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

Science.gov (United States)

Norbury, John W.

1992-01-01

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

Design of the LINAC4 Transfer Line Quadrupole Electromagnets

CERN Document Server

Vanherpe, L

2013-01-01

Beam focusing in the various segments of the Linac4 Transfer Line is provided by quadrupole electromagnets. In total seventeen pulsed, air-cooled quadrupole electromagnets are required. They are made of laminated electrical steel yokes and coils wound from solid copper wire. All magnets have an aperture radius of 50 mm and are required to provide an integrated field gradient of 1.8 T over a magnetic length of 300 mm. This design report summarizes the main magnetic, electrical and mechanical design parameters of the Linac4 Transfer Line Quadrupole Magnets. The effect of the vacuum chamber on the magnetic field quality and the field delay is studied.

Quadrupole moments of highly deformed structures in the A ∼ 135 region: Probing the single-particle motion in a rotating potential

International Nuclear Information System (INIS)

Laird, R.W.; Riley, M.A.; Brown, T.B.; Pfohl, J.; Sheline, R.K.; Kondev, F.G.; Archer, D.E.; Clark, R.M.; Fallon, P.; Devlin, M.; LaFosse, D.R.; Sarantites, D.G.; Hartley, D.J.; Hibbert, I.M.; O'Brien, N.J.; Wadsworth, R.; Joss, D.T.; Nolan, P.J.; Paul, E.S.; Shepherd, S.L.

2002-01-01

The latest generation γ-ray detection system, GAMMASPHERE, coupled with the Microball charged-particle detector, has made possible a new class of nuclear lifetime measurement. For the first time differential lifetime measurements free from common systematic errors for over 15 different nuclei (>30 rotational bands in various isotopes of Ce, Pr, Nd, Pm, and Sm) have been extracted at high spin within a single experiment. This comprehensive study establishes the effective single-particle transition quadrupole moments in the A∼135 light rare-earth region. Detailed comparisons are made with theoretical calculations using the self-consistent cranked mean-field theory which convincingly demonstrates the validity of the additivity of single-particle quadrupole moments in this mass region

Behavioral changes induced by single and multiple electron beam pulses

International Nuclear Information System (INIS)

Pease, V.P.; McNulty, P.J.

1985-01-01

The effects of single, and low-dose, high-dose-rate and multiple electron beam pulses on passive avoidance behavior in mice were studied. Passive avoidance was measured by recording the time that an animal took to enter a chamber from a narrow platform. There were four conditions in the experiment: (1) no shock no radiation-control, (2) radiation only, (3) shock only, and (4) radiation plus shock. Forty animals were run for each data point. Dose rate was held constant at 9 x 10/sup 7/ rads/sec. Average doses for the two single pulses were 7.18 and 8.72 rads. The average total dose for a 25 pulse per second condition was 324.0 rads. The differences between the single versus multiple pulse radiation-only conditions were significant with longer avoidance latencies in the multiple pulse condition. Avoidance latencies were also significantly longer in the shock plus radiation condition for the multiple beam pulse than the single pulse. It is concluded that single and multiple electron beam pulses significantly effect behavior, in this case producing avoidance

Analytical calculation of spin tunneling effect in single molecule magnet Fe8 with considering quadrupole excitation

Directory of Open Access Journals (Sweden)

Y Yousefi

2018-02-01

Full Text Available Spin tunneling effect in Single Molecule Magnet Fe8 is studied by instanton calculation technique using SU(3 generalized spin coherent state in real parameter as a trial function. For this SMM, tunnel splitting arises due to the presence of a Berry like phase in action, which causes interference between tunneling trajectories (instantons. For this SMM, it is established that the use of quadrupole excitation (g dependence changes not only the location of the quenching points, but also the number of these points. Also, these quenching points are the steps in hysteresis loops of this SMM. If dipole and quadrupole excitations in classical energy considered, the number of these steps equals to the number that obtained from experimental data.

Generation of a single-cycle optical pulse

International Nuclear Information System (INIS)

Shverdin, M.Y.; Walker, D.R.; Yavuz, D.D.; Yin, G.Y.; Harris, S.E.

2005-01-01

We make use of coherent control of four-wave mixing to the ultraviolet as a diagnostic and describe the generation of a periodic optical waveform where the spectrum is sufficiently broad that the envelope is approximately a single-cycle in length, and where the temporal shape of this envelope may be synthesized by varying the coefficients of a Fourier series. Specifically, using seven sidebands, we report the generation of a train of single-cycle optical pulses with a pulse width of 1.6 fs, a pulse separation of 11 fs, and a peak power of 1 MW

Progress in the development of superconducting quadrupoles for heavy ion fusion

International Nuclear Information System (INIS)

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

2002-01-01

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

Progress in the development of superconducting quadrupoles for heavy ion fusion

Energy Technology Data Exchange (ETDEWEB)

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.

Progress in the Development of Superconducting Quadrupoles forHeavy-ion Fusion

Energy Technology Data Exchange (ETDEWEB)

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.

Quadrupole to BPM offset determination in Indus-2

International Nuclear Information System (INIS)

Jena, Saroj; Ghodke, A.D.; Singh, G.

2009-01-01

A feasibility of finding the quadrupole to BPM offset using beam based alignment (BBA) technique in Indus-2 has been studied. The measurements of the offsets between BPM and quadrupoles could be performed by using quadratic fitting for the minima of the orbit response w. r. t. changes in the quadrupole strengths. These offsets will be integrated to the orbit data during closed orbit correction. There are 72 quadrupoles and 56 BPMs in Indus-2. However the assessment of Quad-BPM offsets is not feasible in some cases due to non-availability of BPM adjacent to quadrupole and also in some cases because of a large phase advance between quadrupole and nearby BPM. Here single corrector method is used to obtain these offsets and assumed the current of each quadrupole can be varied independently. A graphical user interface (GUI) is developed in MATLAB for the use of BBA in Indus-2. (author)

Single particle analysis of TiO2 in candy products using triple quadrupole ICP-MS.

Science.gov (United States)

Candás-Zapico, S; Kutscher, D J; Montes-Bayón, M; Bettmer, J

2018-04-01

Titanium dioxide (TiO 2 ) belongs to the materials that have gained great importance in many applications. In its particulate form (micro- or nanoparticles), it has entered a huge number of consumer products and food-grade TiO 2 , better known as E171 within the European Union, represents an important food additive. Thus, there is an increasing need for analytical methods able to detect and quantify such particles. In this regard, inductively coupled-mass spectrometry (ICP-MS), in particular single particle ICP-MS (spICP-MS), has gained importance due to its simplicity and ease of use. Nevertheless, the number of applications for Ti nanoparticles is rather limited. In this study, we have applied the spICP-MS strategy by comparing different measuring modes available in triple quadrupole ICP-MS. First, single quadrupole mode using the collision/reaction cell system was selected for monitoring the isotope 47 Ti. Different cell gases like He, O 2 and NH 3 were tested under optimised conditions for its applicability in spICP-MS of standard suspensions of TiO 2 . The determined analytical figures of merit were compared to those obtained by triple quadrupole mode using the 47 Ti or 48 Ti reaction products using O 2 and NH 3 as reaction gases. This comparison demonstrated that the triple quadrupole mode (TQ mode) was superior in terms of sensitivity due to the more efficient removal of spectral interferences. Particle size detection limits down to 26nm were obtained using the best instrumental conditions for TiO 2 particles at a dwell time of 10ms. Finally, the different measuring modes were applied to the analysis of chewing gum samples after a simple extraction procedure using an ultrasonic bath. The obtained results showed a good agreement for the detected particle size range using the different TQ modes. The size range of TiO 2 particles was determined to be between approximately 30 and 200nm, whereas roughly 40% of the particles were smaller than 100nm. For the

Pulse sequences for suppressing leakage in single-qubit gate operations

Science.gov (United States)

Ghosh, Joydip; Coppersmith, S. N.; Friesen, Mark

2017-06-01

Many realizations of solid-state qubits involve couplings to leakage states lying outside the computational subspace, posing a threat to high-fidelity quantum gate operations. Mitigating leakage errors is especially challenging when the coupling strength is unknown, e.g., when it is caused by noise. Here we show that simple pulse sequences can be used to strongly suppress leakage errors for a qubit embedded in a three-level system. As an example, we apply our scheme to the recently proposed charge quadrupole (CQ) qubit for quantum dots. These results provide a solution to a key challenge for fault-tolerant quantum computing with solid-state elements.

Rescuing the nonjet (NJ) azimuth quadrupole from the flow narrative

Science.gov (United States)

Trainor, Thomas A.

2017-04-01

According to the flow narrative commonly applied to high-energy nuclear collisions a cylindrical-quadrupole component of 1D azimuth angular correlations is conventionally denoted by quantity υ2 and interpreted to represent elliptic flow. Jet angular correlations may also contribute to υ2 data "nonflow" depending on the method used to calculate υ2, but 2D graphical methods are available to insure accurate separation. The nonjet (NJ) quadrupole has various properties inconsistent with a flow interpretation, including the observation that NJ quadrupole centrality variation in A-A collisions has no relation to strongly-varying jet modication ("jet quenching") in those collisions commonly attributed to jet interaction with a flowing dense medium. In this presentation I describe isolation of quadrupole spectra from pt-differential υ2(pt) data from the RHIC and LHC. I demonstrate that quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quadrupole spectra indicate a common boosted hadron source for a small minority of hadrons that "carry" the NJ quadrupole structure, that the narrow source-boost distribution is characteristic of an expanding thin cylindrical shell (strongly contradicting hydro descriptions), and that in the boost frame a single universal quadrupole spectrum (Lévy distribution) on transverse mass mt accurately describes data for several hadron species scaled according to their statistical-model abundances. The quadrupole spectrum shape changes very little from RHIC to LHC energies. Taken in combination those characteristics strongly suggest a unique nonflow (and nonjet) QCD mechanism for the NJ quadrupole conventionally represented by υ2.

Rescuing the nonjet (NJ azimuth quadrupole from the flow narrative

Directory of Open Access Journals (Sweden)

Trainor Thomas A.

2017-01-01

Full Text Available According to the flow narrative commonly applied to high-energy nuclear collisions a cylindrical-quadrupole component of 1D azimuth angular correlations is conventionally denoted by quantity υ2 and interpreted to represent elliptic flow. Jet angular correlations may also contribute to υ2 data “nonflow” depending on the method used to calculate υ2, but 2D graphical methods are available to insure accurate separation. The nonjet (NJ quadrupole has various properties inconsistent with a flow interpretation, including the observation that NJ quadrupole centrality variation in A-A collisions has no relation to strongly-varying jet modication (“jet quenching” in those collisions commonly attributed to jet interaction with a flowing dense medium. In this presentation I describe isolation of quadrupole spectra from pt-differential υ2(pt data from the RHIC and LHC. I demonstrate that quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quadrupole spectra indicate a common boosted hadron source for a small minority of hadrons that “carry” the NJ quadrupole structure, that the narrow source-boost distribution is characteristic of an expanding thin cylindrical shell (strongly contradicting hydro descriptions, and that in the boost frame a single universal quadrupole spectrum (Lévy distribution on transverse mass mt accurately describes data for several hadron species scaled according to their statistical-model abundances. The quadrupole spectrum shape changes very little from RHIC to LHC energies. Taken in combination those characteristics strongly suggest a unique nonflow (and nonjet QCD mechanism for the NJ quadrupole conventionally represented by υ2.

Nuclear quadrupole resonance of arsenolite

International Nuclear Information System (INIS)

Madarazo, R.

1988-01-01

A pulsed Nuclear Quadrupole Resonance (NQR) spectrometer was constructed using imported Matec units. Peripherical components were specially assembled and tested for the implantation of the spin-echo technique in the Laboratorio de Centros de Cor of IFUSP. The R.F. operation range is from 50 to 1 ) and spin-spin (T 2 ) relaxation times were carried out at room temperature in arsenolite. The 75 As NQR frequency measured at room temperature is 116.223 MHz. (author) [pt

Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

Science.gov (United States)

Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

2011-05-01

The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

Quadrupole moments as measures of electron correlation in two-electron atoms

International Nuclear Information System (INIS)

Ceraulo, S.C.; Berry, R.S.

1991-01-01

We have calculated quadrupole moments, Q zz , of helium in several of its doubly excited states and in two of its singly excited Rydberg states, and of the alkaline-earth atoms Be, Mg, Ca, Sr, and Ba in their ground and low-lying excited states. The calculations use well-converged, frozen-core configuration-interaction (CI) wave functions and, for interpretive purposes, Hartree-Fock (HF) atomic wave functions and single-term, optimized, molecular rotor-vibrator (RV) wave functions. The quadrupole moments calculated using RV wave functions serve as a test of the validity of the correlated, moleculelike model, which has been used to describe the effects of electron correlation in these two-electron and pseudo-two-electron atoms. Likewise, the quadrupole moments calculated with HF wave functions test the validity of the independent-particle model. In addition to their predictive use and their application to testing simple models, the quadrupole moments calculated with CI wave functions reveal previously unavailable information about the electronic structure of these atoms. Experimental methods by which these quadrupole moments might be measured are also discussed. The quadrupole moments computed from CI wave functions are presented as predictions; measurements of Q zz have been made for only two singly excited Rydberg states of He, and a value of Q zz has been computed previously for only one of the states reported here. We present these results in the hope of stimulating others to measure some of these quadrupole moments

Single attosecond pulse from terahertz-assisted high-order harmonic generation

Science.gov (United States)

Balogh, Emeric; Kovacs, Katalin; Dombi, Peter; Fulop, Jozsef A.; Farkas, Gyozo; Hebling, Janos; Tosa, Valer; Varju, Katalin

2011-08-01

High-order harmonic generation by few-cycle 800 nm laser pulses in neon gas in the presence of a strong terahertz (THz) field is investigated numerically with propagation effects taken into account. Our calculations show that the combination of THz fields with up to 12 fs laser pulses can be an effective gating technique to generate single attosecond pulses. We show that in the presence of the strong THz field only a single attosecond burst can be phase matched, whereas radiation emitted during other half cycles disappears during propagation. The cutoff is extended and a wide supercontinuum appears in the near-field spectra, extending the available spectral width for isolated attosecond pulse generation from 23 to 93 eV. We demonstrate that phase-matching effects are responsible for the generation of isolated attosecond pulses, even in conditions when single-atom response yields an attosecond pulse train.

Single attosecond pulse from terahertz-assisted high-order harmonic generation

International Nuclear Information System (INIS)

Balogh, Emeric; Kovacs, Katalin; Dombi, Peter; Farkas, Gyozo; Fulop, Jozsef A.; Hebling, Janos; Tosa, Valer; Varju, Katalin

2011-01-01

High-order harmonic generation by few-cycle 800 nm laser pulses in neon gas in the presence of a strong terahertz (THz) field is investigated numerically with propagation effects taken into account. Our calculations show that the combination of THz fields with up to 12 fs laser pulses can be an effective gating technique to generate single attosecond pulses. We show that in the presence of the strong THz field only a single attosecond burst can be phase matched, whereas radiation emitted during other half cycles disappears during propagation. The cutoff is extended and a wide supercontinuum appears in the near-field spectra, extending the available spectral width for isolated attosecond pulse generation from 23 to 93 eV. We demonstrate that phase-matching effects are responsible for the generation of isolated attosecond pulses, even in conditions when single-atom response yields an attosecond pulse train.

Single attosecond pulse from terahertz-assisted high-order harmonic generation

Energy Technology Data Exchange (ETDEWEB)

Balogh, Emeric [Department of Optics and Quantum Electronics, University of Szeged, H-6701 Szeged (Hungary); Kovacs, Katalin [Department of Optics and Quantum Electronics, University of Szeged, H-6701 Szeged (Hungary); National Institute for R and D of Isotopic and Molecular Technologies, RO-400293 Cluj-Napoca (Romania); Dombi, Peter; Farkas, Gyozo [Research Institute for Solid State Physics and Optics, H-1525 Budapest (Hungary); Fulop, Jozsef A.; Hebling, Janos [Department of Experimental Physics, University of Pecs, H-7624 Pecs (Hungary); Tosa, Valer [National Institute for R and D of Isotopic and Molecular Technologies, RO-400293 Cluj-Napoca (Romania); Varju, Katalin [HAS Research Group on Laser Physics, University of Szeged, H-6701 Szeged (Hungary)

2011-08-15

High-order harmonic generation by few-cycle 800 nm laser pulses in neon gas in the presence of a strong terahertz (THz) field is investigated numerically with propagation effects taken into account. Our calculations show that the combination of THz fields with up to 12 fs laser pulses can be an effective gating technique to generate single attosecond pulses. We show that in the presence of the strong THz field only a single attosecond burst can be phase matched, whereas radiation emitted during other half cycles disappears during propagation. The cutoff is extended and a wide supercontinuum appears in the near-field spectra, extending the available spectral width for isolated attosecond pulse generation from 23 to 93 eV. We demonstrate that phase-matching effects are responsible for the generation of isolated attosecond pulses, even in conditions when single-atom response yields an attosecond pulse train.

High-mechanical-strength single-pulse draw tower gratings

Science.gov (United States)

Rothhardt, Manfred W.; Chojetzki, Christoph; Mueller, Hans Rainer

2004-11-01

The inscription of fiber Bragg gratings during the drawing process is a very useful method to realize sensor arrays with high numbers of gratings and excellent mechanical strength and also type II gratings with high temperature stability. Results of single pulse grating arrays with numbers up to 100 and definite wavelengths and positions for sensor applications were achieved at 1550 nm and 830 nm using new photosensitive fibers developed in IPHT. Single pulse type I gratings at 1550 nm with more than 30% reflectivity were shown first time to our knowledge. The mechanical strength of this fiber with an Ormocer coating with those single pulse gratings is the same like standard telecom fibers. Weibull plots of fiber tests will be shown. At 830 nm we reached more than 10% reflectivity with single pulse writing during the fiber drawing in photosensitive fibers with less than 16 dB/km transmission loss. These gratings are useful for stress and vibration sensing applications. Type II gratings with reflectivity near 100% and smooth spectral shape and spectral width of about 1 nm are temperature stable up to 1200 K for short time. They are also realized in the fiber drawing process. These gratings are useful for temperature sensor applications.

Fe/sup 57/ polarimetry based on quadrupole interaction

Energy Technology Data Exchange (ETDEWEB)

Gonser, U; Sakai, H; Keune, W [Universitaet des Saarlandes, Saarbruecken (F.R. Germany). Fachbereich Angewandte Physik

1976-01-01

A quadrupole Fe/sup 57/ polarimeter consisting of single crystals of LiNbO/sub 3/:Co/sup 57/ as source (polarizer) and of FeCO/sub 3/ (siderite) as absorber (analyzer) is described. The quadrupole interactions of the two materials are nearly equal in magnitude but opposite in sign and in addition the asymmetry parameter eta equal approximately 0.

Features of single and double ionization processes induced by few cycle laser pulses

International Nuclear Information System (INIS)

Starace, A.F.

2005-01-01

Full text: The advent of laser pulses with attosecond pulse lengths ushers in the regime of few cycle laser pulse interactions with atoms and ions, including the interesting cases of single and half cycle laser pulses. In this talk I will present results of recent studies of single electron ionization/detachment and double electron ionization/detachment produced by a few cycle laser pulse. For the former case, we shall demonstrate that the ionized/detached electron momentum distribution reflects the interference of electron probability wave packets produced by each half cycle of a single cycle pulse. Also, that the ionized/detached electron momentum distribution uniquely characterizes the phase of the single cycle laser pulse within the laser pulse envelope. Regarding double ionization/detachment, our numerical experiments have shown that single cycle and double half cycle pulses produce different electron angular distributions. Some double ionization features that are present only in the single cycle case can only have been produced by electron impact ionization during rescattering of an initially ionized electron and thus represent a sensitive measure of the rescattering process. Refs. 2 (author)

Development of Superconducting Focusing Quadrupoles for Heavy Ion Drivers

Energy Technology Data Exchange (ETDEWEB)

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

2001-09-10

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

Random errors in the magnetic field coefficients of superconducting quadrupole magnets

International Nuclear Information System (INIS)

Herrera, J.; Hogue, R.; Prodell, A.; Thompson, P.; Wanderer, P.; Willen, E.

1987-01-01

The random multipole errors of superconducting quadrupoles are studied. For analyzing the multipoles which arise due to random variations in the size and locations of the current blocks, a model is outlined which gives the fractional field coefficients from the current distributions. With this approach, based on the symmetries of the quadrupole magnet, estimates are obtained of the random multipole errors for the arc quadrupoles envisioned for the Relativistic Heavy Ion Collider and for a single-layer quadrupole proposed for the Superconducting Super Collider

Tunable high-gradient permanent magnet quadrupoles

CERN Document Server

Shepherd, B J A; Marks, N; Collomb, N A; Stokes, D G; Modena, M; Struik, M; Bartalesi, A

2014-01-01

A novel type of highly tunable permanent magnet (PM) based quadrupole has been designed by the ZEPTO collaboration. A prototype of the design (ZEPTO-Q1), intended to match the specification for the CLIC Drive Beam Decelerator, was built and magnetically measured at Daresbury Laboratory and CERN. The prototype utilises two pairs of PMs which move in opposite directions along a single vertical axis to produce a quadrupole gradient variable between 15 and 60 T/m. The prototype meets CLIC's challenging specification in terms of the strength and tunability of the magnet.

Magnetic Measurements of Permanent and Fast-Pulsed Quadrupoles for the CERN LINAC4 Project

CERN Document Server

Golluccio, G; Buzio, M; Dunkel, O; Giloteaux, D; Lombardi, A; Mateo, F; Ramberger, S

2010-01-01

Linac4 is currently under construction at CERN to improve intensity and reliability for the whole accelerator chain. This machine will include about 120 permanent quadrupoles housed in the Drift Tube tanks, as well as about 80 electromagnetic quadrupoles. This paper describes the magnetic measurements carried out at CERN on the first batch of quadrupoles, including several prototypes from different manufacturers, as well as those done on several spare Linac 2 magnets reused in Linac4's 3 MeV test stand. We first describe a prototype test bench based on technology developed for the LHC and able to carry out high-precision harmonic measurements in both continuously-rotating and stepping-coil mode. Next we present the first results obtained in terms of field strength, harmonics quality and effects of fast eddy current transients. Finally, we discuss the expected impact of these findings on the operation of the machine.

Self-phase modulation of a single-cycle THz pulse

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, M. C.

2013-01-01

We demonstrate self-phase modulation (SPM) of a single-cycle THz pulse in a semiconductor, using bulk n-GaAs as a model system. The SPM arises from the heating of free electrons in the electric field of the THz pulse. Electron heating leads to an ultrafast reduction of the plasma frequency, which...... results in a strong modification of the THz-range dielectric function of the material. THz SPM is observed directly in the time domain as a characteristic reshaping of single-cycle THz pulse. In the frequency domain, it corresponds to a strong frequency-dependent refractive index nonlinearity of n...

A single chip pulse processor for nuclear spectroscopy

International Nuclear Information System (INIS)

Hilsenrath, F.; Bakke, J.C.; Voss, H.D.

1985-01-01

A high performance digital pulse processor, integrated into a single gate array microcircuit, has been developed for spaceflight applications. The new approach takes advantage of the latest CMOS high speed A/D flash converters and low-power gated logic arrays. The pulse processor measures pulse height, pulse area and the required timing information (e.g. multi detector coincidence and pulse pile-up detection). The pulse processor features high throughput rate (e.g. 0.5 Mhz for 2 usec gausssian pulses) and improved differential linearity (e.g. + or - 0.2 LSB for a + or - 1 LSB A/D). Because of the parallel digital architecture of the device, the interface is microprocessor bus compatible. A satellite flight application of this module is presented for use in the X-ray imager and high energy particle spectrometers of the PEM experiment on the Upper Atmospheric Research Satellite

Analytical calculation of spin tunneling effect in single molecule magnet Fe8 with considering quadrupole excitation

OpenAIRE

Y Yousefi; H Fakhari; K Muminov; M R Benam

2018-01-01

Spin tunneling effect in Single Molecule Magnet Fe8 is studied by instanton calculation technique using SU(3) generalized spin coherent state in real parameter as a trial function. For this SMM, tunnel splitting arises due to the presence of a Berry like phase in action, which causes interference between tunneling trajectories (instantons). For this SMM, it is established that the use of quadrupole excitation (g dependence) changes not only the location of the quenching points, but also the n...

ISABELLE insertion quadrupoles

International Nuclear Information System (INIS)

Kaugerts, J.; Polk, I.; Sampson, W.; Dahl, P.F.

1979-01-01

Beam focussing and control at the beam intersection regions of ISABELLE is accomplished by a number of superconducting insertion quadrupoles. These magnets differ from the standard ISABELLE quadrupoles in various ways. In particular, the requirements of limited space near the intersections and aperture for beam extraction impose constraints on their configuration. To achieve optimum beam focussing and provide tuning flexibility calls for stronger quadrupole trim windings than those in the standard quadrupoles. The magnetic and mechanical design of the insertion quadrupoles and their associated correction and steering windings to accomplish the above tasks is presented

Interaction of solitary pulses in single mode optical fibres | Usman ...

African Journals Online (AJOL)

Two solitary waves launched, by way of incidence, into an optical fibre from a single pulse if the pulses are in-phase as understood from results of inverse scattering transform method applied to the cubic nonlinear Schrödinger equations, (CNLSE\\'s). The single CNLSE is then understood to describe evolution of coupled ...

Picosecond chirped pulse compression in single-mode fibers

International Nuclear Information System (INIS)

Wenhua Cao; Youwei Zhang

1995-01-01

In this paper, the nonlinear propagation of picosecond chirped pulses in single mode fibers has been investigated both analytically and numerically. Results show that downchirped pulses can be compressed owing to normal group-velocity dispersion. The compression ratio depends both on the initial peak power and on the initial frequency chirp of the input pulse. While the compression ratio depends both on the initial peak power and on the initial frequency chirp of the input pulse. While the compression ratio increases with the negative frequency chirp, it decreases with the initial peak power of the input pulse. This means that the self-phase modulation induced nonlinear frequency chirp which is linear and positive (up-chirp) over a large central region of the pulse and tends to cancel the initial negative chirp of the pulse. It is also shown that, as the negative chirped pulse compresses temporally, it synchronously experiences a spectral narrowing

Boson models of quadrupole collective motion

International Nuclear Information System (INIS)

Zelevinskij, V.G.

1985-01-01

The subject of the lecture is the low-lying excitations of even-even (e-e) spherical nuclei. The predominant role of the quadrupole mode, which determines the structure of spectra and transitions, is obvious on the background of shell periodicity and pair correlations. Typical E2-transitions are strengthened Ω ∼ A 2/3 times in comparison with single particle evaluations. Together with the regularity of the whole picture it gives evidence about collectivization of quadrupole motion. The collective states are combined in bands, where the transition probability are especially great; frequencies ω of the strengthened transitions are small in comparison with pair separation energies of 2 E-bar ∼ 2 MeV. Thus, the description of low-lying excitations of spherical nuclei has to be based on three principles: collectivity (Ω >> 1), adiabaticity (τ ≡ ω/2E-bar << 1) and quadrupole symmetry

Quadrupole collectivity of angular-momentum projected states of nucleons in the high-j intruder single-particle states

International Nuclear Information System (INIS)

Raman, S.; Kahane, S.; Bhatt, K.H.

1999-01-01

Ever since the pioneering work of Elliott (Elliott J P 1958 London Series A 245 128, 562), quadrupole collectivity in deformed nuclei has been economically described in terms of SU 3 symmetry. Microscopic SU 3 symmetry is not present in the deformed intrinsic states of n nucleons in the abnormal-parity single-particle states j a . However, such (j a ) n states do possess some SU 3 -symmetry-like properties as shown in this work. (author)

S-process studies using single and pulsed neutron exposures

Science.gov (United States)

Beer, H.

The formation of heavy elements by slow neutron capture (s-process) is investigated. A pulsed neutron irradiation leading to an exponential exposure distribution is dominant for nuclei from A = 90 to 200. For the isotopes from iron to zirconium an additional 'weak' s-process component must be superimposed. Calculations using a single or another pulsed neutron exposure for this component have been carried out in order to reproduce the abundance pattern of the s-only and s-process dominant isotopes. For the adjustment of these calculations to the empirical values, the inclusion of new capture cross section data on Se76 and Y89 and the consideration of the branchings at Ni63, Se79, and Kr85 was important. The combination of an s-process with a single and a pulsed neutron exposure yielded a better representation of empirical abundances than a two component pulsed s-process.

S-process studies using single and pulsed neutron exposures

International Nuclear Information System (INIS)

Beer, H.

1986-01-01

The formation of heavy elements by slow neutron capture (s-process) is investigated. A pulsed neutron irradiation leading to an exponential exposure distribution is dominant for nuclei from A=90 to 200. For the isotopes from iron to zirconium an additional ''weak'' s-process component must be superimposed. Calculations using a single or another pulsed neutron exposure for this component have been carried out in order to reproduce the abundance pattern of the s-only and s-process dominant isotopes. For the adjustment of these calculations to the empirical values, including new capture cross section data on Se76 and Y89 and the consideration of the branchings at Ni63, Se79, and Kr85 was important. The combination of a s-process with a single and a pulsed neutron exposure yielded a better representation of empirical abundances than a two component pulsed s-process

Broadband excitation by chirped pulses: application to single electron spins in diamond

International Nuclear Information System (INIS)

Niemeyer, I; Shim, J H; Zhang, J; Suter, D; Taniguchi, T; Teraji, T; Abe, H; Onoda, S; Yamamoto, T; Ohshima, T; Isoya, J; Jelezko, F

2013-01-01

Pulsed excitation of broad spectra requires very high field strengths if monochromatic pulses are used. If the corresponding high power is not available or not desirable, the pulses can be replaced by suitable low-power pulses that distribute the power over a wider bandwidth. As a simple case, we use microwave pulses with a linear frequency chirp. We use these pulses to excite spectra of single nitrogen–vacancy centres in a Ramsey experiment. Compared to the conventional Ramsey experiment, our approach increases the bandwidth by at least an order of magnitude. Compared to the conventional continuous wave-ODMR experiment, the chirped Ramsey experiment does not suffer from power broadening and increases the resolution by at least an order of magnitude. As an additional benefit, the chirped Ramsey spectrum contains not only ‘allowed’ single quantum transitions, but also ‘forbidden’ zero- and double quantum transitions, which can be distinguished from the single quantum transitions by phase-shifting the readout pulse with respect to the excitation pulse or by variation of the external magnetic field strength. (paper)

Soft error rate analysis methodology of multi-Pulse-single-event transients

International Nuclear Information System (INIS)

Zhou Bin; Huo Mingxue; Xiao Liyi

2012-01-01

As transistor feature size scales down, soft errors in combinational logic because of high-energy particle radiation is gaining more and more concerns. In this paper, a combinational logic soft error analysis methodology considering multi-pulse-single-event transients (MPSETs) and re-convergence with multi transient pulses is proposed. In the proposed approach, the voltage pulse produced at the standard cell output is approximated by a triangle waveform, and characterized by three parameters: pulse width, the transition time of the first edge, and the transition time of the second edge. As for the pulse with the amplitude being smaller than the supply voltage, the edge extension technique is proposed. Moreover, an efficient electrical masking model comprehensively considering transition time, delay, width and amplitude is proposed, and an approach using the transition times of two edges and pulse width to compute the amplitude of pulse is proposed. Finally, our proposed firstly-independently-propagating-secondly-mutually-interacting (FIP-SMI) is used to deal with more practical re-convergence gate with multi transient pulses. As for MPSETs, a random generation model of MPSETs is exploratively proposed. Compared to the estimates obtained using circuit level simulations by HSpice, our proposed soft error rate analysis algorithm has 10% errors in SER estimation with speed up of 300 when the single-pulse-single-event transient (SPSET) is considered. We have also demonstrated the runtime and SER decrease with the increment of P0 using designs from the ISCAS-85 benchmarks. (authors)

High-throughput analysis of amino acids in plant materials by single quadrupole mass spectrometry

DEFF Research Database (Denmark)

Dahl-Lassen, Rasmus; van Hecke, Jan Julien Josef; Jørgensen, Henning

2018-01-01

that it is very time consuming with typical chromatographic run times of 70 min or more. Results: We have here developed a high-throughput method for analysis of amino acid profiles in plant materials. The method combines classical protein hydrolysis and derivatization with fast separation by UHPLC and detection...... reducing the overall analytical costs compared to methods based on more advanced mass spectrometers....... by a single quadrupole (QDa) mass spectrometer. The chromatographic run time is reduced to 10 min and the precision, accuracy and sensitivity of the method are in line with other recent methods utilizing advanced and more expensive mass spectrometers. The sensitivity of the method is at least a factor 10...

Pulse patterning effect in optical pulse division multiplexing for flexible single wavelength multiple access optical network

Science.gov (United States)

Jung, Sun-Young; Kim, Chang-Hun; Han, Sang-Kook

2018-05-01

A demand for high spectral efficiency requires multiple access within a single wavelength, but the uplink signals are significantly degraded because of optical beat interference (OBI) in intensity modulation/direct detection system. An optical pulse division multiplexing (OPDM) technique was proposed that could effectively reduce the OBI via a simple method as long as near-orthogonality is satisfied, but the condition was strict, and thus, the number of multiplexing units was very limited. We propose pulse pattern enhanced OPDM (e-OPDM) to reduce the OBI and improve the flexibility in multiple access within a single wavelength. The performance of the e-OPDM and patterning effect are experimentally verified after 23-km single mode fiber transmission. By employing pulse patterning in OPDM, the tight requirement was relaxed by extending the optical delay dynamic range. This could support more number of access with reduced OBI, which could eventually enhance a multiple access function.

Single flux pulses affecting the ensemble of superconducting qubits

Science.gov (United States)

Denisenko, M. V.; Klenov, N. V.; Satanin, A. M.

2018-02-01

The present study is devoted to development of a technique for numerical simulation of the wave function dynamics the single Josephson qubits and arrays of noninteracting qubits controlled by ultra-short pulses. We wish to demonstrate the feasibility of a new principle of basic logical operations on the picosecond timescale. The influence of the unipolar pulse ("fluxon") form on the evolution of the state during the execution of the quantum one-qubit operations - "NOT", "READ" and " √{N O T } " - is investigated in the presence of decoherence. In the array of non interacting qubits, the question of the influence of the spread of their energy parameters (tunnel constants) is studied. It is shown that a single unipolar pulse can control a huge array of artificial atoms with 10% spread of geometric parameters in the array.

The development of compact magnetic quadrupoles for ILSE

International Nuclear Information System (INIS)

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

1990-08-01

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

Single and double long pulse laser ablation of aluminum induced in air and water ambient

International Nuclear Information System (INIS)

Akbari Jafarabadi, Marzieh; Mahdieh, Mohammad Hossein

2017-01-01

Highlights: • Laser ablation of aluminum target by single and double pulse (∼ 5 ns delay) in ambient air and distilled water • Comparing with air, in ambient water, plasma confinement results in higher crater depth. • In comparison with single pulse laser ablation, the absorption of the laser pulse energy is higher for double pulse regime. • As a result of ablated material expansion, the crater depth is decreased if the target is placed at lower depth. - Abstract: In this paper, single pulse and double pulse laser ablation of an aluminum target in two interaction ambient was investigated experimentally. The interaction was performed by nanosecond Nd:YAG laser beam in air and four depths (i.e. 9, 13, 17, and 21 mm) of distilled water ambient. The irradiation was carried out in single and collinear double pulse configurations in both air and liquid ambient. Crater geometry (depth and diameter) was measured by an optical microscope. The results indicated that the crater geometry strongly depends on both single pulse and double pulse configurations and interaction ambient. In single pulse regime, the crater diameter is higher for all water depths compared to that of air. However, the crater depth, depend on water depth, is higher or lower than the crater depth in air. In double pulse laser ablation, there are greater values for both crater diameters and crater depths in the water.

Electronic regulation of the SPS extraction quadrupole current pulse shape for improved stability of the extracted beam

CERN Document Server

Carlier, E; Vossenberg, Eugène B; CERN. Geneva. SPS and LEP Division

1996-01-01

In order to minimise the event pile-up and therefore optimise the detection efficiency, Chorus and Nomad experiments ask for a long and rectangular spill profile. At present the fast-slow extractio n is generated by driving the beam into a quadrupolar-octopolar resonance by exciting a quadrupole magnet with a semi-trapezoidal current [1]. The trapezoidal pulse shape is obtained by dischargin g a capacitor into the magnet coils. After a few milliseconds of undamped discharge a fixed resistor is switched into the circuit. The attenuation is then higher and the sine wave continues with a lower gradient. The two gradients can be adjusted by varying the initial capacitor voltage and the time at which the resistor is switched into the circuit. A further degree of freedom in determini ng the spill shape has been added by allowing the possibility of changing the second slope value independently of the initial conditions. This task is achieved by means of a variable current sour ce added in parallel to the fixed resis...

Direct trace analysis of metals and alloys in a quadrupole ion-trap mass spectrometer

CERN Document Server

Song, K S; Yang, M; Cha, H K; Lee, J M; Lee, G H

1999-01-01

An ion-trap mass spectrometer adopting a quadrupole ion-trap and laser ablation/ionization method was constructed. The developed system was tested for composition analysis of some metals (Cu, stainless), and alloys (hastalloy C, mumetal) by mass spectrometry. Samples were analyzed by using laser ablation from a sample probe tip followed by a mass analysis with the quadrupole ion-trap. The quadrupole ion-trap was modified to enable laser ablation by a XeCl excimer laser pulse that passed radially through the ring electrode. A mass scan of the produced ions was performed in the mass selective instability mode wherein trapped ions were successively detected by increasing the rf voltage through the ring electrode. Factors affecting the mass resolution, such as pressure of buffer gas and ablation laser power, are discussed.

Table of Nuclear Electric Quadrupole Moments

International Nuclear Information System (INIS)

Stone, N.J.

2013-12-01

This Table is a compilation of experimental measurements of static electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. Experimental data from all quadrupole moment measurements actually provide a value of the product of the moment and the electric field gradient [EFG] acting at the nucleus. Knowledge of the EFG is thus necessary to extract the quadrupole moment. A single recommended value of the moment is given for each state, based, for each element, wherever possible, upon a standard reference moment for a nuclear state of that element studied in a situation in which the electric field gradient has been well calculated. For several elements one or more subsidiary reference EFG/moment references are required and their use is specified. The literature search covers the period to mid-2013. (author)

Nuclear quadrupole resonance applied for arsenic oxide study

International Nuclear Information System (INIS)

Correia, J.A.S.

1991-04-01

The objectives of this study are mounting a pulsed Nuclear Quadrupole Resonance (NQR) building a flow cryostat capable of varying the temperature continuously from 77 K to 340 K and using the spectrometer and the cryostat to study the polycrystalline arsenic oxide. The spin-lattice relaxation time (T 1 ), the spin-spin relaxation time (T 2 ) and the resonance frequency are obtained as a function of temperature. These data are obtained in 77 to 330 K interval. The relaxation times are obtained using the spin echo technique. The spin echo phenomenon is due to refocusing spins, when a 180 0 C pulse is applied after a 90 0 C pulse. The spin-lattice relaxation time is obtained using the plot of echo amplitude versus the repetition time. The spin-spin relaxation time is obtained using the plot of echo amplitude versus the separation between the 90 0 C - 180 0 C pulses. The theory developed by Bayer is used to explain the spin-lattice relaxation time and the frequency temperature dependence. The spin-spin relaxation time is discussed using the Bloch equations. (author)

Temporal dynamics of high repetition rate pulsed single longitudinal ...

Indian Academy of Sciences (India)

ing (GIG) cavity, single-mode dye laser pumped by high repetition rate ... in a high loss cavity, a detailed theoretical study and optimization of cavity ..... rate for high conversion efficiency and longer pulse width of the single-mode dye laser.

Study on irradiation effects of nucleus electromagnetic pulse on single chip computer system

International Nuclear Information System (INIS)

Hou Minsheng; Liu Shanghe; Wang Shuping

2001-01-01

Intense electromagnetic pulse, namely nucleus electromagnetic pulse (NEMP), lightning electromagnetic pulse (LEMP) and high power microwave (HPM), can disturb and destroy the single chip computer system. To study this issue, the authors made irradiation experiments by NEMPs generated by gigahertz transversal electromagnetic (GTEM) Cell. The experiments show that shutdown, restarting, communication errors of the single chip microcomputer system would occur when it was irradiated by the NEMPs. Based on the experiments, the cause on the effects on the single chip microcomputer system is discussed

Observation of electric quadrupole transitions to Rydberg nd states of ultracold rubidium atoms

NARCIS (Netherlands)

Tong, D.; Farooqi, S.M.; Kempen, van E.G.M.; Pavlovic, Z.; Stanojevic, J.; Coté, R.; Eyler, E.E.; Gould, P.L.

2009-01-01

We report the observation of dipole-forbidden, but quadrupole-allowed, one-photon transitions to high-Rydberg states in Rb. Using pulsed uv excitation of ultracold atoms in a magneto-optical trap, we excite 5s¿nd transitions over a range of principal quantum numbers n=27–59. Compared to

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

Science.gov (United States)

Jaski, Mark S.; Liu, Jie; Donnelly, Aric T.; Downey, Joshua S.; Nudell, Jeremy J.; Jain, Animesh

2018-01-30

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

A pulsed single-frequency Nd:GGG/BaWO4 Raman laser

Science.gov (United States)

Liu, Zhaojun; Men, Shaojie; Cong, Zhenhua; Qin, Zengguang; Zhang, Xingyu; Zhang, Huaijin

2018-04-01

A single-frequency pulsed laser at 1178.3 nm was demonstrated in a crystalline Raman laser. A crystal combination of Nd:GGG and BaWO4 was selected to realize Raman conversion from a 1062.5 nm fundamental wave to a 1178.3 nm Stokes wave. An entangled cavity was specially designed to form an intracavity Raman configuration. Single-longitudinal-mode operation was realized by introducing two Fabry-Perot etalons into the Raman laser cavity. This laser operated at a pulse repetition rate of 50 Hz with 2 ms long envelopes containing micro pulses at a 30 kHz repetition rate. The highest output power was 41 mW with the micro pulse duration of 15 ns. The linewidth was measured to be less than 130 MHz.

Pulse-height defect in single-crystal CVD diamond detectors

Energy Technology Data Exchange (ETDEWEB)

Beliuskina, O.; Imai, N. [The University of Tokyo, Center for Nuclear Study, Wako, Saitama (Japan); Strekalovsky, A.O.; Aleksandrov, A.A.; Aleksandrova, I.A.; Ilich, S.; Kamanin, D.V.; Knyazheva, G.N.; Kuznetsova, E.A.; Mishinsky, G.V.; Pyatkov, Yu.V.; Strekalovsky, O.V.; Zhuchko, V.E. [JINR, Flerov Laboratory of Nuclear Reactions, Dubna, Moscow Region (Russian Federation); Devaraja, H.M. [Manipal University, Manipal Centre for Natural Sciences, Manipal, Karnataka (India); Heinz, C. [II. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Giessen (Germany); Heinz, S. [II. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Giessen (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Hofmann, S.; Kis, M.; Kozhuharov, C.; Maurer, J.; Traeger, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Pomorski, M. [CEA, LIST, Diamond Sensor Laboratory, CEA/Saclay, Gif-sur-Yvette (France)

2017-02-15

The pulse-height versus deposited energy response of a single-crystal chemical vapor deposition (scCVD) diamond detector was measured for ions of Ti, Cu, Nb, Ag, Xe, Au, and of fission fragments of {sup 252} Cf at different energies. For the fission fragments, data were also measured at different electric field strengths of the detector. Heavy ions have a significant pulse-height defect in CVD diamond material, which increases with increasing energy of the ions. It also depends on the electrical field strength applied at the detector. The measured pulse-height defects were explained in the framework of recombination models. Calibration methods known from silicon detectors were modified and applied. A comparison with data for the pulse-height defect in silicon detectors was performed. (orig.)

System and process for pulsed multiple reaction monitoring

Science.gov (United States)

Belov, Mikhail E

2013-05-17

A new pulsed multiple reaction monitoring process and system are disclosed that uses a pulsed ion injection mode for use in conjunction with triple-quadrupole instruments. The pulsed injection mode approach reduces background ion noise at the detector, increases amplitude of the ion signal, and includes a unity duty cycle that provides a significant sensitivity increase for reliable quantitation of proteins/peptides present at attomole levels in highly complex biological mixtures.

Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet synchrotron ionization quadrupole mass spectrometry: application to low-temperature kinetics and product detection.

Science.gov (United States)

Soorkia, Satchin; Liu, Chen-Lin; Savee, John D; Ferrell, Sarah J; Leone, Stephen R; Wilson, Kevin R

2011-12-01

A new pulsed Laval nozzle apparatus with vacuum ultraviolet (VUV) synchrotron photoionization quadrupole mass spectrometry is constructed to study low-temperature radical-neutral chemical reactions of importance for modeling the atmosphere of Titan and the outer planets. A design for the sampling geometry of a pulsed Laval nozzle expansion has been developed that operates successfully for the determination of rate coefficients by time-resolved mass spectrometry. The new concept employs airfoil sampling of the collimated expansion with excellent sampling throughput. Time-resolved profiles of the high Mach number gas flow obtained by photoionization signals show that perturbation of the collimated expansion by the airfoil is negligible. The reaction of C(2)H with C(2)H(2) is studied at 70 K as a proof-of-principle result for both low-temperature rate coefficient measurements and product identification based on the photoionization spectrum of the reaction product versus VUV photon energy. This approach can be used to provide new insights into reaction mechanisms occurring at kinetic rates close to the collision-determined limit.

Superconducting magnetic quadrupole

Energy Technology Data Exchange (ETDEWEB)

Kim, J.W.; Shepard, K.W.; Nolen, J.A.

1995-08-01

A design was developed for a 350 T/m, 2.6-cm clear aperture superconducting quadrupole focussing element for use in a very low q/m superconducting linac as discussed below. The quadrupole incorporates holmium pole tips, and a rectangular-section winding using standard commercially-available Nb-Ti wire. The magnet was modeled numerically using both 2D and 3D codes, as a basis for numerical ray tracing using the quadrupole as a linac element. Components for a prototype singlet are being procured during FY 1995.

Optical π phase shift created with a single-photon pulse.

Science.gov (United States)

Tiarks, Daniel; Schmidt, Steffen; Rempe, Gerhard; Dürr, Stephan

2016-04-01

A deterministic photon-photon quantum logic gate is a long-standing goal. Building such a gate becomes possible if a light pulse containing only one photon imprints a phase shift of π onto another light field. We experimentally demonstrate the generation of such a π phase shift with a single-photon pulse. A first light pulse containing less than one photon on average is stored in an atomic gas. Rydberg blockade combined with electromagnetically induced transparency creates a phase shift for a second light pulse, which propagates through the medium. We measure the π phase shift of the second pulse when we postselect the data upon the detection of a retrieved photon from the first pulse. This demonstrates a crucial step toward a photon-photon gate and offers a variety of applications in the field of quantum information processing.

Nuclear quadrupole-quadrupole interaction in the inelastic scattering of aligned deuterons from deformed nuclei

International Nuclear Information System (INIS)

Clement, H.; Frick, R.; Graw, G.; Schiemenz, P.; Seichert, N.

