Science.gov

Sample records for q resonances

  1. High Q Miniature Sapphire Acoustic Resonator

    NASA Technical Reports Server (NTRS)

    Wang, Rabi T.; Tjoelker, R. L.

    2010-01-01

    We have demonstrated high Q measurements in a room temperature Miniature Sapphire Acoustic Resonator (MSAR). Initial measurements of bulk acoustic modes in room temperature sapphire at 39 MHz have demonstrated a Q of 8.8 x 10(exp 6). The long term goal of this work is to integrate such a high Q resonator with small, low noise quartz oscillator electronics, providing a fractional frequency stability better than 1 x 10(exp -14) @ 1s.

  2. Lumped elements characterize Q in dielectric resonators

    NASA Technical Reports Server (NTRS)

    Hearn, Chase P.

    1993-01-01

    It has been earlier observed (Podcameni et al., 1981) that, as the coupling factor between a microstrip-coupled dielectric resonator and the line becomes much larger than unity, the unloaded quality factor (Q) of the resonator decreases. In this paper it is shown that this effect can be explained using lumped-element models of the coupling line, when the dielectric resonator is either overcoupled or undercoupled to the line.

  3. High Q silicon carbide microdisk resonator

    SciTech Connect

    Lu, Xiyuan; Lee, Jonathan Y.; Feng, Philip X.-L.; Lin, Qiang

    2014-05-05

    We demonstrate a silicon carbide (SiC) microdisk resonator with optical Q up to 5.12 × 10{sup 4}. The high optical quality, together with the diversity of whispering-gallery modes and the tunability of external coupling, renders SiC microdisk a promising platform for integrated quantum photonics applications.

  4. Effects of electromagnetic radiation on the Q of quartz resonators.

    PubMed

    Yong, Yook-Kong; Patel, Mihir; Vig, John; Ballato, Arthur

    2009-02-01

    The quartz resonator Q with aluminum electrodes was studied with respect to its fundamental thickness shear mode frequency and its viscoelastic, viscopiezoelectric, and viscopiezoelectromagnetic behaviors. The governing equations for viscoelasticity, viscopiezoelectricity, and viscopiezoelectromagnetism were implemented for an AT-cut quartz resonator. To simulate the radiation conditions at infinity for the viscopiezoelectromagnetic model, perfectly matched layers over a surface enclosing the resonator were implemented to absorb all incident electromagnetic radiation. The shape of the radiation spectrum of a 5.6 MHz AT-cut quartz resonator was found to compare relatively well the measured results by Campbell and Weber. The mesa-plate resonator was studied for a frequency range of 1.4 GHz to 3.4 GHz. The resonator Q was determined to be influenced predominantly by the quartz viscoelasticity; however at frequencies greater than 2.3 GHz, the quartz electromagnetic radiation had an increasingly significant effect on the resonator Q. At 3.4 GHz, the electromagnetic radiation accounted for about 14% of the loss in resonator Q. At frequencies less than 2 GHz, the calculated resonator Q compared well with the intrinsic Q(x) provided by the formula Q(x) = 16 x 10(6)/f where f was in MHz. At frequencies higher than 2.3 GHz, the aluminum electrodes had significant effects on the resonator Q. At 3.4 GHz, the electromagnetic radiation loss in the electrodes was an order of magnitude greater than their viscoelastic loss; hence, the vibrating aluminum electrodes became an efficient emitter of electromagnetic waves. The effects of electrical resistance in both the electrodes and quartz were determined to be negligible. PMID:19251522

  5. Monolithic Cylindrical Fused Silica Resonators with High Q Factors.

    PubMed

    Pan, Yao; Wang, Dongya; Wang, Yanyan; Liu, Jianping; Wu, Suyong; Qu, Tianliang; Yang, Kaiyong; Luo, Hui

    2016-01-01

    The cylindrical resonator gyroscope (CRG) is a typical Coriolis vibratory gyroscope whose performance is determined by the Q factor and frequency mismatch of the cylindrical resonator. Enhancing the Q factor is crucial for improving the rate sensitivity and noise performance of the CRG. In this paper, for the first time, a monolithic cylindrical fused silica resonator with a Q factor approaching 8 × 10⁵ (ring-down time over 1 min) is reported. The resonator is made of fused silica with low internal friction and high isotropy, with a diameter of 25 mm and a center frequency of 3974.35 Hz. The structure of the resonator is first briefly introduced, and then the experimental non-contact characterization method is presented. In addition, the post-fabrication experimental procedure of Q factor improvement, including chemical and thermal treatment, is demonstrated. The Q factor improvement by both treatments is compared and the primary loss mechanism is analyzed. To the best of our knowledge, the work presented in this paper represents the highest reported Q factor for a cylindrical resonator. The proposed monolithic cylindrical fused silica resonator may enable high performance inertial sensing with standard manufacturing process and simple post-fabrication treatment. PMID:27483263

  6. Gyrotron cavity resonator with an improved value of Q

    DOEpatents

    Stone, David S.; Shively, James F.

    1982-10-26

    A gyrotron cavity resonator is connected smoothly and directly to an output waveguide with a very gradually tapered wall so that values of external Q lower than twice the diffraction limit are obtainable.

  7. Ultra-high Q even eigenmode resonance in terahertz metamaterials

    SciTech Connect

    Al-Naib, Ibraheem Dignam, Marc M.; Yang, Yuping; Zhang, Weili; Singh, Ranjan

    2015-01-05

    We report the simultaneous excitation of the odd and the even eigenmode resonances in a periodic array of square split-ring resonators, with four resonators per unit cell. When the electric field is parallel to their gaps, only the two well-studied odd eigenmodes are excited. As the resonators are rotated relative to one another, we observe the emergence and excitation of an extremely sharp even eigenmode. In uncoupled split-ring resonators, this even eigenmode is typically radiative in nature with a broad resonance linewidth and low Q-factor. However, in our coupled system, for specific range of rotation angles, our simulations revealed a remarkably high quality factor (Q ∼ 100) for this eigenmode, which has sub-radiant characteristics. This type of quad-supercell metamaterial offers the advantage of enabling access to all the three distinct resonance features of the split-ring resonator, which consists of two odd eigenmodes in addition to the high-Q even eigenmode, which could be exploited for high performance multiband filters and absorbers. The high Q even eigenmode could find applications in designing label free bio-sensors and for studying the enhanced light matter interaction effects.

  8. High-Q BBO whispering gallery mode resonators

    NASA Astrophysics Data System (ADS)

    Lin, Guoping; Fürst, Josef U.; Strekalov, Dmitry V.; Grudinin, Ivan S.; Yu, Nan

    2013-02-01

    We report an investigation on optical whispering gallery mode (WGM) resonators made from non z-cut beta barium borate (BBO) crystals. We first fabricated high quality (Q) factor WGM resonators made of an angle-cut BBO crystal. Q factors of 1×108 level have been demonstrated at various wavelengths including UV. They led to new upper bounds for the absorption coefficients of BBO at 1560 nm, 980 nm and 370 nm. We observed only one set of ordinarily polarized WGMs with polarization rotating along the resonator circumference. We also fabricated xy-cut BBO WGM resonators, in which the optic axis is parallel to the resonator plane. In that case, two WGM families with different polarization exist, one with constant the other with oscillatory phase velocity. This enables a novel way of broadband phase matching in WGM resonators with cyclic gain. We experimentally demonstrated efficient second harmonic generation (SHG) to a wide harmonic wavelength range from 780 nm at near infrared to 317 nm in UV. It is also the first reported direct UV SHG in a high-Q WGM resonator. This work lays a foundation for further investigations of WGM properties of non-z cut birefringent resonators and their applications in nonlinear optics.

  9. Preventing Raman Lasing in High-Q WGM Resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute

    2007-01-01

    A generic design has been conceived to suppress the Raman effect in whispering- gallery-mode (WGM) optical resonators that have high values of the resonance quality factor (Q). Although it is possible to exploit the Raman effect (even striving to maximize the Raman gain to obtain Raman lasing), the present innovation is intended to satisfy a need that arises in applications in which the Raman effect inhibits the realization of the full potential of WGM resonators as frequency-selection components. Heretofore, in such applications, it has been necessary to operate high-Q WGM resonators at unattractively low power levels to prevent Raman lasing. (The Raman-lasing thresholds of WGM optical resonators are very low and are approximately proportional to Q(sup -2)). Heretofore, two ways of preventing Raman lasting at high power levels have been known, but both entail significant disadvantages: A resonator can be designed so that the optical field is spread over a relatively large mode volume to bring the power density below the threshold. For any given combination of Q and power level, there is certain mode volume wherein Raman lasing does not start. Unfortunately, a resonator that has a large mode volume also has a high spectral density, which is undesirable in a typical photonic application. A resonator can be cooled to the temperature of liquid helium, where the Raman spectrum is narrower and, therefore, the Raman gain is lower. However, liquid-helium cooling is inconvenient. The present design overcomes these disadvantages, making it possible to operate a low-spectral-density (even a single-mode) WGM resonator at a relatively high power level at room temperature, without risk of Raman lasing.

  10. High Q diamond hemispherical resonators: fabrication and energy loss mechanisms

    NASA Astrophysics Data System (ADS)

    Bernstein, Jonathan J.; Bancu, Mirela G.; Bauer, Joseph M.; Cook, Eugene H.; Kumar, Parshant; Newton, Eric; Nyinjee, Tenzin; Perlin, Gayatri E.; Ricker, Joseph A.; Teynor, William A.; Weinberg, Marc S.

    2015-08-01

    We have fabricated polycrystalline diamond hemispheres by hot-filament CVD (HFCVD) in spherical cavities wet-etched into a high temperature glass substrate CTE matched to silicon. Hemispherical resonators 1.4 mm in diameter have a Q of up to 143 000 in the fundamental wineglass mode, for a ringdown time of 2.4 s. Without trimming, resonators have the two degenerate wineglass modes frequency matched as close as 2 Hz, or 0.013% of the resonant frequency (~16 kHz). Laser trimming was used to match resonant modes on hemispheres to 0.3 Hz. Experimental and FEA energy loss studies on cantilevers and hemispheres examine various energy loss mechanisms, showing that surface related losses are dominant. Diamond cantilevers with a Q of 400 000 and a ringdown time of 15.4 s were measured, showing the potential of polycrystalline diamond films for high Q resonators. These resonators show great promise for use as hemispherical resonant gyroscopes (HRGs) on a chip.

  11. High Q printed helical resonators for oscillators and filters.

    PubMed

    Everard, Jeremy K A; Broomfield, Carl D

    2007-09-01

    High Q compact printed helical resonators which operate from around 1.8 to 2 GHz are described. These consist of a multilayer printed circuit board (PCB) incorporating a printed helical transmission line. Loss in the via hole is reduced by ensuring that the standing wave current at this point is near zero. This ensures a significant increase in Q. Further increased energy storage per unit volume is achieved due to the 3-D helical nature of the resonator. Unloaded Qs of 235 and 195 have been obtained on low loss PCBs with dielectric constants of 2.2 and 10.5, respectively. Two applications for these resonators are described in this paper. The first is the design of a compact low noise oscillator where the ratio of QL/Q0, and hence insertion loss, is adjusted for low noise. The 2-GHz oscillator demonstrates a phase noise of -120 dBc/Hz at 10 kHz which is predicted exactly by the theory. The second is a three-section filter designed to offer the response required by the front end filter of a modern GSM mobile telephone. In the filter design three helical resonators are coupled together to produce a completely printed triplate bandpass filter. PMID:17941381

  12. Engineered Carbon Nanotube Materials for High-Q Nanomechanical Resonators

    NASA Technical Reports Server (NTRS)

    Choi, Daniel S.; Hunt, Brian; Bronikowski, Mike; Epp, Larry; Hoenk, Michael; Hoppe, Dan; Kowalczyk, Bob; Wong, Eric; Xu, Jimmy; Adam, Douglas; Young, Rob

    2003-01-01

    This document represents a presentation offered by the Jet Propulsion Laboratory, with assistance from researchers from Brown University and Northrop Grumman. The presentation took place in Seoul, Korea in July 2003 and attempted to demonstrate the fabrication approach regarding the development of high quality factor (high-Q) mechanical oscillators (in the forms of a tunable nanotube resonator and a nanotube array radio frequency [RF] filter) aimed at signal processing and based on carbon nanotubes. The presentation also addressed parallel efforts to develop both in-plane single nanotube resonators as well as vertical array power devices.

  13. Formation of q{bar q} resonances in the {bar N}N system

    SciTech Connect

    Ivanov, N.Ya.

    1995-11-01

    The formation of q{bar q} resonances lying on the leading Regge trajectories in the {bar N}N system is studied in the quark-gluon string model. The model predicts strong suppression of the decays of q{bar q} states into {bar N}N pairs in relation to two-meson modes. The author`s analysis shows that the contributions of the resonances f{sub 4}(2050) (I{sup G}J{sup PC}= 0{sup +}4{sup ++}), {rho}{sub 5}(2240) (I{sup G}J{sup PC} = 1{sup +}5{sup {minus}{minus}}), and f{sub 6}(2510) (I{sup G}J{sup PC} = 0{sup +}6{sup ++}) to the processes of two-meson {bar N}N annihilation ({bar p}p {yields} {pi}{pi}, {bar K}K, {hor_ellipsis}) are about 1% of the corresponding experimental integrated cross sections. 30 refs., 2 figs., 1 tab.

  14. Meta-metallic coils and resonators: Methods for high Q-value resonant geometries.

    PubMed

    Mett, R R; Sidabras, J W; Hyde, J S

    2016-08-01

    A novel method of decreasing ohmic losses and increasing Q-value in metallic resonators at high frequencies is presented. The method overcomes the skin-depth limitation of rf current flow cross section. The method uses layers of conductive foil of thickness less than a skin depth and capacitive gaps between layers. The capacitive gaps can substantially equalize the rf current flowing in each layer, resulting in a total cross-sectional dimension for rf current flow many times larger than a skin depth. Analytic theory and finite-element simulations indicate that, for a variety of structures, the Q-value enhancement over a single thick conductor approaches the ratio of total conductor thickness to skin depth if the total number of layers is greater than one-third the square of the ratio of total conductor thickness to skin depth. The layer number requirement is due to counter-currents in each foil layer caused by the surrounding rf magnetic fields. We call structures that exhibit this type of Q-enhancement "meta-metallic." In addition, end effects due to rf magnetic fields wrapping around the ends of the foils can substantially reduce the Q-value for some classes of structures. Foil structures with Q-values that are substantially influenced by such end effects are discussed as are five classes of structures that are not. We focus particularly on 400 MHz, which is the resonant frequency of protons at 9.4 T. Simulations at 400 MHz are shown with comparison to measurements on fabricated structures. The methods and geometries described here are general for magnetic resonance and can be used at frequencies much higher than 400 MHz. PMID:27587143

  15. Resonant period and Q of the Celtic Sea and Bristol Channel

    NASA Astrophysics Data System (ADS)

    Heath, R. A.

    1981-03-01

    A simple linear resonant response model fitted to the semi-diurnal tidal constitutents in the Celtic Sea gives estimates of the resonant period of 10.8 to 11.1 with values of Q of about 3. The resonant period of the Bristol Channel is well below that of the semi-diurnal tidal band making estimates of the resonant period and Q less reliable. Estimates based on data near the entrance to the Bristol Channel give periods of 7.3 to 9 h, the lower value of 7.3 h with a Q of between 6 and 9 being probably the best estimate.

  16. High Q calcium titanate cylindrical dielectric resonators for magnetic resonance microimaging.

    PubMed

    Haines, K; Neuberger, T; Lanagan, M; Semouchkina, E; Webb, A G

    2009-10-01

    At high magnetic fields radiation losses, wavelength effects, self-resonance, and the high resistance of typical components all contribute to increased losses in conventional RF coil designs. High permittivity ceramic dielectric resonators create strong uniform magnetic fields in a compact structure at high frequencies and can potentially solve some of the challenges of high field coil design. In this study an NMR probe was constructed for operation at 600 MHz (14.1T) using an inductively fed CaTiO(3) (relative permittivity of 156) cylindrical hollow bore dielectric resonator. The design has an unmatched Q value greater than 2000, and the electric field is largely confined to the dielectric itself, with near zero values in the hollow bore which accommodates the sample. Experimental and simulation mapping of the RF field show good agreement, with the ceramic resonator giving a pulse width approximately 25% less than a loop gap resonator of similar inner dimensions. High resolution images, with voxel dimensions less than 50 microm(3), have been acquired from fixed zebrafish samples, showing excellent delineation of several fine structures. PMID:19656696

  17. High Q calcium titanate cylindrical dielectric resonators for magnetic resonance microimaging

    NASA Astrophysics Data System (ADS)

    Haines, K.; Neuberger, T.; Lanagan, M.; Semouchkina, E.; Webb, A. G.

