Sample records for quadrupole resonance nqr

  1. Explosives detection by nuclear quadrupole resonance (NQR)

    NASA Astrophysics Data System (ADS)

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

    1994-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2006-05-01

    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.

  3. Landmine detection with nuclear quadrupole resonance

    Microsoft Academic Search

    Yingyi Tan; Stacy L. Tantum; Leslie M. Collins

    2002-01-01

    Nuclear quadrupole resonance (NQR) technology for the detection of explosives is of crucial importance in an increasing number of applications. For landmine detection, NQR has proven to be highly effective if the NQR sensor is not exposed to radio frequency interference (RFI). Since strong nonstationary RFI in the field is unavoidable, a robust detection method is required. With the aid

  4. Quadrupole Coupling Parameters and Structural Aspects of Crystalline and Amorphous Solids by NMR and Nqr.

    NASA Astrophysics Data System (ADS)

    Mao, Degen

    Nuclear quadrupole interaction is very sensitive to the local electron distribution and chemical bondings. NMR and NQR techniques have been combined to obtain the quadrupole coupling constant ({Qcc}) and asymmetry parameter (eta) and extract structural information for several borate, gallate, and metavanadate compounds and glasses. ^{71}Ga and ^{69}Ga NMR has been used to study crystalline beta-Ga _2O_3 and several gallate glasses. Quadrupole parameters were acquired for GaO_6 and GaO_4 units in beta-Ga_2 O_3 by the computer simulation of the NMR powder patterns. A sensitive CW NQR spectrometer was built to detect NQR resonances below 2 MHz. The spectrometer includes a modified Robinson oscillator-detector, a new bi-symmetric square wave Zeeman modulator and a computerized data acquisition system. ^{51}V (I = 7/2) NQR resonances below 850 kHz have been detected for several metavanadates at both room temperature and liquid nitrogen temperature. Quadrupole parameters thus obtained are an order of magnitude more accurate than values obtained by previous NMR studies. For a spin 3/2 nucleus, the pure NQR frequency {Q_{cc}over 2}sqrt{1+{eta^2over 3}}is insufficient to determine either Q_{cc} or eta. However, two methods, Zeeman perturbed NQR powder pattern and ^{10}B NQR, can be employed to obtain both Q_{cc } and eta. An example is given for ^{11}B in CaO-B_2O_3. With a double coil tank circuit design, pure ^ {11}B NQR was used to determine the fraction of borons in BO_3 and BO _4 configurations in hydrated zinc borates. ^{11}B NMR and NQR were also used to study lead borate glasses. Small changes in Q_{cc} (less than 2%) and eta (less than 0.1) suggest that BO_3 units with non-bridging oxygens are not present in the lead borate glasses.

  5. Nuclear quadrupole resonance detection of explosives: an overview

    NASA Astrophysics Data System (ADS)

    Miller, Joel B.

    2011-06-01

    Nuclear Quadrupole Resonance (NQR) is a spectroscopic technique closely related to Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI). These techniques, and NQR in particular, induce signals from the material being interrogated that are very specific to the chemical and physical structure of the material, but are relatively insensitive to the physical form of the material. NQR explosives detection exploits this specificity to detect explosive materials, in contrast to other well known techniques that are designed to detect explosive devices. The past two decades have seen a large research and development effort in NQR explosives detection in the United States aimed at transportation security and military applications. Here, I will briefly describe the physical basis for NQR before discussing NQR developments over the past decade, with particular emphasis on landmine detection and the use of NQR in combating IED's. Potential future directions for NQR research and development are discussed.

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

    Microsoft Academic Search

    Vadim S Grechishkin; Nikolai Ya Sinyavskii

    1997-01-01

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

  7. Pure Nuclear Quadrupole Resonance Techniques for Quantum Computation

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Han; Chen, Zilong; Chuang, Isaac

    2003-03-01

    Pure nuclear quadrupole resonance (NQR) at zero magnetic field provides an accessible means for experimentation with the techniques of quantum computation. We present the design and implementation of a novel benchtop NQR apparatus utilizing modern communication electronics, and featuring a high efficiency, low cost class E amplifier with an integrated and tunable probe. Using this apparatus, we study the chlorine and nitrogen NQR resonances in para-dichlorobenzene and sodium nitrite, applying multiple pulse excitation sequences derived using methods of quantum circuits.

  8. INSTRUMENTS AND METHODS OF INVESTIGATION: New technologies: nuclear quadrupole resonance as an explosive and narcotic detection technique

    NASA Astrophysics Data System (ADS)

    Grechishkin, Vadim S.; Sinyavskii, Nikolai Ya

    1997-04-01

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

  9. ¹?N nuclear quadrupole resonance study of polymorphism in famotidine.

    PubMed

    Lu?nik, Janko; Pirnat, Janez; Jazbinšek, Vojko; Lavri?, Zoran; Žagar, Veselko; Sr?i?, Stane; Seliger, Janez; Trontelj, Zvonko

    2014-09-01

    (14)N nuclear quadrupole resonance (NQR) in two known polymorphs of famotidine was measured. At room temperature, seven quadrupolar sets of transition frequencies (?(+), ?(-), and ?(0)) corresponding to seven different nitrogen sites in the crystal structure of each of the two polymorphs were found. This confirms the expected ability of NQR to distinguish polymorph B from its analog A. NQR can also measure their ratio in a solid mixture and in the final dosage form, that is, a tablet. The NQR frequencies, line shapes, and tentative assignation to all seven molecular (14)N atoms were obtained. Unravelment of these two entangled NQR spectra presents a valuable contribution to the NQR database and enables studies of some possible correlations therein. Moreover, nondestructive (14)N NQR studies of commercial famotidine tablets can reveal some details of the drug fabrication process connected with compression. PMID:24668530

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

    SciTech Connect

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

    1993-07-01

    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.

  11. The two-frequency nuclear quadrupole resonance for explosives detection

    Microsoft Academic Search

    G. V. Mozjoukhine

    2000-01-01

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

  12. Optimal filtering in multipulse sequences for nuclear quadrupole resonance detection

    NASA Astrophysics Data System (ADS)

    Osokin, D. Ya.; Khusnutdinov, R. R.; Mozzhukhin, G. V.; Rameev, B. Z.

    2014-05-01

    The application of the multipulse sequences in nuclear quadrupole resonance (NQR) detection of explosive and narcotic substances has been studied. Various approaches to increase the signal to noise ratio (SNR) of signal detection are considered. We discussed two modifications of the phase-alternated multiple-pulse sequence (PAMS): the 180° pulse sequence with a preparatory pulse and the 90° pulse sequence. The advantages of optimal filtering to detect NQR in the case of the coherent steady-state precession have been analyzed. It has been shown that this technique is effective in filtering high-frequency and low-frequency noise and increasing the reliability of NQR detection. Our analysis also shows the PAMS with 180° pulses is more effective than PSL sequence from point of view of the application of optimal filtering procedure to the steady-state NQR signal.

  13. Polarization enhancement technique for nuclear quadrupole resonance detection.

    PubMed

    Kim, Y J; Karaulanov, T; Matlashov, A N; Newman, S; Urbaitis, A; Volegov, P; Yoder, J; Espy, M A

    2014-01-01

    We demonstrate a dramatic increase in the signal-to-noise ratio (SNR) of a nuclear quadrupole resonance (NQR) signal by using a polarization enhancement technique. By first applying a static magnetic field to pre-polarize one spin subsystem of a material, and then allowing that net polarization to be transferred to the quadrupole subsystem, we increased the SNR of a sample of ammonium nitrate by one-order of magnitude. PMID:24882748

  14. Alignment-to-orientation conversion and nuclear quadrupole resonance D. Budker,1, 2,

    E-print Network

    Budker, Dmitry

    Alignment-to-orientation conversion and nuclear quadrupole resonance D. Budker,1, 2, D. F. Kimball, 2003) The role of alignment-to-orientation conversion (AOC) in nuclear quadrupole resonance (NQR physics. PACS numbers: 76.60.Gv, 32.80.Bx The phenomenon of alignment-to-orientation conver- sion (AOC) [1

  15. Exploiting Spin Echo Decay in the Detection of Nuclear Quadrupole Resonance Signals

    Microsoft Academic Search

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

    2007-01-01

    Nuclear quadrupole resonance (NQR) is a radio-frequency technique that can be used to detect the presence of quadrupolar nuclei, such as the 14N nucleus prevalent in many explosives and narcotics. In a typical application, one observes trains of decaying NQR echoes, in which the decay is governed by the spin echo decay time(s) of the resonant line(s). In most detection

  16. Nuclear quadrupole resonance lineshape analysis for different motional models: stochastic Liouville approach.

    PubMed

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

    2011-12-14

    A general theory of lineshapes in nuclear quadrupole resonance (NQR), based on the stochastic Liouville equation, is presented. The description is valid for arbitrary motional conditions (particularly beyond the valid range of perturbation approaches) and interaction strengths. It can be applied to the computation of NQR spectra for any spin quantum number and for any applied magnetic field. The treatment presented here is an adaptation of the "Swedish slow motion theory," [T. Nilsson and J. Kowalewski, J. Magn. Reson. 146, 345 (2000)] originally formulated for paramagnetic systems, to NQR spectral analysis. The description is formulated for simple (Brownian) diffusion, free diffusion, and jump diffusion models. The two latter models account for molecular cooperativity effects in dense systems (such as liquids of high viscosity or molecular glasses). The sensitivity of NQR slow motion spectra to the mechanism of the motional processes modulating the nuclear quadrupole interaction is discussed. PMID:22168707

  17. Narcotics and explosives detection by 14N pure nuclear quadrupole resonance

    NASA Astrophysics Data System (ADS)

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

    1994-03-01

    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.

  18. 14 N NQR spectrum of sildenafil citrate

    NASA Astrophysics Data System (ADS)

    Stephenson, David; Singh, Nadia

    2015-04-01

    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.

  19. A bi-symmetric square wave Zeeman modulator for nuclear quadrupole resonance.

    PubMed

    Mao, D; Petersen, G L; Bray, P J

    1992-11-01

    A simple circuit has been designed to generate a bi-symmetric square wave Zeeman modulation for the detection of nuclear quadrupole resonance. The square waveform not only provides an optimum result among bi-symmetric modulation waveforms, but also allows the observation of the Zeeman perturbed NQR powder pattern without the need for an extra external magnetic field. PMID:1365735

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

    SciTech Connect

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

    1998-06-01

    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.

  1. Experimental implementation of quantum information processing by Zeeman-perturbed nuclear quadrupole resonance

    NASA Astrophysics Data System (ADS)

    Teles, João; Rivera-Ascona, Christian; Polli, Roberson S.; Oliveira-Silva, Rodrigo; Vidoto, Edson L. G.; Andreeta, José P.; Bonagamba, Tito J.

    2015-03-01

    Nuclear magnetic resonance (NMR) has been widely used in the context of quantum information processing (QIP). However, despite the great similarities between NMR and nuclear quadrupole resonance (NQR), no experimental implementation for QIP using NQR has been reported. We describe the implementation of basic quantum gates and their applications on the creation and manipulation of pseudopure states using linearly polarized radiofrequency pulses under static magnetic field perturbation. The NQR quantum operations were implemented using a single-crystal sample of {KClO}3 and observing ^{35}{Cl} nuclei, which possess spin 3/2 and give rise to a two-qubit system. The results are very promising and indicate that NQR can be successfully used for performing fundamental experiments in QIP. One advantage of NQR in comparison with NMR is that the main interaction is internal to the sample, which makes the system more compact, lowering its cost and making it easier to be miniaturized to solid-state devices. Furthermore, as an example, the study of squeezed spin states could receive relevant contributions from NQR.

  2. Experimental implementation of quantum information processing by Zeeman-perturbed nuclear quadrupole resonance

    NASA Astrophysics Data System (ADS)

    Teles, João; Rivera-Ascona, Christian; Polli, Roberson S.; Oliveira-Silva, Rodrigo; Vidoto, Edson L. G.; Andreeta, José P.; Bonagamba, Tito J.

    2015-06-01

    Nuclear magnetic resonance (NMR) has been widely used in the context of quantum information processing (QIP). However, despite the great similarities between NMR and nuclear quadrupole resonance (NQR), no experimental implementation for QIP using NQR has been reported. We describe the implementation of basic quantum gates and their applications on the creation and manipulation of pseudopure states using linearly polarized radiofrequency pulses under static magnetic field perturbation. The NQR quantum operations were implemented using a single-crystal sample of and observing nuclei, which possess spin 3/2 and give rise to a two-qubit system. The results are very promising and indicate that NQR can be successfully used for performing fundamental experiments in QIP. One advantage of NQR in comparison with NMR is that the main interaction is internal to the sample, which makes the system more compact, lowering its cost and making it easier to be miniaturized to solid-state devices. Furthermore, as an example, the study of squeezed spin states could receive relevant contributions from NQR.

  3. (14) N nuclear quadrupole resonance study of piroxicam: confirmation of new polymorphic form v.

    PubMed

    Lavri?, Zoran; Pirnat, Janez; Lužnik, Janko; Puc, Uroš; Trontelj, Zvonko; Sr?i?, Stane

    2015-06-01

    A new polymorphic crystal form of piroxicam was discovered while preparing crystalline samples of piroxicam for (14) N nuclear quadrupole resonance (NQR) analysis. The new crystal form, designated as V, was prepared by evaporative recrystallization from dichloromethane. Three known polymorphic forms (I, II, and III) were also prepared. Our aim was to apply (14) N NQR to characterize the new polymorphic form of piroxicam and compare the results with those of the other known polymorphic forms. Additional analytical methods used for characterization were X-ray powder diffraction (XRPD), thermal analysis, and vibrational spectroscopy. For the first time, a complete set of nine characteristic (14) N NQR frequencies was found for each prepared polymorph of piroxicam. The consistent set of measured frequencies and calculated characteristic quadrupole parameters found for the new polymorphic form V is a convincing evidence that we are dealing with a new form. The already known piroxicam polymorphic forms were characterized similarly. The XRPD results were in accordance with the conclusions of (14) N NQR analysis. The performed study clearly demonstrates a strong potential of (14) N NQR method to be applied as a highly discriminative spectroscopic analytical tool to characterize polymorphic forms. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1909-1918, 2015. PMID:25776345

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

    Microsoft Academic Search

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

    2004-01-01

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

  5. Superconductivity and magnetic fluctuations in Cd(2))Re(2)O(7) via Cd nuclear magnetic resonance and re nuclear quadrupole resonance.

    PubMed

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

    2002-07-01

    We report Cd nuclear magnetic resonance (NMR) and Re nuclear quadrupole resonance (NQR) studies on Cd(2)Re(2)O(7), the first superconductor among pyrochlore oxides (T(c) approximately 1 K). The Re NQR spectrum at zero magnetic field below 100 K rules out any magnetic or charge order. The spin-lattice relaxation rate below T(c) exhibits a pronounced coherence peak and follows the weak-coupling BCS theory with nearly isotropic energy gap. The results of Cd NMR point to a moderate ferromagnetic enhancement at high temperatures followed by a rapid decrease of the density of states below the structural transition temperature of 200 K. PMID:12097064

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

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

  7. The incommensurate phase of 4,4'-dichlorobiphenyl sulphone reinvestigated by 35Cl NQR

    Microsoft Academic Search

    J. Schneider; A. Wolfenson; A. Brunetti

    1994-01-01

    In order to acquire new information about the normal-incommensurate (IC) phase transition and to check the existence of a lock-in transition in 4,4'-dichlorobiphenyl sulphone (4,4'-DCBS), a comprehensive 35Cl nuclear quadrupole resonance (NQR) study is reported. Detailed NQR measurements of frequency, line width and spin relaxation time (Tl) were obtained in the temperature range 80-270 K. The results show that the

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    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.

  9. Giant Quadrupole-Resonance in Ni Isotopes 

    E-print Network

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

    1992-01-01

    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...

  10. Radio frequency quadrupole resonator for linear accelerator

    DOEpatents

    Moretti, Alfred (Downers Grove, IL)

    1985-01-01

    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.

  11. NQR: From imaging to explosives and drugs detection

    NASA Astrophysics Data System (ADS)

    Osán, Tristán M.; Cerioni, Lucas M. C.; Forguez, José; Ollé, Juan M.; Pusiol, Daniel J.

    2007-02-01

    The main aim of this work is to present an overview of the nuclear quadrupole resonance (NQR) spectroscopy capabilities for solid state imaging and detection of illegal substances, such as explosives and drugs. We briefly discuss the evolution of different NQR imaging techniques, in particular those involving spatial encoding which permit conservation of spectroscopic information. It has been shown that plastic explosives and other forbidden substances cannot be easily detected by means of conventional inspection techniques, such as those based on conventional X-ray technology. For this kind of applications, the experimental results show that the information inferred from NQR spectroscopy provides excellent means to perform volumetric and surface detection of dangerous explosive and drug compounds.

  12. NQR DETECTION OF SODIUM NITRITE RECRYSTALLIZED IN WOOD Jrmy Jover(1), (3)

    E-print Network

    Paris-Sud XI, Université de

    often used as a model in Nitrogen- 14 Quadrupole Resonance, namely sodium nitrite NaNO2. It hasNQR DETECTION OF SODIUM NITRITE RECRYSTALLIZED IN WOOD Jérémy Jover(1), (3) , Sarra Aissani(1 sample tubes have been impregnated by an aqueous solution of sodium nitrite (NaNO2). They were

  13. Off-resonance effects and selectivity profiles in pulsed nitrogen-14 nuclear quadrupole resonance.

    PubMed

    Guendouz, L; Robert, A; Retournard, A; Leclerc, S; Aissani, S; Canet, D

    2012-01-01

    In order to alleviate base-line distortions in nitrogen-14 NQR spectra originating from pulse breakthrough, low power radio-frequency (rf) pulses were applied. It is recalled that the required power is four times lower than that for an equivalent NMR experiment. This is easily explained by the fact that, in NMR, half the amplitude of the rf field is active. Moreover, the selectivity profile (i.e. the peak amplitude as a function of the difference between the carrier frequency and the resonance frequency) exhibits a shape which is, in most cases, more favorable in NQR than in NMR. An appropriate theory has been developed for explaining these experimental observations. It is concluded that low power NQR is perfectly feasible and should even be recommended for most applications, provided that the line-width of the NQR signal is not too large. PMID:23063174

  14. Nuclear quadrupole resonance of barium in BaBiO3 and BaPbO3

    NASA Astrophysics Data System (ADS)

    Savosta, M. M.; Doroshev, V. D.; Borodin, V. A.; Pashkevich, Yu. G.; Kamenev, V. I.; Tarasenko, T. N.; Englich, J.; Kohout, J.; Soldatov, A. G.; Barilo, S. N.; Shiryaev, S. V.

    2001-05-01

    The nuclear quadrupole resonance (NQR) on Ba nuclei was studied in four samples of BaBiO3 prepared in different ways and, in addition, in BaPbO3. The spectrum of 137Ba at T=4.2 K consists of a relatively broad line centered near 18 MHz for all BaBiO3 samples and near 13 MHz for BaPbO3. The integrated intensity of the 137Ba resonance in the ceramic sample of BaBiO3 synthesized at 800 °C is approximately twice as large as that in ceramic samples and a single crystal prepared at 930-1080 °C. The decrease of the NQR signal can be attributed to the partial disordering of charge-disproportionated Bi ions on the two inequivalent sites. The broadening of the resonance indicates that local distortions of the crystal structure exist in both compounds. The point-charge model was used to analyze the electric-field gradient on the Ba sites.

  15. Quadrupole resonance scanner for narcotics detection

    NASA Astrophysics Data System (ADS)

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

    1994-10-01

    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.

  16. Quadrupole resonance spectroscopic study of narcotic materials

    NASA Astrophysics Data System (ADS)

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

    1997-02-01

    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.

  17. 73Ge-Nuclear Magnetic Resonance/Nuclear Quadrupole Resonance Investigation of Magnetic Properties of URhGe

    NASA Astrophysics Data System (ADS)

    Kotegawa, Hisashi; Fukumoto, Kenta; Toyama, Toshihiro; Tou, Hideki; Harima, Hisatomo; Harada, Atsushi; Kitaoka, Yoshio; Haga, Yoshinori; Yamamoto, Etsuji; ?nuki, Yoshichika; Itoh, Kohei M.; Haller, Eugene E.

    2015-05-01

    We report on the 73Ge-nuclear magnetic resonance (NMR)/nuclear quadrupole resonance (NQR) results for the ferromagnetic (FM) superconductor URhGe. The magnitude and direction of the internal field, Hint, and the parameters of the electric field gradient at the Ge site were determined experimentally. By using powdered polycrystalline samples oriented by different methods, the field dependences of NMR shift and nuclear spin relaxation rates for H0 || c (easy axis) and H0 || b were obtained. From the NMR shifts for H0 || b, we confirmed a gradual suppression of the Curie temperature and observed a phase separation near the spin reorientation. The observation of the phase separation gives microscopic evidence that the spin reorientation under H0 || b is of first order at low temperatures. The nuclear spin-lattice relaxation rate 1/T1 indicates that the magnetic fluctuations are suppressed for H0 || c, whereas the fluctuations remain strongly for H0 || b. The enhancements of both 1/T1T and the nuclear spin-spin relaxation rate 1/T2 for H0 || b toward the spin reorientation field suggest that the field-induced superconductivity in URhGe emerges under the magnetic fluctuations along the b- and c-axes.

  18. 14N NQR in the tetrazole family

    NASA Astrophysics Data System (ADS)

    Pirnat, Janez; Lužnik, Janko; Jazbinšek, Vojko; Žagar, Veselko; Seliger, Janez; Klapötke, Thomas M.; Trontelj, Zvonko

    2009-10-01

    14N NQR frequencies and spin-lattice relaxation times were measured in technologically important 5-aminotetrazole and 5-aminotetrazole monohydrate at different temperatures between 77 K and 300 K. Five NQR triplets ?+, ?- and ?0 were found for the five inequivalent nitrogen atoms in each compound between 0.7 MHz and 4 MHz. Carr-Purcell based multipulse sequences were used to accumulate quadrupole echo signals before the FFT analysis. Assignment of the frequencies to atomic positions was made and the results are analysed in relation to the molecular chemical bonds and possible H-bonds in the crystal structures. The new NQR frequencies are reasonably related to the previously published NQR spectrum of the third family member, 1H-tetrazole.

  19. Calculation of the nuclear quadrupole resonance spectra of YBa/sub 2/Cu/sub 3/O/sub 7/minus/x/

    SciTech Connect

    Winter, N.W.; Violet, C.E.

    1989-06-01

    Nuclear quadrupole resonance (NQR) and nuclear magnetic resonance (NMR) studies on /sup 63,65/Cu have demonstrated the the resonance properties of these nuclei can give important information about the electronic structure of the high temperature superconductor YBa/sub 2/Cu/sub 3/O/sub 7/minus/x/ as well as the exchange coupling energy between the Cu(2) sites. Measurements for various oxygen stoichiometries have given insight into the effect of oxygen content on the valence state of the Cu. In the work reported here, the electric field gradient (EFG) tensors at the Cu(1) and Cu(2) sites in YBa/sub 2/Cu/sub 3/O/sub 7/minus/x/, have been determined from calculations on large clusters for x = 0 and 1. 13 refs., 2 tabs.

  20. Radio-frequency quadrupole resonator for linear accelerator

    DOEpatents

    Moretti, A.

    1982-10-19

    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.

  1. Nondestructive testing of adhesive bonds by nuclear quadrupole resonance method

    NASA Technical Reports Server (NTRS)

    Hewitt, R. R.

    1971-01-01

    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.

  2. Anomalous H/D isotope effect on 35Cl NQR frequencies in piperidinium p-chlorobenzoate

    NASA Astrophysics Data System (ADS)

    Nakano, Ryo; Honda, Hisashi; Kimura, Taiki; Nakata, Eiichi; Takamizawa, Satoshi; Noro, Sumiko; Ishimaru, Shin'ichi

    2008-01-01

    Anomalous isotope effects were detected in the 35Cl nuclear quadrupole resonance (NQR) frequency of piperidinium p-chlrobenzoate (C5H10NH· ClC6H4COOH) by deuteration of hydrogen atoms. The atoms were determined to form two kinds of N H···O type H-bonds in the crystal structure. Large frequency shifts of the 35Cl resonance lines reaching 288 kHz at 77 K and 278 kHz at room temperature were caused upon deuteration, in spite of the fact that the Cl atoms in the molecule do not form hydrogen bonds in the crystal. Results of single crystal X-ray diffraction measurements and density-functional-theorem calculations suggest that a dihedral-angle change of 1.8° between benzene and the piperidine ring contributes to 35Cl NQR anomalous frequency shifts.

  3. Kalman filtering for enhanced landmine detection using quadrupole resonance

    Microsoft Academic Search

    Yingyi Tan; Stacy L. Tantum; Leslie M. Collins

    2005-01-01

    Quadrupole resonance (QR) is a novel technology recently applied to landmine detection. The detection process is specific to the chemistry of the explosive, and therefore is less susceptible to the types of false alarms experienced by metal detectors and ground-penetrating radars. Although QR is vulnerable to radio-frequency interference (RFI) when the sensor is deployed in the field, adaptive RFI mitigation

  4. Resonance Secondary Radiation enhanced by quadrupole mode of plasmonic arrays

    NASA Astrophysics Data System (ADS)

    Lanterbecq, Déborah; Van Deun, Rik; Morarescu, Rodica; Damman, Pascal; Kolaric, Branko

    2013-11-01

    In this paper, the Resonance Secondary Radiation (RSR), the joined action of the Raman Resonance and Fluorescence emission is described. The observed enhancement of the RSR signal is caused by the quadrupole mode of the plasmonic resonance of gold nanotriangles arrays. The material used in this study has been designed based on two separate nanoscale engineering processes by combining two different materials (oligonucleotides and colloidal arrays) at different length scales. The control of the emission by the plasmonic resonance is demonstrated and thoroughly investigated using extinction, steady state and time-resolved Fluorescence spectroscopy.

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

    SciTech Connect

    Jayakody, J.R.P.

    1993-12-31

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

  6. Measurement of temperature and temperature gradient in millimeter samples by chlorine NQR

    NASA Astrophysics Data System (ADS)

    Lužnik, Janko; Pirnat, Janez; Trontelj, Zvonko

    2009-09-01

    A mini-thermometer based on the 35Cl nuclear quadrupole resonance (NQR) frequency temperature dependence in the chlorates KClO3 and NaClO3 was built and successfully tested by measuring temperature and temperature gradient at 77 K and higher in about 100 mm3 active volume of a mini Joule-Thomson refrigerator. In the design of the tank-circuit coil, an array of small coils connected in series enabled us (a) to achieve a suitable ratio of inductance to capacity in the NQR spectrometer input tank circuit, (b) to use a single crystal of KClO3 or NaClO3 (of 1-2 mm3 size) in one coil as a mini-thermometer with a resolution of 0.03 K and (c) to construct a system for measuring temperature gradients when the spatial coordinates of each chlorate single crystal within an individual coil are known.

  7. 93Nb- and 27Al-NMR/NQR studies of the praseodymium based PrNb2Al20

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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.

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

    PubMed

    Guendouz, Laouès; Aissani, Sarra; Marêché, Jean-François; Retournard, Alain; Marande, Pierre-Louis; Canet, Daniel

    2013-01-01

    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

  9. Electronic structure and biological activity of chosen DDT-type insecticides studied by 35Cl-NQR.

    PubMed

    Jadzyn, Maciej; Nogaj, Boles?aw

    2009-02-01

    A correlation between the electronic structure and biological activity of chosen dichlorodiphenyltrichloroethane (DDT)-type insecticides: 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane, 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene, 2,2-bis(4-chlorophenyl)ethanoic acid and 4,4'-dichlorobenzophenone (used in agriculture) has been analysed on the basis of the (35)Cl-nuclear quadrupole resonance (NQR) spectroscopy. The (35)Cl-NQR resonance frequencies measured at 77 K have been correlated with the lethal dose (LD(50)) parameter that characterises the biological activity of these insecticides. PMID:18942076

  10. A General Numerical Analysis of Time-Domain NQR Experiments

    SciTech Connect

    Harel, Elad; Cho, Herman M.

    2006-12-01

    We introduce a general numerical approach for solving the Liouville equation of a quadrupolar nuclide that we show can be used to analyze time-domain NQR experiments. A computer-based treatment is necessitated by the dimensionality of the Liouville space, which precludes analytical, closed form solutions for I > 3/2. Accurate simulations of experimental nutation curves, forbidden transition intensities, powder and single crystal spectra, and off-resonance irradiation dynamics can be computed with this method. We also examine the validity of perturbative approximations where the signal intensity of a transition is proportional to the transition moment between the eigenstates of the system, thus providing a simple basis for determining selection rules. Our method allows us to calculate spectra for all values of the asymmetry parameter, ?, and sample orientations relative to the coil axis. We conclude by demonstrating the methodology for calculating the response of the quadrupole system to amplitude- and frequency-modulated pulses.

  11. Absence of Magnetic Dipolar Phase Transition and Evolution of Low-Energy Excitations in PrNb2Al20 with Crystal Electric Field ?3 Ground State: Evidence from 93Nb-NQR Studies

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    We report measurements of bulk magnetic susceptibility and 93Nb nuclear quadrupole resonance (NQR) in the Pr-based caged compound PrNb2Al20. By analyzing the magnetic susceptibility and magnetization, the crystal electric field (CEF) level scheme of PrNb2Al20 is determined to be ?3(0 K)-?4(21.32 K)-?5(43.98 K)-?1(51.16 K) within the framework of the localized 4f electron picture. The 93Nb-NQR spectra exhibit neither spectral broadening nor spectral shift upon cooling down to 75 mK. The 93Nb-NQR spin-lattice relaxation rate 1/T1 at 5 K depends on the frequency and remains almost constant below 5 K. The frequency dependence of 1/T1 is attributed to the magnetic fluctuation due to the hyperfine-enhanced 141Pr nuclear moment inherent in the nonmagnetic ?3 CEF ground state. The present NQR results provide evidence that no symmetry-breaking magnetic dipole order occurs down to 75 mK. Also, considering an invariant form of the quadrupole and octupole couplings between a 93Nb nucleus and Pr 4f electrons, Pr 4f quadrupoles and an octupole can couple with a 93Nb nuclear quadrupole moment and nuclear spin, respectively. Together with the results of bulk measurements, the present NQR results suggest that the possibility of a static quadrupole or octupole ordering can be excluded down to 100 mK. At low temperatures below 500 mK, however, the nuclear spin-echo decay rate gradually increases and the decay curve changes from Gaussian decay to Lorentzian decay, suggesting the evolution of a low-energy excitation.

  12. 14N nuclear quadrupole resonance study of phase transitions of 1M and 2Or polytypes of potassium hexacyanoferrate (III)

    NASA Astrophysics Data System (ADS)

    Murgich, Juan; Abanero, Jose A.; Santana R., Magaly; Capparelli, Mario V.

    1986-11-01

    14N nuclear quadrupole resonance (NQR) frequencies were measured between 77-328 K for simple monoclinic (1M) and orthorhombic (2Or) polytypes of potassium hexacyanoferrate (III) (KFR). A reversible first order transition was found at 133 K for 1M and at 138 K for 2Or polytype. The transition was interpreted in terms of the coupling of a quasisoft rotatory mode with a temperature dependent tilt motion of the complex ion. An irreversible interpolytype transition produced by internal strains was observed in a sample formed by 1M and 2Or polytypes and repeatedly cycled between around 80-140 K and room temperature. Selective broadening of lines observed in only a pair of N atoms of each hexacyanoferrate ion was attributed to the occurrence of one dimensional disorder of neighboring K ions. The disorder disappeared after sample recrystallization. It was found that low crystallization rates produced only the 1M structure while high rates increased the occurrence of the 2Or over 1M polytype and even produced a third polytype. Annealing of KFR for two weeks at 160 °C produced minor changes in polytypic composition thus showing a high energy barrier for interpolytypic conversion. The results obtained in KFR are explained in terms of the theory of order-disorder structures in layered compounds.

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

    NASA Astrophysics Data System (ADS)

    Jayakody, Jayakody R. Pemadasa

    1993-01-01

    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.

  14. Quantitative Analysis of Hydration Using Nitrogen-14 Nuclear Quadrupole Resonance.

    PubMed

    Gregorovi?, Alan

    2015-07-01

    Hydration is a quite common process in pharmaceutical solids. Sometimes it is desirable, as it stabilizes the crystal structure; in other cases it is unwanted, as it changes the physical and chemical properties of drugs. We here use (14)N NQR spectroscopy to quantitatively analyze hydration of a model compound, 5-aminotetrazole. (14)N NQR has some great advantages compared to other routinely used techniques to study hydration, like a very simple spectrum, single point calibration, and no need for special sample preparation, but the method's great disadvantage is a rather small sensitivity. Nevertheless, here we demonstrate that (14)N NQR, although being significantly less sensitive than XRD, NIR, and also (35)Cl NQR, is still capable of providing excellent quantitative accuracies. We can achieve errors <1% of the total amount, provided good temperature stabilization is implemented, which then allows long experimental times. We also present results obtained with a SLSE pulse sequence, which is a less robust approach but allows the use of much shorter measuring times (?200×) and could be used for quantitative real time monitoring of hydration or dehydration. PMID:26008906

  15. NQR experiments on Sc-Y alloys at very low temperatures. [Absolute thermometry below 500[mu]K

    SciTech Connect

    Pollack, L.; Smith, E.N.; Richardson, R.C. (Cornell Univ., Ithaca, NY (United States))

    1992-10-01

    The authors performed Nuclear Quadrupole Resonance (NQR) experiments on an alloy of scandium and yttrium. They find that the characteristic resonance frequencies in zero external field are 50% larger than in pure scandium. This increase in frequency makes the Sc-Y alloy a better candidate for absolute thermometry below 500 [mu]K. However, the spin-lattice relaxation time of this alloy is more than an order of magnitude longer than in the pure scandium. In addition, an abrupt increase in the Korringa constant was observed for temperatures below 5mK.

