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1

Nuclear Quadrupole Resonance  

Microsoft Academic Search

Nuclear quadrupole resonance is a recently developed branch of radio-frequency spectroscopy which is concerned with magnetic resonance absorption in crystals. This absorption is due to reorientation of the nonspherical atomic nuclei against crystalline electric fields. Related phenomena in isolated molecules are briefly mentioned in the Introduction A. This is followed in Sec. B by an elementary treatment of the electrostatic

H. G. Dehmelt

1954-01-01

2

Understanding of nuclear quadrupole interactions of 35 Cl, 79 Br and 129 I and binding energies of solid halogens at first-principles level  

Microsoft Academic Search

This paper deals with the understanding at a first-principles level of the nuclear quadrupole interaction (NQI) parameters\\u000a of solid chlorine, bromine and iodine as well as the intermolecular binding of these molecules in the solid. The electronic\\u000a structure investigations that we have carried out to study these properties of the solid halogens are based on the Hartree–Fock\\u000a Cluster approach using

M. M. Aryal; D. R. Mishra; D. D. Paudyal; S. Byahut; N. B. Maharjan; N. P. Adhikari; R. H. Scheicher; Junho Jeong; S. R. Badu; R. H. Pink; Lee Chow; T. P. Das

2007-01-01

3

Calculation of Nuclear Quadrupole Effects in Molecules  

Microsoft Academic Search

Methods are given for the computation of nuclear quadrupole interactions in molecules. They apply primarily to the interpretation of microwave spectra of linear and symmetric top molecules in which either one or two nuclei on the molecular axis show quadrupole coupling to the molecular field. Tables are given of the energy values, based on Casimir's formula, for the quadrupole coupling

J. Bardeen; C. H. Townes

1948-01-01

4

Nuclear Quadrupole Resonance in Superconducting Gallium  

Microsoft Academic Search

The nuclear quadrupole resonance (NQR) of Ga69 is investigated between 0.8 and 4.2°K. (The super-conducting critical temperature is 1.084°K.) Progressive saturation of the resonance is produced at increasing rf power levels of a frequency-modulated marginal oscillator. The nuclear spin-lattice relaxation rate 1T1 (sec-1) is approximately 12T (°K) in the normal state. The contact part of the hyperfine interaction appears to

R. H. Hammond; W. D. Knight

1960-01-01

5

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

6

Erratum: Nuclear quadrupole moment determination of 35 Br, and 127  

E-print Network

Erratum: Nuclear quadrupole moment determination of 35 Cl, 79 Br, and 127 I [Phys. Rev. B 69.20.Ps, 99.10.Cd An error in our implementation of the generalized gradient scheme caused the Br electric leads to the following nuclear quadrupole moments of the 79 Br and 81 Br nuclei: Q 79 Br = 0.318 ± 0

Svane, Axel Torstein

7

Nuclear quadrupole moment determination of 35 Br, and 127  

E-print Network

Nuclear quadrupole moment determination of 35 Cl, 79 Br, and 127 I R. E. Alonso Departamento de Fi effects. The nuclear quadrupole moments of 35 Cl, 79 Br, and 127 I are obtained by comparison of available(35 Cl) 0.0855 b, Q(79 Br) 0.330 b, and Q(127 I) 0.721 b are derived with 3% statistical uncertainty

Svane, Axel Torstein

8

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.

9

Explosives detection by nuclear quadrupole resonance (NQR)  

NASA Astrophysics Data System (ADS)

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 not relevant. Because NQR frequencies of different compounds are quite distinct, we do not encounter false alarms from the NQR signals of other benign materials. We have constructed a laboratory prototype NQR explosives detector which interrogates a volume of 300 liters (10 ft3). This paper presents abbreviated results from a demonstration of the laboratory prototype NQR explosives detector conducted at the Federal Aviation Administration Technical Center in May 1994 on RDX-based explosives.

Garroway, Allen N.; Buess, Michael L.; Yesinowski, James P.; Miller, Joel B.; Krauss, Ronald A.

1994-10-01

10

Sensitive Detection of Nuclear Quadrupole Interactions in Solids  

Microsoft Academic Search

The pure nuclear quadrupole resonance of a low-abundance spin species in zero field is observed for molar concentrations as low as one part in 107 by the application of a nuclear-double-resonance method. The quadrupole resonance is measured in terms of a decrease in the magnetic order of abundant nuclei which are dipolar-coupled to the low-abundance nuclear species. The double-resonance process

R. E. Slusher; E. L. Hahn

1968-01-01

11

Nuclear electric quadrupole moment of bismuth from the molecular method  

NASA Astrophysics Data System (ADS)

Electric-field gradients at bismuth nuclei in BiN and BiP molecules were determined from relativistic Dirac-Coulomb calculations by means of the coupled cluster approach with single and double substitutions with perturbative triple excitation corrections CCSD(T) and CCSD-T approaches. These theoretical values were combined with accurate experimental nuclear quadrupole coupling constants in order to obtain the nuclear electric quadrupole moment (NQM) of the 209Bi nucleus. Our best results indicate an NQM of -420(8) mb, which considerably deviates from the previously accepted standard value given by the atomic method -516(15) mb.

Teodoro, Tiago Quevedo; Haiduke, Roberto Luiz Andrade

2013-11-01

12

Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments  

E-print Network

of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energyTable of Nuclear Magnetic Dipole and Electric Quadrupole Moments N.J.Stone, Oxford Physics, Clarendon Laboratory Parks Road, OXFORD OX1 3PU U.K. This Table is a compilation of experimental

13

Nuclear quadrupole interaction in the low dimensional hf-trichalcogenides  

NASA Astrophysics Data System (ADS)

We report on Time Differential Perturbed Angular Correlation measurements of the nuclear quadrupole interaction of181Hf(?-)181 and its temperature dependence in the low dimensional Hf- trichalcogenides HfS3, HfSe3 and HfTe3. In HfS3 the temperature dependence of the precession frequency is a slowly decreasing function with a negative curvature, the deviation from axial symmetry of the electric field gradient is practically temperature independent. In HfSe3 the NQI shows a peculiar behaviour; between 10K and 300K the quadrupole frequency and the asymmetry parameter increase, between 300K and 400K the frequency decreases while the deviation from axial symmetry increases, indicating a structural phase transition near room temperature. In HfTe3 the quadrupole frequency is practically temperature independent below 600K and increases linearely at higher temperatures, the asymmetry parameter increases steadily in the temperature range from 10K to 600K and then decreases. There is a strong correlation between the strength and the asymmetry of the electric field gradient so that the system depends on one control parameter only.

Saibene, S.; Butz, T.; Lerf, A.; Levy, F.; Abriel, W.

1990-08-01

14

Pure Nuclear Quadrupole Spectra of Chlorine and Antimony Isotopes in Solids  

Microsoft Academic Search

Experimental measurements on nuclear quadrupole resonances of chlorine and antimony isotopes in solids have been made to an accuracy of about 0.001 percent. The results are compared in detail with theoretical results for (1) nuclear quadrupole interaction, (2) interaction between quadrupole coupling and thermal vibrations, and (3) effects of a nuclear hexadecapole. The ratio (eQq)Cl35(eQq)Cl37 varies between 1.268736 and 1.268973

Tien-Chuan Wang

1955-01-01

15

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

16

New table of recommended nuclear electric quadrupole moments  

NASA Astrophysics Data System (ADS)

A new Table of Recommended Nuclear Electric Quadrupole Moments has been prepared and published by the Nuclear Data Section of the IAEA, Vienna Stone (2013). The main feature of the new Table is the adoption, wherever possible, of the best available calculation of the electric field gradient (efg), required to extract the moment from the measured quantity in most measurement methods. All original results have been normalized to take account of differences between the efg used in the original publication and the adopted value. The aim of the new table is to provide a standard reference in which the value given for each moment is the best available and for which full provenance is given.

Stone, N. J.

2015-01-01

17

Zeeman nuclear quadrupole resonance line shapes in powders (I = 3?2)  

Microsoft Academic Search

Theoretical absorption line shapes are presented for Zeeman perturbed nuclear quadrupole resonance transitions (I = 3?2) in polycrystalline materials for the case in which the rf field is parallel to the Zeeman field. For a nuclear spin of 3?2, the pure quadrupole transition frequency ?Q(1+&eegr;2?3)1?2 is insufficient to independently determine either ?Q, the strength of the quadrupole interaction, or &eegr;,

H. R. Brooker; R. B. Creel

1974-01-01

18

Zeeman nuclear quadrupole resonance line shapes in powders (I = 3\\/2)  

Microsoft Academic Search

Theoretical absorption line shapes are presented for Zeeman perturbed nuclear quadrupole resonance transitions (I = 3\\/2) in polycrystalline materials for the case in which the rf field is parallel to the Zeeman field. For a nuclear spin of 3\\/2, the pure quadrupole transition frequency nuQ(1+?2\\/3)1\\/2 is insufficient to independently determine either nuQ, the strength of the quadrupole interaction, or ?,

H. R. Brooker; R. B. Creel

1974-01-01

19

A new approach to stroboscopic resonance measurements of the nuclear quadrupole interaction  

Microsoft Academic Search

A new stroboscopic resonance method for the measurement of the quadrupole interaction of long-lived nuclear isomers excited by pulsed beams with a fixed repetition frequency is demonstrated. The method utilizes the phenomenon of beats which occurs when a magnetic perturbation is introduced in the presence of a pure quadrupole interaction. The nuclear precession is thus controlled by the beat frequencies

P. Raghavan; R. S. Raghavan

1977-01-01

20

Nuclear quadrupole resonance study of hydrogen bonded solid materials.  

PubMed

Nuclear quadrupole resonance is presented as a method for the study of solid hydrogen bonded materials. NQR study of hydrogen bonds in ferroelectric and paraelectric KH2PO4, antiferroelectric and paraelectric squaric acid, ferroelectric croconic acid and antiferroelectric and paraelectric cocrystal 5'-dimethyl-2, 2'-bipyridine - chloranilic acid (1:1) are discussed in more details. A 14N NQR study of the strong short O-HKN hydrogen bond in two polymorphic forms of cocrystal isonicotinamide-oxalic acid (2:1) is presented as well. Various correlations between the NQR parameters and between the NQR and structural parameters have been observed. These correlations may be used to determine the proton position in a hydrogen bond and some other structural parameters from the NQR data. PMID:24062106

Seliger, Janez

2011-09-01

21

Effect of Large Quadrupole Interactions on Nuclear Radiofrequency Spectra at Twice Larmor Frequency  

Microsoft Academic Search

The work of B. T. Feld and W. E. Lamb [Phys. Rev. 67, 15 (1945)] on the effect of a nuclear electrical quadrupole moment on the radiofrequency absorption spectrum of a heteronuclear diatomic molecule in a magnetic field is extended to a special case not considered by them. This is a case in which the electrical quadrupole interaction energy is

Norman F. Ramsey

1948-01-01

22

Nuclear quadrupole resonance studies of transparent conducting oxides.  

PubMed

We report (63,65)Cu spin-lattice relaxation rates measured by nuclear quadrupole resonance (NQR) in the delafossite compound CuYO(2) and CuYO(2):Ca over a temperature range from 200 to 450K. CuYO(2):Ca is a prototype transparent oxide exhibiting p-type electrical conductivity. Relaxation rates in CuYO(2):Ca are enhanced by one to two orders of magnitude relative to undoped material, exhibit much stronger temperature dependence, and contain contributions from magnetic and quadrupolar relaxation mechanisms with roughly equal strengths. Relaxation in undoped CuYO(2) is of purely quadrupolar origin and is attributed to interactions with lattice phonons. The main focus of this paper is the magnetic contribution to the relaxation rate in CuYO(2):Ca which is attributed to the hyperfine fields of carriers. It is argued that the dynamics of the hyperfine field are dominated by the hopping rate for carrier transfers between neighboring atoms in the copper planes of the delafossite structure. Comparison of the magnetic relaxation rates with the DC conductivity permits an estimate of the carrier concentration and mobility. PMID:15388186

Warren, W W; Rajabzadeh, A; Olheiser, T; Liu, J; Tate, J; Jayaraj, M K; Vanaja, K A

2004-01-01

23

Frequency selective detection of nuclear quadrupole resonance (NQR) spin echoes  

NASA Astrophysics Data System (ADS)

Nuclear Quadrupole Resonance (NQR) is a radio frequency (RF) technique that can be used to detect the presence of quadrupolar nuclei, such as the 14N nucleus prevalent in many explosives and narcotics. The technique has been hampered by low signal-to-noise ratios and is further aggravated by the presence of RF interference (RFI). To ensure accurate detection, proposed detectors should exploit the rich form of the NQR signal. Furthermore, the detectors should also be robust to any remaining residual interference, left after suitable RFI mitigation has been employed. In this paper, we propose a new NQR data model, particularly for the realistic case where multiple pulse sequences are used to generate trains of spin echoes. Furthermore, we refine two recently proposed approximative maximum likelihood (AML) detectors, enabling the algorithm to optimally exploit the data model of the entire echo train and also incorporate knowledge of the temperature dependent spin-echo decay time. The AML-based detectors ensure accurate detection and robustness against residual RFI, even when the temperature of the sample is not precisely known, by exploiting the dependencies of the NQR resonant lines on temperature. Further robustness against residual interference is gained as the proposed detector is frequency selective; exploiting only those regions of the spectrum where the NQR signal is expected. Extensive numerical evaluations based on both simulated and measured NQR data indicate that the proposed Frequency selective Echo Train AML (FETAML) detector offers a significant improvement as compared to other existing detectors.

Somasundaram, Samuel D.; Jakobsson, Andreas; Smith, John A. S.; Althoefer, Kaspar A.

2006-05-01

24

Nuclear Quadrupole Resonance of Cu in High-Tc Bi-Pb-Sr-Ca-Cu-O  

Microsoft Academic Search

Nuclear quadrupole resonance (NQR) signals of Cu have been discovered in the high-Tc superconducting oxide Bi-Pb-Sr-Ca-Cu-O with Tc{=}109 K. It has been observed that there are two Cu sites with a different quadrupole coupling. The temperature dependence of the nuclear relaxation rate, 1\\/T1, was similar to that of the CuO2 plane in YBa2Cu3O7. It is found that the 1\\/T1 for

Kenji Fujiwara; Yoshio Kitaoka; Kunisuke Asayama; Hiroyuki Sasakura; Sinnosuke Minamigawa; Kiyotaka Nakahigashi; Shigemitsu Nakanishi; Mineo Kogachi; Nobuo Fukuoka; Akira Yanase

1989-01-01

25

Detecting body cavity bombs with nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

Nuclear Quadrupole Resonance (NQR) is a technology with great potential for detecting hidden explosives. Past NQR research has studied the detection of land mines and bombs concealed within luggage and packages. This thesis focuses on an NQR application that has received less attention and little or no publicly available research: detecting body cavity bombs (BCBs). BCBs include explosives that have been ingested, inserted into orifices, or surgically implanted. BCBs present a threat to aviation and secure facilities. They are extremely difficult to detect with the technology currently employed at security checkpoints. To evaluate whether or not NQR can be used to detect BCBs, a computational model is developed to assess how the dielectric properties of biological tissue affect the radio frequency magnetic field employed in NQR (0.5-5MHz). The relative permittivity of some biological tissue is very high (over 1,000 at 1MHz), making it conceivable that there is a significant effect on the electromagnetic field. To study this effect, the low-frequency approximation known as the Darwin model is employed. First, the electromagnetic field of a coil is calculated in free space. Second, a dielectric object or set of objects is introduced, and the free-space electric field is modified to accommodate the dielectric object ensuring that the relevant boundary conditions are obeyed. Finally, the magnetic field associated with the corrected electric field is calculated. This corrected magnetic field is evaluated with an NQR simulation to estimate the impact of dielectric tissue on NQR measurements. The effect of dielectric tissue is shown to be small, thus obviating a potential barrier to BCB detection. The NQR model presented may assist those designing excitation and detection coils for NQR. Some general coil design considerations and strategies are discussed.

Collins, Michael London

26

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

27

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

28

The nuclear quadrupole moment of 57Fe from microscopic nuclear and atomic calculations  

E-print Network

The nuclear quadrupole moment of the I=3/2- excited nuclear state of 57Fe at 14.41 keV, important in M\\"ossbauer spectroscopy, is determined from the large-scale nuclear shell-model calculations for 57Fe and also from the electronic ab initio and density functional theory calculations including solid state and electron correlation effects for the molecules Fe(CO)_5 and Fe(C_5 H_5)_2. Both independent methods yield very similar results. The recommended value is 0.16(1) eb. The NQM of the isomeric 10+ in 54Fe has also been calculated. The new value (0.5 eb), consistent with the perturbed angular distribution data, is by a factor of two larger than the currently recommended value.

Gabriel Martinez-Pinedo; Peter Schwerdtfeger; Etienne Caurier; Karlheinz Langanke; Witold Nazarewicz; Tilo Sohnel

2001-01-15

29

Effects of Large Nuclear Quadrupoles on Dielectric Properties of Glasses at Very Low Temperatures  

NASA Astrophysics Data System (ADS)

The universal behaviour of amorphous solids at low temperatures, governed by atomic tunneling systems as described by the standard tunneling model, has long been a generally accepted fact. In the last years, however, measurements of dielectric two-pulse polarization echoes have revealed that nuclear quadrupole moments involved in atomic tunneling systems can cause specific material-dependent effects in magnetic fields. We have performed measurements of the dielectric properties of the two multicomponent glasses N-KZFS11 and HY-1, containing several percent of tantalum oxide and holmium oxide respectively. As 181Ta and 165Ho both carry very large nuclear quadrupole moments, these glasses are ideal candidates to study the influence of nuclear quadrupole moments on the properties of glasses at very low temperatures. Our measurements not only show unique dielectric behaviour in both glasses, but also differ significantly from various predictions of the standard tunneling model.

Luck, A.; Fleischmann, A.; Reiser, A.; Enss, C.

2014-12-01

30

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

31

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

32

CATALOG OF NUCLEAR QUADRUPOLE INTERACTIONS AND RESONANCE FREQUENCIES IN SOLIDS. PART I. ELEMENTS AND INORGANIC COMPOUNDS  

Microsoft Academic Search

A tabulation of nuclear quadrupoie resonance data is provided giving the ; quadrupole resonance frequency for a given nucleus in a given compound, and, ; where reported in literature, the coupling constant. Data are given for Al, Sb, ; As, Ba,Be, Bi, B, Cs, Cu, D, Ga, In, Li, Hg, Nb, N, Re, Rb, Na, S, Tc, Cl, Br, I,

S. L. Segel; R. G. Barnes

1962-01-01

33

Nuclear quadrupole resonance of 35Cl nuclei in glassy solution of chlorobenzene in pyridine  

Microsoft Academic Search

Pulsed nuclear quadrupole resonance (NQR) measurements of 35Cl nuclei were performed on 43.5 mol % chlorobenzene solution in pyridine (a) in glassy state (Tg=131 K) after quenching in liquid nitrogen and (b) in crystalline precipitate under slow cooling starting from liquid phase. In both cases the NQR line shape, obtained by the fast Fourier transform (FFT) method, consisted of a

A. E. Wolfenson; A. H. Brunetti; D. J. Pusiol; W. M. Pontuschka

1990-01-01

34

Effect of nuclear quadrupole interactions on the dynamics of two-level systems in glasses.  

PubMed

The standard tunneling model describes quite satisfactorily the properties of amorphous solids at temperatures T < 1K in terms of an ensemble of two-level systems including the logarithmic temperature dependence of the dielectric constant. Yet, experiments have shown that at ultralow temperatures T< 5 mK such a temperature behavior breaks down and the dielectric constant becomes temperature independent (plateau effect). In this Letter we suggest an explanation of this behavior exploiting the effect of the nuclear quadrupole interaction on tunneling. We also predict that the application of a sufficiently large magnetic field B> 10T should restore the logarithmic dependence because of the suppression of the nuclear quadrupole interaction. PMID:16486595

Burin, A L; Polishchuk, I Ya; Fulde, P; Sereda, Y

2006-01-20

35

Utilization of pure nuclear quadrupole resonance spectroscopy for the study of pharmaceutical crystal forms.  

PubMed

Solid-state physical characterization of a pharmaceutical substance is necessary for successful development and approval of the final product. Different physical analytical techniques are available to do so: X-ray diffraction (XRD), IR, Raman, DSC, TG and NMR. Moreover, all of them detect the presence of excipients perturbing the analysis of the pure substance in low doses. In order to study polymorphism and pseudo polymorphism of drug, this paper introduces possible applications of pure nuclear quadrupole resonance, as a non-destructive technique in qualitative and quantitative approaches. Chlorpropamide and diclofenac sodium were used as examples. Unlike the mentioned techniques, the nuclear quadrupole resonance (NQR) signal of pharmaceutical compounds is not perturbed by the presence of solid excipient or other substances unless they possess resonance frequencies in the same frequency range of the compound studied. PMID:15913931

Pérez, S C; Cerioni, L; Wolfenson, A E; Faudone, S; Cuffini, S L

2005-07-14

36

High-frequency nuclear quadrupole resonance apparatus for use in pressure cell  

NASA Astrophysics Data System (ADS)

A high-frequency NMR apparatus for use in pressure cell is described. All components of the resonance circuit are set in the pressure cell. This method makes the resonance frequency much less influenced by large stray capacitance residing at the electrical feedthrough of the pressure cell. With the use of this apparatus, a pressure-induced neutral-ionic phase transition in DMTTF-QBr4 was successfully observed by 79Br nuclear quadrupole resonance, whose resonance frequency is ˜300 MHz.

Iwase, F.; Miyagawa, K.; Kanoda, K.

2012-06-01

37

Microwave Spectrum and Nuclear Quadrupole Interaction of 3-Iodothiophene in the Excited Vibrational States  

Microsoft Academic Search

The rotational spectra of the excited vibrational states of 3-iodothiophene in the frequency region 10–35 GHz were investigated. Thea-typeR-branch transitions of two vibrational modes were assigned, and the rotational constants and the centrifugal distortion constants were determined. The nuclear quadrupole coupling constant tensors were obtained from the hyperfine splittings of the rotational transitions. The vibration–rotation constants of the two vibrational

Yoshiaki Sasada; Yuzuru Niide

1995-01-01

38

Nuclear quadrupole optical hole burning in stoichiometric EuAsO4  

Microsoft Academic Search

The intrinsic site and over forty defect sites have been studied by optical absorption, fluorescence and optical hole burning in EuAsO4. The hole-burning spectra have allowed determination of the nuclear electrical quadrupole parameters P and asymmetry parameters eta for the 5D0 levels for both Eu isotopes at 11 of these sites. A model is presented that explains the observed correlation

R. L. Cone; M. J. M. Leask; M. G. Robinson; B. E. Watts

1988-01-01

39

35Cl nuclear quadrupole resonance study in 4,4'-dichlorobiphenyl sulphone: A possible incommensurate system  

Microsoft Academic Search

Pulsed nuclear quadrupole resonance (NQR) has been used to get information about the nature of the molecular dynamics in two crystalline phases of 4,4'-dichlorobiphenyl sulphone. This work includes detailed experimental measurements of the NQR frequency, spin-lattice relaxation time, and line intensity temperature behavior in the range of temperature where a possible normal-to-incommensurate phase transition occurs. The experimental results show the

D. J. Pusiol; A. E. Wolfenson; A. H. Brunetti

1989-01-01

40

First Principles Study of Nuclear Quadrupole Interactions in Single and Double Chain DNA and Solid Nucleobases  

NASA Astrophysics Data System (ADS)

Nuclear Quadrupole Interactions (NQI) of ^17O, ^14N and ^2H nuclei have been studied for free nucleobases and nucleobases in single strand and double strand DNA and in solid state. Our first-principles investigations were carried out using the Gaussian 2003 set of programs to implement the Hartree-Fock procedure combined with many-body effects included using many-body perturbation theory. As expected for NQI in general, many-body effects are found to be small. Results will be presented for the quadrupole coupling constants (e^2qQ) and asymmetry parameters (?) for the nucleobases in the various environments. Trends in e^2qQ and ? in the different environments will be discussed. In the case of the solid nucleobases, comparisons will be made with available experimental data [1] for ^17O nuclei.[3pt] [1] Gang Wu et al., J. Am. Chem. Soc. 124, 1768 (2002)

Das, T. P.; Pink, R. H.; Badu, S. R.; Dubey, Archana; Scheicher, R. H.; Saha, H. P.; Chow, Lee; Huang, M. B.

2009-03-01

41

High-frequency nuclear quadrupole resonance apparatus for use in pressure cell.  

PubMed

A high-frequency NMR apparatus for use in pressure cell is described. All components of the resonance circuit are set in the pressure cell. This method makes the resonance frequency much less influenced by large stray capacitance residing at the electrical feedthrough of the pressure cell. With the use of this apparatus, a pressure-induced neutral-ionic phase transition in DMTTF-QBr(4) was successfully observed by (79)Br nuclear quadrupole resonance, whose resonance frequency is ?300 MHz. PMID:22755648

Iwase, F; Miyagawa, K; Kanoda, K

2012-06-01

42

Structural implications of nuclear electric quadrupole splittings in high-Tc superconductors  

Microsoft Academic Search

The electric field gradients and nuclear quadrupole coupling constants are calculated for La in La2CuO4, Eu in EuBa2Cu3O7, and Cu and Fe (as a replacement for Cu in YBa2Cu3O7. We use an ionic model which regards the high-Tc superconductors as primarily ionic crystals modified by the introduction of a relatively small number of charge carriers via doping in La2CuO4 and

Frank J. Adrian

1988-01-01

43

Microwave Spectrum and Nuclear Quadrupole Interaction of 3-Iodothiophene in the Excited Vibrational States  

NASA Astrophysics Data System (ADS)

The rotational spectra of the excited vibrational states of 3-iodothiophene in the frequency region 10-35 GHz were investigated. The a-type R-branch transitions of two vibrational modes were assigned, and the rotational constants and the centrifugal distortion constants were determined. The nuclear quadrupole coupling constant tensors were obtained from the hyperfine splittings of the rotational transitions. The vibration-rotation constants of the two vibrational modes were also determined. The energy differences between the ground and excited states associated with the two vibrational modes of the C;u9I bond were estimated by measuring the relative intensities of the absorption lines.

Sasada, Yoshiaki; Niide, Yuzuru

1995-12-01

44

Deuterium and nitrogen-14 nuclear quadrupole resonance spectra of cytosine-amino acid complexes  

NASA Astrophysics Data System (ADS)

The 14N and 2H nuclear quadrupole resonance spectra of cytosine complexes of the acids N-formylglycine, N-benzoylglycine and N-phthaloylglutamic, and of the cytidine complex of salicylic acid have been obtained at 77 K on powdered samples, using the double resonance level crossing technique, DRLC. Both normal abundance and deuterium-enriched forms of the compounds were studied. Use of various assignment aids, discussed at length, make it possible to completely assign the electric field gradient parameters to all 14N and 2H sites in the compounds.

Keiter, Ellen A.; Hiyama, Yukio; Brown, Theodore L.

1983-12-01

45

Measurement of the 14N nuclear quadrupole resonance frequencies by the solid effect  

NASA Astrophysics Data System (ADS)

1H- 14N nuclear quadrupole double resonance using magnetic field cycling between high and low magnetic field and solid effect in the low magnetic field is analyzed in details. The transition probabilities per unit time for the solid-effect transitions are calculated. The double resonance spectra are calculated in the limiting cases of fast and slow nitrogen spin-lattice relaxation. The double resonance spectra are measured in histamine and quinolinic acid. The experimental spectra are analyzed and the 14N NQR frequencies are determined.

Seliger, J.; Žagar, V.

2008-07-01

46

Do we understand the electric quadrupole strength distributions in magic nuclei?  

NASA Astrophysics Data System (ADS)

A comparison between the electric quadrupole ( E2) strength distributions in 40, 48Ca with new results from 52Cr is presented. The deduced E2 strength distributions and the exhaustion of the isoscalar energy-weighted E2 sum rule are very different. Microscopic approaches fail to reproduce these differences. A survey of the available data shows that the exhaustion of the energy-weighted isoscalar E2 sum rule in doubly magic nuclei below the isoscalar giant quadrupole resonance is typically more than two times larger than in semi-magic nuclei. On the other hand, the E2 strength in this energy region exhausts about 50% of the total E2 strength, independent from shell closures.

Enders, J.; Karg, O.; von Neumann-Cosel, P.; Ponomarev, V. Yu.

2007-01-01

47

Investigation of Wavelet-Based Enhancements to Nuclear Quadrupole Resonance Explosives Detectors  

SciTech Connect

Nuclear Quadrupole Resonance (NQR) is effective for the detection and identification of certain types of explosives such as RDX, PETN and TNT. In explosive detection, the NQR response of certain 14N nuclei present in the crystalline material is probed. The 14N nuclei possess a nuclear quadrupole moment which in the presence of an electric field gradient produces an energy level splitting which may be excited by radio-frequency magnetic fields. Pulsing on the sample with a radio signal of the appropriate frequency produces a transient NQR response which may then be detected. Since the resonant frequency is dependent upon both the quadrupole moment of the 14N nucleus and the nature of the local electric field gradients, it is very compound specific. Under DARPA sponsorship, the authors are using multiresolution methods to investigate the enhancement of operation of NQR explosives detectors used for land mine detection. For this application, NQR processing time must be reduced to less than one second. False alarm responses due to acoustic and piezoelectric ringing must be suppressed. Also, as TNT is the most prevalent explosive found in land mines, NQR detection of TNT must be made practical despite unfavorable relaxation tunes. All three issues require improvement in signal-to-noise ratio, and all would benefit from improved feature extraction. This paper reports some of the insights provided by multiresolution methods that can be used to obtain these improvements. It includes results of multiresolution analysis of experimentally observed NQR signatures for RDX responses and various false alarm signatures in the absence of explosive compounds.

Kercel, Stephen W.; Dress, William B.; Hibbs, Andrew D.; Barrall, Geoffrey A.

1998-06-01

48

Hartree-Fock Cluster Study of Electronic Structures and Nuclear Quadrupole Interactions in Solid Nucleobases.  

NASA Astrophysics Data System (ADS)

In recent work [1] we have studied nucleobases attached to a CH3 group to simulate the influence of their binding to the sugar rings and the phosphate groups in DNA and RNA and the effect of this binding on the nuclear quadrupole interactions of ^14N, ^17O and ^2H nuclei. Our results from this work have indicated that for ^17O, the binding to the CH3 group moves our results from the free nucleobases closer to the experimentally observed data [2] in the solid nucleobases. We are now investigating the solid nucleobases by the first --principles Hartree-Fock cluster procedure that we have employed earlier for the halogen molecular solids [3]. Our results for the binding energy of an imidazole molecule in the molecular solid system and the ^14N, ^17O and ^2H nuclear quadrupole interaction parameters will be presented. [1] T.P. Das et al (at this APS meeting), [2] Gang Wu et al, J. Am.Chem. Soc. 124, 1768(2002). [3] M.M. Aryal et al Hyperfine Interactions (to be published).

Scheicher, R. H.; Dubey, Archana; Badu, S. R.; Saha, H. P.; Pink, R. H.; Nagamine, K.; Torikai, E.; Chow, Lee; Das, T. P.

2008-03-01

49

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

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

50

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

51

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

52

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

53

Nuclear quadrupole moment-induced Cotton-Mouton effect in molecules  

SciTech Connect

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: H{sub 2}O, CH{sub 3}NO{sub 2}, CH{sub 3}CH{sub 2}OH, C{sub 6}H{sub 6}, C{sub 6}H{sub 12} (cyclohexane), HI, XeF{sub 2}, WF{sub 5}Cl, and Pt(C{sub 2}dtp){sub 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{sup ?3}–10{sup ?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, E-mail: lijuan.fu@oulu.fi, E-mail: juha.vaara@iki.fi; Vaara, Juha, E-mail: lijuan.fu@oulu.fi, 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)

2014-01-14

54

Analysis of nuclear-quadrupole-resonance spectrum of incommensurate phases: The case of bis(4-chlorophenyl) sulfone  

Microsoft Academic Search

In this work, previous experimental studies of the 35Cl nuclear-quadrupole-resonance (NQR) line shape in the incommensurate phase of bis(4-chlorophenyl) sulfone were extended. The broad spectra in the incommensurate phase (IC) were measured using the Fourier transform of the nuclear signal to avoid systematic errors committed in some studies of this compound. The results were interpreted within the framework of the

J. Schneider; C. Schürrer; A. Wolfenson; A. Brunetti

1998-01-01

55

Hydrogen bonding and proton transfer in cocrystals of 4,4'-bipyridyl and organic acids studied using nuclear quadrupole resonance.  

PubMed

Cocrystals of 4,4'-bipyridyl and several carboxylic acids were grown from the methanol solution of the cocrystal formers. Complete (14)N NQR spectra of these cocrystals have been measured using (1)H-(14)N nuclear quadrupole double resonance. The principal values of the quadrupole coupling tensor are calculated from the (14)N NQR frequencies. A large variation in the (14)N quadrupole coupling constant between 1.3 MHz and 4.7 MHz is observed. A very low (14)N quadrupole coupling constant, characteristic for proton transfer O-H···N ? O(-)···H-N(+), is observed in 4,4'-bipyridyl-oxalic acid (1?:?1). In 4,4'-bipyridyl-5-chlorosalycilic acid (1?:?1) the (14)N NQR data show the presence of a short, strong N···H···O hydrogen bond. A correlation of the principal values of the (14)N quadrupole coupling tensor is observed. The correlation is analyzed in the model, where the deformation of the lone pair electron orbital and the change of the population of the ?-electron orbital produce the variation of the (14)N quadrupole coupling tensor in the hydrogen bonded 4,4'-bipyridyl. The temperature variation of the (14)N quadrupole coupling tensor in 4,4'-bipyridyl-5-chlorosalycilic acid (1?:?1) is analyzed. Proton displacement within the N···H···O hydrogen bond and the change of the population of the ?-electron orbital at the two nitrogen positions in a 4,4'-bipyridyl molecule in the temperature interval between 157 K and 323 K are determined. PMID:25052623

Seliger, Janez; Žagar, Veselko

2014-09-14

56

Thermal Conductivity of Glasses Induced by Nuclear Quadrupole Interaction at Ultra Low Temperatures  

NASA Astrophysics Data System (ADS)

It is investigated how nuclear degrees of freedom of tunneling system (TS) inherent in amorphous solids influence its acoustic properties. It was shown in our previous papers that below 10 mK nuclear quadrupole interaction breaks down the coherent tunneling. This phenomenon results in appearance of the quasi-gap in the distribution function for the tunneling amplitude splitting. The quasi-gap is responsible for the plateau in the temperature dependence of the real part of a dielectric permittivity or speed of sound. In this paper we are interested in ultrasonic absorption and thermal conductivity which are intimately connected. We demonstrate that there exists a temperature interval in a millikelvin region where the sound absorption behavior changes drastically from the behavior predicted by the standard tunneling model (STM). In particular, the sound absorption increases approximately by an order of magnitude. Since in the millikelvin region the heat transport is due to acoustic phonons, the thermal conductivity also should demonstrate a strong increase as compared to standard tunneling model. The application of a strong magnetic field is known to restore the coherent tunneling and the standard distribution for the tunneling splitting amplitude. Thus, one can expect that in a strong magnetic field the thermal conductivity should drop in the temperature interval where the coherent tunneling was initially destroyed.

Polishchuk, I. Y.; Burin, A. L.

2011-03-01

57

Nuclear quadrupole interactions of 11B in a LiB3O5 single crystal  

NASA Astrophysics Data System (ADS)

The rotation patterns of the nuclear magnetic resonance (NMR) spectra of an 11B nucleus in a LiB3O5 (LBO) single crystal were measured in the three mutually perpendicular crystallographic planes at room temperature. We identified three centres denoted as B1, B2, and B3, each of which consists of four sets of 11B NMR spectra originating from the chemically equivalent but magnetically inequivalent sites. The four sets belonging to each centre were properly classified in accordance with crystal symmetry and analysed. The principal values and principal axis orientations of the nuclear quadrupole coupling (NQC) tensors were determined for the first time. The centres B1, B2, and B3 were assigned to boron sites in the crystalline lattice of LBO by comparing the directions of the B-O bonds and the principal axes of the NQC tensor (P). The NQC constant (e2qQ/h) and asymmetry parameter (eegr) were determined as follows: for B1, e2qQ/h = 2.615 ± 0.005 MHz and eegr = 0.266 ± 0.005; for B2, e2qQ/h = 0.176 ± 0.003 MHz and eegr = 0.584 ± 0.003; and for B3, e2qQ/h = 2.690 ± 0.004 MHz and eegr = 0.204 ± 0.003.