1983-01-01

The 2 1 + -excitation of deformed nuclei by tensor polarized deuterons provides an alignment of both nuclei and thus a means to study specifically the quadrupole-quadrupole interaction between both nuclei. The tensor analyzing power Asub(xz)(theta) has been measured for the elastic and inelastic scattering on 24 Mg and 28 Si. The coupled channel analysis including a deformed tensor potential reveals a clear signature of the quadrupole-quadrupole part of the nuclear projectile-target interaction. (orig.)

NMR study of electric quadrupole interactions in GdCo2

International Nuclear Information System (INIS)

Barata, A.C.; Guimaraes, A.P.

1984-01-01

Quadrupole oscillations have been observed with 59 Co pulsed NMR in the intermetallic compound GdCo 2 . From theses oscillations the nuclear electric quadrupoles interaction (EQI) has been studied as a function of temperature in the range 4K-312K. The value measured at 4K, ν sub(Q)=672 +-3 KHz, is the largest so far reported for the cobalt EQI in the RCo 2 intermetallics. The EQI decreases with increasing temperature, reaching 432 +- 10 KHz at 312K. The amplitude of the oscillations tends to decrease with temperature, being also dependent on the easy direction of magnetization of the compound. Thus, above 200K, as the direction of magnetization changes, large oscillations are again visible in the satellite line; the main line shows no oscillations in this range. The observed temperature dependence of the EQI is roughly linear, as found in other transition metal systems. (Author) [pt

Single-mode pulsed dye laser pumped by using a diode-pumped Nd:YAG laser with a long pulse width

International Nuclear Information System (INIS)

Yi, Jong Hoon; Kim, Jin Tae; Moon, Hee Jong; Rho, Si Pyo; Han, Jae Min; Rhee, Yong Joo; Lee, Jong Min

1999-01-01

The lasing characteristics of a single-mode dye laser pumped by using a diode-pumped solid-state laser (DPSSL) with a high repetition rate is described. A 45-mm-long Nd:YAG rod was pumped by three CW diode arrays and it was acousto-optically Q-switched. A KTP crystal was used for intracavity frequency doubling. The pulse width of the laser ranged from 90 ns to 200 ns, depending on the diode current and the Q-switching frequency. The single-mode dye laser had a grazing incidence configuration. The pulse width of the dye laser was reduced to about 1/8 of the pumping laser pulse width. The effects of the DPSSL Q-switching frequency, the driving current, and the cavity loss on the dye laser pulse width were investigated by using a simple plane-parallel cavity. From the measured pulse width of the dye laser as a function of the reflectivity of the dye laser output coupler, we found that the cavity loss due to the frequency selection elements and the output coupler should be less than 70 % in order to avoid a drastically reduced pulse width

The first LHC insertion quadrupole

CERN Multimedia

2004-01-01

An important milestone was reached in December 2003 at the CERN Magnet Assembly Facility. The team from the Accelerator Technology - Magnet and Electrical Systems group, AT-MEL, completed the first special superconducting quadrupole for the LHC insertions which house the experiments and major collider systems. The magnet is 8 metres long and contains two matching quadrupole magnets and an orbit corrector, a dipole magnet, used to correct errors in quadrupole alignment. All were tested in liquid helium and reached the ultimate performance criteria required for the LHC. After insertion in the cryostat, the superconducting magnet will be installed as the Q9 quadrupole in sector 7-8, the first sector of the LHC to be put in place in 2004. Members of the quadrupole team, from the AT-MEL group, gathered around the Q9 quadrupole at its inauguration on 12 December 2003 in building 181.

Single- and multi-pulse femtosecond laser ablation of optical filter materials

International Nuclear Information System (INIS)

Krueger, J.; Lenzner, M.; Martin, S.; Lenner, M.; Spielmann, C.; Fiedler, A.; Kautek, W.

2003-01-01

Ablation experiments employing Ti:sapphire laser pulses with durations from 30 to 340 fs (centre wavelength 800 nm, repetition rate 1 kHz) were performed in air. Absorbing filters (Schott BG18 and BG36) served as targets. The direct focusing technique was used under single- and multi-pulse irradiation conditions. Ablation threshold fluences were determined from a semi-logarithmic plot of the ablation crater diameter versus laser fluence. The threshold fluence decreases for a shorter pulse duration and an increasing number of pulses. The multi-pulse ablation threshold fluences are similar to those of undoped glass material (∼1 J cm -2 ). That means that the multi-pulse ablation threshold is independent on the doping level of the filters. For more than 100 pulses per spot and all pulse durations applied, the threshold fluence is practically constant. This leads to technically relevant ablation threshold values

Quadrupole shunt experiments at SPEAR

International Nuclear Information System (INIS)

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

1996-05-01

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

Magnetic field measurements of LHC inner triplet quadrupoles fabricated at Fermilab

International Nuclear Information System (INIS)

Velev, G.V.; Bossert, R.; Carcagno, R.; DiMarco, J.; Feher, S.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Orris, D.; Schlabach, P.; Strait, J.

2006-01-01

Fermilab, as part of the US-LHC Accelerator Project, is producing superconducting low-beta quadrupole magnets for the Large Hadron Collider (LHC). These 5.5 m long magnets are designed to operate in superfluid helium at 1.9 K with a nominal gradient of 205 T/m in the 70 mm bore. Two quadrupoles separated by a dipole orbit corrector in a single cryogenic assembly comprise the Q2 optical elements of the final focus triplets in the LHC interaction regions. The field quality of the quadrupoles is measured at room temperature during construction of the cold masses as well as during cold testing of the cryogenic assembly. We summarize data from the series measurements of the magnets and discuss various topics of interest

Magnetic field measurements of LHC inner triplet quadrupoles fabricated at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Velev, G.V.; Bossert, R.; Carcagno, R.; DiMarco, J.; Feher, S.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Orris, D.; Schlabach, P.; Strait, J.; /Fermilab

2006-08-01

Fermilab, as part of the US-LHC Accelerator Project, is producing superconducting low-beta quadrupole magnets for the Large Hadron Collider (LHC). These 5.5 m long magnets are designed to operate in superfluid helium at 1.9 K with a nominal gradient of 205 T/m in the 70 mm bore. Two quadrupoles separated by a dipole orbit corrector in a single cryogenic assembly comprise the Q2 optical elements of the final focus triplets in the LHC interaction regions. The field quality of the quadrupoles is measured at room temperature during construction of the cold masses as well as during cold testing of the cryogenic assembly. We summarize data from the series measurements of the magnets and discuss various topics of interest.

Temperature field analysis of single layer TiO2 film components induced by long-pulse and short-pulse lasers

International Nuclear Information System (INIS)

Wang Bin; Zhang Hongchao; Qin Yuan; Wang Xi; Ni Xiaowu; Shen Zhonghua; Lu Jian

2011-01-01

To study the differences between the damaging of thin film components induced by long-pulse and short-pulse lasers, a model of single layer TiO 2 film components with platinum high-absorptance inclusions was established. The temperature rises of TiO 2 films with inclusions of different sizes and different depths induced by a 1 ms long-pulse and a 10 ns short-pulse lasers were analyzed based on temperature field theory. The results show that there is a radius range of inclusions that corresponds to high temperature rises. Short-pulse lasers are more sensitive to high-absorptance inclusions and long-pulse lasers are more easily damage the substrate. The first-damage decision method is drawn from calculations.

LASER PROCESSING ON SINGLE CRYSTALS BY UV PULSE LASER

OpenAIRE

龍見, 雅美; 佐々木, 徹; 高山, 恭宜

2009-01-01

Laser processing by using UV pulsed laser was carried out on single crystal such as sapphire and diamond in order to understand the fundamental laser processing on single crystal. The absorption edges of diamond and sapphire are longer and shorter than the wave length of UV laser, respectively. The processed regions by laser with near threshold power of processing show quite different state in each crystal.

Quadrupole collective excitations in rapidly rotating nuclej

International Nuclear Information System (INIS)

Mikhajlov, I.N.

1983-01-01

The spectrum of collective quadrupole excitations in nuclei is investigated. The average nucleus field has the axial symmetry and rotation occurs relatively to this axis. Dependences of the spectrum of quadrupole oscillations on rotation rate for classic liquid drop (CLD) and for a drop of fermi-liquid (DFL) with fissionability parameter X=0.62 ( 154 Er) are presented. The dependence of probabilities of E2-transitions between single-phonon and phonon-free states on rotation rate for CLD and DFL with fussionability parameter X=0.62 ( 154 Er) is also presented. It is shown that for CLD collective E2-transition of states of yrast-consequence is absolutely forbidden. For DFL transitions are possible that lead to decay of phonon-free state with the excitation of phonons of γ-modes and decrease of angular momentum

Quadrupole shunt experiments at SPEAR

International Nuclear Information System (INIS)

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

1997-01-01

As part of a program to align and stabilize the SPEAR storage ring, a switchable shunt resistor was installed on each quadrupole to bypass a small percentage of the magnet current. The impact of a quadrupole shunt is to move the electron beam orbit in proportion to the off-axis beam position at the quadrupole and to shift the betatron tune. Initially, quadrupole shunts in SPEAR were used to position the electron beam in the center of the quadrupoles. This provided readback offsets for nearby beam position monitors and helped to steer the photon beams with low-amplitude corrector currents. The shunt-induced tune shift measurements were then processed in MAD to derive a lattice model. copyright 1997 American Institute of Physics

Electric quadrupole strength in nuclei

International Nuclear Information System (INIS)

Kirson, M.W.

1979-01-01

Isoscalar electric quadrupole strength distributions in nuclei are surveyed, and it is concluded that the strength is shared, in most cases, roughly equally between low-lying transitions and the giant quadrupole state. The same is not true of the isovector case. A simple extension of the schematic model gives a remarkably successul description of the data, and emphasizes the vital importance of the coupling between high-lying and low-lying quadrupole modes. The standadrd simple representation of the giant quadrupole resonance as produced by operating on the nuclear ground state with the quadrupole transition operator is not applicable to the isoscalar case. It is suggested that giant resonances fall into broad classes of similar states, with considerable qualitative differences between the distinct classes. (author)

Static quadrupole moment of the Kπ = 14+ isomer in 176W

International Nuclear Information System (INIS)

Ionescu-Bujor, M.; Iordachescu, A.; Bucurescu, D.; Brandolini, F.; Lenzi, S. M.; Pavan, P.; Rossi Alvarez, C.; Marginean, N.; Medina, N.H.; Ribas, R.V.; De Poli, M.; Napoli, D. R.; Podolyak, Zs.; Ur, C. A.

2001-01-01

The investigation of high-K isomeric states in the deformed nuclei of the A∼180 region has found renewed interest in recent years. Much experimental and theoretical work was devoted to understand the mechanisms which govern their decay to lower-lying states, particularly the anomalous strong decays to low-K states. Other questions of great importance are the quenching of the pairing correlations and the shape polarization effects in the high-seniority multi-quasiparticle excitations. Our interest focused on the 41 ns K π =14 + 3746 keV isomeric state with anomalous decay in 176 W. On the basis of a precise g-factor measurement we assigned to this isomer a pure four-quasiparticle configuration, composed by two protons in the 7/2 + [404] and 9/2 - [514] orbitals and two neutrons in the 7/2 + [633] and 5/2 - [512] orbitals. In the present work the measurement of its static quadrupole moment has been performed. Prior to our experiment, static quadrupole moments have been measured only for three high-K isomeric states of seniority ≥ 4 in the A∼180 region: 16 + in 178 Hf, 35/2 - in 179 W and 25 + in 182 Os. A deformation very similar to that of the ground state has been deduced for the 16 + isomer in 178 Hf, while for the high-K isomers in 179 W and 182 Os significantly smaller deformations were reported. The quadrupole interaction of the 14 + isomeric state in 176 W has been investigated in the electric field gradient (EFG) of the polycrystalline lattice of metallic Tl by applying the time-differential perturbed angular distribution method. For W impurities in Tl host the EFG strength and its temperature dependence have been recently reported. The isomer was populated in the 164 Dy( 16 O,4n) 176 W reaction using a 83 MeV 16 O pulsed beam (pulse width 1.5 ns, repetition period 800 ns) delivered by the XTU-Tandem of Laboratori Nazionali di Legnaro. The target consisted of 0.5 mg/cm 2 metallic 164 Dy on thick Tl backing in which both the recoiling 176 W nuclei and

Efficient amplitude-modulated pulses for triple- to single-quantum coherence conversion in MQMAS NMR.

Science.gov (United States)

Colaux, Henri; Dawson, Daniel M; Ashbrook, Sharon E

2014-08-07

The conversion between multiple- and single-quantum coherences is integral to many nuclear magnetic resonance (NMR) experiments of quadrupolar nuclei. This conversion is relatively inefficient when effected by a single pulse, and many composite pulse schemes have been developed to improve this efficiency. To provide the maximum improvement, such schemes typically require time-consuming experimental optimization. Here, we demonstrate an approach for generating amplitude-modulated pulses to enhance the efficiency of the triple- to single-quantum conversion. The optimization is performed using the SIMPSON and MATLAB packages and results in efficient pulses that can be used without experimental reoptimisation. Most significant signal enhancements are obtained when good estimates of the inherent radio-frequency nutation rate and the magnitude of the quadrupolar coupling are used as input to the optimization, but the pulses appear robust to reasonable variations in either parameter, producing significant enhancements compared to a single-pulse conversion, and also comparable or improved efficiency over other commonly used approaches. In all cases, the ease of implementation of our method is advantageous, particularly for cases with low sensitivity, where the improvement is most needed (e.g., low gyromagnetic ratio or high quadrupolar coupling). Our approach offers the potential to routinely improve the sensitivity of high-resolution NMR spectra of nuclei and systems that would, perhaps, otherwise be deemed "too challenging".

Temperature field analysis of single layer TiO2 film components induced by long-pulse and short-pulse lasers.

Science.gov (United States)

Wang, Bin; Zhang, Hongchao; Qin, Yuan; Wang, Xi; Ni, Xiaowu; Shen, Zhonghua; Lu, Jian

2011-07-10

To study the differences between the damaging of thin film components induced by long-pulse and short-pulse lasers, a model of single layer TiO(2) film components with platinum high-absorptance inclusions was established. The temperature rises of TiO(2) films with inclusions of different sizes and different depths induced by a 1 ms long-pulse and a 10 ns short-pulse lasers were analyzed based on temperature field theory. The results show that there is a radius range of inclusions that corresponds to high temperature rises. Short-pulse lasers are more sensitive to high-absorptance inclusions and long-pulse lasers are more easily damage the substrate. The first-damage decision method is drawn from calculations. © 2011 Optical Society of America

Measurement of time dependent fields in high gradient superconducting quadrupoles for the Tevatron

International Nuclear Information System (INIS)

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

Flame Motion In Gas Turbine Burner From Averages Of Single-Pulse Flame Fronts

Energy Technology Data Exchange (ETDEWEB)

Tylli, N.; Hubschmid, W.; Inauen, A.; Bombach, R.; Schenker, S.; Guethe, F. [Alstom (Switzerland); Haffner, K. [Alstom (Switzerland)

2005-03-01

Thermo acoustic instabilities of a gas turbine burner were investigated by flame front localization from measured OH laser-induced fluorescence single pulse signals. The average position of the flame was obtained from the superposition of the single pulse flame fronts at constant phase of the dominant acoustic oscillation. One observes that the flame position varies periodically with the phase angle of the dominant acoustic oscillation. (author)

THE CRAB PULSAR AT CENTIMETER WAVELENGTHS. II. SINGLE PULSES

Energy Technology Data Exchange (ETDEWEB)

Hankins, T. H.; Eilek, J. A. [Physics Department, New Mexico Tech, Socorro, NM 87801 (United States); Jones, G., E-mail: thankins@aoc.nrao.edu [Columbia University, New York, NY 10027 (United States)

2016-12-10

We have carried out new, high-frequency, high-time-resolution observations of the Crab pulsar. Combining these with our previous data, we characterize bright single pulses associated with the Main Pulse, both the Low-Frequency and High-Frequency Interpulses, and the two  High-Frequency Components. Our data include observations at frequencies ranging from 1 to 43 GHz with time resolutions down to a fraction of a nanosecond. We find that at least two types of emission physics are operating in this pulsar. Both Main Pulses and Low-Frequency Interpulses, up to ∼10 GHz, are characterized by nanoshot emission—overlapping clumps of narrowband nanoshots, each with its own polarization signature. High-Frequency Interpulses, between 5 and 30 GHz, are characterized by spectral band emission—linearly polarized emission containing ∼30 proportionately spaced spectral bands. We cannot say whether the longer-duration High-Frequency Components pulses are due to a scattering process, or if they come from yet another type of emission physics.

Short-wavelength soft-x-ray laser pumped in double-pulse single-beam non-normal incidence

International Nuclear Information System (INIS)

Zimmer, D.; Ros, D.; Guilbaud, O.; Habib, J.; Kazamias, S.; Zielbauer, B.; Bagnoud, V.; Ecker, B.; Aurand, B.; Kuehl, T.; Hochhaus, D. C.; Neumayer, P.

2010-01-01

We demonstrated a 7.36 nm Ni-like samarium soft-x-ray laser, pumped by 36 J of a neodymium:glass chirped-pulse amplification laser. Double-pulse single-beam non-normal-incidence pumping was applied for efficient soft-x-ray laser generation. In this case, the applied technique included a single-optic focusing geometry for large beam diameters, a single-pass grating compressor, traveling-wave tuning capability, and an optimized high-energy laser double pulse. This scheme has the potential for even shorter-wavelength soft-x-ray laser pumping.

Single-mode pulsed dye laser pumped by using a diode-pumped Nd:YAG laser with a long pulse width

CERN Document Server

Yi, J H; Moon, H J; Rho, S P; Han, J M; Rhee, Y J; Lee, J M

1999-01-01

The lasing characteristics of a single-mode dye laser pumped by using a diode-pumped solid-state laser (DPSSL) with a high repetition rate is described. A 45-mm-long Nd:YAG rod was pumped by three CW diode arrays and it was acousto-optically Q-switched. A KTP crystal was used for intracavity frequency doubling. The pulse width of the laser ranged from 90 ns to 200 ns, depending on the diode current and the Q-switching frequency. The single-mode dye laser had a grazing incidence configuration. The pulse width of the dye laser was reduced to about 1/8 of the pumping laser pulse width. The effects of the DPSSL Q-switching frequency, the driving current, and the cavity loss on the dye laser pulse width were investigated by using a simple plane-parallel cavity. From the measured pulse width of the dye laser as a function of the reflectivity of the dye laser output coupler, we found that the cavity loss due to the frequency selection elements and the output coupler should be less than 70 % in order to avoid a drast...

Timing Solution and Single-pulse Properties for Eight Rotating Radio Transients

Energy Technology Data Exchange (ETDEWEB)

Cui, B.-Y.; McLaughlin, M. A. [Department of Physics and Astronomy West Virginia University Morgantown, WV 26506 (United States); Boyles, J. [Department of Physics and Astronomy West Kentucky University Bowling Green, KY 42101 (United States); Palliyaguru, N. [Physics and Astronomy Department Texas Tech University Lubbock, TX 79409-1051 (United States)

2017-05-01

Rotating radio transients (RRATs), loosely defined as objects that are discovered through only their single pulses, are sporadic pulsars that have a wide range of emission properties. For many of them, we must measure their periods and determine timing solutions relying on the timing of their individual pulses, while some of the less sporadic RRATs can be timed by using folding techniques as we do for other pulsars. Here, based on Parkes and Green Bank Telescope (GBT) observations, we introduce our results on eight RRATs including their timing-derived rotation parameters, positions, and dispersion measures (DMs), along with a comparison of the spin-down properties of RRATs and normal pulsars. Using data for 24 RRATs, we find that their period derivatives are generally larger than those of normal pulsars, independent of any intrinsic correlation with period, indicating that RRATs’ highly sporadic emission may be associated with intrinsically larger magnetic fields. We carry out Lomb–Scargle tests to search for periodicities in RRATs’ pulse detection times with long timescales. Periodicities are detected for all targets, with significant candidates of roughly 3.4 hr for PSR J1623−0841 and 0.7 hr for PSR J1839−0141. We also analyze their single-pulse amplitude distributions, finding that log-normal distributions provide the best fits, as is the case for most pulsars. However, several RRATs exhibit power-law tails, as seen for pulsars emitting giant pulses. This, along with consideration of the selection effects against the detection of weak pulses, imply that RRAT pulses generally represent the tail of a normal intensity distribution.

Timing Solution and Single-pulse Properties for Eight Rotating Radio Transients

Science.gov (United States)

Cui, B.-Y.; Boyles, J.; McLaughlin, M. A.; Palliyaguru, N.

2017-05-01

Rotating radio transients (RRATs), loosely defined as objects that are discovered through only their single pulses, are sporadic pulsars that have a wide range of emission properties. For many of them, we must measure their periods and determine timing solutions relying on the timing of their individual pulses, while some of the less sporadic RRATs can be timed by using folding techniques as we do for other pulsars. Here, based on Parkes and Green Bank Telescope (GBT) observations, we introduce our results on eight RRATs including their timing-derived rotation parameters, positions, and dispersion measures (DMs), along with a comparison of the spin-down properties of RRATs and normal pulsars. Using data for 24 RRATs, we find that their period derivatives are generally larger than those of normal pulsars, independent of any intrinsic correlation with period, indicating that RRATs’ highly sporadic emission may be associated with intrinsically larger magnetic fields. We carry out Lomb-Scargle tests to search for periodicities in RRATs’ pulse detection times with long timescales. Periodicities are detected for all targets, with significant candidates of roughly 3.4 hr for PSR J1623-0841 and 0.7 hr for PSR J1839-0141. We also analyze their single-pulse amplitude distributions, finding that log-normal distributions provide the best fits, as is the case for most pulsars. However, several RRATs exhibit power-law tails, as seen for pulsars emitting giant pulses. This, along with consideration of the selection effects against the detection of weak pulses, imply that RRAT pulses generally represent the tail of a normal intensity distribution.

Semi-classical description of Rydberg atoms in strong, single-cycle electromagnetic pulses

International Nuclear Information System (INIS)

Jensen, R.V.; Sanders, M.M.

1993-01-01

Recent experimental measurements of the excitation and ionization of Rydberg atoms by single-cycle, electromagnetic pulses have revealed a variety of novel features. Because many quantum states are strongly coupled by the broadband radiation in the short pulse, the traditional methods of quantum mechanics are inadequate to account for the experimental results. We have therefore developed a semi-classical description of the interaction of both hydrogenic and non-hydrogenic atoms with single-cycle pulses of intense, electromagnetic radiation which is based on the strong correspondence theory of Percival and Richards. This theory, which was originally introduced for the description of strong atomic collisions, accounts for some of the surprising features of the experimental measurements and provides new predictions for future experimental studies

Ultrafast geometric control of a single qubit using chirped pulses

International Nuclear Information System (INIS)

Hawkins, Patrick E; Malinovskaya, Svetlana A; Malinovsky, Vladimir S

2012-01-01

We propose a control strategy to perform arbitrary unitary operations on a single qubit based solely on the geometrical phase that the qubit state acquires after cyclic evolution in the parameter space. The scheme uses ultrafast linearly chirped pulses and provides the possibility of reducing the duration of a single-qubit operation to a few picoseconds.

Structural science using single crystal and pulse neutron scattering

International Nuclear Information System (INIS)

Noda, Yukio; Kimura, Hiroyuki; Watanabe, Masashi; Ishikawa, Yoshihisa; Tamura, Itaru; Arai, Masatoshi; Takahashi, Miwako; Ohshima, Ken-ichi; Abe, Hiroshi; Kamiyama, Takashi

2008-01-01

The application to single crystal neutron structural analysis is overviewed. Special attention is paid to the pulse neutron method, which will be available soon under J-PARC project in Japan. New proposal and preliminary experiment using Sirius at KENS are described. (author)

SPS Quadrupole Magnets

CERN Multimedia

1974-01-01

A stack of SPS Quadrupole Magnets ready for installation in the tunnel. The SPS uses a total of 216 laminated normal conducting lattice quadrupoles with a length of 3.13 m for the core, 3.3 m overall. The F and D quads. have identical characteristics: inscribed circle radius 44 mm, core height and width 800 mm, maximum gradient 20 Tesla/m.

Single-electron pulse-height spectra in thin-gap parallel-plate chambers

CERN Document Server

Fonte, Paulo J R; Peskov, Vladimir; Policarpo, Armando

1999-01-01

Single-electron pulse-height spectra were measured in 0.6 and 1.2 mm parallel-plate chambers developed for the TOF system of the ALICE /LHC-HI experiment. Mixtures of Ar with ethane, isobutane, and SF/sub 6/ were studied. The observed spectrum shows a clear peak for all gases, suggesting efficient single-electron detection in thin parallel-plate structures. The pulse-height spectrum can be described by the weighted sum of an exponential and a Polya distribution, the Polya contribution becoming more important at higher gains. Additionally, it was found that the maximum gain, above 10/sup 6/, is limited by the appearance of streamers and depends weakly on the gas composition. The suitability of each mixture for single-electron detection is also quantitatively assessed. (8 refs).

Development of a totally computer-controlled triple quadrupole mass spectrometer system

International Nuclear Information System (INIS)

Wong, C.M.; Crawford, R.W.; Barton, V.C.; Brand, H.R.; Neufeld, K.W.; Bowman, J.E.

1983-01-01

A totally computer-controlled triple quadrupole mass spectrometer (TQMS) is described. It has a number of unique features not available on current commercial instruments, including: complete computer control of source and all ion axial potentials; use of dual computers for data acquisition and data processing; and capability for self-adaptive control of experiments. Furthermore, it has been possible to produce this instrument at a cost significantly below that of commercial instruments. This triple quadrupole mass spectrometer has been constructed using components commercially available from several different manufacturers. The source is a standard Hewlett-Packard 5985B GC/MS source. The two quadrupole analyzers and the quadrupole CAD region contain Balzers QMA 150 rods with Balzers QMG 511 rf controllers for the analyzers and a Balzers QHS-511 controller for the CAD region. The pulsed-positive-ion-negative-ion-chemical ionization (PPINICI) detector is made by Finnigan Corporation. The mechanical and electronics design were developed at LLNL for linking these diverse elements into a functional TQMS as described. The computer design for total control of the system is unique in that two separate LSI-11/23 minicomputers and assorted I/O peripherals and interfaces from several manufacturers are used. The evolution of this design concept from totally computer-controlled instrumentation into future self-adaptive or ''expert'' systems for instrumental analysis is described. Operational characteristics of the instrument and initial results from experiments involving the analysis of the high explosive HMX (1,3,5,7-Tetranitro-1,3,5,7-Tetrazacyclooctane) are presented

A z-gradient array for simultaneous multi-slice excitation with a single-band RF pulse.

Science.gov (United States)

Ertan, Koray; Taraghinia, Soheil; Sadeghi, Alireza; Atalar, Ergin

2018-07-01

Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. Two different field design methods are formulated to solve for the required current values of the gradient array elements for the given slice locations. The method requirements are specified, optimization problems are formulated for the minimum current norm and an analytical solution is provided. A 9-channel z-gradient coil array driven by independent, custom-designed gradient amplifiers is used to validate the theory. Performance measures such as normalized slice thickness error, gradient strength per unit norm current, power dissipation, and maximum amplitude of the magnetic field are provided for various slice locations and numbers of slices. Two and 3 slices are excited by a single-band RF pulse in simulations and phantom experiments. The possibility of multi-slice excitation with a single-band RF pulse using a z-gradient array is validated in simulations and phantom experiments. Magn Reson Med 80:400-412, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

CLIC Quadrupole Module final report

CERN Document Server

Artoos, K; Mainaud-Durand, H

2013-01-01

Future Linear colliders will need particle beam sizes in the nanometre range. The beam also needs to be stable all along the beam line. The CLIC Main Beam Quadrupole (MBQ) module has been defined and studied. It is meant as a test stand for stabilisation and pre-alignment with a MB Quadrupole. The main topic that has been tackled concerns the Quadrupole magnet stabilisation to 1nm at 1Hz. This is needed to obtain the desired CLIC luminosity of 2.1034 cm-2m-1. The deliverable was demonstrated by procuring a MBQ and by stabilising a powered and cooled CLIC MBQ quadrupole. In addition, the stabilisation system has to be compatible with the pre-alignment procedures. Pre-alignment movement resolution has been demonstrated to 1m. The last step is the combined test of stability with a quadrupole on a CLIC Module with the pre-alignment.

Pulsed single-photon spectrometer by frequency-to-time mapping using chirped fiber Bragg gratings.

Science.gov (United States)

Davis, Alex O C; Saulnier, Paul M; Karpiński, Michał; Smith, Brian J

2017-05-29

A fiber-integrated spectrometer for single-photon pulses outside the telecommunications wavelength range based upon frequency-to-time mapping, implemented by chromatic group delay dispersion (GDD), and precise temporally-resolved single-photon counting, is presented. A chirped fiber Bragg grating provides low-loss GDD, mapping the frequency distribution of an input pulse onto the temporal envelope of the output pulse. Time-resolved detection with fast single-photon-counting modules enables monitoring of a wavelength range from 825 nm to 835 nm with nearly uniform efficiency at 55 pm resolution (24 GHz at 830 nm). To demonstrate the versatility of this technique, spectral interference of heralded single photons and the joint spectral intensity distribution of a photon-pair source are measured. This approach to single-photon-level spectral measurements provides a route to realize applications of time-frequency quantum optics at visible and near-infrared wavelengths, where multiple spectral channels must be simultaneously monitored.

40-Tesla pulsed-field cryomagnet for single crystal neutron diffraction

Science.gov (United States)

Duc, F.; Tonon, X.; Billette, J.; Rollet, B.; Knafo, W.; Bourdarot, F.; Béard, J.; Mantegazza, F.; Longuet, B.; Lorenzo, J. E.; Lelièvre-Berna, E.; Frings, P.; Regnault, L.-P.

2018-05-01

We present the first long-duration and high duty cycle 40-T pulsed-field cryomagnet addressed to single crystal neutron diffraction experiments at temperatures down to 2 K. The magnet produces a horizontal field in a bi-conical geometry, ±15° and ±30° upstream and downstream of the sample, respectively. Using a 1.15 MJ mobile generator, magnetic field pulses of 100 ms length are generated in the magnet, with a rise time of 23 ms and a repetition rate of 6-7 pulses per hour at 40 T. The setup was validated for neutron diffraction on the CEA-CRG three-axis spectrometer IN22 at the Institut Laue Langevin.

Single-shot femtosecond-pulsed phase-shifting digital holography.

Science.gov (United States)

Kakue, Takashi; Itoh, Seiya; Xia, Peng; Tahara, Tatsuki; Awatsuji, Yasuhiro; Nishio, Kenzo; Ura, Shogo; Kubota, Toshihiro; Matoba, Osamu

2012-08-27

Parallel phase-shifting digital holography is capable of three-dimensional measurement of a dynamically moving object with a single-shot recording. In this letter, we demonstrated a parallel phase-shifting digital holography using a single femtosecond light pulse whose central wavelength and temporal duration were 800 nm and 96 fs, respectively. As an object, we set spark discharge in atmospheric pressure air induced by applying a high voltage to between two electrodes. The instantaneous change in phase caused by the spark discharge was clearly reconstructed. The reconstructed phase image shows the change of refractive index of air was -3.7 × 10(-4).

A Single-Chip CMOS Pulse Oximeter with On-Chip Lock-In Detection

Directory of Open Access Journals (Sweden)

Diwei He

2015-07-01

Full Text Available Pulse oximetry is a noninvasive and continuous method for monitoring the blood oxygen saturation level. This paper presents the design and testing of a single-chip pulse oximeter fabricated in a 0.35 µm CMOS process. The chip includes photodiode, transimpedance amplifier, analogue band-pass filters, analogue-to-digital converters, digital signal processor and LED timing control. The experimentally measured AC and DC characteristics of individual circuits including the DC output voltage of the transimpedance amplifier, transimpedance gain of the transimpedance amplifier, and the central frequency and bandwidth of the analogue band-pass filters, show a good match (within 1% with the circuit simulations. With modulated light source and integrated lock-in detection the sensor effectively suppresses the interference from ambient light and 1/f noise. In a breath hold and release experiment the single chip sensor demonstrates consistent and comparable performance to commercial pulse oximetry devices with a mean of 1.2% difference. The single-chip sensor enables a compact and robust design solution that offers a route towards wearable devices for health monitoring.

A Single-Chip CMOS Pulse Oximeter with On-Chip Lock-In Detection.

Science.gov (United States)

He, Diwei; Morgan, Stephen P; Trachanis, Dimitrios; van Hese, Jan; Drogoudis, Dimitris; Fummi, Franco; Stefanni, Francesco; Guarnieri, Valerio; Hayes-Gill, Barrie R

2015-07-14

Pulse oximetry is a noninvasive and continuous method for monitoring the blood oxygen saturation level. This paper presents the design and testing of a single-chip pulse oximeter fabricated in a 0.35 µm CMOS process. The chip includes photodiode, transimpedance amplifier, analogue band-pass filters, analogue-to-digital converters, digital signal processor and LED timing control. The experimentally measured AC and DC characteristics of individual circuits including the DC output voltage of the transimpedance amplifier, transimpedance gain of the transimpedance amplifier, and the central frequency and bandwidth of the analogue band-pass filters, show a good match (within 1%) with the circuit simulations. With modulated light source and integrated lock-in detection the sensor effectively suppresses the interference from ambient light and 1/f noise. In a breath hold and release experiment the single chip sensor demonstrates consistent and comparable performance to commercial pulse oximetry devices with a mean of 1.2% difference. The single-chip sensor enables a compact and robust design solution that offers a route towards wearable devices for health monitoring.

Devise for measuring the nuclear quadrupole resonance weak signal relaxation at the ISSh-1-12 spectrometer with the SIGMA digital storage

International Nuclear Information System (INIS)

Chernyavskij, V.N.; Konstantinov, G.I.

1984-01-01

The device, consisting of an analog memory device and the Karr-Parsell pulse programming device (radio frequency pulse train is 90 deg - tau - 180 deg - 2 tau - 180 deg - 2 tau ..., where tau is the interval between 90 deg - and 180 deg - pulses), is described. The device is destined for measurement of the time T 2 of nuclear quadrupole resonance spin-spin relaxation weak signal with signal-to-noise ratio 0 - 10 4 ), pulse numbers in series are 2-1024, start output signal amplitude >= 22 V, duration is 1 μs. The device may be also used in pulsed nuclear magnetic and electron paramagnetic resonance spectroscopy

Updating the induction module from single-pulse to double-pulses

International Nuclear Information System (INIS)

Huang Ziping; Wang Huacen; Deng Jianjun

2002-01-01

A double-pulse Linear Induced Accelerator (LIA) module is reconstructed based on a usual simple-pulse LIA module. By changing the length of one of the cables between the inductive cell and the Blumlein pulse forming line, two induction pulses with 90 ns FWHM and 150 kV pulse voltage are generated by the ferrite cores inductive cell. The interval time of the pulses is adjustable by changing the lengths of the cable

A liquid chromatography method with single quadrupole mass spectrometry for quantitative determination of indomethacin in maternal plasma and urine of pregnant patients

Science.gov (United States)

Wang, Xiaoming; Vernikovskaya, Daria I.; Nanovskaya, Tatiana N.; Rytting, Erik; Hankins, Gary D.V.; Ahmed, Mahmoud S.

2013-01-01

A liquid chromatography with single quadrupole mass spectrometry method was developed for the quantitative determination of indomethacin in the maternal plasma and urine of pregnant patients under treatment. A deuterium-labeled isotope of indomethacin (d4-indomethacin) was used as an internal standard. The maternal plasma and urine samples were acidified with 1.0 MHCl then extracted with chloroform to achieve the extraction recovery range of 94% to 104% with variation less than 11%. Chromatographic separation was achieved by a Waters Symmetry C18 column with isocratic elution of 0.05% (v/v) formic acid aqueous solution and acetonitrile (47:53, v/v). An in-source fragmentation was applied on the single quadrupole mass spectrometer equipped with an electrospray ionization source at positive mode. The LC-ESI-MS quantification was performed in the selected ion monitoring mode targeting ions at m/z 139 for indomethacin and m/z 143 for its internal standard. The calibration curves were linear in the concentration ranges between 14.8 and 2.97×103 ng/mL for plasma samples and between 10.5 and 4.21×103 ng/mL for urine samples. The relative standard deviation of this method was less than 8% for intra- and inter-day assays, and the accuracy ranged between 90% and 108%. PMID:23474812

MQXFS1 Quadrupole Design Report

Energy Technology Data Exchange (ETDEWEB)

Ambrosio, Giorgio [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); et al.

2016-04-14

This report presents the reference design of MQXFS1, the first 1.5 m prototype of the low-beta quadrupoles (MQXF) for the LHC High Luminosity Upgrade. The MQXF quadrupoles have 150 mm aperture, coil peak field of about 12 T, and use $Nb_{3}Sn$ conductor. The design is based on the LARP HQ quadrupoles, which had 120 mm aperture. MQXFS1 has 1st generation cable cross-section and magnetic design.

Magnetic Measurement Results of the LCLS Undulator Quadrupoles

Energy Technology Data Exchange (ETDEWEB)

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.

Engineering quadrupole magnetic flow sorting for the isolation of pancreatic islets

Energy Technology Data Exchange (ETDEWEB)

Kennedy, David J. [IKOtech, LLC, 3130 Highland Avenue, 3rd Floor, Cincinnati, OH 45219-2374 (United States)]. E-mail: David.Kennedy@IKOtech.com; Todd, Paul [SHOT, Inc., Greenville, IN (United States); Logan, Sam [SHOT, Inc., Greenville, IN (United States); Becker, Matthew [SHOT, Inc., Greenville, IN (United States); Papas, Klearchos K. [Diabetes Institute for Immunology and Transplantation, University of Minnesota, Minneapolis, MN (United States); Moore, Lee R. [Biomedical Engineering Department, Cleveland Clinic Foundation, Cleveland, OH (United States)

2007-04-15

Quadrupole magnetic flow sorting (QMS) is being adapted from the separation of suspensions of single cells (<15 {mu}m) to the isolation of pancreatic islets (150-350 {mu}m) for transplant. To achieve this goal, the critical QMS components have been modeled and engineered to optimize the separation process. A flow channel has been designed, manufactured, and tested. The quadrupole magnet assembly has been designed and verified by finite element analysis. Pumps have been selected and verified by test. Test data generated from the pumps and flow channel demonstrate that the fabricated channel and peristaltic pumps fulfill the requirements of successful QMS separation.

Engineering quadrupole magnetic flow sorting for the isolation of pancreatic islets

International Nuclear Information System (INIS)

Kennedy, David J.; Todd, Paul; Logan, Sam; Becker, Matthew; Papas, Klearchos K.; Moore, Lee R.

2007-01-01

Quadrupole magnetic flow sorting (QMS) is being adapted from the separation of suspensions of single cells (<15 μm) to the isolation of pancreatic islets (150-350 μm) for transplant. To achieve this goal, the critical QMS components have been modeled and engineered to optimize the separation process. A flow channel has been designed, manufactured, and tested. The quadrupole magnet assembly has been designed and verified by finite element analysis. Pumps have been selected and verified by test. Test data generated from the pumps and flow channel demonstrate that the fabricated channel and peristaltic pumps fulfill the requirements of successful QMS separation

A nuclear pulse amplitude acquisition system based on 80C31 single-chip microcomputer

International Nuclear Information System (INIS)

Zhao Xiuliang; Qu Guopu; Guo Lanying; Zhang Songbai

1999-01-01

A kind of multichannel nuclear pulse amplitude signal acquisition system is described, which is composed of pulse peak detector, integrated S/H circuit, A/D converter and 80C31 single-chip microcomputer

Quadrupole moment and a proton halo structure in 17F (Iπ = 5/2+)

International Nuclear Information System (INIS)

Zhou Dongmei; Zheng Yongnan; Yuan Daqing; Xizhen, Zhang; Zuo Yi; Minamisono, T; Matsuta, M; Fukuda, M; Mihara, M; Zhang Chunlei; Zhiqiang, Wang; Du Enpeng; Luo Hailong; Xu Guoji; Zhu Shengyun

2007-01-01

The quadrupole moment of light nuclei 17 F in the ground state (I π = 5/2 + ) is measured by the β-NMR method. The effective charge of the last proton in a d 5/2 orbit for 17 F is extracted from the measured quadrupole moment Q( 17 F) divided by the quadrupole moment Q sp calculated with a single particle model. A proton effective charge of e eff p = 1.12 ± 0.07e is obtained, which is in agreement with that given by a particle-vibration coupling model calculation within the experimental error. The present value of the proton effective charge is strong evidence for the existence of a proton skin in 17 F (I π = 5/2 + )

Single event effects in pulse width modulation controllers

International Nuclear Information System (INIS)

Penzin, S.H.; Crain, W.R.; Crawford, K.B.; Hansel, S.J.; Kirshman, J.F.; Koga, R.

1996-01-01

SEE testing was performed on pulse width modulation (PWM) controllers which are commonly used in switching mode power supply systems. The devices are designed using both Set-Reset (SR) flip-flops and Toggle (T) flip-flops which are vulnerable to single event upset (SEU) in a radiation environment. Depending on the implementation of the different devices the effect can be significant in spaceflight hardware

Ion trajectories quadrupole mass filters

International Nuclear Information System (INIS)

Ursu, D.; Lupsa, N.; Muntean, F.

1994-01-01

The present paper aims at bringing some contributions to the understanding of ion motion in quadrupole mass filters. The theoretical treatment of quadrupole mass filter is intended to be a concise derivation of the important physical relationships using Mathieu functions. A simple iterative method of numerical computation has been used to simulate ion trajectories in an ideal quadrupole field. Finally, some examples of calculation are presented with the aid of computer graphics. (Author) 14 Figs., 1 Tab., 20 Refs

Permanent quadrupole magnets

International Nuclear Information System (INIS)

Bush, E.D. Jr.

1976-01-01

A family of quadrupole magnets using a soft iron return yoke and circular cross-section permanent magnet poles were fabricated to investigate the feasibility for use in ion or electron beam focusing applications in accelerators and transport lines. Magnetic field measurements yielded promising results. In fixed-field applications, permanent magnets with sufficient gradients would be a low cost substitute for conventional electromagnets, eliminating the need for power supplies, associated wiring, and cooling. Based on preliminary tests, it was seen that permanent quadrupole magnets can offer a low cost, reliable solution in applications requiring small, fixed-field focusing devices for use in ion or electron-beam transport systems. Permanent magnets do require special considerations in design, fabrication, handling, and service that are different than encountered in conventional quadrupole magnets. If these basic conditions are satisfied, the resulting beam-focusing device would be stable, maintenance free, with virtually an indefinite lifetime

Study of {sup 14}N NQR response to SORC pulse sequence

Energy Technology Data Exchange (ETDEWEB)

Konnai, A., E-mail: konnai@nmri.go.jp; Odano, N. [National Maritime Research Institute, Department of Navigation and System Engineering (Japan); Asaji, T. [Nihon University, Department of Chemistry, College of Humanities and Sciences (Japan)

2008-01-15

The behavior of nuclear quadrupole resonance (NQR) signals between RF pulses of the strong off-resonance comb (SORC) as well as the spin-locking spin-echo (SLSE) pulse sequences was studied as for {sup 14}N NQR line {nu}{sub +} of dimethylnitramine (CH{sub 3}){sub 2}NNO{sub 2} at 77 K. The periodic variation of the signal amplitude observed by using SORC pulse sequence could be reasonably explained by the theoretical expression reported in the literature.

Self triggered single pulse beam position monitor

International Nuclear Information System (INIS)

Rothman, J.L.; Blum, E.B.

1993-01-01

A self triggered beam position monitor (BPM) has been developed for the NSLS injection system to provide single pulse orbit measurements in the booster synchrotron, linac, and transport lines. The BPM integrates the negative going portion of 3 nS wide bipolar pickup electrode signals. The gated, self triggering feature confines critical timing components to the front end, relaxing external timing specifications. The system features a low noise high speed FET sampler, a fiber optic gate for bunch and turn selection, and an inexpensive interface to a standard PC data acquisition system

A high excitation magnetic quadrupole lens quadruplet incorporating a single octupole lens for a low spherical aberration probe forming lens system

Science.gov (United States)

Dou, Yanxin; Jamieson, David N.; Liu, Jianli; Li, Liyi

2018-03-01

This paper describes the design of a new probe forming lens system consisting of a high excitation magnetic quadrupole lens quadruplet that incorporates a single magnetic octupole lens. This system achieves both a high demagnification and a low spherical aberration compared to conventional high excitation systems and is intended for deployment for the Harbin 300 MeV proton microprobe for applications in space science and ion beam therapy. This relative simplicity of the ion optical design to include a single octupole lens minimizes the risks associated with the constructional and operational precision usually needed for the probe forming lens system and this system could also be deployed in microprobe systems that operate with less magnetically rigid ions. The design of the new system is validated with reference to two independent ion optical computer codes.

The Israeli EA-FEL Upgrade Towards Long Pulse Operation for Ultra-High Resolution Single Pulse Coherent Spectroscopy

CERN Document Server

Gover, A; Kanter, M; Kapilevich, B; Litvak, B; Peleg, S; Socol, Y; Volshonok, M

2005-01-01

The Israeli Electrostatic Accelerator FEL (EA-FEL) is now being upgraded towards long pulse (1005s) operation and ultra-high resolution (10(-6)) single pulse coherent spectroscopy. We present quantitative estimations regarding the applications of controlled radiation chirp for spectroscopic applications with pulse-time Fourier Transform limited spectral resolution. Additionally, we describe a novel extraction-efficiency-improving scheme based on increase of accelerating voltage (boosting) after saturation is achieved. The efficiency of the proposed scheme is confirmed by theoretical and numerical calculations. The latter are performed using software, based on 3D space-frequency domain model. The presentation provides an overview of the upgrade status: the high-voltage terminal is being reconfigured to accept the accelerating voltage boost system; a new broad band low-loss resonator is being manufactured; multi-stage depressed collector is assembled.

Torques on quadrupoles

OpenAIRE

Torres del Castillo, G.F; Méndez Garrido, A

2006-01-01

Making use of the fact that a 2l-pole can be represented by means of l vectors of the same magnitude, the torque on a quadrupole in an inhomogeneous external field is expressed in terms of the vectors that represent the quadrupole and the gradient of the external field. The conditions for rotational equilibrium are also expressed in terms of these vectors. Haciendo uso de que un multipolo de orden 2l puede representarse mediante l vectores de la misma magnitud, la torca sobre un cuadripolo...

Observation of self-pulsing in singly resonant optical second-harmonic generation with competing nonlinearities

DEFF Research Database (Denmark)

Bache, Morten; Lodahl, Peter; Mamaev, Alexander V.

2002-01-01

We predict and experimentally observe temporal self-pulsing in singly resonant intracavity second-harmonic generation under conditions of simultaneous parametric oscillation. The threshold for self-pulsing as a function of cavity tuning and phase mismatch are found from analysis of a three...

Quadrupole moments of hadrons

International Nuclear Information System (INIS)

Krivoruchenko, M.I.