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

    NASA Technical Reports Server (NTRS)

    Murty, A. N.

    1978-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2004-07-01

    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.

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

    Microsoft Academic Search

    Ed Rao; William J. Hughes

    2001-01-01

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

  19. Pure nuclear quadrupole resonance determination of the electric field gradient asymmetry for broad lines

    E-print Network

    Keren, Amit

    Pure nuclear quadrupole resonance determination of the electric field gradient asymmetry for broad nuclear quadrupole resonance (ADNQR) method to determine the electric field gradient asymmetry parameter g in a coil so that the sym- metry axis of the coil is pointing in the br direction. In the experiment

  20. 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)

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

    2006-11-01

    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.

  1. Chlorine NQR on Derivatives of Chloral

    NASA Astrophysics Data System (ADS)

    Hashimoto, Masao; Weiden, Norbert; Weiss, Alarich

    1980-10-01

    The 35Cl-NQR spectrum of several derivatives of chloral, Cl3CCHO, was studied in the ranee 77 K ? T ? Tm. By use of the spin echo double resonance technique a relative assignment of the resonances to different Cl3C-groups within one crystallized compound was possible. The solid compounds studied are: High temperature phase of chloral hydrate, Cl3CCH(OH)2; parachloral, (Cl3CCHO)3, (?-and ß-isomer); the two phases of chloral hemihydrate Cl3CCHO · 1/2 H2O; chloralide (II); chloralhemithiohydrate, Cl3CCHO · 1/2 H2S. The structure of the molecules in the solid state and the fade out of the NQR resonances are discussed.

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

    E-print Network

    Jerby, Eli

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

  3. Anomalous HID isotope effect on 35Cl NQR frequencies in piperidinium p-chlorobenzoate

    NASA Astrophysics Data System (ADS)

    Nakano, Ryo; Honda, Hisashi; Kimura, Taiki; Nakata, Eiichi; Takamizawa, Satoshi; Noro, Sumiko; Ishimaru, Shin'ichi

    Anomalous isotope effects were detected in the 35CI nuclear quadrupole resonance (NQR) frequency of piperidinium p-chlrobenzoate (C5H10NH· CIC6H4COOH) by deuteration of hydrogen atoms. The atoms were determined to form two kinds of N-H...O type H-bonds in the crystal structure. Large frequency shifts of the 35CI resonance lines reaching 288 kHz at 77 K and 278 kHz at room temperature were caused upon deuteration, in spite of the fact that the CI atoms in the molecule do not form hydrogen bonds in the crystal. Results of single crystal X-ray diffraction measurements and density-functional-theorem calculations suggest that a dihedral-angle change of 1.8° between benzene and the piperidine ring contributes to 35CINQR anomalous frequency shifts.

  4. NMR and NQR investigations of local symmetry in the hidden order phase of URu2Si2

    NASA Astrophysics Data System (ADS)

    Mito, T.; Hattori, M.; Motoyama, G.; Sakai, Y.; Koyama, T.; Ueda, K.; Kohara, T.; Yokoyama, M.; Amitsuka, H.

    2012-12-01

    In order to study local symmetries at the 4e(Si)- and 4d(Ru)-sites above and below hidden order transition temperature TO = 17.5 K in URu2Si2, we have investigated the nuclear quadrupole interaction by 73Ge-nuclear magnetic resonance (NMR) measurement on a 10% 73Ge-substituted sample URu2(Si0.9Ge0.1)2, and by 101Ru-nuclear quadrupole resonance (NQR) measurement on a pure single crystal sample. The present 73Ge-NMR measurements do not give any evidence for change in the local symmetry at 4e-site within experimental accuracy. On the other hand, the precise measurement of 101Ru-NQR frequency has detected an anomaly just below TO as sensitively as the thermal expansion measurement dose. Its temperature dependence shows a linear relation with that of the in-plane lattice parameter, which may be a clue to clarify a modification in microscopic charge distribution at TO.

  5. High-Efficiency Resonant Cavity Quadrupole Moment Monitor

    SciTech Connect

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

    2007-04-13

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

  7. (14)N Quadrupole Resonance line broadening due to the earth magnetic field, occuring only in the case of an axially symmetric electric field gradient tensor.

    PubMed

    Aissani, Sarra; Guendouz, Laouès; Marande, Pierre-Louis; Canet, Daniel

    2015-01-01

    As demonstrated before, the application of a weak static B0 magnetic field (less than 10G) may produce definite effects on the (14)N Quadrupole Resonance line when the electric field gradient tensor at the nitrogen nucleus level is of axial symmetry. Here, we address more precisely the problem of the relative orientation of the two magnetic fields (the static field and the radio-frequency field of the pure NQR experiment). For a field of 6G, the evolution of the signal intensity, as a function of this relative orientation, is in very good agreement with the theoretical predictions. There is in particular an intensity loss by a factor of three when going from the parallel configuration to the perpendicular configuration. By contrast, when dealing with a very weak magnetic field (as the earth field, around 0.5G), this effect drops to ca. 1.5 in the case Hexamethylenetetramine (HMT).This is explained by the fact that the Zeeman shift (due to the very weak magnetic field) becomes comparable to the natural line-width. The latter can therefore be determined by accounting for this competition. Still in the case of HMT, the estimated natural line-width is half the observed line-width. The extra broadening is thus attributed to earth magnetic field. The latter constitutes therefore the main cause of the difference between the natural transverse relaxation time (T2) and the transverse relaxation time derived from the observed line-width (T2(?)). PMID:25910551

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

    Microsoft Academic Search

    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

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

  9. Measurement of in-situ stress in salt and rock using NQR techniques

    SciTech Connect

    Schempp, E.; Hirschfeld, T.; Klainer, S.

    1980-12-01

    A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified.

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

    E-print Network

    Romalis, Mike

    Hz 14 N NQR frequency of ammonium nitrate. A potential application of the magnetometer is detection-to-noise ratio SNR below a few megahertz. The NQR signal from 22 g of powdered ammonium nitrate located 2 cm away from the sensor is detected with a SNR of 9 in a 4.4-s-long multiple echo sequence, which represents

  11. The quadrupole resonator:Construction, RF System Field Calculations and First Applications

    Microsoft Academic Search

    Enrico Chiaveri; E Häbel; E Mahner; J M Tessier

    1998-01-01

    The quadrupole resonator allows measurement of the RF properties of superconducting (sc) films deposited on disk-shaped metallic substrates. We describe the construction of the apparatus, the brazing and electron-beam welding procedures, the arrangements for compensating mechanical tolerances of samples and for assuring reproducible sample illumination. We explain the special features of the RF sy stem and give the results of

  12. Noble gas detection using resonance ionization spectroscopy and a quadrupole mass spectrometer

    Microsoft Academic Search

    C. H. Chen; G. S. Hurst

    1983-01-01

    The technique of Resonance Ionization Spectroscopy (RIS) is being extended to develop a means for counting individual atoms of a selected isotope of a noble gas. In this method, lasers are used for RIS to obtain atomic species (Z) selectivity and a small quadrupole mass spectrometer provides isotopic (A) selectivity. A progress report on the objective of counting each atom

  13. Quadrupole resonances in the rare-earth metals

    SciTech Connect

    Liberman, D.; Zangwill, A.

    1989-01-01

    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.

  14. Fourier transform zero field NMR and NQR

    SciTech Connect

    Zax, D.B.

    1984-09-01

    The characterization of the structural and chemical properties of matter, particularly in disordered condensed phases, is a difficult process. Few analytical methods work effectively on polycrystalline or amorphous solids. In many systems the chemical shifts measured by traditional high resolution solid state NMR methods are insufficiently sensitive or the information contained in the dipole-dipole couplings is more important. In these cases Fourier transform zero field magnetic resonance may make an important contribution. Zero field NMR and NQR is the subjecti of this thesis.

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

    Microsoft Academic Search

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

    2009-01-01

    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

  16. Superconducting clusters and phase separation in Pr1+xBa2-xCu3O7+?: A 63,65Cu nuclear quadrupole resonance and zero-field NMR study

    NASA Astrophysics Data System (ADS)

    Grévin, B.; Berthier, Y.; Mendels, P.; Collin, G.

    2000-02-01

    We present a study on the effect of the Pr3+ substitution for Ba2+ in the Pr1+xBa2-xCu3O7+? system, where small superconducting fractions have been observed in some of the samples with x in the range 0.1quadrupole resonance (NQR) and zero-field NMR are reported for the x=0.3 sample Pr1.3Ba1.7Cu3O7+? in which the largest superconducting fraction has been detected below 90 K. 63,65Cu NQR in this sample shows the presence of a fraction of metallic copper in the CuO2 planes and confirms that the substitution of Pr onto Ba sites leads to oxygen interchain sites O(5) occupancy. The existence of two different magnetic Cu(2) sites is evidenced for x=0.3 from the comparison of the Cu(2) zero-field NMR in the x=0 and x=0.3 samples. The whole set of results is interpreted in the framework of a phase separation mechanism in the CuO2 planes induced by the Ba/Pr substitution. Three characteristic domains are involved, in which respectively localized holes are present, no holes are transferred, and mobile holes reside. We present a model where the observed superconductivity is due to a segregation of local defects in the structure which gives a distribution of clusters containing mobile holes. A local weakening of the Pr4f-O2p hybridization by the Pr/Ba substitution is argued to explain the presence of these clusters.

  17. 139La nuclear magnetic resonance characterisation of La2O3 and La1-xSrxMO3 where M = Cr, Mn or Co.

    PubMed

    Bastow, T J

    1994-02-01

    139La Nuclear magnetic resonance (NMR) spectra have been used to obtain nuclear quadrupole coupling parameters for La2O3 and a series of perovskites La1-xSrxMO3 (where M = Cr, Mn or Co). Depending on the doping level of SrO2 these materials are either paramagnetic or ferromagnetic at room temperature. Magnetic transferred hyperfine effects are strongly in evidence in the Mn compounds. A 59Co NMR spectrum was observed in LaCoO3. A precision measurement of the nuclear quadrupole coupling constant in La2O3 was made by nuclear quadrupole resonance (NQR) spectroscopy. PMID:7827974

  18. Experimental verification of resonance instability bands in quadrupole doublet focusing channels

    NASA Astrophysics Data System (ADS)

    Fukushima, K.; Ito, K.; Okamoto, H.; Yamaguchi, S.; Moriya, K.; Higaki, H.; Okano, T.; Lund, S. M.

    2014-01-01

    The tabletop plasma trap experiment named "S-POD" is employed to explore the stability of intense charged-particle beams focused by a series of quadrupole doublet cells. S-POD is a compact linear Paul-trap, where we generate a single-species non-neutral ion plasma that can approximately reproduce the collective motion of an intense beam focused by periodic linear forces. Unlike conventional beam-dynamics experiments relying on large-scale transport channels and accelerators, it is straightforward in S-POD to control the functional form of quadrupole beam focusing over a wide range of variation to explore a variety of quadrupole focusing lattices. We systematically measure the loss rate of trapped particles as a function of bare betatron tune to locate resonance bands in which the plasma becomes unstable. It is confirmed that a few bands of coherent resonances appear depending on the beam intensity. When there is an imbalance between the horizontal and vertical focusing, those instability bands split. Experimental results indicate that the instability band is relatively insensitive to the phase of quadrupole focusing element placement within the doublet configuration over a significant range of parameters. Experimental observations are compared with transverse slice particle-in-cell simulations carried out using the Warp code.

  19. Fourier transform zero field NMR and NQR

    SciTech Connect

    Zax, D.B.

    1985-01-01

    In many systems the chemical shifts measured by traditional high resolution solid state NMR methods are insufficiently sensitive, or the information contained in the dipole-dipole couplings is more important. In these cases, Fourier transform zero field magnetic resonance may make an important contribution. Zero field NMR and NQR is the subject of this thesis. Chapter I presents the quantum mechanical background and notational formalism for what follows. Chapter II gives a brief review of high resolution magnetic resonance methods, with particular emphasis on techniques applicable to dipole-dipole and quadrupolar couplings. Level crossings between spin-1/2 and quadrupolar spins during demagnetization transfer polarization from high to low lambda nuclei. This is the basis of very high sensitivity zero field NQR measurements by field cycling. Chapter III provides a formal presentation of the high resolution Fourier transform zero field NMR method. Theoretical signal functions are calculated for common spin systems, and examples of typical spectra are presented. Chapters IV and V review the experimental progress in zero field NMR of dipole-dipole coupled spin-1/2 nuclei and for quadrupolar spin systems. Variations of the simple experiment describe in earlier chapters that use pulsed dc fields are presented in Chapter VI.

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

    NASA Technical Reports Server (NTRS)

    Borsa, F.; Rigamonti, A.

    1991-01-01

    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.

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

    Microsoft Academic Search

    I. Usman; Z. Buthelezi; J. Carter; G. R. J. Cooper; R. W. Fearick; S. V. Förtsch; 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

    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

  2. Methods of spectral estimation in local nuclear quadrupole resonance with a dispersion

    Microsoft Academic Search

    V. S. Grechishkin; R. V. Grechishkina; A. A. Persichkin; A. A. Shpilevoi

    2002-01-01

    The spectral estimation in local nuclear quadrupole resonance at a high noise level is performed for the first time using\\u000a the modern techniques of linear prediction (LPSVD) and matrix pencil (ITMPM). The fast Fourier transform with signal accumulation\\u000a does not ensure the required sensitivity in the case of weak signals when the object and the receiver of the spectrometer\\u000a are

  3. Dipole and quadrupole surface plasmon resonances contributions in formation of near-field images of a gold nanosphere

    E-print Network

    Dipole and quadrupole surface plasmon resonances contributions in formation of near-field images surface proximity are studied. The multipolar plasmon size characteristic: plasmon resonance frequencies-field imaging, multipolar surface plasmon resonances, Mie theory, optical properties of noble metal nanospheres

  4. NMR and NQR study of the thermodynamically stable quasicrystals

    SciTech Connect

    Shastri, A.

    1995-02-10

    {sup 27}Al and {sup 61,65}Cu NMR measurements are reported for powder samples of stable AlCuFe and AlCuRu icosahedral quasicrystals and their crystalline approximants, and for a AlPdMn single grain quasicrystal. Furthermore, {sup 27}Al NQR spectra at 4.2 K have been observed in the AlCuFe and AlCuRu samples. From the quadrupole perturbed NMR spectra at different magnetic fields, and from the zero field NQR spectra, a wide distribution of local electric field gradient (EFG) tensor components and principal axis system orientations was found at the Al site. A model EFG calculation based on a 1/1 AlCuFe approximant was successful in explaining the observed NQR spectra. It is concluded that the average local gradient is largely determined by the p-electron wave function at the Al site, while the width of the distribution is due to the lattice contribution to the EFG. Comparison of {sup 63}Cu NMR with {sup 27}Al NMR shows that the EFG distribution at the two sites is similar, but that the electronic contribution to the EFG is considerably smaller at the Cu site, in agreement with a more s-type wave function of the conduction electrons.

  5. Cu nuclear magnetic resonance of aligned single crystals of YBaâCuâOâ. sqrt. \\/sub delta

    Microsoft Academic Search

    C. H. Pennington; D. J. Durand; D. B. Zax; C. P. Slichter; J. P. Rice; D. M. Ginsberg

    1988-01-01

    There are two types of Cu sites in YBaâCuâOâ..sqrt..\\/sub delta\\/, plane and chain. One gives a nuclear quadrupole resonance (NQR) at 22.0 MHz, the other at 31.5 MHz. Measurements of nuclear spin-lattice relaxation time in the superconducting state show that the 31.5-MHz site has a much larger energy gap (as though its T\\/sub c\\/ were 200 K), but different experimental

  6. Cu nuclear magnetic resonance of aligned single crystals of YBa2Cu3O7-delta

    Microsoft Academic Search

    C. H. Pennington; D. J. Durand; D. B. Zax; C. P. Slichter; J. P. Rice; D. M. Ginsberg

    1988-01-01

    There are two types of Cu sites in YBa2Cu3O7-delta, plane and chain. One gives a nuclear quadrupole resonance (NQR) at 22.0 MHz, the other at 31.5 MHz. Measurements of nuclear spin-lattice relaxation time in the superconducting state show that the 31.5-MHz site has a much larger energy gap (as though its Tc were 200 K), but different experimental workers have

  7. Multigap superconductivity in locally noncentrosymmetric SrPtAs: An 75As nuclear quadrupole resonance investigation

    NASA Astrophysics Data System (ADS)

    Brückner, F.; Sarkar, R.; Günther, M.; Kühne, H.; Luetkens, H.; Neupert, T.; Reyes, A. P.; Kuhns, P. L.; Biswas, P. K.; Stürzer, T.; Johrendt, D.; Klauss, H.-H.

    2014-12-01

    We report detailed 75As nuclear quadrupole resonance investigations of the locally noncentrosymmetric superconductor SrPtAs. The spin-lattice relaxation studies prove weakly coupled multigap superconductivity. A retardation of the decay in 1 /T1T evidences a nodeless (fully gapped) superconducting state on the complex multipocket Fermi surface, which is consistent with an anisotropic s -wave order parameter and with proposed unconventional f -wave and chiral d -wave symmetries. A quantitative analysis of these models favors the unconventional f -wave state.

  8. Crossed-coil detection of two-photon excited nuclear quadrupole resonance

    NASA Astrophysics Data System (ADS)

    Eles, Philip T.; Michal, Carl A.

    2005-08-01

    Applying a recently developed theoretical framework for determining two-photon excitation Hamiltonians using average Hamiltonian theory, we calculate the excitation produced by half-resonant irradiation of the pure quadrupole resonance of a spin-3/2 system. This formalism provides expressions for the single-quantum and double-quantum nutation frequencies as well as the Bloch-Siegert shift. The dependence of the excitation strength on RF field orientation and the appearance of the free-induction signal along an axis perpendicular to the excitation field provide an unmistakable signature of two-photon excitation. We demonstrate single- and double-quantum excitation in an axially symmetric system using 35Cl in a single crystal of potassium chlorate ( ?Q = 28 MHz) with crossed-coil detection. A rotation plot verifies the orientation dependence of the two-photon excitation, and double-quantum coherences are observed directly with the application of a static external magnetic field.

  9. Copper Nqr and NMR Study of Metal-Substituted Yttrium BARIUM(2) COPPER(3) OXYGEN(7) and Yttrium BARIUM(2) COPPER(4) OXYGEN(8)

    NASA Astrophysics Data System (ADS)

    Cheng, Show-Jye

    Pulsed nuclear quadrupole resonance (NQR) and nuclear magnetic resonance (NMR) have been used to investigate the effect of metal-substitution for copper in YBa_2Cu_3O_7 (YBCO123) and YBa_2Cu_4O_8 (YBCO124). Among many metal substitutions, Zn has an especially dramatic effect in suppressing the superconducting temperature T_{c}, and hence superconductivity. More interesting is that Zn and Fe have the same T_{c} suppression effect in YBCO124. This study focuses on the Zn substitutions in YBCO123 and Zn, Fe, and Co substitutions in YBCO124. In Zn doped YBCO123, Cu(2), plane site, NQR spectra and the frequency dependence of the spin-lattice relaxation rates have been measured over a temperature range from 77 K to 300 K to study the correlation of the suppression of the relaxation rate with the distance between the probe Cu nuclei and the impurity. It is found that the relaxation rate is insensitive to the variation of the NQR resonance frequency. However, by comparing the results of the Zn doped YBCO124 with those of YBCO123, it can be concluded that the suppression of the relaxation rate for both YBCO compounds in the normal state is caused by destruction of short-range antiferromagnetic correlation with substitution of nonmagnetic ion Zn on the Cu(2) sites. NQR and NMR measurements were carried out on both Cu(2), plane, and Cu(1), chain sites, for various concentrations of Zn, Fe, and Co dopants in YBCO124 over a temperature range from 77 K to 300 K. A strong correlation of the enhancement of Cu(2) spin lattice relaxation rate and suppression of superconductivity by impurities was found. The temperature dependence of the Cu(2) NMR linewidth exhibits a strong RKKY type exchange interaction below 225 K for Zn and Fe doped samples, which indicates the formation of the local magnetic moment. The enhancement of the relaxation rate is caused by the local magnetic moment Fe^ {+3} ion and the moments on Cu(2) neighbors when Zn^{+2} is substituted on Cu(2). This study gives us a clear picture of the spin pseudogap behavior in the high temperature superconductor cuprates. It also suggests that the magnetic moment on the CuO_2 plane may relate to the suppression of T_{c} in metal-substituted YBCO124.

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

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

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

  11. Isoscalar Giant Quadrupole Resonance State in the Relativistic Approach with the Momentum-Dependent Self-Energies

    E-print Network

    Tomoyuki Maruyama; Satoshi Chiba

    1999-09-16

    We study the excited energy of the isoscalar giant quadrupole resonance with the scaling method in the relativistic many-body framework. In this calculation we introduce the momentum-dependent parts of the Dirac self-energies arising from the one-pion exchange on the assumption of the pseudo-vector coupling with nucleon field. It is shown that this momentum-dependence enhances the Landau mass significantly and thus suppresses the quadrupole resonance energy even giving the small Dirac effective mass which causes a problem in the momentum-independent mean-field theory.

  12. NQR study of ternary chalcogenides A3BX3, ABX2, and ABX where A = Cu, Ag, or TI, B = As or Sb, and X = S or Se

    Microsoft Academic Search

    T. J. Bastow; H. J. Whitfield

    1981-01-01

    121Sb, 123Sb, 75As, 63Cu, and 65Cu NQR resonances are reported for CuSbSe2, Tl3SbSe3, Tl3SbS3, Tl3AsS3, Tl3AsSe3, Ag3AsSe3, TlSbS2, CuAsS, AgAsS, and Cu5SbS3I2. Tl3SbSe3 is an incongruently melting compound not observed in an earlier phase-diagram study of the pseudobinary system Tl2Se-Sb2Se3. For isostructural arsenic and antimony chalcogenides the ratio of 75As to 121Sb quadrupole coupling constants is 0.42, and for the

  13. Effects of spin vacancies on the correlated spin dynamics in La{sub 2}Cu{ital {sub 1{minus}x}}Zn{ital {sub x}}O{sub 4} from {sup 63}Cu nuclear quadrupole resonance relaxation

    SciTech Connect

    Carretta, P.; Rigamonti, A.; Sala, R. [Department of Physics A. Volta, Unita INFM and Sezione INFN, Via Bassi 6, I-27100 Pavia (Italy)] [Department of Physics A. Volta, Unita INFM and Sezione INFN, Via Bassi 6, I-27100 Pavia (Italy)

    1997-04-01

    {sup 63}Cu nuclear quadrupole resonance (NQR) relaxation measurements in La{sub 2}CuO{sub 4} doped Zn are used in order to investigate the temperature dependence of the in-plane magnetic correlation length {xi}{sub 2D} and the effects associated to spin vacancies in two dimensional quantum Heisenberg antiferromagnets (QHAF). The relaxation rates {ital T}{sub 1}{sup {minus}1} and {ital T}{sub 2}{sup {minus}1} have been related to the static generalized susceptibility {chi}({bold q},0) and to the decay rate {Gamma}{bold {sub q}} of the normal excitations. By using scaling arguments for {chi}({bold q},0) and {Gamma}{bold {sub q}}, the relaxation rates have been expressed in close form in terms of {xi}{sub 2D}{ital (x,T)} and its dependence on temperature and spin doping {ital x} thus extracted. The experimental findings are analyzed in light of the renormalized classical (RC) and quantum critical (QC) behaviors predicted for {xi}{sub 2D} by recent theories for {ital S}=1/2 HAF in square lattices. It is first shown that in pure La{sub 2}CuO{sub 4}, {xi}{sub 2D} is consistent with a RC regime up to about 900 K, with tendency toward the QC regime above. The spin vacancies reduce the N{acute e}el temperature according to the law {ital T{sub N}(x){approx}T{sub N}(0)(1{endash}3.5x)}. From the temperature dependence of {sup 63}Cu NQR relaxation rate {ital T}{sub 1}{sup {minus}1}, {ital T}{sub 2}{sup {minus}1} and from the composition dependence of {ital T{sub N}} it is consistently proved that the effect on {xi}{sub 2D} can be accounted for by the modification of the spin stiffness in a simple dilutionlike model, the system still remaining in the RC regime, at least for {ital T}{le}900 K. {copyright} {ital 1997 American Institute of Physics.}

  14. arXiv:physics/0302084v124Feb2003 Alignment-to-orientation conversion and nuclear quadrupole resonance

    E-print Network

    Budker, Dmitry

    arXiv:physics/0302084v124Feb2003 Alignment-to-orientation conversion and nuclear quadrupole resonance D. Budker,1, 2, D. F. Kimball,1, S. M. Rochester,1, and J. T. Urban3, § 1 Department of Physics, California 94720-1460 (Dated: February 24, 2003) The role of alignment-to-orientation conversion (AOC

  15. Vol.9, No. 5/May 1992/J. Opt. Soc. Am. B 779 Eu3+ optically detected nuclear quadrupole resonance in

    E-print Network

    Hansen, Peter

    in EuVO4 have been studied with the high-resolution techniques of spectral hole burning and optically to cw spectral hole burning and optically de- tected nuclear quadrupole resonance (ODNQR) using a single the electronic transi- tions and the hole-burning spectra, have been useful in establishing the directions

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

    E-print Network

    I. Usman; Z. Buthelezi; J. Carter; G. R. J. Cooper; R. W. Fearick; S. V. Förtsch; 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

    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.

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

    E-print Network

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

    2011-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Reske, Edward John

    1984-06-01

    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.

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

    Microsoft Academic Search

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

    2004-01-01

    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

  20. Cu nuclear magnetic resonance of aligned single crystals of YBa/sub 2/Cu/sub 3/O/sub 7/. sqrt. /sub delta/

    SciTech Connect

    Pennington, C.H.; Durand, D.J.; Zax, D.B.; Slichter, C.P.; Rice, J.P.; Ginsberg, D.M.

    1988-05-01

    There are two types of Cu sites in YBa/sub 2/Cu/sub 3/O/sub 7/..sqrt../sub delta/, plane and chain. One gives a nuclear quadrupole resonance (NQR) at 22.0 MHz, the other at 31.5 MHz. Measurements of nuclear spin-lattice relaxation time in the superconducting state show that the 31.5-MHz site has a much larger energy gap (as though its T/sub c/ were 200 K), but different experimental workers have differed as to whether this is the chain or plane site. We report nuclear magnetic resonance (NMR) studies at 81.1 kG and 100 K on oriented single crystals, and conclude from symmetry arguments that the 31.5-MHz NQR arises from the plane site.

  1. Magnetic field-cycling NMR and 14N, 17O quadrupole resonance in the explosive pentaerythritol tetranitrate (PETN)

    Microsoft Academic Search

    John A. S. Smith; Timothy J. Rayner; Michael D. Rowe; Jamie Barras; Neil F. Peirson; Andrew D. Stevens; Kaspar Althoefer

    2010-01-01

    The explosive pentaerythritol tetranitrate (PETN) C(CH2–O–NO2)4 has been studied by 1H NMR and 14N NQR. The 14N NQR frequency and spin–lattice relaxation time T1Q for the ?+ line have been measured at temperatures from 255 to 325K. The 1H NMR spin–lattice relaxation time T1 has been measured at frequencies from 1.8kHz to 40MHz and at temperatures from 250 to 390K.

  2. Magnetic field-cycling NMR and 14N, 17O quadrupole resonance in the explosive pentaerythritol tetranitrate (PETN)

    Microsoft Academic Search

    John A. S. Smith; Timothy J. Rayner; Michael D. Rowe; Jamie Barras; Neil F. Peirson; Andrew D. Stevens; Kaspar Althoefer

    2010-01-01

    The explosive pentaerythritol tetranitrate (PETN) C(CH2-O-NO2)4 has been studied by 1H NMR and 14N NQR. The 14N NQR frequency and spin-lattice relaxation time T1Q for the nu+ line have been measured at temperatures from 255 to 325 K. The 1H NMR spin-lattice relaxation time T1 has been measured at frequencies from 1.8 kHz to 40 MHz and at temperatures from

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

    NASA Technical Reports Server (NTRS)

    Borsa, F.; Rigamonti, A.

    1990-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Beguš, Samo; Jazbinšek, Vojko; Pirnat, Janez; Trontelj, Zvonko

    2014-10-01

    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.

  5. First Measurement of the Giant Monopole and Quadrupole Resonances in a Short-Lived Nucleus: {sup 56}Ni

    SciTech Connect

    Monrozeau, C.; Khan, E.; Blumenfeld, Y.; Beaumel, D.; Ebran, J. P.; Frascaria, N.; Gupta, D.; Marechal, F.; Scarpaci, J-A. [Institut de Physique Nucleaire IN2P3/CNRS, Universite Paris Sud, 91406 Orsay Cedex (France); Demonchy, C. E. [Department of Physics, Olivier Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Mittig, W.; Roussel-Chomaz, P.; Gelin, M. [GANIL, DSM/CEA, IN2P3/CNRS, BP 5027, 14076 Caen Cedex 5 (France); Caamano, M.; Cortina-Gil, D. [Universidad Santiago de Compostela, E-15706 Santiago de Compostela (Spain); Garg, U. [Physics Department, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Gillibert, A.; Keeley, N.; Obertelli, A. [CEA/DSM/DAPNIA/SPhN, Saclay, 91191 Gif-sur-Yvette Cedex (France)

    2008-02-01

    The isoscalar giant monopole resonance (GMR) and giant quadrupole resonance (GQR) have been measured in the {sup 56}Ni unstable nucleus by inducing the {sup 56}Ni(d,d{sup '}) reaction at 50A MeV in the Maya active target at the GANIL facility. The GMR and GQR centroids are measured at 19.3{+-}0.5 MeV and 16.2{+-}0.5 MeV, respectively. The corresponding angular distributions are extracted from 3 deg. to 7 deg. A multipole decomposition analysis using distorted wave Born approximation with random phase approximation transition densities shows that both the GMR and the GQR exhaust a large fraction of the energy-weighted sum rule. The demonstration of this new method opens a broad range of giant resonance studies at intermediate-energy radioactive beam facilities.

  6. 35-Cl nuclear quadrupole resonance spectra in diazepam and its 1:1 complex with chloral hydrate

    NASA Astrophysics Data System (ADS)

    Brisson, Colette; Durand, Marcel; Jugie, Gérard; Pasdeloup, Maurice

    1980-11-01

    The 35-Cl NQR spectra of diazepam and some of its related compounds are reported; they yield information about the hydrogen bonded complex that diazepam forms with chloral hydrate. The results reflect large changes in electron distribution at the CCl 3 group while the diazepam chlorine at the 7 position remains almost unaffected.

  7. Quadrupole parameters of 11B in crystalline CaO.B2O3.

    PubMed

    Mao, D; Bray, P J

    1992-12-01

    The quadrupole coupling constant (Qcc) and asymmetry parameter (eta) of 11B in crystalline CaO.B2O3 have been measured employing three different NQR and NMR methods: (1) 11B and 10B NQR; (2) 11B NQR and NMR; and (3) the 11B Zeeman NQR powder pattern. It is found that Qcc = 2594.3 +/- 0.5 kHz and eta = 0.515 +/- 0.001 at 77 K, and Qcc = 2573.5 +/- 0.5 kHz and eta = 0.511 +/- 0.002 at 300 K. These values are in agreement with, but far more accurate than, values obtained from a fourth procedure: measurement of the second-order quadrupolar effects evident in the m = + 1/2<-->m = - 1/2 transition of the 11B NMR spectrum. PMID:1365740

  8. 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)

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

    2009-07-01

    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.

  9. Zero field NMR and NQR

    SciTech Connect

    Zax, D.B.; Bielecki, A.; Zilm, K.W.; Pines, A.; Weitekamp, D.P.

    1985-11-15

    Methods are described and demonstrated for detecting the coherent evolution of nuclear spin observables in zero magnetic field with the full sensitivity of high field NMR. The principle motivation is to provide a means of obtaining solid state spectra of the magnetic dipole and electric quadrupole interactions of disordered systems without the line broadening associated with random orientation with respect to the applied magnetic field. Comparison is made to previous frequency domain and high field methods. A general density operator formalism is given for the experiments where the evolution period is initiated by a sudden switching to zero field and is terminated by a sudden restoration of the field. Analytical expressions for the signals are given for a variety of simple dipolar and quadrupolar systems and numerical simulations are reported for up to six coupled spin-1/2 nuclei. Experimental results are reported or reviewed for /sup 1/H, /sup 2/D, /sup 7/Li, /sup 13/C, and /sup 27/Al nuclei in a variety of polycrystalline materials. The effects of molecular motion and bodily sample rotation are described. Various extensions of the method are discussed, including demagnetized initial conditions and correlation by two-dimensional Fourier transformation of zero field spectra with themselves or with high field spectra.

  10. Crystallization and preliminary analysis of the NqrA and NqrC subunits of the Na+-translocating NADH:ubiquinone oxidoreductase from Vibrio cholerae.

