important section of all ion accelerators, and the calculation of its beam dynamics properties can be achieved using the existing computational tools. These programs, originally designed in 1980s, show effects of aging in their user interfaces and in their output. The authors believe there is room for improvement in both design techniques using a graphical approach and in the amount of analytical calculations before going into CPU burning finite element analysis techniques. Additionally an emphasis on the graphical method of controlling the evolution of the relevant parameters using the drag-to-change paradigm is bound to be beneficial to the designer. A computer code, named DEMIRCI, has been written in C++ to demonstrate these ideas. This tool has been used in the design of Turkish Atomic Energy Authority (TAEK)'s 1.5 MeV proton beamline at Saraykoy Nuclear Research and Training Center (SANAEM). DEMIRCI starts with a simple analytical model, calculates the RFQ b...

Turemen, G; Yasatekin, B

2014-01-01

203

High-Efficiency Resonant Cavity Quadrupole Moment Monitor  

SciTech Connect

Measurement of the beam quadrupole moment at several locations can be used to reconstruct the beam envelope and emittance parameters. The measurements can be performed in a non-intercepting way using a set of quadrupole-mode cavities. We present a cavity design with an optimized quadrupole moment shunt impedance. The cavity properties can be characterized using a wire test method to insure symmetry about the central axis, and alignment to nearby position sensing cavities. The design and characterization of the prototype structure is discussed.

Barov, N.; Nantista, C.D.; Miller, R.H.; Kim, J.S.; /FARTECH, San Diego /SLAC

2007-04-13

204

The use of natural and archeological analogues for understanding the long-term behavior of nuclear glasses  

NASA Astrophysics Data System (ADS)

The knowledge of the long-term behavior of nuclear waste in anticipation of ultimate disposal in a deep geological formation is of prime importance in a waste management strategy. If phenomenological models have been developed to predict the long-term behavior of these materials, validating these models remains a challenge, when considering the time scale of radioactive decay of radionuclides of environmental concern, typically 10 4-10 5 yrs. Here we show how natural or archaeological analogues provide critical constraints not only on the phenomenology of glass alteration and the mechanisms involved, but also on the ability of experimental short-term data to predict long-term alteration in complex environments.

Libourel, Guy; Verney-Carron, Aurelie; Morlok, Andreas; Gin, Stéphane; Sterpenich, Jérôme; Michelin, Anne; Neff, Delphine; Dillmann, Philippe

2011-02-01

205

Electric Quadrupole and Magnetic Dipole Moments of Mirror Nuclei and Self-Conjugate Nuclei  

NASA Astrophysics Data System (ADS)

A transformation, which brings about the unification of the nuclear collective and single particle models, yields sumrules for the magnetic dipole moments and for the electric quadrupole moments of mirror nuclei. These sumrules are applied to cases, for which the numerical values of these moments are known.Translated AbstractElektrische Qadrupol- und Magnetische Dipolmomente von Spiegelkernen und Kernen mit N = ZMit Hilfe einer Transformation, die die Vereinigung von Kollektiv- und Schalenmodell liefert, lassen sich Summenregeln für die magnetischen Dipol- und die elektrischen Quadrupolmomente von Spiegelkernen ableiten. Diese Summenregeln werden auf Spiegelkerne angewandt, für die die numerischen Werte der Momente bekannt sind.

Zickendraht, W.

206

Approximating conductive ellipsoid inductive responses using static quadrupole moments  

E-print Network

object orientation, and resulted in polarizability curvesfour orientations of Tables I and II, while polarizabilitypolarizability estimates made with ellipsoid quadrupole polarizabilities match each other better between upward and downward orientations (

Smith, J. Torquil

2008-01-01

207

Effect of the atomic electric quadrupole moment on positron binding  

NASA Astrophysics Data System (ADS)

The effect of an electric quadrupole moment Q is studied for positron-atom bound systems. It is demonstrated that for Q >50 a.u. the electric quadrupole potential is sufficiently strong to bind a positron (or an electron) even in the absence of the dipole polarization potential. Such large values of Q are not known for atomic ground states; however, they exist in molecules and excited atoms. In the 2s2p3P2o state of beryllium, the quadrupole contribution makes the difference between a stable bound state and an unstable state, which decays to a Be+ ion and positronium. In the majority of atoms the quadrupole contribution is small and can be neglected.

Harabati, C.; Dzuba, V. A.; Flambaum, V. V.

2014-07-01

208

Adjustable rare earth quadrupole drift tube magnets  

SciTech Connect

A prototype permanent-magnet drift tube quadrupole with adjustable field strength has been constructed and tested. The magnet uses iron pole pieces to provide the required field shape along with rare earth permanent-magnet material (samarium cobalt) to energize the magnet. A unique feature of the configuration is the adjustability of the field, accomplished by rotating the outer rings consisting of permanent magnets and iron. In contrast with a previous prototype magnet, this new design uses ball bearings in place of slide bearings to eliminate potential failures. The rotation is now achieved with a bevel gear mechanism. The prototype design also incorporates a new drift tube shell vacuum seal to allow easy disassembly. Tests were made of the magnetic properties and the mechanical performance of this magnet. Field errors are extremely small, and the magnet passed an accelerated ten year lifetime test. It is planned to use this type of magnet to replace 24 of the SuperHILAC prestripper drift tubes.

Feinberg, B.; Tanabe, J.; Halbach, K.; Koehler, G.; Green, M.I.

1987-03-01

209

Filling Factor for an Electrostatic Quadrupole Lattice  

NASA Astrophysics Data System (ADS)

The cost of an accelerator is in part determined by the size of the beam pipe aperture. The effect on total cost is especially large for multiple-beam induction linac designs for IFE drivers, where extra clearance for each beam greatly enlarges the transverse scale of the machine. Limits to the amount of clearance between the beam and the vacuum pipe are set by nonlinear forces (image forces, focusing fringe fields, etc.), which can cause beam heating or beam loss. The filling factor possible (i.e., percent of aperture filled with beam), or ``dynamic aperture,'' is investigated in this work for the intense, space-charge-dominated ion beams of an IFE driver, using the 2-D transverse slice version of the 3-D particle-in-cell simulation code WARP. The focusing field is modeled using a 3-D solution of the Laplace equation for the biased quadrupole focusing elements, as opposed to previous calculations, which used a less-accurate multipole approximation. 80% radial filling of the aperture is found to be possible. Results from the simulations, as well as corroborating data from the High Current Experiment at LBNL, will be presented.

Celata, C. M.; Prost, L.; Grote, D. P.

2005-10-01

210

Autonomously Calibrating a Quadrupole Mass Spectrometer  

NASA Technical Reports Server (NTRS)

A computer program autonomously manages the calibration of a quadrupole ion mass spectrometer intended for use in monitoring concentrations and changes in concentrations of organic chemicals in the cabin air of the International Space Station. The instrument parameters calibrated include the voltage on a channel electron multiplier, a discriminator threshold, and an ionizer current. Calibration is achieved by analyzing the mass spectrum obtained while sweeping the parameter ranges in a heuristic procedure, developed by mass spectrometer experts, that involves detection of changes in signal trends that humans can easily recognize but cannot necessarily be straightforwardly codified in an algorithm. The procedure includes calculation of signal-to-noise ratios, signal-increase rates, and background-noise-increase rates; finding signal peaks; and identifying peak patterns. The software provides for several recovery-from-error scenarios and error-handling schemes. The software detects trace amounts of contaminant gases in the mass spectrometer and notifies associated command- and-data-handling software to schedule a cleaning. Furthermore, the software autonomously analyzes the mass spectrum to determine whether the parameters of a radio-frequency ramp waveform are set properly so that the peaks of the mass spectrum are at expected locations.

Lee, Seungwon; Bornstein, Benjamin J.

2009-01-01

211

Electric quadrupole photoneutron reactions in 16O  

NASA Astrophysics Data System (ADS)

Photoneutron energy spectra from the 16O(?,n0)15O reaction were measured as functions of laboratory angle over a range of excitation energies from 30 to 35 MeV. Angular distribution Legendre-polynomial coefficients were extracted up to third order as functions of excitation energy. Nonzero values of the coefficients a1 (+0.25+/-0.02) and a3 (-0.2+/-0.02) were observed over the energy region explored, indicating interference between states of opposite parity. These values can be accounted for in a simple model incorporating electric quadrupole absorption strength decaying via the ground-state photoneutron channel. When combined with the previously-determined amplitude ratio for the E 1 p-->s and p-->d single-particle transitions, the present results suggest that about 4% of the isovector energy-weighted sum rule is found in the (?,n0) channel in the energy range studied. The value of the (?,n0) cross section was found to vary from 1.5+/-0.1 mb at Ex=30 MeV to 0.8+/-0.1 mb at 35 MeV. The average magnitude of the E2 contribution to this cross section was estimated to be 0.05+/-0.02 mb. This is in reasonable agreement with a recent continuum randomphase approximation shell model calculation, but is in disagreement with a previous measurement.

Kuo, P. C.-K.; Jury, J. W.; Sherman, N. K.; Davidson, W. F.

1984-12-01

212

Understanding ‘sensorimotor understanding’  

Microsoft Academic Search

Sensorimotor theories understand perception to be a process of active, exploratory engagement with the environment, mediated\\u000a by the possession and exercise of a certain body of knowledge concerning sensorimotor dependencies. This paper aims to characterise\\u000a that exercise, and to show that it places constraints upon the content of sensorimotor knowledge itself. Sensorimotor mastery\\u000a is exercised when it is put to

Tom Roberts

2010-01-01

213

Nuclear  

NSDL National Science Digital Library

What part does nuclear energy play in satisfying energy demands? This informational piece, part of a series about the future of energy, introduces students to the uranium atom as an energy source. Here students read about the history of nuclear energy, how energy is derived from uranium, and benefits of nuclear energy. Information is also provided about limitations, particularly disposal problems and radioactivity, and geographical considerations of nuclear power in the United States. Thought-provoking questions afford students chances to reflect on what they've read about the uses of nuclear power. Articles and information on new nuclear plant design and nuclear accidents are available from a sidebar. Five energy-related PBS NewsHour links are provided. A web link to the U.S. Nuclear Regulatory Commission is included. Copyright 2005 Eisenhower National Clearinghouse

Project, Iowa P.

2004-01-01

214

Four-dimensional transverse beam matrix measurement using the multiple-quadrupole scan technique  

NASA Astrophysics Data System (ADS)

Accurate measurements of the transverse beam properties are essential to understand and optimize particle beams. We present an optimized method that uses three quadrupole magnets and one profile monitor to measure the full 4D transverse matrix of the beam. The method has been applied to the SwissFEL Injector Test Facility (SITF) at the Paul Scherrer Institute (Villigen). The SITF is the principal test bed and demonstration plant for the SwissFEL project, which aims at realizing a hard-x-ray free-electron laser in 2017. Simulations, measurements, and results of cross-plane coupling correction are presented.

Prat, Eduard; Aiba, Masamitsu

2014-05-01

215

Commissioning of helium injector for coupled radio frequency quadrupole and separated function radio frequency quadrupole accelerator.  

PubMed

A project to study a new type of acceleration structure has been launched at Peking University, in which a traditional radio frequency quadrupole (RFQ) and a separated function radio frequency quadrupole are coupled in one cavity to accelerate the He+ beam. A helium injector for this project is developed. The injector consists of a 2.45 GHz permanent magnet electron cyclotron resonance ion source and a 1.16 m long low energy beam transport (LEBT). The commissioning of this injector was carried out and an onsite test was held in June 2013. A 14 mA He+ beam with the energy of 30 keV has been delivered to the end of the LEBT, where a diaphragm with the diameter of 7 mm is located. The position of the diaphragm corresponds to the entrance of the RFQ electrodes. The beam emittance and fraction were measured after the 7 mm diaphragm. Its rms emittance is about 0.14 ??mm?mrad and the fraction of He+ is about 99%. PMID:24593446

Peng, Shixiang; Chen, Jia; Ren, Haitao; Zhao, Jie; Xu, Yuan; Zhang, Tao; Zhang, Ailing; Xia, Wenlong; Gao, Shuli; Wang, Zhi; Luo, Yuting; Guo, Zhiyu; Chen, Jia'er

2014-02-01

216

Effects of nuclear structure on average angular momentum in subbarrier fusion  

E-print Network

We investigate the effects of nuclear quadrupole and hexadecapole couplings on the average angular momentum in sub-barrier fusion reactions. This quantity could provide a probe for nuclear shapes, distinguishing between prolate vs. oblate quadrupole and positive vs. negative hexadecapole couplings. We describe the data in the O + Sm system and discuss heavier systems where shape effects become more pronounced.

A. B. Balantekin; J. R. Bennett; S. Kuyucak

1994-07-21

217

Quadrupole collective dynamics from energy density functionals: Collective Hamiltonian and the interacting boson model  

NASA Astrophysics Data System (ADS)

Microscopic energy density functionals have become a standard tool for nuclear structure calculations, providing an accurate global description of nuclear ground states and collective excitations. For spectroscopic applications, this framework has to be extended to account for collective correlations related to restoration of symmetries broken by the static mean field, and for fluctuations of collective variables. In this paper, we compare two approaches to five-dimensional quadrupole dynamics: the collective Hamiltonian for quadrupole vibrations and rotations and the interacting boson model (IBM). The two models are compared in a study of the evolution of nonaxial shapes in Pt isotopes. Starting from the binding energy surfaces of Pt192,194,196, calculated with a microscopic energy density functional, we analyze the resulting low-energy collective spectra obtained from the collective Hamiltonian, and the corresponding IBM Hamiltonian. The calculated excitation spectra and transition probabilities for the ground-state bands and the ?-vibration bands are compared to the corresponding sequences of experimental states.

Nomura, K.; Nikši?, T.; Otsuka, T.; Shimizu, N.; Vretenar, D.

2011-07-01

218

Directions for nuclear research in the transplutonium elements  

SciTech Connect

The study of the heavy nuclides has played a vital role in our understanding of the alpha decay process, nuclear fission, nuclear binding energies and the limits of nuclear stability. This study has led to the understanding of novel shape degrees of freedom, such as the very large quadrupole deformations associated with the fission isomer process, and the very recently discovered octupole deformation. The existence of these unique phenomena in the heavy element region is not accidental. Fission isomerism is due to the delicate balance between nuclear forces holding the nucleus together and Coulomb forces causing nuclear fission. Octupole deformation arises from the increasing strength of matrix elements with increasing oscillator shell. Both illustrate the unique features of the heavy element region. Fission studies have given us information about large collective aspects in nuclei and the importance that nuclear structural effects can play in altering these macro properties. A new class of atomic studies has become possible with the availability of heavy elements. With these isotopes, we are now able to produce electric fields of such magnitude that it becomes possible to spontaneously create positron-electron pairs in the vacuum. We have organized this presentation into three major sections: nuclear structure, fission studies and atomic studies of supercritical systems. In each we will try to emphasize the new directions which can benefit from the continued availability of isotopes supplied by the Trans-plutonium Production Program. 117 references. (WHK)

Wilhelmy, J.B.; Chasman, R.R.; Friedman, A.M.; Ahmad, I.

1983-01-01

219

Higher Order Parametric Excitation Modes for Spaceborne Quadrupole Mass Spectrometers  

NASA Technical Reports Server (NTRS)

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 the 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.

Gershman, D. J.; Block, B. P.; Rubin, M.; Benna, M.; Mahaffy, P. R.; Zurbuchen, T. H.

2011-01-01

220

Quadrupole plasmon excitations in finite-size atomic chain systems  

NASA Astrophysics Data System (ADS)

The existence and the nature of a new mode of electronic collective excitations (quadrupole plasmons) in confined one-dimensional electronic systems, used to mimic finite-size linear metal atomic chains, have been predicted by an eigen-equation method. The eigen-equation based on the time-dependent density-functional theory is presented for calculating the collective excitations in confined systems. With this method, all modes of collective excitations in the 1D systems can be found out. These modes include dipole plasmons and quadrupole plasmons. The dipole plasmon mode corresponds to the antisymmetric oscillation of induced charge, and can be shown as a resonance of the dipole response. In the quadrupole plasmon modes, the induced charge distribution is symmetric, and the dipole response vanishes. The motion of the electrons in the quadrupole modes is similar to the vibration of atoms in the breathing mode of phonons. This type of plasmon can be shown as a resonance of the quadrupole response, and has to be excited by a non-uniform field.

Wu, Reng-lai; Xue, Hong-jie; Yu, Yabin

2014-12-01

221

Higher order parametric excitation modes for spaceborne quadrupole mass spectrometers  

SciTech Connect

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 the 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.

Gershman, D. J.; Block, B. P.; Rubin, M.; Zurbuchen, T. H. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Benna, M.; Mahaffy, P. R. [Solar Systems Exploration Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2011-12-15

222

Mechanical Design of a Second Generation LHC IR Quadrupole  

SciTech Connect

One of the proposed options to increase the LHC luminosity is the replacement of the existing inner triplets at the Interaction Regions with new low-beta larger aperture quadrupoles operating at the same gradient. Lawrence Berkeley National Laboratory (LBNL) is carrying out preliminary studies of a large-bore Nb{sub 3}Sn quadrupole. The mechanical design presents a support structure based on the use of keys and bladders without self-supporting collars. This technology has been proven effective in several successful common coil Nb{sub 3}Sn dipoles built at LBNL, and it is for the first time applied to a cos(2{var_theta}) design. In this paper we present a detailed analysis of the quadrupole mechanical behavior, demonstrating the possibility of delivering, through this method, well-controlled coil precompression during assembly, cool-down and excitation. The study has been performed with the finite element program ANSYS.

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

2003-11-10

223

Stability of an aqueous quadrupole micro-trap  

NASA Astrophysics Data System (ADS)

The recently demonstrated functionality of an aqueous quadrupole micro- or nano-trap opens a new avenue for applications of Paul traps, like confinement of a charged biomolecule which requires a water environment for its chemical stability. Besides the strong viscosity forces, the 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 typical micro-trap parameters, the effects of both dielectrophoresis and electrophoresis significantly influence the trap stability. In particular, an aqueous quadrupole trap could play the role of a synthetic virtual nanopore for the third generation of DNA sequencing technology.

Park, Jae Hyun; Krsti?, Predrag S.

2012-04-01

224

The Photon Polarization Parameter of 2H(n, ?)3H reaction with Inclusion of the Electric Quadrupole Contribution  

NASA Astrophysics Data System (ADS)

We use effective field theory (EFT) for the calculation of neutron—deuteron radiative capture at very low energies. We present here the use of EFT to calculate a low-energy photo-nuclear observable in three-body systems, the photon polarization parameter and fore—aft asymmetry at thermal neutron energies up to next-to-next to leading order (N2LO), with inclusion of the electric quadrupole contribution. The photon polarization parameter in total is found to be Rc = ?0.421 ± 0.003 and is in good agreement with the other modern theoretical calculations based on modern nucleon—nucleon potentials. In comparison with our previous work, a satisfactory agreement with the available experimental data is found by inclusion of the electric quadrupole contribution.

Sadeghi, H.; Mosavi-Khansari, M.

2014-09-01

225

Low-lying 2$^+$ states generated by $pn$-quadrupole correlation and $N=28$ shell quenching  

E-print Network

The quadrupole vibrational modes of neutron-rich $N=28$ isotones (48Ca, 46Ar, 44S and 42Si) are investigated using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory including nuclear pairing correlation. It is found that the quenching of $N=28$ shell gap and the proton holes in the sd-shell trigger strong quadrupole correlation and generate the low-lying 2+ states in 46Ar. The pairing correlation further increases the collectivity of the 2$^{+}_{1}$ state and the observed B(E2) is reproduced well. We also demonstrate that the same mechanism to enhance the low-lying collectivity applies to other $N=28$ isotones 44S and 42Si and it generates a couple of low-lying 2$^+$ states which may be associated with the observed 2$^+$ states. However the evaluated excitation energies of 2$^{+}_{1}$ states of 44S and 42Si and B(E2) of 44S disagree with the observed values, implying the onset of deformation in 44S and 42Si.

Ebata, Shuichiro

2014-01-01

226

Low-lying 2$^+$ states generated by $pn$-quadrupole correlation and $N=28$ shell quenching  

E-print Network

The quadrupole vibrational modes of neutron-rich $N=28$ isotones (48Ca, 46Ar, 44S and 42Si) are investigated using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory including nuclear pairing correlation. It is found that the quenching of $N=28$ shell gap and the proton holes in the sd-shell trigger strong quadrupole correlation and generate the low-lying 2+ states in 46Ar. The pairing correlation further increases the collectivity of the 2$^{+}_{1}$ state and the observed B(E2) is reproduced well. We also demonstrate that the same mechanism to enhance the low-lying collectivity applies to other $N=28$ isotones 44S and 42Si and it generates a couple of low-lying 2$^+$ states which may be associated with the observed 2$^+$ states. However the evaluated excitation energies of 2$^{+}_{1}$ states of 44S and 42Si and B(E2) of 44S disagree with the observed values, implying the onset of deformation in 44S and 42Si.

Shuichiro Ebata; Masaaki Kimura

2014-03-17

227

Large energy-spread beam diagnostics through quadrupole scans  

SciTech Connect

The Facility for Advanced Accelerator and Experimental Tests (FACET) is a new user facility at the SLAC National Accelerator Laboratory, servicing next-generation accelerator experiments. The 1.5% RMS energy spread of the FACET beam causes large chromatic aberrations in optics. These aberrations necessitate updated quadrupole scan fits to remain accurate.

Frederico, Joel; Adli, Erik; Hogan, Mark; Raubenheimer, Tor [SLAC National Accelerator Laboratory (United States)

2012-12-21

228

Quadrupole Magnetic Center Definition Using the Hall Probe Measurement Technique  

E-print Network

coherent light source [LCLS] project [1] requires 5 µm straightness of the particle beam trajectory to avoid using an additional magnetic measurement technique and to use the same sensors that will be used of the probe motion in Z-direction of the quadrupole: clear reference line was made at the probe tip

Kemner, Ken

229

Dodecahedral topology fails to explain quadrupole-octupole alignment  

E-print Network

The CMB quadrupole and octupole, as well as being weaker than expected, align suspiciously well with each other. Non-trivial spatial topology can explain the weakness. Might it also explain the alignment? The answer, at least in the case of the Poincare dodecahedral space, is a resounding no.

Jeff Weeks; Jesper Gundermann

2006-11-20

230

Continuous cell separation using novel magnetic quadrupole flow sorter  

Microsoft Academic Search

A laboratory prototype of a flow cell sorter based on magnetic quadrupole field was built and evaluated. The magnetic force acting on magnetically labeled cells in such a field has a `centrifugal’ character which provides a basis for the design of a continuous separation process. The sorter was tested on a model cell system of human peripheral lymphocytes labeled with

Maciej Zborowski; Liping Sun; Lee R Moore; P Stephen Williams; Jeffrey J. Chalmers

1999-01-01

231

Radio-frequency quadrupole: General properties and specific applications  

NASA Astrophysics Data System (ADS)

The general properties of radio frequency quadrupole accelerators are reviewed and beam dynamics simulation results are presented for their use in a variety of accelerating systems. The low-beta sections of the Fusion Materials Irradiation Test Accelerator, a 200 MHz proton linear accelerator, and a xenon accelerator for heavy ion fusion are included.

Stokes, R. H.; Crandall, K. R.; Hamm, R. W.; Humphry, F. J.; Jameson, R. A.; Knapp, E. A.; Potter, J. M.; Rodenz, G. W.; Stovall, J. E.; Swenson, D. A.

1980-07-01

232

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

ScienceCinema

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.

Giorgio Ambrosio

2010-01-08

233

Targeted Proteomic Quantification on Quadrupole-Orbitrap Mass Spectrometer*  

PubMed Central

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

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

2012-01-01

234

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

NASA Astrophysics Data System (ADS)

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.

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

235

Understanding Carbohydrates  

MedlinePLUS

... Size: A A A Listen En Español Understanding Carbohydrates How much and what type of carbohydrate foods ... selecting the most nutrient dense choices. Explore: Understanding Carbohydrates Glycemic Index and Diabetes Learn about the glycemic ...

236

Understanding language  

E-print Network

My dissertation concerns the nature of linguistic understanding. A standard view about linguistic understanding is that it is a propositional knowledge state. The following is an instance of this view: given a speaker S ...

Pettit, Dean R. (Dean Reid), 1967-

2003-01-01

237

Understanding Coronaviruses  

MedlinePLUS

... Field Search Button Advanced Search NIAID Home Health & Research Topics Labs & Scientific Resources Funding About NIAID News & Events NIAID > Health & Research Topics > Coronaviruses > Understanding Coronaviruses Understanding Overview Symptoms Transmission Diagnosis ...

238

Contribution of atom-probe tomography to a better understanding of glass alteration mechanisms: application to a nuclear glass specimen altered 25 years in a granitic environment  

SciTech Connect

We report and discuss results of atom probe tomography (APT) and energy-filtered transmission electron microscopy (EFTEM) applied to a borosilicate glass sample of nuclear interest altered for nearly 26 years at 90°C in a confined granitic medium in order to better understand the rate-limiting mechanisms under conditions representative of a deep geological repository for vitrified radioactive waste. The APT technique allows the 3D reconstruction of the elemental distribution at the reactive interphase with sub-nanometer precision. Profiles of the B distribution at pristine glass/hydrated glass interface obtained by different techniques are compared to show the challenge of accurate measurements of diffusion profiles at this buried interface on the nanometer length scale. Our results show that 1) Alkali from the glass and hydrogen from the solution exhibit anti-correlated 15 ± 3 nm wide gradients located between the pristine glass and the hydrated glass layer, 2) boron exhibits an unexpectedly sharp profile located just at the outside of the alkali/H interdiffusion layer; this sharp profile is more consistent with a dissolution front than a diffusion-controlled release of boron. The resulting apparent diffusion coefficients derived from the Li and H profiles are DLi = 1.5 × 10-22 m2.s-1 and DH = 6.8 × 10-23 m2.s-1. These values are around two orders of magnitude lower than those observed at the very beginning of the alteration process, which suggests that interdiffusion is slowed at high reaction progress by local conditions that could be related to the porous structure of the interphase. As a result, the accessibility of water to the pristine glass could be the rate-limiting step in these conditions. More generally, these findings strongly support the importance of interdiffusion coupled with hydrolysis reactions of the silicate network on the long-term dissolution rate, contrary to what has been suggested by recent interfacial dissolution-precipitation models for silicate minerals.