1985-01-01

In chiral bag model an expression is obtained for the quark wave functions with account of color and pion interaction of quarks. The quadrupole moments of nonstrange hadrons are calculated. Quadrupole moment of nucleon isobar is found to be Q(Δ)=-6.3x10 -28 esub(Δ)(cm)sup(2). Fredictions of the chiral bag model are in strong disagreement with the non-relativistic quark model

Laced permanent magnet quadrupole drift tube magnets

International Nuclear Information System (INIS)

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

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

CERN Document Server

Ambrosio, G; Wanderer, P; Ferracin, P; Sabbi, G

2017-01-01

The High Luminosity upgrade of the LHC at CERN will use large aperture (150 mm) quadrupole magnets to focus the beams at the interaction points. The high field in the coils requires Nb$_{3}$Sn superconductor technology, which has been brought to maturity by the LHC Accelerator Re-search Program (LARP) over the last 10 years. The key design targets for the new IR quadrupoles were established in 2012, and fabrication of model magnets started in 2014. This paper discusses the results from the first single short coil test and from the first short quadrupole model test. Remaining challenges and plans to address them are also presented and discussed.

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

Energy Technology Data Exchange (ETDEWEB)

Ambrosio, G. [Fermilab; Chlachidze, G. [Fermilab; Wanderer, P. [Brookhaven; Ferracin, P. [CERN; Sabbi, G. [LBNL, Berkeley

2016-10-06

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

Self-organization of single filaments and diffusive plasmas during a single pulse in dielectric-barrier discharges

International Nuclear Information System (INIS)

Babaeva, Natalia Yu; Kushner, Mark J

2014-01-01

Self-organization of filaments in dielectric-barrier discharges (DBDs) probably has many origins. However, the dominant cause is proposed to be the accumulation of charge on the surfaces of the bounding dielectrics that reinforces successive discharge pulses to occur at the same locations. A secondary cause is the electrostatic repulsion of individual plasma filaments. Self-organization typically develops over many discharge pulses. In this paper, we discuss the results of a computational investigation of plasma filaments in overvoltage DBDs that, under select conditions, display self-organized patterns (SOPs) of plasma density during a single discharge pulse. (Overvoltage refers to the rapid application of a voltage in excess of the quasi-dc breakdown voltage.) The origin of the SOPs is a synergistic relationship between the speed of the surface-ionization waves that propagate along each dielectric and the rate at which avalanche occurs across the gap. For our test conditions, SOPs were not observed at lower voltages and gradually formed at higher voltages. The same conditions that result in SOPs, i.e. the application of an overvoltage, also produce more diffuse discharges. A transition from a single narrow filament to a more diffuse structure was observed as overvoltage was approached. The sensitivity of SOPs to the orientation and permittivity of the bounding dielectrics is discussed. (paper)

Chaotic motion in axially symmetric potentials with oblate quadrupole deformation

Energy Technology Data Exchange (ETDEWEB)

Letelier, Patricio S. [Departamento de Matematica Aplicada, IMECC, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil); Ramos-Caro, Javier, E-mail: javier@ime.unicamp.br [Departamento de Matematica Aplicada, IMECC, Universidade Estadual de Campinas, 13083-859, Campinas, SP (Brazil); Lopez-Suspes, Framsol, E-mail: framsol@gmail.com [Facultad de Telecomunicaciones, Universidad Santo Tomas and Escuela de Fisica, Universidad Industrial de Santander, Bucaramanga (Colombia)

2011-10-03

By computing the Poincare's surfaces of section and Lyapunov exponents, we study the effect of introducing an oblate quadrupole in the dynamics associated with two generic spherical potentials of physical interest: the central monopole and the isotropic harmonic oscillator. In the former case we find saddle points in the effective potential, in contrast to the statements presented by Gueron and Letelier in [E. Gueron, P.S. Letelier, Phys. Rev. E 63 (2001) 035201]. The results we show in the second case have application in nuclear or atomic physics. In particular, we find values of oblate deformation leading to a disappearance of shell structure in the single-particle spectrum. -- Highlights: → We find chaotic motion around a monopole with oblate quadrupole deformation. → This corrects the statements introduced in [E. Gueron, P.S. Letelier, Phys. Rev. E 63 (2001) 035201]. → We present an alternative model for the potential due to an oblate deformed nuclei. → This leads to stochastic regions in the phase space of classical orbits. → It suggests that the shell structure of single-particle spectrum tends to disappear.

Dielectric breakdown and healing of anodic oxide films on aluminium under single pulse anodizing

International Nuclear Information System (INIS)

Sah, Santosh Prasad; Tatsuno, Yasuhiro; Aoki, Yoshitaka; Habazaki, Hiroki

2011-01-01

Research highlights: → We examined dielectric breakdown of anodic alumina by single pulse anodizing. → Current transients and morphology of discharge channels are dependent upon electrolyte and voltage. → There is a good correlation between current transient and morphology of discharge channel. → Healing of open discharge pores occurs in alkaline silicate, but not in pentaborate electrolyte. - Abstract: Single pulse anodizing of aluminium micro-electrode has been employed to study the behaviour of dielectric breakdown and subsequent oxide formation on aluminium in alkaline silicate and pentaborate electrolytes. Current transients during applying pulse voltage have been measured, and surface has been observed by scanning electron microscopy. Two types of current transients are observed, depending on the electrolyte and applied voltage. There is a good correlation between the current transient behaviour and the shape of discharge channels. In alkaline silicate electrolyte, circular open pores are healed by increasing the pulse width, but such healing is not obvious in pentaborate electrolyte.

Quench protection of the LHC inner triplet quadrupoles built at Fermilab

CERN Document Server

Bauer, P; Chiesa, L; Di Marco, J; Fehér, S; Lamm, M J; McInturff, A D; Nobrega, A; Orris, D; Tartaglia, M; Tompkins, J C; Zlobin, A V

2001-01-01

High gradient quadrupoles are being developed by the US-LHC Accelerator project for the LHC interaction region inner triplets. These 5.5 m long magnets have a single 70 mm aperture and operate in superfluid helium at a peak gradient of 215 T/m. Through the construction and test of eight 2 meter long model quadrupoles, strip heaters of various geometries and insulation thicknesses have proven to be effective in protecting the magnets from excessively high coil temperatures and coil voltages to ground. This paper reports on the results of the model program to optimize the heater performance within the context of the LHC inner triplet electrical power and quench detection scheme. (6 refs).

A Single-Chip CMOS Pulse Oximeter with On-Chip Lock-In Detection

OpenAIRE

Diwei He; Stephen P. Morgan; Dimitrios Trachanis; Jan van Hese; Dimitris Drogoudis; Franco Fummi; Francesco Stefanni; Valerio Guarnieri; Barrie R. Hayes-Gill

2015-01-01

Pulse oximetry is a noninvasive and continuous method for monitoring the blood oxygen saturation level. This paper presents the design and testing of a single-chip pulse oximeter fabricated in a 0.35 ?m CMOS process. The chip includes photodiode, transimpedance amplifier, analogue band-pass filters, analogue-to-digital converters, digital signal processor and LED timing control. The experimentally measured AC and DC characteristics of individual circuits including the DC output voltage of the...

Single-pulse CARS based multimodal nonlinear optical microscope for bioimaging.

Science.gov (United States)

Kumar, Sunil; Kamali, Tschackad; Levitte, Jonathan M; Katz, Ori; Hermann, Boris; Werkmeister, Rene; Považay, Boris; Drexler, Wolfgang; Unterhuber, Angelika; Silberberg, Yaron

2015-05-18

Noninvasive label-free imaging of biological systems raises demand not only for high-speed three-dimensional prescreening of morphology over a wide-field of view but also it seeks to extract the microscopic functional and molecular details within. Capitalizing on the unique advantages brought out by different nonlinear optical effects, a multimodal nonlinear optical microscope can be a powerful tool for bioimaging. Bringing together the intensity-dependent contrast mechanisms via second harmonic generation, third harmonic generation and four-wave mixing for structural-sensitive imaging, and single-beam/single-pulse coherent anti-Stokes Raman scattering technique for chemical sensitive imaging in the finger-print region, we have developed a simple and nearly alignment-free multimodal nonlinear optical microscope that is based on a single wide-band Ti:Sapphire femtosecond pulse laser source. Successful imaging tests have been realized on two exemplary biological samples, a canine femur bone and collagen fibrils harvested from a rat tail. Since the ultra-broad band-width femtosecond laser is a suitable source for performing high-resolution optical coherence tomography, a wide-field optical coherence tomography arm can be easily incorporated into the presented multimodal microscope making it a versatile optical imaging tool for noninvasive label-free bioimaging.

Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction

Energy Technology Data Exchange (ETDEWEB)

Maddox, B. R., E-mail: maddox3@llnl.gov; Akin, M. C., E-mail: akin1@llnl.gov; Teruya, A.; Hunt, D.; Hahn, D.; Cradick, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Morgan, D. V. [National Security Technologies LLC, Los Alamos, New Mexico 87544 (United States)

2016-08-15

Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from the sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10{sup 7} molybdenum Kα photons.

The monopole and quadrupole vibrations of a hot nucleus

International Nuclear Information System (INIS)

Okolowicz, J.; Drozdz, S.; Ploszajczak, M.; Caurier, E.

1989-03-01

An extended time-dependent Hartree-Fock approach has been applied to a description of the isoscalar giant monopole and quadrupole vibration modes in the excited nuclear system at finite temperature. The temperature dependence of the resonance characteristics is established for both modes. In anticipation of some anharmonic effects the principle of regularity and single-valuedness has been used to extract the energies of the collective modes. (orig.)

Electric quadrupole moments of {beta}-emitter {sup 21}F and {sup 23}Mg

Energy Technology Data Exchange (ETDEWEB)

Onishi, Takashi; Matsuta, Kensaku; Fukuda, Mitsunori [Osaka Univ., Toyonaka (Japan). Faculty of Science] [and others

1997-03-01

For the systematic study of nuclear electromagnetic moments, electric quadrupole moments Q of {beta}-emitting nuclei {sup 21}F and {sup 23}Mg have been measured for the first time through combined technique of the polarized nuclear beams and {beta}-NMR technique. From the quadrupole coupling constants of {sup 21}F and {sup 23}Mg in MgF{sub 2} single crystal, the ratios of the Q`s with the known Q were determined as |Q({sup 21}F)|/|Q({sup 19}F{sup *})|=1.001{+-}0.034 and |Q({sup 23}Mg)|/|Q({sup 25}Mg)|=0.571{+-}0.017. (author)

Three-dimensional quadrupole lenses made with permanent magnets

International Nuclear Information System (INIS)

Ivanov, A.S.

1984-01-01

The performance of accelerator systems with quadrupole magnets can be improved by using permanent magnets in quadrupole lenses. This requires better methods for treating the three-dimensional nature of the magnetic fields and the nonlinear characteristics of the magnets. A numerical method is described for simulating three-dimensional magnetic fields and used to analyze quadrupole lenses and doublets with permanent magnets. The results, which are confirmed experimentally, indicate that both the quadrupole magnetic gradient and the effective field length are changed in permanent-magnet quadrupole lenses when the pole lengths and the gap between the lenses are varied while the other characteristics of the magnets remain unchanged

The effect and correction of coupling generated by the RHIC triplet quadrupoles

International Nuclear Information System (INIS)

Pilat, F.; Peggs, S.; Tepikian, S.; Trbojevic, D.; Wei, J.

1995-01-01

This study explores the possibility of operating the nominal RHIC coupling correction system in local decoupling mode, where a subset of skew quadrupoles are independently set by minimizing the coupling as locally measured by beam position monitors. The goal is to establish a correction procedure for the skew quadrupole errors in the interaction region triplets that does not rely on a priori knowledge of the individual errors. After a description of the present coupling correction scheme envisioned for RHIC, the basics of the local decoupling method will be briefly recalled in the context of its implementation in the TEAPOT simulation code as well as operationally. The method is then applied to the RHIC lattice: a series of simple tests establish that single triplet skew quadrupole errors can be corrected by local decoupling. More realistic correction schemes are then studied in order to correct distributed sources of skew quadrupole errors: the machine can be decoupled either by pure local decoupling or by a combination of global (minimum tune separation) and local decoupling. The different correction schemes are successively validated and evaluated by standard RHIC simulation runs with the complete set of errors and corrections. The different solutions and results are finally discussed together with their implications for the hardware

Expansion-limited aggregation of nanoclusters in a single-pulse laser-produced plume

International Nuclear Information System (INIS)

Gamaly, E. G.; Madsen, N. R.; Rode, A. V.; Golberg, D.

2009-01-01

Formation of carbon nanoclusters in a single-laser-pulse created ablation plume was studied both in vacuum and in a noble gas environment at various pressures. The developed theory provides cluster radius dependence on combination of laser parameters, properties of ablated material, and type and pressure of an ambient gas in agreement with experiments. The experiments were performed on carbon nanoclusters formed by laser ablation of graphite targets with 12 picosecond 532 nm laser pulses at MHz-range repetition rate in a broad range of ambient He, Ar, Kr, and Xe gas pressures from 2x10 -2 to 1500 Torr. The experimental results confirmed our theoretical prediction that the average size of the nanoparticles depends weakly on the type of the ambient gas used, and is determined exclusively by the single laser pulse parameters even at the repetition rate as high as 28 MHz with the time gap 36 ns between the pulses. The most important finding relates to the fact that in vacuum the cluster size is mainly determined by hydrodynamic expansion of the plume while in the ambient gas it is controlled by atomic diffusion in the gas. We demonstrate that the ultrashort pulses can be used for production of clusters with the size less than the critical value, which separates the particles with properties drastically different from those of a material in a bulk. The presented results of experiments on formation of carbon nanoclusters are in close agreement with the theoretical scaling. The developed theory is applicable for cluster formation from any monatomic material, such as silicon for example.

Excitation of random intense single-cycle light-pulse chains in optical fiber

International Nuclear Information System (INIS)

Ding, Y C; Zhang, F L; Gao, J B; Chen, Z Y; Lin, C Y; Yu, M Y

2014-01-01

Excitation of intense periodic single-cycle light pulses in a stochastic background arising from continuous wave stimulated Brillouin scattering (SBS) in a long optical fiber with weak optical feedback is found experimentally and modeled theoretically. Such intense light-pulse chains occur randomly and the optical feedback is a requirement for their excitation. The probability of these forms, among the large number of experimental output signals with identifiable waveforms, appearing is only about 3%, with the remainder exhibiting regular SBS characteristics. It is also found that pulses with low period numbers appear more frequently and the probability distribution for their occurrence in terms of the pulse power is roughly L-shaped, like that for rogue waves. The results from a three-wave-coupling model for SBS including feedback phase control agree well qualitatively with the observed phenomena. (paper)

Effects of single pulse energy on the properties of ceramic coating prepared by micro-arc oxidation on Ti alloy

Energy Technology Data Exchange (ETDEWEB)

Wang, Jun-Hua [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650500 (China); Wang, Jin [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control, Beijing 100084 (China); Lu, Yan [School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Du, Mao-Hua [Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650500 (China); Han, Fu-Zhu, E-mail: hanfuzhu@mail.tsinghua.edu.cn [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Beijing Key Lab of Precision/Ultra-precision Manufacturing Equipments and Control, Beijing 100084 (China)

2015-01-01

Highlights: • Single pulse energy remarkably influences the properties of ceramic coating prepared by MAO on Ti alloy. • The accumulative time of impulse width is an important parameter in the scientific and rational measurement of the film forming law of ceramic coating. • The ceramic coating thickness approximately linearly increases with the cumulative time of impulse width. • Larger impulse width resulted in higher single pulse energy, film forming rates and thicker ceramic coating thickness. • The effects of single pulse energy on the micro-hardness and phase composition of ceramic coating are not as evident as those of frequency and duty cycle. - Abstract: The effects of single pulse energy on the properties of ceramic coating fabricated on a Ti–6Al–4V alloy via micro-arc oxidation (MAO) in aqueous solutions containing aluminate, phosphate, and some additives are investigated. The thickness, micro-hardness, surface and cross-sectional morphology, surface roughness, and compositions of the ceramic coating are studied using eddy current thickness meter, micro-hardness tester, JB-4C Precision Surface roughness meter, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Single pulse energy remarkably influences the ceramic coating properties. The accumulative time of impulse width is an important parameter in the scientific and rational measurement of the film forming law of ceramic coating. The ceramic coating thickness approximately linearly increases with the cumulative time of impulse width. Larger impulse width resulted in higher single pulse energy, film forming rates and thicker ceramic coating thickness. The sizes of oxide particles, micro-pores and micro-cracks slightly increase with impulse width and single pulse energy. The main surface conversion products generated during MAO process in aqueous solutions containing aluminate are rutile TiO{sub 2}, anatase TiO{sub 2}, and a large amount of Al{sub 2}TiO{sub 5}. The effects of

Single-chip pulse programmer for magnetic resonance imaging using a 32-bit microcontroller.

Science.gov (United States)

Handa, Shinya; Domalain, Thierry; Kose, Katsumi

2007-08-01

A magnetic resonance imaging (MRI) pulse programmer has been developed using a single-chip microcontroller (ADmicroC7026). The microcontroller includes all the components required for the MRI pulse programmer: a 32-bit RISC CPU core, 62 kbytes of flash memory, 8 kbytes of SRAM, two 32-bit timers, four 12-bit DA converters, and 40 bits of general purpose I/O. An evaluation board for the microcontroller was connected to a host personal computer (PC), an MRI transceiver, and a gradient driver using interface circuitry. Target (embedded) and host PC programs were developed to enable MRI pulse sequence generation by the microcontroller. The pulse programmer achieved a (nominal) time resolution of approximately 100 ns and a minimum time delay between successive events of approximately 9 micros. Imaging experiments using the pulse programmer demonstrated the effectiveness of our approach.

Microwave radiation mechanism in a pulse-laser-irradiated Cu foil target revisited

International Nuclear Information System (INIS)

Chen Ziyu; Li Jianfeng; Li Jun; Peng Qixian

2011-01-01

The microwave radiation mechanism in a Cu-based foil target irradiated by an intense laser pulse has been investigated. Microwave emission in the frequency range 0.5-4 GHz has been observed from a 200 ps laser pulse of intensity about 10 12 W cm -2 normally incident on the target surface. The total microwave power and energy emitted from the interaction were found to be about 0.4 W and 2 nJ, respectively, corresponding to an efficiency of coupling laser energy to microwave energy of 2x10 -8 . The result agrees well with quadrupole radiation calculated based on a circuit model of a laser plasma, which indicates that the radiative process can be explained by magnetic dipole or electric quadrupole radiation from the laser-produced symmetric poloidal current distribution at the plasma-target interface.

Microwave radiation mechanism in a pulse-laser-irradiated Cu foil target revisited

Energy Technology Data Exchange (ETDEWEB)

Chen Ziyu; Li Jianfeng; Li Jun; Peng Qixian, E-mail: ziyuch@gmail.com [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China)

2011-05-01

The microwave radiation mechanism in a Cu-based foil target irradiated by an intense laser pulse has been investigated. Microwave emission in the frequency range 0.5-4 GHz has been observed from a 200 ps laser pulse of intensity about 10{sup 12} W cm{sup -2} normally incident on the target surface. The total microwave power and energy emitted from the interaction were found to be about 0.4 W and 2 nJ, respectively, corresponding to an efficiency of coupling laser energy to microwave energy of 2x10{sup -8}. The result agrees well with quadrupole radiation calculated based on a circuit model of a laser plasma, which indicates that the radiative process can be explained by magnetic dipole or electric quadrupole radiation from the laser-produced symmetric poloidal current distribution at the plasma-target interface.

Design of an electrostatic magnetic quadrupole accelerator

International Nuclear Information System (INIS)

Mizuno, M.; Ohara, Y.

1993-01-01

A new type of electrostatic acceleration system, electrostatic magnetic quadrupole (ESMQ) acceleration system, is proposed for efficient acceleration of negative ion beams. In this system, permanent magnets are buried in the acceleration electrodes so as to produce a quadrupole magnetic field in the electrode aperture region. Envelope simulation indicates that the quadrupole field can deflect electrons stripped from the negative ions. Beam envelope simulations for deuterium ions and electrons have been carried out using the beam envelope code TRACE. Electrons are largely divergent and most appear likely to hit downstream electrodes. Furthermore, maximum beam divergence of the deuterium ions is reduced to the focusing effect of the quadrupole magnetic field

Single- and dual-wavelength laser pulses induced modification in 10×(Al/Ti)/Si multilayer system

Energy Technology Data Exchange (ETDEWEB)

Salatić, B. [University of Belgrade, Institute of Physics Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Petrović, S., E-mail: spetro@vinca.rs [University of Belgrade, Institute of Nuclear Science-Vinča, POB 522, 11001 Belgrade (Serbia); Peruško, D. [University of Belgrade, Institute of Nuclear Science-Vinča, POB 522, 11001 Belgrade (Serbia); Čekada, M.; Panjan, P. [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Pantelić, D.; Jelenković, B. [University of Belgrade, Institute of Physics Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

2016-01-01

Graphical abstract: - Highlights: • Experimental and numerical study of laser-induced ablation and micro-sized crater formation. • Dual-wavelength pulses induce creation of wider and deeper craters due to synergies of two processes. • Sunflower-like structure formed by dual-wavelength pulses at low irradiance. • Numerical model of nanosecond pulsed laser ablation for complex (Al/Ti)/Si system has been developed. - Abstract: The surface morphology of the ablation craters created in the multilayer 10×(Al/Ti)/Si system by nanosecond laser pulses at single- and dual wavelength has been studied experimentally and numerically. A complex multilayer thin film including ten (Al/Ti) bilayers deposited by ion sputtering on Si(1 0 0) substrate to a total thickness of 260 nm were illuminated at different laser irradiance in the range 0.25–3.5 × 10{sup 9} W cm{sup −2}. Single pulse laser irradiation was done at normal incidence in air, with the single wavelength, either at 532 nm or 1064 nm or with both laser light simultaneously in the ratio of 1:10 for energy per pulse between second harmonic and 1064 nm. Most of the absorbed laser energy was rapidly transformed into heat, producing intensive modifications of composition and morphology on the sample surface. The results show an increase in surface roughness, formation of specific nanostructures, appearance of hydrodynamic features and ablation of surface material with crater formation. Applying a small fraction (10%) of the second harmonic in dual-wavelength pulses, a modification of the 10×(Al/Ti)/Si system by a single laser pulse was reflected in the formation of wider and/or deeper craters. Numerical calculations show that the main physical mechanism in ablation process is normal evaporation without phase explosion. The calculated and experimental results agree relatively well for the whole irradiance range, what makes the model applicable to complex Al/Ti multilayer systems.

Fabrication and optimization of the copper halide Laser's comparison of the double-discharge (Cu Cl) with the single-pulse operation (Cu Br)

International Nuclear Information System (INIS)

Sajad, B.; Behrozinia, S.; Nikzad, P.; Bassam, M. A.

2009-01-01

In this paper, the fabrication of a double-pulse copper chloride laser was investigated to study the effect of various parameters such as buffer gas pressure, temperature, and the delay time between two electrical discharge pulses, on laser output power. Moreover, a single-pulse copper bromide laser was fabricated to optimize the laser output power versus temperature, buffer gas pressure, and electrical input power and discharge frequency. The comparison of the results in single-pulse and double-pulse excitation indicates that the former is easier in operation and more power stability can be achieved using single pulse excitation.

Single-pulse and burst-mode ablation of gold films measured by quartz crystal microbalance

Science.gov (United States)

Andrusyak, Oleksiy G.; Bubelnik, Matthew; Mares, Jeremy; McGovern, Theresa; Siders, Craig W.

2005-02-01

Femtosecond ablation has several distinct advantages: the threshold energy fluence for the onset of damage and ablation is orders of magnitude less than for traditional nanosecond laser machining, and by virtue of the rapid material removal of approximately an optical penetration depth per pulse, femtosecond machined cuts can be cleaner and more precise than those made with traditional nanosecond or longer pulse lasers. However, in many materials of interest, especially metals, this limits ablation rates to 10-100 nm/pulse. We present the results of using multiple pulse bursts to significantly increase the per-burst ablation rate compared to a single pulse with the same integrated energy, while keeping the peak intensity of each individual pulse below the air ionization limit. Femtosecond ablation with pulses centered at 800-nm having integrated energy of up to 30 mJ per pulse incident upon thin gold films was measured via resonance frequency shifts in a gold-electrode-coated quartz-crystal oscillator. Measurements were performed using Michelson-interferometer-based burst generators, with up to 2 ns pulse separations, as well as pulse shaping by programmable acousto-optic dispersive filter (Dazzler from FastLite) with up to 2 ps pulse separations.

High gradient superconducting quadrupoles

International Nuclear Information System (INIS)

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

Electrostatic quadrupoles for heavy-ion fusion

International Nuclear Information System (INIS)

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

Instant recording of the duration of a single mode-locked Nd:YAG laser pulse

International Nuclear Information System (INIS)

Lompre, L.A.; Mainfray, G.; Thebault, J.

1975-01-01

An electro-optic streak camera incorporating a storage memory video system has been developed and used to instantly visualize and record the shape of a 1.06-μ-wavelength pulse generated by a mode-locked Nd:YAG laser. The duration of a single laser pulse (approximately 30 psec) has been directly measured with and without laser amplification. (U.S.)

Space Vector Pulse Width Modulation Strategy for Single-Phase Three-Level CIC T-source Inverter

DEFF Research Database (Denmark)

Shults, Tatiana E.; Husev, Oleksandr O.; Blaabjerg, Frede

2016-01-01

This paper presents a novel space vector pulse-width modulation strategy for a single-phase three-level buck-boost inverter based on an impedance-source network. The case study system is based on T-source inverter with continuous input current. To demonstrate the improved performance of the inver......This paper presents a novel space vector pulse-width modulation strategy for a single-phase three-level buck-boost inverter based on an impedance-source network. The case study system is based on T-source inverter with continuous input current. To demonstrate the improved performance...... of the inverter, the strategy was compared the traditional pulse-width modulation. It is shown that the approach proposed has fewer switching states and does not suffer from neutral point misbalance....

Optimization And Single-Shot Characterization Of Ultrashort Thz Pulses From A Laser Wakefield Accelerator

International Nuclear Information System (INIS)

Plateau, G.R.; Matlis, N.H.; van Tilborg, J.; Geddes, C.G.R.; Toth, Cs.; Schroeder, C.B.; Leemans, W.P.

2009-01-01

We present spatiotemporal characterization of μJ-class ultrashort THz pulses generated from a laser wakefield accelerator (LWFA). Accelerated electrons, resulting from the interaction of a high-intensity laser pulse with a plasma, emit high-intensity THz pulses as coherent transition radiation. Such high peak-power THz pulses, suitable for high-field (MV/cm) pump-probe experiments, also provide a non-invasive bunch-length diagnostic and thus feedback for the accelerator. The characterization of the THz pulses includes energy measurement using a Golay cell, 2D sign-resolved electro-optic measurement and single-shot spatiotemporal electric-field distribution retrieval using a new technique, coined temporal electric-field cross-Correlation (TEX). All three techniques corroborate THz pulses of ∼ 5 μJ, with peak fields of 100's of kV/cm and ∼ 0.4 ps rms duration.

Pulsed-focusing recirculating linacs for muon acceleration

Energy Technology Data Exchange (ETDEWEB)

Johnson, Rolland [Muons, Inc., Batavia, IL (United States)

2014-12-31

Since the muon has a short lifetime, fast acceleration is essential for high-energy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAG-style magnets in the return arcs. A better solution, invented in this project, is to use combined-function dipole-quadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of

Regiospecific analysis of neutral ether lipids by liquid chromatography/electrospray ionization/single quadrupole mass spectrometry: validation with synthetic compounds

DEFF Research Database (Denmark)

Hartvigsen, Karsten; Ravandi, A.; Bukhave, Klaus

2001-01-01

A reversed-phase high-performance liquid chromatography (HPLC) method with on-line electrospray ionization/collision-induced dissociation/mass spectrometry (ESI/CID/MS) is presented for the regiospecific analysis of synthetic reference compounds of neutral ether lipids. The reference compounds were...... characterized by chromatographic retention times, full mass spectra, and fragmentation patterns as an aid to clarify the regiospecificity of ether lipids from natural sources. The results clearly show that single quadrupole mass spectroscopic analysis may elucidate the regiospecific structure of neutral ether...... + H - H2O](+), whereas the reverse situation characterized the sn-3 species. Furthermore, corresponding sn-2 and sn-3 species were separated by the chromatographic system. However, loss of water was promoted as fatty acid unsaturation was raised, which may complicate interpretation of the mass spectra...

Damage threshold of lithium niobate crystal under single and multiple femtosecond laser pulses: theoretical and experimental study

International Nuclear Information System (INIS)

Meng, Qinglong; Zhang, Bin; Zhong, Sencheng; Zhu, Liguo

2016-01-01

The damage threshold of lithium niobate crystal under single and multiple femtosecond laser pulses has been studied theoretically and experimentally. Firstly, the model for the damage threshold prediction of crystal materials based on the improved rate equation has been proposed. Then, the experimental measure method of the damage threshold of crystal materials has been given in detail. On the basis, the variation of the damage threshold of lithium niobate crystal with the pulse duration has also been analyzed quantitatively. Finally, the damage threshold of lithium niobate crystal under multiple laser pulses has been measured and compared to the theoretical results. The results show that the transmittance of lithium niobate crystal is almost a constant when the laser pulse fluence is relative low, whereas it decreases linearly with the increase in the laser pulse fluence below the damage threshold. The damage threshold of lithium niobate crystal increases with the increase in the duration of the femtosecond laser pulse. And the damage threshold of lithium niobate crystal under multiple laser pulses is obviously lower than that irradiated by a single laser pulse. The theoretical data fall in good agreement with the experimental results. (orig.)

Measurement of the quadrupole moments of the strongly deformed nuclei 18173Ta108 and 18375Re108 by hyperfine interaction in metals

International Nuclear Information System (INIS)

Netz, G.

1974-01-01

The quadrupole moments of two single particle proton states were measured in the strongly deformed nuclei region. Both measurements are independent of model because the field gradient is known in a rhenium lattice as well as at the nucleus site of a rhenium atom and also at the nucleus site of an incorporated tantalum atom. The quadrupole moments could thus be directly extracted from the quadrupole interaction frequency, the product of quadrupole moment and field gradient. For the 482 keV state (I = 5/2 + ) in 181 73 Ta 108 one obtains a quadrupole moment of: Q (5/2) = 2.5 +- 0.2 barn. For the 496 keV state (I = 9/2 - ) in 183 75 Re 108 , a quadrupole moment of: Q (0/2) = 3.6 +- 0.4 barn is found. This value agrees well with other experimental data within the framework of the collective model. (orig./LH) [de

Output pulse-shapes of position-sensitive proportional counters using high resistance single wire

International Nuclear Information System (INIS)

Iwatani, Kazuo; Nishiyama, Fumitaka; Hasai, Hiromi

1980-01-01

The measurements and model analysis of the output pulse-shapes from a single wire proportional counter (SWPC) which has a high resistance anode are described. The characteristics of the observed pulse-shapes are determined by only one parameter which is a function of anode resistance and load resistance and they are reproduced by a simple model. Using this model, the methods for position read-out are discussed in a systematical way. (author)

Stabilisation and precision pointing quadrupole magnets in the Compact Linear Collider (CLIC)

CERN Document Server

Janssens, Stef; Linde, Frank; van den Brand, Jo; Bertolini, Alessandro; Artoos, Kurt

This thesis describes the research done to provide stabilisation and precision positioning for the main beam quadrupole magnets of the Compact Linear Collider CLIC. The introduction describes why new particle accelerators are needed to further the knowledge of our universe and why they are linear. A proposed future accelerator is the Compact Linear Collider (CLIC) which consists of a novel two beam accelerator concept. Due to its linearity and subsequent single pass at the interaction point, this new accelerator requires a very small beam size at the interaction point, in order to increase collision effectiveness. One of the technological challenges, to obtain these small beam sizes at the interaction point, is to keep the quadrupole magnets aligned and stable to 1.5 nm integrated r.m.s. in vertical and 5 nm integrated root mean square (r.m.s.) in lateral direction. Additionally there is a proposal to create an intentional offset (max. 50 nm every 20 ms with a precision of +/- 1 nm), for several quadrupole ma...

The Features of Moessbauer Spectra of Hemoglobins: Approximation by Superposition of Quadrupole Doublets or by Quadrupole Splitting Distribution?

International Nuclear Information System (INIS)

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

2004-01-01

Moessbauer spectra of hemoglobins have some features in the range of liquid nitrogen temperature: a non-Lorentzian asymmetric line shape for oxyhemoglobins and symmetric Lorentzian line shape for deoxyhemoglobins. A comparison of the approximation of the hemoglobin Moessbauer spectra by a superposition of two quadrupole doublets and by a distribution of the quadrupole splitting demonstrates that a superposition of two quadrupole doublets is more reliable and may reflect the non-equivalent iron electronic structure and the stereochemistry in the α- and β-subunits of hemoglobin tetramers.

Sensitive detection of chlorine in iron oxide by single pulse and dual pulse laser-induced breakdown spectroscopy

Science.gov (United States)

Pedarnig, J. D.; Haslinger, M. J.; Bodea, M. A.; Huber, N.; Wolfmeir, H.; Heitz, J.

2014-11-01

The halogen chlorine is hard to detect in laser-induced breakdown spectroscopy (LIBS) mainly due to its high excited state energies of 9.2 and 10.4 eV for the most intense emission lines at 134.72 nm and 837.59 nm, respectively. We report on sensitive detection of Cl in industrial iron oxide Fe2O3 powder by single-pulse (SP) and dual-pulse (DP) LIBS measurements in the near infrared range in air. In compacted powder measured by SP excitation (Nd:YAG laser, 532 nm) Cl was detected with limit of detection LOD = 440 ppm and limit of quantitation LOQ = 720 ppm. Orthogonal DP LIBS was studied on pressed Fe2O3 pellets and Fe3O4 ceramics. The transmission of laser-induced plasma for orthogonal Nd:YAG 1064 nm and ArF 193 nm laser pulses showed a significant dependence on interpulse delay time (ipd) and laser wavelength (λL). The UV pulses (λL = 193 nm) were moderately absorbed in the plasma and the Cl I emission line intensity was enhanced while IR pulses (λL = 1064 nm) were not absorbed and Cl signals were not enhanced at ipd = 3 μs. The UV laser enhancement of Cl signals is attributed to the much higher signal/background ratio for orthogonal DP excitation compared to SP excitation and to the increased plasma temperature and electron number density. This enabled measurement at a very short delay time of td ≥ 0.1 μs with respect to the re-excitation pulse and detection of the very rapidly decaying Cl emission with higher efficiency.

Field quality measurements of the LQXB inner triplet quadrupoles for LHC

CERN Document Server

Velev, G V; Carcagno, R; Di Marco, J; Fehér, S; Glass, H; Kashikhin, V V; Kerby, J; Lamm, M J; Makulski, A; Nobrega, A; Nogiec, J; Orris, D; Peterson, T; Rabehl, Roger Jon; Schlabach, P; Strait, J; Sylvester, C D; Tartaglia, M; Tompkins, J C; Zlobin, A V

2005-01-01

As a part of the USLHC program, Fermilab is building half of the inner triplet quadrupole magnets for the LHC. Two identical quadrupoles (MQXB) with a dipole corrector between them in a single cryogenic unit (LQXB) comprise the Q2 optical element of the final focus triplets in the interaction regions. The 5.5 m long MQXB have a 70 mm aperture and operate in superfluid helium at 1.9 K with a peak field gradient of 215 T/m. Manufacturing of the 18 magnets is in an advanced stage. A program of magnetic field quality measurements of the magnets is performed at room temperature during magnet fabrication as well as at superfluid helium temperature during the cold qualification of each magnet. Results of the measurements are summarized in this paper. (12 refs).

Thermogravimetric-quadrupole mass-spectrometric analysis of geochemical samples.

Science.gov (United States)

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.

Pulsed neural networks consisting of single-flux-quantum spiking neurons

International Nuclear Information System (INIS)

Hirose, T.; Asai, T.; Amemiya, Y.

2007-01-01

An inhibitory pulsed neural network was developed for brain-like information processing, by using single-flux-quantum (SFQ) circuits. It consists of spiking neuron devices that are coupled to each other through all-to-all inhibitory connections. The network selects neural activity. The operation of the neural network was confirmed by computer simulation. SFQ neuron devices can imitate the operation of the inhibition phenomenon of neural networks

Circuit description of unipolar DC-to-DC converters for APS storage ring quadrupoles and sextupoles

International Nuclear Information System (INIS)

McGhee, D.G.

1993-01-01

This paper describes the control, interlock, and power circuits for 680 unipolar switch mode DC-to-DC converters used to regulate the Advanced Photon Sources (APS's) storage ring quadrupole and sextupole magnet currents. Quadrupole current stability is ± 6x10 -5 and the sextupole current stability is ±3x10 -4 . The stability is obtained with pulse width modulation, operating at a switching frequency of 20kHz with full current switching. The converters are housed in 200 cabinets located on top of the storage ring tunnel. Raw DC power is distributed from 80 AC-to-DC power supplies, four at each of 20 locations around the storage ring. Voltages, currents, and temperatures are computer monitored and logged for the converters and magnets. All converters and magnets are water cooled with the flow and pressure monitored at the inlet and outlet of groups. Water is interlocked with the raw power supplies and not the individual converters

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

Science.gov (United States)

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

2018-04-01

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

Method for single-shot measurement of picosecond laser pulse-lengths without electronic time dispersion

International Nuclear Information System (INIS)

Kyrala, G.A.

1987-01-01

A two-source shear pattern recording is proposed as a method for single-shot measurement of the pulse shape from nearly monochromatic sources whose pulse lengths are shorter than their coherence times. The basis of this method relies on the assertion that if two identical electromagnetic pulses are recombined with a time delay greater than the sum of their pulse widths, the recordable spatial pattern has no fringes in it. At an arbitrary delay, translated into an actual spatial recording position, the recorded modulated intensity will sample the corresponding laser intensity at that delay time, but with a modulation due to the coherence function of the electromagnetic pulse. Two arrangements are proposed for recording the pattern. The principles, the design parameters, and the methodologies of these arrangements are presented. Resolutions of the configurations and their limitations are given as well

Transition quadrupole moments in the superdeformed band of 40Ca

International Nuclear Information System (INIS)

Chiara, C.J.; Ideguchi, E.; Devlin, M.; LaFosse, D.R.; Lerma, F.; Reviol, W.; Ryu, S.K.; Sarantites, D.G.; Baktash, C.; Galindo-Uribarri, A.; Carpenter, M.P.; Janssens, R.V.F.; Lauritsen, T.; Lister, C.J.; Reiter, P.; Seweryniak, D.; Fallon, P.; Goergen, A.; Macchiavelli, A.O.; Rudolph, D.

2003-01-01

The transition quadrupole moments Q t for the superdeformed band in 40 Ca have been determined through thin-target Doppler-shift attenuation analyses. A best-fit value of Q t =1.30±0.05 e b is obtained when a single value is assumed for the entire band. Fitting separate quadrupole moments for in-band transitions decaying from the high-spin states and the presumably admixed low-spin states results in Q t (high)=1.81 -0.26 +0.41 e b and Q t (low)=1.18 -0.05 +0.06 e b, respectively. Q t values extracted for individual transitions in a Doppler-broadened line-shape analysis also indicate smaller Q t values at lower spins. These results are consistent with the interpretation of this band as an eight-particle-eight-hole superdeformed band with a significant admixture of less-collective configurations at low spins

Visual CRO display of pulse height distribution including discriminator setting for a single channel X-ray analyser

International Nuclear Information System (INIS)

Shaw, S.E.

1979-01-01

An outline for a simple pulse spectroscope which attaches to a standard laboratory CRO is presented. The peak amplitude voltage of each pulse from the linear amplifier of a single channel X-ray analyser is stored for the duration of one oscilloscope trace. For each amplifier pulse, input from the discriminator is tested and if these is coincidence of pulses the oscilloscope beam is blanked for approximately the first 2 cm of its traverse across the screen. Repetition of pulses forms a pulse height distribution with a rectangular dark area marking the position of the discriminator window. (author)

Test and Simulation Results for Quenches Induced by Fast Losses on a LHC Quadrupole

CERN Document Server

Bracco, Ch; Bartmann, W; Bednarek, M; Lechner, A; Sapinski, M; Vittal Shetty, N; Schmidt, R; Solfaroli Camillocci, M; Verweij, A

2014-01-01

A test program for beam induced quenches was started in the LHC in 2011 in order to reduce as much as possible BLM-triggered beam dumps, without jeopardising the safety of the superconducting magnets. A first measurement was performed to asses the quench level of a quadrupole located in the LHC injection region in case of fast (ns) losses. It consisted in dumping single bunches onto an injection protection collimator located right upstream of the quadrupole, varying the bunch intensity up to 3×1010 protons and ramping the quadrupole current up to 2200 A. No quench was recorded at that time. The test was repeated in 2013 with increased bunch intensity (6.5×1010 protons); a quench occurred when powering the magnet at 2500 A. The comparison between measurements during beam induced and quench heaters induced quenches is shown. Results of FLUKA simulations on energy deposition, calculations on quench behaviour using the QP3 code and the respective estimates of quench levels are also presented.

Solid state NMR, basic theory and recent progress for quadrupole nuclei with half-integer spin

International Nuclear Information System (INIS)

Dieter, F.

1998-01-01

This review describes the basic theory and some recently developed techniques for the study of quadrupole nuclei with half integer spins in powder materials. The latter is connected to the introduction of the double rotation (DOR) by A. Samoson et al. (1) and to the introduction of the multiple quantum magic-angle spinning (MQ MAS) technique by L. Frydman et. al. (2). For integer spins, especially the solid-state deuterium magnetic resonance, we refer to the review of G.L. Hoatson and R.L. Vold: '' 2 H-NMR Spectroscopy of Solids and Liquid Crystals'' (3). For single crystals we refer to O. Kanert and M. Mehring: ''Static quadrupole effects in disordered cubic solids''(4) and we would like also to mention the ''classic'' review of M.H. Cohen and F. Reif: ''Quadrupole effects in NMR studies of solids'' (5). Some more recent reviews in the field under study are D. Freude and J. Haase ''Quadrupole effects in solid-state NMR'' (6). Ch. Jager: ''Satellite Transition Spectroscopy of Quadrupolar Nuclei'' (7) and B.F. Chmelka and J.W. Zwanziger: ''Solid State NMR Line Narrowing Methods for Quadrupolar Nuclei - Double Rotation and Dynamic-Angle Spinning'' (8). A survey of nuclear quadrupole frequency data published before the end of 1982 is given by H. Chihara and N. Nakamura in Landolt-Bornstein, Vol. 20 (9). Values of the chemical shift of quadrupole nuclei in solids can be found in books such as ''Multinuclear NMR'' edited by J. Mason (10). In section 9 of ref (6) some electric field gradient and chemical shift data published from 1983 to 1992 for the most studied quadrupole nuclei sup 27 Al, sup 23 Na, and sup 17 O are given

Catastrophic optical mirror damage in diode lasers monitored during single-pulse operation

DEFF Research Database (Denmark)

Zegler, M.; Tomm, J.W.; Reeber, D.

2009-01-01

is achieved. The thermal runaway process is unambiguously related to the occurrence of a “thermal flash.” A one-by-one correlation between nearfield, thermal flash, thermal runaway, and structural damage is observed. The single-pulse excitation technique allows for controlling the propagation...

All systems go for LHC quadrupoles

CERN Multimedia

2003-01-01

The series fabrication of the Main Quadrupole cold masses for the LHC has begun with the delivery of the first unit on February 12th. The superconducting dipole magnets required to bend the proton beams around the LHC are often in the news. Less famous, perhaps, but equally important are the 360 main quadrupole (MQ) magnets, which will perform the principal focusing around the 27 km ring. CERN and CEA-Saclay began collaborating on the development and prototyping of these magnets in 1989. This resulted in five highly successful quadrupole units - also known as short straight sections - one of which was integrated for testing in String 1, and two others of the final design in String 2. Once the tests had confirmed the validity of the design and realization, the fabrication of the 360 cold masses had to be transferred to industry. After highly competitive tendering, the German firm ACCEL Instruments was entrusted both with the construction of the quadrupole magnets themselves, and with their assembly into the co...

Measurement of the ground state spectroscopic quadrupole moments of 191Os and 193Os

International Nuclear Information System (INIS)

Ernst, H.; Hagn, E.; Zech, E.

1979-01-01

Radioactive 191 Os and 193 Os nuclei have been aligned in an Os single crystal at temperatures down to 4 mK. From the temperature dependence of the γ-anisotropy the quadrupole frequencies vsub(Q) = e 2 qQ/h have been determined as vsub(Q)( 191 OsOs) = -278+-9 MHz and vsub(Q)( 193 OsOs) = -96+-15 MHz. With the known electric field gradient for OsOs of eq = (-4.54+-0.24) x 10 17 V/cm 2 the ground state spectroscopic quadrupole moments are deduced to be Q( 191 Os) = +2.53+-0.16 b and Q( 193 Os) = +0.87+-0.15 b. (orig.)

Nonuniform radiation damage in permanent magnet quadrupoles.

Science.gov (United States)

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

2014-08-01

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

Nonuniform radiation damage in permanent magnet quadrupoles

International Nuclear Information System (INIS)

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

2014-01-01

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

Nonuniform radiation damage in permanent magnet quadrupoles

Energy Technology Data Exchange (ETDEWEB)

Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

2014-08-15

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

Polymer optical fiber Bragg grating inscription with a single UV laser pulse

DEFF Research Database (Denmark)

Pospori, Andreas; Marques, A.T.; Bang, Ole

2017-01-01

We experimentally demonstrate the first polymer optical fiber Bragg grating inscribed with only one krypton fluoride laser pulse. The device has been recorded in a single-mode poly(methyl methacrylate) optical fiber, with a core doped with benzyl dimethyl ketal for photosensitivity enhancement. One...... laser pulse with a duration of 15 ns, which provide energy density of 974 mJ/cm2, is adequate to introduce a refractive index change of 0.74×10-4 in the fiber core. After the exposure, the reflectivity of the grating increases for a few minutes following a second order exponential saturation...

Single-pulse characteristics of the Xe(L) amplifier on the Xe35+ (3d→2p) transition array at λ ≅ 2.86 A

International Nuclear Information System (INIS)

Borisov, Alex B; Song Xiangyang; Zhang Ping; McCorkindale, John C; Khan, Shahab F; De Jonghe, Richard; Poopalasingam, Sankar; Zhao, Ji; Boyer, Keith; Rhodes, Charles K

2006-01-01

The triple comparison of (1) single-pulse spectral data, recorded with a CCD-equipped von Hamos spectrometer both axially and transversely; (2) axially measured time-integrated spectra registered on a film and (3) single-pulse x-ray images of the morphology of the self-trapped plasma channel, recorded simultaneously with the single-pulse spectra, establishes several leading characteristics of the saturated amplification observed on the Xe 35+ transition array at λ ≅ 2.86 A. The chief findings are (α) absolute positive correlation of amplification with the formation of a plasma channel, (β) a perfect spectral match of the amplified transitions in the comparison of axially recorded single-pulse and time-integrated film data and (γ) exact spectral correspondence of both the axially registered single-pulse and time-integrated film data with single-pulse transversely measured spectra exhibiting deep spectral hole burning at the position of the Xe 35+ array. (letter to the editor)

Ion-storage in radiofrequency electric quadrupole field

International Nuclear Information System (INIS)

Gheorghe, V.