    2009-10-01

    At high magnetic fields radiation losses, wavelength effects, self-resonance, and the high resistance of typical components all contribute to increased losses in conventional RF coil designs. High permittivity ceramic dielectric resonators create strong uniform magnetic fields in a compact structure at high frequencies and can potentially solve some of the challenges of high field coil design. In this study an NMR probe was constructed for operation at 600 MHz (14.1 T) using an inductively fed CaTiO 3 (relative permittivity of 156) cylindrical hollow bore dielectric resonator. The design has an unmatched Q value greater than 2000, and the electric field is largely confined to the dielectric itself, with near zero values in the hollow bore which accommodates the sample. Experimental and simulation mapping of the RF field show good agreement, with the ceramic resonator giving a pulse width approximately 25% less than a loop gap resonator of similar inner dimensions. High resolution images, with voxel dimensions less than 50 μm 3, have been acquired from fixed zebrafish samples, showing excellent delineation of several fine structures.

  18. Coupling Light from a High-Q Microsphere Resonator Using a UV-induced Surface Grating

    NASA Technical Reports Server (NTRS)

    Ilchenko, V. S.; Starodubov, D. S.; Gorodetsky, M. L.; Maleki, L.; Feinberg, J.

    2000-01-01

    High-Q microspheres with whispering-gallery modes have very narrow resonances that can be used for fiber-optic filters, ultra-compact narrow-linewidth lasers and optical/microwave oscillators. Whispering-gallery modes were previously excited in microspheres using evanescent optical fields. The necessary phase synchronism was obtained by adjusting the incident angle of input light beam (prism coupler) or adjustment of the waveguide propagation constant (fiber taper coupler). For many applications, however, bulky near-field couplers are undesirable. They compromise the symmetry and generate stray fields. Also, the control of coupling is crucial for the performance of microsphere resonators: in analogy with radio frequency circuits, the loading Q-factor should be less than the intrinsic Q-factor, Q(sub L) less than or equal to Q(sub O). Ideally one should combine a stable coupling element and a resonator into a single microsphere component.

  19. High-temperature measurements of Q-factor in rotated X-cut quartz resonators

    NASA Technical Reports Server (NTRS)

    Fritz, I. J.

    1981-01-01

    The Q-factors of piezoelectric resonators fabricated from natural and synthetic quartz with a 34 deg rotated X-cut orientation were measured at temperatures up to 325 C. The synthetic material, which was purified by electrolysis, retains a higher enough Q to be suitable for high temperature pressure-transducer applications, whereas the natural quartz is excessively lossy above 200 C for this application. The results are compared to results obtained previously at AT-cut resonators.

  20. High Resolution and Large Dynamic Range Resonant Pressure Sensor Based on Q-Factor Measurement

    NASA Technical Reports Server (NTRS)

    Gutierrez, Roman C. (Inventor); Stell, Christopher B. (Inventor); Tang, Tony K. (Inventor); Vorperian, Vatche (Inventor); Wilcox, Jaroslava (Inventor); Shcheglov, Kirill (Inventor); Kaiser, William J. (Inventor)

    2000-01-01

    A pressure sensor has a high degree of accuracy over a wide range of pressures. Using a pressure sensor relying upon resonant oscillations to determine pressure, a driving circuit drives such a pressure sensor at resonance and tracks resonant frequency and amplitude shifts with changes in pressure. Pressure changes affect the Q-factor of the resonating portion of the pressure sensor. Such Q-factor changes are detected by the driving/sensing circuit which in turn tracks the changes in resonant frequency to maintain the pressure sensor at resonance. Changes in the Q-factor are reflected in changes of amplitude of the resonating pressure sensor. In response, upon sensing the changes in the amplitude, the driving circuit changes the force or strength of the electrostatic driving signal to maintain the resonator at constant amplitude. The amplitude of the driving signals become a direct measure of the changes in pressure as the operating characteristics of the resonator give rise to a linear response curve for the amplitude of the driving signal. Pressure change resolution is on the order of 10(exp -6) torr over a range spanning from 7,600 torr to 10(exp -6) torr. No temperature compensation for the pressure sensor of the present invention is foreseen. Power requirements for the pressure sensor are generally minimal due to the low-loss mechanical design of the resonating pressure sensor and the simple control electronics.

  1. Triple-band high Q factor Fano resonances in bilayer THz metamaterials

    NASA Astrophysics Data System (ADS)

    Ding, Chunfeng; Wu, Liang; Xu, Degang; Yao, Jianquan; Sun, Xiaohong

    2016-07-01

    In this paper, we proposed a bilayer THz metamaterials, which is constructed by two sets of asymmetric split-ring resonators (ASRRs) with different sizes. Simulation results show that three high Q Fano resonances are excited in the bilayer metamaterials at 0.268, 0.418 THz, and 25 at 0.560 THz, and the Q values are 33, 42, and 25, respectively. The field distributions show that resonances at 0.268 and 0.560 THz originate from one of ASRRs, whereas the resonance at 0.418 THz originates from the other set of ASRRs. Further analysis indicates that the three high Q Fano resonances results from a combined action of the in-plane coupling and the interlayer coupling in the metamaterials: the in-plane coupling lead to resonances enhanced and the interlayer coupling lead to the eigenmode of each set of the ASRRs split into two discrete Fano resonances. This triple-band high Q factor Fano resonance metamaterials would open new degrees of freedom for designing advanced chemical and biological sensors and detectors in the terahertz regime.

  2. Super defect inside photonic crystal ring resonator to enhance Q factor

    NASA Astrophysics Data System (ADS)

    Sreenivasulu, Tupakula; Kolli, Venkateswara Rao; Tarimala, Badrinarayana; Hegde, Gopalkrishna; Sangineni, Mohan; Talabattula, Srinivas

    2016-03-01

    A design is proposed to enhance the quality factor of a photonic crystal ring resonator. A super defect is employed inside the ring resonator, which consists of variation of hole dimensions inside the ring resonator in such a way that the radiation field components of the resonant nanocavity are forced to get cancelled in order to reduce radiation loss. After this forced cancellation, the improved Q factor is calculated as 18,000. This photonic crystal ring resonator can be used for sensing applications like force sensing, pressure sensing, biochemical sensing, and communication applications like demultiplexing.

  3. High Q-factor resonant photoluminescence from Ge-on-insulator micro-disks

    NASA Astrophysics Data System (ADS)

    Xu, Xuejun; Hashimoto, Hideaki; Yoshida, Keisuke; Sawano, Kentarou; Maruizumi, Takuya

    2016-05-01

    Micro-disk resonators with high Q-factor have been experimentally demonstrated on germanium-on-insulator (GOI). GOI substrates fabricated by direct wafer bonding show better crystal quality that germanium films directly grown on Si. Sharp resonant peaks with Q-factor around 1000-4000 have been observed from micro-disks fabricated on GOI substrate by low-temperature photoluminescence measurements. The light emission properties against pump laser power and device temperature are also investigated. Our results indicating that GOI micro-disks are promising resonators for low threshold, ultra-compact Ge lasers on Si.

  4. Efficient coupling into and out of high-Q resonators.

    PubMed

    Harbers, Rik; Moll, Nikolaj; Erni, Daniel; Bona, Gian-Luca; Bächtold, Werner

    2004-08-01

    The temporal-coupled-mode theory is directly applied to the design of devices that feature a resonator with a high quality factor. For the temporal-coupled-mode theory we calculate the decay rate of the resonator to determine the transmission properties of the device. The analysis using the decay rates requires little computational effort, and therefore the optimum device properties can be determined quickly. Two examples, a wavelength filter and a resonator crossing, are presented to illustrate the use of the analysis. PMID:15330480

  5. Conceptual design of a high-Q, 3.4-GHz thin film quartz resonator.

    PubMed

    Patel, Mihir S; Yong, Yook-Kong

    2009-05-01

    Theoretical analyses and designs of high-Q, quartz thin film resonators are presented. The resonators operate at an ultra-high frequency of 3.4 GHz for application to high-frequency timing devices such as cesium chip-scale atomic clocks. The frequency spectra for the 3.4-GHz thin film quartz resonators, which serve as design aids in selecting the resonator dimensions/configurations for simple electrodes, and ring electrode mesa designs are presented here for the first time. The thin film aluminum electrodes are found to play a major role in the resonators because the electrodes are only one third the thickness and mass of the active areas of the plate resonator. Hence, in addition to the material properties of quartz, the elastic, viscoelastic, and thermal properties of the electrodes are included in the models. The frequency-temperature behavior is obtained for the best resonator designs. To improve the frequency-temperature behavior of the resonators, new quartz cuts are proposed to compensate for the thermal stresses caused by the aluminum electrodes and the mounting supports. Frequency response analyses are performed to determine the Q-factor, motional resistance, capacitance ratio, and other figures of merit. The resonators have Q's of about 3800, resistance of about 1300 to 1400 ohms, and capacitance ratios of 1100 to 2800. PMID:19473909

  6. 1/f frequency noise of 2-GHZ high-Q thin-film sapphire resonators.

    PubMed

    Ferre-Pikal, E S; Delgado Arámburo, M C; Walls, F L; Lakin, K M

    2001-03-01

    We present experimental results on intrinsic 1/f frequency modulation (FM) noise in high-overtone thin-film sapphire resonators that operate at 2 GHz. The resonators exhibit several high-Q resonant modes approximately 100 kHz apart, which repeat every 13 MHz. A loaded Q of approximately 20,000 was estimated from the phase response. The results show that the FM noise of the resonators varied between Sy (10 Hz) = -202 dB relative (rel) to 1/Hz and -210 dB rel to 1/Hz. The equivalent phase modulation (PM) noise of an oscillator using these resonators (assuming a noiseless amplifier) would range from [symbol: see text](10 Hz) = -39 to -47 dBc/Hz. PMID:11370364

  7. High-Q lattice mode matched structural resonances in terahertz metasurfaces

    NASA Astrophysics Data System (ADS)

    Xu, Ningning; Singh, Ranjan; Zhang, Weili

    2016-07-01

    The quality (Q) factor of metamaterial resonances is limited by the radiative and non-radiative losses. At terahertz frequencies, the dominant loss channel is radiative in nature since the non-radiative losses are low due to high conductivity of metals. Radiative losses could be suppressed by engineering the meta-atom structure. However, such suppression usually occurs at the fundamental resonance mode which is typically a closed mode resonance such as an inductive-capacitive resonance or a Fano resonance. Here, we report an order of magnitude enhancement in Q factor of all the structural eigenresonances of a split-ring resonator fueled by the lattice mode matching. We match the fundamental order diffractive mode to each of the odd and even eigenresonances, thus leading to a tremendous line-narrowing of all the resonances. Such precise tailoring and control of the structural resonances in a metasurface lattice could have potential applications in low-loss devices, sensing, and design of high-Q metamaterial cavities.

  8. High Q-factor distributed bragg reflector resonators with reflectors of arbitrary thickness.

    PubMed

    Le Floch, Jean-Michel; Tobar, Michael E; Cros, Dominique; Krupka, Jerzy

    2007-12-01

    The Bragg reflection technique improves the Q-factor of a resonator by reducing conductor and dielectric losses. This is achieved by designing a low-loss inner resonant region (usually free space) surrounded by an outer anti-resonant region made of distributed Bragg reflector layers. In this paper we develop a simple non-Maxwellian model and apply it to design three distinct cylindrical Bragg resonators based on the same set of single-crystal sapphire plates and rings by changing only the dimension of the cavity that supports the structure. To accomplish this, the simple model allows an arbitrary thickness for either the horizontal or the cylindrical dielectric reflectors by relaxing the condition that they must be lambda/4 thick. The model also allows for higher-order field variations in both the resonant and the anti-resonant regions. The resonators were constructed and experimental results were compared with the simple model and the rigorous method of lines analysis. For the fundamental mode, an unloaded Q-factor of 234,000 at 9.7 GHz was obtained. This is larger than that for a whispering gallery mode resonator. The resonator also exhibited a greatly reduced spurious mode density when compared to an overmoded whispering gallery mode resonator. PMID:18276575

  9. Platybasia in 22q11.2 Deletion Syndrome Is Not Correlated with Speech Resonance

    PubMed Central

    Kon, Moshe; Mink van der Molen, Aebele B

    2014-01-01

    Background An abnormally obtuse cranial base angle, also known as platybasia, is a common finding in patients with 22q11.2 deletion syndrome (22q11DS). Platybasia increases the depth of the velopharynx and is therefore postulated to contribute to velopharyngeal dysfunction. Our objective was to determine the clinical significance of platybasia in 22q11DS by exploring the relationship between cranial base angles and speech resonance. Methods In this retrospective chart review at a tertiary hospital, 24 children (age, 4.0-13.1 years) with 22q11.2DS underwent speech assessments and lateral cephalograms, which allowed for the measurement of the cranial base angles. Results One patient (4%) had hyponasal resonance, 8 (33%) had normal resonance, 10 (42%) had hypernasal resonance on vowels only, and 5 (21%) had hypernasal resonance on both vowels and consonants. The mean cranial base angle was 136.5° (standard deviation, 5.3°; range, 122.3-144.8°). The Kruskal-Wallis test showed no significant relationship between the resonance ratings and cranial base angles (P=0.242). Cranial base angles and speech ratings were not correlated (Spearman correlation=0.321, P=0.126). The group with hypernasal resonance had a significantly more obtuse mean cranial base angle (138° vs. 134°, P=0.049) but did not have a greater prevalence of platybasia (73% vs. 56%, P=0.412). Conclusions In this retrospective chart review of patients with 22q11DS, cranial base angles were not correlated with speech resonance. The clinical significance of platybasia remains unknown. PMID:25075355

  10. Analysis of silicon-on-insulator slot waveguide ring resonators targeting high Q-factors.

    PubMed

    Zhang, Weiwei; Serna, Samuel; Le Roux, Xavier; Alonso-Ramos, Carlos; Vivien, Laurent; Cassan, Eric

    2015-12-01

    Vertical slot waveguide micro-ring resonators in silicon photonics have already been demonstrated in previous works and applied to several schemes, including sensing and hybrid nonlinear optics. Their performances, first quantified by the reachable Q-factors, are still perceived to be restrained by larger intrinsic propagation losses than those suffered by simple Si wire waveguides. In this Letter, the optical loss mechanisms of slot waveguide micro-ring resonators are thoroughly investigated with a special focus on the coupler loss contribution that turns out to be the key obstacle to achieving high Q-factors. By engineering the coupler design, slotted ring resonators with a 50 μm radius are experienced with a loaded Q-factor up to 10 times improvement from Q=3,000 to Q=30,600. The intrinsic losses due to the light propagation in the bent slot ring itself are proved to be as low as 1.32±0.87  dB/cm at λ=1,550  nm. These investigations of slot ring resonators open high performance potentials for on-chip nonlinear optical processing or sensing in hybrid silicon photonics. PMID:26625052

  11. Extremely high Q-factor mechanical modes in quartz bulk acoustic wave resonators at millikelvin temperature

    SciTech Connect

    Goryachev, M.; Creedon, D. L.; Ivanov, E. N.; Tobar, M. E.; Galliou, S.; Bourquin, R.

    2014-12-04

    We demonstrate that Bulk Acoustic Wave (BAW) quartz resonator cooled down to millikelvin temperatures are excellent building blocks for hybrid quantum systems with extremely long coherence times. Two overtones of the longitudinal mode at frequencies of 15.6 and 65.4 MHz demonstrate a maximum f.Q product of 7.8×10{sup 16} Hz. With this result, the Q-factor in such devices near the quantum ground state can be four orders of magnitude better than previously attained in other mechanical systems. Tested quartz resonators possess the ultra low acoustic losses crucial for electromagnetic cooling to the phonon ground state.

  12. High-Q polymer resonators with spatially controlled photo-functionalization for biosensing applications

    NASA Astrophysics Data System (ADS)

    Beck, Torsten; Mai, Martin; Grossmann, Tobias; Wienhold, Tobias; Hauser, Mario; Mappes, Timo; Kalt, Heinz

    2013-03-01

    We demonstrate the applicability of polymeric whispering gallery mode resonators fabricated on silicon as biosensors. Optical measurements on the passive resonators in the visible spectral range yield Q-factors as high as 1.3×107. Local, covalent surface functionalization, is achieved by spatially controlled UV-exposure of a derivative of the photoreactive crosslinker benzophenone. Protein detection is shown using the specific binding of the biotin-streptavidin system.

  13. High-Q 3D coaxial resonators for cavity QED

    NASA Astrophysics Data System (ADS)

    Yoon, Taekwan; Owens, John C.; Naik, Ravi; Lachapelle, Aman; Ma, Ruichao; Simon, Jonathan; Schuster, David I.