Gin, Stephane [CEA Marcoule DTCD SECM LCLT, Bagnols-sur-Ceze (France); Ryan, Joseph V. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Schreiber, Daniel K. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Neeway, James J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Cabie, M. [Aix-Marseille Universite, CP2M, Marseille (France)

2013-06-26

239

Stability considerations of permanent magnet quadrupoles for CESR phase-III upgrade  

NASA Astrophysics Data System (ADS)

The Cornell electron storage ring (CESR) phase-III upgrade plan includes very strong permanent magnet quadrupoles in front of the cryostat for the superconducting quadrupoles and physically as close as possible to the interaction point. Together with the superconducting quadrupoles, they provide tighter vertical focusing at the interaction point. The quadrupoles are built with neodymium iron boron (NdFeB) material and operate inside the 15 kG solenoid field. Requirements on the field quality and stability of these quadrupoles are discussed and test results are presented.

Lou, W.; Hartill, D.; Rice, D.; Rubin, D.; Welch, J.

1998-06-01

240

Microwave spectrum, van der Waals bond length, and 131Xe quadrupole coupling constant of Xe-SO3  

NASA Astrophysics Data System (ADS)

Nine isotopologues of Xe-SO3 have been observed by pulsed-nozzle Fourier transform microwave spectroscopy. The complex is a symmetric top with a Xe-S van der Waals distance of 3.577(2) Å. The increase in rare gas distance relative to that in Kr-SO3 is equal to the difference in van der Waals radii between Xe and Kr. The 131Xe nuclear quadrupole coupling constant indicates that the electric field gradient at the xenon nucleus is 78% larger than that at the Kr nucleus in Kr-SO3.

Dewberry, Christopher T.; Huff, Anna K.; Mackenzie, Rebecca B.; Leopold, Kenneth R.

2014-10-01

241

120-mm supercondcting quadrupole for interaction regions of hadron colliders  

SciTech Connect

Magnetic and mechanical designs of a Nb{sub 3}Sn quadrupole magnet with 120-mm aperture suitable for interaction regions of hadron colliders are presented. The magnet is based on a two-layer shell-type coil and a cold iron yoke. Special spacers made of a low-Z material are implemented in the coil mid-planes to reduce the level of radiation heat deposition and radiation dose in the coil. The quadrupole mechanical structure is based on aluminum collars supported by an iron yoke and a stainless steel skin. Magnet parameters including maximum field gradient and field harmonics, Nb3Sn coil pre-stress and protection at the operating temperatures of 4.5 and 1.9 K are reported. The level and distribution of radiation heat deposition in the coil and other magnet components are discussed.

Zlobin, A.V.; Kashikhin, V.V.; Mokhov, N.V.; Novitski, I.; /Fermilab

2010-05-01

242

New Mechanical Concept for Nb3Sn Quadrupole  

E-print Network

A new mechanical design concept for the Nb3Sn quadrupoles has been developed with a goal of an accelerator quality magnet that can be industrially produced in large series. This concept can easily be extended to any length and applied on both 1-in-1 and 2-in-1 configurations. It is based on the pole-loading concept and collared coils using dipole-type collars. First conceptual design study using finite element analysis has been carried out using the present base-line HL-LHC IR quadrupole QXF coil geometry for direct comparison with the bladder-and-key structure. The main features of the new design concept are described and the main results of the structural analysis discussed.

Karppinen, Mikko

2014-01-01

243

Permanent-magnet quadrupoles in an RFQ linacs  

SciTech Connect

We investigated the possibility of increasing the current-carrying capability of radio-frequency quadrupole (RFQ) linear accelerators by adding permanent-magnet quadrupole (PMQ) focusing to the existing transverse focusing provided by the rf electric field. Increased transverse focusing would also allow shortening RFQ linacs by permitting a larger accelerating gradient, which is normally accomplished by an undesirable increased transverse rf defocusing effect. We found that PMQs were not helpful in increasing the transverse focusing strength in an RFQ. This conclusion was reached after some particle tracing simulations and some analytical calculations. In our parameter regime, the addition of the magnets increases the betatron frequency but does not result in improved focusing because the increased flutter more than offsets the gain from the increased betatron frequency.

Lysenko, W.P.; Wang, T.F.

1985-01-01

244

CLAS Measurement of Narrow?(1232) Quadrupole Transition Form Factors  

NASA Astrophysics Data System (ADS)

Electroproduction of the ?(1232) can be used to study the mechanisms responsible for quark confinement and resonance formation. In particular, the Q^2 dependence of the multipoles E_1+ and S_1+ in the Narrow? quadrupole transition is especially sensitive to the shape of the nucleon and the evolution from pion to quark degrees of freedom. Recent ?^0 electroproduction data taken using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab permit a complete separation of the response functions ?_TT and ?_LT, which show high sensitivity to the quadrupole strength. New experimental results for the ratios E_1+/M_1+ and S_1+/M_1+ are presented using a partial wave analysis over a Q^2 range of 0.4 to 1.8 GeV^2. Results will be compared to quark models as well as recent unitary models which include the dynamical effects of the pion cloud.

Smith, Cole; Joo, Kyungseon

2002-04-01

245

Simple correlations between electric quadrupole moments of atomic nuclei  

SciTech Connect

Measurements of non-yrast electric quadrupole moments (i.e., diagonal E2 matrix elements) of atomic nuclei are becoming widely available from multiple-step Coulomb excitation. It is shown that, where quadrupole-moment data exist, $\\langle 2_1^+ ||E2|| 2_1^+ \\rangle+\\langle 2_2^+ ||E2|| 2_2^+ \\rangle\\approx 0$ is observed across a wide range of masses and deformations. In addition, $\\langle 4_1^+ ||E2|| 4_1^+ \\rangle+\\langle 4_2^+ ||E2|| 4_2^+ \\rangle+\\langle 4_3^+ ||E2|| 4_3^+ \\rangle\\approx 0$ is observed within two standard deviations for three of the four existing measurements. Rotor models appear to be sufficient in describing these trends.

Allmond, James M [ORNL] [ORNL

2013-01-01

246

Performance of An Adjustable Strength Permanent Magnet Quadrupole  

SciTech Connect

An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic CL and field quality made using an air bearing rotating coil system. The magnetic CL stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic CL. Calibration procedures as well as CL measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

Gottschalk, S.C.; DeHart, T.E.; Kangas, K.W.; /STI Optronics, Bellevue; Spencer, C.M.; /SLAC; Volk, J.T.; /Fermilab

2006-03-01

247

Assessing Understanding  

NSDL National Science Digital Library

Try using an assessment cycle to effectively probe students' understanding of scientific concepts. The diagnostic, formative, summative, and confirmatory assessment can be embedded into any unit of study.

Sterling, Donna R.

2005-01-01

248

Development of quadrupole mass spectrometers using rapid prototyping technology  

Microsoft Academic Search

In this report, we present a prototype design of a quadrupole mass filter (QMF) with hyperbolic electrodes, fabricated at\\u000a the University of Liverpool using digital light processing (DLP), a low-cost and lightweight 3D rapid prototyping (RP) technique.\\u000a Experimental mass spectra are shown for H2+, D2+, and He+ ions to provide proof of principle that the DLP mass filter is working

Boris Brki?; Neil France; Adam T. Clare; Chris J. Sutcliffe; Paul R. Chalker; Stephen Taylor

2009-01-01

249

Gravitational radiation quadrupole formula is valid for gravitationally interacting systems  

SciTech Connect

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 evaluate the appropriate asymptotic quantities by matching along the correct space-time light cones.

Walker, M.; Will, C.M.

1980-12-01

250

Electrostatic quadrupole array for focusing parallel beams of charged particles  

DOEpatents

An array of electrostatic quadrupoles, capable of providing strong electrostatic focusing simultaneously on multiple beams, is easily fabricated from a single array element comprising a support rod and multiple electrodes spaced at intervals along the rod. The rods are secured to four terminals which are isolated by only four insulators. This structure requires bias voltage to be supplied to only two terminals and eliminates the need for individual electrode bias and insulators, as well as increases life by eliminating beam plating of insulators.

Brodowski, John (Smithtown, NY)

1982-11-23

251

Analysis on linac quadrupole misalignment in FACET commissioning 2012  

SciTech Connect

In this note, the analysis on linac quadrupole misalignment is presented for the FACET linac section LI05-09 plus LI11-19. The effectiveness of the beam-based alignment technique is preliminarily confirmed by the measurement. Beam-based alignment technique was adopted at SLAC linac since SLC time. Here the beam-based alignment algorithms are further developed and applied in the FACET commissioning during 2012 run.

Sun, Yipeng; /SLAC

2012-07-05

252

The Dynamic Aperture of an Electrostatic Quadrupole Lattice  

Microsoft Academic Search

In heavy-ion-driven inertial fusion accelerator concepts, dynamic aperture is important to the cost of the accelerator, most especially for designs which envision multibeam linacs, where extra clearance for each beam greatly enlarges the transverse scale of the machine. In many designs the low-energy end of such an accelerator uses electrostatic quadrupole focusing. The dynamic aperture of such a lattice has

C. M. Celata; F. M. Bieniosek; P. A. Seidl; A. Friedman; D. P. Grote; L. Prost

2005-01-01

253

The deuterium quadrupole coupling constants of di- and trihalomethanes  

Microsoft Academic Search

There have recently been published a number of papers reporting the deuterium quadrupole coupling constants (QCC) of small molecules dissolved in liquid- crystalline media (1-5). The results presented show, in many instances, wide variations in QCC values determined by different groups. These differences can be mainly attributed to the presence of different solvent-solute interactions in different liquid-crystal phases. Other causes

A. C. KUNWAR; H. S. GUTOWSKY; E OLDFIELD

1985-01-01

254

Magnetic field measurements of printed-circuit quadrupoles and dipoles  

Microsoft Academic Search

Printed-Circuit (PC) quadrupoles and dipoles have been designed and developed for focusing and bending a space-charge dominated electron beam in the University of Maryland Electron Ring (UMER), currently under development. Due to the rather small aspect ratio (length\\/diameter <1) of the magnets, the field quality, especially the nonlinear fringe field, has been a concern for the success of the UMER

W. W. Zhang; S. Bernal; P. Chin; R. Kishek; M. Reiser; M. Venturini; J. G. Wang; V. Yun

1999-01-01

255

Longitudinal capture in the radio-frequency-quadrupole structure  

SciTech Connect

The radio-frequency-quadrupole (RFQ) linac structure not only can attain easily transverse focusing in the low-beta region, but also can obtain very high capture efficiency because of its low beta-lambda and low-particle rigidity. An optimization study of the zero space-charge longitudinal capture in an RFQ linac that yields configurations with large capture efficiency is described.

Inagaki, S.

1980-03-01

256

Nuclear Energy Level Argument for a Spheroidal Nuclear Model  

Microsoft Academic Search

Recently there has been notable success, particularly by Maria Mayer, in explaining many nuclear phenomena including spins, magnetic moments, isomeric states, etc. on the basis of a single particle model for the separate nucleons in a spherical nucleus. The spherical model, however, seems incapable of explaining the observed large quadrupole moments of nuclei. In this paper it is shown that

James Rainwater

1950-01-01

257

Furthering the understanding of silicate-substitution in ?-tricalcium phosphate: an X-ray diffraction, X-ray fluorescence and solid-state nuclear magnetic resonance study.  

PubMed

High-purity (SupT) and reagent-grade (ST), stoichiometric and silicate-containing ?-tricalcium phosphate (?-TCP: ST0/SupT0 and Si-TCP x=0.10: ST10/SupT10) were prepared by solid-state reaction based on the substitution mechanism Ca3(PO4)(2-x)(SiO4)x. Samples were determined to be phase pure by X-ray diffraction (XRD), and Rietveld analysis performed on the XRD data confirmed inclusion of Si in the ?-TCP structure as determined by increases in unit cell parameters; particularly marked increases in the b-axis and ?-angle were observed. X-ray fluorescence (XRF) confirmed the presence of expected levels of Si in Si-TCP compositions as well as significant levels of impurities (Mg, Al and Fe) present in all ST samples; SupT samples showed both expected levels of Si and a high degree of purity. Phosphorus ((31)P) magic-angle-spinning solid-state nuclear magnetic resonance (MAS NMR) measurements revealed that the high-purity reagents used in the synthesis of SupT0 can resolve the 12 expected peaks in the (31)P spectrum of ?-TCP compared to the low-purity ST0 that showed significant spectral line broadening; line broadening was also observed with the inclusion of Si which is indicative of induced structural disorder. Silicon ((29)Si) MAS NMR was also performed on both Si-TCP samples which revealed Q(0) species of Si with additional Si Q(1)/Q(2) species that may indicate a potential charge-balancing mechanism involving the inclusion of disilicate groups; additional Q(4) Si species were also observed, but only for ST10. Heating and cooling rates were briefly investigated by (31)P MAS NMR which showed no significant line broadening other than that associated with the emergence of ?-TCP which was only realised with the reagent-grade sample ST0. This study provides an insight into the structural effects of Si-substitution in ?-TCP and could provide a basis for understanding how substitution affects the physicochemical properties of the material. PMID:24287162

Duncan, J; Hayakawa, S; Osaka, A; MacDonald, J F; Hanna, J V; Skakle, J M S; Gibson, I R

2014-03-01

258

The exact calculation of quadrupole sources for some incompressible flows  

NASA Technical Reports Server (NTRS)

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.

Brentner, Kenneth S.

1988-01-01

259

Understanding Instructions  

Microsoft Academic Search

The understanding of instructions was explored within the context of cognitive load theory. Instructional material may be difficult to understand if it consists of many elements that must be held in working memory simultaneously. If the number of elements that must be processed exceeds working-memory capacity, then some elements must be combined into schemas before the material can be understood.

Nadine Marcus; Martin Cooper; John Sweller

1996-01-01

260

Nuclear reactions in hot stellar matter and nuclear surface deformation  

E-print Network

Cross-sections for capture reactions of charged particles in hot stellar matter turn out be increased by the quadrupole surface oscillations, if the corresponding phonon energies are of the order of the star temperature. The increase is studied in a model that combines barrier distribution induced by surface oscillations and tunneling. The capture of charged particles by nuclei with well-deformed ground-state is enhanced in stellar matter. It is found that the influence of quadrupole surface deformation on the nuclear reactions in stars grows, when mass and proton numbers in colliding nuclei increase.

V. Yu. Denisov

2006-11-13

261

Nuclear reactions in hot stellar matter and nuclear surface deformations  

SciTech Connect

Cross sections for capture reactions of charged particles in hot stellar matter turn out be increased by the quadrupole surface oscillations when the corresponding phonon energies are of the order of the star temperature. This increase is studied in a model that combines barrier distribution induced by surface oscillations and tunneling. The capture of charged particles by nuclei with well-deformed ground states is enhanced in stellar matter. It is found that the influence of quadrupole surface deformation on the nuclear reactions in stars grows when mass and proton numbers in colliding nuclei increase.

Denisov, V. Yu. [Institute for Nuclear Research, Prospect Nauki 47, 03680 Kiev (Ukraine)

2006-11-15

262

Nuclear reactions in hot stellar matter and nuclear surface deformation  

E-print Network

Cross-sections for capture reactions of charged particles in hot stellar matter turn out be increased by the quadrupole surface oscillations, if the corresponding phonon energies are of the order of the star temperature. The increase is studied in a model that combines barrier distribution induced by surface oscillations and tunneling. The capture of charged particles by nuclei with well-deformed ground-state is enhanced in stellar matter. It is found that the influence of quadrupole surface deformation on the nuclear reactions in stars grows, when mass and proton numbers in colliding nuclei increase.

Denisov, V Y

2006-01-01

263

Understanding Nano  

NSDL National Science Digital Library

Nanotechnology can be a complicated topic. The Understanding Nano website is dedicated to providing clear and concise explanations of nanotechnology applications along with information on companies working in each area.

2013-07-05

264

Bose-Einstein Condensation in an electro-pneumatically transformed quadrupole-Ioffe magnetic trap  

E-print Network

We report a novel approach for preparing a Bose-Einstein condensate (BEC) of $^{87}$Rb atoms using electro-pneumatically driven transfer of atoms into a Quadrupole-Ioffe magnetic trap (QUIC Trap). More than 5$\\times$$10^{8}$ atoms from a Magneto-optical trap are loaded into a spherical quadrupole trap and then these atoms are transferred into an Ioffe trap by moving the Ioffe coil towards the center of the quadrupole coil, thereby, changing the distance between quadrupole trap center and the Ioffe coil. The transfer efficiency is more than 80 \\%. This approach is different from a conventional approach of loading the atoms into a QUIC trap wherein the spherical quadrupole trap is transformed into a QUIC trap by changing the currents in the quadrupole and the Ioffe coils. The phase space density is then increased by forced rf evaporative cooling to achieve the Bose-Einstein condensation having more than $10^{5}$ atoms.

Kumar, Sunil; Verma, Gunjan; Vishwakarma, Chetan; Noaman, Md; Rapol, Umakant

2014-01-01

265

Bose-Einstein Condensation in an electro-pneumatically transformed quadrupole-Ioffe magnetic trap  

E-print Network

We report a novel approach for preparing a Bose-Einstein condensate (BEC) of $^{87}$Rb atoms using electro-pneumatically driven transfer of atoms into a Quadrupole-Ioffe magnetic trap (QUIC Trap). More than 5$\\times$$10^{8}$ atoms from a Magneto-optical trap are loaded into a spherical quadrupole trap and then these atoms are transferred into an Ioffe trap by moving the Ioffe coil towards the center of the quadrupole coil, thereby, changing the distance between quadrupole trap center and the Ioffe coil. The transfer efficiency is more than 80 \\%. This approach is different from a conventional approach of loading the atoms into a QUIC trap wherein the spherical quadrupole trap is transformed into a QUIC trap by changing the currents in the quadrupole and the Ioffe coils. The phase space density is then increased by forced rf evaporative cooling to achieve the Bose-Einstein condensation having more than $10^{5}$ atoms.

Sunil Kumar; Sumit Sarkar; Gunjan Verma; Chetan Vishwakarma; Md. Noaman; Umakant Rapol

2014-08-20

266

Testing of Nb3Sn quadrupole coils using magnetic mirror structure  

SciTech Connect

This paper describes the design and parameters of a quadrupole mirror structure for testing the mechanical, thermal and quench performance of single shell-type superconducting quadrupole coils at field, current and force levels similar to that of real magnet. The concept was experimentally verified by testing two quadrupole coils, previously used in quadrupole models, in the developed mirror structure in the temperature range from 4.5 to 1.9 K. The coils were instrumented with voltage taps, heaters, and strain gauges to monitor their mechanical and thermal properties and quench performance. A new quadrupole coil made of improved Nb{sub 3}Sn RRP-108/127 strand and cable insulation based on E-glass tape was also tested using this structure. The fabrication and test results of the quadrupole mirror models are reported and discussed.

Zlobin, A.V.; Andreev, N.; Barzi, E.; Bossert, R.; Chlachidze, G.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.; Novitski, I.; Tartaglia, M.; Tompkins, J.C.; /Fermilab

2009-07-01

267

TESTING OF NB{sub 3}SN QUADRUPOLE COILS USING MAGNETIC MIRROR STRUCTURE  

SciTech Connect

This paper describes the design and parameters of a quadrupole mirror structure for testing the mechanical, thermal and quench performance of single shell-type superconducting quadrupole coils at field, current and force levels similar to that of real magnet. The concept was experimentally verified by testing two quadrupole coils, previously used in quadrupole models, in the developed mirror structure in the temperature range from 4.5 to 1.9 K. The coils were instrumented with voltage taps, heaters, and strain gauges to monitor their mechanical and thermal properties and quench performance. A new quadrupole coil made of improved Nb{sub 3}Sn RRP-108/127 strand and cable insulation based on E-glass tape was also tested using this structure. The fabrication and test results of the quadrupole mirror models are reported and discussed.

Zlobin, A. V.; Andreev, N.; Barzi, E.; Bossert, R.; Chlachidze, G.; Kashikhin, V. S.; Kashikhin, V. V.; Lamm, M. J.; Novitski, I.; Tartaglia, M.; Tompkins, J. C.; Turrioni, D.; Yamada, R. [Fermi National Accelerator Laboratory, Batavia, IL, 60510 (United States)

2010-04-09

268

An Application of 3-D MEMS Packaging: Out-of-Plane Quadrupole Mass Filters  

Microsoft Academic Search

This paper reports the design, fabrication, and characterization of low-cost out-of-plane quadrupole mass filters that use commercially available dowel pins as electrode rods. The quadrupoles implement a 3-D MEMS packaging technology that relies on deep-reactive ion etching (DRIE)-patterned deflection springs for alignment. Quadrupoles with rod diameter ranging from 0.25 to 1.58 mm and aspect ratio of 30 to 60 were

Luis F. Velasquez-Garcia; Kerry Cheung; Akintunde I. Akinwande

2008-01-01

269

Stability of the coherent quadrupole oscillations excited by the beam-beam interaction  

SciTech Connect

We study the coherent quadrupole motion in the presence of beam-beam interaction, using a linear approximation to the beam-beam force. The corresponding beam-beam limit is determined by evaluating the eigenvalues of a system of linear equations describing the coherent quadrupole motion. We find that the stability of the quadrupole motions imposes severe limits on the beam current, as is the case for the dipole instability. Preliminary results of this study have appeared elsewhere.

Kamiya, Y.; Chao, A.W.

1983-10-01

270

The Erez-Rosen metric and the role of the quadrupole on light propagation  

E-print Network

The gravitational field of a static body with quadrupole moment is described by an exact solution found by Erez and Rosen. Here we investigate the role of the quadrupole in the motion, deflection and lensing of a light ray in the above metric. The standard lensing observables like image positions and magnification have been explicitly obtained in the weak field and small quadrupole limit. In this limit the spacetime metric appears as the natural generalization to quadrupole corrections of the metric form adopted also in current astrometric models. Hence, the corresponding analytical solution of the inverse ray tracing problem as well as the consistency with other approaches are also discussed.

Bini, Donato; de Felice, Fernando; Geralico, Andrea; Vecchiato, Alberto

2014-01-01

271

The Erez-Rosen metric and the role of the quadrupole on light propagation  

E-print Network

The gravitational field of a static body with quadrupole moment is described by an exact solution found by Erez and Rosen. Here we investigate the role of the quadrupole in the motion, deflection and lensing of a light ray in the above metric. The standard lensing observables like image positions and magnification have been explicitly obtained in the weak field and small quadrupole limit. In this limit the spacetime metric appears as the natural generalization to quadrupole corrections of the metric form adopted also in current astrometric models. Hence, the corresponding analytical solution of the inverse ray tracing problem as well as the consistency with other approaches are also discussed.

Donato Bini; Mariateresa Crosta; Fernando de Felice; Andrea Geralico; Alberto Vecchiato

2014-08-22

272

Performance Characteristics of a MEMS Quadrupole Mass Filter With Square Electrodes: Experimental and Simulated Results  

E-print Network

Size reduction in quadrupole mass spectrometers (QMSs) is an ongoing requirement driven by the needs of space exploration, portable, and covert monitoring applications. Microelectromechanical systems (MEMS) technology ...

Hogan, Thomas J.

273

Progress in the Development of Superconducting Quadrupoles forHeavy-ion Fusion  

SciTech Connect

The Heavy Ion Fusion program is developing single aperture superconducting quadrupoles based on NbTi conductor, for use in the High Current Experiment at Lawrence Berkeley National Laboratory. Following the fabrication and testing of prototypes using two different approaches, a baseline design has been selected and further optimized. A prototype cryostat for a quadrupole doublet, with features to accommodate induction acceleration modules, is being fabricated. The single aperture magnet was derived from a conceptual design of a quadrupole array magnet for multi-beam transport. Progress on the development of superconducting quadrupole arrays for future experiments is also reported.

Faltens, A.; Lietzke, A.; Sabbi, G.; Seidl, P.; Lund, S.; Manahan, R.; Martovetsky, N.; Gung, C.; Minervini, J.; Schultz, J.; Myatt, L.; Meinke, R.

2002-08-19

274

Geometry and properties of the plasma in a quadrupole ion pump  

NASA Technical Reports Server (NTRS)

The diameter of the plasma in a quadrupole ionization gauge and quadrupole ion pump has been measured as a function of pressure. The radio-frequency quadrupole systems are tuned in such a way that electrons remain on stable trajectories in the center of the tube. Being emitted at one end, the electrons encounter an inverted field at the other end so that they travel on spiral paths back and forth until they collide with the rest gas molecules, producing ions which are collected as an ion current at a cylinder surrounding the four hyperbolically shaped quadrupole electrodes.

Schwarz, H.

1977-01-01

275

Progress in the development of superconducting quadrupoles for heavy ion fusion  

SciTech Connect

The Heavy Ion Fusion program is developing single aperture superconducting quadrupoles based on NbTi conductor, for use in the High Current Experiment at Lawrence Berkeley National Laboratory. Following the fabrication and testing of prototypes using two different approaches, a baseline design has been selected and further optimized. A prototype cryostat for a quadrupole doublet, with features to accommodate induction acceleration modules, is being fabricated. The single aperture magnet was derived from a conceptual design of a quadrupole array magnet for multi-beam transport. Progress on the development of superconducting quadrupole arrays for future experiments is also reported.

