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1

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

2

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

3

Application of nuclear quadrupole resonance to the study of clathrates. sup 35 Cl NQR and crystallography of clathrated CCl sub 4  

SciTech Connect

The {sup 35}Cl nuclear quadrupole resonance (NQR) spectra of CCl{sub 4} in more than 20 clathrates have been measured in the range 4-200 K. The crystal structures of CCl{sub 4}/Dianin's compound (1), CCl{sub 4}/Fe(AcAc){sub 3} (3), CCl{sub 4}/Ni(SCN){sub 2}(3-MePy){sub 4} (4), and CCl{sub 4}/Ni(exan){sub 2}(4,4{prime}-dm-2,2{prime}-bpy) (19) clathrates are also reported. Site symmetry and site multiplicity of the guest molecule in clathrates were determined by NQR spectroscopy and by x-ray crystallography. The degree of host-guest interaction was estimated from the NQR frequency shifts. The libration frequencies of the guest molecules in trigonal cavities were determined from NQR frequencies by Bayer-Kushida theory analysis.

Pang, Li; Lucken, E.A.C.; Bernardinelli, G. (Univ. de Geneve (Switzerland))

1990-11-21

4

Application of nuclear quadrupole resonance to the study of clathrates. sup 35 Cl NQR and crystallography of clathrated CCl sub 4  

Microsoft Academic Search

The ³⁵Cl nuclear quadrupole resonance (NQR) spectra of CCl in more than 20 clathrates have been measured in the range 4-200 K. The crystal structures of CCl\\/Dianin's compound (1), CCl\\/Fe(AcAc) (3), CCl\\/Ni(SCN)(3-MePy) (4), and CCl\\/Ni(exan)(4,4-dm-2,2-bpy) (19) clathrates are also reported. Site symmetry and site multiplicity of the guest molecule in clathrates were determined by NQR spectroscopy and by x-ray crystallography.

Li Pang; E. A. C. Lucken; G. Bernardinelli

1990-01-01

5

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

E-print Network

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

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

2008-12-10

6

Nuclear quadrupole resonance studies of amorphous, orthorhombic, and rhombohedral arsenic  

Microsoft Academic Search

Pulsed nuclear quadrupole resonance (NQR) experiments have been performed on three forms of elemental arsenic: amorphous (a), rhombohedral (rh), and orthorhombic (or). The temperature dependence of the spin-lattice relaxation time (T1) provides evidence for the existence of disorder (tunneling) modes in a-As. It is found that the NQR line shape of a-As is highly asymmetric, and this asymmetry is attributed

G. E. Jellison Jr.; G. L. Petersen; P. C. Taylor

1980-01-01

7

Nuclear quadrupole resonance studies of amorphous, orthorhombic, and rhombohedral arsenic  

Microsoft Academic Search

Pulsed nuclear quadrupole resonance (NQR) experiments have been performed on three forms of elemental arsenic: amorphous (a), rhombohedral (rh), and orthorhombic (or). The temperature dependence of the spin-lattice relaxation time (T) provides evidence for the existence of disorder (tunneling) modes in a-As. It is found that the NQR line shape of a-As is highly asymmetric, and this asymmetry is attributed

G. E. Jr. Jellison; G. L. Petersen; P. C. Taylor

1980-01-01

8

Methyl quantum tunneling and nitrogen-14 NQR NMR studies using a SQUID magnetic resonance spectrometer  

SciTech Connect

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) techniques have been very successful in obtaining molecular conformation and dynamics information. Unfortunately, standard NMR and NQR spectrometers are unable to adequately detect resonances below a few megahertz due to the frequency dependent sensitivity of their Faraday coil detectors. For this reason a new spectrometer with a dc SQUID (Superconducting Quantum Interference Device) detector, which has no such frequency dependence, has been developed. Previously, this spectrometer was used to observe {sup 11}B and {sup 27}Al NQR resonances. The scope of this study was increased to include {sup 23}Na, {sup 51}V, and {sup 55}Mn NQR transitions. Also, a technique was presented to observe {sup 14}N NQR resonances through cross relaxation of the nitrogen polarization to adjacent proton spins. When the proton Zeeman splitting matches one nitrogen quadrupoler transition the remaining two {sup 14}N transitions can be detected by sweeping a saturating rf field through resonance. Additionally, simultaneous excitation of two nitrogen resonances provides signal enhancement which helps to connect transitions from the same site. In this way, nitrogen-14 resonances were observed in several amino acids and polypeptides. This spectrometer has also been useful in the direct detection of methyl quantum tunneling splittings at 4.2 K. Tunneling, frequencies of a homologous series of carboxylic acids were measured and for solids with equivalent crystal structures, an exponential correlation between the tunneling frequency and the enthalpy of fusion is observed. This correlation provides information about the contribution of intermolecular interactions to the energy barrier for methyl rotation.

Black, B.E. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States)

1993-07-01

9

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

10

Resonant Quadrupole Peter Cameron -BNL  

E-print Network

Resonant Quadrupole Monitor Peter Cameron - BNL #12;LARP Workshop at FNAL6/9/2003 2 Resonant BPM · Resonate above coherent spectrum #12;LARP Workshop at FNAL6/9/2003 3 Basic Method - Quadrupole Oscillations, Quadrupole BTF possible with this system. #12;LARP Workshop at FNAL6/9/2003 4 Dynamic Range Problem · Dynamic

Large Hadron Collider Program

11

Low-frequency nuclear quadrupole resonance with a dc SQUID  

SciTech Connect

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

Chang, J.W.

1991-07-01

12

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

13

Mixed radiation field dosimetry utilizing Nuclear Quadrupole Resonance  

SciTech Connect

This project has proposed to develop a novel dosimetry system that is capable of directly evaluating the chemical/biological damage caused by neutrons, photons, or both in a single measurement. The dosimeter itself will consist of a small volume of biological equivalent material that is probed for radiation damage with Nuclear Quadrupole Resonance (NQR) techniques. NQR has previously been utilized as a sensitive probe of structural and chemical changes at the molecular level for a variety of organic compounds. The biological equivalent materials used in this study will not only have a density similar to tissue (tissue equivalent) but will have the same atomic components as tissue. This is a significant requirement if the important neutron interactions that occur in tissue are to occur in the dosimeter as well. The overall objective of this study is to investigate a methodology to perform accurate mixed-field (neutron and photon) dosimetry for biological systems.

Hintenlang, D.

1991-01-01

14

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

15

14 N NQR spectrum of sildenafil citrate  

NASA Astrophysics Data System (ADS)

The 14N nuclear quadrupole resonance (NQR) spectrum of sildenafil citrate tablets has been recorded allowing the quadrupole coupling constants and asymmetry parameters of all six unique nitrogen atoms in its structure to be determined. A density function calculation gives results that are largely in agreement with the experimental values.

Stephenson, David; Singh, Nadia

2014-10-01

16

Nuclear quadrupole resonance spectra of drawing-induced crystallization in As 2Se 3 fibers  

Microsoft Academic Search

Pulsed 75As nuclear quadrupole resonance (NQR) experiments performed on fibers of As2Se3 drawn at various rates (> 100 m\\/min) reveal structural changes from the bulk, well-annealed glass. In addition to the presence of As?As bonds in the nominally stoichiometric fibers, a distorted crystalline phase (< 10% by volume) occurs at the largest draw rates. Because they are highly distorted, these

P. Hari; P. C. Taylor; W. A. King; W. C. LaCourse

1997-01-01

17

Exploiting temperature dependency in the detection of NQR signals  

Microsoft Academic Search

Nuclear quadrupole resonance (NQR) offers an unequivocal method of detecting and identifying land mines. Unfortunately, the practical use of NQR is restricted by the low signal-to-noise ratio (SNR), and the means to improve the SNR are vital to enable a rapid, reliable, and convenient system. In this paper, an approximate maximum-likelihood detector (AML) is developed, exploiting the temperature dependency of

Andreas Jakobsson; Magnus Mossberg; Michael D. Rowe; John A. S. Smith

2006-01-01

18

Nuclear quadrupole resonance and x-ray investigation of the structure of Na2\\/3CoO2  

Microsoft Academic Search

We have synthesized various samples of the x=2\\/3 phase of sodium cobaltate NaxCoO2 and performed x-ray powder diffractions spectra to compare the diffraction with the structure proposed previously from NMR and nuclear quadrupole resonance (NQR) experiments [H. Alloul, I. R. Mukhamedshin, T. A. Platova, and A. V. Dooglav, EPL 85, 47006 (2009)]. Rietveld analyses of the data are found in

T. A. Platova; I. R. Mukhamedshin; H. Alloul; A. V. Dooglav; G. Collin

2009-01-01

19

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. Schrrer; A. Wolfenson; A. Brunetti

1998-01-01

20

Z .Solid State Nuclear Magnetic Resonance 11 1998 139156 SQUID detected NMR and NQR  

E-print Network

Z .Solid State Nuclear Magnetic Resonance 11 1998 139156 SQUID detected NMR and NQR Matthew P dc Superconducting QUantum Interference Device SQUID is a sensitive detector of magnetic flux to a thin film superconducting coil deposited on the SQUID to form a flux transformer. With this untuned

Augustine, Mathew P.

21

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

22

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. 50100% 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 90145?MHz and 74.599.5?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

23

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

NASA Astrophysics Data System (ADS)

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

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

2008-10-01

24

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

25

35Cl Nuclear Quadrupole Resonance and Thermally Activated Molecular Motion in the 2:1 Crystalline Complex of Antimony Trichloride with Benzene  

Microsoft Academic Search

Nuclear quadrupole resonance (NQR) spectra of chlorine and antimony in the 2SbCl3 C6H6 complex and their temperature behavior between 77 K and the melting point were studied. The spectral lines of two nonequivalent SbCl3 moieties are compared with available X-ray diffraction data. An analysis of the temperature dependence of the resonant frequency and the spinlattice relaxation time for 35Cl

V. A. Mokeeva

2002-01-01

26

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

27

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

PubMed Central

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

2012-01-01

28

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

29

Zeeman Effect of the Nuclear Quadrupole Resonance of 81Br in para-Bromophenol and 35Cl in paraChlorophenol  

Microsoft Academic Search

The Zeeman effect of the 81Br and 35Cl nuclear quadrupole resonance has been studied with high precision on single crystals of para-bromophenol and para-chlorophenol, respectively. The results substantially agree with previous x-ray and NQR studies of para-chlorophenol (x-ray studies are known only for this substance). In p-bromophenol, four physically inequivalent sites were found, instead of two, as reported by other

P. Bucci; P. Cecchi; A. Colligiani

1969-01-01

30

Using nitrogen-14 nuclear quadrupole resonance and electric field gradient information for the study of radiation effects  

SciTech Connect

Nitrogen-14 nuclear quadrupole resonance (NQR) was used in an attempt to detect the effects of ionizing radiation on organic material. Previously reported resonances for urea were detected at 2,913.32 {+-} 0.01 kHz and 2,347.88 {+-} 0.08 kHz with associated T{sub 2}* values 780 {+-} 20 {micro}s and 523 {+-} 24 {micro}s, respectively. The previously unreported {nu}{sub {minus}} line for urea-d{sup 4} was detected at 2,381 {+-} 0.04 Khz and used to determine accurately for the first time the values for the nuclear quadrupole coupling constant {chi} (3,548.74 {+-} 0.03 kHz) and the asymmetry parameter {eta} (0.31571 {+-} 0.00007) for urea-d{sup 4}. The inverse linewidth parameter T{sub 2}* for {nu}{sub +} was measured at 928 {+-} 23 {micro}s and for {nu}{sub {minus}} at 721 {+-} 12 {micro}s. Townes and Dailey analysis was performed and urea-d{sup 4} exhibits a 0.004 increase in lone pair electronic density and a slight decrease in N-H bond electronic density, as compared to urea, probably due to the mass difference. A relationship is proposed, referred to as NQR linewidth analysis, between the dynamic spin relaxation times T{sub 2} and T{sub 2}* and the widths of the distributions of the NQR parameters. Linewidth analysis is presented as a tool for possible use in future NQR work in all area, not just radiation effects. This relationship is tested using sodium nitrite T{sub 2} and T{sub 2}* values for {nu}{sub {minus}} and {nu}{sub {minus}} as a function of temperature.

Iselin, L.H.

1995-12-01

31

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

32

Nuclear-quadrupole double-resonance study of RbH2PO4 in the supercooled high-temperature monoclinic phase  

NASA Astrophysics Data System (ADS)

Rubidium nuclear-quadrupole-resonance (NQR) spectra have been measured in the high-temperature monoclinic phase of RbH2PO4 above Tp=86 C and also in the supercooled high-temperature phase below Tp. At the transition into the high-temperature phase, the rubidium quadrupole-coupling constants drop by a factor of 5. The high-temperature phase is metastable below Tp. The kinetics of the transformation of the metastable phase into the stable tetragonal phase in a polycrystalline sample is determined at room temperature from the time dependence of the rubidium NQR spectra. A comparison of the present rubidium NQR data in the high-temperature monoclinic RbH2PO4 with the rubidium NQR data in monoclinic RbD2PO4 suggests that at low temperatures, supercooled monoclinic RbH2PO4 may be isostructural with the phase III of monoclinic RbD2PO4 whereas above Tp RbH2PO4 may be isostructural with phase II of RbD2PO4.

Seliger, J.; agar, V.; Blinc, R.

1993-06-01

33

Coulomb disorder effects on angle-resolved photoemission and nuclear quadrupole resonance spectra in cuprates  

NASA Astrophysics Data System (ADS)

The role of Coulomb disorder, either of extrinsic origin or introduced by dopant ions in undoped and lightly doped cuprates, is studied. We demonstrate that charged surface defects in an insulator lead to a Gaussian broadening of the angle-resolved photoemisson spectroscopy (ARPES) lines. The effect is due to the long-range nature of the Coulomb interaction. A tiny surface concentration of defects about a fraction of one percent is sufficient to explain the line broadening observed in Sr2CuO2Cl2 , La2CuO4 , and Ca2CuO2Cl2 . Due to the Coulomb screening, the ARPES spectra evolve dramatically with doping, changing their shape from a broad Gaussian form to narrow Lorentzian ones. To understand the screening mechanism and the line-shape evolution in detail, we perform Hartree-Fock simulations with random positions of surface defects and dopant ions. To check validity of the model we calculate the nuclear quadrupole resonance (NQR) line shapes as a function of doping and reproduce the experimentally observed NQR spectra. Our study also indicates opening of a substantial Coulomb gap at the chemical potential. For a surface CuO2 layer the value of the gap is on the order of 10 meV while in the bulk it is reduced to the value about a few meV.

Chen, Wei; Khaliullin, Giniyat; Sushkov, Oleg P.

2009-09-01

34

Rapid detection of arsenic minerals using portable broadband NQR  

NASA Astrophysics Data System (ADS)

The remote real-time detection of specific arsenic species would significantly benefit in minerals processing to mitigate the release of arsenic into aquatic environments and aid in selective mining. At present, there are no technologies available to detect arsenic minerals in bulk volumes outside of laboratories. Here we report on the first room-temperature broadband 75As nuclear quadrupole resonance (NQR) detection of common and abundant arsenic ores in the Earth crust using a large sample (0.78 L) volume prototype sensor. Broadband excitation aids in detection of natural minerals with low crystallinity. We briefly discuss how the proposed NQR detector could be employed in mining operations.

Lehmann-Horn, J. A.; Miljak, D. G.; O'Dell, L. A.; Yong, R.; Bastow, T. J.

2014-10-01

35

Weakly first-order behavior in ferromagnetic transition of UCoGe revealed by 59Co-NQR studies  

NASA Astrophysics Data System (ADS)

We have performed 59Co nuclear quadrupole resonance (NQR) measurements on ferromagnetic (FM) superconductor UCoGe, in which ferromagnetism occurs at TCurie 2.5 K. By measuring NQR spectrum at various temperatures, we investigated the development of local magnetic moment around TCurie, and suggest that FM transition possesses weakly first-order character. This first-order behavior is consistent with the theoretical prediction that the low temperature FM transition in itinerant magnets is generically of first-order.

Hattori, T.; Ishida, K.; Nakai, Y.; Ohta, T.; Deguchi, K.; Sato, N. K.; Satoh, I.

2010-12-01

36

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

37

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

38

NQR study of chalcogenide glasses Ge-As-Se.  

PubMed

A three-component Ge-As-Se system is studied by the nuclear quadrupole resonance (NQR) method on (75)As nuclei and by the nutation NQR spectroscopy. The NQR (75)As spectra of the glasses Ge(0.021) As(0.375) Se(0.604), Ge(0.043) As(0.348) Se(0.609) and Ge(0.068) As(0.318) Se(0.614) reveal broad lines with two peaks assigned to the main structural unit of As(2)Se(3). With increasing average coordination number ( ?r), the spectrum signals are shifted towards higher frequencies. At ?r > 2.54, the spectrum becomes complex, which is a consequence of formation of more complex molecular structures in the glasses of high content of germanium. At fixed frequencies the asymmetry parameter ? of the samples studied is determined. PMID:21452350

Glotova, Olga; Korneva, Irina; Sinyavsky, Nikolay; Ostafin, Michal; Nogaj, Boleslaw

2011-07-01

39

Ferromagnetic critical behavior in U(Co1-xFex)Al (0 ?x ?0.02 ) studied by 59Co nuclear quadrupole resonance measurements  

NASA Astrophysics Data System (ADS)

In order to investigate physical properties around a ferromagnetic (FM) quantum transition point and a tricritical point (TCP) in the itinerant-electron metamagnetic compound UCoAl, we have performed the 59Co nuclear quadrupole resonance (NQR) measurement for the Fe-substituted U(Co1-xFex)Al(x =0 ,0.5 ,1 ,and2 %) in zero external magnetic field. The Fe concentration dependence of 59Co -NQR spectra at low temperatures indicates that the first-order FM transition occurs at least above x =1 % . The magnetic fluctuations along the c axis detected by the nuclear spin-spin relaxation rate 1 /T2 exhibit an anomaly at Tmax20 K and enhance with increasing x . These results are in good agreement with theoretical predictions and indicate the presence of prominent critical fluctuations at the TCP in this system.

Karube, K.; Hattori, T.; Ishida, K.; Kimura, N.

2015-02-01

40

Pulsed Bromine-81 Nuclear Quadrupole Resonance Spectroscopy of Brominated Flame Retardants and Associated Polymer Blends.  

NASA Astrophysics Data System (ADS)

The dispersion of brominated flame retardants in polymers is monitored with bromine-81 NQR using a pulse NQR spectrometer. The NQR spectrometer consists of a homemade 10-300 MHz single-channel NMR console coupled to a broadly tunable probe. The probe is a loop-gap resonator usable from 220 to 300 MHz, and automatically tuned over any 5 MHz region with a stepping motor and an RF bidirectional coupler. Bromine-81 NQR spectra of several brominated aromatic flame retardants, as pure materials and in polymers, were recorded in the range of 227 to 256 MHz in zero applied magnetic field. Two factors affect the bromine-79/81 NQR transition frequencies in brominated aromatics: electron withdrawing substituents on the ring and intermolecular contacts with other bromine atoms in the crystal structure. An existing model for substituents is updated and a point charge model for the intermolecular contacts is developed. In this study, we exploit the bromine-81 NQR transition frequency dependence on intermolecular contacts to learn how a flame retardant is dispersed in a polymer matrix.

Mrse, Anthony A.; Lee, Youngil; Bryant, Pamela L.; Fronczek, Frank R.; Butler, Leslie G.; Simeral, Larry S.

1998-03-01

41

Copper valence, structural separation and lattice dynamics in tennantite (fahlore): NMR, NQR and SQUID studies  

NASA Astrophysics Data System (ADS)

Electronic and magnetic properties of tennantite subfamily of tetrahedrite-group minerals have been studied by copper nuclear quadrupole resonance (NQR), nuclear magnetic resonance (NMR) and SQUID magnetometry methods. The temperature dependences of copper NQR frequencies and line-width, nuclear spin-lattice relaxation rate T {1/-1} and nuclear spin-echo decay rate T {2/-1} in tennantite samples in the temperature range 4.2-210 K is evidence of the presence of field fluctuations caused by electronic spins hopping between copper CuS3 positions via S2 bridging atom. The analysis of copper NQR data at low temperatures points to the magnetic phase transition near 65 K. The magnetic susceptibility in the range 2-300 K shows a Curie-Weiss behavior, which is mainly determined by Fe2+ paramagnetic substituting ions.

Gainov, R. R.; Dooglav, A. V.; Pen'kov, I. N.; Mukhamedshin, I. R.; Savinkov, A. V.; Mozgova, N. N.

2008-01-01

42

Spectra of nuclear quadrupole resonance in vitreous semiconductors  

SciTech Connect

The method of nuclear quadrupole resonance is used to study the chalcogenide semiconductors with compositions As{sub 2}Se{sub 3} and As{sub 14}Sb{sub 4}Se{sub 27}. It is shown that partial crystallization occurs in a sample of vitreous As{sub 2}Se{sub 3} kept for a long time at room temperature; as a result, a change in the shape of the spectrum of the nuclear quadrupole resonance is observed. The {sup 75}As spectrum in vitreous As{sub 14}Sb{sub 4}Se{sub 27} at a temperature of 77 K is measured for the first time. It is assumed that the {sup 121}Sb or {sup 123}Sb nuclei can contribute to the broad line of the quadrupole resonance. It is shown that the use of the nuclear spin-echo Fourier-transform mapping spectroscopy for reconstruction of very broad lines of the nuclear quadrupole resonance provides no advantages compared to the method of reconstruction based on the points in the integrated intensity of the echo signals.

Korneva, I. P., E-mail: kornev@albertina.ru; Sinyavskii, N. Ya. [Baltic State Academy (Russian Federation); Ostafin, M.; Nogaj, B. [A. Mickiewicz University (Poland)

2006-09-15

43

Zeeman Splitting of the Nuclear Quadrupole Resonance Line of Iodine  

Microsoft Academic Search

Zeeman patterns of the nuclear Quadrupole resonance line of I127 were studied with a single crystal of iodine at medium and weak magnetic fields. The asymmetry parameter of coupling, eta, and the angle between bond axis of the iodine molecule and crystallographic c axis, \\\\varphi, were determined from the pattern at a medium magnetic field of about 120 gauss. The

Kineo Tsukada

1956-01-01

44

A computational NQR study on the hydrogen-bonded lattice of cytosine-5-acetic acid.  

PubMed

A computational study at the level of density functional theory (DFT) employing 6-311++G** standard basis set was carried out to evaluate nuclear quadrupole resonance (NQR) spectroscopy parameters in cytosine-5-acetic acid (C5AA). Since the electric field gradient (EFG) tensors are very sensitive to the electrostatic environment at the sites of quadruple nuclei, the most possible interacting molecules with the target one were considered in a five-molecule model system of C5AA using X-ray coordinates transforming. The hydrogen atoms positions were optimized and two model systems of original and H-optimized C5AA were considered in NQR calculations. The calculated EFG tensors at the sites of (17)O, (14)N, and (2)H nuclei were converted to their experimentally measurable parameters, quadrupole coupling constants and asymmetry parameters. The evaluated NQR parameters reveal that the nuclei in original and H-optimized systems contribute to different hydrogen bonding (HB) interaction. The comparison of calculated parameters between optimized isolated gas-phase and crystalline monomer also shows the relationship between the structural deformation and NQR parameters in C5AA. The basis set superposition error (BSSE) calculations yielded no significant errors for employed basis set in the evaluation of NQR parameters. All the calculations were performed by Gaussian 98 package of program. PMID:17926341

Mirzaei, Mahmoud; Hadipour, Nasser L

2008-04-15

45

Zero-field splittings of NQR spectra for bismuth(III) oxy compounds revealed by quadrupole spin echo envelopes  

Microsoft Academic Search

Local magnetic fields up to 250G were earlier found by measuring the NQI parameters in bismuth(III) oxy compounds conventionally\\u000a considered as diamagnets, a strong increase in the 209Bi line intensities being observed in external magnetic fields. An approach based on registration of the quadrupole spin-echo\\u000a envelopes enabled to reveal small (within an inhomogeneous line broadening) splittings in some other compounds

E. A. Kravchenko; V. G. Orlov; V. G. Morgunov; M. P. Shlykov

2007-01-01

46

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

47

Application of nuclear quadrupole resonance in study of minerals  

Microsoft Academic Search

The NQR method has been used to study some structural and chemical properties of minerals that are difficult or impossible to determine by conventional methods. For example, an X-ray determination commonly integrates the data for all cells, whereas NQR can separate the nearly ideal from highly distorted ones. It can thus give a better picture of the ideal structure and

I. N. Penkov; I. A. Sofin

1967-01-01

48

Application of 14N NQR to the study of piroxicam polymorphism.  

PubMed

A study was conducted to test the capability of the (14)N nuclear quadrupole resonance (NQR) method to discriminate qualitatively and quantitatively among different forms of piroxicam. Samples of commercial piroxicam form I and its monohydrate were obtained on the local market. Additionally, samples of form I and II were prepared by recrystallization in 1,2-dichloroethane and ethanol, respectively. DSC and FT-IR were employed as reference methods. A (14)N NQR spectrometer was used to measure samples of different forms and mixtures of piroxicam at 2587 and 3439 ?kHz. DSC and FT-IR clearly confirmed differences between the different piroxicam forms. Measurements of (14)N NQR signals of different forms of piroxicam at 2587 ?kHz detected only spectral peaks of form I. The dependence of (14)N NQR signal intensity on the concentration of form I in mixtures with the monohydrate showed a clear linear relationship at both measured frequencies, though the scattering of data was greater at 3439 ?kHz due to the lower S/N ratio. The (14)N NQR method has the potential to become an additional and important spectroscopic tool in the study of solid-state forms, not only of pure active pharmaceutical ingredients or excipients, but also of their mixtures. This ability lends the method to a possible successful utilization at different levels of pharmaceutical manufacturing and product quality control. PMID:20597116

Lavri?, Zoran; Pirnat, Janez; Lunik, Janko; Seliger, Janez; Zagar, Veselko; Trontelj, Zvonko; Sr?i?, Stane

2010-12-01

49

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

50

Sensitivity of nuclear-quadrupole double-resonance detection of half-integer spin nuclei.  

PubMed

The sensitivity of the Slusher and Hahn's nuclear quadrupole double resonance technique is calculated in general for an arbitrary nuclear spin S of the quadrupole nuclei and for an arbitrary asymmetry parameter eta of the electric field gradient tensor. The nuclear spin S=5/2 ((17)O, (25)Mg, ...) is treated in details. The influence of the cross-relaxation rate between the quadrupole nuclei and the abundant spin system on the sensitivity of double resonance is discussed. The results of the theoretical analysis are applied in the analysis of the (1)H-(17)O nuclear quadrupole double resonance spectra in p-toluenesulfonamide and 2-nitrobenzoic acid. The 17O nuclear quadrupole resonance frequencies from a sulfonamide group are determined for the first time. The proton-oxygen cross-relaxation rates and the proton local frequency in zero external magnetic field are experimentally determined from the nuclear quadrupole double resonance spectra. PMID:18644741

Seliger, J; Zagar, V

2008-10-01

51

93Nb Nuclear Quadrupole Resonance in Orthorhombic Phase of Niobium Pentabromide  

Microsoft Academic Search

The 93Nb NQR has been investigated in one phase of NbBr5 which was identified to be orthorhombic by the X-ray analysis. The resonance frequencies have been measured between 4.2 K and 423 K, its melting point. The coupling constant showed a positive temperature dependence up to melting point. The temperature dependence of the coupling constant is compared between NbBr5 and

Noriaki Okubo; Yoshihito Abe

1982-01-01

52

Zero-field NMR and NQR studies of magnetically ordered state in charge-ordered EuPtP  

NASA Astrophysics Data System (ADS)

EuPtP undergoes two valence transitions and has two kinds of valence states of Eu ions at low temperatures. In the charge-ordered state, this compound shows an antiferromagnetic order ascribed to magnetic divalent Eu ions. We investigated the antiferromagnetically ordered state of EuPtP by nuclear magnetic resonance (NMR) measurement and nuclear quadrupole resonance (NQR) measurement in a zero external magnetic field. The observed 153Eu NMR signals of a magnetic divalent state and Eu,153151 NQR signals of a nonmagnetic trivalent state clearly demonstrate that the spins order in the hexagonal basal plane and the internal magnetic field is not canceled out, even at the Eu3 + layers which are in the middle of magnetic Eu2 + layers. In addition, the observation of 31P and 195Pt NMR spectra allowed us to discuss a possible magnetic structure. We also evaluated the nuclear quadrupole frequencies for both Eu2 + and Eu3 + ion states.

Koyama, T.; Maruyama, T.; Ueda, K.; Mito, T.; Mitsuda, A.; Umeda, M.; Sugishima, M.; Wada, H.

2015-03-01

53

Effect of a weak static magnetic field on nitrogen-14 quadrupole resonance in the case of an axially symmetric electric field gradient tensor.  

PubMed

The application of a weak static B0 magnetic field (less than 1 mT) may produce a well-defined splitting of the (14)N Quadrupole Resonance line when the electric field gradient tensor at the nitrogen nucleus level is of axial symmetry. It is theoretically shown and experimentally confirmed that the actual splitting (when it exists) as well as the line-shape and the signal intensity depends on three factors: (i) the amplitude of B0, (ii) the amplitude and pulse duration of the radio-frequency field, B1, used for detecting the NQR signal, and (iii) the relative orientation of B0 and B1. For instance, when B0 is parallel to B1 and regardless of the B0 value, the signal intensity is three times larger than when B0 is perpendicular to B1. This point is of some importance in practice since NQR measurements are almost always performed in the earth field. Moreover, in the course of this study, it has been recognized that important pieces of information regarding line-shape are contained in data points at the beginning of the free induction decay (fid) which, in practice, are eliminated for avoiding spurious signals due to probe ringing. It has been found that these data points can generally be retrieved by linear prediction (LP) procedures. As a further LP benefit, the signal intensity loss (by about a factor of three) is regained. PMID:24183810

Guendouz, Laous; Aissani, Sarra; March, Jean-Franois; Retournard, Alain; Marande, Pierre-Louis; Canet, Daniel

2013-01-01

54

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 quadrupole waveguide. The device oscillates at the fundamental and high harmonics of the cyclotron frequency

Jerby, Eli

55

A NUCLEAR QUADRUPOLE RESONANCE AND X-RAY STUDY OF THE CRYSTAL STRUCTURE OF PENTACHLOROPHENOL  

Microsoft Academic Search

The crystal structure of pentachlorophenol was solved by the combined ; appiication of nuclear quadrupole resonance and x-ray diffraction. The molecules ; are linked by chains of hydrogen-bonds with a configuration similar to that in ; tetrachiorohydroquinone. The nuclear quadrupole resonance of one of the ortho ; chlorine atoms is specially affected by the intermolecular interaction. This ; interaction is

T. Sakurai

1962-01-01

56

A study of hydrogen bond of imidazole and its 4-nitro derivative by ab initio and DFT calculated NQR parameters  

Microsoft Academic Search

Nuclear quadrupole resonance (NQR) parameters of 14N, 2H of N2H groups are calculated for imidazole and 4-nitroimidazole using HF and B3LYP methods. These computations are performed on the basis of X-ray and neutron diffraction structural data which are collected at 100, 103, 123 and 293 K temperatures. In order to take into account intermolecular hydrogen bonds and the van der

S. K. Amini; N. L. Hadipour; F. Elmi

2004-01-01

57

35Cl-NQR and DFT study of electronic structure of amlodipine and felodipine vascular-selective drugs from the dihydropyridine Ca ++ antagonists group  

NASA Astrophysics Data System (ADS)

Amlodipine (AM) and felodipine (FL) have been studied in solid state by the nuclear quadrupole resonance (NQR) and density functional theory (DFT). The results have shown that NQR data do not permit a differentiation between R and S enantiomers, which is a consequence of the symmetry of the 4-aryl ring, whereas they permit a differentiation between free bases and salts. The HOMO-LUMO gap is smaller for AM than for FL, which suggests smaller energy of excitation for AM. The absolute hardness, chemical potential and electrophilicity of both AM enantiomers are lower than the corresponding values for FL enantiomers, suggesting that AM should be more reactive than FL in unimolecular reactions.

Latosi?ska, J. N.; Latosi?ska, M.; Kasprzak, J.

2008-09-01

58

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

59

Nuclear Quadrupole Resonance Zeeman Study of paraChlorophenol  

Microsoft Academic Search

The major field gradient directions for Cl in para-chlorophenol as determined by NQR and x-ray diffraction are compared quantitatively, and found to agree. The minor field gradient directions are examined qualitatively, and are consistent with those predicted on the basis of Cl&sngbnd;C partial double bonding. From a measurement of the field gradient asymmetry parameter &eegr;, the degree of chlorinecarbon double

G. E. Peterson; P. M. Bridenbaugh

1967-01-01

60

Topology of the interactions pattern in pharmaceutically relevant polymorphs of methylxanthines (caffeine, theobromine, and theophiline): combined experimental (H-?N nuclear quadrupole double resonance) and computational (DFT and Hirshfeld-based) study.  

PubMed

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

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

2014-09-22

61

93Nb- and 27Al-NMR/NQR studies of the praseodymium based PrNb2Al20  

NASA Astrophysics Data System (ADS)

We report a study of 93Nb- and 27Al-nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) in a praseodymium based compound PrNb2Al20. The observed NMR line at around 3 T and 30 K shows a superposition of typical powder patterns of one Nb signal and at least two Al signals. 93Nb-NMR line could be reproduced by using the previously reported NQR frequency ?Q ? 1.8MHz and asymmetry parameter ? ? 0 [Kubo T et al 2014 JPS Conf. Proc. 3 012031]. From 27Al-NMR/NQR, NQR parameters are obtained to be ?Q,A ? 1.53 MHz, and ?A ? 0.20 for the site A, and ?Q,B ? 2.28 MHz, and ?B ? 0.17 for the site B. By comparing this result with the previous 27Al-NMR study of PrT2Al20 (T = Ti, V) [Tokunaga Y et al 2013 Phys. Rev. B 88 085124], these two Al site are assigned to the two of three crystallographycally inequivalent Al sites.

Kubo, Tetsuro; Kotegawa, Hisashi; Tou, Hideki; Higashinaka, Ryuji; Nakama, Akihiro; Aoki, Yuji; Sato, Hideyuki

2015-03-01

62

14N quadrupole resonance and 1H T1 dispersion in the explosive RDX.  