1976-01-01

The confinement of charged particles in a quadrupole radiofrequency electric field are presented. The stability diagrams and phase space trajectories for the quadrupole mass spectrometer and for the ion trap are represented and their main characteristics are discussed. (author)

Millijoule Pulse Energy Second Harmonic Generation With Single-Stage Photonic Bandgap Rod Fiber Laser

DEFF Research Database (Denmark)

Laurila, Marko; Saby, Julien; Alkeskjold, Thomas Tanggaard

2011-01-01

In this paper, we demonstrate, for the first time, a single-stage Q-switched single-mode (SM) ytterbium-doped rod fiber laser delivering record breaking pulse energies at visible and UV light. We use a photonic bandgap rod fiber with a mode field diameter of 59μm based on a new distributed...

Upgrading the Lyon cluster ion accelerator by a radiofrequency quadrupole

International Nuclear Information System (INIS)

Moser, H.O.; Schempp, A.

1987-02-01

The design is presented of an RFQ with variable final energy suitable to post-accelerate cluster ions from the Lyon electrostatic cluster-ion accelerator in the mass ranges from 1 to 25 μ and 1 to 50 μ to kinetic energies of 1.32-2.5 MeV and 2.64-5.0 MeV for cw and pulsed operation, respectively. Furthermore, a beam line is described which matches the electrostatically preaccelerated beam to the RFQ by use of electrostatic quadrupole triplets. When used without RFQ this beam line serves to improve beam parameters on the target, such as the particle flux density or beam divergence. The estimated costs of this project are about DM 345 000.- or FF 1 200 000.- without VAT. (orig.) [de

A high dynamic range pulse counting detection system for mass spectrometry.

Science.gov (United States)

Collings, Bruce A; Dima, Martian D; Ivosev, Gordana; Zhong, Feng

2014-01-30

A high dynamic range pulse counting system has been developed that demonstrates an ability to operate at up to 2e8 counts per second (cps) on a triple quadrupole mass spectrometer. Previous pulse counting detection systems have typically been limited to about 1e7 cps at the upper end of the systems dynamic range. Modifications to the detection electronics and dead time correction algorithm are described in this paper. A high gain transimpedance amplifier is employed that allows a multi-channel electron multiplier to be operated at a significantly lower bias potential than in previous pulse counting systems. The system utilises a high-energy conversion dynode, a multi-channel electron multiplier, a high gain transimpedance amplifier, non-paralysing detection electronics and a modified dead time correction algorithm. Modification of the dead time correction algorithm is necessary due to a characteristic of the pulse counting electronics. A pulse counting detection system with the capability to count at ion arrival rates of up to 2e8 cps is described. This is shown to provide a linear dynamic range of nearly five orders of magnitude for a sample of aprazolam with concentrations ranging from 0.0006970 ng/mL to 3333 ng/mL while monitoring the m/z 309.1 → m/z 205.2 transition. This represents an upward extension of the detector's linear dynamic range of about two orders of magnitude. A new high dynamic range pulse counting system has been developed demonstrating the ability to operate at up to 2e8 cps on a triple quadrupole mass spectrometer. This provides an upward extension of the detector's linear dynamic range by about two orders of magnitude over previous pulse counting systems. Copyright © 2013 John Wiley & Sons, Ltd.

Single-shot spectro-temporal characterization of XUV pulses from a seeded free-electron laser

Science.gov (United States)

de Ninno, Giovanni; Gauthier, David; Mahieu, Benoît; Ribič, Primož Rebernik; Allaria, Enrico; Cinquegrana, Paolo; Danailov, Miltcho Bojanov; Demidovich, Alexander; Ferrari, Eugenio; Giannessi, Luca; Penco, Giuseppe; Sigalotti, Paolo; Stupar, Matija

2015-08-01

Intense ultrashort X-ray pulses produced by modern free-electron lasers (FELs) allow one to probe biological systems, inorganic materials and molecular reaction dynamics with nanoscale spatial and femtoscale temporal resolution. These experiments require the knowledge, and possibly the control, of the spectro-temporal content of individual pulses. FELs relying on seeding have the potential to produce spatially and temporally fully coherent pulses. Here we propose and implement an interferometric method, which allows us to carry out the first complete single-shot spectro-temporal characterization of the pulses, generated by an FEL in the extreme ultraviolet spectral range. Moreover, we provide the first direct evidence of the temporal coherence of a seeded FEL working in the extreme ultraviolet spectral range and show the way to control the light generation process to produce Fourier-limited pulses. Experiments are carried out at the FERMI FEL in Trieste.

Single pulse two photon fluorescence lifetime imaging (SP-FLIM) with MHz pixel rate.

Science.gov (United States)

Eibl, Matthias; Karpf, Sebastian; Weng, Daniel; Hakert, Hubertus; Pfeiffer, Tom; Kolb, Jan Philip; Huber, Robert

2017-07-01

Two-photon-excited fluorescence lifetime imaging microscopy (FLIM) is a chemically specific 3-D sensing modality providing valuable information about the microstructure, composition and function of a sample. However, a more widespread application of this technique is hindered by the need for a sophisticated ultra-short pulse laser source and by speed limitations of current FLIM detection systems. To overcome these limitations, we combined a robust sub-nanosecond fiber laser as the excitation source with high analog bandwidth detection. Due to the long pulse length in our configuration, more fluorescence photons are generated per pulse, which allows us to derive the lifetime with a single excitation pulse only. In this paper, we show high quality FLIM images acquired at a pixel rate of 1 MHz. This approach is a promising candidate for an easy-to-use and benchtop FLIM system to make this technique available to a wider research community.

Superconducting focusing quadrupoles for heavy ion fusion experiments

Energy Technology Data Exchange (ETDEWEB)

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.

Quadrupole moments measured by nuclear orientation

International Nuclear Information System (INIS)

Bouchta, H.

1985-01-01

Quadrupole interactions between the nuclei and solids have been studied with the low temperature nuclear orientation technique. The first series of measurements have been effected on the orientation of 195H g m and 197 Hg m , long lived daughter states in the 195 Au and 197 Au decay. The lifetimes of these states are of the same order as the spin-lattice relaxation time. The reorientation of the intermediate states has been taken into account extending the dipole relaxation mechanism to non-equidistant relaxing substates. The experimental nuclear quadrupole moments, thus deduced are slightly different from theoretical estimations. A new high precision method accessible to levels with 100 ns to 1 m lifetimes, the level mixing resonance on oriented nuclei (LMR/ON) has been elaborated in collaboration with LEUVEN university (Belgium). In this technique the nucleus is subject to a non colinear electric plus magnetic combined interaction. The quadrupole interaction of Ag[7/2, = 40 s] isomer with the electric field gradient in zinc has been established to better than 1% observing its level mixing resonances; and also the ratio of electric field gradients of silver in zinc to cadmium. The electric quadrupole moments of 106 Ag m , 107 Ag m and 109 Ag m have been established combining the level mixing resonances with classical low temperature quadrupole alignment measurements. The experimental values are in good agreement with theoretical calculations based on a semi-microscopical model using Yukawa potential [fr

Two-dimensional exchange and nutation exchange nuclear quadrupole resonance spectroscopy

International Nuclear Information System (INIS)

Mackowiak, M.; Sinyavsky, N.; Velikite, N.; Nikolaev, D.

2002-01-01

A theoretical treatment of the 2D exchange NQR pulse sequence is presented and applied to a quantitative study of exchange processes in molecular crystals. It takes into account the off-resonance irradiation, which critically influences the spin dynamics. The response to the three-pulse sequence of a system of spins I=3/2 in zero applied field, experiencing electric quadrupole couplings, is analysed. The mixing dynamics by exchange and the expected cross-peak intensities as a function of the frequency offset have been derived. The theory is illustrated by a study of the optimization procedure, which is of crucial importance for the detection of the cross- and diagonal-peaks in a 2D-exchange spectrum. The systems investigated are hexachloroethane and tetrachloroethylene. They show threefold and twofold reorientational jumps about the carbon-carbon axis, respectively. A new method of direct determination of rotational angles based on two-dimensional nutation exchange NQR spectroscopy is proposed. The method involves the detection of exchange processes through NQR nutation spectra recorded after the mixing interval. The response of a system of spins I=3/2 to the three-pulse sequence with increasing pulse widths is analyzed. It is shown that the 2D-nutation exchange NQR spectrum exhibits characteristic ridges, which manifest the motional mechanism in a model-independent fashion. The angles through which the molecule rotates can be read directly from elliptical ridges in the 2D spectrum, which are also sensitive to the asymmetry parameter of the electric field gradient tensor. (orig.)

The g-factor and the electric quadrupole moment of the 7/2+ isomer in 125Xe

International Nuclear Information System (INIS)

Alber, D.; Bertschat, H.H.; Grawe, H.; Haas, H.; Mahnke, H.E.; Menningen, M.; Semmler, W.; Sielemann, R.; Zeitz, W.D.

1983-01-01

The time differential perturbed angular distribution method (PAD) was used to measure the g-factor and the electric quadrupole interaction in a Cd single crystal for the tsub(1/2) = 140 ns, Isup(π) = 7/2 + isomer in 125 Xe. The g-factor is g = +0.264(10) and the quadrupole coupling constant e 2 Qq/h = 122.1(6) MHz at 552 K. The lifetime of the Isup(π) = 11/2 + state was measured to be tau = 11.3(1.1) ps by the recoil distance method (RDM). From an analysis of the spectroscopic data using the triaxial-rotor-plus-particle (TRPP) model the quadrupole moment of the 7/2 + isomer is deduced to be Q = 1.40(15) b yielding an electric field gradient (efg) eq = 3.6(4)x10 17 V/cm 2 for Xe Cd. (orig.)

Diode-pumped, single frequency Nd:YLF laser for 60-beam OMEGA laser pulse-shaping system

International Nuclear Information System (INIS)

Okishev, A.V.; Seka, W.

1997-01-01

The operational conditions of the OMEGA pulse-shaping system require an extremely reliable and low-maintenance master oscillator. The authors have developed a diode-pumped, single-frequency, pulsed Nd:YLF laser for this application. The laser generates Q-switched pulses of ∼160-ns duration and ∼10-microJ energy content at the 1,053-nm wavelength with low amplitude fluctuations (<0.6% rms) and low temporal jitter (<7 ns rms). Amplitude and frequency feedback stabilization systems have been used for high long-term amplitude and frequency stability

Fast separation of triterpenoid saponins using supercritical fluid chromatography coupled with single quadrupole mass spectrometry.

Science.gov (United States)

Huang, Yang; Zhang, Tingting; Zhou, Haibo; Feng, Ying; Fan, Chunlin; Chen, Weijia; Crommen, Jacques; Jiang, Zhengjin

2016-03-20

Triterpenoid saponins (TSs) are the most important components of some traditional Chinese medicines (TCMs) and have exhibited valuable pharmacological properties. In this study, a rapid and efficient method was developed for the separation of kudinosides, stauntosides and ginsenosides using supercritical fluid chromatography coupled with single quadrupole mass spectrometry (SFC-MS). The separation conditions for the selected TSs were carefully optimized after the initial screening of eight stationary phases. The best compromise for all compounds in terms of chromatographic performance and MS sensitivity was obtained when water (5-10%) and formic acid (0.05%) were added to the supercritical carbon dioxide/MeOH mobile phase. Beside the composition of the mobile phase, the nature of the make-up solvent for interfacing SFC with MS was also evaluated. Compared to reversed phase liquid chromatography, the SFC approach showed higher resolution and shorter running time. The developed SFC-MS methods were successfully applied to the separation and identification of TSs present in Ilex latifolia Thunb., Panax quinquefolius L. and Panax ginseng C.A. Meyer. These results suggest that this SFC-MS approach could be employed as a useful tool for the quality assessment of natural products containing TSs as active components. Copyright © 2015 Elsevier B.V. All rights reserved.

Quantized TDHF for isoscalar giant quadrupole resonances in spherical nuclei

International Nuclear Information System (INIS)

Drozdz, S.; Okolowicz, J.; Ploszajczak, M.; Caurier, E.

1988-01-01

The time-dependent Hartree-Fock theory supplemented with the regularity and single-valuedness quantization condition for the gauge invariant component of the wavefunction is applied to the description of the centroid energy and escape width of isoscalar giant quadrupole resonances in 16 O, 40 Ca and 110 Zr. Calculations are performed using the Skyrme SIII effective interaction. An important role of the finite oscillation amplitude in the mean-field dynamics is emphasized. (orig.)

High-Energy Gun-Injected Toroidal Quadrupole

International Nuclear Information System (INIS)

Hammel, J.E.; Henins, I.; Kewish, R.W. Jr.; Marshall, J.; Sherwood, A.R.

1971-01-01

A quadrupole device is being used to investigate the trapping and containment of an energetic gun plasma. The quadrupole is designed to contain a peak density of 5 x 10 13 cm -3 at 2.5 keV within the MHD-stable region. At design field there are 5 gyro-radii for 2. 5-keV protons from the separatrix to the ψ crit . The interior conductors are directly driven with a 0.8-MJ capacitor bank. The current to the coils is fed through a single pair of dipole-guarded conductors to each coil. The coils are also supported from the current feed, The dipole guard is in a force-free configuration with 5 gyro-radii for 2. 5-keV protons from the separatrix (between the dipole and quadrupole fields) to the dipole surface. The dipole is designed so that loss of plasma from the dipole region will be directed away from the interior conductors. This feature is necessary for the prevention of contamination by secondary gas produced by plasma lost at the dipole guard. Experiments at one-half design value of magnetic field have shown that the kilovolt energy gun plasma is trapped by depolarization currents around the coils, and that a very high percentage (>50%) of the gun output can be trapped. The plasma density is measured by a unique Michelson interferometer using CO 2 laser light. The energy of the plasma is derived from magnetic pickup loops placed outside the containment region. The leak caused by the dipole guard Held has been examined by double electric probe measurements. The plasma drift thus inferred is an order of magnitude less than that predicted by a model of Meade's or by calculations by us. This casts doubt upon the validity of any such simple model and emphasizes the necessity of further experimental investigation of the matter. New coils which are being built to operate at full design magnetic field strength will allow a check on the containment time of the device for kilovolt energy plasma. (author)

Quadrupole Ion Traps

Indian Academy of Sciences (India)

to do precision spectroscopic measurements on these ions. ... Bonn, investigated the non-magnetic quadrupole mass filter, .... the details of which will be discussed in the subse- ... the radial plane the ion undergoes a circular motion with the.

SUPERCONDUCTING QUADRUPOLE ARRAYS FOR MULTIPLE BEAM TRANSPORT

International Nuclear Information System (INIS)

Rainer Meinke Carl Goodzeit Penny Ball Roger Bangerter

2003-01-01

The goal of this research was to develop concepts for affordable, fully functional arrays of superconducting quadrupoles for multi-beam transport and focusing in heavy ion fusion (HIF)accelerators. Previous studies by the Virtual National Laboratory (VNL) collaboration have shown that the multi-beam transport system (consisting of alternating gradient quadrupole magnets, a beam vacuum system, and the beam monitor and control system) will likely be one of the most expensive and critical parts of such an accelerator. This statement is true for near-term fusion research accelerators as well as accelerators for the ultimate goal of power production via inertial fusion. For this reason, research on superconducting quadrupole arrays is both timely and important for the inertial fusion energy (IFE) research program. This research will also benefit near-term heavy ion fusion facilities such as the Integrated Research Experiment (IRE)and/or the Integrated Beam Experiment (IBX). We considered a 2-prong approach that addresses the needs of both the nearer and longer term requirements of the inertial fusion program. First, we studied the flat coil quadrupole design that was developed by LLNL; this magnet is 150 mm long with a 50 mm aperture and thus is suitable for near term experiments that require magnets of a small length to aperture ratio. Secondly, we studied the novel double-helix quadrupole (DHQ) design in a small (3 x 3) array configuration; this design can provide an important step to the longer term solution of loW--cost, easy to manufacture array constructions. Our Phase I studies were performed using the AMPERES magnetostatic analysis software. Consideration of these results led to plans for future magnet RandD construction projects. The first objective of Phase I was to develop the concept of a superconducting focusing array that meets the specific requirements of a heavy ion fusion accelerator. Detailed parameter studies for such quadrupole arrays were performed

SUPERCONDUCTING QUADRUPOLE ARRAYS FOR MULTIPLE BEAM TRANSPORT

Energy Technology Data Exchange (ETDEWEB)

Rainer Meinke

2003-10-01

The goal of this research was to develop concepts for affordable, fully functional arrays of superconducting quadrupoles for multi-beam transport and focusing in heavy ion fusion (HIF)accelerators. Previous studies by the Virtual National Laboratory (VNL) collaboration have shown that the multi-beam transport system (consisting of alternating gradient quadrupole magnets, a beam vacuum system, and the beam monitor and control system) will likely be one of the most expensive and critical parts of such an accelerator. This statement is true for near-term fusion research accelerators as well as accelerators for the ultimate goal of power production via inertial fusion. For this reason, research on superconducting quadrupole arrays is both timely and important for the inertial fusion energy (IFE) research program. This research will also benefit near-term heavy ion fusion facilities such as the Integrated Research Experiment (IRE)and/or the Integrated Beam Experiment (IBX). We considered a 2-prong approach that addresses the needs of both the nearer and longer term requirements of the inertial fusion program. First, we studied the flat coil quadrupole design that was developed by LLNL; this magnet is 150 mm long with a 50 mm aperture and thus is suitable for near term experiments that require magnets of a small length to aperture ratio. Secondly, we studied the novel double-helix quadrupole (DHQ) design in a small (3 x 3) array configuration; this design can provide an important step to the longer term solution of low-cost, easy to manufacture array constructions. Our Phase I studies were performed using the AMPERES magnetostatic analysis software. Consideration of these results led to plans for future magnet R&D construction projects. The first objective of Phase I was to develop the concept of a superconducting focusing array that meets the specific requirements of a heavy ion fusion accelerator. Detailed parameter studies for such quadrupole arrays were performed

SINGLE-PULSE RADIO OBSERVATIONS OF THE GALACTIC CENTER MAGNETAR PSR J1745–2900

Energy Technology Data Exchange (ETDEWEB)

Yan, Zhen; Shen, Zhi-Qiang; Wu, Ya-Jun; Zhao, Rong-Bing; Fan, Qing-Yuan; Hong, Xiao-Yu; Jiang, Dong-Rong; Li, Bin; Liang, Shi-Guang; Ling, Quan-Bao; Liu, Qing-Hui; Qian, Zhi-Han; Zhang, Xiu-Zhong; Zhong, Wei-Ye; Ye, Shu-Hua [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Wu, Xin-Ji [Department of Astronomy, Peking University, Beijing 100871 (China); Manchester, R. N. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Weltevrede, P. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Yuan, Jian-Ping [Key Laboratory of Radio Astronomy, Chinese Academy of Sciences (China); Lee, Ke-Jia, E-mail: yanzhen@shao.ac.cn [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

2015-11-20

In this paper, we report radio observations of the Galactic Center magnetar PSR J1745–2900 at six epochs between 2014 June and October. These observations were carried out using the new Shanghai Tian Ma Radio Telescope at a frequency of 8.6 GHz. Both the flux density and integrated profile of PSR J1745–2900 show dramatic changes from epoch to epoch, showing that the pulsar was in its “erratic” phase. On MJD 56836, the flux density of this magnetar was about 8.7 mJy, which was 10 times larger than that reported at the time of discovery, enabling a single-pulse analysis. The emission is dominated by narrow “spiky” pulses that follow a log-normal distribution in peak flux density. From 1913 pulses, we detected 53 pulses whose peak flux densities are 10 times greater than that of the integrated profile. They are concentrated in pulse phase at the peaks of the integrated profile. The pulse widths at the 50% level of these bright pulses were between 0.°2 and 0.°9, much narrower than that of the integrated profile (∼12°). The observed pulse widths may be limited by interstellar scattering. No clear correlation was found between the widths and peak flux density of these pulses and no evidence was found for subpulse drifting. Relatively strong spiky pulses are also detected in the other five epochs of observation, showing the same properties as those detected in MJD 56836. These strong spiky pulses cannot be classified as “giant” pulses but are more closely related to normal pulse emission.

AA, wide quadrupole on measurement stand

CERN Multimedia

CERN PhotoLab

1981-01-01

Please look up 8101024 first. Shims and washers on the wide quadrupoles (QFW, QDW; located in the lattice where dispersion was large) served mostly for corrections of those lattice parameters which were a function of momentum. After mounting shims and washers, the quadrupoles were measured to determine their magnetic centre and to catalogue the effect of washer constellations. Raymond Brown is busy measuring a wide quad.

AA, shims and washers on quadrupole ends

CERN Multimedia

CERN PhotoLab

1981-01-01

Due to the fact that much of the field of the quadrupoles was outside the iron (in particular with the wide quadrupoles) and that thus the fields of quadrupoles and bending magnets interacted, the lattice properties of the AA could not be predicted with the required accuracy. After a first running period in 1980, during which detailed measurements were made with proton test beams, corrections to the quadrupoles were made in 1981, in the form of laminated shims at the ends of the poles, and with steel washers. With the latter ones, further refinements were made in an iterative procedure with measurements on the circulating beam. This eventually resulted, amongst other things, in a very low chromaticity, with the Q-values being constant to within +- 0.001 over the total momentum range of 6 %. Here we see the shims and washers on a narrow qudrupole (QFN, QDN). See also 8103203, 8103204, 8103205, 8103206.

Electric quadrupole moments of neutron-rich nuclei {sup 32}Al and {sup 31}Al

Energy Technology Data Exchange (ETDEWEB)

Kameda, D., E-mail: kameda@ribf.riken.jp; Ueno, H. [RIKEN Nishina Center (Japan); Asahi, K.; Nagae, D.; Takemura, M.; Shimada, K. [Tokyo Institute of Technology, Department of Physics (Japan); Yoshimi, A.; Nagatomo, T.; Sugimoto, T. [RIKEN Nishina Center (Japan); Uchida, M.; Arai, T.; Takase, K.; Suda, S.; Inoue, T. [Tokyo Institute of Technology, Department of Physics (Japan); Murata, J.; Kawamura, H. [Rikkyo University, Department of Physics (Japan); Watanabe, H. [Australian National University, Department of Nuclear Physics (Australia); Kobayashi, Y.; Ishihara, M. [RIKEN Nishina Center (Japan)

2007-11-15

The electric quadrupole moments for the ground states of {sup 32}Al and {sup 31}Al have been measured by the {beta} ray-detected nuclear quadrupole resonance method. Spin-polarized {sup 32}Al and {sup 31}Al nuclei were obtained from the fragmentation of {sup 40}Ar projectiles at E/A = 95 MeV/nucleon, and were implanted in a single crystal {alpha}-Al{sub 2}O{sub 3} stopper. The measured Q moment of {sup 32}Al, |Q({sup 32}Al)| = 24(2) mb, is in good agreement with a conventional shell-model calculation with a full sd model space and empirical effective charges, while that of {sup 31}Al is considerably smaller than the sd calculations.

Magnetic phases in Pt/Co/Pt films induced by single and multiple femtosecond laser pulses

Energy Technology Data Exchange (ETDEWEB)

Kisielewski, J., E-mail: jankis@uwb.edu.pl; Kurant, Z.; Sveklo, I.; Tekielak, M.; Maziewski, A. [Faculty of Physics, University of Białystok, Ciołkowskiego 1L, 15-245 Białystok (Poland); Wawro, A. [Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw (Poland)

2016-05-21

Ultrathin Pt/Co/Pt trilayers with initial in-plane magnetization were irradiated with femtosecond laser pulses. In this way, an irreversible structural modification was introduced, which resulted in the creation of numerous pulse fluence-dependent magnetic phases. This was particularly true with the out-of-plane magnetization state, which exhibited a submicrometer domain structure. This effect was studied in a broad range of pulse fluences up to the point of ablation of the metallic films. In addition to this single-pulse experiment, multiple exposure spots were also investigated, which exhibited an extended area of out-of-plane magnetization phases and a decreased damage threshold. Using a double exposure with partially overlapped spots, a two-dimensional diagram of the magnetic phases as a function of the two energy densities was built, which showed a strong inequality between the first and second incoming pulses.

Magnetic phases in Pt/Co/Pt films induced by single and multiple femtosecond laser pulses

International Nuclear Information System (INIS)

Kisielewski, J.; Kurant, Z.; Sveklo, I.; Tekielak, M.; Maziewski, A.; Wawro, A.

2016-01-01

Ultrathin Pt/Co/Pt trilayers with initial in-plane magnetization were irradiated with femtosecond laser pulses. In this way, an irreversible structural modification was introduced, which resulted in the creation of numerous pulse fluence-dependent magnetic phases. This was particularly true with the out-of-plane magnetization state, which exhibited a submicrometer domain structure. This effect was studied in a broad range of pulse fluences up to the point of ablation of the metallic films. In addition to this single-pulse experiment, multiple exposure spots were also investigated, which exhibited an extended area of out-of-plane magnetization phases and a decreased damage threshold. Using a double exposure with partially overlapped spots, a two-dimensional diagram of the magnetic phases as a function of the two energy densities was built, which showed a strong inequality between the first and second incoming pulses.

Permanent magnet quadrupole for the 1-ST tank of LINAC-4

CERN Document Server

Skachkov, Vl; Sergeeva, O; Lombardi, A; Sargsyan, E; Cornuet, D; Venturini , W; Skachkov , V

2006-01-01

A rare-earth (REPM) ∅ 60 mm diameter, 45 mm long quadrupole for the LINAC-4 focusing channel with an integrated gradient of 2.3 T is described. Thin side washers are used for tuning the quad into specified gradient integral with ±0.5 % accuracy. The single washer contribution calculations are discussed. A method for limiting to 30 μ m the magnetic axis offset in the REPM quad is discussed to exclude its compensation by the outer diameter machining before inserting into the drift tube. Nonlinearity of the field is less than 1 % in the reference range of 75 % of beam aperture at the central cross- section near the quad axis . The angular quadrupole arrangement in the drift tube will be provided by machining the main groove on the quad surface in the median plane with 1 mrad accuracy. Calculations of the longitudinal gradient distribution between two...

Theory of the time orbiting potential (TOP) quadrupole magnetic trap for cold atoms

Energy Technology Data Exchange (ETDEWEB)

Minogin, V.G.; Richmond, J.A.; Opat, G.I.

1997-12-31

An analytical theory of the time orbiting potential (TOP) quadrupole magnetic trap for cold atoms is developed. It is shown that the rotating magnetic filed used to create the time-average harmonic potential is responsible for the formation of quasi-energy states of an atom in the trap. It is found that the motion of an atom near the origin of the trap can be represented as consisting of slow motion in the effective potential and fast oscillations with small amplitude. Dipole, quadrupole and higher order atomic transitions between quasi-energy states are shown to be responsible for an additional effective potential for slow atomic motion which is proportional to the fourth power of the atomic co-ordinate. Eigenstates and eigenfunctions are used to calculate the co-ordinate distribution for a single atom. It is concluded that at low temperature the quantum statistical co-ordinate distribution for a single atom exhibits a narrow central peak due to the ground state population, together with relatively broad wings due to the excited state population. (authors). 20 refs., 1 tab., 6 figs.

Ultrashort and coherent single-electron pulses for diffraction at ultimate resolutions

International Nuclear Information System (INIS)

Kirchner, Friedrich Oscar

2013-01-01

Ultrafast electron diffraction is a powerful tool for studying structural dynamics with femtosecond temporal and sub-aangstroem spatial resolutions. It benefits from the high scattering cross-sections of electrons compared X-rays and allows the examination of thin samples, surfaces and gases. One of the main challenges in ultrafast electron diffraction is the generation of electron pulses with a short duration and a large transverse coherence. The former limits the temporal resolution of the experiment while the latter determines the maximum size of the scattering structures that can be studied. In this work, we strive to push the limits of electron diffraction towards higher temporal and spatial resolutions. The decisive step in our approach is to eliminate all detrimental effects caused by Coulomb repulsion between the electrons by reducing the number of electrons per pulse to one. In this situation, the electrons' longitudinal and transverse velocity distributions are determined solely by the photoemission process. By reducing the electron source size on the photocathode, we make use of the small transverse velocity spread to produce electron pulses with a transverse coherence length of 20 nm, which is about an order of magnitude larger than the reported values for comparable experiments. The energy distribution of an ensemble of single-electron pulses from a photoemission source is directly linked to the mismatch between the photon energy and the cathode's work function. This excess energy can be reduced by using a photon energy close to the material's work function. Using a tunable source of ultraviolet pulses, we demonstrate the reduction of the velocity spread of the electrons, resulting in a shorter duration of the electron pulses. The reduced electron pulse durations achieved by a tunable excitation or by other approaches require new characterization techniques for electron pulses. We developed a novel method for the characterization of electron pulses at

Megajoule-class single-pulse KrF laser test facility as a logical step toward inertial fusion commercialization

International Nuclear Information System (INIS)

Harris, D.B.; Pendergrass, J.H.

1985-01-01

The cost and efficiency of megajoule-class KrF laser single pulse test facilities have been examined. A baseline design is described which illuminates targets with 5 MJ with shaped 10-ns pulses. The system uses 24 main amplifiers and operates with an optics operating fluence of 4.0 J/cm 2 . This system has 9.0% efficiency and costs $200/joule. Tradeoff studies indicate that large amplifier modules and high fluences lead to the lowest laser system costs, but that only a 20% cost savings can be realized by going to amplifier modules larger than 200 kJ and/or fluences greater than 4 J/cm 2 . The role of the megajoule-class single-pulse test facility towards inertial fusion commercialization will also be discussed

Measurements of quadrupole magnets

International Nuclear Information System (INIS)

Conradie, J.L.; Fourie, D.T.; Cornell, J.C.; Lloyd, G.C.W.

1987-01-01

Measurements carried out on quadrupole magnets using a long asymmetric rotating coil are described. Although the method itself is fairly well-known, the introduction of microprocessors has made this once-tedious technique into a useful and simple method of evaluating quadrupole magnets. The rotating-coil device and a variety of coil sizes are now commercially available. The coil contains a large number of extremely fine wires, embedded in a carefully balanced fibre-glass rotor, resulting in a reasonable induced voltage when the coil is rotated. A digital harmonic analyser is then used to obtain the integrated multipole content of the waveform, while the coil is rotating. By integrating over time, one can average out random noise and increase the reliability and repeatability of the measurements. Because the harmonic analysis is done in real time, the method is quick, easy and accurate, and has been extended to locate the precise magnetic centre of the quadrupole magnet by adjusting its position relative to the coil axis so as to minimize the dipole content of the output waveform. Results of these measurements are compared with those obtained with an optical method using a suspension of magnetite. The observed light pattern is explained analytically. (author)

A single-probe heat pulse method for estimating sap velocity in trees.

Science.gov (United States)

López-Bernal, Álvaro; Testi, Luca; Villalobos, Francisco J

2017-10-01

Available sap flow methods are still far from being simple, cheap and reliable enough to be used beyond very specific research purposes. This study presents and tests a new single-probe heat pulse (SPHP) method for monitoring sap velocity in trees using a single-probe sensor, rather than the multi-probe arrangements used up to now. Based on the fundamental conduction-convection principles of heat transport in sapwood, convective velocity (V h ) is estimated from the temperature increase in the heater after the application of a heat pulse (ΔT). The method was validated against measurements performed with the compensation heat pulse (CHP) technique in field trees of six different species. To do so, a dedicated three-probe sensor capable of simultaneously applying both methods was produced and used. Experimental measurements in the six species showed an excellent agreement between SPHP and CHP outputs for moderate to high flow rates, confirming the applicability of the method. In relation to other sap flow methods, SPHP presents several significant advantages: it requires low power inputs, it uses technically simpler and potentially cheaper instrumentation, the physical damage to the tree is minimal and artefacts caused by incorrect probe spacing and alignment are removed. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Preliminary studies of the quickly pulsed synchrotron involved in the Beta-Beam project; Etudes preliminaires du synchrotron rapidement pulse du projet Beta-Beam

Energy Technology Data Exchange (ETDEWEB)

Lachaize, A

2007-07-01

This study presents a quickly-pulsed synchrotron able to accelerate He{sup 6} and Ne{sup 18} beams from 100 MeV/u till 3.5 GeV (proton equivalent) The accelerator is made up of 48 bending dipoles and 42 focusing quadrupoles. The design of the HF accelerating system, the bunch injection and the correction of errors in beam dynamics are dealt with.

Quantum computers based on electron spins controlled by ultrafast off-resonant single optical pulses.

Science.gov (United States)

Clark, Susan M; Fu, Kai-Mei C; Ladd, Thaddeus D; Yamamoto, Yoshihisa

2007-07-27

We describe a fast quantum computer based on optically controlled electron spins in charged quantum dots that are coupled to microcavities. This scheme uses broadband optical pulses to rotate electron spins and provide the clock signal to the system. Nonlocal two-qubit gates are performed by phase shifts induced by electron spins on laser pulses propagating along a shared waveguide. Numerical simulations of this scheme demonstrate high-fidelity single-qubit and two-qubit gates with operation times comparable to the inverse Zeeman frequency.

Scattering of electromagnetic pulses by metal nanospheres in the vicinity of a Fano-like resonance

International Nuclear Information System (INIS)

Astapenko, V.A.; Svita, S.Yu.

2015-01-01

In the work, radiation scattering by metal nanospheres in a dielectric matrix in case of ultrashort and long electromagnetic pulses is studied theoretically. Spectral efficiencies of backward and forward scattering by silver nanospheres in glass are calculated with the use of experimental data on the dielectric permittivity of silver. The presence of Fano-like resonances in spectral dependences of scattering efficiency caused by interference of dipole and quadrupole scatterings is shown. Backward and forward scattering of ultrashort pulses is calculated and analyzed. The obtained dependences of the total probability of scattering (during all time of the action of a pulse) on pulse duration demonstrate an essential distinction between an ultrashort case and a long pulse limit

Zeeman perturbed nuclear quadrupole spin echo envelope modulations for spin 3/2 nuclei in polycrystalline specimens

Science.gov (United States)

Ramachandran, R.; Narasimhan, P. T.

The results of theoretical and experimental studies of Zeeman-perturbed nuclear quadrupole spin echo envelope modulations (ZSEEM) for spin 3/2 nuclei in polycrystalline specimens are presented. The response of the Zeeman-perturbed spin ensemble to resonant two pulse excitations has been calculated using the density matrix formalism. The theoretical calculation assumes a parallel orientation of the external r.f. and static Zeeman fields and an arbitrary orientation of these fields to the principal axes system of the electric field gradient. A numerical powder averaging procedure has been adopted to simulate the response of the polycrystalline specimens. Using a coherent pulsed nuclear quadrupole resonance spectrometer the ZSEEM patterns of the 35Cl nuclei have been recorded in polycrystalline specimens of potassium chlorate, barium chlorate, mercuric chloride (two sites) and antimony trichloride (two sites) using the π/2-τ-π/2 sequence. The theoretical and experimental ZSEEM patterns have been compared. In the case of mercuric chloride, the experimental 35Cl ZSEEM patterns are found to be nearly identical for the two sites and correspond to a near-zero value of the asymmetry parameter, η, of the electric field gradient tensor. The difference in the η values for the two 35Cl sites (η ˜0·06 and η˜0·16) in antimony trichloride is clearly reflected in the experimental and theoretical ZSEEM patterns. The present study indicates the feasibility of evaluating η for spin 3/2 nuclei in polycrystalline specimens from ZSEEM investigations.

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

Directory of Open Access Journals (Sweden)

W. Lou

1998-06-01

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

Compact quadrupole triplet for the S-DALINAC polarized electron injector SPIN

Energy Technology Data Exchange (ETDEWEB)

Eckardt, C.; Eichhorn, R.; Enders, J.; Hessler, C.; Poltoratska, Y. [Inst. fuer Kernphysik, Technische Univ. Darmstadt (Germany); Ackermann, W.; Mueller, W.F.O.; Steiner, B.; Weiland, T. [Inst. fuer Theorie Elektromagnetischer Felder, Technische Univ. Darmstadt (Germany)

2007-07-01

An ultra compact quadrupole triplet for the S-DALINAC Polarized Electron Injector SPIN has been developed. This development is due to limiting spatial restrictions. Each individual quadrupole has a length of 8 mm, affixed by two 2 mm aluminum plates, resulting in a length of only 12 mm per quadrupole. The gaps between each quadrupole are set to 18 mm, therefore the complete triplet has a total length of only 72 mm. The quadrupole design includes a large aperture, suitable for CF 35 beam pipes. As fringe fields reach far info neighboring yokes, the assembly requires simulation by a beam dynamics tool for optimal weighting of the current excitation. Measurement of the magnetic field distribution is compared to numerical values and the quadrupole strength is calculated. (orig.)

Self-pulsing in a 2 km single-mode fiber with the seed source broadened via WNS phase modulation

Science.gov (United States)

Zha, Congwen; Sun, Yinhong; Wang, Yanshan; Li, Tenglong; Peng, Wanjing; Ma, Yi; Zhang, Kai

2018-03-01

The seed source with spectral linewidth broadening via phase modulation is potential to achieve the higher output power with effective SBS suppression. However, self-pulsing from the amplifier output is harmful. In this work, we study the self-pulsing characteristics in a long single-mode fiber with lower self-pulsing threshold instead of the high power amplifier. We provide a powerful experimental support for the self-pulsing mechanism in high-power narrow-linewidth fiber lasers, which is important for further output power scaling.

Development and manufacturing of a Nb$_{3}$Sn quadrupole magnet Model at CEA/Saclay for TESLA Interaction Region

CERN Document Server

Durante, Maria; Fratini, M; Leboeuf, D; Segreti, M; Védrine, Pierre; 10.1109/TASC.2004.829129

2004-01-01

One possible application of Nb/sub 3/Sn, whose superconducting properties far exceed those of NbTi, is the fabrication of short and powerful quadrupole magnets for the interaction regions of large particle accelerators. In some projects, as in the future linear collider TESLA, the quadrupole magnets are inside the detector solenoid and must operate in its background field. This situation gives singular Lorentz force distribution in the ends of the magnet. To learn about Nb/sub 3/Sn technology, evaluate fabrication techniques and test the interaction with a solenoidal field, DAPNIA /SACM at CEA/Saclay has started the manufacturing of a 1-m-long, 56- mm-single-aperture quadrupole magnet model. The model relies on the same coil geometry as the LHC arc quadrupole magnets, but has no iron yoke. It will produce a nominal field gradient of 211 T/m at 11,870 A. The coils are wound from Rutherford-type cables insulated with glass fiber tape, before being heat-treated and vacuum-impregnated with epoxy resin. Laminated,...

Two-pulse driving of D+D nuclear fusion within a single Coulomb exploding nanodroplet

International Nuclear Information System (INIS)

Last, Isidore; Jortner, Joshua; Peano, Fabio; Silva, Luis O.

2010-01-01

This paper presents a computational study of D+D fusion driven by Coulomb explosion (CE) within a single, homonuclear deuterium nanodroplet, subjected to double-pulse ultraintense laser irradiation. This irradiation scheme results in the attainment (by the first weaker pulse) of a transient inhomogeneous density profile, which serves as a target for the driving (by the second superintense pulse) of nonuniform CE that triggers overrun effects and induces intrananodroplet (INTRA) D+D fusion. Scaled electron and ion dynamics simulations were utilized to explore the INTRA D+D fusion yields for double-pulse, near-infrared laser irradiation of deuterium nanodroplets. The dependence of the INTRA yield on the nanodroplet size and on the parameters of the two laser pulses was determined, establishing the conditions for the prevalence of efficient INTRA fusion. The INTRA fusion yields are amenable to experimental observation within an assembly of nanodroplets. The INTRA D+D fusion can be distinguished from the concurrent internanodroplet D+D fusion reaction occurring in the macroscopic plasma filament and outside it in terms of the different energies of the neutrons produced in these two channels.

Self-phase modulation of a single-cycle terahertz pulse by nonlinear free-carrier response in a semiconductor

DEFF Research Database (Denmark)

Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias C.

2012-01-01

We investigate the self-phase modulation (SPM) of a single-cycle terahertz pulse in a semiconductor, using bulk n-GaAs as a model system. The SPM arises from the heating of free electrons in the electric field of the terahertz pulse, leading to an ultrafast reduction of the plasma frequency...

Nuclear quadrupole interaction measurements of 19F* and 22Na* on Graphite

International Nuclear Information System (INIS)

Djoko-Surono, Th; Martin, Peter W

1996-01-01

Time differential perturbed angular distribution (TDPAD) technique has been used to investigate nuclear quadrupole interactions of 19 F * and 22 Na * in graphite. We concentrated the measurements on pseudo single crystal graphite called Highly Oriented Pyrolytic Graphite for it has an ordered structure in which the c-axes of the microcrystals aligned in a certain direction with the mosaic spread less than 1 o , while the a- and b-axes randomly oriented on a plane perpendicular to the c-axes. Interactions between quadrupole moment of 19 F * and 22 Na * with its surroundings electric field gradient were studied by detecting the γ-rays distribution, W(Θ,t). For 1 9F * we found one static interaction. The corresponding electric field gradient was V zz =3.24(19)x10 22 V/m 2 . In the case of 22 Na * we found no evidence of nuclear quadrupole interaction, however, we were able to conclude that |QV 22 | 19 bV/m 2 . Using theoretical calculation Q=0.06 barn, we find that |V zz | 20 V/m 2 . These results indicate that the value efg depend on two factors, the host crystal and the core electrons. The core electrons contribution to the total efg is considerably large

Variable Permanent Magnet Quadrupole

International Nuclear Information System (INIS)

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

2007-01-01

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

Simultaneous, single-pulse, synchrotron x-ray imaging and diffraction under gas gun loading

Energy Technology Data Exchange (ETDEWEB)

Fan, D.; Luo, S. N., E-mail: sluo@pims.ac.cn [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Huang, J. W.; Zeng, X. L.; Li, Y.; E, J. C.; Huang, J. Y. [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); Sun, T.; Fezzaa, K. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Wang, Z. [Physics Division P-25, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2016-05-15

We develop a mini gas gun system for simultaneous, single-pulse, x-ray diffraction and imaging under high strain-rate loading at the beamline 32-ID of the Advanced Photon Source. In order to increase the reciprocal space covered by a small-area detector, a conventional target chamber is split into two chambers: a narrowed measurement chamber and a relief chamber. The gas gun impact is synchronized with synchrotron x-ray pulses and high-speed cameras. Depending on a camera’s capability, multiframe imaging and diffraction can be achieved. The proof-of-principle experiments are performed on single-crystal sapphire. The diffraction spots and images during impact are analyzed to quantify lattice deformation and fracture; fracture is dominated by splitting cracks followed by wing cracks, and diffraction peaks are broadened likely due to mosaic spread. Our results demonstrate the potential of such multiscale measurements for studying high strain-rate phenomena at dynamic extremes.

Electrostatic quadrupole array for focusing parallel beams of charged particles

International Nuclear Information System (INIS)

Brodowski, J.

1982-01-01

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

The giant quadrupole resonance in highly excited rotating nuclei

International Nuclear Information System (INIS)

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

1983-01-01

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

Electromagnetic design of superconducting quadrupoles

Directory of Open Access Journals (Sweden)

L. Rossi

2006-10-01

Full Text Available We study how the critical gradient depends on the coil layout in a superconducting quadrupole for particle accelerators. We show that the results relative to a simple sector coil are well representative of the coil layouts that have been used to build several quadrupoles in the past 30 years. Using a semianalytical approach, we derive a formula that gives the 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 layouts (shell, racetrack, block, open midplane.

Effect of dipole-quadrupole Robinson mode coupling upon the beam response to radio-frequency phase noise

Directory of Open Access Journals (Sweden)

R. A. Bosch

2006-09-01

Full Text Available In an electron storage ring, coupling between dipole and quadrupole Robinson oscillations modifies the spectrum of longitudinal beam oscillations driven by radio-frequency (rf generator phase noise. In addition to the main peak at the resonant frequency of the coupled dipole Robinson mode, another peak occurs at the resonant frequency of the coupled quadrupole mode. To describe these peaks analytically for a quadratic synchrotron potential, we include the dipole and quadrupole modes when calculating the beam response to generator noise. We thereby obtain the transfer function from generator-noise phase modulation to beam phase modulation with and without phase feedback. For Robinson-stable bunches confined in a synchrotron potential with a single minimum, the calculated transfer function agrees with measurements at the Aladdin 800-MeV electron storage ring. The transfer function is useful in evaluating phase feedback that suppresses Robinson oscillations in order to obtain quiet operation of an infrared beam line.

Secondary plasma formation after single pulse laser ablation underwater and its advantages for laser induced breakdown spectroscopy (LIBS).

Science.gov (United States)

Gavrilović, M R; Cvejić, M; Lazic, V; Jovićević, S

2016-06-07

In this work we present studies of spatial and temporal plasma evolution after single pulse ablation of an aluminium target in water. The laser ablation was performed using 20 ns long pulses emitted at 1064 nm. The plasma characterization was performed by fast photography, the Schlieren technique, shadowgraphy and optical emission spectroscopy. The experimental results indicate the existence of two distinct plasma stages: the first stage has a duration of approximately 500 ns from the laser pulse, and is followed by a new plasma growth starting from the crater center. The secondary plasma slowly evolves inside the growing vapor bubble, and its optical emission lasts over several tens of microseconds. Later, the hot glowing particles, trapped inside the vapor cavity, were detected during the whole cycle of the bubble, where the first collapse occurs after 475 μs from the laser pulse. Differences in the plasma properties during the two evolution phases are discussed, with an accent on the optical emission since its detection is of primary importance for LIBS. Here we demonstrate that the LIBS signal quality in single pulse excitation underwater can be greatly enhanced by detecting only the secondary plasma emission, and also by applying long acquisition gates (in the order of 10-100 μs). The presented results are of great importance for LIBS measurements inside a liquid environment, since they prove that a good analytical signal can be obtained by using nanosecond pulses from a single commercial laser source and by employing cost effective, not gated detectors.

Role of third-order dispersion in chirped Airy pulse propagation in single-mode fibers

Science.gov (United States)

Cai, Wangyang; Wang, Lei; Wen, Shuangchun

2018-04-01

The dynamic propagation of the initial chirped Airy pulse in single-mode fibers is studied numerically, special attention being paid to the role of the third-order dispersion (TOD). It is shown that for the positive TOD, the Airy pulse experiences inversion irrespective of the sign of initial chirp. The role of TOD in the dynamic propagation of the initial chirped Airy pulse depends on the combined sign of the group-velocity dispersion (GVD) and the initial chirp. If the GVD and chirp have the opposite signs, the chirped Airy pulse compresses first and passes through a breakdown area, then reconstructs a new Airy pattern with opposite acceleration, with the breakdown area becoming small and the main peak of the new Airy pattern becoming asymmetric with an oscillatory structure due to the positive TOD. If the GVD and chirp have the same signs, the finite-energy Airy pulse compresses to a focal point and then inverses its acceleration, in the case of positive TOD, the distance to the focal point becoming smaller. At zero-dispersion point, the finite-energy Airy pulse inverses to the opposite acceleration at a focal point, with the tight-focusing effect being reduced by initial chirp. Under the effect of negative TOD, the initial chirped Airy pulse disperses and the lobes split. In addition, in the anomalous dispersion region, for strong nonlinearity, the initial chirped Airy pulse splits and enters a soliton shedding regime.

A united phenomenological description of quadrupole excitations in even-even nuclei

International Nuclear Information System (INIS)

Lipas, P.O.; Haapakoski, P.; Honkaranta, T.