    PubMed

    Vohl, Georg; Nedielkov, Ruslan; Claussen, Björn; Casutt, Marco S; Vorburger, Thomas; Diederichs, Kay; Möller, Heiko M; Steuber, Julia; Fritz, Günter

    2014-07-01

    The Na+-translocating NADH:ubiquinone oxidoreductase (Na+-NQR) from Vibrio cholerae is a membrane protein complex consisting of six different subunits NqrA-NqrF. The major domains of the NqrA and NqrC subunits were heterologously expressed in Escherichia coli and crystallized. The structure of NqrA1-377 was solved in space groups C222? and P2? by SAD phasing and molecular replacement at 1.9 and 2.1?Å resolution, respectively. NqrC devoid of the transmembrane helix was co-expressed with ApbE to insert the flavin mononucleotide group covalently attached to Thr225. The structure was determined by molecular replacement using apo-NqrC of Parabacteroides distasonis as search model at 1.8?Å resolution. PMID:25005105

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

    SciTech Connect

    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

    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.

  12. Extension of the level mixing resonance (LMR) method to study the alignment and the quadrupole moment of light exotic projectile fragments

    Microsoft Academic Search

    G. Neyens; R. Nouwen; R. Coussement

    1994-01-01

    The level mixing resonance (LMR) method has proven to be a very powerful method to measure the quadrupole interaction frequency of long-lived low-spin nuclear states which decay through gamma-radiation [R. Coussement et al., Hyperfine Interactions 23 (1985) 273, G. Scheveneels et al., ibid., 52 (1989) 257, 179]. In this paper the concept of LMR has been extended for beta-decaying nuclei

  13. Construction of a hybrid quadrupole\\/fourier transform ion cyclotron resonance mass spectrometer for versatile MS\\/MS above 10 kDa

    Microsoft Academic Search

    Steven M. Patrie; Jay P. Charlebois; David Whipple; Neil L. Kelleher; Christopher L. Hendrickson; John P. Quinn; Alan G. Marshall; Biswarup Mukhopadhyay

    2004-01-01

    Technological advancements including an open-cylindrical Penning trap with capacitively coupled ICR cell, selective ion accumulation\\u000a with a resolving quadrupole, and a voltage gradient used during ion extraction from an octopole ion trap, have individually\\u000a improved dynamic range and sensitivity in Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Documented\\u000a here is a new instrument utilizing these technologies toward the

  14. Experimental and theoretical investigations of the nuclear quadrupole resonance of 127I in orthoperiodic acid, H 5IO 6

    NASA Astrophysics Data System (ADS)

    Ramaprabhu, S.; Rama Rao, K. V. S.; Weiss, Alarich

    1983-12-01

    Pure nuclear quadrupole resonance of 127I in H 5IO 6 has been reported to occur at 44.976 MHz (m = ± {3}/{2}?m = ± {1}/{2} transition) and 83.960 MHz (m = ± {5}/{2}? m = ± {3}/{2} transition) at 296 K (ref. 1). Using an externally quenched frequency modulated super regenerative spectrometer Zeeman studies have been performed at 296 K on single crystals of H 5IO 6 growm from aqueous solution by observation of the ± {sol3}/{2}?± {1}/{2} transition. The zero-splitting locus method has been employed for the determination of the EFG parameters. The data show that there are two physically inequivalent sites, having average asymmetry parameters, ?, of 0.25, located in the unit cell. The maximum field gradient is found to lie along the short bond I-O(2) as suggested by Rama Rao and Weiss (ref. 1). The EFG parameters obtained by detailed molecular orbital calculations (CNDO/2 and INDO method) are compared with the experimental results.

  15. Zero-field NMR and NQR spectrometer

    SciTech Connect

    Bielecki, A.; Zax, D.B.; Zilm, K.W.; Pines, A.

    1986-03-01

    In comparison to high-field NMR, zero-field techniques offer advantages in terms of spectral interpretability in studies of polycrystalline or amorphous solids. This article describes a technique and apparatus for time-domain measurements of nuclear magnetism in the absence of applied fields (Fourier transform zero-field NMR and NQR). Magnetic field cycling and high field detection are employed to enhance sensitivity. The field cycling is accomplished with an air-driven shuttle system which moves the sample between regions of high and low magnetic field, in combination with switchable electromagnets in the low-field region. Sudden field steps or pulses are used to initiate coherent nuclear spin evolution in zero field and to monitor such evolution as a function of time. Experimental results are shown and analyzed. Possible variations on the basic method are described and their relative advantages are discussed.

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

    SciTech Connect

    Ziegeweid, M.A.

    1995-11-29

    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.

  17. 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

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

    1990-01-01

    , 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... (Contract No. DE-FG05- 86ER40256), and the Robert A. Welch Foundation. 2.54 MeV when compared with that in ' Ni, or the FWHM should be greater by 2.8 MeV (or some combina- tion of the two effects). The values of Co we obtain from GQR parameters for "Ni...

  18. Optically detected chlorine quadrupole resonance investigation of the symmetry of the excited triplet state of tetrachlorobenzene and tetrachloropyrazine in single crystals of durene

    NASA Astrophysics Data System (ADS)

    von Borczyskowski, C.; Fallmer, E.

    1983-12-01

    Optically detected nuclear quadrupole resonance (ODNQR) transitions are reported for tetrachloropyrazine (TCP) and tetrachlorobenzene (TCB) in single crystals of durene in zero and external magnetic fields. The analysis of the fine structure results in D = 4.192 GHz and E = 0.591 GHz (TCP) compared to D = 4.555 GHz and E = 0.872 GHz (TCB). For the ??* triplet state of TCP a rotation of in-plane spin axes by 12° relative to the ground-state symmetry axes is observed.

  19. 35Cl NQR of 1,5,2-Diazaphosphorine Derivatives

    NASA Astrophysics Data System (ADS)

    Dolgushin, G. V.; Nikitin, P. A.; Sapozhnikov, Yu. E.; Dmitrichenko, M. Yu.; Rozinov, V. G.; Voronkov, M. G.

    1994-02-01

    NQR frequencies and asymmetry parameters (?) of 35Cl chlorine-containing 1,5,2-diazaphosphorine derivatives are reported and discussed. NMDO calculations with total optimization of geometry have been carried out. The ?cal and ?cal values, calculated by means of the Townes and Dailey theory, correlate well with the experimenal data.

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

    NASA Astrophysics Data System (ADS)

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

    2003-02-01

    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.

  1. Application of Nuclear Quadrupole Resonance Relaxometry to Study the Influence of the Environment on the Surface of the Crystallites of Powder

    NASA Astrophysics Data System (ADS)

    Sinyavsky, Nikolay Ya.; Mershiev, Ivan G.; Kupriyanova, Galina S.

    2015-06-01

    The results of the experimental study of the influence of the environment surrounding the surface of the crystallites of a KClO3 powder on the distribution of the spin-spin and spin-lattice relaxation times for 35Cl nuclear quadrupole resonance are described. It was found that the distributions of the spin-lattice relaxation times are unimodal and distributions of the spin-spin relaxation times are bimodal for all samples we studied. T1 - T2 and T1? - T2 correlations by means of the two-dimensional (2D) inverse Laplace transform are obtained. The efficiency of the method for the study of surface phenomena in solids is demonstrated.

  2. NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts

    SciTech Connect

    Not Available

    1991-12-17

    The primary objective of the project is to examine the relations between the catalytic and magnetic properties of the copper-cobalt higher alcohol synthesis catalysts. We have undertaken to investigate the magnetic character by studying the Nuclear Quadrupole resonance of copper and (Zerofield) Nuclear Magnetic Resonance of cobalt in copper cobalt catalysts.

  3. NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts

    SciTech Connect

    Not Available

    1991-07-15

    The primary objective of the project is to examine the relations between the catalytic and magnetic properties of the copper-cobalt higher alcohol synthesis catalysts. We have undertaken to investigate the magnetic character by studying the Nuclear Quadrupole resonance of copper and (Zerofield) Nuclear Magnetic Resonance of cobalt in copper cobalt catalysts.

  4. Nuclear magnetic resonance with dc SQUID (Super-conducting QUantum Interference Device) preamplifiers

    SciTech Connect

    Fan, N.Q.; Heaney, M.B.; Clark, J.; Newitt, D.; Wald, L.; Hahn, E.L.; Bierlecki, A.; Pines, A.

    1988-08-01

    Sensitive radio-frequency (rf) amplifiers based on dc Superconducting QUantum Interface Devices (SQUIDS) are available for frequencies up to 200 MHz. At 4.2 K, the gain and noise temperature of a typical tuned amplifier are 18.6 +- 0.5 dB and 1.7 +- 0.5 K at 93 MHz. These amplifiers are being applied to a series of novel experiments on nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR). The high sensitivity of these amplifiers was demonstrated in the observation of ''nuclear spin noise'', the emission of photons by /sup 35/Cl nuclei in a state of zero polarization. In the more conventional experiments in which one applies a large rf pulse to the spins, a Q-spoiler, consisting of a series array of Josephson junctions, is used to reduce the Q of the input circuit to a very low value during the pulse. The Q-spoiler enables the circuit to recover quickly after the pulse, and has been used in an NQR experiment to achieve a sensitivity of about 2 /times/ 10/sup 16/ nuclear Bohr magnetons in a single free precession signal with a bandwidth of 10 kHz. In a third experiment, a sample containing /sup 35/Cl nuclei was placed in a capacitor and the signal detected electrically using a tuned SQUID amplifier and Q-spoiler. In this way, the electrical polarization induced by the precessing Cl nuclear quadrupole moments was detected: this is the inverse of the Stark effect in NQR. Two experiments involving NMR have been carried out. In the first, the 30 MHz resonance in /sup 119/Sn nuclei is detected with a tuned amplifier and Q-spoiler, and a single pulse resolution of 10/sup 18/ nuclear Bohr magnetons in a bandwidth of 25 kHz has been achieved. For the second, a low frequency NMR system has been developed that uses an untuned input circuit coupled to the SQUID. The resonance in /sup 195/Pt nuclei has been observed at 55 kHz in a field of 60 gauss. 23 refs., 11 figs.

  5. A general numerical analysis of time-domain NQR experiments

    Microsoft Academic Search

    Elad Harel; Herman M. Cho

    2006-01-01

    We introduce a general numerical approach for solving the Liouville equation of an isolated quadrupolar nuclide that can be used to analyze the unitary dynamics of time-domain NQR experiments. A numerical treatment is necessitated by the dimensionality of the Liouville space, which precludes analytical, closed form solutions for I>3\\/2. Accurate simulations of experimental nutation curves, forbidden transition intensities, powder and

  6. NQR 127I Spectroscopy of Layered Inorganic Compounds Intercalated with Aromatic Amines

    NASA Astrophysics Data System (ADS)

    Babushkina, T. A.; Seryukova, I. V.

    1998-07-01

    NQR spectroscopy was used to study the intercalating influence on the iodine electric field gradient of lead(ll) and cadmium(ll) iodides. We used pyridine, piperidine, aniline and quinoline, as guest substances. In the intercalates the NQR frequencies and their dependence on temperature in different crystalline phases were studied. The peculiarities of chemical bonds and crystal structures were discussed.

  7. Excitation of half-integer resonances by random quadrupole field errors in the BETA-BEAM RCS

    E-print Network

    Lachaize, A

    The Rapid Cycling Synchrotron of the Beta-Beam facility has been designed to operatewith horizontal and vertical tunes between 6 and 7 in order to avoid systematicresonances up to the fourth order. Nevertheless, unavoidable magnet imperfections mayexcite non systematic second order resonances which may pertub particle motion.In this paper an Hamiltonian treatment based on a well established formalism [1-3] is used to analyze the resonance excitation and to suggest correction schemes minimizing their effects.[1] A. Schoch. Theory of linear and non linear perturbations of betatron oscillations inalternating gradient synchrotrons. CERN 52-21, 1958.[2] G. Guignard. A general treatment of resonances in accelerators. CERN 78-11, 1978.[3] J-L. Laclare, G. Leleux, and A. Tkatchenko. Resonnances quadrupolaires- aleatoiresquadrupolaires et corrections. DSS-GERS- 74-91/TP-06, 1974.

  8. Quadrupole-Induced Resonant-Particle Transport in a Pure Electron Plasma E. P. Gilson* and J. Fajans

    E-print Network

    Gilson, Erik

    study of resonant particle transport in Malmberg-Penning traps [1­5] and in tandem mirror machines [6­10]. This work, however, was motivated by the cold, trapped antihydrogen ( HH) generation teams, ATHENA [11T L=vz 0:7 s and the E B plasma rotation frequency about the trap axis (caused by the plasma's self

  9. Dipole and quadrupole surface plasmon resonance contributions in formation of near-field images of a gold nanosphere

    Microsoft Academic Search

    M. Shopa; K. Kolwas; A. Derkachova; G. Derkachov

    2010-01-01

    Multipolar plasmon optical excitations at spherical gold nanoparticles and their manifestations in the particle images formatted\\u000a in the particle surface proximity are studied. The multipolar plasmon size characteristic: plasmon resonance frequencies and\\u000a plasmon damping rates were obtained within rigorous size dependent modelling. The realistic, frequency dependent dielectric\\u000a function of a metal was used. The distribution of light intensity and of

  10. NMR and NQR study of the electronic and structural properties of Al-Cu-Fe and Al-Cu-Ru quasicrystals

    SciTech Connect

    Shastri, A.; Borsa, F.; Torgeson, D.R.; Shield, J.E.; Goldman, A.I. (Ames Laboratory, U.S. Department of Energy and Department of Physics Astronomy, Iowa State University, Ames, Iowa 50011 (United States))

    1994-12-01

    [sup 27]Al and [sup 63,65]Cu NMR is reported for powdered stable Al-Cu-Fe and Al-Cu-Ru icosahedral quasicrystals and crystalline approximants, and for an Al-Pd-Mn single-grain quasicrystal. [sup 27]Al NQR spectra at 4.2 K were observed in Al-Cu-Fe and Al-Cu-Ru samples. From quadrupole-perturbed NMR spectra at different magnetic fields, and from zero-field NQR spectra, a wide distribution of local electric-field gradient (EFG) tensor components and principal-axis-system orientations was found at the Al site. A model EFG calculation based on a 1/1 Al-Cu-Fe approximant successfully explained the observed NQR spectra. The average local gradient is largely determined by the [ital p]-electron wave function at the Al site, while the width of the distribution is due to EFG lattice contribution. Comparison of [sup 63]Cu and [sup 27]Al NMR shows the EFG distribution at the two sites is similar, but the electronic contribution to the EFG is considerably smaller at the Cu site, in agreement with a more [ital s]-type wave function of the conduction electrons. Overall spread of EFG values is well reproduced by calculation based on the approximant. However, the experimental spectra indicate a much larger number of nonequivalent sites when compared with the simulated NQR spectra based on the 1/1 approximant. The short-range, local chemical order is well represented by the approximant, but differences in coordination must be included at intermediate range in the quasicrystal. Measured [sup 27]Al Knight shift, magnetic susceptibility, and nuclear spin-lattice relaxation time as a function of temperature indicate reduced density of states at the Fermi level by a factor of 7 or 8 from the value in Al metal, consistent with the notion of a pseudogap for these quasicrystals. No differences in measured parameters were detected as a function of composition of the quasicrystalline alloys.

  11. Temperature and baric dependence of nuclear quadruple resonance spectra in indium and gallium monoselenides

    NASA Astrophysics Data System (ADS)

    Khandozhko, Victor; Raranskii, Nikolai; Balazjuk, Vitaly; Samila, Andriy; Kovalyuk, Zahar

    2013-12-01

    Pulsed radiospectroscopy method has been used to study nuclear quadruple resonance (NQR) spectra of 69Ga and 115In isotopes in the layered semiconductors GaSe and InSe. It has been found that in GaSe and InSe there is a considerable temperature dependence of NQR frequency which in the temperature range of 250 to 390 K is practically linear with conversion slope 1.54 kHz/degree for 69Ga and 2.35 kHz/degree for 115In. In the same crystals the effect of uniaxial pressure on NQR spectra applied along the optical axis ? up to the values of 500 kg/?m2 has been studied. A strong attenuation of NQR spectra intensity with increase in pressure on layered crystal package has been established. The unvaried multiplicity of resonance spectra indicates the absence of structural transformations in these layered crystals over the investigated range of temperatures and pressures.

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

    PubMed Central

    Casutt, Marco S.; Huber, Tamara; Brunisholz, René; Tao, Minli; Fritz, Günter; Steuber, Julia

    2010-01-01

    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

  13. Zero field NMR and NQR with selective pulses and indirect detection

    SciTech Connect

    Millar, J.M.; Thayer, A.M.; Bielecki, A.; Zax, D.B.; Pines, A.

    1985-08-01

    Zero field NMR and NQR spectra are obtained by the application of dc magnetic field pulses to a demagnetized sample. Pulsed dc fields allow for selective excitation of isotopic species and provide a means for coherent manipulation of the spin system in zero field. Using these selective pulses and level crossing techniques, indirect detection of a quadrupolar nucleus may be accomplished via protons without obtaining the proton background signal in the NQR spectrum. Experimental results from a variety of /sup 1/H, /sup 2/H, and /sup 14/N homo- and heteronuclear systems are presented as an illustration of these techniques.

  14. Very high gradient quadrupoles

    Microsoft Academic Search

    J. Strait

    2001-01-01

    High gradient superconducting quadrupoles are an essential component of high energy hadron colliders, both in the arcs and in the insertions. The highest performance quadrupoles today are those for the Large Hadron Collider (LHC) at CERN. These 56 to 70 mm aperture magnets, developed in Europe, the United States, and Japan, reach gradients on the order of 250 T\\/m, which

  15. Multipulse sequences for explosives detection by NQR under conditions of magnetoacoustic and piezoelectric ringing

    Microsoft Academic Search

    V. T. Mikhaltsevitch; T. N. Rudakov; J. H. Flexman; P. A. Hayes; W. P. Chisholm

    2004-01-01

    A number of methods for cancelling magnetoacoustic and piezoelectric ringing signals in the spectroscopy of the nuclear quadrupole\\u000a resonance are presented. The suggested methods include using the sequence (?0)?-(?-?x-2?-?\\u000a y\\u000a -2?-??x\\u000a -2?-??y\\u000a -?)\\u000a n\\u000a and a multipulse analog of the two-pulse Hahn sequence with the first pulse replaced by a short steady-state sequence. Another\\u000a method presented is the method of

  16. Spin dynamics in CuO and Cu[sub 1[minus][ital x

    SciTech Connect

    Carretta, P.; Corti, M.; Rigamonti, A. (Department of Physics Alessandro Volta,'' University of Pavia, Via Bassi 6, 27100 Pavia (Italy))

    1993-08-01

    [sup 63]Cu nuclear quadrupole resonance (NQR), nuclear antiferromagnetic resonance (AFNMR), and spin-lattice relaxation, as well as [sup 7]Li NMR and relaxation measurements in CuO and in Cu[sub 1[minus][ital x

  17. NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts

    SciTech Connect

    Not Available

    1991-01-14

    Copper and cobalt are the key elements in syngas conversion catalyst systems used for higher alcohol synthesis. Their proximity and synergy sensitively control the selectivity and efficiency of the process. It is believed that their outer electronic charge distribution which is responsible for their electrical and magnetic properties might be governing their catalytic properties also. To examine the correlation between catalytic and magnetic properties, a series of copper cobalt catalysts (Co/Cu ratio 5:1 to 5:5) with and without a support were prepared. The nuclear quadrupole resonance spectrum of copper and (zero-field) nuclear magnetic resonance spectrum of cobalt and magnetization and hysteresis character of the catalyst were analyzed. Similar to the catalytic results, the magnetic results also were found to be very sensitive to the preparation technique. The results indicate possible electron exchange between copper and cobalt, and cobalt and the support Titania.

  18. Super hybrid quadrupoles

    NASA Astrophysics Data System (ADS)

    Tosin, Giancarlo; Palma Sanchez, Priscila; Citadini, James Francisco; Castro Vergasta, Camila

    2012-05-01

    A new model of quadrupole composed of permanent magnetic material, coils and soft magnetic material is proposed for the new Brazilian Synchrotron Light Source (Sirius). These quadrupoles must have flexibility about 30% of the total gradient in order to correct the linear effects caused by the insertion devices on the beam dynamics. This flexibility is obtained using coils while permanent magnets are used to supply the constant gradient.

  19. NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts. Quarterly technical progress report, June 15--September 15, 1991

    SciTech Connect

    Not Available

    1991-12-17

    The primary objective of the project is to examine the relations between the catalytic and magnetic properties of the copper-cobalt higher alcohol synthesis catalysts. We have undertaken to investigate the magnetic character by studying the Nuclear Quadrupole resonance of copper and (Zerofield) Nuclear Magnetic Resonance of cobalt in copper cobalt catalysts.

  20. NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts. Quarterly technical progress report, March 15--June 15, 1991

    SciTech Connect

    Not Available

    1991-07-15

    The primary objective of the project is to examine the relations between the catalytic and magnetic properties of the copper-cobalt higher alcohol synthesis catalysts. We have undertaken to investigate the magnetic character by studying the Nuclear Quadrupole resonance of copper and (Zerofield) Nuclear Magnetic Resonance of cobalt in copper cobalt catalysts.

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

    PubMed

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

    2014-02-01

    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

  2. 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)

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

    2014-02-01

    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.

  3. 35Cl NQR Spectra of several 2,2-bis- p-chlorophenyl chloroethane derivatives

    NASA Astrophysics Data System (ADS)

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

    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.

  4. High gradient superconducting quadrupoles

    SciTech Connect

    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

    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.

  5. 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

    Stevens, A; Paschalis, P; Schleich, T

    1992-01-01

    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

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed

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

    2014-01-01

    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

  8. Stabilized radio frequency quadrupole

    DOEpatents

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

    1984-01-01

    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.

  9. Stabilized radio frequency quadrupole

    DOEpatents

    Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

    1984-12-25

    Disclosed is 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. 5 figs.

  10. Co-NQR Study on Successive Magnetic Phase under Pressure in Non-centrosymmetric CeCoGe3

    NASA Astrophysics Data System (ADS)

    Inagaki, T.; Matsumura, M.; Mizoo, M.; Kawamura, Y.; Kato, H.; Nishioka, T.

    2012-12-01

    We have performed Co-NQR study to clarify the complex magnetic phases in approaching to the quantum critical point (QCP). The successive transitions at TN2=12 K and TN3=8 K after the ferrimagnetic-like order at TN1=21 K in ambient pressure are confirmed by the spectral changes of Co-NQR However no critical slowing down of the nuclear spin-lattice relaxation rate 1/T1 or the nuclear spin-spin relaxation rate 1/T2 at TN2 and TN3 was observed, suggesting 1st order transitions. In applying pressure, a large spectral change of Co-NQR occurs in relatively low pressure of 0.3 Gpa. The Co-NQR spectrum becomes simple above about 0.7 GPa, consisting of the two Co sites with spectral weight ratio of 2. No successive transitions were observed in 1.5 GPa, indicating that the successive transitions are confined to relatively low pressure region. The extremely slower decrease of the sublattice magnetization than that expected in the mean field approximation is seen in 1.5 GPa.

  11. Low Frequency NQR using Double Contact Cross-relaxation

    NASA Astrophysics Data System (ADS)

    Stephenson, David; Smith, John A. S.

    2000-02-01

    A cross-relaxation technique is described which involves two spin contacts per double reso-nance cycle. The result is an improvement in signal to noise ratio particularly at low frequencies. Experimental spectra and analyses are presented: 14N in ammonium sulphate showing that the tech-nique gives essentially the same information as previous studies; 14N in ammonium dichromate determining e2Qq/h as (76±3) kHz and ? = 0.84±.04; 7Li in lithium acetylacetonate for which the spectrum (corrected for Zeeman distortion) yields e2Qq/h = (152 ±5) kHz and ?=.5 ±.2. Calculated spectra are presented to demonstrate the ? dependence of the line shapes for 7Li.

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

    PubMed

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

    2015-01-20

    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

  13. Remote sensing by nuclear quadrupole resonance

    Microsoft Academic Search

    Allen N. Garroway; Michael L. Buess; Joel B. Miller; Bryan H. Suits; Andrew D. Hibbs; Geoffrey A. Barrall; Robert Matthews; Lowell J. Burnett

    2001-01-01

    Detection of explosives has the flavor of those mathematical problems that are not invertible. It is easier to hide explosives than to find them. Many approaches have been proposed and executed for the remote detection of explosives, contraband materials, weapons of mass destruction, currency, etc. Most detection technologies suffer from a common problem: the features they look for, such as

  14. Sodium and potassium salts of dichloroisocyanuric acid and their hydrates as antimicrobials agents studied by 35Cl-NQR spectroscopy and DFT calculations

    Microsoft Academic Search

    A. Walczak; B. Brycki; M. Kaczmarek; O. Kh. Poleshchuk; M. Ostafin; B. Nogaj

    2006-01-01

    The electronic structure of dichloroisocyanuric acid derivatives was analysed by 35Cl-NQR spectroscopy and DFT calculations. Here we concentrate our attention on three different factors: type of metallic substituent (sodium and potassium), temperature of the sample (liquid nitrogen and room) and degree of hydration (an amount of water molecules attached to analysed compounds). In particular, all the variations in 35Cl-NQR frequencies

  15. Nuclear Magnetic Resonance

    NASA Astrophysics Data System (ADS)

    Andrew, E. R.

    2009-06-01

    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.

  16. NQR and ? SR in Diluted Two-Dimensional S=1/2 Heisenberg Antiferromagnets

    NASA Astrophysics Data System (ADS)

    Carretta, P.; Rigamonti, A.; Todeschini, E.; Malavasi, L.

    2003-02-01

    139La NQR spectra and relaxation and ? SR precessional frequencies in La2Cu1-xMxO4 (for M = Zn and Mg) are reported in order to study the effect of spin dilution in the planar quantum Heisenberg antiferromagnet (2DQHAF) La2CuO4. The behavior of the spin stiffness ? s(x) and of the in-plane correlation length ? 2D(x,T), of the sublattice magnetization and of the Néel temperature, for a dilution approaching the percolation threshold depart sizeably from the ones expected in dilution-like models. In spite of the marked reduction of ? s the transition to the ordered state occurs at a temperature, where ? 2D(x,TN) reaches a value close to the one in undoped 2DQHAF.

  17. Implosion of quadrupole gravitational waves

    E-print Network

    W. B. Bonnor; M. S. Piper

    1996-10-10

    Einstein's vacuum equations are solved up to the second approximation for imploding quadrupole gravitational waves. The implosion generates a black hole singularity irrespective of the strength of the waves.

  18. Chemical phase separation in carbon doped YBa 2Cu 3O 6+ x: a 63,65Cu NQR study

    NASA Astrophysics Data System (ADS)

    Grévin, B.; Berthier, Y.; Monot, I.; Wang, J.; Weiss, F.

    1997-02-01

    We report on 63,65Cu NQR spectra and nuclear spin-lattice relaxation rate (1/ T1) measurements at 4.2 K in YBa 2Cu 3O 6+ x powder samples with carbon concentrations ranging from 500 to 3000 ppm. A new NQR line appears at 30.90 MHz ( 63Cu line), the intensity of which is strongly correlated with the amount of carbon in the sample. The measurement of the spin-lattice relaxation rate for Cu corresponding to the different lines measured shows different relaxation behaviors. Furthermore a drastic change is observed for T1 between the two samples. We discuss the implications of these findings in the framework of chemical phase separation and compare to previous carbon retention studies in YBa 2Cu 3O 6+ x by other techniques.

  19. Vibrational pseudo-diffusive motion of the oxygen octahedra in La{sub 2}CuO{sub 4} and Sr doped La{sub 2}CuO{sub 4} from anelastic and {sup 139}La NQR relaxation

    SciTech Connect

    Cordero, F. [CNR, Roma (Italy)] [CNR, Roma (Italy); Campana, A.; Corti, M.; Rigamonti, A. [Unita INFM, Pavia (Italy)] [Unita INFM, Pavia (Italy); Cantelli, R. [Univ. di Roma La Sapienza (Italy). Dipt. di Fisica] [Univ. di Roma La Sapienza (Italy). Dipt. di Fisica; Ferretti, M. [Univ. di Genova (Italy). Dipt. di Chimica e Chimica Industriale] [Univ. di Genova (Italy). Dipt. di Chimica e Chimica Industriale

    1999-04-20

    The vibrational dynamics in nearly stoichiometric La{sub 2}CuO{sub 4+{delta}} has been studied by means of anelastic relaxation and by {sup 139}La NQR relaxation. Evidence of dynamical tilting of the octahedra in a double well local potential is obtained with both the experimental techniques. Anelastic relaxation at the quadrupole frequency {nu}{sub Q} {approximately} 19 MHz occurs at T {approximately} 330 K. The data are analyzed in terms of a model of pseudo-diffusive cooperative motion. The measured effective barrier is 2800 K, higher than the one of the local potential because of the cooperative character of the motion. Upon Sr doping the {sup 139}La relaxation is still dominated by the octahedra tilting waves for T > 100 K, while at low temperatures the magnetic relaxation mechanism related to Cu{sup 2+} spin fluctuation dominates. It is argued how the freezing of the tilts (occurring below 100 K in the undoped La{sub 2}CuO{sub 4}) might correspond to the formation of static stripes.

  20. Resonance

    NSDL National Science Digital Library

    Kuphaldt, Tony R.

    All About Circuits is a website that â??provides a series of online textbooks covering electricity and electronics.â? 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).

  1. NQR study of local structures and cooling rate dependent superconductivity in La sub 2 CuO sub 4+. delta

    SciTech Connect

    Reyes, A.P.; Ahrens, E.T.; Hammel, P.C.; Heffner, R.H.; Thompson, J.D.; Canfield, P.C.; Fisk, Z. (Los Alamos National Lab., NM (United States)); Schirber, J.E. (Sandia National Labs., Albuquerque, NM (United States))

    1992-01-01

    Structural properties of oxygen-annealed polycrystals of La{sub 2}CuO{sub 4 + {delta}} ({delta}{approximately}0.03) have been studied using {sup 139}La NQR spectroscopy. Superconducting critical temperatures were found to depend on the rate of cooling through a narrow temperature range at about 195K. Preliminary analysis of the {sup 139}La NQR spectra suggest that the oxygen-rich phase-separated region is composed of two structurally distinct phases, both of which are metallic and super-conducting. One phase has a structure closely related to the stoichiometric oxygen-poor compound. The second shows a considerable amount of apical oxygen disorder, a large shift in NQR frequency {nu}{sub Q}, and a volume fraction which increases with cooling rate. The formation of the second phase below {minus}200K is indicative of the freezing Of CuO{sub 6} octahedral tilting. Abrupt shifts in {nu}{sub Q} above {Tc} were also observed for both phases, suggestive of a local structural anomaly or charge transfer to the Cu-O plane.

  2. Vibrational analysis of tevatron quadrupoles

    SciTech Connect

    Moore, C.D.

    1996-01-01

    There is motion of the beam in the Tevatron on various time scales from years (slow motion of the tunnel) to tenths of milliseconds (betatron tune motion). This paper will discuss a very restricted frequency range from a few Hertz to a few tens of Hertz. The assumption behind the analysis presented here is that the beam motion is due to transverse motion of Tevatron quadrupoles. The introduction of the low beta insertions in the Tevatron has necessitated the installation of remote monitoring sensors on the quadrupoles since the quadrupoles are strong and are located in regions where the beta functions are large. In general the magnet and support structures are mirror symmetric around the interaction points.

  3. Hybridized quadrupole-dipole exciton effects in a Cu2O -organic heterostructure

    Microsoft Academic Search

    Oleksiy Roslyak; Joseph L. Birman

    2007-01-01

    In the present work, we discuss resonant hybridization of the 1S quadrupole Wannier-Mott exciton (WE) in a Cu2O quantum well with the Frenkel dipole exciton in an adjacent layer of organic DCM2:CA:PA. The coupling between excitons is due to interaction between the gradient of electric field induced by the DCM2 Frenkel exciton (FE) and the quadrupole moment of the 1S

  4. Electromagnetic Design of Superconducting Quadrupoles

    E-print Network

    Todesco, E

    2006-01-01

    We study how the critical gradient depends on the coil lay-out in a superconducting quadrupole for particle accelerators. We show that the results relative to a simple sector coil are well representative of the coil lay-outs that have been used to build several quadrupoles in the past 30 years. Using a semi-analytical approach we derive a formula that gives that critical gradient as a function of the coil cross-sectional area, of the magnet aperture, and of the superconducting cable parameters. This formula is used to evaluate the efficiency of several types of coil lay-outs (shell, racetrack, block, open mid-plane).

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

    SciTech Connect

    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

    We have performed 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements on single-crystalline Ba1-xKxFe2As2 for x = 0.27–1. 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 spin–lattice 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.

  6. LCLS Undulator Quadrupole Fiducialization Plan

    SciTech Connect

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

    2010-11-24

    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.

  7. Quadrupole splitting in sodium ferrocyanide

    Microsoft Academic Search

    M. J. Evans; P. J. Black

    1970-01-01

    Mossbauer spectra from a single crystal of hydrated sodium ferrocyanide indicate a shift in line position with crystal orientation which is consistent with a quadrupole splitting of 0.56 gamma o. Voigt profile analysis of spectra from powders indicates a smaller broadening of the Lorentz component, 0.27 Gamma o; the inconsistency is explained by preferred orientation in the absorber samples.

  8. Image restoration using fast Fourier and wavelet transforms

    NASA Astrophysics Data System (ADS)

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

    1994-02-01

    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.

  9. Space charge induced nonlinear effects in quadrupole ion traps.

    PubMed

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

    2014-03-01

    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. PMID:24385397

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

    SciTech Connect

    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

    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%.