PubMed

The explosive hexahydro-1,3,5-trinitro-s-triazine (CH2-N-NO2)3, commonly known as RDX, has been studied by 14N NQR and 1H NMR. NQR frequencies and relaxation times for the three ?+ and ?- lines of the ring 14N nuclei have been measured over the temperature range 230-330 K. The 1H NMR T1 dispersion has been measured for magnetic fields corresponding to the 1H NMR frequency range of 0-5.4 M Hz. The results have been interpreted as due to hindered rotation of the NO2 group about the N-NO2 bond with an activation energy close to 92 kJ mol(-1). Three dips in the 1H NMR dispersion near 120, 390 and 510 kHz are assigned to the ?0, ?- and ?+ transitions of the 14NO2 group. The temperature dependence of the inverse line-width parameters T2? of the three ?+ and ?- ring nitrogen transitions between 230 and 320 K can be explained by a distribution in the torsional oscillational amplitudes of the NO2 group about the N-NO2 bond at crystal defects whose values are consistent with the latter being mainly edge dislocations or impurities in the samples studied. Above 310 K, the 14N line widths are dominated by the rapid decrease in the spin-spin relaxation time T2 due to hindered rotation of the NO2 group. A consequence of this is that above this temperature, the 1H T1 values at the quadrupole dips are dominated by the spin mixing time between the 1H Zeeman levels and the combined 1H and 14N spin-spin levels. PMID:21978662

Smith, John A S; Blanz, Martin; Rayner, Timothy J; Rowe, Michael D; Bedford, Simon; Althoefer, Kaspar

2011-12-01

63

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, Sn, Er, and 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

64

NQR Line Broadening Due to Crystal Lattice Imperfections and Its Relationship to Shock Sensitivity  

NASA Astrophysics Data System (ADS)

The hydrodynamic hot spot model is used to explain the difference between shock sensitive and shock insensitive explosives. Among the major factors that influence the shock sensitivity of energetic compounds are the quality and particle size of the energetic crystals used to formulate the cast plastic bonded explosive. As do all energetic compounds, RDX and HMX exhibit internal crystal defects the magnitude and type of which depend on the manufacturing process used to synthesize and re-crystallize the energetic compound. Nuclear Quadrupole Resonance (NQR) spectroscopy was used to determine the crystal quality of RDX, HMX and CL-20 obtained from various manufacturers. The NQR experimental results are discussed. Cast plastic bonded explosives were made using the RDX and HMX obtained from the various manufacturers and subsequently subjected to the NOL large-scale gap test (LSGT). The results of the LSGT are discussed and correlated with the NQR results. A relationship between the crystal defect density and shock initiation pressure of the plastic bonded explosive is developed and discussed.

Caulder, S. M.; Buess, M. L.; Garroway, A. N.; Miller, P. J.

2004-07-01

65

Possibility of studying the internal field in a current-carrying conductor using nuclear quadrupole resonance  

NASA Astrophysics Data System (ADS)

A non-invasive method is proposed to probe the Landauer's residual resistivity dipoles in a current-carrying mesoscopic metal. The local voltage fluctuations induce extra local electric field gradients which can then be measured using nuclear quadrupole resonance. We have estimated that such kinds of experiments are indeed feasible.

Fu, Yaotian; Hing Sing Tang

1994-02-01

66

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

E-print Network

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

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

1999-01-01

67

Lattice vibrational motion in tetracyanoquinodimethane (TCNQ): A 14N nuclear quadrupole resonance study  

Microsoft Academic Search

The mean square angular amplitudes of motion are obtained from the analysis of the 14N nuclear quadrupole resonance thermal averaging in pure TCNQ. The temperature dependence of the mean square angular amplitudes is given. The results are compared with those found at room temperature by x ray by Long et al. [Acta Cryst. 18, 932 (1965)].

Juan Murgich

1979-01-01

68

Quadrupole resonances in the rare-earth metals  

SciTech Connect

Calculations that employ a relativistic time-dependent local-density approximation to atomic absorption are used to examine a recent claim to the observation of giant quadrupolar resonances in the electron-energy-loss spectrum of Ce metal near the 4p edge. We confirm the existence of 4p..-->..4f resonances in this energy range but find the polarization effects much smaller than in typical giant dipole resonances.

Liberman, D.; Zangwill, A.

1989-01-01

69

Studies of the electronic structure and biological activity of chosen 1,4-benzodiazepines by 35Cl NQR spectroscopy and DFT calculations  

NASA Astrophysics Data System (ADS)

Selected derivatives of 1,4-benzodiazepine: lorazepam, lormetazepam, oxazepam and temazepam, used as active substances in anxiolytic drugs, have been studied by 35Cl NQR method in order to find the correlation between electronic structure and biological activity. The 35Cl NQR resonance frequencies ( ?Q) measured at 77 K have been correlated with the following parameters characterising their biological activity: biological half-life period ( t0.5), affinity to benzodiazepine receptor (IC 50) and mean dose equivalent. The results of experimental study of some benzodiazepine derivatives by nuclear quadrupole resonance of 35Cl nuclei are compared with theoretical results based on DFT calculations which were carried out by means of Gaussian'98 W software.

Bronisz, K.; Ostafin, M.; Poleshchuk, O. Kh.; Mielcarek, J.; Nogaj, B.

2006-11-01

70

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. Frtsch; 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

71

Fine structure of the isoscalar giant quadrupole resonance in 40Ca due to Landau damping?  

Microsoft Academic Search

The fragmentation of the Isoscalar Giant Quadrupole Resonance (ISGQR) in 40Ca has been investigated in high energy-resolution experiments using proton inelastic scattering at Ep=200 MeV. Fine structure is observed in the region of the ISGQR and its characteristic energy scales are extracted from the experimental data by means of a wavelet analysis. The experimental scales are well described by Random

I. Usman; Z. Buthelezi; J. Carter; G. R. J. Cooper; R. W. Fearick; S. V. Frtsch; H. Fujita; Y. Fujita; Y. Kalmykov; P. von Neumann-Cosel; R. Neveling; P. Papakonstantinou; A. Richter; R. Roth; A. Shevchenko; E. Sideras-Haddad; F. D. Smit

2011-01-01

72

Observation of H+ Ions in K2OsCl6 by Chlorine Nuclear Quadrupole Resonance  

NASA Astrophysics Data System (ADS)

Chlorine nuclear quadrupole resonance spectra of K2OsCl6 crystals containing hydrogen ions are observed at 77 and 298 K. The relative positions and intensities of the observed satellite lines indicate that the impurity ions are situated at the vacant octahedral sites in the lattice. Further, the results provide evidence for the motion of the hydrogen ions through the lattice at 298 K with a characteristic residence time of the order of 10-4 sec.

Armstrong, Robin L.; Mintz, J. David; D'Iorio, Marie

1980-03-01

73

Determining the radiofrequency dipole and quadrupole effects in quarter wave resonators  

Microsoft Academic Search

The asymmetry of a quarter wave resonator (QWR) around the beam axis z causes deflection and additional (de)focusing of the beam: these effects are immediately related to the first terms, the dipole and the quadrupole, in a Fourier-Bessel multipole expansion of the quasistatic potential phi the non-relativistic impulse approximation for heavy ion acceleration is given. General features of multipole dependencies

Marco Cavenago

1992-01-01

74

Structural Investigation by Means of Nuclear Quadrupole Resonance III (Arsenic Tribromide)  

Microsoft Academic Search

The structure of AsBr3 is investigated by means of nuclear quadrupole resonance at about 10C, and is compared with Braekken's results of X-ray analysis. AsBr3 has the orthorhombic symmetry, and the Br-As-Br bond angles are 9938' 16', 9914' 18' and 10251' 13'. The polar angles specifying the directions of the As-Br bonds with respect to the crystal axes are (624'

Kenji Shimomura

1957-01-01

75

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

DOEpatents

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

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

1993-01-01

76

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

77

Evidence for low-temperature internal dynamics in Cu 12As 4S 13 according to copper NQR and nuclear relaxation  

NASA Astrophysics Data System (ADS)

63,65Cu nuclear quadrupole resonance (NQR) was applied to study the natural mineral Cu 12As 4S 13 (tennantite) in the temperature range 4.2-210 K. The obtained results point to the presence of field fluctuations caused by internal motions in tennantite. Consistently with the crystal structure, the experimental data can be described by an occurrence of a magnetic phase transition, which takes place near 65 K. The low-temperature phase is characterized by Cu(II) electron magnetic moments freezing in the form of a spin-glass-like constitution.

Gainov, R. R.; Dooglav, A. V.; Pen'kov, I. N.

2006-12-01

78

14N nuclear quadrupole resonance and proton spinlattice relaxation study of phase transition in pyridazine perchlorate  

Microsoft Academic Search

The temperature dependence of the 14N nuclear quadrupole resonance frequencies in pyridazine perchlorate has been measured by double resonance. The results show that in the low temperature phase the pyridazinium ions are static, while in the high temperature phase the ions reorient around the normal to the plane of the ring between six equivalent orientations in agreement with the X-ray

J. Seliger; V. agar; T. Asaji

2009-01-01

79

A High-Efficiency Resonant Cavity for Measurement of a Beam Quadrupole Moment  

SciTech Connect

Many particle accelerator applications can benefit from online pulse-by-pulse nonintercepting emittance measurement system. Recently, there has been much interest in performing such a measurement with a set of resonant quadrupole-mode cavities. This article explores a geometry to achieve an enhanced shunt impedance in such a cavity by adding a set of posts forming capacitive gaps near the beam pipe outer radius. For typical diagnostic cavity applications, a five-fold increase in shunt impedance can be obtained with this method. The effect of errors in cavity fabrication on the required mode structure are explored.

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

2005-10-26

80

X-Ray Diffraction and Nuclear Quadrupole Resonance Studies of Chromium Trichloride  

Microsoft Academic Search

The infinite-layer compound CrCl3 is found to undergo a first-order phase transformation near 240K. The crystal structures of the high- and low-temperature phases have been elucidated by detailed x-ray diffraction and 35Cl nuclear quadrupole resonance studies. The previously reported structure for CrCl3 is shown to be incorrect. The present single-crystal diffraction results at 298 and 225K give monoclinic (C2\\/m: a0=5.959

Bruno Morosin; Albert Narath

1964-01-01

81

Simplest photonuclear reactions accompanied by the excitation of isovector giant dipole and quadrupole resonances: Semimicroscopic description  

SciTech Connect

A semimicroscopic approach based on the continuum version of the random-phase approximation (CRPA) and on a semiphenomenological inclusion of the fragmentation effect is applied to describing cross sections for photoabsorption and direct plus semidirect and inverse reactions accompanied by the excitation of isovector giant dipole and quadrupole resonances. In addition to the spinless part of the Landau-Migdal interaction and a partly self-consistent phenomenological mean field of the nucleus, that version of the approach which is used here takes into account isovector separable velocity-dependent forces, as well as the effect of the fragmentation shift of the giant-resonance energy. The results obtained by calculating various features of the aforementioned cross sections for a number of magic and semimagic medium-mass nuclei are compared with respective experimental data.

Tulupov, B. A., E-mail: tulupov@cpc.inr.ac.ru [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Urin, M. H. [National Research Nuclear University MEPhI (Russian Federation)

2012-09-15

82

Electron cyclotron resonance near the axis of a quadrupole linear trap  

SciTech Connect

The quasi-longitudinal propagation of an extraordinary electromagnetic wave in the vicinity of the electron cyclotron resonance layer in an open linear trap with a quadrupole magnetic field is studied analytically, taking into account the inhomogeneity of the magnetic field in a paraxial approximation. The ray trajectories are derived from a simplified dispersion equation, that is, nonetheless able to accurately describe the transition from finite to zero perpendicular refractive index. A criterion for an on-axis resonance point to be an attractor for the ray trajectories is formulated, which generalizes a similar criterion for axisymmetric linear traps derived in a recent paper [D. S. Bagulov and I. A. Kotelnikov, Phys. Plasmas 19, 082502 (2012)].

Kotelnikov, I. A. [Budker Institute of Nuclear Physics, Lavrentyev Av. 11, Novosibirsk 630090 (Russian Federation); Rome, M. [INFN Sezione di Milano and Dipartimento di Fisica, Universita degli Studi di Milano, Via Celoria 16, I-20133 Milano (Italy)

2012-12-15

83

Defective BN Nanotubes: A Density Functional Theory Study of B-11 and N-14 NQR Parameters  

NASA Astrophysics Data System (ADS)

A density functional theory (DFT) study is performed to investigate the influence of structural defects on the electronic structure properties of perfect boron nitride nanotubes (BNNTs). To this aim, as representative models, the single-walled (6,0) BNNT consisting of 36 boron, 36 nitrogen, and 12 hydrogen atoms and the single-walled (4,4) BNNT consisting of 36 boron, 36 nitrogen, and 16 hydrogen atoms are considered. The nuclear quadrupole resonance (NQR) parameters are calculated and compared in two perfect and defective models of the considered BNNTs. The results indicate that due to formation of non-hexagonal rings in the defective model because of removing a B-N bond, the NQR parameters at the sites of first neighbouring nuclei are significantly influenced by imposed perturbation, however, the sites of other nuclei, farther from perturbation, remain almost unchanged. The calculations are performed at the level of the BLYP method and 6-31G* standard basis set using the GAUSSIAN 98 package

Giahi, Masoud; Mirzaei, Mahmoud

2009-04-01

84

Pure Quadrupole Resonance of OXYGEN(17) Compounds by Proton Double Resonance  

Microsoft Academic Search

('17)O pure quadruple resonance spectra were observed in ice Ih, O(,3), H(,2)O(,2), IrClCO(PPh(,3))(,2)('17)O(,2) (Vaska's Compound) and the bromine analog of the latter. Double resonance between ('17)O and ('1)H in zero applied field was used as described by Slusher and Hahn except that the ice and O(,3) samples did not require modulation of the resonant RF. Observed resonances were: ice 1.70(5),

William Thomas Dixon

1980-01-01

85

NQR Study of Dynamics in Incommensurate Phases  

NASA Astrophysics Data System (ADS)

Dynamic processes in solids exhibiting structurally incommensurate phases are briefly reviewed, and the application of NMR and NQR is discussed. The unique utility of these methods, - arising due to, on one hand, the microscopic resonant nature of the probe used and, on the other, the presence of periodic, though incommensurable, structure - , is brought out by presenting recent results in a prototype system (Rb2ZnCl4) in the presence of randomly quenched disorder. In particular, the interesting new methodology of measuring, by analysing NQR spin echo modulation, ultra-slow diffusion like collective motions of ensembles of atoms in the presence of pinning effects due to disorder is illustrated with new results.

Sastry, V. S. S.; Venu, K.; Maheswari, S. Uma; Subramanian, R. K.

2000-02-01

86

Fine structure of the isoscalar giant quadrupole resonance in 40Ca due to Landau damping?  

E-print Network

The fragmentation of the Isoscalar Giant Quadrupole Resonance (ISGQR) in 40Ca has been investigated in high energy-resolution experiments using proton inelastic scattering at E_p = 200 MeV. Fine structure is observed in the region of the ISGQR and its characteristic energy scales are extracted from the experimental data by means of a wavelet analysis. The experimental scales are well described by Random Phase Approximation (RPA) and second-RPA calculations with an effective interaction derived from a realistic nucleon-nucleon interaction by the Unitary Correlation Operator Method (UCOM). In these results characteristic scales are already present at the mean-field level pointing to their origination in Landau damping, in contrast to the findings in heavier nuclei and also to SRPA calculations for 40Ca based on phenomenological effective interactions, where fine structure is explained by the coupling to two-particle two-hole (2p-2h) states.

I. Usman; Z. Buthelezi; J. Carter; G. R. J. Cooper; R. W. Fearick; S. V. Frtsch; H. Fujita Y. Fujita; Y. Kalmykov; P. von Neumann-Cosel; R. Neveling; P. Papakonstantinou; A. Richter; R. Roth; A. Shevchenko; E. Sideras-Haddad; F. D. Smit

2011-03-04

87

SP(6,R) Symmetry and the Giant Quadrupole Resonance in MAGNESIUM-24.  

NASA Astrophysics Data System (ADS)

Microscopic nuclear calculations are approached by partitioning the many-nucleon Hilbert space as a direct sum of symplectic bands. Computational techniques and algorithms which utilize commutator methods, and which are more powerful than the more straight-forward purely shell-model approach, are developed for calculating the matrix elements of two-body operators within such an Sp(6,R) (R-HOOK) U(3) symmetry-adapted basis. These techniques may be generalized to n-body operators of any n. These computational tools are applied to the study of the Giant Quadrupole Resonance in ('24)Mg: the final calculation presented uses a microscopic Hamiltonian consisting of the kinetic energy plus the semi-realistic two-body Brink -Boeker B1 potential within a space consisting of three symplectic bands up to 6(H/2PI)(omega) total excitation.

Reske, Edward John

1984-06-01

88

Fluctuation properties of the strength function associated with the giant quadrupole resonance in {sup 208}Pb  

SciTech Connect

We performed fluctuation analysis by means of the local scaling dimension for the strength function of the isoscalar (IS) giant quadrupole resonance (GQR) in {sup 208}Pb where the strength function is obtained by the shell model calculation including 1p1h and 2p2h configurations. It is found that at almost all energy scales, fluctuation of the strength function obeys the Gaussian orthogonal ensemble (GOE) random matrix theory limit. This is contrasted with the results for the GQR in {sup 40}Ca, where at the intermediate energy scale of about 1.7 MeV, a deviation from the GOE limit was detected. It is found that the physical origin for this different behavior of the local scaling dimension is ascribed to the difference in the properties of the damping process.

Aiba, Hirokazu; Matsuo, Masayuki; Nishizaki, Shigeru; Suzuki, Toru [Kyoto Koka Women's College, 38 Kadono-cho Nishikyogoku, Ukyo-ku, 615-0882 Kyoto (Japan); Department of Physics, Faculty of Science, Niigata University, 950-2181 Niigata (Japan); Faculty of Humanities and Social Sciences, Iwate University, 3-18-34 Ueda, 020-8550 Morioka (Japan); Department of Physics, Tokyo Metropolitan University, 192-0397 Hachioji (Japan)

2011-02-15

89

Zeeman Study on Nuclear Quadrupole Resonances in AsI3 and AsI3\\\\cdot3S8  

Microsoft Academic Search

Principal axis systems and asymmetry parameter of the electric field gradient tensors were determined by studying Zeeman effect of nuclear quadrupole resonances of As75 and I127. The iodine resonance in AsI3 showed that there are three principal axis system swhose z axes form a trigonal pyramid having an apex angle of 91.7 2.5. The fact that this angle did not

Yoshihito Abe

1958-01-01

90

Zeeman effect of nuclear quadrupole resonance in 1-chloro-2,4-dinitrobenzene  

Microsoft Academic Search

The Zeeman effect of NQR was studied in 1-chloro-2,4-dinitrobenzene. A low value of the asymmetry parameter (0.10) was obtained. Four physically inequivalent field gradients were located and their orientations in the crystallographic abc system were determined using symmetry considerations. From these data the orientations of the molecules in the unit cell were determined. The results agree well with the two-dimensional

M. S. Vijaya; J. Ramakrishna

1973-01-01

91

Two-dimensional NQR using ultra-broadband electronics.  

PubMed

We have recently developed an ultra-broadband instrument that can effectively excite and detect NMR and NQR signals over a wide frequency range. Our current system operates between 100 kHz and 3.2 MHz using an un-tuned sample coil. The major benefits of this instrument compared to conventional NQR/NMR systems include increased robustness, ease of use (in particular for multi-frequency experiments), and elimination of the need for tuning adjustments in the hardware. Here we describe its use for performing two-dimensional (2D) scans, which allow improved interpretation of complex NQR spectra by detecting the connected resonances. Our method relies on population transfers between the three energy levels of spin-1 nuclei (such as (14)N) by using multi-frequency excitation and a single RF coil. Experimental results on pure samples and mixtures are also presented. PMID:24495675

Mandal, S; Song, Y-Q

2014-03-01

92

Temperature dependences of the 39K and 85Rb quadrupole coupling constants in paraelectric KH2PO4, KH2AsO4, RbH2PO4, and RbH2AsO4  

NASA Astrophysics Data System (ADS)

Temperature dependences of 39K and 85Rb nuclear-quadrupole resonance frequencies have been measured in tetragonal paraelectric phases of KH2PO4, KH2AsO4, RbH2PO4, and RbH2AsO4. The measured quadrupole coupling constants are compared to the quadrupole coupling constants calculated in a point-charge model in which a cation bears a positive charge e whereas the negative charge -e of a PO-4 or AsO-4 ion is, in a time average, equally shared by the four oxygen atoms. The influence of the anisotropic thermal expansion of the crystal lattices on the temperature dependence of the quadrupole coupling constants is calculated in the same model. Both the calculated and measured quadrupole coupling constants as well as the calculated and measured temperature coefficients of the quadrupole coupling constants agree within the experimental error. Thus the ``antiferroelectric'' Slater configurations of the H2PO4 and of the H2AsO4 groups which seem to have a strong influence on the 75As NQR frequencies in the tetragonal paraelectric phase are of a local nature and they have nearly no influence on the potassium and rubidium NQR frequencies.

Seliger, J.; agar, V.

1994-06-01

93

Density functional calculations of 14N and 11B NQR parameters in the H-capped (6,0) and (4,4) single-walled BN nanotubes  

NASA Astrophysics Data System (ADS)

Density functional theory (DFT) calculations were performed to calculate nitrogen-14 and boron-11 nuclear quadrupole resonance (NQR) spectroscopy parameters in the representative considered models of zigzag and armchair boron nitride nanotubes (BNNTs) for the first time. The considered models consisting of 1 nm length of H-capped (6,0) and (4,4) single-walled BNNT were first allowed to fully relax and then the NQR calculations were performed on the geometrically optimized models. The evaluated nuclear quadrupole coupling constants and asymmetry parameters for the mentioned nuclei reveal that the considered models can be divided into four layers of nuclei with an equivalent electrostatic environment where those nuclei at the ends of tubes have a very strong electrostatic environment compared to the other nuclei along the length of tubes. Those nuclei at the center of the tube length also have an equivalent electrostatic environment. The calculations were performed based on the B3LYP DFT method and 6-311G** and 6-311++G** standard basis sets using the Gaussian 98 package of program.

Mirzaei, Mahmoud; Hadipour, Nasser L.

2008-02-01

94

Magnetic correlations in La(2-x)Sr(x)CuO4 from NQR relaxation and specific heat  

NASA Technical Reports Server (NTRS)

La-139 and Cu-63 Nuclear Quadrupole Resonance (NQR) relaxation measurements in La(2-x)Sr(x)CuO4 for x ranging from 0 up to 0.3, with particular emphasis on the effect of doping on the Cu(2+) magnetic correlations and dynamics, are reviewed. In the low doping limit, x less than or equal to 0.05, the results can be interpreted consistently in terms of a simple phenomenological 'two-fluids' model whereby the effect of thermally-activated mobile O(2p) holes is the one of disrupting locally the Cu(2+) spin correlations. For x greater than or equal to 0.1, the results indicate the onset, as T approaches T(sub c)(+), of a strong coupling between Cu(2+) spins and the Fermi liquid of O(2p) holes leading to the apparent disappearance of localized Cu(2+) moment in connection with the opening of a superconducting gap.

Borsa, F.; Rigamonti, A.

1991-01-01

95

Giant Quadrupole Resonances in 208Pb, the nuclear symmetry energy and the neutron skin thickness  

E-print Network

Recent improvements in the experimental determination of properties of the Isovector Giant Quadrupole Resonance (IVGQR), as demonstrated in the A=208 mass region, may be instrumental for characterizing the isovector channel of the effective nuclear interaction. We analyze properties of the IVGQR in 208Pb, using both macroscopic and microscopic approaches. The microscopic method is based on families of non-relativistic and covariant Energy Density Functionals (EDF), characterized by a systematic variation of isoscalar and isovector properties of the corresponding nuclear matter equations of state. The macroscopic approach yields an explicit dependence of the nuclear symmetry energy at some subsaturation density, for instance S(\\rho=0.1 fm^{-3}), or the neutron skin thickness \\Delta r_{np} of a heavy nucleus, on the excitation energies of isoscalar and isovector GQRs. Using available data it is found that S(\\rho=0.1 fm{}^{-3})=23.3 +/- 0.6 MeV. Results obtained with the microscopic framework confirm the correlation of the \\Delta r_{np} to the isoscalar and isovector GQR energies, as predicted by the macroscopic model. By exploiting this correlation together with the experimental values for the isoscalar and isovector GQR energies, we estimate \\Delta r_{np} = 0.14 +/- 0.03 fm for 208Pb, and the slope parameter of the symmetry energy: L = 37 +/- 18 MeV.

X. Roca-Maza; M. Brenna; B. K. Agrawal; P. F. Bortignon; G. Col; Li-Gang Cao; N. Paar; D. Vretenar

2013-03-05

96

Chemical mass shifts in resonance ejection experiments in quadrupole ion traps and ESI-FT-orbitrap mass spectrometry  

Microsoft Academic Search

Chemical mass shifts are measured in quadrupole ion traps operated in the mass-selective instability scan with resonance ejection. Chemical mass shift is the result of compound-dependent collisional modification of the ejection delay produced by field faults near the endcap electrode apertures. Both dissociative and non-dissociative collisions can occur but the dissociative collisions make the predominant contribution to the chemical mass

Hongyan Li

2003-01-01

97

Fine Structure in the Energy Region of the Isoscalar Giant Quadrupole Resonance: Characteristic Scales from a Wavelet Analysis  

Microsoft Academic Search

Fine structure in the energy region of the isoscalar giant quadrupole resonance in nuclei is observed in high-resolution proton scattering experiments at iThemba LABS over a wide mass range. A novel method based on wavelet transforms is introduced for the extraction of scales characterizing the fine structure. A comparison with microscopic model calculations including two-particle two-hole (2p2h) degrees of freedom

A. Shevchenko; J. Carter; R. W. Fearick; S. V. Frtsch; 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

2004-01-01

98

Thermochemical properties of aromatic radicals determined by Fouriertransform ion cyclotron resonance and flowing afterglow quadrupole-octopole-quadrupole mass spectrometry  

Microsoft Academic Search

Flowing Afterglow Guided-Ion Beam (FA-GIB) mass spectrometry allows the determination of a variety of thermochemical values for ionic and neutral molecules, including proton affinities, electron affinities, halide affinities, bond dissociation energies, and reaction threshold energies for endoergic ion-molecule reactions. Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry is another powerful mass spectrometry technique, one uniquely suited to kinetics studies of ion-molecule

John W Torchia

2005-01-01

99

Suppression of electron correlations in the collapsed tetragonal phase of CaFe2As2 under ambient pressure demonstrated by As75 NMR/NQR measurements  

SciTech Connect

The static and the dynamic spin correlations in the low-temperature collapsed tetragonal and the high-temperature tetragonal phase in CaFe2As2 have been investigated by As75 nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. Through the temperature (T) dependence of the nuclear spin lattice relaxation rates (1/T1) and the Knight shifts, although stripe-type antiferromagnetic (AFM) spin correlations are realized in the high-temperature tetragonal phase, no trace of the AFM spin correlations can be found in the nonsuperconducting, low-temperature, collapsed tetragonal (cT) phase. Given that there is no magnetic broadening in As75 NMR spectra, together with the T-independent behavior of magnetic susceptibility ? and the T dependence of 1/T1T?, we conclude that Fe spin correlations are completely quenched statically and dynamically in the nonsuperconducting cT phase in CaFe2As2.

Furukawa, Yuji [Ames Laboratory; Roy, Beas [Ames Laboratory; Ran, Sheng [Ames Laboratory; Budko, Sergey L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

2014-03-20

100

Coexistence of multiple charge-density waves and superconductivity in SrPt2As2 revealed by 75As-NMR /NQR and 195Pt-NMR  

NASA Astrophysics Data System (ADS)

The relationship between charge-density wave (CDW) orders and superconductivity in arsenide superconductor SrPt2As2 with Tc=5.2 K which crystallizes in the CaBe2Ge2 -type structure was studied by 75As nuclear magnetic resonance (NMR) measurements up to 520 K, and 75As nuclear quadrupole resonance (NQR) and 195Pt-NMR measurements down to 1.5 K. At high temperature, 75As-NMR spectrum and nuclear-spin-relaxation rate (1 /T1) have revealed two distinct CDW orders, one realized in the As-Pt-As layer below TCDWAs (1 )=410 K and the other in the Pt-As-Pt layer below TCDWAs (2 )=255 K . The 1 /T1 measured by 75As-NQR shows a clear Hebel-Slichter peak just below Tc and decreases exponentially well below Tc. Concomitantly, 195Pt Knight shift decreases below Tc. Our results indicate that superconductivity in SrPt2As2 is in the spin-singlet state with an s -wave gap and is robust under the two distinct CDW orders in different layers.

Kawasaki, Shinji; Tani, Yoshihiko; Mabuchi, Tomosuke; Kudo, Kazutaka; Nishikubo, Yoshihiro; Mitsuoka, Daisuke; Nohara, Minoru; Zheng, Guo-qing

2015-02-01

101

Sub parts-per-million mass measurement accuracy of intact proteins and product ions achieved using a dual electrospray ionization quadrupole fourier transform ion cyclotron resonance mass spectrometer  

Microsoft Academic Search

High mass measurement accuracy (MMA) is demonstrated for intact proteins and subsequent collision-induced dissociation product\\u000a ions using internal calibration. Internal calibration was accomplished using a dual electrospray ionization source coupled\\u000a with a hybrid quadrupole Fourier transform ion cyclotron resonance (Q-FT-ICR) mass spectrometer. Initially, analyte ions generated\\u000a via the first electrospray (ESI) emitter are isolated and dissociated in the external quadrupole.

D. Keith Williams Jr.; Adam M. Hawkridge; David C. Muddiman

2007-01-01

102

Nuclear Quadrupole Resonance and Electron Spin Resonance in C(NH2)3Al(SO4)2.6H2O and Isomorphous Compounds  

Microsoft Academic Search

The temperature dependence of the nuclear quadrupole coupling parameters, eQqh, of Al and Ga has been measured in the ferroelectric compound C(NH2)3Al(SO4)2.6H2O (GAlSH) and three other isomorphous compounds that result when Ga replaces Al and SeO4 replaces SO4. Measurements were also made on deuterated GAlSH. The temperature dependence of the electron spin resonance (ESR) of Cr3+, substituted for Al or

Gerald Burns

1961-01-01

103

Investigation of the Fission Decay of the Isoscalar Giant Quadrupole Resonance in 238U by Electron and Positron-Induced Fission  

Microsoft Academic Search

The controversial results for the fission decay of the isoscalar giant quadrupole resonance in 238U have been investigated by electron- and positron-induced fission experiments (Ee=10-35 MeV). The measured cross-section ratio sigma-sigma+ and absolute cross sections were analyzed with use of available distorted-wave Born-approzimation virtual-photon spectra. Within this analysis no fission decay of the giant quadropole resonance could be detected, in

H. Strher; R. D. Fischer; J. Drexler; K. Huber; U. Kneissl; R. Ratzek; H. Ries; W. Wilke; H. J. Maier

1981-01-01

104

Nuclear quadrupole quantum beat spectroscopy in the electronic ground state of a polyatomic molecule by an IR-UV double resonance method  

NASA Astrophysics Data System (ADS)

The feasibility of determining nuclear quadrupole hyperfine splittings in the ground electronic state of a polyatomic molecule using a double resonance quantum beat method has been demonstrated. Pyrimidine molecules were coherently excited into single rotational states of the S 0 20 1 (13a 1) vibrational level. The resulting hyperfine level coherences were then probed, after a variable time delay, by excitation to the S 1 O 0 level with subsequent fluorescence detection. Analysis showed that the quadrupole structure in the 20 1 (13a 1) level is similar to that previously measured in the vibrational ground state. Applications of this method and possible experimental extensions are discussed.

Carter, Robert T.; Walther, Th.; Bitto, H.; Huber, J. Robert

1995-06-01

105

Electronic properties of Y-Ba-Cu-O superconductors as seen by Cu and O NMR/NQR  

SciTech Connect

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) allow the investigation of electronic properties at the atomic level. The authors will report on such studies of typical members of the the Y-Ba-Cu-O family such as YBa2Cu30(6 + x) (1-2-3-(6 + x)), YBa2Cu4O8 (1-2-4) and Y2Ba4Cu7015 (2-4-7) with many examples of recent work performed in their laboratory. In particular, they will deal with Knight shift and relaxation studies of copper and oxygen. They will discuss important issues of current studies such as: (1) Existence of a common electronic spin-susceptibility in the planes (and perhaps in the chains) of 1-2-4; (2) Strong evidence for the existence of a pseudo spin-gap of the antiferromagnetic fluctuations in 1-2-4 and 2-4-7; (3) Evidence for d-wave pairing in 1-2-4; (4) Strong coupling of inequivalent Cu-O planes in 2-4-7 and possible origin for the high Tc value of this compound; and (5) The possibility to describe NMR data in the framework of a charge-excitation picture.

Brinkmann, D.

1995-04-01

106

Electronic properties of Y-Ba-Cu-O superconductors as seen by Cu and O NMR/NQR  

NASA Technical Reports Server (NTRS)

Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) allow the investigation of electronic properties at the atomic level. We will report on such studies of typical members of the the Y-Ba-Cu-O family such as YBa2Cu30(6 + x) (1-2-3-(6 + x)), YBa2Cu4O8 (1-2-4) and Y2Ba4Cu7015 (2-4-7) with many examples of recent work performed in our laboratory. In particular, we will deal with Knight shift and relaxation studies of copper and oxygen. We will discuss important issues of current studies such as: (1) Existence of a common electronic spin-susceptibility in the planes (and perhaps in the chains) of 1-2-4; (2) Strong evidence for the existence of a pseudo spin-gap of the antiferromagnetic fluctuations in 1-2-4 and 2-4-7; (3) Evidence for d-wave pairing in 1-2-4; (4) Strong coupling of inequivalent Cu-O planes in 2-4-7 and possible origin for the high Tc value of this compound; and (5) The possibility to describe NMR data in the framework of a charge-excitation picture.

Brinkmann, D.

1995-01-01

107

Experimental Test of a Newly Proposed Empirical Relationship between the Centroid and Width of the Giant Quadrupole-Resonance and the Neutron Binding-Energy of the Nucleus  

E-print Network

. Ye Physics Department, University ofNotre Dame, Notre Dame, Indiana 46556 A. Galonsky, T. Murakami, * and J. S. Winfield Department ofPhysics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing..., Michigan 48824 Y.-W. Lui and D. H. Youngblood Cyclotron Institute, Texas A &M University, College Station, Texas 77843 (Received 27 October 1989) Via the inelastic scattering of 50 MeV/nucleon ' N ions, the giant quadrupole resonance in "Ni and Ni has...

Garg, U.; Beard, K. B.; Ye, D.; Galonsky, A.; Murakami, T.; Winfield, J. S.; Lui, YW; Youngblood, David H.

1990-01-01

108

Magnetic correlations in La(2-x)Sr(x)CuO4 from NQR relaxation and specific heat  

NASA Technical Reports Server (NTRS)

La-139 and Cu-63 Nuclear Quadrupole Resonance (NQR) relaxation measurements in La(2-x)Sr(x)CuO4 for O = to or less than 0.3 and in the temperature range 1.6 + 450 K are analyzed in terms of Cu(++) magnetic correlations and dynamics. It is described how the magnetic correlations that would result from Cu-Cu exchange are reduced by mobile charge defects related to x-doping. A comprehensive picture is given which explains satisfactorily the x and T dependence of the correlation time, of the correlation length and of the Neel temperature T(sub n)(x) as well as being consistent with known electrical resistivity and magnetic susceptibility measurements. It is discussed how, in the superconducting samples, the mobile defects also cause the decrease, for T yields T(sub c)(+) of the hyperfine Cu electron-nucleus effective interaction, leading to the coexistence of quasi-localized, reduced magnetic moments from 3d Cu electrons and mobile oxygen p-hole carriers. The temperature dependence of the effective hyperfine field around the superconducting transition yields an activation energy which could be related to the pairing energy. New specific heat measurements are also presented and discussed in terms of the above picture.

Borsa, F.; Rigamonti, A.