1975-05-01

A phenomenological model is developed for the collective quadrupole properties of all even-even nuclei. Rotational, vibrational, and transitional nuclei are included in the model on an equal footing. A Bohr-type intrinsic Hamiltonian for harmonic quadrupole vibrations about an axially deformed shape is solved exactly. States of good angular momentum are projected out of the intrinsic states, and they are made orthogonal by a Schmidt scheme. The angular-momentum and phonon-number composition of the states is analyzed at various stages; states with K=1 are found spurious. Excitation energies for the ground, β and γ bands are calculated as expectation values of a radically simplified nuclear Hamiltonian in our projected and orthogonalized states. With increasing deformation the calculated energies evolve smoothly from the evenly spaced phonon spectrum to the Bohr-Mottelson rotational-vibrational spectrum according to the scheme of Sheline and Sakai. The basic model contains only two parameters (deformation d and energy scale) to fix the entire quadrupole spectrum of a nucleus. The results are given in the form of graphs suitable for immediate application; numerical results are readily produced by our computer code. The ground bands are fitted comparably to the VMI model, while the β and γ bands are reproduced qualitatively. The nuclei 152 Sm, 152 Gd, and 114 Cd are used as test cases. Quadrupole moments and E2 transition rates are also calculated. Intra-ground-band transition ratios and branching ratios from the β and γ bands are given in terms of the single parameter d. The results are applied to 152 Sm, with fair success. Finally the model to include two more parameters (anisotropy) is extended. The improvement over the basic model is modest in view of added parameters and computational effort. (author)

Nuclear electric quadrupole interactions in liquids entrapped in cavities

Energy Technology Data Exchange (ETDEWEB)

Furman, Gregory B., E-mail: gregoryf@bgu.ac.il; Meerovich, Victor M.; Sokolovsky, Vladimir L. [Ben Gurion University of the Negev, Physics Department (Israel)

2016-12-15

Liquids entrapped in cavities and containing quadrupole nuclei are considered. The interaction of the quadrupole moment of a nucleus with the electric field gradient is studied. In such a system, molecules are in both rotational and translational Brownian motions which are described by the diffusion equation. Solving this equation, we show that the intra- and intermolecular nuclear quadrupole interactions are averaged to zero in cavities with the size larger than several angstroms.

Continuous single pulse resolved measurement of beam diameters at 200 kHz using optical transmission filters

Science.gov (United States)

Fruechtenicht, Johannes; Letsch, Andreas; Voss, Andreas; Abdou Ahmed, Marwan; Graf, Thomas

2012-02-01

We present a novel laser beam measurement setup which allows the determination of the beam diameter for each single pulse of a pulsed laser beam at repetition rates of up to 200 kHz. This is useful for online process-parameter control e.g. in micromachining or for laser source characterization. Basically, the developed instrument combines spatial transmission filters specially designed for instantaneous optical determination of the second order moments of the lateral intensity distribution of the light beam and photodiodes coupled to customized electronics. The acquisition is computer-based, enabling real-time operation for online monitoring or control. It also allows data storage for a later analysis and visualization of the measurement results. The single-pulse resolved beam diameter can be measured and recorded without any interruption for an unlimited number of pulses. It is only limited by the capacity of the data storage means. In our setup a standard PC and hard-disk provided 2 hours uninterrupted operation and recording of varying beam diameters at 200 kHz. This is about three orders of magnitude faster than other systems. To calibrate our device we performed experiments in cw and pulsed regimes and the obtained results were compared to those obtained with a commercial camera based system. Only minor deviations of the beam diameter values between the two instruments were observed, proving the reliability of our approach.

THE FORTUITOUS LATITUDE OF THE PIERRE AUGER OBSERVATORY AND TELESCOPE ARRAY FOR RECONSTRUCTING THE QUADRUPOLE MOMENT

International Nuclear Information System (INIS)

Denton, Peter B.; Weiler, Thomas J.

2015-01-01

Determining anisotropies in the arrival directions of cosmic rays at the highest energy is an important task in astrophysics. It is common and useful to partition the sky into spherical harmonics as a measure of anisotropy. The two lowest nontrivial spherical harmonics, the dipole and the quadrupole, are of particular interest, since these distributions encapsulate a dominant single source and a plane of sources, as well as offering relatively high statistics. The best experiments for the detection of ultra high energy cosmic rays currently are all ground-based, with highly nonuniform exposures on the sky resulting from the fixed experimental locations on the Earth. This nonuniform exposure increases the complexity and error in inferring anisotropies. It turns out that there is an optimal latitude for an experiment at which nonuniform exposure does not diminish the inference of the quadrupole moment. We derive the optimal latitude and find that (presumably by a fortuitous coincidence) this optimal latitude runs through the largest cosmic ray experiment, the Pierre Auger Observatory (PAO) in the Southern Hemisphere, and close to the largest cosmic ray experiment in the Northern Hemisphere, the Telescope Array (TA). Consequently, assuming a quadrupole distribution, PAO and TA can reconstruct the cosmic ray quadrupole distribution to a high precision without concern for their partial sky exposure

PRINCIPLE OF SKEW QUADRUPOLE MODULATION TO MEASURE BETATRON COUPLING

International Nuclear Information System (INIS)

LUO, Y.; PILAT, F.; ROSER, T.

2004-01-01

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

Partial Shading Detection in Solar System Using Single Short Pulse of Load

Directory of Open Access Journals (Sweden)

Bartczak Mateusz

2017-03-01

Full Text Available A single photovoltaic panel under uniform illumination has only one global maximum power point, but the same panel in irregularly illuminated conditions can have more maxima on its power-voltage curve. The irregularly illuminated conditions in most cases are results of partial shading. In the work a single short pulse of load is used to extract information about partial shading. This information can be useful and can help to make some improvements in existing MPPT algorithms. In the paper the intrinsic capacitance of a photovoltaic system is used to retrieve occurrence of partial shading.

Monolithic Ytterbium All-single-mode Fiber Laser with Direct Fiber-end Delivery of nJ-level Femtosecond Pulses

DEFF Research Database (Denmark)

Turchinovich, Dmitry

2008-01-01

We demonstrate a monolithic, i.e. without any free-space coupling, all-single-mode passively modelocked Yb-fiber laser, with direct fiber-end delivery of 364−405 fs pulses of 4 nJ pulse energy using a low-loss hollow-core photonic crystal fiber compression....

SKEW QUADRUPOLE FOCUSING LATTICES AND APPLICATIONS

International Nuclear Information System (INIS)

Parker, B.

2001-01-01

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

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

International Nuclear Information System (INIS)

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

Integrated single grating compressor for variable pulse front tilt in simultaneously spatially and temporally focused systems.

Science.gov (United States)

Block, Erica; Thomas, Jens; Durfee, Charles; Squier, Jeff

2014-12-15

A Ti:Al(3)O(2) multipass chirped pulse amplification system is outfitted with a single-grating, simultaneous spatial and temporal focusing (SSTF) compressor platform. For the first time, this novel design has the ability to easily vary the beam aspect ratio of an SSTF beam, and thus the degree of pulse-front tilt at focus, while maintaining a net zero-dispersion system. Accessible variation of pulse front tilt gives full spatiotemporal control over the intensity distribution at the focus and could lead to better understanding of effects such as nonreciprocal writing and SSTF-material interactions.

Beam-based alignment of C-shaped quadrupole magnets

International Nuclear Information System (INIS)

Portmann, G.; Robin, D.

1998-06-01

Many storage rings have implemented a method of finding the positional offset between the electrical center of the beam position monitors (BPM) and the magnetic center of the adjacent quadrupole magnets. The algorithm for accomplishing this is usually based on modulating the current in the quadrupole magnet and finding the beam position that minimizes the orbit perturbation. When the quadrupole magnet is C-shaped, as it is for many light sources, the modulation method can produce an erroneous measurement of the magnetic center in the horizontal plane. When the current in a C-shaped quadrupole is changed, there is an additional dipole component in the vertical field. Due to nonlinearities in the hysteresis cycle of the C-magnet geometry, the beam-based alignment technique at the Advanced Light Source (ALS) deviated horizontally by .5 mm from the actual magnetic center. By modifying the technique, the offsets were measured to an accuracy of better than 50 microm

Full 3D modelling of pulse propagation enables efficient nonlinear frequency conversion with low energy laser pulses in a single-element tripler

Science.gov (United States)

Kardaś, Tomasz M.; Nejbauer, Michał; Wnuk, Paweł; Resan, Bojan; Radzewicz, Czesław; Wasylczyk, Piotr

2017-02-01

Although new optical materials continue to open up access to more and more wavelength bands where femtosecond laser pulses can be generated, light frequency conversion techniques are still indispensable in filling the gaps on the ultrafast spectral scale. With high repetition rate, low pulse energy laser sources (oscillators) tight focusing is necessary for a robust wave mixing and the efficiency of broadband nonlinear conversion is limited by diffraction as well as spatial and temporal walk-off. Here we demonstrate a miniature third harmonic generator (tripler) with conversion efficiency exceeding 30%, producing 246 fs UV pulses via cascaded second order processes within a single laser beam focus. Designing this highly efficient and ultra compact frequency converter was made possible by full 3-dimentional modelling of propagation of tightly focused, broadband light fields in nonlinear and birefringent media.

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

Science.gov (United States)

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

2014-08-22

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

Nuclei quadrupole coupling constants in diatomic molecule

International Nuclear Information System (INIS)

Ivanov, A.I.; Rebane, T.K.

1993-01-01

An approximate relationship between the constants of quadrupole interaction of nuclei in a two-atom molecule is found. It enabled to establish proportionality of oscillatory-rotation corrections to these constants for both nuclei in the molecule. Similar results were obtained for the factors of electrical dipole-quadrupole screening of nuclei. Applicability of these relationships is proven by the example of lithium deuteride molecule. 4 refs., 1 tab

Intense ion beam transport in magnetic quadrupoles: Experiments on electron and gas effects

International Nuclear Information System (INIS)

Seidl, P.A.; Molvik, A.W.; Bieniosek, F.M.; Cohen, R.H.; Faltens, A.; Friedman, A.; Kireef Covo, M.; Lund, S.M.; Prost, L.; Vay, J-L.

2004-01-01

Heavy-ion induction linacs for inertial fusion energy and high-energy density physics have an economic incentive to minimize the clearance between the beam edge and the aperture wall. This increases the risk from electron clouds and gas desorbed from walls. We have measured electron and gas emission from 1 MeV K + incident on surfaces near grazing incidence on the High-Current Experiment (HCX) at LBNL. Electron emission coefficients reach values >100, whereas gas desorption coefficients are near 10 4 . Mitigation techniques are being studied: A bead-blasted rough surface reduces electron emission by a factor of 10 and gas desorption by a factor of 2. We also discuss the results of beam transport (of 0.03-0.18 A K + ) through four pulsed room-temperature magnetic quadrupoles in the HCX at LBNL. Diagnostics are installed on HCX, between and within quadrupole magnets, to measure the beam halo loss, net charge and expelled ions, from which we infer gas density, electron trapping, and the effects of mitigation techniques. A coordinated theory and computational effort has made significant progress towards a self-consistent model of positive-ion beam and electron dynamics. We are beginning to compare experimental and theoretical results

Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials.

Science.gov (United States)

Maxwell, Adam D; Cain, Charles A; Hall, Timothy L; Fowlkes, J Brian; Xu, Zhen

2013-03-01

In this study, the negative pressure values at which inertial cavitation consistently occurs in response to a single, two-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (P(cav)) for a single pulse as a function of peak negative pressure (p(-)) followed a sigmoid curve, with the probability approaching one when the pressure amplitude was sufficient. The statistical threshold (defined as P(cav) = 0.5) was between p(-) = 26 and 30 MPa in all samples with high water content but varied between p(-) = 13.7 and >36 MPa in other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p(-) = 28.2 megapascals was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at various pressure levels and dimensions of cavitation-induced lesions in tissue. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Real-time monitoring of Lévy flights in a single quantum system

Science.gov (United States)

Issler, M.; Höller, J.; Imamoǧlu, A.

2016-02-01

Lévy flights are random walks where the dynamics is dominated by rare events. Even though they have been studied in vastly different physical systems, their observation in a single quantum system has remained elusive. Here we analyze a periodically driven open central spin system and demonstrate theoretically that the dynamics of the spin environment exhibits Lévy flights. For the particular realization in a single-electron charged quantum dot driven by periodic resonant laser pulses, we use Monte Carlo simulations to confirm that the long waiting times between successive nuclear spin-flip events are governed by a power-law distribution; the corresponding exponent η =-3 /2 can be directly measured in real time by observing the waiting time distribution of successive photon emission events. Remarkably, the dominant intrinsic limitation of the scheme arising from nuclear quadrupole coupling can be minimized by adjusting the magnetic field or by implementing spin echo.

Variable-field permanent-magnet quadrupole for the SSC

International Nuclear Information System (INIS)

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

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. 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

Variable-field permanent magnet quadrupole for the SSC

International Nuclear Information System (INIS)

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

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. 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

Dual-Pulse Pulse Position Modulation (DPPM) for Deep-Space Optical Communications: Performance and Practicality Analysis

Science.gov (United States)

Li, Jing; Hylton, Alan; Budinger, James; Nappier, Jennifer; Downey, Joseph; Raible, Daniel

2012-01-01

Due to its simplicity and robustness against wavefront distortion, pulse position modulation (PPM) with photon counting detector has been seriously considered for long-haul optical wireless systems. This paper evaluates the dual-pulse case and compares it with the conventional single-pulse case. Analytical expressions for symbol error rate and bit error rate are first derived and numerically evaluated, for the strong, negative-exponential turbulent atmosphere; and bandwidth efficiency and throughput are subsequently assessed. It is shown that, under a set of practical constraints including pulse width and pulse repetition frequency (PRF), dual-pulse PPM enables a better channel utilization and hence a higher throughput than it single-pulse counterpart. This result is new and different from the previous idealistic studies that showed multi-pulse PPM provided no essential information-theoretic gains than single-pulse PPM.

Field measurement of a Fermilab-built full scale prototype quadrupole magnet for the LHC interaction regions

CERN Document Server

Bossert, R; Di Marco, J; Fehér, S; Glass, H; Kerby, J S; Lamm, M J; Nobrega, A; Nicol, T H; Ogitsu, T; Orris, D; Page, T; Rabehl, Roger Jon; Sabbi, G L; Schlabach, P; Strait, J B; Sylvester, C D; Tartaglia, M; Tompkins, J C; Velev, G V; Zlobin, A V

2002-01-01

Superconducting low-beta quadrupole magnets for the interaction regions of the Large Hadron Collider have been developed by the US- LHC Accelerator Project. These 70 mm bore 5.5 m long quadrupoles are intended to operate in superfluid helium at 1.9 K with a nominal field gradient of 215 T/m. Following a series of 2 m long models, a full scale cryostated cold mass has been fabricated and cold tested at Fermilab. Magnetic field measurements of the prototype, including determination of the field axis using a single stretched wire, have been performed. These measurements and comparisons with results from the model magnets as well as field quality and alignment requirements are reported in this paper. (8 refs).

ISR Superconducting Quadrupoles

CERN Multimedia

1977-01-01

Michel Bouvier is preparing for curing the 6-pole superconducting windings inbedded in the cylindrical wall separating liquid helium from vacuum in the quadrupole aperture. The heat for curing the epoxy glue was provided by a ramp of infrared lamps which can be seen above the slowly rotating cylinder. See also 7703512X, 7702690X.

Multishot versus single-shot pulse sequences in very high field fMRI: a comparison using retinotopic mapping.

Directory of Open Access Journals (Sweden)

Jascha D Swisher

Full Text Available High-resolution functional MRI is a leading application for very high field (7 Tesla human MR imaging. Though higher field strengths promise improvements in signal-to-noise ratios (SNR and BOLD contrast relative to fMRI at 3 Tesla, these benefits may be partially offset by accompanying increases in geometric distortion and other off-resonance effects. Such effects may be especially pronounced with the single-shot EPI pulse sequences typically used for fMRI at standard field strengths. As an alternative, one might consider multishot pulse sequences, which may lead to somewhat lower temporal SNR than standard EPI, but which are also often substantially less susceptible to off-resonance effects. Here we consider retinotopic mapping of human visual cortex as a practical test case by which to compare examples of these sequence types for high-resolution fMRI at 7 Tesla. We performed polar angle retinotopic mapping at each of 3 isotropic resolutions (2.0, 1.7, and 1.1 mm using both accelerated single-shot 2D EPI and accelerated multishot 3D gradient-echo pulse sequences. We found that single-shot EPI indeed led to greater temporal SNR and contrast-to-noise ratios (CNR than the multishot sequences. However, additional distortion correction in postprocessing was required in order to fully realize these advantages, particularly at higher resolutions. The retinotopic maps produced by both sequence types were qualitatively comparable, and showed equivalent test/retest reliability. Thus, when surface-based analyses are planned, or in other circumstances where geometric distortion is of particular concern, multishot pulse sequences could provide a viable alternative to single-shot EPI.

Optical design and studies of a tiled single grating pulse compressor for enhanced parametric space and compensation of tiling errors

Science.gov (United States)

Daiya, D.; Patidar, R. K.; Sharma, J.; Joshi, A. S.; Naik, P. A.; Gupta, P. D.

2017-04-01

A new optical design of tiled single grating pulse compressor has been proposed, set-up and studied. The parametric space, i.e. the laser beam diameters that can be accommodated in the pulse compressor for the given range of compression lengths, has been calculated and shown to have up to two fold enhancement in comparison to our earlier proposed optical designs. The new optical design of the tiled single grating pulse compressor has an additional advantage of self compensation of various tiling errors like longitudinal and lateral piston, tip and groove density mismatch, compared to the earlier designs. Experiments have been carried out for temporal compression of 650 ps positively chirped laser pulses, at central wavelength 1054 nm, down to 235 fs in the tiled grating pulse compressor set up with the proposed design. Further, far field studies have been performed to show the desired compensation of the tiling errors takes place in the new compressor.

Initial value gravitational quadrupole radiation theorem

International Nuclear Information System (INIS)

Winicour, J.

1987-01-01

A rigorous version of the quadrupole radiation formula is derived using the characteristic initial value formulation of a general relativistic fluid space-time. Starting from initial data for a Newtonian fluid, an algorithm is presented that determines characteristic initial data for a one-parameter family of general relativistic fluid space-times. At the initial time, a one-parameter family of space-times with this initial data osculates the evolution of the Newtonian fluid and has leading order news function equal to the third time derivative of the transverse Newtonian quadrupole moment

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

Science.gov (United States)

Fan, Non Q.; Clarke, John

1993-01-01

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

Theoretical investigation of flute modes in a magnetic quadrupole

International Nuclear Information System (INIS)

Wu, H.S.

1988-01-01

This research developed theories and conducted numerical investigations of electrostatic flute modes in a plasma confined in a magnetic quadrupole. Chapter I presents the discussion of relevant background. Chapter II contains a brief discussion of the basic flute-mode operator L 0 for intermediate- and low-frequency regimes. Chapter III develops a simple theory for a flute mode with frequency between the electron and ion bounce frequencies in the uniform density and temperature regions of a magnetic quadrupole. The frequency is predicted to be inversely proportional to the wave number. Chapter IV describes the kinetic approach. Chapter V contains the derivation of an eigenvalue equation for electrostatic waves with frequencies below the ion frequency in the private flux region of a magnetic quadrupole. Chapter VI develops a theory for electrostatic waves with frequency below the ion bounce frequency in the shared flux region of a magnetic quadrupole. Chapter VII contains the derivation of a dispersion equation for flute modes with frequencies between the electron and ion bounce frequencies in a plasma confined to a magnetic quadrupole. Chapter VIII presents a summary of the research described

Status of the quadrupoles for RHIC [Relativistic Heavy Ion Collider

International Nuclear Information System (INIS)

Thompson, P.A.; Cottingham, J.G.; Garber, M.

1989-01-01

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

Field quality of the LHC inner triplet quadrupoles being fabricated at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Gueorgui V. Velev et al.

2003-06-02

Fermilab, as part of the US-LHC Accelerator Project, has designed and is producing superconducting low-beta quadrupole magnets for the Large Hadron Collider (LHC). These 70 mm bore, 5.5 m long magnets operate in superfluid helium at 1.9 K with a maximum operating gradient of 214 T/m. Two quadrupoles, combined with a dipole orbit corrector, form a single LQXB cryogenic assembly, the Q2 optical element of the final focus triplets in the LHC interaction regions. Field quality was measured at room temperature during fabrication of the cold masses as well as at superfluid helium temperature in two thermal cycles for the first LQXB cryogenic assembly. Integral cold measurements were made with a 7.1 m long rotating coil and with a 0.8 m long rotating coil at 8 axial positions and in a range of currents. In addition to the magnetic measurements, this paper reports on the quench performance of the cold masses and on the measurements of their internal alignment.

Collisional damping of giant monopole and quadrupole resonances

International Nuclear Information System (INIS)

Yildirim, S.; Gokalp, A.; Yilmaz, O.; Ayik, S.

2001-01-01

Collisional damping widths of giant monopole and quadrupole excitations for 120 Sn and 208 Pb at zero and finite temperatures are calculated within Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological Skyrme and Gogny forces, and are compared with each other. The results for the collisional widths of giant monopole and quadrupole vibrations at zero temperature as a function of the mass number show that the collisional damping of giant monopole vibrations accounts for about 30 - 40% of the observed widths at zero temperature, while for giant quadrupole vibrations it accounts for only 20 - 30% of the observed widths at zero temperature. (orig.)

Nuclear quadrupole resonance applied for arsenic oxide study; Estudo do oxido de arsenio atraves de ressonancia quadrupolar nuclear

Energy Technology Data Exchange (ETDEWEB)

Correia, J A.S.

1991-04-01

The objectives of this study are mounting a pulsed Nuclear Quadrupole Resonance (NQR) building a flow cryostat capable of varying the temperature continuously from 77 K to 340 K and using the spectrometer and the cryostat to study the polycrystalline arsenic oxide. The spin-lattice relaxation time (T{sub 1}), the spin-spin relaxation time (T{sub 2}) and the resonance frequency are obtained as a function of temperature. These data are obtained in 77 to 330 K interval. The relaxation times are obtained using the spin echo technique. The spin echo phenomenon is due to refocusing spins, when a 180{sup 0} C pulse is applied after a 90{sup 0} C pulse. The spin-lattice relaxation time is obtained using the plot of echo amplitude versus the repetition time. The spin-spin relaxation time is obtained using the plot of echo amplitude versus the separation between the 90{sup 0} C - 180{sup 0} C pulses. The theory developed by Bayer is used to explain the spin-lattice relaxation time and the frequency temperature dependence. The spin-spin relaxation time is discussed using the Bloch equations. (author).

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

Science.gov (United States)

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 ( ωQ = 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.

Feedback stabilization system for pulsed single longitudinal mode tunable lasers

Science.gov (United States)

Esherick, Peter; Raymond, Thomas D.

1991-10-01

A feedback stabilization system for pulse single longitudinal mode tunable lasers having an excited laser medium contained within an adjustable length cavity and producing a laser beam through the use of an internal dispersive element, including detection of angular deviation in the output laser beam resulting from detuning between the cavity mode frequency and the passband of the internal dispersive element, and generating an error signal based thereon. The error signal can be integrated and amplified and then applied as a correcting signal to a piezoelectric transducer mounted on a mirror of the laser cavity for controlling the cavity length.

Self-pulsing and chaos in inhomogeneously broadened single mode lasers

Energy Technology Data Exchange (ETDEWEB)

Graham, R; Cho, Y

1983-08-01

A four-dimensional model and a six-dimensional model describing the self-pulsing instabilities and chaotic dynamics of inhomogeneously broadened single-mode lasers are derived as the first two steps of an infinite hierarchy of approximations increasing in accuracy and complexity. The results of a linear stability analysis of the time-independent states and some numerical solutions are given to show the various types of dynamic behavior which can occur in these models. The dynamic behavior is found to be much more complex than in the homogeneously broadened case and is obtained under physically more realistic conditions. 10 references.

Fifth-order aberrations in magnetic quadrupole-octupole systems

International Nuclear Information System (INIS)

Ling, K.M.

1990-01-01

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

Searching for Single Pulses Using Heimdall

Science.gov (United States)

Walsh, Gregory; Lynch, Ryan

2018-01-01

In radio pulsar surveys, the interstellar medium causes a frequency dependent dispersive delay of a pulsed signal across the observing band. If not corrected, this delay substantially lowers S/N and makes most pulses undetectable. The delay is proportional to an unknown dispersion measure (DM), which must be searched over with many trial values. A number of new, GPU-accelerated codes are now available to optimize this dedispersion task, and to search for transient pulsed radio emission. We report on the use of Heimdall, one such GPU-accelerated tree dedispersion utility, to search for transient radio sources in a Green Bank Telescope survey of the Cygnus Region and North Galactic Plane. The survey is carried out at central frequency of 820 MHz with a goal of finding Fast Radio Bursts, Rotating Radio Transients, young pulsars, and millisecond pulsars. We describe the the survey, data processing pipeline, and follow-up of candidate sources.

Generating Efficient Femtosecond Mid-infrared Pulse by Single Near-infrared Pump Wavelength in Bulk Nonlinear Crystal Without Phase-matching

DEFF Research Database (Denmark)

Zhou, Binbin; Guo, Hairun; Bache, Morten

2014-01-01

We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8-2.92 μm are generated using the single pump wavelengths from 1.25-1.45 μm. © 2014 Optical Society of America...

Implementation of $ab$ $initio$ perturbed angular correlation observables for analysis of fluctuating quadrupole interactions

CERN Document Server

Barbosa, Marcelo

A review about the nuclear properties, namely the nuclear moments (magnetic dipole moment and electric quadrupole moment) and their interaction with electromagnetic fields external to the nucleus (hyperfine interactions), as well as the angular distribution of radiation produced by $\\gamma$-decay, is presented. A detailed description about the theory of Perturbed Angular Correlations was done, including the comparison between $\\gamma-\\gamma$- correlations and $e^{-}- \\gamma$ correlations. For dynamic nuclear interactions, an introduction to the theory of stochastic states in PAC was performed. We focused on ab-initio implementation of observables for analyzing fluctuating quadrupole hyperfine interactions on time dependent perturbed angular correlations experiments. The development of computacional codes solving the full problem, adapted to fit data obtained on single crystals or polycrystals for two-state transient fields with any axial symmetry and orientation was the main purpose of this work. The final pa...

Numerical calculation of spin echo amplitude in pulsed NMR: effects of quadrupole interaction

International Nuclear Information System (INIS)

Sobral, R.R.

1986-01-01

The spin echo obtained by nuclear magnetic resonance, in systems which atomic nuclei interact with magnetic fields and electric field gradients, present oscillations in function of the time interval between two excitations pulses. Using the density matrix formalism, the amplitudes of these echo is calculated, analytically. In this work, echo amplitudes obtained under different excitation conditions for nuclei of different nuclear spin values are calculated. The numerical results are compared with disposable analytical solutions. Applications of this method to the case of electric field gradient without axial symmetry were studied. Within the used approximation limits, an expression for attnuation of oscillatory behaviour of echo amplitude in function of the time interval between experimentally observed pulses was obtained. (M.C.K.) [pt

ISR "Terwilliger" Quadrupole

CERN Multimedia

1983-01-01

There were 48 of these Quadrupoles in the ISR. They were distributed around the rings according to the so-called Terwilliger scheme. Their aperture was 184 mm, their core length 300 mm, their gradient 5 T/m. Due to their small length as compared to the aperture, the end fringe field errors had to be compensated by suitably shaping the poles.

Global study of quadrupole correlation effects

International Nuclear Information System (INIS)

Bender, M.; Bertsch, G.F.; Heenen, P.-H.

2006-01-01

We discuss the systematics of ground-state quadrupole correlations of binding energies and mean-square charge radii for all even-even nuclei, from 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

Single-treatment skin tightening by radiofrequency and long-pulsed, 1064-nm Nd: YAG laser compared.

Science.gov (United States)

Key, Douglas J

2007-02-01

To compare single-treatment facial skin tightening achieved with the current radiofrequency (RF) protocol with single-treatment tightening achieved with the long-pulsed, 1064-nm Nd:YAG laser. A total of 12 patients were treated with RF energy on one side of the face and laser energy on the other. Results were evaluated on a numerical scale (0-12 with 12 = greatest enhancement) from pre- and posttreatment photographs by a blinded panel. Upper face improvement (posttreatment score minus pretreatment score) was essentially the same on both sides (30.2 and 31.3% improvement for laser and RF, respectively, P=0.89). Lower face improvement was greater in the laser-treated side (35.7 and 23.8% improvement for laser and RF, respectively), but the difference was not significant (P=0.074). Overall face improvement was significantly greater on the laser-treated side (47.5 and 29.8% improvement for laser and RF, respectively, P=0.028). A single high-fluence treatment with the long-pulse 1064-nm Nd:YAG laser may improve skin laxity more than a single treatment with the RF device. Further controlled split-face or very large non-self controlled studies are needed to conclusively determine the relative efficacies of the two technologies. (c) 2007 Wiley-Liss, Inc.

Design and construction of a large aperture, quadrupole electromagnet prototype for ILSE

International Nuclear Information System (INIS)

Stuart, M.; Faltens, A.; Fawley, W.M.; Peters, C.; Vella, M.C.

1995-04-01

We are currently constructing a prototype quadrupole electromagnet for the proposed Induction Linac Systems Experiment (ILSE) at LBL. ILSE will address many physi and engineering issues relevant to the design of a heavy-ion fusion driver accelerator. The pulsed electromagnet has two layers of current windings and will produce a field gradient exceeding 25 T/m at a repetition rate of 1 Hz steady-state. In this paper, we discuss how the interaction of various concerns such as maximum dynamic aperture, short lattice period, field quality, iron yoke weight, heat transfer, and voltage standoff have led to our particular design choices. We also present 2- and 3-D numerical calculations concerning field topography and the results of transport simulations of space-charge dominated ion beams with ILSE parameters

The effect of the shape of single, sub-ms voltage pulses on the rates of surface immobilization and hybridization of DNA

International Nuclear Information System (INIS)

Cabeca, R; Rodrigues, M; Chu, V; Conde, J P; Prazeres, D M F

2009-01-01

Electric fields generated by single square and sinusoidal voltage pulses with amplitudes below 2 V were used to assist the covalent immobilization of single-stranded, thiolated DNA probes, onto a chemically functionalized SiO 2 surface and to assist the specific hybridization of single-stranded DNA targets with immobilized complementary probes. The single-stranded immobilized DNA probes were either covalently immobilized (chemisorption) or electrostatically adsorbed (physisorption) to a chemically functionalized surface. Comparing the speed of electric field assisted immobilization and hybridization with the corresponding control reactions (without electric field), an increase of several orders of magnitude is observed, with the reaction timescaled down from 1 to 2 h to a range between 100 ns and 1 ms. The influence of the shape of the voltage pulse (square versus sinusoidal) and its duration were studied for both immobilization and hybridization reactions. The results show that pulsed electric fields are a useful tool to achieve temporal and spatial control of surface immobilization and hybridization reactions of DNA.

An injection seeded single frequency Nd:YAG Q-switched laser with precisely controllable laser pulse firing time

Science.gov (United States)

Wu, Frank F.; Khizhnyak, Anatoliy; Markov, Vladimir

2010-02-01

We have realized a single frequency Q-switched Nd:YAG laser with precisely controllable lasing time and thus enabled synchronization of multi-laser systems. The use of injection seeding to the slave ring oscillator results in unidirectional Q-switched laser oscillation with suppression of bidirectional Q-switched oscillation that otherwise would be initiated from spontaneous emission if the seeding laser is not present. Under normal condition, the cavity is high in loss during the pumping period; then a Pockels cell opens the cavity to form the pulse build up, with a second Pockels cell to perform cavity dumping, generating the Q-switched pulse output with optimized characteristics. The two Pockels cells can be replaced by a single unit if an adjustable gated electrical pulse is applied to the Pockels cell in which the pulse front is used to open the cavity and the falling edge to dump the laser pulse. Proper selection of the pump parameters and Pockels-cell gating enables operation of the system in a mode in which the Q-switched pulse can be formed only under the seeding condition. The advantage of the realized regime is in stable laser operation with no need in adjustment of the seeded light wavelength and the mode of the cavity. It is found that the frequency of the Q-switched laser radiation matches well to the injected seeded laser mode. By using two-stage amplifiers, an output energy better than 300 mJ has been achieved in MOPA configuration without active control of the cavity length and with pulse width adjustability from several nanoseconds to 20 ns. The Q-switched oscillator operates not only at precisely controlled firing time but also can be tuned over wide range. This will enable multi-laser systems synchronization and frequency locking down each other if necessary.

Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

Science.gov (United States)

Hofmann, Ingo

2013-04-01

Using laser accelerated protons or ions for various applications—for example in particle therapy or short-pulse radiographic diagnostics—requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in focusing capability, if parameters are such that the solenoid length approximately equals its diameter. The scaling also shows that this is usually not the case above a few MeV; consequently, a solenoid needs to be pulsed or superconducting, whereas the quadrupoles can remain conventional. It is also important that the transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al. [Phys. Rev. Lett. 103, 135001 (2009PRLTAO0031-900710.1103/PhysRevLett.103.135001].

Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

Directory of Open Access Journals (Sweden)

Ingo Hofmann

2013-04-01

Full Text Available Using laser accelerated protons or ions for various applications—for example in particle therapy or short-pulse radiographic diagnostics—requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in focusing capability, if parameters are such that the solenoid length approximately equals its diameter. The scaling also shows that this is usually not the case above a few MeV; consequently, a solenoid needs to be pulsed or superconducting, whereas the quadrupoles can remain conventional. It is also important that the transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al. [Phys. Rev. Lett. 103, 135001 (2009PRLTAO0031-900710.1103/PhysRevLett.103.135001].

Semimicroscopic description of the giant quadrupole resonances in deformed nuclei

International Nuclear Information System (INIS)

Kurchev, G.; Malov, L.A.; Nesterenko, V.O.; Soloviev, V.G.

1976-01-01

The calculation results of the giant quadrupole isoscalar and isovector resonances performed within the random phase approximation are represented. The strength functions for E2-transitions are calculated for doubly even deformed nuclei in the regions 150 (<=) A < 190 and 228 (<=) A < 248 in the energy interval (0-40) MeV. The following integral characteristics of giant quadrupole resonances are obtained: the position, widths, the contribution to the energy weighted sum rule and the contribution to the total cross section of photoabsorption. The calculations have shown that giant quadrupole resonances are common for all the considered nuclei. The calculated characteristics of the isoscalar giant quadrupole resonance agree with the available experimental data. The calculations also show that the semimicroscopic theory can be successfully applied for the description of giant multipole resonances

Kinetic energy in the collective quadrupole Hamiltonian from the experimental data

Energy Technology Data Exchange (ETDEWEB)

Jolos, R.V., E-mail: jolos@theor.jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Dubna State University, 141980 Dubna (Russian Federation); Kolganova, E.A. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Dubna State University, 141980 Dubna (Russian Federation)

2017-06-10

Dependence of the kinetic energy term of the collective nuclear Hamiltonian on collective momentum is considered. It is shown that the fourth order in collective momentum term of the collective quadrupole Hamiltonian generates a sizable effect on the excitation energies and the matrix elements of the quadrupole moment operator. It is demonstrated that the results of calculation are sensitive to the values of some matrix elements of the quadrupole moment. It stresses the importance for a concrete nucleus to have the experimental data for the reduced matrix elements of the quadrupole moment operator taken between all low lying states with the angular momenta not exceeding 4.

Quadrupole magnets for IR-FEL at RRCAT

International Nuclear Information System (INIS)

Ruwali, Kailash; Singh, Kushraj; Mishra, Anil Kumar; Biswas, Bhaskar

2013-01-01

The IR-FEL project at RRCAT needs quadrupole magnets for focusing 15 to 35 MeV electron beam through a dog-leg type beam line. This bend needs tighter relative tolerances on the central quadrupole triplet . The magnetic design, fabrication and magnetic characterization of five quadrupole magnets were carried out. The poles are detachable and wider than the coils. This significantly improves the good field region of the magnet. The magnet cross-section was optimized using 2D POISON code and entry-exit tapers were optimized using 3D code TOSCA.. The aperture radius of the magnet is 30 mm and the total core length is 180 mm. The integrated gradient of magnet is 0.51 T. The magnetic measurements were carried out using Danfysik make rotating coil bench model 690. Integrated gradient and multipoles present in the magnet aperture were measured at various excitation levels. The details of magnetic development and the magnetic measurements are discussed in this paper. (author)

Cavity QED with single trapped Ca+-ions

International Nuclear Information System (INIS)

Mundt, A.B.

2003-02-01

This thesis reports on the design and setup of a vacuum apparatus allowing the investigation of cavity QED effects with single trapped 40 Ca + ions. The weak coupling of ion and cavity in the 'bad cavity limit' may serve to inter--convert stationary and flying qubits. The ion is confined in a miniaturized Paul trap and cooled via the Doppler effect to the Lamb--Dicke regime. The extent of the atomic wave function is less than 30 nm. The ion is enclosed by a high finesse optical cavity. The technically--involved apparatus allows movement of the trap relative to the cavity and the trapped ion can be placed at any position in the standing wave. By means of a transfer lock the cavity can be resonantly stabilized with the S 1/2 ↔ D 5/2 quadrupole transition at 729 nm (suitable as a qubit) without light at that wavelength being present in the cavity. The coupling of the cavity field to the S 1/2 ↔ D 5/2 quadrupole transition is investigated with various techniques in order to determine the spatial dependence as well as the temporal dynamics. The orthogonal coupling of carrier and first--order sideband transitions at field nodes and antinodes is explored. The coherent interaction of the ion and the cavity field is confirmed by exciting Rabi oscillations with short resonant pulses injected into the cavity. Finally, first experimental steps towards the observation of cavity enhanced spontaneous emission have been taken. (author)

Detection of caffeine in tea, instant coffee, green tea beverage, and soft drink by direct analysis in real time (DART) source coupled to single-quadrupole mass spectrometry.

Science.gov (United States)

Wang, Lei; Zhao, Pengyue; Zhang, Fengzu; Bai, Aijuan; Pan, Canping

2013-01-01

Ambient ionization direct analysis in real time (DART) coupled to single-quadrupole MS (DART-MS) was evaluated for rapid detection of caffeine in commercial samples without chromatographic separation or sample preparation. Four commercial samples were examined: tea, instant coffee, green tea beverage, and soft drink. The response-related parameters were optimized for the DART temperature and MS fragmentor. Under optimal conditions, the molecular ion (M+H)+ was the major ion for identification of caffeine. The results showed that DART-MS is a promising tool for the quick analysis of important marker molecules in commercial samples. Furthermore, this system has demonstrated significant potential for high sample throughput and real-time analysis.

Analysis and mitigation of systematic errors in spectral shearing interferometry of pulses approaching the single-cycle limit [Invited

International Nuclear Information System (INIS)

Birge, Jonathan R.; Kaertner, Franz X.

2008-01-01

We derive an analytical approximation for the measured pulse width error in spectral shearing methods, such as spectral phase interferometry for direct electric-field reconstruction (SPIDER), caused by an anomalous delay between the two sheared pulse components. This analysis suggests that, as pulses approach the single-cycle limit, the resulting requirements on the calibration and stability of this delay become significant, requiring precision orders of magnitude higher than the scale of a wavelength. This is demonstrated by numerical simulations of SPIDER pulse reconstruction using actual data from a sub-two-cycle laser. We briefly propose methods to minimize the effects of this sensitivity in SPIDER and review variants of spectral shearing that attempt to avoid this difficulty

Rf quadrupole beam dynamics

International Nuclear Information System (INIS)

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

1979-01-01

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

Rise time of voltage pulses in NbN superconducting single photon detectors

Energy Technology Data Exchange (ETDEWEB)

Smirnov, K. V. [Moscow State Pedagogical University, 1 Malaya Pirogovskaya St., 119435 Moscow (Russian Federation); CJSC “Superconducting Nanotechnology” (Scontel), 5/22-1 Rossolimo St., 119021 Moscow (Russian Federation); National Research University Higher School of Economics, Moscow Institute of Electronics and Mathematics, 34 Tallinskaya St., 109028 Moscow (Russian Federation); Divochiy, A. V.; Karpova, U. V.; Morozov, P. V. [CJSC “Superconducting Nanotechnology” (Scontel), 5/22-1 Rossolimo St., 119021 Moscow (Russian Federation); Vakhtomin, Yu. B.; Seleznev, V. A. [Moscow State Pedagogical University, 1 Malaya Pirogovskaya St., 119435 Moscow (Russian Federation); CJSC “Superconducting Nanotechnology” (Scontel), 5/22-1 Rossolimo St., 119021 Moscow (Russian Federation); Sidorova, M. V. [Moscow State Pedagogical University, 1 Malaya Pirogovskaya St., 119435 Moscow (Russian Federation); Zotova, A. N.; Vodolazov, D. Yu. [Institute for Physics of Microstructure, Russian Academy of Sciences, GSP-105, 603950 Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Avenue, 603950 Nizhny Novgorod (Russian Federation)

2016-08-01

We have found experimentally that the rise time of voltage pulse in NbN superconducting single photon detectors increases nonlinearly with increasing the length of the detector L. The effect is connected with dependence of resistance of the detector R{sub n}, which appears after photon absorption, on its kinetic inductance L{sub k} and, hence, on the length of the detector. This conclusion is confirmed by our calculations in the framework of two temperature model.

Gating circuit for single photon-counting fluorescence lifetime instruments using high repetition pulsed light sources

International Nuclear Information System (INIS)

Laws, W.R.; Potter, D.W.; Sutherland, J.C.

1984-01-01

We have constructed a circuit that permits conventional timing electronics to be used in single photon-counting fluorimeters with high repetition rate excitation sources (synchrotrons and mode-locked lasers). Most commercial time-to-amplitude and time-to-digital converters introduce errors when processing very short time intervals and when subjected to high-frequency signals. This circuit reduces the frequency of signals representing the pulsed light source (stops) to the rate of detected fluorescence events (starts). Precise timing between the start/stop pair is accomplished by using the second stop pulse after a start pulse. Important features of our design are that the circuit is insensitive to the simultaneous occurrence of start and stop signals and that the reduction in the stop frequency allows the start/stop time interval to be placed in linear regions of the response functions of commercial timing electronics

Simultaneous analysis of nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry.

Science.gov (United States)

Huang, Yang; Zhang, Tingting; Zhao, Yumei; Zhou, Haibo; Tang, Guangyun; Fillet, Marianne; Crommen, Jacques; Jiang, Zhengjin

2017-09-10

Nucleobases, nucleosides and ginsenosides, which have a significant impact on the physiological activity of organisms, are reported to be the active components of ginseng, while they are less present in ginseng extracts. Few analytical methods have been developed so far to simultaneously analyze these three classes of compounds with different polarities present in ginseng extracts. In the present study, a simple and efficient analytical method was successfully developed for the simultaneous separation of 17 nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry (SFC-MS). The effect of various experimental factors on the separation performance, such as the column type, temperature and backpressure, the type of modifier and additive, and the concentration of make-up solvent were systematically investigated. Under the selected conditions, the developed method was successfully applied to the quality evaluation of 14 batches of ginseng extracts from different origins. The results obtained for the different batches indicate that this method could be employed for the quality assessment of ginseng extracts. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of seasonal harvesting on a single-species discrete population model with stage structure and birth pulses

International Nuclear Information System (INIS)

Gao Shujing; Chen Lansun

2005-01-01

In this paper, we propose an exploited single-species discrete model with stage structure for the dynamics in a fish population for which births occur in a single pulse once per time period. Using the stroboscopic map, we obtain an exact cycle of the system, and obtain the threshold conditions for its stability. Bifurcation diagrams are constructed with the birth rate as the bifurcation parameter, and these are observed to display complex dynamic behaviors, including chaotic bands with period windows, pitch-fork and tangent bifurcation. This suggests that birth pulse provides a natural period or cyclicity that makes the dynamical behavior more complex. Moreover, we show that the timing of harvesting has a strong impact on the persistence of the fish population, on the volume of mature fish stock and on the maximum annual-sustainable yield. An interesting result is obtained that, after the birth pulse, the earlier culling the mature fish, the larger harvest can tolerate

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

Science.gov (United States)

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

2018-03-01

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

Superconducting Panofsky quadrupoles

International Nuclear Information System (INIS)

Harwood, L.H.

1981-01-01

A design for a rectangular aperture quadrupole magnet without pole-tips was introduced by Hand and Panofsky in 1959. This design was quite radical but simple to construct. Few magnets of this design were ever built because of the large power needed. With the advent of superconducting coils there has been a renewed interest in them. The mathematical basis, field characteristics, and present and future construction of these magnets are described

Quadrupole interactions in pionic and muonic tantalum and rhenium

International Nuclear Information System (INIS)

Konijn, J.; Doesburg, W. van; Ewan, G.T; Johansson, T.; Tibell, G.

1981-01-01

The hyperfine splitting of pionic and muonic X-rays in natural Re has been studied using the known ratio (accurate to 1.6 parts in 10 5 ) of the quadrupole moments of the two naturally occurring 185 Re and 187 Re isotopes. From the hyperfine splitting of the 5g → 4f and 4f → 3d pionic X-rays the effective quadrupole hyperfine constants were determined to be 187 A 2 sup(e)sup(f)sup(f) (4f) = 1.163 +- 0.010 keV and 187 A 2 sup(e)sup(f)sup(f) (3d) = 5.39 +- 0.63 keV, giving strong interaction quadrupole shifts epsilon 2 (4f) = 46 +- 10 eV and epsilon 2 (3d) = 1.3 +- 0.6 keV. The strong interaction monopole shifts epsilon 0 and widths GAMMA 0 of the 5g, 4f and 3d levels have also been measured. For the two higher orbits, standard optical-potential calculations fit the measured shifts and widths quite well. The observed deeper-lying 3d state, however, has shifts and widths that differ by a factor of 2 or more from the predictions. From the measured quadrupole hyperfine constants of the 4f level we calculate the spectroscopic quadrupole moments to be 187 Qsup(μ) = 2.09 +- 0.04 b, 187 Qsup(π) = 2.07 +- 0.02 b, 185 Qsup(μ) = 2.21 +- 0.04 b, and 185 Qsup(π) = 2.18 +- 0.02 b. In addition, muonic X-rays from 181 Ta were observed; using the same methods for determining the quadrupole moments as above, a value of 181 Qsup(μ) = 3.28 +- 0.06 b was obtained, in good agreement with earlier published data. (orig.)

Quadrupole photoionization of endohedral Xe-C60

International Nuclear Information System (INIS)

Govil, Karan; Deshmukh, P C

2009-01-01

The effect of an endohedral confinement on the quadrupole photoionization of atomic Xe is studied using the relativistic random phase approximation (RRPA). The atom's confinement is modelled by placing atomic Xe at the centre of a C 60 cage represented by an annular potential around it. A new confinement resonance is reported in the 4p quadrupole cross-section along with 'correlation confinement resonances' in 4d, 5s and 5p photoionizations at about 185 eV. The effect of the confinement on the non-dipole photoelectron angular distribution parameter γ is also reported.