Ahn, Sang Won; Kim, In Gyoo; Choh, Sung Ho; Kang, Hee Jae

2004-01-01

58

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

59

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

60

C P -Violating Effect of the Th Nuclear Magnetic Quadrupole Moment: Accurate Many-Body Study of ThO  

NASA Astrophysics Data System (ADS)

Investigations of C P violation in the hadron sector may be done using measurements in the ThO molecule. Recent measurements in this molecule improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Another time-reversal (T ) and parity (P )-violating effect in 229ThO is induced by the nuclear magnetic quadrupole moment. We perform nuclear and molecular calculations to express this effect in terms of the strength constants of T , P -odd nuclear forces, neutron EDM, QCD vacuum angle ? , quark EDM, and chromo-EDM.

Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.; Flambaum, V. V.

2014-12-01

61

Narcotics and explosives detection by 14N pure nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

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 not relevant. Because NQR frequencies of different compounds are quite distinct, we do not encounter false alarms from the NQR signals of other benign materials. We have constructed a proof-of-concept NQR explosives detector which interrogates a volume of 300 liters (10 ft3). With minimal modification to the existing explosives detector, we can detect operationally relevant quantities of (free base) cocaine within the 300-liter inspection volume in 6 seconds. We are presently extending this approach to the detection of heroin base and also examining 14N and 35,37Cl pure NQR for detection of the hydrochloride forms of both materials. An adaptation of this NQR approach may be suitable for scanning personnel for externally carried contraband and explosives. We first outline the basics of the NQR approach, highlighting strengths and weaknesses, and then present representative results for RDX and cocaine detection. We also present a partial compendium of relevant NQR parameters measured for some materials of interest.

Garroway, Allen N.; Buess, Michael L.; Yesinowski, James P.; Miller, Joel B.

1994-03-01

62

Low-power stimulated emission nuclear quadrupole resonance detection system utilizing Rabi transitions  

NASA Astrophysics Data System (ADS)

The application of CW radar techniques to Nuclear Quadrupole Resonance (NQR) detection of nitrogen based explosives and chlorine based narcotics enables the use of low power levels, in the range of 10's of watts, to yield high signal strengths. By utilizing Rabi transitions the nucleus oscillates between states one and two under the time dependent incident electromagnetic field and alternately absorbs energy from the incident field while emitting coherent energy via stimulated emission. Through the application of a cancellation algorithm the incident field is eliminated from the NQR response, allowing the receive signal to be measured while transmitting. The response signal is processed using matched filters of the NQR response which enables the direct detection of explosives. This technology has applicability to the direct detection of explosives and narcotics for security screening, all at safe low power levels, opposed to the current XRay and Millimeter wave screening systems that detect objects that may contain explosives and utilize high power. The quantum mechanics theoretical basis for the approach and an application for a system for security screening are described with empirical results presented to show the effects observed.

Apostolos, John; Mouyos, William; Feng, Judy; Chase, Walter

2013-06-01

63

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

64

Superconductivity and Magnetic Fluctuations in Cd2Re2O7 via Cd Nuclear Magnetic Resonance and Re Nuclear Quadrupole Resonance  

Microsoft Academic Search

We report Cd nuclear magnetic resonance (NMR) and Re nuclear quadrupole resonance (NQR) studies on Cd 2Re2O7, the first superconductor among pyrochlore oxides (Tc~=1 K). The Re NQR spectrum at zero magnetic field below 100 K rules out any magnetic or charge order. The spin-lattice relaxation rate below Tc exhibits a pronounced coherence peak and follows the weak-coupling BCS theory

O. Vyaselev; K. Arai; K. Kobayashi; J. Yamazaki; K. Kodama; M. Takigawa; M. Hanawa; Z. Hiroi

2002-01-01

65

Nuclear quadrupole resonance and nuclear magnetic resonance of copper in the high-Tc superconductor YBa2Cu3O7-delta  

Microsoft Academic Search

The 65Cu and 63Cu zero-field nuclear quadrupole resonance (NQR), nuclear magnetic resonance (NMR) at 4.7 and 8.5 T and the spin-lattice relaxation time T1 at 8.5 T are measured in the superconducting oxide YBa2Cu3O7-delta between 80 and 300 K. No sign of magnetic order or localized moments are found. The NQR linewidth is strongly dependent on the oxygen content. We

I. Furo; A. Jánossy; L. Mihály; P. Bánki; I. Pócsik; I. Bakonyi; I. Heinmaa; E. Joon; E. Lippmaa

1987-01-01

66

Understanding Nucleons in the Nuclear Medium  

SciTech Connect

Recent cross section (e, e'pN) short-range correlation experiments have clearly shown the strong dominance of tensor correlations for (e, e'p) missing momenta greater than the Fermi momentum; while recent {sup 2}H(e, e'p)n and {sup 4}He(e, e'p)t asymmetry experiments at low missing momentum have shown small changes from the free nucleon form factor. By doing asymmetry experiments as a function of missing momentum, these results can be linked together and observed as a change of sign in the measured asymmetry. This idea will be presented within the context of the recently completed Jefferson Lab Hall A quasi-elastic, polarized {sup 3}He(e, e'N) experiments (N = 0,p, n, d) where the asymmetries of several reaction channels were measured with three, orthogonal target-spin directions. Together, these various experiments will help us to better understand nucleons in the nuclear medium.

Higinbotham, D. W. [Jefferson Lab, Newport News, VA 23606 (United States); Sulkosky, V. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2010-08-05

67

Magnetic-field-induced quadrupole coupling in the nuclear magnetic resonance of noble-gas atoms and molecules  

SciTech Connect

An analytic response theory formulation for the leading-order magnetic field-induced and field-dependent quadrupole splitting in nuclear magnetic resonance spectra is presented and demonstrated with first-principles calculations for {sup 21}Ne, {sup 36}Ar, and {sup 83}Kr in noble gas atoms. The case of molecules was studied for {sup 33}S in the sulphur hexafluoride molecule, as well as for {sup 47/49}Ti, {sup 91}Zr, and {sup 177,179}Hf in group(IV) tetrahalides. According to our calculations, the hitherto experimentally unknown field-induced quadrupole splitting in molecules rises to 10{sup 2} Hz for {sup 177,179}Hf nuclei in HfF{sub 4} and 10{sup 1} Hz for {sup 47/49}Ti in TiCl{sub 4}, and is hence of observable magnitude.

Manninen, Pekka [Laboratory of Physical Chemistry, Department of Chemistry, P.O. Box 55 (A.I. Virtasen aukio 1), FIN-00014 University of Helsinki (Finland); NMR Research Group, Department of Physical Sciences, P.O. Box 3000, FIN-90014 University of Oulu (Finland); Vaara, Juha [Laboratory of Physical Chemistry, Department of Chemistry, P.O. Box 55 (A.I. Virtasen aukio 1), FIN-00014 University of Helsinki (Finland); Pyykkoe, Pekka [Laboratory for Instruction in Swedish, Department of Chemistry, P.O. Box 55 (A.I. Virtasen aukio 1), FIN-00014 University of Helsinki (Finland)

2004-10-01

68

First - Principles Cluster Investigation of Nuclear Quadrupole Interactions of ^69,71Ga and ^17N Nuclei in Gallium Nitride  

NASA Astrophysics Data System (ADS)

As part of our investigations of electronic structure and properties of GaN, in particular the recent study of trapped muonium hyperfine interactions [1] in this system, we have been investigating the nuclear quadrupole interactions of ^69,71Ga and ^17N Nuclei in pure GaN using the Hartree-Fock Cluster procedure together with incorporation of many-body effects. Our results will be presented and compared with both available experimental quadrupole coupling constants [2] and earlier theoretical results [2] by the point charge model and band-structure methods. [1] K. Shimomura et al., (Submitted for Publication) [2] L. W. Park et al., Phys. Rev. B65, 195210 (2002)

Paudyal, D. D.; Byahut, S.; Aryal, M. M.; Choh, S. H.; Jeong, Junho; Scheicher, R. H.; Das, T. P.

2004-03-01

69

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

70

Understanding appropriate use criteria in nuclear medicine.  

PubMed

There has been a significant increase in cardiac radionuclide imaging over the past decade, leading to a corresponding increase in scrutiny from Federal and private health plans questioning the necessity of these tests. In response to efforts by third-party payers to limit all types of cardiovascular imaging studies, the American College of Cardiology Foundation, in conjunction with other professional societies, developed appropriate use criteria. The goal of this article is to explain how the criteria were created and define the 3 categories of indications: appropriate, inappropriate, and uncertain. Tips for using appropriate use criteria and tables, including a definition of several key terms technologists should be familiar with, will be provided. In addition, reimbursement, benchmark data, and practical considerations for implementation will be discussed. Finally, several tools to aid in calculating appropriateness are suggested. With a basic understanding, the appropriate use criteria are relatively easy to apply. It is important for facilities to begin to voluntarily incorporate them into their practice and document levels of appropriateness now as payers are developing 2 trends that are not favorable for nuclear cardiology: preauthorization and denial of payment for inappropriate studies. PMID:22553087

Farrell, Mary Beth; Cerqueira, Manuel D

2012-06-01

71

Nuclear magnetic and quadrupole resonance studies of local environments in magnetic and superconducting systems  

NASA Astrophysics Data System (ADS)

Spin-echo nuclear magnetic and quadrupole resonance (NMR/NQR) studies, along with complementary x-ray diffraction and bulk magnetization measurements, have been carried out on the magnetic superconducting system RuSr2RECu 2O8 (RE 1212, RE = Gd or Eu) and systems based on or derived from SrRuO3. In RE1212, two sets of Ru NMR signals are found, indicating the existence of a mixed valence for Ru. This result suggests a hole doping mechanism to account for the superconductivity that originates in the CuO2 planes. The evolution of the Ru NMR spectra in external magnetic fields provides information concerning the magnetic structure of the Ru sublattice which is consistent with the previously proposed type-I antiferromagnetic (AFM) structure. Based on this model, the interplane magnetic coupling and the in-plane spin-flop critical field are determined. While substituting for the Ru-site in SrRuO3, Mn and vacancies suppress the ferromagnetic (FM) ordering temperature drastically. Cr, on the other hand, increases the ordering temperature. The valence states for Mn, Cr, and Ru are determined from the NMR spectra, which, combined with dc magnetization, also provide information with regard to the various magnetic interactions. The hybridization of the Ru 4d and Mn or Cr 3d orbitals is believed to play a key role in the variation of the ordering temperature. Upon cooling, three consecutive and distinct magnetic transitions are observed for Sr2RuGdO6 at T1 = 33 K, T2 = 17, and T3 < 2 K which are attributed to the Ru-Ru, Ru-Gd, and Gd-Gd AFM interactions, respectively. Weak FM is associated with the transition at 17 K. These features point to the unique role played by Gd in this system. Ru NMR spectra, in the presence of an external magnetic field, demonstrate the existence of a FM phase in the AFM matrix which behaves superparamagnetically. These results strongly suggest that, at low temperature, the magnetic ground state of Sr2RuGdO6 involves complex coexistence and competition of different interactions.

Han, Zhaohui

2006-12-01

72

Superconductivity and Magnetic Fluctuations in Cd2Re2O7 via Cd Nuclear Magnetic Resonance and Re Nuclear Quadrupole Resonance  

NASA Astrophysics Data System (ADS)

We report Cd nuclear magnetic resonance (NMR) and Re nuclear quadrupole resonance (NQR) studies on Cd 2Re2O7, the first superconductor among pyrochlore oxides (Tc~=1 K). The Re NQR spectrum at zero magnetic field below 100 K rules out any magnetic or charge order. The spin-lattice relaxation rate below Tc exhibits a pronounced coherence peak and follows the weak-coupling BCS theory with nearly isotropic energy gap. The results of Cd NMR point to a moderate ferromagnetic enhancement at high temperatures followed by a rapid decrease of the density of states below the structural transition temperature of 200 K.

Vyaselev, O.; Arai, K.; Kobayashi, K.; Yamazaki, J.; Kodama, K.; Takigawa, M.; Hanawa, M.; Hiroi, Z.

2002-06-01

73

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

74

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

75

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

SciTech Connect

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}{sub 2} and {beta}{sub 3}. The system is considered to oscillate between positive and negative {beta}{sub 3} values by rounding an infinite potential core in the ({beta}{sub 2},{beta}{sub 3}) plane with {beta}{sub 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 {sup 150}Nd, {sup 152}Sm, {sup 154}Gd, and {sup 156}Dy is presented.

Minkov, N.; Yotov, P.; Drenska, S. [Institute of Nuclear Research and Nuclear Energy, 72 Tzarigrad Road, BG-1784 Sofia (Bulgaria); Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Bonatsos, D.; Lenis, D.; Petrellis, D. [Institute of Nuclear Physics, N.C.S.R. 'Demokritos', GR-15310 Aghia Paraskevi, Attiki (Greece)

2006-04-15

76

Characterization of solid phases and study of transformation kinetics in m-chlorofluorobenzene by 35Cl nuclear quadrupole resonance.  

PubMed

Polymorphism is of widespread occurrence in the world of molecular crystals. In this work we present experimental results showing the existence of four solid phases in m-chlorofluorobenzene. A glass structure is achieved by quenching the liquid phase at 77 K. This glassy state crystallizes in a disordered phase at T~143 K, which in turn transforms to the high-temperature stable phase (phase I) at T~153 K. Depending on the thermal history of the sample, a different ordered phase (phase III) can be obtained. The disorder is attributed to a molecular orientational disorder. There is no evidence of molecular reorientation in any phase. A study of the disorder-order phase transformation kinetics, using nuclear quadrupole resonance, is presented. The results are analyzed following Cahn's theory. Nucleation seems to take place at grain boundaries. Growth rates for different temperatures have been determined. PMID:22209621

Pérez, Silvina; Wolfenson, Alberto

2012-02-01

77

Magnetic Criticality and Unconventional Superconductivity in CeCoIn5: Study of 115In-Nuclear Quadrupole Resonance under Pressure  

Microsoft Academic Search

We report the systematic evolution of the superconducting (SC) characteristics of the heavy-fermion (HF) superconductor CeCoIn5 via nuclear-quadrupole-resonance (NQR) measurement under pressure (P). The application of P significantly suppresses the nuclear spin-lattice relaxation rate 1\\/T1 that is dominated by antiferromagnetic (AFM) spin fluctuations (SFs) specific to a quantum critical point (QCP). It is demonstrated that the marked suppression of AFM

M. Yashima; S. Kawasaki; Y. Kawasaki; G.-q. Zheng; Y. Kitaoka; H. Shishido; R. Settai; Y. Haga; Y. Onuki

2004-01-01

78

First-principles study of boron oxygen hole centers in crystals: Electronic structures and nuclear hyperfine and quadrupole parameters  

SciTech Connect

The electronic structures, nuclear hyperfine coupling constants, and nuclear quadrupole parameters of fundamental boron oxygen hole centers (BOHCs) in zircon (ZrSiO{sub 4}, I4{sub 1}/amd) and calcite (CaCO{sub 3}, R3c) have been investigated using ab initio Hartree-Fock (HF) and various density functional theory (DFT) methods based on the supercell models with all-electron localized basis sets. Both exact HF exchange and appropriate correlation functionals are important in describing the BOHCs, and the parameter-free hybrid method based on Perdew, Burke, and Ernzerhof density functionals (PBE0) turns out to be the best DFT method in reproducing the electron paramagnetic resonance (EPR) data. Our results reveal three distinct types of simple-spin (S = 1/2) [BO{sub 3}]{sup 2-} centers in calcite: (i) the classic [BO{sub 3}]{sup 2-} radical with the D{sub 3h} symmetry and the unpaired spin equally distributed on the three oxygen atoms (i.e. the O{sub 3}{sup 5-} type); (ii) the previously reported [BO{sub 2}]{sup 0} center with the unpaired spin equally distributed on two of the three oxygen atoms (O{sub 2}{sup 3-}); and (iii) a new variety with {approx}90% of its unpaired spin localized on one (O{sup -}) of the three oxygen atoms with a long B-O bond (1.44 A). Calculations confirm the unusual [BO{sub 4}]{sup 0} center in zircon and show it to arise from a highly distorted configuration with 90% of the unpaired spin on one oxygen atom that has a considerably longer B-O bond (1.68 A) than its three counterparts (1.45 A). The calculated magnitudes and directions of {sup 11}B and {sup 17}O hyperfine coupling constants and nuclear quadrupole constants for the [BO{sub 4}]{sup 0} center in zircon are in excellent agreement with the 15 K EPR experimental data. These BOHCs are all characterized by a small negative spin density on the central B atom arising from spin polarization. Our calculations also demonstrate that the spin densities on BOHCs are affected substantially by crystalline environments, and so periodic boundary treatment, such as the supercell scheme, is a must in accounting for the electronic and spin structures of BOHCs in crystals. These atomistic and electronic models of BOHCs in the crystalline matrices provide new insights into their precursors and counterparts in glasses and other amorphous materials.

Li Zucheng; Pan Yuanming [Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada)

2011-09-15

79

Non-cyclic geometric phase of nuclear quadrupole resonance signals of powdered samples.  

PubMed

The non-cyclic geometric phase of ¹?N and ³?Cl NQR signals induced by the character of trajectory of nuclear magnetization motion upon pulse r.f. excitation of powdered samples is studied. Analytical expressions for the geometric phases of NQR signals of the nuclei of spins I=1 and 3/2 upon nuclear magnetization rotation induced by means of r.f. pulses with frequency detuned from the resonance and for any impulse duration for a separate crystallite are obtained. It is shown that the geometric phase recorded for the signal from a powdered sample at ??=0 can be different from zero and can oscillate upon changes in duration of the r.f. excitation pulse. An alternative variant of the nutation experiment aimed at obtaining the asymmetry parameter ? from locations of frequency singularities in the nutation phase spectrum for nuclei of spin I=3/2 in powder substances is proposed. PMID:21463929

Glotova, O; Ponamareva, N; Sinyavsky, N; Nogaj, B

2011-01-01

80

A no-tune no-match wideband probe for nuclear quadrupole resonance spectroscopy in the VHF range  

NASA Astrophysics Data System (ADS)

Nuclear quadrupole resonance (NQR) spectroscopy is a method for the characterization of chemical compounds containing so-called quadrupolar nuclei. Similar to nuclear magnetic resonance (NMR), the sample under investigation is irradiated with strong radiofrequency (RF) pulses, which stimulate the emission of weak RF signals from the quadrupolar nuclei. The signals are then amplified and Fourier transformed so as to obtain a spectrum. In principle, narrowband NQR spectra can be measured with NMR spectrometers. However, pure NQR signals require the absence of a static magnetic field and several special applications require the characterization of a substance over a large bandwidth, e.g. 50–100% of the central frequency, which is hardly possible with standard NMR equipment. Dedicated zero-field NQR equipment is not widespread and current concepts employ resonating probes which are tuned and matched over a wide range by using mechanical capacitors driven by stepper motors. While providing the highest signal to noise ratio (SNR) such probes are slow in operation and can only be operated from dedicated NMR consoles. We developed a low-cost NQR wideband probe without tuning and matching for applications in the very high frequency (VHF) range below 300?MHz. The probe coil was realized as part of a reactive network which approximates an exponential transmission line. The input reflection coefficient of the two developed prototype probe coils is ? 20?dB between 90–145?MHz and 74.5–99.5?MHz, respectively. Two wideband NQR spectra of published test substances were acquired with an SNR of better than 20?dB after sufficient averaging. The measured signals and the SNR correspond very well to the theoretically expected values and demonstrate the feasibility of the method. Because there is no need for tuning and matching, our probes can be operated easily from any available NMR console.

Scharfetter, Hermann; Petrovic, Andreas; Eggenhofer, Heidi; Stollberger, Rudolf

2014-12-01

81

Nuclear Power and the Environment, Understanding the Atom Series.  

ERIC Educational Resources Information Center

This booklet is one of the booklets in the "Understanding the Atom Series" published by the U. S. Atomic Energy Commission for high school science teachers and their students. Discussion concentrates on the radiological and thermal aspects of the environmental effects of nuclear power plants; on the procedures followed by the Atomic Energy…

Atomic Energy Commission, Oak Ridge, TN. Div. of Technical Information.

82

Multiband Superconductivity in Filled-Skutterudite Compounds (Pr1-xLax)Os4Sb12: An Sb Nuclear-Quadrupole-Resonance Study  

Microsoft Academic Search

We report on the systematic evolution of normal-state properties and superconducting characteristics in filled-skutterudite compounds (Pr1-xLax)Os4Sb12 determined using Sb nuclear-quadrupole-resonance (NQR) experiments. The Sb-NQR spectra in these compounds have split into two sets, arising from different Sb12 cages containing either Pr or La, which enables us to measure two kinds of nuclear spin-lattice relaxation time T1Pr and T1La. In the

Mamoru Yogi; Takayuki Nagai; Yojyu Imamura; Hidekazu Mukuda; Yoshio Kitaoka; Daisuke Kikuchi; Hitoshi Sugawara; Yuji Aoki; Hideyuki Sato; Hisatomo Harima

2006-01-01

83

The nuclear quadrupole coupling of the halogen pseudohalides: A comparison of ab initio and DFT studies with spectroscopic data  

NASA Astrophysics Data System (ADS)

Electric field gradients (in both principal (PA) and inertial (IA) axes) have been calculated at the equilibrium structures of the halogen azides, isocyanates and isothiocyanates; these have been converted into the corresponding nuclear quadrupole coupling constants (NQCC). Möller-Plesset (MP2) and DFT (B3LYP) methodologies, together with cc-pVTZ and TZVP basis sets, enable comparison of the effects of methodology and basis set, and experiment. The experimental and theoretical 35Cl, 79Br, 127I NQCC are closely related in linear relationships for both methodologies. The NQCC results also correlate with Pauling electronegativity of the halogen (also including H). The availability of experimental data for the present compounds at the 14N centres is low, and some seems suspect. The study was extended to include a variety of related model compounds, where the small coupling constants have been evaluated by FT-MW spectroscopy. Both methodologies give good correlations with these model compound experimental results, but the B3LYP 14N results are significantly more successful with the central N atom of the azides. These relationships confirm our previous studies, which show that very good agreement between theory and experiment is obtained for all these nuclei. The largest magnitude 14N N ? NQCC-PA tensor elements are the tangential terms ?T, whereas the smallest elements lie close to the direction of the lone pair of electrons ( ?LPN), in contrast to many amines; the out-of-plane ( ??), and in-plane ( ?T) elements vary smoothly as the halogen size increases. The NQCC-PA magnitude varies significantly with halogen change at the N ? atoms in the azides, but at N ? there are almost unchanging values for each of the tensor elements, under these conditions.

Palmer, Michael H.; Nelson, Alistair D.

2007-02-01

84

Understanding China`s nuclear non-proliferation policy  

SciTech Connect

China`s nuclear-export activities appear to contradict its official non-proliferation policy. Scrutiny of China`s nuclear exports and non- proliferation commitments indicate an adherence to strict `letter-of-the-law` obligations. Yet, China`s commitment to the norms and values of the non- proliferation regime is controversial. The difference between China`s legal obligations and the international norms of acceptable export behavior is a function of the ambiguity inherent in international treaties and agreements. Stephen Meyer`s motivational hypothesis is used to evaluate China`s nuclear-export decision-making process. China`s motivational profile created by the combination of 16 incentives and disincentives on one hand, and international and domestic conditions on the other. Two case studies are used to illustrate that this profile is not static. As environmental conditions and China`s national priorities change, so does China`s motivational profile. In the past, U. S. attempts to alter China`s nuclear-export activities were successful when the targeted changes were congruent with China`s national priorities. For the United States to influence China`s future nuclear-export activities, it must first understand China`s national priorities and determine the corresponding export motivations that influence China`s decision-making process. The United States should then work to change conditions, which would shift the balance of incentives and disincentives, thereby changing the outcome of China`s cost-benefit calculus.

Nichols, P.J.

1999-06-01

85

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

86

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

87

Peptide backbone orientation and dynamics in spider dragline silk and two-photon excitation in nuclear magnetic and quadrupole resonance  

NASA Astrophysics Data System (ADS)

In the first part of the dissertation, spider dragline silk is studied by solid state NMR techniques. The dependence of NMR frequency on molecular orientation is exploited using the DECODER experiment to determine the orientation of the protein backbone within the silk fibre. Practical experimental considerations require that the silk fibres be wound about a cylindrical axis perpendicular to the external magnetic field, complicating the reconstruction of the underlying orientation distribution and necess-itating the development of numerical techniques for this purpose. A two-component model of silk incorporating static b-sheets and polyglycine II helices adequately fits the NMR data and suggests that the b-sheets are well aligned along the silk axis (20 FWHM) while the helices are poorly aligned (68 FWHM). The effects of fibre strain, draw rate and hydration on orientation are measured. Measurements of the time-scale for peptide backbone motion indicate that when wet, a strain-dependent frac-tion of the poorly aligned component becomes mobile. This suggests a mechanism for the supercontraction of silk involving latent entropic springs that undergo a local strain-dependent phase transition, driving supercontraction. In the second part of this dissertation a novel method is developed for exciting NMR and nuclear quadrupole resonance (NQR) by rf irradiation at multiple frequencies that sum to (or differ by) the resonance frequency. This is fundamentally different than traditional NMR experiments where irradiation is applied on-resonance. With excitation outside the detection bandwidth, two-photon excitation allows for detection of free induction signals during excitation, completely eliminating receiver dead-time. A theoretical approach to describing two-photon excitation is developed based on average Hamiltonian theory. An intuition for two-photon excitation is gained by analogy to the coherent absorption of multiple photons requiring conservation of total energy and momentum. It is shown that two-photon excitation efficiency impro-ves when the two applied rf frequencies deviate from half-resonance. For two-photon NQR, it is shown that observable magnetization appears perpendicular to the excita-tion coil, requiring a second coil for detection, and that double quantum coherences are also generated. Several model systems and experimental geometries are used to demonstrate the peculiarities of two-photon excitation in NMR and NQR.

Eles, Philip Thomas

2005-07-01

88

Strong coupling between antiferromagnetic and superconducting order parameters of CeRhIn5 studied by I115n nuclear quadrupole resonance spectroscopy  

Microsoft Academic Search

We report on a pressure (P) -induced evolution of magnetism and superconductivity (SC) in a helical magnet CeRhIn5 with an incommensurate wave vector Qi=((1)\\/(2),(1)\\/(2),0.297) through the I115n nuclear quadrupole resonance (NQR) measurements under P . Systematic measurements of the I115n -NQR spectrum reveal that the commensurate antiferromagnetism (AFM) with Qc=((1)\\/(2),(1)\\/(2),(1)\\/(2)) is realized above Pm˜1.7GPa . An important finding is that

M. Yashima; H. Mukuda; Y. Kitaoka; H. Shishido; R. Settai; Y. Onuki

2009-01-01

89

In-vivo study of the nuclear quadrupole interaction of99Mo (?- 99)Tc in nitrogenase of Klebsiella pneumoniaein nitrogenase of Klebsiella pneumoniae  

NASA Astrophysics Data System (ADS)

We report on the first TDPAC-measurements of the nuclear quadrupole interaction (NQI) of (NQI) of99Mo(?-)99Tc in the nitrogenase of the bacteria Klebsiella pneumoniae. Because nitrogenase is the only Mo-containing enzyme in Klebsiella pneumoniae under the chosen conditions, no further isolation of this enzyme was necessary. The majority of the incorporated99Mo is subjected to a well defined NQI with ?=365(7) Mrad/s, ?=1 and a reorientational correlation time of ?co???10nsec and is attributed to the active site of the FeMo cofactor. During sample preparation we noted a pronounced affinity of the bacteria to99mTc.

Mottner, P.; Lerf, A.; Ni, X.; Butz, T.; Erfkamp, J.; Müller, A.

1990-08-01

90

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

NASA Astrophysics Data System (ADS)

Rotational correlation times of metal ion aqua complexes can be determined from O17 NMR relaxation rates if the quadrupole coupling constant of the bound water oxygen-17 nucleus is known. The rotational correlation time is an important parameter for the efficiency of Gd3+ complexes as magnetic resonance imaging contrast agents. Using a combination of density functional theory with classical and Car-Parrinello molecular dynamics simulations we performed a computational study of the O17 quadrupole coupling constants in model aqua ions and the [Gd(DOTA)(H2O)]- complex used in clinical diagnostics. For the inner sphere water molecule in the [Gd(DOTA)(H2O)]- complex the determined quadrupole coupling parameter ??1+?2/3 of 8.7MHz is very similar to that of the liquid water (9.0MHz ). Very close values were also predicted for the the homoleptic aqua ions of Gd3+ and Ca2+. We conclude that the O17 quadrupole coupling parameters of water molecules coordinated to closed shell and lanthanide metal ions are similar to water molecules in the liquid state.

Yazyev, Oleg V.; Helm, Lothar

2006-08-01

91

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

92

14N nuclear-quadrupole-resonance study of orientational ordering in the smectic phases of achiral TBBA and chiral TBACA  

Microsoft Academic Search

The 14N quadrupole coupling constant and asymmetry parameter eta have been measured (using a double-resonance technique) as a function of temperature in the smectic A, smectic C, and smectic H phases of achiral TBBA and chiral TBACA, as well as in the smectic VI and the solid phase of TBBA. In the low-temperature smectic H and smectic VI phases of

J. Seliger; V. Zagar; R. Blinc

1978-01-01

93

Coupling of nuclear quadrupole and octupole degrees of freedom in an angular momentum dependent potential of two deformation variables  

SciTech Connect

We propose a collective rotation-vibration Hamiltonian of nuclei in which the axial quadrupole {beta}2 and octupole {beta}3 variables are coupled through the centrifugal interaction. We consider that the system oscillates between positive and negative {beta}3-values by rounding a potential core in the ({beta}2,{beta}3)- space. We examine the effect of the 'rounding' in the structure of the spectrum.

Minkov, N.; Yotov, P.; Drenska, S. [Institute of Nuclear Research and Nuclear Energy, 72 Tzarigrad Road, 1784 Sofia (Bulgaria); Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Bonatsos, Dennis; Lenis, D.; Petrellis, D. [Institute of Nuclear Physics, N.C.S.R. 'Demokritos', GR-15310 Aghia Paraskevi, Attiki (Greece)

2006-04-26

94

Magnetic Criticality and Unconventional Superconductivity in CeCoIn5: Study of 115In-Nuclear Quadrupole Resonance under Pressure  

NASA Astrophysics Data System (ADS)

We report the systematic evolution of the superconducting (SC) characteristics of the heavy-fermion (HF) superconductor CeCoIn5 via nuclear-quadrupole-resonance (NQR) measurement under pressure (P). The application of P significantly suppresses the nuclear spin-lattice relaxation rate 1/T1 that is dominated by antiferromagnetic (AFM) spin fluctuations (SFs) specific to a quantum critical point (QCP). It is demonstrated that the marked suppression of AFM SFs leads to a reduction in the SC energy gap or in the coupling strength of the Cooper pair. Tc, nevertheless, increases with increasing P due to the increase in HF bandwidth. This is expected to make the lifetime of quasi-particles sufficiently long.

Yashima, M.; Kawasaki, S.; Kawasaki, Y.; Zheng, G.-q.; Kitaoka, Y.; Shishido, H.; Settai, R.; Haga, Y.; ?nuki, Y.

2004-08-01

95

A theoretical study of 17O, 14N and 2H nuclear quadrupole coupling tensors in the real crystalline structure of acetaminophen  

NASA Astrophysics Data System (ADS)

A systematic computational investigation was carried out to characterize the 17O, 14N and 2H electric field gradient, EFG, tensors in the acetaminophen real crystalline structure. To include the hydrogen bonding effects in the calculations, the most probable interacting molecules with the target molecule in the crystalline phase were considered through the various molecular clusters. The calculations were performed with the B3LYP method and 6-311++G ?? and 6-311+G ? standard basis sets using the Gaussian 98 suite of programs. Calculated EFG tensors were used to evaluate the 17O, 14N, and 2H nuclear quadrupole resonance, NQR, parameters in acetaminophen crystalline structure, which are in good agreement with the available experimental data. The difference between the calculated NQR parameters of the monomer and molecular clusters shows how much hydrogen bonding interactions affect the EFG tensors of each nucleus. These results indicate that both O-H⋯O and N-H⋯O hydrogen bonding have major influence on the NQR parameters. Moreover, the quantum chemical calculation indicated that the intermolecular hydrogen bonding interactions play an essential role in determining the relative orientation of quadrupole coupling principal components in the molecular frame axes.

Behzadi, Hadi; Esrafili, Mehdi D.; Hadipour, Nasser L.

2007-03-01

96

Ruthenium pure quadrupole resonance spectroscopy  

NASA Astrophysics Data System (ADS)

The unique chemistry of ruthenium and consequent potential importance of the quadrupole coupling constants and asymmetry parameters of 99Ru and 101Ru has prompted us to initiate an apparently original investigation of the pure nuclear quadrupole resonance spectroscopy of these two isotopes. A means for prediction of the expected resonance frequencies based on Mossbauer data is given and detailed circuit diagrams of a spectrometer which has been constructed primarily for ruthenium studies are presented. Preliminary searches carried out for ruthenium tris-acetylacetonate and bis-ruthenium tetroxide have so far failed to yield signals. Possible explanations for this are discussed and the value of continuing the work defended.

Carter, J. C.; Good, M. L.

97

Strong coupling between antiferromagnetic and superconducting order parameters of CeRhIn5 studied by I115n nuclear quadrupole resonance spectroscopy  

NASA Astrophysics Data System (ADS)

We report on a pressure (P) -induced evolution of magnetism and superconductivity (SC) in a helical magnet CeRhIn5 with an incommensurate wave vector Qi=((1)/(2),(1)/(2),0.297) through the I115n nuclear quadrupole resonance (NQR) measurements under P . Systematic measurements of the I115n -NQR spectrum reveal that the commensurate antiferromagnetism (AFM) with Qc=((1)/(2),(1)/(2),(1)/(2)) is realized above Pm˜1.7GPa . An important finding is that the size of SC gap and Tc increase as the magnitude of the AFM moment decreases in the P region, where SC uniformly coexists with the commensurate AFM. This result provides evidence of strong coupling between the commensurate AFM order parameter (OP) and SC OP.

Yashima, M.; Mukuda, H.; Kitaoka, Y.; Shishido, H.; Settai, R.; ?nuki, Y.

2009-06-01

98

Nuclear quadrupole resonance study of RuSr2R2-xCexCu2O10+?(R=Eu,Gd) and the effects of electronic doping  

NASA Astrophysics Data System (ADS)

Cu nuclear quadrupole resonance measurements have been made on the single CuO2 layer underdoped high temperature superconducting cuprate (HTSC) RuSr2R2-xCexCu2O10+?(R=Eu,Gd) . It is found that the nearly constant superconducting transition temperature for x=0.6 and 0.8 can be attributed to a similar hole concentration in the CuO2 planes and the hole concentration is significantly lower for the nonsuperconducting x=1.0 sample. Similar to other HTSCs, the Cu63 spin-lattice relaxation rate decreases with increasing hole concentration in the CuO2 planes. There is evidence of a spatially inhomogeneous spin fluctuation spectrum that exists even for the superconducting samples. Similar inhomogeneities have been reported in some of the other HTSCs and, hence, the current results provide further evidence of inhomogeneities in the HTSCs.

Williams, G. V. M.

2006-02-01

99

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

100

Evaluation of nitrogen nuclear hyperfine and quadrupole coupling parameters for the proximal imidazole in myoglobin-azide, -cyanide, and -mercaptoethanol complexes by electron spin echo envelope modulation spectroscopy.  