  11. Sign-Selected Quadrupole Train

    SciTech Connect

    Bernstein, R.; NuTeV Collaboration

    1994-05-03

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

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

    E-print Network

    Suter, Dieter

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

  13. Stabilized radio-frequency quadrupole

    DOEpatents

    Lancaster, H.D.; Fugitt, J.A.; Howard, D.R.

    1982-09-29

    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.

  14. Laced permanent magnet quadrupole drift tube magnets

    SciTech Connect

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

    1989-03-01

    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.

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

    E-print Network

    Jeter, Edward Hilton

    2013-02-22

    . . ACKNOWLEDGEMF2&S . . TABLE OF CONTENTS . . LIST OF FIGURES . CHAPTER I INTRODUCIION . . II MEDICAL IMAGING. . III MAGNETIC RESONANCE IMAGING. IV RELAXOMETRY WITH PREPOLARIZED MRI . V RELAXOMETRY OF PROTEIN SYSTEMS. . . VI QUADRUPOLE INTERACIIONS.... . . . . . . . I 4 . . . . . . . . 3 I . . . . . . . . 7 1 . . . . . . . . 72 . . . . . . . . 74 . . . . . . . . 74 . . . . . . . 75 CHAPTER I INTRODUCTION The focus of this research is to develop medical imaging techniques that are more speci6c and less...

  16. NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts. Quarterly technical progress report, September 14--December 15, 1990

    SciTech Connect

    Not Available

    1991-01-14

    Copper and cobalt are the key elements in syngas conversion catalyst systems used for higher alcohol synthesis. Their proximity and synergy sensitively control the selectivity and efficiency of the process. It is believed that their outer electronic charge distribution which is responsible for their electrical and magnetic properties might be governing their catalytic properties also. To examine the correlation between catalytic and magnetic properties, a series of copper cobalt catalysts (Co/Cu ratio 5:1 to 5:5) with and without a support were prepared. The nuclear quadrupole resonance spectrum of copper and (zero-field) nuclear magnetic resonance spectrum of cobalt and magnetization and hysteresis character of the catalyst were analyzed. Similar to the catalytic results, the magnetic results also were found to be very sensitive to the preparation technique. The results indicate possible electron exchange between copper and cobalt, and cobalt and the support Titania.

  17. Nuclear quadrupole moment of scandium

    SciTech Connect

    Bieron, J.; Grant, I.P. [Mathematical Institute, University of Oxford, 24-29 St. Giles, Oxford OX13LB (United Kingdom); Fischer, C.F. [Department of Computer Science, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    1997-07-01

    The multiconfiguration Dirac-Fock model is employed to evaluate the effects of relativity and electron correlation on the hyperfine interaction constants of the 3d{sup 2} {sup 3}F{sub 3}, {sup 3}F{sub 4}, {sup 1}G{sub 4}, and 3d4p {sup 3}F{sub 4} levels of ScII. The wave function expansions are obtained with the active space method, where configuration state functions of a specific parity and J value are generated by substitutions from the reference configurations to an active set of orbitals. The active set is then increased in a systematic way, allowing the convergence of the hyperfine interaction constants to be studied. The calculated electric quadrupole hyperfine constants, together with previously computed values for other levels of ScII, are used to evaluate the nuclear electric quadrupole moment of isotope 45 of scandium, for which the value Q={minus}0.231(4) b is found. {copyright} {ital 1997} {ital The American Physical Society}

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

    SciTech Connect

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

    1991-03-05

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

  19. Lighthill quadrupole radiation in supersonic propeller acoustics

    Microsoft Academic Search

    N. Peake; D. G. Crighton

    1991-01-01

    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

  20. Electrostatic quadrupoles for heavy-ion fusion

    SciTech Connect

    Seidl, P.; Faltens, A.

    1993-05-01

    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.

  1. Peculiarities of phases of the WMAP quadrupole

    E-print Network

    Pavel D. Naselsky; Oleg V. Verkhodanov

    2008-03-13

    We present the analysis on the quadrupole phases of the Internal Linear Combination map, ILC(I) and (III) derived by the WMAP team (1 and 3-year data release). This approach allows us to see the global trend of non-Gaussianity of the quadrupoles for the ILC(III) map through phase correlations with the foregrounds. Significant phase correlations is found in between the ILC(III) quadrupole and the WMAP foregrounds phases for K-W band: the phases of the ILC(III) quadrupole xi_{2,1}, xi_{2,2} and those of the foregrounds at K-W bands Phi_{2,1}, Phi_{2,2} display significant symmetry: xi_{2,1}+Phi_{2,1} ~= xi_{2,2}+Phi_{2,2}, which is a strong indication that the morphology of the ILC(III) quadrupole is mere reflection of that the foreground quadrupole through coupling. To clarify this issue we exploit the symmetry of the CMB power, which is invariant under permutation of the index m=12. By simple rotation of the ILC(III) phases with the same angle we reach the phases of foreground quadrupole. We discuss possible sources of phase correlation and come to the conclusion that the phases of the ILC(III) quadrupole reflect most likely systematic effects such as changing of the gain factor for the 3-year data release with respect to the 1-year, rather than manifestation of the primordial non-Gaussianity.

  2. Successive magnetic transition in non-centrosymmetric CeCoGe3 probed by Co-NQR

    NASA Astrophysics Data System (ADS)

    Matsumura, M.; Sato, Y.; Mizoo, M.; Kawamura, Y.; Kato, H.; Nishioka, T.

    2011-01-01

    Co-NQR measurements for non-centrosymmetric superconductor CeCoGe3 have been performed in ambient and under pressure up to 1.5 GPa to investigate the magnetic structures for the successive magnetic transition at TN1=21 K, TN2=12 K and TN3=8 K. In ambient pressure, the crystallographically equivalent one Co site becomes three sites at TN1 > T > TN2, and further becomes four sites at TN2 > T. Applying pressure at 4.2 K, the four Co sites becomes two sites above 0.3 Gpa. These Co sites acquire slightly different internal field parallel to the c-axis, consistent with the anisotropic magnetization with easy c-axis. The T-dependences of the internal fields and the spectral weights for respective sites are estimated. The magnetic structure in each phase is discussed referring to the recent results of neutron scattering.

  3. 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)

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

    2010-04-01

    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.

  4. Successive Phase Transitions and High Ionic Conductivity of Trichlorogermanate (II) Salts as Studied by 35C1 NQR and Powder X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Yamada, K.; Isobe, K.; Okuda, T.; Furukawa, Y.

    1994-02-01

    A series of trichlorogermanate(II) salts (AGeCl3, A = Rb, Cs, CH3N H3, and (CH3)4N) have been synthesized and characterized by 35Cl NQR , 35Cl NMR , AC conductivity, DTA, and X-ray diffraction techniques. In the temperature range studied two, two, five, and four phases were confirmed for the Rb, Cs, CH3NH3, and (CH3)4N salts, respectively. From the 35Cl NQR and structural data, isolated pyramidal GeCl3 anions were recognized in the low temperature phases. With increasing temperature the relaxation times of the 35Cl NQR decreased exponentially and the signals disappeared far below the melting point. This suggests that the reorientation of the anion about the pseudo three-fold axis is excited. With further increase in temperature, the ionic conductivity of CH3NH3GeCl3 and (CH3)4NGeCl3 increased drastically at the phase transitions to their cubic perovskite phases (CH3NH3GeCl3:?= 10-1 Sm-1 at 400 K, (CH3)4NGeCl3: ? = 5 x 10-2 Sm-1 at 420 K). The mobile ion was confirmed to be the chloride ion by means of 35Cl NMR and X-ray diffraction.

  5. Oxygen Content Dependence of 63Cu(1) NQR and Proton NMR in Hydrogen-Doped Antiferromagnetic YBa2Cu3O6+xHy

    NASA Astrophysics Data System (ADS)

    Niki, Haruo; Kano, Kikuhiro; Takase, Mitsuhiro; Majikina, Kensei; Yagasaki, Katsuma; Shinohara, Takeshi; Omori, Mamoru; Tomiyoshi, Shoichi; Akiba, Etsuo

    1998-07-01

    The oxygen content dependence of 63Cu NQR at the Cu(1) site and proton NMR have been measured in the antiferromagnetic phase of powdered samples of hydrogen-doped YBa2Cu3O6+xHy (0.07 NQR occur around 35 and 15 K, respectively. These enhancements increase with increasing oxygen concentration. The maximum values of T1-1 and T2-1 for the sample with x = 0.17 reach 200 sec-1 and more than 7 msec-1, respectively. The predominant source for the relaxation mechanism of 63Cu(l) NQR and the line broadening of 1H NMR are found to be the fluctuating magnetic field due to the staggered Cu2+ moments.

  6. Estimation of dipole-quadrupole dispersion energies.

    NASA Technical Reports Server (NTRS)

    Alvarez-Rizzatti, M.; Mason, E. A.

    1973-01-01

    The calculation of the dipole-quadrupole dispersion coefficient is discussed through a perturbation and a variation method. Accurate combination rules are obtained from both methods, one new and one already known. Further approximations permit computations in terms of accessible parameters. Values are calculated for the interactions of atomic pairs formed from hydrogen, alkali, and rare-gas atoms. A new relation giving the dipole-quadrupole coefficient in terms of the dipole-dipole coefficient and the dipole and quadrupole polarizabilities seems accurate, but needs further testing.

  7. Klystron having electrostatic quadrupole focusing arrangement

    DOEpatents

    Maschke, A.W.

    1983-08-30

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

  8. Klystron having electrostatic quadrupole focusing arrangement

    DOEpatents

    Maschke, Alfred W. (East Moriches, NY)

    1983-08-30

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

  9. Permanent magnet edge-field quadrupole

    DOEpatents

    Tatchyn, Roman O. (Mountain View, CA)

    1997-01-01

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

  10. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    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.

  11. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  12. Laced permanent magnet quadrupole drift tube magnets

    SciTech Connect

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

    1988-10-01

    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 an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and the vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs.

  13. Analysis of the performance of a phase alternated multiple pulse sequence in spin I = 7/2 zero-field NQR spectroscopy

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, A.

    Zero-field nuclear magnetic resonance spectroscopy of solids containing quadrupole nuclei usually results in broad spectral lines. This line-broadening is due mainly to the inhomogeneity of the electric field gradient (EFG) at the quadrupolar nuclear site. High resolution spectra of such solids can be obtained with the application of suitably designed multiple radiofrequency (RF) pulse sequences. The performance is reported for a periodic and cyclic phase alternated multiple RF pulse sequence (PAPS) in a spin I = 7/2 system in zero external magnetic field. Average Hamiltonian theory based on the Magnus expansion is used to solve the time-dependent Liouville-von Neumann equation of motion of the spin system under the effect of the PAPS sequence. Single transition operators are employed in the spin dynamics calculations. It is shown that the multiple pulse seqeuncearation pulse, suppresses the EFG inhomogeneity to a maximum extent when = 2 . [-- ] 2 , where is the prep1 2 2 N 1 2 1

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

    NASA Astrophysics Data System (ADS)

    Rao, S. V. L. S.; Jain, Piyush; Pande, Rajni; Roy, Shweta; Mathew, Jose V.; Kumar, Rajesh; Pande, Manjiri; Krishnagopal, S.; Gupta, S. K.; Singh, P.

    2014-04-01

    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+) beam, we tested it by accelerating both the proton (H+) and D+ beams. The RFQ was operated in pulsed mode and accelerated both H+ and D+ 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.

  15. Compressive mass analysis on quadrupole ion trap systems.

    PubMed

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

    2014-07-01

    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

  16. Dipole gravity waves from unbound quadrupoles

    E-print Network

    Franklin Felber

    2010-06-10

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

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

    E-print Network

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

    2014-01-01

    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 ...

  18. Levitated spinning graphene flakes in an electric quadrupole ion trap

    NASA Astrophysics Data System (ADS)

    Kane, B. E.

    2010-09-01

    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 inferred from modulation of light scattering off the rotating flake when an electric field resonant with the rotation rate is applied. Possible applications of these techniques will be presented, both to fundamental measurements of the mechanical and electronic properties of graphene and to new approaches to graphene crystal growth, modification, and manipulation.

  19. Microfluidic quadrupole and floating concentration gradient

    PubMed Central

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

    2014-01-01

    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

  20. T1? in Quadrupole-Perturbed NMR

    NASA Astrophysics Data System (ADS)

    Seliger, J.

    Spin-lattice relaxation time in the rotating frame, T1?, is calculated in quadrupole-perturbed NMR in the weak collision limit. It is assumed that the RF magnetic field excites only a single transition in the quadrupole-perturbed NMR spectrum. The results of the calculation show that T1?, associated with the central ( {1}/{2}?- {1}/{2}) transition in quadrupole-perturbed NMR of half-integer spin nuclei does not reflect the low-frequency fluctuations of the electric field-gradient tenser. On the other hand, the low-frequency fluctuations of the electric held-gradient tenser give the largest contribution to T1? when measured on the outer[± I?±( I-1)] satellite transitions.

  1. The large quadrupole of water molecules

    PubMed Central

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

    2011-01-01

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

  2. Magnetic Measurement Results of the LCLS Undulator Quadrupoles

    SciTech Connect

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

    2011-08-18

    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.

  3. Accelerator Magnets:. Dipole, Quadrupole and Sextupole

    NASA Astrophysics Data System (ADS)

    Hwang, C. S.

    2004-02-01

    The main characteristics of the magnet design and performance of lattice magnets including dipole, quadrupole, and sextupole magnets, will be presented. The design and construction constraints of the conventional, steel iron yoke, and the direct-current magnets are also discussed. The equations of the ideal pole shapes of the dipole, quadrupole, and sextupole, are used to design the magnets. Several two- or three-dimensional calculation codes are introduced to simulate the magnets. Moreover, a brief description of the injection magnets is also presented. Finally, field measurement and mapping methods are introduced and the results from field measurements by means of a Hall probe are discussed.

  4. SKEW QUADRUPOLE FOCUSING LATTICES AND APPLICATIONS.

    SciTech Connect

    PARKER,B.

    2001-06-18

    In this paper we revisit using skew quadrupole fields in place of traditional normal upright quadrupole fields to make beam focusing structures. We illustrate by example skew lattice decoupling, dispersion suppression and chromatic correction using the neutrino factory Study-II muon storage ring design. Ongoing BNL investigation of flat coil magnet structures that allow building a very compact muon storage ring arc and other flat coil configurations that might bring significant magnet cost reduction to a VLHC motivate our study of skew focusing.

  5. Space-charge effects with mass-selective axial ejection from a linear quadrupole ion trap.

    PubMed

    Qiao, Hui; Gao, Cong; Mao, Dunmin; Konenkov, Nikolai; Douglas, D J

    2011-12-15

    Methods to reduce mass shifts caused by space charge with mass-selective axial ejection from a linear quadrupole ion trap are investigated. For axial ejection, dipole excitation is applied to excite ions at q???0.85. The trapping radiofrequency (rf) voltage is scanned to bring ions of different m/z values into resonance for excitation. In the fringing field at the quadrupole exit, excited ions gain axial kinetic energy, overcoming the trapping potential, and are ejected from the trap. Space charge causes the frequencies of ion oscillation to decrease. Thus, greater rf voltages are required to bring ions into resonance for excitation and ejection, and the ions shift to higher apparent masses in a mass spectrum. At the same time, the peaks broaden, lowering resolution. The effects of injection q value, ejection q value, excitation amplitude, quadrupole dc voltages applied to the electrodes, applying an rf voltage to the exit lens, and scan speed, on mass shifts have been studied experimentally. Most experiments were done with only ions of protonated reserpine (m/z 609.3 and its isotopic peaks) in the trap. Some experiments were done with ions of protonated reserpine and ions of m/z 622 in the trap. In general, the mass shifts are reduced with higher ejection q values, higher excitation amplitudes, with quadrupole dc applied, and at higher scan speeds. The application of quadrupole dc appears to increase the ion cloud temperature, which lowers mass shifts. Thus, a proper choice of operating conditions can reduce, but not eliminate, mass shifts caused by space charge. PMID:22095499

  6. Hybridized quadrupole-dipole exciton effects in a Cu2O -organic heterostructure

    NASA Astrophysics Data System (ADS)

    Roslyak, Oleksiy; Birman, Joseph L.

    2007-06-01

    In the present work, we discuss resonant hybridization of the 1S quadrupole Wannier-Mott exciton (WE) in a Cu2O quantum well with the Frenkel dipole exciton in an adjacent layer of organic DCM2:CA:PA. The coupling between excitons is due to interaction between the gradient of electric field induced by the DCM2 Frenkel exciton (FE) and the quadrupole moment of the 1S transition in the cuprous oxide. The specific choice of the organic allows us to use the mechanism of “solid state solvation” [C. Madigan and V. Bulovic, Phys. Rev. Lett. 91, 247403 (2003)] to dynamically tune the WE and FE into resonance for ?3.3ns (comparable with the big lifetime of the WE) of the “slow” phase of the solvation. The quadrupole-dipole hybrid utilizes the big oscillator strength of the FE, along with the big lifetime of the quadrupole exciton, unlike dipole-dipole hybrid exciton which utilizes the big oscillator strength of the FE and big radius of the dipole allowed WE. Due to the strong spatial dispersion and big mass of the quadrupole WE, the hybridization is not masked by the kinetic energy or the radiative broadening. The lower branch of the hybrid dispersion exhibits a pronounced minimum and may be used in applications. Also, we investigate and report noticeable change in the coupling due to an induced “Stark effect” from the strong local electric field of the FE. We investigated the fine energy structure of the quantum well confined ortho and para excitons in cuprous oxide.

  7. Giant Quadrupole and Monopole Resonances in Si-28 

    E-print Network

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

    1985-01-01

    . Knopfle, G. J. Wagner, A. Kiss, M. Rogge, C. Mayer- Boricke, and Th. Bauer, Phys. Lett. 64B, 263 (1976). ' G. R. Satchler, Part. Nucl. 5, 105 (1973); Nucl. Phys. A195, 1 (1972). ~ 8T. Kishimoto (unpublished). ~9R. Pitthan, F. R. Buskirk, J. N. Dyer, E... including zero degrees. A total of 66% of the EO energy-weighted sum rule was identified (using a Satchler version 2 form factor) centered at E?=17.9 MeV having a width of 4.8 MeV and 34% of the E2 energy-weighted sum rule was identified above E = 15.3 MeV...

  8. NQR: a non-destructive method for studying oxygen content and defects in YBa 2Cu 3O 6+x superconducting thin films

    NASA Astrophysics Data System (ADS)

    Grévin, B.; Berthier, Y.; Pourtier, F.; Villégier, J. C.; Schmatz, U.

    1997-02-01

    NQR spectra of 63,65Cu isotopes were measured in YBa 2Cu 3O 6+x thin films at 1.4 K, which were prepared by cathodic sputtering and chemical vapor deposition. By comparison with powder spectra, we show that the films obtained by cathodic sputtering are overdoped. We discuss the possible reasons of the lower Tc commonly obtained in YBa 2Cu 3O 6+x thin films by comparison with powders and single crystals. Furthermore, we show that thin films synthesized by chemical vapor deposition could be affected by carbon retention.

  9. Development of a nuclear quadrupole based technique for

    E-print Network

    Keren, Amit

    Development of a nuclear quadrupole based technique for measuring charge homogeneity, and its application for YBCO SHAHAR LEVY #12;DEVELOPMENT OF A NUCLEAR QUADRUPOLE BASED TECHNIQUE FOR MEASURING CHARGE

  10. LHC INTERACTION REGION QUADRUPOLE CRYOSTAT DESIGN

    Microsoft Academic Search

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

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

  11. LHC interaction region quadrupole cryostat design

    Microsoft Academic Search

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

    2002-01-01

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

  12. Hydrogen isotope analysis by quadrupole mass spectrometry

    Microsoft Academic Search

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

    1981-01-01

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

  13. Closed orbit response to quadrupole strength variation

    SciTech Connect

    Wolski, Andrzej; Zimmermann, Frank

    2004-01-20

    We derive two formulae relating the variation in closed orbit in a storage ring to variations in quadrupole strength, neglecting nonlinear and dispersive effects. These formulae correct results previously reported [1,2,3]. We compare the results of the formulae applied to the ATF with simulations using MAD, and consider their application to beam-based alignment.

  14. Hybrid Rare Earih Quadrupole Drift Tube Magnets

    Microsoft Academic Search

    K. Halbach; M. I. Green; R. MacGill; J. Tanabe; J. Milburn

    1985-01-01

    A prototype quadrupole permanent magnet with adjustable field strength has been constructed and tested. The magnet consists of iron pole pieces to provide the required field shape along with rare earth permanent magnet material (samarium cobalt) to energize the magnet. A unique feature of the configuration is the adjustability of the field by rotating the outer rings consisting of permanent

  15. Hybrid Rare Earth Quadrupole Drift Tube Magnets

    Microsoft Academic Search

    K. Halbach; B. Feinberg; M. I. Green; R. MacGill; J. Milburn; J. Tanabe

    1985-01-01

    A prototype quadrupole permanent magnet with adjustable field strength has been constructed and tested. The magnet consists of iron pole pieces to provide the required field shape along with rare earth permanent magnet material (samarium cobalt) to energize the magnet. A unique feature of the configuration is the adjustability of the field by rotating the outer rings consisting of permanent

  16. Thermal analysis of SC quadrupoles in accelerator interaction regions

    SciTech Connect

    Novitski, Igor; Zlobin, Alexander V.; /Fermilab

    2006-09-01

    This paper presents results of a thermal analysis and operation margin calculation performed for NbTi and Nb{sub 3}Sn low-beta quadrupoles in collider interaction regions. Results of the thermal analysis for NbTi quadrupoles are compared with the relevant experimental data. An approach to quench limit measurements for Nb{sub 3}Sn quadrupoles is discussed.

  17. Correlated Spin Dynamics and Phase Transitions in Pure and in Disordered 2D S = 1/2 Antiferromagnets: Insights from NMR-NQR

    NASA Astrophysics Data System (ADS)

    Rigamonti, A.; Carretta, P.; Papinutto, N.

    A recall of the phase diagram for two-dimensional quantum Heisenberg antiferromagnets (2DQHAF) and of the main issues involving phase transitions and spin dynamics in these systems is first given. After a pedagogical description of the basic aspects for the NMR-NQR relaxation rates in terms of amplitudes and decay rates of spin fluctuations, the problem of the temperature dependence of the correlation length in prototype, pure 2DQHAF (CFTD and La2CuO4) is addressed. Then spin- and charge-doped systems (Zn/Mg for Cu and Sr for La substitutions in La2CuO4) are considered and the effects on the spin stiffness, on the correlation length and on the staggered Cu2+ magnetic moment are reported, in particular near the percolation threshold. A critical outline of the properties of the cluster spin glass phase in Sr- doped La2CuO4 is given. Finally the results of a 63Cu NQR-NMR relaxation study around the quantum critical point (in CeCu6-xAux) are presented. It is pointed out how the 2D response function with anomalous exponent and energy/ temperature scaling indicated by neutron scattering is basically confirmed, while the 63Cu relaxation measurements reveal novel effects involving low-energy spin excitations and the role of an external magnetic field.

  18. Global study of quadrupole correlation effects

    SciTech Connect

    Bender, M. [Department of Physics and Institute for Nuclear Theory, Box 351560, University of Washington, Seattle, Washington 98195 (United States); Physics Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Bertsch, G.F. [Department of Physics and Institute for Nuclear Theory, Box 351560, University of Washington, Seattle, Washington 98195 (United States); Heenen, P.-H. [Service de Physique Nucleaire Theorique, Universite Libre de Bruxelles, CP 229, B-1050 Brussels (Belgium)

    2006-03-15

    We discuss the systematics of ground-state quadrupole correlations of binding energies and mean-square charge radii for all even-even nuclei, from {sup 16}O up to the superheavies, for which data are available. To that aim we calculate their correlated J=0 ground state by means of the angular-momentum and particle-number projected generator coordinate method, using the axial mass quadrupole moment as the generator coordinate and self-consistent mean-field states restricted only by axial, parity, and time-reversal symmetries. The calculation is performed within the framework of a nonrelativistic self-consistent mean-field model by use of the same Skyrme interaction SLy4 and to a density-dependent pairing force to generate the mean-field configurations and to mix them. These are the main conclusions of our study: (i) The quadrupole correlation energy varies between a few 100 keV and about 5.5 MeV. It is affected by shell closures, but varies only slightly with mass and asymmetry. (ii) Projection on angular momentum J=0 provides the major part of the energy gain of up to about 4 MeV; all nuclei in the study, including doubly magic ones, gain energy by deformation. (iii) The mixing of projected states with different intrinsic axial deformations adds a few 100 keV up to 1.5 MeV to the correlation energy. (iv) Typically nuclei below mass A{<=}60 have a larger correlation energy than static deformation energy whereas the heavier deformed nuclei have larger static deformation energy than correlation energy. (v) Inclusion of the quadrupole correlation energy improves the description of mass systematics, particularly around shell closures, and of differential quantities, namely two-nucleon separation energies and two-nucleon gaps. The correlation energy provides an explanation of 'mutually enhanced magicity'. (vi) The correlation energy tends to decrease the shell effect on binding energies around magic numbers, but the magnitude of the suppression is not large enough to explain the relative overbinding at N=82 and N=126 neutron-shell closures in mean-field models. (vii) Charge radii are also found to be sensitive to the quadrupole correlations. Static quadrupole deformations lead to a significant improvement of the overall systematics of charge radii. The dynamical correlations improve the local systematics of radii, in particular around shell closures. Although the dynamical correlations might reduce the charge radii for specific nuclei, they lead to an overall increase of radii when included, in particular in light nuclei.

  19. Lighthill quadrupole radiation in supersonic propeller acoustics

    NASA Astrophysics Data System (ADS)

    Peake, N.; Crighton, D. G.

    1991-02-01

    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 approximation that the number of blades, B, is large. It is proved that to leading order the problem of the radiation in a given direction reduces to one of determining the two-dimensional flow field at just one radial station, legitimately achieved by linearized supersonic analysis. Simple formulas are derived for the far-field acoustic pressure generated by unswept blades, from which absolute level predictions can be made accurately and quickly. These formulas predict a significantly greater intensity, over broad angular ranges, than is predicted by the linear theory for thickness noise sources.

  20. LARP Long Nb3Sn Quadrupole Design

    SciTech Connect

    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

    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.

  1. Hydrogen isotope analysis by quadrupole mass spectrometry

    Microsoft Academic Search

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

    1981-01-01

    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

  2. Electrostatic quadrupole DC accelerators for BNCT applications

    SciTech Connect

    Kwan, J.W.; Anderson, O.A.; Reginato, L.L.; Vella, M.C.; Yu, S.S.

    1994-04-01

    A dc electrostatic quadrupole (ESQ) accelerator is capable of producing a 2.5 MeV, 100 mA proton beam for the purpose of generating neutrons for Boron Neutron Capture Therapy. The ESQ accelerator is better than the conventional aperture column in high beam current application due to the presence of stronger transverse field for beam focusing and for suppressing secondary electrons. The major challenge in this type of accelerator is in developing the proper power supply system.

  3. Muon cooling in a quadrupole magnet channel

    SciTech Connect

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

    2007-10-01

    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.

  4. 15 T And Beyond - Dipoles and Quadrupoles

    SciTech Connect

    Sabbi, GianLuca

    2008-05-19

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

  5. Well-proportioned universes suppress CMB quadrupole

    E-print Network

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

    2004-07-05

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

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

    SciTech Connect

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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.

  8. Design of superconducting quadrupole magnets for CEBAF's Hall A spectrometer

    Microsoft Academic Search

    R. Kreutz; E. Brutsch; K. Dreher; H. Gruneberg; H. Lutkehaus; W. Nick; H. Peschel; B. Rzezonka; F. Sommer; P. Schafer

    1993-01-01

    The detailed design for the construction of the Q2\\/Q3 quadrupole magnets for CEBAF's Resolution Spectrometers is presented. The quadrupoles have a warm bore diameter of 600 mm and a cryostat length of 3 m. The quadrupole coil will be wound from a cable conductor carrying a current of 1850 A, the field gradient is 3.5 T\\/m. A set of eight

  9. Thermogravimetric-quadrupole mass-spectrometric analysis of geochemical samples.

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  10. Noise reduction in negative-ion quadrupole mass spectrometry

    DOEpatents

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

    1993-01-01

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

  11. Noise reduction in negative-ion quadrupole mass spectrometry

    DOEpatents

    Chastagner, P.

    1993-04-20

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

  12. Magnetic mirror structure for testing shell-type quadrupole coils

    SciTech Connect

    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

    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.

  13. High-Precision Resonant Cavity Beam Position, Emittance And Third-Moment Monitors

    Microsoft Academic Search

    N. Barov; J. S. Kim; A. W. Weidemann; R. H. Miller; C. D. Nantista

    2006-01-01

    Linear colliders and FEL facilities need fast, nondestructive beam position and profile monitors to facilitate machine tune-up, and for use with feedback control. FAR-TECH, Inc., in collaboration with SLAC, is developing a resonant cavity diagnostic to simultaneously measure the dipole, quadrupole and sextupole moments of the beam distribution. Measurements of dipole and quadrupole moments at multiple locations yield information about

  14. High-Precision Resonant Cavity Beam Position, Emittance and Third-Moment Monitors

    Microsoft Academic Search

    N. Barov; J. S. Kim; A. W. Weidemann; R. H. Miller; C. D. Nantista

    2005-01-01

    Linear colliders and FEL facilities need fast, nondestructive beam position and profile monitors to facilitate machine tune-up, and for use with feedback control. FAR-TECH, Inc., in collaboration with SLAC, is developing a resonant cavity diagnostic to simultaneously measure the dipole, quadrupole and sextupole moments of the beam distribution. Measurements of dipole and quadrupole moments at multiple locations yield information about

  15. Analytical Solutions of Singular Isothermal Quadrupole Lens

    NASA Astrophysics Data System (ADS)

    Chu, Zhe; Lin, W. P.; Yang, Xiaofeng

    2013-06-01

    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.

  16. Low-temperature order in the heavy-fermion compound CeCu{sub 6}

    SciTech Connect

    Pollack, L.; Hoch, M.J.R.; Jin, C.; Smith, E.N.; Parpia, J.M.; Hawthorne, D.L.; Geller, D.A.; Lee, D.M.; Richardson, R.C. [Cornell Microkelvin Laboratory, Materials Science Center, Cornell University, Ithaca, New York 14853 (United States); Hinks, D.G. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bucher, E. [AT& T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)

    1995-12-01

    We have used nuclear-quadrupole-resonance (NQR) techniques to study Cu nuclei in two single-crystal samples of CeCu{sub 6} between 200 {mu}K and 20 mK. We present measurements of the NQR intensities and spin-lattice relaxation times, {ital T}{sub 1}, at frequencies corresponding to three different sites in the crystal. Below 5 mK we observe deviations from standard metallic behavior in both signal intensity and spin-lattice relaxation times. These deviations are unusual in that they are site dependent; they reveal the presence of one or more types of order in this system.

  17. Structural and magnetic phase transitions in (Chloroanilinium) 2 CuX 4 (X = Cl, Br)

    Microsoft Academic Search

    T. Asaji

    2004-01-01

    Successive structural phase transitions of (4-ClC6H4NH3)2CuCl4, which occur in a very narrow temperature range were reinvestigated by Fourier transform nuclear quadrupole resonance (FT\\u000a NQR) measurements. The phase transitions at 275.5 and 277.0 K were confirmed. The effect of the deuteration of the ammonium\\u000a end on these transitions was studied. The35Cl NQR frequencies of organic cation were observed to decrease by

  18. Multi-Pass Quadrupole Mass Analyzer

    NASA Technical Reports Server (NTRS)

    Prestage, John D.

    2013-01-01

    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.

  19. Hybrid rare earth quadrupole drift tube magnets

    SciTech Connect

    Halbach, K.; Feinberg, B.; Green, M.I.; MacGill, R.; Milburn, J.; Tanabe, J.

    1985-10-01

    A prototype quadrupole permanent magnet with adjustable field strength has been constructed and tested. The magnet consists of iron pole pieces to provide the required field shape along with rare earth permanent magnet material (samarium cobalt) to energize the magnet. A unique feature of the configuration is the adjustability of the field by rotating the outer rings consisting of permanent magnets and iron. Magnetic tests show small field errors coming from well understood assembly details. Mechanical tests show the design needs further consideration to ensure reliability. It is planned to use this type of magnet in the SuperHILAC prestripper drift tubes.

  20. Hybrid rare earth quadrupole drift tube magnets

    SciTech Connect

    Halbach, K.; Feinberg, B.; Green, M.I.; MacGill, R.; Milburn, J.; Tanabe, J.

    1985-05-01

    A prototype quadrupole permanent magnet with adjustable field strength has been constructed and tested. The magnet consists of iron pole pieces to provide the required field shape along with rare earth permanent magnet material (samarium cobalt) to energize the magnet. A unique feature of the configuration is the adjustability of the field by rotating the outer rings consisting of permanent magnets and iron. Magnetic tests show small field errors coming from well understood assembly details. Mechanical tests show the design needs further consideration to ensure reliability. It is planned to use this type of magnet in the SuperHILAC prestripper drift tubes. 3 refs., 5 figs.

  1. Quadrupole Transfer Function for Emittance Measurement

    E-print Network

    Cameron, Peter; Jansson, Andreas; Tan, Cheng-Yang

    2008-01-01

    Historically the use of the quadrupole moment measurement has been impeded by the requirement for large dynamic range, as well as measurement sensitivity to beam position. We investigate the use of the transfer function technique [1-3] in combination with the sensitivity and 160dB revolution line rejection of the direct diode detection analog front end [4] to open the possibility of an emittance diagnostic that may be implemented without operational complication, quasi- parasitic to the operation of existing tune measurement systems. Such a diagnostic would be particularly useful as an emittance monitor during acceleration ramp development in machines like RHIC and the LHC.