High and ulta-high gradient quadrupole magnets

International Nuclear Information System (INIS)

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 + /e - super colliders are presented. At a current of 400A, the lens achieved a gradient of 2.475 T/cm, and had an efficiency of 76.6%

Quadrupole formula for Kaluza-Klein modes in the braneworld

International Nuclear Information System (INIS)

Kinoshita, Shunichiro; Kudoh, Hideaki; Sendouda, Yuuiti; Sato, Katsuhiko

2005-01-01

The quadrupole formula in four-dimensional Einstein gravity is a useful tool to describe gravitational wave radiation. We derive the quadrupole formula for the Kaluza-Klein (KK) modes in the Randall-Sundrum braneworld model. The quadrupole formula provides a transparent representation of the exterior weak gravitational field induced by localized sources. We find that a general isolated dynamical source gives rise to the 1/r 2 correction to the leading 1/r gravitational field. We apply the formula to an evaluation of the effective energy carried by the KK modes from the viewpoint of an observer on the brane. Contrary to the ordinary gravitational waves (zero mode), the flux of the induced KK modes by the non-spherical part of the quadrupole moment vanishes at infinity and only the spherical part contributes to the flux. Since the effect of the KK modes appears in the linear order of the metric perturbations, the effective energy flux observed on the brane is not always positive, but can become negative depending on the motion of the localized sources

Sensitivity of (α,α') cross sections to excited-state quadrupole moments

International Nuclear Information System (INIS)

Baker, F.T.; Scott, A.; Ronningen, R.M.; Hamilton, J.H.; Kruse, T.H.; Suchannek, R.; Savin, W.

1977-01-01

Inelastic α particle scattering at 21 and 24 MeV has been used to estimate the electric quadrupole moment of the second 2 + state in 180 Hf. Sensitivity to the assumed quadrupole moment is due almost entirely to reorientation via the nuclear force. Results suggest that the technique may be a useful method of estimating excited state quadrupole moments, particularly for states with high excitation energies or with J greater than 2

Studies of heavy ion beam transport in a magnetic quadrupole channel

International Nuclear Information System (INIS)

Klabunde, J.; Reiser, M.; Schonlein, A.; Spadtke, P.; Struckmeier, J.

1983-01-01

In connection with the West German Heavy Ion Fusion Program the first stage (six periods) of a magnetic quadrupole channel (FODO type) to study the transport of intense ion beams was built at GSI. Different ion beams can be used and the variation of the brightness of these beams (hence of the tune depression sigma/sigma /SUB o/ ) is sufficiently large that regions of theoretically predicted instabilities can be covered. The initial studies are being carried out with a high-brightness beam of 190 keV Ar+ ions and currents of a few mA. Since the pulse length is > 0.5 ms and the pressure is between 10 -6 and 10 -7 torr partial space charge neutralization occurs. Clearing electrodes can be used to remove the electrons from the beam. Results of theoretical studies, measurements of charge neutralization effects and first results of transport experiments are reported

Optimization of an electrostatic quadrupole doublet focusing systems

Energy Technology Data Exchange (ETDEWEB)

Hussein, Oday A., E-mail: oah@sc.nahrainuniv.edu.iq [Department of Physics, College of Science, Al-Nahrain University, Baghdad (Iraq); Sise, Omer [Department of Science Education, Faculty of Education, Suleyman Demirel University, Isparta (Turkey)

2017-05-15

Highlights: • The imaging properties of an electrostatic quadrupole doublet lens were analyzed with the aid of computer simulation. • The optimal electrode voltages which lead to stigmatic image in both planes of the quadrupole doublet lens with minimum spot size at position sensitive detector (PSD) were found for two operation modes: point-to-point focusing and parallel-to-point focusing. • The imaging properties of are very sensitive to the lunching angle of the electron-beam. - Abstract: The imaging properties of an electrostatic quadrupole doublet lens were analyzed with the aid of computer simulation. The optimal electrode voltages which lead to stigmatic image in both planes of the quadrupole doublet lens with minimum spot size at position sensitive detector (PSD) were found for two operation modes: point-to-point focusing and parallel-to-point focusing. The optical properties as: Magnifications, spot sizes in the image plane and aberration figures were discussed. The results showed that the focusing of the lens was strong in the xy-plane in comparison with the focusing in the xz-plane. The distortion of the image was greater when the image position will be close to the lens in comparison with object position. Also, the imaging properties were very sensitive to the lunching angle of the electron-beam.

Gas-phase mechanisms in the growth of ZrCyN1-y thin films by pulsed reactive crossed-beam laser ablation

International Nuclear Information System (INIS)

Spillmann, H.; Clerc, C.; Doebeli, M.; Willmott, P.R.

2002-01-01

Superhard zirconium carbonitride films have been grown via pulsed reactive crossed-beam laser ablation (PRCLA) using zirconium metal and a nitrogen- and carbon-containing gas pulse mixture. The control of stoichiometry was much simplified by using the thermally stable gas-phase species N 2 and CH 4 . The gas-phase processes are investigated using quadrupole mass spectroscopy and optical emission spectroscopy. The excitation of the ablation plume depends intimately on the collision partner of the gas pulse, in particular on its density of states and the probability of energy transfer to internal degrees of freedom

Label-free screening of single biomolecules through resistive pulse sensing technology for precision medicine applications

Science.gov (United States)

Harrer, S.; Kim, S. C.; Schieber, C.; Kannam, S.; Gunn, N.; Moore, S.; Scott, D.; Bathgate, R.; Skafidas, S.; Wagner, J. M.

2015-05-01

Employing integrated nano- and microfluidic circuits for detecting and characterizing biological compounds through resistive pulse sensing technology is a vibrant area of research at the interface of biotechnology and nanotechnology. Resistive pulse sensing platforms can be customized to study virtually any particle of choice which can be threaded through a fluidic channel and enable label-free single-particle interrogation with the primary read-out signal being an electric current fingerprint. The ability to perform label-free molecular screening with single-molecule and even single binding site resolution makes resistive pulse sensing technology a powerful tool for analyzing the smallest units of biological systems and how they interact with each other on a molecular level. This task is at the core of experimental systems biology and in particular ‘omics research which in combination with next-generation DNA-sequencing and next-generation drug discovery and design forms the foundation of a novel disruptive medical paradigm commonly referred to as personalized medicine or precision medicine. DNA-sequencing has approached the 1000-Dollar-Genome milestone allowing for decoding a complete human genome with unmatched speed and at low cost. Increased sequencing efficiency yields massive amounts of genomic data. Analyzing this data in combination with medical and biometric health data eventually enables understanding the pathways from individual genes to physiological functions. Access to this information triggers fundamental questions for doctors and patients alike: what are the chances of an outbreak for a specific disease? Can individual risks be managed and if so how? Which drugs are available and how should they be applied? Could a new drug be tailored to an individual’s genetic predisposition fast and in an affordable way? In order to provide answers and real-life value to patients, the rapid evolvement of novel computing approaches for analyzing big data in

Label-free screening of single biomolecules through resistive pulse sensing technology for precision medicine applications.

Science.gov (United States)

Harrer, S; Kim, S C; Schieber, C; Kannam, S; Gunn, N; Moore, S; Scott, D; Bathgate, R; Skafidas, S; Wagner, J M

2015-05-08

Employing integrated nano- and microfluidic circuits for detecting and characterizing biological compounds through resistive pulse sensing technology is a vibrant area of research at the interface of biotechnology and nanotechnology. Resistive pulse sensing platforms can be customized to study virtually any particle of choice which can be threaded through a fluidic channel and enable label-free single-particle interrogation with the primary read-out signal being an electric current fingerprint. The ability to perform label-free molecular screening with single-molecule and even single binding site resolution makes resistive pulse sensing technology a powerful tool for analyzing the smallest units of biological systems and how they interact with each other on a molecular level. This task is at the core of experimental systems biology and in particular 'omics research which in combination with next-generation DNA-sequencing and next-generation drug discovery and design forms the foundation of a novel disruptive medical paradigm commonly referred to as personalized medicine or precision medicine. DNA-sequencing has approached the 1000-Dollar-Genome milestone allowing for decoding a complete human genome with unmatched speed and at low cost. Increased sequencing efficiency yields massive amounts of genomic data. Analyzing this data in combination with medical and biometric health data eventually enables understanding the pathways from individual genes to physiological functions. Access to this information triggers fundamental questions for doctors and patients alike: what are the chances of an outbreak for a specific disease? Can individual risks be managed and if so how? Which drugs are available and how should they be applied? Could a new drug be tailored to an individual's genetic predisposition fast and in an affordable way? In order to provide answers and real-life value to patients, the rapid evolvement of novel computing approaches for analyzing big data in

Large permanent magnet quadrupoles for an electron storage ring

International Nuclear Information System (INIS)

Herb, S.W.

1987-01-01

We have built large high quality permanent magnet quadrupoles for use as interaction region quadrupoles in the Cornell Electron Storage Ring where they must operate in the 10 kG axial field of the CLEO experimental detector. We describe the construction and the magnetic measurement and tuning procedures used to achieve the required field quality and stability. (orig.)

Status of Long Coil Production for the MQXFB Nb3Sn Prototype Quadrupole for the HiLumi LHC

Energy Technology Data Exchange (ETDEWEB)

Lackner, Friedrich; Ferracin, Paolo; Todesco, Ezio; Triquet, Stephan; Pozzobon, Marc; Luzieux, S.; Perez, J. C.; Scheuerlein, Christian; Cavanna, Eugenio; Ohnweiler, Timm; Revilak, Philipp; Genestier, Thibault; Principe, Rosario; Prin, Herve; Duret, Max; Savary, Frederic

2017-01-01

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

Design of the 70 mm twin aperture superconducting quadrupole for the LHC dump insertion

CERN Document Server

Kirby, G A; Taylor, T M; Trinquart, G

1996-01-01

The LHC dump insertion features a pair of superconducting quadrupoles located on either side of a 340 m long straight section. Two horizontally deflecting kickers, located in between the quadrupole pairs, and a septum in the centre of the insertion, vertically deflect the two counter-rotating beams past the quadrupoles on the downstream sides, and into the dump areas. Due to the layout, the optical ß function in the quadrupoles is around 640 m, the largest around the LHC at injection. The quadrupoles must therefore have enlarged aperture and specially designed cryostats to allow for the safe passage of both the circulating and ejected beams. In this paper we present the design of the twin aperture dump quadrupole based on the 70 mm four layer coil proposed for the LHC low-ß quadrupoles. In preparation for model construction, we report on improvements of the coil design and a study of the retaining structures.

CESAR, 2 MeV electron storage ring; construction period; quadrupole.

CERN Multimedia

Service Photo; CERN PhotoLab

1962-01-01

One of the 24 quadrupoles. They were made of massive (non-laminated) soft iron, which at the low field-strength (35 G on the pole-tips) presented problems. Later they were fitted with shims on all 4 poles, to correct the quadrupole and sextupole components.

Excitation of giant monopole and quadrupole resonances

Energy Technology Data Exchange (ETDEWEB)

Ogata, H. [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Yamagata, T.; Tanaka, M. [and others; Ikegami, H.; Muraoka, M. [eds.; Osaka Univ., Suita (Japan). Research Center for Nuclear Physics

1980-01-01

Recent studies on the giant monopole resonance (GMR) and the giant quadrupole resonance (GQR) in /sup 144/Sm and /sup 208/Pb using the ..cap alpha..-scattering performed at RCNP are summarized. The observed angular range covered 1.6/sup 0/ -- 7/sup 0/ with a coupled system of a dipole and a triplet quadrupole magnet. The incident energy was changed from 84 to 119 MeV. The resonance shapes and energy-weighted sum-rule strengths of the GMR and the GQR were reliably deduced as a function of incident energy. The quadrupole strength of --20% was found in the GMR region. The observed excitation function of the GMR was compared with the DWBA calculation, in which the Satchler's Version I was used as a form factor representing the compressional motion of the nucleus. It was found that the experimental excitation function of the GMR shows steeper decrease as lowering the incident energy than the DWBA prediction whereas that of the GQR is successfully described by the DWBA. This suggests that examination of the model describing the GMR is necessary.

Puzzle of the 6Li Quadrupole Moment: Steps toward Solving It

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Kukulin, V.I.; Pomerantsev, V.N.

2005-01-01

The problem of the origin of the quadrupole deformation in the 6 Li ground state is investigated with allowance for the three-deuteron component of the 6 Li wave function. Two long-standing puzzles related to the tensor interaction in the 6 Li nucleus are known: that of an anomalous smallness of the 6 Li quadrupole moment (being negative, it is smaller in magnitude than the 7 Li quadrupole moment by a factor of 5) and that of an anomalous behavior of the tensor analyzing power T 2q in the scattering of polarized 6 Li nuclei on various targets. It is shown that a large (in magnitude) negative exchange contribution to the 6 Li quadrupole moment from the three-deuteron configuration cancels almost completely the 'direct' positive contribution due to the αd folding potential. As a result, the total quadrupole moment proves to be close to zero and highly sensitive to fine details of the tensor nucleon-nucleon interaction in the 4 He nucleus and of its wave function

Pulsed flow modulation two-dimensional comprehensive gas chromatography-tandem mass spectrometry with supersonic molecular beams.

Science.gov (United States)

Poliak, Marina; Fialkov, Alexander B; Amirav, Aviv

2008-11-07

Pulsed flow modulation (PFM) two-dimensional comprehensive gas chromatography (GC x GC) was combined with quadrupole-based mass spectrometry (MS) via a supersonic molecular beam (SMB) interface using a triple-quadrupole system as the base platform, which enabled tandem mass spectrometry (MS-MS). PFM is a simple GC x GC modulator that does not consume cryogenic gases while providing tunable second GC x GC column injection time for enabling the use of quadrupole-based mass spectrometry regardless its limited scanning speed. The 20-ml/min second column flow rate involved with PFM is handled, splitless, by the SMB interface without affecting the sensitivity. The combinations of PFM GC x GC-MS with SMB and PFM GC x GC-MS-MS with SMB were explored with the analysis of diazinon and permethrin in coriander. PFM GC x GC-MS with SMB is characterized by enhanced molecular ion and tailing-free fast ion source response time. It enables universal pesticide analysis with full scan and data analysis with reconstructed single ion monitoring on the enhanced molecular ion and another prominent high mass fragment ion. The elimination of the third fragment ion used in standard three ions method results in significantly reduced matrix interference. GC x GC-MS with SMB improves the GC separation, and thereby our ability for sample identification using libraries. GC-MS-MS with SMB provides better reduction (elimination) of matrix interference than GC x GC-MS. However, it is a target method, which is not always applicable. GC x GC-MS-MS does not seem to further reduce matrix interferences over GC-MS-MS and unlike GC x GC-MS, it is incompatible with library identification, but it is beneficial to have both GC x GC and MS-MS capabilities in the same system.

Isabelle dipole and quadrupole coil configurations

International Nuclear Information System (INIS)

Dahl, P.F.; Hahn, H.

1980-01-01

The coil configurations of the ISABELLE dipole and quadrupole magnets have been reviewed and a number of improvements were suggested for incorporation into the final design. The coil designs are basically single layer multiple block approximations to cosine current distributions, wound from a high aspect ratio non-keystoned braided conductor. The blocks are separated by knife-edge wedges to maximize the quench propagation velocity. The current density variation is obtained by an appropriate distribution of the spacer turns and, to a lesser degree, by the wedge locations. The use of inert turns is necessary to minimize the peak field enhancement both in the ends and in the two dimensional section. Schemes for deriving turns distributions yielding harmonic coefficients satisfying the stringent ISABELLE tolerances on field uniformity, while allowing for simplicity in winding and taking into account quench propagation considerations, will be discussed, as well as our approach to the coil end configuration

Permanent quadrupole magnets

International Nuclear Information System (INIS)

Bush, E.D. Jr.

1976-01-01

A family of quadrupole magnets using a soft iron return yoke and circular cross-section permanent magnet poles were fabricated to investigate the feasibility for use in ion or electron beam focusing applications in accelerators and transport lines. Magnetic field measurements yielded promising results. In fixed-field applications, permanent magnets with sufficient gradients would be a low cost substitute for conventional electromagnets, eliminating the need for power supplies, associated wiring, and cooling. (author)

Nuclear quadrupole interactions in ferroelectric compounds of HF181

International Nuclear Information System (INIS)

Kunzler, J.V.

1971-01-01

Measurements of nuclear quadrupole interaction constants in perovkite-type compounds of PbHfO 3 , SnhfO 3 , CaHfO 3 e SrHfO 3 have been performed using the perturbed angular correlation technique. A range of fundamental frequencies from 150 to 550 Megaradians persecond was determined. The variation of quadrupole constants has been discussed through the molecular orbital theory

Rotating effects on the Landau quantization for an atom with a magnetic quadrupole moment

Energy Technology Data Exchange (ETDEWEB)

Fonseca, I. C.; Bakke, K., E-mail: kbakke@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, João Pessoa, PB 58051-970 (Brazil)

2016-01-07

Based on the single particle approximation [Dmitriev et al., Phys. Rev. C 50, 2358 (1994) and C.-C. Chen, Phys. Rev. A 51, 2611 (1995)], the Landau quantization associated with an atom with a magnetic quadrupole moment is introduced, and then, rotating effects on this analogue of the Landau quantization is investigated. It is shown that rotating effects can modify the cyclotron frequency and breaks the degeneracy of the analogue of the Landau levels.

Rotating effects on the Landau quantization for an atom with a magnetic quadrupole moment

Science.gov (United States)

Fonseca, I. C.; Bakke, K.

2016-01-01

Based on the single particle approximation [Dmitriev et al., Phys. Rev. C 50, 2358 (1994) and C.-C. Chen, Phys. Rev. A 51, 2611 (1995)], the Landau quantization associated with an atom with a magnetic quadrupole moment is introduced, and then, rotating effects on this analogue of the Landau quantization is investigated. It is shown that rotating effects can modify the cyclotron frequency and breaks the degeneracy of the analogue of the Landau levels.

Rotating effects on the Landau quantization for an atom with a magnetic quadrupole moment

International Nuclear Information System (INIS)

Fonseca, I. C.; Bakke, K.

2016-01-01

Based on the single particle approximation [Dmitriev et al., Phys. Rev. C 50, 2358 (1994) and C.-C. Chen, Phys. Rev. A 51, 2611 (1995)], the Landau quantization associated with an atom with a magnetic quadrupole moment is introduced, and then, rotating effects on this analogue of the Landau quantization is investigated. It is shown that rotating effects can modify the cyclotron frequency and breaks the degeneracy of the analogue of the Landau levels

Single-particle motion in large-amplitude quadrupole shape transition

International Nuclear Information System (INIS)

Yamada, Kazuya

1991-01-01

The microscopic structure of the single-particle motion for the spherical-deformed transitional nuclei is analysed by using the self-consistent collective-coordinate method (SCC method). The single-particle motion in the moving-frame of reference called the collective vibrating coordinate frame is introduced by the generalized Bogoliubov transformation depending on the collective coordinate. The numerical calculations of the single-particle (quasi-particle) energy level diagrams and their occupation probabilities for the static deformation are carried out for the Sm isotopes. A clear change of the single-particle distribution structure appears in the course of deformation. (author)

Long-duration nano-second single pulse lasers for observation of spectra from bulk liquids at high hydrostatic pressures

International Nuclear Information System (INIS)

Thornton, Blair; Sakka, Tetsuo; Masamura, Tatsuya; Tamura, Ayaka; Takahashi, Tomoko; Matsumoto, Ayumu

2014-01-01

The influence of laser pulse duration on the spectral emissions observed from bulk ionic solutions has been investigated for hydrostatic pressures between 0.1 and 30 MPa. Transient pressure, shadowgraph imaging and spectroscopic measurements were performed for single pulses of duration 20 and 150 ns. The transient pressure measurements show that for hydrostatic pressures up to 30 MPa, propagation of the high-pressure shockwave generated by the focused laser causes the local pressure to reduce below ambient levels during the time frame that spectroscopic measurements can be made. The pressure impulse and subsequent reduction in pressure are larger, with the latter lasting longer for the 150 ns pulse compared to a 20 ns pulse of the same energy. The 150 ns pulse generates larger cavities with significant enhancement of the spectral emissions observed compared to the 20 ns duration pulse for pressures up to 30 MPa. The results demonstrate that laser-induced breakdown using a long ns duration pulse offers an advantage over conventional, short ns duration pulses for the analysis of bulk ionic solutions at hydrostatic pressures between 0.1 and 30 MPa. - Highlights: • Long-ns-duration laser pulses enhance the spectra observed from bulk solutions. • Laser-induced shockwaves momentarily reduce pressures to below ambient levels. • 150 ns pulses generate larger cavities than 20 ns pulses of the same energy. • Hydrostatic pressures < 30 MPa have no significant effect on the observed spectra

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

Energy Technology Data Exchange (ETDEWEB)

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.

A study of trapped ion dynamics by photon-correlation and pulse-probe techniques

International Nuclear Information System (INIS)

Rink, J.; Dholakia, K.; Zs, G.; Horvath, K.; Hernandez-Pozos, J. L.; Power, W.; Segal, D. M.; Thompson, R. C.; Walker, T.

1995-01-01

We demonstrate non-evasive methods for observing ion and ion cloud oscillation frequencies in a quadrupole ion trap. These trap resonances are measured for small clouds using a photon correlation technique. For large clouds the rotation frequency can be detected with the help of an additional pulsed probe laser. We show applications of the photon correlation method such as estimating the dynamic properties of a combined trap and detecting ion crystals

Dynamical quadrupole structure factor of frustrated ferromagnetic chain

Science.gov (United States)

Onishi, Hiroaki

2018-05-01

We investigate the dynamical quadrupole structure factor of a spin-1/2 J1-J2 Heisenberg chain with competing ferromagnetic J1 and antiferromagnetic J2 in a magnetic field by exploiting density-matrix renormalization group techniques. In a field-induced spin nematic regime, we observe gapless excitations at q = π according to quasi-long-range antiferro-quadrupole correlations. The gapless excitation mode has a quadratic form at the saturation, while it changes into a linear dispersion as the magnetization decreases.

Quadrupole moment of the superdeformed band in 131Ce

International Nuclear Information System (INIS)

He, Y.; Godfrey, M.J.; Jenkins, I.; Kirwan, A.J.; Nolan, P.J.

1990-01-01

A mean lifetime measurement has been carried out on the states in the superdeformed band found in 131 Ce using the Doppler shift attenuation method (DSAM). The measured intrinsic nuclear quadrupole moment is Q o approx= 6 eb, assuming constant deformation, which corresponds to a quadrupole deformation β 2 approx= 0.35. This is considerably smaller than the value deduced for 132 Ce. (author)

Sudden change of quadrupole moment between the first 5/2- states of 197Hg and 199Hg

International Nuclear Information System (INIS)

Herzog, P.; Krien, K.; Freitag, M.; Reuschenbach, M.; Walitzki, H.

1980-01-01

Low-temperature time differential perturbed angular correlation experiments with the 164 KeV-134 keV cascade of sup(197m)Hg in a zinc matrix give evidence that the hitherto accepted value of the quadrupole moment of the first 5/2 - state of 197 Hg is erroneous. A new value is derived from a time differential perturbed angular correlation experiment with the 374 keV-158 keV cascade of sup(199m)Hg implanted into a Be single crystal and comparison with an analogous experiment for sup(197m)Hg. Taking Q(5/2 - , 199 Hg) = +0.95(7) b we derive Q(5/2 - , 197 Hg) = 0.081(6) b. This change of quadrupole moment is discussed in the framework of the shell model. (orig.)

Computation of a quadrupole magnet for the APS storage ring

Energy Technology Data Exchange (ETDEWEB)

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

1990-01-01

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

Empirical modeling of single-wake advection and expansion using full-scale pulsed lidar-based measurements

DEFF Research Database (Denmark)

Machefaux, Ewan; Larsen, Gunner Chr.; Troldborg, Niels

2015-01-01

In the present paper, single-wake dynamics have been studied both experimentally and numerically. The use of pulsed lidar measurements allows for validation of basic dynamic wake meandering modeling assumptions. Wake center tracking is used to estimate the wake advection velocity experimentally...... fairly well in the far wake but lacks accuracy in the outer region of the near wake. An empirical relationship, relating maximum wake induction and wake advection velocity, is derived and linked to the characteristics of a spherical vortex structure. Furthermore, a new empirical model for single...

Modified Dual Three-Pulse Modulation technique for single-phase inverter topology

Science.gov (United States)

Sree Harsha, N. R.; Anitha, G. S.; Sreedevi, A.

2016-01-01

In a recent paper, a new modulation technique called Dual Three Pulse Modulation (DTPM) was proposed to improve the efficiency of the power converters of the Electric/Hybrid/Fuel-cell vehicles. It was simulated in PSIM 9.0.4 and uses analog multiplexers to generate the modulating signals for the DC/DC converter and inverter. The circuit used is complex and many other simulation softwares do not support the analog multiplexers as well. Also, the DTPM technique produces modulating signals for the converter, which are essentially needed to produce the modulating signals for the inverter. Hence, it cannot be used efficiently to switch the valves of a stand-alone inverter. We propose a new method to generate the modulating signals to switch MOSFETs of a single phase Dual-Three pulse Modulation based stand-alone inverter. The circuits proposed are simulated in Multisim 12.0. We also show an alternate way to switch a DC/DC converter in a way depicted by DTPM technique both in simulation (MATLAB/Simulink) and hardware. The circuitry is relatively simple and can be used for the further investigations of DTPM technique.

Fluorescence detection of single molecules using pulsed near-field optical excitation and time correlated photon counting

International Nuclear Information System (INIS)

Ambrose, W.P.; Goodwin, P.M.; Martin, J.C.; Keller, R.A.

1994-01-01

Pulsed excitation, time correlated single photon counting and time gated detection are used in near-field optical microscopy to enhance fluorescence images and measure the fluorescence lifetimes of single molecules of Rhodamine 6G on silica surfaces. Time gated detection is used to reject prompt scattered background and to improve the image signal to noise ratio. The excited state lifetime of a single Rhodamine 6G molecule is found to depend on the position of the near-field probe. We attribute the lifetime variations to spontaneous emission rate alterations by the fluorescence reflected from and quenching by the aluminum coated probe

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Development of LHC-IR model quadrupoles in the US

CERN Document Server

Sabbi, G

2007-01-01

Insertion quadrupoles with large aperture and high gradient are required to achieve the luminosity upgrade goal of 1035 cm-2 s-1 at the Large Hadron Collider (LHC). In 2004, the US Department of Energy established the LHC Accelerator Research Program (LARP) to develop a technology base for the upgrade. The focus of the magnet program, which is a collaboration of three US laboratories, BNL, FNAL and LBNL, is on development of high gradient quadrupoles using Nb$_{3}$Sn in order to operate at high field and with sufficient temperature margin. Other program components address issues regarding magnet design, radiation-hard materials, long magnet scale-up, quench protection, fabrication techniques and conductor and cable R&D. This paper reports on the development od model quadrupoles and outlines the long-term goals of the program.

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

Science.gov (United States)

Filatov, Michael; Zou, Wenli; Cremer, Dieter

2012-10-01

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

Energy Extraction Resistors for the Main Dipole and Quadrupole Circuits of the LHC

CERN Document Server

Dahlerup-Petersen, K; Popov, V; Sytchev, V V; Vasilev, L B; Zubko, V G

2000-01-01

When the LHC will be operating at its maximum beam energy, its superconducting dipole chains store a total magnetic energy of more than 11 GJ. At the same time, the QF and QD quadrupole circuits store a total energy of 400 MJ. Even with the sectorisation of each of the three principal power circuits into eight individually powered segments, the stored energy of a single circuit is considerable. During normal operation the energy in the dipole circuits is safely returned to the mains grid, using the thyristor-based, 'booster' unit of the power converters, operating in inversion. For the quadrupole chains, where the converter is of a mono-polar topology, the stored energy is dissipated into the resistive part of the warm d.c. power lines (busbars and cables) in a slow, controlled run-down. When a magnet quenches, however, such a slow energy transfer, taking 20 minutes from the rated LHC current, will not be possible. The 'cold' diode, taking over the magnet current in case of a quench, will not survive this slo...

A RD-ESPRIT algorithm for coherent DOA estimation in monostatic MIMO radar using a single pulse

Science.gov (United States)

Chen, Chen; Zhang, Xiaofei

2014-08-01

This paper discusses the problem of coherent direction of arrival (DOA) estimation in a monostatic multi-input multi-output (MIMO) radar using a single pulse, and proposes a reduced dimension (RD)-estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm. We reconstruct the received data and then utilise it to construct a set of Toeplitz matrices. After that, we use RD-ESPRIT to obtain the DOAs of the sources. The proposed algorithm is effective for coherent angle estimation based on a single pulse, and it has much better angle estimation performance than the forward backward spatial smoothing (FBSS)-ESPRIT algorithm and the ESPRIT-like of Li, as well as very close angle estimation performance to the ESPRIT-like of Han. For complexity comparison, our algorithm has very close complexity to the FBSS-ESPRIT algorithm, and lower complexity than the ESPRIT-like of Han and the ESPRIT-like of Li. Simulation results present the effectiveness and improvement of our approach.

A linear radiofrequency quadrupole ion trap for the cooling and bunching of radioactive ion beams

CERN Document Server

Kellerbauer, A G; Dilling, J; Henry, S; Herfurth, F; Kluge, H J; Lamour, E; Moore, R B; Scheidenberger, C; Schwarz, S; Sikler, G; Szerypo, J

2002-01-01

A linear radiofrequency quadrupole ion guide and beam buncher has been installed at the ISOLTRAP mass spectrometry experiment at the ISOLDE facility at CERN. The apparatus is being used as a beam cooling, accumulation, and bunching system. It operates with a buffer gas that cools the injected ions and converts the quasicontinuous 60- keV beam from the ISOLDE facility to 2.5-keV beam pulses with improved normalized transverse emittance. Recent measurements suggest a capture efficiency of the ion guide of up to 40% and a cooling and bunching efficiency of at least 12% which is expected to still be increased. The improved ISOLTRAP setup has so far been used very successfully in three on-line experiments. (12 refs).

Effects of laser wavelengths and pulse energy ratio on the emission enhancement in dual pulse LIBS

International Nuclear Information System (INIS)

Ahmed, Rizwan; Iqbal, Javed; Baig, M Aslam

2015-01-01

We present new studies on the effects of laser wavelengths, pulse energy ratio and interpulse delay between two laser pulses in the collinear dual pulse configuration of laser-induced breakdown spectroscopy (LIBS) on an iron sample in air using the fundamental (1064 nm) and the second harmonics (532 nm) of Nd:YAG lasers. In the dual pulse LIBS, an optimum value of interpulse delay with an appropriate combination of laser wavelengths, and laser pulse energy ratio, yields a 30 times signal intensity enhancement in the neutral iron lines as compared with single pulse LIBS. A comparison in the spatial variations of electron temperature along the axis of the plume expansion in single and double pulse LIBS has also been studied. (letter)

Calculation of the quadrupole-lense fringing field

International Nuclear Information System (INIS)

Arzumanov, A.A.

1978-01-01

With the aim of decreasing the scattering field effect at electrode edge or quadrupole lens poles with conformal transformations the scattering fields of electric quadrupole lens, two-electrode lens with the electrodes in a hyperbola form, as well as magnetic lens with hyperbolic poles are calculated. For the two-electrode system with kappa=0.1 (kappa - is coefficient, characterizing the rate of field intensity change in the lens) field distortion equals 1.8%. The comparison of experimental data with the calculation data has shown that with a rather high accuracy the scattering field effect in electric and magnetic lenses with hyperbolic poles may be taken into account

Single-photon Coulomb explosion of methanol using broad bandwidth ultrafast EUV pulses.

Science.gov (United States)

Luzon, Itamar; Jagtap, Krishna; Livshits, Ester; Lioubashevski, Oleg; Baer, Roi; Strasser, Daniel

2017-05-31

Single-photon Coulomb explosion of methanol is instigated using the broad bandwidth pulse achieved through high-order harmonics generation. Using 3D coincidence fragment imaging of one molecule at a time, the kinetic energy release (KER) and angular distributions of the products are measured in different Coulomb explosion (CE) channels. Two-body CE channels breaking either the C-O or the C-H bonds are described as well as a proton migration channel forming H 2 O + , which is shown to exhibit higher KER. The results are compared to intense-field Coulomb explosion measurements in the literature. The interpretation of broad bandwidth single-photon CE data is discussed and supported by ab initio calculations of the predominant C-O bond breaking CE channel. We discuss the importance of these findings for achieving time resolved imaging of ultrafast dynamics.

Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

International Nuclear Information System (INIS)

Maschke, A. W.

1985-01-01

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

Quadrupole moment in the excited 2Psub(1/2) state

International Nuclear Information System (INIS)

Amusia, M.Ya.; Yakhontov, V.L.

1984-01-01

Computation of the quadrupole moment values in the 2Psub(1/2) states of hydrogen and meso-hydrogen is carried out. It is shown that allowance for the hyperfine interaction of the electron with the proton in the first order of perturbation theory results in giant values of the quadrupole moment of the atoms. (author)

Construction of a single/multiple wavelength RZ optical pulse source at 40 GHz by use of wavelength conversion in a high-nonlinearity DSF-NOLM

DEFF Research Database (Denmark)

Yu, Jianjun; Yujun, Qian; Jeppesen, Palle

2001-01-01

A single or multiple wavelength RZ optical pulse source at 40 GHz is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of high nonlinearity-dispersion shifted fiber.......A single or multiple wavelength RZ optical pulse source at 40 GHz is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of high nonlinearity-dispersion shifted fiber....

Single shot diffraction of picosecond 8.7-keV x-ray pulses

Directory of Open Access Journals (Sweden)

F. H. O’Shea

2012-02-01

Full Text Available We demonstrate multiphoton, single shot diffraction images of x rays produced by inverse Compton scattering a high-power CO_{2} laser from a relativistic electron beam, creating a pulse of 8.7 keV x rays. The tightly focused, relatively high peak brightness electron beam and high photon density from the 2 J CO_{2} laser yielded 6×10^{7} x-ray photons over the full opening angle in a single shot. Single shot x-ray diffraction is performed by passing the x rays though a vertical slit and on to a flat silicon (111 crystal. 10^{2} diffracted photons were detected. The spectrum of the detected x rays is compared to simulation. The diffraction and detection of 10^{2} x rays is a key step to a more efficient time resolved diagnostic in which the number of observed x rays might reach 10^{4}; enabling a unique, flexible x-ray source as a sub-ps resolution diagnostic for studying the evolution of chemical reactions, lattice deformation and melting, and magnetism.

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

International Nuclear Information System (INIS)

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

Communication: The electronic structure of matter probed with a single femtosecond hard x-ray pulse

Directory of Open Access Journals (Sweden)

J. Szlachetko

2014-03-01

Full Text Available Physical, biological, and chemical transformations are initiated by changes in the electronic configuration of the species involved. These electronic changes occur on the timescales of attoseconds (10−18 s to femtoseconds (10−15 s and drive all subsequent electronic reorganization as the system moves to a new equilibrium or quasi-equilibrium state. The ability to detect the dynamics of these electronic changes is crucial for understanding the potential energy surfaces upon which chemical and biological reactions take place. Here, we report on the determination of the electronic structure of matter using a single self-seeded femtosecond x-ray pulse from the Linac Coherent Light Source hard x-ray free electron laser. By measuring the high energy resolution off-resonant spectrum (HEROS, we were able to obtain information about the electronic density of states with a single femtosecond x-ray pulse. We show that the unoccupied electronic states of the scattering atom may be determined on a shot-to-shot basis and that the measured spectral shape is independent of the large intensity fluctuations of the incoming x-ray beam. Moreover, we demonstrate the chemical sensitivity and single-shot capability and limitations of HEROS, which enables the technique to track the electronic structural dynamics in matter on femtosecond time scales, making it an ideal probe technique for time-resolved X-ray experiments.

On quantum quadrupole radiation

International Nuclear Information System (INIS)

Fonda, L.; Mankoc-Borstnik, N.

1981-02-01

In this paper it is shown that for the electromagnetic decay of a quantum system in a coherent rotational state the total quadrupole radiation is proportional to (d 5 Q/dt 5 )(dQ/dt)sup(*)+c.c. For the radiation flux out of a sphere of large radius a different quantity, closer to the classical expression (d 3 Q/dt 3 ) 2 , is found. (author)

Towards diffractive imaging with single pulses of FEL radiation. Dynamics within irradiatied samples and their influence on the analysis of imaging data

Energy Technology Data Exchange (ETDEWEB)

Wang, Fenglin

2010-08-15

3D single particle coherent diffraction imaging (CDI) of bioparticles (such as proteins, macromolecules and viruses) is one of the main possible applications of the new generation of light sources: free-electron lasers (FELs), which are now available at FLASH (Hamburg, Germany) and LCLS (Stanford, U.S.A.). The extremely bright and ultrashort FEL pulses potentially enable CDI to achieve high resolution down to subnanometer length scale. However, intense FEL pulses cause serious radiation damage in bioparticles, even during single shots, which may set the resolution limits for CDI with FELs. Currently, since the signal-to-noise ratio is very low for small biological particles, direct experimental study of radiation damage in the single particle imaging is fairly difficult. Single atomic (noble gas) clusters become good objects to reveal effects of radiation damage processes on CDI with FEL radiation. This thesis studies three aspects of the radiation damage problem, which are treated in three independent chapters: (1) Molecular Dynamics simulations to quantitively describe radiation damage processes within irradiated atomic clusters during single pulses; (2) reconstruction analysis of single-shot CDI diffraction patterns of atomic clusters, which may potentially help to understand the radiation damage occurring in biological samples; and (3) testing the effects of coating water layers in CDI, which is supposed to minimize the radiation damage in irradiated bioparticles. (orig.)

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

International Nuclear Information System (INIS)

Bini, Donato; Crosta, Mariateresa; Vecchiato, Alberto; De Felice, Fernando; Geralico, Andrea

2013-01-01

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

The System of Nanosecond 280-KeV He+ Pulsed Beam

International Nuclear Information System (INIS)

Junphong, P.; Ano, V.; Lekprasert, B.; Suwannakachorn, D.; Thongnopparat, N.; Vilaithong, T.; Chiang Mai U.; Wiedemann, H.; SLAC/SLAC, SSRL

2006-01-01

At Fast Neutron Research Facility, the 150 kV-pulses neutron generator is being upgraded to a 280-kV-pulsed-He beam for time-of-flight Rutherford backscattering spectrometry. It involves replacing the existing beam line elements by a multicusp ion source, a 400-kV accelerating tube, 45-double focusing dipole magnet and quadrupole lens. The multicusp ion source is a compact filament-driven of 2.6 cm in diameter and 8 cm in length. The current extracted is 20.4 μ A with 13 kV of extraction voltage and 8.8 kV of Einzel lens voltage. The beam emittance has found to vary between 6-12 mm mrad. The beam transport system has to be redesigned based on the new elements. The important part of a good pulsed beam depends on the pulsing system. The two main parts are the chopper and buncher. An optimized geometry for the 280 keV pulsed helium ion beam will be presented and discussed. The PARMELA code has been used to optimize the space charge effect, resulting in pulse width of less than 2 ns at a target. The calculated distance from a buncher to the target is 4.6 m. Effects of energy spread and phase angle between chopper and buncher have been included in the optimization of the bunch length

Surprise in simplicity: an unusual spectral evolution of a single pulse GRB 151006A

Science.gov (United States)

Basak, R.; Iyyani, S.; Chand, V.; Chattopadhyay, T.; Bhattacharya, D.; Rao, A. R.; Vadawale, S. V.

2017-11-01

We present a detailed analysis of GRB 151006A, the first gamma-ray burst (GRB) detected by AstroSat Cadmium-Zinc-Telluride Imager (CZTI). We study the long-term spectral evolution by exploiting the capabilities of Fermi and Swift satellites at different phases, which is complemented by the polarization measurement with the CZTI. While the light curve of the GRB in different energy bands shows a simple pulse profile, the spectrum shows an unusual evolution. The first phase exhibits a hard-to-soft evolution until ∼16-20 s, followed by a sudden increase in the spectral peak reaching a few MeV. Such a dramatic change in the spectral evolution in the case of a single pulse burst is reported for the first time. This is captured by all models we used namely, Band function, blackbody+Band and two blackbodies+power law. Interestingly, the Fermi Large Area Telescope also detects its first photon (>100 MeV) during this time. This new injection of energy may be associated with either the beginning of afterglow phase, or a second hard pulse of the prompt emission itself that, however, is not seen in the otherwise smooth pulse profile. By constructing Bayesian blocks and studying the hardness evolution we find a good evidence for a second hard pulse. The Swift data at late epochs (>T90 of the GRB) also show a significant spectral evolution consistent with the early second phase. The CZTI data (100-350 keV), though having low significance (1σ), show high values of polarization in the two epochs (77-94 per cent), in agreement with our interpretation.

Electric quadrupole interactions on /sup 12/B and /sup 12/N implanted in Mg studied by nuclear depolarization due to level mixing

Energy Technology Data Exchange (ETDEWEB)

Tanihata, I; Kogo, S; Sugimoto, K [Osaka Univ., Toyonaka (Japan). Lab. of Nuclear Studies

1977-04-25

Electric quadrupole interactions on polarized /sup 12/B and /sup 12/N implanted in a Mg single crystal have been studied by a new method in which the nuclear depolarization due to level mixing caused by an external magnetic field is detected.

Analytical results for a conditional phase shift between single-photon pulses in a nonlocal nonlinear medium

Science.gov (United States)

Viswanathan, Balakrishnan; Gea-Banacloche, Julio

2018-03-01

It has been suggested that second-order nonlinearities could be used for quantum logic at the single-photon level. Specifically, successive two-photon processes in principle could accomplish the phase shift (conditioned on the presence of two photons in the low-frequency modes) |011 〉→i |100 〉→-|011 〉 . We have analyzed a recent scheme proposed by Xia et al. [Phys. Rev. Lett. 116, 023601 (2016)], 10.1103/PhysRevLett.116.023601 to induce such a conditional phase shift between two single-photon pulses propagating at different speeds through a nonlinear medium with a nonlocal response. We present here an analytical solution for the most general case, i.e., for an arbitrary response function, initial state, and pulse velocity, which supports their numerical observation that a π phase shift with unit fidelity is possible, in principle, in an appropriate limit. We also discuss why this is possible in this system, despite the theoretical objections to the possibility of conditional phase shifts on single photons that were raised some time ago by Shapiro [Phys. Rev. A 73, 062305 (2006)], 10.1103/PhysRevA.73.062305 and by Gea-Banacloche [Phys. Rev. A 81, 043823 (2010)], 10.1103/PhysRevA.81.043823 one of us.

A portable high-field pulsed-magnet system for single-crystal x-ray scattering studies

International Nuclear Information System (INIS)

Islam, Zahirul; Lang, Jonathan C.; Ruff, Jacob P. C.; Ross, Kathryn A.; Gaulin, Bruce D.; Nojiri, Hiroyuki; Matsuda, Yasuhiro H.; Qu Zhe

2009-01-01

We present a portable pulsed-magnet system for x-ray studies of materials in high magnetic fields (up to 30 T). The apparatus consists of a split-pair of minicoils cooled on a closed-cycle cryostat, which is used for x-ray diffraction studies with applied field normal to the scattering plane. A second independent closed-cycle cryostat is used for cooling the sample to near liquid helium temperatures. Pulsed magnetic fields (∼1 ms in total duration) are generated by discharging a configurable capacitor bank into the magnet coils. Time-resolved scattering data are collected using a combination of a fast single-photon counting detector, a multichannel scaler, and a high-resolution digital storage oscilloscope. The capabilities of this instrument are used to study a geometrically frustrated system revealing strong magnetostrictive effects in the spin-liquid state.

Analysis of magnetic nanoparticles using quadrupole magnetic field-flow fractionation

International Nuclear Information System (INIS)

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

2005-01-01

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

Waferscale Electrostatic Quadrupole Array for Multiple Ion Beam Manipulation

OpenAIRE

Vinayakumar, K. B.; Persaud, A.; Seidl, P. A.; Ji, Q.; Waldron, W. L.; Schenkel, T.; Ardanuc, S.; Lal, A.

2018-01-01

We report on the first through-wafer silicon-based Electrostatic Quadrupole Array (ESQA) to focus high energy ion beams. This device is a key enabler for a wafer based accelerator architecture that lends itself to orders-of-magnitude reduction in cost, volume and weight of charged particle accelerators. ESQs are a key building block in developing compact Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) [1]. In a MEQALAC electrostatic forces are used to focus ions, and elec...

Mechanical Design of a Second Generation LHC IR Quadrupole

International Nuclear Information System (INIS)

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

2003-01-01

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

Method for pulse to pulse dose reproducibility applied to electron linear accelerators

International Nuclear Information System (INIS)

Ighigeanu, D.; Martin, D.; Oproiu, C.; Cirstea, E.; Craciun, G.

2002-01-01

An original method for obtaining programmed beam single shots and pulse trains with programmed pulse number, pulse repetition frequency, pulse duration and pulse dose is presented. It is particularly useful for automatic control of absorbed dose rate level, irradiation process control as well as in pulse radiolysis studies, single pulse dose measurement or for research experiments where pulse-to-pulse dose reproducibility is required. This method is applied to the electron linear accelerators, ALIN-10 of 6.23 MeV and 82 W and ALID-7, of 5.5 MeV and 670 W, built in NILPRP. In order to implement this method, the accelerator triggering system (ATS) consists of two branches: the gun branch and the magnetron branch. ATS, which synchronizes all the system units, delivers trigger pulses at a programmed repetition rate (up to 250 pulses/s) to the gun (80 kV, 10 A and 4 ms) and magnetron (45 kV, 100 A, and 4 ms).The accelerated electron beam existence is determined by the electron gun and magnetron pulses overlapping. The method consists in controlling the overlapping of pulses in order to deliver the beam in the desired sequence. This control is implemented by a discrete pulse position modulation of gun and/or magnetron pulses. The instabilities of the gun and magnetron transient regimes are avoided by operating the accelerator with no accelerated beam for a certain time. At the operator 'beam start' command, the ATS controls electron gun and magnetron pulses overlapping and the linac beam is generated. The pulse-to-pulse absorbed dose variation is thus considerably reduced. Programmed absorbed dose, irradiation time, beam pulse number or other external events may interrupt the coincidence between the gun and magnetron pulses. Slow absorbed dose variation is compensated by the control of the pulse duration and repetition frequency. Two methods are reported in the electron linear accelerators' development for obtaining the pulse to pulse dose reproducibility: the method

High-temperature quadrupole mass spectrometer for studying vaporization from materials heated by a CO2 laser

International Nuclear Information System (INIS)

Fredin, L.; Hansen, G.P.; Sampson, M.P.; Margrave, J.L.; Behrens, R.G.

1986-09-01

To evaluate the effectiveness of mass spectrometry techniques in studying vaporization from selected materials, we designed a mass spectrometer than can be used either with a continuous wave or pulsed laser heating system or with a conventional furnace heating system. Our experimental apparatus, the components of which are described in detail, consisted of a quadrupole mass spectrometer positioned in a crossed-beam configuration, controlling electronics, a data acquisition system, a vacuum system, a cryogenic collimation system, and a laser heating system. Results of mass spectral scans taken during laser pyrolysis of polymeric materials and laser vaporization of graphite were compatible with data reported in other studies. Results of mass spectral studies of laser-induced combustion in the Ti + C system are also presented

Note: Pulsed single longitudinal mode optical parametric oscillator for sub-Doppler spectroscopy of jet cooled transient species

Science.gov (United States)

Zhang, Qiang; Zhu, Boxing; Zhang, Deping; Gu, Jingwang; Zhao, Dongfeng; Chen, Yang

2017-12-01

We present a pulsed single longitudinal mode optical parametric oscillator that was recently constructed for sub-Doppler spectroscopic studies of transient species in a supersonic slit jet expansion environment. The system consists of a Littman-type grazing-incidence-grating resonator and a KTP crystal and is pumped at 532 nm. By spatially filtering the pump laser beam and employing an active cavity-length-stabilization scheme, a frequency down-conversion efficiency up to 18% and generation of Fourier-transform limited pulses with a typical pulse duration of ˜5.5 ns and a bandwidth less than 120 MHz have been achieved. In combination with a slit jet expansion, a sub-Doppler spectrum of SiC2 has been recorded at ˜498 nm, showing a spectral resolution of Δν/ν ≈ 6.2 × 10-7.