PubMed

Electron spin echo envelope modulation (ESEEM) spectroscopy and computer simulation of spectra has been used to evaluate the nitrogen nuclear hyperfine and quadrupole coupling parameters for the proximal imidazole nitrogen directly coordinated to iron in three low-spin heme complexes, myoglobin-azide, -cyanide, and -mercaptoethanol (MbN3, MbCN, and MbRS). The variability in the weak electron-nuclear coupling parameters reveals the electronic flexibility within the heme group that depends on properties of the exogenous ligands. For example, the isotropic component of the nitrogen nuclear hyperfine coupling ranges from 4.4 MHz for MbN3 to 2.2 MHz for both MbCN and MbRS. The weaker coupling in MbCN and MbRS is taken as evidence for delocalization of unpaired electron spin from iron into the exogenous anionic ligands. The value of e2Qq, the nuclear quadrupole coupling constant for the axial imidazole nitrogen in MbCN and MbRS, was 2.5 MHz but was significantly larger, 3.2 MHz, in MbN3. This large value is considered evidence for a weakened sigma bond between the proximal imidazole and ferric iron in this form, and for a feature contributing to the origin of the high spin-low spin equilibrium exhibited by MbN3 [Beetlestone, J., & George, P. (1964) Biochemistry 5, 707-714]. The ESEEM results have allowed a correlation to be made between the orientation of the g tensor axes, the orientation of the p-pi orbital of the proximal imidazole nitrogen, and sigma- and pi-bonding features of the axial ligands. Furthermore, the proximal imidazole is suggested to act as a pi-acceptor in low-spin heme complexes in order to support strong sigma electron donation from the lone pair orbital to iron. An evaluation of the nitrogen nuclear hyperfine coupling parameters for the porphyrin pyrrole sites in MbRS reveals a large inequivalence in isotropic components consistent with an orientation of rhombic axes (and g tensor axes) that eclipses the Fe-Npyrrole vector directions. PMID:8395204

Magliozzo, R S; Peisach, J

1993-08-24

101

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

102

Weak Magnetic Order in Bilayered-Hydrate NaxCoO2\\\\cdotyH2O Structure Probed by Co Nuclear Quadrupole Resonance Proposed Phase Diagram in Superconducting NaxCoO2\\\\cdotyH2O---  

Microsoft Academic Search

A weak magnetic order was found in a nonsuperconducting bilayered-hydrate NaxCoO2\\\\cdotyH2O sample by Co nuclear quadrupole resonance (NQR) measurement. The nuclear spin-lattice relaxation rate divided by temperature 1\\/T_1T shows a prominent peak at 5.5 K, below which a Co NQR peak splits due to an internal field at the Co site. From the analyses of the Co NQR spectrum at

Yoshihiko Ihara; Kenji Ishida; Chishiro Michioka; Masaki Kato; Kazuyoshi Yoshimura; Kazunori Takada; Takayoshi Sasaki; Hiroya Sakurai; Eiji Takayama-Muromachi

2005-01-01

103

Enhancing the Superconducting Transition Temperature of CeRh1-xIrxIn5 due to the Strong-Coupling Effects of Antiferromagnetic Spin Fluctuations: An In115 Nuclear Quadrupole Resonance Study  

Microsoft Academic Search

We report on systematic evolutions of antiferromagnetic (AFM) spin fluctuations and unconventional superconductivity (SC) in heavy-fermion (HF) compounds CeRh1-xIrxIn5 via an In115 nuclear-quadrupole-resonance experiment. The nuclear spin-lattice relaxation rate 1\\/T1 has revealed the marked development of AFM spin fluctuations as approaching an AFM ordered state. Concomitantly, the superconducting transition temperature Tc and the energy gap Delta0 increase drastically from Tc=0.4K

Shinji Kawasaki; Mitsuharu Yashima; Yoichi Mugino; Hidekazu Mukuda; Yoshio Kitaoka; Hiroaki Shishido; Yoshichika Onuki

2006-01-01

104

Nuclear Propulsion for Space, Understanding the Atom Series.  

ERIC Educational Resources Information Center

The operation of nuclear rockets with respect both to rocket theory and to various fuels is described. The development of nuclear reactors for use in nuclear rocket systems is provided, with the Kiwi and NERVA programs highlighted. The theory of fuel element and reactor construction and operation is explained with particular reference to rocket…

Corliss, William R.; Schwenk, Francis C.

105

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

106

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.

107

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.

108

Effective quadrupole-quadrupole interaction from density functional theory  

NASA Astrophysics Data System (ADS)

The density functional theory of nuclear structure provides a many-particle wave function that is useful for static properties, but an extension of the theory is necessary to describe correlation effects or other dynamic properties. We propose a procedure to extend the theory by mapping the properties of a self-consistent mean-field theory onto an effective shell-model Hamiltonian with quadrupole-quadrupole interaction. In this initial study, we consider the sd-shell nuclei Ne20, Mg24, Si28, and Ar36. The method is first tested with the USD shell-model Hamiltonian, using its mean-field approximation to construct an effective Hamiltonian and partially recover correlation effects. We find that more than half of the correlation energy is due to the quadrupole interaction. We then follow a similar procedure but using the SLy4 Skyrme energy functional as our starting point and truncating the space to the spherical sd shell. The constructed shell-model Hamiltonian is found to satisfy minimal consistency requirements to reproduce the properties of the mean-field solution. The quadrupolar correlation energies computed with the mapped Hamiltonian are reasonable compared with those computed by other methods. The method also provides a well-defined renormalization of the quadrupole operator in the shell-model space, the “effective charge” of the phenomenological shell model.

Alhassid, Y.; Bertsch, G. F.; Fang, L.; Sabbey, B.

2006-09-01

109

Understanding electron and nuclear spin dynamics in Cr^5+ doped K3NbO8  

NASA Astrophysics Data System (ADS)

Chromium(V) doped in the diamagnetic host potassium niobate, a simple spin S=.5ex1-.1em/ -.15em.25ex2 , I = 0 system, has been proposed as an alternative standard for field calibration and g-standard for high-field EPR [1]. This system constitutes a dilute two-level model relevant for use as a electron spin qubit [2] and as such coherent electron spin manipulation at X-band (˜9.5 GHz) was observed over a wide range temperature. Rabi oscillations are observed for the first time in a spin system based on transition metal oxides up to room temperature. At 4 K, a Rabi frequency ?R of 20 MHz together with the phase coherence relaxation (spin-spin relaxation) time, T2 of ˜10 ?s results in the single qubit figure of merit QM (=?RT2/?) as about 500, showing that a diluted ensemble of Cr(V) (S = 1/2) doped K3NbO8 is a potential candidate for solid-state quantum information processing. Also, the field and temperature dependence of the T1 (spin-lattice relaxation) and T2 times was investigated [3] for a further understanding of the relaxation mechanisms governing the phase decoherence in this system. These studies show that the coupling of the electron spin with the neighboring ^39K nuclei (I = 3/2) is one of the prominent T2 mechanisms. The hyperfine and quadrupole interactions with ^39K nuclei was resolved by using the high-frequency (240 GHz) pulsed electron nuclear double resonance (ENDOR). [3pt] [1]. B. Cage, A. Weekley, L. -C. Brunel and N. S. Dalal, Anal. Chem. 71, 1951 (1999). [0pt] [2]. S. Nellutla, K.-Y. Choi, M. Pati, J. van Tol, I. Chiroescu and N. S. Dalal, Phys. Rev. Lett. 99, 137601 (2007). [0pt] [3]. S. Nellutla, G. W. Morley, M. Pati, N. S. Dalal and J. van Tol, Phys. Rev. B. 78, 054426 (2008).

Nellutla, Saritha

2009-03-01

110

Nuclear Magnetic Resonance Diffusion Studies of 23Na in Beta Alumina, Effect of Water on the 23Na Quadrupole Interaction  

Microsoft Academic Search

Measurements of the 23Na nuclear magnetic resonance spectra in samples of sodium beta alumina are interpreted in terms of sodium diffusion and water absorption. Intense motional narrowing is observed below room temperature consistent with the low activation energy for diffusion. The 23Na spectra from finely powdered material show effects, similar to those observed in zeolites, due to absorbed water. The

D. Kline; H. S. Story; W. L. Roth

1972-01-01

111

Hydrogen bonding in 1,2-diazine-chloranilic acid (2 : 1) studied by a 14N nuclear quadrupole coupling tensor and multi-temperature X-ray diffraction.  

PubMed

Protons involved in the H-bond system in 1,2-diazine-chloranilic acid (2 : 1) are assumed to be in jumping motion in the double-minimum potential corresponding to the two extreme electronic states of O-H...N and O-...H-N+. 14N nuclear quadrupole coupling constants were determined by 1H-14N nuclear quadrupole double resonance. Assuming that the observed coupling constants are result of a fast exchange of the two extreme electronic states, the coupling constants for each state were estimated by use of the equilibrium populations of the two extreme states determined from multi-temperature X-ray single-crystal diffraction. It was suggested that not only the population but also the electron distribution of the extreme electronic states itself changes with temperature. PMID:19305902

Seliger, Janez; Zagar, Veselko; Gotoh, Kazuma; Ishida, Hiroyuki; Konnai, Akiko; Amino, Daiki; Asaji, Tetsuo

2009-04-01

112

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

113

An analytical method for estimating the {sup 14}N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies  

SciTech Connect

The use of {sup 14}N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing {sup 14}N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The {sup 14}N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation.

Iselin, L.H.

1992-12-31

114

Microscopic properties of the heavy-fermion superconductor PuCoIn5 explored by nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

We report 115In nuclear quadrupolar resonance (NQR) measurements on the heavy-fermion superconductor PuCoIn5, in the temperature range 0.29K ? T ? 75K. The NQR parameters for the two crystallographically inequivalent In sites are determined, and their temperature dependence is investigated. A linear shift of the quadrupolar frequency with lowering temperature below the critical value Tc is revealed, in agreement with the prediction for composite pairing. The nuclear spin-lattice relaxation rate T1-1(T) clearly signals a superconducting (SC) phase transition at Tc ? 2.3 K, with strong spin fluctuations, mostly in-plane, dominating the relaxation process in the normal state near to Tc. Analysis of the T1-1 data in the SC state suggests that PuCoIn5 is a strong-coupling d-wave superconductor.

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

2014-05-01

115

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

116

Evidence for Unconventional Strong-Coupling Superconductivity in PrOs4Sb12: An Sb Nuclear Quadrupole Resonance Study  

Microsoft Academic Search

We report Sb-NQR results which evidence a heavy-fermion (HF) behavior and an unconventional superconducting (SC) property in Pr(Os4Sb12 with Tc=1.85 K. The temperature (T) dependence of nuclear-spin-lattice-relaxation rate, 1\\/T1, and NQR frequency unravel a low-lying crystal-electric-field splitting below T0˜10 K, associated with Pr3+(4f2)-derived ground state. In the SC state, 1\\/T1 shows neither a coherence peak just below Tc K nor

H. Kotegawa; M. Yogi; Y. Imamura; Y. Kawasaki; G.-Q. Zheng; Y. Kitaoka; S. Ohsaki; H. Sugawara; Y. Aoki; H. Sato

2003-01-01

117

Understanding the risk significance of nuclear plant technical specifications  

SciTech Connect

The paper represents a pseudo-quantitative method for using a graphical interpretation of the integrated plant risk model, called a Master Plant Logic Diagram (MPLD) to understand the risk importance of individual plant Technical Specification requirements, and the extent to which operation within these constraints should be managed to maintain plant risk at an acceptable level. The paper will use a simplified MPLD developed for a BWR power plant to demonstrate how the technique can provide important insights into this very important area.

Pong, L.T. [WNP-2 Nuclear Power Plant, Richland, WA (United States); Hunt, R.N.M. [Halliburton NUS, Idaho Falls, ID (United States). Risk and Reliability Division

1996-07-01

118

Evidence for Unconventional Strong-Coupling Superconductivity in PrOs4Sb12: An Sb Nuclear Quadrupole Resonance Study  

NASA Astrophysics Data System (ADS)

We report Sb-NQR results which evidence a heavy-fermion (HF) behavior and an unconventional superconducting (SC) property in Pr(Os4Sb12 with Tc=1.85 K. The temperature (T) dependence of nuclear-spin-lattice-relaxation rate, 1/T1, and NQR frequency unravel a low-lying crystal-electric-field splitting below T0˜10 K, associated with Pr3+(4f2)-derived ground state. In the SC state, 1/T1 shows neither a coherence peak just below Tc K nor a T3-like power-law behavior observed for anisotropic HF superconductors with the line-node gap. The isotropic energy gap with its size ?/kB=4.8 K seems to open up across Tc below T*˜2.3 K. It is surprising that Pr(Os4Sb12 looks like an isotropic HF superconductor—it may indeed argue for Cooper pairing via quadrupolar fluctuations.

Kotegawa, H.; Yogi, M.; Imamura, Y.; Kawasaki, Y.; Zheng, G.-Q.; Kitaoka, Y.; Ohsaki, S.; Sugawara, H.; Aoki, Y.; Sato, H.

2003-01-01

119

Multiband Superconductivity in Filled-Skutterudite Compounds (Pr1-xLax)Os4Sb12: An Sb Nuclear-Quadrupole-Resonance Study  

NASA Astrophysics Data System (ADS)

We report on the systematic evolution of normal-state properties and superconducting characteristics in filled-skutterudite compounds (Pr1-xLax)Os4Sb12 determined using Sb nuclear-quadrupole-resonance (NQR) experiments. The Sb-NQR spectra in these compounds have split into two sets, arising from different Sb12 cages containing either Pr or La, which enables us to measure two kinds of nuclear spin-lattice relaxation time T1Pr and T1La. In the normal state, the temperature (T) dependence of 1/T1PrT showed almost the same behavior as that for pure PrOs4Sb12 regardless of the increase in La content. In contrast, 1/T1LaT markedly decreases with increasing La concentration. These results show that 4 f2-derived magnetic fluctuations are almost localized at the Pr site. In the superconducting state for Pr-rich compounds of x=0.05 and 0.2, 1/T1Pr exponentially decreases down to T=0.7 K with no coherence peak below Tc as well as in PrOs4Sb12. A remarkable finding is that the residual density of states (RDOS) at the Fermi level below Tc is induced by La substitution for Pr. The impurity effect, usually observed in unconventional superconductors with a line-node gap, may not be the origin of the RDOS induced by the La substitution, since RDOS does not increase and Tc does not decrease with increasing La content. RDOS is more naturally explained if a small part (˜5.5%) of the total Fermi surface (FS) becomes gapless for x=0.05 and 0.2. These results are proposed to be understood in terms of a multiband-superconductivity (MBSC) model that assumes a full gap for part of the FS and the presence of point nodes for a small 4 f2-derived FS inherent in PrOs4Sb12. The former could be relevant with FS existing in LaOs4Sb12 and with the anisotropic gap with point nodes being markedly suppressed by either applying a magnetic field or substituting La for Pr. For La-rich compounds of x=0.8 and 1, on the other hand, 1/T1La exhibits a coherence peak and the nodeless energy gap characteristic for weak-coupling BCS s-wave superconductors. With increasing Pr content, Tc increases and the energy gap increases from 2?0/kBTc=3.45 for pure La compounds up to 2?0/kBTc=4.2 and 5.2 for the 60% Pr and 80% Pr compounds, respectively. The Pr substitution for La enhances the pairing interaction and induces an anisotropy in the energy-gap structure. The novel strong-coupling superconductivity in PrOs4Sb12 is inferred to be mediated by the local interaction between 4 f2-derived crystal-electric-field states with the electric quadrupole degree of freedom and conduction electrons. This coupling causes a mass enhancement of quasi-particles for a part of FS and induces a small FS, which is responsible for point nodes in the superconducting gap function. Note that the small FS does not play any primary role for the strong-coupling superconductivity in PrOs4Sb12.

Yogi, Mamoru; Nagai, Takayuki; Imamura, Yojyu; Mukuda, Hidekazu; Kitaoka, Yoshio; Kikuchi, Daisuke; Sugawara, Hitoshi; Aoki, Yuji; Sato, Hideyuki; Harima, Hisatomo

2006-12-01

120

Identification of 20(S)-protopanaxatriol metabolites in rats by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry and nuclear magnetic resonance spectroscopy.  

PubMed

20(S)-Protopanaxatriol (PPT), one of the aglycones of ginsenosides, has been shown to exert cardioprotective effects against myocardial ischemic injury. However, studies on PPT metabolism have rarely been reported. This study is the first to investigate the in vivo metabolism of PPT following oral administration by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) and nuclear magnetic resonance (NMR) spectroscopy. The structures of the metabolites were identified based on the characteristics of their MS data, MS(2) data, and chromatographic retention times. A total of 22 metabolites, including 17 phase I and 5 phase II metabolites, were found and tentatively identified by comparing their mass spectrometry profiles with those of PPT. Two new monooxygenation metabolites, (20S,24S)-epoxy-dammarane-3,6,12,25-tetraol and (20S,24R)-epoxy-dammarane-3,6,12,25-tetraol, were chemicallly synthesized and unambiguously characterized according to the NMR spectroscopic data. The metabolic pathways of PPT were proposed accordingly for the first time. Results revealed that oxidation of (1) double bonds at ?((24,25)) to form 24,25-epoxides, followed by rearrangement to yield 20,24-oxide forms; and (2) vinyl-methyl at C-26/27 to form corresponding carboxylic acid were the predominant metabolic pathways. Phase II metabolic pathways were proven for the first time to consist of glucuronidation and cysteine conjugation. This study provides valuable and new information on the metabolism of PPT, which is indispensable for understanding the safety and efficacy of PPT, as well as its corresponding ginsenosides. PMID:24184656

He, Chunyong; Zhou, Dandan; Li, Jia; Han, Han; Ji, Guang; Yang, Li; Wang, Zhengtao

2014-01-01

121

IMPLEMENTATION OF A -NQR SYSTEM AT THE NSCL FOR GROUND STATE QUADRUPOLE MOMENT  

E-print Network

The nuclear electric quadrupole moment, Q, is a direct measure of the nuclear charge distribution, and provides an important test of nuclear structure models. The detected nuclear quadrupole resonance (-NQR, my family, all my teachers and friends iii #12;ACKNOWLEDGMENTS I am very grateful to my advisor

Mantica, Paul F.

122

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

SciTech Connect

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.

A.W. Thomas; P.A.M. Guichon

2007-01-03

123

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

124

Study of electric quadrupole interaction in non-cubic compounds of Ba and Mo  

Microsoft Academic Search

etc. , of the quadrupole coupling constant, e~_~2, and hence of the electric field gradient (efg) acting at the nuclear site responsible for the interaction provide d the quadrupole moment of the nuclear state is known. In general the efg at a nuclear site in a compound is given by eq = eqlat t (i - iYoo) + eq e

R. P. Sharma; M. B. Kurup; K. G. Prasad

1978-01-01

125

Enhancing the Superconducting Transition Temperature of CeRh1-xIrxIn5 due to the Strong-Coupling Effects of Antiferromagnetic Spin Fluctuations: An In115 Nuclear Quadrupole Resonance Study  

NASA Astrophysics Data System (ADS)

We report on systematic evolutions of antiferromagnetic (AFM) spin fluctuations and unconventional superconductivity (SC) in heavy-fermion (HF) compounds CeRh1-xIrxIn5 via an In115 nuclear-quadrupole-resonance experiment. The nuclear spin-lattice relaxation rate 1/T1 has revealed the marked development of AFM spin fluctuations as approaching an AFM ordered state. Concomitantly, the superconducting transition temperature Tc and the energy gap ?0 increase drastically from Tc=0.4K and 2?0/kBTc=5 in CeIrIn5 up to Tc=1.2K and 2?0/kBTc=8.3 in CeRh0.3Ir0.7In5, respectively. The present work suggests that the AFM spin fluctuations in close proximity to the AFM quantum critical point are indeed responsible for the strong-coupling unconventional SC in HF compounds.

Kawasaki, Shinji; Yashima, Mitsuharu; Mugino, Yoichi; Mukuda, Hidekazu; Kitaoka, Yoshio; Shishido, Hiroaki; ?nuki, Yoshichika

2006-04-01

126

The giant quadrupole resonance in highly excited, rotating nuclei  

NASA Astrophysics Data System (ADS)

The giant quadrupole resonance in highly excited, fast rotating nuclei is studied as a function of both the nuclear temperature and the nuclear angular momentum. The photo-absorption cross sections for quadrupole radation in 156Dy, 160Er and 164Er are evaluated within the linear response theory. The strength functions of the ?-ray spectrum obtained from the decay of highly excited nuclear states by deexcitation of the isoscalar quadrupole mode show a fine structure, which depends on the temperature T, the angular momentum I and the deformation of the nucleus ?. The splitting of the modes associated with the signature-conserving and signature-changing components of the quadrupole field is discussed.

Civitarese, O.; Furui, S.; Ploszajczak, M.; Faessler, Amand

1983-10-01

127

RF Quadrupole Beam Dynamics  

Microsoft Academic Search

A method has been developed to analyze the beam dynamics of the radio frequency quadrupole accelerating structure. Calculations show that this structure can accept a dc beam at low velocity, bunch it with high capture efficiency, and accelerate it to a velocity suitable for injection into a drift tube linac.

R. H. Stokes; K. R. Crandall; J. E. Stovall; D. A. Swenson

1979-01-01

128

RF quadrupole beam dynamics  

Microsoft Academic Search

A method was developed to analyze the beam dynamics of the radiofrequency quadrupole accelerating structure. Calculations show that this structure can accept a dc beam at low velocity, bunch it with high capture efficiency, and accelerate it to a velocity suitable for injection into a drift tube linac.

R. H. Stokes; K. R. Crandall; J. E. Stovall; D. A. Swenson

1979-01-01

129

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

130

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

131

Weak Magnetic Order in Bilayered-Hydrate NaxCoO2\\cdotyH2O Structure Probed by Co Nuclear Quadrupole Resonance —Proposed Phase Diagram in Superconducting NaxCoO2\\cdotyH2O---  

NASA Astrophysics Data System (ADS)

A weak magnetic order was found in a nonsuperconducting bilayered-hydrate NaxCoO2\\cdotyH2O sample by Co nuclear quadrupole resonance (NQR) measurement. The nuclear spin-lattice relaxation rate divided by temperature 1/T_1T shows a prominent peak at 5.5 K, below which a Co NQR peak splits due to an internal field at the Co site. From the analyses of the Co NQR spectrum at 1.5 K, the internal field is evaluated to be ˜300 Oe and found to be in the ab-plane. The magnitude of the internal field suggests that the ordered moment is as small as ˜0.015 ?B using the hyperfine coupling constant reported previously. It is shown that the NQR frequency ?Q correlates with magnetic fluctuations from measurements of NQR spectra and 1/T_1T in various samples. The higher-?Q sample has stronger magnetic fluctuations. A possible phase diagram for NaxCoO2\\cdotyH2O is depicted using Tc and ?Q, in which the crystal distortion along the c-axis of the tilted CoO2 octahedron is considered to be a physical parameter. Superconductivity with the highest Tc is seemingly observed in the vicinity of a magnetic phase, suggesting strongly that magnetic fluctuations play an important role in the occurrence of superconductivity.

Ihara, Yoshihiko; Ishida, Kenji; Michioka, Chishiro; Kato, Masaki; Yoshimura, Kazuyoshi; Takada, Kazunori; Sasaki, Takayoshi; Sakurai, Hiroya; Takayama-Muromachi, Eiji

2005-03-01

132

Understanding Earthquake Processes in the Central and Eastern US and Implications for Nuclear Reactor Safety  

NASA Astrophysics Data System (ADS)

All of the early site permits and new reactor licensing applications, which have been submitted to the U.S. Nuclear Regulatory Commission (U.S. NRC), are located in the Central and Eastern United States (CEUS). Furthermore, among the 104 commercial nuclear power plants (NPPs) already licensed to operate in the US, 96 are located in the CEUS. While there are many considerations in siting commercial NPPs, the perceived lower seismic hazard in the CEUS compared to the Western United States is one of the reasons why the majority of operating and potential future nuclear reactors are located in the CEUS. However, one important criterion used in the licensing and safe operation of a nuclear power plant is its seismic design basis, which establishes the plant's ability to withstand ground motions produced by moderate- to large-sized earthquakes without suffering any damage to its critical safety related structures, systems, and components. The seismic design basis for a NPP is site specific and determined using up-to-date knowledge and information about seismic sources surrounding the site and seismic wave propagation characteristics. Therefore, an in-depth understanding of the processes generating earthquakes (tectonic or man-made) and the seismic wave propagation characteristics in the CEUS is crucial. The U.S. NRC's seismic review process for evaluating new reactor siting applications heavily relies upon up-to-date scientific knowledge of seismic sources within at least 320 km of a proposed site. However, the availability of up-to-date knowledge and information about potential seismic sources in low-seismicity regions is limited and relevant data are sparse. Recently, the NRC participated in a joint effort to develop new seismic source models to be used in the CEUS seismic hazard studies for nuclear facilities. In addition, efforts are underway to better understand the seismic potential of the Eastern Tennessee Seismic Zone. While very large and successful scientific experiments such as EarthScope, provide great opportunities to gather new data to further enhance our current understanding of the seismicity and tectonics of the CEUS region, there is also a heightened need for continuation of small-scale scientific missions geared toward understanding of seismic sources in low-seismicity regions. Although such regions are not high-priority areas of research and they do not usually receive the needed attention of funding agencies and the larger scientific community, extensive studies in these areas are still needed. Creating awareness and interest of the needs for seismic studies in such regions is a critical issue from a regulatory perspective. The U.S. NRC's open government philosophy based processes provide excellent opportunities for the involvement of research and educational communities in the regulatory processes related to seismic hazards in the US. This presentation will discuss the available processes for public participation in the US NRC new reactor licensing decisions and highlight some key research areas that will benefit seismic hazard estimations in the CEUS.

Seber, D.; Tabatabai, S.

2012-12-01

133

QUADRUPOLE RESONANCES OF ATOMIC NUCLEI  

Microsoft Academic Search

Collective states of atomic nuclei excited by absorption of quadrupole ; gamma quanta are considered in the shell model approximation. It is shown that ; in heavy nuclei the residual interaction leads to the appearance of two groups of ; states that are preferred with respect to energy and to the probability for ; quadrupole gamma absorption. The group of

V. G. Shevchenko; N. P. Yudin; B. A. Yurev

1963-01-01

134

Towards an improved understanding of the relative scintillation efficiency of nuclear recoils in liquid xenon  

E-print Network

Liquid xenon (LXe) particle detectors are a powerful technology in the field of dark matter direct detection, having shown impressive results in recent years and holding strong possibility for leading the field in sensitivity to galactic weakly interacting massive particles (WIMPs) in the future. The search for WIMPs requires the capability to detect the recoiling nuclei that result when these particles interact with normal matter. In order to make meaningful statements about an observed signal, or lack thereof, the energy scale of recoiling nuclei in LXe must be known. Our understanding of this energy scale is contained in a quantity called the relative scintillation efficiency of nuclear recoils, or L_eff, and has been studied extensively in the literature, producing seemingly contradictory results. I examine all the measurements of L_eff that exist, both direct and indirect, and extract the energy dependent behavior that is statistically consistent globally with all values. Additionally, I examine the meas...

Manalaysay, A

2010-01-01

135

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

136

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

137

Understanding ploidy complex and geographic origin of the Buchloe dactyloides genome using cytoplasmic and nuclear marker systems  

Microsoft Academic Search

Characterizing and inferring the buffalograss [Buchloe dactyloides (Nutt.) Engelm.] genome organization and its relationship to geographic distribution are among the purposes of the buffalograss\\u000a breeding and genetics program. This buffalograss study was initiated to: (1) better understand the buffalograss ploidy complex\\u000a using various marker systems representing nuclear and organelle genomes; (2) determine whether the geographic distribution\\u000a was related to nuclear

H. Budak; R. C. Shearman; O. Gulsen; I. Dweikat

2005-01-01

138

New Method for Precise Determination of the Isovector Giant Quadrupole Resonances in Nuclei  

NASA Astrophysics Data System (ADS)

The intense, nearly monoenergetic, 100% polarized ??-ray beams available at the HI??S facility, along with the realization that the E1-E2 interference term that appears in the Compton scattering polarization observable has opposite signs in the forward and backward angles, make it possible to obtain an order-of-magnitude improvement in the determination of the parameters of the isovector giant quadrupole resonance (IVGQR). Accurate IVGQR parameters will lead to a more detailed knowledge of the symmetry energy in the nuclear equation of state which is important for understanding nuclear matter under extreme conditions such as those present in neutron stars. Our new method is demonstrated for the case of Bi209.

Henshaw, S. S.; Ahmed, M. W.; Feldman, G.; Nathan, A. M.; Weller, H. R.

2011-11-01

139

Simultaneous quadrupole and octupole shape phase transitions in Thorium  

E-print Network

The evolution of quadrupole and octupole shapes in Th isotopes is studied in the framework of nuclear Density Functional Theory. Constrained energy maps and observables calculated with microscopic collective Hamiltonians indicate the occurrence of a simultaneous quantum shape phase transition between spherical and quadrupole-deformed prolate shapes, and between non-octupole and octupole-deformed shapes, as functions of the neutron number. The nucleus $^{224}$Th is closest to the critical point of a double phase transition. A microscopic mechanism of this phenomenon is discussed in terms of the evolution of single-nucleon orbitals with deformation.

Z. P. Li; B. Y. Song; J. M. Yao; D. Vretenar; J. Meng

2013-04-13

140

Ion masking improves resolution in quadrupole mass spectrometers  

NASA Technical Reports Server (NTRS)

Mass spectrometers analyze molecular composition by determining mass-to-charge ratio of ion fragments of molecules. Study adds significantly to quantitative understanding of quadrupole mass filter. It includes development of quantitative theory of ion oscillations, computer analysis of ion behavior, and identification of determining factors in peak tail size.

Ierokomos, N.; Ruecker, M. R.

1973-01-01

141

Understanding Nuclear Weapons and Arms Control: A Guide to the Issues. New Edition.  

ERIC Educational Resources Information Center

Intended for secondary and college level students and teachers, this guide discusses the nuclear arms control issue. There are four sections. Section I discusses U.S. nuclear strategy from 1945 to the present, strategic nuclear weapons competition between the United States and the Union of Soviet Socialist Republics (U.S.S.R.), U.S.…

Mayers, Teena

142

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

143

How genomic studies have improved our understanding of the mechanisms of transcriptional regulation by NR5A nuclear receptors.  

PubMed

SF-1 and LRH-1 are transcription factors that belong to the NR5A family of nuclear receptors that both have an essential role during development. Recent studies at the genome-wide scale have enabled the characterization of the cistrome and transcriptome regulated by SF-1 and LRH-1 in different cell lines and tissues. Those studies have allowed us to make a significant leap forward in our understanding of the mechanisms of transcriptional regulation of NR5A nuclear receptors in stem cells and cancer. PMID:25449416

Ruggiero, Carmen; Doghman, Mabrouka; Lalli, Enzo

2014-10-31

144

Resonant Quadrupole Peter Cameron -BNL  

E-print Network

Resonant Quadrupole Monitor Peter Cameron - BNL #12;LARP Workshop at FNAL6/9/2003 2 Resonant BPM · M. Kesselman et al - PAC 2001 · Stub-tuned 1/4 wave resonator · Simulated in Spice · frequency ~ 240MHz (8.5xRF) · Qloaded ~ 100 optimal coupling · In-tunnel hybrid for and · Resonate difference mode

Large Hadron Collider Program

145

Chapter 11. The Electrostatic Quadrupoles  

E-print Network

will be fabricated in modules each 13 ffi in azimuth, approximately 1:6 m in length. One tank will be filled with 2 tanks will share unequally 1=4 of the total electrostatic quadrupoles. The four fold symmetry tank leaving the transition piece (bellows) free. Every tank will be an independent unit, i

Brookhaven National Laboratory - Experiment 821

146

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

147

Investigation of the electronic effects in a series of halo derivatives of organosilicon compounds by the method of nuclear quadrupole resonance of 79 Br, 81 Br, and 127 I  

Microsoft Academic Search

1.The NQR spectra of certain bromo and iodo derivatives of organosilicon compounds were investigated.2.The correlation of the NQR frequencies and the quadrupole coupling constants with the induction and conjugation constants of the substituents at the silicon atom was constructed.

G. K. Semin; E. V. Bryukhova; M. A. Kadina; G. V. Frolova

1971-01-01

148

A Science-Based Approach to Understanding Waste Form Durability in Open and Closed Nuclear Fuel Cycles  

SciTech Connect

There are two compelling reasons for understanding source term and near-field processes in a radioactive waste geologic repository. First, almost all of the radioactivity is initially in the waste form, mainly in the spent nuclear fuel (SNF) or nuclear waste glass. Second, over long periods, after the engineered barriers are degraded, the waste form is a primary control on the release of radioactivity. Thus, it is essential to know the physical and chemical state of the waste form after hundreds of thousands of years. The United States Department of Energy's Yucca Mountain Repository Program has initiated a long-term program to develop a basic understanding of the fundamental mechanisms of radionuclide release and a quantification of the release as repository conditions evolve over time. Specifically, the research program addresses four critical areas: a) SNF dissolution mechanisms and rates; b) formation and properties of U{sup 6+}- secondary phases; c) waste form-waste package interactions in the near-field; and d) integration of in-package chemical and physical processes. The ultimate goal is to integrate the scientific results into a larger scale model of source term and near-field processes. This integrated model will be used to provide a basis for understanding the behavior of the source term over long time periods (greater than 10{sup 5} years). Such a fundamental and integrated experimental and modeling approach to source term processes can also be readily applied to development of advanced waste forms as part of a closed nuclear fuel cycle. Specifically, a fundamental understanding of candidate waste form materials stability in high temperature/high radiation environments and near-field geochemical/hydrologic processes could enable development of advanced waste forms 'tailored' to specific geologic settings. (authors)

Peters, M.T. [Applied Science and Technology, Argonne National Laboratory, 9700 South Cass Ave., Argonne, IL, 60439 (United States); Ewing, R.C. [Department of Geological Sciences, The University of Michigan, 2534 C.C. Little Bldg., 1100 N. University, Ann Arbor, MI, 48109-1005 (United States)

2007-07-01

149

A science-based approach to understanding waste form durability in open and closed nuclear fuel cycles  

NASA Astrophysics Data System (ADS)

There are two compelling reasons for understanding source term and near-field processes in a radioactive waste geologic repository. First, almost all of the radioactivity is initially in the waste form, mainly in the spent nuclear fuel (SNF) or nuclear waste glass. Second, over long periods, after the engineered barriers are degraded, the waste form is a primary control on the release of radioactivity. Thus, it is essential to know the physical and chemical state of the waste form after hundreds of thousands of years. The United States Department of Energy's Yucca Mountain Repository Program has initiated a long-term program to develop a basic understanding of the fundamental mechanisms of radionuclide release and a quantification of the release as repository conditions evolve over time. Specifically, the research program addresses four critical areas: (a) SNF dissolution mechanisms and rates; (b) formation and properties of U 6+-secondary phases; (c) waste form-waste package interactions in the near-field; and (d) integration of in-package chemical and physical processes. The ultimate goal is to integrate the scientific results into a larger scale model of source term and near-field processes. This integrated model will be used to provide a basis for understanding the behaviour of the source term over long time periods (greater than 10 5 years). Such a fundamental and integrated experimental and modelling approach to source term processes can also be readily applied to development of advanced waste forms as part of a closed nuclear fuel cycle. Specifically, a fundamental understanding of candidate waste form materials stability in high temperature/high radiation environments and near-field geochemical/hydrologic processes could enable development of advanced waste forms 'tailored' to specific geologic settings.

Peters, M. T.; Ewing, R. C.

2007-05-01

150

Heavy ion linear accelerator with high-frequency quadrupole focusing  

NASA Astrophysics Data System (ADS)

Based on results of works on the NICA/MPD (Joint Institute for Nuclear Research, Dubna) project, the possibility of designing a heavy ion linear accelerator with high-frequency quadrupole focusing both in the input part and in the main part of the accelerator is shown. Parameters of the linear 197Au31+ ion accelerator are presented. Special attention is paid to technical questions of calculating, designing, manufacturing, and tuning the accelerator.

Belyaev, O. K.; Budanov, Yu. A.; Zvonarev, I. A.; Ivanov, S. V.; Kudryavtsev, V. G.; Mazurov, E. V.; Mal'tsev, A. P.; Timofeev, A. A.; Kobets, V. V.; Meshkov, I. N.

2013-12-01

151

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

152

Microlensing modulation by quadrupole variation  

E-print Network

We investigate microlensing in the case where the lens is considered as an extended object. We use a multipolar expansion of the lens potential and show that the time-varying nature of the quadrupole contribution allows to separate it from the mass and spin contributions and leads to specific modulations of the amplification signal. As example we study the case of binary system lenses in our galaxy. The modulation is observable if the rotation period of the system is smaller than the time over which the amplification is significant and if the impact parameter of the passing light ray is sufficiently close to the Einstein radius so that the amplification is large. Observations of this modulation can reveal important information on the quadrupole and thus on the gravitational radiation emitted by the binary lens. Even if not observed directly, because of their importance the quadrupole modulation has to be included in the error budget for high magnification ($\\mu\\leq7$) microlensing events.