1990-01-01

109

A miniaturized NQR spectrometer for a multi-channel NQR-based detection device.  

PubMed

A low frequency (0.5-5 MHz) battery operated sensitive pulsed NQR spectrometer with a transmitter power up to 5 W and a total mass of about 3 kg aimed at detecting (14)N NQR signals, predominantly of illicit materials, was designed and assembled. This spectrometer uses a standard software defined radio (SDR) platform for the data acquisition unit. Signal processing is done with the LabView Virtual instrument on a personal computer. We successfully tested the spectrometer by measuring (14)N NQR signals from aminotetrazole monohydrate (ATMH), potassium nitrate (PN), paracetamol (PCM) and trinitrotoluene (TNT). Such a spectrometer is a feasible component of a portable single or multichannel (14)N NQR based detection device. PMID:25233110

Begu, Samo; Jazbinek, Vojko; Pirnat, Janez; Trontelj, Zvonko

2014-10-01

110

A miniaturized NQR spectrometer for a multi-channel NQR-based detection device  

NASA Astrophysics Data System (ADS)

A low frequency (0.5-5 MHz) battery operated sensitive pulsed NQR spectrometer with a transmitter power up to 5 W and a total mass of about 3 kg aimed at detecting 14N NQR signals, predominantly of illicit materials, was designed and assembled. This spectrometer uses a standard software defined radio (SDR) platform for the data acquisition unit. Signal processing is done with the LabView Virtual instrument on a personal computer. We successfully tested the spectrometer by measuring 14N NQR signals from aminotetrazole monohydrate (ATMH), potassium nitrate (PN), paracetamol (PCM) and trinitrotoluene (TNT). Such a spectrometer is a feasible component of a portable single or multichannel 14N NQR based detection device.

Begu, Samo; Jazbinek, Vojko; Pirnat, Janez; Trontelj, Zvonko

2014-10-01

111

85Rb, 87Rb, and 17O nuclear-quadrupole-resonance study of Rb(H1-xDx)2PO4  

NASA Astrophysics Data System (ADS)

The 85Rb, 87Rb, and 17O nuclear-quadrupole-resonance frequencies and line shapes have been measured in RbH2PO4 and in Rb(H1-xDx)2PO4 (x=0.5,0.7) with the nuclear-quadrupole double-resonance technique. The results show that in the paraelectric phase the Rb+ ions move in a single-site potential, whereas the protons are dynamically disordered between two sites in the O-H...O hydrogen bonds. The ferroelectric phase transition in RbH2PO4 is associated with the freezing out of the proton motion in the O-H...O hydrogen bonds that induces a shift of the Rb+ ions along the ferroelectric axis. In the partially deuterated compounds the O-H...O hydrogen bonds are practically identical to the ones in pure RbH2PO4 and are thus only weakly influenced by the surrounding O-D...O bonds. The O-D...O bonds are, however, significantly more asymmetric and presumably longer than the O-H...O bonds.

Seliger, J.; agar, V.; Blinc, R.; Schmidt, V. H.

1990-09-01

112

Nuclear Quadrupole Interactions of 7Li and 51V in a Li3VO4 Single Crystal Studied by Nuclear Magnetic Resonance  

NASA Astrophysics Data System (ADS)

The rotation patterns of the nuclear magnetic resonances of 7Li (I=3/2) and 51V (I=7/2) in the nonlinear optical Li3VO4 single crystal were measured in two mutually perpendicular crystal planes. From these results, the quadrupole coupling constants and the asymmetry parameters at room temperature were determined for the first time as follows: e2qQ/h=53.68 2 kHz and ?=0.169 for 7Li, and e2qQ/h=1.44 2 MHz and ?=0 for 51V. The symmetry for the electric field gradient (EFG) of V ions surrounded by four oxygen atoms is higher than that of Li ions surrounded by four oxygen atoms. The principal axes of the EFG tensor are a=Y, b=Z, c=X for 7Li, and a=b=X, c=Z for 51V nucleus. Also, the 7Li and the 51V spin-lattice relaxation rates were measured, and the behavior is quite similar for both nuclei. The measured relaxation rate was found to be linear in the square of the temperature. The Raman process with a T2 dependence is considered to be more effective than the direct process for nuclear quadrupole relaxation.

Lim, Ae Ran; Park, Sung Ho; Kim, Jung Nam; Jang, Min Su

2003-02-01

113

Electron density distribution in cladribine (2-chloro-2?-deoxyadenosine) - A drug against leukemia and multiple sclerosis - Studied by multinuclear NQR spectroscopy and DFT calculations  

NASA Astrophysics Data System (ADS)

2-Chloro-2'-deoxyadenosine (Cladribine) chemotherapeutic drug has been studied experimentally in solid state by 35Cl NQR and NMR-NQR double resonance and theoretically by the Density Functional Theory. Fifteen resonance frequencies on 14N have been detected and assigned to particular nitrogen sites in the 2-CdA molecule. The effects of tautomerism, regioisomerism, conformations and molecular aggregations, related to intermolecular hydrogen bond formation, on the NQR parameters have been analysed within the DFT and AIM ( Atoms in Molecules) formalism. The properties of the whole molecule, the so-called global reactivity descriptors, have been calculated for a comparison of both syn and anti conformations of 2-CdA molecule to check the effect of crystal packing on molecular conformation.

Latosi?ska, J. N.; Latosi?ska, M.; Seliger, J.; agar, V.; Kazimierczuk, Z.

2009-07-01

114

Detection of an Unconventional Superconducting Phase in the Vicinity of the Strong First-Order Magnetic Transition in CrAs Using ^{75}As-Nuclear Quadrupole Resonance.  

PubMed

Pressure-induced superconductivity was recently discovered in the binary helimagnet CrAs. We report the results of measurements of nuclear quadrupole resonance for CrAs under pressure. In the vicinity of the critical pressure P_{c} between the helimagnetic (HM) and paramagnetic (PM) phases, a phase separation is observed. The large internal field remaining in the phase-separated HM state indicates that the HM phase disappears through a strong first-order transition. This indicates the absence of a quantum critical point in CrAs; however, the nuclear spin-lattice relaxation rate 1/T_{1} reveals that substantial magnetic fluctuations are present in the PM state. The absence of a coherence effect in 1/T_{1} in the superconducting state provides evidence that CrAs is the first Cr-based unconventional superconductor. PMID:25839303

Kotegawa, Hisashi; Nakahara, Shingo; Akamatsu, Rui; Tou, Hideki; Sugawara, Hitoshi; Harima, Hisatomo

2015-03-20

115

Zeeman Effect Study of the Nuclear Quadrupole Resonance of 81Br in 4,4'-Dibromodiphenylether and 4,4'-Dibromodiphenylether  

Microsoft Academic Search

The Zeeman effect of the 81Br NQR line was studied on single crystals of 4,4?-dibromodiphenylether and 4,4?-dibromodiphenylthioether. The relative orientations of the electric-field-gradient tensors acting upon the Br nuclei in the same molecule have been determined. The angle between the two Z-axis directions is 1290? 5? in the former compound and 10715? 4? in the latter. The angle

R. Ambrosetti; R. Angelone; P. Cecchi; A. Colligiani

1971-01-01

116

Detection of {sup 14}N and {sup 35}Cl in cocaine base and hydrochloride using NQR, NMR, and SQUID techniques  

SciTech Connect

Results from {sup 14}N pure NQR of cocaine in the free base form (cocaine base) yield a nuclear quadrupole coupling constant (NQCC) e{sup 2}Qq/h of 5.0229 ({+-}0.0001) MHz and an asymmetry parameter {eta} of 0.0395 ({+-}0.0001) at 295 K, with corresponding values of 5.0460 ({+-}0.0013) MHz and 0.0353 ({+-}0.0008) at 77 K. Both pure NQR (at 295-77 K) and a superconducting quantum interference device (SQUID) detector (at 4.2 K) were used to measure the very low (<1 MHz) {sup 14}N transition frequencies in cocaine hydrochloride; at 295 K the NQCC is 1.1780 ({+-}0.0014) MHz and the asymmetry parameter is 0.2632 ({+-}0.0034). Stepping the carrier frequency enables one to obtain a powder pattern without the severe intensity distortions that otherwise arise from finite pulse power. A powder pattern simulation using an NQCC value of 5.027 MHz and an asymmetry parameter {eta} of 0.2 agrees reasonably well with the experimental stepped-frequency spectrum. The use of pure NQR for providing nondestructive, quantitative, and highly specific detection of crystalline compounds is discussed, as are experimental strategies. 31 refs., 8 figs., 1 tab.

Yesinowski, J.P.; Buess, M.L.; Garroway, A.N. [Naval Research Lab., Washington, DC (United States); Ziegeweid, M.; Pines, A. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)

1995-07-01

117

I: Low Frequency NMR and NQR Using a dc SQUID. II: Variable-temperature 13C CP/MAS of Organometallics  

SciTech Connect

NMR and NQR at low frequencies are difficult prospects due to small nuclear spin polarization. Furthermore, the sensitivity'of the inductive pickup circuitry of standard spectrometers is reduced as the frequency is lowered. I have used a cw-SQUID (Superconducting QUantum Interference Device) spectrometer, which has no such frequency dependence, to study the local atomic environment of {sup 14}N via the quadrupolar interaction. Because {sup 14}N has spin I = 1 and a 0-6 MHz frequency range, it is not possible to obtain well-resolved spectra in high magnetic fields. I have used a technique to observe {sup 14}N NQR resonances via their effect on neighboring protons mediated by the heteronuclear dipolar interaction to study peptides and narcotics. The sensitivity of the SQUID is not enough to measure low-frequency surface (or other low spin density) systems. The application of spin-polarized xenon has been previously used to enhance polarization in conventional NMR experiments. Because xenon only polarizes spins with which it is in contact, it is surface selective. While differences in chemical shifts between surface and bulk spins are not large, it is expected that the differences in quadrupole coupling constant should be very large due to the drastic change of the electric field gradient surrounding spins at the surface. With this in mind, I have taken preliminary steps to measure SQUID detected polarization transfer from Xe to another spin species at 4.2 K and in small magnetic fields (<50 G). In this regime, the spin-lattice relaxation of xenon is dependent on the applied magnetic field. The results of our efforts to characterize the relaxation of xenon are presented. The final section describes the solid-state variable-temperature (VT) one- and two-dimensional {sup 13}C cross polarization (CP)/magic angle spinning (MAS) NMR of Hf({eta}{sup 5}-C{sub 5}H{sub 5}){sub 2}({eta}{sup 1}-C{sub 5}H{sub 5}){sub 2}, Zr({eta}{sup 5}-C{sub 5}H{sub 5}){sub 3}({eta}{sup 1}-C{sub 5}H{sub 5}) and Sn({eta}{sup 1}-C{sub 5}H{sub 5}){sub 4}. This work was undertaken in the hope of gaining insight into the intramolecuhrr dynamics, specifically which fluxional processes exist in the solid state, by what mechanism rearrangements are occurring, and the activation energies by which these processes are governed.

Ziegeweid, M.A.

1995-11-29

118

Coherent manipulation of quadrupole biexcitons in cuprous  

E-print Network

Coherent manipulation of quadrupole biexcitons in cuprous oxide by 2D femtosecond spectroscopy excitons from the ortho­para excitons picture is that the positions of the biexciton resonances are defined

Mukamel, Shaul

119

Nuclear magnetic resonance experiments with dc SQUID amplifiers  

SciTech Connect

The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al{sub 2}O{sub 3}/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 {times} 10{sup 17} in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO{sub 3} crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

Heaney, M.B. (California Univ., Berkeley, CA (USA). Dept. of Physics Lawrence Berkeley Lab., CA (USA))

1990-11-01

120

Fermilab Tevatron quadrupoles  

SciTech Connect

Details on the design, construction, and performance tests of Energy Saver/Doubler quadrupoles are presented along with recent data from the test of a special high gradient low beta prototype quadrupole.

Cooper, W.E.; Fisk, H.E.; Gross, D.A.; Lundy, R.A.; Schmidt, E.E.; Turkot, F.

1983-03-01

121

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

SciTech Connect

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

Shimada, Rintaro; Hamaguchi, Hiro-o, E-mail: hhama@nctu.edu.tw [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan (China)

2014-05-28

122

Nuclear Quadrupole Resonance in TiCl4, ThCl4, NbCl5, and TaCl5  

Microsoft Academic Search

The chlorine resonance in titanium tetrachloride has been re-examined, confirming the existence of four resonances. A chlorine-35 resonance at about 6 Mc has been discovered in thorium tetrachloride. The frequency suggests highly ionic bonding, which contradicts earlier conclusions from x-ray studies. Some double-bond character may be present in the Th&sngbnd;Cl bond.Niobium and chlorine resonances have been discovered in niobium pentachloride.

Allan H. Reddoch

1961-01-01

123

In-NQR study of heavy fermion superconductor Ce2PdIn8 under pressure  

NASA Astrophysics Data System (ADS)

115In nuclear quadrupole resonance measurements were performed in the normal state of the heavy fermion superconductor Ce2PdIn8 under hydrostatic pressure up to about 2.3 GPa. The observed behavior of the spin-lattice relaxation rate revealed a systematic suppression of antiferromagnetic critical fluctuations with increasing pressure.

Fukazawa, Hideto; Shimatani, Sho; Shigeta, Kazuhiko; Kohori, Yoh; Kaczorowski, Dariusz

2015-03-01

124

Detection of an Unconventional Superconducting Phase in the Vicinity of the Strong First-Order Magnetic Transition in CrAs Using As 75 -Nuclear Quadrupole Resonance  

NASA Astrophysics Data System (ADS)

Pressure-induced superconductivity was recently discovered in the binary helimagnet CrAs. We report the results of measurements of nuclear quadrupole resonance for CrAs under pressure. In the vicinity of the critical pressure Pc between the helimagnetic (HM) and paramagnetic (PM) phases, a phase separation is observed. The large internal field remaining in the phase-separated HM state indicates that the HM phase disappears through a strong first-order transition. This indicates the absence of a quantum critical point in CrAs; however, the nuclear spin-lattice relaxation rate 1 /T1 reveals that substantial magnetic fluctuations are present in the PM state. The absence of a coherence effect in 1 /T1 in the superconducting state provides evidence that CrAs is the first Cr-based unconventional superconductor.

Kotegawa, Hisashi; Nakahara, Shingo; Akamatsu, Rui; Tou, Hideki; Sugawara, Hitoshi; Harima, Hisatomo

2015-03-01

125

NQR investigation of pressure-induced charge transfer in oxygen-deficient YBa sub 2 Cu sub 3 O sub 7-. delta. (. delta. = 0. 38)  

SciTech Connect

Measurements of the pressure dependence of {sup 63}Cu nuclear quadrupole frequency in YBa{sub 2}Cu{sub 3}O{sub 6.62} from ambient pressure up to 1.5 GPa at 4k have been performed. {Tc} was found to increase with pressure: d{Tc}/dp {approximately} 5 K/GPa. All observed NQR lines are linear in pressure: dln{nu}{sub Q}/dp=z. We found positive z for the empty chain sites, consistent with ionic (Cu{sup 1+}) configuration in which the atom simply feels a squeezing lattice. Planar coppers close to the empty chains have positive z, while those that are close to full chains have z {approximately} 0. We present an analysis of the NQR result on the basis of the charge transfer model in which the mobile charges migrate from the chain to the plane sites. We deduced that a transfer of 0.021 holes to the O(2,3) sites would explain the result in YBa{sub 2}Cu{sub 3}O{sub 6.62}, whereas only 0.007 holes transfer in fully oxygenated YBa{sub 2}Cu{sub 3}O{sub 7}.

Reyes, A.P.; Ahrens, E.T.; Hammel, P.C.; Heffner, R.H. (Los Alamos National Lab., NM (United States)); Takigawa, M. (International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center)

1992-01-01

126

The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupole  

SciTech Connect

The ion current achievable from high intensity ECR sources for highly charged ions is limited by the high space charge. This makes classical extraction systems for the transport and subsequent matching to a radio frequency quadrupole (RFQ) accelerator less efficient. The direct plasma injection (DPI) method developed originally for the laser ion source avoids these problems and uses the combined focusing of the gap between the ion source and the RFQ vanes (or rods) and the focusing of the rf fields from the RFQ penetrating into this gap. For high performance ECR sources that use superconducting solenoids, the stray magnetic field of the source in addition to the DPI scheme provides focusing against the space charge blow-up of the beam. A combined extraction/matching system has been designed for a high performance ECR ion source injecting into an RFQ, allowing a total beam current of 10 mA from the ion source for the production of highly charged {sup 238}U{sup 40+} (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The stray magnetic field is shown to be critical in the case of a matched beam.

Rodrigues, G., E-mail: gerosro@gmail.com; Kanjilal, D.; Roy, A. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi (India)] [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi (India); Becker, R. [Institut fur Angewandte Physik der Universitaet, D-60054 Frankfurt/M (Germany)] [Institut fur Angewandte Physik der Universitaet, D-60054 Frankfurt/M (Germany); Hamm, R. W. [R and M Technical Enterprises, Inc., 4725 Arlene Place, Pleasanton, California 94566 (United States)] [R and M Technical Enterprises, Inc., 4725 Arlene Place, Pleasanton, California 94566 (United States); Baskaran, R. [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)] [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)

2014-02-15

127

The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupole.  

PubMed

The ion current achievable from high intensity ECR sources for highly charged ions is limited by the high space charge. This makes classical extraction systems for the transport and subsequent matching to a radio frequency quadrupole (RFQ) accelerator less efficient. The direct plasma injection (DPI) method developed originally for the laser ion source avoids these problems and uses the combined focusing of the gap between the ion source and the RFQ vanes (or rods) and the focusing of the rf fields from the RFQ penetrating into this gap. For high performance ECR sources that use superconducting solenoids, the stray magnetic field of the source in addition to the DPI scheme provides focusing against the space charge blow-up of the beam. A combined extraction/matching system has been designed for a high performance ECR ion source injecting into an RFQ, allowing a total beam current of 10 mA from the ion source for the production of highly charged (238)U(40+) (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The stray magnetic field is shown to be critical in the case of a matched beam. PMID:24593474

Rodrigues, G; Becker, R; Hamm, R W; Baskaran, R; Kanjilal, D; Roy, A

2014-02-01

128

The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupole  

NASA Astrophysics Data System (ADS)

The ion current achievable from high intensity ECR sources for highly charged ions is limited by the high space charge. This makes classical extraction systems for the transport and subsequent matching to a radio frequency quadrupole (RFQ) accelerator less efficient. The direct plasma injection (DPI) method developed originally for the laser ion source avoids these problems and uses the combined focusing of the gap between the ion source and the RFQ vanes (or rods) and the focusing of the rf fields from the RFQ penetrating into this gap. For high performance ECR sources that use superconducting solenoids, the stray magnetic field of the source in addition to the DPI scheme provides focusing against the space charge blow-up of the beam. A combined extraction/matching system has been designed for a high performance ECR ion source injecting into an RFQ, allowing a total beam current of 10 mA from the ion source for the production of highly charged 238U40+ (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The stray magnetic field is shown to be critical in the case of a matched beam.

Rodrigues, G.; Becker, R.; Hamm, R. W.; Baskaran, R.; Kanjilal, D.; Roy, A.

2014-02-01

129

Downregulation of Na(+)-NQR complex is essential for Vibrio alginolyticus in resistance to balofloxacin.  

PubMed

Increasingly isolated frequency of antibiotic-resistant V. alginolyticus strains in clinic and aquaculture has been reported, but the mechanisms of V. alginolyticus antibiotic resistance are largely absent. In the present study, native/SDS-PAGE based proteomics, which may provide information on protein-protein interaction, was utilized to investigate differential proteins of V. alginolyticus in resistance to balofloxacin. Ten proteins were altered, in which V12G01_04671, V12G01_00457, V12G01_15927, V12G01_15240, NqrA (spot 26), and NqrF (spot 30) were downregulated, while V12G01_22043, TolC, V12G01_15130, V12G01_19297 were upregulated. Importantly, the two components of Na(+)-NQR complex, NqrA and NqrF, were vertically lined and was further investigated. Western blotting assay indicated that downregulation of the two proteins contrasted sharply with upregulation of a control protein TolC, which was consistent with the result obtained from 2-DE gel analysis. Furthermore, overexpression of NqrA, NqrF and TolC resulted in decrease and elevation of bacterial survival ability in medium with balofloxacin, respectively. These results indicate that downregulation of Na(+)-NQR complex is essential for V. alginolyticus resistance to balofloxacin. This is the first report on the role of Na(+)-NQR complex in antibiotic resistance. This finding highlights the way to an understanding of antibiotic-resistant mechanisms in content of metabolic regulation. PMID:22465713

Li, Peipei; Liu, Xianjie; Li, Hui; Peng, Xuan-Xian

2012-05-17

130

Isomorphism and disorder in o-chlorohalobenzenes studied by NQR.  

PubMed

In this work we present experimental results that allow to characterize different solid modifications found in o-chlorohalobenzenes. Three disordered phases have been found in o-chlorobromobenzene. The stable phase at high temperature (phase I) is also obtained by quenching the sample at 77 K. Slow cooling allow to obtain the low temperature phase III which, on heating, transforms to phase II at 183 K and this, in turns, transforms to phase I at T~210 K. The disorder evidenced through the Nuclear Quadrupole Resonance spectra, is attributed to a random occupation of chlorine and bromine sites. In all phases there is evidence of molecular reorientations out of the benzene ring plane around the pseudo-symmetry axis between the atoms of Cl and Br. In o-chlorofluorobenzene two phases have been found depending on the cooling rate. One phase is disordered due to the random exchange of the occupation of Cl and F sites. In this case, there is also evidence of molecular reorientations out of the benzene ring plane, but in this case the reorientation is around the pseudo-symmetry axis that pass through the C-Cl bonds. Comparisons with the behavior of o-dichlorobenzene are also made. PMID:24440588

Prez, Silvina C; Wolfenson, Alberto; Zuriaga, Mariano

2014-01-01

131

The determination of deuterium atom coordinates and nuclear quadrupole interactions in lanthanum nicotinate dihydrate crystals by Nd3+-deuterium double resonance  

Microsoft Academic Search

We have obtained the ENDOR (electron nuclear double resonance) spectra of the four deuterons of the two D2O molecules coordinated to Nd3+ dilutely substituted for La3+ in La2(C5H4NCO2)6 (D2O4)4 (dimeric lanthanum nicotinate dihydrate) molecules in single crystals. From the measurements of the values of the anisotropic magnetic hyperfine interactions between Nd3+ and the deuterons we have determined the coordinates of

Clyde A. Hutchison; Thomas E. Orlowski

1980-01-01

132

The determination of deuterium atom coordinates and nuclear quadrupole interactions in lanthanum nicotinate dihydrate crystals by Nd3+deuterium double resonance  

Microsoft Academic Search

We have obtained the ENDOR (electron nuclear double resonance) spectra of the four deuterons of the two D2O molecules coordinated to Nd3+ dilutely substituted for La3+ in La2(C5H4NCO2)6 (D2O4)4 (dimeric lanthanum nicotinate dihydrate) molecules in single crystals. From the measurements of the values of the anisotropic magnetic hyperfine interactions between Nd3+ and the deuterons we have determined the coordinates of

Clyde A. Hutchison Jr; Thomas E. Orlowski

1980-01-01

133

Order-disorder effects of small guests in clathrates studied by nuclear quadrupole resonance and crystallography. Part I. Carbon tetrachloride and related molecules in Ni(SCN) 2 (3-methylpyridine) 4  

Microsoft Academic Search

NQR spectroscopy and X-ray crystallography have been jointly applied to the study of the small guest molecules CH2Cl2, CHCl3, CCl4, CBr2Cl2, C(CH3)2Cl2 etc. in the Werner host complex Ni(SCN)2(3-methylpyridine)4. Specific host-guest dipole-dipole interactions play an important role in order-disorder effects for guest molecules in the cavities of orthorhombic system,Fddd. Thus a weakly polar molecule such as CBr2Cl2 exhibits a disordered

Li Pang; Edwin A. C. Lucken; Grald Bernardinelli

1992-01-01

134

High gradient superconducting quadrupoles  

SciTech Connect

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

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

1987-07-01

135

F-doping dependence of 75As nuclear quadrupole resonance frequency in LaFeAs(O1-xFx)  

NASA Astrophysics Data System (ADS)

We report the F-doping dependence of 75As nuclear quadruple resonance frequency (75?Q) in the iron-oxypnictide LaFeAs(O1-xFx) (x = 0, 0.07, 0.08, 0.11 and 0.14). It was revealed that 75?Q becomes larger with increasing x up to 0.14. From point charge calculations, we found that experimental F-doping dependence of 75?Q cannot be accounted for by the effect of surrounding ions. Therefore, the on-site charge distribution at the 75As site modified by the hybridization between As-4p and Fe-3d orbitals gives dominant contribution to 75?Q in LaFeAs(O1-xFx).

Kitagawa, S.; Nakai, Y.; Iye, T.; Ishida, K.; Kamihara, Y.; Hirano, M.; Hosono, H.

2010-12-01

136

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

PubMed Central

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

Stevens, A; Paschalis, P; Schleich, T

1992-01-01

137

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

138

Variable Permanent Magnet Quadrupole  

SciTech Connect

A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments.

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

2007-05-23

139

Localization and Function of the Membrane-bound Riboflavin in the Na+-translocating NADH:Quinone Oxidoreductase (Na+-NQR) from Vibrio cholerae*  

PubMed Central

The sodium ion-translocating NADH:quinone oxidoreductase (Na+-NQR) from the human pathogen Vibrio cholerae is a respiratory membrane protein complex that couples the oxidation of NADH to the transport of Na+ across the bacterial membrane. The Na+-NQR comprises the six subunits NqrABCDEF, but the stoichiometry and arrangement of these subunits are unknown. Redox-active cofactors are FAD and a 2Fe-2S cluster on NqrF, covalently attached FMNs on NqrB and NqrC, and riboflavin and ubiquinone-8 with unknown localization in the complex. By analyzing the cofactor content and NADH oxidation activity of subcomplexes of the Na+-NQR lacking individual subunits, the riboflavin cofactor was unequivocally assigned to the membrane-bound NqrB subunit. Quantitative analysis of the N-terminal amino acids of the holo-complex revealed that NqrB is present in a single copy in the holo-complex. It is concluded that the hydrophobic NqrB harbors one riboflavin in addition to its covalently attached FMN. The catalytic role of two flavins in subunit NqrB during the reduction of ubiquinone to ubiquinol by the Na+-NQR is discussed. PMID:20558724

Casutt, Marco S.; Huber, Tamara; Brunisholz, Ren; Tao, Minli; Fritz, Gnter; Steuber, Julia

2010-01-01

140

LARP Long Quadrupole Design  

Microsoft Academic Search

A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4 m-long quadrupole magnets (LQ) wound with Nb3Sn conductor. The goal of these magnets is to be a proof of principle that Nb3Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based

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

2008-01-01

141

Stabilized radio frequency quadrupole  

DOEpatents

A long-vane stabilized radio frequency resonator for accelerating charged particles and including means defining a radio frequency resonator cavity, a plurality of long vanes mounted in the defining means for dividing the cavity into sections, and means interconnecting opposing ones of the plurality of vanes for stabilizing the resonator.

Lancaster, Henry D. (Orinda, CA); Fugitt, Jock A. (Berkeley, CA); Howard, Donald R. (Danville, CA)

1984-01-01

142

Solid-State NMR/NQR and First-Principles Study of Two Niobium Halide Cluster Compounds  

E-print Network

1 Solid-State NMR/NQR and First-Principles Study of Two Niobium Halide Cluster Compounds Berislav : 10.1016/j.ssnmr.2014.02.001 #12;2 Abstract Two hexanuclear niobium halide cluster compounds solid-state NMR/NQR techniques and PAW/GIPAW calculations. For niobium sites the NMR parameters were

Boyer, Edmond

143

Space Charge Induced Nonlinear Effects in Quadrupole Ion Traps  

NASA Astrophysics Data System (ADS)

A theoretical method was proposed in this work to study space charge effects in quadrupole ion traps, including ion trapping, ion motion frequency shift, and nonlinear effects on ion trajectories. The spatial distributions of ion clouds within quadrupole ion traps were first modeled for both 3D and linear ion traps. It is found that the electric field generated by space charge can be expressed as a summation of even-order fields, such as quadrupole field, octopole field, etc. Ion trajectories were then solved using the harmonic balance method. Similar to high-order field effects, space charge will result in an "ocean wave" shape nonlinear resonance curve for an ion under a dipolar excitation. However, the nonlinear resonance curve will be totally shifted to lower frequencies and bend towards ion secular frequency as ion motion amplitude increases, which is just the opposite effect of any even-order field. Based on theoretical derivations, methods to reduce space charge effects were proposed.

Guo, Dan; Wang, Yuzhuo; Xiong, Xingchuang; Zhang, Hua; Zhang, Xiaohua; Yuan, Tao; Fang, Xiang; Xu, Wei

2014-03-01

144

NQR investigation of pressure-induced charge transfer in oxygen-deficient YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} ({delta} = 0.38)  

SciTech Connect

Measurements of the pressure dependence of {sup 63}Cu nuclear quadrupole frequency in YBa{sub 2}Cu{sub 3}O{sub 6.62} from ambient pressure up to 1.5 GPa at 4k have been performed. {Tc} was found to increase with pressure: d{Tc}/dp {approximately} 5 K/GPa. All observed NQR lines are linear in pressure: dln{nu}{sub Q}/dp=z. We found positive z for the empty chain sites, consistent with ionic (Cu{sup 1+}) configuration in which the atom simply feels a squeezing lattice. Planar coppers close to the empty chains have positive z, while those that are close to full chains have z {approximately} 0. We present an analysis of the NQR result on the basis of the charge transfer model in which the mobile charges migrate from the chain to the plane sites. We deduced that a transfer of 0.021 holes to the O(2,3) sites would explain the result in YBa{sub 2}Cu{sub 3}O{sub 6.62}, whereas only 0.007 holes transfer in fully oxygenated YBa{sub 2}Cu{sub 3}O{sub 7}.

Reyes, A.P.; Ahrens, E.T.; Hammel, P.C.; Heffner, R.H. [Los Alamos National Lab., NM (United States); Takigawa, M. [International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center

1992-03-01

145

Quadrupole plasmon excitations in finite-size atomic chain systems  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

146

Quadrupole transitions revealed by Borrmann spectroscopy.  

PubMed

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

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

2008-07-10

147

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

148

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

149

Resonance  

NSDL National Science Digital Library

All About Circuits is a website that ??provides a series of online textbooks covering electricity and electronics.? Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Resonance, is the sixth chapter in the Volume II textbook. Topics covered in this chapter include: electric pendulum, simple parallel resonance, simple series resonance, resonance in series-parallel circuits, and Q and bandwidth of a resonant circuit. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

150

Genomic Plasticity of the rrn-nqrF Intergenic Segment in the Chlamydiaceae?  

PubMed Central

In Chlamydiaceae, the nucleotide sequence between the 5S rRNA gene and the gene for subunit F of the Na+-translocating NADH-quinone reductase (nqrF or dmpP) has varied lengths and gene contents. We analyzed this site in 45 Chlamydiaceae strains having diverse geographical and pathological origins and including members of all nine species. PMID:17158668

Liu, Zhi; Rank, Roger; Kaltenboeck, Bernhard; Magnino, Simone; Dean, Deborah; Burall, Laurel; Plaut, Roger D.; Read, Timothy D.; Myers, Garry; Bavoil, Patrik M.

2007-01-01

151

35Cl NQR spectra of certain chlorine-containing chromium compounds  

NASA Astrophysics Data System (ADS)

The coordination of chlorobenzene to Cr(CO)3 and ClC6H5Cr+ fragments is shown to result in a considerable rise in the NQR frequency of chlorine atoms. The field constant in (chlorobenzene)chromium tricarbonyl was found to grow markedly, relative to pure chlorobenzene.

Kuznetsov, S. I.; Bryukhova, E. V.; Semin, G. K.

2015-03-01

152

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

153

35Cl NQR Spectra of several 2,2-bis- p-chlorophenyl chloroethane derivatives  

NASA Astrophysics Data System (ADS)

Measurement of NQR line frequency at 77 K have been performed for the following compounds: 1-chloro-2,2-bis-(p-chlorophenyl) ethylene (DDMU), 1,1-dichloro-2,2-bis-(p-chlorophenyl) ethylene (DDE), 1,1-dichloro-2,2-bis-(p-chlorophenyl) ethane (ODD), 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT). An attempt to assign spectrum lines to particular Cl nuclei in a molecule has been made. Molecular and crystallographic inequivalences occurring in these compounds have been considered. Comparison of the NQR and crystallographic data revealed the influence of phenyl rings conformation on electric charge distribution in the studied molecules.

Nogaj, B.; Pietrzak, J.; Wielopolska, E.; Schroeder, G.; Jarczewski, A.

154

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

155

Measurements of spectroscopic quadrupole moments of neutron-deficient Au isotopes with quadrupole-interaction-resolved NMR-ON  

NASA Astrophysics Data System (ADS)

We report on measurements of quadrupole-interaction-resolved nuclear magnetic resonance on oriented nuclei ( QI-NMR-ON) of{3}/{2}+193Au (T {1}/{2} = 17.5 h)and{3}/{2}+195Au(T {1}/{2}=183 d) hcp-Co. The results for the magnetic and electric hyperfine splittings are: 193Au: ?M = 67.72(2) MHz; ?Q = - 15.69(4) MHz; 195Au; ?M = 71.65(1) MHz; ?Q = - 14.34(2) MHz. Taking into account hyperfine anomalies, the magnetic moments are deduced to be: ?( 193Au) = 0.1396(6) ? N; ?( 195Au) = 0.1487(6) ? N. With the known quadrupole moment of 193Au, Q = + 0.664(20), b, the electric field gradient of Au in hcp-Co is deduced to be eq = - 0.977(29) 10 17V/ cm2, with which Q( 195Au) = + 0.607(18) b is obtained for the spectroscopic quadrupole moment of 195Au. In addition, the experimentally known quadrupole splitting frequencies of 186Au, 198Au and 199Au in hcp-Co can be reinterpreted, giving the results: Q( 186Au) = + 3.14(16) b; Q( 198Au) = + 0.640(19) b; Q( 199Au) = + 0.510(16) b.

Hinfurtner, B.; Knig, C.; Hagn, E.; Zech, E.; Eder, R.; Forkel, D.; Isolde Collaboration

1993-09-01

156

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

SciTech Connect

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%.

Peng, Shixiang, E-mail: sxpeng@pku.edu.cn; Chen, Jia; Ren, Haitao; Zhao, Jie; Xu, Yuan; Zhang, Tao; Xia, Wenlong; Gao, Shuli; Wang, Zhi; Luo, Yuting; Guo, Zhiyu [SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871 (China)] [SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871 (China); Zhang, Ailing; Chen, Jia'er [SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871 (China) [SKLNPT and IHIP, School of Physics, Peking University, Beijing 100871 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

2014-02-15

157

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

SciTech Connect

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

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

2008-05-15

158

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

159

Hybridization-driven gap in U3Bi4Ni3: a 209Bi NMR/NQR study  

SciTech Connect

We report {sup 209}Bi nuclear-magnetic-resonance and nuclear-quadrupole-resonance measurements on a single crystal of the Kondo insulator U{sub 3}Bi{sub 4}Ni{sub 3}. The {sup 209}Bi nuclear-spin-lattice relaxation rate (T{sub 1}{sup -1}) shows activated behavior and is well fit by a spin gap of 220 K. The {sup 209}Bi Knight shift (K) exhibits a strong temperature dependence arising from 5f electrons, in which K is negative at high temperatures and increases as the temperature is lowered. Below 50 K, K shows a broad maximum and decreases slightly upon further cooling. Our data provide insight into the evolution of the hyperfine fields in a fully gapped Kondo insulator based on 5f electron hybridization.