The Analysis of Quadrupole Magnetic Focusing Effect by Finite Element Method

International Nuclear Information System (INIS)

Utaja

2003-01-01

Quadrupole magnets will introduce focusing effect to a beam of the charge particle passing parallel to the magnet faces. The focusing effect is need to control the particle beam, so that it is in accordance with necessity requirement stated. This paper describes the analysis of focusing effect on the quadrupole magnetic by the finite element method. The finite element method in this paper is used for solve the potential distribution of magnetic field. If the potential magnetic field distribution in every node have known, a charge particle trajectory can be traced. This charge particle trajectory will secure the focusing effect of the quadrupole magnets. (author)

Structures and Nuclear Quadrupole Coupling Tensors of a Series of Chlorine-Containing Hydrocarbons

Science.gov (United States)

Dikkumbura, Asela S.; Webster, Erica R.; Dorris, Rachel E.; Peebles, Rebecca A.; Peebles, Sean A.; Seifert, Nathan A.; Pate, Brooks

2016-06-01

Rotational spectra for gauche-1,2-dichloroethane (12DCE), gauche-1-chloro-2-fluoroethane (1C2FE) and both anti- and gauche-2,3-dichloropropene (23DCP) have been observed using chirped-pulse Fourier-transform microwave (FTMW) spectroscopy in the 6-18 GHz region. Although the anti conformers for all three species are predicted to be more stable than the gauche forms, they are nonpolar (12DCE) or nearly nonpolar (predicted dipole components for anti-1C2FE: μ_a = 0.11 D, μ_b = 0.02 D and for anti-23DCP: μ_a = 0.25 D, μ_b = 0.02 D); nevertheless, it was also possible to observe and assign the spectrum of anti-23DCP. Assignments of parent spectra and 37Cl and 13C substituted isotopologues utilized predictions at the MP2/6-311++G(2d,2p) level and Pickett's SPCAT/SPFIT programs. For the weak anti-23DCP spectra, additional measurements also utilized a resonant-cavity FTMW spectrometer. Full chlorine nuclear quadrupole coupling tensors for gauche-12DCE and both anti- and gauche-23DCP have been diagonalized to allow comparison of coupling constants. Kraitchman's equations were used to determine r_s coordinates of isotopically substituted atoms and r_0 structures were also deduced for gauche conformers of 12DCE and 1C2FE. Structural details and chlorine nuclear quadrupole coupling constants of all three molecules will be compared, and effects of differing halogen substitution and carbon chain length on molecular properties will be evaluated.

Saturated multikilovolt x-ray amplification with Xe clusters: single-pulse observation of Xe(L) spectral hole burning

International Nuclear Information System (INIS)

Borisov, Alex B; Davis, Jack; Song, Xiangyang; Koshman, Yevgeniya; Dai Yang; Boyer, Keith; Rhodes, Charles K

2003-01-01

Single-pulse measurements of spectral hole burning of Xe(L) 3d → 2p hollow atom transition arrays observed from a self-trapped plasma channel provide new information on the dynamics of saturated amplification in the λ ∼ 2.8-2.9 A region. The spectral hole burning on transitions in the Xe 34+ and Xe 35+ arrays reaches full suppression of the spontaneous emission and presents a corresponding width Δ h-bar ω x ∼ = 60 eV, a value adequate for efficient amplification of multikilovolt x-ray pulses down to a limiting length τ x ∼ 30 as. The depth of the suppression at 2.86 A indicates that the gain-to-loss ratio is ≥10. An independent determination of the x-ray pulse energy from damage produced on the surface of a Ti foil in the far field of the source gives a pulse energy of 20-30 μJ, a range that correlates well with the observation of the spectral hole burning and indicates an overall extraction efficiency of ∼10%. (letter to the editor)

Relaxation of quadrupole orientation in an optically pumped alkali vapour

Energy Technology Data Exchange (ETDEWEB)

Bernabeu, E; Tornos, J

1985-04-01

The relaxation of quadrupole orientation (alignment) in an optically pumped alkali vapour is theoretically studied by taking into account the relaxation processes by alkali-buffer gas, alkali-alkali with spin exchange and alkali-cell wall (diffusion process) collisions. The relaxation transients of the quadrupole orientation are obtained by introducing a first-order weak-pumping approximation (intermediate pumping) less restrictive than the usually considered (zeroth order) one.

Nuclear quadrupole interactions in ferroelectric compounds of HF/sup 181/

Energy Technology Data Exchange (ETDEWEB)

Kunzler, J V

1971-01-01

Measurements of nuclear quadrupole interaction constants in perovkite-type compounds of PbHfO/sub 3/, SnhfO/sub 3/, CaHfO/sub 3/ e SrHfO/sub 3/ have been performed using the perturbed angular correlation technique. A range of fundamental frequencies from 150 to 550 Megaradians per second was determined. The variation of quadrupole constants has been discussed through the molecular orbital theory.

Superconducting Quadrupole for the ISR High Luminosity insertion:end view

CERN Multimedia

1977-01-01

Connection end view of the prototype quadrupole before insertion of the inner vacuum chamber with inbedded 6-pole windings. The main components of the structure can be seen: (from inside outwards) the superconducting quadrupole coils surrounded by glass epoxy bandage rings and stainless steel spacers, the low-carbon steel yoke quadrants and the aluminium alloy shrinking rings. See also photos 7702690X, 7702307, 7702308, 7812604X.

Compact high-field superconducting quadrupole magnet with holmium poles

Energy Technology Data Exchange (ETDEWEB)

Barlow, D.B.; Kraus, R.H. Jr.; Lobb, C.T.; Menzel, M.T. (Los Alamos National Lab., NM (United States)); Walstrom, P.L. (Grumman Space Systems, Los Alamos, NM (United States))

1992-03-15

A compact high-field superconducting quadrupole magnet was designed and built with poles made of the rare-earth metal holmium. The magnet is intended for use in superconducting coupled-cavity linear accelerators where compact high-field quadrupoles are needed, but where the use of permanent magnets is ruled out because of trapped-flux losses. The magnet has a clear bore diameter of 1.8 cm, outside diameter of 11 cm, length of 11 cm, and pole tip length of 6 cm. The effect of using holmium, a material with a higher saturation field than iron, was investigated by replacing poles made of iron with identical poles made of holmium. The magnet was operated at a temperature of 4.2 K and reached a peak quadrupole field gradient of 355 T/m, a 10% increase over the same magnet with iron poles. This increase in performance is consistent with calculations based on B-H curves that were measured for holmium at 4.2 K. (orig.).

Femtosecond laser ablation of silver foil with single and double pulses

CSIR Research Space (South Africa)

Roberts, DE

2009-01-01

Full Text Available The average ablation depth per pulse of silver foil by 130 fs laser pulses has been measured in vacuum over a range of three orders of magnitude of pulse fluence up to 900 J cm-2. In addition, double pulses with separations up to 3.4 ns have been...

Construction and Qualification of the Pre-Series MQM Superconducting Quadrupoles for the LHC Insertions

CERN Document Server

Ostojic, R; Lucas, J; Venturini-Delsolaro, W; Landgrebe, D

2004-01-01

The LHC insertions will be equipped with individually powered MQM superconducting quadrupoles, produced in three versions with magnetic lengths of 2.4 m, 3.4 m, and 4.8 m. The quadrupoles feature a 56 mm aperture coil, designed on the basis of an 8.8 mm wide Rutherford-type NbTi cable for a nominal gradient of 200 T/m at 1.9 K and 5390 A. A total of 96 quadrupoles are in production in Tesla Engineering, UK. In this report we describe the construction of the pre-series MQM quadrupoles and present the results of the qualification tests.

The tensile effect on crack formation in single crystal silicon irradiated by intense pulsed ion beam

Science.gov (United States)

Liang, Guoying; Shen, Jie; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Yan, Sha; Zhang, Xiaofu; Yu, Xiao; Le, Xiaoyun

2017-10-01

Improving antifatigue performance of silicon substrate is very important for the development of semiconductor industry. The cracking behavior of silicon under intense pulsed ion beam irradiation was studied by numerical simulation in order to understand the mechanism of induced surface peeling observed by experimental means. Using molecular dynamics simulation based on Stillinger Weber potential, tensile effect on crack growth and propagation in single crystal silicon was investigated. Simulation results reveal that stress-strain curves of single crystal silicon at a constant strain rate can be divided into three stages, which are not similar to metal stress-strain curves; different tensile load velocities induce difference of single silicon crack formation speed; the layered stress results in crack formation in single crystal silicon. It is concluded that the crack growth and propagation is more sensitive to strain rate, tensile load velocity, stress distribution in single crystal silicon.

AA, wide quadrupole on measurement stand

CERN Multimedia

CERN PhotoLab

1981-01-01

Please look up 8101024 and 8103203 first. Wide quadrupole (QFW, QDW) with end-shims and shimming washers on the measurement stand. With the measurement coil one measured the harmonics of the magnetic field, determined the magnetic centre, and catalogued the effect of washer constellations.

Design, simulation and construction of quadrupole magnets for focusing electron beam in powerful industrial electron accelerator

Directory of Open Access Journals (Sweden)

S KH Mousavi

2015-09-01

Full Text Available In this paper the design and simulation of quadrupole magnets and electron beam optical of that by CST Studio code has been studied. Based on simulation result the magnetic quadrupole has been done for using in beam line of first Iranian powerful electron accelerator. For making the suitable magnetic field the effects of material and core geometry and coils current variation on quadrupole magnetic field have been studied. For test of quadrupole magnet the 10 MeV beam energy and 0.5 pi mm mrad emittance of input beam has been considered. We see the electron beam through the quadrupole magnet focus in one side and defocus in other side. The optimum of distance between two quadrupole magnets for low emittance have been achieved. The simulation results have good agreement with experimental results

Observation of a phononic quadrupole topological insulator

Science.gov (United States)

Serra-Garcia, Marc; Peri, Valerio; Süsstrunk, Roman; Bilal, Osama R.; Larsen, Tom; Villanueva, Luis Guillermo; Huber, Sebastian D.

2018-03-01

The modern theory of charge polarization in solids is based on a generalization of Berry’s phase. The possibility of the quantization of this phase arising from parallel transport in momentum space is essential to our understanding of systems with topological band structures. Although based on the concept of charge polarization, this same theory can also be used to characterize the Bloch bands of neutral bosonic systems such as photonic or phononic crystals. The theory of this quantized polarization has recently been extended from the dipole moment to higher multipole moments. In particular, a two-dimensional quantized quadrupole insulator is predicted to have gapped yet topological one-dimensional edge modes, which stabilize zero-dimensional in-gap corner states. However, such a state of matter has not previously been observed experimentally. Here we report measurements of a phononic quadrupole topological insulator. We experimentally characterize the bulk, edge and corner physics of a mechanical metamaterial (a material with tailored mechanical properties) and find the predicted gapped edge and in-gap corner states. We corroborate our findings by comparing the mechanical properties of a topologically non-trivial system to samples in other phases that are predicted by the quadrupole theory. These topological corner states are an important stepping stone to the experimental realization of topologically protected wave guides in higher dimensions, and thereby open up a new path for the design of metamaterials.

The effect of quadrupole force to the spectra of nuclei in the f7/2 shell

International Nuclear Information System (INIS)

Zhang Qingying

1992-01-01

The effect of quadrupole force on the spectra of nuclei in the f 7/2 shell is tested. The nuclear spectra are calculated by using the surface delta interaction plus quadrupole interaction and the modified surface delta interaction respectively. The results calculated with the former are much better than those with the latter, the role of the isospin modified term in the modified surface delta interaction can be substituted by the quadrupole interaction term. It is also shown that the effect of quadrupole interaction in the f 7/2 shell is important although the quadrupole deformations of nuclei in this region are not large

Nuclear quadrupole relaxation and viscosity in liquid metals

International Nuclear Information System (INIS)

Schirmacher, W.

1976-01-01

It is shown that the nuclear quadrupole relaxation rate due to the molecular motions in liquid metals is related to the shear and bulk viscosity and hence to the absorption coefficient of ultrasound. Application of the 'extended liquid phonon' model of Ortoleva and Nelkin - which is the third of a series of continued-fraction-approximations for the van Hove neutron scattering function - gives a relation to the self diffusion constant. The predictions of the theory concerning the temperature dependence are compared with quadrupole relaxation measurements of Riegel et al. and Kerlin et al. in liquid gallium. Agreement is found only with the data of Riegel et al. (orig.) [de

Low-frequency quadrupole impedance of undulators and wigglers

Directory of Open Access Journals (Sweden)

A. Blednykh

2016-10-01

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

Radiation and penetration matrix elements for magnetic quadrupole transitions between Nilsson states in odd nuclei

International Nuclear Information System (INIS)

Feresin, A.P.; Guseva, I.S.

1984-01-01

Single-particle matrix elements for magnetic quadrupole gamma radiation in odd deformed nuclei, calculated with the aid of Nilsson-potential wave functions, are presented. Also given are the internal conversion penetration matrix elements, calculated in the same manner. The penetration matrix elements are needed to estimate the nuclear penetration parameter, which determines the deviation of experimental internal conversion coefficients from their standard values given in tables. Matrix elements are given for transitions between all pairs of Nilsson single-particle states with ΔN = 1 and ΔK = 0, 1, and 2 for the nuclear shells with 4< or =N< or =7 and for the two deformation values epsilon = 0.2 and 0.3

Ellipsoidal universe can solve the cosmic microwave background quadrupole problem.

Science.gov (United States)

Campanelli, L; Cea, P; Tedesco, L

2006-09-29

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

Anisotropy effect of crater formation on single crystal silicon surface under intense pulsed ion beam irradiation

Science.gov (United States)

Shen, Jie; Yu, Xiao; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Liang, Guoying; Yu, Xiang; Huang, Wanying; Shahid, Ijaz; Zhang, Xiaofu; Yan, Sha; Le, Xiaoyun

2018-04-01

Due to the induced extremely fast thermal and dynamic process, Intense Pulsed Ion Beam (IPIB) is widely applied in material processing, which can bring enhanced material performance and surface craters as well. To investigate the craters' formation mechanism, a specific model was built with Finite Element Methods (FEM) to simulate the thermal field on irradiated single crystal silicon. The direct evidence for the existence of the simulated 6-fold rotational symmetric thermal distribution was provided by electron microscope images obtained on single crystal silicon. The correlation of the experiment and simulation is of great importance to understand the interaction between IPIB and materials.

Design of the CLIC Quadrupole Vacuum Chambers

CERN Document Server

Garion, C

2010-01-01

The Compact Linear Collider, under study, requires vacuum chambers with a very small aperture, of the order of 8 mm in diameter, and with a length up to around 2 m for the main beam quadrupoles. To keep the very tight geometrical tolerances on the quadrupoles, no bake out is allowed. The main issue is to reach UHV conditions (typically 10-9 mbar static pressure) in a system where the vacuum performance is driven by water outgassing. For this application, a thinwalled stainless steel vacuum chamber with two ante chambers equipped with NEG strips, is proposed. The mechanical design, especially the stability analysis, is shown. The key technologies of the prototype fabrication are given. Vacuum tests are carried out on the prototypes. The test set-up as well as the pumping system conditions are presented.

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

Science.gov (United States)

Gurusinghe, Ranil M; Tubergen, Michael J

2016-05-26

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

Femtosecond pulse radiolysis based on photocathode electron accelerator

International Nuclear Information System (INIS)

Yoshida, Y.; Yang, Jinfeng; Kondoh, T.; Kozawa, T.; Tagawa, S.

2006-01-01

of the electron bunch would be indispensable in EVS. To rotate the electron bunch, a magnetic bunch compressor, which was constructed with two 45 degree-bending magnets and four quadrupole magnets (two pairs) to provide a necessary path length dependence on energy, was used. The electron beam generated from the rf gun was accelerated by a linear accelerator up to 32 MeV with energy-phase correlation in the bunch. Finally, the necessary rotation of the electron bunch was achieved by passing the electron beam through the compressor and optimizing the magnetic fields of the quadrupole magnets. In the experiment, the transient absorption kinetics of hydrated electrons in water was measured in the cases with and without the rotation of the electron bunch. The rise time of hydrated electrons of 1.2 ps was improved by rotating the electron bunch in EVS. The experimental results indicate that EVS is a powerful tool to improve the time resolution of pulse radiolysis. Moreover, the optical density in EVS is independent on the optical path length. The higher optical density can be obtained at low-charge electron beam. (authors)

Pulse Propagation in Presence of Polarization Mode Dispersion and Chromatic Dispersion in Single Mode Fibers

Directory of Open Access Journals (Sweden)

Hassan Abid Yasser

2013-01-01

Full Text Available The presence of (first and second orders polarization mode dispersion (PMD, chromatic dispersion, and initial chirp makes effects on the propagated pulses in single mode fiber. Nowadays, there is not an accurate mathematical formula that describes the pulse shape in the presence of these effects. In this work, a theoretical study is introduced to derive a generalized formula. This formula is exactly approached to mathematical relations used in their special cases. The presence of second-order PMD (SOPMD will not affect the orthogonality property between the principal states of polarization. The simulation results explain that the interaction of the SOPMD components with the conventional effects (chromatic dispersion and chirp will cause a broadening/narrowing and shape distortion. This changes depend on the specified values of SOPMD components as well as the present conventional parameters.

Magnetic field in the end region of the SSC quadrupole magnet

International Nuclear Information System (INIS)

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

Investigations on pulsed laser ablation of Sn at 1064 nm wavelength

Energy Technology Data Exchange (ETDEWEB)

Torrisi, L [Dipartimento di Fisica, Universita di Messina, Ctr. Papardo 31, 98166 S. Agata, Messina (Italy); Margarone, D [Dipartimento di Fisica, Universita di Messina, Ctr. Papardo 31, 98166 S. Agata, Messina (Italy)

2006-11-01

A Nd:Yag laser operating at 1064 nm, 900 mJ maximum pulse energy and 9 ns pulse duration, is employed to irradiate solid tin targets placed in a high vacuum (10{sup -7} mbar). The Sn plasma produced on the target surface is investigated with different analysis techniques, such as ion collectors, mass quadrupole spectrometry, electron microscopy and surface profilers. Measurements of ablation threshold, ablation yield, atomic and molecular emission, ion and neutral emission are reported. A time-of-flight technique is employed to calculate the velocity and the kinetic energy of the ion emission from the plasma. The angular distributions of the ejected ion species and of their kinetic energy are strongly peaked along the normal to the target surface. A valuation of the electric field generated inside the non-equilibrium plasma is given and discussed.

Micro-pulse polarization lidar at 1.5  μm using a single superconducting nanowire single-photon detector.

Science.gov (United States)

Qiu, Jiawei; Xia, Haiyun; Shangguan, Mingjia; Dou, Xiankang; Li, Manyi; Wang, Chong; Shang, Xiang; Lin, Shengfu; Liu, Jianjiang

2017-11-01

An all-fiber, eye-safe and micro-pulse polarization lidar is demonstrated with a polarization-maintaining structure, incorporating a single superconducting nanowire single-photon detector (SNSPD) at 1.5 μm. The time-division multiplexing technique is used to achieve a calibration-free optical layout. A single piece of detector is used to detect the backscatter signals at two orthogonal states in an alternative sequence. Thus, regular calibration of the two detectors in traditional polarization lidars is avoided. The signal-to-noise ratio of the lidar is guaranteed by using an SNSPD, providing high detection efficiency and low dark count noise. The linear depolarization ratio (LDR) of the urban aerosol is observed horizontally over 48 h in Hefei [N31°50'37'', E117°15'54''], when a heavy air pollution is spreading from the north to the central east of China. Phenomena of LDR bursts are detected at a location where a building is under construction. The lidar results show good agreement with the data detected from a sun photometer, a 532 nm visibility lidar, and the weather forecast information.

Trapping of Electron Cloud LLC/Cesrta Quadrupole and Sextupole Magnets

International Nuclear Information System (INIS)

Wang, L.

2011-01-01

The Cornell Electron Storage Ring (CESR) has been reconfigured as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R and D (1). One of the primary goals of the CesrTA program is to investigate the interaction of the electron cloud with low emittance positron beam to explore methods to suppress the electron cloud, develop suitable advanced instrumentation required for these experimental studies and benchmark predictions by simulation codes. This paper reports the simulation of the electron-cloud formation in CESRTA and ILC quadrupole and sextupole magnets using the 3D code CLOUDLAND. We found that electrons can be trapped with a long lifetime in a quadrupole and sextupole magnet due to the mirror field trapping mechanism. We study the effects of magnet strength, bunch current, ante-chamber effect, bunch spacing effect and secondary emission yield (SEY) in great detail. The development of an electron cloud in magnets is the main concern where a weak solenoid field is not effective. Quadrupole and sextupole magnets have mirror field configurations which may trap electrons by the mirror field trapping mechanism (2). Fig.1 shows the orbit of a trapped electron in a quadrupole magnet. The electron makes gyration motion (called transverse motion) and also moves along the field line (called longitudinal motion). At the mirror point (middle of the field line), there is a maximum longitudinal energy and minimum transverse energy. When the electron moves away from the mirror point, its longitudinal energy reduces and the transverse energy increases as the magnetic field increases. If the magnetic field is strong enough, the longitudinal energy becomes zero at one point and then the electron is turned back by the strong field. Note that the electrons are trapped in the region near the middle of the field lines. Although all quadrupole and sextupole magnets can trap electrons in principle, the

Microstructural evolution and mechanical performance of resistance spot welded DP1000 steel with single and double pulse welding

NARCIS (Netherlands)

Chabok, Ali; van der Aa, Ellen; De Hosson, Jeff; Pei, Yutao T.

2017-01-01

Two welding schemes of single and double pulse were used for the resistance spot welding of DP1000 dual phase steel. The changes in the mechanical performance and variant pairing of martensite under two different welding conditions were scrutinized. It is demonstrated that, although both welds fail

Control quantum evolution speed of a single dephasing qubit for arbitrary initial states via periodic dynamical decoupling pulses.

Science.gov (United States)

Song, Ya-Ju; Tan, Qing-Shou; Kuang, Le-Man

2017-03-08

We investigate the possibility to control quantum evolution speed of a single dephasing qubit for arbitrary initial states by the use of periodic dynamical decoupling (PDD) pulses. It is indicated that the quantum speed limit time (QSLT) is determined by initial and final quantum coherence of the qubit, as well as the non-Markovianity of the system under consideration during the evolution when the qubit is subjected to a zero-temperature Ohmic-like dephasing reservoir. It is shown that final quantum coherence of the qubit and the non-Markovianity of the system can be modulated by PDD pulses. Our results show that for arbitrary initial states of the dephasing qubit with non-vanishing quantum coherence, PDD pulses can be used to induce potential acceleration of the quantum evolution in the short-time regime, while PDD pulses can lead to potential speedup and slow down in the long-time regime. We demonstrate that the effect of PDD on the QSLT for the Ohmic or sub-Ohmic spectrum (Markovian reservoir) is much different from that for the super-Ohmic spectrum (non-Markovian reservoir).

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

Science.gov (United States)

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

2016-08-01

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

Energies and transition probabilities from the full solution of nuclear quadrupole-octupole model

International Nuclear Information System (INIS)

Strecker, M.; Lenske, H.; Minkov, N.

2013-01-01

A collective model of nuclear quadrupole-octupole vibrations and rotations, originally restricted to a coherent interplay between quadrupole and octupole modes, is now developed for application beyond this restriction. The eigenvalue problem is solved by diagonalizing the unrestricted Hamiltonian in the basis of the analytic solution obtained in the case of the coherent-mode assumption. Within this scheme the yrast alternating-parity band is constructed by the lowest eigenvalues having the appropriate parity at given angular momentum. Additionally we include the calculation of transition probabilities which are fitted with the energies simultaneously. As a result we obtain a unique set of parameters. The obtained model parameters unambiguously determine the shape of the quadrupole-octupole potential. From the resulting wave functions quadrupole deformation expectation values are calculated which are found to be in agreement with experimental values. (author)

Isotopic dependence of the giant quadrupole resonance in the stable even-mass molybdenum nuclei

International Nuclear Information System (INIS)

Moalem, A.; Gaillard, Y.; Bemolle, A.M.; Buenerd, M.; Chauvin, J.; Duhamel, G.; Lebrun, D.; Martin, P.; Perrin, G.; de Saintignon, P.

1979-01-01

Inelastic scattering of 110 MeV 3 He particles is used to probe the quadrupole strength in the even Mo isotopes. The peak position of the giant quadrupole resonance is found to decrease more rapidly than predicted by the A/sup -1/3/ law, a behavior very similar to that exhibited by the photonuclear giant dipole resonance. The width and strength of the giant quadrupole resonance are practically constant in 92 Mo through 100 Mo

Gold nanoshell photomodification under a single-nanosecond laser pulse accompanied by color-shifting and bubble formation phenomena

International Nuclear Information System (INIS)

Akchurin, Garif; Khlebtsov, Boris; Akchurin, Georgy; Tuchin, Valery; Zharov, Vladimir; Khlebtsov, Nikolai

2008-01-01

Laser-nanoparticle interaction is crucial for biomedical applications of lasers and nanotechnology to the treatment of cancer or pathogenic microorganisms. We report on the first observation of laser-induced coloring of gold nanoshell solution after a one nanosecond pulse and an unprecedentedly low bubble formation (as the main mechanism of cancer cell killing) threshold at a laser fluence of about 4 mJ cm -2 , which is safe for normal tissue. Specifically, silica/gold nanoshell (140/15 nm) suspensions were irradiated with a single 4 ns (1064 nm) or 8 ns (900 nm) laser pulse at fluences ranging from 0.1 mJ cm -2 to 50 J cm -2 . Solution red coloring was observed by the naked eye confirmed by blue-shifting of the absorption spectrum maximum from the initial 900 nm for nanoshells to 530 nm for conventional colloidal gold nanospheres. TEM images revealed significant photomodification of nanoparticles including complete fragmentation of gold shells, changes in silica core structure, formation of small 20-30 nm isolated spherical gold nanoparticles, gold nanoshells with central holes, and large and small spherical gold particles attached to a silica core. The time-resolved monitoring of bubble formation phenomena with the photothermal (PT) thermolens technique demonstrated that after application of a single 8 ns pulse at fluences 5-10 mJ cm -2 and higher the next pulse did not produce any PT response, indicating a dramatic decrease in absorption because of gold shell modification. We also observed a dependence of the bubble expansion time on the laser energy with unusually very fast PT signal rising (∼3.5 ns scale at 0.2 J cm -2 ). Application of the observed phenomena to medical applications is discussed, including a simple visual color test for laser-nanoparticle interaction

Design and construction of superconducting quadrupole magnets for ion beam fusion

International Nuclear Information System (INIS)

Wang, S.T.; Ludwig, H.; Turner, L.R.

1978-01-01

A high gradient superconducting quadrupole has been designed and developed as the heavy ion beam focussing element in the low velocity portions of an rf linac for the Argonne Ion Beam Fusion Reactor. The quadrupole magnets will require an extremely short magnet coil length (approximately 20 cm to 30 cm) and extremely high central gradients (approximately 100 T/m to 200 T/m). The useful warm bore will be about 4 to 6 cm and the integral gradient homogeneity should be constant to +-5% over the useful warm bore. Special techniques have been developed which are especially suitable for multilayer coil winding and coil assembly with high average current density over the coil cross section. A 5-layer quadrupole with 9 cm winding bore has been built and tested to the full performance of about 100 T/m with little training. The achieved average current density is 22,000 A/cm 2 at a peak field in conductor of about 5.0 T. An 8-layer quadrupole is under construction for a design gradient of 140 T/m over 9 cm winding bore. The peak field will be about 7.2 T

A superconducting quadrupole array for transport of multiple high current beams

International Nuclear Information System (INIS)

Faltens, A.; Shuman, D.

1999-01-01

We present a conceptual design of a superconducting quadrupole magnet array for the side-by-side transport of multiple high current particle beams in induction linear accelerators. The magnetic design uses a modified cosine 20 current distribution inside a square cell boundary. Each interior magnet's neighbors serve as the return flux paths and the poles are placed as close as possible to each other to facilitate this. No iron is present in the basic 2-D magnetic design; it will work at any current level without correction windings. Special 1/8th quadrupoles are used along the transverse periphery of the array to contain and channel flux back into the array, making every channel look as part of an infinite array. This design provides a fixed dimension array boundary equal to the quadrupole radius that can be used for arrays of any number of quadrupole channels, at any field level. More importantly, the design provides magnetic field separation between the array and the induction cores which may be surrounding it. Flux linkage between these two components can seriously affect the operation of both of them

Single mode operation in a pulsed Ti:sapphire laser oscillator with a grazing-incidence four-mirror cavity

CERN Document Server

Ko, D K; Binks, D J; Gloster, L A W; King, T A

1998-01-01

We demonstrate stable single mode operation in a pulsed Ti:sapphire laser oscillator with a novel grazing-incidence four-mirror coupled cavity. This cavity consists of a grating, a gain medium, and four mirrors and, therefore, has a four-arm interferometer configuration. Through the interferometric effect, we could suppress the adjacent modes and obtain stable single mode operation with a bandwidth of < 200 MHz. We also have developed a general analysis of the laser modes and the threshold conditions for configuration and the experimental results agree well with the theoretical predictions.

Storage of multiple single-photon pulses emitted from a quantum dot in a solid-state quantum memory

Science.gov (United States)

Tang, Jian-Shun; Zhou, Zong-Quan; Wang, Yi-Tao; Li, Yu-Long; Liu, Xiao; Hua, Yi-Lin; Zou, Yang; Wang, Shuang; He, De-Yong; Chen, Geng; Sun, Yong-Nan; Yu, Ying; Li, Mi-Feng; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan; Li, Chuan-Feng; Guo, Guang-Can

2015-01-01

Quantum repeaters are critical components for distributing entanglement over long distances in presence of unavoidable optical losses during transmission. Stimulated by the Duan–Lukin–Cirac–Zoller protocol, many improved quantum repeater protocols based on quantum memories have been proposed, which commonly focus on the entanglement-distribution rate. Among these protocols, the elimination of multiple photons (or multiple photon-pairs) and the use of multimode quantum memory are demonstrated to have the ability to greatly improve the entanglement-distribution rate. Here, we demonstrate the storage of deterministic single photons emitted from a quantum dot in a polarization-maintaining solid-state quantum memory; in addition, multi-temporal-mode memory with 1, 20 and 100 narrow single-photon pulses is also demonstrated. Multi-photons are eliminated, and only one photon at most is contained in each pulse. Moreover, the solid-state properties of both sub-systems make this configuration more stable and easier to be scalable. Our work will be helpful in the construction of efficient quantum repeaters based on all-solid-state devices. PMID:26468996

Hyperfine interaction of {sup 25}Al in {alpha}-Al{sub 2}O{sub 3} and its quadrupole moment

Energy Technology Data Exchange (ETDEWEB)

Matsuta, K., E-mail: matsuta@vg.phys.sci.osaka-u.ac.jp; Mihara, M. [Osaka University, Department of Physics (Japan); Nagatomo, T. [RIKEN (Japan); Matsumiya, R. [Osaka University, Department of Physics (Japan); Momota, S. [Kochi University of Technology (Japan); Ohtsubo, T. [Niigata University, Department of Physics (Japan); Izumikawa, T. [Niigata University, Radioisotope Center (Japan); Hirano, H.; Takahashi, S. [Niigata University, Department of Physics (Japan); Nishimura, D.; Komurasaki, J. [Osaka University, Department of Physics (Japan); Kitagawa, A.; Kanazawa, M.; Torikoshi, M.; Sato, S. [National Institute of Radiological Sciences (Japan); Fukuda, M. [Osaka University, Department of Physics (Japan); Minamisono, T. [Fukui University of Technology (Japan); Sumikama, T. [Tokyo University of Science (Japan); Tanaka, K.; Takechi, M. [RIKEN (Japan)

2007-11-15

The electric quadrupole (Q) moment of short-lived nucleus {sup 25}Al (I{sup {pi}} = 5/2{sup +}, T{sub 1/2} = 7.18 s) has been measured for the first time, by means of the {beta}-NQR technique. The spin polarization of {sup 25}Al was produced in heavy ion collisions and was kept in a {alpha}-Al{sub 2}O{sub 3} single crystal for as long as 2 s and the quadrupole coupling frequency was obtained as vertical bar eqQ / h({sup 25}Al in Al{sub 2}O{sub 3}) vertical bar = (4.05 {+-}0.30) MHz. From the result, the Q moment was determined as |Q({sup 25}Al)| = (240 {+-}20) mb. The present Q moment is larger by 30% than the shell model value of 184 mb, calculated by OXBASH code, which may show additional deformation of the nucleus.

Electrostatic deposition of a micro solder particle using a single probe by applying a single rectangular pulse

International Nuclear Information System (INIS)

Nakabayashi, Daizo; Sawai, Kenji; Saito, Shigeki; Takahashi, Kunio

2012-01-01

Recently, micromanipulation techniques have been in high demand. A technique to deposit a metal microparticle onto a metal substrate by using a single metal probe has been proposed as one of the techniques. A solder particle with a diameter of 20–30 µm, initially adhering to the probe tip, is detached and deposited onto a substrate. The success rate of the particle deposition was 44% in the previous research, and is insufficient for industrial applications. In this paper, a technique of particle deposition by applying a single rectangular pulse is proposed, and the mechanism of the deposition is described. In the mechanism, an electric discharge between the probe and the particle when the particle reaches the substrate plays an important role in the particle deposition. Moreover, the mechanism of the proposed technique is verified by experiments of particle deposition, which are observed using a high-speed camera, a scanning electron microscope (SEM) and an oscilloscope. The success rate of the particle deposition has increased to 93% by the proposed technique. Furthermore, the damage to the particle by the electric discharge is evaluated using an RC circuit model, and the applicability of the proposed technique is discussed. (paper)

Conceptual design of a quadrupole magnet for eRHIC

Energy Technology Data Exchange (ETDEWEB)

Witte, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, J. S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-05-03

eRHIC is a proposed upgrade to the existing Relativistic Heavy Ion Collider (RHIC) hadron facility at Brookhaven National Laboratory, which would allow collisions of up to 21 GeV polarized electrons with a variety of species from the existing RHIC accelerator. eRHIC employs an Energy Recovery Linac (ERL) and an FFAG lattice for the arcs. The arcs require open-midplane quadrupole magnets of up to 30 T/m gradient of good field quality. In this paper we explore initial quadrupole magnet design concepts based on permanent magnetic material which allow to modify the gradient during operation.

LARP Long Nb3Sn Quadrupole Design

International Nuclear Information System (INIS)

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

2008-01-01

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

LARP Long Nb3Sn Quadrupole Design

International Nuclear Information System (INIS)

Ambrosio, G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidize, G.; Dietderich, D.; Feher, S.; Felice, H.; Ferracin, P.; Fermilab; Brookhaven; LBL, Berkeley; Texas A-M

2007-01-01

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

LARP Long Nb3Sn Quadrupole Design

International Nuclear Information System (INIS)

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

2007-01-01

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

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

Science.gov (United States)

Irwansyah, Kuse, Naoyuki; Usagawa, Tsuyoshi

2017-08-01

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

Simultaneous and Sequential MS/MS Scan Combinations and Permutations in a Linear Quadrupole Ion Trap.

Science.gov (United States)

Snyder, Dalton T; Szalwinski, Lucas J; Cooks, R Graham

2017-10-17

Methods of performing precursor ion scans as well as neutral loss scans in a single linear quadrupole ion trap have recently been described. In this paper we report methodology for performing permutations of MS/MS scan modes, that is, ordered combinations of precursor, product, and neutral loss scans following a single ion injection event. Only particular permutations are allowed; the sequences demonstrated here are (1) multiple precursor ion scans, (2) precursor ion scans followed by a single neutral loss scan, (3) precursor ion scans followed by product ion scans, and (4) segmented neutral loss scans. (5) The common product ion scan can be performed earlier in these sequences, under certain conditions. Simultaneous scans can also be performed. These include multiple precursor ion scans, precursor ion scans with an accompanying neutral loss scan, and multiple neutral loss scans. We argue that the new capability to perform complex simultaneous and sequential MS n operations on single ion populations represents a significant step in increasing the selectivity of mass spectrometry.

Quadrupole magnetic mapping of the high resolution spectrometers of Thomas Jefferson National Accelerator Laboratory, Hall A. (Q.M.M. project: Quadrupole Magnetic Measurement)

International Nuclear Information System (INIS)

Quemener, Gilles

1997-01-01

This thesis describes the magnetic measurements that have been performed on the superconducting quadrupoles of the High Resolution Spectrometers of TJNAF, Hall A (USA), which are designed to measure particle momentum up to 4 GeV.c -1 with a σp/p = 10 -4 resolution. The mapping method is based on rotating coil technique, the originality being a segmentation of the probe along the quad axis. Together with an accurate magnet modelling, the measurement of the flux variations through the set of rotating coils allows to determine the magnetic field at each point. We use the 3D field formalism, i.e., the Fourier-Bessel expansion of the field obtained by solving the Laplace equation. We describe the QMM method and then the apparatus consisting in two probes of length 1.6 m and 3.2 m built to map the three quadrupoles Q1, Q2, Q3. Data processing uses Fourier analysis. The mapping of the Electron Arm took place in situ in 1996. A first set of results concerns integral measurements including the properties of excitation cycle of the magnets (saturation and hysteresis). Second set of results in terms of local field yields the 3D field maps of the quadrupoles. After having applied corrections to the data we obtain a local field accuracy of 5 Gauss on each component, i.e. an uncertainty of 5.10 -4 relative to the quadrupole central field. We use SNAKE ray-tracing code with the implementation of QMM field maps and obtain preliminary results on HRS optics. (author)

Pulsed irradiation of enriched UO{sub 2} in the Annular Core Pulse Reactor (ACPR)

Energy Technology Data Exchange (ETDEWEB)

Schmidt, T R; Lucoff, D M; Reil, K O; Croucher, D W [Sandia Laboratories (United States)

1974-07-01

A series of experiments have been conducted in the Annular Core Pulse Reactor (ACPR) to determine the energy deposition and behavior of enriched UO{sub 2} under pulse conditions. In the experiment single unirradiated pellets with enrichments up to 25 percent were pulse heated to melt temperatures. Temperature and fission product inventory measurements were made and compared with neutron transport calculations. (author)

Kinetic equilibrium of space charge dominated beams in a misaligned quadrupole focusing channel

International Nuclear Information System (INIS)

Goswami, A.; Sing Babu, P.; Pandit, V. S.

2013-01-01

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

The System of Nanosecond 280-keV-He⁺ Pulsed Beam

CERN Document Server

Junphong, Pimporn; Lekprasert, Banyat; Suwannakachorn, Dusadee; Thongnopparat, N; Vilaithong, Thiraphat; Wiedemann, Helmut

2005-01-01

At Fast Neutron Research Facility,the 150 kV-pulseds neutron generator is being upgraded to produce a 280-keV-pulsed-He beam for time-of-flight Rutherford backscattering spectrometry. It involves replacing the existing beam line elements by a multicusp ion source, a 400-kV accelerating tube, 45o-double focusing dipole magnet and quadrupole lens. The Multicusp ion source is a compact filament-driven of 2.6 cm in diameter and 8 cm in length. The current extracted is 20.4 μA with 13 kV of extraction voltage and 8.8 kV of Einzel lens voltage. The beam emittance has been found to vary between 6-12 mm mrad. The beam transport system has to be redesigned based on the new elements. The important part of a good pulsed beam depends on the pulsing system. The two main parts are the chopper and buncher. An optimized geometry for the 280 keV pulsed helium ion beam will be presented and discussed. The PARMELA code has been used to optimize the space charge effect, resulting in pulse width of less than 2 ns at a t...

MQRAD, a computer code for synchrotron radiation from quadrupole magnets

International Nuclear Information System (INIS)

Morimoto, Teruhisa.

1984-01-01

The computer code, MQRAD, is developed for the calculation of the synchrotron radiation from the particles passing through quadrupole magnets at the straight section of the electron-positron colliding machine. This code computes the distributions of photon numbers and photon energies at any given points on the beam orbit. In this code, elements such as the quadrupole magnets and the drift spaces can be divided into many sub-elements in order to obtain the results with good accuracy. The synchrotron radiation produced by inserted quadrupole magnets at the interaction region of the electron-positron collider is one of the main background sources to the detector. The masking system against the synchrotron radiation at TRISTAN is very important because of the relatively high beam energy and the long straight section, which are 30 GeV and 100 meters, respectively. MQRAD has been used to design the masking system of the TOPAZ detector and the result is presented here as an example. (author)

The puzzle of the 6Li quadrupole moment: steps toward the solution

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Kukulin, V.I.; Pomerantsev, V.N.

2005-01-01

The problem of origin of the ground-state 6 Li quadrupole deformation has been investigated with account of the three-deuteron component of this nucleus wave function. two long-standing puzzles related to the tensor interaction in 6 Li are known. The first one lies in the anomalously small value of the 6 Li quadrupole moment which, being negative, is in absolute magnitude smaller by the factor of 5 than that of 6 Li. The second puzzle consists in the anomalous behavior of the tensor analyzing power T 2q in scattering of polarized 6 Li nuclei from various targets. It is shown that the large (in absolute magnitude) negative contribution to the 6 Li quadrupole moment resulting from the three-deuteron configuration cancels almost completely the direct positive contribution due to the folding αd-potential. As a result, the total quadrupole moment turns out to be close to zero and highly sensitive to fine details of the tensor NN interaction and of the 4 He wave function [ru

Effect of supply voltage and body-biasing on single-event transient pulse quenching in bulk fin field-effect-transistor process

International Nuclear Information System (INIS)

Yu Jun-Ting; Chen Shu-Ming; Chen Jian-Jun; Huang Peng-Cheng; Song Rui-Qiang

2016-01-01

Charge sharing is becoming an important topic as the feature size scales down in fin field-effect-transistor (FinFET) technology. However, the studies of charge sharing induced single-event transient (SET) pulse quenching with bulk FinFET are reported seldomly. Using three-dimensional technology computer aided design (3DTCAD) mixed-mode simulations, the effects of supply voltage and body-biasing on SET pulse quenching are investigated for the first time in bulk FinFET process. Research results indicate that due to an enhanced charge sharing effect, the propagating SET pulse width decreases with reducing supply voltage. Moreover, compared with reverse body-biasing (RBB), the circuit with forward body-biasing (FBB) is vulnerable to charge sharing and can effectively mitigate the propagating SET pulse width up to 53% at least. This can provide guidance for radiation-hardened bulk FinFET technology especially in low power and high performance applications. (paper)

Ab initio determination of the nuclear quadrupole moments of 114In, 115In, and 117In

International Nuclear Information System (INIS)

Errico, Leonardo A.; Renteria, Mario

2006-01-01

We present here ab initio determinations of the nuclear-quadrupole moment Q of hyperfine-probe-nuclear states of three different In isotopes: the 5 + 192 keV excited state of 114 In (probe for nuclear quadrupole alignment spectroscopy), the 9/2 + ground state of 115 In (nuclear magnetic and nuclear quadrupole resonance probe), and the 3/2 + 659 keV excited state of 117 In (perturbed angular correlations probe). These nuclear-quadrupole moments were determined by comparing experimental nuclear-quadrupole frequencies to the electric field gradient tensor calculated with high accuracy at In sites in metallic indium within the density functional theory. These ab initio calculations were performed with the full-potential linearized augmented plane wave method. The results obtained for the quadrupole moments of 114 In [Q( 114 In)=-0.14(1) b] are in clear discrepancy with those reported in the literature [Q( 114 In)=+0.16(6) b and +0.739(12) b]. For 115 In and 117 In our results are in excellent agreement with the literature and in the last case Q( 117 In) is determined with more precision. In the case of Q( 117 In), its sign cannot be determined because standard γ-γ perturbed angular correlations experiments are not sensitive to the sign of the nuclear-quadrupole frequency

Compact femtosecond electron diffractometer with 100 keV electron bunches approaching the single-electron pulse duration limit

International Nuclear Information System (INIS)

Waldecker, Lutz; Bertoni, Roman; Ernstorfer, Ralph

2015-01-01

We present the design and implementation of a highly compact femtosecond electron diffractometer working at electron energies up to 100 keV. We use a multi-body particle tracing code to simulate electron bunch propagation through the setup and to calculate pulse durations at the sample position. Our simulations show that electron bunches containing few thousands of electrons per bunch are only weakly broadened by space-charge effects and their pulse duration is thus close to the one of a single-electron wavepacket. With our compact setup, we can create electron bunches containing up to 5000 electrons with a pulse duration below 100 fs on the sample. We use the diffractometer to track the energy transfer from photoexcited electrons to the lattice in a thin film of titanium. This process takes place on the timescale of few-hundred femtoseconds and a fully equilibrated state is reached within 1 ps

Test Results of the LARP Nb$_3$Sn Quadrupole HQ03a

CERN Document Server

DiMarco, J; Anerella, M; Bajas, H; Chlachidze, G; Borgnolutti, F; Bossert, R; Cheng, D W; Dietderich, D; Felice, H; Pan, H; Ferracin, P; Ghosh, A; Godeke, A; Hafalia, A R; Marchevsky, M; Orris, D; Ravaioli, E; Sabbi, G; Salmi, T; Schmalzle, J; Stoynev, S; Strauss, T; Sylvester, C; Tartaglia, M; Todesco, E; Wanderer, P; Wang, X R; Yu, M

2016-01-01

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

Electron tunnelling through single azurin molecules can be on/off switched by voltage pulses

Energy Technology Data Exchange (ETDEWEB)

Baldacchini, Chiara [Biophysics and Nanoscience Centre, DEB-CNISM, Università della Tuscia, I-01100 Viterbo (Italy); Institute of Agro-Environmental and Forest Biology, CNR, I-05010 Porano (Italy); Kumar, Vivek; Bizzarri, Anna Rita; Cannistraro, Salvatore, E-mail: cannistr@unitus.it [Biophysics and Nanoscience Centre, DEB-CNISM, Università della Tuscia, I-01100 Viterbo (Italy)

2015-05-04

Redox metalloproteins are emerging as promising candidates for future bio-optoelectronic and nano-biomemory devices, and the control of their electron transfer properties through external signals is still a crucial task. Here, we show that a reversible on/off switching of the electron current tunnelling through a single protein can be achieved in azurin protein molecules adsorbed on gold surfaces, by applying appropriate voltage pulses through a scanning tunnelling microscope tip. The observed changes in the hybrid system tunnelling properties are discussed in terms of long-sustained charging of the protein milieu.