    Three-dimensional microwave resonators provide an alternative approach to transmission-line resonators used in most current circuit QED experiments. Their large mode volume greatly reduces the surface dielectric losses that limits the coherence of superconducting circuits, and the well-isolated and controlled cavity modes further suppress coupling to the environment. In this work, we focus on unibody 3D coaxial cavities which are only evanescently coupled and free from losses due to metal-metal interfaces, allowing us to reach extremely high quality-factors. We achieve quality-factor of up to 170 million using 4N6 Aluminum at superconducting temperatures, corresponding to an energy ringdown time of ~4ms. We extend our methods to other materials including Niobium, NbTi, and copper coated with Tin-Lead solder. These cavities can be further explored to study their properties under magnetic field or upon coupling to superconducting Josephson junction qubits, e.g. 3D transmon qubits. Such 3D cavity QED system can be used for quantum information applications, or quantum simulation in coupled cavity arrays.

  14. Efficient upconversion of subterahertz radiation in a high-Q whispering gallery resonator.

    PubMed

    Strekalov, D V; Savchenkov, A A; Matsko, A B; Yu, N

    2009-03-15

    We demonstrate efficient upconversion of subterahertz radiation into the optical domain in a high-Q whispering gallery mode resonator with quadratic optical nonlinearity. The 5x10(-3) power conversion efficiency of a cw 100 GHz signal is achieved with only 16 mW of optical pump. PMID:19282908

  15. Studies on a Q/A selector for the SECRAL electron cyclotron resonance ion source

    SciTech Connect

    Yang, Y.; Sun, L. T.; Feng, Y. C.; Fang, X.; Lu, W.; Zhang, W. H.; Cao, Y.; Zhang, X. Z.; Zhao, H. W.

    2014-08-15

    Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world because they are capable of producing high current beams of highly charged ions. However, the design of the Q/A selector system for these devices is challenging, because it must have a sufficient ion resolution while controlling the beam emittance growth. Moreover, this system has to be matched for a wide range of ion beam species with different intensities. In this paper, research on the Q/A selector system at the SECRAL (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou) platform both in experiment and simulation is presented. Based on this study, a new Q/A selector system has been designed for SECRAL II. The features of the new design including beam simulations are also presented.

  16. Studies on a Q/A selector for the SECRAL electron cyclotron resonance ion source.

    PubMed

    Yang, Y; Sun, L T; Feng, Y C; Fang, X; Lu, W; Zhang, W H; Cao, Y; Zhang, X Z; Zhao, H W

    2014-08-01

    Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world because they are capable of producing high current beams of highly charged ions. However, the design of the Q/A selector system for these devices is challenging, because it must have a sufficient ion resolution while controlling the beam emittance growth. Moreover, this system has to be matched for a wide range of ion beam species with different intensities. In this paper, research on the Q/A selector system at the SECRAL (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou) platform both in experiment and simulation is presented. Based on this study, a new Q/A selector system has been designed for SECRAL II. The features of the new design including beam simulations are also presented. PMID:25173256

  17. Laser-machined ultra-high-Q microrod resonators for nonlinear optics

    NASA Astrophysics Data System (ADS)

    Del'Haye, Pascal; Diddams, Scott A.; Papp, Scott B.

    2013-06-01

    Optical whispering-gallery microresonators are useful tools in microphotonics and non-linear optics at very low threshold powers. Here, we present details about the fabrication of ultra-high-Q whispering-gallery-mode resonators made by CO2-laser lathe machining of fused-quartz rods. The resonators can be fabricated in less than 1 min and the obtained optical quality factors exceed Q = 1 × 109. Demonstrated resonator diameters are in the range between 170 μm and 8 mm (free spectral ranges between 390 GHz and 8 GHz). Using these microresonators, a variety of optical nonlinearities are observed, including Raman scattering, Brillouin scattering, and four-wave mixing.

  18. L-shell resonant transfer excitation in Cuq++H2 (q=18,19) collisions

    NASA Astrophysics Data System (ADS)

    Závodszky, P. A.; Wroblewski, J. A.; Ferguson, S. M.; Gorczyca, T. W.; Houck, J. H.; Woitke, O.; Tanis, J. A.; Badnell, N. R.

    1997-09-01

    Resonant transfer excitation (RTE) involving L-1Mn (n>=M) resonant states has been investigated for Na-like and Ne-like Cuq++H2 collisions (q=18 and 19). The M- to L-shell x-ray production cross sections (RTEX's) of these resonance states are studied by x-ray projectile ion coincidences. Previous measurements of L-shell RTEX for Nbq+ (q=28-31) ions showed the measured cross sections to be nearly a factor of 2 smaller than the calculated ones. For Cu18+ the present results show the position and width of the measured RTEX maximum cross section to be in agreement with the calculations; however, the measured absolute cross sections are about 60% higher than the predicted ones. In the case of Ne-like Cu19+ projectiles, the metastable component in the beam made it impossible to observe RTEX's.

  19. Active Q switching of a fiber laser with a microsphere resonator.

    PubMed

    Kieu, Khanh; Mansuripur, Masud

    2006-12-15

    We propose and demonstrate an active Q-switched fiber laser using a high-Q microsphere resonator as the Q-switching element. The laser cavity consists of an Er-doped fiber as the gain medium, a glass microsphere reflector (coupled through a fiber taper) at one end of the cavity, and a fiber Bragg grating reflector at the other end. The reflectivity of the microsphere is modulated by changing the gap between the microsphere and the fiber taper. Active Q switching is realized by oscillating the microsphere in and out of contact with the taper. Using this novel technique, we have obtained giant pulses (maximum peak power approximately 102 W, duration approximately 160 ns) at a low pump-power threshold (approximately 3 mW). PMID:17130905

  20. Fano resonances in a multimode waveguide coupled to a high-Q silicon nitride ring resonator.

    PubMed

    Ding, Dapeng; de Dood, Michiel J A; Bauters, Jared F; Heck, Martijn J R; Bowers, John E; Bouwmeester, Dirk

    2014-03-24

    Silicon nitride (Si3N4) optical ring resonators provide exceptional opportunities for low-loss integrated optics. Here we study the transmission through a multimode waveguide coupled to a Si3N4 ring resonator. By coupling single-mode fibers to both input and output ports of the waveguide we selectively excite and probe combinations of modes in the waveguide. Strong asymmetric Fano resonances are observed and the degree of asymmetry can be tuned through the positions of the input and output fibers. The Fano resonance results from the interference between modes of the waveguide and light that couples resonantly to the ring resonator. We develop a theoretical model based on the coupled mode theory to describe the experimental results. The large extension of the optical modes out of the Si3N4 core makes this system promising for sensing applications. PMID:24664026

  1. Development of high- Q superconducting resonators for use as kinetic inductance detectors

    NASA Astrophysics Data System (ADS)

    Baselmans, J. J. A.; Yates, S. J. C.; de Korte, P.; Hoevers, H.; Barends, R.; Hovenier, J. N.; Gao, J. R.; Klapwijk, T. M.

    One of the greatest challenges in the development of future space based instruments for sub-mm astronomy is the fabrication of very sensitive and large detector arrays. Within this context we have started the development of Microwave Kinetic Inductance Detectors (MKID's). The heart of each detector consists of a high- Q superconducting quarter wavelength microwave resonator. As a result it is easy to multiplex the readout by frequency division multiplexing. The predicted fundamental sensitivity limit of the MKID is due to quasiparticle creation-recombination noise, leading to a NEP˜1×10-20W/√{Hz}, low enough for any envisionable application in the sub-mm, optical and X-ray wavelength ranges. We describe experiments with these resonators, made of 150 nm Ta films with a 5 nm Nb seed layer on high purity Si substrates with a resonance frequency around 3 GHz. We measure the Q factors, responsivity, noise and noise equivalent power of several resonators. We find Q factors in excess of 1 × 10 5, high enough for the multiplexing of more than 10 4 pixels. The quasiparticle lifetime in our film is measured to be 25 μs. which gives, together with the measured phase noise, a NEP of ˜4×10-16W/√{Hz} at 1 kHz. At lower frequencies the noise increases.

  2. High-Q X-band distributed Bragg resonator utilizing an aperiodic alumina plate arrangement.

    PubMed

    Bale, Simon; Everard, Jeremy

    2010-01-01

    This paper describes a high-Q X-band distributed Bragg resonator that uses an aperiodic arrangement of non-lambda/4 low loss alumina plates mounted in a cylindrical waveguide. An ABCD parameter waveguide model was developed to simulate and optimize the cavity. The dielectric plates and air waveguide dimensions were optimized to achieve maximum quality factor by redistributing the energy loss within the cavity. An unloaded quality factor (Q(0)) of 196,000 was demonstrated at 9.93 GHz. PMID:20040428

  3. Selective excitation of high-Q resonant modes in a bottle/quasi-cylindrical microresonator

    NASA Astrophysics Data System (ADS)

    Dong, Yongchao; Jin, Xueying; Wang, Keyi

    2016-08-01

    We fabricate a bottle/quasi-cylindrical microresonator by using a fusion splicer. This method does not require a real-time control of the translation stages and can easily fabricate a resonator with expected size and shape. Selective excitation of whispering gallery modes (WGMs) in the resonator is realized with a fiber taper coupled at various positions of the resonator along the bottle axis. Most importantly, we obtain a clean and regular spectrum with very high quality factor (Q) modes up to 3.1×107 in the quasi-cylindrical region of the resonator. Moreover, we package the coupling system into a whole device that can be moved freely. The vibration performance tests of the packaged device show that the coupling system with the taper coupled at the quasi-cylindrical region has a remarkable anti-vibration ability. The portability and robustness of the device make it attractive in practical applications.

  4. High-Q, ultrathin-walled microbubble resonator for aerostatic pressure sensing

    NASA Astrophysics Data System (ADS)

    Yang, Yong; Saurabh, Sunny; Ward, Jonathan M.; Nic Chormaic, Síle

    2016-01-01

    Sensors based on whispering gallery resonators have minute footprints and can push achievable sensitivities and resolutions to their limits. Here, we use a microbubble resonator, with a wall thickness of 500 nm and an intrinsic Q-factor of $10^7$ in the telecommunications C-band, to investigate aerostatic pressure sensing via stress and strain of the material. The microbubble is made using two counter-propagating CO$_2$ laser beams focused onto a microcapillary. The measured sensitivity is 19 GHz/bar at 1.55 $\\mu$m. We show that this can be further improved to 38 GHz/bar when tested at the 780 nm wavelength range. In this case, the resolution for pressure sensing can reach 0.17 mbar with a Q-factor higher than $5\\times10^7$.

  5. Multiple folded resonator for LD pulse end pumped Q-switched Yb:YAG slab laser.

    PubMed

    Jun, Liu; Jianguo, Xin; Ye, Lang; Jiabin, Chen

    2014-09-01

    In this paper, a multiple folded resonator is presented which consists of a multiple optical folding setup, a flat total reflector, a flat output coupler, a Q-switch crystal and a polarizer. By this technique, the output energy of 32.6mJ and pulse width of 13.4ns with a repetition rate of 5Hz was obtained, which is three times higher than that reported in the past publications by the use of the currently existing technique of the Q-switched slab gain lasers with the unstable resonator. The output beam with a quality of M² = 1.55 in the slow axis and M² = 1.40 in the fast axis was also obtained. PMID:25321590

  6. Package of a dual-tapered-fiber coupled microsphere resonator with high Q factor

    NASA Astrophysics Data System (ADS)

    Dong, Yongchao; Wang, Keyi; Jin, Xueying

    2015-09-01

    We package a high-quality (Q) factor optical whispering gallery mode (WGM) microsphere resonator side coupled to two tapered fibers without changing the initial coupling conditions, achieving a final Q as high as 2.7×106. The mechanical stability of the coupling system is improved by placing the tapers in contact with the microsphere. The packaged device can be easily sealed in a targeted hermetic box according to different practical applications, which provides long term maintenance of the coupling efficiency and high-Q factor. Moreover, we test the temperature dependence of the packaged device and demonstrate its capability for thermal tuning of the drop wavelength. This device has a variety of advantages, such as portability, low-cost, and ease of fabrication.

  7. AlN/3C-SiC composite plate enabling high-frequency and high-Q micromechanical resonators.

    PubMed

    Lin, Chih-Ming; Chen, Yung-Yu; Felmetsger, Valery V; Senesky, Debbie G; Pisano, Albert P

    2012-05-22

    An AlN/3C-SiC composite layer enables the third-order quasi-symmetric (QS(3)) Lamb wave mode with a high quality factor (Q) characteristic and an ultra-high phase velocity up to 32395 ms(-1). A Lamb wave resonator utilizing the QS(3) mode exhibits a low motional impedance of 91 Ω and a high Q of 5510 at a series resonance frequency (f(s)) of 2.92 GHz, resulting in the highest f(s)·Q product of 1.61 × 10(13) Hz among the suspended piezoelectric thin film resonators reported to date. PMID:22495881

  8. μ-'Diving suit' for liquid-phase high-Q resonant detection.

    PubMed

    Yu, Haitao; Chen, Ying; Xu, Pengcheng; Xu, Tiegang; Bao, Yuyang; Li, Xinxin

    2016-03-01

    A resonant cantilever sensor is, for the first time, dressed in a water-proof 'diving suit' for real-time bio/chemical detection in liquid. The μ-'diving suit' technology can effectively avoid not only unsustainable resonance due to heavy liquid-damping, but also inevitable nonspecific adsorption on the cantilever body. Such a novel technology ensures long-time high-Q resonance of the cantilever in solution environment for real-time trace-concentration bio/chemical detection and analysis. After the formation of the integrated resonant micro-cantilever, a patterned photoresist and hydrophobic parylene thin-film are sequentially formed on top of the cantilever as sacrificial layer and water-proof coat, respectively. After sacrificial-layer release, an air gap is formed between the parylene coat and the cantilever to protect the resonant cantilever from heavy liquid damping effect. Only a small sensing-pool area, located at the cantilever free-end and locally coated with specific sensing-material, is exposed to the liquid analyte for gravimetric detection. The specifically adsorbed analyte mass can be real-time detected by recording the frequency-shift signal. In order to secure vibration movement of the cantilever and, simultaneously, reject liquid leakage from the sensing-pool region, a hydrophobic parylene made narrow slit structure is designed surrounding the sensing-pool. The anti-leakage effect of the narrow slit and damping limited resonance Q-factor are modelled and optimally designed. Integrated with electro-thermal resonance excitation and piezoresistive frequency readout, the cantilever is embedded in a micro-fluidic chip to form a lab-chip micro-system for liquid-phase bio/chemical detection. Experimental results show the Q-factor of 23 in water and longer than 20 hours liquid-phase continuous working time. Loaded with two kinds of sensing-materials at the sensing-pools, two types of sensing chips successfully show real-time liquid-phase detection to ppb

  9. Compact, high-Q, zero temperature coefficient, TE011 sapphire-rutile microwave distributed Bragg reflector resonators.

    PubMed

    Tobar, M E; Cros, D; Blondy, P; Ivanov, E N

    2001-05-01

    Some novel new resonator designs based on the distributed Bragg reflector are presented. The resonators implement a TE011 resonance in a cylindrical sapphire dielectric, which is confined by the addition of rutile and sapphire dielectric reflectors at the end faces. Finite element calculations are utilized to optimize the dimensions to obtain the highest Q-factors and zero frequency-temperature coefficient for a resonator operating near 0 degree C. We show that a Q-factor of 70,000 and 65,000 can be achieved with and without the condition of zero frequency-temperature coefficients, respectively. PMID:11381707

  10. Radiation-induced conductivity and high-temperature Q changes in quartz resonators

    SciTech Connect

    Koehler, D R

    1981-01-01

    While high temperature electrolysis has proven beneficial as a technique to remove interstitial impurities from quartz, reliable indices to measure the efficacy of such a processing step are still under development. The present work is directed toward providing such an index. Two techniques have been investigated - one involves measurement of the radiation induced conductivity in quartz along the optic axis, and the second involves measurement of high temperature Q changes. Both effects originate when impurity charge compensators are released from their traps, in the first case resulting in ionic conduction and in the second case resulting in increased acoustic losses. Radiation induced conductivity measurements have been carried out with a 200 kV, 14 mA x-ray machine producing 5 rads/s. With electric fields of the order of 10/sup 4/ V/cm, the noise level in the current measuring system is equivalent to an ionic current generated by quartz impurities in the 1 ppB range. The accuracy of the high temperature ( 300 to 800/sup 0/K) Q/sup -1/ measurement technique will be determined. A number of resonators constructed of quartz material of different impurity contents have been tested and both the radiation induced conductivity and the high temperature Q/sup -1/ results compared with earlier radiation induced frequency and resonator resistance changes. 10 figures.

  11. Theory and experimental verifications of the resonator Q and equivalent electrical parameters due to viscoelastic and mounting supports losses.