Florian Dubath; Maria Alice Gasparini; Ruth Durrer

2007-01-11

153

A coherent understanding of low-energy nuclear recoils in liquid xenon  

SciTech Connect

Liquid xenon detectors such as XENON10 and XENON100 obtain a significant fraction of their sensitivity to light (?<10 GeV) particle dark matter by looking for nuclear recoils of only a few keV, just above the detector threshold. Yet in this energy regime a correct treatment of the detector threshold and resolution remains unclear. The energy dependence of the scintillation yield of liquid xenon for nuclear recoils also bears heavily on detector sensitivity, yet numerous measurements have not succeeded in obtaining concordant results. In this article we show that the ratio of detected ionization to scintillation can be leveraged to constrain the scintillation yield. We also present a rigorous treatment of liquid xenon detector threshold and energy resolution. Notably, the effective energy resolution differs significantly from a simple Poisson distribution. We conclude with a calculation of dark matter exclusion limits, and show that existing data from liquid xenon detectors strongly constrain recent interpretations of light dark matter.

Sorensen, Peter, E-mail: pfs@llnl.gov [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 (United States)

2010-09-01

154

A coherent understanding of low-energy nuclear recoils in liquid xenon  

E-print Network

Liquid xenon detectors such as XENON10 and XENON100 obtain a significant fraction of their sensitivity to light (xenon for nuclear recoils also bears heavily on detector sensitivity, yet numerous measurements have not succeeded in obtaining concordant results. In this article we show that the ratio of detected ionization to scintillation can be leveraged to constrain the scintillation yield. We also present a rigorous treatment of liquid xenon detector threshold and energy resolution. Notably, the effective energy resolution differs significantly from a simple Poisson distribution. We conclude with a calculation of dark matter exclusion limits, and show that existing data from liquid xenon detectors strongly constrain recent interpretations of light dark matter.

Peter Sorensen

2010-09-07

155

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

156

Understanding generalized inversions of nuclear magnetic resonance transverse relaxation time in porous media  

NASA Astrophysics Data System (ADS)

The nuclear magnetic resonance transverse relaxation time T2, measured using the Carr-Purcell-Meiboom-Gill (CPMG) experiment, is a powerful method for obtaining unique information on liquids confined in porous media. Furthermore, T2 provides structural information on the porous material itself and has many applications in petrophysics, biophysics, and chemical engineering. Robust interpretation of T2 distributions demands appropriate processing of the measured data since T2 is influenced by diffusion through magnetic field inhomogeneities occurring at the pore scale, caused by the liquid/solid susceptibility contrast. Previously, we introduced a generic model for the diffusion exponent of the form -ant_e^k (where n is the number and te the temporal separation of spin echoes, and a is a composite diffusion parameter) in order to distinguish the influence of relaxation and diffusion in CPMG data. Here, we improve the analysis by introducing an automatic search for the optimum power k that best describes the diffusion behavior. This automated method is more efficient than the manual trial-and-error grid search adopted previously, and avoids variability through subjective judgments of experimentalists. Although our method does not avoid the inherent assumption that the diffusion exponent depends on a single k value, we show through simulation and experiment that it is robust in measurements of heterogeneous systems that violate this assumption. In this way, we obtain quantitative T2 distributions from complicated porous structures and demonstrate the analysis with examples of ceramics used for filtration and catalysis, and limestone of relevance to the construction and petroleum industries.

Mitchell, J.; Chandrasekera, T. C.

2014-12-01

157

Understanding generalized inversions of nuclear magnetic resonance transverse relaxation time in porous media.  

PubMed

The nuclear magnetic resonance transverse relaxation time T2, measured using the Carr-Purcell-Meiboom-Gill (CPMG) experiment, is a powerful method for obtaining unique information on liquids confined in porous media. Furthermore, T2 provides structural information on the porous material itself and has many applications in petrophysics, biophysics, and chemical engineering. Robust interpretation of T2 distributions demands appropriate processing of the measured data since T2 is influenced by diffusion through magnetic field inhomogeneities occurring at the pore scale, caused by the liquid/solid susceptibility contrast. Previously, we introduced a generic model for the diffusion exponent of the form -ante(k) (where n is the number and te the temporal separation of spin echoes, and a is a composite diffusion parameter) in order to distinguish the influence of relaxation and diffusion in CPMG data. Here, we improve the analysis by introducing an automatic search for the optimum power k that best describes the diffusion behavior. This automated method is more efficient than the manual trial-and-error grid search adopted previously, and avoids variability through subjective judgments of experimentalists. Although our method does not avoid the inherent assumption that the diffusion exponent depends on a single k value, we show through simulation and experiment that it is robust in measurements of heterogeneous systems that violate this assumption. In this way, we obtain quantitative T2 distributions from complicated porous structures and demonstrate the analysis with examples of ceramics used for filtration and catalysis, and limestone of relevance to the construction and petroleum industries. PMID:25494741

Mitchell, J; Chandrasekera, T C

2014-12-14

158

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

159

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

160

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

SciTech Connect

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

161

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

162

The Equations of Motion for Binary Systems with Relativistic Quadrupole-Quadrupole Moments Interaction  

NASA Astrophysics Data System (ADS)

The first post-Newtonian (1-PN) equations of motion for binary systems with monopole, spin and quadrupole interaction are for the first time derived in an explicit and complete form making use of the DSX(Damour, Soffel, and Xu) scheme especially their second paper. For the relativistic corrections in quadrupole-quadrupole moments terms, we have used Maple software (exact symbolic manipulation) to calculate these complex tems. The equations of motion are expressed in the local coordinate system of body A (resp. B) as well as in a global coordinate system. The monopole-spin-quadrupole "force" is decomposed into nine coupling parts, monopole-spin-quadrupole moments of body A coupled with monopole-spin-quadrupole moments of body B. If neglect the relativistic quadrupole-quadrupole terms, the equation is agree with the results of the paper of Chongming Xu, Xuejun Wu and Gerhard Schafer (Phys. Rev. D55, 1997). If the total spin and quadrupole moments are equal to zero, the eq! uation is just the Lorentz-Droste-Einstein-Infeld-Hoffmann equation for the case of two bodies. The new terms containing quadrupole moments might be of some importance for a precise description of coalescing neutron star binaries, which are the most important source of gravitational wave. Furthermore, the equation for binary systems can easily be extended to n-body equations of motion.

Xu, C.; Wu, X.

163

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

164

181Ta perturbed-angular-correlation study of electric quadrupole interactions in yttrium metal and yttrium-hydrogen solid solutions  

Microsoft Academic Search

The perturbed-angular-correlation (PAC) technique has been used to study the electric quadrupole interaction (QI) of the nuclear probe 181Ta in yttrium metal and yttrium-hydrogen solid solutions alpha-YHx with 0<=x<=0.2. The temperature dependence of the quadrupole frequency nuq of 181Ta in yttrium metal, measured in the range 290 K<=T<=1700 K, follows the linear relation nuq(T) = nuq(0)(1-AT) with nuq(0) = 423(3)

M. Forker; U. Hütten; M. Müller

2000-01-01

165

Static Theory of the Giant Quadrupole Resonance in Deformed Nuclei  

Microsoft Academic Search

The modes and frequencies of the giant quadrupole resonance of heavy deformed nuclei have been calculated. The quadrupole operator is computed and the absorption cross section is derived. The quadrupole sum rule is discussed, and the relevant oscillator strengths have been evaluated for various orientations of the nucleus. The giant quadrupole resonances have energies between 20 and 25 MeV. The

Michael Danos; Walter Greiner; C. Byron Kohr

1966-01-01

166

Spin Echo Modulation Caused by the Quadrupole Interaction and Multiple Spin Echoes  

Microsoft Academic Search

A spin echo amplitude for a spin system consisting of one nuclear species of spin I with a large Zeeman energy and a small quadrupole interaction has been calculated for the case the excitation is carried out by two succeeding arbitrary rf pulses. The spin echo amplitude shows an oscillatory behavior which depends on the time interval between the first

Hisashi Abe; Hiroshi Yasuoka; Akira Hirai

1966-01-01

167

Monte Carlo simulations of quadrupole collision cells  

NASA Astrophysics Data System (ADS)

This paper outlines a method for modelling the transmission of ions through a quadrupole collision cell. The resulting output obtained by using the computer programs is discussed and comments are made relating to instrument design.

Woods, M. D.; Gordon, D. B.; Barber, M.

1992-12-01

168

Clusterization and quadrupole deformation in nuclei  

SciTech Connect

We study the interrelation of the clusterization and quadrupole deformation of atomic nuclei, by applying cluster models. Both the energetic stability and the exclusion principle is investigated. Special attention is paid to the relative orientations of deformed clusters.

Cseh, J.; Algora, A. [Institute of Nuclear Research, Debrecen (Hungary); Antonenko, N. V.; Jolos, R. V.; Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, Giessen (Germany); Darai, J. [Institute of Experimental Physics, University of Debrecen, Debrecen (Hungary); Hess, P. O. [Instituto de Ciencias Nucleares, UNAM (Mexico)

2006-04-26

169

Klystron having electrostatic quadrupole focusing arrangement  

DOEpatents

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

Maschke, Alfred W. (East Moriches, NY)

1983-08-30

170

Klystron having electrostatic quadrupole focusing arrangement  

DOEpatents

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

Maschke, A.W.

1983-08-30

171

Nonuniform radiation damage in permanent magnet quadrupoles.  

PubMed

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. PMID:25173260

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

2014-08-01

172

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

173

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

174

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

175

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

176

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

177

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

178

76 FR 31997 - Final Memorandum of Understanding Between the U.S. Nuclear Regulatory Commission and the U.S...  

Federal Register 2010, 2011, 2012, 2013

...Between the U.S. Nuclear Regulatory Commission and the U.S. Department of Homeland Security on Chemical Facility Anti-Terrorism Standards AGENCY: Nuclear Regulatory Commission. ACTION: Notice of...

2011-06-02

179

Collective states of odd nuclei in a model with quadrupole-octupole degrees of freedom  

SciTech Connect

We apply the collective axial quadrupole-octupole Hamiltonian to describe the rotation-vibration motion of odd nuclei with Coriolis coupling between the even-even core and the unpaired nucleon.We consider that the core oscillates coherently with respect to the quadrupole and octupole axialdeformation variables. The coupling between the core and the unpaired nucleon provides a split paritydoublet structure of the spectrum. The formalism successfully reproduces the parity-doublet splitting in a wide range of odd-A nuclei. It provides model estimations for the third angular-momentum projection K on the intrinsic symmetry axis and the related intrinsic nuclear structure.

Minkov, N., E-mail: nminkov@inrne.bas.bg; Drenska, S. B.; Yotov, P. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria); Bonatsos, D. [NCSR Demokritos, Institute of Nuclear Physics (Greece)], E-mail: bonat@inp.demokritos.gr; Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet (Germany)], E-mail: Werner.Scheid@theo.physik.uni-giessen.de

2007-08-15

180

The magnetic and quadrupole moment of oriented nuclei measured with the {beta}-LMR-NMR  

SciTech Connect

By combining two well established methods, the {beta}-level mixing resonance ({beta}-LMR) and the {beta}-nuclear magnetic resonance ({beta}-NMR), it is possible to determine the magnetic moment and the quadrupole moment of nuclei with low spin. The combined method can be applied on spin oriented ground state {beta}-decaying nuclei. It was tested on the known {sup 12}B and successfully applied on the neutron rich {sup 18}N. We found for the magnetic moment {mu}({sup 18}N)=0.157(7)n.m. and for the quadrupole moment Q({sup 18}N)=30(3)mbarn.

Teughels, S.; Neyens, G.; Coulier, N.; Georgiev, G.; Ternier, S.; Vyvey, K.; Balabanski, D. L.; Coussement, R. [Instituut voor Kern- en Stralingsfysica, University of Leuven, Celestijnenlaan 200-D, B-3001 Leuven (Belgium); Rogers, W. F. [Westmont College, 955 La Paz Road, Santa Barbara, California 93108 (United States); Cortina-Gil, D.; De Oliveira, F.; Lewitowicz, M.; Mittig, W.; Roussel-Chomaz, P. [Grand Accelerateur National d'Ions Lourds, B.P. 5027, F-14021 Caen Cedex (France); Lepine-Szily, A. [Institute of Physics, University of Sao Paulo, C.P. 66318, 05389-970, Sao Paulo (Brazil)

1998-12-21

181

Production of 62Zn radioactive nuclear beam and on-line PAC investigation of quadrupole interaction in nano-magnetic material Fe73.5Cu1Nb3Si13.5B9  

NASA Astrophysics Data System (ADS)

An Isotope Separator On-Line (ISOL), dedicated to on-line perturbed angular correlation (PAC) and positron annihilation spectroscopy (PAS), has been constructed at CIAE based on the HI-13 tandem accelerator, and a 30 keV radioactive beam of 62Zn with intensity of 2 ×107/s produced by it. Using the 62Zn radioactive beam the investigation of the nano-crystalline soft magnetic Fe73.5Cu1Nb3Si13.5B9 materials has been fulfiled for the first time by the on-line time differential PAC technique. Two quadrupole interaction frequencies ? 01 ( = 440 Mrad/s) and ? 02 ( = 90 Mrad/s) were gained, indicating there are two implantation sites of 62Zn. The frequency ? 02 shows a fluctuation of the crystal lattice constants and proves the characteristic distribution model of nano-crystalline grain boundary. The frequency ? 01 demonstrates that the implanted 62Zn occupies the site of the ordered grain core. The fractions of ? 01 and ? 02 are f01 = 38 % and f02 = 62 %, respectively.

Zuo, Yi; Zheng, Yongnan; Xu, Yongjun; Cui, Baoqun; Li, Liqiang; Ma, Yingjun; Ping, Fan; Yuan, Daqing; Gao, Shuang; Zhu, Shengyun

2013-05-01

182

Microwave Spectrum, Structural Parameters and Quadrupole Coupling for Azaborine and 1-ETHYL-AZABORINE  

NASA Astrophysics Data System (ADS)

The first microwave spectra for the unusual and elusive aromatic molecules, 1,2-dihydro-1,2-azaborine (azaborine) and 1-ethyl-azaborine have been measured, in the 7-18 GHz range, providing accurate rotational constants, nitrogen and boron quadrupole coupling strengths, important bond lengths and other structural parameters. Azaborine (BNC_4H_6)is an aromatic, B-N substituted analog of benzene, the quintessential aromatic molecule. The experimental bond lengths determined for azaborine are: R(B-N) = 1.45(3) Å, R(B-C) = 1.51(1) Å, and R(N-C) = 1.37(3) Å. Accurate measurements of 14N, 11B, and 10B nuclear quadrupole coupling were obtained. The inertial defect ? = 0.02 amu Å^2 indicating a planar structure. A Townes-Dailey population analysis of the B and N quadrupole coupling constants provided the valence p-electron occupancy

Daly, Adam; Kukolich, Stephen G.; Tanjaroon, Chakree; Marwitz, Adam J. V.; Liu, Shih-Yuan

2010-06-01

183

Dipole gravity waves from unbound quadrupoles  

E-print Network

Dipole gravitational disturbances from gravitationally unbound mass quadrupoles propagate to the radiation zone with signal strength at least of quadrupole order if the quadrupoles are nonrelativistic, and of dipole order if relativistic. Angular distributions of parallel-polarized and transverse-polarized dipole power in the radiation zone are calculated for simple unbound quadrupoles, like a linear-oscillator/stress-wave pair and a particle storage ring. Laboratory tests of general relativity through measurements of dipole gravity waves in the source region are proposed. A NASA G2 flywheel module with a modified rotor can produce a post-Newtonian dc bias signal at a gradiometer up to 1 mE. At peak luminosity, the repulsive dipole impulses of proton bunches at the LHC can produce an rms velocity of a high-Q detector surface up to 4 micron/s. Far outside the source region, Newtonian lunar dipole gravity waves can produce a 1-cm displacement signal at LISA. Dipole signal strengths of astrophysical events involving unbound quadrupoles, like near collisions and neutron star kicks in core-collapse supernovae, are estimated.

Franklin Felber

2010-02-01

184

Variable gradient permanent-magnet quadrupole lenses  

SciTech Connect

Rare earth (RE) permanent-magnet quadrupoles (PMQs) have been used for many applications in particle accelerators. They have the advantage over electromagnets of being lightweight and reliable. One difficulty associated with PMQs is that the quadrupole gradient is not easily adjusted. Over a certain range, the magnetization of RE magnets is a reversible function of temperature. We have developed a scheme to use this property to make variable gradient PMQs. The field gradient changes required for tuning are typically on the order of a few percent. For many RE magnets, this requires temperature changes of a few tens of degrees centigrade and is accomplished by actively heating or cooling the quadrupoles. 8 refs., 7 figs.

O'Shea, P.G.; Zaugg, T.J.; Maggs, R.G.; Schafstall, P.; Dyson, J.E.

1989-01-01

185

The large quadrupole of water molecules  

PubMed Central

Many quantum mechanical calculations indicate water molecules in the gas and liquid phase have much larger quadrupole moments than any of the common site models of water for computer simulations. Here, comparisons of multipoles from quantum mechanical?molecular mechanical (QM?MM) calculations at the MP2?aug-cc-pVQZ level on a B3LYP?aug-cc-pVQZ level geometry of a waterlike cluster and from various site models show that the increased square planar quadrupole can be attributed to the p-orbital character perpendicular to the molecular plane of the highest occupied molecular orbital as well as a slight shift of negative charge toward the hydrogens. The common site models do not account for the p-orbital type electron density and fitting partial charges of TIP4P- or TIP5P-type models to the QM?MM dipole and quadrupole give unreasonable higher moments. Furthermore, six partial charge sites are necessary to account reasonably for the large quadrupole, and polarizable site models will not remedy the problem unless they account for the p-orbital in the gas phase since the QM calculations show it is present there too. On the other hand, multipole models by definition can use the correct multipoles and the electrostatic potential from the QM?MM multipoles is much closer than that from the site models to the potential from the QM?MM electron density. Finally, Monte Carlo simulations show that increasing the quadrupole in the soft-sticky dipole-quadrupole-octupole multipole model gives radial distribution functions that are in good agreement with experiment. PMID:21476758

Niu, Shuqiang; Tan, Ming-Liang; Ichiye, Toshiko

2011-01-01

186

The large quadrupole of water molecules  

NASA Astrophysics Data System (ADS)

Many quantum mechanical calculations indicate water molecules in the gas and liquid phase have much larger quadrupole moments than any of the common site models of water for computer simulations. Here, comparisons of multipoles from quantum mechanical/molecular mechanical (QM/MM) calculations at the MP2/aug-cc-pVQZ level on a B3LYP/aug-cc-pVQZ level geometry of a waterlike cluster and from various site models show that the increased square planar quadrupole can be attributed to the p-orbital character perpendicular to the molecular plane of the highest occupied molecular orbital as well as a slight shift of negative charge toward the hydrogens. The common site models do not account for the p-orbital type electron density and fitting partial charges of TIP4P- or TIP5P-type models to the QM/MM dipole and quadrupole give unreasonable higher moments. Furthermore, six partial charge sites are necessary to account reasonably for the large quadrupole, and polarizable site models will not remedy the problem unless they account for the p-orbital in the gas phase since the QM calculations show it is present there too. On the other hand, multipole models by definition can use the correct multipoles and the electrostatic potential from the QM/MM multipoles is much closer than that from the site models to the potential from the QM/MM electron density. Finally, Monte Carlo simulations show that increasing the quadrupole in the soft-sticky dipole-quadrupole-octupole multipole model gives radial distribution functions that are in good agreement with experiment.

Niu, Shuqiang; Tan, Ming-Liang; Ichiye, Toshiko

2011-04-01

187

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

188

Magnetic Measurement Results of the LCLS Undulator Quadrupoles  

SciTech Connect

This note details the magnetic measurements and the magnetic center fiducializations that were performed on all of the thirty-six LCLS undulator quadrupoles. Temperature rise, standardization reproducibility, vacuum chamber effects and magnetic center reproducibility measurements are also presented. The Linac Coherent Light Source (LCLS) undulator beam line has 33 girders, each with a LCLS undulator quadrupole which focuses and steers the beam through the beam line. Each quadrupole has main quadrupole coils, as well as separate horizontal and vertical trim coils. Thirty-six quadrupoles, thirty-three installed and three spares were, manufactured for the LCLS undulator system and all were measured to confirm that they met requirement specifications for integrated gradient, harmonics and for magnetic center shifts after current changes. The horizontal and vertical dipole trims of each quadrupole were similarly characterized. Each quadrupole was also fiducialized to its magnetic center. All characterizing measurements on the undulator quads were performed with their mirror plates on and after a standardization of three cycles from -6 to +6 to -6 amps. Since the undulator quadrupoles could be used as a focusing or defocusing magnet depending on their location, all quadrupoles were characterized as focusing and as defocusing quadrupoles. A subset of the undulator quadrupoles were used to verify that the undulator quadrupole design met specifications for temperature rise, standardization reproducibility and magnetic center reproducibility after splitting. The effects of the mirror plates on the undulator quadrupoles were also measured.

Anderson, Scott; Caban, Keith; Nuhn, Heinz-Dieter; Reese, Ed; Wolf, Zachary; /SLAC; ,

2011-08-18

189

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

44 Emergency Management and Assistance 1 2014-10-01 2014-10-01...Between Federal Emergency Management Agency and Nuclear Regulatory Commission A Appendix A to Part 353 Emergency Management and Assistance FEDERAL EMERGENCY...

2014-10-01

190

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

Code of Federal Regulations, 2013 CFR

44 Emergency Management and Assistance 1 2013-10-01 2013-10-01...Between Federal Emergency Management Agency and Nuclear Regulatory Commission A Appendix A to Part 353 Emergency Management and Assistance FEDERAL EMERGENCY...

2013-10-01

191

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

Code of Federal Regulations, 2012 CFR

44 Emergency Management and Assistance 1 2012-10-01 2011-10-01...Between Federal Emergency Management Agency and Nuclear Regulatory Commission A Appendix A to Part 353 Emergency Management and Assistance FEDERAL EMERGENCY...

2012-10-01

192

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

Code of Federal Regulations, 2011 CFR

44 Emergency Management and Assistance 1 2011-10-01 2011-10-01...Between Federal Emergency Management Agency and Nuclear Regulatory Commission A Appendix A to Part 353 Emergency Management and Assistance FEDERAL EMERGENCY...

2011-10-01

193

Quadrupole resonance spectroscopic study of narcotic materials  

Microsoft Academic Search

Bulk narcotic detection systems based upon Quadrupole Resonance Analysis (QRA) technology have a major advantage over imaging technologies, in that QRA is chemical-specific and consequently has a lower rate of false alarms. QRA is a magnetic resonance technology which occurs as a result of the inherent molecular properties of the atomic nuclei in crystalline and amorphous solids. The QRA response

Timothy J. Rayner; Rebecca West; Allen N. Garroway; R. Lyndquist; James P. Yesinowski

1997-01-01

194

Explosives detection with quadrupole resonance analysis  

Microsoft Academic Search

The increase in international terrorist activity over the past decade has necessitated the exploration of new technologies for the detection of plastic explosives. Quadrupole resonance analysis (QRA) has proven effective as a technique for detecting the presence of plastic, sheet, and military explosive compounds in small quantities, and can also be used to identify narcotics such as heroin and cocaine

Timothy J. Rayner; Benjamin D. Thorson; Simon Beevor; Rebecca West; Ronald A. Krauss

1997-01-01

195

Quadrupole ionization gage measures ultrahigh vacuum  

NASA Technical Reports Server (NTRS)

Quadrupole system, energized with a 200 MHz electric field, restrains ionizing electrons within the center of the ionization gage. Oscillatory trajectory of the electrons increases the probability of ionizing the gas molecules, lowers background X-ray level, and increases the signal-to-noise ratio.

Schwarz, H. J.

1970-01-01

196

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

197

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

198

Quadrupole Induced Resonant Particle Transport in a Pure Electron Plasma  

E-print Network

Quadrupole Induced Resonant Particle Transport in a Pure Electron Plasma by Erik Peter Gilson B;Quadrupole Induced Resonant Particle Transport in a Pure Electron Plasma Copyright Fall 2001 by Erik Peter Gilson #12;1 Abstract Quadrupole Induced Resonant Particle Transport in a Pure Electron Plasma by Erik

Gilson, Erik

199

Covariant Spectator Theory of np scattering: Deuteron Quadrupole Moment  

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

Gross, Franz

2015-01-01

200

Covariant spectator theory of n p scattering: Deuteron quadrupole moment  

NASA Astrophysics Data System (ADS)

The deuteron quadrupole moment is calculated using two covariant spectator theory model wave functions obtained from the 2007 high-precision fits to n p scattering data. Included in the calculation are a new class of isoscalar n p interaction currents automatically generated by the nuclear force model used in these fits. The prediction for model WJC-1, with larger relativistic P -state components, is 2.5 % smaller than the experimental result, in common with the inability of models prior to 2014 to predict this important quantity. However, model WJC-2, with very small P -state components, gives agreement to better than 1%, similar to the results obtained recently from chiral effective field theory predictions to next-to-next-to-next-to-leading order.

Gross, Franz

2015-01-01

201

78 FR 19540 - Memorandum of Understanding Between the U.S. Nuclear Regulatory Commission and the Bureau of Land...  

Federal Register 2010, 2011, 2012, 2013

...Department of the Interior (BLM) entered into a Memorandum of Understanding (MOU) concerning the development of uranium or thorium resources on BLM administered public lands, including Federal mineral estates. The MOU sets forth the cooperative...

2013-04-01

202

Nuclear Schiff moment and soft vibrational modes  

E-print Network

The atomic electric dipole moment (EDM) currently searched by a number of experimental groups requires that both parity and time-reversal invariance be violated. According to current theoretical understanding, the EDM is induced by the nuclear Schiff moment. The enhancement of the Schiff moment by the combination of static quadrupole and octupole deformation was predicted earlier. Here we study a further idea of the possible enhancement in the absence of static deformation but in a nuclear system with soft collective vibrations of two types. Both analytical approximation and numerical solution of the simplified problem confirm the presence of the enhancement. We discuss related aspects of nuclear structure which should be studied beyond mean-field and random phase approximations.

Vladimir Zelevinsky; Alexander Volya; Naftali Auerbach

2008-03-20

203

17O and 39K quadrupole resonance study of the ferroelastic phase transition in KH3(SeO3)2  

Microsoft Academic Search

The 17O-proton nuclear double-resonance spectra of KH3(SeO3)2 have been measured above and below the ferroelastic transition and the quadrupole coupling has been determined for all three chemically nonequivalent oxygen sites in the unit cell. The 17O-proton magnetic dipolar coupling as well as the 17O quadrupole coupling data clearly show the presence of proton motion between two equilibrium sites in the

J. Seliger; V. Zagar; R. Blinc; A. Novak

1986-01-01

204

LARP Long Nb3Sn Quadrupole Design  

SciTech Connect

A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4m-long quadrupole magnets (LQ) wound with Nb{sub 3}Sn conductor. The goal of these magnets is to be a proof of principle that Nb{sub 3}Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on the design of the LARP Technological Quadrupoles, presently under development at FNAL and LBNL, with 90-mm aperture and gradient higher than 200 T/m. The design of the first LQ model will be completed by the end of 2007 with the selection of a mechanical design. In this paper we present the coil design addressing some fabrication technology issues, the quench protection study, and three designs of the support structure.

Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidize, G.; Dietderich, D.; Feher, S.; Ferracin, P.; Ghosh, A.; Hafalia, R.; Hannaford, R.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Lietzke, A.; McInturff, A.; Muratore, J.; Nobrega, F.; Novitsky, I.; Sabbi, G.L.; Schmalzle, J.; Tartaglia, M.; Turrioni, D.; Wanderer, P.; Whitson, G.; Zlobin, A.V.

2008-06-01

205

Permanent-magnet quadrupoles in RFQ Linacs  

SciTech Connect

We investigated the possibility of increasing the current-carrying capability of radio-frequency quadrupole (RFQ) linear accelerators by adding permanentmagnet 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 accompanied 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.

1985-10-01

206

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

207

Quadrupole Magnetic Lens Using Permanent Ceramic Magnets  

Microsoft Academic Search

A quadrupole lens pair is described utilizing permanent ceramic magnets. The field gradient is 470 Oe?cm, across a 7.94-cm aperture. Variation in lens strength is achieved by driving the lenses over a mild steel magnetic shunt welded to the inside of the beam tube. The lenses are of relatively low cost, light weight, and simple construction. Of the two units

J. W. Jagger; P. J. Riley

1967-01-01

208

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

209

Radio frequency quadrupole resonator for linear accelerator  

DOEpatents

An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.

Moretti, Alfred (Downers Grove, IL)

1985-01-01

210

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

211

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

212

Multi-Pass Quadrupole Mass Analyzer  

NASA Technical Reports Server (NTRS)

Analysis of the composition of planetary atmospheres is one of the most important and fundamental measurements in planetary robotic exploration. Quadrupole mass analyzers (QMAs) are the primary tool used to execute these investigations, but reductions in size of these instruments has sacrificed mass resolving power so that the best present-day QMA devices are still large, expensive, and do not deliver performance of laboratory instruments. An ultra-high-resolution QMA was developed to resolve N2 +/CO+ by trapping ions in a linear trap quadrupole filter. Because N2 and CO are resolved, gas chromatography columns used to separate species before analysis are eliminated, greatly simplifying gas analysis instrumentation. For highest performance, the ion trap mode is used. High-resolution (or narrow-band) mass selection is carried out in the central region, but near the DC electrodes at each end, RF/DC field settings are adjusted to allow broadband ion passage. This is to prevent ion loss during ion reflection at each end. Ions are created inside the trap so that low-energy particles are selected by low-voltage settings on the end electrodes. This is beneficial to good mass resolution since low-energy particles traverse many cycles of the RF filtering fields. Through Monte Carlo simulations, it is shown that ions are reflected at each end many tens of times, each time being sent back through the central section of the quadrupole where ultrahigh mass filtering is carried out. An analyzer was produced with electrical length orders of magnitude longer than its physical length. Since the selector fields are sized as in conventional devices, the loss of sensitivity inherent in miniaturizing quadrupole instruments is avoided. The no-loss, multi-pass QMA architecture will improve mass resolution of planetary QMA instruments while reducing demands on the RF electronics for high-voltage/high-frequency production since ion transit time is no longer limited to a single pass. The QMA-based instrument will thus give way to substantial reductions of the mass of flight instruments.

Prestage, John D.

2013-01-01

213

Spacecraft applications of quadrupole mass spectrometry  

NASA Technical Reports Server (NTRS)

Techniques of mass spectrometry are reviewed and the theory of the quadrupole mass spectrometer (QMS) is discussed. The QMS is shown to have several advantages over older types of mass spectrometers. The QMS has been flown on a large number of rockets and several satellites. More sophisticated versions of the QMS are proposed for future satellites. Special emphasis is placed on problems of contamination which are likely to be encountered on a large and complex satellite like the Advanced Technology Satellite ATS-G. The development of a QMS to detect and forestall such contamination is discussed.

Thekaekara, M. P.

1972-01-01

214

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

Iowa Public Television. Explore More Project

2004-01-01

215

Low-lying 2+ states generated by p n -quadrupole correlation and N =28 shell quenching  

NASA Astrophysics Data System (ADS)

The quadrupole vibrational modes of neutron-rich N =28 isotones (48Ca, 46Ar, 44S, and 42Si) are investigated by using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory with several choice of energy density functionals, including nuclear pairing correlation. It is found that the quenching of the N =28 shell gap and the proton holes in the s d shell trigger quadrupole correlation and increase the collectivity of the low-lying 2+ state in 46Ar . It is also found that the pairing correlation plays an important role to increase the collectivity. 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 can be associated with the observed 2+ states.

Ebata, Shuichiro; Kimura, Masaaki

2015-01-01

216

Explosives detection with quadrupole resonance analysis  

NASA Astrophysics Data System (ADS)

The increase in international terrorist activity over the past decade has necessitated the exploration of new technologies for the detection of plastic explosives. Quadrupole resonance analysis (QRA) has proven effective as a technique for detecting the presence of plastic, sheet, and military explosive compounds in small quantities, and can also be used to identify narcotics such as heroin and cocaine base. QRA is similar to the widely used magnetic resonance (MR) and magnetic resonance imaging (MRI) techniques, but has the considerable advantage that the item being inspected does not need to be immersed in a steady, homogeneous magnetic field. The target compounds are conclusively identified by their unique quadrupole resonance frequencies. Quantum magnetics has develop and introduced a product line of explosives and narcotics detection devices based upon QRA technology. The work presented here concerns a multi-compound QRA detection system designed to screen checked baggage, cargo, and sacks of mail at airports and other high-security facilities. The design philosophy and performance are discussed and supported by test results from field trials conducted in the United States and the United Kingdom. This detection system represents the current state of QRA technology for field use in both commercial and government sectors.

Rayner, Timothy J.; Thorson, Benjamin D.; Beevor, Simon; West, Rebecca; Krauss, Ronald A.

1997-02-01

217

Is it possible to enhance the nuclear Schiff moment by nuclear collective modes?  

SciTech Connect

The nuclear Schiff moment is predicted to be enhanced in nuclei with static quadrupole and octupole deformation. The analogous suggestion of the enhanced contribution to the Schiff moment from the soft collective quadrupole and octupole vibrations in spherical nuclei is tested in the framework of the quasiparticle random phase approximation with separable quadrupole and octupole forces applied to the odd {sup 217-221}Ra and {sup 217-221}Rn isotopes. In this framework, we confirm the existence of the enhancement effect due to the soft modes, but only in the limit when the frequencies of quadrupole and octupole vibrations are close to zero.

Auerbach, N. [Tel Aviv University, School of Physics and Astronomy (Israel)], E-mail: auerbach@post.tau.ac.il; Dmitriev, V. F. [Budker Institute of Nuclear Physics (Russian Federation)], E-mail: v.f.dmitriev@inp.nsk.su; Flambaum, V. V. [University of New South Wales, School of Physics (Australia)], E-mail: flambaum@phys.unsw.edu.au; Lisetskiy, A. [GSI, Theory Department (Germany)], E-mail: olisetsk@theory.gsi.de; Sen'kov, R. A. [Budker Institute of Nuclear Physics (Russian Federation)], E-mail: senkov@nscl.msu.edu; Zelevinsky, V. G. [Michigan State University, National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy (United States)], E-mail: zelevins@nscl.msu.edu

2007-09-15

218

The Nuclear Zeeman Effect, and Quadrupole Splitting in 119Sn  

Microsoft Academic Search

The recoilless absorption of 24 keV ?-rays from 119Snm has been studied with the aid of a velocity spectrometer. Observations with the absorbing nuclei in different environments have enabled a value of 0.83 ± 0.03 n.m. to be given for the magnetic moment of the first excited state in 119Sn, and an upper limit of 3 × 10-8 eV to

A J F Boyle; D St P Bunbury; C Edwards

1961-01-01

219

The Nuclear Zeeman Effect, and Quadrupole Splitting in 119Sn  

Microsoft Academic Search

The recoilless absorption of 24 keV gamma-rays from 119Snm has been studied with the aid of a velocity spectrometer. Observations with the absorbing nuclei in different environments have enabled a value of 0.83 +\\/- 0.03 n.m. to be given for the magnetic moment of the first excited state in 119Sn, and an upper limit of 3 × 10-8 eV to

A. J. F. Boyle; D. St. P. Bunbury; C. Edwards

1961-01-01

220

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

221

Quadrupole Induced Resonant Particle Transport in a Pure Electron Plasma  

E-print Network

Quadrupole Induced Resonant Particle Transport in a Pure Electron Plasma E. Gilson1 and J. Fajans2 that a certain class of resonant electrons follows trajectories that take them out of the plasma. Even though are o® resonance, the lifetime of the plasma is not greatly a®ected by the quadrupole ¯eld, but near

Gilson, Erik

222

Engineering Design Review Charge Quadrupole Cold Mass MQXB  

E-print Network

Engineering Design Review ­ Charge Quadrupole Cold Mass ­ MQXB Page 1 of 5 17 February 2000 is the design of the Fermilab inner triplet quadrupole cold mass, end plate to end plate. The cryostat design includes: The design, construction and testing of a series of short (2 m) model magnets in order to develop

Large Hadron Collider Program

223

Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam  

DOEpatents

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

Maschke, A.W.