Faltens, A.; Lietzke, A.; Sabbi, G.; Seidl, P.; Lund, S.; Manahan, B.; Martovetsky, N.; Gung, C.; Minervini, J.; Schultz, J.; Myatt, L.; Meinke, R.

2002-05-24

276

Superconducting focusing quadrupoles for heavy ion fusion experiments  

SciTech Connect

The Heavy Ion Fusion (HIF) Program is developing superconducting focusing magnets for both near-term experiments and future driver accelerators. In particular, single bore quadrupoles have been fabricated and tested for use in the High Current Experiment (HCX) at Lawrence Berkeley National Laboratory (LBNL). The next steps involve the development of magnets for the planned Integrated Beam Experiment (IBX) and the fabrication of the first prototype multi-beam focusing arrays for fusion driver accelerators. The status of the magnet R&D program is reported, including experimental requirements, design issues and test results.

Sabbi, G.L.; Faltens, A.; Leitner, M.; Lietzke, A.; Seidl, P.; Barnard, J.; Lund, S.; Martovetsky, N.; Gung, C.; Minervini, J.; Radovinsky, A.; Schultz, J.; Meinke, R.

2003-05-01

277

Electrostatic quadrupole accelerator for the heavy ion fusion project  

SciTech Connect

A full scale (2 MeV, 800 mA, K{sup +}), low emittance injector for the Heavy Ion Fusion Project has been built at LBL. It consists of a 700 keV diode pre-injector followed by an electrostatic quadrupole accelerator (ESQ) which provides strong focusing for the space-charge dominated beam and simultaneously accelerates the ions to 2 MeV. The actual operation of this new machine has exceeded design parameters. Design of the accelerator, report on experiments performed in connection with the evaluation and characterization of the ESQ and corresponding 3D Particle in Cell simulations will be presented.

Henestroza, E.; Yu, S.; Eylong, S. [Lawrence Berkeley Lab., CA (United States)

1994-12-31

278

Quench margin measurement in Nb3Sn quadrupole magnet  

SciTech Connect

One of the possible practical applications of the Nb{sub 3}Sn accelerator magnets is the LHC luminosity upgrade that involves replacing the present NbTi focusing quadrupoles in two high-luminosity interaction regions (IR). The IR magnets are exposed to strong radiation from the interaction point that requires a detailed investigation of the magnet operating margins under the expected radiation-induced heat depositions. This paper presents the results of simulation and measurement of quench limits and temperature margins for a Nb{sub 3}Sn model magnet using a special midplane strip heater.

Kashikhin, V.V.; Bossert, R.; Chlachidze, G.; Lamm, M.; Novitski, I.; Zlobin, A.V.; /Fermilab

2008-08-01

279

The nucleus as a condensate of monopole and quadrupole pairing vibrations  

NASA Astrophysics Data System (ADS)

It has been shown that the aligned wave function, and the wave function obtained by restricting pairs of particles to be coupled to angular momentum zero and two, as assumed by the quadrupole phonon model (QPM) and by the interacting boson model (IBM) are, for strongly deformed systems, rather different. They become similar in the vibrational limit and display different degrees of similarity for intermediate (anharmonic) situations. To what extent this difference reveals itself in the predicted properties of the low-energy nuclear spectrum is an open question. In an attempt to clarify this point we have calculated the spectrum and the electromagnetic and two-nucleon transfer probabilities for some strongly anharmonic and transitional nuclei, in the framework of the nuclear field theory (NFT) version of the pair aligned model. These calculations, which are microscopic, depend on the strength of the pairing and particle-hole interactions. We find that for standard values of these parameters, the moment of inertia of both the ?- and the ?-bands are too small. While the main pattern of the phase transition observed in the Sm isotopes is displayed by the model, major deviations are observed concerning the properties of the ?-vibrations, and in connection with the two-nucleon transfer strength associated with the 2 + member of the ground state rotational band.

Broglia, R. A.; Maglione, E.; Sofia, H. M.; Vitturi, A.

1982-02-01

280

Understanding Science  

NSDL National Science Digital Library

This page, from University of California Museum of Paleontology, features free, image-rich teaching resources that communicate what science is and how it works, with a focus on the process of science and its dynamic nature. The project is geared toward K-16 teacher preparation as well as broader public understanding of the nature of science.

Paleontology, University O.

281

Understanding Autobiographical  

E-print Network

. Schacter William R. Kenan, Jr. Professor of Psychology, Harvard University, and author of The Seven Sins, and then breaks down in aging; its social and cultural aspects; and its relation to personality and the self shown its practical relevance by deepening our understanding of several clinical disorders ­ as well

282

Understanding Instructions.  

ERIC Educational Resources Information Center

This guide is intended to help adult basic education (ABE) teachers teach their students to understand instructions in their daily lives. The 25 learning activities included all develop students' skills in the area of following directions by using basic situations drawn from everyday life. The following activities are included: sequencing pictures…

Milburn, Val

283

Compressive mass analysis on quadrupole ion trap systems.  

PubMed

Conventionally, quadrupole ion trap mass spectrometers eject ions of different mass-to-charge ratio (m/z) in a sequential fashion by performing a scan of the rf trapping voltage amplitude. Due to the inherent sparsity of most mass spectra, the detector measures no signal for much of the scan time. By exploiting this sparsity property, we propose a new compressive and multiplexed mass analysis approach--multi Resonant Frequency Excitation (mRFE) ejection. This new approach divides the mass spectrum into several mass subranges and detects all the subrange spectra in parallel for increased mass analysis speed. Mathematical estimation of standard mass spectrum is demonstrated while statistical classification on the parallel measurements remains viable because of the sparse nature of the mass spectra. This method can reduce mass analysis time by a factor of 3-6 and increase system duty cycle by 2×. The combination of reduced analysis time and accurate compound classification is demonstrated in a commercial quadrupole ion trap (QIT) system. PMID:24806048

Chen, Evan Xuguang; Gehm, Michael; Danell, Ryan; Wells, Mitch; Glass, Jeffrey T; Brady, David

2014-07-01

284

Compressive Mass Analysis on Quadrupole Ion Trap Systems  

NASA Astrophysics Data System (ADS)

Conventionally, quadrupole ion trap mass spectrometers eject ions of different mass-to-charge ratio ( m/z) in a sequential fashion by performing a scan of the rf trapping voltage amplitude. Due to the inherent sparsity of most mass spectra, the detector measures no signal for much of the scan time. By exploiting this sparsity property, we propose a new compressive and multiplexed mass analysis approach— multi Resonant Frequency Excitation (mRFE) ejection. This new approach divides the mass spectrum into several mass subranges and detects all the subrange spectra in parallel for increased mass analysis speed. Mathematical estimation of standard mass spectrum is demonstrated while statistical classification on the parallel measurements remains viable because of the sparse nature of the mass spectra. This method can reduce mass analysis time by a factor of 3-6 and increase system duty cycle by 2×. The combination of reduced analysis time and accurate compound classification is demonstrated in a commercial quadrupole ion trap (QIT) system.

Chen, Evan Xuguang; Gehm, Michael; Danell, Ryan; Wells, Mitch; Glass, Jeffrey T.; Brady, David

2014-07-01

285

A Tandem-electrostatic-quadrupole for accelerator-based BNCT  

NASA Astrophysics Data System (ADS)

A project to develop a Tandem-electrostatic-quadrupole (TESQ) accelerator for accelerator-based boron neutron capture therapy (AB-BNCT) is described. A folded Tandem, with 1.25 MV terminal voltage, combined with an electrostatic quadrupole (ESQ) chain is being proposed. The project goal is a machine capable of delivering 30 mA of 2.5 MeV protons to be used in conjunction with a neutron production target based on the 7Li(p, n) 7Be reaction slightly beyond its resonance at 2.25 MeV. This machine is conceptually shown to be capable of accelerating a 30 mA proton beam to 2.5 MeV. These are the specifications needed to produce sufficiently intense and clean epithermal neutron beams, based on the 7Li(p, n) 7Be reaction, to perform BNCT treatment for deep-seated tumors in less than an hour. This electrostatic machine is the technologically simplest and cheapest solution for optimized AB-BNCT.

Kreiner, A. J.; Kwan, J. W.; Burlón, A. A.; Di Paolo, H.; Henestroza, E.; Minsky, D. M.; Valda, A. A.; Debray, M. E.; Somacal, H.

2007-08-01

286

Extracting the Omega- electric quadrupole moment from lattice QCD data  

SciTech Connect

The Omega- has an extremely long lifetime, and is the most stable of the baryons with spin 3/2. Therefore the Omega- magnetic moment is very accurately known. Nevertheless, its electric quadrupole moment was never measured, although estimates exist in different formalisms. In principle, lattice QCD simulations provide at present the most appropriate way to estimate the Omega- form factors, as function of the square of the transferred four-momentum, Q2, since it describes baryon systems at the physical mass for the strange quark. However, lattice QCD form factors, and in particular GE2, are determined at finite Q2 only, and the extraction of the electric quadrupole moment, Q_Omega= GE2(0) e/(2 M_Omega), involves an extrapolation of the numerical lattice results. In this work we reproduce the lattice QCD data with a covariant spectator quark model for Omega- which includes a mixture of S and two D states for the relative quark-diquark motion. Once the model is calibrated, it is used to determine Q_Omega. Our prediction is Q_Omega= (0.96 +/- 0.02)*10^(-2) efm2 [GE2(0)=0.680 +/- 0.012].

G. Ramalho, M.T. Pena

2011-03-01

287

Quadrupole Approximation for Para-Positronium in Relativistic Schrödinger Theory  

E-print Network

The non-relativistic energy levels of para-positronium are calculated in the quadrupole approximation of the interaction potential. This approximation technique takes into account the anisotropy of the electrostatic electron-positron interaction in the lowest order. The states due to different values of the quantum number $(l_z)$ of angular momentum are found to be no longer degenerate as is the case in the conventional theory. The physical origin of this elimination of the conventional degeneracy may intuitively be attributed to the state-dependent inertial \\emph{broadening} of the rotating charge clouds; the corresponding \\emph{anisotropic} deformation (in the quadrupole approximation) lowers then the negative electrostatic interaction energy. The result of this influence of anisotropy is that the states with $l_z=0$ adopt smaller binding energy whereas the states with maximal value of $|l_z|$ (for fixed principal quantum number $n$) have the largest binding energy within the angular momentum multiplet $(-|l_{z,\\mathrm{max}}| \\le l_z \\le |l_{z,\\mathrm{max}}|)$. This yields a certain kind of electric fine-structure splitting with the splitted RST levels being placed in a relatively narrow band around the (highly degenerated) conventional levels.

M. Mattes; M. Sorg

2011-09-11

288

High Reliability Prototype Quadrupole for the Next Linear Collider  

NASA Astrophysics Data System (ADS)

The Next Linear Collider (NLC) will require over 5600 magnets, each of which must be highly reliable and/or quickly repairable in order that the NLC reach its 85/ overall availability goal. A multidiscipline engineering team was assembled at SLAC to develop a more reliable electromagnet design than historically had been achieved at SLAC. This team carried out a Failure Mode and Effects Analysis (FMEA) on a standard SLAC quadrupole magnet system. They overcame a number of longstanding design prejudices, producing 10 major design changes. This paper describes how a prototype magnet was constructed and the extensive testing carried out on it to prove full functionality with an improvement in reliability. The magnet's fabrication cost will be compared to the cost of a magnet with the same requirements made in the historic SLAC way. The NLC will use over 1600 of these 12.7 mm bore quadrupoles with a range of integrated strengths from 0.6 to 132 Tesla, a maximum gradient of 135 Tesla per meter, an adjustment range of 0 to -20/ and core lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micron during the 20/ adjustment. A magnetic measurement set-up has been developed that can measure sub-micron shifts of a magnetic center. The prototype satisfied the center shift requirement over the full range of integrated strengths.

Spencer, C. M.

2001-01-01

289

Understanding Flight  

SciTech Connect

Through the years the explanation of flight has become mired in misconceptions that have become dogma. Wolfgang Langewiesche, the author of 'Stick and Rudder' (1944) got it right when he wrote: 'Forget Bernoulli's Theorem'. A wing develops lift by diverting (from above) a lot of air. This is the same way that a propeller produces thrust and a helicopter produces lift. Newton's three laws and a phenomenon called the Coanda effect explain most of it. With an understanding of the real physics of flight, many things become clear. Inverted flight, symmetric wings, and the flight of insects are obvious. It is easy to understand the power curve, high-speed stalls, and the effect of load and altitude on the power requirements for lift. The contribution of wing aspect ratio on the efficiency of a wing, and the true explanation of ground effect will also be discussed.

Anderson, David

2001-01-31

290

Understanding Depression  

PubMed Central

To understand the effects of depression on a patient's life, the physician must be aware how depression manifests itself. Somatic tension, strategies to relieve discomfort and social withdrawal must be recognized as symptoms of depression. An awareness of life situations which can give rise to these symptoms, as well as the effect of the physician's own reactions to the patient's depression, are helpful. PMID:21289767

McNair, F. E.

1981-01-01

291

Understanding Drought  

NSDL National Science Digital Library

Understanding Drought--This webcast provides an introduction to drought. It presents the measures and scales of drought and how drought is monitored. It also covers how drought is predicted, the impacts of drought, and provides information about drought-related resources. This content serves as a foundation to learning more about climate variability and operational climate services and prepares users for the national implementation of NIDIS. This module was last updated on Sept 28, 2009.

Comet

2009-02-11

292

Understanding Core-Collapse Supernovae  

NASA Astrophysics Data System (ADS)

Our understanding of core-collapse supernovae continues to improve as better microphysics is included in increasingly realistic neutrino-radiationhydrodynamic simulations. Recent multi-dimensional models with spectral neutrino transport, which slowly develop successful explosions for a range of progenitors between 12 and 25 solar mass, have motivated changes in our understanding of the neutrino reheating mechanism. In a similar fashion, improvements in nuclear physics, most notably explorations of weak interactions on nuclei and the nuclear equation of state, continue to refine our understanding of how supernovae explode. Recent progresses on both the macroscopic and microscopic effects that affect core-collapse supernovae are discussed.

Hix, W. R.; Lentz, E. J.; Baird, M.; Messer, O. E. B.; Mezzacappa, A.; Lee, C.-T.; Bruenn, S. W.; Blondin, J. M.; Marronetti, P.

2010-03-01

293

Testing Understanding and Understanding Testing.  

ERIC Educational Resources Information Center

Provides examples in which graphs are used in the statements of problems or in their solutions as a means of testing understanding of mathematical concepts. Examples (appropriate for a beginning course in calculus and analytic geometry) include slopes of lines and curves, quadratic formula, properties of the definite integral, and others. (JN)

Pedersen, Jean; Ross, Peter

1985-01-01

294

CXXXIII. Magnetic moments and quadrupole moments of odd-mass nuclei in jj-coupling  

Microsoft Academic Search

Magnetic moments and quadrupole moments of nuclei are treated in a model which considers all particles outside the core of completed levels on an equal footing. It is shown that in this way better agreement with experimental magnetic moments is obtained than from the simpler Schmidt model. The manner in which electric quadrupole moments arise in odd-neutron nuclei without the

B. H. Flowers

1952-01-01

295

Measuring the Magnetic Center Behavior of an ILC Superconducting Quadrupole Prototype  

SciTech Connect

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 technique 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.

Spencer, Cherrill M.; Adolphsen, Chris; Berndt, Martin; Jensen, David R.; Rogers, Ron; Sheppard, John C.; Lorant, Steve St; Weber, Thomas B.; Weisend, John, II; /SLAC; Brueck, Heinrich; /DESY; Toral, Fernando; /Madrid, CIEMAT

2011-02-07

296

Description of surface quadrupole oscillations of heated spherical nuclei in the Brownian-motion approximation  

SciTech Connect

The Brownian motion of a quadrupole quantum oscillator is considered as a model of surface quadrupole oscillations of heated spherical nuclei. The integrals of the motion related to energy and angular momentum conservation are constructed and the wave functions are obtained for states with definite values of these integrals of the motion in the phonon representation.

Svin'in, I.R.

1982-07-01

297

Effects of Extreme Magnetic Quadrupole Fields on Penning Traps and the Consequences for Antihydrogen Trapping  

SciTech Connect

Measurements on electrons confined in a Penning trap show that extreme quadrupole fields destroy particle confinement. Much of the particle loss comes from the hitherto unrecognized ballistic transport of particles directly into the wall. The measurements scale to the parameter regime used by ATHENA and ATRAP to create antihydrogen, and suggest that quadrupoles cannot be used to trap antihydrogen.

Fajans, J.; Bertsche, W.; Burke, K.; Chapman, S.F. [Department of Physics, University of California at Berkeley, and the Lawrence Berkeley National Laboratory, Berkeley California 94720 (United States); Werf, D.P. van der [Department of Physics, University of Wales Swansea, Singleton Park SA2 8PP (United Kingdom)

2005-10-07

298

Application of an explosive detection device based on quadrupole resonance (QR) technology in aviation security  

Microsoft Academic Search

The Federal Aviation Administration has deployed Advanced Technology (AT) based explosive detection devices for screening checked baggage in US domestic airports. The paper addresses the application of quadrupole resonance (QR) technology to detect explosives in checked baggage in aviation security. This technology was deployed in combination with advanced X-ray by the US government. The paper focuses on the quadrupole resonance

Ed Rao; William J. Hughes

2001-01-01

299

Magnetic measurements of the 5 meter QC series quadrupoles at Lawrence Berkeley Laboratory  

SciTech Connect

From May 1991 to September 1992, magnetic measurements were performed on six 5 meter prototype SSC quadrupoles designed and built at Lawrence Berkeley Laboratory (LBL). In addition, one of the quadrupoles was disassembled, reassembled and remeasured. The purpose of this paper is to review the magnetic measurements program and give an summary of some of the results of the magnet testing.

Barale, P.; Benjegerdes, B.; Caspi, S.; Green, M.I.; Lietzke, A.; Schermer, R.; Taylor, C.; Van Dyke, D.

1993-05-01

300

Friction in nuclear dynamics  

SciTech Connect

The problem of dissipation in nuclear dynamics is related to the breaking down of nuclear symmetries and the transition from ordered to chaotic nucleonic motions. In the two extreme idealizations of the perfectly Ordered Regime and the fully Chaotic Regime, the nucleus should behave as an elastic solid or an overdamped fluid, respectively. In the intermediate regime a complicated visco-elastic behaviour is expected. The discussion is illustrated by a simple estimate of the frequency of the giant quadrupole resonance in the Ordered Regime and by applications of the wall and window dissipation formulae in the Chaotic Regime. 51 refs.

Swiatecki, W.J.

1985-03-01

301

Understanding Planetesimals  

NASA Astrophysics Data System (ADS)

Planetesimals represent turning points in planetary formation, when the materials required for building planets are first incorporated into bodies with radii from tens to hundreds of kilometers or larger, and are sometimes differentiated into metallic cores and silicate mantles. These early celestial bodies are the accretionary step between the dust of the planetary nebula and the cadre of rocky planets. Thus, planetesimals hold the keys to understanding how Earth was formed, when water was deposited on Earth, and why Earth and other rocky planets may differ in composition.

Elkins-Tanton, Linda T.

2014-03-01

302

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

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

303

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

304

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

305

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

306

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

307

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

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

308

A new insight on the structural changes of linear quadrupole liquids  

NASA Astrophysics Data System (ADS)

Molecular-dynamics simulations for linear quadrupole liquids are presented. The study is carried out for two different molecular lengths at constant density and a number of temperatures and quadrupole moments. All the simulated thermodynamic states correspond to the condensed phases and some of them show typical features of a solid structure. Furthermore, a change on the preferred intermolecular orientation in the liquid phase is observed from a shifted parallel molecular arrangement to a perpendicular orientation as the quadrupole raises. This change depends on the quadrupole moment as well as on the molecular length and is put in relation with the solid structure of different "diatomic" molecules such as nitrogen, ethane, and acetylene. The appearance of a plastic solid phase at low quadrupole moment and density is also justified. A thoroughly discussion about the availability of classical perturbation theories for this kind of systems is presented.

Cortada, María; Calero, Sofia; Lago, Santiago

2005-11-01

309

Quadrupole Collectivity in GERMANIUM-72, Palladium -110, and ERBIUM-168.  

NASA Astrophysics Data System (ADS)

Quadrupole collective properties of three nuclei, ('72)Ge, ('110)Pd and ('168)Er have been studied by Coulomb excitation using heavy-ion beams such as ('16)O, ('40)Ca, ('58)Ni and ('208)Pb. Deexcitation gamma rays in coincidence with both the scattered projectiles and recoiling target nuclei were detected over a wide range of scattering angles, to measure the Coulomb excitation cross-sections. The Coulomb excitation code GOSIA was used to extract the E2 matrix elements in a model-independent way. Almost a complete set of E2 matrix elements for low-lying levels has been measured for the nuclei ('72)Ge, ('110)Pd and ('168)Er. A direct measurement has been performed of the lifetimes of 8 levels in ('110)Pd using the Recoil Distance Method. The excellent agreement with the Coulomb excitation results proves the correctness of the method used to analyze Coulomb excitation experiments. In ('72)Ge, 14 E2 matrix elements have been determined and limits for 7 matrix elements have been found. These include: 4 transition in-band matrix elements, 5 diagonal matrix elements and 12 inter-band matrix elements. After correcting the ground 0('+) state for mixing with an intruder 0('+) state, the E2 matrix elements in the ground and gamma bands can be explained by quadrupole collective motion, with shape parameters (gamma)(DBLTURN)28.5(DEGREES) and (beta)(DBLTURN)0.30. In ('110)Pd the measured lifetimes together with Coulomb excitation results gave new spectroscopic information about low-lying states, which now can be arranged into collective rotational bands based on the ground, 2(,2)('+), 0(,2)('+) and 0(,3)('+) states, and having deformation (gamma)(DBLTURN)18(DEGREES) and (beta) from 0.21 to 0.36. For the nucleus ('168)Er, 54 E2 matrix elements have been determined. These include: 9 transition ground -band matrix elements, 7 diagonal ground-band matrix elements, 14 transition gamma-band matrix elements, 5 diagonal gamma -band matrix elements and 21 inter-band matrix elements between the ground and gamma bands. No significant deviations from the correlations predicted by the rotational model have been found. In the three cases studied, i.e. ('72)Ge, ('110)Pd and ('168)Er, the E2 data exhibit strong correlations, which shows that collective quadrupole motion is the dominant feature of low-lying spectra in all three nuclei.

Kotlinski, Bohdan

310

COMPENSATION OF FAST KICKER ROLLS WITH SKEW QUADRUPOLES  

SciTech Connect

The development of the third generation light sources lead to the implementation of the top-up operation, when injection occurs while users collect data. The beam excursions due to the non-closure of the injection bump can spoil the data and need to be suppressed. In the horizontal plane compensation can be achieved by adjusting timing and kick amplitudes. The rolls of the kicker magnets create non-closure in the vertical plane and usually there is no means for correction. In the paper we describe proposed compensation scheme utilizing two skew quadrupoles placed inside the injection bump. The third generation light sources implement top-up operation firstly introduced at Advanced Photon Source. In this mode the circulating beam current is supported near constant by frequent injection of small charge, while photon beam is delivered for users. The beam perturbations caused by the mismatched injection bump can provide undesired noise in the user data. Usually the injection trigger is distributed to the users end stations so that those affected would be able to blank data acquisition. Nevertheless, as good operational practice such transients should be suppressed as much as possible. In the horizontal plane (which is commonly used for injection) one can adjust individual kicker strength as well as trigger delay while observing motion of the stored beam centroid. In the vertical plane such means are unavailable in the most cases. The possible solutions include dedicated weak vertical kickers and motorized adjustment of the roll angle of the injection kickers. Both abovementioned approaches are expensive and can significantly deteriorate reliability. We suggest two employ two skew quadrupoles (to correct both angle and position) placed inside the injection bump. In this case the beam position itself serves as measure of the kicker strength (assuming that kickers are well matched) and vertical kicks from the skew quadrupoles will be self synchronized with injection bump. In this paper we will consider the case when injection hardware (kickers and septa) are located in the same straight. Such an approach simplifies consideration but it can be generalized.

Pinayev, I.

2011-03-28

311

Understanding ayurveda.  

PubMed

Ayurveda needs to achieve its full potential both in India and globally. This requires imparting to its students full appreciation of Ayurveda's power and strength, particularly proper understanding of the advantages of applying it to treat chronic and acute diseases. To this end, we explain the necessity of learning Sanskrit as a medium of study, and the advantages of learning the Texts in the traditional way, rather than relying on translations with all the loss of meaning and precision, which that entails. We emphasize the use of Triskandhakosha as a means to fully understand Ayurveda fundamental concepts and technical terms, so that all their shades of meaning are fully understood, and all their usages given in different places in the texts. Only by such methods can full appreciation of Ayurvedic wisdom be achieved, and the full depth and power of its knowledge be applied. Only then will its true status among systems of medicine come to be appreciated, either in India or more widely in the world as a whole. PMID:21829307

Gadgil, Vaidya Dilip

2010-01-01

312

Quasiclassical description of bremsstrahlung accompanying alpha decay including quadrupole radiation  

E-print Network

We present a quasiclassical theory of alpha decay accompanied by bremsstrahlung with a special emphasis on the case of 210Po, with the aim of finding a unified description that incorporates both the radiation during the tunneling through the Coulomb wall and the finite energy E_gamma of the radiated photon up to E_gamma on the order of Q_alpha/sqrt(eta), where Q_alpha is the alpha-decay Q-value and eta is the Sommerfeld parameter. The corrections with respect to previous quasiclassical investigations are found to be substantial, and excellent agreement with a full quantum mechanical treatment is achieved. Furthermore, we find that a dipole-quadrupole interference significantly changes the alpha-gamma angular correlation. We obtain good agreement between our theoretical predictions and experimental results.