    PubMed

    Yong, Yook-Kong; Patel, Mihir S; Tanaka, Masako

    2010-08-01

    A novel analytical/numerical method for calculating the resonator Q and its equivalent electrical parameters due to viscoelastic, conductivity, and mounting supports losses is presented. The method presented will be quite useful for designing new resonators and reducing the time and costs of prototyping. There was also a necessity for better and more realistic modeling of the resonators because of miniaturization and the rapid advances in the frequency ranges of telecommunication. We present new 3-D finite elements models of quartz resonators with viscoelasticity, conductivity, and mounting support losses. The losses at the mounting supports were modeled by perfectly matched layers (PMLs). A previously published theory for dissipative anisotropic piezoelectric solids was formulated in a weak form for finite element (FE) applications. PMLs were placed at the base of the mounting supports to simulate the energy losses to a semi-infinite base substrate. FE simulations were carried out for free vibrations and forced vibrations of quartz tuning fork and AT-cut resonators. Results for quartz tuning fork and thickness shear AT-cut resonators were presented and compared with experimental data. Results for the resonator Q and the equivalent electrical parameters were compared with their measured values. Good equivalences were found. Results for both low- and high-Q AT-cut quartz resonators compared well with their experimental values. A method for estimating the Q directly from the frequency spectrum obtained for free vibrations was also presented. An important determinant of the quality factor Q of a quartz resonator is the loss of energy from the electrode area to the base via the mountings. The acoustical characteristics of the plate resonator are changed when the plate is mounted onto a base substrate. The base affects the frequency spectra of the plate resonator. A resonator with a high Q may not have a similarly high Q when mounted on a base. Hence, the base is an

  12. A fast way for calculating longitudinal wakefields for high Q resonances

    SciTech Connect

    Cheng-Yang Tan and James M Steimel

    2001-12-03

    We have come up with a way for calculating longitudinal wakefields for high Q resonances by mapping the wake functions to a two dimension vector space. Then in this space, a transformation which is basically a scale change and a rotation, allows us to calculate the new wakefield by knowing only one previous wakefield and one previous particle passage through the cavity. We will also compare this method to the brute force method which needs to know all the passages of the previous particles through the cavity.

  13. Discovery of Bragg confined hybrid modes with high Q factor in a hollow dielectric resonator

    NASA Astrophysics Data System (ADS)

    le Floch, Jean-Michel; Tobar, Michael E.; Mouneyrac, David; Cros, Dominique; Krupka, Jerzy

    2007-10-01

    The authors report on observation of Bragg confined mode in a hollow cylindrical dielectric cavity. A resonance was observed at 13.4GHz with an unloaded Q factor of order 2×105, which is more than a factor of 6 above the dielectric loss limit. Previously, such modes have only been realized from pure transverse electric modes with no azimuthal variations and only the Eϕ component. From rigorous numeric simulations, it is shown that the mode is a hybrid mode with nonzero azimuthal variations and with dominant Er and Eϕ electric field components and Hz magnetic field component.

  14. Carbon Nanofiber-Based, High-Frequency, High-Q, Miniaturized Mechanical Resonators

    NASA Technical Reports Server (NTRS)

    Kaul, Anupama B.; Epp, Larry W.; Bagge, Leif

    2011-01-01

    High Q resonators are a critical component of stable, low-noise communication systems, radar, and precise timing applications such as atomic clocks. In electronic resonators based on Si integrated circuits, resistive losses increase as a result of the continued reduction in device dimensions, which decreases their Q values. On the other hand, due to the mechanical construct of bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators, such loss mechanisms are absent, enabling higher Q-values for both BAW and SAW resonators compared to their electronic counterparts. The other advantages of mechanical resonators are their inherently higher radiation tolerance, a factor that makes them attractive for NASA s extreme environment planetary missions, for example to the Jovian environments where the radiation doses are at hostile levels. Despite these advantages, both BAW and SAW resonators suffer from low resonant frequencies and they are also physically large, which precludes their integration into miniaturized electronic systems. Because there is a need to move the resonant frequency of oscillators to the order of gigahertz, new technologies and materials are being investigated that will make performance at those frequencies attainable. By moving to nanoscale structures, in this case vertically oriented, cantilevered carbon nanotubes (CNTs), that have larger aspect ratios (length/thickness) and extremely high elastic moduli, it is possible to overcome the two disadvantages of both bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators. Nano-electro-mechanical systems (NEMS) that utilize high aspect ratio nanomaterials exhibiting high elastic moduli (e.g., carbon-based nanomaterials) benefit from high Qs, operate at high frequency, and have small force constants that translate to high responsivity that results in improved sensitivity, lower power consumption, and im - proved tunablity. NEMS resonators have recently been demonstrated using topdown

  15. Neutral Pion Electroproduction in the Resonance Region at High $Q^2$

    SciTech Connect

    Villano, A N; Bosted, P E; Connell, S H; Dalton, M M; Jones, M K; Adams, G S; Afanasev, A; Ahmidouch, A; Angelescu, T; Arrington, J; Asaturyan, R; Baker, O K; Benmouna, N; Berman, B L; Breuer, H; Christy, M E; Cui, Y; Danagoulian, S; Day, D; Dodario, T; Dunne, J A; Dutta, D; El Khayari, N; Elliot, B; Ent, R; Fenker, H C; Frolov, V V; Gan, L; Gaskell, D; Gasparian, A; Grullon, S; Hafidi, K; Hinton, W; Holt, R J; Huber, G M; Hungerford, E; Joo, K; Kalantarians, N; Keppel, C E; Kinney, E R; Kubarovsky, V; Li, Y; Liang, Y; Lu, M; Lung, A; Mack, D; Malace, S; Markowitz, P; McKee, P; Meekins, D G; Mkrtchhyan, H; Napolitano, J; Niculescu, G; Niculescu, I; Opper, A K; Pamela, P; Potterveld, D H; Reimer, Paul E; Reinhold, J; Roche, J; Rock, S E; Schulte, E; Segbefia, E; Smith, C; Smith, G R

    2009-09-01

    The process $ep \\to e^{\\prime}p^{\\prime}\\pi^0$ has been measured at $Q^2$ = 6.4 and 7.7 \\ufourmomts in Jefferson Lab's Hall C. Unpolarized differential cross sections are reported in the virtual photon-proton center of mass frame considering the process $\\gamma^{\\ast}p \\to p^{\\prime}\\pi^0$. Various details relating to the background subtractions, radiative corrections and systematic errors are discussed. The usefulness of the data with regard to the measurement of the electromagnetic properties of the well known $\\Delta(1232)$ resonance is covered in detail. Specifically considered are the electromagnetic and scalar-magnetic ratios $R_{EM}$ and $R_{SM}$ along with the magnetic transition form factor $G_M^{\\ast}$. It is found that the rapid fall off of the $\\Delta(1232)$ contribution continues into this region of momentum transfer and that other resonances

  16. Resonant photoacoustic detection of NO2 traces with a Q-switched green laser

    NASA Astrophysics Data System (ADS)

    Slezak, Verónica; Codnia, Jorge; Peuriot, Alejandro L.; Santiago, Guillermo

    2003-01-01

    Resonant photoacoustic detection of NO2 traces by means of a high repetition pulsed green laser is presented. The resonator is a cylindrical Pyrex glass cell with a measured Q factor 380 for the first radial mode in air at atmospheric pressure. The system is calibrated with known mixtures in dry air and a minimum detectable volume concentration of 50 parts in 109 is obtained (S/N=1). Its sensitivity allows one to detect and quantify NO2 traces in the exhaust gases of cars. Previously, the analysis of gas adsorption and desorption on the walls and of changes in the sample composition is carried out in order to minimize errors in the determination of NO2 content upon application of the extractive method. The efficiency of catalytic converters of several models of automobiles is studied and the NO2 concentration in samples from exhausts of different types of engine (gasoline, diesel, and methane gas) at idling operation are measured.

  17. Frequency Locking and Stabilization Regimes in High-Power Gyrotrons with Low-Q Resonators

    NASA Astrophysics Data System (ADS)

    Zotova, I. V.; Ginzburg, N. S.; Denisov, G. G.; Rozental', R. M.; Sergeev, A. S.

    2016-02-01

    Using a nonstationary self-consistent model, we analyze the frequency locking and stabilization regimes arising in gyrotrons with low-Q resonators under the action of an external signal or when reflections from a remote nonresonant load are introduced. In the simulations, we used the parameters of high-power gyrotrons designed for controlled thermonuclear fusion with optimized resonator profile. This approach makes it possible to determine output characteristics of the gyrotrons operated in considered regimes taking into account the effect of the incident wave (external or reflected) on the longitudinal field structure with greater precision compared with the earlier results based on the fixed RF-field structure approximation, while qualitative results of the two approaches coincide. Analysis of the effect of reflections from a remote load has demonstrated a substantial dependence of the efficiency of the gyrotron frequency stabilization on the ratio between the characteristic time scale of the synchronism detuning fluctuations and the signal delay time.

  18. Development of high-Q superconducting resonators for use as Kinetic Inductance detectors

    NASA Astrophysics Data System (ADS)

    Baselmans, J.; Barends, R.; Hovenier, N.; Gao, J.; Hoevers, H.; de Korte, P.; Klapwijk, T.

    One of the largest challenges in the development of future radiation detectors for space applications is the fabrication of large detector arrays This because future missions require camera s with many pixels in combination with background limited sensitivity Within this context we have started the development of Microwave Kinetic Inductance Detectors MKID s The MKID is a relatively new detector concept pioneered by J Zmuidzinas and P Day et al 1 which belongs to the class of pair breaking detectors where radiation is absorbed in a superconducting film by breaking Cooper pairs into quasiparticles The operating temperature of the device is 1 10 of the transition temperature of the superconducting film Hence an Aluminum KID should be operated at 100 mK The MKID measures the change in quasiparticle and Cooper pair density by probing the complex surface impedance of the superconductor This is done by making use of an extremely high Q superconducting quarter wavelength microwave thin film resonator Every resonator each with slightly different resonance frequency can be observed simultaneously With only one wideband cryogenic amplifier 2 coaxial cables from room temperature to the cold stage and commercially available readout electronics a camera with in excess of 100 000 pixels could become a reality KIDs can address the spectrum from far infrared to X-ray depending on the antenna or absorber coupled to the microwave resonator 1 P K Day H G LeDuc B A Mazin A Vayonakis and J Zmuidzinas Nature 425 p 817-821 2003

  19. High-Q sapphire-rutile frequency-temperature compensated microwave dielectric resonators.

    PubMed

    Tobar, M E; Krupka, J; Hartnett, J G; Ivanov, E N; Woode, R A

    1998-01-01

    A sapphiro-rutile composite resonator was constructed from a cylindrical sapphire monocrystal with two thin disks of monocrystal rutile held tightly against the ends. Because rutile exhibits low loss and an opposite temperature coefficient of permittivity to sapphire, it is an ideal material for compensating the frequency-temperature dependence of a sapphire resonator. Most of the electromagnetic modes in the composite structure exhibited turning points (or compensation points) in the frequency-temperature characteristic. The temperatures of compensation for the WG quasi TM modes were measured to be below 90 K with Q-factors of the order of a few million depending on the mode. For WG quasi TE modes, the temperatures of compensation were measured to be between 100 to 160 K with Q-factors of the order of a few hundreds of thousands, depending on the mode. The second derivatives of the compensation points were measured to be of the order 0.1 ppm/K(2 ), which agreed well with the predicted values. PMID:18244235

  20. High-Q microsphere resonators for angular velocity sensing in gyroscopes

    SciTech Connect

    An, Panlong; Zheng, Yongqiu; Yan, Shubin Xue, Chenyang Liu, Jun; Wang, Wanjun

    2015-02-09

    A resonator gyroscope based on the Sagnac effect is proposed using a core unit that is generated by water-hydrogen flame melting. The relationship between the quality factor Q and diameter D is revealed. The Q factor of the spectral lines of the microsphere cavity coupling system, which uses tapered fibers, is found to be 10{sup 6} or more before packaging with a low refractive curable ultraviolet polymer, although it drops to approximately 10{sup 5} after packaging. In addition, a rotating test platform is built, and the transmission spectrum and discriminator curves of a microsphere cavity with Q of 3.22×10{sup 6} are measured using a semiconductor laser (linewidth less than 1 kHz) and a real-time proportional-integral circuit tracking and feedback technique. Equations fitting the relation between the voltage and angular rotation rate are obtained. According to the experimentally measured parameters, the sensitivity of the microsphere-coupled system can reach 0.095{sup ∘}/s.

  1. High-Q microsphere resonators for angular velocity sensing in gyroscopes

    NASA Astrophysics Data System (ADS)

    An, Panlong; Zheng, Yongqiu; Yan, Shubin; Xue, Chenyang; Wang, Wanjun; Liu, Jun

    2015-02-01

    A resonator gyroscope based on the Sagnac effect is proposed using a core unit that is generated by water-hydrogen flame melting. The relationship between the quality factor Q and diameter D is revealed. The Q factor of the spectral lines of the microsphere cavity coupling system, which uses tapered fibers, is found to be 106 or more before packaging with a low refractive curable ultraviolet polymer, although it drops to approximately 105 after packaging. In addition, a rotating test platform is built, and the transmission spectrum and discriminator curves of a microsphere cavity with Q of 3.22 ×106 are measured using a semiconductor laser (linewidth less than 1 kHz) and a real-time proportional-integral circuit tracking and feedback technique. Equations fitting the relation between the voltage and angular rotation rate are obtained. According to the experimentally measured parameters, the sensitivity of the microsphere-coupled system can reach 0.095∘/s .

  2. Differentially piezoresistive transduction of high-Q encapsulated SOI-MEMS resonators with sub-100 nm gaps.

    PubMed

    Li, Cheng-Syun; Li, Ming-Huang; Li, Sheng-Shian

    2015-01-01

    A differentially piezoresistive (piezo-R) readout proposed for single-crystal-silicon (SCS) microelectromechanical systems (MEMS) resonators is implemented in a foundrybased resonator platform, demonstrating effective feedthrough cancellation using just simple piezoresistors from the resonator supports while maximizing their capacitively transduced driving areas. The SCS resonators are fabricated by a CMOS foundry using an SOI-MEMS technology together with a polysilicon refill process. A high electromechanical coupling coefficient is attained by the use of 50-nm transducer gap spacing. Moreover, a vacuum package of the fabricated resonators is carried out through wafer-level bonding process. In this work, the corner supporting beams of the resonator serve not only mechanical supports but also piezoresistors for detecting the motional signal, hence substantially simplifying the overall resonator design to realize the piezo-R sensing. In addition, the fabricated resonators are capable of either capacitive sensing or piezo-R detection under the same capacitive drive. To mitigate feedthrough signals from parasitics, a differential measurement configuration of the piezo-R transduction is implemented in this work, featuring more than 30-dB improvement on the feedthrough level as compared with the single-ended piezo-R counterpart and purely capacitive sensing readout. Furthermore, the high-Q design of the mechanical supports is also investigated, offering Q more than 10 000 with efficient piezo-R transduction for MEMS resonators. PMID:25585404

  3. Universal nonlinear scattering in ultra-high Q whispering gallery-mode resonators.

    PubMed

    Lin, Guoping; Diallo, Souleymane; Dudley, John M; Chembo, Yanne K

    2016-06-27

    Universal nonlinear scattering processes such as Brillouin, Raman, and Kerr effects are fundamental light-matter interactions of particular theoretical and experimental importance. They originate from the interaction of a laser field with an optical medium at the lattice, molecular, and electronic scale, respectively. These nonlinear effects are generally observed and analyzed separately, because they do not often occur concomitantly. In this article, we report the simultaneous excitation of these three fundamental interactions in mm-size ultra-high Q whispering gallery mode resonators under continuous wave pumping. Universal nonlinear scattering is demonstrated in barium fluoride and strontium fluoride, separately. We further propose a unified theory based on a spatiotemporal formalism for the understanding of this phenomenology. PMID:27410640

  4. Time-domain self-consistent theory of frequency-locking regimes in gyrotrons with low-Q resonators

    SciTech Connect

    Ginzburg, N. S.; Sergeev, A. S.; Zotova, I. V.

    2015-03-15

    A time-domain theory of frequency-locking gyrotron oscillators with low-Q resonators has been developed. The presented theory is based on the description of wave propagation by a parabolic equation taking into account the external signal by modification of boundary conditions. We show that the developed model can be effectively used for simulations of both single- and multi-mode operation regimes in gyrotrons driven by an external signal. For the case of low-Q resonators typical for powerful gyrotrons, the external signal can influence the axial field profile inside the interaction space significantly and, correspondingly, the value of the electron orbital efficiency.

  5. Time-domain self-consistent theory of frequency-locking regimes in gyrotrons with low-Q resonators

    NASA Astrophysics Data System (ADS)

    Ginzburg, N. S.; Sergeev, A. S.; Zotova, I. V.