1984-04-16

224

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

225

Ion-quadrupole effects in ion-molecule collisions.  

NASA Technical Reports Server (NTRS)

Ion-quadrupole effects are investigated via numerical calculations of capture cross sections and computer-plotter studies of ion trajectories in the quadrupole field. Capture cross sections are roughly equal to Langevin values for low rotational temperatures; a large fraction of multiple reflection captures are calculated corresponding to formation of ion-molecule complexes.

Dugan, J. V., Jr.; Palmer, R. W.

1972-01-01

226

Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam  

DOEpatents

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

Maschke, Alfred W. (East Moriches, NY)

1985-01-01

227

Cation-? interactions in iminium ion activation: correlating quadrupole moment & enantioselectivity.  

PubMed

A linear correlation between quadrupole moment (Qzz) and enantioselectivity (es) advocates the notion that a cation-? interaction is a contributing factor in the addition of uncharged nucleophiles to iminium salts derived from MacMillan's 1st generation catalyst. The quadrupole moment of the aryl shielding group is a useful qualitative parameter for predicting selectivity (Qzz < 0 ? high es). PMID:25434331

Holland, M C; Metternich, J B; Mück-Lichtenfeld, C; Gilmour, R

2014-12-01

228

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

229

Commissioning 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 the quadrupoles. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing such a system. 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). A previous study investigated the error associated with each step by using a permanent quadrupole magnet on an optical mover system. The study reported an error of 11{micro}m for step 1 and a repeatability of 4{micro}m for step 2. However, the set up used a FARO arm to measure tooling balls and didn't allow to accurately check step 2 for errors; an uncertainty of 100{micro}m was reported. Therefore, even though the repeatability was good, there was no way to check that the error in step 2 was small. Following the recommendations of that study, we used a CMM (Coordinate Measuring Machine) instead of the FARO arm for measuring the tooling balls. In addition, a roller cam positioner system replaced the optical movers for moving the quadrupole. With the exception of the quadrupole itself, the system was identical to what will be used in fiducializing the undulator quadrupoles. In this study, we investigate the new vibrating wire set up, including the error associated with each step of fiducialization. A vibrating wire system was constructed to fiducialize the quadrupoles between undulator segments in the LCLS. This note is a continuation of previous work to study the ability of the system to fulfill the fiducialization requirements.

Levashov, Michael Y

2010-12-03

230

Contribution of electric quadrupole resonance in optical metamaterials  

NASA Astrophysics Data System (ADS)

Optical metamaterials are artificial structures composed of nanoscale units with unit dimension smaller than optical wavelength. They can exhibit negative index of refraction when both effective permittivity and permeability are negative. Although, negative permittivity is straightforward to obtain, negative permeability is nonexistent in nature. Only recently has it been achieved using strong magnetic resonances in suitably designed metal plasmonic nanostructures. However, similar to the magnetic resonance, electric quadrupole resonance can also be greatly enhanced by plasmon resonances. The contribution of the electric quadrupole resonance to the effective properties of metamaterials has not been well understood and often neglected. We show by simulation that, for many metamaterial structures, electric quadrupole radiation is comparable to that of magnetic dipole and we propose an experimental scheme to determine individual contribution of the electric dipole, magnetic dipole and electric quadrupole. We also show that the electric quadrupole radiation can greatly affect effective permeability, and therefore is of central importance for designing metamaterials with negative permeability.

Cho, David; Wang, Feng; Zhang, Xiang; Shen, Y. Ron

2008-03-01

231

Double-photoionization of helium including quadrupole radiation effects  

SciTech Connect

Non-perturbative time-dependent close-coupling calculations are carried out for the double photoionization of helium including both dipole and quadrupole radiation effects. At a photon energy of 800 eV, accessible at CUlTent synchrotron light sources, the quadrupole interaction contributes around 6% to the total integral double photoionization cross section. The pure quadrupole single energy differential cross section shows a local maxima at equal energy sharing, as opposed to the minimum found in the pure dipole single energy differential cross section. The sum of the pure dipole and pure quadrupole single energy differentials is insensitive to non-dipole effects at 800 eV. However, the triple differential cross section at equal energy sharing of the two ejected electrons shows strong non-dipole effects due to the quadrupole interaction that may be experimentally observable.

Colgan, James [Los Alamos National Laboratory; Ludlow, J A [AUBURN UNIV; Lee, Teck - Ghee [AUBURN UNIV; Pindzola, M S [AUBURN UNIV; Robicheaux, F [AUBURN UNIV

2009-01-01

232

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

233

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

234

Radio-frequency quadrupole linear accelerator  

SciTech Connect

The radio-frequency quadrupole (RFQ) is a new linear accelerator concept in which rf electric fields are used to focus, bunch, and accelerate the beam. Because the RFQ can provide strong focusing at low velocities, it can capture a high-current dc ion beam from a low-voltage source and accelerate it to an energy of 1 MeV/nucleon within a distance of a few meters. A recent experimental test at the Los Alamos Scientific Laboratory (LASL) has confirmed the expected performance of this structure and has stimulated interest in a wide variety of applications. The general properties of the RFQ are reviewed and examples of applications of this new accelerator are presented.

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

1980-01-01

235

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

236

Quadrupole resonance scanner for narcotics detection  

NASA Astrophysics Data System (ADS)

Interest in non-invasive, non-hazardous, bulk detection technologies for narcotics interdiction has risen over the last few years. As part of our continuing research and development programs in detection of narcotics and explosives using sensitive magnetic measuring devices, we present the first commercially available prototype Quadrupole Resonance (QR) scanner for narcotics detection. The portable narcotics detection system was designed in modular form such that a single QR base system could be easily used with a variety of custom detection heads. The QR system presented in this paper is suitable for scanning items up to 61 X 35 X 13 cm in size, and was designed to scan mail packages and briefcase-sized items for the presence of narcotics. System tests have shown that detection sensitivity is comparable that obtained in laboratory systems.

Shaw, Julian D.; Moeller, C. R.; Magnuson, Erik E.; Sheldon, Alan G.

1994-10-01

237

HANLE EFFECT FOR STELLAR DIPOLES AND QUADRUPOLES  

SciTech Connect

We derive exact expressions for the degree of lineal polarization over a resolved or integrated stellar disc due to resonance scattering and the Hanle effect from a dipolar or quadrupolar distribution of magnetic fields. We apply the theory of scattering polarization within the formalism of the spherical tensors representation for the density matrix and radiation field. The distribution of linear polarization over the stellar disk for different configurations of the magnetic field is studied and its topology discussed. For an unresolved dipole, the resulting polarization can be expressed in terms of just three functions (of the inclination angle and effective dipole strength) that are calculated numerically and their behavior discussed. Dipolar and (aligned) quadrupoles are considered in some detail, but the techniques here-in particular, the extensive use of the spherical tensor formalism for polarization-can easily be applied to more general field configurations.

Manso Sainz, R.; Gonzalez, M. J. Martinez [Instituto de Astrofisica de Canarias, Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain)

2012-11-20

238

Systematics of isovector and isoscalar giant quadrupole resonances in normal and superfluid spherical nuclei  

NASA Astrophysics Data System (ADS)

The isoscalar (IS) and isovector (IV) quadrupole responses of nuclei are systematically investigated using the time-dependent Skyrme energy density functional including pairing in the BCS approximation. Using two different Skyrme functionals, Sly4 and SkM*, respectively 263 and 324 nuclei have been found to be spherical along the nuclear charts. The time-dependent evolution of these nuclei has been systematically investigated, giving access to their quadrupole responses. It is shown that the mean energy of the collective high-energy state globally reproduces the experimental IS and IV collective energy but fails to reproduce their lifetimes. It is found that the mean collective energy depends rather significantly on the functional used in the mean-field channel. Pairing by competing with parity effects can slightly affect the collective response around magic numbers and induces a reduction of the collective energy compared to the average trend. Low-lying states, that can only be considered if pairing is included, are investigated. While the approach provides a fair estimate of the low-lying state energy, it strongly underestimates the transition rate B(E2). Finally, the possibility to access the density dependence of the symmetry energy through parallel measurements of both the IS and IV giant quadrupole resonances is discussed.

Scamps, Guillaume; Lacroix, Denis

2013-10-01

239

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

240

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

241

Contribution of the electric quadrupole resonance in optical metamaterials  

NASA Astrophysics Data System (ADS)

Optical metamaterials can exhibit negative index of refraction when both the effective permittivity and permeability are negative. The negative permeability is usually considered to be associated with a magnetic dipole resonance and the contribution from electric quadrupoles is neglected. Here, we show by simulation that the electric quadrupole contribution is actually comparable to that from magnetic dipoles. We propose an experimental scheme to determine the relative contributions from the electric dipole, magnetic dipole, and electric quadrupole of a metallic nanostructure. This can be important in the design of metamaterials.

Cho, David J.; Wang, Feng; Zhang, Xiang; Shen, Y. Ron

2008-09-01

242

NUCLEAR SPIN RESONANCE  

Microsoft Academic Search

The first experiments on nuclear quadrupole interactions in crystals ; were carried out by R. V. Pound (Phys. Rev., magnetic resonance lines and by H. ; G. Dehmelt and H. Kruger (Naturwiss., 37: 111(1950)) who observed the absorption ; of radiowaves in a neutral magnetic field. The work was subsequently continued ; in two directions: toward the study of large,

V. S. Grechishkin; N. E. Ainbinder

1963-01-01

243

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

244

PRINCIPLE OF SKEW QUADRUPOLE MODULATION TO MEASURE BETATRON COUPLING.  

SciTech Connect

The measurement of the residual betatron coupling via skew quadrupole modulation is a new diagnostics technique that has been developed and tested at the Relativistic Heavy Ion Collider (RHIC) as a very promising method for the linear decoupling on the ramp. By modulating the strengths of different skew quadrupole families the two eigentunes are precisely measured with the phase lock loop system. The projections of the residual coupling coefficient onto the skew quadrupole coupling modulation directions are determined. The residual linear coupling could be corrected according to the measurement. An analytical solution for skew quadrupole modulation based on Hamiltonian perturbation approximation is given, and simulation code using smooth accelerator model is also developed. Some issues concerning the practical applications of this technique are discussed.

LUO.Y.PILAT,F.ROSER,T.ET AL.

2004-07-05

245

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

246

Quadrupole resonance spectroscopic study of narcotic materials  

NASA Astrophysics Data System (ADS)

Bulk narcotic detection systems based upon Quadrupole Resonance Analysis (QRA) technology have a major advantage over imaging technologies, in that QRA is chemical-specific and consequently has a lower rate of false alarms. QRA is a magnetic resonance technology which occurs as a result of the inherent molecular properties of the atomic nuclei in crystalline and amorphous solids. The QRA response is characterized by 1) the precessional frequency of the nucleus, and 2) the nature of the electric field gradient experienced by the nucleus,due to its molecular environment. Another important detection parameter is linewidth, resonant quality. All of these parameters depend on sample purity and manufacturing process. Quantum Magnetics recently carried out a study on the QRA signatures of various narcotic materials with the support of the US Army, US Customs, and the Office of National Drug Control Policy. The aim of the study was to fully characterize the variation in QRA spectroscopic parameters of different samples of cocaine base and cocaine hydrochloride. The results from this study ar discussed here.

Rayner, Timothy J.; West, Rebecca; Garroway, Allen N.; Lyndquist, R.; Yesinowski, James P.

1997-02-01

247

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

248

Thermal Analysis of the ILC Superconductin Quadrupole  

SciTech Connect

Critical to a particle accelerator's functioning, superconducting magnets serve to focus and aim the particle beam. The Stanford Linear Accelerator Center (SLAC) has received a prototype superconducting quadrupole designed and built by the Centro de Investigaciones Energ{acute e}ticas, Medioambientales y Tecnol{acute o}gicas (CIEMAT) to be evaluated for the International Linear Collider (ILC) project. To ensure proper functioning of the magnet, the device must be maintained at cryogenic temperatures by use of a cooling system containing liquid nitrogen and liquid helium. The cool down period of a low temperature cryostat is critical to the success of an experiment, especially a prototype setup such as this one. The magnet and the dewar each contain unique heat leaks and material properties. These differences can lead to tremendous thermal stresses. The system was analyzed mathematically, leading to ideal liquid helium and liquid nitrogen flow rates during the magnet's cool-down to 4.2 K, along with a reasonable estimate of how long this cool-down will take. With a flow rate of ten gaseous liters of liquid nitrogen per minute, the nitrogen shield will take approximately five hours to cool down to 77 K. With a gaseous helium flow rate of sixty liters per minute, the magnet will take at least nineteen hours to cool down to a temperature of 4.2 K.

Ross, Ian; /Rose-Hulman Inst., Terre Haute /SLAC

2006-09-13

249

Using the quadrupole moment frequency response of bunched beam to measure its transverse emittance  

SciTech Connect

The quadrupole moment measured with a quadrupole pickup has been used to measure the transverse emittance of the beam. Unfortunately, the poor S/N ratio in the measurement makes it difficult to produce good and consistent emittance results. One way to enhance the S/N is to kick the beam with a quadrupole kicker and then measure its quadrupole frequency response (QFR) with a quadrupole pickup. This paper will show that if the bunched beam is extremely short, the quadrupole tunes are well decoupled and far apart, and the quadrupole tune spread is smaller than the synchrotron tune, then the emittance can be extracted from the QFR.

Tan, Cheng-Yang; /Fermilab

2007-10-01

250

Application of the Thermal Quadrupoles Method to Semitransparent Solids  

NASA Astrophysics Data System (ADS)

In this study, the thermal quadrupoles method is extended to semitransparent layered solids. Using this method, the surface temperature of semitransparent multilayered materials is calculated as a function of the optical and thermal properties of each layer. This result eventually leads to determination of the thermal diffusivity, thermal resistance, and/or optical absorption coefficient of layered materials using photothermal techniques. The thermal quadrupoles method is applied to determine the thermal contact resistance in glass stacks.

Salazar, A.; Fuente, R.; Mendioroz, A.; Apiñaniz, E.; Celorrio, R.

2012-11-01

251

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

252

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

253

Understanding classification  

Microsoft Academic Search

In practical data analysis, the understandability of models plays an important role in their acceptance. In the data mining literature, however, understandability plays is hardly ever mentioned. If it is mentioned, it is interpreted as meaning that the models have to be simple. In this thesis we argue that understandability should be interpreted as explainable. That is, for predictive models

M. Subianto

2009-01-01

254

Quadrupole contribution to the third-order optical activity spectroscopy.  

PubMed

Time-resolved nonlinear optical activity measurement spectroscopy can be a useful tool for studying biomolecular and chemical reaction dynamics of chiral molecules. Only recently, the two-dimensional (2D) circularly polarized photon echo (CP-PE) spectroscopy of polypeptides and a photosynthetic light-harvesting complex were discussed, where the beam configuration was specifically controlled in such a way to eliminate the quadrupole contribution to the CP-PE signal. In this paper, we generalize the CP-PE spectroscopy by including the transition quadrupole contributions from peptide amide I vibrational transition and chlorophyll electronic transition. By using a density functional theory calculation method, the corresponding amide I vibrational and chlorophyll Q(y) electronic transition quadrupole tensor elements are determined. Amplitude of nonlinear optical transition pathway involving a quadrupole transition is found to be comparable to those of magnetic dipole terms for two different cases considered, i.e., dipeptides and photosynthetic antenna complex. However, due to the rotational averaging factors, the overall quadrupole contribution is an order of magnitude smaller than the magnetic dipole contribution. This suggests that the conventional 2D photon echo method and experimental scheme can be directly used to measure the 2D CP-PE signal from proteins and molecular complexes and that the 2D CP-PE signal is mainly dictated by the magnetic dipole contribution. PMID:17640137

Choi, Jun-Ho; Cho, Minhaeng

2007-07-14

255

Higher order parametric excitation modes for spaceborne quadrupole mass spectrometers  

NASA Astrophysics Data System (ADS)

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.

2011-12-01

256

Entanglement, magnetic and quadrupole moments properties of the mixed spin Ising-Heisenberg diamond chain  

NASA Astrophysics Data System (ADS)

Thermal entanglement, magnetic and quadrupole moments properties of the mixed spin-1/2 and spin-1 Ising-Heisenberg model on a diamond chain are considered. Magnetization and quadrupole moment plateaus are observed for the antiferromagnetic couplings. Thermal negativity as a measure of quantum entanglement of the mixed spin system is calculated. Different behavior for the negativity is obtained for the various values of Heisenberg dipolar and quadrupole couplings. The intermediate plateau of the negativity has been observed at the absence of the single-ion anisotropy and quadrupole interaction term. When dipolar and quadrupole couplings are equal there is a similar behavior of negativity and quadrupole moment.

Abgaryan, V. S.; Ananikian, N. S.; Ananikyan, L. N.; Hovhannisyan, V.

2015-02-01

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

Spin dependence of intrinsic and transition quadrupole moments  

SciTech Connect

The relation connecting an angular momentum dependence of the {gamma}-transition energies with the reduced transition probabilities B[E2;(I+2){sub gr}{yields}I{sub gr}] in the ground-state rotational band is derived based on the Bohr Hamiltonian. The relation is applicable to both {beta}-rigid and {beta}-soft both being {gamma}-rigid nuclei. Based on this result the approximate expression is obtained for the intrinsic quadrupole moment and, therefore, for the spectroscopic quadrupole moment in terms of the reduced E2 transition probabilities. It is shown that an angular momentum dependence of the intrinsic quadrupole moment can be well approximated by a linear function of I. The results obtained are direct consequences of the Bohr Hamiltonian with the Davidson potential.

Jolos, R.V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Institut fuer Theoretische Physik, Justus-Liebig-Universitaet Giessen, D-35392 Giessen (Germany); Brentano, P. von; Dewald, A. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937 Cologne (Germany); Pietralla, N. [Nuclear Structure Laboratory, Department of Physics and Astronomy, State University of New York, Stony Brook, New York 11794-3800 (United States)

2005-08-01

259

Enhanced quadrupole effects for atoms in optical vortices.  

PubMed

We show that the normally weak optical quadrupole interaction in atoms is enhanced significantly when the atom interacts at near resonance with an optical vortex. In particular, the forces and torque acting on the atom are shown here to scale up with the square of the winding number l of the vortex. Because the integer l can be arranged to be large, this property allows for processes involving dipole-forbidden, but quadrupole-allowed, transitions in atoms, such as cesium and oxygen, to come into play. We show that the mechanical effects of vortex light on atoms involving translational and rotational motion as well as trapping should be significantly enhanced for quadrupole transitions and present novel features with useful implications for the emerging field of atomtronics. PMID:23473140

Lembessis, V E; Babiker, M

2013-02-22

260

Design and performance of the SRRC quadrupole magnets  

NASA Astrophysics Data System (ADS)

Forty-eight quadrupole magnets have been manufactured in this present work for the SRRC storage ring. Four families of quadrupole magnets with various magnetic lengths are used in the storage ring. The same pole contour with a bore diameter of 76 mm is computed via the 'MAGNET' program. The magnet design and procedure of mechanical fabrication and assembly are also described. The auxiliary coils are incorporated in the main coils for trimming the field strength of each individual magnet. Pole tip ends have a 6 mm x 6 mm chamfer so as to reduce the dodecapole in the end of magnet. Field mapping results having achieved the deviation of integral quadrupole field within +/-1 x 10(exp - 3) in a 30 mm bore radius region is also confirmed.

Chang, C. H.; Chen, H. H.; Hwang, C. S.; Hwang, G. J.; Tseng, P. K.

1994-07-01

261

Advanced Hydrotest Facility (AHF) large bore quadrupole focusing magnet system  

SciTech Connect

The Advanced Hydrotest Facility (AHF) at Los Alamos will provide proton radiography of large-scale, dynamic events. The large bore (Case II) quadrupole focusing magnets are a subsystem in this facility, consisting of four complete imaging lines with a total of eight imaging plates and 52 quadrupole magnets. Each large bore quadrupole has an inner winding diameter of 660 mm and provides a gradient of 10.4 T/m with a 300 mm field of view. Each magnet is a two-layer saddle, contained by a three cm steel shell. The conductor is a Rutherford cable, soldered into a C-shaped copper channel. The magnets are cooled by the forced-flow of two-phase helium through coolant pipes. Since the winding must absorb bursts of 0.35 J/kg irradiation, both NbTi and Nb{sub 3}Sn designs are being considered.

Jason, A. J. (Andrew J.); Walstrom, P. L. (Peter L.); Waynert, J. A. (Joseph A.); Schultz, J. (Joel); Camille, R. J.; Antaya, T. (Thomas); Myatt, R. L.; Minervini, J.; Radovinsky, A.; Smith, B. A. (Brian A.)

2002-01-01

262

Self-consistent calculations of quadrupole moments of spherical nuclei  

NASA Astrophysics Data System (ADS)

The self-consistent Theory of Finite Fermi Systems based on the Energy Density Functional byFayans et al. with the set DF3-a of parameters fixed previously is used to calculate three kinds of quadrupolemoments. At first, we examined systematically quadrupole moments of odd neighbors of semi-magic lead andtin isotopes and N = 50, N = 82 isotones. Second, we found quadrupole moments of the first 2+ states in thesame two chains of isotopes. Finally, we evaluated quadrupole moments of odd-odd nuclei neighboring to doublemagic ones. Reasonable agreement with available experimental data has been obtained. Predictions are made forquadrupole moments of nuclei in the vicinity of unstable magic nuclei

Kamerdzhiev, S.; Krewald, S.; Tolokonnikov, S.; Saperstein, E. E.; Voitenkov, D.

2012-12-01

263

Anharmonic contributions in real RF linear quadrupole traps  

NASA Astrophysics Data System (ADS)

The radiofrequency quadrupole linear ion trap is a widely used device in physics and chemistry. When used for trapping of large ion clouds, the presence of anharmonic terms in the radiofrequency potential limits the total number of stored ions. In this paper, we have studied the anharmonic content of the trapping potential for different implementations of a quadrupole trap, searching for the geometry best suited for the trapping of large ion clouds. This is done by calculating the potential of a real trap using SIMION8.0, followed by a fit, which allows us to obtain the evolution of anharmonic terms for a large part of the inner volume of the trap.

Pedregosa, J.; Champenois, C.; Houssin, M.; Knoop, M.

2010-02-01

264

High and ulta-high gradient quadrupole magnets  

SciTech Connect

Small bore conventional dc quadrupoles with apertures from 1 to 2.578cm were designed and prototypes built and measured. New fabrication techniques including the use of wire electric discharge milling (EDM) to economically generate the pole tip contours and aperture tolerances are described. Magnetic measurement data from a prototype of a 1cm aperture quadrupole with possible use in future e/sup +//e/sup -/ super colliders are presented. At a current of 400A, the lens achieved a gradient of 2.475 T/cm, and had an efficiency of 76.6%.

Brunk, W.O.; Walz, D.R.

1985-05-01

265

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

266

Electric quadrupole excitations in the interactions of Y-89 with relativistic nuclei  

NASA Technical Reports Server (NTRS)

The first complete calculations of electric quadrupole excitations in relativistic nucleus-nucleus collisions are presented herein. Neutron emission from Y-89 is studied and quadrupole effects are found to be a significant fraction of the cross section.

Norbury, John W.

1989-01-01

267

A LIGA Fabricated Quadrupole Array for Mass Spectroscopy  

NASA Technical Reports Server (NTRS)

A linear array of nine quadrupoles was fabricated using the LIGA process. Pole heights ranging from 1 to 3 mm were fabricated using synchrotron X-ray exposures to form free standing polymethylmethacrylate (PMMA) molds into which copper, gold or nickel were electroplated.

Jackson, K.; Wiberg, D. V.; Hecht, M. H.; Orient, O. J.; Chutjian, A.; Yee, K.; Fuerstenau, S.; Brennen, R. A.; Hruby, J.; Bonivert, W.

1997-01-01

268

Hybrid quadrupole excitons and polaritons in cuprous oxide  

NASA Astrophysics Data System (ADS)

In this thesis I consider novel type of materials such as hybrid organic/inorganic heteoro-structures and polystyrene micro-spheres/inorganic composites. The organic/inorganic compound is presented by DCM2:CA:PS/cuprous oxide material. Using "solid state solvent" mechanism I propose to bring the Frenkel exciton (FE) of the DCM2 into resonance with 1S quadrupole Wanier-Mott exciton (WE) in cuprous oxide. This two types of the excitons form new type of quadrupole-dipole hybrid exciton. This hybrid is characterized by long lifetime and big oscillator strength inherited from the organic FE. In the part I of the thesis I investigate the enhancement of the quadrupole properties generic to cuprous oxide exciton by means of such resonant hybridization. I consider enhancement of photo-thermal bi-stability and second harmonic generation. The second part is devoted to the problems of light-matter interaction in cuprous oxide crystals such as weak interaction with LA phonons and whispering gallery modes (WGM) in adjacent layer of polystyrene micro-spheres. While the first effect is likely to impeded BEC of the polaritons, the second mechanism provides necessary temporal coherence. It is possible by trapping the light part of the polariton into resonant WGM through big gradient of the evanescent tail which provides big lifetime of such evanescent polariton. Due to big gradient of the evanescent field it couples "naturally" to the quadrupole WE in cuprous oxide.

Roslyak, Oleksiy

269

LHC interaction region quadrupole cryostat design and fabrication  

Microsoft Academic Search

The cryostat of a Large Hadron Collider (LHC) Interaction Region (IR) quadrupole magnet consists of all components of the inner triplet except the magnet assembly itself. It serves to support the magnet accurately and reliably within the vacuum vessel, to house all required cryogenic piping, and to insulate the cold mass from heat radiated and conducted from the environment. It

Thomas H. Nicol; Christine Darve; Yuenian Huang; Thomas M. Page

2002-01-01

270

Particle Orbits in Quadrupole-Duodecapole Halo Suppressor  

NASA Astrophysics Data System (ADS)

Dynamics of continuous space-charged-dominated beam propagating through a periodic quadrupole-duodecapole focusing channel is studied both numerically and analytically using test-particle-core model and Particle-In-Cell (PIC) simulation code TOPOPIC. The results of TOPOPIC indicate that with initially matched beam, utilization of quadrupole-duodecapole channel results in less beam emittance growth and fewer halo particles than that in a pure quadrupole channel. The Poincare section of plot obtained from the test-particle-core model is used to systematically determine the beam intensity dependent resonant dominated behavior of the test-particles, which reveals the mechanism of the halo suppression in quadrupole-duodecapole channel. Results of study show that, for appropriate field strength, the nonlinear duodecapole force removes the resonant structures due to space charge. Motions of particles, originally trapped in the nonlinear resonant island or chaos region related to space charge, turn out to be along regular tori and these particles have less probability to get into beam halos.

Li, Chao; Xin, Qi; Yuan, He; Lei, Yang; Batygin, Y. K.

2015-01-01

271

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

272

Large energy-spread beam diagnostics through quadrupole scans  

NASA Astrophysics Data System (ADS)

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

2012-12-01

273

Radio-frequency quadrupole: General properties and specific applications  

Microsoft Academic Search

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. Bibtex entry for this abstract Preferred format for

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

1980-01-01

274

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

275

181Ta perturbed-angular-correlation study of electric quadrupole interactions in yttrium metal and yttrium-hydrogen solid solutions  

NASA Astrophysics Data System (ADS)

The perturbed-angular-correlation (PAC) technique has been used to study the electric quadrupole interaction (QI) of the nuclear probe 181Ta in yttrium metal and yttrium-hydrogen solid solutions ?-YHx with 0?x?0.2. The temperature dependence of the quadrupole frequency ?q of 181Ta in yttrium metal, measured in the range 290 K?T?1700 K, follows the linear relation ?q(T) = ?q(0)(1-AT) with ?q(0) = 423(3) MHz and A = 4.74(4)×10-4 K-1. The absorption of hydrogen enhances the temperature dependence of the QI: the parameters ?q(0) and A of the linear temperature variation of the 181Ta QI in ?-YHx measured between 25 K and 1000 K for 0?x?0.2 both increase with increasing concentration x. These trends are consistent with the anionic model of the electronic state of hydrogen in rare earth metals. At T?500 K a dynamic QI caused by diffusing hydrogen has been observed. The activation energy for hydrogen jumps in ?-YH0.10 deduced from the temperature dependence of the quadrupole relaxation rate is Ea = 0.49(15) eV.

Forker, M.; Hütten, U.; Müller, M.

2000-08-01

276

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.

277

Understanding Sarcoidosis  

MedlinePLUS

... Register for ENews Home > Lung Disease > Sarcoidosis Understanding Sarcoidosis Sarcoidosis is a disease caused by inflammation. Scientists ... pain, or shortness of breath. How Serious Is Sarcoidosis? Nobody can predict how sarcoidosis will affect one ...

278

Quadrupole radiation from terahertz dipole antennas.  

PubMed

We report what is to our knowledge the first detailed investigation of the polarization state of radiation from lens-coupled terahertz dipole antennas. The radiation exhibits a weak but measurable component that is polarized orthogonally to the orientation of the emitter dipole. The angular radiation pattern of this cross-polarized emission reveals that it is quadrupolar, rather than dipolar, in nature. One can understand this result by taking into account the photocurrent flowing in the strip lines that feed the dipole antenna. A Fresnel-Kirchhoff scalar diffraction calculation is used for calculating the frequency-dependent angular distribution of the radiation pattern, providing satisfactory agreement with the measurements. PMID:18066277

Rudd, J V; Johnson, J L; Mittleman, D M

2000-10-15

279

Targeted proteomic quantification on quadrupole-orbitrap mass spectrometer.  

PubMed

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

2012-12-01

280

Systematic study of electric quadrupole excitations in the stable even mass Sn nuclei  

NASA Astrophysics Data System (ADS)

The spherical semimagic 116,118,120,122,124Sn nuclei have been investigated intensively using nuclear resonance fluorescence techniques. The measurement of the photon scattering cross sections, angular distributions, and linear polarization or azimuthal asymmetries of the resonantly scattered (unpolarized and polarized) photons enabled a model independent determination of reduced transition probabilities, level spins, and parities. Besides the enhanced dipole excitations to the well-known (2+1?3-1)1^- two-phonon states several electric quadrupole transitions were detected in the investigated energy region below 4 MeV. Quasiparticle phonon model calculations reveal several collective and noncollective 2+ states in this energy region. In contrast to the known two-phonon (2+1?3-1)1^- states, the wave functions of the observed 2+ states are dominated by one-phonon components. However, the fragmentation of the B(E2)? strength is influenced by two-phonon 2+ admixtures.

Bryssinck, J.; Govor, L.; Ponomarev, V. Yu.; Bauwens, F.; Beck, O.; Belic, D.; von Brentano, P.; de Frenne, D.; Eckert, T.; Fransen, C.; Govaert, K.; Herzberg, R.-D.; Jacobs, E.; Kneissl, U.; Maser, H.; Nord, A.; Pietralla, N.; Pitz, H. H.; Werner, V.

2000-02-01

281

Temperature dependence of 23Na NMR quadrupole parameters and spin-lattice relaxation rate in NaNO 2 powder  

Microsoft Academic Search

The nuclear quadrupole coupling constant (e2qQ\\/h) and the spin-lattice relaxation rate (1\\/T1) of 23Na NMR in the NaNO2 powder were investigated by employing a magic angle spinning probe and a wideline probe, respectively, at 9.4T as a function of temperature (T) in the range of 300–458K. The linearity between e2qQ\\/h and the squared spontaneous polarization (Ps2) was obeyed up to

J. K. Jung; O. H. Han; S. H. Choh

1999-01-01

282

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

283

Measurements of field decay and snapback effect on Tevatron dipole and quadrupole magnets  

SciTech Connect

Since the beginning of 2002 an intensive measurement program has been performed at the Fermilab Magnet Test Facility (MTF) to understand dynamic effects in Tevatron magnets. Based on the results of this program a new correction algorithm was proposed to compensate for the decay of the sextupole field during the dwell at injection and for the subsequent field ''snapback'' during the first few seconds of the energy ramp. Beam studies showed that the new correction algorithm works better than the original one, and improves the Tevatron efficiency by at least 3%. The beam studies also indicated insufficient correction during the first 6s of the injection plateau where an unexpected discrepancy of 0.15 sextupole units of extra drift was observed. This paper reports on the most recent measurements of the Tevatron dipoles field at the beginning of the injection plateau. Results on the field decay and snapback in the Tevatron quadrupoles are also presented.

Velev, G.V.; Ambrosio, G.; Annala, G.; Bauer, P.; Carcagno, R.; DiMarco, J.; Glass, H.; Hanft, R.; Kephart, R.; Lamm, M.; Martens, M.; Schlabach, P.; Sylvester, C.; Tartaglia, M.; Tompkins, J.; /Fermilab

2005-05-01

284

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.

University of California Museum of Paleontology

285

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

286

Understanding Artworlds.  

ERIC Educational Resources Information Center

This curriculum unit consists of four lessons that are designed to broaden students' understanding of art and culture; each lesson can stand alone or be used in conjunction with the others. The introduction offers a conceptual framework of the Artworlds unit, which takes an inquiry-based approach. The unit's first lesson, "Worlds within Worlds,"…

Erickson, Mary; Clover, Faith

287

Understanding Prejudice.  

ERIC Educational Resources Information Center

To help students understand prejudice, teachers in Verona, New York, planned a unit which incorporated the use of fiction, television, and film. Students were asked to select and read books in the general area of prejudice. A sample reading list of works under the headings of Negro, Jew, Italian, and Irish was provided. After writing extensive…

Babcock, David

1967-01-01

288

BIODIVERSITY Understanding  

E-print Network

? The decline of forest habitat and the related loss of biodiversity is a worldwide environmental issueBIODIVERSITY FOREST Understanding Biological Health in Our Forests College of Agricultural Sciences) program encourages forest-management activities that conserve native biodiversity. This brochure provides

Boyer, Elizabeth W.

289

Understanding Exploration  

NSDL National Science Digital Library

This classroom activity, which is structured as a series of mini-research projects, helps students understand how technological advances have aided the exploration of Antarctica. The printable handout includes a set of 10 research topics in three categories, explorers, Antarctica today, and technological advances for you to assign to small student teams.

290

Precise dipole moments and quadrupole coupling constants of the cis and trans conformers of 3-aminophenol: determination of the absolute conformation.  

PubMed

The rotational constants and the nitrogen nuclear quadrupole coupling constants of cis-3-aminophenol and trans-3-aminophenol are determined using Fourier-transform microwave spectroscopy. We examine several J = 2 <-- 1 and 1 <-- 0 hyperfine-resolved rotational transitions for both conformers. The transitions are fit to a rigid rotor Hamiltonian including nuclear quadrupole coupling to account for the 14N nuclear spin. For cis-3-aminophenol we obtain rotational constants of A = 3734.930 MHz, B = 1823.2095 MHz, and C = 1226.493 MHz, for trans-3-aminophenol of A = 3730.1676 MHz, B = 1828.25774 MHz, and C = 1228.1948 MHz. The dipole moments are precisely determined using Stark effect measurements for several hyperfine transitions to micro(a) = 1.7718 D, micro(b) = 1.517 D for cis-3-aminophenol and micro(a) = 0.5563 D, micro(h) = 0.5375 D for trans-3-aminophenol. Whereas the rotational constants and quadrupole coupling constants do not allow to determinate the absolute configuration of the two conformers, this assignment is straightforward based on the dipole moments. High-level ab initio calculations (B3LYP/6-31G* to MP2/aug-cc-pVTZ) are performed providing error estimates of rotational constants and dipole moments obtained for large molecules by these theoretical methods. PMID:19791450

Filsinger, Frank; Wohlfart, Kirstin; Schnell, Melanie; Grabow, Jens-Uwe; Küpper, Jochen

2008-02-01

291

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

292

Diabatization based on the dipole and quadrupole: The DQ method  

NASA Astrophysics Data System (ADS)

In this work, we present a method, called the DQ scheme (where D and Q stand for dipole and quadrupole, respectively), for transforming a set of adiabatic electronic states to diabatic states by using the dipole and quadrupole moments to determine the transformation coefficients. It is more broadly applicable than methods based only on the dipole moment; for example, it is not restricted to electron transfer reactions, and it works with any electronic structure method and for molecules with and without symmetry, and it is convenient in not requiring orbital transformations. We illustrate this method by prototype applications to two cases, LiH and phenol, for which we compare the results to those obtained by the fourfold-way diabatization scheme.