U. D. Jentschura; A. I. Milstein; I. S. Terekhov; H. Boie; H. Scheit; D. Schwalm

2006-06-02

313

Quasiclassical description of bremsstrahlung accompanying {alpha} decay including quadrupole radiation  

SciTech Connect

We present a quasiclassical theory of {alpha} decay accompanied by bremsstrahlung with a special emphasis on the case of {sup 210}Po, with the aim of finding a unified description that incorporates both the radiation during the tunneling through the Coulomb wall and the finite energy E{sub {gamma}} of the radiated photon up to E{sub {gamma}}{approx}Q{sub {alpha}}/{radical}({eta}), where Q{sub {alpha}} is the {alpha}-decay Q-value and {eta} is the Sommerfeld parameter. The corrections with respect to previous quasiclassical investigations are found to be substantial, and excellent agreement with a full quantum mechanical treatment is achieved. Furthermore, we find that a dipole-quadrupole interference significantly changes the {alpha}-{gamma} angular correlation. We obtain good agreement between our theoretical predictions and experimental results.

Jentschura, U. D. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany); Institut fuer Theoretische Physik, Philosophenweg 16, D-69120 Heidelberg (Germany); Milstein, A. I.; Terekhov, I. S. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany); Budker Institute of Nuclear Physics, RU-630090 Novosibirsk (Russian Federation); Boie, H.; Scheit, H.; Schwalm, D. [Max-Planck-Institut fuer Kernphysik, Postfach 103980, D-69029 Heidelberg (Germany)

2008-01-15

314

Quadrupole-octupole coupled states in {sup 112}Cd  

SciTech Connect

The properties of negative-parity states in the 2.5 MeV region in {sup 112}Cd have been investigated with the (n,n{sup {prime}}{gamma}) reaction. For many of these levels, lifetimes have been measured, and B(E1) and B(E2) values for their decays have been determined. Several transitions exhibit enhanced B(E2) values for decay to the 3{sub 1}{sup {minus}} octupole state, indicative of quadrupole-octupole coupled (2{sup +}{circle_times}3{sup {minus}}) states. The B(E1) values observed are typically in the range of 1{endash}5{times}10{sup {minus}4} Weisskopf units (W.u.), irrespective of the final state. {copyright} {ital 1999} {ital The American Physical Society}

Garrett, P.E.; McGrath, C.A.; Yeh, M.; Yates, S.W. [University of Kentucky, Lexington, Kentucky 40506-0055 (United States)] [University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Garrett, P.E. [Lawrence Livermore National Laboratory, L-414, P.O. Box 808, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, L-414, P.O. Box 808, Livermore, California 94550 (United States); Lehmann, H.; Jolie, J. [Institut de Physique, Universite de Fribourg, Perolles, CH-1700 Fribourg (Switzerland)] [Institut de Physique, Universite de Fribourg, Perolles, CH-1700 Fribourg (Switzerland)

1999-05-01

315

Neutron-dominant quadrupole collective motion in {sup 16}C  

SciTech Connect

Inelastic proton scattering to the 2{sub 1}{sup +} state of neutron-rich {sup 16}C is studied in inverse kinematics using a 33-MeV/nucleon beam. The deformation parameter {beta}{sub pp{sup '}}=0.47(5) obtained is consistent with the global systematics of even-even nuclei, based on the homogeneous quantum liquid-drop model. This result contrasts that of a recent lifetime measurement for the 2{sub 1}{sup +} state in {sup 16}C, where an anomalously reduced E2 transition strength is observed. A combination of these two results yields a large M{sub n}/M{sub p} ratio of about 7, indicating a dominant neutron contribution to the quadrupole collectivity.

Ong, H.J.; Sakurai, H.; Iwasaki, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Imai, N.; Aoi, N.; Gomi, T.; Ishihara, M.; Kubo, T.; Michimasa, S.; Minemura, T.; Motobayashi, T.; Takeuchi, S.; Yamada, K.; Yanagisawa, Y.; Yoneda, K. [RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Dombradi, Zs.; Fueloep, Z.S. [ATOMKI, H-4001, Debrecen, P.O. Box 51 (Hungary); Saito, A.; Baba, H.; Notani, M. [CNS, University of Tokyo, RIKEN Campus, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)] (and others)

2006-02-15

316

Plasma-beam traps and radiofrequency quadrupole beam coolers.  

PubMed

Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented. PMID:24593614

Maggiore, M; Cavenago, M; Comunian, M; Chirulotto, F; Galatà, A; De Lazzari, M; Porcellato, A M; Roncolato, C; Stark, S; Caruso, A; Longhitano, A; Cavaliere, F; Maero, G; Paroli, B; Pozzoli, R; Romé, M

2014-02-01

317

Radio-frequency quadrupole: A new linear accelerator  

NASA Astrophysics Data System (ADS)

The radio frequency quadrupole (RFQ) linear accelerator is discussed. In the RFQ, the use of RF electric fields for radial focusing, combined with special programming of the bunching, allows high current dc beams to be captured and accelerated with only small beam loss and low radial emittance growth. Advantages of the RFQ linac include a low injection energy (20 to 50 keV for protons) and a final energy high enough so the beam can be further accelerated with high efficiency in a Wideroee or Alvarez linac. The beam dynamics parameters of three RFQ systems are described. These are the final design for the prototype test of the Fusion Materials Irradiation Test accelerator, the final design for the prototype test of the Pion Generator for Medical Irradiations, and an improved low velocity linac for heavy ion fusion.

Stokes, R. H.; Wangler, T. P.; Crandall, K. R.

318

The Dynamic Aperture of an Electrostatic Quadrupole Lattice  

SciTech Connect

In heavy-ion-driven inertial fusion accelerator concepts, dynamic aperture is important to the cost of the accelerator, most especially for designs which envision multibeam linacs, where extra clearance for each beam greatly enlarges the transverse scale of the machine. In many designs the low-energy end of such an accelerator uses electrostatic quadrupole focusing. The dynamic aperture of such a lattice has been investigated here for intense, space-charge-dominated ion beams using the 2-D transverse slice version of the 3-D particle-in-cell simulation code WARP. The representation of the focusing field used is a 3-D solution of the Laplace equation for the biased focusing elements, as opposed to previous calculations, which used a less-accurate multipole approximation. 80-85% radial filling of the aperture is found to be possible. Results from the simulations, as well as corroborating data from the High Current Experiment at LBNL, are presented.

Celata, C.M.; Bieniosek, F.M.; Prost, L.; Seidl, P.A.; Friedman,A.; Grote, D.P.

2005-05-01

319

Investigation of a quadrupole ultra-high vacuum ion pump  

NASA Technical Reports Server (NTRS)

The new nonmagnetic ion pump resembles the quadrupole ionization gage. The dimensions are larger, and hyperbolically shaped electrodes replace the four rods. Their surfaces follow y sq. = 36 + x sq. (x, y in centimeters). The electrodes, 55 cm long, are positioned lengthwise in a tube. At one end a cathode emits electrons; at the other end a narrowly wound flat spiral of tungsten clad with titanium on cathode potential can be heated for titanium evaporation. Electrons accelerated by a dc potential of the surface electrodes oscillate between the ends on rotational trajectories, if a high frequency potential superimposed on the dc potential is properly adjusted. Pumping speeds (4-100 liter/sec) for different gases at different peak voltages (1000-3000V) at corresponding frequencies (57-100 MHz), and at different pressures 0.00001 to the minus 9 power Torr were observed. The lowest pressure reached was below 10 to the minus 10 power Torr.

Schwarz, H. J.

1974-01-01

320

Quadrupole moments of rotating neutron stars and strange stars  

NASA Astrophysics Data System (ADS)

We present results for models of neutron stars and strange stars constructed using the Hartle-Thorne slow-rotation method with a wide range of equations of state, focusing on the values obtained for the angular momentum J and the quadrupole moment Q, when the gravitational mass M and the rotational frequency ? are specified. Building on previous work, which showed surprising uniformity in the behaviour of the moment of inertia for neutron-star models constructed with widely different equations of state, we find similar uniformity for the quadrupole moment. These two quantities, together with the mass, are fundamental for determining the vacuum space-time outside neutron stars. We study particularly the dimensionless combination of parameters QM/J2 (using units for which c = G = 1). This quantity goes to 1 in the case of a Kerr-metric black hole and deviations away from 1 then characterize the difference between neutron-star and black hole space-time. It is found that QM/J2 for both neutron stars and strange stars decreases with increasing mass, for a given equation of state, reaching a value of around 2 (or even less) for maximum-mass models, meaning that their external space-time is then not very far from that of the Kerr metric. If QM/J2 is plotted against R/2M (where R is the radius), it is found that the relationship is nearly unique for neutron-star models, independent of the equation of state, while it is significantly different for strange stars. This gives a new way of possibly distinguishing between them.

Urbanec, M.; Miller, J. C.; Stuchlík, Z.

2013-08-01

321

Understanding Leukemias  

NSDL National Science Digital Library

This tutorial is designed to aid medical students at all levels understand the laboratory diagnosis of leukemias. It includes introductory material on the basic laboratory tests specific to diagnoses, their general application and pitfalls in interpretation. The introductory material is followed by a series of short clinical vignettes illustrating the major categories of leukemia. This tutorial focuses on diagnosis and relative little on treatment is included. QuickTime movie player, Flash player and Java script runtime plug-in scripts are required for some pages. The tutorial concludes with a short self-help quiz covering the major points developed. The plug-ins noted above are available free at the following sites: http://www.apple.com/quicktime/download/win.html and http://www.sun.com/ . Questions should be directed to Dr. Mark Braun; braunm@indiana.edu.Annotated: falseDisease diagnosis: neoplastic

Braun, Mark

2009-11-09

322

Nuclear Chemistry Beta decay of 71,73  

E-print Network

of primary interest are the nuclear magnetic dipole moment and nuclear electric quadrupole moment. The dipole way to deduce the electromagnetic moments of nuclei is via Collinear Laser Spectroscopy (CLS). The CLS. Methods Phys. Res. A 2012, 678, 114. Beta decay of nuclei around 90 Se: search for signatures of a N=56

Mantica, Paul F.

323

Ion motion in the rectangular wave quadrupole field and digital operation mode of a quadrupole ion trap mass spectrometer.  

PubMed

A quadrupolar electric field driven by a rectangular wave voltage can be used for mass-selective storage and analysis. The ion motion in such an electric field is derived, and the stability of ions is presented in the a-q diagram that is commonly used for sinusoidal wave quadrupole mass spectrometry in association with the solution of the Mathieu equation. The pseudo-potential well is discussed in an approximation that leads to the relation of secular frequency to operating parameters. A scheme for a digital ion trap mass spectrometer is described, based on this theory. An ion optics simulation was performed to check the theory of resonant ejection, and to prove the feasibility of the mass scan method for a practical ion trap of such geometry. PMID:16308895

Ding, L; Kumashiro, S

2006-01-01

324

Nuclear moments in covariant density functional theory  

NASA Astrophysics Data System (ADS)

Recent progresses on microscopic and self-consistent description of the nuclear moments in covariant density functional theory based on a point-coupling interaction are briefly reviewed. In particular, the electric quadrupole moments of Cd isotopes and the magnetic moments of Pb isotopes are discussed.

Meng, J.; Zhao, P. W.; Zhang, S. Q.; Hu, J. N.; Li, J.

2014-05-01

325

Simple Bridge for Pulsed Nuclear Magnetic Resonance  

Microsoft Academic Search

An asymmetrical rf bridge for pulsed magnetic resonance experiments is described. The balancing adjustments, which can be made quickly and easily, ensure a proper impedance match to transmitter and receiver. The bridge is particularly well suited for pure nuclear quadrupole resonance experiments.

K. R. Jeffrey; R. L. Armstrong

1967-01-01

326

Electrospray Ionization Multiple Stage Quadrupole Ion-Trap and Tandem Quadrupole Mass Spectrometric Studies on Phosphatidylglycerol from Arabidopsis leaves  

PubMed Central

Phosphatidylglycerol (PG) is the major phospholipid of plant chloroplasts. PG from Arabidopsis thaliana has an unusual fatty acyl chain, 3-trans-hexadecenoyl (?316:1) in the sn-2 position of the major 18:3/?316:1-PG species, as well as in 18:2/?316:1-PG and 16:0/?316:1-PG. Upon low-energy collisionally activated dissociation (CAD) in a tandem quadrupole or in an ion-trap mass spectrometer, the [M – H]? ions of the PG molecules containing ?316:1 give product-ion spectra that are readily distinguishable from those arising from PGs without the ?316:1 species. The ?316:1-fatty acyl-containing PGs are characterized by MS2 product-ion mass spectra that contain predominant [M – H – 236]? ions arising from loss of the ?316:1-fatty acyl substituent as a ketene. This is attributable to the fact that the ?-hydrogen of the ?316:1-fatty acid substituent involved in the ketene loss is an allylic hydrogen, which is very labile. This leads to preferential neutral loss of 236 and drastic decline in the neutral loss of 254 (i.e., loss as a fatty acid), the unique features that signify the presence of ?316:1-fatty acyl containing PGs. The neutral loss scan of 236, thus provides a sensitive tandem quadrupole mass spectrometric means to identify ?316:1-containing PG species in lipid mixtures. This low-energy tandem mass spectrometric approach also permits the structures of the Arabidopsis PGs that consist of two isomeric structures to be unveiled. PMID:17303435

Hsu, Fong-Fu; Turk, John; Williams, Todd D.; Welti, Ruth

2009-01-01

327

Understanding Genetics  

NSDL National Science Digital Library

While most people may retain a smattering of information and basic concepts about the field of genetics, some may also wish to refresh their knowledge base, and the Understanding Genetics website is a fine way to get back up to speed. Created and maintained by the good people at the Tech Museum of Innovation in San Jose, the homepage is well thought out, and provides a nice entry point to many of the features available here. Visitors can peruse the questions posed to geneticists in the "Ask a Geneticist" feature, browse a selection of recent news stories regarding genetics, and take a survey on the ethical questions posed by the issues of stem cell research and genetically modified foods. The feature story is a fine resource as well, as it provides basic, non-jargon-laden answers to such question as "What is a gene?" and "How do genes work?". The site also contains a number of activities that can be done at home, including a fun exercise that teaches users how to extract DNA from strawberries.

328

Multi-spectral plasmon induced transparency via in-plane dipole and dual-quadrupole coupling.  

PubMed

We experimentally demonstrated an approach based on dipole and dual-quadrupole coupling to construct a planar metamaterial supporting multi-spectral plasmon induced transparency. The structure consists of two short silver wires (dipole) and two long silver wires (dual-quadrupole). The in-plane coupling between the dipole and the dual-quadrupole leads to two transmission windows even in the absorbance linewidth of the dipole. This phenomenon is well described and understood by numerical analyses and a classical oscillator model. PMID:24921261

Miyata, Masashi; Hirohata, Jumpei; Nagasaki, Yusuke; Takahara, Junichi

2014-05-19

329

Development of a GC/Quadrupole-Orbitrap Mass Spectrometer, Part II: New Approaches for Discovery Metabolomics.  

PubMed

Identification of unknown peaks in gas chromatography/mass spectrometry (GC/MS)-based discovery metabolomics is challenging, and remains necessary to permit discovery of novel or unexpected metabolites that may elucidate disease processes and/or further our understanding of how genotypes relate to phenotypes. Here, we introduce two new technologies and an analytical workflow that can facilitate the identification of unknown peaks. First, we report on a GC/Quadrupole-Orbitrap mass spectrometer that provides high mass accuracy, high resolution, and high sensitivity analyte detection. Second, with an "intelligent" data-dependent algorithm, termed molecular-ion directed acquisition (MIDA), we maximize the information content generated from unsupervised tandem MS (MS/MS) and selected ion monitoring (SIM) by directing the MS to target the ions of greatest information content, that is, the most-intact ionic species. We combine these technologies with (13)C- and (15)N-metabolic labeling, multiple derivatization and ionization types, and heuristic filtering of candidate elemental compositions to achieve (1) MS/MS spectra of nearly all intact ion species for structural elucidation, (2) knowledge of carbon and nitrogen atom content for every ion in MS and MS/MS spectra, (3) relative quantification between alternatively labeled samples, and (4) unambiguous annotation of elemental composition. PMID:25166283

Peterson, Amelia C; Balloon, Allison J; Westphall, Michael S; Coon, Joshua J

2014-10-21

330

Linear trap with three orthogonal quadrupole fields for dust charging experiments  

SciTech Connect

Investigations of charging processes on a single dust grain under controlled conditions in laboratory experiments are the unique way to understand the behavior of dust grains in complex plasma (in space, in laboratory, or in technological applications). An electrodynamic trap is often utilized for both holding a single grain and continuously measuring its charge-to-mass ratio. We propose a modified design of the linear quadrupole trap with the electrodes split into two parts; each of them being supplied by a designated source. The paper presents basic calculations and the results of the trap prototype tests. These tests have confirmed our expectations and have shown that the suggested solution is fully applicable for the dust charging experiments. The uncertainty of determination of the dust grain charge does not exceed 10{sup -3}. The main advantages of the suggested design in comparison with other traps used for dust investigations can be summarized as: The trap (i) is more opened, thus it is suitable for a simultaneous application of the ion and electron beams and UV source; (ii) facilitates investigations of dust grains in a broader range of parameters; and (iii) allows the grain to move along the axis in a controlled way.

Beranek, Martin; Nemecek, Zdenek; Safrankova, Jana; Jerab, Martin; Pavlu, Jiri [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Cermak, Ivo [CGC Instruments, Chemnitz (Germany)

2012-11-15

331

Factorial Experimental Designs Elucidate Significant Variables Affecting Data Acquisition on a Quadrupole Orbitrap Mass Spectrometer  

NASA Astrophysics Data System (ADS)

Instrument parameter values for a quadrupole Orbitrap mass spectrometer were optimized for performing global proteomic analyses. Fourteen factors were evaluated for their influence on data-dependent acquisition with an emphasis on both the rate of sequencing and spectral quality by maximizing two individually tested response variables (unique peptides and protein groups). Of the 14 factors, 12 factors were assigned significant contrast values ( P < 0.05) for both response variables. Fundamentally, when optimizing parameters, a balance between spectral quality and duty cycle needs to be reached in order to maximize proteome coverage. This is especially true when using a data-dependent approach for sequencing complex proteomes. For example, maximum ion injection time, automatic gain control settings, and minimum threshold settings for triggering MS/MS isolation and activation all heavily influence ion signal, the number of spectra collected, and spectral quality. To better assess the effect these parameters have on data acquisition, all MS/MS data were parsed according to ion abundance by calculating the percent of the AGC target reached for each MS/MS event and then compared with successful peptide-spectrum matches. This proved to be an effective approach for understanding the effect of ion abundance on successful peptide-spectrum matches and establishing minimum ion abundance thresholds for triggering MS/MS isolation and activation.

Randall, Shan M.; Cardasis, Helene L.; Muddiman, David C.

2013-10-01

332

Fluorescence Imaging for Visualization of the Ion Cloud in a Quadrupole Ion Trap Mass Spectrometer  

NASA Astrophysics Data System (ADS)

Laser-induced fluorescence is used to visualize populations of gaseous ions stored in a quadrupole ion trap (QIT) mass spectrometer. Presented images include the first fluorescence image of molecular ions collected under conditions typically used in mass spectrometry experiments. Under these "normal" mass spectrometry conditions, the radial ( r) and axial ( z) full-width at half maxima (FWHM) of the detected ion cloud are 615 and 214 ?m, respectively, corresponding to ~6 % of r 0 and ~3 % of z 0 for the QIT used. The effects on the shape and size of the ion cloud caused by varying the pressure of helium bath gas, the number of trapped ions, and the Mathieu parameter q z are visualized and discussed. When a "tickle voltage" is applied to the exit end-cap electrode, as is done in collisionally activated dissociation, a significant elongation in the axial, but not the radial, dimension of the ion cloud is apparent. Finally, using spectroscopically distinguishable fluorophores of two different m/ z values, images are presented that illustrate stratification of the ion cloud; ions of lower m/ z (higher q z ) are located in the center of the trapping region, effectively excluding higher m/ z (lower q z ) ions, which form a surrounding layer. Fluorescence images such as those presented here provide a useful reference for better understanding the collective behavior of ions in radio frequency (rf) trapping devices and how phenomena such as collisions and space-charge affect ion distribution.

Talbot, Francis O.; Sciuto, Stephen V.; Jockusch, Rebecca A.

2013-12-01

333

Matching an H- beam into a radio frequency quadrupole at Rutherford Appleton Laboratorya)  

NASA Astrophysics Data System (ADS)

A major component of work being carried out to upgrade the ISIS spallation neutron source at Rutherford Appleton Laboratory (RAL) is the Front End Test Stand (FETS). FETS is aimed at improving the luminosity of the linac, and consists of a Penning ion source, Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ), and Medium Energy Beam Transport (MEBT). It may serve as a first part of the accelerator chain providing a 60 mA, 3 MeV H- beam up to a 10% duty cycle. The current output of the source and the transmission of the LEBT are reasonable, but there are issues with the alignment to provide a centred beam matched into the acceptance of the RFQ. Improvements have been made to the post acceleration to address this problem. Measurements with a collimated beam have been performed to understand the behaviour of the solenoids and steerer magnets. Comparing these results with simulations proved that, besides possible mechanical imperfections of the ion source and post acceleration assembly, agreement can only be achieved if the magnetic fields are distorted.

Gabor, C.; Back, J. J.; Faircloth, D. C.; Lawrie, S. R.; Letchford, A. P.

2014-02-01

334

Rotational and magnetic shunt permanent magnet quadrupoles with variable magnetic strength  

SciTech Connect

Next Linear Collider (NLC) and Very Large Hadron Collider (VLHC) projects suppose to use permanent magnets as bending, focusing and correcting elements. Prototypes of two permanent magnet quadrupoles with variable strength were built and successfully tested in Fermilab. Quadrupoles have 12.7 mm aperture diameter, 100 T/m gradient with an adjustment range of 0 to -20%. Special designs provide high precision magnetic center stability during strength change. SmCo5 permanent magnet bricks were used in these prototypes. Rotational quadrupole consists of four sections. Two central sections are rotated in counter directions to adjust the strength. Magnetic shunt quadrupole design provides variable shunting of the magnetic flux. The numerical simulation, designs, measuring results are described.

Vladimir Kashikhin et al.

2002-03-28

335

Extended bodies in a Kerr spacetime: exploring the role of a general quadrupole tensor  

E-print Network

The equatorial motion of extended bodies in a Kerr spacetime is investigated in the framework of the Mathisson-Papapetrou-Dixon model, including the full set of effective components of the quadrupole tensor. The numerical integration of the associated equations shows the specific role of the mass and current quadrupole moment components. While most of the literature on this topic is limited to spin-induced (purely electric) quadrupole tensor, the present analysis highlights the effect of a completely general quadrupole tensor on the dynamics. The contribution of the magnetic-type components is indeed related to a number of interesting features, e.g., enhanced inward/outward spiraling behavior of the orbit and spin-flip-like effects, which may have observational counterparts. Finally, the validity limit of the Mathisson-Papapetrou-Dixon model is also discussed through explicit examples.

Donato Bini; Andrea Geralico

2014-08-23

336

Extended bodies in a Kerr spacetime: exploring the role of a general quadrupole tensor  

E-print Network

The equatorial motion of extended bodies in a Kerr spacetime is investigated in the framework of the Mathisson-Papapetrou-Dixon model, including the full set of effective components of the quadrupole tensor. The numerical integration of the associated equations shows the specific role of the mass and current quadrupole moment components. While most of the literature on this topic is limited to spin-induced (purely electric) quadrupole tensor, the present analysis highlights the effect of a completely general quadrupole tensor on the dynamics. The contribution of the magnetic-type components is indeed related to a number of interesting features, e.g., enhanced inward/outward spiraling behavior of the orbit and spin-flip-like effects, which may have observational counterparts. Finally, the validity limit of the Mathisson-Papapetrou-Dixon model is also discussed through explicit examples.

Bini, Donato

2014-01-01

337

Measurement of the quadrupole moment of the /sup 112/Sn(6/sup +/) isomer  

SciTech Connect

The quadrupole coupling constant of the /sup 112/Sn(6/sup +/) isomer in the hexagonal Cd host is measured by using the time-differential perturbed angular distribution (TDPAD) method. Values of the quadrupole coupling constants e/sup 2/qQ/h = 66.25 +- 4.00 MHz and 57.56 +- 6.90 MHz are found at 290/sup 0/ and 500/sup 0/, respectively. The quadrupole moment of the 6/sup +/ state in /sup 112/Sn is derived in terms of the electric field gradient for Sn in Cd given by Herrlander. The deduced quadrupole moment Q is 0.29 +- 0.07b. The simple shell model estimate shows that the /sup 112/Sn(6/sup +/) state is possibly a mixed configuration of ( g/sup 6//sub 7/2/)6/sup +/ and ( g/sup 7//sub 7/2/xd/sup 5//sub 5/2/)6/sup +/.

ZHU Shengyun; DONG Mingli; SHEN Weiqi

1985-04-01

338

Design and operation of a laminar-flow electrostatic-quadrupole-focused acceleration column  

SciTech Connect

This report deals with the design principles involved in the design of a laminar-flow electrostatic-quadrupole-focused acceleration column. In particular, attention will be paid to making the parameters suitable for incorporation into a DC MEQALAC design.

Maschke, A.W.

1983-06-20

339

Photoionization of Ca 4s in a spherical attractive well potential: dipole, quadrupole and relativistic effects  

NASA Astrophysics Data System (ADS)

A study of the outer 4s subshell of the Ca atom in a spherical attractive potential well (SAW) of variable depth is performed to determine the effect of an external potential on dipole (E1) and quadrupole (E2) photoionization processes. As the depth of the potential well increases, dramatic changes are observed in the 4s cross-section, as well as in the photoelectron angular distribution. The existence of Cooper minima in the 4s dipole channels give rise to very significant effects of quadrupole interactions, even at extremely low energies, in the vicinity of the E1 Cooper minimum. It is shown that the entrapment of Ca in a spherical attractive well (Ca@SAW) further enhances the importance of quadrupole interactions determining the photoionization parameters. The complicated behavior of both dipole and quadrupole Cooper minima, as functions of well depth, is delineated, along with the importance of relativistic effects.