    2015-03-01

    A time-domain theory of frequency-locking gyrotron oscillators with low-Q resonators has been developed. The presented theory is based on the description of wave propagation by a parabolic equation taking into account the external signal by modification of boundary conditions. We show that the developed model can be effectively used for simulations of both single- and multi-mode operation regimes in gyrotrons driven by an external signal. For the case of low-Q resonators typical for powerful gyrotrons, the external signal can influence the axial field profile inside the interaction space significantly and, correspondingly, the value of the electron orbital efficiency.

  6. Frequency-Temperature Compensation Techniques for High-Q Microwave Resonators

    NASA Astrophysics Data System (ADS)

    Hartnett, John G.; Tobar, Michael E.

    Low-noise high-stability resonator oscillators based on high-Q monolithic sapphire ``Whispering Gallery'' (WG)-mode resonators have become important devices for telecommunication, radar and metrological applications. The extremely high quality factor of sapphire, of 2 x10^5 at room temperature, 5 x10^7 at liquid nitrogen temperature and 5 x10^9 at liquid helium temperature has enabled the lowest phase noise and highly frequency-stable oscillators in the microwave regime to be constructed. To create an oscillator with exceptional frequency stability, the resonator must have its frequency-temperature dependence annulled at some temperature, as well as a high quality factor. The Temperature Coefficient of Permittivity (TCP) for sapphire is quite large, at 10-100parts per million/K above 77K. This mechanism allows temperature fluctuations to transform to resonator frequency fluctuations.A number of research groups worldwide have investigated various methods of compensating the TCP of a sapphire dielectric resonator at different temperatures. The usual electromagnetic technique of annulment involves the use of paramagnetic impurities contributing an opposite temperature coefficient of the magnetic susceptibility to the TCP. This technique has only been realized successfully in liquid helium environments. Near 4K the thermal expansion and permittivity effects are small and only small quantities of the paramagnetic ions are necessary to compensate the mode frequency. Compensation is due to impurity ions that were incidentally left over from the manufacturing process.Recently, there has been an effort to dispense with the need for liquid helium and make a compact flywheel oscillator for the new generation of primary frequency standards such as the cesium fountain at the Laboratoire Primaire du Temps et des Fréquences (LPTF), France. To achieve the stability limit imposed

  7. Panels with low-Q-factor resonators with theoretically infinite sound-proofing ability at a single frequency

    NASA Astrophysics Data System (ADS)

    Lazarev, L. A.

    2015-07-01

    An infinite panel with two types of resonators regularly installed on it is theoretically considered. Each resonator is an air-filled cavity hermetically closed by a plate, which executes piston vibrations. The plate and air inside the cavity play the roles of mass and elasticity, respectively. Every other resonator is reversed. At a certain ratio between the parameters of the resonators at the tuning frequency of the entire system, the acoustic-pressure force that directly affects the panel can be fully compensated by the action forces of the resonators. In this case, the sound-proofing ability (transmission loss) tends to infinity. The presented calculations show that a complete transmission-loss effect can be achieved even with low- Q resonators.

  8. Aliasing Effects of Q-bursts on Background Spectra of Schumann Resonances

    NASA Astrophysics Data System (ADS)

    Guha, A.; Mushtak, V. C.; Williams, E.; Neska, M.; Nagy, T. G.; Satori, G.

    2013-12-01

    The Earth's Schumann resonances (SR) manifest as a 'background' signal and as an occasional transient excitation (Q-burst) of substantially larger amplitude. The background signal is generally attributed to the superposition of radiated ELF signal from average lightning flashes originating in convective scale thunderstorms predominant in the late afternoon, and whose waveforms are all overlapping. The larger transient excitations are attributed to exceptionally energetic lightning flashes in larger mesoscale convective systems. These flashes stand out strongly against the background signal, and often produce sprites in the mesosphere. These exceptional events are often delayed in the diurnal cycle by many hours into the evening and even the early morning over land areas. This study is concerned with the idea that the spectral energy of a single transient event can compete with the background energy over 5-15 minute time scales, and so serve to alias the background spectrum and destroy that 'fingerprint' for the geographical origin of the background lightning. In the present work, an attempt is made to detect these large by simultaneous observation of SR electric field spectra from two stations in Europe, Belsk, Poland (BLK: 49.190 N, 22.550 E) and Nagycenk, Hungary (NCK: 47.60 N, 16.70 E), separated by 0.47 Mm, along with the same strokes identified by the World Wide Lighting Location Network (WWLLN). First, the energy contents (EC) for each five second spectra with up to four SR modes for the two stations are computed. Q-burst events are selected if: (1) the Core Standard Deviation (CSD) in any 5 second segment is above 16 CSD (2) the ratio of CSDs at both stations is within 0.5 to 2, and (3) the event occurs within 1-3 time samples at each station. Simultaneous observations at these nearby stations enable us to distinguish the cultural noise and lightning strokes originating close to each station. At the same time, the propagation path form the originating Q

  9. Neutral pion electroproduction in the resonance region at high Q{sup 2}

    SciTech Connect

    Villano, A. N.; Stoler, P.; Kubarovsky, V.; Adams, G. S.; Napolitano, J.; Bosted, P. E.; Jones, M. K.; Ent, R.; Fenker, H. C.; Gaskell, D.; Lung, A.; Mack, D.; Meekins, D. G.; Roche, J.; Smith, G. R.; Wojtsekhowski, B.; Wood, S. A.; Connell, S. H.; Dalton, M. M.; Ahmidouch, A.

    2009-09-15

    The process ep{yields}ep{pi}{sup 0} has been measured at Q{sup 2}=6.4 and 7.7 (GeV/c{sup 2}){sup 2} in Jefferson Lab's Hall C. Unpolarized differential cross sections are reported in the virtual photon-proton center-of-mass frame considering the process {gamma}*p{yields}p{pi}{sup 0}. Various details relating to the background subtractions, radiative corrections, and systematic errors are discussed. The usefulness of the data with regard to the measurement of the electromagnetic properties of the well-known {delta}(1232) resonance is covered in detail. Specifically considered are the electromagnetic and scalar-magnetic ratios R{sub EM} and R{sub SM} along with the magnetic transition form factor G{sub M}*. It is found that the rapid falloff of the {delta}(1232) contribution continues into this region of momentum transfer and that other resonances may be making important contributions in this region.

  10. Neutral pion electroproduction in the resonance region at high Q{sup 2}.

    SciTech Connect

    Villano, A. N.; Stoler, P.; Bosted, P. E.; Connell, S. H.; Dalton, M. M.; Arrington, J.; Hafidi, K.; Holt, R. J.; Schulte, E.; Reimer, P. E.; Zheng, X.; Physics; Rensselaer Polytechnic Inst.; Thomas Jefferson National Accelerator Facility; Univ. of the Johannesburg; Univ. of the Witwatersrand

    2009-09-01

    The process ep {yields} ep{pi}{sup 0} has been measured at Q{sup 2} = 6.4 and 7.7 (GeV/c{sup 2}){sup 2} in Jefferson Lab's Hall C. Unpolarized differential cross sections are reported in the virtual photon-proton center-of-mass frame considering the process {gamma}*p {yields} p{pi}{sup 0}. Various details relating to the background subtractions, radiative corrections, and systematic errors are discussed. The usefulness of the data with regard to the measurement of the electromagnetic properties of the well-known {Delta}(1232) resonance is covered in detail. Specifically considered are the electromagnetic and scalar-magnetic ratios R{sub EM} and R{sub SM} along with the magnetic transition form factor G*{sub M}. It is found that the rapid falloff of the {Delta}(1232) contribution continues into this region of momentum transfer and that other resonances may be making important contributions in this region.

  11. Distributed bragg reflector resonators with cylindrical symmetry and extremely high Q-factors.

    PubMed

    Tobar, Michael E; le Floch, Jean-Michel; Cros, Dominique; Hartnett, John G

    2005-01-01

    A simple non-Maxwellian method is presented that allows the approximate solution of all the dimensions of a multilayered dielectric TE0qp mode cylindrical resonant cavity that constitutes a distributed Bragg reflection (DBR) resonator. The analysis considers an arbitrary number of alternating dielectric and free-space layers of cylindrical geometry enclosed by a metal cylinder. The layers may be arranged along the axial direction, the radial direction, or both. Given only the aspect ratio of the cavity, the desired frequency and the dielectric constants of the material layers, the relevant dimensions are determined from only a set of simultaneous equations, and iterative techniques are not required. The formulas were verified using rigorous method of lines (MoL) calculations and previously published experimental work. We show that the simple approximation gives dimensions close to the values of the optimum Bragg reflection condition determined by the rigorous analysis. The resulting solution is more compact with a higher Q-factor when compared to other reported cylindrical DBR structures. This is because it properly takes into account the effect of the aspect ratio on the Bragg antiresonance condition along the z-axis of the resonator. Previous analyses assumed the propagation in the z-direction was independent of the aspect ratio, and the layers of the Bragg reflector were a quarter of a wavelength thick along the z-direction. When the aspect ratio is properly taken into account, we show that the thickness of the Bragg reflectors are equivalent to the thickness of plane wave Bragg reflectors (or quarter wavelength plates). Thus it turns out that the sizes of the reflectors are related to the free-space propagation constant rather than the propagation constant in the z-direction. PMID:15742559

  12. High-Q cross-plate phononic crystal resonator for enhanced acoustic wave localization and energy harvesting

    NASA Astrophysics Data System (ADS)

    Yang, Aichao; Li, Ping; Wen, Yumei; Yang, Chao; Wang, Decai; Zhang, Feng; Zhang, Jiajia

    2015-05-01

    A high-Q cross-plate phononic crystal resonator (Cr-PCR) coupled with an electromechanical Helmholtz resonator (EMHR) is proposed to improve acoustic wave localization and energy harvesting. Owing to the strongly directional wave-scattering effect of the cross-plate corners, strong confinement of acoustic waves emerges. Consequently, the proposed Cr-PCR structure exhibits ∼353.5 times higher Q value and ∼6.1 times greater maximum pressure amplification than the phononic crystal resonator (Cy-PCR) (consisting of cylindrical scatterers) of the same size. Furthermore, the harvester using the proposed Cr-PCR and the EMHR has ∼22 times greater maximum output-power volume density than the previous harvester using Cy-PCR and EMHR structures.

  13. Photoelastic ultrasound detection using ultra-high-Q silica optical resonators.

    PubMed

    Chistiakova, Maria V; Armani, Andrea M

    2014-11-17

    As a result of its non-invasive and non-destructive nature, ultrasound imaging has found a variety of applications in a wide range of fields, including healthcare and electronics. One accurate and sensitive approach for detecting ultrasound waves is based on optical microcavities. Previous research using polymer microring resonators demonstrated detection based on the deformation of the cavity induced by the ultrasound wave. An alternative detection approach is based on the photoelastic effect in which the ultrasound wave induces a strain in the material that is converted to a refractive index change. In the present work, photoelastic-based ultrasound detection is experimentally demonstrated using ultra high quality factor silica optical microcavities. As a result of the increase in Q and in coupled power, the noise equivalent pressure is reduced, and the device response is increased. A finite element method model that includes both the acoustics and optics components of this system is developed, and the predictive accuracy of the model is determined. PMID:25402057

  14. A time domain based method for the accurate measurement of Q-factor and resonance frequency of microwave resonators

    SciTech Connect

    Gyüre, B.; Márkus, B. G.; Bernáth, B.; Simon, F.; Murányi, F.

    2015-09-15

    We present a novel method to determine the resonant frequency and quality factor of microwave resonators which is faster, more stable, and conceptually simpler than the yet existing techniques. The microwave resonator is pumped with the microwave radiation at a frequency away from its resonance. It then emits an exponentially decaying radiation at its eigen-frequency when the excitation is rapidly switched off. The emitted microwave signal is down-converted with a microwave mixer, digitized, and its Fourier transformation (FT) directly yields the resonance curve in a single shot. Being a FT based method, this technique possesses the Fellgett (multiplex) and Connes (accuracy) advantages and it conceptually mimics that of pulsed nuclear magnetic resonance. We also establish a novel benchmark to compare accuracy of the different approaches of microwave resonator measurements. This shows that the present method has similar accuracy to the existing ones, which are based on sweeping or modulating the frequency of the microwave radiation.

  15. High-energy resonantly diode-pumped Q-switched Er:YAG laser at 1617 nm

    NASA Astrophysics Data System (ADS)

    Yu, Zhenzhen; Wang, Mingjian; Hou, Xia; Chen, Weibiao

    2016-04-01

    We report high-energy linearly polarized operation of an Er:YAG laser at 1617 nm, resonantly pumped by quasi-continuous-wave 1470-nm laser diodes. A U-shape resonator incorporating two 0.25 at.% Er:YAG rods and an acousto-optic Q-switch was employed. Polarized output with pulse energy of 20.5 mJ and pulse width of 52 ns at a 50 Hz repetition rate was obtained. At the maximum output energy, the output beam quality M 2 was approximately 1.02 and 1.03 in horizontal and vertical directions, respectively. To the best of our knowledge, this polarized pulse energy is the highest ever reported for a directly diode-pumped Q-switched Er:YAG laser operating at 1617 nm.

  16. High-Q lithium niobate microdisk resonators on a chip for efficient electro-optic modulation.

    PubMed

    Wang, Jie; Bo, Fang; Wan, Shuai; Li, Wuxia; Gao, Feng; Li, Junjie; Zhang, Guoquan; Xu, Jingjun

    2015-09-01

    Lithium niobate (LN) microdisk resonators on a LN-silica-LN chip were fabricated using only conventional semiconductor fabrication processes. The quality factor of the LN resonator with a 39.6-μm radius and a 0.5-μm thickness is up to 1.19 × 10(6), which doubles the record of the quality factor 4.84 × 10(5) of LN resonators produced by microfabrication methods allowing batch production. Electro-optic modulation with an effective resonance-frequency tuning rate of 3.0 GHz/V was demonstrated in the fabricated LN microdisk resonator. PMID:26368411

  17. Excitation of a high-Q subradiant resonance mode in mirrored single-gap asymmetric split ring resonator terahertz metamaterials

    NASA Astrophysics Data System (ADS)

    Al-Naib, Ibraheem; Singh, Ranjan; Rockstuhl, Carsten; Lederer, Falk; Delprat, Sebastien; Rocheleau, David; Chaker, Mohamed; Ozaki, Tsuneyuki; Morandotti, Roberto

    2012-08-01

    We propose a mirrored arrangement of asymmetric single split ring resonators (ASRs) that dramatically enhances the quality factor of the inductive-capacitive resonance. In a regular non-mirrored arrangement, the surface current modes are all oriented in phase. Hence, light scattered by individual ASRs interferes constructively. In contrast, the proposed configuration sustains surface currents that are oppositely oriented for neighboring ASRs, in turn leading to the cancellation of the net dipole moment accompanied by destructive interference of the scattered fields. The proposed arrangement holds promise to suppress radiation losses in terahertz, microwave and infrared plasmonic metamaterials.

  18. Continuous-wave and Q-switched operation of a resonantly pumped Ho:YAlO3 laser.

    PubMed

    Yao, Bao-Quan; Duan, Xiao-Ming; Zheng, Liang-Liang; Ju, You-Lun; Wang, Yue-Zhu; Zhao, Guang-Jun; Dong, Qin

    2008-09-15

    We demonstrated continuous-wave (CW) and Q-switched operation of a room-temperature Ho:YAlO(3) laser that is resonantly end-pumped by a diode-pumped Tm:YLF laser at 1.91 microm. The CW Ho:YAlO(3) laser generated 5.5 W of linearly polarized (EII c ) output at 2118 nm with beam quality factor of M(2) approximately 1.1 for an incident pump power of 13.8 W, corresponding to optical-to-optical conversion efficiency of 40%. Up to 1- mJ energy per pulse at pulse repetition frequency (PRF) of 5 kHz, and the maximum average power of 5.3-W with FWHM pulse duration of 30.5 ns at 20 kHz were achieved in Q-switched mode. PMID:18795004

  19. Photon trapping in a high-Q cavity by non-resonant atoms coupled with an external broadband vacuum field

    NASA Astrophysics Data System (ADS)

    Basharov, A. M.

    2012-05-01

    A new effect of the decay suppression of photon mode non-resonant to the cavity atoms coupled with an external broadband vacuum field has been described. At a certain number Nacr of cavity atoms, the emission of cavity photons due to the non-resonant interaction with cavity atoms has been stopped by the Stark interaction of cavity atoms with the external broadband vacuum field. In the case of high-Q cavity this provides the effect of radiation trapping. The cavity photon has obtained an additional energy shift. These results have been obtained on the basis of a theory of localized quantum open systems developed with the help of the quantum stochastic differential equation of the generalized Langevin (non-Wiener) type.