Baek, Seung H [Los Alamos National Laboratory

2009-01-01

160

Laced permanent magnet quadrupole drift tube magnets  

SciTech Connect

Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL, marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the individual quadrupole magnets in a drift tube linac is never reversed, we can take advantage of this asymmetrical saturation to provide about 20% greater focusing strength than is available with conventional quadrupoles, while replacing the vanadium permendur poletips with iron poletips. Comparisons between these magnets and conventional tape-wound quadrupoles will be presented. 3 refs., 5 figs.

Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.

1989-03-01

161

Roles of the Sodium-Translocating NADH:Quinone Oxidoreductase (Na+-NQR) on Vibrio cholerae Metabolism, Motility and Osmotic Stress Resistance  

PubMed Central

The Na+ translocating NADH:quinone oxidoreductase (Na+-NQR) is a unique respiratory enzyme catalyzing the electron transfer from NADH to quinone coupled with the translocation of sodium ions across the membrane. Typically, Vibrio spp., including Vibrio cholerae, have this enzyme but lack the proton-pumping NADH:ubiquinone oxidoreductase (Complex I). Thus, Na+-NQR should significantly contribute to multiple aspects of V. cholerae physiology; however, no detailed characterization of this aspect has been reported so far. In this study, we broadly investigated the effects of loss of Na+-NQR on V. cholerae physiology by using Phenotype Microarray (Biolog), transcriptome and metabolomics analyses. We found that the V. cholerae ?nqrA-F mutant showed multiple defects in metabolism detected by Phenotype Microarray. Transcriptome analysis revealed that the V. cholerae ?nqrA-F mutant up-regulates 31 genes and down-regulates 55 genes in both early and mid-growth phases. The most up-regulated genes included the cadA and cadB genes, encoding a lysine decarboxylase and a lysine/cadaverine antiporter, respectively. Increased CadAB activity was further suggested by the metabolomics analysis. The down-regulated genes include sialic acid catabolism genes. Metabolomic analysis also suggested increased reductive pathway of TCA cycle and decreased purine metabolism in the V. cholerae ?nqrA-F mutant. Lack of Na+-NQR did not affect any of the Na+ pumping-related phenotypes of V. cholerae suggesting that other secondary Na+ pump(s) can compensate for Na+ pumping activity of Na+-NQR. Overall, our study provides important insights into the contribution of Na+-NQR to V. cholerae physiology. PMID:24811312

Minato, Yusuke; Halang, Petra; Quinn, Matthew J.; Faulkner, Wyatt J.; Aagesen, Alisha M.; Steuber, Julia; Stevens, Jan F.; Hse, Claudia C.

2014-01-01

162

Roles of the sodium-translocating NADH:quinone oxidoreductase (Na+-NQR) on vibrio cholerae metabolism, motility and osmotic stress resistance.  

PubMed

The Na+ translocating NADH:quinone oxidoreductase (Na+-NQR) is a unique respiratory enzyme catalyzing the electron transfer from NADH to quinone coupled with the translocation of sodium ions across the membrane. Typically, Vibrio spp., including Vibrio cholerae, have this enzyme but lack the proton-pumping NADH:ubiquinone oxidoreductase (Complex I). Thus, Na+-NQR should significantly contribute to multiple aspects of V. cholerae physiology; however, no detailed characterization of this aspect has been reported so far. In this study, we broadly investigated the effects of loss of Na+-NQR on V. cholerae physiology by using Phenotype Microarray (Biolog), transcriptome and metabolomics analyses. We found that the V. cholerae ?nqrA-F mutant showed multiple defects in metabolism detected by Phenotype Microarray. Transcriptome analysis revealed that the V. cholerae ?nqrA-F mutant up-regulates 31 genes and down-regulates 55 genes in both early and mid-growth phases. The most up-regulated genes included the cadA and cadB genes, encoding a lysine decarboxylase and a lysine/cadaverine antiporter, respectively. Increased CadAB activity was further suggested by the metabolomics analysis. The down-regulated genes include sialic acid catabolism genes. Metabolomic analysis also suggested increased reductive pathway of TCA cycle and decreased purine metabolism in the V. cholerae ?nqrA-F mutant. Lack of Na+-NQR did not affect any of the Na+ pumping-related phenotypes of V. cholerae suggesting that other secondary Na+ pump(s) can compensate for Na+ pumping activity of Na+-NQR. Overall, our study provides important insights into the contribution of Na+-NQR to V. cholerae physiology. PMID:24811312

Minato, Yusuke; Fassio, Sara R; Kirkwood, Jay S; Halang, Petra; Quinn, Matthew J; Faulkner, Wyatt J; Aagesen, Alisha M; Steuber, Julia; Stevens, Jan F; Hse, Claudia C

2014-01-01

163

Laced permanent magnet quadrupole drift tube magnets  

Microsoft Academic Search

Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL (Lawrence Berkeley Laboratory), marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce

B. Feinberg; G. U. Behrsing; K. Halbach; J. S. Marks; M. E. Morrison; D. H. Nelson

1989-01-01

164

NQR Investigation of Anion Dynamics in Rb2Zn(Cl1 - xBrx)4  

NASA Astrophysics Data System (ADS)

The structural stability of Rb2Zn(Cl1 - xBrx)4 (x = 1% and 3%) is investigated using the 35Cl quadrupole resonance frequency and spin lattice relaxation time (T1Q) in the paraelectric (PE) phase. The PE to incommensurate (IC) phase transition temperature T1, observed at 302 K in the pure compound, is lowered to 300 K for x = 1 % and to 293 K for x = 3%. These effects are smaller than in the earlier reported case of 3% Cs substitution in Rb2ZnCl4 , which reduces T1 by 25 K. While bigger cation substitution affects only the barrier for anion dynamics about directions perpendicular to the a-axis (direction of low temperature IC modulation wave), bigger anion substitution is found to affect the barrier for anion dynamics about the a-axis as well. The present study also indicates that the cusp like dip in T1Q observed while approaching T1 from above (characterizing the soft mode condensation associated with the structural phase transition) is essentially unaffected by anion impurity substitution, in contrast to the case where bigger cation substitution tends to smear the transitional effects. These results seem to suggest the dominant role played by cations in stabilizing the PE phase of these A2BX4 systems, in comparison to anions.

Subramanian, R. K.; Maheswari, S. Uma; Venu, K.; Sastry, V. S. S.

1996-06-01

165

Ground-state electric quadrupole moment of Al31  

NASA Astrophysics Data System (ADS)

The ground-state electric quadrupole moment of Al31(I?=5/2+,T1/2=644(25)ms) has been measured by means of ?-ray-detected nuclear magnetic resonance spectroscopy using a spin-polarized Al31 beam produced in the projectile fragmentation reaction. The obtained Q moment, |Qexp(Al31)|=112(32)emb, is in agreement with conventional shell model calculations within the sd valence space. Previous results on the magnetic moment also support the validity of the sd model in this isotope, and thus it is concluded that Al31 is located outside of the island of inversion.

Nagae, D.; Ueno, H.; Kameda, D.; Takemura, M.; Asahi, K.; Takase, K.; Yoshimi, A.; Sugimoto, T.; Shimada, K.; Nagatomo, T.; Uchida, M.; Arai, T.; Inoue, T.; Kagami, S.; Hatakeyama, N.; Kawamura, H.; Narita, K.; Murata, J.

2009-02-01

166

Quadrupole effects in 63 Cu NMR spectroscopy of copper nanocrystals  

Microsoft Academic Search

Quadrupole effects in room-temperature continuous-wave (CW)63Cu nuclear magnetic resonance (NMR) spectra, ?\\/2 pulse length shortening and amplitudes of two-pulse generated echoes were\\u000a investigated on nanocrystalline copper powders produced by cryogenic melting and by ball milling techniques. Systematic measurements\\u000a on the parent polycrystalline copper and on copper-based copper-palladium dilute alloys on the basis of the same experimental\\u000a techniques were also made

K. Tompa; P. Bnki; M. Bokor; G. Lasanda; L. K. Varga; Y. Champion; L. Takcs

2004-01-01

167

Potential Antiferromagnetic Fluctuations in Hole-Doped Iron-Pnictide Superconductor Ba1-xKxFe2As2 Studied by 75As Nuclear Magnetic Resonance Measurement0.1143/JPSJ.81.054704  

SciTech Connect

We have performed 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements on single-crystalline Ba1-xKxFe2As2 for x = 0.271. 75As nuclear quadruple resonance frequency (?Q) increases linearly with increasing x. The Knight shift K in the normal state shows Pauli paramagnetic behavior with a weak temperature T dependence. K increases gradually with increasing x. By contrast, the nuclear spinlattice relaxation rate 1/T1 in the normal state has a strong T dependence, which indicates the existence of large antiferomagnetic (AF) spin fluctuations for all x's. The T dependence of 1/T1 shows a gaplike behavior below approximately 100 K for 0.6 < x < 0.9. This behaviors is well explained by the change in the band structure with the expansion of hole Fermi surfaces and the shrinkage and disappearance of electron Fermi surfaces at the Brillouin zone (BZ) with increasing x. The anisotropy of 1/T1, represented by the ratio of 1/T1ab to 1/T1c, is always larger than 1 for all x's, which indicates that stripe-type AF fluctuations are dominant in this system. The K in the superconducting (SC) state decreases, which corresponds to the appearance of spin-singlet superconductivity. The T dependence of 1/T1 in the SC state indicates a multiple-SC-gap feature. A simple two-gap model analysis shows that the larger superconducting gap gradually decreases with increasing x from 0.27 to 1 and a smaller gap decreases rapidly and nearly vanishes for x > 0.6 where electron pockets in BZ disappear.

Hirano, Masanori; Yamada, Yuji; Saito, Taku; Nagashima, Ryo; Konishi, Takehisa; Toriyama, Tatsuya; Ohta, Yukinori; Fukazawa, Hideto; Kohori, Yoh; Furukawa, Yuji; Kihou, Kunihiro; Lee, Chul-Ho; Eisaki, Hiroshi

2012-04-12

168

A Vibrating Wire System For Quadrupole Fiducialization  

SciTech Connect

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

Wolf, Zachary

2010-12-13

169

Ru-NQR Study for Novel Phase Transition in CeRu2Al10  

NASA Astrophysics Data System (ADS)

We have performed Ru-NQR measurements on CeRu2Al10 exhibiting novel phase transition at an abnormally high temperature T0 = 27.3 K and on NdRu2Al10 with a magnetic transition temperature Tm = 2.4 K as a reference RKKY system. The splitting of the NQR line due to internal fields below T0 shows a mean-field-like monotonic increase, indicating no change in the magnetic structure below T0. The internal field strength is one order larger than those at Al sites in CeRu2Al10, and is comparable to that at the Ru site in NdRu2Al10 despite the sevenfold smaller magnitude of the 4f moment, being indicative of an enhanced conduction electron polarization at the Ru site. One of the causes of the high T0 might be the enhanced exchange coupling through the CeRuCe path mediated by the enhanced conduction electron polarization. Being similar to that in the Al site, the nuclear spinlattice relaxation rate 1/T1 shows a gap-like decrease below T0 without enhancement owing to a critical slowing down at T0, in contrast to the mean field 2nd-order transition.

Matsumura, Masahiro; Tomita, Naoya; Matsuoka, Junichirou; Kishimoto, Yasuki; Kato, Harukazu; Kitagawa, Kentaro; Nishioka, Takashi; Tanida, Hiroshi; Sera, Masafumi

2014-10-01

170

A mutation in Na(+)-NQR uncouples electron flow from Na(+) translocation in the presence of K(+).  

PubMed

The sodium-pumping NADH:ubiquinone oxidoreductase (Na(+)-NQR) is a bacterial respiratory enzyme that obtains energy from the redox reaction between NADH and ubiquinone and uses this energy to create an electrochemical Na(+) gradient across the cell membrane. A number of acidic residues in transmembrane helices have been shown to be important for Na(+) translocation. One of these, Asp-397 in the NqrB subunit, is a key residue for Na(+) uptake and binding. In this study, we show that when this residue is replaced with asparagine, the enzyme acquires a new sensitivity to K(+); in the mutant, K(+) both activates the redox reaction and uncouples it from the ion translocation reaction. In the wild-type enzyme, Na(+) (or Li(+)) accelerates turnover while K(+) alone does not activate. In the NqrB-D397N mutant, K(+) accelerates the same internal electron transfer step (2Fe-2S ? FMNC) that is accelerated by Na(+). This is the same step that is inhibited in mutants in which Na(+) uptake is blocked. NqrB-D397N is able to translocate Na(+) and Li(+), but when K(+) is introduced, no ion translocation is observed, regardless of whether Na(+) or Li(+) is present. Thus, this mutant, when it turns over in the presence of K(+), is the first, and currently the only, example of an uncoupled Na(+)-NQR. The fact the redox reaction and ion pumping become decoupled from each other only in the presence of K(+) provides a switch that promises to be a useful experimental tool. PMID:25486106

Shea, Michael E; Mezic, Katherine G; Jurez, Oscar; Barquera, Blanca

2015-01-20

171

Lighthill quadrupole radiation in supersonic propeller acoustics  

Microsoft Academic Search

Sound generation by the Lighthill quadrupole is an important mechanism in the noise of supersonic and transonic propellers. Full numerical calculation of the quadrupole radiation, however, requires knowledge of the flow at all points exterior to the blades (involving transonic aerodynamics) and the evaluation of special functions. This paper describes how these difficulties may be largely avoided, using an asymptotic

N. Peake; D. G. Crighton

1991-01-01

172

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

173

Deformation effects in Giant Monopole Resonance  

E-print Network

The isoscalar giant monopole resonance (GMR) in Samarium isotopes (from spherical $^{144}$Sm to deformed $^{148-154}$Sm) is investigated within the Skyrme random-phase-approximation (RPA) for a variety of Skyrme forces. The exact RPA and its separable version (SRPA) are used for spherical and deformed nuclei, respectively. The quadrupole deformation is shown to yield two effects: the GMR broadens and attains a two-peak structure due to the coupling with the quadrupole giant resonance.

J. Kvasil; V. O. Nesterenko; A. Repko; D. Bozik; W. Kleinig; P. -G. Reinhard

2014-07-11

174

Dyson representation of the interacting boson model with pairing plus quadrupole pairing plus quadrupole-quadrupole forces  

SciTech Connect

With a usual choice of the effective nucleon-nucleon interactions consisting of a pairing force, a quadrupole pairing force, and a quadrupole-quadrupole force, the microscopic approach, as described in our previous work, based on the Dyson boson expansion and based on the so-called modified Jancovici-Schiff substitution is followed to obtain a set of eigenequations for determining the IBM bosons and to find the microscopic expressions of the coefficients appearing in the interaction terms of the IBM Hamiltonian. The results given in the present paper can be used directly in calculating the collective spectra of nuclei with identical valence nucleons outside closed shells.

Yang, T.S.; Liu, Y.; Tian, X.C.

1983-04-01

175

QUADRUPOLE BEAM-BASED ALIGNMENT AT RHIC.  

SciTech Connect

Successful implementation of a beam-based alignment algorithm, tailored to different types of quadrupoles at RHIC, provides significant benefits to machine operations for heavy ions and polarized protons. This algorithm was used to calibrate beam position monitor centers relative to interaction region quadrupoles to maximize aperture. This approach was also used to determine the optimal orbit through transition jump quadrupoles to minimize orbit changes during the transition jump for heavy ion acceleration. This paper provides background discussion and results from first measurements during the RHIC 2005 run.

NIEDZIELA, J.; MONTAG, C.; SATOGATA, T.

2005-05-16

176

Photon decay of giant resonances  

Microsoft Academic Search

Measurements have been made of the photon decay of the giant multipole resonances in ²°⁸Pb. The giant resonances were excited by inelastic scattering of 380 MeV ¹⁷O projectile and the photons were detected in the ORNL Spin Spectrometer. The results show a quadrupole resonance ground state gamma branch of 20% while only less than or equal to 2% of the

F. E. Bertrand; J. R. Beene; M. L. Halbert

1984-01-01

177

Giant resonances: Progress, new directions, new challenges  

SciTech Connect

A review of some recent developments in the field of giant multipole resonances is presented. Particular emphasis is placed on directions that the authors feel will be followed in this field during the next several years. In particular, the use of high-energy heavy ions to excite the giant resonances is shown to provide exciting new capabilities for giant resonance studies. Among subjects covered are: Coulomb excitation of giant resonances, photon decay of giant resonances, the recent controversy over the identity of the giant monopole resonance, the most recent value for incompressibility of nuclear matter from analysis of giant monopole data, the isospin character of the 63 A/sup /minus/1/3/ GQR, agreement between (e,e/prime/) and (hadron, hadron/prime/) excitation of the giant quadrupole resonance, prospects for multiphonon giant resonance observation, and isolation of the isovector giant quadrupole resonance. 55 refs., 23 figs., 4 tabs.

Bertrand, J.R.; Beene, J.R.

1989-01-01

178

Dipole-quadrupole interference spectroscopy: Observation of an autoionizing He 1D Rydberg series  

NASA Astrophysics Data System (ADS)

We have used dipole-quadrupole interference spectroscopy to observe an optically forbidden quadrupole Rydberg series of helium autoionizing levels. The technique measures the forward-backward asymmetry of photoelectron angular distributions produced in the vacuum ultraviolet photoionization of helium. The resonant behavior of this asymmetry in the region of a quadrupole autoionizing level enables the determination of the position, width, and Fano line-profile parameter q of the level. We have obtained these quantities for the He 2(1,0)n+1D Rydberg series for n=2-7. We find that for n?3 all three quantities have the expected n scaling, with a quantum defect of 0.31. For n?3 the average q parameter lies close to zero, whereas for n=2 it is negative.

Krssig, B.; Kanter, E. P.; Southworth, S. H.; Young, L.; Wehlitz, R.; deHarak, B. A.; Martin, N. L. S.

2012-11-01

179

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

180

Nonuniform radiation damage in permanent magnet quadrupoles  

SciTech Connect

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 LANLs 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. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

2014-08-15

181

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

182

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

183

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

184

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

185

Laced permanent magnet quadrupole drift tube magnets  

Microsoft Academic Search

A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in

B. Feinberg; G. U. Behrsing; K. Halbach; J. S. Marks; M. E. Morrison; D. H. Nelson

1988-01-01

186

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

187

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

188

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

189

Structural and Functional Investigation of Flavin Binding Center of the NqrC Subunit of Sodium-Translocating NADH:Quinone Oxidoreductase from Vibrio harveyi.  

PubMed

Na+-translocating NADH:quinone oxidoreductase (NQR) is a redox-driven sodium pump operating in the respiratory chain of various bacteria, including pathogenic species. The enzyme has a unique set of redox active prosthetic groups, which includes two covalently bound flavin mononucleotide (FMN) residues attached to threonine residues in subunits NqrB and NqrC. The reason of FMN covalent bonding in the subunits has not been established yet. In the current work, binding of free FMN to the apo-form of NqrC from Vibrio harveyi was studied showing very low affinity of NqrC to FMN in the absence of its covalent bonding. To study structural aspects of flavin binding in NqrC, its holo-form was crystallized and its 3D structure was solved at 1.56 resolution. It was found that the isoalloxazine moiety of the FMN residue is buried in a hydrophobic cavity and that its pyrimidine ring is squeezed between hydrophobic amino acid residues while its benzene ring is extended from the protein surroundings. This structure of the flavin-binding pocket appears to provide flexibility of the benzene ring, which can help the FMN residue to take the bended conformation and thus to stabilize the one-electron reduced form of the prosthetic group. These properties may also lead to relatively weak noncovalent binding of the flavin. This fact along with periplasmic location of the FMN-binding domains in the vast majority of NqrC-like proteins may explain the necessity of the covalent bonding of this prosthetic group to prevent its loss to the external medium. PMID:25734798

Borshchevskiy, Valentin; Round, Ekaterina; Bertsova, Yulia; Polovinkin, Vitaly; Gushchin, Ivan; Ishchenko, Andrii; Kovalev, Kirill; Mishin, Alexey; Kachalova, Galina; Popov, Alexander; Bogachev, Alexander; Gordeliy, Valentin

2015-01-01

190

Structural and Functional Investigation of Flavin Binding Center of the NqrC Subunit of Sodium-Translocating NADH:Quinone Oxidoreductase from Vibrio harveyi  

PubMed Central

Na+-translocating NADH:quinone oxidoreductase (NQR) is a redox-driven sodium pump operating in the respiratory chain of various bacteria, including pathogenic species. The enzyme has a unique set of redox active prosthetic groups, which includes two covalently bound flavin mononucleotide (FMN) residues attached to threonine residues in subunits NqrB and NqrC. The reason of FMN covalent bonding in the subunits has not been established yet. In the current work, binding of free FMN to the apo-form of NqrC from Vibrio harveyi was studied showing very low affinity of NqrC to FMN in the absence of its covalent bonding. To study structural aspects of flavin binding in NqrC, its holo-form was crystallized and its 3D structure was solved at 1.56 resolution. It was found that the isoalloxazine moiety of the FMN residue is buried in a hydrophobic cavity and that its pyrimidine ring is squeezed between hydrophobic amino acid residues while its benzene ring is extended from the protein surroundings. This structure of the flavin-binding pocket appears to provide flexibility of the benzene ring, which can help the FMN residue to take the bended conformation and thus to stabilize the one-electron reduced form of the prosthetic group. These properties may also lead to relatively weak noncovalent binding of the flavin. This fact along with periplasmic location of the FMN-binding domains in the vast majority of NqrC-like proteins may explain the necessity of the covalent bonding of this prosthetic group to prevent its loss to the external medium. PMID:25734798

Bertsova, Yulia; Polovinkin, Vitaly; Gushchin, Ivan; Ishchenko, Andrii; Kovalev, Kirill; Mishin, Alexey; Kachalova, Galina; Popov, Alexander; Bogachev, Alexander; Gordeliy, Valentin

2015-01-01

191

Solid-state NMR/NQR and first-principles study of two niobium halide cluster compounds.  

PubMed

Two hexanuclear niobium halide cluster compounds with a [Nb6X12](2+) (X=Cl, Br) diamagnetic cluster core, have been studied by a combination of experimental solid-state NMR/NQR techniques and PAW/GIPAW calculations. For niobium sites the NMR parameters were determined by using variable Bo field static broadband NMR measurements and additional NQR measurements. It was found that they possess large positive chemical shifts, contrary to majority of niobium compounds studied so far by solid-state NMR, but in accordance with chemical shifts of (95)Mo nuclei in structurally related compounds containing [Mo6Br8](4+) cluster cores. Experimentally determined ?iso((93)Nb) values are in the range from 2,400 to 3,000 ppm. A detailed analysis of geometrical relations between computed electric field gradient (EFG) and chemical shift (CS) tensors with respect to structural features of cluster units was carried out. These tensors on niobium sites are almost axially symmetric with parallel orientation of the largest EFG and the smallest CS principal axes (Vzz and ?33) coinciding with the molecular four-fold axis of the [Nb6X12](2+) unit. Bridging halogen sites are characterized by large asymmetry of EFG and CS tensors, the largest EFG principal axis (Vzz) is perpendicular to the X-Nb bonds, while intermediate EFG principal axis (Vyy) and the largest CS principal axis (?11) are oriented in the radial direction with respect to the center of the cluster unit. For more symmetrical bromide compound the PAW predictions for EFG parameters are in better correspondence with the NMR/NQR measurements than in the less symmetrical chlorine compound. Theoretically predicted NMR parameters of bridging halogen sites were checked by (79/81)Br NQR and (35)Cl solid-state NMR measurements. PMID:24581866

Peri?, Berislav; Gautier, Rgis; Pickard, Chris J; Bosio?i?, Marko; Grbi?, Mihael S; Poek, Miroslav

2014-01-01

192

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

193

Purely electric and magnetic dipole resonances in metamaterial dielectric resonators through perturbation theory inspired geometries  

E-print Network

In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometry in a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole ...

Campione, Salvatore; Warne, Larry K; Sinclair, Michael B

2014-01-01

194

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

195

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

196

A Tandem-electrostatic-quadrupole for accelerator-based BNCT  

NASA Astrophysics Data System (ADS)

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

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

2007-08-01

197

Image restoration using fast Fourier and wavelet transforms  

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.

Harrod, William J.; Nagy, James G.; Plemmons, Robert J.

1994-02-01

198

Systematics of quadrupole moments and energies  

E-print Network

We define the "quadrupole ratio" r_{Q}=\\dfrac{Q_{0}(S)}{Q_{0}(B)} where Q_{0}(S) is the intrinsic quadrupole moment obtained from the static quadrupole moment of the 2_{1}^{+} state of an even-even nucleus and Q_{0}(B) the intrinsic quadrupole moment obtained from B(E2)_{0\\rightarrow2} . In both cases we assume a simple rotational formula connecting the rotating frame to the laboratory frame. The quantity r_{Q} would be one if the rotational model were perfect and the energy ratio E(4)/E(2) would be 10/3. In the simple vibrational model, r_{Q} would be zero and E(4)/E(2) would be two. There are some regions where the rotational limit is almost met and fewer where the vibrational limit is also almost met. For most cases, however, it is between these two limits, i.e. 0light nuclei. In most cases the quadrupole ratio is positive but there are two regions with negative ratios. The first case is that of light nuclei and the second has certain nuclei close to ^{208} Pb.

S. Yeager; L. Zamick; Y. Y. Sharon; S. J. Q. Robinson

2012-08-13

199

Measurement of the spectroscopic quadrupole moment of 186Au: Experimental verification of the large prolate deformation of the186Au ground state  

NASA Astrophysics Data System (ADS)

We report the first on-line measurements of quadrupole-interaction-resolved nuclear magnetic resonance on oriented nuclei. The 10-min 186Au activity was obtained as daughter after cold implantation of mass-separated 186Hg into a hcp Co single crystal at the NICOLE facility at ISOLDE-3 (CERN). The quadrupole interaction of 186Co(hcp) was fully resolved, and the spectroscopic quadrupole moment of 186Au was determined to be Q=+3.12(20) b. This implies ?2=+0.246(16), proving the large prolate deformation of the 186Au ground state.

Hinfurtner, B.; Hagn, E.; Zech, E.; Eder, R.

1991-08-01

200

Heavy ion excitation and photon decay of giant resonances  

SciTech Connect

Results are presented for excitation of giant multipole resonances by inelastic scattering of 350 and 500 MeV /sup 16/O projectiles from /sup 90/Zr and /sup 208/Pb. The giant quadrupole resonance is excited with large cross sections and a very large resonance peak to continuum ratio is obtained. Extracted cross sections agree with DWBA calculations which use standard collective model form factors. Using 380 MeV 170 to excite the giant resonances, the ..gamma..-ray decay has been measured for the giant quadrupole resonance region of /sup 208/Pb. 10 references.

Bertrand, F.E.; Beene, J.R.; Sjoreen, T.P.

1983-01-01

201

Giant Quadrupole and Monopole Resonances in Si-28  

E-print Network

. The fit that produced a low X with the 16.1 16.6 17.0 17.4 17.7 0+ 2+ 0.6 +0.4 1.42+0.09 4.1 +0.7 1.56+0. 11 3.9 +0.4 0.76+0.05 4.3 +1.0 2.14+0.14 7.9 +1.0 -1.52+0. 12 4.4 2.0 8.4 10.2 8.1 E?(MeV) No. of I. values TABLE I. Results... 15.3 8.8 33.1 9.1 13.3 30.7 15.3?18.3 18.3?23.0 23.3?24.7 p+ 2+ p+ 2+ 0+ 2+ 39 +5 9.1 +0.7 20 +9 22.7 +1.4 6.5 +1.4 2.32+0. 15 1.2 0.7 1.3 LUI, BRONSON, YOUNGBLOOD, TOBA, AND GARG 31 00 I I Si (a,a') ? E&=129 MeV IO) 10 10...

Lui, YW; Bronson, J. D.; Youngblood, David H.; Toba, Y.; Garg, U.

1985-01-01

202

Microfluidic quadrupole and floating concentration gradient  

PubMed Central

The concept of fluidic multipoles, in analogy to electrostatics, has long been known as a particular class of solutions of the Navier-Stokes equation in potential flows, however, experimental observations of fluidic multipoles and of their characteristics have not been reported yet. Here we present a two-dimensional microfluidic quadrupole and a theoretical analysis consistent with the experimental observations. The microfluidic quadrupole was formed by simultaneously injecting and aspirating fluids from two pairs of opposing apertures in a narrow gap formed between a microfluidic probe and a substrate. A stagnation point was formed at the center of the microfluidic quadrupole, and its position could be rapidly adjusted hydrodynamically. Following the injection of a solute through one of the poles, a stationary, tunable, and movable i.e. floating concentration gradient was formed at the stagnation point. Our results lay the foundation for future combined experimental and theoretical exploration of microfluidic planar multipoles including convective-diffusive phenomena. PMID:21897375

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

2014-01-01

203

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

204

Quadrupole mass filters with added hexapole fields.  

PubMed

Conventional mass analysis has been investigated experimentally with six quadrupole mass filters with added hexapole fields; three with added hexapole fields of 4%, 8% and 12% with equal diameter rods, and three with added hexapole fields of 4%, 8% and 12% with unequal diameter rods to remove an added octopole field. Compared with conventional quadrupoles, these rod sets have very large field distortions. With the positive resolving dc applied to the y rods (Mathieu parameter a(x) < 0) only low resolution (10-100) and low transmission are seen. With the polarity reversed (a(x) > 0) much higher resolution (> or = 1000) and transmission are possible. Increasing the magnitude of the added hexapole field decreases the limiting resolution at m/z 609. Removing the added octopole field increases the limiting resolution. In some cases structure is formed on the peaks. For a given scan line slope, U/V(rf), the resolution decreases as the amplitude of the added hexapole field increases. These results are consistent with changes to the stability diagrams, calculated here. With a(x) > 0, adding a hexapole field causes the x stability boundary to move outward with all rod sets. With a(x) < 0, the boundaries become diffuse and the tip of the stability diagram becomes rounded, limiting the resolution to ca. 10-100. Where comparisons are possible, experiments show the rod sets with added hexapole fields have transmission 10-300 times less than a conventional quadrupole. Thus these quadrupoles are less useful for mass analysis than conventional quadrupoles. However, it is surprising, given the highly distorted fields, that some of the quadrupoles give resolution of 1000 or more. PMID:20552578

Xiao, Zilan; Zhao, XianZhen; Douglas, D J

2010-07-30

205

Resonance ionization mass spectrometry of lead and bismuth mixtures  

SciTech Connect

Resonance ionization of lead and bismuth has been demonstrated using an excimer laser pumped dye laser in three-photon, one-color ionization schemes, using a quadrupole mass spectrometer for detection.

Fearey, B.L.; Miller, C.M.; Anderson, J.E.; Nogar, N.S.; Rowe, M.W.

1988-01-01

206

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

207

Electric quadrupole transition probabilities for atomic lithium  

SciTech Connect

Electric quadrupole transition probabilities for atomic lithium have been calculated using the weakest bound electron potential model theory (WBEPMT). We have employed numerical non-relativistic HartreeFock wavefunctions for expectation values of radii and the necessary energy values have been taken from the compilation at NIST. The results obtained with the present method agree very well with the Coulomb approximation results given by Caves (1975). Moreover, electric quadrupole transition probability values not existing in the literature for some highly excited levels have been obtained using the WBEPMT.

elik, Gltekin, E-mail: gultekin@selcuk.edu.tr [Department of Physics, Faculty of Science, Seluk University, Campus 42049 Konya (Turkey); Gke, Yasin; Y?ld?z, Murat [Department of Physics, Faculty of Science, Karamanoglu Mehmetbey University, Karaman (Turkey)

2014-05-15

208

Chip-Scale Quadrupole Mass Filters for Portable Mass Spectrometry  

E-print Network

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

Cheung, Kerry

209

Quadrupole anisotropy from photon quantum effects  

E-print Network

We consider quantum effects of an electromagnetic field in a radiation-dominated almost FRW spacetime. The dominant non-local quantum correction to the photon distribution is a quadrupole moment, corresponding to an effective anisotropic pressure in the energy-momentum tensor.

Alexei V Nesteruk; Roy Maartens

1995-11-15

210

Hydrogen isotope analysis by quadrupole mass spectrometry  

Microsoft Academic Search

The analysis of isotopes of hydrogen (H, D, T) and helium (He, 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

211

Super Strong Permanent Magnet Quadrupole for  

Microsoft Academic Search

The field strength generated by permanent magnets has been further extended by introduction of saturated iron. A permanent magnet quadrupole (PMQ) lens with such saturated iron is one of the candidates for the final focus lens for an e+e- Linear Collider accelerator, because of its compactness and low power consumption. The first prototype of the PMQ has been fabricated and

Takanori Mihara; Yoshihisa Iwashita; Masayuki Kumada; Antokhin Evgeny; Cherrill M. Spencer

212

Tevatron low-beta quadrupole triplet interconnects  

SciTech Connect

Installation of cold iron quadrupole magnets in the Low Beta (Superconducting High-Luminosity) upgrade at Fermilab required a newly designed magnet interconnect. The interconnect design and construction experience is presented. Considered are the connections carrying cryogenic fluids, beam vacuum, insulating vacuum, superconducting bus leads, their insulation and mechanical support. Details of the assembly and assembly experience are presented. 2 refs.

Oleck, A.R.; Carson, J.A.; Koepke, K.; Sorenson, D.

1992-04-01

213

LARP Long $Nb_{3}Sn$ Quadrupole  

E-print Network

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 Nb3Sn conductor. The goal of these magnets is to be a proof of principle that Nb3Sn is a viable technology for a possible LHC luminosity upgrade.

Ambrosio, G

2008-01-01

214

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.

215

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

216

Microscopic magnetic nature of water absorbed Na0.35CoO2 investigated by NMR, NQR and ?+SR  

NASA Astrophysics Data System (ADS)

In order to clarify the variation of the microscopic magnetic nature with the carrier density in NaxCoO2yHO, we have measured positive muon-spin rotation/relaxation (?+SR) spectra for H2O as well as D2O absorbed samples. Based on the zero field (ZF-) ?+SR measurements, there was no clear difference between the two superconducting phases (SC-I and SC-II). Furthermore, the ZF-spectrum for the H2O absorbed sample exhibits a clear oscillation in the whole T range measured (1.4-100 K), suggesting the formation of [H3O]+-like H2?+O ions in the sample. Further, the absence of an oscillation in the D2O absorbed sample also evidences the presence of H2?+O. We also measured 59Co nuclear quadrupole resonance spectra of magnetic sample. The temperature dependence of spectra shows that there is no evidence of charge ordering and CDW ordering around magnetic transition temperature.

Ohta, Hiroto; Mnsson, Martin; Ikedo, Yutaka; Sugiyama, Jun; Michioka, Chishiro; Yoshimura, Kazuyoshi; Brewer, Jess H.; Ansaldo, Eduardo J.; Stubbs, Scott L.; Chow, Kim H.; Lord, James S.