  2. On the proper kinetic quadrupole CMB removal and the quadrupole anomalies

    NASA Astrophysics Data System (ADS)

    Notari, Alessio; Quartin, Miguel

    2015-06-01

    It has been pointed out recently that the quadrupole-octupole alignment in the CMB data is significantly affected by the so-called kinetic Doppler quadrupole (DQ), which is the temperature quadrupole induced by our proper motion. Assuming our velocity is the dominant contribution to the CMB dipole we have v/c=?=(1.231 ± 0.003) × 10?3, which leads to a non-negligible DQ of Script O(?2). Here we stress that one should properly take into account that CMB data are usually not presented in true thermodynamic temperature, which induces a frequency dependent boost correction. The DQ must therefore be multiplied by a frequency-averaged factor, which we explicitly compute for several Planck CMB maps finding that it varies between 1.67 and 2.47. This is often neglected in the literature and turns out to cause a small but non-negligible difference in the significance levels of some quadrupole-related statistics. For instance the alignment significance in the SMICA 2013 map goes from 2.3? to 3.3? with the frequency dependent DQ, instead of 2.9? ignoring the frequency dependence in the DQ. Moreover as a result of a proper DQ removal, the agreement across different map-making techniques is improved.

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

    Microsoft Academic Search

    Carla Soler; Jordi Mañes; Yolanda Picó

    2005-01-01

    Liquid chromatography-triple quadrupole\\/mass spectrometry (LC-TQ\\/MS) and liquid chromatography-quadrupole ion trap\\/mass spectrometry (LC-QIT\\/MS) for determining bupirimate, hexaflumuron, tebufenpyrad, buprofezin, pyriproxyfen, and fluvalinate in fruits have been compared. The differences in the mass spectra obtained by triple and ion trap quadrupoles are discussed, showing how both of them provide interesting features. The evaluation of the two instruments was carried out by ethyl

  4. Spin-isospin resonances with relativistic RPA approaches

    SciTech Connect

    Meng Jie [School of Physics and Nuclear Energy, Beihang University, Beijing 100191 (China); State Key Lab Nucl. Phys. and Tech., School of Physics, Peking University, Beijing 100871 (China); Liang Haozhao [State Key Lab Nucl. Phys. and Tech., School of Physics, Peking University, Beijing 100871 (China); Institut de Physique Nucleaire, IN2P3-CNRS and Universite Paris-Sud, 91406 Orsay (France); Nguyen Van Giai [Institut de Physique Nucleaire, IN2P3-CNRS and Universite Paris-Sud, 91406 Orsay (France)

    2010-05-12

    The relativistic RPA approaches are applied to calculate the charge-exchange spin flip resonances. Comparing the RPA calculations based on the relativistic Hartree and relativistic Hartree-Fock theories, the different physical mechanisms in determining the Gamow-Teller resonance are investigated. Then, the theoretical descriptions of spin-dipole and spin-quadrupole resonances are presented. In particular, the energy hierarchies of different components in these resonances are focused on.

  5. Supersonic Quadrupole Noise Theory for High-Speed Helicopter Rotors

    NASA Astrophysics Data System (ADS)

    Farassat, F.; Brentner, K. S.

    1998-12-01

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

  6. Quadrupole Collectivity in Neutron Deficient Sn Isotopes

    NASA Astrophysics Data System (ADS)

    Gade, Alexandra

    2014-03-01

    One of the overarching goals of nuclear physics is the development of a comprehensive model of the atomic nucleus with predictive power across the nuclear chart. Of particular importance for the development of nuclear models is experimental data that consistently track the effect of isospin and changed binding, for example. The chain of Sn isotopes has been a formidable testing ground for nuclear models as some spectroscopic data is available from N = Z = 50 100Sn in the proximity of the proton dripline to 134Sn, beyond the very neutron-rich doubly magic nucleus 132Sn. In even-even nuclei, the electromagnetic quadrupole excitation strength is a measure of quadrupole collectivity, sensitive to the presence of shell gaps, nuclear deformation, and nucleon-nucleon correlations, for example. In the Sn isotopes, this transition strength has been reported from 104Sn to 130Sn, spanning a chain of 14 even-even Sn isotopes. The trend is asymmetric with respect to midshell and not even the largest-scale shell-model calculations have been able to describe the evolution of transition strength across the isotopic chain without varying effective charges. Implications will be discussed. This work was supported by the National Science Foundation under Grant No. PHY-1102511.

  7. LHC interaction region quadrupole cryostat design

    NASA Astrophysics Data System (ADS)

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

    2002-05-01

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

  8. SSC Quadrupole Magnet Performance at LBL

    SciTech Connect

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

    1992-10-01

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

  9. Ion-quadrupole effects in ion-molecule collisions.

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  10. Adjustable Permanent Quadrupoles for the Next Linear Collider

    Microsoft Academic Search

    C. M. Spencer; Cherrill M

    2001-01-01

    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 20% and effective lengths from 324 mm to 972 mm.

  11. Adjustable permanent quadrupoles for the Next Linear Collider

    Microsoft Academic Search

    James T. Volk; J. DiMarco; G. W. Foster; W. Fowler; V. S. Kashikhin; A. Makarov; V. Tsvetkov; C. E. Rago; A. Ringwall; C. M. Spencer; Z. Wolf

    2001-01-01

    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 -20% and effective lengths from 324 mm to 972 mm,.

  12. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOEpatents

    Maschke, A.W.

    1984-04-16

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

  13. Commissioning a Vibrating Wire System for Quadrupole Fiducialization

    SciTech Connect

    Levashov, Michael Y

    2010-12-03

    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.

  14. Double-photoionization of helium including quadrupole radiation effects

    SciTech Connect

    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

    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.

  15. Coupling Current and AC Loss in LHC Superconducting Quadrupoles

    E-print Network

    Di Castro, M; Richter, D; Sanfilippo, S; Wolf, R

    2008-01-01

    One of the issues for the operation of the LHC accelerator at CERN are the field errors generated by coupling currents in the superconducting cables of the main dipoles and quadrupoles, especially during the initial phase of the energy ramp from injection conditions. Coupling current effects have already been measured in the superconducting dipoles, and results are reported elsewhere. This paper reports similar measurements that we have recently performed on different types of LHC superconducting quadrupoles (arc quadrupole, dispersion suppressor and matching section quadrupoles) to quantify the above effects and compare them to the values specified from the beam tolerances. Loss and field errors due to ramping are mainly determined by the contact resistance Rc between the strands of the magnets cables. In this paper the Rc is calculated for several quadrupoles measured using both the measured energy loss and the magnetic field errors during ramping of magnets.

  16. Experimental results of the betatron sum resonance

    SciTech Connect

    Wang, Y.; Ball, M.; Brabson, B. [Indiana Univ., Bloomington, IN (United States)] [and others

    1993-06-01

    The experimental observations of motion near the betatron sum resonance, {nu}{sub x} + 2{nu}{sub z} = 13, are presented. A fast quadrupole (Panofsky-style ferrite picture-frame magnet with a pulsed power supplier) producing a betatron tune shift of the order of 0.03 at rise time of 1 {mu}s was used. This quadrupole was used to produce betatron tunes which jumped past and then crossed back through a betatron sum resonance line. The beam response as function of initial betatron amplitudes were recorded turn by turn. The correlated growth of the action variables, J{sub x} and J{sub z}, was observed. The phase space plots in the resonance frame reveal the features of particle motion near the nonlinear sum resonance region.

  17. RADIATION RESISTANT HTS QUADRUPOLES FOR RIA.

    SciTech Connect

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

    2004-10-03

    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.

  18. An improved integrally formed radio frequency quadrupole

    DOEpatents

    Abbott, S.R.

    1987-10-05

    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.

  19. Equations of motion for binary systems with relativistic quadrupole-quadrupole moments interaction

    Microsoft Academic Search

    Xuejun Wu; Yuejuan He; Chongming Xu

    1998-01-01

    By making use of the scheme developed by Damour, Soffel and Xu, in terms of Maple-computer algebra system, the first post-Newtonian\\u000a equations of motion for binary systems with monopole, spin and quadrupole interaction are for the first time derived in an\\u000a explicit and complete form. The equations of motion are expressed in the local coordinate system as well as in

  20. In-plane charge modulation below T(c) and charge-density-wave correlations in the chain layer in YBa2Cu3O7

    PubMed

    Grevin; Berthier; Collin

    2000-08-01

    Nuclear quadrupole resonance (NQR) measurements have been performed on Cu(2) plane sites and Cu(1) chain sites in fully doped YBa2Cu3O7 between 300 and 4.2 K. The sharp increase of the Cu(1) NQR linewidth across the superconducting transition and the T dependence of the Cu(1) spin lattice relaxation rate confirm the existence of a charge-density-wave state (CDW) in the chains. The simultaneous broadening of the Cu(2) linewidth below T(c) and the anomalous T dependence of Cu(1) and Cu(2) NQR parameters indicate that these in-chain CDW correlations are strongly involved in the appearance of an in-plane charge modulated structure below T(c). PMID:10991539

  1. In-Plane Charge Modulation below Tc and Charge-Density-Wave Correlations in the Chain Layer in YBa2Cu3O7

    NASA Astrophysics Data System (ADS)

    Grévin, B.; Berthier, Y.; Collin, G.

    2000-08-01

    Nuclear quadrupole resonance (NQR) measurements have been performed on Cu(2) plane sites and Cu(1) chain sites in fully doped YBa2Cu3O7 between 300 and 4.2 K. The sharp increase of the Cu(1) NQR linewidth across the superconducting transition and the T dependence of the Cu(1) spin lattice relaxation rate confirm the existence of a charge-density-wave state (CDW) in the chains. The simultaneous broadening of the Cu(2) linewidth below Tc and the anomalous T dependence of Cu(1) and Cu(2) NQR parameters indicate that these in-chain CDW correlations are strongly involved in the appearance of an in-plane charge modulated structure below Tc.

  2. Resonances on-demand for plasmonic nano-particles.

    PubMed

    Ginzburg, Pavel; Berkovitch, Nikolai; Nevet, Amir; Shor, Itay; Orenstein, Meir

    2011-06-01

    A method for designing plasmonic particles with desired resonance spectra by exploiting the interaction of local geometry with surface charge distribution and applying evolutionary algorithm is presented. The method is based on repetitive perturbations of an initial particle's shape while calculating the eigenvalues of the various quasistatic resonances. Novel family of particles with collocated dipole-quadrupole resonances was designed, as an example for the unique power of the method. PMID:21528909

  3. The Low-Energy Quadrupole Mode of Nuclei

    E-print Network

    Frauendorf, S

    2015-01-01

    The phenomenological classification of collective quadrupole excitations by means of the Bohr Hamiltonian is reviewed with focus on signatures for triaxility. The variants of the microscopic Bohr Hamiltonian derived by means of the Adiabatic Time Dependent Mean Field theory from the Pairing plus Quadrupole-Quadrupole interaction, the Shell Correction Method, the Skyrme Energy Density Functional, the Relativistic Mean Field Theory, and the Gogny interaction are discussed and applications to concrete nuclides reviewed. The Generator Coordinate Method for the five dimensional quadrupole deformation space and first applications to triaxial nuclei are presented. The phenomenological classification in the framework of the Interacting Boson Model is discussed with a critical view on the boson number counting rule. The recent success in calculating the model parameters by mapping the mean field deformation energy surface on the bosonic one is discussed and the applications listed. A critical assessment of the models ...

  4. Electro-Magnetic Quadrupole Magnets in the LCLS FEL Undulator

    SciTech Connect

    Emma, P.

    2005-01-31

    We discuss various aspects of electro-magnetic quadrupole (EMQ) magnets for the LCLS FEL undulator, including their utility in beam-based alignment (BBA), magnet design issues, and impact on tunnel environment, reliability, and cost.

  5. Alignment tolerances of IR quadrupoles in the LHC

    SciTech Connect

    Tanaji Sen

    1999-11-05

    Luminosity in the LHC will depend critically on the alignment of the triplet quadrupoles. These quadrupoles are closest to the interaction points (IPs), have large gradients and the {beta} functions have their largest values within these quadrupoles. Within a triplet, the cold masses of the Q1 and Q3 quadrupoles will be housed in separate cryostats while Q2a and Q2b will be placed in a single cryostat. The absolute alignments of Q1, Q3 and the Q2a/Q2b pair with respect to the desired axes will be determined during installation. The relative alignment of Q2a and Q2b however will be fixed once they are placed in their common cryostat at Fermilab. In this note, we examine the required relative alignment tolerances of Q2a and Q2b. An early study of some alignment tolerances was done by Weisz [1].

  6. Field quality and stability of permanent magnet quadrupoles

    SciTech Connect

    Herb, S.

    1985-10-01

    We plan to increase the peak luminosity of the Cornell Electron Storage Ring by providing tighter vertical focussing at the interaction points. The final focussing devices will be large permanent magnet quadrupoles operating inside the 10-15 kG solenoidal field of the experimental detector. We present the results of tests demonstrating that quadrupoles with the required field quality and resistance to demagnetization can be built from commercially available Rare Earth Cobalt magnets.

  7. Variable-field permanent-magnet quadrupole for the SSC

    Microsoft Academic Search

    David B. Barlow; Robert H. Kraus Jr; Ricardo P. Martinez; Ross E. Meyer

    1994-01-01

    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.

  8. Variable-field permanent magnet quadrupole for the SSC

    Microsoft Academic Search

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

    1993-01-01

    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.

  9. Adjustable rare earth quadrupole drift tube magnets

    SciTech Connect

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

    1987-03-01

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

  10. Thermal Analysis of the ILC Superconductin Quadrupole

    SciTech Connect

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

    2006-09-13

    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.

  11. Autonomously Calibrating a Quadrupole Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon; Bornstein, Benjamin J.

    2009-01-01

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

  12. Errors in radio-frequency quadrupole structures

    SciTech Connect

    Lysenko, W.P.

    1983-01-01

    Performance degradation caused by certain radio-frequency quadrupole (RFQ) machine errors was studied using an efficient 3-D particle-tracing simulation code for a high-brightness example. Matched beams, for which no emittance growth occurs, exist for periodic structures and were used as input beams for particle tracing in the presence of errors. We considered both slowly varying and fast (random) errors that destroy periodicity. Random dipole errors cause emittance growth because of the mismatches they introduce and also result in a motion of the beam centroid that causes a reduction in acceptance. Because of the way RFQs are manufactured, the random error amplitudes can be kept below harmful levels. More important are the slow errors, which are harmful because they reduce acceptance even though they maintain a match (up to the point of particle loss). Slow dipole errors steer the beam toward the wall, and voltage deficiencies cause instabilities in the longitudinal direction resulting in particles not being accelerated to full energy.

  13. Development of electrostatic quadrupoles for heavy ion fusion

    SciTech Connect

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

    1996-12-31

    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.

  14. SPIN COUPLING RESONANCE STUDY IN AGS.

    SciTech Connect

    RANJBAR,V.; AHRENS,L.; BAI,M.; BROWN,K.; GLENN,W.; HUANG,H.; LUCCIO,A.; MACKAY,W.W.; PTITSYN,V.; ROSER,T.; TSOUPAS,N.; LEE,S.Y.

    2002-06-02

    In the AGS spin resonances due to coupling may account for as much as a 50 percent loss in polarization at a reduced acceleration rate. The major source of coupling in the AGS is the solenoidal snake. In the past some preliminary work was done to understand this phenomena, and a method to overcome these resonances was attempted. However in the polarized proton run of 2002 we sought to study more thoroughly the response of these coupled spin resonances to the strength of the solenoidal snake, skew quadrupoles and vertical and horizontal betatron tune separation. In this paper we present our results and compare them with those predicted by a modified DEPOL program.

  15. The phase diagrams and doped-hole segregation in La{sub 2}CuO{sub 4+{delta}} and La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} (x {le} 0.15, {delta} {le} 0.12)

    SciTech Connect

    Johnston, D.C.; Borsa, F.; Canfield, P.C. [Iowa State Univ. of Science and Technology, Ames, IA (United States)] [and others

    1993-10-31

    The magnetic and structural phase diagrams of the La{sub 2}CuO{sub 4+{delta}} system and the La{sub 2-x}Sr{sub x}CuO{sub 4+{delta}} are reviewed, with emphasis on recent results obtained from magnetic and structural neutron diffraction, thermogravimetric analysis, iodometric titration, magnetic susceptibility {chi}(T), and {sup 129}La nuclear quadrupole resonance (NQR) measurements.

  16. Higher order parametric excitation modes for spaceborne quadrupole mass spectrometers

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  17. Higher Order Parametric Excitation Modes for Spaceborne Quadrupole Mass Spectrometers

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  18. MEQALAC: (multiple electrostatic quadrupole linac): a new approach to low beta rf acceleration

    SciTech Connect

    Mobley, R.M.; Brodowski, J.J.; Gammel, G.M.; Keane, J.T.; Maschka, A.W.; Sanders, R.T.

    1980-01-01

    MEQALAC is an acronym for a multiple-beam electrostatic-quadrupole array linear accelerator. The principle of operation is very simple. It makes use of the fact that electrostatic quadrupoles focus more effectively at low velocities than conventional magnetic quadrupoles. Moreover, the pole-tip field of an electrostatic quadrupole is limited by field emission of electrons, and is not a function of the size of the quadrupole. Conventional magnetic quadrupoles, on the other hand, require increasingly high current densities if one attempts to scale to smaller size.

  19. Hyperfine and quadrupole interactions of trigonal 157 Gd 3+ centers in SrF 2 and BaF 2 . Analysis of distortions in the nearest atomic environment

    Microsoft Academic Search

    A. D. Gorlov; A. P. Potapov

    2000-01-01

    Trigonal 157Gd3+ impurity centers in SrF2 and BaF2 were experimentally studied by EPR and double electron-nuclear resonance (DENR) techniques. Parameters of the hyperfine and\\u000a quadrupole interactions between these centers were determined. Possible distortions of the nearest atomic environment of the\\u000a impurity centers are estimated within the framework of a superposition model using the EPR and DENR data for the centers

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

    SciTech Connect

    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

    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.

  1. Quadrupole moments of odd-odd near-magic nuclei

    NASA Astrophysics Data System (ADS)

    Voitenkov, D.; Achakovskiy, O.; Kamerdzhiev, S.; Tolokonnikov, S.

    2012-12-01

    Ground state quadrupole moments of odd-odd near-double-magic nuclei are calculated in the approximation of non-interacting odd neutron and odd proton. Under such a simple approximation the problem is reduced to the calculations of quadrupole moments of corresponding odd-even nuclei. These calculations are performed within the self-consistent Theory of Finite Fermi Systems based on the Energy Density Functional by Fayans et al. with the known DF3-a parameters. A reasonable agreement with the available experimental data is obtained for odd-odd nuclei and odd near-magic nuclei investigated. The self-consistent approach under consideration allowed us to predict the unknown quadrupole moments of odd-even and odd-odd nuclei near the double-magic 56,78Ni, 100,132Sn nuclides.

  2. Cryogen free superconducting splittable quadrupole magnet for linear accelerators

    SciTech Connect

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

    2011-09-01

    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.

  3. Study of a micro chamber quadrupole mass spectrometer

    SciTech Connect

    Wang Jinchan; Zhang Xiaobing; Mao Fuming; Xiao Mei; Cui Yunkang; Engelsen, Daniel den; Lei Wei [Jiangsu Information Display Engineering Research Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096 (China)

    2008-03-15

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

  4. Variable-field permanent-magnet quadrupole for the SSC

    SciTech Connect

    Barlow, D.B.; Kraus, R.H. Jr.; Martinez, R.P.; Meyer, R.E. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States)

    1994-07-01

    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{degree} rotation of the outer ring of iron and magnet material.

  5. Variable-field permanent-magnet quadrupole for the SSC

    NASA Astrophysics Data System (ADS)

    Barlow, David B.; Kraus, Robert H., Jr.; Martinez, Ricardo P.; Meyer, Ross E.

    1994-07-01

    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 deg rotation of the outer ring of iron and magnet material.

  6. Stability of an Aqueous Quadrupole Micro-Trap

    PubMed Central

    Park, Jae Hyun; Krsti?, Predrag S.

    2011-01-01

    Recently demonstrated functionality of an aqueous quadrupole micro- or nano-trap opens a new avenue for applications of the Paul traps, like is confinement of a charged biomolecule which requires water environment for its chemical stability. Besides strong viscosity forces, motion of a charged particle in the aqueous trap is subject to dielectrophoretic and electrophoretic forces. In this study, we describe the general conditions for stability of a charged particle in an aqueous quadrupole trap. We find that for the typical micro-trap parameters, effects of both dielectrophoresis and electrophoresis significantly influence the trap stability. In particular, the aqueous quadrupole trap could play of a role of a synthetic virtual nanopore for the 3rd generation of DNA sequencing technology. PMID:22466254

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

    PubMed

    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

    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

  8. Variable-field permanent magnet quadrupole for the SSC

    SciTech Connect

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

    1993-10-01

    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.

  9. Quadrupole moment of the nucleon in chiral constituent quark model

    E-print Network

    Harleen Dahiya; Neetika Sharma

    2010-09-10

    The electromagnetic form factors are the most fundamental quantities to describe the internal structure of the nucleon and the shape of a spatially extended particle is determined by its {\\it intrinsic} quadrupole moment which is first order moment of the charge density operator. With some experimental indications of a deformed nucleon, we have calculated the {\\it intrinsic} quadrupole moment of the octet and decuplet baryons in the framework of chiral constituent quark model \\chiCQM which is quite successful in explaining some of the important baryon properties in the nonperturbative regime.

  10. An Estimate of the Maximum Gradients in Superconducting Quadrupoles

    E-print Network

    Todesco, Ezio

    2007-01-01

    In this paper we show that the electromagnetic design of several superconducting quadrupoles, built for particle accelerators, can be rather well approximated by a 36 degree sector coil with a wedge, canceling the first two field harmonics. We therefore carry out a complete analysis of this lay-out, obtaining an approximated equation for the critical gradient as a function of the coil area, magnet aperture, and of the superconducting properties of the cable. Using this model, we estimate through numerical methods the maximum critical gradient that can be obtained in quadrupole of a given aperture for Nb-Ti, Nb-Ti-Ta and Nb3Sn.

  11. A 40 mm bore quadrupole magnet for the SSC

    SciTech Connect

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

    1990-09-01

    A 40 mm bore quadrupole magnet design, called QC'', has been made for the SSC with the following parameters: 208 T/m gradient at 6500A, 2-layer cos 2 {theta}'' winding arrangement with 30 strand cable and one spacer wedge per coil. Structural support is provided by self-supporting interlocking collars; two types of symmetrical laminations are pre-assembled into collar packs for ease of assembly. This paper will describe the design of a prototype quadrupole magnet for the SSC and preliminary tests results on 1 m models. 7 refs., 6 figs., 2 tabs.

  12. High and ulta-high gradient quadrupole magnets

    SciTech Connect

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

    1985-05-01

    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%.

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

    PubMed

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

    2015-02-01

    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

  14. Stochastic Resonance

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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.

  15. Quadrupole terms in defect energies in transition metal oxides

    Microsoft Academic Search

    A. M. Stoneham; M. J. L. Sangster; J. H. Harding

    1990-01-01

    In a previous paper it was shown that, for defects in transition metal oxides, there was evidence for an additional term in the potential energy beyond the usual monopole and dipole terms of the shell model. This appeared to be a quadrupole term in which the open 3d shells of the host ions, as well as any impurities, responded to

  16. Hydrogen atom in a magnetic field: The quadrupole moment

    NASA Astrophysics Data System (ADS)

    Potekhin, Alexander Y.; Turbiner, Alexander V.

    2001-06-01

    The quadrupole moment of a hydrogen atom in a magnetic field B for field strengths from 0 to 4.414×1013 G is calculated by two different methods. The first method is variational, and based on a single trial function. The second method deals with a solution of the Schrödinger equation in the form of a linear combination of Landau orbitals.

  17. Table of nuclear magnetic dipole and electric quadrupole moments

    Microsoft Academic Search

    N. J. Stone

    2005-01-01

    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

  18. LHC interaction region quadrupole cryostat design and fabrication

    Microsoft Academic Search

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

    2002-01-01

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

  19. Quadrupole Model Magnet R&D Alexander Zlobin, Fermilab

    E-print Network

    Large Hadron Collider Program

    Ti superconductor. Quadrupole parameters: ­ 70 mm coil aperture ­ 205 T/m nominal gradient with 20% margin ­ 1.9 K Generation LHC IRs Baseline LHC inner triplets consist of single-bore, high-gradient quads based on Nb analysis shows that the aperture limit for Nb3Sn quads is 110 mm for the present operating field gradient

  20. Chaos and catastrophies in quadrupole oscillations of nuclei

    SciTech Connect

    Bolotin, Y.L.; Gonchar, V.Y.; Inopin, E.V.

    1987-02-01

    The dynamics of the quadrupole oscillations of nuclei is studied. The possibility of a transition from the regular regime to a chaotic regime is investigated, and the critical energy of such a transition is determined for different values of the parameters of the potential.

  1. The exact calculation of quadrupole sources for some incompressible flows

    Microsoft Academic Search

    Kenneth S. Brentner

    1988-01-01

    This paper is concerned with the application of the acoustic analogy of Lighthill to the acoustic and aerodynamic problems associated with moving bodies. The Ffowcs Williams-Hawkings equation, which is an interpretation of the acoustic analogy for sound generation by moving bodies, manipulates the source terms into surface and volume sources. Quite often in practice the volume sources, or quadrupoles, are

  2. The Low-Energy Quadrupole Mode of Nuclei

    E-print Network

    S. Frauendorf

    2015-06-20

    The phenomenological classification of collective quadrupole excitations by means of the Bohr Hamiltonian is reviewed with focus on signatures for triaxility. The variants of the microscopic Bohr Hamiltonian derived by means of the Adiabatic Time Dependent Mean Field theory from the Pairing plus Quadrupole-Quadrupole interaction, the Shell Correction Method, the Skyrme Energy Density Functional, the Relativistic Mean Field Theory, and the Gogny interaction are discussed and applications to concrete nuclides reviewed. The Generator Coordinate Method for the five dimensional quadrupole deformation space and first applications to triaxial nuclei are presented. The phenomenological classification in the framework of the Interacting Boson Model is discussed with a critical view on the boson number counting rule. The recent success in calculating the model parameters by mapping the mean field deformation energy surface on the bosonic one is discussed and the applications listed. A critical assessment of the models is given with focus on the limitations due to the adiabatic approximation. The Tidal Wave approach and the Triaxial Projected Shell Model are presented as practical approaches to calculate spectral properties outside the adiabatic region.

  3. Binary systems with monopole, spin, and quadrupole moments

    Microsoft Academic Search

    Chongming Xu; Xuejun Wu; Gerhard Schäfer

    1997-01-01

    The first post-Newtonian equations of motion for binary systems with monopole, spin, and quadrupole interactions are for the first time derived in an explicit and complete form making use of the scheme developed by Damour, Soffel, and Xu, especially their second paper. The equations of motion are expressed in the local coordinate system of body A (B) as well as

  4. Large-Aperture Nb3Sn Quadrupoles for 2 nd generation LHC IRs1

    Microsoft Academic Search

    A. V. Zlobin; E. Barzi; D. Chichili; Yu. Huang; V. V. Kashikhin; M. Lamm; P. J. Limon; N. Mokhov; I. Novitski; T. Peterson; J. B. Strait; S. Yadav

    The 1 st generation of low-beta quadrupoles for the LHC interaction region (IR) was designed to achieve the nominal LHC luminosity of 10 34 cm -2 s -1 . Given that the lifetime of the 1 st generation IR quadrupoles is limited by ionizing radiation to 6-7 years, the 2 nd generation of IR quadrupoles has to be developed with

  5. Tuning multiple Fano resonances in plasmonic pentamer clusters

    NASA Astrophysics Data System (ADS)

    Liu, Shao-Ding; Zhang, Ming-Jiang; Wang, Wen-Jie; Wang, Yun-Cai

    2013-04-01

    Multiple Fano resonances in plasmonic pentamer clusters composed of nanorings are observed and investigated. Molecular point group theory is used to understand the formation of multiple Fano resonances. By modifying the radius of the center ring or the angle between the center and the surrounding rings, the modulation depths and the spectral positions of the multiple Fano resonances can be tuned within a wide range. For pentamers composed of split nanorings, another Fano resonance can be excited because of the excitation of the quadrupole mode of the surrounding split nanorings.

  6. CROSSING A COUPLING SPIN RESONANCE WITH AN RF DIPOLE.

    SciTech Connect

    BAI,M.; ROSER,T.

    2001-06-18

    In accelerators, due to quadrupole roll errors and solenoid fields, the polarized proton acceleration often encounters coupling spin resonances. In the Brookhaven AGS, the coupling effect comes from the solenoid partial snake which is used to overcome imperfection resonances. The coupling spin resonance strength is proportional to the amount of coupling as well as the strength of the corresponding intrinsic spin resonance. The coupling resonance can cause substantial beam polarization loss if its corresponding intrinsic spin resonance is very strong. A new method of using an horizontal rf dipole to induce a full spin flip crossing both the intrinsic and its coupling spin resonances is studied in the Brookhaven's AGS. Numerical simulations show that a full spin flip can be induced after crossing the two resonances by using a horizontal rf dipole to induce a large vertical coherent oscillation.

  7. Dynamics of [C3H5N2]6[Bi4Br18] by means of 1H NMR relaxometry and quadrupole relaxation enhancement

    NASA Astrophysics Data System (ADS)

    Masierak, W.; Florek-Wojciechowska, M.; Oglodek, I.; Jakubas, R.; Privalov, A. F.; Kresse, B.; Fujara, F.; Kruk, D.

    2015-05-01

    1H spin-lattice field cycling relaxation dispersion experiments in the intermediate phase II of the solid [C3H5N2]6[Bi4Br18] are presented. Two motional processes have been identified from the 1H spin-lattice relaxation dispersion profiles and quantitatively described. It has been concluded that these processes are associated with anisotropic reorientations of the imidazolium ring, characterized by correlation times of the order of 10-8 s-10-9 s and of about 10-5 s. Moreover, quadrupole relaxation enhancement (QRE) effects originating from slowly fluctuating 1H-14N dipolar interactions have been observed. From the positions of the relaxation maxima, the quadrupole coupling parameters for the 14N nuclei in [C3H5N2]6[Bi4Br18] have been determined. The 1H-14N relaxation contribution associated with the slow dynamics has been described in terms of a theory of QRE [Kruk et al., Solid State Nucl. Magn. Reson. 40, 114 (2011)] based on the stochastic Liouville equation. The shape of the QRE maxima (often referred to as "quadrupole peaks") has been consistently reproduced for the correlation time describing the slow dynamics and the determined quadrupole coupling parameters.

  8. Dynamics of [C3H5N2]6[Bi4Br18] by means of (1)H NMR relaxometry and quadrupole relaxation enhancement.

    PubMed

    Masierak, W; Florek-Wojciechowska, M; Oglodek, I; Jakubas, R; Privalov, A F; Kresse, B; Fujara, F; Kruk, D

    2015-05-28

    (1)H spin-lattice field cycling relaxation dispersion experiments in the intermediate phase II of the solid [C3H5N2]6[Bi4Br18] are presented. Two motional processes have been identified from the (1)H spin-lattice relaxation dispersion profiles and quantitatively described. It has been concluded that these processes are associated with anisotropic reorientations of the imidazolium ring, characterized by correlation times of the order of 10(-8) s-10(-9) s and of about 10(-5) s. Moreover, quadrupole relaxation enhancement (QRE) effects originating from slowly fluctuating (1)H-(14)N dipolar interactions have been observed. From the positions of the relaxation maxima, the quadrupole coupling parameters for the (14)N nuclei in [C3H5N2]6[Bi4Br18] have been determined. The (1)H-(14)N relaxation contribution associated with the slow dynamics has been described in terms of a theory of QRE [Kruk et al., Solid State Nucl. Magn. Reson. 40, 114 (2011)] based on the stochastic Liouville equation. The shape of the QRE maxima (often referred to as "quadrupole peaks") has been consistently reproduced for the correlation time describing the slow dynamics and the determined quadrupole coupling parameters. PMID:26026454

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  10. Stars as resonant absorbers of gravitational waves

    E-print Network

    McKernan, B; Kocsis, B; Haiman, Z

    2014-01-01

    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 (MBHB) can act as GW-charged batteries, cooling 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.

  11. Stars as resonant absorbers of gravitational waves

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

  12. Electron-scale nested quadrupole Hall field in Cluster observations of magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Jain, N.; Sharma, A. S.

    2015-06-01

    This paper presents the first evidence of a new and unique feature of spontaneous reconnection at multiple sites in electron current sheet, viz. a "nested quadrupole" structure of the Hall field at electron scales, in Cluster observations. The new nested quadrupole is a consequence of electron-scale processes in reconnection. Whistler response of the upstream plasma to the interaction of electron flows from neighboring reconnection sites produces a large-scale quadrupole Hall field enclosing the quadrupole fields of the multiple sites, thus forming a nested structure. Electron-magnetohydrodynamic simulations of an electron current sheet yields a mechanism of the formation of a nested quadrupole.

  13. Ultrasensitive THz sensing with high-Q Fano resonances in metasurfaces

    E-print Network

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

    2014-01-01

    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 ...