Kumar, Ashish; Varma, Hari R.; Pradhan, Gagan B.; Deshmukh, Pranawa C.; Manson, Steven T.

2014-09-01

340

DEVELOPMENT AND TEST OF COLLARING METHODS FOR Nb{sub 3}SN QUADRUPOLE MAGNETS  

SciTech Connect

Fermilab is developing Nb{sub 3}Sn quadrupole magnets for the planned upgrade of interaction regions of the Large Hadron Collider (LHC). Two distinctly different approaches have been employed, one using quadrupole-symmetric and one using dipole-symmetric collar laminations. This paper describes the design features of both collar types, collaring techniques for brittle Nb{sub 3}Sn coils, and compares the advantages and disadvantages of the two approaches. Results of mechanical analysis for quadrupoles based on dipole-type and quadrupole-type collars are presented. Magnet construction issues and test results are reported. Test results include coil and component strain measurements during construction. Plans for the completion and test of the first dipole-symmetric assembly are described.

Bossert, R.; Ambrosio, G.; Andreev, N.; Chlachidze, G.; Kashikhin, V. V.; Lamm, M.; Nobrega, F.; Novitski, I.; Tartaglia, M.; Yu, M.; Zlobin, A. V. [Fermi National Accelerator Laboratory, Batavia, Il. 60510 (United States)

2010-04-09

341

Efficient computation of the quadrupole light deflection in the Gaia relativity model  

E-print Network

Efficient computation of the quadrupole light deflection for both stars/quasars and solar system objects within the framework of the baseline Gaia relativity model (GREM) is discussed. Two refinements have been achieved with the goal to improve the performance of the model: -- The quadrupole deflection formulas for both cases are simplified as much as possible considering the Gaia nominal orbit (only approximate minimal distances between Gaia and the giant planets were used here), physical parameters of the giant planets and the envisaged accuracy of 1 \\muas for individual systematic effects. The recommended formulas are given by Eq. (\\ref{light_185}) for stars/quasars and by Eq. (\\ref{source_180}) for solar system objects. -- Simple expressions for the upper estimate of the quadrupole light deflection have been found allowing, with a few additional arithmetical operations, to judge a priori if the quadrupole light deflection should be computed or not for a given source and for a given requested accuracy. The...

Zschocke, Sven

2009-01-01

342

Set Up and Test Results for a Vibrating Wire System for Quadrupole Fiducialization  

SciTech Connect

Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of a quadrupole. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing it. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). The following break up of error was suggested for the fiducialization steps: 10{micro}m for step 1 (finding the center), 20{micro}m for step 2 (finding the wire), and 10{micro}m for step 3 (tooling ball measurements). The purpose of this study is to investigate whether the vibrating wire system meets the requirements for LCLS. In particular, if it can reliably fiducialize a quadrupole magnetic center to within 25{micro}m in both vertical and horizontal directions. The behavior of individual system components is compared to the expected performance. A vibrating wire system was constructed to fiducialize the quadrupoles between undulator segments in the LCLS. This note studies the ability of the system to fulfill the fiducialization requirements.

Levashov, Michael Y.

2010-12-01

343

Set Up and Test Results for a Vibrating Wire System for Quadrupole Fiducialization  

SciTech Connect

Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of a quadrupole. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing it. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). The following break up of error was suggested for the fiducialization steps: 10{micro}m for step 1 (finding the center), 20{micro}m for step 2 (finding the wire), and 10{micro}m for step 3 (tooling ball measurements). The purpose of this study is to investigate whether the vibrating wire system meets the requirements for LCLS. In particular, if it can reliably fiducialize a quadrupole magnetic center to within 25{micro}m in both vertical and horizontal directions. The behavior of individual system components is compared to the expected performance. A vibrating wire system was constructed to fiducialize the quadrupoles between undulator segments in the LCLS. This note studies the ability of the system to fulfill the fiducialization requirements.

Not Available

2010-11-29

344

Ion injection and activation in the quadrupole ion trap mass spectrometer  

SciTech Connect

The goal of this thesis is to provide understanding concerning ion injection and ion activation in the quadrupole ion trap mass spectrometer. Ion trap mass spectrometry has a variety of applications concerned with the analysis large proteins and biomolecules. However, such experiments have been plagued by limited mass measurement accuracy as ions are not ejected in a predictable manner. Examination of the solution to the [open quotes]forced[close quotes], [open quotes]damped[close quotes] Mathieu equation and an understanding of the behavior of ions under the influence of space charge allow a qualitative prediction of ion behavior and such predictions have a direct outcome on the ability to perform experiments with high mass accuracy. For ions which are sufficiently separated in m/z ratio, mass measurement errors occur as a result of off-resonance energy absorption by the ion which leads to early ejection of the ion, while errors for ions which are in close proximity, [le]1 da/charge separation, result from combination of off-resonance absorption and the presence of space charge conditions which lead to irregular peak separations. However, the analysis of large biomolecules requires the efficient collection of ions injected into the trap and energy deposition processes which were not typically available. The use of a combination of the helium buffer gas with a small amount of a heavier mass target effects both the trapping efficiency and the deposition of much higher internal energies in the selected ion without deleterious effects of ion loss due to scattering. For ions with m/z ratios greater than 8000 da/charge the use of buffer mixtures is shown to increase the trapping efficiency by as much as 200%. In addition, collision-induced dissociation experiments performed on thermometer-type species, such as pyrene, confirm that up to 23 volts of internal energy may be deposited in a single MS/MS experiment and should be applicable for the dissociation of biomolecules.

Morand, K.L.

1992-01-01

345

Permanent Magnet Skew Quadrupoles for the Low Emittance LER Lattice of PEP-II  

SciTech Connect

The vertical emittance of the low energy ring (LER) in the PEP-II B-Factory was reduced by using skew quadrupoles consisting of permanent magnet material. The advantages over electric quadrupoles or rotating existing normal quadrupoles are discussed. To assure a high field quality, a Biot-Savart calculation was used to cancel the natural 12-pole component by using different size poles over a few layers. A magnetic measurement confirmed the high quality of the magnets. After installation and adjusting the original electric 12 skew and 16 normal quadrupoles the emittance contribution from the region close to the interaction point, which was the biggest part in the original design, was considerably reduced. To strengthen the vertical behavior of the LER beam, a low emittance lattice was developed. It lowered the original vertical design emittance from 0.54 nm-rad to 0.034 nm-rad. In order to achieve this, additional skew quadrupoles were required to bring the coupling correction out of the arcs and closer to the detector solenoid in the straight (Fig. 1). It is important, together with low vertical dispersion, that the low vertical emittance is not coupled into the horizontal, which is what we get if the coupling correction continues into the arcs. Further details of the lattice work is described in another paper; here we concentrate on the development of the permanent skew (PSK) quadrupole solution. Besides the permanent magnets there are two other possibilities, using electric magnets or rotating normal quadrupoles. Electric magnets would have required much more additional equipment like magnets stands, power supply, and new vacuum chamber sections. Rotating existing quadrupoles was also not feasible since they are mostly mounted together with a bending magnet on the same support girder.

Decker, F.-J.; Anderson, S.; Kharakh, D.; Sullivan, M.; /SLAC

2011-07-05

346

Performance of Nb3Sn quadrupole magnets under localized thermal load  

SciTech Connect

This paper describes the results of design and analyses performed on 120-mm Nb{sub 3}Sn and NbTi quadrupole magnets with parameters relevant for the LHC IR upgrade. A realistic radiation heat load is evaluated in a wide luminosity range and translated into the magnet quench performance. The simulation results are supported by thermal measurements on a 90-mm Nb{sub 3}Sn quadrupole coil.

Kashikhin, V.V.; Bossert, r.; Chlachidze, G.; Lamm, M.; Mokhov, N.V.; Novitski, I.; Zlobin, A.V.; /Fermilab

2009-06-01

347

PERFORMANCE OF NB{sub 3}SN QUADRUPOLE MAGNETS UNDER LOCALIZED THERMAL LOAD  

SciTech Connect

This paper describes the results of design and analyses performed on 120-mm Nb{sub 3}Sn and NbTi quadrupole magnets with parameters relevant for the LHC IR upgrade. A realistic radiation heat load is evaluated in a wide luminosity range and translated into the magnet quench performance. The simulation results are supported by thermal measurements on a 90-mm Nb{sub 3}Sn quadrupole coil.

Kashikhin, V. V.; Bossert, R.; Chlachidze, G.; Lamm, M.; Mokhov, N. V.; Novitski, I.; Zlobin, A. V. [Fermi National Accelerator Laboratory, Batavia, IL, 60510 (United States)

2010-04-09

348

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-print Network

LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY December 2003 Major Subject: Physics LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV Submitted to Texas A&M University in partial fulfillment of the requirements...

Ryjkov, Vladimir Leonidovich

2005-02-17

349

The use of a triple quadrupole linear ion trap mass spectrometer with electrospray ionisation for fragmentation studies of selected antifungal drugs.  

PubMed

Fragmentation studies of three antifungal drugs, clotrimazole, fluconazole and clioquinol ,were performed. A triple quadrupole linear ion trap mass spectrometer was used for this purpose. This type of equipment enables MS(3) spectra to be obtained which lead to better understanding of fragmentation pathways. Nevertheless, it is rarely used for fragmentation studies. The results obtained here for the antifungal drugs gave further insight into fragmentation pathways of clotrimazole and fluconazole. Moreover, fragmentation of clioquinol was investigated which had not been presented before. PMID:21953959

Zgo?a-Grze?kowiak, Agnieszka; Grze?kowiak, Tomasz

2011-10-30

350

Electromagnetic Moments of Neutron-rich Nuclei Studied with Polarized Radioactive Nuclear Beams  

Microsoft Academic Search

Taking advantage of spin-polarized radioactive nuclear beams obtained from the projectile fragmentation reaction, magnetic moments and electric quadrupole moments have been studied at RIKEN for light-mass neutron-rich nuclei. In this paper we report on recent results obtained for the electric quadrupole moment Q of ^17B and the magnetic moment mu of ^17C nuclei, measured with the beta-detected NMR technique. The

K. Asahi; H. Ogawa; H. Miyoshi; D. Kameda; K. Yogo; A. Goto; T. Suga; K. Sakai; H. Ueno; H. Watanabe; W. Sato; Y. Kobayashi; A. Yoshimi; A. Yoshida; T. Kubo; M. Ishihara; N. Imai; Y. X. Watanabe; K. Yoneda; N. Fukuda; N. Aoi; W.-D. Schmidt-Ott; G. Neyens; S. Teughels

2001-01-01

351

Coulomb and nuclear breakup of 8B  

NASA Astrophysics Data System (ADS)

The cross sections for the (8B,7Be-p) breakup reaction on 58Ni and 208Pb targets at the beam energies of 25.8 MeV and 415 MeV have been calculated within a one-step prior-form distorted-wave Born approximation. The relative contributions of Coulomb and nuclear breakup of dipole and quadrupole multipolarities as well as their interference have been determined. The nuclear breakup contributions are found to be substantial in the angular distributions of the 7Be fragment for angles in the range of 30°-80° at 25.8 MeV beam energy. The Coulomb-nuclear interference terms make the dipole cross section larger than that of quadrupole even at this low beam energy. However, at the incident energy of 415 MeV, these effects are almost negligible in the angular distributions of the (7Be-p) coincidence cross sections at angles below 4°.

Shyam, R.; Thompson, I. J.

1999-05-01

352

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

SciTech Connect

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 electrodes 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.

Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard; Startsev, Edward A.; Wang, Hua [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Koppell, Stewart [University of Texas at Austin, Austin, Texas 78712 (United States)] [University of Texas at Austin, Austin, Texas 78712 (United States); Talley, Matthew [Brigham Young University, Provo, Utah 84602 (United States)] [Brigham Young University, Provo, Utah 84602 (United States)

2013-05-15

353

Simulation of Ions Confined by Quadrupole Electric Fields  

NASA Astrophysics Data System (ADS)

Computer simulations are routinely used to develop physical insight into ionic systems confined by static and time-varying quadrupole electric fields. However, after nearly 30 years of numerical exploration, three questions remain: which numerical techniques produce accurate simulations for the least computational expense? How can thermal equilibrium initial conditions be generated? How should temperature be calculated? Trapped ion simulations generally employ molecular dynamics techniques, where ion trajectories are numerically calculated at discrete points in time. While many numerical methods have been applied to these systems, it is unclear which technique is fastest or what time-step is required. In this work, the computational speed of and time-step for 11 commonly used techniques are assessed through analysis of four numerical error components. The most rapid method and required step-size depend strongly on the system parameters, with any one of the Beeman, Gear6, 5th-order Adams-Bashforth-Moulton, or 4th-order Runge-Kutta algorithms proving most appropriate. The 11 algorithms are then applied to a realistic multi-ion system and verify that the four tests accurately predict the required step size. When equilibrium properties are desired, simulations should commence from initial conditions that conform closely to thermal equilibrium; however little has been published on initial condition generation and assessment for the multi-ion system. A method is presented for generating thermal equilibrium via laser cooling and recoil heating, a ramp-down stage, where the heating and cooling are gradually reduced, and an equilibration phase where the ensemble is evolved under only the trapping forces. Furthermore, it is demonstrated that thermal equilibrium can be assessed using well-known tests of distribution normality. When time-varying fields are present, temperature calculation becomes difficult, as the ion motion contains both thermal and nonthermal components. The literature describes four temperature calculation procedures for multi-ion simulation; however neither their accuracy nor mathematical underpinnings have been addressed. In this work, through detailed derivations, numerical calculations, and simulations, their accuracy is determined for a wide range of parameters. Furthermore, by extending an existing temperature calculation technique, a new method is created and is shown to be highly accurate while requiring low computational expense.

Cummings, Michael David

354

Rotating dipole and quadrupole field for a multiple cathode system  

SciTech Connect

A multiple cathode system has been designed to provide the high average current polarized electron bunches for the future electron-ion collider eRHIC [1]. One of the key research topics in this design is the technique to generate a combined dipole and quadrupole rotating field at high frequency (700 kHz). This type of field is necessary for combining bunches from different cathodes to the same axis with minimum emittance growth. Our simulations and the prototype test results to achieve this will be presented. The future eRHIC project, next upgrade of EHIC, will be the first electron-heavy ion collider in the world. For polarized-electron and polarized proton collisions, it requires a polarized electron source with high average current ({approx}50 mA), short bunch ({approx}3 mm), emittance of about 20 {micro}m and energy spread of {approx}1% at 10 MeV. The state-of-art polarized electron cathode can generate average current of about more than 1 mA, but much less than 50 mA. The current is limited by the quantum efficiency, lifetime, space charge and ultra-high vacuum requirement of the polarized cathode. A possible approach to achieve the 50 mA beam is to employ multiple cathodes, such as 20 cathodes, and combine the multiple bunched beams from cathodes to the same axis. We name it as 'Gatling gun' because its operations bear similarity to a multi-barrel Gatling gun. The electron spin direction is not affected by electric field but will follow to the direction of the magnetic bending. This requires that, to preserve the spin polarization from cathode, the fixed bending field after the solenoid and the rotating bending field in combiner must be either a pair of electric bendings or a pair of magnetic bendings. We choose the scheme with a pair of magnetic bendings because it is much easier than the scheme with a pair of electric bendings at our 200 keV electron energy level.

Chang, X.; Ben-Zvi, I.; Kewisch, J.; Litvinenko, V.; Meng, W.; Pikin, A.; Ptitsyn, V.; Rao, T.; Sheehy, B.; Skarita, J.; Wang, E.; Wu, Q.; Xin, T.

2011-03-28

355

Alignment of Magnetic Elements in the Quadrupole-Corrector Assemblies for the RHIC Interaction Region  

NASA Astrophysics Data System (ADS)

Three strong focussing quadrupoles of 13cm aperture are located on either side of the six crossing points in RHIC. These quadrupoles, with magnetic lengths of 1.44m, 3.40m and 2.10m, are referred to as the Q1, Q2 and Q3 magnets respectively. In order to compensate for the field errors in these quadrupoles, various styles of lumped correctors are used. The Q2 magnets are attached to one such corrector magnet to form a single assembly. Similarly, one corrector is attached to each end of the Q3 magnets. The magnetic center of each corrector should be aligned within 0.25mm of the magnetic axis of the quadrupole to which it is attached. It was not always possible to achieve this tolerance with the production fixture. The magnetic centers of the various elements in a corrector-quadrupole assembly were determined with a harmonic antenna system. Any assembly with excessive corrector offset was then straightened by employing corrective weld stripes on the outer stainless steel shell. The alignment results obtained with this procedure will be described.

Jain, A.; Anerella, M.; Cozzolino, J.; Ganetis, G.; Thomas, R.; Wanderer, P.

1997-05-01

356

Origin-independent calculation of quadrupole intensities in X-ray spectroscopy.  

PubMed

For electronic excitations in the ultraviolet and visible range of the electromagnetic spectrum, the intensities are usually calculated within the dipole approximation, which assumes that the oscillating electric field is constant over the length scale of the transition. For the short wavelengths used in hard X-ray spectroscopy, the dipole approximation may not be adequate. In particular, for metal K-edge X-ray absorption spectroscopy (XAS), it becomes necessary to include higher-order contributions. In quantum-chemical approaches to X-ray spectroscopy, these so-called quadrupole intensities have so far been calculated by including contributions depending on the square of the electric-quadrupole and magnetic-dipole transition moments. However, the resulting quadrupole intensities depend on the choice of the origin of the coordinate system. Here, we show that for obtaining an origin-independent theory, one has to include all contributions that are of the same order in the wave vector consistently. This leads to two additional contributions depending on products of the electric-dipole and electric-octupole and of the electric-dipole and magnetic-quadrupole transition moments, respectively. We have implemented such an origin-independent calculation of quadrupole intensities in XAS within time-dependent density-functional theory, and demonstrate its usefulness for the calculation of metal and ligand K-edge XAS spectra of transition metal complexes. PMID:23205980

Bernadotte, Stephan; Atkins, Andrew J; Jacob, Christoph R

2012-11-28

357

Measurements of magnetization multipoles in four centimeter quadrupoles for the SSC  

SciTech Connect

Higher multipoles due to magnetization of the superconductor in superconducting dipole and quadrupole magnets has been observed in over twenty years. This report presents measurements of the 12 pole and 20 pole multipoles in a model one-meter long four-centimeter bore SSC type quadrupole built at the Lawrence Berkeley Laboratory (LBL). The measurements were compared with calculations of the field structure using magnetization theory. Good agreement was observed between the measured multipoles and the calculated multipoles. Under conditions equivalent to injection into the SSC at an energy of 2 TeV, about 1.0 unit of 12 pole was observed and 0.05 units of 20 pole was observed. (One unit of field error is a field error of one part in ten thousand). Magnetization multipole measurements were also done on the first full length (5 meter) SSC quadrupole prototype. Measurements of flux creep decay were made on three one meter quadrupoles and the first five meter long quadrupole. 7 refs., 9 figs.

Green, M.A.; Barale, P.J.; Benjegerdes, R.W.; Gilbert, W.S.; Green, M.I.; Scanlan, R.M.; Sopher, J.; Taylor, C.E.

1991-06-01

358

Understanding Lustre Internals  

SciTech Connect

Lustre was initiated and funded, almost a decade ago, by the U.S. Department of Energy (DoE) Office of Science and National Nuclear Security Administration laboratories to address the need for an open source, highly-scalable, high-performance parallel filesystem on by then present and future supercomputing platforms. Throughout the last decade, it was deployed over numerous medium-to-large-scale supercomputing platforms and clusters, and it performed and met the expectations of the Lustre user community. As it stands at the time of writing this document, according to the Top500 list, 15 of the top 30 supercomputers in the world use Lustre filesystem. This report aims to present a streamlined overview on how Lustre works internally at reasonable details including relevant data structures, APIs, protocols and algorithms involved for Lustre version 1.6 source code base. More importantly, it tries to explain how various components interconnect with each other and function as a system. Portions of this report are based on discussions with Oak Ridge National Laboratory Lustre Center of Excellence team members and portions of it are based on our own understanding of how the code works. We, as the authors team bare all responsibilities for all errors and omissions in this document. We can only hope it helps current and future Lustre users and Lustre code developers as much as it helped us understanding the Lustre source code and its internal workings.

Wang, Feiyi [ORNL; Oral, H Sarp [ORNL; Shipman, Galen M [ORNL; Drokin, Oleg [ORNL; Wang, Di [ORNL; Huang, He [ORNL

2009-04-01

359

Nuclear Magnetic Resonance Spectroscopy  

NSDL National Science Digital Library

This website serves as a primer for understanding the fundamentals of NMR spectroscopy. Plenty of useful figures and animations that enhance the understanding of nuclear spin, shielding, and how these phenomena serve as the basis for NMR.

2011-05-18

360

Understanding the TMI2 accident: an overview  

Microsoft Academic Search

The accident at Three Mile Island Unit 2 (TMI-2) on March 28, 1979 has had a profound impact on the nuclear power industry despite the fact that the health consequences to the public were insignificant. There is considerable benefit to the nuclear power industry in understanding the progression of this severe core damage accident and its relationship to the very

R. R. Hobbins; J. M. Broughton; C. M. Allison

1986-01-01

361

Measurement of Electric Quadrupole Moments for 31Al Using Spin Polarized RI Beams  

SciTech Connect

The electromagnetic moment is a sensitive probe to investigate microscopic structure. In order to measure the electromagnetic moment, {beta}-NMR and {beta}-NQR methods are employed taking advantage of the fragment spin polarization produced by the fragmentation reaction. The measurement of the electric quadrupole moment for ground-state 31Al has been been carried out by {beta}-NQR method. Spin-polarized 31Al nuclei were obtained from the fragmentation of 40Ar projectiles, and were implanted in {alpha}-Al2O3 stopper. The electric quadrupole moment was deduced from the measured quadrupole coupling constant. The obtained value is |Q(31Al)| 104(9) e{center_dot}mb.

Nagae, D.; Asahi, K.; Takemura, M.; Takase, K.; Uchida, M.; Shimada, K.; Arai, T.; Inoue, T.; Kagami, S.; Hatakeyama, N. [Department of Physics, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551 (Japan); Ueno, H.; Kameda, D.; Yoshimi, A.; Sugimoto, T.; Nagatomo, T.; Kobayashi, Y. [RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan)

2007-06-13

362

E2 and E3 transitions from quadrupole-octupole coupled states in 144Nd  

NASA Astrophysics Data System (ADS)

Lifetime measurements of the 3-1, 5-1, and 1-1 states in 144Nd show that the absolute E2 and E3 transition rates from the 5-1 and 1-1 states are consistent with their structure being formed by the coupling of the lowest quadrupole (2+1) and octupole (3-1) excitations. A level at 2205 keV has been identified as having J?=4- and may be another member of this quadrupole-octupole coupled quintuplet. The energy spacing of the quintuplet can be explained by anharmonicities in the quadrupole-octupole interaction and the influence of the ?2(2f7/2,1i13/2) configuration.

Robinson, S. J.; Jolie, J.; Börner, H. G.; Schillebeeckx, P.; Ulbig, S.; Lieb, K. P.

1994-07-01

363

Magnetic field in the end region of the SSC quadrupole magnet  

SciTech Connect

Recent advances in methods of computing magnetic fields have made it possible to study the field in the end region of the SS quadrupole magnet in detail. The placement of conductor in the straight section, away from the ends, was designed to produce a practically pure quadrupole field in the two-dimensional sense. The ends of the coils were designed to produce a practically pure quadrupole field in the integral sense using a method that ignores the presence of the iron yoke. Subsequently, the effect of presence of the yoke on the field was analyzed. The paper presents the end configuration together with the computed integrated multipole components, local multipole components, and local field components. A comparison with measurements is included. 5 refs., 5 figs., 1 tab.

Caspi, S.; Helm, M.; Laslett, L.J.

1991-06-01

364

Properties of quadrupole-octupole coupled states in ^116Cd from the (n, n^'?) reaction  

NASA Astrophysics Data System (ADS)

Negative-parity levels in the 2.4 MeV region, arising from the coupling of the 2^+1 quadrupole and 3^-1 octupole states, have been investigated with the (n, n^'?) reaction. The measured ?-ray excitation functions, ?-? coincidences and angular distributions were utilized to characterize the decays of these states. The level lifetimes have been measured with the Doppler-shift attenuation method, and B(E1) and B(E2) values for the associated transitions have been determined. The enhanced B(E2) values for decay to the 3^- octupole state from many of the candidate negative-parity states were observed to be consistent with the expected signature of quadrupole-octupole coupled states. The properties of these states will be compared with the systematics of quadrupole-octupole coupled states in Cd isotopes and IBM calculations.

Sumithrarachchi, C. S.; Garrett, P. E.; Green, K. L.; Kadi, M.; Jolie, J.; Warr, N.; Yates, S. W.

2009-10-01

365

Decline of the current quadrupole moment during the merger phase of binary black hole coalescence  

E-print Network

Utilizing the tools of tendex and vortex, we study the highly dynamic plunge and merger phases of several $\\pi$-symmetric binary black hole coalescences. In particular, we observe a decline of the strength of the current quadrupole moment as compared to that of the mass quadrupole moment during the merger phase, contrary to a naive estimate according to the dependence of these moments on the separation between the black holes. We further show that this decline of the current quadrupole moment is achieved through the remnants of the two individual spins becoming nearly aligned or anti-aligned with the total angular momentum. We also speculate on the implication of our observations for achieving a consistency between the electric and magnetic parity quasinormal modes.