2010-12-01

217

First-principles study of 75As NQR in arsenic-chalcogenide compounds  

Microsoft Academic Search

We present a theoretical study of the nuclear quadrupole interaction, nuQ, of 75As in crystalline and amorphous materials containing sulfur and selenium, and compare them with experiment. We studied a combination of hydrogen-terminated molecular clusters and periodic cells at various levels of quantum chemical theory. The results show clearly that the standard density functional theory (DFT) approximations, LDA and GGA,

Arthur H. Edwards; P. C. Taylor; Kristy A. Campbell; Andrew C. Pineda

2011-01-01

218

Nuclear Charge Radii and Electric Quadrupole Moments  

E-print Network

Isotope shifts of the mean square radii (MSR) and electric quadrupole moments of even-even nuclei with 20particle Nilsson potential with the Seo set of correction term parameters, the pairing forces in the BCS formalism and a long range interaction in the local approximation are used. A collective hamiltonian is obtained using a generator coordinate method (GCM) with the gaussian overlap approximation (GOA). A potential energy of the nucleus consists of a microscopic-macroscopic Strutinsky energy and a zero point vibrational term. A liquid droplet model is used as the macroscopic part of the potential. A BCS wave function is taken as a generator function and two collective variables, quadrupole and hexadecapole deformations, serve as the generator coordinates.

Nerlo-Pomorska, B; Nerlo-Pomorska, Bozena; Mach, Beata

1993-01-01

219

Nuclear Charge Radii and Electric Quadrupole Moments  

E-print Network

Isotope shifts of the mean square radii (MSR) and electric quadrupole moments of even-even nuclei with 20particle Nilsson potential with the Seo set of correction term parameters, the pairing forces in the BCS formalism and a long range interaction in the local approximation are used. A collective hamiltonian is obtained using a generator coordinate method (GCM) with the gaussian overlap approximation (GOA). A potential energy of the nucleus consists of a microscopic-macroscopic Strutinsky energy and a zero point vibrational term. A liquid droplet model is used as the macroscopic part of the potential. A BCS wave function is taken as a generator function and two collective variables, quadrupole and hexadecapole deformations, serve as the generator coordinates.

Bozena Nerlo-Pomorska; Beata Mach

1993-11-24

220

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.; Felice, H.; Ferracin, P.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.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.

2007-08-27

221

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

222

On quadrupole vibrations in nearly spherical nuclei  

NASA Astrophysics Data System (ADS)

A new understanding of low-lying quadrupole vibrations in nuclei is emerging through lifetime measurements performed with fast neutrons at the accelerator laboratory of the University of Kentucky in combination with high-sensitivity measurements with other probes. In the stable cadmium nuclei, which have long been considered to be the best examples of vibrational behavior, we find that many E2 transition probabilities are well below harmonic vibrator expectations, and the B(E2)s cannot be explained with calculations incorporating configuration mixing between vibrational phonon states and intruder excitations. These data place severe limits on the collective models, and it is suggested that the low-lying levels of the Cd isotopes may not be of vibrational origin. An additional example of an apparent quadrupole vibrational nucleus, 62Ni, is considered.

Yates, S. W.

2012-09-01

223

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 Nb3Sn conductor. The goal of these magnets is to be a proof of principle that Nb3Sn 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.; Chlachidze, G.; Dietderich, D.; Feher, S.; Felice, H.; Ferracin, P.; /Fermilab /Brookhaven /LBL, Berkeley /Texas A-M

2007-08-01

224

Superconducting state of filled-skutterudite RPt4Ge12 (R = La, Pr): 73Ge-NQR studies  

NASA Astrophysics Data System (ADS)

We report 73Ge-NQR studies on filled-skutterudite superconductors LaPt4Ge12 and PrPt4Ge12 under zero external field. In PrPt4Ge12, the measurement of the nuclear spin-lattice relaxation rate 1/T1 has revealed a distinct coherence peak just below Tc followed by an exponential decrease well below Tc, evidencing that PrPt4Ge12 is an s-wave superconductor with the isotropic gap in a weak-coupling regime. In LaPt4Ge12, the 1/T1 exhibits the exponential decrease well below Tc, suggesting the isotropic s-wave superconductivity. Even though 73Ge-NQR-1/T1 in LaPt4Ge12 has been measured under zero field, its coherence peak was absent, which contrasts with the result in Pr-compound. This may point to a possible anisotropy in the Fermi surface and/or some damping effect of quasiparticles in association with electron-phonon interactions.

Kanetake, F.; Mukuda, H.; Kitaoka, Y.; Sugawara, H.; Magishi, K.; Itoh, K. M.; Haller, E. E.

2010-12-01

225

An ultra-broadband low-frequency magnetic resonance system.  

PubMed

MR probes commonly employ resonant circuits for efficient RF transmission and low-noise reception. These circuits are narrow-band analog devices that are inflexible for broadband and multi-frequency operation at low Larmor frequencies. We have addressed this issue by developing an ultra-broadband MR probe that operates in the 0.1-3MHz frequency range without using conventional resonant circuits for either transmission or reception. This "non-resonant" approach significantly simplifies the probe circuit and allows robust operation without probe tuning while retaining efficient power transmission and low-noise reception. We also demonstrate the utility of the technique through a variety of NMR and NQR experiments in this frequency range. PMID:24632101

Mandal, S; Utsuzawa, S; Cory, D G; Hrlimann, M; Poitzsch, M; Song, Y-Q

2014-05-01

226

An ultra-broadband low-frequency magnetic resonance system  

NASA Astrophysics Data System (ADS)

MR probes commonly employ resonant circuits for efficient RF transmission and low-noise reception. These circuits are narrow-band analog devices that are inflexible for broadband and multi-frequency operation at low Larmor frequencies. We have addressed this issue by developing an ultra-broadband MR probe that operates in the 0.1-3 MHz frequency range without using conventional resonant circuits for either transmission or reception. This non-resonant approach significantly simplifies the probe circuit and allows robust operation without probe tuning while retaining efficient power transmission and low-noise reception. We also demonstrate the utility of the technique through a variety of NMR and NQR experiments in this frequency range.

Mandal, S.; Utsuzawa, S.; Cory, D. G.; Hrlimann, M.; Poitzsch, M.; Song, Y.-Q.

2014-05-01

227

Two-color photoexcitation of Rydberg states via an electric quadrupole transition  

SciTech Connect

We report the observation of an electric quadrupole transition between the 4s{sup '}[1/2]{sub 0}{sup o} and 3d[3/2]{sub 2}{sup o} states in the spectrum of argon and use it in the first step of a scheme to excite Rydberg states. The initial identification of the transition is based on one-color, two-photon photoionization. A different experiment utilizing two-color, two-photon photoexcitation to Rydberg states confirms the identification. Despite the unavoidable background of one-color, two-photon photoionization, the latter experimental technique makes possible two-photon spectroscopy of Rydberg states using a resonant intermediate state populated by an electric quadrupole transition.

Li Leping; Gu Quanli; Knee, J. L. [Department of Chemistry, Wesleyan University, Middletown, Connecticut 06459 (United States); Wright, J. D.; DiSciacca, J. M.; Morgan, T. J. [Department of Physics, Wesleyan University, Middletown, Connecticut 06459 (United States)

2008-03-15

228

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

NASA Astrophysics Data System (ADS)

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

Deiglmayr, Johannes; Samannshausen, Heiner; Pillet, Pierre; Merkt, Frdric

2014-11-01

229

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

PubMed

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

Deiglmayr, Johannes; Sassmannshausen, Heiner; Pillet, Pierre; Merkt, Frdric

2014-11-01

230

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

231

Muon cooling in a quadrupole magnet channel  

SciTech Connect

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

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

2007-10-01

232

LARP Long Nb3Sn Quadrupole Design  

Microsoft Academic Search

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 NbSn conductor. The goal of these magnets is to be a proof of principle that NbSn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on

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

2007-01-01

233

LARP Long Nb_{3}Sn Quadrupole Design  

Microsoft Academic Search

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 NbSn conductor. The goal of these magnets is to be a proof of principle that NbSn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on

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

2008-01-01

234

Polarization angle affects energy of plasmonic features in Fano resonant regular lattices  

NASA Astrophysics Data System (ADS)

Plasmonic nanoparticles in ordered lattices exhibit spectral features supported by Fano resonant coupling between dipole and/or quadrupole oscillations and constructively interfering diffracted modes. This work showed that the angle at which incident resonant irradiation was polarized relative to the axes of a rectangular 655 649 nm2 lattice of 264 nm diameter gold nanospheres predictably modulated the energy of plasmonic spectral features. Measured peak wavelengths varied sinusoidally as polarization angle was rotated 360. Quadrupole and dipole lattice resonance oscillations were phase shifted by 90, consistent with theory. Experimental wavelengths were within 12 nanometers (1.8%) of wavelengths simulated for the lattice using a coupled dipole/quadrupole approximation.

DeJarnette, D.; Jang, G. G.; Blake, P.; Roper, D. K.

2014-10-01

235

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

SciTech Connect

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

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

2010-10-15

236

INVESTIGATION OF BORIDES OF TRANSITION METALS AND PURE BORON BY THE METHOD OF NUCLEAR MAGNETIC RESONANCE  

Microsoft Academic Search

The method of nuclear magnetic resonance was used to investigate ; diborides of TiC, Zr, Nb, Ta, Cr, and MOB in which quadrupole ; effects of the first and second orders were discovered. The constants of ; quadrupole binding were found. The same constarts were computed under the ; assumption that boron atoms possess hybridized spd⁴ orbits that affect the

O. T. Malyuchkov; V. A. Povitskii

1962-01-01

237

Ab initio correlated calculations of rare-gas dimer quadrupoles  

SciTech Connect

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

Donchev, Alexander G. [Algodign, LLC, Bolshaya Sadovaya 8, Moscow 123001 (Russian Federation)

2007-10-15

238

Noise reduction in negative-ion quadrupole mass spectrometry  

DOEpatents

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

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

1993-01-01

239

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

240

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

241

Coexistence of Antiferromagnetism with Superconductivity in CePt2In7: Microscopic Phase Diagram Determined by In115 NMR and NQR  

NASA Astrophysics Data System (ADS)

Single crystals of the heavy-fermion antiferromagnet CePt2In7 with a Nel temperature (TN) of 5.2 K at ambient pressure have been investigated by zero-field In115-nuclear magnetic and quadrupole resonance measurements as a function of applied pressure. Within the antiferromagnetic state, the character of Ce's 4f electron appears to change from localized to itinerantlike at P*2.4 GPa, approximately the pressure where superconductivity first emerges. With increased pressure, the superconducting transition Tc reaches a maximum just at or slightly before antiferromagnetic order disappears, and not at the pressure Pc3.4 GPa, where the steeply decreasing Nel boundary extrapolates to zero temperature. For P >Pc, the spin relaxation rate drops sharply by more than 2 orders of magnitude at Tc, suggestive of a first-order transition.

Sakai, H.; Tokunaga, Y.; Kambe, S.; Ronning, F.; Bauer, E. D.; Thompson, J. D.

2014-05-01

242

ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS  

SciTech Connect

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

Chu Zhe; Lin, W. P. [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Yang Xiaofeng, E-mail: chuzhe@shao.ac.cn, E-mail: linwp@shao.ac.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

2013-06-20

243

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

244

The Pipe-Quadrupole, an Alternative for High Gradient Interaction Region Quadrupole Designs  

SciTech Connect

In the design of interaction region (IR) quadrupoles for high luminosity colliders such as the LHC or a possible upgrade of the Tevatron, the radiation heating of the coil windings is an important issue. Two obvious solutions to this problem can be chosen. The first is to reduce the heat load by added shielding, increased cooling with fins or using Nb{sub 3}Sn to increase the temperature margin. The second solution eliminates the conductor from the areas with the highest radiation intensity, which are located on the symmetry-axes of the midplanes of the coils. A novel quadrupole design is presented, in which the conductor is wound on four half-moon shaped supports, forming elongated toroid sections. The assembly of the four shapes yields a quadrupole field with an active flux return path, and a void in the high radiation area. This void can be occupied by a liquid helium cooling pipe to lower the temperature of the windings from the inside. The coil layout, harmonic optimization and mechanical design are shown, together with the calculated temperature rise for the radiation load of the LHC interaction region quadrupoles.

Oort, J.M. van; Scanlan, R.M.

1996-12-12

245

Field stabilization studies for a radio frequency quadrupole accelerator  

NASA Astrophysics Data System (ADS)

The Radio Frequency Quadrupole (RFQ) linear accelerator is an accelerator that efficiently focuses, bunches and accelerates a high intensity DC beam from an ion source, for various applications. Unlike other conventional RF linear accelerators, the electromagnetic mode used for its operation is not the lowest frequency mode supported by the structure. In a four vane type RFQ, there are several undesired electromagnetic modes having frequency close to that of the operating mode. While designing an RFQ accelerator, care must be taken to ensure that the frequencies of these nearby modes are sufficiently separated from the operating mode. If the undesired nearby modes have frequencies close to the operating mode, the electromagnetic field pattern in the presence of geometrical errors will not be stabilized to the desired field profile, and will be perturbed by the nearby modes. This will affect the beam dynamics and reduce the beam transmission. In this paper, we present a detailed study of the electromagnetic modes supported, which is followed by calculations for implementation of suitable techniques to make the desired operating mode stable against mixing with unwanted modes for an RFQ being designed for the proposed Indian Spallation Neutron Source (ISNS) project at Raja Ramanna Centre for Advanced Technology, Indore. Resonant coupling scheme, along with dipole stabilization rods has been proposed to increase the mode separation. The paper discusses the details of a generalized optimization procedure that has been used for the design of mode stabilization scheme.

Gaur, R.; Kumar, V.

2014-07-01

246

Controlled ion fragmentation in a 2-D quadrupole ion trap for external ion accumulation in ESI FTICR mass spectrometry  

Microsoft Academic Search

Undesired fragmentation of electrospray generated ions in an rf multipole traps can be problematic in many applications. Of\\u000a special interest here is ion dissociation in a 2-D quadrupole ion trap external to a Fourier transform ion cyclotron resonance\\u000a mass spectrometer (FTICR MS) used in proteomic studies. In this work, we identified the experimental parameters that determine\\u000a the efficiency of ion

Mikhail E. Belov; Michael V. Gorshkov; Harold R. Udseth; Richard D. Smith

2001-01-01

247

Resonance Control Cooling System for the APT/LEDA RFQ  

SciTech Connect

The Radio Frequency Quadrupole (RFQ) resonance control cooling system (RCCS) for the Low Energy Demonstration Accelerator (LEDA) in support of the Accelerator Production of Tritium (APT) is described. Constant flow regulating valves to distribute the required flow to the 424 channels and to permit use of centrifugal pumps is discussed. Control system schema are described to regulate resonance frequency during steady state operation.

Domer, G.A.; Floersch, R.H.

1998-11-04

248

Photon decay of giant resonances  

SciTech Connect

Measurements have been made of the photon decay of the giant multipole resonances in /sup 208/Pb. The giant resonances were excited by inelastic scattering of 380 MeV /sup 17/O projectile and the photons were detected in the ORNL Spin Spectrometer. The results show a quadrupole resonance ground state gamma branch of 20% while only less than or equal to 2% of the GQR decay proceeds through the 2.6 MeV, 3/sup -/ state. Nearly one half of the GQR decay through a 3/sup -/ state at 4.974 MeV. Photon decay from the dipole and monopole resonances and high spin resonances (4+,6+) are also observed.

Bertrand, F.E.; Beene, J.R.; Halbert, M.L.

1984-01-01

249

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

250

Second generation high gradient quadrupoles for the LHC interaction regions  

Microsoft Academic Search

Conceptual designs of large-aperture high-gradient Nb3Sn quadrupoles, suitable for use in a second generation LHC interaction region, are presented. A quadrupole with a 90 mm coil aperture and the same 200 T\\/m gradient as in the current LHC IR is technically feasible and would allow ?*=0.25 in to be achieved, doubling the LHC luminosity

T. Sen; J. Strait; A. V. Zlobin

2001-01-01

251

The LHC main dipoles and quadrupoles toward series production  

Microsoft Academic Search

The Large Hadron Collider (LHC) is under construction at CERN. Most of its 27 km underground tunnel will be filled with superconducting magnets, mainly 15 m long dipoles and 3.3 m long quadrupoles. In total 1248 dipole and 400 quadrupole magnets will be built (including spares), all wound with copper stabilized NbTi Rutherford cables and designed to operate in superfluid

Lucio Rossi

2003-01-01

252

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

253

Performance of electromagnet and permanent magnet quadrupoles with iron poles  

Microsoft Academic Search

The largest field that can be obtained at the pole tip of an iron core quadrupole is limited by saturation in the iron and by its excitation by either the current density in the coil or the remanent field of the permanent magnet material. An analytical model is used to find the saturation limited performance of quadrupoles with either electromagnet

E. B. Blum; K. Halbach

1992-01-01

254

Computation of a quadrupole magnet for the APS storage ring  

SciTech Connect

The storage ring of the Advanced Photon Source will include 400 quadrupole magnets for focusing the beam. A prototype quadrupole has been designed, constructed, and measured. This paper describes the two- and three-dimensional (2-D and 3-D) field computations performed for this design. 2 refs., 6 figs., 1 tab.

Turner, L.R.; Kim, S.H.; Thompson, K.M.

1990-01-01

255

H/D isotope effect of 1H MAS NMR spectra and 79Br NQR frequencies of piperidinium p-bromobenzoate and pyrrolidinium p-bromobenzoate  

NASA Astrophysics Data System (ADS)

H/D isotope effects onto 79Br NQR frequencies of piperidinium p-bromobenzoate were studied by deuterium substitution of hydrogen atoms which form two kinds of N-H?O type hydrogen bonds, and the isotope shift of ca. 100 kHz were detected for a whole observed temperature range. In addition, 1H MAS NMR spectra measurements of piperidinium and pyrrolidinium p-bromobenzoate were carried out and little isotope changes of NMR line shape were detected. In order to reveal effects of molecular arrangements into the obtained isotope shift of NQR frequencies, single-crystal X-ray measurement of piperidinium p-bromobenzoate- d2 and density-functional-theory calculation were carried out. Our estimation showed the dihedral-angle change between piperidine and benzene ring contributes to isotope shift rather than those of N-H lengths by deuterium substitution.

Honda, Hisashi; Kyo, Shinshin; Akaho, Yousuke; Takamizawa, Satoshi; Terao, Hiromitsu

2010-04-01

256

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

257

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

258

Motion of Water Molecules and Hydrogen Bonds in Zinc Hexachlorostannate (IV) Hexahydrate as Studied by 1H NMR and 35Cl NQR  

NASA Astrophysics Data System (ADS)

The 1H NMR spin-lattice relaxation time T1, 35Cl NQR frequency ?Q, and 35Cl NQR spin-lattice relaxation time T1Q of [Zn(H2O)6] [SnCl6] (zinc hexachlorostannate(IV) hexahydrate) have been measured at temperatures between 77 and 350 K. The NQR spin echo signal with ?Q = 15.689 MHz at 77 K showed a positive temperature coefficient attributable to O-H-Cl type H-bonds in the crystal. ?Q at 77 K is strongly correlated with the electronegativity ?M of the metal M in the series of stannates [M(H2O)6] [SnCl6] (M = Mg, Ca, Mn, Co, Ni, Zn). A T1 minimum observed for the Zn salt is ascribed to 180 flips of water molecules with an activation energy of 20 kJ mol-1. The motion is influenced by repulsive forces among the water molecules within a cation rather than by attractive forces between the H-bonded H and CI atoms. T1Q proved to be mainly governed by lattice vibrations, weakly modulated by the fluctuating electric field gradient caused by the 180 flip motions.

Ishikawa, A.; Sasane, A.; Hirakawa, Y.; Mori, Y.

1996-06-01

259

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

260

RADIATION RESISTANT HTS QUADRUPOLES FOR RIA.  

SciTech Connect

Extremely high radiation, levels with accumulated doses comparable to those in nuclear reactors than in accelerators, and very high heat loads ({approx}15 kw) make the quadrupole magnets in the fragment separator one of the most challenging elements of the proposed Rare Isotope Accelerator (RIA). Removing large heat loads, protecting the superconducting coils against quenching, the long term survivability of magnet components, and in particular, insulation that can retain its functionality in such a harsh environment, are the major challenges associated with such magnets. A magnet design based on commercially available high temperature superconductor (HTS) and stainless steel tape insulation has been developed. HTS will efficiently remove these large heat loads and stainless steel can tolerate these large radiation doses. Construction of a model magnet has been started with several coils already built and tested. This paper presents the basic magnet design, results of the coil tests, the status and the future plans. In addition, preliminary results of radiation calculations are also presented.

GUPTA,R.; ANERELLA,M.; HARRISON,M.; ET AL.

2004-10-03

261

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

262

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

263

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

264

Development of Superconducting Focusing Quadrupoles for Heavy Ion Drivers  

SciTech Connect

Heavy Ion Fusion (HIF) is exploring a promising path to a practical inertial-confinement fusion reactor. The associated heavy ion driver will require a large number of focusing quadrupole magnets. A concept for a superconducting quadrupole array, using many simple racetrack coils, was developed at LLNL. Two, single-bore quadrupole prototypes of the same design, with distinctly different conductor, were designed, built, and tested. Both prototypes reached their short sample currents with little or no training. Magnet design, and test results, are presented and discussed.

Martovetsky, N; Manahan, R; Lietzke, A F

2001-09-10

265

Automated beam based alignment of the ALS quadrupoles  

SciTech Connect

Knowing the electrical offset of the storage ring beam position monitors (BPM) to an adjacent quadrupole magnetic center is important in order to correct the orbit in the ring. The authors describe a simple, fast and reliable technique to measure the BPM electrical centers relative to the quadrupole magnetic centers. By varying individual quadrupole magnets and observing the effects on the orbit they were able to measure the BPM offsets in half the horizontal and vertical BPMs (48) in the ALS. These offsets were measured to an accuracy of better than 50{mu}m. The technique is completely automated and takes less than 3 hours for the whole ring.

Portmann, G.; Robin, D.; Schachinger, L.

1995-04-01

266

Gamma decay of isoscalar and isovector giant resonances following heavy-ion inelastic scattering  

SciTech Connect

Results from studies of gamma decay of giant resonances in /sup 208/Pb and /sup 90/Zr following inelastic excitation by 22 and 84 MeV/nucleon /sup 17/O ions are presented. Data on ground state decay of isoscalar giant quadrupole and isovector giant dipole resonances are presented and compared with calculations. Decays from resonances to low lying excited states are also discussed. Preliminary results from an attempt to isolate the isovector quadrupole resonance in /sup 208/Pb using its gamma decay are presented.

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

1987-01-01

267

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

268

Mechanical design of a second generation LHC IR quadrupole  

Microsoft Academic Search

One of the proposed options to increase the LHC luminosity is the replacement of the existing inner triplets at the interaction regions with new low-beta larger aperture quadrupoles operating at the same gradient. Lawrence Berkeley National Laboratory (LBNL) is carrying out preliminary studies of a large-bore Nb3Sn quadrupole. The mechanical design presents a support structure based on the use of

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

2004-01-01

269

Quadrupole hyperfine interaction in iron(III) dicarboxylic acid complexes  

Microsoft Academic Search

Mssbauer and infrared spectroscopic studies of a series of iron(III) complexes of dicarboxylic acids, maleic, malonic, succinic, glutaric, adipic, pimelic, suberic, azealic and sebacic have been carried out at room temperature. All complexes exhibit a quadrupole doublet with isomer shift () values in the range of 0.62 0.72 mms1 (with respect to SNP) and quadrupole splitting, EQ=0.530.74 mm s1. It

R. B. Lanjewar; A. M. Waditwar; A. N. Garg

1988-01-01

270

Development and Test of LARP Technological Quadrupole (TQC) Magnet  

Microsoft Academic Search

In support of the development of a large-aperture 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

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

2007-01-01

271

Development and Test of TQC models, LARP Technological Quadrupole Magnets  

Microsoft Academic Search

In support of the development of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, two-layer quadrupole models (TQC and TQS) with 90mm aperture are being constructed at Fermilab and LBNL within the framework of the US LHC Accelerator Research Program (LARP). This paper describes the development and test of TQC01b, the second TQC model, and

R. C. Bossert; G. Ambrosio; N. Andreev; E. Barzi; R. Carcagno; S. Feher; V. S. Kashikhin; V. V. Kashikhin; F. Nobrega; I. Novitski; D. Orris; M. Tartaglia; A. V. Zlobin; S. Caspi; D. Dietderich; P. Ferracin; A. R. Hafalia; G. Sabbi

2008-01-01

272

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

273

Field measurement for large quadrupole magnets  

NASA Astrophysics Data System (ADS)

The results of the field measurement of the large quadrupole magnet of the MAGNEX spectrometer are presented and analyzed in the view of the possible application of modern techniques of ray reconstruction. The experimental data are checked against the symmetry conditions expected for the magnet. The observed deviations are related both to imperfections on the magnet manufacturing and to the not ideal positioning of the measurement device. In particular a quantitative estimation of the experimental error in the alignment of the probe with respect to the magnet is achieved. The measured field is also compared with the results from three-dimensional finite elements calculation. The obtained discrepancies between the measured and calculated field are too large for a direct application of the latter to ray-reconstruction methods. Nevertheless, these calculations are reliably used to study the impact of the observed inaccuracies in the probe alignment on the overall precision of field reconstruction and to set quantitative constraints on the field interpolation algorithms.

Lazzaro, A.; Cappuzzello, F.; Cunsolo, A.; Cavallaro, M.; Foti, A.; Orrigo, S. E. A.; Rodrigues, M. R. D.; Winfield, J. S.

2008-06-01

274

Suspending graphene using a quadrupole ion trap  

NASA Astrophysics Data System (ADS)

Creating a technology to suspend, manipulate, and probe an isolated graphene layer in vacuum may have applications ranging from new growth and fabrication strategies to fundamental measurements of these materials when they are completely uncoupled from a substrate. A sufficiently charged piece of graphene will remain flat due to electrostatic repulsion and can be confined using ac electric fields in a quadrupole trap. I will describe a trap built for this purpose which uses a design borrowed from atomic physics that is optimized for easy optical and physical access to the trapped particle [1]. Charged particles are injected into the trap using electrospray emission [2] of graphene suspended in organic solvents[3] and are probed with a 532 nm laser. I will provide details of the trap design and present preliminary data on characterization of the trapped graphene particles. [4pt] [1] Maiwald et al., Nature Physics 5, 551 (2009). [0pt] [2] Pearson et al., Phys. Rev. A 73, 032307 (2006). [0pt] [3] Hernandez et al., Nature Nanotechnology 3, 563 (2008).

Kane, Bruce

2010-03-01

275

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

276

Excitation of giant resonances via direct reactions  

SciTech Connect

Experimental measurements of electric giant multipole resonances are discussed. The parameters of the giant quadrupole resonance are now firmly established by an extensive set of measurements. The GQR is providing a significant influence in other areas of nuclear physics. The monopole resonance has now been established and its observation has provided the first direct measure of the nuclear compressibility. A strong case for the existence of a giant octupole resonance is now being made through a variety of hadron reactions. However, the supply of giant multipole resonances has not been exhausted. The newer techniques such as higher energy proton scattering, charge exchange reactions, heavy-ion scattering and pion reactions offer considerable hope for identifying new resonances during the next few years.

Bertrand, F.E.

1982-01-01

277

Resonances and resonance widths  

SciTech Connect

Two-dimensional betatron resonances are much more important than their simple one-dimensional counterparts and exhibit a strong dependence on the betatron phase advance per cell. A practical definition of ''width'' is expanded upon in order to display these relations in tables. A primarily pedagogical introduction is given to explain the tables, and also to encourage a wider capability for deriving resonance behavior and wider use of ''designer'' resonances.

Collins, T.

1986-05-01

278

H-mode accelerating structures with permanent-magnet quadrupole beam focusing  

NASA Astrophysics Data System (ADS)

We have developed high-efficiency normal-conducting rf accelerating structures by combining H-mode resonator cavities and a transverse beam focusing by permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of interdigital H-mode (IH-PMQ) structures is 10-20 times higher than that of a conventional drift-tube linac, while the transverse size is 4-5 times smaller. Results of the combined 3D modelingelectromagnetic computations, multiparticle beam-dynamics simulations with high currents, and thermal-stress analysisfor an IH-PMQ accelerator tank are presented. The accelerating-field profile in the tank is tuned to provide the best propagation of a 50-mA deuteron beam using coupled iterations of electromagnetic and beam-dynamics modeling. Measurements of a cold model of the IH-PMQ tank show a good agreement with the calculations. Examples of cross-bar H-mode structures with PMQ focusing for higher beam velocities are also presented. H-PMQ accelerating structures following a short radio-frequency quadrupole accelerator can be used both in the front end of ion linacs or in stand-alone applications.

Kurennoy, S. S.; Rybarcyk, L. J.; O'Hara, J. F.; Olivas, E. R.; Wangler, T. P.

2012-09-01

279

H-mode accelerating structures with permanent-magnet quadrupole beam focusing  

DOE PAGESBeta

We have developed high-efficiency normal-conducting rf accelerating structures by combining H -mode resonator cavities and a transverse beam focusing by permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. The shunt impedance of interdigital H -mode (IH-PMQ) structures is 1020 times higher than that of a conventional drift-tube linac, while the transverse size is 45 times smaller. Results of the combined 3D modelingelectromagnetic computations, multiparticle beam-dynamics simulations with high currents, and thermal-stress analysisfor an IH-PMQ accelerator tank are presented. The accelerating-field profile in the tank is tuned to provide the best propagation of a 50-mA deuteron beam using coupled iterations of electromagnetic and beam-dynamics modeling. Measurements of a cold model of the IH-PMQ tank show a good agreement with the calculations. Examples of cross-bar H -mode structures with PMQ focusing for higher beam velocities are also presented. H -PMQ accelerating structures following a short radio-frequency quadrupole accelerator can be used both in the front end of ion linacs or in stand-alone applications.

Kurennoy, S. S.; Rybarcyk, L. J.; OHara, J. F.; Olivas, E. R.; Wangler, T. P.

2012-09-01

280

Stochastic Resonance  

NASA Astrophysics Data System (ADS)

Preface; 1. Introduction and motivation; 2. Stochastic resonance: its definitions, history and debates; 3. Stochastic quantization; 4. Suprathreshold stochastic resonance: encoding; 5. Suprathreshold stochastic resonance: large N encoding; 6. Suprathreshold stochastic resonance: decoding; 7. Suprathreshold stochastic resonance: large N decoding; 8. Optimal stochastic quantization; 9. SSR, neural coding, and performance tradeoffs; 10. Stochastic resonance in the auditory system; 11. The future of stochastic resonance and suprathreshold stochastic resonance; Appendices; References; Index.

McDonnell, Mark D.; Stocks, Nigel G.; Pearce, Charles E. M.; Abbott, Derek

2012-10-01

281

Probing of the charge distribution in iron pnictides  

NASA Astrophysics Data System (ADS)

A powerful tool to probe the electronic charge distribution in correlated oxides is nuclear magnetic/quadrupole resonance (NMR/NQR). Indeed, through sensitivity to the electric field gradient (EFG), NMR/NQR allows to probe locally the symmetry of the charge distribution, its homogeneity, as well as its sensitivity to structural and doping changes. In context of our own results, we discuss here the state of knowledge in iron pnictides. It appears that the iron pnictides feature a complex behaviour of their charge distribution, with a non-trivial link between the measured EFG and the structural and doping variations.

Lang, G.; Grafe, H.-J.; Hammerath, F.; Manthey, K.; Paar, D.; Behr, G.; Werner, J.; Hamann-Borrero, J.; Bchner, B.

2010-12-01

282

On the crystal structures of some protonic complexes of oxo-ligands with tetrachloroauric acid, [(RO) n H][AuCl 4] (R: Py, Ph 3As; n: 1, 2), prepared from deuterated and non-deuterated solvent systems  

Microsoft Academic Search

The possible structural change of the dimeric cations [(RO)nH]+ (R=Py, Ph3As) in [(RO)nH][AuCl4] crystals due to the lowering of temperature or hydrogendeuterium exchange was studied by 35Cl NQR and powder X-ray diffraction measurements. Temperature dependence of the nuclear quadrupole resonance (NQR) frequencies of [(Ph3AsO)2H][AuCl4] and [(PyO)2H][AuCl4] suggested the symmetric hydrogen bond was retained down to 4.2 K. A crystalline polymorph

Tetsuo Asaji; Fukue Tajima; Masao Hashimoto

2002-01-01

283

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

284

Tailoring dielectric resonator geometries for directional scattering and Huygens' metasurfaces.  

PubMed

In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity dielectric cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometry in a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole resonances to achieve local behavior. These properties are confirmed through the multipolar expansion and show that the use of geometries suggested by perturbation theory is a viable route to achieve purely dipole resonances for metamaterial applications such as wave-front manipulation with Huygens' metasurfaces. Our results are fully scalable across any frequency bands where high-permittivity dielectric materials are available, including microwave, THz, and infrared frequencies. PMID:25836097

Campione, Salvatore; Basilio, Lorena I; Warne, Larry K; Sinclair, Michael B

2015-02-01

285

Coupled plasmon resonances in monolayers of metal nanoparticles and nanoshells  

NASA Astrophysics Data System (ADS)

We report on the coupled plasmon resonances in a monolayer consisting of metal or metallodielectric nanoparticles with the dipole and quadrupole single-particle resonances. The theoretical models included spherical gold and silver particles and also gold and silver nanoshells on silica and polystyrene cores forming two dimensional random clusters or square-lattice arrays on a dielectric substrate (glass in water). The parameters of the individual particles were chosen so that a quadrupole plasmon resonance could be observed along with the dipole-scattering band. By using an exact multipole cluster-on-a-substrate solution, we showed that particle-substrate coupling can be neglected in the calculation of the monolayer-extinction spectra, at least for the glass-in-water configuration. When the surface particle density in the monolayer was increased, the dipole resonance became suppressed and the spectrum for the cooperative system was determined only by the quadrupole plasmon. The dependence of this effect on the single-particle parameters and on the cluster structure was examined in detail. In particular, the selective suppression of the long-wavelength extinction band was shown to arise from the cooperative suppression of the dipole-scattering mode, whereas the short-wavelength absorption spectrum for the monolayer was shown to be little different from the single-particle spectrum. For experimental studies, the silica/gold-nanoshell monolayers were fabricated by the deposition of nanoshells on a glass substrate functionalized by silane-thiol cross-linkers. The measured single-particle and monolayer-extinction spectra are in reasonable agreement with simulations based on the nanoshell geometrical parameters (scanning electron microscopy data). Finally, we evaluated the sensitivity of the coupled quadrupole resonance to the dielectric environment to show a universal linear relation between the relative shift in the coupled-quadrupole-resonance wavelength and the relative increment in the environment refractive index.

Khlebtsov, Boris N.; Khanadeyev, Vitaliy A.; Ye, Jian; Mackowski, Daniel W.; Borghs, Gustaaf; Khlebtsov, Nikolai G.

2008-01-01

286

Nuclear quadrupole coupling parameters and structural nature of the nonlinear optical material Li2B4O7 by NMR.  