  14. Borman effect in resonant diffraction of X-rays

    SciTech Connect

    Oreshko, A. P., E-mail: ap.oreshko@physics.msu.ru [Moscow State University (Russian Federation)

    2013-08-15

    A dynamic theory of resonant diffraction (occurring when the energy of incident radiation is close to the energy of the absorption edge of an element in the composition of a given substance) of synchronous X-rays is developed in the two-wave approximation in the coplanar Laue geometry for large grazing angles in perfect crystals. A sharp decrease in the absorption coefficient in the substance with simultaneously satisfied diffraction conditions (Borman effect) is demonstrated, and the theoretical and first experimental results are compared. The calculations reveal the possibility of applying this approach in analyzing the quadrupole-quadrupole contribution to the absorption coefficient.

  15. Test results of LHC interaction regions quadrupoles produced by Fermilab

    SciTech Connect

    Bossert, R.; Carson, J.; Chichili, D.R.; Feher, S.; Kerby, J.; Lamm, M.J.; Nobrega, A.; Nicol, T.; /Fermilab; Ogitsu, T.; /KEK, Tsukuba; Orris, D.; Page, T.; Peterson, T.; Rabehl, R.; Robotham, W.; /Fermilab; Scanlan, R.; /LBL, Berkeley; Schlabach, P.; Sylvester, C.; Strait, J.; Tartaglia, M.; Tompkins, J.C.; Velev, G.; /Fermilab

    2004-10-01

    The US-LHC Accelerator Project is responsible for the production of the Q2 optical elements of the final focus triplets in the LHC interaction regions. As part of this program Fermilab is in the process of manufacturing and testing cryostat assemblies (LQXB) containing two identical quadrupoles (MQXB) with a dipole corrector between them. The 5.5 m long Fermilab designed MQXB have a 70 mm aperture and operate in superfluid helium at 1.9 K with a peak field gradient of 215 T/m. This paper summarizes the test results of several production MQXB quadrupoles with emphasis on quench performance and alignment studies. Quench localization studies using quench antenna signals are also presented.

  16. SKEW QUADRUPOLES IN RHIC DIPOLE MAGNETS AT HIGH FIELDS.

    SciTech Connect

    JAIN, A.; GUPTA, P.; THOMPSON, P.; WANDERER, P.

    1995-06-11

    In the RHIC arc dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RDIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.

  17. Skew quadrupole in RHIC dipole magnets at high fields

    SciTech Connect

    Jain, A.; Gupta, R.; Thompson, P.; Wanderer, P. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    In the RHIC are dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RHIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.

  18. Skew quadrupole in RHIC dipole magnets at high fields

    SciTech Connect

    Jain, A.; Gupta, P.; Thompson, P.; Wanderer, P.

    1995-07-01

    In the RHIC arc dipoles, the center of the cold mass lies above the center of the cryostat. At the maximum design field, the magnetic flux lines leak through the yoke to the asymmetrically located cryostat, which provides an additional return path. This introduces a systematic top-bottom asymmetry leading to a skew quadrupole term at high fields. A similar asymmetry is also created by any difference in weights of the upper and the lower yoke halves. Data from measurements of several RHIC dipoles are presented to study this effect. In the current production series of the RHIC dipoles, an attempt is made to compensate the effect of the cryostat by an asymmetry in the iron yoke. Seven dipoles with this type of yoke have been cold tested, and show a reduced saturation in the skew quadrupole term, as expected.

  19. Nb3Sn Quadrupoles Designs For The LHC Upgrades

    SciTech Connect

    Felice, Helene

    2008-05-19

    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.

  20. Superferric quadrupoles for FAIR Super FRS energy buncher

    NASA Astrophysics Data System (ADS)

    Pal, G.; Bhunia, U.; Akhter, J.; Nandi, C.; Datta, A.; Sarma, P. R.; Roy, S.; Bajirao, S.; Bhattacharyya, S.; Bhattacharyya, T. K.; Dey, M. K.; Mallik, C.; Bhandari, R. K.

    2012-12-01

    The quadrupole magnets for FAIR Super FRS energy buncher have large usable aperture, high magnetic pole-tip field and high gradient field quality. The iron-dominated magnets with superconducting coils have to be used in this application. The NbTi coil, laminated iron, and support structure of about 22 tons is immersed in liquid helium. The 4.5 K helium chamber is completely covered with a thermal shield cooled by helium at 50-80 K on its outer and inner surface. The helium chamber and thermal shield is enclosed in a vacuum shell. The paper presents design details of the long quadrupole. Coupled thermal, magnetic and structural analysis was carried out to design the magnet iron, magnet coil, helium vessel and support links and ensure the required gradient field quality is achieved. The paper also presents the design of support links and outer vacuum chamber.

  1. 120-mm superconducting quadrupole for interaction regions of hadron colliders

    E-print Network

    Zlobin, A V; Mokhov, N V; Novitski, I

    2012-01-01

    Magnetic and mechanical designs of a Nb3Sn 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.

  2. Performance of An Adjustable Strength Permanent Magnet Quadrupole

    SciTech Connect

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

    2006-03-01

    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.

  3. The chlorine nuclear quadrupole coupling tensor in chlorotrifluoroethylene

    NASA Astrophysics Data System (ADS)

    Hillig, K. W.; Bittner, E. R.; Kuczkowski, R. L.; Lewis-Bevan, W.; Gerry, M. C. L.

    1988-12-01

    The 273 hyperfine components from 56 rotational transitions of chlorotrifluoroethylene were measured with a Fourier transform microwave spectrometer. A global least-squares fit was made to the rotational constants, quartic distortion constants, and 35Cl quadrupole coupling constants; the RMS deviation of the fit was 1.6 kHz. It is shown that such high-resolution measurements enable ?ab to be determined without the near degeneracies usually necessary with less precise data. The principle tensor quadrupole coupling constants are x?zz = -77.46(10), xxx = 38.85(10), and ?yy = xcc = 38.614(3) MHz. The values are comparable to other vinyl chlorides, removing some anomalies from previous studies.

  4. New Mechanical Concept for Nb$_{3}$Sn Quadrupole

    E-print Network

    Karppinen, Mikko

    2014-01-01

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

  5. 120-mm supercondcting quadrupole for interaction regions of hadron colliders

    SciTech Connect

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

    2010-05-01

    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.

  6. Analysis on linac quadrupole misalignment in FACET commissioning 2012

    SciTech Connect

    Sun, Yipeng; /SLAC

    2012-07-05

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

  7. Heavy ion linear accelerator with high-frequency quadrupole focusing

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  8. 120-mm supercondcting quadrupole for interaction regions of hadron colliders

    Microsoft Academic Search

    A. V. Zlobin; V. V. Kashikhin; N. V. Mokhov; I. Novitski

    2010-01-01

    Magnetic and mechanical designs of a NbSn 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

  9. Design and Measurement of the NSLS II Quadrupole Prototypes

    SciTech Connect

    Rehak,M.; Jain, A. K.; Skaritka, J.; Spataro, C.

    2009-05-04

    The design and measurement of the NSLS-II ring quadrupoles prototypes are presented. These magnets are part of a larger prototype program described in [1]. Advances in software, hardware, and manufacturing have led to some new level of insight in the quest for the perfect magnet design. Three geometric features are used to minimize the first three allowed harmonics by way of optimization. Validations through measurement and confidence levels in calculations are established.

  10. Borehole dipole and quadrupole modes in anisotropic formations

    Microsoft Academic Search

    Bikash K. Sinha; Jahir Pabon; Chaur-Jian Hsu

    2003-01-01

    Sonic measurements while drilling are made in the presence of a drill collar (in the form of a thick steel pipe) that provides an additional path for the acoustic energy propagating from the transmitter to an array of receivers. Low-frequency asymptotes of both dipole and quadrupole modes yield the formation far-field shear slowness. Intrinsic or stress-induced anisotropy of surrounding formation

  11. Development of quadrupole mass spectrometers using rapid prototyping technology

    Microsoft Academic Search

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

    2009-01-01

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

  12. Electrostatic quadrupole array for focusing parallel beams of charged particles

    DOEpatents

    Brodowski, John (Smithtown, NY)

    1982-11-23

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

  13. Hybrid permanent magnet quadrupoles for the Recycler Ring at Fermilab

    Microsoft Academic Search

    B. C. Brown; S. M. Pruss; G. W. Foster; H. D. Glass; D. J. Harding; G. R. Jackson; M. R. May; T. H. Nicol; J.-F. Ostiguy; R. Schlabach; J. T. Volk

    1997-01-01

    Hybrid Permanent Magnet Quadrupoles are used in several applications for the Fermilab Recycler Ring and associated beam transfer lines. Most of these magnets use a 0.6096 m long iron shell and provide integrated gradients up to 1.4 T-m\\/m with an iron pole tip radius of 41.6 mm. A 58.4 mm pole radius design is also required. Bricks of 25. 4

  14. Nb3Sn arc quadrupole magnets for VLHC

    Microsoft Academic Search

    Vadim V. Kashikhint; Alexander V. Zlobin

    2001-01-01

    Superconducting quadrupoles with a field gradient of 400-450 T\\/m for a future Very Large Hadron Collider (VLHC) are being studied at Fermilab. To reach the target field gradient in a 40-50 mm aperture, Nb 3Sn superconductor is used at an operating temperature of 4.2 K. Two cases with different magnet functions, beam separation distances and coil arrangements have been analyzed

  15. NMR-NQR study of the crossover from the spin-glass to the superconducting phase in La{sub 2{minus}x}Sr{sub x}CuO{sub 4}

    SciTech Connect

    Julien, M.H.; Carretta, P.; Borsa, F.; Rigamonti, A. [Unita INFM di Pavia (Italy). Dipt. di Fisica] [Unita INFM di Pavia (Italy). Dipt. di Fisica

    1999-04-20

    {sup 139}La and {sup 63}Cu NQR relaxation rates are used to obtain insights on the effects of itinerant holes on the magnetic in-plane correlation length, for x {le} 0.04 in La{sub 2{minus}x}Sr{sub x}CuO{sub 4}. For these concentrations, corresponding to spin-glass behavior at low temperature, evidence for the microsegregation of holes along stripes is presented. Preliminary relaxation results for an amount of Sr doping leading to superconductivity are also presented and discussed in terms of the crossover from the spin-glass to the underdoped superconducting regime: for x = 0.06 a slowing down of spin fluctuations is evidenced and superconductivity is found to coexist with spin-freezing.

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

    SciTech Connect

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

    1987-01-01

    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.

  17. The PEP-II-Factory septum quadrupole magnets

    SciTech Connect

    Swan, J.M.; Harvey, A.R.; Holmes, R.H.; Kendall, C.M.; Yamamoto, R.M.; Yokota, Ted T. [Lawrence Livermore National Lab., CA (United States); Tanabe, J.T.; Schlueter, R.D. [Lawrence Berkeley Lab., CA (United States)

    1995-06-02

    The PEP-II B-Factory is presently engaged design and fabrication of several unique magnets referred to as septum quadrupoles. This family of magnets is required to contain a low energy beam of positrons (3.1 GeV) and a high energy electron beam (9.0 GeV) in adjacent beam pipes housed within a common magnet. One beam will be focused while the other passes through an almost field free region. To do this, an asymmetric magnet must be designed having a pure, high quality quadrupole field in the magnet aperture and an adjacent low field bypass channel. A current sheet or ``septum`` coil must be placed between these two regions to produce the desired magnetic results. Design of this high current density septum coil presents many challenges since space between the two vacuum beam pipes where the coil must reside is very limited. This paper will describe the overall design of the septum quadrupoles and the solutions employed to achieve the required magnetic performance.

  18. The exact calculation of quadrupole sources for some incompressible flows

    NASA Technical Reports Server (NTRS)

    Brentner, Kenneth S.

    1988-01-01

    This paper is concerned with the application of the acoustic analogy of Lighthill to the acoustic and aerodynamic problems associated with moving bodies. The Ffowcs Williams-Hawkings equation, which is an interpretation of the acoustic analogy for sound generation by moving bodies, manipulates the source terms into surface and volume sources. Quite often in practice the volume sources, or quadrupoles, are neglected for various reasons. Recently, Farassat, Long and others have attempted to use the FW-H equation with the quadrupole source and neglected to solve for the surface pressure on the body. The purpose of this paper is to examine the contribution of the quadrupole source to the acoustic pressure and body surface pressure for some problems for which the exact solution is known. The inviscid, incompressible, 2-D flow, calculated using the velocity potential, is used to calculate the individual contributions of the various surface and volume source terms in the FW-H equation. The relative importance of each of the sources is then assessed.

  19. The exact calculation of quadrupole sources for some incompressible flows

    NASA Astrophysics Data System (ADS)

    Brentner, Kenneth S.

    1988-05-01

    This paper is concerned with the application of the acoustic analogy of Lighthill to the acoustic and aerodynamic problems associated with moving bodies. The Ffowcs Williams-Hawkings equation, which is an interpretation of the acoustic analogy for sound generation by moving bodies, manipulates the source terms into surface and volume sources. Quite often in practice the volume sources, or quadrupoles, are neglected for various reasons. Recently, Farassat, Long and others have attempted to use the FW-H equation with the quadrupole source and neglected to solve for the surface pressure on the body. The purpose of this paper is to examine the contribution of the quadrupole source to the acoustic pressure and body surface pressure for some problems for which the exact solution is known. The inviscid, incompressible, 2-D flow, calculated using the velocity potential, is used to calculate the individual contributions of the various surface and volume source terms in the FW-H equation. The relative importance of each of the sources is then assessed.

  20. Particle dynamics in damped nonlinear quadrupole ion traps

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    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.

  1. Spin dynamics in a two-dimensional disordered S=(1)/(2) Heisenberg paramagnet from {sup 63}Cu NQR relaxation in Zn-doped La{sub 2}CuO{sub 4}

    SciTech Connect

    Carretta, P.; Rigamonti, A.; Sala, R. [Department of Physics A. Volta, Unita INFM and Sezione INFN di Pavia, Via Bassi, 6, 27100-I Pavia (Italy)] [Department of Physics A. Volta, Unita INFM and Sezione INFN di Pavia, Via Bassi, 6, 27100-I Pavia (Italy)

    1997-02-01

    {sup 63}Cu NQR T{sub 1} and T{sub 2} relaxation measurements in La{sub 2}Cu{sub 1{minus}x}Zn{sub x}O{sub 4}, for 0{le}x{le}0.11 and in the temperature range T{sub N}{le}T{le}900 K, are presented. The results are used to derive insights into the Cu{sup 2+} correlated spin dynamics in the paramagnetic phase of the S=(1)/(2) two-dimensional (2D) Heisenberg (H) antiferromagnets (AF), and into the disorder effects associated with the spin vacancy due to Zn{sup 2+} (S=0) for Cu{sup 2+} substitution. In particular, by using scaling arguments for the static generalized susceptibility, {chi}({rvec q},0), and for the decay rate, {Gamma}{sub {rvec q}}, of the normal excitations, T{sub 2} and T{sub 1} are related to the in-plane correlation length {xi}{sub 2D}(x,T) and its dependence on temperature and Zn doping, x, is extracted. The experimental findings are analyzed in light of the quantum critical and renormalized classical behaviors for {xi}{sub 2D} predicted by recent theories for S=1/2 HAF on square lattices. It is shown that up to T{approx_equal}900 K, {xi}{sub 2D} is consistent with the assumption of a renormalized classical regime, in agreement with recent neutron scattering results and at variance with previous interpretations of the NQR data. It is discussed how Zn affects {xi}{sub 2D} through the modification in the spin stiffness and comparison with the disorder induced by itinerant extra holes is made.

  2. Parametric-Resonance Ionization Cooling in Twin-Helix.

    SciTech Connect

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

    2011-09-01

    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.

  3. Testing of NB3SN Quadrupole Coils Using Magnetic Mirror Structure

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

    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 Nb3Sn 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.

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

    E-print Network

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

    2014-08-20

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    We report a novel approach for preparing a Bose–Einstein 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 Bose–Einstein condensation of more than 105 atoms.

  6. Testing of Nb3Sn quadrupole coils using magnetic mirror structure

    SciTech Connect

    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

    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.

  7. Electric quadrupole transitions in x-ray spectra: 3d transition-metal oxides

    Microsoft Academic Search

    N. V. Dobrodey; Yu. V. Luniakov

    1995-01-01

    The intensities of the electric quadrupole transitions in the x-ray spectra of the 3d-transition-metal monoxide diatomic molecules were calculated using the discrete variational method of the local-density approximation. The quadrupole transition intensities have been found to be negligible for the left-hand-side 3d metal oxides. It was shown that the electric quadrupole transitions can appreciably contribute to the MKbeta5 emission spectra

  8. A high performance quadrupole quintuplet lens system for the CSIRO–GEMOC nuclear microprobe

    Microsoft Academic Search

    Chris G Ryan; David N Jamieson

    1999-01-01

    A new probe forming system for the CSIRO–GEMOC nuclear microprobe, based on a quadrupole quintuplet lens configuration is described. The lens system uses a novel quadrupole lens design with a 30 mm pole-tip extension, which allows a working distance of 85 mm. Each quadrupole has cut-outs at 45°, in the yoke positioned between poles, to allow unrestricted access for detectors

  9. TDPAC investigations of the111Cd quadrupole interaction in ternary chalcopyrite semiconductors

    NASA Astrophysics Data System (ADS)

    Unterricker, S.; Butz, T.; Tröger, W.

    1991-07-01

    The quadrupole interaction at room temperature of111Cd in CdSiP2, CdGeP2, and CdSnP2 is investigated by111mCd-TDPAC. The results are compared with those of former111In(111Cd) measurements. We observed axially symmetric quadrupole interactions with identical quadrupole coupling constants provided that radiation damage was annealed. This proves that also In probes are positioned at Cd-sites (A-sites) in these ternary compounds.

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

    SciTech Connect

    Kamiya, Y.; Chao, A.W.

    1983-10-01

    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.

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

    PubMed

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

    2015-05-01

    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

  12. Progress in the development of superconducting quadrupoles for heavy ion fusion

    SciTech Connect

    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

    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.

  13. Progress in the Development of Superconducting Quadrupoles forHeavy-ion Fusion

    SciTech Connect

    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

    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.

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

    SciTech Connect

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

    1995-02-01

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

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

    E-print Network

    Hogan, Thomas J.

    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 ...

  16. Aperture limitations for 2nd generation Nb3Sn LHC IR quadrupoles

    SciTech Connect

    Alexander V. Zlobin; Vadim V. Kashikhin; James B. Strait

    2003-06-02

    One of the straightforward ways towards the higher luminosity in the LHC is a replacement of the present 70-mm NbTi quadrupoles with Nb{sub 3}Sn quadrupoles which would provide the same field gradient but in a larger aperture. Conceptual designs of such quadrupoles with 90 mm aperture have been developed and studied. This paper discusses the possibilities and limitations of increasing the aperture of Nb{sub 3}Sn low-beta quadrupoles for a LHC luminosity upgrade up to 110 mm.

  17. Quench margin measurement in Nb3Sn quadrupole magnet

    SciTech Connect

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

    2008-08-01

    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.

  18. 2-MV electrostatic quadrupole injector for heavy-ion fusion

    NASA Astrophysics Data System (ADS)

    Bieniosek, F. M.; Celata, C. M.; Henestroza, E.; Kwan, J. W.; Prost, L.; Seidl, P. A.; Friedman, A.; Grote, D. P.; Lund, S. M.; Haber, I.

    2005-01-01

    High current and low emittance are principal requirements for heavy-ion injection into a linac driver for inertial fusion energy. An electrostatic quadrupole injector is capable of providing these high charge density and low emittance beams. We have modified the existing 2-MV injector to reduce beam emittance and to double the pulse length. We characterize the beam delivered by the modified injector to the High Current Transport Experiment and the effects of finite rise time of the extraction voltage pulse in the diode on the beam head. We demonstrate techniques for mitigating aberrations and reducing beam emittance growth in the injector.

  19. Radio-frequency quadrupole: general properties and specific applications

    SciTech Connect

    Stokes, R.H.; Crandall, K.R.; Hamm, R.W.

    1980-01-01

    The radio-frequency quadrupole (RFQ) linac structure is being developed for the acceleration of low-velocity ions. Recent experimental tests have confirmed its expected performance and have led to an increased interest in a wide range of possible applications. The general properties of RFQ accelerators are reviewed and beam dynamics simulation results are presented for their use in a variety of accelerating systems. These include the low-beta sections of the Fusion Materials Irradiation Test Accelerator, a 200-MHz proton linear accelerator, and a xenon accelerator for heavy ion fusion.

  20. Test of eight superconducting arc quadrupoles for RHIC

    SciTech Connect

    Wanderer, P.; Anerella, M.; Ganetis, G. [and others

    1993-12-31

    Test results from a group of eight superconducting quadrupoles at Brookhaven National Laboratory are presented. The magnets have been designed for use in the arc regions of the Relativistic Heavy Ion Collider now under construction at Brookhaven. Novel features of the design include a single-layer coil, the use of injection-molded phenolic for the pole spacers, and a yoke that also serves as a collar. This R&D series has been used to verify the magnet quench performance and field quality prior to the start of the production run in industry.

  1. Superconducting focusing quadrupoles for heavy ion fusion experiments

    SciTech Connect

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

    2003-05-01

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

  2. Electrostatic quadrupole accelerator for the heavy ion fusion project

    SciTech Connect

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

    1994-12-31

    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.

  3. Scaling laws for aberrations in magnetic quadrupole lens systems

    SciTech Connect

    Moses, R.W.; Heighway, E.A.; Christian, R.S.; Dragt, A.J.

    1987-01-01

    A comparison has been made of the third-order (spherical) abberrations in magnetic quadrupole lenses for use in conventional charged particle beam transport systems. An analytical description of the abberrations is presented and this is compared with the results of high order numerical integration. The dependence of the aberration strength on the system geometry and f number is given and a comparison of doublet and triplet systems made. The reduction of the aberrations in both doublet and triplet systems using embedded magnetic octupole lenses is also discussed and analytical predictions are given.

  4. Tests of high gradient superconducting quadrupole magnets for the Tevatron

    SciTech Connect

    Lamm, M.J.; Carson, J.; Gourlay, S.; Hanft, R.; Koepke, K.; Mantsch, P.; McInturff, A.D.; Riddiford, A.; Strait, J.

    1989-09-01

    Tests have been completed on three prototype magnets and two production magnets to be used for the Tevatron D{phi}/B{phi} low- {beta} insertion. These cold iron, two shell quadrupoles are made of 36 strand Rutherford type NbTi superconducting cable. Magnet field gradients well in excess of the design 1.41 T/cm have been achieved at a transfer function of 0.291 T/cm/kA. Quench performance at 4.2 K and 3.7 K and magnetic multipole measurement data are presented and discussed. 9 refs., 4 figs., 4 tabs.

  5. Transport properties of a discrete helical electrostatic quadrupole

    SciTech Connect

    Meitzler, C.R.; Antes, K.; Datte, P.; Huson, F.R. (Texas Accelerator Center, The Woodlands, TX (United States)); Xiu, L. (Houston Univ., TX (United States). Inst. for Beam Particle Dynamics)

    1991-01-01

    The helical electrostatic quadrupole (HESQ) lens has been proposed as a low energy beam transport system which permits intense H{sup {minus}} beams to be focused into an RFQ without seriously increasing the beam's emittance. A stepwise continuous HESQ lens has been constructed, and preliminary tests have shown that the structure does provide focusing. In order to understand the transport properties of this device, further detailed studies have been performed. Emittances were measured 3.5 cm from the end of the HESQ at two different voltages on the HESQ electrodes. A comparison of these experimental results with a linear model of the HESQ beam transport is made. 4 refs., 5 figs.

  6. Optically plugged quadrupole trap for Bose-Einstein condensates

    SciTech Connect

    Naik, D.S.; Raman, C. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2005-03-01

    We created sodium Bose-Einstein condensates in an optically plugged quadrupole magnetic trap. A focused, 532-nm laser beam repelled atoms from the coil center where Majorana loss is significant. We produced condensates containing up to 3x10{sup 7} atoms, a factor of 60 improvement over previous work and a number comparable to the best all-magnetic traps, and transferred up to 9x10{sup 6} atoms into a purely optical trap. We compare our observations with a simple model of evaporative cooling, concluding that a laser in the range of 1 W (rather than 5 W) may suffice.

  7. Miniature quadrupole mass spectrometer having a cold cathode ionization source

    DOEpatents

    Felter, Thomas E. (Livermore, CA)

    2002-01-01

    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.

  8. Nb{sub 3}Sn ARC quadrupole magnets for VLHC

    SciTech Connect

    Vadim V. Kashikhin and Alexander V. Zlobin

    2001-07-30

    Superconducting quadrupoles with a field gradient of 400-450 T/m for a future Very Large Hadron Collider (VLHC) are being studied at Fermilab. To reach the target field gradient in a 40-50 mm aperture, Nb{sub 3}Sn superconductor is used at an operating temperature of 4.2 K. Two cases with different magnet functions, beam separation distances and coil arrangements have been analyzed and optimized in order to provide the required field quality and magnet parameters.

  9. Single layer quadrupole design for SSC (Superconducting Super Collidar)

    SciTech Connect

    Thompson, P.A.; Cottingham, J.; Dahl, P.; Garber, M.; Ghosh, A.; Goodzeit, C.; Greene, A.; Hahn, H.; Herrera, J.; Kahn, S.

    1987-01-01

    The proposed Superconducting Super Collider (SSC) will require 1360 regular arc quadrupoles. This paper describes a single layer design for these magnets. This design is economically competitive with the more conventional two layer design and appears to be well suited to mass production because of its simplicity. The design uses 9 turns of Cu(NbTi) superconducting cable to produce an 155 Tesla/meter gradient at the 20 TeV peak energy. The systematic field harmonics are all better than the requirements. Detailed results of both magnetic and mechanical analyses are presented.

  10. Finding the Magnetic Center of a Quadrupole to High Resolution

    SciTech Connect

    Fischer, G.E.; Cobb, J.K.; Jenson, D.R.; /SLAC

    2005-08-12

    In a companion pro, collposal it is proposed to align quadrupoles of a transport line to within transverse tolerances of 5 to 10 micrometers. Such a proposal is meaningful only if the effective magnetic center of such lenses can in fact be repeatably located with respect to some external mechanical tooling to comparable accuracy. It is the purpose of this note to describe some new methods and procedures that will accomplish this aim. It will be shown that these methods are capable of yielding greater sensitivity than the more traditional methods used in the past. The notion of the ''nodal'' point is exploited.

  11. Powder MAS NMR lineshapes of quadrupolar nuclei in the presence of second-order quadrupole interaction.

    PubMed

    Ajoy, G; Ramakrishna, J; Bahçeli, S; Klinowski, J

    2000-07-01

    We derive a complete analytical solution for the powder magic angle spinning (MAS) nuclear magnetic resonance (NMR) lineshape in the presence of second-order quadrupole interaction, considering a radiofrequency (rf) pulse of finite width, a finite MAS frequency, and a non-zero asymmetry parameter. (Ix) is calculated using two approaches. The first applies time-dependent perturbation theory in the presence of the rf pulse and stationary perturbation theory (SPT) in its absence. The second is based on the Magnus expansion of the density matrix in the interaction representation during the pulse and SPT in its absence. We solve the problem in the laboratory frame using the properties of the Fourier transform and spin operators. Diagonalisation is not required. Both approaches agree well with each other under all conditions and also with the transition probability approach for the central transition. The Magnus expansion exists at all times and the effect of the non-secular terms is negligible. We describe an analytical method of averaging (Ix) over the Euler angles and simulate the 11B MAS NMR lineshapes for crystalline and vitreous B2O3. A critical analysis is given of all earlier calculations of the MAS NMR lineshape. PMID:10928635

  12. Quadrupole moments of rotating neutron stars and strange stars

    E-print Network

    Urbanec, Martin; Stuchlik, Zdenek

    2013-01-01

    We present results for models of neutron stars and strange stars constructed using the Hartle-Thorne slow-rotation method with a wide range of equations of state, focusing on the values obtained for the angular momentum $J$ and the quadrupole moment $Q$, when the gravitational mass $M$ and the rotational frequency $\\Omega$ are specified. Building on previous work, which showed surprising uniformity in the behaviour of the moment of inertia for neutron-star models constructed with widely-different equations of state, we find similar uniformity for the quadrupole moment. These two quantities, together with the mass, are fundamental for determining the vacuum space-time outside neutron stars. We study particularly the dimensionless combination of parameters $QM/J^2$ (using units for which $c=G=1$). This quantity goes to 1 in the case of a Kerr-metric black hole and deviations away from 1 then characterize the difference between neutron-star and black-hole space-times. It is found that $QM/J^2$ for both neutron s...

  13. Performance of Nb3Sn Quadrupole Under High Stress

    SciTech Connect

    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

    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.

  14. Quadrupole Approximation for Para-Positronium in Relativistic Schrödinger Theory

    E-print Network

    M. Mattes; M. Sorg

    2011-09-11

    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.

  15. The quadrupole model for rigid-body gravity simulations

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

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

  16. Adjustable Permanent Quadrupoles for the Next Linear Collider

    NASA Astrophysics Data System (ADS)

    Spencer, C. M.

    2001-10-01

    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 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.

  17. Adjustable permanent quadrupoles for the next linear collider

    SciTech Connect

    James T. Volk et al.

    2001-06-22

    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.

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

    E-print Network

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

    1999-01-01

    -weighted sum rule (EWSR) is consistent with two peaks at E-x = 12.1 +/- 0.4 MeV and 15.5 +/- 0.3 MeV containing (36 +/- 10)% and (68 /- 9)% of the EWSR and the E2 strength distribution containing (103(-20)(+18))% of the EWSR is consistent with three peaks at E...

  19. Digital Methods of Detecting a Low-Frequency Nuclear Quadrupole Resonance

    Microsoft Academic Search

    É. O. Azizov; V. S. Grechishkin; A. V. Gaevskii; V. V. Korostelev

    2003-01-01

    absorption signal [2] was used. In 1985, a new device operating at a frequency of 5192 kHz (RDX) [3] was developed to detect TS-2.5, TS-6, and M-14 mines (its operation frequency for tetryl detection was 5290 kHz). In the process of mine fabrication, molten tetryl solidifies directly in the mine body and represents a solid solution; therefore, the N 14

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

    E-print Network

    Clemmer, David E.

    Ion Trap/Ion Mobility/Quadrupole/Time-of-Flight Mass Spectrometry for Peptide Mixture Analysis IN, 47405 An ion trap/ion mobility/quadrupole/time-of-flight mass spectrometer has been developed tube where ions separate ac- cording to differences in gas-phase ion mobilities. Upon exiting the drift

  1. COMPARISON OF PRIORITY POLLUTANT RESPONSE FACTORS FOR TRIPLE AND SINGLE QUADRUPOLE MASS SPECTROMETERS

    EPA Science Inventory

    Seventy-four percent of the electron impact GC/MS response factors (RF) determined on a triple quadrupole mass spectrometer for 53 extractable priority pollutants were found to be within + or - 15 percent of values determined in an independent interlaboratory single quadrupole GC...

  2. Effects of extreme magnetic quadrupole fields on penning traps and the consequences for antihydrogen trapping.

    PubMed

    Fajans, J; Bertsche, W; Burke, K; Chapman, S F; van der Werf, D P

    2005-10-01

    Measurements on electrons confined in a Penning trap show that extreme quadrupole fields destroy particle confinement. Much of the particle loss comes from the hitherto unrecognized ballistic transport of particles directly into the wall. The measurements scale to the parameter regime used by ATHENA and ATRAP to create antihydrogen, and suggest that quadrupoles cannot be used to trap antihydrogen. PMID:16241731

  3. SECOND GENERATION HIGH GRADIENT QUADRUPOLES FOR THE LHC INTERACTION REGIONS1

    E-print Network

    Large Hadron Collider Program

    . A quadrupole with a 90 mm coil aperture and the same 200 T/m gradient as in the current LHC IR is technically a nominal field gradient of 200 T/m at the high luminosity insertions with 70-mm coils, and operate at 1.9KSECOND GENERATION HIGH GRADIENT QUADRUPOLES FOR THE LHC INTERACTION REGIONS1 T. Sen, J. Strait

  4. Measuring the Magnetic Center Behavior of an ILC Superconducting Quadrupole Prototype

    SciTech Connect

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

    2011-02-07

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

  5. Impact of Quadrupole offset and Undulator end-kicks on the

    E-print Network

    [5, 6, 7, 8]. Therefore, in this report we study the quadrupole offset and undulator end-kick due kicked due to gap dependent end fields with a similar impact. In this report, the effect of bothImpact of Quadrupole offset and Undulator end-kicks on the European-XFEL facility Performance Yuhui

  6. Adjustable permanent quadrupoles using rotating magnet material rods for the Next Linear Collider

    Microsoft Academic Search

    J. DiMarco; G. W. Foster; W. Fowler; V. S. Kashikhin; A. Makarov; C. E. Rago; A. Ringwall; C. M. Spencer; V. Tsvetkov; J. T. Volk; Z. Wolf

    2002-01-01

    The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 132 Tesla, with a maximum gradient of 135 Tesla per meter, an adjustment range of +0 -20% and effective lengths from 324 mm to 972 mm. The

  7. Design and Manufacture of a Hybrid Final Focus Quadrupole Model for CLIC

    Microsoft Academic Search

    Alexey Vorozhtsov; Michele Modena; Davide Tommasini

    2012-01-01

    A tunable hybrid quadrupole magnet design has been proposed for the final focus in the Compact Linear Collider (CLIC) that is currently under study. The proposed design is a combination of an iron dominated electromagnetic quadrupole with a bore diameter of 8.25 mm with permanent magnet blocks placed between the poles made of soft magnetic CoFe alloy “Permendur”. The possibility

  8. Adjustable Permanent Quadrupoles Using Rotating Magnet Material Rods for the Next Linear Collider

    Microsoft Academic Search

    Cherrill M

    2002-01-01

    The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 132 Tesla, with a maximum gradient of 135 Tesla per meter, an adjustment range of +0 -20% and effective lengths from 324 mm to 972 mm. The

  9. Study of condensational growth of water droplets by Mie resonance spectroscopy

    Microsoft Academic Search

    K. H. Fung; I. N. Tang; H. R. Munkelwitz

    1987-01-01

    An optical technique using MIE resonance scattering spectroscopy to monitor the growth of a saline solution droplet is presented. This technique utilizes a quadrupole particle trap to suspend a charged NaCl solution droplet in water vapor environment and a COâ laser to momentarily perturb the droplet-vapor equilibrium. The condensational growth of this droplet is monitored by means of multiple Mie

  10. Isotopically selective counting of noble gas atoms, using resonance ionization spectroscopy

    Microsoft Academic Search

    C. H. Chen

    1984-01-01

    The technique of Resonance Ionization Spectroscopy (RIS) is being extended to develop a means for counting individual atoms of a selected isotope of a noble gas. In this method, lasers are used for RIS to obtain atomic species (Z) selectivity and a small quadrupole mass spectrometer provides isotopic (A) selectivity. A progress report on the objective of counting each atom

  11. Theoretical aspects of resonant X-ray emission spectroscopy

    Microsoft Academic Search

    A. Kotani

    2004-01-01

    We report recent theoretical topics for resonant X-ray emission spectroscopy (RXES) in d and f electron systems: (1) RXES in high Tc cuprates, (2) effects of electric quadrupole excitation, and (3) magnetic circular dichroism (MCD) in RXES for ferromagnetic systems. In high Tc cuprates, RXES with Cu 1s excitation detects a 6eV charge transfer excitation whose intensity is affected by

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

    SciTech Connect

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

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

  14. Auxiliary Frequency Parametric Excitation of Quadrupole Mass Spectrometers

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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.