Fan Zhang

2014-03-03

366

Decline of the current quadrupole moment during the merger phase of binary black hole coalescence  

E-print Network

Utilizing the tools of tendex and vortex, we study the highly dynamic plunge and merger phases of several $\\pi$-symmetric binary black hole coalescences. In particular, we observe a decline of the strength of the current quadrupole moment as compared to that of the mass quadrupole moment during the merger phase, contrary to a naive estimate according to the dependence of these moments on the separation between the black holes. We further show that this decline of the current quadrupole moment is achieved through the remnants of the two individual spins becoming nearly aligned or anti-aligned with the total angular momentum. We also speculate on the implication of our observations for achieving a consistency between the electric and magnetic parity quasinormal modes.

Zhang, Fan

2014-01-01

367

Design and Field Measurements of Printed-Circuit Quadrupoles and Dipoles  

SciTech Connect

Air-core printed-circuit (PC) quadrupoles and dipoles have been developed for the University of Maryland electron ring, currently under construction. The quadrupoles and dipoles are characterized by very small magnetic fields (about 15 G at the aperture edge) and small aspect ratios (length/diameter < 1). We review the theory behind the design of the PC lenses and bending elements, and present general expressions for estimating the values of integrated field and integrated field gradient as functions of design parameters. The new quadrupole magnet represents an improvement over an earlier version which was based on an empirical approach. Further, we summarize the results of multipole content of the magnet fields as measured with a rotating coil apparatus of special construction. The results are compared with calculations with an iron-free magnetics code and are related to different types of errors in the manufacture and assembly of the PC magnets.

Zhang, W.W.; Bernal, S.; Li, H.; Godlove, T.; Kishek, R.A.; O'Shea, P.G.; Reiser, M.; Yun, V.; /Maryland U., IPR; Venturini, M.; /SLAC

2011-11-08

368

Development of a GC/Quadrupole-Orbitrap Mass Spectrometer, Part I: Design and Characterization.  

PubMed

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

Peterson, Amelia C; Hauschild, Jan-Peter; Quarmby, Scott T; Krumwiede, Dirk; Lange, Oliver; Lemke, Rachelle A S; Grosse-Coosmann, Florian; Horning, Stevan; Donohue, Timothy J; Westphall, Michael S; Coon, Joshua J; Griep-Raming, Jens

2014-10-21

369

Field test results of a nuclear quadrupole resonance land mine detection system  

NASA Astrophysics Data System (ADS)

We report on field test results conducted during 1999 in Bosnia and at the Army Mine Training School, Fort Leonard Wood, MO, on a ne prototype landmine detection system. In all test, non-metallic, anti-personnel (AP) and anti-tank (AT) landmines were detected via the NQR explosive signature with a probability of detection of 100 percent. The initial false alarm rate for the AP mine test was < 5 percent and was reduced to zero by a subsequent remeasurement. The test included typical burial depths and a variety of ground and weather conditions. In addition, the system can tolerate very high levels of metallic clutter and has repeatedly achieved zero false alarm rate when scanning for buried explosives at an EOD test range.

Hibbs, Andrew D.; Barrall, Geoffrey A.; Beevor, Simon; Burnett, Lowell J.; Derby, K.; Drew, A. J.; Gregory, David M.; Hawkins, C. S.; Huo, S.; Karunaratne, A.; Lathrop, Daniel K.; Lee, Young K.; Matthews, Robert; Milberger, Steve; Oehmen, B.; Petrov, T.; Skvoretz, David C.; Vierkoetter, S. A.; Walsh, David O.; Wu, Chin

2000-08-01

370

Nuclear quadrupole resonance: a technique to control hydration processes in the pharmaceutical industry.  

PubMed

Pharmaceuticals can exist in many solid forms, which can have different physical and chemical properties. These solid forms include polymorphs, solvates, amorphous, and hydrates. Particularly, hydration process can be quite common since pharmaceutical solids can be in contact with water during manufacturing process and can also be exposed to water during storage. In the present work, it is proved that NQR technique is capable of detecting different hydrated forms not only in the pure raw material but also in the final product (tablets), being in this way a useful technique for quality control. This technique was also used to study the dehydration process from pentahydrate to trihydrate. PMID:21314133

Limandri, Silvina; Visñovezky, Claudia; Pérez, Silvina C; Schurrer, Clemar A; Wolfenson, Alberto E; Ferro, Maribel; Cuffini, Silvia L; de Souza, Joel Gonçalves; Aguiar, F Armani; de Gaitani, C Masetto

2011-03-01

371

Rotationally induced nuclear quadrupole coupling in spherical-top molecules 2014  

E-print Network

to 189OsO4 M. L. Palma and J. Bordé Laboratoire de Spectroscopie Moléculaire (*), Université Pierre gradient du champ élec- trique par rapport aux coordonnées normales. Pour 189OsO4, nous comparons l-induced and vibration-induced coupling is discussed for189OsO4 ; the use of spin-vibration-rotation interaction

Paris-Sud XI, Université de

372

Field test results of a nuclear quadrupole resonance land mine detection system  

Microsoft Academic Search

We report on field test results conducted during 1999 in Bosnia and at the Army Mine Training School, Fort Leonard Wood, MO, on a ne prototype landmine detection system. In all test, non-metallic, anti-personnel (AP) and anti-tank (AT) landmines were detected via the NQR explosive signature with a probability of detection of 100 percent. The initial false alarm rate for

Andrew D. Hibbs; Geoffrey A. Barrall; Simon Beevor; Lowell J. Burnett; K. Derby; A. J. Drew; Dave Gregory; C. S. Hawkins; S. Huo; A. Karunaratne; Daniel K. Lathrop; Young K. Lee; Robert Matthews; Steve Milberger; B. Oehmen; T. Petrov; David C. Skvoretz; S. A. Vierkoetter; David O. Walsh; Chin Wu

2000-01-01

373

Theory for nanoparticle retention time in the helical channel of quadrupole magnetic field-flow fractionation  

NASA Astrophysics Data System (ADS)

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.

Williams, P. Stephen; Carpino, Francesca; Zborowski, Maciej

2009-05-01

374

Quadrupole Moments of N and Delta in the 1/N_c Expansion  

E-print Network

We calculate expressions for the quadrupole moments of nonstrange baryons in which the number of QCD color charges is N_c. Using only the assumption of single-photon exchange, we obtain 4 relations among the 6 moments, and show how all of them may be obtained from Q_{\\Delta^+ p} up to O(1/N_c^2) corrections. We compare to the N_c=3 case, and obtain relations between the neutron charge radius and quadrupole moments. We also discuss prospects for the measurement of these moments.

Alfons J. Buchmann; Janice A. Hester; Richard F. Lebed

2002-05-10

375

Electric Quadrupole Shift Cancellation in Single-Ion Optical Frequency Standards  

NASA Astrophysics Data System (ADS)

The electric quadrupole shift is presently the most significant source of uncertainty on the systematic shifts for several single-ion optical frequency standards. We present a simple method for canceling this shift based on measurements of the Zeeman spectrum of the clock transition. This method is easy to implement and yields very high cancellation levels. A fractional uncertainty of 5×10-18 for the canceled quadrupole shift is estimated for a measurement of the absolute frequency of the 5s 2S1/2 4d 2D5/2 clock transition of 88Sr+.

Dubé, P.; Madej, A. A.; Bernard, J. E.; Marmet, L.; Boulanger, J.-S.; Cundy, S.

2005-07-01

376

3-mm anisotropy measurement and the quadrupole component in the cosmic background radiation  

SciTech Connect

The large-scale anisotropy in the cosmic background radiation has been measured at 3-mm wavelength with a liquid-helium--cooled balloon-borne radiometer sensitive enough to detect the dipole in one gondola rotation (1 min). Statistical errors on the dipole and quadrupole components are below 0.1 mK with less than 0.1 mK galactic contribution. The authors find a dipole consistent with previous measurements but disagree with recent quadrupole reports. The measurement is also useful in the search for spectral distortions.

Lubin, P.M.; Epstein, G.L.; Smoot, G.F.

1983-02-21

377

3 mm Anisotropy Measurement: On the Quadrupole Component in theCosmic Background Radiation  

SciTech Connect

We have mapped the large-scale anisotropy in the cosmic background radiation at 3 mm wavelength using a liquid-helium-cooled balloon-borne radiometer sensitive enough to detect the dipole in one gondola rotation (1 minute). Statistical errors on the dipole and quadrupole components are below 0.1 mK with less than 0.1 m K galactic contribution. We find a dipole consistent with previous measurements but disagree with recent quadrupole reports. The measurement is also useful in searching for spectral distortions.

Lubin, Philip M.; Epstein, Gerald L.; Smoot, George F.

1982-11-01

378

Electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole channel  

SciTech Connect

This work studies the electron-beam envelopes and matching for a combined wiggler and alternating-gradient quadrupole field for a free-electron laser (FEL) that will be operated in the VUV or XUV wavelength region. The quadrupole field is assumed to vary continuously along the symmetry axis. The linearized equations of electron motion are solved analytically by using the two-scale perturbation method for a plane polarized wiggler. The electron-beam envelopes and the envelope equations, as well as the matching conditions in phase space, are obtained from the electron trajectories. A comparison with the numerical solution is presented.

Wang, T.F.; Cooper, R.K.

1985-01-01

379

Quadrupole moments of some doubly-even molibden nuclei and the onset of collectivity  

SciTech Connect

A good description of the quadrupole moments is obtained by investigating {sup 94,96,98,100,102,104,106,108}Mo isotopes in terms of the interacting boson model. After the positiveparity states and electromagnetic-transition rates B(E2) of even-mass Mo nuclei were calculated it was seen that there is a good agreement between the obtained results and some previous experimental data. At the end of the quadrupole moment calculations it was proved that the results agree well with the previous experimental data.

Turkan, N., E-mail: nurettin_turkan@yahoo.com [Bozok University Faculty of Arts and Science (Turkey); Ibis, I. [Bozok University Institute of Science (Turkey); Maras, I. [Celal Bayar University Faculty of Arts and Science (Turkey)

2012-07-15

380

Bound states of a charged particle in the field of an electric quadrupole in two dimensions  

E-print Network

The Schr\\"odinger equation for a charged particle in the field of a nonrelativistic electric quadrupole in two dimensions is known to be separable in spherical coordinates. We investigate the occurrence of bound states of negative energy and find that the particle can be bound by a quadrupole of any magnitude. This result is remarkably different from the one for a charged particle in the field of a nonrelativistic electric dipole in three dimensions where a minimum value of the dipole strength is necessary for capture. Present results differ from those obtained earlier by other author.

Francisco M. Fernández

2013-12-02

381

Nuclear Mass Dependence of Chaotic Dynamics in Ginocchio Model  

E-print Network

The chaotic dynamics in nuclear collective motion is studied in the framework of a schematic shell model which has only monopole and quadrupole degrees of freedom. The model is shown to reproduce the experimentally observed global trend toward less chaotic motion in heavier nuclei. The relation between current approach and the earlier studies with bosonic models is discussed.

Naotaka Yoshinaga; Nobuaki Yoshida; Takaomi Shigehara; Taksu Cheon

1995-12-29

382

Nuclear photonics  

SciTech Connect

With the planned new {gamma}-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 10{sup 13}{gamma}/s and a band width of {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -3}, a new era of {gamma} beams with energies up to 20MeV comes into operation, compared to the present world-leading HI{gamma}S facility at Duke University (USA) with 10{sup 8}{gamma}/s and {Delta}E{gamma}/E{gamma} Almost-Equal-To 3 Dot-Operator 10{sup -2}. In the long run even a seeded quantum FEL for {gamma} beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused {gamma} beams. Here we describe a new experiment at the {gamma} beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for {gamma} beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for {gamma} beams are being developed. Thus, we have to optimize the total system: the {gamma}-beam facility, the {gamma}-beam optics and {gamma} detectors. We can trade {gamma} intensity for band width, going down to {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -6} and address individual nuclear levels. The term 'nuclear photonics' stresses the importance of nuclear applications. We can address with {gamma}-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, {gamma} beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to {mu}m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

Habs, D.; Guenther, M. M.; Jentschel, M.; Thirolf, P. G. [Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Max Planck Institut fuer Quantenoptik, D-85748 Garching (Germany); Institut Laue-Langevin, F-38042 Grenoble (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany)

2012-07-09

383

Does quadrupole stability imply LLSVP fixity? ARISING FROM C. P. Conrad, B. Steinberger & T. H. Torsvik Nature 498, 479482 (2013)  

E-print Network

Does quadrupole stability imply LLSVP fixity? ARISING FROM C. P. Conrad, B. Steinberger & T. H convergence. In a recent Letter, Conrad et al.1 performed a multipole expansion of the Earth's plate motions, the conclusion by Conrad et al.1 that the presence of stationary quadrupole divergence implies fixity

Cai, Long

384

Ab initio study of the 57 Fe quadrupole splitting in the heme models of ?- and ?-subunits in tetrameric deoxyhemoglobin  

Microsoft Academic Search

Ab initio X? discrete variation method was used for calculation of quadrupole splitting for the rough heme models in ?- and\\u000a ?-subunits of tetrameric deoxyhemoglobin accounting small stereochemical variations. The differences of theoretical values\\u000a of quadrupole splitting for these heme models were obtained.

E. I. Yuryeva; M. I. Oshtrakh

2005-01-01

385

Ab initio study of the 57 Fe quadrupole splitting in the heme models of ?- and ?-subunits in tetrameric deoxyhemoglobin  

Microsoft Academic Search

Ab initio X? discrete variation method was used for calculation of quadrupole splitting for the rough heme models in ?- and\\u000a ?-subunits of tetrameric deoxyhemoglobin accounting small stereochemical variations. The differences of theoretical values\\u000a of quadrupole splitting for these heme models were obtained.

E. I. Yuryeva; M. I. Oshtrakh

386

Nuclear spin relaxation of sodium cations in bacteriophage Pf1 solutions D. N. Sobieski, N. R. Krueger, S. Vyas,a  

E-print Network

Nuclear spin relaxation of sodium cations in bacteriophage Pf1 solutions D. N. Sobieski, N. R The nuclear magnetic resonance NMR spectra for the I=3/2 23 Na cation dissolved into filamentous bacteriophage the 23 Na nuclear quadrupole moment and the electric field gradient produced by the negatively charged Pf

Augustine, Mathew P.

387

Nuclear astrophysics  

NASA Astrophysics Data System (ADS)

Nuclear astrophysics is that branch of astrophysics which helps understanding of the Universe, or at least some of its many faces, through the knowledge of the microcosm of the atomic nucleus. It attempts to find as many nuclear physics imprints as possible in the macrocosm, and to decipher what those messages are telling us about the varied constituent objects in the Universe at present and in the past. In the last decades much advance has been made in nuclear astrophysics thanks to the sometimes spectacular progress made in the modelling of the structure and evolution of the stars, in the quality and diversity of the astronomical observations, as well as in the experimental and theoretical understanding of the atomic nucleus and of its spontaneous or induced transformations. Developments in other subfields of physics and chemistry have also contributed to that advance. Notwithstanding the accomplishment, many long-standing problems remain to be solved, and the theoretical understanding of a large variety of observational facts needs to be put on safer grounds. In addition, new questions are continuously emerging, and new facts endangering old ideas. This review shows that astrophysics has been, and still is, highly demanding to nuclear physics in both its experimental and theoretical components. On top of the fact that large varieties of nuclei have to be dealt with, these nuclei are immersed in highly unusual environments which may have a significant impact on their static properties, the diversity of their transmutation modes, and on the probabilities of these modes. In order to have a chance of solving some of the problems nuclear astrophysics is facing, the astrophysicists and nuclear physicists are obviously bound to put their competence in common, and have sometimes to benefit from the help of other fields of physics, like particle physics, plasma physics or solid-state physics. Given the highly varied and complex aspects, we pick here some specific nuclear physics topics which largely pervade nuclear astrophysics.

Arnould, M.; Takahashi, K.

1999-03-01

388

Measurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural carbonates  

E-print Network

­7,9,10 The two stable isotopes of lithium (6 Li and 7 Li) have a large mass difference ($16%), resulting and analysis. Our interest in lithium isotope analyses stems from the crea- tion of d7 Li and Li/Ca recordMeasurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural

Weston, Ken

389

DESIGN OF A THIN QUADRUPOLE TO BE USED IN THE AGS SYNCHROTRON  

SciTech Connect

The Alternating Gradient Synchrotron (AGS) employs two partial helical snakes[l] to preserve the polarization of the proton beam during acceleration. In order to compensate for the focusing effect of the partial helical snakes on the beam optics in the AGS during acceleration of the beam, we introduced eight quadrupoles in straight sections of the AGS at the proximity of the partial snakes. At injection energies, the strength of each quad is set at a high value, and is ramped down to zero as the effect of the snakes diminishes by the square of beam's rigidity. Four of the eight compensation quadrupoles had to be placed in very short straight sections -30 cm in length, therefore the quadruples had be thin with an overall length of less than 30 cm. In this paper we will discus: (a) the mechanical and magnetic specifications of the ''thin'' quadrupole. (b) the method to minimize the strength of the dodecapole harmonic, (c) the method to optimize the thickness of the laminations that the magnet iron is made, (d) mechanical tolerances of the magnet, (e) comparison of the measured and calculated magnetic multipoles of the quadrupole.

TSOUPAS,N.; AHRENS, L.; ALFORQUE, R.; BAI, M.; BROWN, K.; COURANT, E.; ET AL.

2007-06-25

390

Ion Trap/Ion Mobility/Quadrupole/Time-of-Flight Mass Spectrometry for Peptide Mixture Analysis  

E-print Network

Ion Trap/Ion Mobility/Quadrupole/Time-of-Flight Mass Spectrometry for Peptide Mixture Analysis for the analysis of peptide mixtures. In this approach, a mixture of peptides is electrosprayed into the gas phase. The mixture of ions that is created is accumulated in an ion trap and periodi- cally injected into a drift

Clemmer, David E.

391

The importance of quadrupole sources in prediction of transonic tip speed propeller noise  

Microsoft Academic Search

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 varrhou2 quadrupole, where u is the disturbance velocity component

D. B. Hanson; M. R. Fink

1979-01-01

392

The importance of quadrupole sources in prediction of transonic tip speed propeller noise  

Microsoft Academic Search

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

D. B. Hanson; M. R. Fink

1978-01-01

393

Electron Cloud Generation and Trapping in a Quadrupole Magnet at the Los Alamos Proton Storage Ring  

SciTech Connect

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 100 {micro}s. 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.

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

2008-03-17

394

Progenitor cell isolation with a high-capacity quadrupole magnetic flow sorter  

Microsoft Academic Search

Rapid and efficient sorting is important for progenitor cell isolation. Therefore, we have built and evaluated a high-speed, continuous flow, quadrupole magnetic sorter. The cross-over behavior of non-magnetic particles, combined with separation theory is used to optimize performance. CD34+ progenitor cells are separated to purities from 64–95% and a throughput of 107cells\\/s.

Lee R Moore; Alexander R Rodriguez; P. Stephen Williams; Kara McCloskey; Brian J Bolwell; Masayuki Nakamura; Jeffrey J Chalmers; Maciej Zborowski

2001-01-01

395

Splitting of the giant monopole and quadrupole resonances in Sm-154  

E-print Network

Strength functions for the isoscalar giant monopole and quadrupole resonances in Sm-154 have been measured with inelastic scattering of 240 MeV alpha particles at small angles. The E0 strength distribution containing (104(-20)(+15))% of the energy...

Youngblood, David H.; Lui, YW; Clark, HL.

1999-01-01

396

A new high-gradient correction quadrupole for the Fermilab luminosity upgrade  

SciTech Connect

Special superconducting correction quadrupoles are needed for the luminosity upgrade of the Fermilab Tevatron Collider. These correctors are part of the low-beta system for the interaction regions at B/phi/ and D/phi/. The requirements are high gradient and low current. A quadrupole has been designed that meets the operating gradient of 0.63 T/cm at 1086 A. The one-layer quadrupole is wound with a cable consisting of five individually insulated rectangular strands. The five strands are overwrapped with Kapton and epoxy impregnated glass tape. The winding, curing and collaring of the magnet is accomplished in the same manner as Tevatron-like magnets using Rutherford style cable. Once the magnet is complete the five strands are connected in series. A prototype quadrupole has been assembled and tested. The magnet reached a plateau current of 1560 A corresponding to a gradient of 0.91 T/cm without training. The measured field harmonics are substantially better than required. 8 refs., 6 figs., 4 tabs.

Mantsch, P.; Carson, J.; Riddiford, A.; Lamm, M.J.

1989-03-01

397

Relations Involving Static Quadrupole Moments of $2^+$ states and B(E2)'s  

E-print Network

We define the ``quadrupole ratio'' $r_Q = \\dfrac{Q_0(S)}{Q_0(B)}$ where $Q_0(S)$ is the intrinsic quadrupole moment obtained from the static quadrupole moment of the $2_1^+$ state of an even-even nucleus and $Q_0(B)$ the intrinsic quadrupole moment obtained from $B(E2)_{0 \\to 2}$. In both cases we assume a simple rotational formula connecting the rotating frame to the laboratory frame. The quantity $r_Q$ would be one if the rotational model were perfect and the energy ratio $E(4)/E(2)$ would be 10/3. In the simple vibrational model, $r_Q$ would be zero and $E(4)/E(2)$ would be two. There are some regions where the rotational limit is almost met and fewer where the vibrational limit is also almost met. For most cases, however, it is between these two limits, i.e. $0 < r_Q < 1$. There are a few cases where $r_Q$ is bigger than one, especially for light nuclei.

Sean Yeager; Larry Zamick

2008-07-29

398

Study of gas evolution during oil shale pyrolysis by TQMS (triple quadrupole mass spectrometer)  

Microsoft Academic Search

Real-time gas evolution during pyrolysis of two Green River Formation (Colorado) oil shales, one eastern US Devonian shale, and two Chinese shales was monitored using a triple quadrupole mass spectrometer (TQMS). We calculated kinetic parameters for hydrocarbon generation. For water, carbon oxides, and sulfur gases, we compared evolution profiles and identified the organicinorganic precursors of each species. We also monitored

M. S. Oh; T. T. Coburn; R. W. Crawford; A. K. Burnham

1988-01-01

399

Conceptual Design of a Superconducting Quadrupole with Elliptical Acceptance and Tunable Higher Order Multipoles  

Microsoft Academic Search

For charged particle beams that are wider in the dispersive plane compared to the transverse plane it is cost efficient to utilize magnets that accept beams with elliptic cross section. In this paper we presents the conceptual design of a quadrupole magnet with elliptic cross section and with tunable higher order multipoles. The design consists of 18 superconducting race-track coils

Shashikant Manikonda; Jerry Nolen; Martin Berz; Kyoko Makino

2009-01-01

400

Experimental verification of resonance instability bands in quadrupole doublet focusing channels  

NASA Astrophysics Data System (ADS)

The tabletop plasma trap experiment named "S-POD" is employed to explore the stability of intense charged-particle beams focused by a series of quadrupole doublet cells. S-POD is a compact linear Paul-trap, where we generate a single-species non-neutral ion plasma that can approximately reproduce the collective motion of an intense beam focused by periodic linear forces. Unlike conventional beam-dynamics experiments relying on large-scale transport channels and accelerators, it is straightforward in S-POD to control the functional form of quadrupole beam focusing over a wide range of variation to explore a variety of quadrupole focusing lattices. We systematically measure the loss rate of trapped particles as a function of bare betatron tune to locate resonance bands in which the plasma becomes unstable. It is confirmed that a few bands of coherent resonances appear depending on the beam intensity. When there is an imbalance between the horizontal and vertical focusing, those instability bands split. Experimental results indicate that the instability band is relatively insensitive to the phase of quadrupole focusing element placement within the doublet configuration over a significant range of parameters. Experimental observations are compared with transverse slice particle-in-cell simulations carried out using the Warp code.

Fukushima, K.; Ito, K.; Okamoto, H.; Yamaguchi, S.; Moriya, K.; Higaki, H.; Okano, T.; Lund, S. M.

2014-01-01

401

Development and Coil Fabrication for the LARP 3.7-m Long Nb3Sn Quadrupole  

SciTech Connect

The U.S. LHC Accelerator Research Program (LARP) has started the fabrication of 3.7-m long Nb{sub 3}Sn quadrupole models. The Long Quadrupoles (LQ) are 'Proof-of-Principle' magnets which are to demonstrate that Nb{sub 3}Sn technology is mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, developed at FNAL and LBNL, which have design gradients higher than 200 T/m and an aperture of 90 mm. The plans for the LQ R&D and a design update are presented and discussed in this paper. The challenges of fabricating long accelerator-quality Nb{sub 3}Sn coils are presented together with the solutions adopted for the LQ coils (based on the TQ experience). During the fabrication and inspection of practice coils some problems were found and corrected. The fabrication at BNL and FNAL of the set of coils for the first Long Quadrupole is in progress.

Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidize, G.; Dietderich, D.; Felice, H.; Ferracin, P.; Ghosh, A.; Hafalia, R.; Hannaford, R.; Jochen, G.; Kashikhin, V.V.; Kovach, P.; Lamm, M.; Lietzke, A.; McInturff, A.; Muratore,, J.; Nobreaga, F.; Novitsky, I.; Peggs, S.; Prestemon, S.; Sabbi, G. L.; Schmalzle, J.; Turrioni, D.; Wanderer, P.; Whitson, G.; Zlobin, A. V.

2008-08-17

402

Projected and slice emittance measurements using multi-quadrupole scan and streak readout at PITZ  

E-print Network

Projected and slice emittance measurements using multi-quadrupole scan and streak readout at PITZ R electron beam. One of the main characteristics of the beam is its normalized emittance. Development of injectors is targeted towards producing beams with low normalized emittance, thus high resolution emittance

403

Anomalous 14N quadrupole coupling constant of methyl isocyanide in liquid crystals  

NASA Astrophysics Data System (ADS)

The 14N quadrupole coupling constant (QCC) for methyl isocyanide obtained from 1H and 14N N.M.R. measurements in liquid crystal solutions is reported as a function of temperature for two liquid crystal solvents. A marked linear temperature dependence is observed in both solvents. The measured QCC varies by 20 per cent over a 50°C range.