PubMed

The structural nature underlying the nonlinear optical (NLO) properties of Li2B4O7 is characterized by nuclear magnetic resonance (NMR). The rotation patterns of (11)B NMR were measured. We observed sixteen different spectra which were divided into two groups, corresponding to two types of boron atoms, 4-coordinated B(1) and 3-coordinated B(2), which have different boron-oxygen rings and lie at chemically inequivalent sites. From these results, the quadrupole parameter and the principal axis of the electric field gradient (EFG) tensor were determined for the two borons. PMID:25618744

Lim, Ae Ran; Kim, In Gyoo

2015-01-01

287

Relativistic coupled-cluster theory of quadrupole moments and hyperfine structure constants of 5d states in Ba{sup +}  

SciTech Connect

The narrow optical frequency resonances of the 6s {sup 2}S{sub 1/2}{yields}5d {sup 2}D{sub 3/2} and 6s {sup 2}S{sub 1/2}{yields}5d {sup 2}D{sub 5/2} forbidden transitions in Ba{sup +} have been proposed as suitable frequencies for a new optical frequency standard. The major sources of errors in measurements of singly ionized systems are due to the quadratic Zeeman and electric quadrupole shifts. We report here the most accurate calculations to date for the hyperfine structure constants and electric-quadrupole moments of the 5d {sup 2}D{sub 3/2} and 5d {sup 2}D{sub 5/2} states in Ba{sup +}, which determine the quadratic Zeeman and electric quadrupole shifts. Relativistic coupled-cluster theory has been employed to calculate these quantities and large electron correlation effects are observed. It is also shown that for the high accuracy calculation of the 5d {sup 2}D{sub 5/2} state in Ba{sup +}, all order core polarization effects play a significant role.

Sahoo, Bijaya Kumar [Max Planck Institute for the Physics of Complex Systems, D-01187 Dresden (Germany)

2006-08-15

288

Role of bromine in restoring superconductivity in YBa2Cu3Oy  

Microsoft Academic Search

63,65Cu nuclear quadrupole resonance (NQR), 63,65Cu and 79,81Br nuclear magnetic resonance (NMR), and Br K-edge x-ray-absorption fine-structure (XAFS) measurement techniques have been used to study the local structures of Cu and Br in well-characterized samples of deoxygenated and brominated YBa2Cu3Oy (YBCO). The combined results provide a detailed picture of the role of bromine in reoxygenating the YBCO structure and an

D. M. Potrepka; J. I. Budnick; D. B. Fenner; W. A. Hines; M. Balasubramanian; A. R. Moodenbaugh

1999-01-01

289

A microelectromechanical systems-enabled, miniature triple quadrupole mass spectrometer.  

PubMed

Miniaturized mass spectrometers are becoming increasingly capable, enabling the development of many novel field and laboratory applications. However, to date, triple quadrupole tandem mass spectrometers, the workhorses of quantitative analysis, have not been significantly reduced in size. Here, the basis of a field-deployable triple quadrupole is described. The key development is a highly miniaturized ion optical assembly in which a sequence of six microengineered components is employed to generate ions at atmospheric pressure, provide a vacuum interface, effect ion guiding, and perform fragmentation and mass analysis. Despite its small dimensions, the collision cell efficiently fragments precursor ions and yields product ion spectra that are very similar to those recorded using conventional instruments. The miniature triple quadrupole has been used to detect thiabendazole, a common pesticide, in apples at a level of 10 ng/g. PMID:25708099

Wright, Steven; Malcolm, Andrew; Wright, Christopher; O'Prey, Shane; Crichton, Edward; Dash, Neil; Moseley, Richard W; Zaczek, Wojciech; Edwards, Peter; Fussell, Richard J; Syms, Richard R A

2015-03-17

290

Variable-field permanent magnet quadrupole for the SSC  

SciTech Connect

A set of compact variable-field permanent-magnet quadrupoles have been designed, fabricated, and tested for use In the SSC linac matching section. The quadrupoles have 24 mm-diameter apertures and 40 mm-long poles. The hybrid (permanent-magnet and iron) design, uses a fixed core of magnet material (NdFeB) and iron (C-1006) surrounded by a rotating ring of the same magnet material and iron. The quadrupole gradient-length product can be smoothly varied from a minimum of 0.7 T up to a maximum, of 4.3 T by a 90{degrees} rotation of the outer ring of iron and magnet material.

Barlow, D.B.; Kraus, R.H. Jr.; Martinez, R.P.; Meyer, R.E.

1993-10-01

291

Cryogen free superconducting splittable quadrupole magnet for linear accelerators  

SciTech Connect

A new superconducting quadrupole magnet for linear accelerators was fabricated at Fermilab. The magnet is designed to work inside a cryomodule in the space between SCRF cavities. SCRF cavities must be installed inside a very clean room adding issues to the magnet design, and fabrication. The designed magnet has a splittable along the vertical plane configuration and could be installed outside of the clean room around the beam pipe previously connected to neighboring cavities. For more convenient assembly and replacement a 'superferric' magnet configuration with four racetrack type coils was chosen. The magnet does not have a helium vessel and is conductively cooled from the cryomodule LHe supply pipe and a helium gas return pipe. The quadrupole generates 36 T integrated magnetic field gradient, has 600 mm effective length, and the peak gradient is 54 T/m. In this paper the quadrupole magnetic, mechanical, and thermal designs are presented, along with the magnet fabrication overview and first test results.

Kashikhin, V.S.; Andreev, N.; Kerby, J.; Orlov, Y.; Solyak, N.; Tartaglia, M.; Velev, G.; /Fermilab

2011-09-01

292

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

293

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

2013-09-11

294

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

295

High and ultra-high gradient quadrupole magnets  

NASA Astrophysics Data System (ADS)

Small bore conventional dc quadrupoles with apertures from 1 to 2.578 cm 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(+)/e(-) 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

296

High and ultra-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%.

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

1985-10-01

297

Coupling Spin Resonances In RHIC And AGS  

NASA Astrophysics Data System (ADS)

The polarization of proton beam during the acceleration process in a particle accelerator is affected by the existence of spin resonances. Coupling spin resonances can be excited in the presence of the betatron coupling introduced by rolled quadrupoles and solenoids, as well as in when the stable direction of the spin deviates from the vertical (for instance, by partial Snakes or spin rotators). In this study, We extended the ASPIRRIN code to account for the effect of solenoid magnets and related betatron coupling on the spin resonances. The examples of the coupling spin resonance for RHIC are given. In addition, an analysis is presented for spin coupling resonances produced in the AGS due to the partial Snakes.

Khalil, Nermeen

298

The feasibility of Quadrupole Dip Imaging with PMRI: focus on multiple sclerosis  

E-print Network

. Quadrupole Dip Imaging (QDI) is a novel MR technique based on the magnitude of the quadrupole dip in the T? dispersion profile of substances containing rotationally immobilized proteins. The implementation of QDI requires field-cycled (FC) relaxometry...

Jeter, Edward Hilton

2013-02-22

299

Progress of LHC low-? quadrupole magnets at KEK  

Microsoft Academic Search

Development of the LHC low-? insertion quadrupole magnet has been in progress at KEK since 1995 as a cooperative program between CERN and KEK. Five 1-m short model magnets have been fabricated and three of them have been tested. From the various test results of the first two models, the coil configuration was further optimized to reduce the higher magnetic

T. Shintomi; Y. Ajima; E. E. Burkhardt; T. Haruyama; N. Higashi; M. Iida; N. Kimura; S. Murai; T. Nakamoto; T. Ogitsu; H. Ohhata; N. Ohuchi; A. Orikasa; O. Osaki; R. J. M. Y. Ruber; K. Sugita; K. Tanaka; A. Terashima; K. Tsuchiya; A. Yamamoto; H. Yamaoka

2001-01-01

300

Status of the LHC inner triplet quadrupole program at Fermilab  

Microsoft Academic Search

Fermilab, in collaboration with LBNL and BNL, is developing a quadrupole for installation in the interaction region inner triplets of the LHC. This magnet is required to have an operating gradient of 215 T\\/m across a 70 mm coil bore, and operates in superfluid helium at 1.9 K. A 2 m magnet program addressing mechanical, magnetic, quench protection, and thermal

N. Andreev; T. Arkan; P. Bauer; R. Bossert; J. Brandt; J. Carson; S. Caspi; D. R. Chichili; L. Chiesa; C. Darve; J. Dimarco; S. Feher; A. Ghosh; H. Glass; Y. Huang; J. Kerby; M. Lamm; A. A. Markarov; A. D. McInturff; T. Nicol; A. Nobrega; I. Novitski; T. Ogitsu; D. Orris; J. P. Ozelis; T. Page; T. Peterson; R. Rabehl; W. Robotham; G. Sabbi; R. Scanlan; P. Schlabach; C. Sylvester; J. Strait; M. Tartaglia; J. C. Tompkins; G. Velev; S. Yadav; A. V. Zlobin

2001-01-01

301

Field alignment of quadrupole magnets for the LHC interaction regions  

Microsoft Academic Search

High-gradient superconducting quadrupole magnets are being developed by the US LHC Accelerator Project for the Interaction Regions of the Large Hadron Collider. Determination of the magnetic axis for alignment of these magnets will be performed using a single stretched wire system. These measurements will be done both at room and cryogenic temperatures with very long wire lengths, up to 20

J. DiMarco; H. Glass; M. J. Lamm; P. Schlabach; C. Sylvester; J. C. Tompkins; I. Krzywinski

2000-01-01

302

Table of nuclear magnetic dipole and electric quadrupole moments  

Microsoft Academic Search

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

N. J. Stone

2005-01-01

303

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

304

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

305

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

306

On the exact solution of the harmonic quadrupole collective hamiltonian  

Microsoft Academic Search

Explicit expressions for the eigenfunctions of the harmonic quadrupole collective Hamiltonian both in the lab and intrinsic systems of references are given. Two alternative approaches, the technique of projective coherent states and the theory of harmonic polynomials in collective coordinates, are used. Symmetry properties and recursive formulae for the internally labelled wave functions are established. Applications to the yrast states

A. Gheorghe; A. A. Raduta; V. Ceausescu

1978-01-01

307

Dodecahedral topology fails to explain quadrupole-octupole alignment  

E-print Network

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

Jeff Weeks; Jesper Gundermann

2006-11-20

308

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

SciTech Connect

The beginning of the development of Nb3Sn magnets for particle accelerators goes back to the 1960s. 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

2008-02-13

309

Design and fabrication of the prototype superconducting quadrupole for the CERN LHC project  

Microsoft Academic Search

Within the framework of the LHC (Large Hadron Collider) R&D program, CERN and CEA\\/Saclay have established a collaboration to carry out the design, building and testing of a superconducting LHC prototype quadrupole at the Saclay laboratory. The cold mass of this quadrupole is presently under construction at Saclay. The quadrupole design features a twin aperture configuration, a gradient of 250

J. M. Baze; D. Cacaut; M. Chapman; J. P. Jacquemin; C. Lyraud; C. Michez; Y. Pabot; J. Perot; J. M. Rifflet; J. C. Toussaint; P. Vedrine; R. Perin; N. Siegel; T. Tortschanoff

1992-01-01

310

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

Microsoft Academic Search

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 Nb3Sn 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

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

2008-01-01

311

Stars as resonant absorbers of gravitational waves  

NASA Astrophysics Data System (ADS)

Quadrupole oscillation modes in stars can resonate with incident gravitational waves (GWs), and grow non-linear at the expense of GW energy. Stars near massive black hole binaries (MBHBs) can act as GW-charged batteries, discharging radiatively. Mass-loss from these stars can prompt MBHB accretion at near-Eddington rates. GW opacity is independent of amplitude, so distant resonating stars can eclipse GW sources. Absorption by the Sun of GWs from Galactic white dwarf binaries may be detectable with second-generation space-based GW detectors as a shadow within a complex diffraction pattern.

McKernan, B.; Ford, K. E. S.; Kocsis, B.; Haiman, Z.

2014-11-01

312

Giant-Resonances in Ca-40  

E-print Network

V have been identified as 0 and 2+, and exhaust 6 and 2.5% of the corresponding energy-weighted sum rule, respec- tively. Structure at about 15.8 MeV can be tentatively assigned 3 . The giant quadrupole resonance at E?= 17.7+ 0.2 MeV exhausting 48+ 8...% of E2 energy-weighted sum rule dominates the spectra in this energy region. The giant monopole resonance is not observed. The angular distribution of the 10.6 MeV state shows 1 characteristics and can be ex- plained as an isoscalar dipole state...

Lui, YW; Bronson, J. D.; Rozsa, C. M.; Youngblood, David H.; Bogucki, P.; Garg, U.

1981-01-01

313

Giant-Resonances in Sn-112  

E-print Network

PHYSICAL REVIEW C VOLUME 30, NUMBER 1 Giant resonances in "2Sn JULY 1984 Y.-W. Lui, P. Bogucki, J. D. Bronson, and D. H. Youngblood Cyclotron Institute, Texas AckM University, College Station, Texas 77843 U. Garg Physics Department, University... in Ref. 5. The observed angular distributions for the two components are shown in Fig. 2 together with the DWBA predictions for L =0 and 2 transfer. The low-excitation component in the giant resonance peak is well fitted by the quadrupole calculation...

Lui, YW; Bogucki, P.; Bronson, J. D.; Youngblood, David H.; Garg, U.

1984-01-01

314

Ultrasensitive THz sensing with high-Q Fano resonances in metasurfaces  

E-print Network

High quality factor resonances are extremely promising for designing ultra-sensitive refractive index label-free sensors since it allows intense interaction between electromagnetic waves and the analyte material. Metamaterial and plasmonic sensing has recently attracted a lot of attention due to subwavelength confinement of electromagnetic fields in the resonant structures. However, the excitation of high quality factor resonances in these systems has been a challenge. We excite an order of magnitude higher quality factor resonances in planar terahertz metamaterials that we exploit for ultrasensitive sensing. The low-loss quadrupole and Fano resonances with extremely narrow linewidths enable us to measure the minute spectral shift caused due to the smallest change in the refractive index of the surrounding media. We achieve sensitivity levels of 7.75 x 10^3 nm/ RIU with quadrupole and 5.7 x 10^4 nm/ RIU with the Fano resonances which could be further enhanced by using thinner substrates. These findings would ...

Singh, Ranjan; Al-Naib, Ibraheem; Cong, Longqing; Withayachumnankul, Withawat; Zhang, Weili

2014-01-01

315

Development and beam test of a continuous wave radio frequency quadrupole accelerator  

NASA Astrophysics Data System (ADS)

The front end of any modern ion accelerator includes a radio frequency quadrupole (RFQ). While many pulsed ion linacs successfully operate RFQs, several ion accelerators worldwide have significant difficulties operating continuous wave (CW) RFQs to design specifications. In this paper we describe the development and results of the beam commissioning of a CW RFQ designed and built for the National User Facility: Argonne Tandem Linac Accelerator System (ATLAS). Several innovative ideas were implemented in this CW RFQ. By selecting a multisegment split-coaxial structure, we reached moderate transverse dimensions for a 60.625-MHz resonator and provided a highly stabilized electromagnetic field distribution. The accelerating section of the RFQ occupies approximately 50% of the total length and is based on a trapezoidal vane tip modulation that increased the resonator shunt impedance by 60% in this section as compared to conventional sinusoidal modulation. To form an axially symmetric beam exiting the RFQ, a very short output radial matcher with a length of 0.75?? was developed. The RFQ is designed as a 100% oxygen-free electronic (OFE) copper structure and fabricated with a two-step furnace brazing process. The radio frequency (rf) measurements show excellent rf properties for the resonator, with a measured intrinsic Q equal to 94% of the simulated value for OFE copper. An O5+ ion beam extracted from an electron cyclotron resonance ion source was used for the RFQ commissioning. In off-line beam testing, we found excellent coincidence of the measured beam parameters with the results of beam dynamics simulations performed using the beam dynamics code TRACK, which was developed at Argonne. These results demonstrate the great success of the RFQ design and fabrication technology developed here, which can be applied to future CW RFQs.

Ostroumov, P. N.; Mustapha, B.; Barcikowski, A.; Dickerson, C.; Kolomiets, A. A.; Kondrashev, S. A.; Luo, Y.; Paskvan, D.; Perry, A.; Schrage, D.; Sharamentov, S. I.; Sommer, R.; Toter, W.; Zinkann, G.

2012-11-01

316

Characterization of protonated phospholipids as fragile ions in quadrupole ion trap mass spectrometry  

PubMed Central

Some ions exhibit ion fragility in quadrupole ion trap mass spectrometry (QIT-MS) during mass analysis with resonance ejection. In many cases, different ions generated from the same compound exhibit different degrees of ion fragility, with some ions (e.g., the [M+H]+ ion) stable and other ions (e.g., the [M+Na]+ ion) fragile. The ion fragility for quadrupole ion trap (QIT) mass spectrometry (MS) for protonated and sodiated ions of three phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, PC (16:0/16:0), 1,2-dipalmitoyl-sn-glycero-3-phophoethanolamine, PE (16:0/16:0), and N-palmitoyl-D-erythro-sphingosylphosphorylcholine, SM (d18:1/16:0), was determined using three previously developed experiments: 1) the peak width using a slow scan speed, 2) the width of the isolation window for efficient isolation, and 3) the energy required for collision-induced dissociation. In addition, ion fragility studies were designed and performed to explore a correlation between ion fragility in QIT mass analysis and ion fragility during transport between the ion source and the ion trap. These experiments were: 1) evaluating the amount of thermal-induced dissociation as a function of heated capillary temperature, and 2) determining the extent of fragmentation occurring with increasing tube lens voltage. All phospholipid species studied exhibited greater ion fragility as protonated species in ion trap mass analysis than as sodiated species. In addition, the protonated species of both SM (d18:0/16:0) and PC (16:0/16:0) exhibited greater tendencies to fragment at higher heated capillary temperatures and high tube lens voltages, whereas the PE (16:0/16:0) ions did not appear to exhibit fragility during ion transport. PMID:22247650

Garrett, Timothy J.; Merves, Matthew; Yost, Richard A.

2011-01-01

317

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

SciTech Connect

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

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

1987-01-01

318

Multinuclear NMR/NQR study of HgBa 2CuO 4+ xF y superconductors with different oxygen and fluorine content  

NASA Astrophysics Data System (ADS)

We have measured 63,65Cu NMR/NQR spectra, 199Hg and 19F NMR spectra and spin-lattice relaxation rate on a series of powder HgBa 2CuO 4+ xF y samples with different oxygen and fluorine content. Comparison of 63Cu and 199Hg relaxation data to numerical calculations for several types of the order parameter symmetry gives the best coincidence with the d-wave symmetry. 19F NMR line width and relaxation rate are strongly influenced by the magnetic flux-line motion. The 19F magnetization recovery curve is described by a stretched exponential function. The 19F spin-lattice relaxation strongly depends on the fluorine content evidencing that at higher doping level part of F atoms occupy the apical O2 position.

Gippius, A. A.; Antipov, E. V.; Klein, O.; Lders, K.

2000-07-01

319

Improved ion optics for introduction of ions into a 9.4-T Fourier transform ion cyclotron resonance mass spectrometer.  

PubMed

Enhancements to the ion source and transfer optics of our 9.4?T Fourier transform ion cyclotron resonance (ICR) mass spectrometer have resulted in improved ion transmission efficiency for more sensitive mass measurement of complex mixtures at the MS and MS/MS levels. The tube lens/skimmer has been replaced by a dual ion funnel and the following octopole by a quadrupole for reduced ion cloud radial expansion before transmission into a mass-selective quadrupole. The number of ions that reach the ICR cell is increased by an order of magnitude for the funnel/quadrupole relative to the tube lens/skimmer/octopole. PMID:25601704

Chen, Yu; Leach, Franklin E; Kaiser, Nathan K; Dang, Xibei; Ibrahim, Yehia M; Norheim, Randolph V; Anderson, Gordon A; Smith, Richard D; Marshall, Alan G

2015-01-01

320

Nb3Sn Quadrupoles Designs For The LHC Upgrades  

SciTech Connect

In preparation for the LHC luminosity upgrades, high field and large aperture Nb{sub 3}Sn quadrupoles are being studied. This development has to incorporate all the relevant features for an accelerator magnet like alignment and cooling channels. The LARP HQ model is a high field and large bore quadrupole that will meet these requirements. The 2-layer coils are surrounded by a structure based on key and bladder technology with supporting iron yoke and aluminum shell. This structure is aimed at pre-stress control, alignment and field quality. We present here the magnetic and mechanical design of HQ, along with recent progress on the development of the first 1-meter model.

Felice, Helene

2008-05-19

321

Development and Test of TQC models, LARP Technological Quadrupole Magnets  

SciTech Connect

In support of the development of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, two-layer quadrupole models (TQC and TQS) with 90mm aperture are being constructed at Fermilab and LBNL within the framework of the US LHC Accelerator Research Program (LARP). This paper describes the development and test of TQC01b, the second TQC model, and the experience during construction of TQE02 and TQC02, subsequent models in the series. ANSYS analysis of the mechanical structure, its underlying assumptions, and changes based on experience with TQC01 are presented and discussed. Construction experience, in-process measurements, and modifications to the assembly since TQC01 are described. The test results presented here include magnet strain and quench performance during training of TQC01b, as well as quench studies of current ramp rate dependence.

Bossert, R.C.; Ambrosio, G.; Andreev, N.; Barzi, E.; Carcagno, R.; Feher, S.; Kashikhin, V.S.; Kashikhin, V.V.; Nobrega, F.; Novitski, I.; Orris, D.; Tartaglia, M.; Zlobin, A.V.; Caspi, S.; Dietderich, D.; Ferracin, P.; Hafalia, A.R.; Sabbi, G.

2008-06-01

322

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

323

Diabatization based on the dipole and quadrupole: The DQ method  

SciTech Connect

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, E-mail: gagliard@umn.edu, E-mail: truhlar@umn.edu; Truhlar, Donald G., E-mail: gagliard@umn.edu, E-mail: truhlar@umn.edu [Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431 (United States)

2014-09-21

324

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

325

Performance of An Adjustable Strength Permanent Magnet Quadrupole  

SciTech Connect

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

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

2006-03-01

326

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

327

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

328

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

329

Superconducting Quadrupole Doublet for the Los Alamos Meson Physics Facility  

Microsoft Academic Search

A superconducting quadrupole doublet for beam focusing has been operated with a 30-kG field at the center of the 30-cm-long straight section of the magnets and a 3-kG?cm field gradient. The magnets used twisted multifilament Nb&sngbnd;Ti superconductor imbedded in a Cu matrix of 0.050-in. diameter and operate at currents up to 500 A. Each magnet is equipped with a persistent

J. D. Rogers; W. V. Hassenzahl; H. L. Laquer; J. K. Novak; R. W. Stokes

1971-01-01

330

Magnetic field programming in quadrupole magnetic field-flow fractionation  

NASA Astrophysics Data System (ADS)

Magnetic field-flow fractionation (MgFFF) is a technique for the separation and characterization of magnetic nanoparticles. It is explained that the analysis of polydisperse samples requires a programmed decay of field and field gradient during sample elution. A procedure for achieving reproducible field decay with asymptotic approach to zero field using a quadrupole electromagnet is described. An example of an analysis of a polydisperse sample under programmed field decay is given.

Stephen Williams, P.; Carpino, Francesca; Moore, Lee R.; Zborowski, Maciej

331

Levitated spinning graphene flakes in an electric quadrupole ion trap  

Microsoft Academic Search

A method is described for levitating micron-sized few-layer graphene flakes in an electric quadrupole ion trap. Starting from a liquid suspension containing graphene, charged flakes are injected into the trap using the electrospray ionization technique and are probed optically. At micro-torr pressures, torques from circularly polarized light cause the levitated particles to rotate at frequencies >1MHz , which can be

B. E. Kane

2010-01-01

332

NORMAL CONDUCTING QN QUADRUPOLE FOR THE HERA LUMINOSITY UPGRADE  

Microsoft Academic Search

The magnet QN is a septum quadrupole with a narrow septum coil for focusing the protons with a gradient of 30T\\/m, needed for the HERA Luminosity upgrade (1). It is 1.93m long and has a pole radius of 35mm. The field error must be limited to 3*10 -4 at 25mm reference radius over the whole excitation range of Gmax=20 Gmin.

E. Bondarchuk; N. Doinikov; B. Kitaev; V. Korshakov; V. Krasnoperov; V. Lokiev; N. Maximenkova; V. Muratov; A. Nikiforovski; A. Simakov; K. Sinram; F. Willeke; G. Woebke

333

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

334

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

335

Transverse beam emittance measurement using quadrupole variation at KIRAMS-430  

NASA Astrophysics Data System (ADS)

In order to produce a 430 MeV/u carbon ion (12 C 6+) beam for medical therapy, the Korea Institute of Radiological & Medical Sciences (KIRAMS) has carried out the development of a superconducting isochronous cyclotron, the KIRAMS-430. At the extraction of the cyclotron, an Energy Selection System (ESS) is located to modulate the fixed beam energy and to drive the ion beam through High Energy Beam Transport (HEBT) into the treatment room. The beam emittance at the ion beamline is to be measured to provide information on designing a beam with high quality. The well-known quadrupole variation method was used to determine the feasibility of measuring the transverse beam emittance. The beam size measured at the beam profile monitor (BPM) is to be utilized and the transformation of beam by transfer matrix is to be applied being taken under various transport condition of varying quadrupole magnetic strength. Two different methods where beam optics are based on the linear matrix formalism and particle tracking with a 3-D magnetic field distribution obtained by using OPERA3D TOSCA, are applied to transport the beam. The fittings for the transformation parameters are used to estimate the transverse emittance and the twiss parameters at the entrance of the quadrupole in the ESS. Including several systematic studies, we conclude that within the uncertainty the estimated emittances are consistent with the ones calculated by using Monte Carlo simulations.

An, Dong Hyun; Hahn, Garam; Park, Chawon

2015-02-01

336

Particle dynamics in damped nonlinear quadrupole ion traps  

NASA Astrophysics Data System (ADS)

We examine the motions of particles in quadrupole ion traps as a function of damping and trapping forces, including cases where nonlinear damping or nonlinearities in the electric field geometry play significant roles. In the absence of nonlinearities, particles are either damped to the trap center or ejected, while their addition brings about a rich spectrum of stable closed particle trajectories. In three-dimensional (3D) quadrupole traps, the extended orbits are typically confined to the trap axis, and for this case we present a 1D analysis of the relevant equation of motion. We follow this with an analysis of 2D quadrupole traps that frequently show diamond-shaped closed orbits. For both the 1D and 2D cases, we present experimental observations of the calculated trajectories in microparticle ion traps. We also report the discovery of a new collective behavior in damped 2D microparticle ion traps, where particles spontaneously assemble into a remarkable knot of overlapping, corotating diamond orbits, self-stabilized by air currents arising from the particle motion.

Vinitsky, Eugene A.; Black, Eric D.; Libbrecht, Kenneth G.

2015-04-01

337

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

338

Parametric-Resonance Ionization Cooling in Twin-Helix.  

SciTech Connect

Parametric-resonance Ionization Cooling (PIC) is proposed as the final 6D cooling stage of a highluminosity muon collider. For the implementation of PIC, we developed an epicyclic twin-helix channel with correlated optics. Wedge-shaped absorbers immediately followed by short rf cavities are placed into the twin-helix channel. Parametric resonances are induced in both planes using helical quadrupole harmonics. We demonstrate resonant dynamics and cooling with stochastic effects off using GEANT4/G4beamline. We illustrate compensation of spherical aberrations and benchmark COSY Infinity, a powerful tool for aberration analysis and compensation.

V.S. Morozov, Ya.S. Derbenev, A. Afanasev, R.P. Johnson, Erdelyi. B., J.A. Maloney

2011-09-01

339

Measurement of coupling resonance driving terms with the AC dipole  

SciTech Connect

Resonance driving terms for linear coupled betatron motion in a synchrotron ring can be determined from corresponding spectral lines of an excited coherent beam motion. An AC dipole is one of instruments to excite such a motion. When a coherent motion is excited with an AC dipole, measured Courant-Snyder parameters and betatron phase advance have apparent modulations, as if there is an additional quadrupole field at the location of the AC dipole. Hence, measurements of these parameters using the AC dipole require a proper interpretation of observed quantities. The situation is similar in measurements of resonance driving terms using the AC dipole. In this note, we derive an expression of coupled betatron motion excited with two AC dipoles in presence of skew quadrupole fields, discuss an impact of this quadrupole like effect of the AC dipole on a measurement of coupling resonance driving terms, and present an analytical method to determine the coupling resonance driving terms from quantities observed using the AC dipole.

Miyamoto, R.

2010-10-01

340

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

E-print Network

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

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

2014-08-20

341

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

NASA Astrophysics Data System (ADS)

We report a novel approach for preparing a BoseEinstein condensate (BEC) of 87Rb atoms using an electro-pneumatically driven transfer of atoms into a quadrupole-Ioffe magnetic trap (QUIC trap). More than 5 {{10}8} atoms from a magneto-optical trap are loaded into a spherical quadrupole trap and then transferred into an Ioffe trap by moving the Ioffe coil towards the center of the quadrupole coil thereby changing the distance between the quadrupole trap center and the Ioffe coil. The transfer efficiency is more than 80%. This approach is different from the conventional approach of loading the atoms into a QUIC trap wherein the spherical quadrupole trap is transformed into a QUIC trap by changing the currents in the quadrupole and the Ioffe coils. The phase space density is then increased by forced rf evaporative cooling to achieve BoseEinstein condensation of more than 105 atoms.

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

2015-02-01

342

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

343

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

344

Performance of Series-Design Prototype Main Quadrupoles for the LHC  

Microsoft Academic Search

After the successful construction of two first-generation prototypes of the main quadrupoles for the LHC, three series-design prototypes have been further manufactured at CEA-Saclay. Together with the sextupole-dipole corrector magnets and tuning quadrupoles, these twin-aperture main quadrupoles are assembled into the cold masses of the so-called short straight sections. Already during their fabrication, the collared coils and later the completed

J Billan; L Bottura; M Peyrot; Vittorio Remondino; J M Rifflet; A Siemko; F Simon; Theodor Tortschanoff

2000-01-01

345

Development and Coil Fabrication for the LARP 3.7-m Long Nb3Sn Quadrupole  

Microsoft Academic Search

The U.S. LHC Accelerator Research Program (LARP) has started the fabrication of 3.7-m long Nb3Sn quadrupole models. The Long Quadrupoles (LQ) are ldquoProof-of-Principlerdquo magnets which are to demonstrate that Nb3Sn technology is mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, developed at FNAL and LBNL, which have design gradients

Giorgio Ambrosio; Nikolai Andreev; Michael Anerella; Emanuela Barzi; Rodger Bossert; Shlomo Caspi; Guram Chlachidize; Daniel R. Dietderich; Helene Felice; Paolo Ferracin; Arup Ghosh; R. Hafalia; R. Hannaford; G. Jochen; V. V. Kashikhin; P. Kovach; Michael Lamm; A. Lietzke; Al D. McInturff; Joseph F. Muratore; F. Nobrega; I. Novitsky; S. Peggs; Soren Prestemon; Gianluca Sabbi; Jesse Schmalzle; Daniele Turrioni; Peter Wanderer; G. Whitson; Alexander V. Zlobin

2009-01-01

346

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

SciTech Connect

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

Kamiya, Y.; Chao, A.W.

1983-10-01

347

Development and Coil Fabrication for the LARP 3.7-m Long Nb3Sn Quadrupole  

Microsoft Academic Search

The U.S. LHC Accelerator Research Program (LARP) has started the fabrication of 3.7-m long NbSn quadrupole models. The Long Quadrupoles (LQ) are 'Proof-of-Principle' magnets which are to demonstrate that NbSn technology is mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, developed at FNAL and LBNL, which have design gradients

G. Ambrosio; N. Andreev; M. Anerella; E. Barzi; R. Bossert; S. Caspi; G. Chlachidize; D. Dietderich; H. Felice; P. Ferracin; A. Ghosh; R. Hafalia; R. Hannaford; G. Jochen; V. V. Kashikhin; P. Kovach; M. Lamm; A. Lietzke; A. McInturff; Muratore; F. Nobreaga; I. Novitsky; S. Peggs; S. Prestemon; G. L. Sabbi; J. Schmalzle; D. Turrioni; P. Wanderer; G. Whitson; A. V. Zlobin

2008-01-01

348

Electron-Induced Dissociation of Peptides in a Triple Quadrupole Mass Spectrometer Retrofitted with an Electromagnetostatic Cell  

NASA Astrophysics Data System (ADS)

Dissociation of peptides induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to >30 eV was carried out using a radio-frequency-free electromagnetostatic (EMS) cell retrofitted into a triple quadrupole mass spectrometer. The product-ion mass spectra exhibited EID originating from electronically excited even-electron precursor ions, reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. The spectra demonstrate, within the limits of the triple quadrupole's resolving power, that high-energy EID product-ion spectra produced with an EMS cell exhibit essentially the same qualitative structural information, i.e., amino acid side-chain (SC) losses and backbone cleavages, as observed in high-energy EID spectra produced with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The levels of fragmentation efficiency evident in the product-ion spectra recorded in this study, as was the case for those recorded in earlier studies with FT ICR mass spectrometers, is currently at the margin of analytical utility. Given that this shortcoming can be remedied, EMS cells incorporated into QqQ or QqTOF mass spectrometers could make tandem high-energy EID mass spectrometry more widely accessible for analysis of peptides, small singly charged molecules, pharmaceuticals, and clinical samples.

Voinov, Valery G.; Bennett, Samuel E.; Barofsky, Douglas F.

2015-02-01

349

Electron-induced dissociation of peptides in a triple quadrupole mass spectrometer retrofitted with an electromagnetostatic cell.  

PubMed

Dissociation of peptides induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to >30 eV was carried out using a radio-frequency-free electromagnetostatic (EMS) cell retrofitted into a triple quadrupole mass spectrometer. The product-ion mass spectra exhibited EID originating from electronically excited even-electron precursor ions, reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. The spectra demonstrate, within the limits of the triple quadrupole's resolving power, that high-energy EID product-ion spectra produced with an EMS cell exhibit essentially the same qualitative structural information, i.e., amino acid side-chain (SC) losses and backbone cleavages, as observed in high-energy EID spectra produced with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The levels of fragmentation efficiency evident in the product-ion spectra recorded in this study, as was the case for those recorded in earlier studies with FT ICR mass spectrometers, is currently at the margin of analytical utility. Given that this shortcoming can be remedied, EMS cells incorporated into QqQ or QqTOF mass spectrometers could make tandem high-energy EID mass spectrometry more widely accessible for analysis of peptides, small singly charged molecules, pharmaceuticals, and clinical samples. PMID:25652934

Voinov, Valery G; Bennett, Samuel E; Barofsky, Douglas F

2015-05-01

350

Geometry and properties of the plasma in a quadrupole ion pump  

NASA Technical Reports Server (NTRS)

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

Schwarz, H.

1977-01-01

351

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

E-print Network

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

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

2014-08-22

352

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

E-print Network

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

Hogan, Thomas J.

353

Time resolved laser-induced fluorescence of electrosprayed ions confined in a linear quadrupole trap  

SciTech Connect

We have designed and constructed a linear quadrupole ion trap for the measurement of laser-induced fluorescence (LIF) of mass selected gas-phase ions produced by electrospray ionization. The instrument consists of a simple electrospray source, radiofrequency octopole guide, a dc quadrupole bender, a quadrupole mass filter, the linear quadrupole trap (which is equipped with optics for LIF collection and a channeltron ion detector), and several multielement focusing lenses. With this instrument, the LIF decay lifetime of gas-phase Rhodamine 640 radical cations is determined for the first time.