  15. Low-temperature nuclear magnetic resonance investigation of systems frustrated by competing exchange interactions

    NASA Astrophysics Data System (ADS)

    Roy, Beas

    This doctoral thesis emphasizes on the study of frustrated systems which form a very interesting class of compounds in physics. The technique used for the investigation of the magnetic properties of the frustrated materials is Nuclear Magnetic Resonance (NMR). NMR is a very novel tool for the microscopic study of the spin systems. NMR enables us to investigate the local magnetic properties of any system exclusively. The NMR experiments on the different systems yield us knowledge of the static as well as the dynamic behavior of the electronic spins. Frustrated systems bear great possibilities of revelation of new physics through the new ground states they exhibit. The vandates AA'VO(PO4)2 [AA' ? Zn2 and BaCd] are great prototypes of the J1-J2 model which consists of magnetic ions sitting on the corners of a square lattice. Frustration is caused by the competing nearest-neighbor (NN) and next-nearest neighbor (NNN) exchange interactions. The NMR investigation concludes a columnar antiferromagnetic (AFM) state for both the compounds from the sharp peak of the nuclear spin-lattice relaxation rate (1/T1) and a sudden broadening of the 31P-NMR spectrum. The important conclusion from our study is the establishment of the first H-P-T phase diagram of BaCdVO(PO4)2. Application of high pressure reduces the saturation field (HS) in BaCdVO(PO4)2 and decreases the ratio J2/J1, pushing the system more towards a questionable boundary (a disordered ground state) between the columnar AFM and a ferromagnetic ground state. A pressure up to 2.4 GPa will completely suppress HS. The Fe ions in the `122' iron-arsenide superconductors also sit on a square lattice thus closely resembling the J1-J2 model. The 75As-NMR and Nuclear Quadrupole Resonance (NQR) experiments are conducted in the compound CaFe2As2 prepared by two different heat treatment methods (`as-grown' and `annealed'). Interestingly the two samples show two different ground states. While the ground state of the `as-grown' sample shows a non-magnetic collapsed tetragonal phase (with no magnetic fluctuations), the ground state of the `annealed' sample shows a magnetically long-range ordered orthorhombic phase. The temperature dependence of 1/T1 and that of Knight shift showed that the electron correlations completely disappear in the nonsuperconducting collapsed tetragonal phase in `as-grown' sample of CaFe2As2 indicating quenching of Fe moments. The insulating A-site spinel compound CoAl2O4 exhibits frustration due to competing NN and NNN exchange interactions. This compound has been studied for a long time yet there has been a contradiction as to what the ground state of this compound is. The origin of this ambiguity was pointed out to be microstructure effects such as site-inversion between Co and Al. Thus depending on the value of degree of site inversion x [(Co{1-x}Alx)[Al{2-x}Cox]O4], the ground states differ. A very high quality sample was prepared (x ? 0.06) and 27Al and 59Co NMR were performed to study the ground state of this compound. Together with the results from heat capacity, magnetic measurements and neutron diffraction measurements we conclude that the ground state is collinear AFM. We settled a long debated problem for the ground state of CoAl2O4. The compound BiMn2PO6 is a magnetically frustrated system with three-dimensional magnetic ordering. Frustration in this compound is caused by the comparable values of the exchange interactions along the chain, along the rung and in between the ladders. Thus the magnetic structure of this compound is quite complex with the temperature dependence of magnetic susceptibility exhibiting peak at 30 K, a jump at 43 K and a change of slope at 10 K. 31P-NMR study was done on this system to investigate the nature of transitions (if any) at these temperatures. NMR study suggested a long-range AFM transition at 30 K with a sharp peak in 1/T1. No signature of transition at 43 K suggested its origin is extrinsic. Between 10 K and 30 K the NMR spectra proved the existence of a commensurate magnetic order while below 10 K, the shape of

  16. Magnetic resonance cell

    SciTech Connect

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

    1984-05-01

    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.

  17. Shape-Dependent Surface Plasmon Resonance of AG Nanocrystallines in Opaa Template

    NASA Astrophysics Data System (ADS)

    Han, Shanshan; Yang, Xiu-Chun

    2012-08-01

    Transparent Ag/OPAA composite films were prepared by filling silver nanocrystallines (NCs) into an ordered porous anodic alumina (OPAA) templates using a direct current (DC) deposition technique. The broad and significant absorption peak in visible light region for each transparent Ag/OPAA composite could be attributed to surface plasmon resonance (SPR) of Ag NCs. The SPR peak could be separated into three peaks by Lorentzian fits, which corresponded to transverse quadrupole resonance, transverse dipole resonance and longitudinal resonance, respectively. The influences of size, shape and volume fraction of Ag NCs on the maxima and intensities of SPR peaks were discussed.

  18. Abstract--A Modular Design and Modular Program is introduced here for high gradient quadrupoles. The proposed

    E-print Network

    Gupta, Ramesh

    high gradient quadrupole designs using flat racetrack coils have been considered earlier, they have creates a gradient in flat racetrack coils quadrupoles that is close to the gradient that is achieved. In such designs, turns at midplane are away from the coil radius. Very high gradient quadrupoles, such as those

  19. Abstract--The development of insertion quadrupoles with 205 T/m gradient and 90 mm bore represents a promising

    E-print Network

    Large Hadron Collider Program

    is needed in order to achieve high gradient. The required coil thickness for this application is about 30 mm2LC03 1 Abstract-- The development of insertion quadrupoles with 205 T/m gradient and 90 mm bore Hadron Collider, Quadrupole, Superconducting Magnets. I. INTRODUCTION IGH gradient NbTi quadrupoles

  20. Effects of charge inhomogeneities on elementary excitations in La2-xSrxCuO?

    DOE PAGESBeta

    Park, S. R.; Hamann, A.; Pintschovius, L.; Lamago, D.; Khaliullin, G.; Fujita, M.; Yamada, K.; Gu, G. D.; Tranquada, J. M.; Reznik, D.

    2011-12-01

    Purely local experimental probes of many copper oxide superconductors show that their electronic states are inhomogeneous in real space. For example, scanning tunneling spectroscopic imaging shows strong variations in real space, and according to nuclear quadrupole resonance (NQR) studies, the charge distribution in the bulk varies on the nanoscale. However, the analysis of the experimental results utilizing spatially averaged probes often ignores this fact. We have performed a detailed investigation of the doping dependence of the energy and linewidth of the zone-boundary Cu-O bond-stretching vibration in La2-xSrxCuO? by inelastic neutron scattering. Both our results as well as previously reported angle-dependentmore »momentum widths of the electronic spectral function detected by angle-resolved photoemission can be reproduced by including the same distribution of local environments extracted from the NQR analysis.« less

  1. Effects of charge inhomogeneities on elementary excitations in La2-xSrxCuO?

    SciTech Connect

    Park, S. R.; Hamann, A.; Pintschovius, L.; Lamago, D.; Khaliullin, G.; Fujita, M.; Yamada, K.; Gu, G. D.; Tranquada, J. M.; Reznik, D.

    2011-12-01

    Purely local experimental probes of many copper oxide superconductors show that their electronic states are inhomogeneous in real space. For example, scanning tunneling spectroscopic imaging shows strong variations in real space, and according to nuclear quadrupole resonance (NQR) studies, the charge distribution in the bulk varies on the nanoscale. However, the analysis of the experimental results utilizing spatially averaged probes often ignores this fact. We have performed a detailed investigation of the doping dependence of the energy and linewidth of the zone-boundary Cu-O bond-stretching vibration in La2-xSrxCuO? by inelastic neutron scattering. Both our results as well as previously reported angle-dependent momentum widths of the electronic spectral function detected by angle-resolved photoemission can be reproduced by including the same distribution of local environments extracted from the NQR analysis.

  2. Investigation of a quadrupole ultra-high vacuum ion pump

    NASA Technical Reports Server (NTRS)

    Schwarz, H. J.

    1974-01-01

    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.

  3. Thermal noise in aqueous quadrupole micro- and nano-traps

    PubMed Central

    2012-01-01

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

  4. Plasma-beam traps and radiofrequency quadrupole beam coolers

    SciTech Connect

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

    2014-02-15

    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.

  5. Restoring the skew quadrupole moment in the Tevatron dipoles

    SciTech Connect

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

    2005-05-01

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

  6. Guidelines for the design of very large aperture quadrupole magnets

    SciTech Connect

    Daeel, A.; Jorda, J.P.; Kircher, F.; Mayri, C. [CEA-DSM/DAPNIA, Gif-sur-Yvette (France). Service Technique de Cryogenie et de Magnetisme] [CEA-DSM/DAPNIA, Gif-sur-Yvette (France). Service Technique de Cryogenie et de Magnetisme

    1996-07-01

    Very large aperture quadrupole magnets have been recently considered as possible spectrometers on high energy colliders. The interesting characteristics are zero field on beam axis, low fields at small angles, transverse field at large angles. Dimension range is 1 m to 5 m for clear bore and 2 m to 8 m for length; typical maximum field is 2.5 T. Superconducting magnets with cosine 2 {theta} structure, coils with one or two layers and iron yoke have been modeled. Use of two types of conductors have been investigated: Rutherford cable and aluminium stabilized composite. The paper describes the optimization procedure and gives diagrams of feasibility. Two alternative structures are mentioned: superferric and active shield magnets.

  7. Nb3Sn Quadrupole Magnets for the LHC IR

    SciTech Connect

    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

    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.

  8. Quadrupole collectivity of neutron-rich Neon isotopes

    E-print Network

    R. R. Rodriguez-Guzman; J. L. Egido; L. M. Robledo

    2003-02-04

    The angular momentum projected Generator Coordinate Method, with the quadrupole moment as collective coordinate and the Gogny force (D1S) as the effective interaction, is used to describe the properties of the ground state and low-lying excited states of the even-even Neon isotopes $^{20-34}$Ne, that is, from the stability valley up to the drip-line. It is found that the ground state of the N=20 nucleus $^{30}$Ne is deformed but to a lesser extent than the N=20 isotope of the Magnesium. In the calculations, the isotope $^{32}$Ne is at the drip-line in good agreement with other theoretical predictions. On the other hand, rather good agreement with experimental data for many observables is obtained.

  9. Quadrupole collectivity in neutron-rich Fe and Cr isotopes.

    PubMed

    Crawford, H L; Clark, R M; Fallon, P; Macchiavelli, A O; Baugher, T; Bazin, D; Beausang, C W; Berryman, J S; Bleuel, D L; Campbell, C M; Cromaz, M; de Angelis, G; Gade, A; Hughes, R O; Lee, I Y; Lenzi, S M; Nowacki, F; Paschalis, S; Petri, M; Poves, A; Ratkiewicz, A; Ross, T J; Sahin, E; Weisshaar, D; Wimmer, K; Winkler, R

    2013-06-14

    Intermediate-energy Coulomb excitation measurements are performed on the N ? 40 neutron-rich nuclei (66,68)Fe and (64)Cr. The reduced transition matrix elements providing a direct measure of the quadrupole collectivity B(E2;2(1)(+) ? 0(1)(+)) are determined for the first time in (68)Fe(42) and (64)Cr(40) and confirm a previous recoil distance method lifetime measurement in (66)Fe(40). The results are compared to state-of-the-art large-scale shell-model calculations within the full fpgd neutron orbital model space using the Lenzi-Nowacki-Poves-Sieja effective interaction and confirm the results of the calculations that show these nuclei are well deformed. PMID:25165918

  10. Alternative Mechanical Structure for LARP Nb3Sn Quadrupoles

    SciTech Connect

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

    2010-08-01

    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.

  11. Nuclear electric quadrupole moment of gold from the molecular method

    NASA Astrophysics Data System (ADS)

    Santiago, Régis Tadeu; Haiduke, Roberto Luiz Andrade

    2015-04-01

    The nuclear electric quadrupole moment (NQM) of gold is reviewed by means of the molecular method and data from as many as 15 linear systems. The electric-field gradients (EFGs) used to this end were obtained with the Dirac-Coulomb Hamiltonian and coupled-cluster theory, CCSD(T) and CCSD-T, by means of an augmented relativistic basis set for gold. The direct approach was found to be inadequate for the diatomic molecules investigated, which is probably due to improper treatment of the static electron correlation. However, these effects are much less relevant for OCAu X (X =F ,Cl ,Br , and I ) complexes. Thus, the indirect version of the molecular method is preferred in this case. Hence, a NQM value of 515(15) mb is determined for 197Au from linear regressions performed with the best EFGs determined for ten of these systems.

  12. Covariant Spectator Theory of np scattering: Deuteron Quadrupole Moment

    DOE PAGESBeta

    Gross, Franz

    2015-01-01

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

  13. Covariant Spectator Theory of np scattering: Deuteron Quadrupole Moment

    DOE PAGESBeta

    Gross, Franz

    2015-01-01

    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 chiral effect field theory predictions to order next-to-next-to-next-to-leading order.

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

    SciTech Connect

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

    1988-01-01

    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.

  15. Optical resonator

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    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.

  16. Superconducting fluctuations and {sup 63}Cu NQR-NMR relaxation in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}: Effect of magnetic field and a test for the pairing-state symmetry

    SciTech Connect

    Carretta, P. [Department of Physics ``A. Volta,`` Sezione di Pavia, Istituto Nazionale di Fisica Nucleare and Unita Instituto Nazionale di Fisica della Materia, University of Pavia, Via Bassi 6, I-27100, Pavia (Italy)] [Department of Physics ``A. Volta,`` Sezione di Pavia, Istituto Nazionale di Fisica Nucleare and Unita Instituto Nazionale di Fisica della Materia, University of Pavia, Via Bassi 6, I-27100, Pavia (Italy); Livanov, D.V. [Department of Theoretical Physics, Moscow Institute of Steel and Alloys, 117936 Moscow (Russia)] [Department of Theoretical Physics, Moscow Institute of Steel and Alloys, 117936 Moscow (Russia); Rigamonti, A. [Department of Physics ``A. Volta,`` Sezione di Pavia, Istituto Nazionale di Fisica Nucleare and Unita Instituto Nazionale di Fisica della Materia, University of Pavia, Via Bassi 6, I-27100, Pavia (Italy)] [Department of Physics ``A. Volta,`` Sezione di Pavia, Istituto Nazionale di Fisica Nucleare and Unita Instituto Nazionale di Fisica della Materia, University of Pavia, Via Bassi 6, I-27100, Pavia (Italy); Varlamov, A.A. [Department of Theoretical Physics, Moscow Institute of Steel and Alloys, 117936 Moscow (Russia)] [Department of Theoretical Physics, Moscow Institute of Steel and Alloys, 117936 Moscow (Russia); [Laboratorium ``Forum,`` Instituto Nazionale di Fisica della Materia, Department of Physics, University of Florence, Florence (Italy)

    1996-10-01

    Evidence is presented of superconducting fluctuations in the {sup 63}Cu NQR-NMR relaxation rate in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}, as obtained from a careful comparison of measurements carried out in the absence and in the presence of a field parallel to the {ital c} axis. It is shown that the field causes a reduction of the relaxation rate {ital W} in a range of about 10 K above {ital T}{sub {ital c}}. This effect is related to the suppression by the magnetic field of the phase-sensitive positive Maki-Thompson contribution while the negative contribution from the DOS fluctuations is almost field independent. Furthermore, it is argued how the fluctuation effects on {ital W} can be used to discuss the pairing state symmetry, at variance with the insensitivity of the transport measurements. It is pointed out that the existence of the Maki-Thompson contribution to {ital W} evidences an {ital s}-wave symmetry component for the pairing in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. {copyright} {ital 1996 The American Physical Society.}

  17. Monte Carlo simulations of solute ordering in nematic liquid crystals: Shape anisotropy and quadrupole-quadrupole interactions as orienting mechanisms

    NASA Astrophysics Data System (ADS)

    Polson, James M.; Burnell, E. Elliott

    1997-04-01

    Monte Carlo computer simulations were used to investigate the effects of shape anisotropy and electrostatic interactions as mechanisms for orientational ordering of solutes in nematic liquid crystals. The simulation results were analyzed in terms of two theories of solute ordering which derive mean-field orientational potentials from the intermolecular pair potential. In the calculations, solute and solvent molecular shapes were approximated by hard ellipsoids. Most simulations also incorporated the interaction between point quadrupole moments placed at the centers of the ellipsoids. In the hard-core systems, orientational order parameters and distribution functions were calculated for a collection of different solutes under a variety of conditions. A theory due to Terzis and Photinos [Mol. Phys. 83, 847 (1994)] was found to underestimate the effect of shape anisotropy on orientational ordering drastically. The introduction of an effective solvent packing fraction was unable to improve the predictive power of the theory significantly. The quadrupolar systems were used to investigate a mean-field model for solute ordering which considers an interaction between the solute molecular quadrupole moment with an average electric-field gradient. The simulations indicate that the electric-field gradient sampled by the solute is highly dependent on the properties of the solute, contrary to some experimental evidence. Further, the effects of the intermolecular quadrupolar interactions on orientational ordering and the electric-field gradient were analyzed using a mean-field potential derived here and based on the theory due to Emsley, Palke, and Shilstone [Liq. Cryst. 9, 649 (1991)]. This model was found to provide a qualitatively correct but quantitatively imprecise prediction of orientational ordering.

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

    SciTech Connect

    Gökçe, Yasin, E-mail: ygokce58@gmail.com [Department of Physics, Faculty of Science, Karamanoglu Mehmetbey University, Karaman (Turkey); Çelik, Gültekin [Department of Physics, Faculty of Science, Selçuk 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

    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 Hartree–Fock 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.

  19. Electric quadrupole transitions in x-ray spectra: 3d transition-metal oxides

    NASA Astrophysics Data System (ADS)

    Dobrodey, N. V.; Luniakov, Yu. V.

    1995-02-01

    The intensities of the electric quadrupole transitions in the x-ray spectra of the 3d-transition-metal monoxide diatomic molecules were calculated using the discrete variational method of the local-density approximation. The quadrupole transition intensities have been found to be negligible for the left-hand-side 3d metal oxides. It was shown that the electric quadrupole transitions can appreciably contribute to the MK?5 emission spectra of the right-hand-side 3d metal oxides, along with the dipole transitions.

  20. Moments of the neutron charge form factor and the N->Delta quadrupole transition

    E-print Network

    P. Grabmayr; A. J. Buchmann

    2001-04-20

    Recent data allow a new parametrization of the neutron charge form factor G_En. A parameter-free quark model relation between G_En and the N->Delta quadrupole form factor is used to predict the latter from the G_En data. In particular, the neutron charge radius is related to N->Delta quadrupole moment, while the fourth moment of G_En connects to the N->Delta quadrupole transition radius. From the latter we derive an experimental value for the charge radius of the light constituent quarks. Finally, the C2/M1 ratio in pion electroproduction is predicted from the elastic neutron form factor data.

  1. TDPAC investigations of the 111 Cd quadrupole interaction in ternary chalcopyrite semiconductors

    Microsoft Academic Search

    S. Unterricker; T. Butz; W. Tröger

    1991-01-01

    The quadrupole interaction at room temperature of111Cd in CdSiP2, CdGeP2, and CdSnP2 is investigated by111mCd-TDPAC. The results are compared with those of former111In(111Cd) measurements. We observed axially symmetric quadrupole interactions with identical quadrupole coupling constants provided\\u000a that radiation damage was annealed. This proves that also In probes are positioned at Cd-sites (A-sites) in these ternary\\u000a compounds.

  2. Measurement of time dependent fields in high gradient superconducting quadrupoles for the Tevatron

    SciTech Connect

    Lamm, M.J.; Coulter, K.; Gourlay, S.; Jaffery, T.S.

    1990-10-01

    Magnetic field measurements have been performed on prototype and production magnets from two high gradient superconducting quadrupoles designs. One design is a double shell quadrupole with 36 strand Rutherford cable. The other design is a single shell quadrupole with 5 individually monolithic strands connected in series. These magnets have similar bore diameters and cable dimensions. However, there are significant differences between the two designs, as well as differences between prototype and production magnets within each design, with regard to Cu to superconductor ratio, filament diameter and filament spacing to strand diameter. The time dependence of fixed currents of the measured magnetic fields is discussed. 9 refs., 6 figs., 1 tab.

  3. Gravitational waves from inspiraling compact binaries: The quadrupole-moment term

    E-print Network

    Eric Poisson

    1997-09-12

    A rotating star's oblateness creates a deformation in the gravitational field outside the star, which is measured by the quadrupole-moment tensor. We consider the effect of the quadrupole moment on the orbital motion and rate of inspiral of a compact binary system, composed of neutron stars and/or black holes. We find that in the case of circular orbits, the quadrupole-monopole interaction affects the relation between orbital radius and angular velocity, and also the rate of inspiral, by a quantity of order (v/c)^4, where v is the orbital velocity and c the speed of light.

  4. Nb3Sn quadrupoles in the LHC IR Phase I upgrade

    SciTech Connect

    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

    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.

  5. Nb3Sn Quadrupoles in the LHC IR Phase I Upgrade

    SciTech Connect

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

    2008-06-23

    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.

  6. Multipole Surface Plasmon Resonance in Electrodeposited Gold Nanoparticles

    NASA Astrophysics Data System (ADS)

    Mandke, Mohanrao V.; Pathan, Habib M.

    2014-05-01

    Electrodeposition is a convenient, economical and template-free tool to create the gold nanostructures. A two-electrode electrochemical process is used for the deposition process. In this method by controlling the deposition time and electrode potential, nearly spherical and rod-like gold nanostructures were synthesized through the reduction of Chlorauric acid with citric acid as a complexing agent. Spherical gold nanostructures of different size around 2 nm to 30 nm and rod-like nanostructures with an aspect ratio 0.5 were grown directly on fluorine-doped tin oxide (FTO)-coated glass substrate. The growth mechanism of gold nanostructures is explained with the help of oriented attachment process. The contact angle measurement showed the hydrophilic nature of gold nanostructures using water with contact angle of about 56°. The optical properties showed a dipole, quadrupole and an octupole plasmon resonance mode at around 625 nm, 530 nm and 422 nm respectively. The dipole resonance peak extends further to give a broad absorption band in the near infrared region of electromagnetic waves. The refractive index sensitivity of gold nanoparticles in various solvents was investigated by calculating the red shift of surface plasmon resonance (SPR) peaks. The quadrupole plasmon resonance mode showed maximum SPR sensitivity as compared to dipole and octupole plasmon resonance mode. The controlled formation of gold nanoparticles with variation of SPR over wide range of visible region supports the potential applications in biosensors, nanoelectronics and plasmon enhanced light absorption in photovoltaics, etc.

  7. Intrinsic quadrupole tensor in the geometric interpretation of the interacting boson approximation (IBA-1)

    SciTech Connect

    Marshalek, Eugene R. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2006-10-15

    For the first time, complete quantal expressions are provided for the intrinsic components of the quadrupole tensor in the geometric Holstein-Primakoff representation of the IBA-1. These expressions are valid throughout the Casten triangle.

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

    SciTech Connect

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

    2010-04-09

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

  9. Field quality measurements and abalysis of the LARP technology quadrupole models

    SciTech Connect

    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

    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.

  10. A high performance quadrupole quintuplet lens system for the CSIRO-GEMOC nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Ryan, Chris G.; Jamieson, David N.

    1999-10-01

    A new probe forming system for the CSIRO-GEMOC nuclear microprobe, based on a quadrupole quintuplet lens configuration is described. The lens system uses a novel quadrupole lens design with a 30 mm pole-tip extension, which allows a working distance of 85 mm. Each quadrupole has cut-outs at 45°, in the yoke positioned between poles, to allow unrestricted access for detectors into a target chamber at 135° to the beam. Four cut-outs are used to maintain four-fold symmetry. Each lens has a bore of 14 mm. The extra degrees of freedom in the quintuplet configuration allow optimisation to reduce spherical aberration, to minimise spherical and parasitic aberration cross-terms (involving ??), and to attain an orthomorphic demagnification of 67 using a short overall system length (object to target) of 4.7 m. The system also has built-in redundancy; two quadrupole positions are very insensitive to parasitic multipole fields.

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

    SciTech Connect

    Maschke, A.W.

    1983-06-20

    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.

  12. MODAL ANALYSIS AND MEASUREMENT OF WATER COOLING INDUCED VIBRATIONS ON A CLIC MAIN BEAM QUADRUPOLE

    E-print Network

    Paris-Sud XI, Université de

    , the mechanical jitter of the CLIC main beam quadrupoles should be smaller than 1.5 nm integrated root mean square resin and the total mass of the coil is about 88 kg. Shims and insulating material are inserted between

  13. Kinetic equilibrium of space charge dominated beams in a misaligned quadrupole focusing channel

    NASA Astrophysics Data System (ADS)

    Goswami, A.; Sing Babu, P.; Pandit, V. S.

    2013-07-01

    The dynamics of intense beam propagation through the misaligned quadrupole focusing channel has been studied in a self-consistent manner using nonlinear Vlasov-Maxwell equations. The equations of motion of the beam centroid have been developed and found to be independent of any specific beam distribution. A Vlasov equilibrium distribution and beam envelope equations have been obtained, which provide us a theoretical tool to investigate the dynamics of intense beam propagating in a misaligned quadrupole focusing channel. It is shown that the displaced quadrupoles only cause the centroid of the beam to wander off axis. The beam envelope around the centroid obeys the familiar Kapchinskij-Vladimirskij envelope equation that is independent of the centroid motion. However, the rotation of the quadrupole about its optical axis affects the beam envelope and causes an increase in the projected emittances in the two transverse planes due to the inter-plane coupling.

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

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

    E-print Network

    Cheung, Kerry

    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 ...

  16. Rotational and magnetic shunt permanent magnet quadrupoles with variable magnetic strength

    SciTech Connect

    Vladimir Kashikhin et al.

    2002-03-28

    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.

  17. Field Quality Measurements and Analysis of the LARP Technology Quadrupole Models

    SciTech Connect

    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

    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.

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

    SciTech Connect

    Levashov, Michael Y.

    2010-12-01

    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.

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

    SciTech Connect

    Not Available

    2010-11-29

    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.

  20. Measurement of density-sensitive electric quadrupole transitions in neonlike laser-produced plasmas

    SciTech Connect

    Young, B.K.F.; Osterheld, A.L.; Walling, R.S.; Goldstein, W.H.; Phillips, T.W.; Stewart, R.E.; Charatis, G.; Busch, G.E.

    1989-03-13

    We report on the measurement of density-sensitive electric quadrupole transitions in neonlike molybdenum and silver laser-produced plasmas. These observations are unique in that they represent data which are simultaneously space and time resolved. The electron densities were determined using holographic interferometry. We test the predicted density sensitivity of the electric quadrupole transitions and find excellent agreement with calculations using a detailed, steady-state, collisional-radiative model of the neonlike charge state.

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

    SciTech Connect

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

    2010-04-09

    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.

  2. Design report of the QTG quadrupoles for the CERN CNGS line

    E-print Network

    Zickler, T

    2000-01-01

    This report presents the actual QTG design. The quadrupole magnets are part of the "CERN Neutrino to Gran Sasso" transfer line TT40. The design is optimized for a nominal beam energy of 400 GeV. The quadrupoles are resistive iron-dominated magnets with a gradient of 40 T/m and an inscribed radius of 22.5 mm. The 2200 mm long yokes will be built form low carbon steel laminations stacked between non-laminated end plates.

  3. Quadrupole source in prediction of the noise of rotating blades - A new source description

    Microsoft Academic Search

    F. Farassat

    1987-01-01

    The aim of this paper is to perform a theoretical study of the quadrupole term of the Ffowcs Williams-Hawkings (FW-H) equation to obtain practical results for applications to rotating blades. The quadrupole term of the FW-H equation is algebraically manipulated into volume, surface and line sources using generalized function theory and differential geometry. The volume source is of the type

  4. Adjustable Permanent Quadrupoles Using Rotating Magnet Material Rods for the Next Linear Collider

    Microsoft Academic Search

    James T Volk

    2001-01-01

    The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 132 Tesla, with a maximum gradient of 135 Tesla per meter, an adjustment range of +0-20% and effective lengths from 324 mm to 972 mm. The magnetic

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

    SciTech Connect

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

    2011-07-05

    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.

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

    SciTech Connect

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

    2008-08-01

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

  7. Performance of Nb3Sn quadrupole magnets under localized thermal load

    SciTech Connect

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

    2009-06-01

    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.

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

    Microsoft Academic Search

    Tilman Esslinger; Immanuel Bloch; Theodor W. Hänsch

    1998-01-01

    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

  9. Errors and optics study of a permanent magnet quadrupole system

    NASA Astrophysics Data System (ADS)

    Schillaci, F.; Maggiore, M.; Rifuggiato, D.; Cirrone, G. A. P.; Cuttone, G.; Giove, D.

    2015-05-01

    Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines [1]. Nowadays, energy and angular spread of the laser-driven beams are the main issues in application and different solutions for dedicated beam-transport lines have been proposed [2,3]. In this context a system of permanent magnet quadrupoles (PMQs) is going to be realized by INFN [2] researchers, in collaboration with SIGMAPHI [3] company in France, to be used as a collection and pre-selection system for laser driven proton beams. The definition of well specified characteristics, both in terms of performances and field quality, of the magnetic lenses is crucial for the system realization, for an accurate study of the beam dynamics and the proper matching with a magnetic selection system already realized [6,7]. Hence, different series of simulations have been used for studying the PMQs harmonic contents and stating the mechanical and magnetic tolerances in order to have reasonable good beam quality downstream the system. In this paper is reported the method used for the analysis of the PMQs errors and its validation. Also a preliminary optics characterization is presented in which are compared the effects of an ideal PMQs system with a perturbed system on a monochromatic proton beams.

  10. Fast quadrupole pulsed power supply in the AGS

    SciTech Connect

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

    1984-01-01

    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.

  11. Quadrupole beam-based alignment in the RHIC interaction regions

    SciTech Connect

    Ziegler, J.; Satogata, T.

    2011-03-28

    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.

  12. A graphical approach to radio frequency quadrupole design

    NASA Astrophysics Data System (ADS)

    Turemen, G.; Unel, G.; Yasatekin, B.

    2015-07-01

    The design of a radio frequency quadrupole, an important section of all ion accelerators, and the calculation of its beam dynamics properties can be achieved using the existing computational tools. These programs, originally designed in 1980s, show effects of aging in their user interfaces and in their output. The authors believe there is room for improvement in both design techniques using a graphical approach and in the amount of analytical calculations before going into CPU burning finite element analysis techniques. Additionally an emphasis on the graphical method of controlling the evolution of the relevant parameters using the drag-to-change paradigm is bound to be beneficial to the designer. A computer code, named DEMIRCI, has been written in C++ to demonstrate these ideas. This tool has been used in the design of Turkish Atomic Energy Authority (TAEK)'s 1.5 MeV proton beamline at Saraykoy Nuclear Research and Training Center (SANAEM). DEMIRCI starts with a simple analytical model, calculates the RFQ behavior and produces 3D design files that can be fed to a milling machine. The paper discusses the experience gained during design process of SANAEM Project Prometheus (SPP) RFQ and underlines some of DEMIRCI's capabilities.

  13. A Graphical Approach to Radio Frequency Quadrupole Design

    E-print Network

    Turemen, G; Yasatekin, B

    2014-01-01

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

  14. Hybrid permanent magnet quadrupoles for the Recycler Ring at Fermilab

    SciTech Connect

    Brown, B.C.; Pruss, S.M.; Foster, G.W.; Glass, H.D.; Harding, D.J.; Jackson, G.R.; May, M.R.; Nicol, T.H.; Ostiguy, J.-F.; Schlabach, R.; Volk, J.T.