Hoyer, Chad E.; Xu, Xuefei; Ma, Dongxia; Gagliardi, Laura; Truhlar, Donald G.

2014-09-01

293

Development and Test of LARP Technological Quadrupole (TQC) Magnet  

SciTech Connect

In support of the development of a large-aperture Nb{sub 3}Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, two-layer quadrupole models (TQC and TQS) with 90 mm aperture are being constructed at Fermilab and LBNL within the framework of the US LHC Accelerator Research Program (LARP). This paper describes the construction and test of model TQC01. ANSYS calculations of the structure are compared with measurements during construction. Fabrication experience is described and in-process measurements are reported. Test results at 4.5 K are presented, including magnet training, current ramp rate studies and magnet quench current. Results of magnetic measurements at helium temperature are also presented.

Feher, S.; Bossert, R.C.; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; Pischalnikov, Yu.; Sylvester, C.; Tartaglia, M.; Turrioni, D.; Whitson, G.; Yamada, R.; Zlobin, A.V.; Caspi, S.; Dietderich, D.; Ferracin, P.; Hannaford, R.; Hafalia, A.R.; Sabbi, G.

2007-06-01

294

Development and test of LARP technological quadrupole (TQC) magnet  

SciTech Connect

In support of the development of a large-aperture Nb{sub 3}Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, two-layer quadrupole models (TQC and TQS) with 90-mm aperture are being constructed at Fermilab and LBNL within the framework of the US LHC Accelerator Research Program (LARP). This paper describes the construction and test of model TQC01. ANSYS calculations of the structure are compared with measurements during construction. Fabrication experience is described and in-process measurements are reported. Test results at 4.5K are presented, including magnet training, current ramp rate studies and magnet quench current . Results of magnetic measurements at helium temperature are also presented.

Feher, S.; Bossert, R.C.; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; /Fermilab /LBL, Berkeley

2006-08-01

295

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

296

The development of compact magnetic quadrupoles for ILSE  

SciTech Connect

Magnetic focussing is selected for the 4 MeV to 10 MeV section of the Induction Linac Systems Experiments (ILSE) to study the transport of magnetically focussed spacecharge-dominated beams and to explore the engineering problems in accurate positioning of the magnetic fields in an array of quadrupoles. A prototype development program for such magnets is currently under way. A compact design was selected to decrease the overall accelerator diameter and its cost. The design evolved from a cosine 2{theta} current distribution, corrected for end effects. Current-dominated magnets are used in a pulsed mode to allow higher current densities compared to standard dc water-cooled conductors. The POISSON and MAFCO codes were used in the design of the magnets. The construction of the quadrupoles is aimed at achieving location accuracy of the magnetic center to within 1 mil (2.54 {times} 10{sup {minus}5} m) of the mechanical center.

Faltens, A.; Mukherjee, S.; Brady, V.

1990-08-01

297

Ion remeasurement in the RF quadrupole ion trap  

SciTech Connect

The development of the mass-selective instability mode of operation for the quadrupole ion trap has provided impetus for mass spectrometric applications of the device. In the technique, the amplitude of the confining rf voltage is increased linearly with time causing trajectories of stored ions to become unstable in the axial direction sequentially from low to high mass/charge. Ejected ions are subsequently detected by an external electron multiplier. Thus, the technique is straightforward but also destructive in nature; any further manipulations of the original ion packet are precluded by ion ejection and subsequent collision with the detector surface. The authors have modified a Teledyne 3DQ quadrupole ion trap mass spectrometer to allow in situ detection and ion remeasurement via image current detection.

Goeringer, D.E.; McLuckey, S.A. [Oak Ridge National Lab., TN (United States)

1995-12-31

298

3D simulations of an electrostatic quadrupole injector  

SciTech Connect

Analysis of the dynamics of a space charge dominated beam in a lattice of electrostatic focusing structures requires a full three-dimensional conic that includes self-consistent space charge fields and the fields from the complex conductor shapes. The existing WARP3d code, a particle simulation code which has been developed for heavy-ion fusion (HIF) applications contains machinery for handling particles in three-dimensional fields. A successive overrelaxation field solver with subgrid-scale placement of boundaries for rounded surface and four-fold symmetry has been added to the code. The electrostatic quadrupole (ESQ) injector for the ILSE accelerator facility being planned at Lawrence Berkeley Laboratory is shown as an application. The issue of concern is possible emittance degradation because the focusing voltages are a significant fraction of the particles` energy and because there are significant nonlinear fields arising from the shapes of the quadrupole structures.

Grote, D.P. [California Univ., Davis, CA (United States)]|[Lawrence Livermore National Lab., CA (United States); Friedman, A. [Lawrence Livermore National Lab., CA (United States); Yu, S. [Lawrence Berkeley Lab., CA (United States)

1993-02-01

299

Radio-frequency quadrupole resonator for linear accelerator  

DOEpatents

An RFQ resonator for a linear accelerator having a reduced level of interfering modes and producing a quadrupole mode for focusing, bunching and accelerating beams of heavy charged particles, with the construction being characterized by four elongated resonating rods within a cylinder with the rods being alternately shorted and open electrically to the shell at common ends of the rods to provide an LC parallel resonant circuit when activated by a magnetic field transverse to the longitudinal axis.

Moretti, A.

1982-10-19

300

Isoscalar quadrupole excitations in the two-center shell model  

Microsoft Academic Search

Elementary modes of excitation of a particle-hole character are studied in the framework of the two-center shell model. It is argued from available experimental evidence on 24Mg that the isoscalar quadrupole strength in this system must be carried by T = 0 excitations of this nature relative to a two-center potential which is rotating, such that the total angular momentum

R. H. Lemmer; C. Toepffer

1979-01-01

301

Giant 4p-Quadrupole Resonances in the Rare Earths  

Microsoft Academic Search

X-ray absorption of Ce, obtained by partial secondary yield, is compared with previously obtained electron-energy loss measurements in reflection mode. The absence of a strong feature below 4p3\\/2 threshold in photon absorption provides confirmation that the peak in EELS is nondipole in character. Theoretical analysis supports interpretation in terms of a p-f giant quadrupole resonance, a result which broadens the

J. A. D. Matthew; F. P. Netzer; C. W. Clark; J. F. Morar

1987-01-01

302

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

303

MEASURING LOCAL GRADIENT AND SKEW QUADRUPOLE ERRORS IN RHIC IRS.  

SciTech Connect

The measurement of local linear errors at RHIC interaction regions using an ''action and phase'' analysis of difference orbits has already been presented. This paper evaluates the accuracy of this technique using difference orbits that were taken when known gradient errors and skew quadrupole errors were intentionally introduced. It also presents action and phase analysis of simulated orbits when controlled errors are intentionally placed in a RHIC simulation model.

CARDONA,J.; PEGGS,S.; PILAT,R.; PTITSYN,V.

2004-07-05

304

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

305

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

306

CMB quadrupole suppression. II. The early fast roll stage  

SciTech Connect

Within the effective field theory of inflation, an initialization of the classical dynamics of the inflaton with approximate equipartition between the kinetic and potential energy of the inflaton leads to a brief fast roll stage that precedes the slow roll regime. The fast roll stage leads to an attractive potential in the wave equations for the mode functions of curvature and tensor perturbations. The evolution of the inflationary perturbations is equivalent to the scattering by this potential and a useful dictionary between the scattering data and observables is established. Implementing methods from scattering theory we prove that this attractive potential leads to a suppression of the quadrupole moment for CMB and B-mode angular power spectra. The scale of the potential is determined by the Hubble parameter during slow roll. Within the effective field theory of inflation at the grand unification (GUT) energy scale we find that if inflation lasts a total number of e-folds N{sub tot}{approx}59, there is a 10%-20% suppression of the CMB quadrupole and about 2%-4% suppression of the tensor quadrupole. The suppression of higher multipoles is smaller, falling off as 1/l{sup 2}. The suppression is much smaller for N{sub tot}>59, therefore if the observable suppression originates in the fast roll stage, there is the upper bound N{sub tot}{approx}59.

Boyanovsky, D.; Vega, H. J. de [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61, Avenue de l'Observatoire, 75014 Paris (France); LPTHE, Universite Pierre et Marie Curie (Paris VI) et Denis Diderot (Paris VII), Laboratoire Associe au CNRS UMR 7589, Tour 24, 5eme. etage, 4, Place Jussieu, 75252 Paris, Cedex 05 (France); Sanchez, N. G. [Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61, Avenue de l'Observatoire, 75014 Paris (France)

2006-12-15

307

Position Stability Monitoring of THEthe LCLS Undulator Quadrupoles  

SciTech Connect

X-ray FELs demand that the positions of undulator components be stable to less than 1 {mu}m per day. Simultaneously, the undulator length increases significantly in order to saturate at x-ray wavelengths. To minimize the impact of the outside environment, the Linac Coherent Light Source (LCLS) undulator is placed underground, but reliable data about ground motion inside such a tunnel was not available in the required stability range during the planning phase. Therefore, a new position monitor system had been developed and installed with the LCLS undulator. This system is capable of measuring x, y, roll, pitch and yaw of each of the 33 undulator quadrupoles with respect to stretched wires. Instrument resolution is about 10 nm and instrument drift is negligible. Position data of individual quadrupoles can be correlated along the entire 132-m long undulator. The system has been under continuous operation since 2009. This report describes long term experiences with the running system and the observed positional stability of the undulator quadrupoles.

Nuhn, Heinz Dieter; Gassner, Georg; Peters, Franz; /SLAC

2012-03-26

308

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.

2014-09-14

309

Collection understanding  

E-print Network

research. In addition, I would like to thank Dr. Richard Furuta for his interpretation of this work. Thanks also to Dr. Enrique Mallen for providing the image collection of the Online Picasso Project. v TABLE OF CONTENTS Page ABSTRACT... ................................................................................................................................61 vii LIST OF FIGURES Page Figure 1. System overview???????????????????????...26 Figure 2. System design????????????????????????....27 Figure 3. Using streaming collage for understanding the Online Picasso Collection......29 Figure 4...

Chang, Michelle T.

2004-09-30

310

Nuclear Quadrupole Resonance Studies of the Sorc Sequence and Nuclear Magnetic Resonance Studies of Polymers  

Microsoft Academic Search

The behavior of induction signals during steady -state pulse irradiation in ^{14} N NQR was investigated experimentally. Because Strong Off-resonance Comb (SORC) signals recur as long as the pulsing continues, very efficient signal-averaging can result. The dependence of these steady-state SORC signals on pulse parameters and on frequency offset are presented, together with a discussion of the applicability of the

Jayakody R. Pemadasa Jayakody

1993-01-01

311

Nuclear quadrupole resonance studies of the SORC sequence and nuclear magnetic resonance studies of polymers  

SciTech Connect

The behavior of induction signals during steady-state pulse irradiation in {sup 14}N NQR was investigated experimentally. Because Strong Off-resonance Comb (SORC) signals recur as long as the pulsing continues, very efficient signal-averaging can result. The dependence of these steady-state SORC signals on pulse parameters and on frequency offset are presented, together with a discussion of the applicability of the method. Also as part of the NQR work, cocaine base has been detected using conventional NQR techniques. The experimental results show that SORC detection can be of sufficient sensitivity to form the basis of narcotics screening devices for both mail and airline baggage. A new NMR technique, to obtain the correlation time of the random thermal motion of a polymer at temperatures near the glass transition has been introduced. The temperature dependence is a result of thermal motion. For slow-motion of a polymer chain near the glass transition, the CSA parameter begins to decrease. This motional narrowing can be interpreted to yield the correlation time of the thermal motion. In this work nitrocellulose isotopically highly enriched with {sup 15}N was studied at four different temperatures between 27{degrees} and 120{degrees} Celsius and the correlation times for polymer backbone motions were obtained. Naflon films containing water (D{sub 2}O and H{sub 2} {sup 17}O) and methanol (CH{sub 3}OD, CH{sub 3} {sup 17}OH), have been studied using deuteron and oxygen-17 NMR spectroscopy. Glassy behavior of the water domains at low temperature is evidenced by the specific nature of the {sup 2}H NMR lineshapes. Activation energies extracted from {sup 2}H spin-lattice relaxation data on the high temperature side of the T{sub 1} minimum exhibit a steady increase with increasing water content. In spite of a high degree of molecular mobility, angular-dependent spectra of both unstretched and stretched samples reflect considerable anisotrophy of the host polymer.

Jayakody, J.R.P.

1993-12-31

312

Nuclear Quadrupole Resonance Studies of the Sorc Sequence and Nuclear Magnetic Resonance Studies of Polymers.  

NASA Astrophysics Data System (ADS)

The behavior of induction signals during steady -state pulse irradiation in ^{14} N NQR was investigated experimentally. Because Strong Off-resonance Comb (SORC) signals recur as long as the pulsing continues, very efficient signal-averaging can result. The dependence of these steady-state SORC signals on pulse parameters and on frequency offset are presented, together with a discussion of the applicability of the method. Also as part of the NQR work, Cocaine base has been detected using conventional NQR techniques. The experimental results show that SORC detection can be of sufficient sensitivity to form the basis of narcotics screening devices for both mail and airline baggage. A new NMR technique, to obtain the correlation time of the random thermal motion of a polymer at temperatures near the glass transition has been introduced. The temperature dependence is a result of thermal motion. For slow-motion of a polymer chain near the glass transition, the CSA parameter begins to decrease. This motional narrowing can be interpreted to yield the correlation time of the thermal motion. In this work Nitrocellulose isotopically highly enriched with ^{15}N was studied at four different temperatures between 27^ circ and 120^circ Celsius and the correlation times for polymer backbone motions were obtained. Nafion films containing, water (D_2 O and H_2^{17}O) and methanol (CH_3OD, CH _3^{17}OH), have been studied using Deuteron and Oxygen-17 NMR spectroscopy. Glassy behavior of the water domains at low temperature is evidenced by the specific nature of the ^2H NMR lineshapes. Activation energies extracted from ^2H spin-lattice relaxation data on the high temperature side of the T_1 minimum exhibit a steady increase with increasing water content. In spite of a high degree of molecular mobility, angular-dependent spectra of both unstretched and stretched samples reflect considerable anisotropy of the host polymer. Activation volumes corresponding to a specific dynamical process were obtained from measurements of spin-lattice relaxation vs. pressure. From the NMR measurements of Nafion films containing methanol, it was found that the molecular motion is much more rapid than the molecular motion of water in Nafion membranes.

Jayakody, Jayakody R. Pemadasa

1993-01-01

313

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

314

[Electromagnetic studies of nuclear structure and reactions]. [Nuclear Physics Group, Univ. of New Hampshire  

SciTech Connect

The experimental goals are focused on developing an understanding of strong interactions and the structure of hadronic systems by determination of the electromagnetic response; these goals will be accomplished through coincidence detection of final states. Nuclear modeling objectives are to organize and interpret the data through a consistent description of a broad spectrum of reaction observables; calculations are performed in a nonrelativistic diagrammatic framework as well as a relativistic QHD approach. Work is described according to the following arrangement: direct knockout reactions (completion of [sup 16]O(e,e[prime]p), [sup 12]C(e,e[prime]pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in [sup 12]C(e,e[prime]p[sub 0]) and [sup 16]O(e,e[prime]p[sub 0]), comparison of the [sup 12]C(e, e[prime]p[sub 0]) and [sup 16]O(e,e[prime]p[sub 3]) reactions, quadrupole strength in the [sup 16]O(e,e[prime][alpha][sub 0]) reaction, quadrupole strength in the [sup 12]C(e,e[prime][alpha]) reaction, analysis of the [sup 12]C(e,e[prime]p[sub 1]) and [sup 16]O(e,e[prime]p[sub 3]) angular distributions, analysis of the [sup 40]Ca(e,e[prime]x) reaction at low q, analysis of the higher-q [sup 12]C(e,e[prime]x) data from Bates), models of nuclear structure (experimental work, Hartree-Fock calculations, phonon excitations in spherical nuclei, shell model calculations, variational methods for relativistic fields), and instrumentation development efforts (developments at CEBAF, CLAS contracts, BLAST developments).

Not Available

1992-01-01

315

Understanding resilience  

PubMed Central

Resilience is the ability to adapt successfully in the face of stress and adversity. Stressful life events, trauma, and chronic adversity can have a substantial impact on brain function and structure, and can result in the development of posttraumatic stress disorder (PTSD), depression and other psychiatric disorders. However, most individuals do not develop such illnesses after experiencing stressful life events, and are thus thought to be resilient. Resilience as successful adaptation relies on effective responses to environmental challenges and ultimate resistance to the deleterious effects of stress, therefore a greater understanding of the factors that promote such effects is of great relevance. This review focuses on recent findings regarding genetic, epigenetic, developmental, psychosocial, and neurochemical factors that are considered essential contributors to the development of resilience. Neural circuits and pathways involved in mediating resilience are also discussed. The growing understanding of resilience factors will hopefully lead to the development of new pharmacological and psychological interventions for enhancing resilience and mitigating the untoward consequences. PMID:23422934

Wu, Gang; Feder, Adriana; Cohen, Hagit; Kim, Joanna J.; Calderon, Solara; Charney, Dennis S.; Mathé, Aleksander A.

2013-01-01

316

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

317

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

318

Understanding Life  

NSDL National Science Digital Library

Understanding Life is the educational website of The Physiological Society, providing "support for the teaching and learning of physiology." A good place to start is the What is Physiology? area, which offers an overview of this field of human inquiry. The Resources area is a well-designed archive of instructional materials that include "The story of a single heartbeat," "The Science of Life," and "Planning an experiment." It's worth noting that visitors can create their own accounts on the site so they can receive specialized newsletters, tailored website content, and become eligible to enter scientific competitions. Moving along, the Events area lists important goings-on that will be of interest to educators and those involved with science pedagogy. [KMG

319

Understanding Condensation  

NSDL National Science Digital Library

Monica Hartman, Assistant Director for Science in St. Clair County, Michigan, conducted this research while she was the learning specialist in a small suburban district just outside a large Midwestern city. While teaching full time in this district she was also completing her doctoral program in education at the University of Michigan. In this chapter, she tells the story of a "science talk" about condensation among fifth graders. She acted as a source and facilitator of change as she and the fifth-grade teacher worked collaboratively to help students share responsibility for their own learning. She describes their continual assessment of student understanding that occurred as their students struggled to explain observations and as they, the teachers, carefully resisted the temptation to end the struggle by saying "that's right!"

Hartman, Monica

2007-12-01

320

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

321

Systematic of isovector and isoscalar giant quadrupole resonances in normal and superfluid deformed nuclei  

E-print Network

The systematic study of isoscalar (IS) and isovector (IV) giant quadrupole responses (GQR) in normal and superfluid nuclei presented in [G. Scamps and D. Lacroix, Phys. Rev. 88, 044310 (2013)] is extended to the case of axially deformed and triaxial nuclei. The static and dynamical energy density functional based on Skyrme effective interaction are used to study static properties and dynamical response functions over the whole nuclear chart. Among the 749 nuclei that are considered, 301 and 65 are respectively found to be prolate and oblate while 54 do not present any symmetry axis. For these nuclei, the IS- and IV-GQR response functions are systematically obtained. In these nuclei, different aspects related to the interplay between deformation and collective motion are studied. We show that some aspects like the fragmentation of the response induced by deformation effects in axially symmetric and triaxial nuclei can be rather well understood using simple arguments. Besides this simplicity, more complex effects show up like the appearance of non-trivial deformation effects on the collective motion damping or the influence of hexadecapole or higher-orders effects. A specific study is made on the triaxial nuclei where the absence of symmetry axis adds further complexity to the nuclear response. The relative importance of geometric deformation effects and coupling to other vibrational modes are discussed.

Guillaume Scamps; Denis Lacroix

2014-01-21

322

Uranium isotope measurements by quadrupole ICP-MS for process monitoring of enrichment  

SciTech Connect

Historically, uranium isotopic ratio measurements in the nuclear industry have been performed using Thermal Ionization Mass Spectrometry (TIMS); primarily due to the high level of precision that can be achieved. TIMS analysis, however, requires sample purification and intricate sample loading. Quadrupole (low resolution, single detector) inductively coupled plasma--mass spectrometry, Q-ICP-MS, overcomes these disadvantages and is a cost-effective alternative, i.e., in terms of initial capital, maintenance, and operating costs. This paper presents a simple, single standard approach for measuring uranium isotope content in various solid and liquid nuclear materials along with some comparison data of Q-ICP-MS and TIMS. Intensity ratios of {sup 234}U, {sup 235}U, {sup 236}U, and {sup 238}U to total U intensity are produced, providing the enrichment level or percent {sup 235}U. A detailed description of the instrument and data collection parameters are also provided. Optimal precision and accuracy are achieved through the use of a single standard which is closely matched to the enrichment and concentration of the samples. Depending upon the standard chosen, enrichments between depleted and 97% can be quantified. Standard deviations for the major uranium isotopes are typically within 0.02 absolute and at least an order of magnitude lower for the minor U isotope abundances.

Policke, T.A.; Bolin, R.N.; Harris, T.L. [BWX Technologies, Inc., Lynchburg, VA (United States). Engineering and Quality Assurance Dept.

1998-12-31

323

Design and construction of a radiation resistant quadrupole using metal oxide insulated CICC  

SciTech Connect

The construction of a engineering test model of a radiation resistant quadrupole is described. The cold-iron quadrupole uses coils fabricated from metal-oixide (synthetic spinel) insulated Cable-In-Conduit-Conductor (CICC). The superconductor is NbTi in a copper matrix. The quadrupole is designed to produce a pole-tip field of 2 T with an operating current of 7,000 A.

Albert F. Zeller

2012-12-28

324

The statistical mechanics of ion-dipole-tetrahedral quadrupole mixtures  

NASA Astrophysics Data System (ADS)

We examine the solution of the Ornstein-Zernike equations for the correlation functions of a fluid mixture in which the molecular interactions consist of a hard sphere plus a multipolar potential that contains coulombic, dipolar as well as quadrupolar terms. In particular we consider the case in which the molecule has a dipole moment in the z direction of the molecular axis system and a non-linear tetrahedral quadrupole tensor of the form ?xx = - ?yy, ?zz = 0 = ???, ? ? ? in the molecular frame. This model is a good representation of the dipolar and quadrupolar properties of water and our analysis will form the basis for constructing a Civilized Model electrolyte in which ions are dissolved in a solvent whose molecules possess water-like multipole moments. One of our main results is that for any theory which retains only the subset of rotational invariants that either appear in the interaction potentials or are generated by angular convolution from those appearing in the interaction potentials, e.g. the linearized hypernetted chain (LHNC) or mean spherical approximations (MSA), the equations for an ion-dipole-tetrahedral quadrupolar mixture only differ from those for an ion-dipole-linear quadrupole mixture (?xx = ?yy = - 1/2?zz, ??? = 0, ? ? ?) in minor details. We have investigated the thermodynamic properties of a fluid of hard spheres with the dipole and tetrahedral moments of water using thermodynamic perturbation theory. We find that contributions to the thermodynamic properties from dipole-quadrupole interaction are very important. For a pure hard sphere tetrahedral quadrupolar fluid there is considerable difference between the results from perturbation theory and from the MSA, for which we have obtained an analytic solution.

Carnie, Steven L.; Chan, Derek Y. C.; Walker, Glen R.

325

CMB quadrupole suppression. I. Initial conditions of inflationary perturbations  

SciTech Connect

We investigate the issue of initial conditions of curvature and tensor perturbations at the beginning of slow roll inflation and their effect on the power spectra. Renormalizability and small backreaction constrain the high k behavior of the Bogoliubov coefficients that define these initial conditions. We introduce a transfer function D(k) which encodes the effect of generic initial conditions on the power spectra. The constraint from renormalizability and small backreaction entails that D(k)(less-or-similar sign){mu}{sup 2}/k{sup 2} for large k, implying that observable effects from initial conditions are more prominent in the low multipoles. This behavior affects the CMB quadrupole by the observed amount {approx}10%-20% when {mu} is of the order of the energy scale of inflation. The effects on high l-multipoles are suppressed by a factor {approx}1/l{sup 2} due to the falloff of D(k) for large wave vectors k. We show that the determination of generic initial conditions for the fluctuations is equivalent to the scattering problem by a potential V({eta}) localized just prior to the slow roll stage. Such potential leads to a transfer function D(k) which automatically obeys the renormalizability and small backreaction constraints. We find that an attractive potential V({eta}) yields a suppression of the lower CMB multipoles. Both for curvature and tensor modes, the quadrupole suppression depends only on the energy scale of V({eta}), and on the time interval where V({eta}) is nonzero. A suppression of the quadrupole for curvature perturbations consistent with the data is obtained when the scale of the potential is of the order of k{sub Q}{sup 2} where k{sub Q} is the wave vector whose physical wavelength is the Hubble radius today.

Boyanovsky, D.; Vega, H. J. de [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61, Avenue de l'Observatoire, 75014 Paris (France); LPTHE, Universite Pierre et Marie Curie (Paris VI) et Denis Diderot (Paris VII), Laboratoire Associe au CNRS UMR 7589, Tour 24, 5eme. etage, 4, Place Jussieu, 75252 Paris, Cedex 05 (France); Sanchez, N. G. [Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61, Avenue de l'Observatoire, 75014 Paris (France)

2006-12-15

326

Design, development, and acceleration trials of radio-frequency quadrupole  

SciTech Connect

A deuteron radio frequency quadrupole (RFQ) accelerator has been designed, fabricated, and tested at BARC, which will be used for neutron generation. The RFQ operates at a frequency of 350 MHz and needs an inter-vane voltage of 44 kV to accelerate the deuteron beam to 400 keV within a length of 1.03 m. The error analysis shows that the offset of two opposite vanes in the same direction by 100 ?m leads to a change in resonant frequency by 1.3 MHz and a significant change of fields in the quadrants (?±40% with respect to average field). From the 3D analysis, we have observed that the unwanted dipole mode frequencies are very near to the quadrupole mode frequency which will make structure sensitive to the perturbations. In order to move the dipole modes away from the quadrupole modes, we have used the dipole stabilizer rods. The 5 wire transmission line theory was used to study the perturbative analysis of the RFQ and based on this a computer program has been written to tune the cavity to get required field distribution. Based on these studies, a 1.03 m long RFQ made of OFE copper has been fabricated and tested. Even though the RFQ was designed for deuteron (D{sup +}) beam, we tested it by accelerating both the proton (H{sup +}) and D{sup +} beams. The RFQ was operated in pulsed mode and accelerated both H{sup +} and D{sup +} beams to designed values of 200 and 400 keV, respectively. The measured parameters are in good agreement with the designed values validating our simulations and fabrication processes. In this paper, simulations, RF measurements, and beam commissioning results are presented.

Rao, S. V. L. S., E-mail: svlsrao@gmail.com; Jain, Piyush; Pande, Rajni; Roy, Shweta; Mathew, Jose V.; Kumar, Rajesh; Pande, Manjiri; Krishnagopal, S.; Gupta, S. K.; Singh, P. [Ion Accelerator Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)] [Ion Accelerator Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2014-04-15

327

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

SciTech Connect

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

Feinberg, B. [Lawrence Berkeley Lab., CA (United States)

1995-02-01

328

A radio-frequency quadrupole accelerator longitudinal field stabilizer  

SciTech Connect

The fields in a 600-MHz model of a radio-frequency quadrupole (RFQ) accelerator have been longitudinally stabilized over 86% of its length. The stabilizing elements consist of four external transverse electromagnetic (TEM) lines. Each line is coupled to the RFQ by two magnetic loops attached to voltage maxima of the TEM line. These resonant lines stabilize the RFQ fields by providing an alternate longitudinal power flow path in the RFQ. Stabilization depends on the TEM line Q and the TEM line RFQ coupling. Each stabilizer coupling-loop location in the RFQ needs to be fully azimuthally stabilized. Substantial coupling between stabilizer elements destroys stabilization. 3 refs., 13 figs., 2 tabs.

Gray, E.R.; Spalek, G.; Shapiro, A.

1988-01-01

329

Miniature quadrupole mass spectrometer having a cold cathode ionization source  

DOEpatents

An improved quadrupole mass spectrometer is described. The improvement lies in the substitution of the conventional hot filament electron source with a cold cathode field emitter array which in turn allows operating a small QMS at much high internal pressures then are currently achievable. By eliminating of the hot filament such problems as thermally "cracking" delicate analyte molecules, outgassing a "hot" filament, high power requirements, filament contamination by outgas species, and spurious em fields are avoid all together. In addition, the ability of produce FEAs using well-known and well developed photolithographic techniques, permits building a QMS having multiple redundancies of the ionization source at very low additional cost.

Felter, Thomas E. (Livermore, CA)

2002-01-01

330

Orbital and spin magnetic quadrupole response in heavy nuclei  

NASA Astrophysics Data System (ADS)

We compute the magnetic quadrupole strength function in heavy spherical and deformed nuclei in proton-neutron random-phase approximation using a separable Hamiltonian that couples magnetic and electric channels and adopting a technique that avoids the diagonalization of the eigenvalue matrix. We intend to check if the different sensitivity of the spin dipole and orbital responses to the multipole terms of the Hamiltonian leads to an energy separation of the two modes sufficient for the identification of the twist mode. We explore also the possibility of a K splitting induced by deformation, in analogy to the electric giant dipole resonance, also briefly studied for the sake of completeness.

Kvasil, J.; Lo Iudice, N.; Nesterenko, V. O.; Macková, A.; Alexa, P.

2001-05-01

331

Quadrupole collective states within the Bohr collective Hamiltonian  

E-print Network

The article reviews the general version of the Bohr collective model for the description of quadrupole collective states, including a detailed study the model's kinematics. The general form of the classical and quantum Bohr Hamiltonian is presented together with a discussion of the tensor structure of the collective wave functions and with a short review of various methods of solving the Bohr Hamiltonian eigenvalue equation.The methods of derivation of the classical and quantum Bohr Hamiltonian from the microscopic many-body theory are recalled and the microscopic approach to the Bohr Hamiltonian is applied to interpret collective properties of 12 heavy even-even nuclei in the Hf-Hg region.

L. Prochniak; S. G. Rohozinski

2009-11-02

332

Small Aperture BPM to Quadrupole Assembly Tolerance Study  

SciTech Connect

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

Fong, K. W.

2010-12-07

333

Direct measurement of micromotion speed in a linear quadrupole trap  

NASA Astrophysics Data System (ADS)

We demonstrate a simple method to directly measure the micromotion speed and amplitude of ions far away from the nodal line of the linear quadrupole trap using the cross-correlation technique. For the ions very close to the trap nodal line, the micromotion speed and amplitude of ions can also be deduced through linear fitting. This work gives us a direct picture to the ions' micromotion modes at different displacements in the linear trap. With this work, an absolute measurement of the second-order Doppler effect in the research of atomic clocks based on large number of ions becomes possible.

Wang, B.; Zhang, J. W.; Lu, Z. H.; Wang, L. J.

2010-07-01

334

Optimized Superconducting Quadrupole Arrays for Multiple Beam Transport  

SciTech Connect

This research project advanced the development of reliable, cost-effective arrays of superconducting quadrupole magnets for use in multi-beam inertial fusion accelerators. The field in each array cell must be identical and meet stringent requirements for field quality and strength. An optimized compact array design using flat double-layer pancake coils was developed. Analytical studies of edge termination methods showed that it is feasible to meet the requirements for field uniformity in all cells and elimination of stray external field in several ways: active methods that involve placement of field compensating coils on the periphery of the array or a passive method that involves use of iron shielding.

Meinke, Rainer, B.; Goodzeit, Carl, L.; Ball, Millicent, J.

2005-09-20

335

Nuclear chemistry research and spectroscopy with radioactive sources. Twentieth annual progress report, September 1, 1983-August 31, 1984  

SciTech Connect

Research under this continuing DOE contract centers on radioactive decay studies of nuclei far from stability produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). These investigations encompass three aspects of nuclear structure research: nuclear spectroscopic measurements involving detailed ..gamma gamma..t, ..gamma..e/sup -/t, and X..gamma..t three-parameter coincidence spectrometry; on-line laser hyperfine structure (hfs) and isotope shift spectroscopy for determining quadrupole moments, nuclear spins, and mean nuclear charge radii; and computer calculations of nuclear model predictions for comparison with the experimental level schemes. The focus of this research program is on odd-mass nuclei in which the odd nucleon probes the core, making possible observation of such phenomena as the onset of abrupt shape changes, the occurrence of shape coexistence, and shell-model intruder states. These phenomena are critical tests of concepts fundamental to an understanding of low-energy nuclear structure, such as nuclear deformations, shell models, collective models, and particle-core couplings.

Fink, R.W.

1984-08-31

336

Comparison of liquid chromatography using triple quadrupole and quadrupole ion trap mass analyzers to determine pesticide residues in oranges.  

PubMed

Liquid chromatography-triple quadrupole/mass spectrometry (LC-TQ/MS) and liquid chromatography-quadrupole ion trap/mass spectrometry (LC-QIT/MS) for determining bupirimate, hexaflumuron, tebufenpyrad, buprofezin, pyriproxyfen, and fluvalinate in fruits have been compared. The differences in the mass spectra obtained by triple and ion trap quadrupoles are discussed, showing how both of them provide interesting features. The evaluation of the two instruments was carried out by ethyl acetate extraction of oranges spiked with the studied pesticides at LOQ and 10 times the LOQ. Results obtained by LC-TQ/MS correlated well with those obtained by LC-QIT/MS. Recoveries were 70-94% by LC-TQ/MS and 72-92% by LC-QIT/MS with the R.S.D. from five replicate analysis 4-14% and 8-18%, respectively. Matrix effects were tested for both techniques by standard addition to blank extracts. Although the matrix effects are not originated in mass analyzer but in the LC/MS interface, they were, generally, more marked by LC-QIT-MS than by LC-TQ/MS. The limits of quantification (LOQs) were 0.005-0.2 mg kg(-1) by both equipments--appropriate values for determining these pesticides in orange from the regulatory point of view. The results indicate that the TQ provides higher precision, better linearity, it is more robust, and when the purpose of the analysis is quantitative determination, preferable over the QIT. However, the application of both mass spectrometers to analyze orange samples conventionally treated showed that any can be used for qualitative and quantitative purposes. PMID:15844516

Soler, Carla; Mañes, Jordi; Picó, Yolanda

2005-03-01

337

Problematic Aspects of Nuclear Education.  

ERIC Educational Resources Information Center

Reviewing research on children's understanding of nuclear war, Tizard suggests that educators and researchers have yet to understand the factors influencing children's attitudes, anxieties, and knowledge of nuclear issues. (Author/SK)

Tizard, Barbara

1984-01-01

338

Heavy ion plasma confinement in an RF quadrupole trap  

NASA Technical Reports Server (NTRS)

The confinement of an electron free plasma in a pure quadrupole RF electric trap was considered. The ultimate goal was to produce a large density of mercury ions, in order to realize a trapped ion frequency standard using the hyperfine resonance of 199 Hg(+) at 40.7 GHz. An attempt was made to obtain an iodine plasma consisting of equal numbers of positive and negative ions of atomic iodine, the positive iodine ions, being susceptible to charge-exchange with mercury atoms, will produce the desired mercury ions. The experiment showed that the photoproduction of ions pairs in iodine using the necessary UV radiation occurs with a small cross-section, making it difficult to demonstrate the feasibility of space charge neutralization in a quadrupole trap. For this reason it was considered expedient to choose thallium iodide, which has a more favorable absorption spectrum (in the region of 2000 to 2100 A). The results indicate that, although the ionic recombination is a serious limiting factor, a considerable improvement can be obtained in practice for the density of trapped ions, with a considerable advantage in lifetimes for spectroscopic purposes. The ion pair formation by photoionization is briefly reviewed.

Schermann, J.; Major, F. G.

1971-01-01

339

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

340

VIBRATION MEASUREMENTS IN A RHIC QUADRUPOLE AT CRYOGENIC TEMPERATURES.  

SciTech Connect

One of the concerns in using compact superconducting magnets in the final focus region of the ILC is the influence of the cryogen flow on the vibration characteristics. As a first step towards characterizing such motion at nanometer levels, a project was undertaken at BNL to measure the vibrations in a spare RHIC quadrupole under cryogenic conditions. Given the constraints of cryogenic operation, and limited space available, it was decided to use a dual head laser Doppler vibrometer for this work. The performance of the laser vibrometer was tested in a series of room temperature tests and compared with results from Mark L4 geophones. The laser system was then used to measure the vibration of the cold mass of the quadrupole with respect to the outside warm enclosure. These measurements were carried out both with and without the flow of cold helium through the magnet. The results indicate only a minor increase in motion in the horizontal direction (where the cold mass is relatively free to move).