  20. System test of an optoelectronic gyroscope based on a high Q-factor InP ring resonator

    NASA Astrophysics Data System (ADS)

    Dell'Olio, Francesco; Indiveri, Fabrizio; Innone, Filomena; Dello Russo, Pasquale; Ciminelli, Caterina; Armenise, Mario N.

    2014-12-01

    The experimental results of the system test of an optical resonant passive gyroscope based on a high Q-factor ring resonator in InP technology are reported. The open loop configuration based on the phase modulation was preferred among the analyzed configuration options, especially because it is potentially suitable for the monolithic integration of the entire sensor on a single chip. The setup components are described with a special emphasis on a custom digital readout board based on a field-programmable gate array. The board processes the input signals according to the proportional-integral algorithm which has been implemented through an optimized firmware. For the system test, the sensor rotation has been simulated using two properly driven acousto-optic modulators. The results reported here prove the gyro functionality and are a good starting point for the full development of the sensor.

  1. Encapsulated high frequency (235 kHz), high-Q (100 k) disk resonator gyroscope with electrostatic parametric pump

    NASA Astrophysics Data System (ADS)

    Ahn, C. H.; Nitzan, S.; Ng, E. J.; Hong, V. A.; Yang, Y.; Kimbrell, T.; Horsley, D. A.; Kenny, T. W.

    2014-12-01

    In this paper, we explore the effects of electrostatic parametric amplification on a high quality factor (Q > 100 000) encapsulated disk resonator gyroscope (DRG), fabricated in <100> silicon. The DRG was operated in the n = 2 degenerate wineglass mode at 235 kHz, and electrostatically tuned so that the frequency split between the two degenerate modes was less than 100 mHz. A parametric pump at twice the resonant frequency is applied to the sense axis of the DRG, resulting in a maximum scale factor of 156.6 μV/(°/s), an 8.8× improvement over the non-amplified performance. When operated with a parametric gain of 5.4, a minimum angle random walk of 0.034°/√h and bias instability of 1.15°/h are achieved, representing an improvement by a factor of 4.3× and 1.5×, respectively.

  2. Computation of diffusion function measures in q-space using magnetic resonance hybrid diffusion imaging.

    PubMed

    Wu, Yu-Chien; Field, Aaron S; Alexander, Andrew L

    2008-06-01

    The distribution of water diffusion in biological tissues may be estimated by a 3-D Fourier transform (FT) of diffusion-weighted measurements in q-space. In this study, methods for estimating diffusion spectrum measures (the zero-displacement probability, the mean-squared displacement, and the orientation distribution function) directly from the q-space signals are described. These methods were evaluated using both computer simulations and hybrid diffusion imaging (HYDI) measurements on a human brain. The HYDI method obtains diffusion-weighted measurements on concentric spheres in q-space. Monte Carlo computer simulations were performed to investigate effects of noise, q-space truncation, and sampling interval on the measures. This new direct computation approach reduces HYDI data processing time and image artifacts arising from 3-D FT and regridding interpolation. In addition, it is less sensitive to the noise and q-space truncation effects than conventional approach. Although this study focused on data using the HYDI scheme, this computation approach may be applied to other diffusion sampling schemes including Cartesian diffusion spectrum imaging. PMID:18541492

  3. Q spoiling in deformed optical microdisks due to resonance-assisted tunneling.

    PubMed

    Kullig, Julius; Wiersig, Jan

    2016-08-01

    A recent experiment by Kwak et al. [Sci. Rep. 5, 9010 (2015)10.1038/srep09010] demonstrated the relevance of resonance-assisted tunneling for optical microcavities where resonance chains emerge in phase space due to boundary deformations. In this paper we adapt the perturbative description of resonance-assisted tunneling to calculate optical modes and the imaginary part of their complex wavenumber which determines the lifetime of the mode. We demonstrate our method at three example cavity shapes and compare our results to numerical data and perturbation theory for weakly deformed microdisk cavities. PMID:27627293

  4. Q spoiling in deformed optical microdisks due to resonance-assisted tunneling

    NASA Astrophysics Data System (ADS)

    Kullig, Julius; Wiersig, Jan

    2016-08-01

    A recent experiment by Kwak et al. [Sci. Rep. 5, 9010 (2015), 10.1038/srep09010] demonstrated the relevance of resonance-assisted tunneling for optical microcavities where resonance chains emerge in phase space due to boundary deformations. In this paper we adapt the perturbative description of resonance-assisted tunneling to calculate optical modes and the imaginary part of their complex wavenumber which determines the lifetime of the mode. We demonstrate our method at three example cavity shapes and compare our results to numerical data and perturbation theory for weakly deformed microdisk cavities.

  5. Radio frequency spectral characterization and model parameters extraction of high Q optical resonators.

    PubMed

    Abdallah, Zeina; Boucher, Yann G; Fernandez, Arnaud; Balac, Stéphane; Llopis, Olivier

    2016-01-01

    A microwave domain characterization approach is proposed to determine the properties of high quality factor optical resonators. This approach features a very high precision in frequency and aims to acquire a full knowledge of the complex transfer function (amplitude and phase) characterizing an optical resonator using a microwave vector network analyzer. It is able to discriminate between the different coupling regimes, from the under-coupling to the selective amplification, and it is used together with a model from which the main resonator parameters are extracted, i.e. coupling factor, intrinsic losses, phase slope, intrinsic and external quality factor. PMID:27251460

  6. Radio frequency spectral characterization and model parameters extraction of high Q optical resonators

    NASA Astrophysics Data System (ADS)

    Abdallah, Zeina; Boucher, Yann G.; Fernandez, Arnaud; Balac, Stéphane; Llopis, Olivier

    2016-06-01

    A microwave domain characterization approach is proposed to determine the properties of high quality factor optical resonators. This approach features a very high precision in frequency and aims to acquire a full knowledge of the complex transfer function (amplitude and phase) characterizing an optical resonator using a microwave vector network analyzer. It is able to discriminate between the different coupling regimes, from the under-coupling to the selective amplification, and it is used together with a model from which the main resonator parameters are extracted, i.e. coupling factor, intrinsic losses, phase slope, intrinsic and external quality factor.

  7. Radio frequency spectral characterization and model parameters extraction of high Q optical resonators

    PubMed Central

    Abdallah, Zeina; Boucher, Yann G.; Fernandez, Arnaud; Balac, Stéphane; Llopis, Olivier

    2016-01-01

    A microwave domain characterization approach is proposed to determine the properties of high quality factor optical resonators. This approach features a very high precision in frequency and aims to acquire a full knowledge of the complex transfer function (amplitude and phase) characterizing an optical resonator using a microwave vector network analyzer. It is able to discriminate between the different coupling regimes, from the under-coupling to the selective amplification, and it is used together with a model from which the main resonator parameters are extracted, i.e. coupling factor, intrinsic losses, phase slope, intrinsic and external quality factor. PMID:27251460

  8. High-Q micromechanical resonators for mass sensing in dissipative media

    NASA Astrophysics Data System (ADS)

    Tappura, Kirsi; Pekko, Panu; Seppä, Heikki

    2011-06-01

    Single crystal silicon-based micromechanical resonators are developed for mass sensing in dissipative media. The design aspects and preliminary characterization of the resonators are presented. For the suggested designs, quality factors of about 20 000 are typically measured in air at atmospheric pressure and 1000-2000 in contact with liquid. The performance is based on a wine-glass-type lateral bulk acoustic mode excited in a rectangular resonator plate. The mode essentially eliminates the radiation of acoustic energy into the sample media leaving viscous drag as the dominant fluid-based dissipation mechanism in the system. For a mass loading distributed over the central areas of the resonator a sensitivity of 27 ppm ng-1 is measured exhibiting good agreement with the results of the finite element method-based simulations. It is also shown that the mass sensitivity can be somewhat enhanced, not only by the proper distribution of the loaded mass, but also by introducing shallow barrier structures on the resonator.

  9. Magnetic Resonance Q Mapping Reveals a Decrease in Microvessel Density in the arcAβ Mouse Model of Cerebral Amyloidosis

    PubMed Central

    Ielacqua, Giovanna D.; Schlegel, Felix; Füchtemeier, Martina; Xandry, Jael; Rudin, Markus; Klohs, Jan

    2016-01-01

    Alterations in density and morphology of the cerebral microvasculature have been reported to occur in Alzheimer's disease patients and animal models of the disease. In this study we compared magnetic resonance imaging (MRI) techniques for their utility to detect age-dependent changes of the cerebral vasculature in the arcAβ mouse model of cerebral amyloidosis. Dynamic susceptibility contrast (DSC)-MRI was performed by tracking the passage of a superparamagnetic iron oxide nanoparticle in the brain with dynamic gradient echo planar imaging (EPI). From this measurements relative cerebral blood volume [rCBV(DSC)] and relative cerebral blood flow (rCBF) were estimated. For the same animal maps of the relaxation shift index Q were computed from high resolution gradient echo and spin echo data that were acquired before and after superparamagnetic iron oxide (SPIO) nanoparticle injection. Q-values were used to derive estimates of microvessel density. The change in the relaxation rates ΔR2* obtained from pre- and post-contrast gradient echo data was used for the alternative determination of rCBV [rCBV(ΔR2*)]. Linear mixed effects modeling found no significant association between rCBV(DSC), rCBV(ΔR2*), rCBF, and Q with genotype in 13-month old mice [compared to age-matched non-transgenic littermates (NTLs)] for any of the evaluated brain regions. In 24-month old mice there was a significant association for rCBV(DSC) with genotype in the cerebral cortex, and for rCBV(ΔR2*) in the cerebral cortex and cerebellum. For rCBF there was a significant association in the cerebellum but not in other brain regions. Q-values in the olfactory bulb, cerebral cortex, striatum, hippocampus, and cerebellum in 24-month old mice were significantly associated with genotype. In those regions Q-values were reduced between 11 and 26% in arcAβ mice compared to age-matched NTLs. Vessel staining with CD31 immunohistochemistry confirmed a reduction of microvessel density in the old arcAβ mice

  10. Q^2 Dependence of the S_{11}(1535) Photocoupling and Evidence for a P-wave resonance in eta electroproduction

    SciTech Connect

    Haluk Denizli; James Mueller; Steven Dytman; M.L. Leber; R.D. Levine; J. Miles; Kui Kim; Gary Adams; Moscov Amaryan; Pawel Ambrozewicz; Marco Anghinolfi; Burin Asavapibhop; G. Asryan; Harutyun Avakian; Hovhannes Baghdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; Steve Barrow; V. Batourine; Marco Battaglieri; Kevin Beard; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Nicola Bianchi; Angela Biselli; Billy Bonner; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Catalina Cetina; Shifeng Chen; Philip Cole; Alan Coleman; Patrick Collins; Philip Coltharp; Dieter Cords; Pietro Corvisiero; Donald Crabb; Volker Crede; John Cummings; Natalya Dashyan; Raffaella De Vita; Enzo De Sanctis; Pavel Degtiarenko; Lawrence Dennis; Alexandre Deur; Kalvir Dhuga; Richard Dickson; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; P. Dragovitsch; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Lamiaa Elfassi; Latifa Elouadrhiri; A. Empl; Paul Eugenio; Laurent Farhi; Renee Fatemi; Gleb Fedotov; Gerald Feldman; Robert Feuerbach; Tony Forest; Valera Frolov; Herbert Funsten; Sally Gaff; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Pascal Girard; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Ralf Gothe; Keith Griffioen; Michel Guidal; Matthieu Guillo; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; David Heddle; F. Hersman; Kenneth Hicks; Ishaq Hleiqawi; Maurik Holtrop; Jingliang Hu; Charles Hyde; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; Narbe Kalantarians; J.H. Kelley; James Kellie; Mahbubul Khandaker; K. Kim; Wooyoung Kim; Andreas Klein; Franz Klein; Mike Klusman; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; David Lawrence; Kenneth Livingston; Haiyun Lu; K. Lukashin; Marion MacCormick; Joseph Manak; Nikolai Markov; Simeon McAleer; Bryan McKinnon; John McNabb; Bernhard Mecking; Mac Mestayer; Curtis Meyer; Tsutomu Mibe; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; Rory Miskimen; Viktor Mokeev; Kei Moriya; Steven Morrow; M. Moteabbed; Valeria Muccifora; Gordon Mutchler; Pawel Nadel-Turonski; James Napolitano; Rakhsha Nasseripour; Steve Nelson; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Grant O'Rielly; Mikhail Osipenko; Alexander Ostrovidov; Kijun Park; Evgueni Pasyuk; Craig Paterson; Gerald Peterson; Sasha Philips; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Ermanno Polli; S. Pozdniakov; Barry Preedom; John Price; Yelena Prok; Dan Protopopescu; Liming Qin; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; David Rowntree; Philip Rubin; Franck Sabatie; Konstantin Sabourov; Julian Salamanca; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Aziz Shafi; Youri Sharabian; Jeremiah Shaw; Nikolay Shvedunov; Sebastio Simionatto; Alexander Skabelin; Elton Smith; Lee Smith; Daniel Sober; Daria Sokhan; M. Spraker; Aleksey Stavinskiy; Samuel Stepanyan; Stepan Stepanyan; Burnham Stokes; Paul Stoler; I.I. Strakovsky; Steffen Strauch; Mauro Taiuti; Simon Taylor; David Tedeschi; Ulrike Thoma; R. Thompson; Avtandil Tkabladze; Svyatoslav Tkachenko; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Kebin Wang; Daniel Watts; Lawrence Weinstein; Henry Weller; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Junho Yun; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2007-07-01

    New cross sections for the reaction $ep \\to e'\\eta p$ are reported for total center of mass energy $W$=1.5--2.3 GeV and invariant squared momentum transfer $Q^2$=0.13--3.3 GeV$^2$. This large kinematic range allows extraction of new information about response functions, photocouplings, and $\\eta N$ coupling strengths of baryon resonances. A sharp structure is seen at $W\\sim$ 1.7 GeV. The shape of the differential cross section is indicative of the presence of a $P$-wave resonance that persists to high $Q^2$. Improved values are derived for the photon coupling amplitude for the $S_{11}$(1535) resonance. The new data greatly expands the $Q^2$ range covered and an interpretation of all data with a consistent parameterization is provided.

  11. High-sensitivity and wide-directivity ultrasound detection using high Q polymer microring resonators

    PubMed Central

    Ling, Tao; Chen, Sung-Liang; Guo, L. Jay

    2011-01-01

    Small size ultrahigh Q polymer microrings working at near visible wavelength have been experimentally demonstrated as ultralow noise ultrasound detectors with wide directivity at high frequencies (>20 MHz). By combining a resist reflow and a low bias continuous etching and passivation process in mold fabrication, imprinted polymer microrings with drastically improved sidewall smoothness were obtained. An ultralow noise-equivalent pressure of 21.4 Pa over 1–75 MHz range has been achieved using a fabricated detector of 60 μm diameter. The device’s wide acceptance angle with high sensitivity considerably benefits ultrasound-related imaging. PMID:21673832

  12. Molybdenum-rhenium alloy based high-Q superconducting microwave resonators

    SciTech Connect

    Singh, Vibhor Schneider, Ben H.; Bosman, Sal J.; Merkx, Evert P. J.; Steele, Gary A.

    2014-12-01

    Superconducting microwave resonators (SMRs) with high quality factors have become an important technology in a wide range of applications. Molybdenum-Rhenium (MoRe) is a disordered superconducting alloy with a noble surface chemistry and a relatively high transition temperature. These properties make it attractive for SMR applications, but characterization of MoRe SMR has not yet been reported. Here, we present the fabrication and characterization of SMR fabricated with a MoRe 60–40 alloy. At low drive powers, we observe internal quality-factors as high as 700 000. Temperature and power dependence of the internal quality-factors suggest the presence of the two level systems from the dielectric substrate dominating the internal loss at low temperatures. We further test the compatibility of these resonators with high temperature processes, such as for carbon nanotube chemical vapor deposition growth, and their performance in the magnetic field, an important characterization for hybrid systems.

  13. High speed on-chip current measurement using a low-Q tunable LC resonator

    NASA Astrophysics Data System (ADS)

    Campbell, Brooks; Chen, Z.; Chiaro, B.; Dunsworth, A.; Neill, C.; O'Malley, P. J. J.; Quintana, C.; Vainsencher, A.; Wenner, J.; Barends, R.; Chen, Y.; Fowler, A.; Jeffrey, E.; Kelly, J.; Lucero, E.; Megrant, A.; Mutus, J.; Neeley, M.; Roushan, P.; Sank, D.; White, T. C.; Martinis, John M.