Barbara, Thomas M.

404

Helium and neon implantation and memory observed in a quadrupole mass spectrometer  

Microsoft Academic Search

High accuracy static quadrupole mass spectrometer (QMS) measurement of helium and neon may be impaired by implantation and long lasting thermal desorption effects of the previously trapped atoms. A QMS produces only moderately accelerated ions of 100–200 eV. The ions decelerate at stainless steel surfaces somewhere in the QMS and a part of them will be trapped in surface near

Ingo Rau; Alfred Putzka

1999-01-01

405

Optical Measurement of the Effect of Electric Fields on the Nuclear Spin Coherence of Rare-Earth Ions in Solids  

NASA Astrophysics Data System (ADS)

We show that the coherence properties of the nuclear spin states of rare-earth ions in solids can be manipulated by small applied electric fields. This was done by measuring the Stark effect on the nuclear quadrupole transitions of Eu151 in Y2SiO5 (YSO) using a combination of Raman heterodyne optical detection and Stark modulated quadrupole echoes to achieve high sensitivity. The measured Stark coefficients were 0.42 and 1.0 Hz cm /V for the two quadrupole transitions at 34.54 and 46.20 MHz, respectively. The long decoherence time of the nuclear spin states (25 ms) allowed us to make the measurements in very low electric fields of ˜10 V/cm, which produced 100% modulation of the nuclear spin echo, and to measure Stark shifts of ˜1 Hz or 20 ppm of the inhomogeneous linewidth.

Macfarlane, R. M.; Arcangeli, A.; Ferrier, A.; Goldner, Ph.

2014-10-01

406

Effects of longitudinal quadrupoles on the phase behavior of a Gay-Berne fluid  

NASA Astrophysics Data System (ADS)

The effects of longitudinal quadrupole moments on the formation of liquid crystalline phases are studied by means of constant NPT Monte Carlo simulation methods. The popular Gay-Berne model mesogen is used as the reference fluid, which displays the phase sequences isotropic-smectic A-smectic B and isotropic-smectic B at high (T*=2.0) and low (T*=1.5) temperatures, respectively. With increasing quadrupole magnitude the smectic phases are observed to be stabilized with respect to the isotropic liquid, while the smectic B is destabilized with respect to the smectic A. At the lower temperature, a sufficiently large quadrupole magnitude results in the injection of the smectic A phase into the phase sequence and the replacement of the smectic B phase by the tilted smectic J phase. The nematic phase is also injected into the phase sequence at both temperatures considered, and ultimately for sufficiently large quadrupole magnitudes no coherent layered structures were observed. The stabilization of the smectic A phase supports the commonly held belief that, while the inclusion of polar groups is not a prerequisite for the formation of the smectic A phase, quadrupolar interactions help to increase the temperature and pressure range for which the smectic A phase is observed. The quality of the layered structure is worsened with increasing quadrupole magnitude. This behavior, along with the injection of the nematic phase into the phase sequence, indicate that the general tendency of the quadrupolar interactions is to destabilize the layered structure. A pressure dependence upon the smectic layer spacing is observed. This behavior is in much closer agreement with experimental findings than has been observed previously for nonpolar Gay-Berne and hard spherocylinder models.

Withers, Ian M.

2003-11-01

407

Piagetian Perspectives on Understanding Children's Understanding.  

ERIC Educational Resources Information Center

Introduces theme issue on Piagetian constructivist perspective on children's understanding. Summarizes feature articles which argue that teaching should be based on Piaget's theory; and elucidate the development of social and moral understanding, perspective-taking, play, written language, friendship and popularity, and mathematics. Emphasizes the…

Taylor, Janet B.

1996-01-01

408

Measurement of the sign of the spectroscopic quadrupole moment for the 2(1)+ state in 70Se: no evidence for oblate shape.  

PubMed

Using a method whereby molecular and atomic ions are independently selected, an isobarically pure beam of 70Se ions was postaccelerated to an energy of 206 MeV using REX-ISOLDE. Coulomb-excitation yields for states in the beam and target nuclei were deduced by recording deexcitation gamma rays in the highly segmented MINIBALL gamma-ray spectrometer in coincidence with scattered particles in a silicon detector. At these energies, the Coulomb-excitation yield for the first 2+ state is expected to be strongly sensitive to the sign of the spectroscopic quadrupole moment through the nuclear reorientation effect. Experimental evidence is presented here for a prolate shape for the first 2+ state in 70Se, reopening the question over whether there are, as reported earlier, deformed oblate shapes near to the ground state in the light selenium isotopes. PMID:17359019

Hurst, A M; Butler, P A; Jenkins, D G; Delahaye, P; Wenander, F; Ames, F; Barton, C J; Behrens, T; Bürger, A; Cederkäll, J; Clément, E; Czosnyka, T; Davinson, T; de Angelis, G; Eberth, J; Ekström, A; Franchoo, S; Georgiev, G; Görgen, A; Herzberg, R-D; Huyse, M; Ivanov, O; Iwanicki, J; Jones, G D; Kent, P; Köster, U; Kröll, T; Krücken, R; Larsen, A C; Nespolo, M; Pantea, M; Paul, E S; Petri, M; Scheit, H; Sieber, T; Siem, S; Smith, J F; Steer, A; Stefanescu, I; Syed, N U H; Van de Walle, J; Van Duppen, P; Wadsworth, R; Warr, N; Weisshaar, D; Zieli?ska, M

2007-02-16

409

Measurement of the Sign of the Spectroscopic Quadrupole Moment for the 2{sub 1}{sup +} State in {sup 70}Se: No Evidence for Oblate Shape  

SciTech Connect

Using a method whereby molecular and atomic ions are independently selected, an isobarically pure beam of {sup 70}Se ions was postaccelerated to an energy of 206 MeV using REX-ISOLDE. Coulomb-excitation yields for states in the beam and target nuclei were deduced by recording deexcitation {gamma} rays in the highly segmented MINIBALL {gamma}-ray spectrometer in coincidence with scattered particles in a silicon detector. At these energies, the Coulomb-excitation yield for the first 2{sup +} state is expected to be strongly sensitive to the sign of the spectroscopic quadrupole moment through the nuclear reorientation effect. Experimental evidence is presented here for a prolate shape for the first 2{sup +} state in {sup 70}Se, reopening the question over whether there are, as reported earlier, deformed oblate shapes near to the ground state in the light selenium isotopes.

Hurst, A. M.; Herzberg, R.-D.; Jones, G. D.; Paul, E. S.; Petri, M. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Butler, P. A. [Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); ISOLDE, CERN, CH-1211 Geneva 23 (Switzerland); Jenkins, D. G.; Barton, C. J.; Kent, P.; Steer, A.; Wadsworth, R. [Department of Physics, University of York, York YO10 5DD (United Kingdom); Delahaye, P.; Wenander, F.; Ames, F.; Franchoo, S.; Georgiev, G.; Koester, U.; Sieber, T. [ISOLDE, CERN, CH-1211 Geneva 23 (Switzerland); Behrens, T.; Kroell, T. [Physik Department E12, Technische Universitaet Muenchen, 85748 Garching (Germany)] (and others)

2007-02-16

410

Coherent excitation of the 6S1/2 to 5D3/2 electric-quadrupole transition in 138Ba+  

NASA Astrophysics Data System (ADS)

The electric dipole-forbidden, quadrupole 6S1/2?5D3/2 transition in Ba+ near 2051 nm, with a natural linewidth of 13 mHz, is attractive for potential observation of parity nonconservation, and also as a clock transition for a barium ion optical frequency standard. This transition also offers a direct means of populating the metastable 5D3/2 state to measure the nuclear magnetic octupole moment in the odd barium isotopes. Light from a diode-pumped, solid-state Tm,Ho:YLF laser operating at 2051 nm is used to coherently drive this transition between resolved Zeeman levels in a single trapped 138Ba+ ion. The frequency of the laser is stabilized to a high-finesse Fabry-Pérot cavity at 1025 nm after being frequency doubled. Rabi oscillations on this transition indicate a laser-ion coherence time of 3 ms, most likely limited by ambient magnetic field fluctuations.

Kleczewski, Adam; Hoffman, Matthew R.; Sherman, J. A.; Magnuson, Eric; Blinov, B. B.; Fortson, E. N.

2012-04-01

411

Computer simulations using a longitudinal quadrupolar Gay Berne model: effect of the quadrupole magnitude on the formation of the smectic phase  

NASA Astrophysics Data System (ADS)

Systems of Gay-Berne particles with longitudinal linear quadrupoles are studied by molecular dynamics simulations. The effect of the magnitude of the quadrupole on the smectic phase is investigated. It is found that the quadrupole destabilises the formation of the smectic phase which disappears altogether with high-magnitude quadrupoles. As the magnitude of the quadrupole is reduced a variety of smectic phases are formed, including smectic A, smectic C and smectic B, with the eventual formation of a crystal. The maximum magnitude of the tilt observed is 17.2°, comparable with experimentally observed magnitudes.

Neal, M. P.; Parker, A. J.

1998-09-01

412

Nuclear Astrophysics  

E-print Network

Nuclear physics has a long and productive history of application to astrophysics which continues today. Advances in the accuracy and breadth of astrophysical data and theory drive the need for better experimental and theoretical understanding of the underlying nuclear physics. This paper will review some of the scenarios where nuclear physics plays an important role, including Big Bang Nucleosynthesis, neutrino production by our sun, nucleosynthesis in novae, the creation of elements heavier than iron, and neutron stars. Big-bang nucleosynthesis is concerned with the formation of elements with A <= 7 in the early Universe; the primary nuclear physics inputs required are few-nucleon reaction cross sections. The nucleosynthesis of heavier elements involves a variety of proton-, alpha-, neutron-, and photon-induced reactions, coupled with radioactive decay. The advent of radioactive ion beam facilities has opened an important new avenue for studying these processes, as many involve radioactive species. Nuclear physics also plays an important role in neutron stars: both the nuclear equation of state and cooling processes involving neutrino emission play a very important role. Recent developments and also the interplay between nuclear physics and astrophysics will be highlighted.

Carl R. Brune

2005-02-28

413

Nuclear astrophysics.  

NASA Astrophysics Data System (ADS)

Nuclear astrophysics is that branch of astrophysics which helps understanding of the Universe, or at least some of its many faces, through the knowledge of the microcosm of the atomic nucleus. It attempts to find as many nuclear physics imprints as possible in the macrocosm, and to decipher what those messages are telling us about the varied constituent objects in the Universe at present and in the past. This review shows that astrophysics has been, and still is, highly demanding to nuclear physics in both its experimental and theoretical components. On top of the fact that large varieties of nuclei have to be dealt with, these nuclei are immersed in highly unusual environments which may have a significant impact on their static properties, the diversity of their transmutation modes, and on the probabilities of these modes. In order to have a chance of solving some of the problems nuclear astrophysics is facing the astrophysics and nuclear physicists are obviously bound to put their competence in common, and have sometimes to benefit from the help of other fields of physics, like particle physics, plasma physics or solid-state physics. Given the highly varied and complex aspects, the authors pick here some specific nuclear physics topics which largely pervade nuclear astrophysics.

Arnould, M.; Takahashi, K.

414

A Strategy for Direct Identification of Protein S-nitrosylation Sites by Quadrupole Time-of-Flight Mass Spectrometry  

PubMed Central

S-nitrosylation of proteins serves an important role in regulating diverse cellular processes including signal transduction, DNA repair and neurotransmission. Identification of the S-nitrosylation sites is crucial for understanding the significance of this post-translational modification (PTM) in modulating the function of a protein. However, it is very challenging to identify S-nitrosylation sites directly by mass spectrometric (MS) methods due to the labile nature of the S-NO bond. Here we describe a strategy for direct identification of protein S-nitrosylation sites in an electrospray ionization (ESI) quadrupole time-of-flight (QTOF) mass spectrometer without prior chemical derivatization of S-nitrosylated peptides. Both sample buffer composition and MS hardware parameters were carefully adjusted to ensure that S-nitrosylated peptide ions could be analyzed by the QTOF MS with optimal signal/noise ratios. It was crucial that the proteins were preserved in a sample solution containing 1 mM EDTA and 0.1 mM neocuproine at neutral pH. Proteins dissolved in this solution are amenable to in-solution tryptic digestion, which is important for the analysis of biological samples. S-nitrosylated peptides were effectively analyzed by LC/MS/MS on QTOF MS, with an optimized cone voltage of 20 V and collision energy of 4 V. We have successfully applied this method to thioredoxin, a key antioxidant protein, and identified within it an S-nitrosylation site at Cys73. PMID:18635375

Wang, Yan; Liu, Tong; Wu, Changgong; Li, Hong

2008-01-01

415

Trapping of Electron Cloud LLC/Cesrta Quadrupole and Sextupole Magnets  

SciTech Connect

The Cornell Electron Storage Ring (CESR) has been reconfigured as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R&D [1]. One of the primary goals of the CesrTA program is to investigate the interaction of the electron cloud with low emittance positron beam to explore methods to suppress the electron cloud, develop suitable advanced instrumentation required for these experimental studies and benchmark predictions by simulation codes. This paper reports the simulation of the electron-cloud formation in CESRTA and ILC quadrupole and sextupole magnets using the 3D code CLOUDLAND. We found that electrons can be trapped with a long lifetime in a quadrupole and sextupole magnet due to the mirror field trapping mechanism. We study the effects of magnet strength, bunch current, ante-chamber effect, bunch spacing effect and secondary emission yield (SEY) in great detail. The development of an electron cloud in magnets is the main concern where a weak solenoid field is not effective. Quadrupole and sextupole magnets have mirror field configurations which may trap electrons by the mirror field trapping mechanism [2]. Fig.1 shows the orbit of a trapped electron in a quadrupole magnet. The electron makes gyration motion (called transverse motion) and also moves along the field line (called longitudinal motion). At the mirror point (middle of the field line), there is a maximum longitudinal energy and minimum transverse energy. When the electron moves away from the mirror point, its longitudinal energy reduces and the transverse energy increases as the magnetic field increases. If the magnetic field is strong enough, the longitudinal energy becomes zero at one point and then the electron is turned back by the strong field. Note that the electrons are trapped in the region near the middle of the field lines. Although all quadrupole and sextupole magnets can trap electrons in principle, the trapping mechanism is also greatly sensitive to the detail dynamics of the electrons [3]. Both the positron beam and the spacing charge force of electron cloud itself play important roles. This paper reports the simulation of electron cloud in CESRTA/ILC quadrupole and sextupole magnets. Table 1 shows the main parameters used in the simulation.

Wang, L; Pivi, M.; /SLAC

2011-08-18

416

Preparing Non-nuclear Engineers for the Nuclear Field  

E-print Network

Preparing Non-nuclear Engineers for the Nuclear Field Elizabeth K. Ervin The University. An understanding of power generation is important for all modern-day engineers, and nuclear energy serves as a good perspectives are shifting, only a limited number of American programs have nuclear-related components. Twenty

Ervin, Elizabeth K.

417

Structural characterization of N-linked oligosaccharides on monoclonal antibody cetuximab by the combination of orthogonal matrix-assisted laser desorption\\/ionization hybrid quadrupole–quadrupole time-of-flight tandem mass spectrometry and sequential enzymatic digestion  

Microsoft Academic Search

Cetuximab is a novel therapeutic monoclonal antibody with two N-glycosylation sites: a conserved site in the CH2 domain and a second site within the framework 3 of the variable portion of the heavy chain. The detailed structures of these oligosaccharides were successfully characterized using orthogonal matrix-assisted laser desorption\\/ionization hybrid quadrupole–quadrupole time-of-flight mass spectrometry (oMALDI Qq–TOF MS) and tandem mass spectrometry

Jun Qian; Tun Liu; Li Yang; Ann Daus; Richard Crowley; Qinwei Zhou

2007-01-01

418

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

SciTech Connect

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 temporarily 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.

Gulyuz, Kerim; Stedwell, Corey N.; Wang Da; Polfer, Nick C. [Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611 (United States)

2011-05-15

419

Triaxial rotor model description of quadrupole interference in collective nuclei: The P{sub 3} term  

SciTech Connect

The triaxial rotor model with independent inertia and electric quadrupole tensors is applied to the P{sub 3} term, P{sub 3}=<0{sub 1}||T(E2)||2{sub 1}><2{sub 1}||T(E2)||2{sub 2}><2{sub 2}||T(E2)||0{sub 1}>, which is a standard measure of quadrupole interference in collective nuclei. It is shown that the model naturally explains nuclei with anomalous signs for their P{sub 3} terms. Measurements of Q(2{sub 1}) in multiple-step Coulomb excitation can be significantly dependent on the sign of this term. The example of {sup 194}Pt is considered.

Allmond, J. M. [Department of Physics, University of Richmond, Virginia 23173 (United States); School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Wood, J. L.; Kulp, W. D. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2009-08-15

420

CONSTRAINING THE QUADRUPOLE MOMENT OF STELLAR-MASS BLACK HOLE CANDIDATES WITH THE CONTINUUM FITTING METHOD  

SciTech Connect

Black holes in general relativity are known as Kerr black holes and are characterized solely by two parameters, the mass M and the spin J. All the higher multipole moments of the gravitational field are functions of these two parameters. For instance, the quadrupole moment is Q = -J {sup 2}/M, which implies that a measurement of M, J, and Q for black hole candidates would allow one to test whether these objects are really black holes as described by general relativity. While future gravitational-wave experiments will be able to test the Kerr nature of these objects with very high accuracy, in this paper we show that it is possible to put constraints on the quadrupole moment of stellar-mass black hole candidates by using presently available X-ray data of the thermal spectrum of their accretion disk.

Bambi, Cosimo [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Barausse, Enrico, E-mail: cosimo.bambi@ipmu.jp, E-mail: barausse@umd.edu [Department of Physics, University of Maryland, College Park, MD 20742 (United States)

2011-04-20

421

Fabrication and test of LARP technological quadrupole models of TQC series  

SciTech Connect

In support of the development of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, several two-layer technological quadrupole models of TQC series with 90 mm aperture and collar-based mechanical structure have been developed at Fermilab in collaboration with LBNL. This paper summarizes the results of fabrication and test of TQC02a, the second TQC model based on RRP Nb3Sn strand, and TQC02b, built with both MJR and RRP strand. The test results presented include magnet strain and quench performance during training, as well as quench studies of current ramp rate and temperature dependence from 1.9K to 4.5K.

Bossert, R.C.; Ambrosio, G.; Andreev, N.; Barzi, E.; Chlachidze, G.; Feher, S.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.; Nobrega, A.; Novitski, I.; /Fermilab /LBL, Berkeley /Brookhaven

2008-08-01

422

Effects of quadrupole fringe fields in final focus systems for linear colliders  

NASA Astrophysics Data System (ADS)

Quadrupole fringe fields in the final focus system can be a source of aberrations in the interaction point transverse beam sizes. This paper investigates the fringe field impact on the transverse beam size in the ATF2, ILC, and CLIC lattices in the linear and non-linear regimes. The linear effects are studied by replacing the hard-edge quadrupolar field by the more realistic gradient fall-off. To address the nonlinear effects, the fringe fields are represented as high order kicks added to both sides of the hard-edge magnets. It will be shown that the linear fringe fields effects can be easily cured by tuning the quadrupole strengths. On the other hand, mitigation of the nonlinear fringe fields effects is more difficult and requires use of octupole magnets or, alternatively, increasing the value of interaction point horizontal beta function ?x*.

Patecki, Marcin; Tomás, Rogelio

2014-10-01

423

Fourier transform spectrometer remote sensing of O2 A-band electric quadrupole transitions  

NASA Astrophysics Data System (ADS)

We observed electric quadrupole transitions in the O2 A-band, b1?g+?X3?g-(0,0), in high solar zenith angle atmospheric spectra recorded with the high-resolution solar-viewing Fourier transform spectrometer at Park Falls, WI. We identified 12 ?N=±3 transitions for the first time, including the first detection of NO-branch transitions and extended the TS-branch observations of Brault [J Mol Spectrosc 1980;80:384-8] up to N?=23. Additionally, we observed six electric quadrupole transitions of the ?N=-1 PO-branch. These observations demonstrate the excellent sensitivity and long-term stability of the new generation of solar-viewing Fourier transform spectrometers.

Miller, Charles E.; Wunch, Debra

2012-07-01

424

Simulation studies of space-charge-dominated beam transport in large aperture ratio quadrupoles  

SciTech Connect

For many cases of interest in the design of heavy-ion fusion accelerators, the maximum transportable current in a magnetic quadrupole lattice scales as ({alpha}/L){sup 2} where {alpha} is the useful dynamic aperture and L is the half-lattice period. There are many cost benefits to maximizing the usable aperture which must be balanced against unwanted effects such as possible emittance growth and particle loss from anharmonic fringe fields. We have used two independent simulation codes to model space-charge dominated beam transport both in an azimuthally-pure quadrupole FODO lattice design and in a more conventional design. Our results indicate that careful matching will be necessary to minimize emittance growth and that ({alpha}/L) ratios of 0.2 or larger are possible for particular parameters.

Fawley, W.M.; Laslett, L.J.; Celata, C.M.; Faltens, A. [Lawrence Berkeley Lab., CA (United States); Haber, I. [Naval Research Lab., Washington, DC (United States)

1993-05-01

425

Motion of pole-dipole and quadrupole particles in nonminimally coupled theories of gravity  

SciTech Connect

We study theories of gravity with nonminimal coupling between polarized media with pole-dipole and quadrupole moments and an arbitrary function of the space-time curvature scalar R and the squares of the Ricci and Riemann curvature tensors. We obtain the general form of the equation of motion and show that an induced quadrupole moment emerges as a result of the curvature tensor dependence of the function coupled to the matter. We derive the explicit forms of the equations of motion in the particular cases of coupling to a function of the curvature scalar alone, coupling to an arbitrary function of the square of the Riemann curvature tensor, and coupling to an arbitrary function of the Gauss-Bonnet invariant. We show that in these cases the extra force resulting from the nonminimal coupling can be expressed in terms of the induced moments.

Mohseni, Morteza [Physics Department, Payame Noor University, 19395-4697 Tehran (Iran, Islamic Republic of)

2010-06-15

426

Shape Phase Transition from Octupole Deformation to Octupole Vibrations: The Analytic Quadrupole Octupole Axially Symmetric Model  

SciTech Connect

An analytic collective model in which the relative presence of the quadrupole and octupole deformations is determined by a parameter ({phi}0), while axial symmetry is obeyed, is developed. The model [to be called the Analytic Quadrupole Octupole Axially symmetric model (AQOA)] involves an infinite well potential, provides predictions for energy and B(EL) ratios which depend only on {phi}0, draws the border between the regions of octupole deformation and octupole vibrations in an essentially parameter-independent way, and in the actinide region describes well 226Th and 226Ra, for which experimental energy data are shown to suggest that they lie close to this border. The similarity of the AQOA results with {phi}0 = 45 deg. for ground state band spectra and B(E2) transition rates to the predictions of the X(5) model is pointed out.

Bonatsos, Dennis; Lenis, D.; Petrellis, D. [Institute of Nuclear Physics, N.C.S.R. 'Demokritos', GR-15310 Aghia Paraskevi, Attiki (Greece); Minkov, N.; Yotov, P. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigrad Road, BG-1784 Sofia (Bulgaria)

2006-04-26

427

Effects of line shifts and the ion quadrupole contribution of spectral line asymmetries.  

SciTech Connect

Line asymmetries and the corresponding shift of spectral lines due to the electron penetration of the radiator orbitals and the ion quadrupole contribution become more significant with increasing principal quantum number and increasing electron density. The mean field static shift due to electron penetration of the orbitals gives rise to an overall shift of the line to lower energy and a significant asymmetry near line center, but does not generate much redhlue far wing asymmetry. The ion quadrupole contribution results in a small blue shift of the spectral line and a small change in asymmetry near line center, but it gives rise to a significant redhlue wing asymmetry in the far wings of the line. Experimental data fiom recent spherical implosion experiments on OMEGA shows evidence of the mean field static shift and may also show the effects of level interactions between the Ar Lyman -{gamma}, -{delta}, -{var_epsilon} lines and also the Ar He -{gamma}, -{delta} lines.

Gunderson, M. A. (Mark A.); Delamater, N. D. (Norman D.); Kilcrease, D. P. (David P.); Haynes, D. A. (Donald A.)

2002-01-01

428

Design Studies of Nb3Sn High-Gradient Quadrupole Models for LARP  

SciTech Connect

Insertion quadrupoles with large aperture and high gradient are required to achieve the luminosity upgrade goal of 10{sup 35} cm{sup -2} s{sup -1} at the Large Hadron Collider (LHC). In 2004, the US Department of Energy established the LHC Accelerator Research Program (LARP) to develop a technology base for the upgrade. Nb{sub 3}Sn conductor is required in order to operate at high field and with sufficient temperature margin. We report here on the conceptual design studies of a series of 1 m long 'High-gradient Quadrupoles' (HQ) that will explore the magnet performance limits in terms of peak fields, forces and stresses. The HQ design is expected to provide coil peak fields of more than 15 T, corresponding to gradients above 300 T/m in a 90 mm bore. Conductor requirements, magnetic, mechanical and quench protection issues for candidate HQ designs will be presented and discussed.

Andreev, Nikolai; Caspi, Shlomo; Dietderich, Daniel; Ferracin, Paolo; Ghosh, Arup; Kashikhin, Vadim; Lietzke, Al; Novitski, Igor; Zlobin, Alexander; McInturff, Alfred; Sabbi, GianLuca

2007-06-01

429

Magnetic measurement of quadrupole and sextupole magnets for the MIT-Bates South Hall Ring (SHR)  

SciTech Connect

Final results of magnetic measurements of 128 quadrupoles and 32 sextupoles are presented. There are many places in the SHR complex where these magnets will be operated from a common power supply. For the quadrupole magnets there are 4 octets, 4 triplets and 18 doublets; these magnets have been matched to {plus_minus}0.1% in excitation response for the operating range corresponding to 0.3--1.0 GeV. For the sextupoles there are four octets where the (pairwise) matching has generally been made to the {plus_minus}0.3% level. Parameterization of the data as well as fits are described and examples of the magnet groupings are shown.