JAIN, A.; AYDIN, S.; HE, P.; ANERELLA, M.; GANETIS, G.; HARRISON, M.; PARKER, B.; PLATE, S.

2005-10-17

341

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

342

Performance of a Nb(3)Sn Quadrupole Under High Stress  

E-print Network

Future upgrades of the Large Hadron Collider (LHC) will require large aperture and high gradient quadrupoles. Nb(3)Sn is the most viable option for this application but is also known for its strain sensitivity. In high field magnets, with magnetic fields above 12 T, the Lorentz forces will generate mechanical stresses that may exceed 200 MPa in the windings. The existing measurements of critical current versus strain of Nb(3)Sn strands or cables are not easily applicable to magnets. In order to investigate the impact of high mechanical stress on the quench performance, a series of tests was carried out within a LBNL/CERN collaboration using the magnet TQS03 (a LHC Accelerator Research Program (LARP) 1-meter long, 90-mm aperture Nb(3)Sn quadrupole). The magnet was tested four times at CERN under various pre-stress conditions. The average mechanical compressive azimuthal pre-stress on the coil at 4.2 K ranged from 120 MPa to 200 MPa. This paper reports on the magnet performance during the four tests focusing on...

Felice, H; Ferracin, P; De Rijk, G; Bajko, M; Caspi, S; Bingham, B; Giloux, C; Bordini, B; Milanese, A; Bottura, L; Sabbi, G L; Hafalia, R; Godeke, A; Dietderich, D

2011-01-01

343

Performance of Nb3Sn Quadrupole Under High Stress  

SciTech Connect

Future upgrades of the Large Hadron Collider (LHC) will require large aperture and high gradient quadrupoles. Nb{sub 3}Sn is the most viable option for this application but is also known for its strain sensitivity. In high field magnets, with magnetic fields above 12 T, the Lorentz forces will generate mechanical stresses that may exceed 200 MPa in the windings. The existing measurements of critical current versus strain of Nb{sub 3}Sn strands or cables are not easily applicable to magnets. In order to investigate the impact of high mechanical stress on the quench performance, a series of tests was carried out within a LBNL/CERN collaboration using the magnet TQS03 (a LHC Accelerator Research Program (LARP) 1-meter long, 90-mm aperture Nb{sub 3}Sn quadrupole). The magnet was tested four times at CERN under various pre-stress conditions. The average mechanical compressive azimuthal pre-stress on the coil at 4.2 K ranged from 120 MPa to 200 MPa. This paper reports on the magnet performance during the four tests focusing on the relation between pre-stress conditions and the training plateau.

Felice, H.; Bajko, M.; Bingham, B.; Bordini, B.; Bottura, L.; Caspi, S.; Rijk, G. De; Dietderich, D.; Ferracin, P.; Giloux, C.; Godeke, A.; Hafalia, R.; Milanese, A.; Rossi, L.; Sabbi, G. L.

2010-08-01

344

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

345

Adjustable permanent quadrupoles 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 138 Tesla, with a maximum gradient of 141 Tesla per meter, an adjustment range of +0 to {minus}20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micron during the 20% adjustment. In an effort to reduce costs and increase reliability, several designs using hybrid permanent magnets have been developed. Four different prototypes have been built. All magnets have iron poles and use Samarium Cobalt to provide the magnetic fields. Two use rotating permanent magnetic material to vary the gradient, one uses a sliding shunt to vary the gradient and the fourth uses counter rotating magnets. Preliminary data on gradient strength, temperature stability, and magnetic center position stability are presented. These data are compared to an equivalent electromagnetic prototype.

James T. Volk et al.

2001-06-22

346

Dynamic collective theory of the quadrupole giant resonance in deformed nuclei  

Microsoft Academic Search

The theory of photon excitation has been extended into the region immediately above the giant dipole resonance. This has been accomplished by use of the hydrodynamical model. The dynamic coupling of the giant quadrupole oscillations with surface vibrations, rotational modes and single particle motions have been taken into account. The quadrupole operator is computed, the resulting energy spectrum, transition probabilities

Rainer Ligensa; Walter Greiner

1967-01-01

347

The quadrupole coupling constant of HNC. [hydrogen isocyanide hyperfine structure measurements  

NASA Technical Reports Server (NTRS)

The letter reports resolved measurements of the quadrupole hyperfine structure of HNC (hydrogen isocyanide). These measurements were made in the direction of the cool interstellar dust cloud L134, and were used to make an experimental determination of a fundamental spectroscopic constant of HNC, its quadrupole coupling constant.

Snyder, L. E.; Hollis, J. M.; Buhl, D.

1977-01-01

348

Origin of Low-Energy Quadrupole Collectivity in Vibrational Nuclei H. Fujita,2,3  

E-print Network

Origin of Low-Energy Quadrupole Collectivity in Vibrational Nuclei C. Walz,1 H. Fujita,2,3 A is a separation of energy (respectively momentum) scales such that the high-energy degrees of freedom) energy scale. In the IBM the relevant low-energy degrees of freedom for the description of quadrupole

Ponomarev, Vladimir

349

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

350

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

351

Development and application of an analytical method using gas chromatography/triple quadrupole mass spectrometry for  

E-print Network

Development and application of an analytical method using gas chromatography/triple quadrupole mass to the development of gas chromatography/triple quadrupole mass spectrometry methods that allow the identification estimated using gas chromatography/mass spectrometry (GC/MS).[7,10,11] The efficiency of GC/MS methods

Clement, Prabhakar

352

Quantitative analysis of sphingolipids for lipidomics using triple quadrupole and quadrupole linear ion trap mass spectrometers[S  

PubMed Central

Sphingolipids are a highly diverse category of bioactive compounds. This article describes methods that have been validated for the extraction, liquid chromatographic (LC) separation, identification and quantitation of sphingolipids by electrospray ionization, tandem mass spectrometry (ESI-MS/MS) using triple quadrupole (QQQ, API 3000) and quadrupole-linear-ion trap (API 4000 QTrap, operating in QQQ mode) mass spectrometers. Advantages of the QTrap included: greater sensitivity, similar ionization efficiencies for sphingolipids with ceramide versus dihydroceramide backbones, and the ability to identify the ceramide backbone of sphingomyelins using a pseudo-MS3 protocol. Compounds that can be readily quantified using an internal standard cocktail developed by the LIPID MAPS Consortium are: sphingoid bases and sphingoid base 1-phosphates, more complex species such as ceramides, ceramide 1-phosphates, sphingomyelins, mono- and di-hexosylceramides, and these complex sphingolipids with dihydroceramide backbones. With minor modifications, glucosylceramides and galactosylceramides can be distinguished, and more complex species such as sulfatides can also be quantified, when the internal standards are available. JLR LC ESI-MS/MS can be utilized to quantify a large number of structural and signaling sphingolipids using commercially available internal standards. The application of these methods is illustrated with RAW264.7 cells, a mouse macrophage cell line. These methods should be useful for a wide range of focused (sphingo)lipidomic investigations. PMID:19036716

Shaner, Rebecca L.; Allegood, Jeremy C.; Park, Hyejung; Wang, Elaine; Kelly, Samuel; Haynes, Christopher A.; Sullards, M. Cameron; Merrill, Alfred H.

2009-01-01

353

[Electromagnetic studies of nuclear structure and reactions]. Progress summary  

SciTech Connect

The experimental goals are focused on developing an understanding of strong interactions and the structure of hadronic systems by determination of the electromagnetic response; these goals will be accomplished through coincidence detection of final states. Nuclear modeling objectives are to organize and interpret the data through a consistent description of a broad spectrum of reaction observables; calculations are performed in a nonrelativistic diagrammatic framework as well as a relativistic QHD approach. Work is described according to the following arrangement: direct knockout reactions (completion of {sup 16}O(e,e{prime}p), {sup 12}C(e,e{prime}pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in {sup 12}C(e,e{prime}p{sub 0}) and {sup 16}O(e,e{prime}p{sub 0}), comparison of the {sup 12}C(e, e{prime}p{sub 0}) and {sup 16}O(e,e{prime}p{sub 3}) reactions, quadrupole strength in the {sup 16}O(e,e{prime}{alpha}{sub 0}) reaction, quadrupole strength in the {sup 12}C(e,e{prime}{alpha}) reaction, analysis of the {sup 12}C(e,e{prime}p{sub 1}) and {sup 16}O(e,e{prime}p{sub 3}) angular distributions, analysis of the {sup 40}Ca(e,e{prime}x) reaction at low q, analysis of the higher-q {sup 12}C(e,e{prime}x) data from Bates), models of nuclear structure (experimental work, Hartree-Fock calculations, phonon excitations in spherical nuclei, shell model calculations, variational methods for relativistic fields), and instrumentation development efforts (developments at CEBAF, CLAS contracts, BLAST developments).

Not Available

1992-12-31

354

A superconducting quadrupole magnet array for a heavy ion fusion driver  

SciTech Connect

A multi-channel quadrupole array has been proposed to increase beam intensity and reduce space charge effects in a Heavy Ion Fusion Driver. A single array unit composed of several quadrupole magnets, each with its own beam line, will be placed within a ferromagnetic accelerating core whose cost is directly affected by the array size. A large number of focusing arrays will be needed along the accelerating path. The use of a superconducting quadrupole magnet array will increase the field and reduce overall cost. We report here on the design of a compact 3 x 3 superconducting quadrupole magnet array. The overall array diameter and length including the cryostat is 900 x 700 mm. Each of the 9 quadrupole magnets has a 78 mm warm bore and an operating gradient of 50 T/m over an effective magnetic length of 320 mm.

Caspi, S.; Bangerter, r.; Chow, K.; Faltens, A.; Gourley, S.; Hinkins, R.; Gupta, R.; Lee, E.; McInturff, A.; Scanlan, R.; Taylor, C.; Wolgast, D.

2000-06-27

355

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

356

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

357

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

358

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

359

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

360

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

361

A Cryogenic Test Stand for LHC Quadrupole Magnets  

SciTech Connect

A new test stand for testing LHC interaction region (IR) quadrupole magnets at the Fermilab Magnet Test Facility has been designed and operated. The test stand uses a double bath system with a lambda plate to provide the magnet with a stagnant bath of pressurized He II at 1.9 K and 0.13 MPa. A cryostated magnet 0.91 m in diameter and up to 13 m in length can be accommodated. This paper describes the system design and operation. Issues related to both 4.5 K and 1.9 K operations and magnet quenching are highlighted. An overview of the data acquisition and cryogenics controls systems is also included.

Carcagno, R.H.; Huang, Y.; Orris, D.F.; Peterson, T.J.; Rabehl, R.J. [Fermi National Accelerator Laboratory, Batavia, Illinois, 60510 (United States)

2004-06-23

362

Thermal noise in aqueous quadrupole micro- and nano-traps  

PubMed Central

Recent simulations and experiments with aqueous quadrupole micro-traps have confirmed a possibility for control and localization of motion of a charged particle in a water environment, also predicting a possibility of further reduction of the trap size to tens of nano-meters for trapping charged bio-molecules and DNA segments. We study the random thermal noise due to Brownian motion in water which significantly influences the trapping of particles in an aqueous environment. We derive the exact, closed-form expressions for the thermal fluctuations of position and velocity of a trapped particle and thoroughly examine the properties of the rms for the fluctuations as functions of the system parameters and time. The instantaneous signal transferring mechanism between the velocity and position fluctuations could not be achieved in the previous phase-average approaches. PMID:22369362

2012-01-01

363

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

364

Quadrupole moment of the first excited state of 136Ba  

NASA Astrophysics Data System (ADS)

The static electric quadrupole moment Q(2+1) of the first excited state of 136Ba and the reduced transition probability B(E20+1-->2+1) have been measured using the reorientation effect in Coulomb excitation. It is found that Q(2+1)=-0.19+/-0.06 (+0.07+/-0.07) e b and B(E20+1-->2+1) =0.419+/-0.004 (0.417+/-0.004) e2b2 for constructive (destructive) interference involving the second 2+ state. These results agree well with one of the previous measurements of these quantities, but disagree markedly with another which is of similar precision to the present work.

Rothschild, P. J.; Baxter, A. M.; Burnett, S. M.; Fewell, M. P.; Gyapong, G. J.; Spear, R. H.

1986-08-01

365

Dipole and electric quadrupole excitations in 40,48Ca  

NASA Astrophysics Data System (ADS)

Photon scattering experiments have been performed to investigate the structure of the two doubly magic nuclei 40,48Ca. The method is highly selective to induce low-order multipole transitions, i.e., E1, M1, and E2 from the ground state. We determined the energies and spins of excited states and the absolute strengths of the ? decays in a model independent way. We find the summed electric dipole strengths below 10 MeV to exhaust the energy weighted sum rule by 0.023 and 0.27 %, respectively. The summed electric quadrupole strengths are ?B(E2)?=332 e2 fm4 and 407 e2 fm4 for 40Ca and 48Ca, respectively. In order to explain the difference in the E1 strengths of the two isotopes several theoretical models are discussed.

Hartmann, T.; Enders, J.; Mohr, P.; Vogt, K.; Volz, S.; Zilges, A.

2002-03-01

366

Design and fabrication of the BNL radio frequency quadrupole  

SciTech Connect

The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS will utilize a Radio Frequency Quadrupole for acceleration between the polarized source and the Alvarez Linac. Although operation will commence with a few ..mu.. amperes of H/sup -/ current, it is anticipated that future polarized H/sup -/ sources will have a considerably improved output. The RFQ will operate at 201.25 MHz and will be capable of handling a beam current of 0.02 amperes with a duty cycle of 0.25%. The resulting low average power has allowed novel solutions to the problems of vane alignment, rf current contacts, and removal of heat from the vanes. The cavity design philosophy will be discussed together with the thermodynamics of heat removal from the vane. Details of the fabrication will be presented with a status report.

McKenzie-Wilson, R.B.

1983-01-01

367

Plasma-beam traps and radiofrequency quadrupole beam coolers  

SciTech Connect

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.

Maggiore, M., E-mail: mario.maggiore@lnl.infn.it; Cavenago, M.; Comunian, M.; Chirulotto, F.; Galatà, A.; De Lazzari, M.; Porcellato, A. M.; Roncolato, C.; Stark, S. [INFN-LNL, viale dell’Università 2, 35020 Legnaro (Italy)] [INFN-LNL, viale dell’Università 2, 35020 Legnaro (Italy); Caruso, A.; Longhitano, A. [INFN-LNS, via S. Sofia 54, 95123 Catania (Italy)] [INFN-LNS, via S. Sofia 54, 95123 Catania (Italy); Cavaliere, F.; Maero, G.; Paroli, B.; Pozzoli, R.; Romé, M. [INFN Sezione di Milano and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)] [INFN Sezione di Milano and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)

2014-02-15

368

Plasma-beam traps and radiofrequency quadrupole beam coolers  

NASA Astrophysics Data System (ADS)

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.

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

369

Degradation studies of Fermilab low beta quadrupole cable  

SciTech Connect

The production of high gradient superconducting quadrupoles for the Tevatron D0/B0 Low Beta insertion is currently underway at Fermilab. The two-shell design utilizes a 36-strand Rutherford style cable produced by Lawrence Berkeley Laboratory. A measure of cable quality is usually given by a comparison of the critical current of the cable with the sum of the critical currents of the strand. A recent study involving variations in the cabling conditions and dimensional parameters has resulted in a significant decrease in degradation. Over the period of cable production degradation has been reduced from an average of 12% to less than 4%. Some cable samples measured by Brookhaven National Laboratory exhibit Jc's in excess of 3100 A/mm{sup 2} 5T. The adjustments to the cabling procedure which are believed to be responsible for the reduction in Jc degradation will be discussed. 14 refs., 3 figs.

Gourlay, S.A. (Fermi National Accelerator Lab., Batavia, IL (USA)); Garber, M. (Brookhaven National Lab., Upton, NY (USA)); Royet, J.; Scanlon, R.M. (Lawrence Berkeley Lab., CA (USA))

1990-10-01

370

Propagation Hanle effect of quadrupole polaritons in Cu2O  

NASA Astrophysics Data System (ADS)

The generalized theory of the Hanle effect is developed for the case of propagation quantum beats. Time-integrated quantum beats of two polariton wave packets with the same group velocities and polarizations belonging to two different Zeeman components in Voigt geometry of the quadrupole-active ortho-exciton (Gamma) 5+ level in Cu2O crystal gives rise to the propagation Hanle effect. It is characterized by a quasiresonant dependence of the emitted light intensity on the magnetic field strength, as well as by a supplementary periodic dependence with the period inverse proportional to the sample thickness. The developed theory with the account of the effective propagation way explains recent experimental results published by Kono and Nagasawa.

Moskalenko, S. A.; Liberman, M. A.

2002-05-01

371

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

372

Restoring the skew quadrupole moment in the Tevatron dipoles  

SciTech Connect

In early 2003 it was realized that mechanical changes in the Tevatron dipoles had led to a deterioration of the magnetic field quality that was hindering operation of the accelerator. After extensive study, a remediation program was started in late 2003 that will continue through 2005. The mechanical and magnetic effects are discussed. The readjustment process and experience are reported, along with other observations on aging magnets. In January 2003 two lines of inquiry converged, leading to the recognition that the severe betatron coupling that was hindering operation of the Tevatron could be explained by a systematic shift on the skew quadrupole field in the dipole magnets of the same size expected from observed mechanical movement of the coils inside the magnet yokes [1]. This paper reports on subsequent magnet studies that were conducted in parallel with additional beam studies and accelerator modeling [2] exploring the feasibility of the eventual remediation effort [3].

Harding, D.J.; Bauer, P.C.; Blowers, J.N.; DiMarco, J.; Glass, H.D.; Hanft, R.W.; Carson, J.A.; Robotham, W.F.; Tartaglia, M.A.; Tompkins, J.C.; Velev, G.; /Fermilab

2005-05-01

373

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

374

Quadrupole effects in high-resolution phosphorus-31 solid-state NMR spectra of triphenylphosphine copper(I) complexes  

NASA Astrophysics Data System (ADS)

High-resolution 31P solid-state NMR spectra of triphenylphosphine copper(I) complexes, obtained by combining proton dipolar decoupling, proton-phosphorus cross polarization, and magic-angle sample spinning, often reveal asymmetric quartets rather than single resonance lines. These splittings arise from coupling with the nuclear spin {3}/{2} of the quadrupolar copper nucleus. Theoretical NMR spectra of spins I = {1}/{2} coupled to spins S > {1}/{2} are presented for powders spinning at the magic angle. Scalar as well as dipolar interactions are considered for the S = 1 and S = {3}/{2} cases. The magnetic field dependence of the observed asymmetric quartets in bis(triphenylphosphine)copper(I)nitrate can be accounted for by assuming a combination of scalar and dipolar coupling between phosphorus and copper. The spectra allow the determination of the scalar coupling constant, the dipolar coupling constant, and the copper quadrupole constant. Also, their signs can be established.

Menger, E. M.; Veeman, W. S.

375

Nuclear structure of {sup 231}Ra  

SciTech Connect

The study of the upper border of the octupole deformation region near A=225, where the octupole deformation vanishes in the presence of a well developed quadrupole field, is of great relevance in order to understand the interplay of octupole and quadrupole collectivities. Within the IS322 collaboration at CERN we carry out a systematic investigation of the heavy Fr-Th nuclei that presently includes {sup 227}Fr, {sup 227,228,229}Ra, {sup 229}Ac and {sup 229,231}Th. The heaviest Ra isotope we have studied so far and in which the fast timing {beta}{gamma}{gamma}(t) method has been applied is {sup 231}Ra.

Boutami, R.; Fraile, L. M.; Borge, M. J. G.; Lopez-Jimenez, M. J.; Teijeiro, A. G. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); Aas, A. J.; Hageboe, E. [Department of Chemistry, Univ. of Oslo, P.O. Box 1033, Blindern, N-0315 Oslo (Norway); Fogelberg, B.; Mach, H. [Department of Neutron Research, Univ. of Uppsala, S-61182 Nykoeping (Sweden); Garcia-Raffi, L. M.; Martinez, T.; Rubio, B.; Tain, J. L. [Instituto de Fisica Corpuscular, CSIC-Univ. Valencia, E-46100 Burjassot (Spain); Grant, I. S. [Schuster Laboratory, Univ. of Manchester, Manchester M13 9PL (United Kingdom); Gulda, K.; Kurcewicz, W. [Department of Physics, Univ. of Warsaw, Pl-00 681 Warsaw (Poland); Loevhoeiden, G. [Department of Physics, Univ. of Oslo, P.O. Box 1048, Blindern, N-0316 Oslo (Norway); Tengblad, O. [Instituto de Estructura de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid (Spain); EP Division, CERN, CH-1211 Geneva 23 (Switzerland); Thorsteinsen, T. F. [Department of Physics, Univ. of Bergen, N-5000 Bergen (Norway)

1999-11-16

376

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

377

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

378

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

379

Matching an H{sup –} beam into a radio frequency quadrupole at Rutherford Appleton Laboratory  

SciTech Connect

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{sup –} 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., E-mail: christoph.gabor@stfc.ac.uk; Faircloth, D. C.; Lawrie, S. R.; Letchford, A. P. [STFC, Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX (United Kingdom)] [STFC, Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX (United Kingdom); Back, J. J. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)] [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

2014-02-15

380

Study of electric quadrupole interactions at 111Cd on Zn sites in RZn (R = Ce, Gd, Tb, Dy) compounds using the PAC spectroscopy  

NASA Astrophysics Data System (ADS)

Nuclear quadrupole interactions at Zn sites in the intermetallic compounds RZn (R = Ce, Gd, Tb, Dy) have been investigated by perturbed gamma-gamma angular correlation (PAC) spectroscopy using 111In(111Cd) as probe nuclei. Measurements were carried out in the temperature range of 10-295 K. These compounds exhibit CsCl type cubic structure and while CeZn shows antiferromagnetic behaviour, the compounds GdZn, TbZn, DyZn are ferromagnetic. The results show that the EFG in these compounds is sensitive to the distribution of rare-earth 4f-electron charges.

Bosch-Santos, Brianna; Carbonari, Artur W.; Cabrera-Pasca, Gabriel A.; Costa, Messias S.; Saxena, Rajendra N.

2013-05-01

381

Temperature and angular momentum dependence of the quadrupole deformation in sd-shell  

E-print Network

Temperature and angular momentum dependence of the quadrupole deformation is studied in the middle of the sd-shell for 28Si and 27Si isotopes using the spherical shell model approach. The shell model calculations have been performed using the standard USD interaction and the canonical partition function constructed from the calculated eigen-solutions. It is shown that the extracted average quadrupole moments show a transitional behavior as a function of temperature and the inferred transitional temperature is shown to vary with angular-momentum. The quadrupole deformation of the individual eigen-states is also analyzed.

P. A. Ganai; J. A. Sheikh; I. Maqbool; R. P. Singh

2009-06-16

382

The effect of vacancy ordering on quadrupole shifts in Mössbauer spectra of maghemite.  

PubMed

Electric field gradient (EFG) lattice sums for the vacancy-disordered and vacancy-ordered forms of maghemite were evaluated using a point charge model. The calculated EFGs produced a wide range of magnitudes and principal directions for the quadrupole interaction for both forms of maghemite. Small perturbations of the crystallographic parameters were shown to have a significant effect on the quadrupole shift. The effects observed were significant enough to show that quadrupole shifts should be considered when fitting the Mössbauer spectra of maghemite. PMID:21493972

Spiers, K M; Paganin, D M; Cashion, J D

2011-05-01

383

The First Reactor, Understanding the Atom Series.  

ERIC Educational Resources Information Center

This booklet is one of the "Understanding the Atom" Series. Consisting of three sections, it is an account of the development of the first nuclear reactor by a team of scientists led by Enrico Farmi. The first section briefly reviews the early work on nuclear fission and neutron emission, the impact of Einstein's letter to President Roosevelt, the…

Allardice, Corbin; And Others

384

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

385

An Investigation of the Isovector Giant Quadrupole Resonance in Bismuth-209 using Polarized Compton Scattering  

NASA Astrophysics Data System (ADS)

Giant multipole resonances are a fundamental property of nuclei and arise from the collective motion of the nucleons inside the nucleus. Careful studies of these resonances and their properties provides insight into the nature of nuclear matter and constraints which can be used to test our theories. An investigation of the Isovector Giant Quadrupole Resonance (IVGQR) in 209Bi has been preformed using the High Intensity gamma-ray Source (HI g? S) facility. Intense nearly monochromatic polarized g? -rays were incident upon a 209Bi target producing nuclear Compton scattered gamma-rays that were detected using the HI g? S NaI(Tl) Detector Array (HINDA). The HINDA array consists of six large (10"x10") NaI(Tl) core crystals, each surrounded by an optically segmented 3" thick NaI(Tl) annulus. The scattered gamma-rays both parallel and perpendicular to the plane of polarization were detected at scattering angles of 55° and 125° with respect to the beam axis. This was motivated by the realization that the term representing the interference between the electric dipole ( E1) and electric quadrupole (E2) amplitudes, which appears in the theoretical expression for the ratio of the polarized cross sections, has a sign difference between the forward and backward angles and also changes sign as the incident gamma-ray energy is scanned over the E2 resonance energy. The ratio of cross sections perpendicular and parallel to the plane of polarization of the incident gamma-ray were measured for thirteen different incident gamma-ray energies between 15 and 26 MeV at these two angles and used to extract the parameters of the IVGQR in 209Bi. The polarization ratio was calculated at 55° and 125° using a model consisting of E1 and E2 giant resonances as well as a modified Thomson scattering amplitude. The parameters of the E1 giant resonance came from previous measurements of the Giant Dipole Resonance (GDR) in 209Bi. The finite size of the nucleus was accounted for by introducing a charge form factor in the (modified) Thomson amplitude. This form factor was obtained from measurements of the charge density in inelastic electron scattering experiments. The resulting curves were fit to the data by varying the E2 parameters until a minimum value of the chi2 was found. The resulting parameters from the fit yield an IVGQR in 209Bi located at Eres = 23.0 +/- 0.13(stat)+/-0.25(sys) MeV with a width of Gamma = 3.9 +/- 0.7(stat)+/-1.3(sys) MeV and a strength of 0.56 +/- 0.04(stat)+/-0.10(sys) Isovector Giant Quadrupole Energy Weighted Sum Rules (IVQ-EWSRs). The ability to make precise measurements of the parameters of the IVGQR demonstrated by this work opens up new challenges to both experimental and theoretical work in nuclear structure. A detailed search for the missing sum rule strength in the case of 209Bi should be performed. In addition, a systematic study of a number of nuclei should be studied with this technique in order to carefully examine the A dependence of the energy, width and sum rule strength of the IVGQR as a function of the mass number A. The unique properties of the HI g? S facility makes it the ideal laboratory at which to perform these studies. Such a data base will provide more stringent tests of nuclear theory. The effective parameters of collective models can be fine tuned to account for such precision data. This should lead to new insights into the underlying interactions responsible for the nature of the IVGQR. Furthermore, with the recent advances in computational power and techniques, microscopic shell model based calculations should be possible and could lead to new insights into the underlying properties of nuclear matter which are responsible for the collective behavior evidenced by the existence and properties of the IVGQR.

Henshaw, Seth S.

386

Single-crystal EPR, 35,37Cl and 14,15N ENDOR and ESEEM studies on (Ph 4As)[Tc VINCl 4/Tc VOCl 4]. II. Determination of the 35,37Cl and 14,15N hyperfine and quadrupole tensors by ENDOR and ESEEM  

NASA Astrophysics Data System (ADS)

Single-crystal ENDOR and ESEEM studies on 35,37Cl and 14,15N nuclei are reported for the 4d 1 ( S= 1/2) complex (Ph 4As) [TcNCl 4], a spin system consisting of four 35Cl and four 37Cl nuclei ( I= 3/2), and one 14N ( 15N) nucleus with I = 1 ( I = 1/2), respectively ( I( 99Tc) = 9/2). The 35,37Cl spectra are characterized by different ratios of the hyperfine, nuclear Zeeman and the nuclear quadrupole interaction depending on the B0 field orientation: HQ < Hhf+ HNZ, and HQ t˜ Hhf+ HNZ and HQ? Hhf+ HNZ. A general description of this situation is given and the characteristics of ENDOR and ESEEM are discussed. The 14N spectra are also strongly influenced by nuclear quadrupole interaction; the isotropic 14N ( 15N) coupling is unexpectedly large. Molecular orbital calculations (EHMO and NDDO) are made to account for the hyperfine parameters and indicate that the 14,15N coupling is mainly determined by spin polarization. The hyperfine and nuclear quadrupole couplings are used to discuss the actual symmetry and the bonding situation of the incorporated TcNCl 4- anion. For the interpretation of the quadrupole data the Townes-Dailey model has been used.

Köhler, K.; Kirmse, R.; Böttcher, R.; Abram, U.; Gribnau, M. C. M.; Keijzers, C. P.; De Boer, E.

1990-05-01

387

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

NASA Astrophysics Data System (ADS)

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; Geralico, Andrea

2014-04-01

388

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

389

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

390

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

NASA Technical Reports Server (NTRS)

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

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

1973-01-01

391

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

392

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

393

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

394

Low CMB quadrupole from dark energy isocurvature perturbations  

NASA Astrophysics Data System (ADS)

We explicate the origin of the temperature quadrupole in the adiabatic dark energy model and explore the mechanism by which scale invariant isocurvature dark energy perturbations can lead to its sharp suppression. The model requires anticorrelated curvature and isocurvature fluctuations and is favored by the Wilkinson Microwave Anisotropy Probe data at about the 95% confidence level in a flat scale invariant model. In an inflationary context, the anticorrelation may be established if the curvature fluctuations originate from a variable decay rate of the inflaton; such models however tend to overpredict gravitational waves. This isocurvature model can in the future be distinguished from alternatives involving a reduction in large scale power or modifications to the sound speed of the dark energy through the polarization and its cross correlation with the temperature. The isocurvature model retains the same polarization fluctuations as its adiabatic counterpart but reduces the correlated temperature fluctuations. We present a pedagogical discussion of dark energy fluctuations in a quintessence and k-essence context in the Appendix.

Gordon, Christopher; Hu, Wayne

2004-10-01

395

Development of a quadrupole ion trap mass spectrometer  

NASA Astrophysics Data System (ADS)

Because of its potential to be made portable the quadrupole ion trap (QPIT) is a prime candidate for specialized applications such as atmospheric studies, other field measurements, or measurements anywhere a laboratory instrument would be prohibitively inconvenient. To utilize the QPIT in such ways it is necessary to design and construct custom built instruments. A QPIT mass spectrometer was constructed as the foundation for such future development. Two ionization schemes were employed. Direct electron bombardment was used for in situ ion production, and UV photoionization was used to produce ions external to the trap. Calibration measurements determined that the system performed as theory dictated. It was also demonstrated that the system was capable of sampling the atmosphere and detecting the presence of an atmospheric contaminant. Finally, DC bias foils were invented as a novel approach to mass isolation in the trap. The use of DC bias foils was demonstrated to be an exceptionally easy and inexpensive method of controlling the contents of the QPIT.

Hebert, Joseph Ellis

396

Nuclear photonics  

NASA Astrophysics Data System (ADS)

With the planned new ?-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 1013 ?/s and a band width of ?E?/E??10-3, a new era of ? beams with energies up to 20MeV comes into operation, compared to the present world-leading HI?S facility at Duke University (USA) with 108 ?/s and ?E?/E??3?10-2. In the long run even a seeded quantum FEL for ? beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused ? beams. Here we describe a new experiment at the ? beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for ? beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for ? beams are being developed. Thus, we have to optimize the total system: the ?-beam facility, the ?-beam optics and ? detectors. We can trade ? intensity for band width, going down to ?E?/E??10-6 and address individual nuclear levels. The term "nuclear photonics" stresses the importance of nuclear applications. We can address with ?-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, ? 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 ?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.; Günther, M. M.; Jentschel, M.; Thirolf, P. G.

2012-07-01

397

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

398

Conceptual design of large-bore superconducting quadrupoles with active magnetic shielding for the AHF  

SciTech Connect

The Advanced Hydrotest Facility, under study by LANL, uses large-bore superconducting quadrupole magnets. In the paper we discuss the conceptual design of such quadrupoles using active shielding. The magnets are specified to achieve gradients of up to 24 T/m with a 28-cm warm bore and to have 0.01% field quality. Concepts for quench protection and the magnet cryosystems are also briefly discussed to confirm the viability of the proposed design.

Vladimir Kashikhin et al.

2003-06-09

399

Quadrupole interaction of technetium-99 nuclei in polycrystalline KTcO/sub 4/  

SciTech Connect

A polycrystalline KTcO/sub 4/ specimen was studied by /sup 99/Tc NMR in the temperature range of -50 to 200/sup 0/C to determine the value of the quadrupole interaction of the nuclei in a weakly distorted tetrahedron. Analysis of the results shows that the quadrupole-coupling constant remains constant within the limits of experimental error over the whole temperature range.

Tarasov, V.P.; Privalov, V.I.; Petrushin, S.A.; Kirakosyan, G.A.; Kryuchov, S.V.; German, K.E.; Buslaev, Yu.A.

1983-10-01

400

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

401

Relativistic Quadrupole Polarizability for the Ground State of Hydrogen-Like Ions  

NASA Astrophysics Data System (ADS)

The static quadrupole polarizabilities for hydrogen-like ions from Z = 1 to Z = 100 in the 1S1/2 ground state are calculated to high precision by solving the Dirac equation using the B-spline Galerkin method. The results are consistent with the expression of Kaneko [J. Phys. B 10 (1977) 3347] at low Z. The quadrupole oscillator strength sum ?nf(2)gn is computed to be zero to a very high degree of precision.

Zhang, Yong-Hu; Tang, Li-Yan; Zhang, Xian-Zhou; Shi, Ting-Yun; Jim, Mitroy

2012-06-01

402

Compact IR Quadrupoles for Linear Colliders Based on Rutherford-type Cable  

SciTech Connect

The upcoming and disrupted beams in the interaction region (IR) of a linear collider are focused by doublets consisting of two small-aperture superconducting quadrupoles. These magnets need an effective compact magnetic shielding to minimize magnetic coupling between the two channels and sufficient temperature margin to withstand radiation-induced heat depositions in the coil. This paper presents conceptual designs of IR quadrupoles for linear colliders based on NbTi and Nb{sub 3}Sn Rutherford-type cables.

Lopes, M.L.; Kashikhin, V.S.; Kashikhin, V.V.; Zlobin, A.V.; /Fermilab

2008-08-01

403

Global investigation of the fine structure of the isoscalar giant quadrupole resonance  

Microsoft Academic Search

Fine structure in the region of the isoscalar giant quadrupole resonance (ISGQR) in Ni, Y, °Zr, ¹²°Sn, ¹Er, and ²°Pb has been observed in high-energy-resolution (E35-50 keV) inelastic proton scattering measurements at E=200 MeV at iThemba LABS. Calculations of the corresponding quadrupole excitation strength functions performed within models based on the random-phase approximation (RPA) reveal similar fine structure when the

A. Shevchenko; O. Burda; Y. Kalmykov; P. von Neumann-Cosel; V. Yu. Ponomarev; A. Richter; J. Wambach; J. Carter; E. Sideras-Haddad; G. R. J. Cooper; R. W. Fearick; S. V. Foertsch; J. J. Lawrie; R. Neveling; F. D. Smit; H. Fujita; Y. Fujita; D. Lacroix

2009-01-01

404

The application of quadrupole mass filters in field desorption mass spectrometry.  

PubMed

The advantages and limitations which quadrupole mass filters afford to the field desorption technique with respect to use for routine work are discussed and experimentally confirmed by the analyses of some drugs using a field desorption quadrupole mass spectrometer. The possibility of fast identification of drug intoxication is demonstrated by the analysis of the chloroform extract of urine in a case of overdose of hypnotics. PMID:1131391

Gierlich, H H; Heinen, H J; Beckey, H D

1975-02-01

405

Manufacturing and Test of a Short Quadrupole Magnet Model at CEA\\/Saclay  

Microsoft Academic Search

IRFU\\/SACM at CEA\\/Saclay has undertaken an R&D program on Nb3Sn aimed at designing, building and testing a 1-m-long, 56-mm-single-aperture quadrupole magnet model. Model design is based on the design of LHC arc quadrupole magnets, without iron yoke. It is expected to reach a nominal field gradient of 211 T\\/m at 11,870 A. The main goal of the program is to

Lionel Quettier; Maria Durante; Michel Segreti; Fabrice Simon; Didier Leboeuf; Yannick Le Noa

2009-01-01

406

Three-dimensional profiling with the Sandia nuclear microprobe  

Microsoft Academic Search

A nuclear microprobe analysis system attached to Sandia's EN tandem Van de Graaff accelerator is described. A magnetic quadrupole doublet lens is used for the final focus and 2 ..mu..m beam diameters have been obtained. Several illustrative applications of the microprobe, including the first three-dimensional concentration profiles using Rutherford backscattering and elastic recoil detection ever measured, are given.