    Superconducting quantum computing technology requires precise high frequency analog waveforms to perform single and multi-qubit gates. Due to signal path irregularities, gates are tuned-up by perturbing the drive signal until qubit state populations indicate the desired gate function. A more direct approach is to measure the effect of circuit imperfections by sampling control waveforms directly, as seen by the qubits. We proceed by measuring the resonant frequency shift of a capacitively shunted SQUID and converting the control waveform to DC flux applied to the SQUID. By measuring the reflected phase of a CW tone applied to this resonant circuit while applying the resonance-shifting flux pulse, we are able to reconstruct the current waveform of the input pulse at the SQUID loop. This device's geometry is the same as the z-control lines used in qubit experiments to control the qubit frequency. I will present this method of on-chip waveform sampling for superconducting circuits in addition to proof of concept data. This technique opens the door for improved gate bring up and a deeper understanding of qubit control as well as the circuit parasitics that deform these waveforms.

  14. Single-crystal sapphire resonator at millikelvin temperatures: Observation of thermal bistability in high- Q factor whispering gallery modes

    NASA Astrophysics Data System (ADS)

    Creedon, Daniel L.; Tobar, Michael E.; Le Floch, Jean-Michel; Reshitnyk, Yarema; Duty, Timothy

    2010-09-01

    Resonance modes in single crystal sapphire (α-Al2O3) exhibit extremely high electrical and mechanical Q factors ( ≈109 at 4 K), which are important characteristics for electromechanical experiments at the quantum limit. We report the cool down of a bulk sapphire sample below superfluid liquid-helium temperature (1.6 K) to as low as 25 mK. The electromagnetic properties were characterized at microwave frequencies, and we report the observation of electromagnetically induced thermal bistability in whispering gallery modes due to the material T3 dependence on thermal conductivity and the ultralow dielectric loss tangent. We identify “magic temperatures” between 80 and 2100 mK, the lowest ever measured, at which the onset of bistability is suppressed and the frequency-temperature dependence is annulled. These phenomena at low temperatures make sapphire suitable for quantum metrology and ultrastable clock applications, including the possible realization of the quantum-limited sapphire clock.

  15. Diffusion maps clustering for magnetic resonance q-ball imaging segmentation.

    PubMed

    Wassermann, Demian; Descoteaux, Maxime; Deriche, Rachid

    2008-01-01

    White matter fiber clustering aims to get insight about anatomical structures in order to generate atlases, perform clear visualizations, and compute statistics across subjects, all important and current neuroimaging problems. In this work, we present a diffusion maps clustering method applied to diffusion MRI in order to segment complex white matter fiber bundles. It is well known that diffusion tensor imaging (DTI) is restricted in complex fiber regions with crossings and this is why recent high-angular resolution diffusion imaging (HARDI) such as Q-Ball imaging (QBI) has been introduced to overcome these limitations. QBI reconstructs the diffusion orientation distribution function (ODF), a spherical function that has its maxima agreeing with the underlying fiber populations. In this paper, we use a spherical harmonic ODF representation as input to the diffusion maps clustering method. We first show the advantage of using diffusion maps clustering over classical methods such as N-Cuts and Laplacian eigenmaps. In particular, our ODF diffusion maps requires a smaller number of hypothesis from the input data, reduces the number of artifacts in the segmentation, and automatically exhibits the number of clusters segmenting the Q-Ball image by using an adaptive scale-space parameter. We also show that our ODF diffusion maps clustering can reproduce published results using the diffusion tensor (DT) clustering with N-Cuts on simple synthetic images without crossings. On more complex data with crossings, we show that our ODF-based method succeeds to separate fiber bundles and crossing regions whereas the DT-based methods generate artifacts and exhibit wrong number of clusters. Finally, we show results on a real-brain dataset where we segment well-known fiber bundles. PMID:18317506

  16. Q-band ferromagnetic resonance for CoPt-based stacked perpendicular recording media with interlayer exchange coupling

    NASA Astrophysics Data System (ADS)

    Hinata, Shintaro; Saito, Shin; Hasegawa, Daiji; Takahashi, Migaku

    2011-04-01

    The ferromagnetic interlayer exchange coupling Jinter for stacked perpendicular recording media with a granular layer (GL)/interlayer (IL)/alloy capping layer (CL) structure was quantitatively evaluated by Q-band ferromagnetic resonance (FMR). Two resonances with acoustic and optical precession modes were observed in the FMR signals from the stacked media. Fitting using the Landau-Lifshitz-Gilbert (LLG) equation indicated that Jinter increased from 0.55 to 1.83 erg/cm2 when the Pt IL thickness was reduced from 2.0 to 1.0 nm for media based on Co82Cr10Pt8-CL (4 nm) and Co74Pt16Cr10-8 mol (SiO2)-GL (16 nm). The optimum Pt IL thickness at which the switching field distribution was minimized due to a large reduction in the saturation field of the stacked media was found to correspond to the boundary condition between antiparallel and parallel precession of the magnetic moments of the GL and CL in FMR.

  17. High Q-factor microring resonator wrapped by the curved waveguide

    PubMed Central

    Cai, Dong-Po; Lu, Jyun-Hong; Chen, Chii-Chang; Lee, Chien-Chieh; Lin, Chu-En; Yen, Ta-Jen

    2015-01-01

    In this work, we study the performances of ring resonators of different type by analyzing the bending loss and the condition of the critical coupling. We propose that the bending loss of microring can be reduced by wrapping a concentrically curved waveguide. The difference of propagation constant between two concentrically curved waveguides can be tuned by adjusting the bus waveguide width to optimize the critical coupling. Furthermore, we propose to enlarge the difference of the propagation constant between two concentrically curved waveguides to maintain the circulating light in the ring to obtain higher quality factor. In this study, the highest quality factor that we measured is 7 × 105. PMID:25993265

  18. A tunable general purpose Q-band resonator for CW and pulse EPR/ENDOR experiments with large sample access and optical excitation.

    PubMed

    Reijerse, Edward; Lendzian, Friedhelm; Isaacson, Roger; Lubitz, Wolfgang

    2012-01-01

    We describe a frequency tunable Q-band cavity (34 GHz) designed for CW and pulse Electron Paramagnetic Resonance (EPR) as well as Electron Nuclear Double Resonance (ENDOR) and Electron Electron Double Resonance (ELDOR) experiments. The TE(011) cylindrical resonator is machined either from brass or from graphite (which is subsequently gold plated), to improve the penetration of the 100 kHz field modulation signal. The (self-supporting) ENDOR coil consists of four 0.8mm silver posts at 2.67 mm distance from the cavity center axis, penetrating through the plunger heads. It is very robust and immune to mechanical vibrations. The coil is electrically shielded to enable CW ENDOR experiments with high RF power (500 W). The top plunger of the cavity is movable and allows a frequency tuning of ±2 GHz. In our setup the standard operation frequency is 34.0 GHz. The microwaves are coupled into the resonator through an iris in the cylinder wall and matching is accomplished by a sliding short in the coupling waveguide. Optical excitation of the sample is enabled through slits in the cavity wall (transmission ∼60%). The resonator accepts 3mm o.d. sample tubes. This leads to a favorable sensitivity especially for pulse EPR experiments of low concentration biological samples. The probehead dimensions are compatible with that of Bruker flexline Q-band resonators and it fits perfectly into an Oxford CF935 Helium flow cryostat (4-300 K). It is demonstrated that, due to the relatively large active sample volume (20-30 μl), the described resonator has superior concentration sensitivity as compared to commercial pulse Q-band resonators. The quality factor (Q(L)) of the resonator can be varied between 2600 (critical coupling) and 1300 (over-coupling). The shortest achieved π/2-pulse durations are 20 ns using a 3 W microwave amplifier. ENDOR (RF) π-pulses of 20 μs ((1)H @ 51 MHz) were obtained for a 300 W amplifier and 7 μs using a 2500 W amplifier. Selected applications of the

  19. A tunable general purpose Q-band resonator for CW and pulse EPR/ENDOR experiments with large sample access and optical excitation

    NASA Astrophysics Data System (ADS)

    Reijerse, Edward; Lendzian, Friedhelm; Isaacson, Roger; Lubitz, Wolfgang

    2012-01-01

    We describe a frequency tunable Q-band cavity (34 GHz) designed for CW and pulse Electron Paramagnetic Resonance (EPR) as well as Electron Nuclear Double Resonance (ENDOR) and Electron Electron Double Resonance (ELDOR) experiments. The TE 011 cylindrical resonator is machined either from brass or from graphite (which is subsequently gold plated), to improve the penetration of the 100 kHz field modulation signal. The (self-supporting) ENDOR coil consists of four 0.8 mm silver posts at 2.67 mm distance from the cavity center axis, penetrating through the plunger heads. It is very robust and immune to mechanical vibrations. The coil is electrically shielded to enable CW ENDOR experiments with high RF power (500 W). The top plunger of the cavity is movable and allows a frequency tuning of ±2 GHz. In our setup the standard operation frequency is 34.0 GHz. The microwaves are coupled into the resonator through an iris in the cylinder wall and matching is accomplished by a sliding short in the coupling waveguide. Optical excitation of the sample is enabled through slits in the cavity wall (transmission ˜60%). The resonator accepts 3 mm o.d. sample tubes. This leads to a favorable sensitivity especially for pulse EPR experiments of low concentration biological samples. The probehead dimensions are compatible with that of Bruker flexline Q-band resonators and it fits perfectly into an Oxford CF935 Helium flow cryostat (4-300 K). It is demonstrated that, due to the relatively large active sample volume (20-30 μl), the described resonator has superior concentration sensitivity as compared to commercial pulse Q-band resonators. The quality factor ( Q L) of the resonator can be varied between 2600 (critical coupling) and 1300 (over-coupling). The shortest achieved π/2-pulse durations are 20 ns using a 3 W microwave amplifier. ENDOR (RF) π-pulses of 20 μs ( 1H @ 51 MHz) were obtained for a 300 W amplifier and 7 μs using a 2500 W amplifier. Selected applications of the

  20. Single-crystal sapphire resonator at millikelvin temperatures: Observation of thermal bistability in high-Q factor whispering gallery modes

    SciTech Connect

    Creedon, Daniel L.; Tobar, Michael E.; Le Floch, Jean-Michel; Reshitnyk, Yarema; Duty, Timothy

    2010-09-01

    Resonance modes in single crystal sapphire ({alpha}-Al{sub 2}O{sub 3}) exhibit extremely high electrical and mechanical Q factors ({approx_equal}10{sup 9} at 4 K), which are important characteristics for electromechanical experiments at the quantum limit. We report the cool down of a bulk sapphire sample below superfluid liquid-helium temperature (1.6 K) to as low as 25 mK. The electromagnetic properties were characterized at microwave frequencies, and we report the observation of electromagnetically induced thermal bistability in whispering gallery modes due to the material T{sup 3} dependence on thermal conductivity and the ultralow dielectric loss tangent. We identify ''magic temperatures'' between 80 and 2100 mK, the lowest ever measured, at which the onset of bistability is suppressed and the frequency-temperature dependence is annulled. These phenomena at low temperatures make sapphire suitable for quantum metrology and ultrastable clock applications, including the possible realization of the quantum-limited sapphire clock.

  1. Effects of Coenzyme Q10 on Skeletal Muscle Oxidative Metabolism in Statin Users Assessed Using 31P Magnetic Resonance Spectroscopy: a Randomized Controlled Study

    PubMed Central

    Buettner, Catherine; Greenman, Robert L.; Ngo, Long H.; Wu, Jim S.

    2016-01-01

    Objectives Statins partially block the production of coenzyme Q10 (CoQ10), an essential component for mitochondrial function. Reduced skeletal muscle mitochondrial oxidative capacity has been proposed to be a cause of statin myalgia and can be measured using 31phosphorus magnetic resonance spectroscopy (31P-MRS). The purpose of this study is to assess the effect of CoQ10 oral supplementation on mitochondrial function in statin users using 31P-MRS. Design/Setting In this randomized, double-blind, placebo-controlled pilot study, 21 adults aged 47–73 were randomized to statin+placebo (n=9) or statin+CoQ10 (n=12). Phosphocreatine (PCr) recovery kinetics of calf muscles were assessed at baseline (off statin and CoQ10) and 4 weeks after randomization to either statin+CoQ10 or statin+placebo. Results Baseline and post-treatment PCr recovery kinetics were assessed for 19 participants. After 4 weeks of statin+ CoQ10 or statin+placebo, the overall relative percentage change (100*(baseline−follow up)/baseline) in PCr recovery time was −15.1% compared with baseline among all participants, (p-value=0.258). Participants randomized to statin+placebo (n=9) had a relative percentage change in PCr recovery time of −18.9%, compared to −7.7% among participants (n=10) receiving statin+CoQ10 (p-value=0.448). Conclusions In this pilot study, there was no significant change in mitochondrial function in patients receiving 4 weeks of statin+CoQ10 oral therapy when compared to patients on statin+placebo. PMID:27610419

  2. Nuclear Magnetic Resonance Solution Structures of Lacticin Q and Aureocin A53 Reveal a Structural Motif Conserved among Leaderless Bacteriocins with Broad-Spectrum Activity.

    PubMed

    Acedo, Jeella Z; van Belkum, Marco J; Lohans, Christopher T; Towle, Kaitlyn M; Miskolzie, Mark; Vederas, John C

    2016-02-01

    Lacticin Q (LnqQ) and aureocin A53 (AucA) are leaderless bacteriocins from Lactococcus lactis QU5 and Staphylococcus aureus A53, respectively. These bacteriocins are characterized by the absence of an N-terminal leader sequence and are active against a broad range of Gram-positive bacteria. LnqQ and AucA consist of 53 and 51 amino acids, respectively, and have 47% identical sequences. In this study, their three-dimensional structures were elucidated using solution nuclear magnetic resonance and were shown to consist of four α-helices that assume a very similar compact, globular overall fold (root-mean-square deviation of 1.7 Å) with a highly cationic surface and a hydrophobic core. The structures of LnqQ and AucA resemble the shorter two-component leaderless bacteriocins, enterocins 7A and 7B, despite having low levels of sequence identity. Homology modeling revealed that the observed structural motif may be shared among leaderless bacteriocins with broad-spectrum activity against Gram-positive organisms. The elucidated structures of LnqQ and AucA also exhibit some resemblance to circular bacteriocins. Despite their similar overall fold, inhibition studies showed that LnqQ and AucA have different antimicrobial potency against the Gram-positive strains tested, suggesting that sequence disparities play a crucial role in their mechanisms of action. PMID:26771761

  3. Electroexcitation of the Roper resonance for 1.7 < Q**2 < 4.5 -GeV2 in vec-ep ---> en pi+

    SciTech Connect

    Aznauryan, Inna; Burkert, Volker; Kim, Wooyoung; Park, Kil; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Bagdasaryan, H.; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Baltzell, Nathan; Barrow, Steve; Batourine, V.; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bonner, Billy; Bookwalter, Craig; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, Wilbert; Brooks, William; Bultmann, S.; Bueltmann, Stephen; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Casey, Liam; Cazes, Antoine; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Cords, Dieter; Corvisiero, Pietro; Crabb, Donald; Crede, Volker; Cummings, John; Dale, Daniel; Dashyan, Natalya; De Masi, Rita; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dhamija, Seema; Dharmawardane, Kahanawita; Dhuga, Kalvir; Dickson, Richard; Djalali, Chaden; Dodge, Gail; Donnelly, J.; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fatemi, Renee; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Forest, Tony; Fradi, Ahmed; Funsten, Herbert; Gabrielyan, Marianna; Garcon, Michel; Gavalian, Gagik; Gevorgyan, Nerses; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gohn, Wesley; Golovach, Evgeny; Gonenc, Atilla; Gordon, Christopher; Gothe, Ralf; Graham, L.; Griffioen, Keith; Guidal, Michel; Guillo, Matthieu; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hafnaoui, Khadija; Hakobyan, Hayk; Hakobyan, Rafael; Hanretty, Charles; Hardie, John; Hassall, Neil; Heddle, David; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Keller, Dustin; Kellie, James; Khandaker, Mahbubul; Kim, Kui; Klein, Andreas; Klein, Andreas; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, Dave; Lee, T.; Lima, Ana; Livingston, Kenneth; Lu, Haiyun; Lukashin, Konstantin; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Morand, Ludyvine; Moreno, Brahim; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Nasseripour, Rakhsha; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; O'Rielly, Grant; Osipenko, Mikhail; Ostrovidov, Alexander; Park, S.; Pasyuk, Evgueni; Paterson, Craig; Anefalos Pereira, S.; Philips, Sasha; Pierce, Jerome; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Polli, Ermanno; Popa, Iulian; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Prok, Yelena; Protopopescu, Dan; Qin, Liming; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Rowntree, David; Rubin, Philip; Sabatie, Franck; Saini, Mukesh; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schott, Diane; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shaw, J.; Shvedunov, Nikolay; Skabelin, Alexander; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinskiy, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham

    2008-10-01

    DOI: http://dx.doi.org/10.1103/PhysRevC.78.045209
    The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for 1.7 < Q2 < 4.5 GeV2 from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for pi+ electroproduction on protons at W=1.15-1.69 GeV. The analysis is made using two approaches, dispersion relations and a unitary isobar model, which give consistent results. It is found that the transverse helicity amplitude A_{1/2} for the gamma* p -> N(1440)P11 transition, which is large and negative at Q2=0, becomes large and positive at Q2 ~ 2 GeV2, and then drops slowly with Q2. The longitudinal helicity amplitude S_{1/2}, which was previously found from CLAS ep -> eppi0,enpi+ data to be large and positive at Q2=0.4,0.65 GeV2, drops with Q2. Available model predictions for gamma* p -> N(1440)P11 allow us to conclude that these results provide strong evidence in favor of N(1440)P11 as a first radial excitation of

  4. Creating traveling waves from standing waves from the gyrotropic paramagnetic properties of Fe{sup 3+} ions in a high-Q whispering gallery mode sapphire resonator

    SciTech Connect

    Benmessai, Karim; Tobar, Michael Edmund; Bazin, Nicholas; Bourgeois, Pierre-Yves; Kersale, Yann; Giordano, Vincent

    2009-05-01

    We report observations of the gyrotropic change in magnetic susceptibility of the Fe{sup 3+} electron paramagnetic resonance at 12.037 GHz (between spin states |1/2> and |3/2>) in sapphire with respect to the applied magnetic field. Measurements were made by observing the response of the high-Q whispering gallery doublet in a Hemex sapphire resonator cooled to 5 K. The doublets initially existed as standing waves at zero field and were transformed to traveling waves due to the gyrotropic response.