Friedrich, Jochen; Fu Jinmei; Hendrickson, Christopher L.; Marshall, Alan G.; Wang Yisheng [Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310-4005 (United States); Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei, Taiwan (China)

2004-11-01

354

Progress in the Development of Superconducting Quadrupoles forHeavy-ion Fusion  

SciTech Connect

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

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

2002-08-19

355

Progress in the development of superconducting quadrupoles for heavy ion fusion  

SciTech Connect

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

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

2002-05-24

356

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

357

Radio frequency quadrupole for Landau damping in accelerators  

NASA Astrophysics Data System (ADS)

We propose using a radio frequency quadrupole (RFQ) to introduce both the longitudinal spread of betatron frequency and the transverse spread of synchrotron frequency for Landau damping of transverse beam instabilities in accelerators. The existing theory of stability diagrams for Landau damping is applied to the case of a RFQ. As an example, the required quadrupolar strength is calculated for stabilizing the Large Hadron Collider beams at 7 TeV. It is shown that this strength can be provided by a superconducting rf device only a few meters long.

Grudiev, A.

2014-01-01

358

Electrostatic quadrupole accelerator for the heavy ion fusion project  

SciTech Connect

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

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

1994-12-31

359

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

360

Quench observation using quench antennas on RHIC IR quadrupole magnets  

SciTech Connect

Quench observation using quench antennas is now being performed routinely on RHIC dipole and quadrupole magnets. Recently, a quench antenna was used on a RHIC IR magnet which is heavily instrumented with voltage taps. It was confirmed that the signals detected in the antenna coils do not contradict the voltage tap signals. The antenna also detects a sign of mechanical disturbance which could be related to a training quench. This paper summarizes signals detected in the antenna and discusses possible causes of these signals.

Ogitsu, T.; Terashima, A.; Tsuchiya, K. [KEK, National Laboratory for High Energy Physics, Tsukuba, Ibaraki (Japan); Ganetis, G.; Muratore, J.; Wanderer, P. [Brookhaven National Lab., Upton, NY (United States)

1995-07-01

361

Quench margin measurement in Nb3Sn quadrupole magnet  

SciTech Connect

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

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

2008-08-01

362

Status of the quadrupoles for RHIC (Relativistic Heavy Ion Collider)  

SciTech Connect

The proposed Relativistic Heavy Ion Collider (RHIC) will require 408 regular arc quadrupoles. Two full size prototypes have been constructed and tested. The construction uses the single layer, collarless concept which has been successful in the RHIC dipoles. Both the magnets attained short sample current, which is 60% higher than the operating current. This corresponds to a gradient of 113 T/m with clear bore of 80 mm. The preliminary field measurements are in agreement with the calculations, with the exception of an unexpectedly large show sextupole. 2 refs., 5 figs., 1 tab.

Thompson, P.A.; Cottingham, J.G.; Garber, M.; Ghosh, A.; Goodzeit, C.; Greene, A.; Herrera, J.; Kahn, S.; Kelly, E.; Morgan, G.

1989-01-01

363

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

364

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

365

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

366

Novel methods for detecting buried explosive devices  

SciTech Connect

Oak Ridge National Laboratory (ORNL) and Quantum Magnetics, Inc. (QM) are exploring novel landmine detection technologies. Technologies considered here include bioreporter bacteria, swept acoustic resonance, nuclear quadrupole resonance (NQR), and semiotic data fusion. Bioreporter bacteria look promising for third-world humanitarian applications; they are inexpensive, and deployment does not require high-tech methods. Swept acoustic resonance may be a useful adjunct to magnetometers in humanitarian demining. For military demining, NQR is a promising method for detecting explosive substances; of 50,000 substances that have been tested, none has an NQR signature that can be mistaken for RDX or TNT. For both military and commercial demining, sensor fusion entails two daunting tasks, identifying fusible features in both present-day and emerging technologies, and devising a fusion algorithm that runs in real-time on cheap hardware. Preliminary research in these areas is encouraging. A bioreporter bacterium for TNT detection is under development. Investigation has just started in swept acoustic resonance as an approach to a cheap mine detector for humanitarian use. Real-time wavelet processing appears to be a key to extending NQR bomb detection into mine detection, including TNT-based mines. Recent discoveries in semiotics may be the breakthrough that will lead to a robust fused detection scheme.

Kercel, S.W.; Burlage, R.S.; Patek, D.R.; Smith, C.M. [Oak Ridge National Lab., TN (United States); Hibbs, A.D.; Rayner, T.J. [Quantum Magnetics, Inc., San Diego, CA (United States)

1997-04-01

367

Determination of quadrupole strengths in the gamma*p-->Delta(1232) transition at Q2= 0.20 (GeV/c)2  

E-print Network

We report new precise p$(\\vec{e},e^\\prime p)\\pi^0$ measurements at the peak of the $\\Delta^{+}(1232)$ resonance at $Q^2=\\unit[0.20](GeV/c)^2$ performed at the Mainz Microtron (MAMI). The new data are sensitive to both the electric quadrupole ($E2$) and the coulomb quadrupole ($C2$) amplitudes of the $\\gamma^* N\\to\\Delta$ transition. They yield precise quadrupole to dipole amplitude ratios CMR $= (-5.09 \\pm 0.28_{stat+sys}\\pm 0.30_{model})%$ and EMR $= (-1.96 \\pm 0.68_{stat+sys} \\pm 0.41_{model})%$ for $M^{3/2}_{1+} = (39.57 \\pm 0.75_{stat+sys}\\pm 0.40_{model})(10^{-3}/m_{\\pi^+})$. The new results are in disagreement with Constituent Quark Model predictions and in qualitative agreement with models that account for mesonic contributions, including recent Lattice calculations. They thus give further credence to the conjecture of deformation in hadronic systems favoring the attribution of the origin of deformation to the dominance of mesonic effects.

N. F. Sparveris; P. Achenbach; C. Ayerbe Gayoso; D. Baumann; J. Bernauer; A. M. Bernstein; R. Bohm; D. Bosnar; T. Botto; A. Christopoulou; D. Dale; M. Ding; M. O. Distler; L. Doria; J. Friedrich; A. Karabarbounis; M. Makek; H. Merkel; U. Muller; I. Nakagawa; R. Neuhausen; L. Nungesser; C. N. Papanicolas; A. Piegsa; J. Pochodzalla; M. Potokar; M. Seimetz; S. Sirca; S. Stave; S. Stiliaris; Th. Walcher; M. Weis

2006-11-20

368

Determination of quadrupole strengths in the gamma*p-->Delta(1232) transition at Q2= 0.20 (GeV/c)2  

E-print Network

We report new precise p$(\\vec{e},e^\\prime p)\\pi^0$ measurements at the peak of the $\\Delta^{+}(1232)$ resonance at $Q^2=\\unit[0.20](GeV/c)^2$ performed at the Mainz Microtron (MAMI). The new data are sensitive to both the electric quadrupole ($E2$) and the coulomb quadrupole ($C2$) amplitudes of the $\\gamma^* N\\to\\Delta$ transition. They yield precise quadrupole to dipole amplitude ratios CMR $= (-5.09 \\pm 0.28_{stat+sys}\\pm 0.30_{model})%$ and EMR $= (-1.96 \\pm 0.68_{stat+sys} \\pm 0.41_{model})%$ for $M^{3/2}_{1+} = (39.57 \\pm 0.75_{stat+sys}\\pm 0.40_{model})(10^{-3}/m_{\\pi^+})$. The new results are in disagreement with Constituent Quark Model predictions and in qualitative agreement with models that account for mesonic contributions, including recent Lattice calculations. They thus give further credence to the conjecture of deformation in hadronic systems favoring the attribution of the origin of deformation to the dominance of mesonic effects.

Sparveris, N F; Baumann, D; Bernauer, J; Bernstein, A M; Bosnar, D; Botto, T; Bhm, R; Christopoulou, A; Dale, D; Ding, M; Distler, M O; Doria, L; Friedrich, J; Gayoso, C A; Karabarbounis, A; Makek, M; Merkel, H; Mller, U; Nakagawa, I; Neuhausen, R; Nungesser, L; Papanicolas, C N; Piegsa, A; Pochodzalla, J; Potokar, M; Seimetz, M; Sirca, S; Stave, S; Stiliaris, S; Walcher, T; Weis, M; Walcher, Th.

2006-01-01

369

Giant Quadrupole-Resonance in Mg-24, Al-27 and Si-28  

E-print Network

60 50 I I 40 30 Ex (MeY) 20 IO 0 IO0 Cg~ FIG. 1. Inelastic n spectra from 2 Mg, VAl, and Si taken at 126 MeV. The dashed lines indicate the back- ground chosen for analysis. The regions where H(n, o)H and breakup ~ particles from 5He and ~Li... 34 "s 1.78 -19.4 1.85 10 -0 38 25 9 ~ 2+0.9 14 12 10 O~ 8 C3 060 80 I I 100 120 140 Ea (MeV) 160 180 FIG. 3. The solid lines are the calculated cross sec- tion at the second maximum in the L = 2 angular dis- tribution for Mg...

Youngblood, David H.; Rozsa, C. M.; Moss, JM; Brown, D. R.; Bronson, J. D.

1977-01-01

370

Nuclear quadrupole resonance in the chalcogenide and pnictide amorphous semiconductors. Interim report  

Microsoft Academic Search

The absence of long range periodic order in amorphous semiconductors makes the interpretation of the usual scattering experiments, such as x-ray, neutron, or electron scattering, both difficult and model dependent. For this reason information concerning the static and dynamic properties of these solids must be gathered using many different experimental techniques. In the chalcogenide (group VI) and pnictide (group V)

1983-01-01

371

Correlation between X-ray crystallography and nuclear quadrupole resonance data: Antimony halides and chalcogenides  

Microsoft Academic Search

For 53 compounds containing 73 crystallographic types of SbX\\u000a n\\u000a coordination polyhedra (X is a halogen and\\/or chalcogen), parameters of the Voronoi-Dirichlet (VD) polyhedra characterizing\\u000a the asymmetry of the crystal field in the vicinity of Sb nucleithe displacement of the Sb nucleus from the centroid of its\\u000a VD polyhedron (D\\u000a A) and the noncentrosymmetry parameter of the atomic environment (A

D. V. Pushkin; V. N. Serezhkin; M. O. Karasev; E. A. Kravchenko

2010-01-01

372

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

E-print Network

* 17th August 2007 Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Ave, Argonne and high temperature. The Mossbauer method gives hyperfine interactions between the resonant nucleus and electronic environment like isomer shifts, quadrupole splittings, and magnetic fields, which provide

Jackson, Jennifer M.

373

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

374

Quadrupole Approximation for Para-Positronium in Relativistic Schrdinger Theory  

E-print Network

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

M. Mattes; M. Sorg

2011-09-11

375

A Quadrupole Band-Pass Filter for LANSCE protons  

NASA Astrophysics Data System (ADS)

Neutrons are produced for many purposes at the LANSCE facility by 800 MeV protons into a thick tungsten target. The reactions also yield a continuum of protons, emerging at energies up to about 700 MeV; these protons are currently absorbed to allow neutron experiments. We have designed a quadrupole doublet band-pass filter to focus a narrow range of proton energies onto small samples, for instance the size of electronic circuit elements. Wrong proton energies are spread over a wider area and diluted. One may thus irradiate such small samples with protons from about 50 to 700 MeV by adjuting the quadrupole current. For a typical example with an existing doublet, a one cm diameter sample could receive protons at 470 MeV with 38 MeV FWHM energy resolution at a flux of 1.9x107 protons per second within that energy band, using the 30 degree port of the WNR facility. The flux of protons below 440 MeV or above 530 MeV is reduced by a factor of ten or more. Since the produced range of proton energies is similar to that of protons above the atmosphere, such a band-pass system would be of great use to study proton-induced processes in the components of orbiting systems.

Wender, Stephen; Peterson, R. J.; Morrow, Jonathon

2010-11-01

376

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

377

Precision Magnet Measurements for X-Band Accelerator Quadrupole Triplets  

SciTech Connect

An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray (MEGa-Ray) technology at LLNL. Beamline magnets will include an emittance compensation solenoid, windowpane steering dipoles, and quadrupole magnets. Demanding tolerances have been placed on the alignment of these magnets, which directly affects the electron bunch beam quality. A magnet mapping system has been established at LLNL in order to ensure the delivered magnets match their field specification, and the mountings are aligned and capable of reaching the specified alignment tolerances. The magnet measurement system will be described which uses a 3-axis Lakeshore gauss probe mounted on a 3-axis translation stage. Alignment accuracy and precision will be discussed, as well as centering measurements and analysis. The dependence on data analysis over direct multi-pole measurement allows a significant improvement in useful alignment information. Detailed analysis of measurements on the beamline quadrupoles will be discussed, including multi-pole content both from alignment of the magnets, and the intrinsic level of multi-pole magnetic field.

Marsh, R A; Anderson, S G; Armstrong, J P

2012-05-16

378

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

379

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

380

Photon decay of giant resonances  

SciTech Connect

The total gamma-decay probability, the ground-state gamma branching ratio, and the branching ratios to a number of low-lying states as a function of excitation energy have been determined in /sup 208/Pb to approximately 15 MeV. The total yield of ground-state E2 gamma radiation in /sup 208/Pb can only be understood if decay of compound states is considered. Other observations in /sup 208/Pb include the absence of a significant branch from the giant quadrupole resonance (GQR) to the low-lying collective states at 2.6 MeV and 4.08 MeV, and a strong branch to a 3/sup -/ state at 4.97 MeV. 20 refs., 6 figs., 1 tab.

Bertrand, F.E.; Beene, J.R.; Halbert, M.L.

1986-01-01

381

Magnetic resonance cell  

SciTech Connect

There is disclosed a nuclear magnetic alignment device for use in a nuclear magnetic resonance gyroscope and the like. One embodiment includes a container for gas having a layer of rubidium hydride on its inner surface. The container comprising a spherical portion and a tip portion, is rotationally symmetric about an axis of symmetry. Enclosed within the container is a nuclear moment gas having a nuclear electric quadrupole moment, such as xenon-131, and an optically pumpable substance, such as rubidium. A portion of the rubidium is a vapor. The remainder is a condensed pellet which is deposited in the tip of the container such that the pellet is also rotationally symmetric about the axis of symmetry of the container. A layer of rubidium hydride is deposited on the inner surface of the container. The device further includes means for orienting the symmetry axis of the container at an angle to an applied magnetic field such that the relaxation time constant of the aligned nuclear moment gas is substantially at a maximum.

Kwon, T.M.; Volk, C.H.

1984-05-01

382

Classical trajectories and RRKM modeling of collisional excitation and dissociation of benzylammonium and tert -butyl benzylammonium ions in a quadrupole-hexapole-quadrupole tandem mass spectrometer  

Microsoft Academic Search

Collision-induced dissociation of the benzylammonium and the 4-tert-butyl benzylammonium ions was studied experimentally in an electrospray ionization quadrupole-hexapole-quadrupole tandem\\u000a mass spectrometer. Ion fragmentation efficiencies were determined as functions of the kinetic energy of ions and the collider\\u000a gas (argon) pressure. A theoretical Monte Carlo model of ion collisional excitation, scattering, and decomposition was developed.\\u000a The model includes simulation of the

Vadim D. Knyazev; Stephen E. Stein

2010-01-01

383

Quadrupole Oscillation of a Single-Vortex Bose-Einstein Condensate: Evidence for Kelvin Modes  

Microsoft Academic Search

We study the two transverse quadrupole modes of a cigar-shaped Bose-Einstein condensate with a single centered vortex. We show that the counterrotating mode is more strongly damped than in the absence of a vortex, whereas the corotating mode is not affected appreciably by the vortex. We interpret this result as a decay of the counterrotating quadrupole mode into two excitations

V. Bretin; P. Rosenbusch; F. Chevy; G. V. Shlyapnikov; J. Dalibard

2003-01-01

384

Microwave Collision Diameters II. Theory and Correlation with Molecular Quadrupole Moments  

Microsoft Academic Search

Observed microwave collision diameters are interpreted as arising exclusively from transitions induced during the collision. Collision diameters greater than kinetic theory values arise from dipole-dipole or dipole-quadrupole interactions. The former case affords a quantitative test of the theory. In the latter case measurements of collision diameters yield quadrupole moment measurements which are correlated with molecular structure.

William V. Smith; Raydeen Howard

1950-01-01

385

Analysis of magnetic nanoparticles using quadrupole magnetic field-flow fractionation  

NASA Astrophysics Data System (ADS)

The new technique of quadrupole magnetic field-flow fractionation is described. It is a separation and characterization technique for particulate magnetic materials. Components of a sample are eluted from the separation channel at times dependent on the strength of their interaction with the magnetic field. A quadrupole electromagnet allows a programmed reduction of field strength during analysis of polydisperse samples.

Carpino, Francesca; Moore, Lee R.; Zborowski, Maciej; Chalmers, Jeffrey J.; Williams, P. Stephen

2005-05-01

386

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

387

Automatic Identification of Proteins with a MALDI-Quadrupole Ion Trap Mass Spectrometer  

E-print Network

Automatic Identification of Proteins with a MALDI-Quadrupole Ion Trap Mass Spectrometer Andrew N transmission interface. The ion interface contains a quadrupole ion guide in- stalled between the skimmer, automatic identification of proteins. A mass spectrometry-based method can satisfy this need if it (1

Chait, Brian T.

388

Closed forms for the matrix elements of the quadrupole collective operators  

Microsoft Academic Search

Compact analytical expressions for the matrix elements for the spherical phonon operators and the elementary anharmonicities in a basis of explicit eigenfunctions of the harmonic quadrupole collective Hamiltonian are established. An algorithm for the calculation of the matrix elements of any many-phonon quadrupole operator is also presented.

A. A. Raduta; V. Ceausescu; A. Gheorghe

1978-01-01

389

Electromagnetic decay of giant resonances  

SciTech Connect

Coincidence experiments were done to investigate the photon and neutron emission from the giant resonance regions of /sup 208/Pb and /sup 90/Zr using the ORNL Spin Spectrometer, a 72-segment NaI detector system. We have determined the total gamma-decay probability, the ground-state gamma branching ratio, and the branching ratios to a number of low-lying states as a function of excitation energy in /sup 208/Pb to approx.15 MeV. Similar data were also obtained on /sup 90/Zr. The total yield of ground-state E2 gamma radiation in /sup 208/Pb and the comparative absence of such radiation in /sup 90/Zr can only be understood if decay of compound (damped) states is considered. Other observations in /sup 208/Pb include the absence of a significant branch from the giant quadrupole resonance (GQR) to the 3/sup -/ state at 2.6 MeV, a strong branch to a 3/sup -/ state at 4.97 MeV from the same region, and transitions to various 1/sup -/ states between 5 to 7 MeV from the E* approx. 14 MeV region (EO resonance).

Beene, J.R.; Bertrand, F.E.; Halbert, M.L.; Auble, R.L.; Hensley, D.C.; Horen, D.J.; Robinson, R.L.; Sayer, R.O.; Sjoreen, T.P.

1985-01-01

390

Optical resonator  

NASA Technical Reports Server (NTRS)

The invention discloses a semi-ring Fabry-Perot (SRFP) optical resonator structure comprising a medium including an edge forming a reflective facet and a waveguide within the medium, the waveguide having opposing ends formed by the reflective facet. The performance of the SRFP resonator can be further enhanced by including a Mach-Zehnder interferometer in the waveguide on one side of the gain medium. The optical resonator can be employed in a variety of optical devices. Laser structures using at least one SRFP resonator are disclosed where the resonators are disposed on opposite sides of a gain medium. Other laser structures employing one or more resonators on one side of a gain region are also disclosed.

Taghavi-Larigani, Shervin (Inventor); Vanzyl, Jakob J. (Inventor); Yariv, Amnon (Inventor)

2006-01-01

391

Proton resonance for oscillating field of the order of static magnetic field  

NASA Astrophysics Data System (ADS)

A spin decoupling method in nuclear quadrupole resonance spin echo experiment is used to detect the proton magnetic resonance absorption spectrum. The behavior of proton resonance in ? phase of polycrystalline p-dichlorobenzene as a function of the intensity of the proton decoupling oscillating field ( H2) is measured. Good agreement between the experimental resonance frequency and Shirley's theory for a non-interacting 1/2 spin system is observed. To our knowledge this is the first time the NMR proton frequency dependence on linear polarized excitation field intensity for H2/ Ho as high as 1.8 is measured.

Schurrer, Clemar; Prez, Silvina; Wolfenson, Alberto

2010-05-01

392

Resonance scraping  

SciTech Connect

Protons lost in a ring leave at a few preferred locations, determined by some non-linear property of the dipoles. This paper suggests taking control of lost protons by beating the magnets at their own game - by means of a designed resonance used as a beam scraper. It is a study of suitable resonances, including estimates of the required multipole element strengths. The appropriate resonances are two-dimensional. A large number of figures is included.

Collins, T.

1986-06-01

393

Test Results of a Superconducting Quadrupole Model Designed for Linear Accelerator Applications  

SciTech Connect

The first model of a superconducting quadrupole for use in a Linear Accelerator was designed, built and tested at Fermilab. The quadrupole has a 78 mm aperture, and a cold mass length of 680 mm. A superferric magnet configuration with iron poles and four racetrack coils was chosen based on magnet performance, cost, and reliability considerations. Each coil is wound using enamel insulated, 0.5 mm diameter, NbTi superconductor. The quadrupole package also includes racetrack type dipole steering coils. The results of the quadrupole design, manufacturing and test, are presented. Specific issues related to the quadrupole magnetic center stability, superconductor magnetization and mechanical stability are discussed. The magnet quench performance and results of magnetic measurements will also be briefly discussed.

Kashikhin, Vladimir S.; Andreev, Nikolai; Chlachidze, Guram; DiMarco, Joseph; Kashikhin, Vadim V.; Lamm, Michael J.; Lopes, Mauricio L.; Orris, Darryl; Tartaglia, Michael; Tompkins, John C.; Velev, Gueorgui; /Fermilab

2008-08-01

394

Anomaly-induced quadrupole moment of the neutron in magnetic field  

SciTech Connect

Neutrons cannot possess a quadrupole moment in the vacuum. Nevertheless, we show that, in the presence of an external magnetic field, the neutrons acquire a new type of quadrupole moment Q{sup ij} = {chi}{sigma}{sup i} B{sup j} involving the components of spin and magnetic field. This 'chiral magnetic' quadrupole moment arises from the interplay of the chiral anomaly and the magnetic field; we estimate its value for the neutron in the static limit and find {chi} {approx_equal} 1.35 {center_dot} 10{sup -2} fm{sup 4}. The detection of the quadrupole moment of the neutron would provide a novel test of the role of the chiral anomaly in low-energy QCD and can be possible in the presence of both magnetic and inhomogeneous electric fields. The quadrupole moment of the neutron may affect, e.g., the properties of neutron stars and magnetars.

Kharzeev, D.E.; Yee, H.-U., Zahed, I.

2011-08-18

395

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

396

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

397

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

398

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

399

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

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

400

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

401

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

402

Auxiliary Frequency Parametric Excitation of Quadrupole Mass Spectrometers  

NASA Technical Reports Server (NTRS)

The apparatus introduces a second adjustable resonant point in a QMS at a frequency that is close to a multiple of the fundamental frequency by adjusting driving point impedance characteristics of the QMS. The apparatus measures the first and second resonant point of the QMS to account for changes in the operational characteristics of the QMS.

Gershman, Daniel (Inventor); Block, Bruce (Inventor); Rubin, Martin (Inventor); Zurbuchen, Thomas (Inventor)

2013-01-01

403

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

404

Excitation and photon decay of giant multipole resonances - the role and future of medium-energy heavy ions  

SciTech Connect

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

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

1988-01-01

405

174 Anal. Chem. 1991. 63.174-178 Use of a Single-Quadrupole Mass Spectrometer for  

E-print Network

collisional activation in two regions of a triple-quadrupole mass spec- trometer: (a) in the region between174 Anal. Chem. 1991. 63.174-178 Use of a Single-Quadrupole Mass Spectrometer for Collision by eiectrospray ionization in a simple and inexpensive singie- quadrupole mass spectrometer Is demonstrated

Chait, Brian T.

406

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.

R. J. Rabehl et al.

2004-03-09

407

Covariant Spectator Theory of np scattering: Deuteron Quadrupole Moment  

DOE PAGESBeta

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

408

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

409

Super Strong Permanent Magnet Quadrupole for a Linear Collider  

SciTech Connect

The field strength generated by permanent magnets has been further extended by the introduction of saturated iron. A permanent magnet quadrupole (PMQ) lens with such saturated iron is one of the candidates for the final focus lens for an e{sup +}e{sup -} Linear Collider accelerator, because of its compactness and low power consumption. The first prototype of the PMQ has been fabricated and demonstrated to have an integrated strength of 28.5T with an overall length of 10 cm and a 7mm bore radius. Two drawbacks should be considered: its negative temperature coefficient of field strength and its fixed strength. A thermal compensation material is being tested to cure the first problem. The other problem may be solved by rotating sectioned magnet bricks, but that may lead to movement of the magnetic center and introduction of multipoles beyond some strict requirements.

Mihara, Takanori

2004-02-19

410

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.; Galat, A.; De Lazzari, M.; Porcellato, A. M.; Roncolato, C.; Stark, S. [INFN-LNL, viale dellUniversit 2, 35020 Legnaro (Italy)] [INFN-LNL, viale dellUniversit 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.; Rom, M. [INFN Sezione di Milano and Dipartimento di Fisica, Universit degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)] [INFN Sezione di Milano and Dipartimento di Fisica, Universit degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)

2014-02-15

411

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; Galat, A; De Lazzari, M; Porcellato, A M; Roncolato, C; Stark, S; Caruso, A; Longhitano, A; Cavaliere, F; Maero, G; Paroli, B; Pozzoli, R; Rom, M

2014-02-01

412

Alternative Mechanical Structure for LARP Nb3Sn Quadrupoles  

SciTech Connect

An alternative structure for the 120 mm Nb{sub 3}Sn quadrupole magnet presently under development for use in the upgrade for LHC at CERN is presented. The goals of this structure are to build on the existing technology developed in LARP with the LQ and HQ series magnets and to further optimize the features required for operation in the accelerator. These features include mechanical alignment needed for field quality and provisions for cold mass cooling with 1.9 K helium in a helium pressure vessel. The structure will also optimize coil azimuthal and axial pre-load for high gradient operation, and will incorporate features intended to improve manufacturability, thereby improving reliability and reducing cost.

Anerella, M.; Cozzolino, J.; Ambrosio, G.; Caspi, S.; Felice, H.; Kovach, P.; Lamm, M.; Sabbi, G.; Schmalzle, J.; Wanderer, P.

2010-08-01

413

Nb3Sn Quadrupole Magnets for the LHC IR  

SciTech Connect

The development of insertion quadrupoles with 205 T/m gradient and 90 mm bore represents a promising strategy to achieve the ultimate luminosity goal of 2.5 x 10{sup 34} cm{sup -2}s{sup -1} at the Large Hadron Collider (LHC). At present, Nb{sub 3}Sn is the only practical conductor which can meet these requirements. Since Nb{sub 3}Sn is brittle, and considerably more strain sensitive than NbTi, the design concepts and fabrication techniques developed for NbTi magnets need to be modified appropriately. In addition, IR magnets must provide high field quality and operate reliably under severe radiation loads. The results of conceptual design studies addressing these issues are presented.

Sabbi, G.; Caspi, S.; Chiesa, L.; Coccoli, M.; Dietderich, D.r.; Ferracin, P.; Gourlay, S.A.; Hafalia, R.R.; Lietzke, A.F.; McInturff, A.D.; Scanlan, R.M.

2001-08-01

414

Gravitoelectromagnetic resonances  

Microsoft Academic Search

The interaction between gravitational and electromagnetic radiation has a rather long research history. It is well known, in particular, that gravity-wave distortions can drive propagating electromagnetic signals. Since forced oscillations provide the natural stage for resonances to occur, gravitoelectromagnetic resonances have been investigated as a means of more efficient gravity-wave detection methods. In this report, we consider the coupling between

Christos G. Tsagas

2011-01-01

415

Overcoming field imperfections of quadrupole mass filters with mass analysis in islands of stability.  

PubMed

We have constructed, and tested as mass filters, linear quadrupoles with added hexapole fields of 4%, 8%, and 12%, with and without added octopole fields. A hexapole field can be added to the field of a linear quadrupole by rotating the two y rods toward an x rod. This also adds an octopole field which can be removed by making the x rods greater in diameter than the y rods. In comparison to conventional quadrupole mass filters these rod sets have severely distorted quadrupole fields, with a mix of both even and odd higher spatial harmonics. They allow evaluating the performance of rod sets with strong geometric and field distortions as mass filters. Conventional mass analysis at the tip of the stability diagram has been compared to mass analysis using islands of stability. The stability islands are produced by applying an auxiliary quadrupole excitation field to the quadrupole. We show that with normal mass analysis at the tip of the stability diagram, the transmission, resolution, and peak shapes are relatively poor in comparison to a conventional rod set. However, the use of islands of stability dramatically improves the resolution and peak shape, and in some cases ion transmission, suggesting that mass analysis with islands of stability may provide a method to overcome a wide range of field imperfections in linear quadrupole mass filters. PMID:19522524

Zhao, XianZhen; Xiao, Zilan; Douglas, D J

2009-07-15

416

Alternate Oscillation between Scissors and Quadrupole Modes in Sodium BoseEinstein Condensates  

NASA Astrophysics Data System (ADS)

Using an additional off-axis Helmholtz coil, we modulated the strength of a magnetic field at the center of a cloverleaf trap for sodium Bose-Einstein condensates so that it passed through zero for a few milliseconds. At a modulation time of 1 ms, a scissors mode and a high-lying quadrupole mode were generated independently, which had the same Landau damping rates of 39(10) 1/s. However, at 2 ms, alternate oscillation between the scissors mode and the high-lying quadrupole mode, whose frequency was twice that of the scissors mode, was observed with the frequency of the low-lying quadrupole mode.

Yamazaki, Masahiro; Wakayama, Kazuki; Harada, Miho; Morinaga, Atsuo

2015-04-01

417

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

418

Electric quadrupole transition probabilities and line strengths of Ti{sup 11+}  

SciTech Connect

Electric quadrupole transition probabilities and line strengths have been calculated using the weakest bound electron potential model for sodium-like titanium, considering many transition arrays. We employed numerical Coulomb approximation and non-relativistic HartreeFock wavefunctions for the expectation values of radii in determination of parameters of the model. The necessary energy values have been taken from experimental data in the literature. The calculated electric quadrupole line strengths have been compared with available data in the literature and good agreement has been obtained. Moreover, some electric quadrupole transition probability and line strength values not existing in the literature for some highly excited levels have been obtained using this method.

Gke, Yasin, E-mail: ygokce58@gmail.com [Department of Physics, Faculty of Science, Karamanoglu Mehmetbey University, Karaman (Turkey); elik, Gltekin [Department of Physics, Faculty of Science, Seluk University, Campus 42049 Konya (Turkey); Y?ld?z, Murat, E-mail: muraty70@gmail.com [Department of Physics, Faculty of Science, Karamanoglu Mehmetbey University, Karaman (Turkey)

2014-07-15

419

Nb3Sn quadrupoles in the LHC IR Phase I upgrade  

SciTech Connect

After a number of years of operation at nominal parameters, the LHC will be upgraded to a higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.

Zlobin, A.V.; Johnstone, J.A.; Kashikhin, V.V.; Mokhov, N.V.; Rakhno, I.L.; /Fermilab; de Maria, R.; Peggs, S.; Robert-Demolaize, G.; Wanderer, P.; /Brookhaven

2008-06-01

420

Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade  

SciTech Connect

After a number of years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet parameters and issues related to using Nb{sub 3}Sn quadrupoles including aperture, gradient, magnetic length, field quality, operation margin, et cetera are discussed.

Zlobin,A.; Johnstone, J.; Kashikhin, V.; Mokhov, N.; Rakhno, I.; deMaria, R.; Peggs, S.; Robert-Demolaize, F.; Wanderer, P.

2008-06-23

421

Giant resonances and intermediate energy heavy ions: Electromagnetic decay experiments  

SciTech Connect

We briefly explore how large cross sections for excitation of both isoscalar and isovector giant multipole resonances which can be obtained using intermediate energy heavy-ion reactions can be utilized in photon-decay coincidence experiments to provide new information on subjects ranging from basic nuclear structure properties to resonance damping and pre-compound decay. We also discuss experiments in which photon-decay techniques are used as a tag to isolate and identify very weakly excited modes, enabling us to explore such diverse subjects as hadronic excitation of the giant dipole resonance, the distribution of isovector quadrupole strength in {sup 208}Pb, and the excitation of two-phonon giant resonance strength. 25 refs., 12 figs.

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

1991-01-01

422

Development of a tandem-electrostatic-quadrupole accelerator facility for BNCT.  

PubMed

In this work we describe the present status of an ongoing project to develop a tandem-electrostatic-quadrupole (TESQ) accelerator facility for accelerator-based (AB) BNCT at the Atomic Energy Commission of Argentina in Buenos Aires. The project final goal is a machine capable of delivering 30 mA of 2.4 MeV protons to be used in conjunction with a neutron production target based on the (7)Li(p,n)(7)Be reaction slightly beyond its resonance at 2.25 MeV. These are the specifications needed to produce sufficiently intense and clean epithermal neutron beams, based on the (7)Li(p,n)(7)Be reaction, to perform BNCT treatment for deep-seated tumors in less than an hour. An electrostatic machine is the technologically simplest and cheapest solution for optimized AB-BNCT. The machine being designed and constructed is a folded TESQ with a high-voltage terminal at 1.2 MV intended to work in air. Such a machine is conceptually shown to be capable of transporting and accelerating a 30 mA proton beam to 2.4 MeV. The general geometric layout, its associated electrostatic fields, and the acceleration tube are simulated using a 3D finite element procedure. The design and construction of the ESQ modules is discussed and their electrostatic fields are investigated. Beam transport calculations through the accelerator are briefly mentioned. Likewise, work related to neutron production targets, strippers, beam shaping assembly and patient treatment room is briefly described. PMID:19376714

Kreiner, A J; Thatar Vento, V; Levinas, P; Bergueiro, J; Di Paolo, H; Burlon, A A; Kesque, J M; Valda, A A; Debray, M E; Somacal, H R; Minsky, D M; Estrada, L; Hazarabedian, A; Johann, F; Suarez Sandin, J C; Castell, W; Davidson, J; Davidson, M; Giboudot, Y; Repetto, M; Obligado, M; Nery, J P; Huck, H; Igarzabal, M; Fernandez Salares, A

2009-07-01

423

Laser-Induced Acoustic Desorption Coupled with a Linear Quadrupole Ion Trap Mass Spectrometer  

PubMed Central

In recent years, laser-induced acoustic desorption (LIAD) coupled with a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer has been demonstrated to provide a valuable technique for the analysis of a wide variety of nonvolatile, thermally labile compounds, including analytes that could not previously be analyzed by mass spectrometry. Although FT-ICR instruments are very powerful, they are also large and expensive, and hence mainly used as research instruments. In contrast, linear quadrupole ion trap (LQIT) mass spectrometers are common due to several qualities that make these instruments attractive for both academic and industrial settings, such as high sensitivity, large dynamic range, and experimental versatility. Further, the relatively small size of the instruments, comparatively low cost and the lack of a magnetic field provide some distinct advantages over FT-ICR instruments. Hence, we have coupled the LIAD technique with a commercial LQIT, the Finnigan LTQ mass spectrometer. The LQIT was modified for a LIAD probe by outfitting the removable back plate of the instrument with a 6 ConFlat flange (CFF) port, gate valve and sample lock. Reagent ions were created using the LQIT's atmospheric pressure ionization source and trapped in the mass analyzer for up to 10 s to allow chemical ionization reactions with the neutral molecules desorbed via LIAD. These initial experiments focused on demonstrating the feasibility of performing LIAD in the LQIT. Hence, the results are compared to those obtained using an FT-ICR mass spectrometer. Despite the lower efficiency in the transfer of desorbed neutral molecules into the ion trap, and the smaller maximum number of available laser pulses, the higher intrinsic sensitivity of the LQIT resulted in a net higher sensitivity relative to the FT-ICR. PMID:20000769

Habicht, Steven C.; Amundson, Lucas M.; Duan, Penggao; Vinueza, Nelson R.; Kenttmaa, Hilkka I.