Resolution limit of probe-forming systems with magnetic quadrupole lens triplets and quadruplets

International Nuclear Information System (INIS)

Ponomarev, A.G.; Melnik, K.I.; Miroshnichenko, V.I.; Storizhko, V.E.; Sulkio-Cleff, B.

2003-01-01

Over the past decade, in MeV ion beam microanalysis efforts to achieve a spatial resolution better than 0.1 μm with a beam current of ∼100 pA have been connected with microprobes of new generation where the probe is formed by means of separated magnetic quadrupole lens structures . However, as was pointed out in , no dramatic improvements in spatial resolution have been produced so far. For better understanding of the situation the authors carried out theoretical studies of multiparameter sets of probe-forming systems based on separated triplets and quadruplets of magnetic quadrupole lenses. Comparisons were made between the highest current values attained at different systems for a given beam spot size. The maximum parasitic sextupole and octupole field components were found whose contributions to spot broadening are tolerable. It is shown that the use of modern electrostatic accelerators and precision magnetic quadrupole lenses makes it possible to eliminate the effect of chromatic aberrations and second- and third-order parasitic aberrations resulting from distortions of the quadrupole lens symmetry. Therefore probe-forming systems with triplets and quadruplets of magnetic quadrupole lenses have a lower theoretical spatial resolution limit which is restricted mainly by intrinsic spherical third-order aberrations in state-of-the-art microprobes

Pulse laser induced change in thermal radiation from a single spherical particle on thermally bad conducting surface : an analytical solution

International Nuclear Information System (INIS)

Moksin, M.M.; Grozescu, V.I.; Yunus, W.M.M.; Azmi, B.Z.; Talib, Z.A.; Wahab, Z.A.

1996-01-01

A relatively simple analytical expression was derived that provided a description of the radius and thermal properties of a single particle from the change in grey body radiation emission subsequent to pulse laser heating of the particle

Global set of quadrupole deformation parameters for even-even nuclei

International Nuclear Information System (INIS)

Raman, S.; Nestor, C.W. Jr.

1986-01-01

A compilation of experimental results has been completed for the reduced electric quadrupole transition probability [B(E2)up arrow] between the 0 + ground state and the first 2 + state in even-even nuclei. This compilation together with certain simple relationships noted by other authors can be used to make reasonable predictions of unmeasured B(E2)up arrow values. The quadrupole deformation parameter β 2 immediately follows, because β 2 is proportional to [B(E2)up arrow]/sup 1/2/. 8 refs., 7 figs

A molecule with small rotational constants containing an atom with a large nuclear quadrupole moment: The microwave spectrum of trans-1-iodoperfluoropropane

Science.gov (United States)

Dewberry, C. T.; Grubbs, G. S.; Cooke, S. A.

2009-09-01

Using pulsed jet chirped-pulse, and cavity-based Fourier transform microwave spectroscopies over 900 transitions have been recorded for the title molecule in the 1-4 GHz and 8-18 GHz regions. The C,C and C carbon-13 species have been observed in natural abundance allowing a substitution structure for the CCC backbone to be determined. Nearly all the transitions observed were either a-type R branches or b-type Q branches. No c-type transitions were observed consistent with only the trans conformer being present under our experimental conditions. The χaa,χbb,χcc and χab components of the iodine nuclear quadrupole coupling tensor have been determined. Of note, several forbidden, ΔJ±2 transitions, and one ΔJ±3 transition were observed with quite reasonable intensity. These observations have been rationalized through considerations of near degeneracies between energy levels connected via a large χab value (≈1 GHz).

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Dynamics of splashing of molten metals during irradiation with single CO2 laser pulses

Science.gov (United States)

Arutyunyan, R. V.; Baranov, V. Yu; Bol'shov, Leonid A.; Dolgov, V. A.; Malyuta, D. D.; Mezhevov, V. S.; Semak, V. V.

1988-03-01

An experimental investigation was made of the dynamics of the loss of the melt as a result of interaction with single-mode CO2 laser radiation pulses of 5-35 μs duration. The dynamics of splashing of the melt during irradiation with short pulses characterized by a Gaussian intensity distribution differed from that predicted by models in which the distribution of the vapor pressure was assumed to be radially homogeneous.

The team responsible for testing and measuring the LHC insertion quadrupoles

CERN Multimedia

Patrice Loïez

2003-01-01

The LHC main magnet system includes about 600 superconducting quadrupoles for beam focusing. Superconducting Matching Quadrupole Magnets (MQMs) are just one of several varieties of quadrupole; they will be installed in the accelerator´s eight ´insertion zones´, four of which are also experimental areas, where the beams will intersect to produce proton-proton collisions. The first MQM, built by the UK firm Tesla Engineering, has passed its acceptance tests. The team responsible for the tests is pictured here with the 3.5-metre-long magnet. Photo 01: Bottom row, left to right, Michäel Ky, Antoine Dias Goncalves, Gilles Rittaud, Yannick Riva; middle row, left to right, Vladimir Bretin, Noël Dalexandro, Bert Lust, Patrick Viret; top row, left to right, Christian Giloux, Ranko Ostojic, Walter Venturini Delsolaro, Lassaâd Gharsallah.

Wavelength dependence of the single pulse femtosecond laser ablation threshold of indium phosphide in the 400-2050 nm range

International Nuclear Information System (INIS)

Borowiec, A.; Tiedje, H.F.; Haugen, H.K.

2005-01-01

We present single pulse femtosecond laser ablation threshold measurements of InP obtained by optical, scanning electron, and atomic force microscopy. The experiments were conducted with laser pulses 65-175 fs in duration, in the wavelength range from 400 to 2050 nm, covering the photon energy region above and below the bandgap of InP. The ablation thresholds determined from depth and volume measurements varied from 87 mJ/cm 2 at 400 nm to 250 mJ/cm 2 at 2050 nm. In addition, crater depths and volumes were measured over a range of laser fluences extending well above the ablation threshold

Preliminary proposal of a Nb3Sn quadrupole model for the low β insertions of the LHC

International Nuclear Information System (INIS)

Ambrosio, G.; Ametrano, F.; Bellomo, G.; Broggi, F.; Rossi, L.; Volpini, G.

1995-09-01

In recent years Nb 3 Sn based conductors have shown wide applicability for superconducting magnets in many research areas like high field solenoids for laboratory experiment, for NMR spectroscopy and high field magnets for fusion. Nb 3 Sn technology is progressing fast, increasing both technical reliability and availability. The Nb 3 Sn technology, which has a higher critical field than NbTi, seems attractive for IR (Insertion Region) quadrupoles of large colliders . In this paper it is proposed the construction of a superconducting quadrupole wound with Nb 3 Sn cable for a second generation IR inner triplet low β quadrupoles, for the Large Hadron Collider at CERN. The low β quadrupoles, control the beam focusing at collision points, therefore a gain in term of focus strength and/or coil aperture can increase significantly machine performance. Two are the main steps for the whole project: 1) design and construction of a 1 metre long quadrupole to demonstrate the actual feasibility, which is the subject of this proposal; 2) study for integration of the quadrupole in the machine and final design of 5 m long quadrupoles finalized to the LHC

Single attosecond pulse generation in an orthogonally polarized two-color laser field combined with a static electric field

International Nuclear Information System (INIS)

Xia Changlong; Zhang Gangtai; Wu Jie; Liu Xueshen

2010-01-01

We investigate theoretic high-order harmonic generation and single attosecond pulse generation in an orthogonally polarized two-color laser field, which is synthesized by a mid-infrared (IR) pulse (12.5 fs, 2000 nm) in the y component and a much weaker (12 fs, 800 nm) pulse in the x component. We find that the width of the harmonic plateau can be extended when a static electric field is added in the y component. We also investigate emission time of harmonics in terms of a time-frequency analysis to illustrate the physical mechanism of high-order harmonic generation. We calculate the ionization rate using the Ammosov-Delone-Krainov model and interpret the variation of harmonic intensity for different static electric field strengths. When the ratio of strengths of the static and the y-component laser fields is 0.1, a continuous harmonic spectrum is formed from 220 to 420 eV. By superposing a properly selected range of the harmonic spectrum from 300 to 350 eV, an isolated attosecond pulse with a duration of about 75 as is obtained, which is near linearly polarized.

A low-cost multichannel pulse-height analyzer PHA 256 using single-chip microcomputer

International Nuclear Information System (INIS)

Koehler, M.; Meiling, W.

1985-01-01

The PHA 256 multichannel analyzer on the base of the U8820 single-chip microcomputer applied for radiation measurements, for example in monitoring systems with scintillation detectors, is described. The analyzer contains a power supply unit and 7 boards, namely, the processor board; data and program memory; 8-bit analog-to-digital converter; driver to display device; keyboard with 23 function keys; pulse amplifier and high-voltage supply (up to 2 kV). Software used provides preprocessing of spectra supported by following functions: addition and subtraction of different spectra, spectrum monitoring by use of a 5-point-algorithm, calculation of peak areas with linearly interpolated background

Single-Cycle Terahertz Pulse Generation from OH1 Crystal via Cherenkov Phase Matching

Science.gov (United States)

Uchida, Hirohisa; Oota, Kengo; Okimura, Koutarou; Kawase, Kodo; Takeya, Kei

2018-06-01

OH1 crystal is an organic nonlinear optical crystal with a large nonlinear optical constant. However, it has dispersion of refractive indices in the terahertz (THz) frequency. This limits the frequencies that satisfy the phase matching conditions for THz wave generation. In this study, we addressed the phase matching conditions for THz wave generation by combining an OH1 crystal with prism-coupled Cherenkov phase matching. We observed the generation of single-cycle THz pulses with a spectrum covering a frequency range of 3 THz. These results prove that combining prism-coupled Cherenkov phase matching with nonlinear optical crystals yields a THz wave generation method that is insusceptible to crystal dispersion.

Single attosecond pulse generation by using plasmon-driven double optical gating technology in crossed metal nanostructures

Science.gov (United States)

Feng, Liqiang; Liu, Katheryn

2018-05-01

An effective method to obtain the single attosecond pulses (SAPs) by using the multi-cycle plasmon-driven double optical gating (DOG) technology in the specifically designed metal nanostructures has been proposed and investigated. It is found that with the introduction of the crossed metal nanostructures along the driven and the gating polarization directions, not only the harmonic cutoff can be extended, but also the efficient high-order harmonic generation (HHG) at the very highest orders occurs only at one side of the region inside the nanostructure. As a result, a 93 eV supercontinuum with the near stable phase can be found. Further, by properly introducing an ultraviolet (UV) pulse into the driven laser polarization direction (which is defined as the DOG), the harmonic yield can be enhanced by two orders of magnitude in comparison with the singe polarization gating (PG) technology. However, as the polarized angle or the ellipticity of the UV pulse increase, the enhancement of the harmonic yield is slightly reduced. Finally, by superposing the selected harmonics from the DOG scheme, a 30 as SAP with intensity enhancement of two orders of magnitude can be obtained.

Nuclear quadrupole moment of the 99Tc ground state

International Nuclear Information System (INIS)

Errico, Leonardo; Darriba, German; Renteria, Mario; Tang Zhengning; Emmerich, Heike; Cottenier, Stefaan

2008-01-01

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

Characterization and tuning of ultrahigh gradient permanent magnet quadrupoles

Directory of Open Access Journals (Sweden)

S. Becker

2009-10-01

Full Text Available The application of quadrupole devices with high field gradients and small apertures requires precise control over higher order multipole field components. We present a new scheme for performance control and tuning, which allows the illumination of most of the quadrupole device aperture because of the reduction of higher order field components. Consequently, the size of the aperture can be minimized to match the beam size achieving field gradients of up to 500  T m^{-1} at good imaging quality. The characterization method based on a Hall probe measurement and a Fourier analysis was confirmed using the high quality electron beam at the Mainz Microtron MAMI.

Nb3Sn Quadrupoles Designs For The LHC Upgrades

International Nuclear Information System (INIS)

Felice, Helene

2008-01-01

In preparation for the LHC luminosity upgrades, high field and large aperture Nb 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.

Brain activity modification produced by a single radioelectric asymmetric brain stimulation pulse: a new tool for neuropsychiatric treatments. Preliminary fMRI study

Directory of Open Access Journals (Sweden)

Castagna A

2011-10-01

Full Text Available Salvatore Rinaldi1,2, Vania Fontani1, Alessandro Castagna1 1Department of Neuro-Psycho-Physio Pathology, Rinaldi Fontani Institute, Florence, Italy; 2Medical School of Occupational Medicine, University of Florence, Florence, Italy Purpose: Radioelectric asymmetric brain stimulation technology with its treatment protocols has shown efficacy in various psychiatric disorders. The aim of this work was to highlight the mechanisms by which these positive effects are achieved. The current study was conducted to determine whether a single 500-millisecond radioelectric asymmetric conveyor (REAC brain stimulation pulse (BSP, applied to the ear, can effect a modification of brain activity that is detectable using functional magnetic resonance imaging (fMRI. Methods: Ten healthy volunteers, six females and four males, underwent fMRI during a simple finger-tapping motor task before and after receiving a single 500-millisecond REAC-BSP. Results: The fMRI results indicate that the average variation in task-induced encephalic activation patterns is lower in subjects following the single REAC pulse. Conclusion: The current report demonstrates that a single REAC-BSP is sufficient to modulate brain activity in awake subjects, able to be measured using fMRI. These initial results open new perspectives into the understanding of the effects of weak and brief radio pulses upon brain activity, and provide the basis for further indepth studies using REAC-BSP and fMRI. Keywords: fMRI, brain stimulation, brain modulation, REAC, neuropsychiatric treatments

ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS

International Nuclear Information System (INIS)

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

2013-01-01

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.

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Fiscal 1999 regional consortium R and D project. Report of R and D results on regional consortium energy (R and D of hybrid pulse plasma coating (HPPC) system - 2nd year); 1999 nendo hybrid gata pulse plasma coating (HPPC) system no kenkyu kaihatsu seika hokokusho. 2

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

A surface reforming system was developed which enables DLC or ceramic films to be uniformly and adhesively coated on the surfaces of objects such as metallic dies and tools of complicated shape, which used to be impossible by a conventional dry coating. This paper describes the fiscal 1999 results. The technologies consist of pulse introduction of gaseous materials, pulse generation of plasma, application of negative high-voltage pulse, the HPPC (hybrid pulse plasma coating) system of advanced hybrid control, etc. Technologies were developed for 1 Hz pulse on/off introduction of methane and toluene gas, with the film forming experiment carried out. The density of Ar plasma formed by RF was measured by a Langmuir probe method. High densities of plasma were successfully achieved by a magnetic field. In the experiment of applying a negative pulse voltage to a model metallic die, it was possible to apply up to 14 kV pulse voltage. Elucidated was a plasma chemical phenomenon at the time of pulse gas introduction and pulse plasma formation, using a quadrupole mass spectrometer capable of measuring ion types in plasma, with the control conditions optimized. (NEDO)

Control of concerted two bond versus single bond dissociation in CH3Co(CO)4 via an intermediate state using pump-dump laser pulses

Science.gov (United States)

Ambrosek, David; González, Leticia

2007-10-01

Wavepacket propagations on ab initio multiconfigurational two-dimensional potential energy surfaces for CH3Co(CO)4 indicate that after irradiation to the lowest first and second electronic excited states, concerted dissociation of CH3 and the axial CO ligand takes place. We employ a pump-dump sequence of pulses with appropriate frequencies and time delays to achieve the selective breakage of a single bond by controlling the dissociation angle. The pump and dump pulse sequence exploits the unbound surface where dissociation occurs in a counterintuitive fashion; stretching of one bond in an intermediate state enhances the single dissociation of the other bond.

Control of concerted two bond versus single bond dissociation in CH(3)Co(CO)(4) via an intermediate state using pump-dump laser pulses.

Science.gov (United States)

Ambrosek, David; González, Leticia

2007-10-07

Wavepacket propagations on ab initio multiconfigurational two-dimensional potential energy surfaces for CH(3)Co(CO)(4) indicate that after irradiation to the lowest first and second electronic excited states, concerted dissociation of CH(3) and the axial CO ligand takes place. We employ a pump-dump sequence of pulses with appropriate frequencies and time delays to achieve the selective breakage of a single bond by controlling the dissociation angle. The pump and dump pulse sequence exploits the unbound surface where dissociation occurs in a counterintuitive fashion; stretching of one bond in an intermediate state enhances the single dissociation of the other bond.

Pulse Compression of Phase-matched High Harmonic Pulses from a Time-Delay Compensated Monochromator

Directory of Open Access Journals (Sweden)

Ito Motohiko

2013-03-01

Full Text Available Pulse compression of single 32.6-eV high harmonic pulses from a time-delay compensated monochromator was demonstrated down to 11±3 fs by compensating the pulse front tilt. The photon flux was intensified up to 5.7×109 photons/s on target by implementing high harmonic generation under a phase matching condition in a hollow fiber used for increasing the interaction length.

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-06-25

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

Toeless pulse shaping with a single delay-line network

International Nuclear Information System (INIS)

Tauhata, L.; Binns, D.C.

1976-04-01

New unipolar delay-line clippers producing negligible cancellation remnant have been developed. Near perfect clipping is achieved using a combination of several types of coaxial cable tranformers working as a phase inverter, a new pulse adder, or an impedance transformer. Only passive elements are used in the bridge network. The construction is simple and the performance is extremely stable and wide in dynamic range and frequency band width. Completely symmetrical bipolar pulses are also easily obtained using this technique

Stabilization of the Electron-Nuclear Spin Orientation in Quantum Dots by the Nuclear Quadrupole Interaction

Science.gov (United States)

Dzhioev, R. I.; Korenev, V. L.

2007-07-01

The nuclear quadrupole interaction eliminates the restrictions imposed by hyperfine interaction on the spin coherence of an electron and nuclei in a quantum dot. The strain-induced nuclear quadrupole interaction suppresses the nuclear spin flip and makes possible the zero-field dynamic nuclear polarization in self-organized InP/InGaP quantum dots. The direction of the effective nuclear magnetic field is fixed in space, thus quenching the magnetic depolarization of the electron spin in the quantum dot. The quadrupole interaction suppresses the zero-field electron spin decoherence also for the case of nonpolarized nuclei. These results provide a new vision of the role of the nuclear quadrupole interaction in nanostructures: it elongates the spin memory of the electron-nuclear system.

Simultaneous fabrication of laser-active colour centres and permanent microgratings in lithium fluoride by a single femtosecond pulse

International Nuclear Information System (INIS)

Kurobori, Toshio; Kawamura, Ken-ichi; Hirano, Masahiro; Hosono, Hideo

2003-01-01

We report, for the first time, simultaneous fabrication of laser-active F 2 and F 3 + colour centres in lithium fluoride and permanent periodic gratings with fringe spacings as fine as sub-micron size by two interfering infrared femtosecond (fs) laser pulses. In particular, the optical properties (absorption and luminescence) of F 2 and F 3 + colour centres produced by a single fs laser pulse are compared with those created by damage from radiation such as x-rays. The present technique of simultaneously fabricating laser-active colour centres and functional fine-periodic structures in photo-insensitive transparent materials may well be a useful method for making miniaturized optical devices. (letter to the editor)

Implications of the spatial dependence of the single-event-upset threshold in SRAMs measured with a pulsed laser

International Nuclear Information System (INIS)

Buchner, S.; Langworthy, J.B.; Stapor, W.J.; Campbell, A.B.; Rivet, S.

1994-01-01

Pulsed laser light was used to measure single event upset (SEU) thresholds for a large number of memory cells in both CMOS and bipolar SRAMs. Results showed that small variations in intercell upset threshold could not explain the gradual rise in the curve of cross section versus linear energy transfer (LET). The memory cells exhibited greater intracell variations implying that the charge collection efficiency within a memory cell varies spatially and contributes substantially to the shape of the curve of cross section versus LET. The results also suggest that the pulsed laser can be used for hardness-assurance measurements on devices with sensitive areas larger than the diameter of the laser beam

Final 6D Muon Ionization Colling using Strong Focusing Quadrupoles

Energy Technology Data Exchange (ETDEWEB)

Hart, T. L. [Mississippi U.; Acosta, J. G. [Mississippi U.; Cremaldi, L. M. [Mississippi U.; Oliveros, S. J. [Mississippi U.; Summers, D. J. [Mississippi U.; Neuffer, D. V. [Fermilab

2016-11-15

Abstract Low emittance muon beam lines and muon colliders are potentially a rich source of BSM physics for future exper- imenters. A muon beam normalized emittance of ax,y,z = (280, 280, 1570)µm has been achieved in simulation with short solenoids and a betatron function of 3 cm. Here we use ICOOL and MAD-X to explore using a 400 MeV/c muon beam and strong focusing quadrupoles to achieve a normalized transverse emittance of 100 µm and complete 6D cooling. The low beta regions, as low as 5 mm, produced by the quadrupoles are occupied by dense, low Z absorbers, such as lithium hydride or beryllium, that cool the beam transversely. Equilibrium transverse emittance is linearly proportional to the transverse betatron function. Reverse emittance exchange with septa and/or wedges is then used to decrease transverse emittance from 100 to 25 µm at the expense of longitudinal emittance for a high energy lepton collider. Cooling challenges include chromaticity correction, ssband overlap, quadrupole acceptance, and staying in phase with RF.

Moessbauer and calorimetric studies of portland cement hydration in the presence of black gram pulse

International Nuclear Information System (INIS)

Rai, Sarita; Kurian, Sajith; Dwivedi, V. N.; Das, S. S.; Singh, N. B.; Gajbhiye, N. S.

2009-01-01

Effect of different concentrations of naturally occurring admixture in the form of fine powder of black gram pulse (BGP) on the hydration of Portland cement was studied by isothermal calorimetry and 57 Fe Moessbauer spectroscopy. The spectra were recorded for anhydrous cement and the hydration products at room temperature and 77 K. In the presence of BGP, the spectra showed superparamagnetic doublets at room temperature and the sextet at 77 K, due to the presence of fine particles of iron containing component. Moessbauer studies of hydration products confirmed the formation of nanosize hydration products containing Fe 3+ . The isomer shift (δ) and the quadrupole splitting (ΔE Q ) values of C 4 AF in the cement confirmed iron in an octahedral and tetrahedral environment with +3 oxidation state. The high value of quadrupole splitting showed the high asymmetry of the electron environment around the iron atom. The overall mechanism of the hydration of cement in presence of BGP is discussed.

Development of bipolar pulse accelerator for intense pulsed ion beam acceleration

International Nuclear Information System (INIS)

Fujioka, Y.; Mitsui, C.; Kitamura, I.; Takahashi, T.; Masugata, K.; Tanoue, H.; Arai, K.

2003-01-01

To improve the purity of an intense pulsed ion beams a new type of pulsed ion beam accelerator named 'bipolar pulse accelerator (BPA)' was proposed. In the accelerator purity of the beam is expected. To confirm the principle of the accelerator experimental system was developed. The system utilizes B y type magnetically insulated acceleration gap and operated with single polar negative pulse. A coaxial gas puff plasma gun placed in the grounded anode was used as an ion source, and source plasma (nitrogen) of current density approx. = 25 A/cm 2 , duration approx. = 1.5 μs was injected into the acceleration gap. The ions are successfully accelerated from the grounded anode to the drift tube by applying negative pulse of voltage 180 kV, duration 60 ns to the drift tube. Pulsed ion beam of current density approx. = 40 A/cm 2 , duration approx. 60 ns was obtained at 42 mm downstream from the anode surface. (author)

Nonlinear behaviors in a pulsed dielectric barrier discharge at atmospheric pressure

Energy Technology Data Exchange (ETDEWEB)

Zhang Jiao; Wang Yanhui, E-mail: wangyh@dlut.edu.cn; Wang Dezhen

2011-08-01

In this paper, the temporal nonlinear behaviors of pulsed dielectric barrier discharge in atmospheric helium are studied numerically by a one-dimensional fluid model. The results show that the common single-period pulsed discharge with two current pulses per single voltage pulse can take place over a broad parameter range. The rising and falling times of the voltage pulse can affect the discharge characteristics greatly. When the discharge is ignited by a pulse voltage with long rising and falling times, a single-period pulsed discharge with multiple current peaks can be observed. Under appropriate rising and falling times of the voltage pulse, a stable period-two discharge can occur over wide frequency and voltage ranges. Also this period-two discharge can exhibit different current and voltage characteristics with changing the duty cycle. With other parameters fixed, the pulsed DBD could be driven to chaos through period-doubling route by increasing either the falling time or the frequency of voltage pulse.

Variable high gradient permanent magnet quadrupole (QUAPEVA)

Science.gov (United States)

Marteau, F.; Ghaith, A.; N'Gotta, P.; Benabderrahmane, C.; Valléau, M.; Kitegi, C.; Loulergue, A.; Vétéran, J.; Sebdaoui, M.; André, T.; Le Bec, G.; Chavanne, J.; Vallerand, C.; Oumbarek, D.; Cosson, O.; Forest, F.; Jivkov, P.; Lancelot, J. L.; Couprie, M. E.

2017-12-01

Different applications such as laser plasma acceleration, colliders, and diffraction limited light sources require high gradient quadrupoles, with strength that can reach up to 200 T/m for a typical 10 mm bore diameter. We present here a permanent magnet based quadrupole (so-called QUAPEVA) composed of a Halbach ring and surrounded by four permanent magnet cylinders. Its design including magnetic simulation modeling enabling us to reach 201 T/m with a gradient variability of 45% and mechanical issues are reported. Magnetic measurements of seven systems of different lengths are presented and confirmed the theoretical expectations. The variation of the magnetic center while changing the gradient strength is ±10 μm. A triplet of QUAPEVA magnets is used to efficiently focus a beam with large energy spread and high divergence that is generated by a Laser Plasma Acceleration source for a free electron laser demonstration and has enabled us to perform beam based alignment and control the dispersion of the beam.

The LHC Main Quadrupoles during Series Fabrication

CERN Document Server

Tortschanoff, Theodor; Durante, M; Hagen, P; Klein, U; Krischel, D; Payn, A; Rossi, L; Schellong, B; Schmidt, P; Simon, F; Schirm, K-M; Todesco, E

2006-01-01

By the end of August 2005 about 320 of the 400 main LHC quadrupole magnets have been fabricated and about 220 of them assembled into their cold masses, together with corrector magnets. About 130 of them have been cold tested in their cryostats and most of the quadrupoles exceeded their nominal excitation, i.e. 12,000 A, after no more than two training quenches. During this series fabrication, the quality of the magnets and cold masses was thoroughly monitored by means of warm magnetic field measurements, of strict geometrical checking, and of various electrical verifications. A number of modifications were introduced in order to improve the magnet fabrication, mainly correction of the coil geometry for achieving the specified field quality and measures for avoiding coil insulation problems. Further changes concern the electrical connectivity and insulation of instrumentation, and of the corrector magnets inside the cold masses. The contact resistances for the bus-bar connections to the quench protection diode...

Spin, quadrupole moment, and deformation of the magnetic-rotational band head in Pb193

Science.gov (United States)

Balabanski, D. L.; Ionescu-Bujor, M.; Iordachescu, A.; Bazzacco, D.; Brandolini, F.; Bucurescu, D.; Chmel, S.; Danchev, M.; de Poli, M.; Georgiev, G.; Haas, H.; Hübel, H.; Marginean, N.; Menegazzo, R.; Neyens, G.; Pavan, P.; Rossi Alvarez, C.; Ur, C. A.; Vyvey, K.; Frauendorf, S.

2011-01-01

The spectroscopic quadrupole moment of the T1/2=9.4(5) ns isomer in Pb193 at an excitation energy Eex=(2585+x) keV is measured by the time-differential perturbed angular distribution method as |Qs|=2.6(3) e b. Spin and parity Iπ=27/2- are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the 1i13/2 subshell with the (3s1/2-21h9/21i13/2)11- proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation ɛ2=-0.11, similar to that of the 11-proton intruder states, which nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.

Amorphization of silicon by femtosecond laser pulses

International Nuclear Information System (INIS)

Jia, Jimmy; Li Ming; Thompson, Carl V.

2004-01-01

We have used femtosecond laser pulses to drill submicron holes in single crystal silicon films in silicon-on-insulator structures. Cross-sectional transmission electron microscopy and energy dispersive x-ray analysis of material adjacent to the ablated holes indicates the formation of a layer of amorphous Si. This demonstrates that even when material is ablated using femtosecond pulses near the single pulse ablation threshold, sufficient heating of the surrounding material occurs to create a molten zone which solidifies so rapidly that crystallization is bypassed

Collective Quadrupole Excitations of Transactinide Nuclei

CERN Document Server

Zajac, K; Pomorski, K; Rohozinski, S G; Srebrny, J

2003-01-01

The quadrupole excitations of transuranic nuclei are described in the frame of the microscopic Bohr Hamiltonian modified by adding the coupling with the collective pairing vibrations. The energies of the states from the ground-state bands in U to No even-even isotopes as well as the B(E2) transition probabilities are reproduced within the model containing no adjustable parameters.

Light field driven streak-camera for single-shot measurements of the temporal profile of XUV-pulses from a free-electron laser; Lichtfeld getriebene Streak-Kamera zur Einzelschuss Zeitstrukturmessung der XUV-Pulse eines Freie-Elektronen Lasers

Energy Technology Data Exchange (ETDEWEB)

Fruehling, Ulrike

2009-10-15

The Free Electron Laser in Hamburg (FLASH) is a source for highly intense ultra short extreme ultraviolet (XUV) light pulses with pulse durations of a few femtoseconds. Due to the stochastic nature of the light generation scheme based on self amplified spontaneous emission (SASE), the duration and temporal profile of the XUV pulses fluctuate from shot to shot. In this thesis, a THz-field driven streak-camera capable of single pulse measurements of the XUV pulse-profile has been realized. In a first XUV-THz pump-probe experiment at FLASH, the XUV-pulses are overlapped in a gas target with synchronized THz-pulses generated by a new THz-undulator. The electromagnetic field of the THz light accelerates photoelectrons produced by the XUV-pulses with the resulting change of the photoelectron momenta depending on the phase of the THz field at the time of ionisation. This technique is intensively used in attosecond metrology where near infrared streaking fields are employed for the temporal characterisation of attosecond XUV-Pulses. Here, it is adapted for the analysis of pulse durations in the few femtosecond range by choosing a hundred times longer far infrared streaking wavelengths. Thus, the gap between conventional streak cameras with typical resolutions of hundreds of femtoseconds and techniques with attosecond resolution is filled. Using the THz-streak camera, the time dependent electric field of the THz-pulses was sampled in great detail while on the other hand the duration and even details of the time structure of the XUV-pulses were characterized. (orig.)

Pulse triggering mechanism of air proportional counters

International Nuclear Information System (INIS)

Aoyama, T.; Mori, T.; Watanabe, T.

1983-01-01

This paper describes the pulse triggering mechanism of a cylindrical proportional counter filled with air at atmospheric pressure for the incidence of β-rays. Experimental results indicate that primary electrons created distantly from the anode wire by a β-ray are transformed into negative ions, which then detach electrons close to the anode wire and generate electron avalanches thus triggering pulses, while electrons created near the anode wire by a β-ray directly trigger a pulse. Since a negative ion pulse is triggered by a single electron detached from a negative ion, multiple pulses are generated by a large number of ions produced by the incidence of a single β-ray. It is therefore necessary not to count pulses triggered by negative ions but to count those by primary electrons alone when use is made of air proportional counters for the detection of β-rays. (orig.)

Development and Test of LARP Technological Quadrupole (TQC) Magnet

Energy Technology Data Exchange (ETDEWEB)

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

2007-06-01

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

Development and Test of LARP Technological Quadrupole (TQC) Magnet

International Nuclear Information System (INIS)

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

2007-01-01

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

Development and test of LARP technological quadrupole (TQC) magnet

Energy Technology Data Exchange (ETDEWEB)

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

2006-08-01

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

Development and test of LARP technological quadrupole (TQC) magnet

International Nuclear Information System (INIS)

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

2006-01-01

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

Study and optimal correction of a systematic skew quadrupole field in the Tevatron

International Nuclear Information System (INIS)

Snopok, Pavel; Johnstone, Carol; Berz, Martin; Ovsyannikov, Dmitry A.; Ovsyannikov, Alexander D.

2006-01-01

Increasing demands for luminosity in existing and future colliders have made lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high-order performance of the Tevatron and the strong nonlinear behavior introduced when a significant skew quadrupole error is combined with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code COSY INFINITY [M. Berz, COSY INFINITY version 8.1 user's guide and reference manual, Department of Physics and Astronomy MSUHEP-20704, Michigan State University (2002). URL http://cosy.pa.msu.edu/cosymanu/index.html]. Two correction schemes with one family locally correcting each arc and eight independent correctors in the straight sections for global correction are proposed and shown to dramatically improve linearity and performance of the baseline Tevatron lattice

Determination of the effective quadrupole moment in $^{181}$Ta with pionic x-rays

CERN Document Server

Beetz, R; Fransson, K; Konijn, J; Panman, J; Tauscher, Ludwig; Tibell, G

1978-01-01

From the hyperfine splitting of the 5g to 4f and the 6g to 4f pionic X-rays in /sup 181/Ta, an effective quadrupole moment of Q/sub eff /=3.58+or-0.03 b was determined. The strong interaction monopole shift epsilon /sub 0/ and the width Gamma /sub 0/ of the 4f level were measured to be epsilon /sub 0/=540+or-100 eV and Gamma /sub 0 /=225+or-57 eV, in good agreement with the values obtained with the standard optical potential description of the pion-nucleus interaction. Estimating the influence of the finite nuclear size, the deformation induced through the strong interaction between the pion and the finite nucleus, and the relative magnitude between the strong and the electromagnetic quadrupole coupling constants values for the spectroscopic quadrupole moment of Q=3.30+or-0.06 b, and for the intrinsic quadrupole moment of Q/sub 0/=7.06+or-0.12 b are obtained. (28 refs).

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Parametric study on femtosecond laser pulse ablation of Au films

International Nuclear Information System (INIS)

Ni Xiaochang; Wang Chingyue; Yang Li; Li Jianping; Chai Lu; Jia Wei; Zhang Ruobing; Zhang Zhigang

2006-01-01

Ablation process of 1 kHz rate femtosecond lasers (pulse duration 148 fs, wavelength 775 nm) with Au films on silica substrates has been systemically studied. The single-pulse threshold can be obtained directly. For the multiple pulses the ablation threshold varies with the number of pulses applied to the surface due to the incubation effect. From the plot of accumulated laser fluence N x φ th (N) and the number of laser pulses N, incubation coefficient of Au film can be obtained (s = 0.765). As the pulse energy is increased, the single pulse ablation rate is increasing following two ablation logarithmic regimes, which can be explained by previous research

Superconducting self-correcting harmonic coils for pulsed superconducting dipole or multipole magnets

International Nuclear Information System (INIS)

Dael, A.; Kircher, F.; Perot, J.

1975-01-01

Due to the zero resistance of a superconducting wire, an induced current in a closed superconducting circuit is continuously exactly opposed to its cause. This phenomenon was applied to the correction of the field harmonics of a pulsed magnet by putting short-circuited superconducting coils of particular symmetry in the useful aperture of the magnet. After a review of the main characteristics of such devices, the construction of two correcting coils (quadrupole and sextupole) is described. Experimental results of magnetic efficiency and time behavior are given; they are quite encouraging, since the field harmonics were reduced by one or two orders of magnitude

Cooling the vertical surface by conditionally single pulses

Science.gov (United States)

Karpov, Pavel; Nazarov, Alexander; Serov, Anatoly; Terekhov, Victor

2017-10-01

You Sprays with periodic supply of the droplet phase have great opportunities to control the heat exchange processes. Varying pulse duration and frequency of their repetition, we can achieve the optimal conditions of evaporative cooling with minimization of the liquid flow rate. The paper presents experimental data on studying local heat transfer on a large subcooled surface, obtained on the original setup with multinozzle controlled system of impact irrigation by the gas-droplet flow. A contribution to intensification of the spray parameters (flow rate, pulse duration, repetition frequency) per a growth of integral heat transfer was studied. Data on instantaneous distribution of the heat flux value helped us to describe the processes occurring on the studied surface. These data could describe the regime of "island" film cooling.

Can a single pulse transcranial magnetic stimulation targeted to the motor cortex interrupt pain processing?

Science.gov (United States)

Kisler, Lee-Bareket; Gurion, Ilan; Granovsky, Yelena; Sinai, Alon; Sprecher, Elliot; Shamay-Tsoory, Simone; Weissman-Fogel, Irit

2018-01-01

The modulatory role of the primary motor cortex (M1), reflected by an inhibitory effect of M1-stimulation on clinical pain, motivated us to deepen our understanding of M1's role in pain modulation. We used Transcranial Magnetic Stimulation (TMS)-induced virtual lesion (VL) to interrupt with M1 activity during noxious heat pain. We hypothesized that TMS-VL will effect experimental pain ratings. Three VL protocols were applied consisting of single-pulse TMS to transiently interfere with right M1 activity: (1) VLM1- TMS applied to 11 subjects, 20 msec before the individual's first pain-related M1 peak activation, as determined by source analysis (sLORETA), (2) VL-50 (N = 16; TMS applied 50 ms prior to noxious stimulus onset), and (3) VL+150 (N = 16; TMS applied 150 ms after noxious stimulus onset). Each protocol included 3 conditions ('pain-alone', ' TMS-VL', and 'SHAM-VL'), each consisted of 30 noxious heat stimuli. Pain ratings were compared, in each protocol, for TMS-VL vs. SHAM-VL and vs. pain-alone conditions. Repeated measures analysis of variance, corrected for multiple comparisons revealed no significant differences in the pain ratings between the different conditions within each protocol. Therefore, our results from this exploratory study suggest that a single pulse TMS-induced VL that is targeted to M1 failed to interrupt experimental pain processing in the specific three stimulation timing examined here.

Preliminary proposal of a Nb{sub 3}Sn quadrupole model for the low {beta} insertions of the LHC

Energy Technology Data Exchange (ETDEWEB)

Ambrosio, G; Ametrano, F; Bellomo, G; Broggi, F; Rossi, L; Volpini, G [Milan Univ. (Italy). Dip. di Fisica; [INFN, Sezione di Milano (Italy). Laboratorio Acceleratori e Superconduttivita` Applicata

1995-09-01

In recent years Nb{sub 3}Sn based conductors have shown wide applicability for superconducting magnets in many research areas like high field solenoids for laboratory experiment, for NMR spectroscopy and high field magnets for fusion. Nb{sub 3}Sn technology is progressing fast, increasing both technical reliability and availability. The Nb{sub 3}Sn technology, which has a higher critical field than NbTi, seems attractive for IR (Insertion Region) quadrupoles of large colliders . In this paper it is proposed the construction of a superconducting quadrupole wound with Nb{sub 3}Sn cable for a second generation IR inner triplet low {beta} quadrupoles, for the Large Hadron Collider at CERN. The low {beta} quadrupoles, control the beam focusing at collision points, therefore a gain in term of focus strength and/or coil aperture can increase significantly machine performance. Two are the main steps for the whole project: (1) design and construction of a 1 metre long quadrupole to demonstrate the actual feasibility, which is the subject of this proposal; (2) study for integration of the quadrupole in the machine and final design of 5 m long quadrupoles finalized to the LHC.

Characterization and modulation of femtosecond laser pulse

International Nuclear Information System (INIS)

Dorrer, Christophe

1999-01-01

This work brings some solutions to the characterization and control of femtosecond laser pulses. Spectral interferometry has been extensively studied; whereas this is a rather old technique, it has found new specific applications to short pulses. Several important points concerning the experimental implementation of this technique are treated. Sources of errors have been tracked and simple solutions have been found to enhance its reliability. A recently demonstrated technique for the complete characterization of short pulses has been used to characterize short pulses from Chirped Pulse Amplification Systems. This transposition of shearing interferometry to the optical frequency domain, known as Spectral Phase Interferometry for Direct Electric-field Reconstruction (SPlDER), is conceptually very interesting: for example, the inversion from the experimental data to the electric field to be characterized is completely algebraic. A reliable tool for the characterization and optimization of Chirped pulse amplification systems has been built on this principle. This is the first single-shot real-time characterization implementation of this technique. An improvement of the method has also allowed the first single-shot real-time characterization of a short pulse using a single mono-dimensional integrative detector and an algebraic inversion of the experimental data. The control of these pulses is also of prior interest. Through a collaboration with Thomson CSF-LCR, the demonstration of the use of an optically addressed light valve at the Fourier plane of a zero-dispersion line for spectral phase modulation has been made. This device allows a high-resolution control of the spectral phase of a short pulse. It is a well-adapted tool for the correction of the residual spectral phase, at the output of Chirped Pulse Amplification systems and the temporal synthesis of shaped pulses for specific experiments. (author) [fr

Effect of quadrupole fringe fields on the tune of Indus-2

International Nuclear Information System (INIS)

Kant, Pradeep; Husain, Riyasat; Ghodke, A.D.; Singh, Gurnam

2009-01-01

Being an unavoidable part in a real magnet design, fringe fields of different kind of magnets have various effects on the beam parameters of the storage ring. The fringe field of a bending magnet (dipole) generates closed orbit distortion and disturbs the dispersion function whereas the fringe field of a quadrupole affects other parameters of the ring like tune values and twiss functions. The fringe field pattern of the quadrupoles of Indus-2 was measured by the Magnet Group. The measurements were performed along the various radial tracks in a quadrupole from -30 to 30 mm in steps of 5 mm at various excitation current levels. The pattern of the gradient at these different current levels was obtained by a line fit of the magnetic field at each point. The data was used to get the effect on the tune of Indus-2. The paper describes the results of the effect on the tune. (author)

Deterioration of the Skew Quadrupole Moment in Tevatron Dipoles Over Time

CERN Document Server

Syphers, Michael J

2005-01-01

During the 20 years since it was first commissioned, the Fermilab Tevatron has developed strong coupling between the two transverse degrees of freedom. A circuit of skew quadrupole magnets is used to correct for coupling and, though capable, its required strength has increased since 1983 by more than an order of magnitude. In more recent years changes to the Tevatron for colliding beams operation have altered the skew quadrupole corrector distribution and strong local coupling become evident, often encumbering routine operation during the present physics run. Detailed magnet measurements were performed on each individual magnet during construction, and in early 2003 it was realized that measurements could be performed on the magnets in situ which could determine coil movements within the iron yoke since the early 1980's. It was discovered that the superconducting coils had become vertically displaced relative to their yokes since their construction. The ensuing systematic skew quadrupole field introduced by t...

Single pulse analysis of intracranial pressure for a hydrocephalus implant.

Science.gov (United States)

Elixmann, I M; Hansinger, J; Goffin, C; Antes, S; Radermacher, K; Leonhardt, S

2012-01-01

The intracranial pressure (ICP) waveform contains important diagnostic information. Changes in ICP are associated with changes of the pulse waveform. This change has explicitly been observed in 13 infusion tests by analyzing 100 Hz ICP data. An algorithm is proposed which automatically extracts the pulse waves and categorizes them into predefined patterns. A developed algorithm determined 88 %±8 % (mean ±SD) of all classified pulse waves correctly on predefined patterns. This algorithm has low computational cost and is independent of a pressure drift in the sensor by using only the relationship between special waveform characteristics. Hence, it could be implemented on a microcontroller of a future electromechanic hydrocephalus shunt system to control the drainage of cerebrospinal fluid (CSF).

Analysis of pulsed injection for microgravity receiver tank chilldown

Science.gov (United States)

Honkonen, Scott C.; Pietrzyk, Joe R.; Schuster, John R.

The dominant heat transfer mechanism during the hold phase of a tank chilldown cycle in a low-gravity environment is due to fluid motion persistence following the charge. As compared to the single-charge per vent cycle case, pulsed injection maintains fluid motion and the associated high wall heat transfer coefficients during the hold phase. As a result, the pulsed injection procedure appears to be an attractive method for reducing the time and liquid mass required to chill a tank. However, for the representative conditions considered, no significant benefit can be realized by using pulsed injection as compared to the single-charge case. A numerical model of the charge/hold/vent process was used to evaluate the pulsed injection procedure for tank chilldown in microgravity. Pulsed injection results in higher average wall heat transfer coefficients during the hold, as compared to the single-charge case. However, these high levels were not coincident with the maximum wall-to-fluid temperature differences, as in the single-charge case. For representative conditions investigated, the charge/hold/vent process is very efficient. A slightly shorter chilldown time was realized by increasing the number of pulses.

Optimisation of applied field pulses for microwave assisted magnetic recording

Directory of Open Access Journals (Sweden)

Simon John Greaves

2017-05-01

Full Text Available Grains in a recording medium experience field pulses from a write head during recording. In general, a short head field rise time and a square pulse shape have been viewed as optimal. This work investigates the optimum field pulse shape for microwave assisted magnetic recording on single layer and ECC media. A square pulse was found to give the best recording performance on single layer media, but an initially negative field pulse increasing at a constant rate was more suitable for ECC media.

Generation efficiency of single-photon current pulses in the Geiger mode of silicon avalanche photodiodes

International Nuclear Information System (INIS)

Verkhovtseva, A. V.; Gergel, V. A.

2009-01-01

Statistical fluctuations of the avalanche's multiplication efficiency were studied as applied to the single-photon (Geiger) mode of avalanche photodiodes. The distribution function of partial multiplication factors with an anomalously wide (of the order of the average) dispersion was obtained. Expressions for partial feedback factors were derived in terms of the average gain and the corresponding dependences on the diode's overvoltage were calculated. Final expressions for the photon-electric pulse's conversion were derived by averaging corresponding formulas over the coordinate of initiating photoelectron generation using the functions of optical photon absorption in silicon.

Electric quadrupole interaction in cubic BCC α-Fe

International Nuclear Information System (INIS)

Błachowski, A.; Komędera, K.; Ruebenbauer, K.; Cios, G.; Żukrowski, J.; Górnicki, R.

2016-01-01

Mössbauer transmission spectra for the 14.41-keV resonant line in "5"7Fe have been collected at room temperature by using "5"7Co(Rh) commercial source and α-Fe strain-free single crystal as an absorber. The absorber was magnetized to saturation in the absorber plane perpendicular to the γ-ray beam axis applying small external magnetic field. Spectra were collected for various orientations of the magnetizing field, the latter lying close to the [110] crystal plane. A positive electric quadrupole coupling constant was found practically independent on the field orientation. One obtains the following value V_z_z = +1.61(4) × 10"1"9 Vm"−"2 for the (average) principal component of the electric field gradient (EFG) tensor under assumption that the EFG tensor is axially symmetric and the principal axis is aligned with the magnetic hyperfine field acting on the "5"7Fe nucleus. The nuclear spectroscopic electric quadrupole moment for the first excited state of the "5"7Fe nucleus was adopted as +0.17 b. Similar measurement was performed at room temperature using as-rolled polycrystalline α-Fe foil of high purity in the zero external field. Corresponding value for the principal component of the EFG was found as V_z_z = +1.92(4) × 10"1"9 Vm"−"2. Hence, it seems that the origin of the EFG is primarily due to the local (atomic) electronic wave function distortion caused by the spin–orbit interaction between effective electronic spin S and incompletely quenched electronic angular momentum L. It seems as well that the lowest order term proportional to the product L·λ·S dominates, as no direction dependence of the EFG principal component is seen. The lowest order term is isotropic for a cubic symmetry as one has λ=λ 1 for cubic systems with the symbol 1 denoting unit operator and λ being the coupling parameter. - Highlights: • Precision of MS the same as MAPON • Real scans versus magnetization direction • A challenge for ab initio calculations