Tieger, D.R.; Zumbro, J.D.; Sapp, W.W. [Bates Linear Accelerator Center, Middleton, MA (US)

1993-07-01

430

Magnetic measurement of quadrupole and sextupole magnets for the MIT-Bates South Hall Ring (SHR)  

SciTech Connect

Final results of magnetic measurements of 128 quadrupoles and 32 sextupoles are presented. There are many places in the SHR complex where these magnets will be operated from a common power supply. For the quadrupole magnets there are 4 octets, 4 triplets and 18 doublets; these magnets have been matched to [plus minus]0.1% in excitation response for the operating range corresponding to 0.3--1.0 GeV. For the sextupoles there are four octets where the (pairwise) matching has generally been made to the [plus minus]0.3% level. Parameterization of the data as well as fits are described and examples of the magnet groupings are shown.

Tieger, D.R.; Zumbro, J.D.; Sapp, W.W. (Bates Linear Accelerator Center, Middleton, MA (United States))

1993-01-01

431

Adjustable Permanent Quadrupoles Using Rotating Magnet Material Rods for the Next Linear Collider  

SciTech Connect

The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 132 Tesla, with a maximum gradient of 135 Tesla per meter, an adjustment range of +0-20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micrometer during the 20% adjustment. In an effort to reduce estimated costs and increase reliability, several designs using hybrid permanent magnets have been developed. All magnets have iron poles and use either Samarium Cobalt or Neodymium Iron to provide the magnetic fields. Two prototypes use rotating rods containing permanent magnetic material to vary the gradient. Gradient changes of 20% and center shifts of less than 20 microns have been measured. These data are compared to an equivalent electromagnet prototype.

James T Volk et al.

2001-09-24

432

Deuterium and sodium quadrupole interactions in sodium hydroxide. II. The monoclinic phase  

NASA Astrophysics Data System (ADS)

The temperature dependence of the 23NaOH pure quadrupole resonance (NQR) frequency has been studied from 77 to 550 K and shows a change in slope and a discontinuous change in frequency of 6±2 kHz at the orthorhombic to monoclinic phase transition at 505 K. At 292 K the 23Na NQR frequency is 1.778±0.001 MHz, ?<0.04. The temperature dependence of the deuterium quadrupole coupling was fit to a librating molecule model between 293 and 570 K (QCC=245±2 kHz, ?=0.05±0.01 at 293 K) and confirms that the frequency of the OD- libration decreases in the high temperature monoclinic phase.

Amm, D. T.; Segel, S. L.; Bastow, T. J.; Jeffrey, K. R.

1986-01-01

433

NMR studies of quadrupole couplings in dimethyl sulfone and carbon disulfide  

SciTech Connect

NMR spectra of dimethyl sulfone (DMS) and carbon disulfide were measured in liquid crystalline solvents. The order parameters were derived from the proton spectra (DMS) or /sup 13/C chemical shifts (CS/sub 2/). From the observed quadrupolar splittings, the components of the quadrupole coupling tensors of /sup 33/S and /sup 17/O were derived. Information on the quadrupole coupling constants (QCC) of /sup 33/S and /sup 17/O in DMS was also obtained by T/sub 1/ relaxation time measurements in a chloroform solution. The data were supplemented by ab initio calculations of the components of the electric field gradient (EFG) tensors in these molecules. The QCC of /sup 33/S and /sup 17/ in DMS are of the order of 1.8 and 8.5 MHz, respectively, while the value for /sup 33/S in CS/sub 2/ is about 13.8 MHz.

Loewenstein, A.; Igner, D.

1988-04-21

434

Core polarization for the electric quadrupole moment of neutron-rich aluminum isotopes  

SciTech Connect

The core polarization effects for the electric quadrupole moments of the neutron-rich {sup 31}Al, {sup 33}Al, and {sup 35}Al isotopes in the vicinity of the island of inversion are investigated by means of the microscopic particle-vibration coupling model in which the Skyrme Hartee-Fock-Bogoliubov and quasiparticle random-phase approximations are used to calculate the single-quasiparticle wave functions and the excitation modes. It is found that the polarization charge for the proton 1d{sub 5/2} hole state in {sup 33}Al is quite sensitive to coupling to the neutrons in the pf-shell associated with the pairing correlations and that the polarization charge in {sup 35}Al becomes larger due to the stronger collectivity of the low-lying quadrupole vibrational mode in the neighboring {sup 36}Si nucleus.

Yoshida, Kenichi [RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198 (Japan)

2009-05-15

435

Recoil velocity of pulsar/magnetar induced by magnetic dipole and quadrupole radiation  

NASA Astrophysics Data System (ADS)

Recoil velocity is examined as a back reaction to the magnetic dipole and quadrupole radiations from a pulsar/magnetar born with rapid rotation. The model is extended from notable Harrison-Tademaru one by including arbitrary field-strength of the magnetic quadrupole moment. The process is slow one operating on a spindown timescale. Resultant velocity depends on not the magnitude, but rather the ratio of the two moments and their geometrical configuration. The model does not necessarily lead to high spatial velocity for a magnetar with a strong magnetic field. This fact is consistent with the recent observational upper bound. The maximum velocity predicted with this model is slightly smaller than that of observed fast-moving pulsars.

Kojima, Yasufumi

2013-03-01

436

Identification and Quadrupole-Moment Measurement of a Superdeformed Band in {sup 84}Zr  

SciTech Connect

High-spin states in {sup 84}Zr were studied using the early implementation phase of the Gammasphere array and the ``Microball`` charged-particle detector system. A cascade of nine {gamma} rays with a dynamic moment of inertia which is characteristic of superdeformed rotational bands in the {ital A}=80 region has been identified and assigned to {sup 84}Zr. The measured transition quadrupole moment of the band corresponds to a prolate quadrupole deformation of {beta}{sub 2}=0.53 and confirms the superdeformed nature of this band. This is the first direct experimental confirmation of the existence of the predicted superdeformed shell gap at {ital N}{congruent}44 particle number.

Jin, H.; Baktash, C.; Brinkman, M.J.; Gross, C.J.; Sarantites, D.G.; Lee, I.Y.; Cederwall, B.; Cristancho, F.; Doering, J.; Durham, F.E.; Hua, P.; Johns, G.D.; Korolija, M.; LaFosse, D.R.; Landulfo, E.; Macchiavelli, A.O.; Rathbun, W.; Saladin, J.X.; Stracener, D.W.; Tabor, S.L.; Werner, T.R. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); [Department of Physics, Rutgers University, New Brunswick, New Jersey 08903 (United States); [UNISOR, Oak Ridge Institute of Science and Education, Oak Ridge, Tennessee 37831 (United States); [Chemistry Department, Washington University, St. Louis, Missouri 63130 (United States); [Nuclear Science Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); [Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States); [Department of Physics, Tulane University, New Orleans, Louisiana 70118 (United States); [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); [Institute of Theoretical Physics, Warsaw University, PL-00-681, Warsaw (Poland)

1995-08-21

437

Search for quadrupole strength in the electroexcitation of the delta+(1232).  

PubMed

High-precision 1H(e,e'p)pi(0) 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, R(SM) = (-6.5+/-0.2(stat+sys)+/-2.5(mod))% and R(EM) = (-2.1+/-0.2(stat+sys)+/-2.0(mod))%, are dominated by model error. Previous R(SM) and R(EM) results should be reconsidered after the model uncertainties associated with the method of their extraction are taken into account. PMID:11290083

Mertz, C; Vellidis, C E; Alarcon, R; Barkhuff, D H; Bernstein, A M; Bertozzi, W; Burkert, V; Chen, J; Comfort, J R; Dodson, G; Dolfini, S; Dow, K; Farkhondeh, M; Finn, J M; Gilad, S; Gothe, R W; Jiang, X; Joo, K; Kaloskamis, N I; Karabarbounis, A; Kelly, J J; Kowalski, S; Kunz, C; Lourie, R W; McIntyre, J I; Milbrath, B D; Miskimen, R; Mitchell, J H; Papanicolas, C N; Perdrisat, C F; Sarty, A J; Shaw, J; Soong, S B; Tieger, D; Tschalaer, C; Turchinetz, W; Ulmer, P E; Van Verst, S; Warren, G A; Weinstein, L B; Williamson, S; Woo, R J; Young, A

2001-04-01

438

Magnetic measurements on the ring dipoles and quadrupoles for the Los Alamos proton storage ring  

SciTech Connect

This paper discusses magnetic measurements and shimming performed on the ring dipoles and quadrupoles for the Los Alamos Proton Storage Ring (PSR). For the dipoles, point-by-point field maps were obtained using a search coil that could be scanned over a three-dimensional grid. By appropriate machining of removable end blocks, all magnet lengths were adjusted to within 0.01% of a nominal value and all integrated multipoles were set within tolerance. Integrated fields of 20 PSR quadrupoles were measured using a rotating ''Morgan Coil'' and a digital spectrum analyzer. The magnets were shimmed to specifications by adjusting steel bolts threaded through the field clamps. 3 refs., 5 figs., 4 tabs.

Schermer, R.I.; Blind, B.; Jason, A.J.; Sawyer, G.A.

1985-01-01

439

Molecular Reorientation in Liquids. Deuteron Quadrupole Relaxation in Liquid Deuterium Oxide and Perdeuterobenzene  

Microsoft Academic Search

Temperature-dependence measurements have been made on the deuteron spin—lattice relaxation times for liquid deuterium oxide and perdeuterobenzene. The quadrupole spin—lattice relaxation is expressed in terms of motional models previously developed for magnetic dipole—dipole relaxation. The deuterium oxide data are discussed in terms of microwave, dielectric relaxation, and hydrogen-bonding phenomena. The T1 values follow rather closely a proportionality to absolute temperature

D. E. Woessner

1964-01-01

440

Relative sensitivities of Bayard-Alpert gauges and a quadrupole mass spectrometer for hydrogen isotope molecules  

Microsoft Academic Search

To apply mass spectrometers and ionization gauges to thermonuclear fusion devices such as pressure gauges, we measured the relative sensitivities (normalized to Hâ) of Bayard--Alpert (B--A) gauges (UGD-1S and UGS-1A, ANELVA Co.) and a quadrupole mass spectrometer (MSQ-150A, ULVAC Co.) for hydrogen isotopes. In the case of the B--A gauges, the relative sensitivities were determined as R\\/sup HD\\/\\/sub B\\/ =

Kuniaki Watanabe; Hitoshi Miyake; Masao Matsuyama

1987-01-01

441

Determination of iodine and molybdenum in milk by quadrupole ICP-MS  

Microsoft Academic Search

A reliable method for the determination of iodine and molybdenum in milk samples, using alkaline digestion with tetramethylammonium hydroxide and hydrogen peroxide, followed by quadrupole ICP-MS analysis, has been developed and tested using certified reference materials. The use of He+O2 (1.0mlmin?1 and 0.6mlmin?1) in the collision-reaction cell of the mass spectrometer to remove 129Xe+ – initially to enable the determination

Helen J. Reid; Abdul A. Bashammakh; Phillip S. Goodall; Mark R. Landon; Ciaran O’Connor; Barry L. Sharp

2008-01-01

442

Quantum theory of magnetic quadrupole lenses for spin-1\\/2 particles  

Microsoft Academic Search

General guidelines for constructing a quantum theory of charged-particle beam\\u000aoptics starting ab initio from the basic equations of quantum mechanics,\\u000aappropriate to the situation under study. In the context of spin-1\\/2 particles,\\u000athese guidelines are used starting with the Dirac equation. The spinor theory\\u000ajust constructed is used to obtain the transfer maps for normal and skew\\u000amagnetic quadrupoles

Sameen Ahmed Khan; Galileo Galilei

1998-01-01

443

Adaptation of a 3-D Quadrupole Ion Trap for Dipolar DC Collisional Activation  

Microsoft Academic Search

Means to allow for the application of a dipolar DC pulse to the end-cap electrodes of a three-dimensional (3-D) quadrupole\\u000a ion trap for as short as a millisecond to as long as hundreds of milliseconds are described. The implementation of dipolar\\u000a DC does not compromise the ability to apply AC waveforms to the end-cap electrodes at other times in the

Boone M. Prentice; Robert E. Santini; Scott A. McLuckey

444

Registration of currents of positive and negative ions in quadrupole mass spectrometer with one measuring channel  

SciTech Connect

A modernized system for registration of the ion currents of MS7302 and MS7303 quadrupole mass spectrometers is described. Charge conversion in interaction of negative ions with a metal surface is used to measure their current, which allows the currents of both positive and negative ions to be measured with a single measuring channel and permits electrical switching from one registration mode to anther without loss of vacuum or stopping of the instrument.

Gall', R.N.; Gor'kovoi, V.V.; Elokhin, V.A.; Kuz'min, A.F.; Protopopov, S.V.

1987-04-01

445

A new method of alpha ray measurement using a Quadrupole Mass Spectrometer  

Microsoft Academic Search

We propose a new method of alpha (?)-ray measurement that detects helium atoms with a Quadrupole Mass Spectrometer (QMS). A demonstration is undertaken with a plastic-covered 241Am ?-emitting source to detect ?-rays stopped in the capsule. We successfully detect helium atoms that diffuse out of the capsule by accumulating them for 1–20h in a closed chamber. The detected amount is

Y. Iwata; Y. Inoue; M. Minowa

2007-01-01

446

Linear radio frequency quadrupole for the cooling and bunching of radioactive ion beams  

SciTech Connect

A linear radio frequency quadrupole has been built for the transport, cooling, and bunching of radioactive ions extracted from an ECR source. The device uses the buffer gas cooling technique and was designed such as to extend the technique for the cooling of very light ions using H{sub 2} as buffer gas. We describe here the technical specifications of the device and present results of the first tests concerning the cooling and bunching of stable ions.

Darius, G.; Ban, G.; Bregeault, J.; Delahaye, P.; Desrues, Ph.; Durand, D.; Flechard, X.; Herbane, M.; Labalme, M.; LeBrun, Ch.; Lienard, E.; Mauger, F.; Merrer, Y.; Mery, A.; Naviliat-Cuncic, O.; Szerypo, J.; Vallerand, Ph.; Vandamme, Ch. [Laboratoire de Physique Corpusculaire, Caen (France); CERN-ISOLDE, Geneva (Switzerland); Laboratoire de Physique Corpusculaire, Caen (France); LPSC, Grenoble (France); Laboratoire de Physique Corpusculaire, Caen (France); Sekt. Phys., LMU, Munich (Germany); Laboratoire de Physique Corpusculaire, Caen (France)

2004-11-01

447

Hartree–Fock and DFT calculations of quadrupole coupling constants in water clusters and ice  

Microsoft Academic Search

Periodic ab initio calculations of the 17O and 2H quadrupole coupling constants (QCC) and their shifts have been performed for ice VIII and ice IX. Cluster calculations were done for smaller water clusters and chains. The ice VIII crystal structure was optimized at the Hartree–Fock and BLYP (DFT) levels with a 6-311g** basis. Out of the methods tested here the

Maria Alfredsson; Kersti Hermansson

1999-01-01

448

Interfacing an aspiration ion mobility spectrometer to a triple quadrupole mass spectrometer  

SciTech Connect

This article presents the combination of an aspiration-type ion mobility spectrometer with a mass spectrometer. The interface between the aspiration ion mobility spectrometer and the mass spectrometer was designed to allow for quick mounting of the aspiration ion mobility spectrometer onto a Sciex API-300 triple quadrupole mass spectrometer. The developed instrumentation is used for gathering fundamental information on aspiration ion mobility spectrometry. Performance of the instrument is demonstrated using 2,6-di-tert-butyl pyridine and dimethyl methylphosphonate.

Adamov, Alexey; Viidanoja, Jyrki; Kaerpaenoja, Esko; Paakkanen, Heikki; Ketola, Raimo A.; Kostiainen, Risto; Sysoev, Alexey; Kotiaho, Tapio [Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 University of Helsinki (Finland); Division of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 (Finland) and Moscow Engineering Physics Institute, State University, Kashirskoe shosse 31, 115409, Moscow (Russian Federation); Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 University of Helsinki (Finland); Environics Ltd., Graanintie 5, P.O. Box 349, FI-50101, Mikkeli (Finland); Division of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 University of Helsinki (Finland) and Drug Discovery and Development Technology Center, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 (Finland); Division of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 (Finland); Moscow Engineering Physics Institute, State University, Kashirskoe shosse 31, 115409, Moscow (Russian Federation); Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 (Finland) and Division of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 (Finland)

2007-04-15

449

Finite Element Model of Training in the superconducting quadrupole magnet SQ02  

SciTech Connect

This paper describes the use of 3D finite element models to study training in superconducting magnets. The simulations are used to examine coil displacements when the electromagnetic forces are cycled, and compute the frictional energy released during conductor motion with the resulting temperature rise. A computed training curve is then presented and discussed. The results from the numerical computations are compared with test results of the Nb{sub 3}Sn racetrack quadrupole magnet SQ02.

Caspi, Shlomo; Ferracin, Paolo

2007-11-01

450

Accuracy of traditional Legendre estimators of quadrupole ratios for the N to Delta transition  

E-print Network

We evaluate the accuracy of traditional estimators often used to extract N to Delta quadrupole ratios from cross section angular distributions for pion electroproduction. We find that neither M1+ dominance nor sp truncation is sufficiently accurate for this purpose. Truncation errors are especially large for EMR, for which it is also essential to perform Rosenbluth separation. The accuracy of similar truncated Legendre analyses for E0+, S0+, and especially M1- is even worse.

J. J. Kelly

2005-07-06

451

Characterization of metabolites of 20(S)-protopanaxadiol in rats using ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry.  

PubMed

In this study, ultra-performance liquid chromatography (UPLC)/quadrupole-time-of-flight mass spectrometry (QTOF-MS) was applied to the rapid analysis of 20(S)-protopanaxadiol (PPD) metabolites in rats after oral administration, enabling the structural characterization of 23 metabolites in plasma, bile, urine, and feces. 16 of these, including M1-M5, M9, and M11-M15, have not been previously reported. The results also indicated that demethylation, dehydration, dehydrogenation, oxidation, deoxidation, and glucuronidation were the major metabolic reactions of PPD in vivo. This study provides important information about the metabolism of PPD which will be helpful for fully understanding its mechanism of action. Furthermore, structural modi?cation of PPD in vivo may aid in obtaining new chemical derivatives for pharmacological screening. PMID:23877070

Jin, Xin; Li, Song-Lin; Zhang, Zhen-hai; Zhu, Fen-xia; Sun, E; Wei, Ying-jie; Jia, Xiao-bin

2013-08-15

452

A theoretical study of repeating sequence in HRP II: a combination of molecular dynamics simulations and (17)O quadrupole coupling tensors.  

PubMed

Histidine rich protein II derived peptide (HRP II 169-182) was investigated by molecular dynamics, MD, simulation and (17)O electric field gradient, EFG, tensor calculations. MD simulation was performed in water at 300 K with alpha-helix initial structure. It was found that peptide loses its initial alpha-helix structure rapidly and is converted to random coil and bent secondary structures. To understand how peptide structure affects EFG tensors, initial structure and final conformations resulting from MD simulations were used to calculate (17)O EFG tensors of backbone carbonyl oxygens. Calculations were performed using B3LYP method and 6-31+G basis set. Calculated (17)O EFG tensors were used to evaluate quadrupole coupling constants, QCC, and asymmetry parameters, eta(Q). Difference between the calculated QCC and eta(Q) values revealed how hydrogen-bonding interactions affect EFG tensors at the sites of each oxygen nucleus. PMID:18708277

Behzadi, Hadi; Esrafili, Mehdi D; van der Spoel, David; Hadipour, Nasser L; Parsafar, Gholamabbas

2008-10-01

453

Understanding Cancer Series: Cancer  

MedlinePLUS

... Cancer Statistics Research & Funding News About NCI Understanding Cancer Series Posted: 01/28/2005 Reviewed: 09/30/ ... Search for Clinical Trials NCI Publications Español Understanding Cancer Series: Cancer Slide Number and Title What is ...

454

The quadrupole moments of spherical-top molecules in orbitally degenerate states  

NASA Astrophysics Data System (ADS)

It is shown that in gases of spherical-top molecules with orbitally degenerate ground electronic terms the orientational mechanism contributes to the generation of birefringence in the presence of a non-uniform electric field. The orientation of molecules by such a field results from the existence of the non-zero quadrupole moments which are available in the molecules under consideration. The contribution to the optical anisotropy arising from the degeneracy has a complicated temperature dependence. At low temperatures, when the ground vibronic state is mainly populated, this contribution is a linear function of inverse temperature as in the case of anisotropic molecules with the symmetry lower than cubic. At intermediate and high temperatures the dependence of the optical anisotropy on T is sufficiently determined by the Jahn-Teller effect taking place when the electronic state has orbital degeneracy. Numerical estimation shows that the effective magnitudes of quadrupole moments of some spherical-top molecules, for example VCl4, ReF6 and IrF6 (G3/2 ground electronic term), are comparable to the quadrupole moments of the diatomic molecules.

Ogurtsov, I. Ya.; Ostrovski, V. L.

455

Cryogenic performance of a conduction-cooling splittable quadrupole magnet for ILC cryomodules  

NASA Astrophysics Data System (ADS)

A conduction-cooled splittable superconducting quadrupole magnet was designed and fabricated at Fermilab for use in cryomodules of the International Linear Collider (ILC) type, in which the magnet was to be assembled around the beam tube to avoid contaminating the ultraclean superconducting radio frequency cavity volume. This quadrupole was first tested in a liquid helium bath environment at Fermilab, where its quench and magnetic properties were characterized. Because the device is to be cooled by conduction when installed in cryomodules, a separate test with a conduction-cooled configuration was planned at KEK and Fermilab. The magnet was converted to a conduction-cooled configuration by adding conduction-cooling passages made of high-purity aluminum. Efforts to convert and refabricate the magnet into a cryostat equipped with a double-stage pulse-tube-type cryocooler began in 2011, and a thermal performance test, including a magnet excitation test of up to 30 A, was conducted at KEK. In this test, the magnet with the conduction-cooled configuration was successfully cooled to 4 K within 190 h, with an acceptable heat load of less than 1 W at 4 K. It was also confirmed that the conduction-cooled splittable superconducting quadrupole magnet was practical for use in ILC-type cryomodules.

Kimura, N.; Andreev, N.; Kashikhin, V. S.; Kerby, J.; Takahashi, M.; Tartaglia, M. A.; Tosaka, T.; Yamamoto, A.

2014-01-01

456

Microwave polarization in the direction of galaxy clusters induced by the CMB quadrupole anisotropy  

E-print Network

Electron scattering induces a polarization in the cosmic microwave background (CMB) signal measured in the direction of a galaxy cluster due to the presence of a quadrupole component in the CMB temperature distribution. Measuring the polarization towards distant clusters provides the unique opportunity to observe the evolution of the CMB quadrupole at moderate redshifts, z~0.5-3. We demonstrate that for the local cluster population the polarization degree will depend on the cluster celestial position. There are two extended regions in the sky, which are opposite to each other, where the polarization is maximal, 0.1(tau/0.02) microK in the Rayleigh-Jeans part of the CMB spectrum (tau being the Thomson optical depth across the cluster) exceeding the contribution from the cluster transverse peculiar motion if v_tpolarization components produced in clusters. These polarization effects, which are of the order of (v_t/c)^2 tau, (v_t/c) tau^2 and (kT_e/m_ec^2) tau^2, as well as the polarization due to the CMB quadrupole, were previously calculated by Sunyaev and Zel'dovich for the Rayleigh-Jeans region. We fully confirm their earlier results and present exact frequency dependencies for all these effects. The polarization is considerably higher in the Wien region of the CMB spectrum.

S. Y. Sazonov; R. A. Sunyaev

1999-03-18

457

Gravitational-wave observations of binary black holes: Effect of non-quadrupole modes  

E-print Network

We study the effect of non-quadrupolar modes in the detection and parameter estimation of gravitational waves (GWs) from non-spinning black-hole binaries. We evaluate the loss of signal-to-noise ratio and the systematic errors in the estimated parameters when one uses a quadrupole-mode template family to detect GW signals with all the relevant modes, for target signals with total masses $20 M_\\odot \\leq M \\leq 250 M_\\odot$ and mass ratios $1 \\leq q \\leq 18$. Target signals are constructed by matching numerical-relativity simulations describing the late inspiral, merger and ringdown of the binary with post-Newtonian/effective-one-body waveforms describing the early inspiral. We find that waveform templates modeling only the quadrupolar modes of the GW signal are sufficient (loss of detection rate $effect of non-quadrupole modes will introduce systematic errors in the estimated parameters. The systematic errors are larger than the expected $1\\,\\sigma$ statistical errors for binaries with large, unequal masses ($q\\gtrsim4, M \\gtrsim 150 M_\\odot$), for sky-averaged signal-to-noise ratios larger than $8$. We provide a summary of the regions in the parameter space where neglecting non-quadrupole modes will cause unacceptable loss of detection rates and unacceptably large systematic biases in the estimated parameters.

Vijay Varma; Parameswaran Ajith; Sascha Husa; Juan Calderon Bustillo; Mark Hannam; Michael Puerrer

2014-09-08

458

Quadrupole and octupole radiation from sup 16 O near 39 MeV excitation  

SciTech Connect

The angular distributions of cross section and analyzing power for the radiative capture reaction {sup 15}N({ital {rvec p}},{gamma}{sub 0}){sup 16}O have been measured at excitation energies of 35.0 and 39.0 MeV in