2009-01-01

424

Magnetic Resonance  

Cancer.gov

Focus Group on Magnetic Resonance Spectroscopy (MRS) in Clinical Oncology(April 1999) To explore the technical requirements for MRS and the application of hydrogen and multinuclear spectroscopy for tumor response to therapy.

425

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

E-print Network

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

Sean Yeager; Larry Zamick

2008-08-28

426

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

427

High-performance MEMS square electrode quadrupole mass filters for chip-scale mass spectrometry  

E-print Network

We report exciting experimental data from a low-cost, high-performance square electrode quadrupole mass filter with integrated ion optics intended for chips-cale mass spectrometry. The device showed a mass range of 650 amu ...

Cheung, Kerry

428

A compact beam focusing and steering element using quadrupoles with independently excited poles  

NASA Astrophysics Data System (ADS)

Beam steering elements for accelerator beam transport are conventionally and conveniently incorporated into beamlines by fitting magnetic dipole elements around the vacuum tube of the line. Two steerers in each plane (X and Y) together with a quadrupole doublet constitute a module providing full control of the direction, position and focus of the beam. In some installations however, there may be insufficient space on the beamline to mount separate steerer elements. To provide steering capabilities in such a situation we have used a magnetic quadrupole doublet with the coils of each pole independently excited to synthesise the desired combination of quadrupole, horizontal dipole and vertical dipole fields. This paper describes the quadrupole steerer and its multichannel power supply and presents calculated magnetic field distributions together with raytracing simulation of its performance.

Grime, Geoffrey W.

2013-07-01

429

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

430

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

431

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

E-print Network

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

Donato Bini; Andrea Geralico

2014-08-23

432

Field Quality Measurements and Analysis of the LARP Technology Quadrupole Models  

SciTech Connect

One of the US-LHC accelerator research program goals is to develop and prove the design and technology of Nb{sub 3}Sn quadrupoles for an upgrade of the LHC Interaction Region (IR) inner triplets. Four 1-m long technology quadrupole models with a 90 mm bore and field gradient of 200 T/m based on similar coils and different mechanical structures have been developed. In this paper, we present the field quality measurements of the first several models performed at room temperature as well as at superfluid helium temperature in a wide field range. The measured field harmonics are compared to the calculated ones. The field quality of Nb{sub 3}Sn quadrupole models is compared with the NbTi quadrupoles recently produced at Fermilab for the first generation LHC IRs.

Chlachidze, G.; DiMarco, J.; Kashikhin, V.V.; Lamm, M.; Schlabach, P.; Tartaglia, M.; Tompkins, J.C.; Velev, G.V.; Zlobin, A.V.; Caspi, S.; Ferracin, P.; Sabbi, G.I.; Bossert, R.

2008-06-01

433

Field quality measurements and abalysis of the LARP technology quadrupole models  

SciTech Connect

One of the US-LHC accelerator research program goals is to develop and prove the design and technology of Nb{sub 3}Sn quadrupoles for an upgrade of the LHC Interaction Region (IR) inner triplets. Four 1-m long technology quadrupole models with a 90 mm bore and field gradient of 200 T/m based on similar coils and different mechanical structures have been developed. In this paper, we present the field quality measurements of the first several models performed at room temperature as well as at superfluid helium temperature in a wide field range. The measured field harmonics are compared to the calculated ones. The field quality of Nb{sub 3}Sn quadrupole models is compared with the NbTi quadrupoles recently produced at Fermilab for the first generation LHC IRs.

Bossert, R.; Chlachidze, G.; DiMarco, J.; Kashikhin, V.V.; Lamm, M.; Schlabach, P.; Tartaglia, M.; Tompkins, J.C.; Velev, G.V.; Zlobin, A.V.; Caspi, S.; /Fermilab /LBL, Berkeley

2007-08-01

434

Tandem quadrupole Fourier-transform mass spectrometry of oligopeptides and small proteins.  

PubMed Central

Modifications to the newly developed tandem quadrupole Fourier-transform mass spectrometer have made it possible to record mass spectra on oligopeptides and small proteins in the mass range between 2 and 13 kDa. PMID:3468502

Hunt, D F; Shabanowitz, J; Yates, J R; Zhu, N Z; Russell, D H; Castro, M E

1987-01-01

435

Rotational and magnetic shunt permanent magnet quadrupoles with variable magnetic strength  

SciTech Connect

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

Vladimir Kashikhin et al.

2002-03-28

436

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

437

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

438

Development of TQC01, a 90 mm Model Quadrupole for LHC Upgrade Based on SS Collar  

Microsoft Academic Search

As a first step toward the development of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, two-layer technological quadrupole models (TQS01 at LBNL and TQC01 at Fermilab) are being constructed within the framework of the US LHC Accelerator Research Program (LARP). Both models use the same coil design, but have different coil support structures. This

R. C. Bossert; G. Ambrosio; N. Andreev; E. Barzi; S. Caspi; D. R. Dietderich; P. Ferracin; A. Ghosh; S. A. Gourlay; A. R. Hafalia; C. R. Hannaford; V. S. Kashikhin; V. V. Kashikhin; A. F. Lietzke; S. Mattafirri; A. D. McInturff; I. Novitski; G. L. Sabbi; D. Turrioni; G. Whitson; R. Yamada; A. V. Zlobin

2006-01-01

439

Field quality in Fermilab-built models of quadrupole magnets for the LHC interaction region  

Microsoft Academic Search

Superconducting quadrupole magnets for the interaction regions of the Large Hadron Collider are being developed by the US-LHC Accelerator Project. These 70 mm bore quadrupole magnets are intended to operate in superfluid helium at 1.9 K with a nominal field gradient of 215 T\\/m. A series of 2 m model magnets has been built and cold tested at Fermilab to

N. Andreev; T. Arkan; P. Bauer; R. Bossert; J. Brandt; S. Caspi; D. R. Chichili; J. Carson; J. DiMarco; S. Feher; A. Ghosh; H. Glass; V. V. Kashikhin; J. Kerby; M. J. Lamm; A. D. McInturff; A. A. Makarov; A. Nobrega; I. Novitski; T. Ogitsu; D. Orris; J. P. Ozelis; T. Peterson; R. Rabehl; W. Robotham; G. Sabbi; R. Scanlan; P. Schlabach; C. Sylvester; J. Strait; M. Tartaglia; J. C. Tompkins; G. Velev; S. Yadav; A. V. Zlobin

2001-01-01

440

The quadrupole interaction of 100 Rh in various intermetallic compounds of palladium  

Microsoft Academic Search

The nuclear quadrupole interaction of the 75 keV excited state of100Rh in the ordered intermetallic compounds PdHg, PdPb2 PdSb and PdTe was measured. Using an estimate for the nuclear quadrupole moment of the 75 keV state in100Rh and point ion lattice sums for the lattice electric field gradient (EFG) at the Rh site, the electronic contributionVzzel to the total EFG

R. Vianden; E. N. Kaufmann; R. A. Naumann; G. Schmidt

1979-01-01

441

The quadrupole interaction of100Rh in various intermetallic compounds of palladium  

Microsoft Academic Search

The nuclear quadrupole interaction of the 75 keV excited state of100Rh in the ordered intermetallic compounds PdHg, PdPb2 PdSb and PdTe was measured. Using an estimate for the nuclear quadrupole moment of the 75 keV state in100Rh and point ion lattice sums for the lattice electric field gradient (EFG) at the Rh site, the electronic contribution V {zz\\/el} to the

R. Vianden; E. N. Kaufmann; R. A. Naumann; G. Schmidt

1979-01-01

442

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

SciTech Connect

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

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

2011-07-05

443

Performance of Nb3Sn quadrupole magnets under localized thermal load  

SciTech Connect

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

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

2009-06-01

444

Bose-Einstein condensation in a quadrupole-Ioffe-configuration trap  

Microsoft Academic Search

We demonstrate Bose-Einstein condensation of rubidium atoms in a simple low-power magnetic trap. This trap combines the quadrupole with the Ioffe configuration (QUIC trap) and consists of just three coils. Magneto-optically trapped 87Rb atoms are first loaded into the linear trapping potential of a magnetic quadrupole, which is then converted into the parabolic geometry of an Ioffe trap. During this

Tilman Esslinger; Immanuel Bloch; Theodor W. Hnsch

1998-01-01

445

Progress in the Long ${\\\\rm Nb}_{3}{\\\\rm Sn}$ Quadrupole R&D by LARP  

Microsoft Academic Search

After the successful test of the first long ${\\\\rm Nb}_{3}{\\\\rm Sn}$ quadrupole (LQS01) the US LHC Accelerator Research Program (LARP, a collaboration of BNL, FNAL, LBNL and SLAC) is assessing training memory, reproducibility, and other accelerator quality features of long ${\\\\rm Nb}_{3}{\\\\rm Sn}$ quadrupole magnets. LQS01b (a reassembly of LQS01 with more uniform and higher pre-stress) was subjected to a

G. Ambrosio; N. Andreev; M. Anerella; E. Barzi; D. Bocian; R. Bossert; M. Buehler; S. Caspi; G. Chlachidze; D. Dietderich; J. DiMarco; J. Escallier; H. Felice; P. Ferracin; A. Ghosh; A. Godeke; R. Hafalia; R. Hannaford; G. Jochen; M. J. Kim; P. Kovach; M. Lamm; M. Marchevsky; J. Muratore; F. Nobrega; D. Orris; E. Prebys; S. Prestemon; G. L. Sabbi; J. Schmalzle; C. Sylvester; M. Tartaglia; D. Turrioni; G. Velev; P. Wanderer; G. Whitson; A. V. Zlobin

2012-01-01

446

The Nuclear Quadrupole Interaction of 204m Pb in Lead Oxides  

Microsoft Academic Search

The nuclear quadrupole interaction of 204mPb in lead oxides has been measured by ?? time differential perturbed angular correlation. Ab-initio calculations of the electric field gradients and X-ray diffraction allowed the assignment of the detected nuclear quadrupole\\u000a interactions to the different Pb sites in the PbO phases litharge and massicote as well as in Pb3O4. The TDPAC probe 204mPb was

S. Friedemann; F. Heinrich; H. Haas; W. Trger

2004-01-01

447

The angular overlap model applied to the calculation of nuclear quadrupole interactions  

Microsoft Academic Search

By the application of the angular overlap model to the calculation of nuclear quadrupole interactions (NQI), it is shown that\\u000a it is possible to predict the NQI for the111Cd nucleus in a cadmium complex with known coordination geometry. This fact makes it relevant to apply such calculations to\\u000a nuclear quadrupole interaction data for111Cd substituted zinc enzymes. It is demonstrated that

R. Bauer; S. J. Jensen; B. Schmidt-Nielsen

1988-01-01

448

Electric Quadrupole Moments of the Decuplet and the Strangeness Content of the Proton  

E-print Network

In the SU3 Skyrme model the electric quadrupole moments of $\\frac{3}{2}^+$ baryons show a strong sensitivity with respect to flavor distortions in baryon wavefunctions. SU3 symmetric wavefunctions lead to quadrupole moments proportional to the charge of the baryon whereas for strongly broken flavor symmetry a proportionality to baryonic isospin emerges. Since the flavor distortions in the wavefunctions also determine the strangeness content of the proton the Skyrme model provides a link between both quantities.

J. Kroll; B. Schwesinger

1994-05-11

449

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-print Network

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

Ryjkov, Vladimir Leonidovich

2005-02-17

450

Fabrication and test of LARP technological quadrupole models of TQC series  

Microsoft Academic Search

In support of the development of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, several two-layer technological quadrupole models of TQC series with 90 mm aperture and collar-based mechanical structure have been developed at Fermilab in collaboration with LBNL. This paper summarizes the results of fabrication and test of TQC02a, the second TQC model based

R. C. Bossert; G. Ambrosio; N. Andreev; E. Barzi; G. Chlachidze; S. Feher; V. S. Kashikhin; V. V. Kashikhin; M. Lamm; A. Nobrega; I. Novitski

2008-01-01

451

Test Results of LARP Quadrupole Magnets Using a Shell-Based Support Structure (TQS)  

Microsoft Academic Search

Amongst the magnet development program of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider luminosity upgrade, six quadrupole magnets were built and tested using a shell based key and bladder technology (TQS). The 1 m long 90 mm aperture magnets are part of the US LHC Accelerator Research Program (LARP) aimed at demonstrating Nb3Sn technology by the year

Shlomo Caspi; Daniel R. Dietderich; Helene Felice; Paolo Ferracin; R. Hafalia; C. R. Hannaford; A. F. Lietzke; Juan Lizarazo; GianLuca Sabbi; X. R. Wang; Arup Ghosh; Peter Wanderer; Giorgio Ambrosio; Emanuela Barzi; Rodger Bossert; Guram Chlachidze; Sandor Feher; Vadim V. Kashikhin; Michael Lamm; Michael A. Tartaglia; Alexander V. Zlobin; Marta Bajko; Bernardo Bordini; Gijs DeRijk; Christian Giloux; Mikko Karppinen; Juan C. Perez; Lucio Rossi; Andrzej Siemko; Ezio Todesco

2009-01-01

452

Fabrication and Test of LARP Technological Quadrupole Models of TQC Series  

Microsoft Academic Search

In support of the development of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, several two-layer technological quadrupole models of TQC series with 90 mm aperture and collar-based mechanical structure have been developed at Fermilab in collaboration with LBNL. This paper summarizes the results of fabrication and test of TQC02a, the second TQC model based

Rodger C. Bossert; Giorgio Ambrosio; Nilolai Andreev; Emanuela Barzi; Guram Chlachidze; Sandor Feher; Vladimir S. Kashikhin; Vadim V. Kashikhin; Michael Lamm; Alfred Nobrega; Igor Novitski; Darryl Orris; Michael Tartaglia; Alexander V. Zlobin; Shlomo Caspi; Daniel R. Dietderich; Paolo Ferracin; A. R. Hafalia; GianLuca Sabbi; Arup Ghosh; Peter Wanderer

2008-01-01

453

Fabrication and Test of LARP Technological Quadrupole Models of TQC Series  

Microsoft Academic Search

In support of the development of a large-aperture Nb3Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, several two-layer technological quadrupole models of TQC series with 90 mm aperture and collar-based mechanical structure have been developed at Fermilab in collaboration with LBNL. This paper summarizes the results of fabrication and test of TQC02a, the second TQC model based

Rodger C. Bossert; Giorgio Ambrosio; Nikolai Andreev; Emanuela Barzi; Guram Chlachidze; Sandor Feher; Vladimir S. Kashikhin; Vadim V. Kashikhin; Michael Lamm; Alfred Nobrega; Igor Novitski; Darryl Orris; Michael Tartaglia; Alexander V. Zlobin; Shlomo Caspi; Daniel R. Dietderich; Paolo Ferracin; A. R. Hafalia; Gianluca Sabbi; Arup Ghosh; Peter Wanderer

2009-01-01

454

Test and Analysis of Technology Quadrupole Shell (TQS) Magnet Models for LARP  

Microsoft Academic Search

Test results are reported on four quadrupole magnet model tests (TQS01a, TQS01b, TQS01c, TQS02) in support of the development of a large-aperture superconducting quadrupole for the US LHC Accelerator Research Program (LARP). All four magnet assemblies used key and bladder technology to compress and support the coils within an iron yoke and an aluminum shell. The first three models tested

S. Caspi; G. Ambrosio; A. N. Andreev; E. Barzi; R. Bossert; D. R. Dietderich; P. Ferracin; A. Ghosh; A. R. Hafalia; V. V. Kashikhin; A. F. Lietzke; I. Novitski; G. L. Sabbi; A. V. Zlobin

2008-01-01

455

Field Quality Measurements and Analysis of the LARP Technology Quadrupole Models  

Microsoft Academic Search

One of the US-LHC accelerator research program goals is to develop and prove the design and technology of quadrupoles for an upgrade of the LHC Interaction Region (IR) inner triplets. Four 1-m long technology quadrupole models with a 90 mm bore and field gradient of 200 T\\/m based on similar coils and different mechanical structures have been developed. In this

G. V. Velev; R. Bossert; S. Caspi; G. Chlachidze; J. Dimarco; P. Ferracin; V. V. Kashikhin; M. Lamm; G. L. Sabbi; P. Schlabach; M. Tartaglia; J. C. Tompkins; A. V. Zlobin

2008-01-01

456

Fast quadrupole pulsed power supply in the AGS  

SciTech Connect

As part of the Polarized Proton Project at the AGS, a pulsed power supply system has been developed to energize a set of twelve fast quadrupoles which are symmetrically distributed around the 1/2-mile circumference of the machine. During a typical acceleration cycle, which is normally repeated every 2.4 s, these magnets are energized with bursts of triangular current pulses. The rise-time of each pulse is less than 2 ..mu..s and the width at the base varies from 1 to 3.5 ms depending on the pulse. Within a burst, pulses alternate in polarity and vary in amplitude from 160 A to 2700 A peak. Pulse separation is on the order of 40 ms. Due to the distributed nature of the load and high di/dt, each magnet is powered by a separate modulator. Magnets are driven via coaxial pulse transmission cables up to 200 ft long. In the modulators, the high power pulses are switched with thyratron/ignitron switch pairs. All modulators are charged in parallel with a common system of programmable high voltage power supplies. The overall system is controlled with a distributed network of microcomputers. This paper describes the development, construction and initial performance of the pulsed power supply system.

Nawrocky, R.J.; Halama, H.J.; Lambiase, R.F.; Montemurro, P.A.

1984-01-01

457

Quadrupole beam-based alignment in the RHIC interaction regions  

SciTech Connect

Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements. BBA data has been collected over the past two runs for all three of the active experimental IRs at RHIC, updating results from the 2005 run which were taken with incorrectly installed offsets. The technique was successfully applied to expose a systematic misuse of the BPM survey offsets in the control system. This is likely to benefit polarized proton operations as polarization transmission through acceleration ramps depends on RMS orbit control in the arcs, but a quantitative understanding of its impact is still under active investigation. Data taking is ongoing as are refinements to the BBA technique aimed at reducing systematic errors and properly accounting for dispersive effects. Further development may focus on non-triplet BPMs such as those located near snakes, or arc quadrupoles that do not have individually shunted power supplies (a prerequisite for the current method) and as such, will require a modified procedure.

Ziegler, J.; Satogata, T.

2011-03-28

458

Radio-frequency quadrupole vane-tip geometries  

SciTech Connect

Radio-frequency quadrupole (RFQ) linacs are becoming widely accepted in the accelerator community. They have the remarkable capability of simultaneously bunching low-energy ion beams and accelerating them to energies at which conventional accelerators can be used, accomplishing this with high-transmission efficiencies and low-emittance growths. The electric fields, used for radial focusing, bunching, and accelerating, are determined by the geometry of the vane tips. The choice of the best vane-tip geometry depends on considerations such as the peak surface electric field, per cent of higher multipole components, and ease of machining. We review the vane-tip geometry based on the ideal two-term potential function and briefly describe a method for calculating the electric field components in an RFQ cell with arbitrary vane-tip geometry. We describe five basic geometries and use the prototype RFQ design for the Fusion Materials Irradiation Test (FMIT) accelerator as an example to compare the characteristics of the various geometries.

Crandall, K.R.; Mills, R.S.; Wangler, T.P.

1983-01-01

459

Miniature mass spectrometer systems based on a microengineered quadrupole filter.  

PubMed

Two miniature mass spectrometer systems based on a microengineered quadrupole mass filter have been developed. One of the instruments has a footprint of 27 cm x 20 cm and is intended for laboratory use when space is at a premium. The other is portable and intended for use in the field. It is battery powered, weighs 14.9 kg, and is housed in a rugged case. This is the first example of a portable mass spectrometer incorporating an analyzer fabricated using microelectromechanical systems (MEMS) techniques. The starting material for construction of the filters is a bonded silicon on insulator substrate, which is selectively etched using batch processing techniques to form coupling optics and springs that accurately hold 0.5 mm diameter stainless steel rods in the required geometry. Assembled filters measure 35 mm x 6 mm x 1.5 mm and are mounted, together with an ion source and channeltron detector, in small, interchangeable cartridges, which plug into a 220 cm(3) vacuum chamber. Recovery from accidental contamination or when servicing is required can be achieved within 5-10 min, as the cartridge is easily exchanged with a spare. A potential application to environmental monitoring has been investigated. The headspace above water spiked with dibutyl mercaptan was sampled with a solid phase microextraction (SPME) fiber, which was then injected directly into the vacuum chamber of the mass spectrometer. Using this method, the limit of detection was found to be approximately 5 ppm for a 15 s sampling period. PMID:20108919

Malcolm, Andrew; Wright, Steven; Syms, Richard R A; Dash, Neil; Schwab, Marc-Andr; Finlay, Alan

2010-03-01

460

Quadrupole collectivity in neutron-rich Cd isotopes  

NASA Astrophysics Data System (ADS)

The proximity to the closed shells at Z = 50 and N = 82 makes the neutron-rich Cd isotopes a perfect test case for nuclear theories. The energy of the first excited 2+-state in the even 122-128 shows an irregular behaviour as the Cd isotopes exhibit only a slight increase for 122Cd to 126Cd and even a decrease from 126Cd to 128Cd. This anomaly can so far not be reproduced by shell model calculations. Only beyond mean field calculations with a resultant prolate deformation are capable to describe this anomalous behaviour. In order to gain more information about the neutron-rich Cd isotopes a Coulomb excitation experiment was performed with MINIBALL at REX-ISOLDE, CERN. The extracted transition strengths B (E2,0+gs ? 2+1) for 122,124,126,128Cd agree with beyond mean field calculations. The spectroscopic quadrupole moments Qs (2+1) are compared with measurements on odd neutron-rich Cd isotopes.

Bnig, S.; Krll, Th; Ilieva, S.; Scheck, M.; Is411; Is477; Is524; the Miniball collaborations

2015-02-01

461

Motional averaging of quadrupole interactions in Al4Sr and Ga4Sr studied using PAC  

NASA Astrophysics Data System (ADS)

Perturbed angular correlation of gamma rays (PAC) was used to study diffusion of ^111In/Cd probe atoms in Al4Sr and Ga4Sr phases. These phases have the tetragonal Al4Ba structure, with two inequivalent Al sublattices that have axially symmetric and collinear electric field gradients. Measurements of nuclear quadrupole interactions in each phase revealed three dynamical regimes. Static quadrupole interactions were observed below 500^oC. Between 500 and 700^oC, the two quadrupole interaction signals were observed to approach each other and merge at 700^oC (slow fluctuation regime). Only a single quadrupole interaction signal was observed above 700^oC (fast fluctuation regime). These changes are attributed to jumping of probe atoms between the two sublattices, leading to motional averaging of the two electric field gradients as temperature and jump frequency increase. The two signals merge at a temperature at which the jump frequency between the sublattices is equal to the difference in the static quadrupole interaction frequencies. Temperature dependences of the quadrupole interaction frequencies will be contrasted with those measured earlier on phases including Al4Ba and In4Ba.

Cawthorne, Samantha; Collins, Gary S.

2009-11-01

462

Contemporary research with nuclear resonance fluorescence at the S-DALINAC  

NASA Astrophysics Data System (ADS)

In the last decades many nuclear resonance fluorescence experiments aiming for low-lying dipole excitations were performed at the Darmstadt High Intensity Photon Setup at S-DALINAC facility. On the electric dipole side, quadrupole-octupole coupled states and the Pygmy Dipole Resonance are of particular interest. On the magnetic dipole side, the so-called scissors mode is in the focus of interest. Furthermore, using the method of resonant self absorption, the decay behavior of J?= 1- states was investigated in 140Ce .

Zweidinger, M.; Beck, T.; Beller, J.; Gayer, U.; Mertes, L.; Pai, H.; Pietralla, N.; Ries, P.; Romig, C.; Werner, V.

2015-02-01

463

Dark resonance  

SciTech Connect

We construct explicit models of particle dark matter where the attractive force in the dark matter sector creates a narrow near-threshold resonance that qualitatively changes the energy dependence of the annihilation cross section. In these models, the resonant enhancement of the dark matter annihilation can easily source the excess of energetic leptons observed by the PAMELA experiment. The distinct feature of these models is that by construction the enhancement of the annihilation cross section shuts off when the dark matter velocity falls below the typical Milky Way values, thus automatically satisfying constraints on dark matter annihilation imposed by the CMB anisotropies and gamma ray constraints from satellite galaxies. However, the resonant enhancement of annihilation can be probed through the most recent FERMI-LAT constraints on the diffuse galactic gamma ray emission.

An, Haipeng; Pospelov, Maxim, E-mail: han@perimeterinstitute.ca, E-mail: mpospelov@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, Waterloo, ON, N2J 2W9 (Canada)

2012-11-01

464

Resonance conditions  

E-print Network

Non-linear parametric resonances occur frequently in nature. Here we summarize how they can be studied by means of perturbative methods. We show in particular how resonances can affect the motion of a test particle orbiting in the vicinity of a compact object. These mathematical toy-models find application in explaining the structure of the observed kHz Quasi-Periodic Oscillations: we discuss which aspects of the reality naturally enter in the theory, and which one still remain a puzzle.

P. Rebusco

2005-10-14

465

Resonance production  

NASA Astrophysics Data System (ADS)

Recent results on rgr(770)0, K(892)*0, f0(980), phgr(1020), Dgr(1232)++ and Lgr(1520) production in A+A and p+p collisions at SPS and RHIC energies are presented. These resonances are measured via their hadronic decay channels and used as a sensitive tool to examine the collision dynamics in the hadronic medium through their decay and regeneration. The modification of resonance mass, width and shape due to phase space and dynamical effects are discussed.

Fachini, Patricia

2004-08-01

466

HD gas analysis with gas chromatography and quadrupole mass spectrometer  

NASA Astrophysics Data System (ADS)

A gas analyzer system has been developed to analyze Hydrogen-Deuteride (HD) gas for producing frozen-spin polarized HD targets, which are used for hadron photoproduction experiments at SPring-8. Small amounts of ortho-H 2 and para-D 2 gas mixtures ( 0.01%) in a purified HD gas are a key to realize a frozen-spin polarized target. However, there was an intrinsic difficulty to measure these small mixtures in the HD gas with a quadrupole mass spectrometer (QMS) because D + and [H 2D] + produced from the ionization of HD molecules were misidentified as H 2 and D 2 molecules, respectively, and became backgrounds for the measurement of the H 2 and D 2 concentrations. In addition, the ortho-H 2 and para-D 2 are not distinguished from the para-H 2 and ortho-D 2, respectively, with the QMS. In order to obtain reliable concentrations of these gas mixtures in the HD gas, we produced a new gas analyzer system combining two independent measurements with a gas chromatograph and the QMS. Helium or neon gas was used as a carrier gas for the gas chromatograph which was cooled at 110 K. The para-H 2, ortho-H 2, HD, and D 2 are separated using the retention time of the gas chromatograph and the mass/charge ratio. Although the para-D 2 is not separated from the ortho-D 2, the total amount of the D 2 is measured without the [H 2D] + background. The ortho-H 2 concentration is also measured separately from the D + background. It is found that the new gas analyzer system can measure small concentrations of 0.01% for the ortho-H 2 and D 2 with good S/N ratios.

Ohta, T.; Bouchigny, S.; Didelez, J.-P.; Fujiwara, M.; Fukuda, K.; Kohri, H.; Kunimatsu, T.; Morisaki, C.; Ono, S.; Rouill, G.; Tanaka, M.; Ueda, K.; Uraki, M.; Utsuro, M.; Wang, S. Y.; Yosoi, M.

2011-06-01

467

Autostereogram resonators  

NASA Astrophysics Data System (ADS)

Autostereograms, or "Magic Eye" pictures, are repeating patterns designed to give the illusion of depth. Here we discuss optical resonators that create light patterns which, when viewed from a suitable position by a monocular observer, are autostereograms of the three-dimensional shape of one of the mirror surfaces.

Leavey, Sean; Rae, Katherine; Murray, Adam; Courtial, Johannes

2012-09-01

468

Fano resonance-induced negative optical scattering force on plasmonic nanoparticles.  

PubMed

We demonstrate theoretically that Fano resonance can induce a negative optical scattering force acting on plasmonic nanoparticles in the visible light spectrum when an appropriate manipulating laser beam is adopted. Under the illumination of a zeroth-order Bessel beam, the plasmonic nanoparticle at its Fano resonance exhibits a much stronger forward scattering than backward scattering and consequently leads to a net longitudinal backward optical scattering force, termed Fano resonance-induced negative optical scattering force. The extinction spectra obtained based on the Mie theory show that the Fano resonance arises from the interference of simultaneously excited multipoles, which can be either a broad electric dipole mode and a narrow electric quadrupole mode, or a quadrupole and an octupole mode mediated by the broad electric dipole. Such Fano resonance-induced negative optical scattering force is demonstrated to occur for core-shell, homogeneous, and hollow metallic particles and can therefore be expected to be universal for many other nanostructures exhibiting Fano resonance, adding considerably to the flexibility of optical micromanipulation on the plasmonic nanoparticles. More interestingly, the flexible tunability of the Fano resonance by particle morphology opens up the possibility of tailoring the optical scattering force accordingly, offering an additional degree of freedom to optical selection and sorting of plasmonic nanoparticles. PMID:25635617

Chen, Huajin; Liu, Shiyang; Zi, Jian; Lin, Zhifang

2015-02-24

469

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

470

Final Development and Test Preparation of the First 3.7 m Long Nb3Sn Quadrupole by LARP  

Microsoft Academic Search

The test of the first LARP (LHC Accelerator Research Program) Long Quadrupole is a significant milestone toward the development of Nb3Sn quadrupoles for LHC (Large Hadron Collider) Luminosity Upgrades. These 3.7-m long magnets, scaled from the 1-m long Technological Quadrupoles, are used to develop our capabilities to fabricate and assemble Nb3Sn coils and structures with lengths comparable to accelerator magnet

G. Ambrosio; N. Andreev; M. Anerella; E. Barzi; B. Bingham; D. Bocian; B. Bordini; R. Bossert; L. Bottura; S. Caspi; G. Chlachidize; W. M. De Rapper; D. Dietderich; J. Escallier; H. Felice; P. Ferracin; A. Ghosh; A. Godeke; R. Hannaford; G. Jochen; V. V. Kashikhin; P. Kovach; M. Lamm; A. McInturff; J. Muratore; F. Nobrega; I. Novitsky; D. Orris; S. Peggs; E. Prebys; S. Prestemon; G. L. Sabbi; J. Schmalzle; C. Sylvester; M. Tartaglia; D. Turrioni; G. Velev; P. Wanderer; G. Willering; A. V. Zlobin

2010-01-01

471

Fabrication and Test of a 3.7 m Long Support Structure for the LARP Quadrupole Magnet LQS01  

Microsoft Academic Search

The 3.7 m long quadrupole magnet LQS01 represents a major step of the US LHC Accelerator Research Program (LARP) towards the development of long Nb3Sn accelerator quadrupole magnets for a LHC Luminosity upgrade. The magnet support structure is a scale up of the 1 m long Technology Quadrupole TQS design with some modifications suggested by TQS model test results. It

Paolo Ferracin; Giorgio Ambrosio; Michael Anerella; Brad Bingham; Rodger Bossert; Shlomo Caspi; D. W. Cheng; Helene Felice; A. R. Hafalia; C. R. Hannaford; F. Nobrega; Soren Prestemon; Gianluca Sabbi; Jesse Schmalzle; Frederic Trillaud; Peter Wanderer; Alexander V. Zlobin

2009-01-01

472

Resonant diffraction of synchrotron radiation in rubidium dihydrophosphate crystals  

NASA Astrophysics Data System (ADS)

Purely resonant Bragg reflections 006, 5 bar 5 0, and 666 in a rubidium dihydrophosphate (RbH2PO4) crystal at the K edge of rubidium have been experimentally and theoretically investigated. These reflections remain forbidden when the resonant dipole-dipole ( E1 E1) contribution to the resonant atomic factor is taken into account; they may be due to the dipole-quadrupole ( E1 E2) transitions as well as to the anisotropy atomic factor, which is caused by thermal atomic displacements (thermally induced contribution) and/or local jumps of hydrogen atoms. A numerical simulation showed that, at room temperature (experimental conditions), the thermally induced contribution to the forbidden reflections is dominant.

Mukhamedzhanov, E. Kh.; Kovalchuk, M. V.; Borisov, M. M.; Ovchinnikova, E. N.; Troshkov, E. V.; Dmitrienko, V. E.

2010-03-01

473

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

NASA Astrophysics Data System (ADS)

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

2014-01-01

474

Electric Quadrupole Moments of the D States of Alkaline-Earth-Metal Ions  

SciTech Connect

The electric quadrupole moment for the 4d {sup 2}D{sub 5/2} state of {sup 88}Sr{sup +}; one of the most important candidates for an optical clock, has been calculated using the relativistic coupled-cluster theory. This is the first application of this theory to determine atomic electric quadrupole moments. The result of the calculation is presented and the important many-body contributions are highlighted. The calculated electric quadrupole moment is (2.94{+-}0.07)ea{sub 0}{sup 2}, where a{sub 0} is the Bohr radius and e the electronic charge while the measured value is (2.6{+-}0.3)ea{sub 0}{sup 2}. This is so far the most accurate determination of the electric quadrupole moment for the above mentioned state. We have also calculated the electric quadrupole moments for the metastable 4d {sup 2}D{sub 3/2} state of {sup 88}Sr{sup +} and for the 3d {sup 2}D{sub 3/2,5/2} and 5d {sup 2}D{sub 3/2,5/2} states of {sup 43}Ca{sup +} and {sup 138}Ba{sup +}, respectively.

Sur, Chiranjib; Latha, K.V.P.; Sahoo, Bijaya K.; Chaudhuri, Rajat K.; Das, B.P.; Mukherjee, D. [Non-Accelerator Particle Physics Group, Indian Institute of Astrophysics, Bangalore - 560 034 (India); Department of Physical Chemistry, Indian Association for the Cultivation of Science, Kolkata - 700 032 (India) and Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India)

2006-05-19