B. L. Doyle; N. D. Wing

1983-01-01

407

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

408

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 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

409

Two Alternate High Gradient Quadrupoles; An Upgraded Tevatron IR and A"Pipe" Design  

SciTech Connect

With the U.S. cancellation of the SSC project, the only large approved hadron accelerator project is CERN's LHC. One of the more critical elements in the performance of a collider is the quadrupole lens at the beam collision points. These quadrupoles, usually referred to as the 'insertion quads' normally form a set of triplets around the interaction region. Their focal power directly affects the luminosity available at the crossing point In order to achieve as high a gradient as possible, the CERN design team has proposed a very efficient high gradient quadrupole which is based on a graded four-layer winding structure. At Fermilab's Tevatron, an upgraded two layer winding quadrupole has been in operation since 1989, and has provided a 50% higher gradient than its predecessor. The quadrupole was basically state of the art when it was designed in 1985. Since then however, improvements have been made in cabling, conductor perfonnance, etc. Naturally, operation of a modernized version of this .design can provide higher capabilities. This improved two layer design can serve as an alternative to the more intricate graded four layer design now envisioned for the LHC, provided it can obtain the proposed gradient. A high gradient quadrupole with a 'pipe' layout can be considered as a possible candidate for future large collider insertion regions. It is possible to fine-tune the design to obtain a good field-quality, the conductor is well cooled in case of a large radiation heat load, and the overall structure is smaller than a conventional quadrupole with a comparable field gradient.

McInturff, A.D.; Oort, J.M. van; Scanlan, R.M.

1995-04-01

410

Note on the electric quadrupole absorption in the nuclear photo-reaction  

Microsoft Academic Search

Summary  The behavior of the EQ absorption cross section in the « Giant resonance » region is discussed through the analysis of the\\u000a angular distributions of emitted particles by using the direct interaction model. The difference between proton’s and neutron’s\\u000a angular distributions is attributed to the difference between the effective charges of the proton and the neutron for EQ radiation.\\u000a The

S. Fujii; O. Sugimoto

1959-01-01

411

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

412

Design and testing of a low impedance transceiver circuit for nitrogen-14 nuclear quadrupole resonance.  

PubMed

A low impedance transceiver circuit consisting of a transmit-receive switch circuit, a class-D amplifier and a transimpedance amplifier (TIA) was newly designed and tested for a nitrogen-14 NQR. An NQR signal at 1.37MHz from imidazole was successfully observed with the dead time of ~85µs under the high Q transmission (Q~120) and reception (Q~140). The noise performance of the low impedance TIA with an NQR probe was comparable with a commercial low noise 50? amplifier (voltage input noise: 0.25 nV/Hz) which was also connected to the probe. The protection voltage for the pre-amplifier using the low impedance transceiver was ~10 times smaller than that for the pre-amplifier using a 50? conventional transceiver, which is suitable for NQR remote sensing applications. PMID:25293696

Sato-Akaba, Hideo

2014-01-01

413

?-detected nuclear quadrupole resonance and relaxation of 8Li+ in sapphire  

NASA Astrophysics Data System (ADS)

We report detailed behaviour of low energy 8Li implanted near the surface of ?- Al2O3 single crystal, as revealed by beta-detected NQR of 8Li. We find that the implanted 8Li occupies at least two sites with non-cubic symmetry in the Al2O3 lattice. In both sites the 8Li experiences axially symmetric electric field gradient, with the main principal axis along the c-crystallographic direction. The temperature and field dependence of the spin lattice relaxation of 8Li in ?-Al2O3, indicate that the 8Li diffusion is negligible on the scale of its lifetime, 1.21 s.

Salman, Z.; Chow, K. H.; Hossain, M. D.; Kiefl, R. F.; Levy, C. D. P.; Parolin, T. J.; Pearson, M. R.; Saadaoui, H.; Wang, D.; MacFarlane, W. A.

2014-12-01

414

Nuclear Double Irradiation in Sodium Bromate  

Microsoft Academic Search

Two different frequency magnetic resonance transitions involving a common energy level are observed simultaneously using the Br79 nuclear quadrupole energy levels split by a magnetic field of 7000 G. Irradiation of different transitions with frequencies near 180 Mc\\/sec may enhance the absorption of a transition near 14 Mc\\/sec, or produce population inversion enabling observation of a stimulated emission at the

J. W. Doane; R. A. Hultsch

1964-01-01

415

Design of large aperture superferric quadrupole magnets for an in-flight fragment separator  

SciTech Connect

Superferric quadrupole magnets to be used for in-flight fragment separator have been designed. A quadrupole magnet triplet for beam focusing is placed in a cryostat together with superconducting correction coils. To maximize acceptance of rare isotope beams produced by projectile fragmentation, it is essential to use large-aperture quadrupole magnets. The pole tip radius is 17 cm in the current design, and we tried to enlarge the aperture with 3D analysis on magnetic fields. In the front end of the separator, where a target and beam dump are located, we plan to use two sets of quadrupole triplets made of high-Tc superconductor (HTS) operating at 20-50 K considering high radiation heat load. The HTS magnet will use warm iron poles. Both low-Tc and high-Tc superconductors are acquired for test winding, and two kinds of dewar and cryostat are under construction to perform the coil and magnet tests. The magnetic design of superferric quadrupole is mainly discussed.

Zaghloul, Aziz; Kim, Dogyun; Kim, Jangyoul; Kim, Mijung; Kim, Myeongjin; Yun, Chongcheoul; Kim, Jongwon [Rare Isotope Science Project, Institute for Basic Science, Yuseong, Daejeon, 305-811 (Korea, Republic of)

2014-01-29

416

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

417

On the electron scattering and dephasing by the nuclear spins  

Microsoft Academic Search

We show that scattering of the conduction electrons by nuclear spins via the\\u000ahyperfine interaction may lead the upper limit on the mean free path in clean\\u000ametals. Nuclear spins with s >1\\/2 may cause a strong dephasing in dirty limit\\u000adue to the quadrupole coupling to the random potential fluctuations caused by\\u000astatic impurities and lattice imperfections.

A. M. Dyugaev; I. D. Vagner; P. Wyder

2000-01-01

418

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

419

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

420

Modal analysis of AC quadrupole magnet system for CSNS/RCS  

NASA Astrophysics Data System (ADS)

The quadrupole magnet of the China Spallation Neutron Source (CSNS) Rapid-cycling Synchrotron (RCS) is operated at a 25 Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the quadrupole magnet. By taking the quadrupole magnet and girder as specific model system, a method for analyzing and studying the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. The theoretical modal analysis results coincide with the experimental testing results. It shows that the dynamic characteristic parameters of the structure can be obtained by modal analysis which will provide a theoretical basis for the further study and the magnet girder optimal design of CSNS/RCS.

Liu, Ren-Hong; Qu, Hua-Min; Kang, Ling; Zhang, Jun-Song; Wang, Hai-Jing

2013-08-01

421

Magnetic and Mechanical Analysis of the HQ Model Quadrupole Designs for LARP  

SciTech Connect

Insertion quadrupoles with large bore and high gradient are required to upgrade the luminosity of the Large Hadron Collider (LHC). The US LHC Accelerator Research Program is developing Nb{sub 3}Sn technology for the upgrade. This effort includes a series of 1 m long Technology Quadrupoles (TQ), to demonstrate the reproducibility at moderate field, and High-gradient Quadrupoles (HQ) to explore the magnet performance limits in terms of peak fields, forces and stresses. The HQ models are expected to achieve peak fields of 15 T or higher. A coil aperture of 90 mm, corresponding to gradients above 300 T/m, was chosen as the baseline. Peak stresses above 150 MPa are expected. Progress on the magnetic and mechanical design of the HQ models will be reported.

Felice, Helene; Caspi, Shlomo; Ferracin, Paolo; Kashikhin, Vadim; Novitski, Igor; Sabbi, GianLuca; Zlobin, Alexander

2008-06-01

422

Design of Normal-conducting Quadrupole Magnets for Linac4 at CERN  

E-print Network

Linac4 is the first element of the LHC Injectors Upgrade Project and will replace the existing Linac2 as linear injector of protons for the CERN accelerators. A new transfer line will link Linac4 to the Proton Synchrotron Booster (PSB). Approximately hundred normal-conducting electro-magnets are required for beam steering and focusing along the linac and the transfer line. This text concentrates on the design of the Linac4 quadrupole magnets. The design and the first magnetic measurements of the inter-tank quadrupole electro-magnets are discussed. In addition, the design and optimization of the transfer line quadrupole magnets are highlighted. The compatibility of the magnetic requirements and the power converter constraints for the latter magnet type is assessed.

Vanherpe, L; Vorozhtsov, A; Zickler, T; 10.1109/TASC.2013.2282302

2014-01-01

423

Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport  

SciTech Connect

The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam.

Molvik, A.W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F.; Friedman, A.; Roy, P.K.; Seidl, P.; Lund, S.M.; Faltens, A.; Vay, J.L.; Prost, L.

2007-06-04

424

Arene-cation interactions of positive quadrupole moment aromatics and arene-anion interactions of negative quadrupole moment aromatics.  

PubMed

Intermolecular interactions involving aromatic pi-electron density are widely believed to be governed by the aromatic molecular quadrupole moment, Theta(zz). Arene-cation binding is believed to occur primarily with negative Theta(zz) aromatics, and arene-anion binding is believed to occur largely with positive Theta(zz) aromatics. We have performed quantum mechanical computations that show the cation binding of positive Theta(zz) aromatics and the anion binding of negative Theta(zz) aromatics is quite common in the gas phase. The pi-electron density of hexafluorobenzene, the prototypical positive Theta(zz ) aromatic (experimental Theta(zz) = 9.5 +/- 0.5 DA), has a Li+ binding enthalpy of -4.37 kcal/mol at the MP2(full)/6-311G**level of theory. The RHF/6-311G** calculated Theta(zz) value of 1,4-dicyanobenzene is +11.81 DA, yet it has an MP2(full)/6-311G** Li+ binding enthalpy of -12.65 kcal/mol and a Na+ binding enthalpy of -3.72 kcal/mol. The pi-electron density of benzene, the prototypical negative Theta(zz) aromatic (experimental Theta(zz) = -8.7 +/- 0.5 DA), has a F- binding enthalpy of -5.51 kcal/mol. The RHF/6-311G** calculated Theta(zz) of C6H2I4 is -10.45 DA, yet it has an MP2(full)/6-311++G** calculated F- binding enthalpy of -20.13 kcal/mol. Our results show that as the aromatic Theta(zz) value increases the cation binding enthalpy decreases; a plot of cation binding enthalpies versus aromatic Theta(zz) gives a line of best of fit with R2 = 0.778. No such correlation exists between the aromatic Theta(zz) value and the anion binding enthalpy; the line of best fit has R2 = 0.297. These results are discussed in terms of electrostatic and polarizability contributions to the overall binding enthalpies. PMID:17107123

Clements, Aimee; Lewis, Michael

2006-11-23

425

Electromagnetic properties of 100Mo: Experimental results and theoretical description of quadrupole degrees of freedom  

NASA Astrophysics Data System (ADS)

The Coulomb excitation experiment to study electromagnetic properties of the heaviest stable Mo isotope, 100Mo, was performed using a 76 MeV 32S beam from the Warsaw cyclotron U-200P. Magnitudes and relative signs of 26 E1, E2, E3, and M1 matrix elements coupling nine low-lying states in 100Mo were determined using the least-squares code gosia. Diagonal matrix elements (related to the spectroscopic quadrupole moments) of the 21+, 22+, and 23+ states as well as the 41+ state were extracted. The resulting set of reduced E2 matrix elements was complete and precise enough to obtain, using the quadrupole sum rules approach, quadrupole deformation parameters of 100Mo in its two lowest 0+ states: ground and excited. The overall deformation of the 01+ and 02+ states in 100Mo is of similar magnitude, in both cases larger compared to what was found for the neighboring isotopes 96Mo and 98Mo. At the same time, the asymetry parameters obtained for both states strongly differ, indicating a triaxial shape of the 100Mo nucleus in the ground state and a prolate shape in the excited 0+ state. Low-energy quadrupole excitations of the 100Mo nucleus were studied in the frame of the general quadrupole collective Bohr Hamiltonian model (GBH). The potential energy and inertial functions were calculated using the adiabatic time-dependent Hartree-Fock-Bogoliubov (ATDHFB) method starting from two possible variants of the Skyrme effective interaction: SIII and Sly4. The overall quadrupole deformation parameters resulting from the GBH calculations with the SLy4 variant of the Skyrme interaction are slightly closer to the experimentally obtained values than those obtained using SIII.

Wrzosek-Lipska, K.; Próchniak, L.; Zieli?ska, M.; Srebrny, J.; Hady?ska-Kl?k, K.; Iwanicki, J.; Kisieli?ski, M.; Kowalczyk, M.; Napiorkowski, P. J.; Pi?tak, D.; Czosnyka, T.

2012-12-01

426

Dipole and quadrupole excitations in 88Sr up to 6.8 MeV  

NASA Astrophysics Data System (ADS)

Dipole and quadrupole excitations in the semimagic N=50 nucleus 88Sr were investigated at the superconducting Darmstadt electron linear accelerator S-DALINAC with bremsstrahlung of an end-point energy of 6.8 MeV . Many new dipole excitations could be identified, and their reduced excitation probabilities were determined. The experimental findings are discussed in the context of quasiparticle-phonon-model and shell-model calculations. A breaking of the N=50 core is essential to describe the structure of the observed excitations. The two-phonon quadrupole-octupole J? = 1- state exhibits unusual features which are presently not understood.

Käubler, L.; Schnare, H.; Schwengner, R.; Prade, H.; Dönau, F.; von Brentano, P.; Eberth, J.; Enders, J.; Fitzler, A.; Fransen, C.; Grinberg, M.; Herzberg, R.-D.; Kaiser, H.; von Neumann-Cosel, P.; Pietralla, N.; Richter, A.; Rusev, G.; Stoyanov, Ch.; Wiedenhöver, I.

2004-12-01

427

Global investigation of the fine structure of the isoscalar giant quadrupole resonance  

Microsoft Academic Search

Fine structure in the region of the isoscalar giant quadrupole resonance (ISGQR) in Ni58, Y89, Zr90, Sn120, Er166, and Pb208 has been observed in high-energy-resolution (DeltaE1\\/2~=35-50 keV) inelastic proton scattering measurements at E0=200 MeV at iThemba LABS. Calculations of the corresponding quadrupole excitation strength functions performed within models based on the random-phase approximation (RPA) reveal similar fine structure when the

A. Shevchenko; O. Burda; J. Carter; G. R. J. Cooper; R. W. Fearick; S. V. Förtsch; H. Fujita; Y. Fujita; Y. Kalmykov; D. Lacroix; J. J. Lawrie; P. von Neumann-Cosel; R. Neveling; V. Yu. Ponomarev; A. Richter; E. Sideras-Haddad; F. D. Smit; J. Wambach

2009-01-01

428

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

429

arXiv:astro-ph/0406496v122Jun2004 A Low CMB Quadrupole from Dark Energy Isocurvature Perturbations  

E-print Network

arXiv:astro-ph/0406496v122Jun2004 A Low CMB Quadrupole from Dark Energy Isocurvature Perturbations, Chicago IL 60637 We explicate the origin of the temperature quadrupole in the adiabatic dark energy model and explore the mechanism by which scale invariant isocurvature dark energy perturbations can lead to its

Hu, Wayne

430

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

431

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

432

The Department of PhysicsPRESENTS Nuclear Physics & Society  

E-print Network

The Department of PhysicsPRESENTS Nuclear Physics & Society A free, four-day short course on nuclear physics and public policy for anyone who wants to better understand nuclear power nuclear weapons P.M. Applications of Nuclear Physics on Earth: Nuclear power, weapons, and nuclear medicine. Topics

Gilfoyle, Jerry

433

Students' Understanding of Tides.  

ERIC Educational Resources Information Center

Reports the findings of research into students' understanding of tides. Students from secondary school and pre-service primary school teacher trainees were chosen as subjects and their understanding was assessed by questionnaire. (Author/CCM)

Viiri, Jouni

2000-01-01

434

Video Understanding Francois BREMOND  

E-print Network

Video Understanding Francois BREMOND Orion team, INRIA Sophia Antipolis FRANCE Key words of video sequences video understanding= from people detection and tracking to behavior recognition (fighting) of crowds (overcrowding) interactions of people and vehicles (aircraft refueling) Video

Prié, Yannick

435

Nuclear magnetic double resonance based on strong rf magnetic-field-induced coupling between spin systems  

Microsoft Academic Search

The origin of the rf magnetic-field-induced coupling between spin systems is discussed. A new nuclear-double-resonance technique employing this coupling is proposed, which has particular value in measuring pure nuclear-quadrupole-resonance spectra of integer-spin nuclei by nuclear double resonance. The sensitivity of the new technique is discussed for the case of 1H-14N double resonance in zero static magnetic field, as well as

J. Seliger; R. Blinc; M. Mali; R. Osredkar; A. Prelesnik

1975-01-01

436

39K Nuclear Magnetic Resonance in KMnF3 and Temperature Dependence of the Generalized Order Parameter at the Structural Phase Transition  

Microsoft Academic Search

The 39K nuclear-magnetic-resonance spectrum in KMnF3 single crystal displays, below the structural phase transition at 186 °K, a second-order quadrupole shift of the central line superimposed to the magnetic hyperfine shift. From the analysis of the data the value of the quadrupole coupling constant below TC is derived and is shown to be proportional to the square of the rotational

F. Borsa

1973-01-01

437

Magnetic design of large-bore superconducting quadrupoles for the AHF  

Microsoft Academic Search

The Advanced Hydrotest Facility (AHF), under study by LANL, utilizes large bore superconducting quadrupole magnets to image protons for radiography of fast events. In this concept, 50-GeV proton bunches pass through a thick object and are imaged by a lens system that analyzes the scattered beam to determine object details. Twelve simultaneous views of the object are obtained using multiple

Vladimir S Kashikhin; P. L. Walstrom; N. Andreev; P. J. Limon; V. V. Kashikhin; J. Tompkins

2002-01-01

438

Cyclotron-resonance maser in a periodically loaded quadrupole transmission line Y. Leibovitch and E. Jerby*  

E-print Network

Cyclotron-resonance maser in a periodically loaded quadrupole transmission line Y. Leibovitch and E; revised manuscript received 17 February 1999 A cyclotron-resonance maser CRM is implemented in a periodic, 84.40.Ik, 84.47. w I. INTRODUCTION Cyclotron-resonance masers CRMs and gyrotrons are known as high

Jerby, Eli

439

Magnetic quadrupole formation of elliptical sheet electron beams for high-power microwave devices  

Microsoft Academic Search

Sheet electron beams are attractive for high-power microwave sources due to their ability to transport high current, at reduced current density, through thin clearance apertures and in close proximity to walls or RF structures. This paper reports on the theoretical investigation of magnetic quadrupole formation of elliptical sheet electron beams for use in high-power microwave devices. The beam envelope equations

M. A. Basten; J. H. Booske; J. Anderson

1994-01-01

440

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

E-print Network

Measurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural method for lithium isotope ratio (7 Li/6 Li) determinations with low total lithium consumption ( lithium from all matrix elements using small volume resin (2 ml/3.4 meq AG 50W-X8) and low volume elution

Weston, Ken

441

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

442

Dipole and electric quadrupole excitations in 32S up to 9.9 MeV  

NASA Astrophysics Data System (ADS)

Real photon scattering experiments have been performed on the N=Z nucleus 32S to investigate energies and absolute strengths of dipole and electric quadrupole excitations up to a maximum energy of Ex=9.9 MeV. Evidence for a 2+?3- two-phonon state, which is well established in heavier nuclei, is discussed.

Babilon, M.; Hartmann, T.; Mohr, P.; Vogt, K.; Volz, S.; Zilges, A.

2002-03-01

443

Scheme to funnel ion beams with a radio-frequency quadrupole  

SciTech Connect

We describe a proposed method to funnel ion beams using a new form of the radio-frequency quadrupole (RFQ) structure. This RFQ accepts two bunched ion beams and combines them into a single final beam with interlaced microstructure pulses. It also provides uninterrupted periodic transverse focusing to facilitate the funneling of beams with high current and low emittance.

Stokes, R.H.; Minerbo, G.N.

1985-01-01

444

Calibration of electromagnetic calorimeters in high energy experiments with a Radio Frequency Quadrupole accelerator  

Microsoft Academic Search

A fast, effective calibration technique has been developed for future Superconducting Supercollider (SSC) calorimeters based upon the radiative capture of protons from a pulsed Radio Frequency Quadrupole (RFQ) accelerator in a fluoride target. The intense flux of low energy photons acts as a clean ``pulse generator'' calibration signal equivalent to 20 GeV or more. This calibration technique has been demonstrated

H. Ma; H. Newman; R. Y. Zhu; R. Hamm

1989-01-01

445

Correlation between y-Type Ions Observed in Ion Trap and Triple Quadrupole Mass Spectrometers  

PubMed Central

Multiple reaction monitoring mass spectrometry (MRM-MS) is a technique for high-sensitivity targeted analysis. In proteomics, MRM-MS can be used to monitor and quantify a peptide based on the production of expected fragment peaks from the selected peptide precursor ion. The choice of which fragment ions to monitor in order to achieve maximum sensitivity in MRM-MS can potentially be guided by existing MS/MS spectra. However, because the majority of discovery experiments are performed on ion trap platforms, there is concern in the field regarding the generalizability of these spectra to MRM-MS on a triple quadrupole instrument. In light of this concern, many operators perform an optimization step to determine the most intense fragments for a target peptide on a triple quadrupole mass spectrometer. We have addressed this issue by targeting, on a triple quadrupole, the top six y-ion peaks from ion trap-derived consensus library spectra for 258 doubly charged peptides from three different sample sets and quantifying the observed elution curves. This analysis revealed a strong correlation between the y-ion peak rank order and relative intensity across platforms. This suggests that y-type ions obtained from ion trap-based library spectra are well-suited for generating MRM-MS assays for triple quadrupoles and that optimization is not required for each target peptide. PMID:19603825

Sherwood, Carly A.; Eastham, Ashley; Lee, Lik Wee; Risler, Jenni; Vitek, Olga; Martin, Daniel B.

2009-01-01

446

Doppler effects due to thermal macromotion of ions in an rf quadrupole trap  

Microsoft Academic Search

The second-order Doppler shift is an important source of systematic error in rf quadrupole trapped ion frequency standards. This shift can be reduced by cooling the secular motion of the ion cloud with a light background gas at low pressure. Using a thermalized ion cloud model, it is possible to relate the Doppler shift to the temperature of the ion

L. S. Cutler; C. A. Flory; R. P. Giffard; M. D. McGuire

1986-01-01

447

Development of Radiation Resistant Quadrupoles Based on High Temperature Superconductors for the Fragment Separator  

Microsoft Academic Search

A very high radiation dose on the quadrupole magnets in RIA's fragment separator makes them as one of the most challenging element in the RIA proposal. To overcome this problem, a new design is proposed that reduces both radiation dose and heat load by an order of magnitude. The proposed warm iron design will use commercially available High Temperature Superconductor

R. Gupta; M. Harrison; A. Zeller

448

Electric quadrupole moment of graphene and its effect on intermolecular interactions.  

PubMed

Carbon atoms in aromatic compounds exhibit a permanent electric quadrupole moment due to the aromatic ? electron distribution. In the case of small aromatic hydrocarbons, this quadrupole contributes significantly to their intermolecular interactions, but when the honeycomb lattice is expanded to infinity, the quadrupolar field sums to zero and its significance vanishes. Therefore, electrostatic interactions with graphene are often omitted in force field molecular modeling. However, for a finite sheet, the electrostatic field decays only slowly with increasing size and is always non-negligible near edges. In addition, in a corrugated graphene sheet, the electrostatic field near the surface does not vanish completely and remains sizeable. In the present study, we investigated the magnitude of the graphene quadrupolar field as a function of model size and graphene corrugation, and estimated the error resulting from its neglect in molecular dynamics simulations. Exfoliation energies in benzene and hexafluorobenzene were calculated using the potential of mean force method with and without explicit quadrupoles. The effect on exfoliation energies was found to be quite small. However, the quadrupole moment may be important for graphene sheet association (aggregation) as it affects barrier heights, and consequently kinetics of association. Our results indicate that quadrupolar interactions may need to be considered in molecular modeling when graphene is corrugated or bent. PMID:24407154

Kocman, Mikuláš; Pykal, Martin; Jure?ka, Petr

2014-02-21

449

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

450

Temperature dependence of 23Na NMR quadrupole parameters and spin-lattice relaxation rate in NaNO 2 powder  

NASA Astrophysics Data System (ADS)

The nuclear quadrupole coupling constant (e 2qQ/h) and the spin-lattice relaxation rate (1/ T1) of 23Na NMR in the NaNO 2 powder were investigated by employing a magic angle spinning probe and a wideline probe, respectively, at 9.4 T as a function of temperature ( T) in the range of 300-458 K. The linearity between e 2qQ/h and the squared spontaneous polarization ( Ps2) was obeyed up to near the critical temperature ( Tc=437 K), which is consistent with the previous reports. Moreover, the asymmetry parameter ( ?) at 23Na site is found to be linear with Ps, firstly noticed in this work. The linearity between ln[(1/ T1) reo/(1- Ps2)(1- Ps)] and 1/ T is found to be satisfied up to near the Tc, where (1/ T1) reo is the relaxation rate for the reorientational motion of the NO 2-. From this linearity, the reorientational motion of NO 2- ion in powder samples is found to have an activation energy, ? U=0.22±0.01 eV, which is in good agreement with the value obtained with single crystals.

Jung, J. K.; Han, O. H.; Choh, S. H.

1999-05-01

451

Index to the Understanding the Atom Series.  

ERIC Educational Resources Information Center

This index was prepared for the set of 51 booklets in the "Understanding the Atom Series" published by the U. S. Atomic Energy Commission for high school students and their teachers. In addition to the index, a complete list of the series is provided in which the booklets are grouped into the categories of physics, chemistry, biology, nuclear…

Atomic Energy Commission, Oak Ridge, TN. Div. of Technical Information.

452

Atomic Energy Basics, Understanding the Atom Series.  

ERIC Educational Resources Information Center

This booklet is part of the "Understanding the Atom Series," though it is a later edition and not included in the original set of 51 booklets. A basic survey of the principles of nuclear energy and most important applications are provided. These major topics are examined: matter has molecules and atoms, the atom has electrons, the nucleus,…

Atomic Energy Commission, Oak Ridge, TN. Div. of Technical Information.

453

Consideration of nuclear policy  

Microsoft Academic Search

As an American psychologist who has been overseas since February 1961, it has been interesting to note some reactions to United States nuclear policies and programs. It is quite apparent that our national image has suffered under continued nuclear testing and that fear, and some hysteria, have been widespread. The negative psychology which is evident is understandable and obviously not

Robert E. Valett

1962-01-01

454

The magnetic properties of the SLC intersection region superconducting quadrupole triplets  

SciTech Connect

The measured magnetic field parameters of the quadrupoles which comprise the final triplet lens system for the SLAC Linear Collider intersection region are presented here. The minimum design gradient specifications for these quadrupoles are 1.7T/cm at 4.6K and 1.6T/cm at 4.6K in a 0.6T external solenoidal field. These gradients are about three times larger than those available with the conventional iron/copper quadrupoles now used in the SLC. Superconducting quadrupoles of two lengths have been specified for the SLC triplets. The effective magnetic length of type Q/sub 1/ is 66.498 +- 0.305cm and of Q/sub 2/ is 121.106 +- 0.61cm. The superconducting performance characteristics of the quadrupoles that have been measured are: maximum critical current as a function of bath temperature, rate of change of magnetic field, and as a percentage of the ''short sample''. ''Short sample'' performance is defined as the current reached by the cable in a perpendicular magnetic field equal to the peak field in the winding at bath temperature. The maximum gradient achieved during testing was 2.04T/cm (4.25K) and 2.07T/cm (3.2K). This represented 95% of the strand critical current value. The magnetic length of the first Q/sub 2/ was measured to be 120.85 +- .1 cm. The Fourier harmonic coefficients of the magnetic field were measured as a function of current and are reported. 3 refs., 5 figs., 7 tabs.

McInturff, A.D.; Carson, J.A.; Fisk, H.E.; Erickson, R.A.

1987-09-25

455

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

456

Nuclear magnetic resonance (nmr) studies on alkali-metal atoms adsorbed on a W(110) surface  

NASA Astrophysics Data System (ADS)

The nuclear quadrupole interaction of nuclear spin polarized alkali-metal atoms ( 6Li, 7Li, 23Na) adsorbed on a clean and oxygen covered W(110) surface was studied by NMR experiments. The NMR signal was deduced from the change of nuclear polarization of desorbing ions due to a radio frequency field. Additionally energy splittings of nuclear states in an external magnetic field were found arising from the interaction of nuclear quadrupole moments with electric field gradients. Positive and negative values of the electric field gradient in the range of 10 15 to 5 × 10 16 V/cm 2 were measured. They depend on the surface temperature. The structure of the surface allows an asymmetry of the electric field gradient tensor which could be measured as well. The electric field gradient is caused by the electronic charge distribution in the vicinity of the absorbed alkali-metal atoms. A simple model which describes qualitatively the results is proposed.

Koch, E.; Horn, B.; Fick, D.

1986-08-01

457

Understanding the Carbon Cycle  

NSDL National Science Digital Library

In this unit, students use Internet resources, slide presentations, and modeling to explain how understanding the carbon cycle helps scientists understand and prepare for global climate change, what might happen if sources of carbon produced more than sinks could remove, and what might happen if sinks absorbed more than sources produced. They should understand how the carbon cycle affects various life forms and the role that carbon plays in their lives. Procedures, a glossary, assessments, and scoring rubrics are provided.

458

Profiling the metabolism of astragaloside IV by ultra performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry.  

PubMed

Astragaloside IV is a compound isolated from the Traditional Chinese Medicine Astragalus membranaceus, that has been reported to have bioactivities against cardiovascular disease and kidney disease. There is limited information on the metabolism of astragaloside IV, which impedes comprehension of its biological actions and pharmacology. In the present study, an ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS)-based approach was developed to profile the metabolites of astragaloside IV in rat plasma, bile, urine and feces samples. Twenty-two major metabolites were detected. The major components found in plasma, bile, urine and feces included the parent chemical and phases I and II metabolites. The major metabolic reactions of astragaloside IV were hydrolysis, glucuronidation, sulfation and dehydrogenation. These results will help to improve understanding the metabolism and reveal the biotransformation profiling of astragaloside IV in vivo. The metabolic information obtained from our study will guide studies into the pharmacological activity and clinical safety of astragaloside IV. PMID:25407723

Cheng, Xu-Dong; Wei, Ming-Gang

2014-01-01

459

Teaching for Understanding.  

ERIC Educational Resources Information Center

Provides a chart comparing state and national objectives. Assesses student understanding of photosynthesis and explains the process of teaching students producer-consumer relationships. (Contains 14 references.) (YDS)

Smith, Deborah C.; Wesley, Ann

2000-01-01

460

Design and construction of a 1 m model of the low current superconducting quadrupole for the LHC insertions  

E-print Network

About one hundred individually powered low current superconducting quadrupoles will be installed in the LHC insertions. One of the design requirements was to keep the excitation current of the magnet below 6 kA in view of minimizing the costs of the powering circuits. The design of the quadrupole is based on a 8.2 mm NbTi cable, and is designed for a nominal gradient of 200 T/m at 1.9 K. In this paper we present the design of the quadrupole and discuss the construction details of the 1 m single aperture model which has been recently completed.

Kirby, G A; Ostojic, R; Rodríguez-Mateos, F; Krischel, D; Schillo, M

2000-01-01

461

Understanding Solubility and Density  

NSDL National Science Digital Library

Understanding Solubility and Density is a graduate-level professional development course designed to enhance your understanding and teaching of physical science. In two sessions, you will investigate physical science topics using hands-on activities and online resources including video segments, interactive activities, readings, and other multimedia materials. These resources are drawn from Teachers' Domain, WGBH's digital library service.

2010-01-01

462

Understanding Arizona's Riparian Areas  

E-print Network

Understanding Arizona's Riparian Areas AZ 1432 August 2007 #12;ContaCt: GeorGe Zaimes Assistant and activities. #12;i Understanding Arizona's Riparian Areas Editor: George Zaimes Funding provided. Sprinkle). #12;ii CONTENTS CHAPTER 1 Defining Arizona's Riparian Areas and their Importance

Crimmins, Michael A.

463

Understanding the Heartbeat  

ERIC Educational Resources Information Center

Rather than speak from a place of authoritative knowing on Aboriginal matters, why not work from a place of wondering and invite our students to learn with us in gaining a deeper understanding of First Nations perspective? Two teachers from Rockridge Secondary School in West Vancouver did just that. One afternoon a new understanding of the…

Olson, Jennifer; Selzer, Jessica

2012-01-01

464

Parrot "Understands" Zero  

ERIC Educational Resources Information Center

The walnut sized brain of the African grey parrot may actually be capable of comprehending abstract mathematical concepts. The bird seems to understand a numerical concept akin to zero--an abstract notion that humans don't typically understand until they are three or four years old. Alex, the 28-year-old parrot who lives in a Brandeis University…

Journal of College Science Teaching, 2005

2005-01-01

465

Understanding Genetics of Deafness  

E-print Network

of their parents are affected. This deafness can also be passed on to future generations. Genetic tests canUnderstanding the Genetics of Deafness A Guide for Patients and Families Harvard Medical School Center For Hereditary Deafness #12;Understanding the Genetics of Deafness A Guide for Patients

Goodrich, Lisa V.

466

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

467

Geophysical applications of nuclear resonant spectroscopy Wolfgang Sturhahn and Jennifer M. Jackson*  

E-print Network

and electronic environment like isomer shifts, quadrupole splittings, and magnetic fields, which provide important information on valence, spin state, and magnetic ordering. Both methods use a nuclear resonant composition, the elastic and transport properties, and the thermodynamic pa- rameters of materials identified

Jackson, Jennifer M.

468

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

469

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

NASA Astrophysics Data System (ADS)

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 (˜10-5 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+, 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.

2011-05-01

470

Core polarization for the electric quadrupole moment of neutron-rich Aluminum isotopes  

E-print Network

The core polarization effect for the electric quadrupole moment of the neutron-rich $^{31}$Al, $^{33}$Al and $^{35}$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 approximation are used to calculate the single-quasiparticle wave functions and the excitation modes. It is found that the polarization charge for the proton $1d_{5/2}$ hole state in $^{33}$Al is quite sensitive to coupling to the neutrons in the $pf$-shell associated with the pairing correlations, and that the polarization charge in $^{35}$Al becomes larger due to the stronger collectivity of the low-lying quadrupole vibrational mode in the neighboring $^{36}$Si nucleus.

Kenichi Yoshida

2009-02-18

471

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

472

Quench performance of superconducting quadrupole magnets for the new Fermilab low beta insertion  

SciTech Connect

Construction and testing of the components for the new Tevatron D0/B0 low beta insertion has been nearly completed. The devices include superconducting cold iron quadrupoles utilizing a 2-shell, cos2{theta} coil geometry with a 7.6 cm aperture. The maximum design gradient is 1.41 T/cm at an operating current of 4832 A. They have the highest current density with the highest peak field on the winding of any quadrupole yet built. This paper summarizes the quench performance and ramp rate sensitivity of the 2-shell design and relates the performance characteristics to the relevant aspects of design and fabrication. 8 refs., 6 figs., 3 tabs.

Gourlay, S.A.; Carson, J.A.; Hanft, R.; Jaffery, T.S.; Koepke, K.; Lamm, M.J.; Mantsch, P.M.; McInturff, A.D.; Mokhtarani, A.; Orris, D.; Peterson, T.

1991-05-01

473

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

474

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