    1997-10-01

    Hybrid Permanent Magnet Quadrupoles are used in several applications for the Fermilab Recycler Ring and associated beam transfer lines. Most of these magnets use a 0.6096 m long iron shell and provide integrated gradients up to 1.4 T-m/m with an iron pole tip radius of 41.6 mm. A 58.4 mm pole radius design is also required. Bricks of 25. 4 mm thick strontium ferrite supply the flux to the back of the pole to produce the desired gradients (0.6 to 2.75 T/m). For temperature compensation, Ni-Fe alloy strips are interspersed between ferrite bricks to subtract flux in a temperature dependent fashion. Adjustments of the permeance of each pole using iron between the pole and the flux return shell permits the matching of pole potentials. Magnetic potentials of the poles are adjusted to the desired value to achieve the prescribed strength and field uniformity based on rotating coil harmonic measurements. Procurement, fabrication, pole potential adjustment, and measured fields will be reported.

  15. A toroidal trap for the cold $^{87}Rb$ atoms using a rf-dressed quadrupole trap

    E-print Network

    Chakraborty, A; Ram, S P; Tiwari, S K; Rawat, H S

    2015-01-01

    We demonstrate the trapping of cold $^{87}Rb$ atoms in a toroidal geometry using a rf-dressed quadrupole magnetic trap formed by superposing a strong radio frequency (rf) field on a quadrupole trap. This rf-dressed quadrupole trap has minimum of the potential away from the quadrupole trap centre on a circular path which facilitates the trapping in the toroidal geometry. In the experiments, the laser cooled atoms were first trapped in the quadrupole trap, then cooled evaporatively using a weak rf-field, and finally trapped in the rf-dressed quadrupole trap. The radius of the toroid could be varied by varying the frequency of the dressing rf-field. It has also been demonstrated that a single rf source and an antenna can be used for the rf-evaporative cooling as well as for rf-dressing of atoms. The atoms trapped in the toroidal trap may have applications in realization of an atom gyroscope as well as in studying the quantum gases in low dimensions.

  16. Nuclear spin-lattice relaxation times of metallic antimony at low temperatures

    NASA Astrophysics Data System (ADS)

    Genio, E. B.; Xu, J.; Lang, T.; Ihas, G. G.; Sullivan, N. S.

    1995-11-01

    We have used pulsed Nuclear Quadrupole Resonance (NQR) techniques to measure the nuclear spin-lattice relaxation times in antimony at low temperatures. High quality echoes with strong signal/noise ratios were only observed for finely powdered samples of high purity (99.9999%). The samples were carefully annealed and diluted with fine silica to below the percolation limit to minimize RF heating. The powder mixture was immersed in liquid3He to ensure good thermal contact to a sintered silver heat exchanger attached to a copper nuclear demagnetization refrigerator. We report the temperature dependence of the nuclear spin-lattice relaxation times for the multiple level nuclear spin system.

  17. Magnetic and Electronic Properties of URu2Si2 Revealed by Comparison with Nonmagnetic References ThRu2Si2 and LaRu2Si2

    NASA Astrophysics Data System (ADS)

    Emi, Naoya; Hamabata, Ryosuke; Nakayama, Daisuke; Miki, Toshihiro; Koyama, Takehide; Ueda, Koichi; Mito, Takeshi; Kohori, Yoh; Matsumoto, Yuji; Haga, Yoshinori; Yamamoto, Etsuji; Fisk, Zachary; Tsujii, Naohito

    2015-06-01

    We have carried out nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements on ThRu2Si2 and LaRu2Si2, which are the nonmagnetic references of the intriguing heavy fermion URu2Si2. The comparisons of URu2Si2 with the reference materials allow us to analyze the already known NMR and NQR data on URu2Si2 phenomenologically and semiquantitatively. The study of 101Ru-NQR frequency suggests the relatively close electronic configuration of URu2Si2, including the valence of the actinide ion, to that of the tetravalent ThRu2Si2 at high temperatures, as well as the delocalization of 5f electrons at low temperatures. Ising-like spin fluctuations along the c-axis were brought to light by 29Si-NMR data in the so-called hidden order phase of URu2Si2. The unique magnetic property is plausibly associated with the mechanism of the unconventional superconductivity.

  18. Fabrication and Test of 90-mm Nb3Sn Quadrupole Model Based on Dipole-type Collar

    SciTech Connect

    Bossert, R.; Andreev, N.; Chlachidze, G.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; Tartaglia, M.; Velev, G.; Zlobin, A.V.; /Fermilab

    2010-07-29

    A series of 90-mm TQC quadrupole models with a collar-based mechanical structure has been fabricated and tested within the framework of the US-LHC Accelerator Research Program (LARP) using quadrupole-symmetric stainless steel collar laminations. This paper describes the design features, construction and test of TQC02Eb, the first TQC made with dipole-type collar and collaring techniques. Magnet test includes quench performance and field quality measurements at 4.5 and 1.9 K. Results of model performance for TQC quadrupoles based on dipole-type and quadrupole-type collars are compared and discussed.

  19. Dark resonance

    SciTech Connect

    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

    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.

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

    PubMed

    Rose, Katrin; Cottenier, Stefaan

    2012-08-28

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

  1. Dark Resonance

    E-print Network

    Haipeng An; Maxim Pospelov

    2012-06-11

    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 experiments on PAMELA and FERMI satellites. 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.

  2. Design and multiphysics analysis of a 176Â MHz continuous-wave radio-frequency quadrupole

    NASA Astrophysics Data System (ADS)

    Kutsaev, S. V.; Mustapha, B.; Ostroumov, P. N.; Barcikowski, A.; Schrage, D.; Rodnizki, J.; Berkovits, D.

    2014-07-01

    We have developed a new design for a 176 MHz cw radio-frequency quadrupole (RFQ) for the SARAF upgrade project. At this frequency, the proposed design is a conventional four-vane structure. The main design goals are to provide the highest possible shunt impedance while limiting the required rf power to about 120 kW for reliable cw operation, and the length to about 4 meters. If built as designed, the proposed RFQ will be the first four-vane cw RFQ built as a single cavity (no resonant coupling required) that does not require ?-mode stabilizing loops or dipole rods. For this, we rely on very detailed 3D simulations of all aspects of the structure and the level of machining precision achieved on the recently developed ATLAS upgrade RFQ. A full 3D model of the structure including vane modulation was developed. The design was optimized using electromagnetic and multiphysics simulations. Following the choice of the vane type and geometry, the vane undercuts were optimized to produce a flat field along the structure. The final design has good mode separation and should not need dipole rods if built as designed, but their effect was studied in the case of manufacturing errors. The tuners were also designed and optimized to tune the main mode without affecting the field flatness. Following the electromagnetic (EM) design optimization, a multiphysics engineering analysis of the structure was performed. The multiphysics analysis is a coupled electromagnetic, thermal and mechanical analysis. The cooling channels, including their paths and sizes, were optimized based on the limiting temperature and deformation requirements. The frequency sensitivity to the RFQ body and vane cooling water temperatures was carefully studied in order to use it for frequency fine-tuning. Finally, an inductive rf power coupler design based on the ATLAS RFQ coupler was developed and simulated. The EM design optimization was performed using cst Microwave Studio and the results were verified using both hfss and ansys. The engineering analysis was performed using hfss and ansys and most of the results were verified using the newly developed cst Multiphysics package.

  3. A frequency and amplitude scanned quadrupole mass filter for the analysis of high m/z ions

    NASA Astrophysics Data System (ADS)

    Shinholt, Deven L.; Anthony, Staci N.; Alexander, Andrew W.; Draper, Benjamin E.; Jarrold, Martin F.

    2014-11-01

    Quadrupole mass filters (QMFs) are usually not used to analyze high m/z ions, due to the low frequency resonant circuit that is required to drive them. Here we describe a new approach to generating waveforms for QMFs. Instead of scanning the amplitude of a sine wave to measure the m/z spectrum, the frequency of a trapezoidal wave is digitally scanned. A synchronous, narrow-range (<0.2%) amplitude scan overlays the frequency scan to improve the sampling resolution. Because the frequency is the primary quantity that is scanned, there is, in principle, no upper m/z limit. The frequency signal is constructed from a stabilized base clock using a field programmable gate array. This signal drives integrating amplifiers which generate the trapezoidal waves. For a trapezoidal wave the harmonics can be minimized by selecting the appropriate rise and fall times. To achieve a high resolving power, the digital signal has low jitter, and the trapezoidal waveform is generated with high fidelity. The QMF was characterized with cesium iodide clusters. Singly and multiply charged clusters with z up to +5 were observed. A resolving power of ˜1200 (FWHM) was demonstrated over a broad m/z range. Resolution was lost above 20 000 Th, partly because of congestion due to overlapping multiply charged clusters. Ions were observed for m/z values well in excess of 150 000 Th.

  4. Accelerator-Based Boron Neutron Capture Therapy and the Development of a Dedicated Tandem-Electrostatic-Quadrupole

    NASA Astrophysics Data System (ADS)

    Kreiner, A. J.; Di Paolo, H.; Burlon, A. A.; Kesque, J. M.; Valda, A. A.; Debray, M. E.; Giboudot, Y.; Levinas, P.; Fraiman, M.; Romeo, V.; Somacal, H. R.; Minsky, D. M.

    2007-10-01

    There is a generalized perception that the availability of suitable particle accelerators installed in hospitals, as neutron sources, may be crucial for the advancement of Boron Neutron Capture Therapy (BNCT). Progress on an ongoing project to develop a Tandem-ElectroStatic-Quadrupole (TESQ) accelerator for Accelerator-Based (AB)-BNCT is described here. 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. A folded tandem, with 1.25 MV terminal voltage, combined with an ESQ chain is being designed and constructed. A 30 mA proton beam of 2.5 MeV 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. The first design and construction of an ESQ module is discussed and its electrostatic fields are investigated theoretically and experimentally. Also new beam transport calculations through the accelerator are presented.

  5. Resonant diffraction of synchrotron radiation in rubidium dihydrophosphate crystals

    SciTech Connect

    Mukhamedzhanov, E. Kh.; Kovalchuk, M. V.; Borisov, M. M. [Russian Research Centre 'Kurchatov Institute' (Russian Federation); Ovchinnikova, E. N.; Troshkov, E. V. [Moscow State University (Russian Federation); Dmitrienko, V. E., E-mail: dmirtien@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2010-03-15

    Purely resonant Bragg reflections 006, 55bar 0, and 666 in a rubidium dihydrophosphate (RbH{sub 2}PO{sub 4}) crystal at the K edge of rubidium have been experimentally and theoretically investigated. These reflections remain forbidden when the resonant dipole-dipole (E1E1) contribution to the resonant atomic factor is taken into account; they may be due to the dipole-quadrupole (E1E2) 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.

  6. Multistage Fragmentation of Ion Trap Mass Spectrometry System and Pseudo-MS3 of Triple Quadrupole Mass Spectrometry Characterize Certain (E)-3-(Dimethylamino)-1-arylprop-2-en-1-ones: A Comparative Study

    PubMed Central

    Abdelhameed, Ali S.; Kadi, Adnan A.; Abdel-Aziz, Hatem A.; Angawi, Rihab F.; Attwa, Mohamed W.; Al-Rashood, Khalid A.

    2014-01-01

    A new approach was recently introduced to improve the structure elucidation power of tandem mass spectrometry simulating the MS3 of ion trap mass spectrometry system overcoming the different drawbacks of the latter. The fact that collision induced dissociation in the triple quadrupole mass spectrometer system provides richer fragment ions compared to those achieved in the ion trap mass spectrometer system utilizing resonance excitation. Moreover, extracting comprehensive spectra in the ion trap needs multistage fragmentation, whereas similar fragment ions may be acquired from one stage product ion scan using the triple quadrupole mass spectrometer. The new strategy was proven to enhance the qualitative performance of tandem mass spectrometry for structural elucidation of different chemical entities. In the current study we are endeavoring to prove our hypothesis of the efficiency of the new pseudo-MS3 technique via its comparison with the MS3 mode of ion trap mass spectrometry system. Ten pharmacologically and synthetically important (E)-3-(dimethylamino)-1-arylprop-2-en-1-ones (enaminones 4a–j) were chosen as model compounds for this study. This strategy permitted rigorous identification of all fragment ions using triple quadrupole mass spectrometer with sufficient specificity. It can be used to elucidate structures of different unknown components. The data presented in this paper provide clear evidence that our new pseudo-MS3 may simulate the MS3 of ion trap spectrometry system. PMID:24701185

  7. Building Resonance

    NSDL National Science Digital Library

    Jeffrey Barker

    This demonstration of how buildings respond to seismic shaking uses cardboard and stiff paper (such as postcards or computer cards). The effects of building resonance can be found by experimenting with taller and shorter buildings, and varying the frequency of shaking.

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

    SciTech Connect

    Baze, J.M.; Cacaut, D.; Jacquemin, J.P.; Lyraud, C.; Michez, C.; Pabot, Y.; Perot, J.; Rifflet, J.M.; Toussaint, J.C.; Vedrine, P. (CEA/Saclay/DSM/DPhPE/STIPE, 91191 Gif-sur-Yvette (FR))

    1992-01-01

    Within the framework of the LHC R and D program, CERN and CEA/Saclay have established a collaboration to carry out, amongst others, 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 design features a twin aperture configuration, a gradient of 250T/m, a length of 3m and a free coil aperture of 56mm. European industries participate in this project by delivering components and fabrication the tooling according to specifications prepared by Saclay. This paper gives details of the magnet design and construction. Coil winding will start in summer 1991 and the first prototype should be assembled and ready for testing by mid 1992.

  9. Magnetic field in the end region of the SSC quadrupole magnet

    SciTech Connect

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

    1991-06-01

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

  10. Magnetic field in the end region of the SSC quadrupole magnet

    SciTech Connect

    Caspi, S.; Helm, M.; Laslett, L.J. (Lawrence Berkeley Lab., CA (United States))

    1992-01-01

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

  11. Use of computer algebra for the study of quadrupole spin systems

    NASA Astrophysics Data System (ADS)

    Isbister, D. J.; Krishnan, Mangala S.; Sanctuary, B. C.

    1995-12-01

    Analytical computation of the effect of radiofrequency pulses and free evolution between pulses are studied in a spin system dominated by the nuclear electric quadrupole interaction using 'symbolic computer algebra'. The program MAPLE is used to compute spin density matrices for single spin systems with spin magnitude I = 1, 3/2, 2 and 5/2. In all cases except I = 5/2, the pure nuclear electric quadrupole Hamiltonian with arbitrary asymmetry parameter ? is used to obtain results for a single pulse and an evolution period following the pulse. In the spin 5/2 system ? is set to zero. The calculations are done using a simple matrix representation of the density operator and the Baker-Campbell-Hausdorff formula. In addition, the validity of dropping non-secular (i.e., time-dependent) terms from the Hamiltonian for the pulse in the quadrupole interaction frame is examined for the spin 1 case using a truncated Magnus expansion.

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

    SciTech Connect

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

    2008-06-01

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

  13. Design and Field Measurements of Printed-Circuit Quadrupoles and Dipoles

    SciTech Connect

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

    2011-11-08

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

  14. SU(6) quadrupole phonon model for even and odd nuclei and the SU(3) limit

    NASA Astrophysics Data System (ADS)

    Paar, V.; Brant, S.; Canto, L. F.; Leander, G.; Vouk, M.

    1982-04-01

    Analogous to the equivalence between the SU(6) quadrupole-phonon model (TQM) and the interacting boson model (IBM), the equivalence is pointed out for odd systems between the SU(6) particle quadrupole-phonon coupling model (PTQM) and the interacting boson-fermion model (IBFM). PTQM is formulated starting from the Dyson representation for the odd system. Different aspects of the SU(3) limit of TQM and PTQM are studied; the quadrupole-phonon block structure of rotational bands in even and odd nuclei and analytic expressions based on the coherent state; signature effects generated in PTQM; electromagnetic properties and correction factors for PTQM; overlaps of the PTQM analogs of Nilsson states with Coriolis-coupled Nilsson states and the relation to the rotational model representation.

  15. Surface-enhanced pair transfer in quadrupole states of neutron-rich Sn isotopes

    E-print Network

    Masayuki Matsuo; Yasuyoshi Serizawa

    2010-07-10

    We investigate the neutron pair transfer modes associated with the low-lying quadrupole states in neutron-rich Sn isotopes by means of the quasiparticle random phase approximation based on the Skyrme-Hartree-Fock-Bogoliubov mean field model. The transition strength of the quadrupole pair-addition mode feeding the $2_1^+$ state is enhanced in the Sn isotopes with $A \\geq 132$. The transition density of the pair-addition mode has a large spatial extension in the exterior of nucleus, reaching far to $r\\sim 12-13$ fm. The quadrupole pair-addition mode reflects sensitively a possible increase of the effective pairing interaction strength in the surface and exterior regions of neutron-rich nuclei.

  16. Antimagnetic rotation and sudden change of electric quadrupole transition strength in 143Eu

    E-print Network

    S. Rajbanshi; S. Roy; Somnath Nag; Abhijit Bisoi; S. Saha; J. Sethi; T. Trivedi; T. Bhattacharjee; S. Bhattacharyya; S. Chattopadhyay; G. Gangopadhyay; G. Mukherjee; R. Palit; R. Raut; M. Saha Sarkar; A. K. Singh; A. Goswami

    2015-05-22

    Lifetimes of the states in the quadrupole structure in 143Eu have been measured using the Doppler shift attenuation method as well as parity of the states in the sequence has been firmly identified from polarization measurement using the Indian National Gamma Array. The decreasing trends of the deduced quadrupole transition strength B(E2) with spin, along with increasing J (2) /B(E2) values before band crossing, conclusively establish the origin of these states as arising out of antimagnetic rotation. The abrupt increase in the B(E2) values after the band crossing in the quadrupole band, a novel feature observed in the present experiment, may indicates the crossing of different shears configurations resulting in re-opening of shears structure. The results are well reproduced by numerical calculation within the framework of semi-classical geometric model.

  17. Development of a GC/Quadrupole-Orbitrap mass spectrometer, part I: design and characterization.

    PubMed

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

    2014-10-21

    Identification of unknown compounds is of critical importance in GC/MS applications (metabolomics, environmental toxin identification, sports doping, petroleomics, and biofuel analysis, among many others) and remains a technological challenge. Derivation of elemental composition is the first step to determining the identity of an unknown compound by MS, for which high accuracy mass and isotopomer distribution measurements are critical. Here, we report on the development of a dedicated, applications-grade GC/MS employing an Orbitrap mass analyzer, the GC/Quadrupole-Orbitrap. Built from the basis of the benchtop Orbitrap LC/MS, the GC/Quadrupole-Orbitrap maintains the performance characteristics of the Orbitrap, enables quadrupole-based isolation for sensitive analyte detection, and includes numerous analysis modalities to facilitate structural elucidation. We detail the design and construction of the instrument, discuss its key figures-of-merit, and demonstrate its performance for the characterization of unknown compounds and environmental toxins. PMID:25208235

  18. Optimization of quadrupole ion storage mass spectrometric conditions for the analysis of selected polybrominated diphenyl ethers. Comparative approach with negative chemical ionization and electron impact mass spectrometry.

    PubMed

    Larrazábal, David; Angeles Martínez, Ma; Eljarrat, Ethel; Barceló, Damiá; Fabrellas, Begoña

    2004-10-01

    Gas chromatography coupled to quadrupole ion storage mass spectrometry (QISTMS) operating in the non-resonant mode is presented as an innovative approach for the analysis of selected polybrominated diphenyl ethers (PBDEs). Although reductions in complexity and time needed for optimization are achieved in comparison with the resonant option, precise adjustment of the mass spectrometric conditions is required. Differences in isolation and fragmentation patterns of target species with degree of bromination were observed. The reliability of the method was confirmed by using standard solutions through the evaluation of certain quality parameters such as accuracy (92-108%), injection repeatability and reproducibility (coefficient of variation below 10% and 15%, respectively). Detection limits ranged from 62 to 621 fg, providing sensitivity similar to that of negative chemical ionisation (NCIMS) and greater than that of electron ionization mass spectrometry. The applicability of QISTMS method to real samples and matrix effects were evaluated through the analysis of some PBDE congeners in a sewage sludge sample from a Spanish waste-water treatment plant. Comparable results were obtained using QISTMS and NCIMS. According to these observations, QISTMS performed in the non-resonant mode may constitute a low-cost, rapid and reliable alternative to high-resolution devices for the analysis of selected PBDEs in environmental samples. PMID:15468104

  19. Electric Quadrupole Shift Cancellation in Single-Ion Optical Frequency Standards

    SciTech Connect

    Dube, P.; Madej, A.A.; Bernard, J.E.; Marmet, L.; Boulanger, J.-S.; Cundy, S. [Institute for National Measurement Standards, National Research Council, Ottawa, K1A 0R6 (Canada)

    2005-07-15

    The electric quadrupole shift is presently the most significant source of uncertainty on the systematic shifts for several single-ion optical frequency standards. We present a simple method for canceling this shift based on measurements of the Zeeman spectrum of the clock transition. This method is easy to implement and yields very high cancellation levels. A fractional uncertainty of 5x10{sup -18} for the canceled quadrupole shift is estimated for a measurement of the absolute frequency of the 5s {sup 2}S{sub 1/2}-4d {sup 2}D{sub 5/2} clock transition of {sup 88}Sr{sup +}.

  20. Search for Quadrupole Strength in the Electro-excitation of the Delta(1232)

    E-print Network

    C. Mertz; C. Vellidis; R. Alarcon; D. H. Barkhuff; A. M. Bernstein; W. Bertozzi; V. Burkert; J. Chen; J. R. Comfort; G. Dodson; S. Dolfini; K. Dow; M. Farkhondeh; J. M. Finn; S. Gilad; R. W. Gothe; X. Jiang; K. Joo; N. I. Kaloskamis; A. Karabarbounis; J. J. Kelly; S. Kowalski; C. Kunz; R. W. Lourie; J. I. McIntyre; B. D. Milbrath; R. Miskimen; J. H. Mitchell; C. N. Papanicolas; C. F. Perdrisat; A. J. Sarty; J. Shaw; S. -B. Soong; D. Tieger; C. Tschalaer; W. Turchinetz; P. E. Ulmer; S. Van Verst; G. A. Warren; L. B. Weinstein; S. Williamson; R. J. Woo; A. Young

    2000-12-06

    High-precision H(e,e'p)pi0 measurements at Q2=0.126 (GeV/c)2 are reported, which allow the determination of quadrupole amplitudes in the gamma* N->Delta transition; they simultaneously test the reliability of electroproduction models. The derived quadrupole-to-dipole amplitude ratios, Rsm=(-6.5 +- 0.2{stat+sys} +- 2.5{mod}) % and Rem=(-2.1 +- 0.2{stat+sys} +- 2.0{mod}) %, are dominated by model error. Previous Rsm and Rem results should be reconsidered after the model uncertainties associated with the method of their extraction are taken into account.

  1. Mitigating radiation loads in Nb(3)Sn quadrupoles for LHC upgrades

    SciTech Connect

    Mokhov, N.V.; Rakhno, I.L.; /Fermilab

    2006-08-01

    Challenging beam-induced energy deposition issues are addressed for the next generation of the LHC high-luminosity interaction regions based on Nb{sub 3}Sn quadrupoles. Detailed MARS15 Monte Carlo energy deposition calculations are performed for various coil diameters, thicknesses and materials of the inner absorber at a field gradient of 200 T/m. It is shown that using the inner absorber made of tungsten-based materials can make the final focus superconducting quadrupoles compatible with a luminosity of 10{sup 35} cm{sup -2}s{sup -1}.

  2. 3 mm Anisotropy Measurement: On the Quadrupole Component in theCosmic Background Radiation

    SciTech Connect

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

    1982-11-01

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

  3. Resonance ionization of rubidium in an ion trap mass spectrometer

    SciTech Connect

    Whitten, W.B.; Ramsey, J.M.; Goeringer, D.E.; Buckley, B.T.

    1990-01-01

    We have recently initiated a study of resonance ionization processes in a quadrupole ion storage trap. The trap is a commercially available Ion Trap Detector that uses the voltage dependence of ion mass instability to obtain a mass spectrum of the trapped ions. We have modified the trap to permit laser excitation of atomic and molecular species within the quadrupole electrodes. Mass resolved resonance ionization spectra have been obtained for NO and Rb, described below. Rb was selected for this study for a number of reasons. We want to explore the potential of the ion trap for high resolution (Doppler free) resonance ionization spectroscopy with CW laser excitation. Rb can be excited to upper Rydberg levels with a series of transitions that can be induced with commercially available semiconductor diode lasers. In addition, levels in the same energy range can be reached through two-photon processes with visible wavelength tunable dye lasers or with single-photon processes after the laser is frequency doubled. The upper Rydberg levels can be ionized by photons, electric field, or collisions. Collisional ionization of a reservoir of Rydberg atoms may be a sensitive scheme for detecting electronegative species. RB has two stable isotopes with nonzero nuclear spin so that isotopic and hyperfine splittings can be used to assess the spectral resolution that is attained.

  4. DESIGN AND STUDY OF A SUPERFERRIC MODEL DIPOLE AND QUADRUPOLE MAGNETS FOR THE GSI FAST-PULSED SYNCHROTRON SIS100

    Microsoft Academic Search

    A. Kovalenko; N. Agapov; V. Bartenev; A. Donyagin; I. Eliseeva; H. Khodzhibagiyan; G. Kuznetsov; A. Smirnov; M. Voevodin; G. Moritz

    2004-01-01

    New experimental results from the investigation of a model superferric Nuclotron-type dipole and quadrupole magnets are presented. The magnets operate at pulse repetition rate f = 1 Hz, providing the peak magnetic field B = 2 T and the field gradient G = 34 T\\/m in the dipoles and quadrupoles respectively. The superconducting coil is made from a hollow multi-filamentary

  5. Abstract--High gradient quadrupoles are being developed by the US-LHC Accelerator Project for the LHC interaction

    E-print Network

    Large Hadron Collider Program

    Abstract-- High gradient quadrupoles are being developed by the US-LHC Accelerator Project these magnets against excessively high coil temperatures and coil voltage to ground as a result of a spontaneous interaction regions will consist of high gradient quadrupoles from KEK and the US-LHC accelerator project

  6. ENGINEERING DESIGN OF HTS QUADRUPOLE FOR FRIB* John P. Cozzolino, Michael Anerella, Arup K. Ghosh, Ramesh C. Gupta, William Sampson,

    E-print Network

    Gupta, Ramesh

    110 mm Design Gradient 15 T/m Magnetic Length 600 mm Coil Overall Length 680 mm Yoke Length 546 mmENGINEERING DESIGN OF HTS QUADRUPOLE FOR FRIB* John P. Cozzolino, Michael Anerella, Arup K. Ghosh, NSCL, Michigan State University, East Lansing, MI 48824, USA Abstract The coils of the first quadrupole

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

    E-print Network

    Hu, Wayne

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

  8. Isotopically selective counting of noble gas atoms, using resonance ionization spectroscopy

    SciTech Connect

    Chen, C.H.

    1984-04-01

    The technique of Resonance Ionization Spectroscopy (RIS) is being extended to develop a means for counting individual atoms of a selected isotope of a noble gas. In this method, lasers are used for RIS to obtain atomic species (Z) selectivity and a small quadrupole mass spectrometer provides isotopic (A) selectivity. A progress report on the objective of counting each atom of a particular isotope of a noble gas is given. 10 references, 4 figures.

  9. Modeling scattering enhancements at isolated resonances using energy conservation, reciprocity, symmetry, and the optical theorem

    Microsoft Academic Search

    Philip L. Marston; Curtis F. Osterhoudt

    2003-01-01

    Sound scattered by some objects in water exhibits isolated narrow resonances that are sufficiently large in amplitude to dominate the low-frequency scattering. Examples include the quadrupole mode of thin spherical shells and of solid plastic spheres [B. T. Hefner and P. L. Marston, J. Acoust. Soc. Am. 107, 1930-1936 (2000)] and organ-pipe modes of water-filled pipes [C. F. Osterhoudt and

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

    SciTech Connect

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

    2011-09-15

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

  11. Phase-Space Exploration in Nuclear Giant Resonance Decay

    E-print Network

    S. Drozdz; S. Nishizaki; J. Speth; J. Wambach

    1994-07-08

    The rate of phase-space exploration in the decay of isovector and isoscalar giant quadrupole resonances in $^{40}$Ca is analyzed. The study is based on the time dependence of the survival probability and of the spectrum of generalized entropies evaluated in the space of 1p-1h and 2p-2h states. If the 2p-2h background shows the characteristics typical for chaotic systems, the isovector excitation evolves almost statistically while the isoscalar excitation remains largely localized, even though it penetrates the whole available phase space.

  12. If It's Resonance, What is Resonating?

    ERIC Educational Resources Information Center

    Kerber, Robert C.

    2006-01-01

    The phenomenon under the name "resonance," which, is based on the mathematical analogy between mechanical resonance and the behavior of wave functions in quantum mechanical exchange phenomena was described. The resonating system does not have a structure intermediate between those involved in the resonance, but instead a structure which is further…

  13. All-Resonant Control of Superconducting Resonators

    E-print Network

    Frederick W. Strauch

    2012-08-17

    An all-resonant method is proposed to control the quantum state of superconducting resonators. This approach uses a tunable artificial atom linearly coupled to resonators, and allows for efficient routes to Fock state synthesis, qudit logic operations, and synthesis of NOON states. This resonant approach is theoretically analyzed, and found to perform signficantly better than existing proposals using the same technology.

  14. LLC resonant converter with two resonant tanks

    Microsoft Academic Search

    Eun-Soo Kim; Joo-Hoon Kim; Kwang-Ho Lee; Yong-Seog Jeon; Jae-Sam Lee; Dong-Young Huh

    2010-01-01

    To cope with the high power density and low cost in switching power supply, LLC resonant converters with the two resonant tank circuits composed of resonance capacitors and two transformers are proposed in this paper. Each transformers used for the proposed resonant circuits are parallel connected in the primary and series connected in the secondary to reduce the current unbalance.

  15. Competition between Quadrupole and Magnetic Kondo Effects in Non-Kramers Doublet Systems

    NASA Astrophysics Data System (ADS)

    Kusunose, Hiroaki; Onimaru, Takahiro

    2015-03-01

    We discuss possible competition between magnetic and quadrupole Kondo effects in non-Kramers doublet systems in cubic symmetry. The quadrupole Kondo effect leads to non-Fermi-liquid (NFL) ground state, while the magnetic one favors ordinary Fermi-liquid (FL) ground state. In terms of the j-j coupling scheme, we argue that the orbital fluctuation must develop in the vicinity of the NFL-FL boundary. A change of temperature dependence of the f-electron entropy in both the FL and NFL regimes is demonstrated by the Wilson's numerical renormalization-group (NRG) method on the basis of the extended two-channel Kondo exchange model. We present implications to PrT2X20 (T=Ti, V, Ir; X=Al, Zn) systems which exhibit both quadrupole ordering and peculiar superconductivity. We discuss how the magnetic field lifts the non-Kramers degeneracy. Our model also represents the alternative FL state accompanied by a free magnetic spin, as a consequence of stronger competition between the magnetic and the quadrupole Kondo effects.

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

    Microsoft Academic Search

    D. B. Hanson; M. R. Fink

    1978-01-01

    A theoretical analysis is presented for the harmonic noise of high speed, open rotors. Far field acoustic radiation equations based on the Ffowcs-Williams\\/Hawkings theory are derived for a static rotor with thin blades and zero lift. Near the plane of rotation, the dominant sources are the volume displacement and the rho U(2) quadrupole, where u is the disturbance velocity component

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

    Microsoft Academic Search

    D. B. Hanson; M. R. Fink

    1979-01-01

    A theoretical analysis is presented for the harmonic noise of high speed, open rotors. Far field acoustic radiation equations based on the Ffowcs Williams\\/Hawkings theory are derived for a static rotor with thin blades and zero lift. Near the plane of rotation, the dominant sources are the volume displacement and the varrhou2 quadrupole, where u is the disturbance velocity component

  18. Analysis of electric quadrupole radiation in the time domain: application to large-current radiators

    Microsoft Academic Search

    RAFAEL GOMEZ; JUAN A. MORENTE

    1985-01-01

    In this paper, the fields created by a hertzian electric quadrupole fed by a non-sinusoidal signal are analysed in the time domain. The results are compared with those obtained for an electric dipole and are applied to the study of the field created by the practical antenna, the large-current radiator.

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

    E-print Network

    Weston, Ken

    Measurement of lithium isotope ratios by quadrupole-ICP-MS: application to seawater and natural method for lithium isotope ratio (7 Li/6 Li) determinations with low total lithium consumption ( of natural carbonates (foraminifera) containing 1 to 2 ppm lithium. This lithium separation method

  20. Magnetic field measurements of quadrupoles in the High-Current Experiment

    NASA Astrophysics Data System (ADS)

    Seidl, P. A.; Kireeff Covo, M.; Baca, D.; Faltens, A.; Molvik, A. W.; Ritchie, G.; Sabbi, G.; Shuman, D.

    2005-05-01

    The High-Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program to explore heavy-ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. Four pulsed magnetic quadrupoles are being used to study gas and electron effects with a 0.2 A, 1-MeV K + beam. The magnets, originally designed and built for a prototype pulsed magnetic quadrupole array, have an elliptical beam tube (6×10 cm) and iron yoke. The magnet coil and field length are ?31 cm, and operating gradients are 10-40 T/m. To establish that the field quality of the prototype quadrupoles is satisfactory for the experiments, a 1-cm pickup loop was used to measure the flux Br( ?) at the magnet mid-plane and also at the lead and return ends. A longer probe was used to measure the integrated flux of B ?( ?) along the magnet. The field quality appears satisfactory for the short transport experiments through these quadrupoles.