  5. Pulsed-laser excitation of acoustic modes in open high-Q photoacoustic resonators for trace gas monitoring: results for C2H4

    NASA Astrophysics Data System (ADS)

    Brand, Christian; Winkler, Andreas; Hess, Peter; Miklós, András; Bozóki, Zoltán; Sneider, János

    1995-06-01

    The pulsed excitation of acoustic resonances was studied with a continuously monitoring photoacoustic detector system. Acoustic waves were generated in C2H4/N 2 gas mixtures by light absorption of the pulses from a transversely excited atmospheric CO2 laser. The photoacoustic part consisted of high-Q cylindrical resonators (Q factor 820 for the first radial mode in N2) and two adjoining variable acoustic filter systems. The time-resolved signal was Fourier transformed to a frequency spectrum of high resolution. For the first radial mode a Lorentzian profile was fitted to the measured data. The outside noise suppression and the signal-to-noise ratio were investigated in a normal laboratory environment in the flow-through mode. The acoustic and electric filter system combined with the

  6. Improved L-C resonant decay technique for Q measurement of quasilinear power inductors: New results for MPP and ferrite powdered cores

    NASA Technical Reports Server (NTRS)

    Niedra, Janis M.; Gerber, Scott S.

    1995-01-01

    The L-C resonant decay technique for measuring circuit Q or losses is improved by eliminating the switch from the inductor-capacitor loop. A MOSFET switch is used instead to momentarily connect the resonant circuit to an existing voltage source, which itself is gated off during the decay transient. Very reproducible, low duty cycle data could be taken this way over a dynamic voltage range of at least 10:1. Circuit Q is computed from a polynomial fit to the sequence of the decaying voltage maxima. This method was applied to measure the losses at 60 kHz in inductors having loose powder cores of moly permalloy and an Mn-Zn power ferrite. After the copper and capacitor losses are separated out, the resulting specific core loss is shown to be roughly as expected for the MPP powder, but anomalously high for the ferrite powder. Possible causes are mentioned.

  7. Diverse output states from an all-normal dispersion ytterbium-doped fiber laser: Q-switch, dissipative soliton resonance, and noise-like pulse

    NASA Astrophysics Data System (ADS)

    Xu, Z. W.; Zhang, Z. X.

    2013-06-01

    An all-normal-dispersion ytterbium-doped fiber ring laser has been demonstrated, with different operation regimes: Q-switch, CW mode-locking and noise-like pulses, depending on the pump power and suitable orientation of the polarization controllers. As a transition between Q-switch and CW mode-locking, Q-switched mode-locking has also been observed. Moreover, our experiment shows that the CW mode-locking operation is the result of dissipative soliton resonance in the all-normal-dispersion fiber laser without external filter, which is a new way to generate high-energy pulses. This fiber laser with diverse outputs has many potential applications, and is helpful to investigate laser dynamics.

  8. Exclusive single pion electroproduction off the proton in the high-lying resonances at Q2 < 5 GeV2 from CLAS

    SciTech Connect

    Park, Kijun

    2014-09-01

    The differential cross sections and structure functions for the exclusive electroproduction process ep --> e'n pi+ were measured in the range of the invariantmass for the np+ system 1.6 GeV lte W lte 2.0 GeV, and the photon virtuality 1.8 GeV2 lte Q2 lte 4.0 GeV2 using CLAS at Jefferson Lab. For the first time, these kinematics are probed in the exclusive p+ production from the protons with nearly full coverage in the azimuthal and polar angles of the np+ center-of-mass system. In this analysis, approximately 39,000 differential cross-section data points in terms of W, Q2, cosq theta* _ pi, and phi*_p-, were obtained. The preliminary differential cross section and structure function analyses are carried out, which allow us to extract the helicity amplitudes in high-lying resonances.

  9. Induced Proton Polarization for pi0 Electroproduction at Q2 = 0.126 GeV2/c2 Around the Delta(1232) Resonance

    SciTech Connect

    Glen Warren; Ricardo Alarcon; Christopher Armstrong; Burin Asavapibhop; David Barkhuff; William Bertozzi; Volker Burkert; J. Chen; Jian-Ping Chen; Joseph Comfort; Daniel Dale; George Dodson; S. Dolfini; K. Dow; Martin Epstein; Manouchehr Farkhondeh; John Finn; Shalev Gilad; Ralf Gothe; Xiaodong Jiang; Mark Jones; Kyungseon Joo; A. Karabarbounis; James Kelly; Stanley Kowalski; C. Kunz; D. Liu; R.W. Lourie; Richard Madey; Demetrius Margaziotis; Pete Markowitz; Justin McIntyre; C. Mertz; Brian Milbrath; Rory Miskimen; Joseph Mitchell; S. Mukhopadhyay; Costas Papanicolas; Charles Perdrisat; Vina Punjabi; Liming Qin; Paul Rutt; Adam Sarty; Jeffrey Shaw; S.B. Soong; D. Tieger; Christoph Tschalaer; William Turchinetz; Paul Ulmer; Scott Van Verst; C. Vellidis; Lawrence Weinstein; Steven Williamson; Rhett Woo; Alaen Young

    1998-12-01

    We present a measurement of the induced proton polarization P{sub n} in {pi}{sup 0} electroproduction on the proton around the {Delta} resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W = 1231 MeV and Q{sup 2} = 0.126 GeV{sup 2}/c{sup 2}, respectively. We measured a large induced polarization, P{sub n} = -0.397 {+-} 0.055 {+-} 0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model.

  10. Invited Article: Dielectric material characterization techniques and designs of high-Q resonators for applications from micro to millimeter-waves frequencies applicable at room and cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Le Floch, Jean-Michel; Fan, Y.; Humbert, Georges; Shan, Qingxiao; Férachou, Denis; Bara-Maillet, Romain; Aubourg, Michel; Hartnett, John G.; Madrangeas, Valerie; Cros, Dominique; Blondy, Jean-Marc; Krupka, Jerzy; Tobar, Michael E.

    2014-03-01

    Dielectric resonators are key elements in many applications in micro to millimeter wave circuits, including ultra-narrow band filters and frequency-determining components for precision frequency synthesis. Distributed-layered and bulk low-loss crystalline and polycrystalline dielectric structures have become very important for building these devices. Proper design requires careful electromagnetic characterization of low-loss material properties. This includes exact simulation with precision numerical software and precise measurements of resonant modes. For example, we have developed the Whispering Gallery mode technique for microwave applications, which has now become the standard for characterizing low-loss structures. This paper will give some of the most common characterization techniques used in the micro to millimeter wave regime at room and cryogenic temperatures for designing high-Q dielectric loaded cavities.

  11. A High-Q Resonant Pressure Microsensor with Through-Glass Electrical Interconnections Based on Wafer-Level MEMS Vacuum Packaging

    PubMed Central

    Luo, Zhenyu; Chen, Deyong; Wang, Junbo; Li, Yinan; Chen, Jian

    2014-01-01

    This paper presents a high-Q resonant pressure microsensor with through-glass electrical interconnections based on wafer-level MEMS vacuum packaging. An approach to maintaining high-vacuum conditions by integrating the MEMS fabrication process with getter material preparation is presented in this paper. In this device, the pressure under measurement causes a deflection of a pressure-sensitive silicon square diaphragm, which is further translated to stress build up in “H” type doubly-clamped micro resonant beams, leading to a resonance frequency shift. The device geometries were optimized using FEM simulation and a 4-inch SOI wafer was used for device fabrication, which required only three photolithographic steps. In the device fabrication, a non-evaporable metal thin film as the getter material was sputtered on a Pyrex 7740 glass wafer, which was then anodically bonded to the patterned SOI wafer for vacuum packaging. Through-glass via holes predefined in the glass wafer functioned as the electrical interconnections between the patterned SOI wafer and the surrounding electrical components. Experimental results recorded that the Q-factor of the resonant beam was beyond 22,000, with a differential sensitivity of 89.86 Hz/kPa, a device resolution of 10 Pa and a nonlinearity of 0.02% F.S with the pressure varying from 50 kPa to 100 kPa. In addition, the temperature drift coefficient was less than −0.01% F.S/°C in the range of −40 °C to 70 °C, the long-term stability error was quantified as 0.01% F.S over a 5-month period and the accuracy of the microsensor was better than 0.01% F.S. PMID:25521385

  12. Ultra-high frequency, high Q/volume micromechanical resonators in a planar AlN phononic crystal

    NASA Astrophysics Data System (ADS)

    Ghasemi Baboly, M.; Alaie, S.; Reinke, C. M.; El-Kady, I.; Leseman, Z. C.

    2016-07-01

    This paper presents the first design and experimental demonstration of an ultrahigh frequency complete phononic crystal (PnC) bandgap aluminum nitride (AlN)/air structure operating in the GHz range. A complete phononic bandgap of this design is used to efficiently and simultaneously confine elastic vibrations in a resonator. The PnC structure is fabricated by etching a square array of air holes in an AlN slab. The fabricated PnC resonator resonates at 1.117 GHz, which corresponds to an out-of-plane mode. The measured bandgap and resonance frequencies are in very good agreement with the eigen-frequency and frequency-domain finite element analyses. As a result, a quality factor/volume of 7.6 × 1017/m3 for the confined resonance mode was obtained that is the largest value reported for this type of PnC resonator to date. These results are an important step forward in achieving possible applications of PnCs for RF communication and signal processing with smaller dimensions.

  13. Electronic structure of Q-A in reaction centers from Rhodobacter sphaeroides. I. Electron paramagnetic resonance in single crystals.

    PubMed Central

    Isaacson, R A; Lendzian, F; Abresch, E C; Lubitz, W; Feher, G

    1995-01-01

    The magnitude and orientation of the electronic g-tensor of the primary electron acceptor quinone radical anion, Q-A, has been determined in single crystals of zinc-substituted reaction centers of Rhodobacter sphaeroides R-26 at 275 K and at 80 K. To obtain high spectral resolution, EPR experiments were performed at 35 GHz and the native ubiquinone-10 (UQ10) in the reaction center was replaced by fully deuterated UQ10. The principal values and the direction cosines of the g-tensor axes with respect to the crystal axes a, b, c were determined. Freezing of the single crystals resulted in only minor changes in magnitude and orientation of the g-tensor. The orientation of Q-A as determined by the g-tensor axes deviates only by a few degrees (< or = 8 degrees) from the orientation of the neutral QA obtained from an average of four different x-ray structures of Rb. sphaeroides reaction centers. This deviation lies within the accuracy of the x-ray structure determinations. The g-tensor values measured in single crystals agree well with those in frozen solutions. Variations in g-values between Q-A, Q-B, and UQ10 radical ion in frozen solutions were observed and attributed to different environments. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 9 PMID:8527644

  14. Simulation of coupled bunch mode growth driven by a high-Q resonator: A transient response approach

    SciTech Connect

    Stahl, S.; Bogacz, S.A.

    1989-03-01

    In this article the use of a longitudinal phase-space tracking code, ESME, to simulate the growth of a coupled-bunch instability in the Fermilab Booster is examined. A description of the calculation of the resonant response is given, and results are presented for the growth of the coupled bunch instability in a ring in which all of the rf buckets are equally populated and in one in which several consecutive buckets are empty. 4 refs., 6 figs.

  15. Compact high-pulse-energy passively Q-switched Nd:YLF laser with an ultra-low-magnification unstable resonator: application for efficient optical parametric oscillator.

    PubMed

    Cho, C Y; Huang, Y P; Huang, Y J; Chen, Y C; Su, K W; Chen, Y F

    2013-01-28

    We exploit an ultra-low-magnification unstable resonator to develop a high-pulse-energy side-pumped passively Q-switched Nd:YLF/Cr⁴⁺:YAG laser with improving beam quality. A wedged laser crystal is employed in the cavity to control the emissions at 1047 nm and 1053 nm independently through the cavity alignment. The pulse energies at 1047 nm and 1053 nm are found to be 19 mJ and 23 mJ, respectively. The peak powers for both wavelengths are higher than 2 MW. Furthermore, the developed Nd:YLF lasers are employed to pump a monolithic optical parametric oscillator for confirming the applicability in nonlinear wavelength conversions. PMID:23389131

  16. On-Chip All-Optical Passive 3.55 Gbit/s NRZ-to-PRZ Format Conversion Using a High-Q Silicon-Based Microring Resonator

    NASA Astrophysics Data System (ADS)

    Zhai, Yao; Chen, Shao-Wu; Ren, Guang-Hui

    2010-10-01

    We report the experimental result of all-optical passive 3.55 Gbit/s non-return-to-zero (NRZ) to pseudo-return-to-zero (PRZ) format conversion using a high-quality-factor (Q-factor) silicon-based microring resonator notch filter on chip. The silicon-based microring resonator has 23800 Q-factor and 22 dB extinction ratio (ER), and the PRZ signals has about 108ps width and 4.98 dB ER.

  17. Recoil Polarization Measurements for Neutral Pion Electroproduction at Q^2=1 (GeV/c)^2 Near the Delta Resonance

    SciTech Connect

    James Kelly; et. Al.

    2005-09-01

    We measured angular distributions of differential cross section, beam analyzing power, and recoil polarization for neutral pion electroproduction at Q{sup 2} = 1.0 (GeV/c){sup 2} in 10 bins of W across the Delta resonance. A total of 16 independent response functions were extracted, of which 12 were observed for the first time. Comparisons with recent model calculations show that response functions governed by real parts of interference products are determined relatively well near 1.232 GeV, but variations among models is large for response functions governed by imaginary parts and for both increases rapidly with W. We performed a nearly model-independent multipole analysis that adjusts complex multipoles with high partial waves constrained by baseline models. Parabolic fits to the W dependence of the multipole analysis around the Delta mass gives values for SMR = (-6.61 +/- 0.18)% and EMR = (-2.87 +/- 0.19)% that are distinctly larger than those from Legendre analysis of the same data. Similarly, the multipole analysis gives Re(S0+/M1+) = (+7.1 +/- 0.8)% at W=1.232 GeV, consistent with recent models, while the traditional Legendre analysis gives the opposite sign because its truncation errors are quite severe. Finally, using a unitary isobar model (UIM), we find that excitation of the Roper resonance is dominantly longitudinal with S1/2 = (0.05 +/- 0.01) GeV{sup (-1/2)} at Q{sup 2}=1. The ReS0+ and ReE0+ multipoles favor pseudovector coupling over pseudoscalar coupling or a recently proposed mixed-coupling scheme, but the UIM does not reproduce the imaginary parts of 0+ multipoles well.

  18. Parameterisation of [σ1/2-σ3/2] for Q2>=0 and non-resonance contribution to the GDH sum rule

    NASA Astrophysics Data System (ADS)

    Bianchi, N.; Thomas, E.

    1999-03-01

    A description of the virtual photon absorption cross section difference [σ1/2-σ3/2] for the proton and neutron is obtained with a parameterisation based on a Regge type approach. The parametrisation is obtained from global fits to the cross section data derived from the spin asymmetries measured in deep inelastic scattering of longitudinally polarised leptons from polarised 1H, 3He and 2H targets in the range 0.3 GeV2<Q2<70 GeV2 and 4 GeV2Q2-transition. The contribution above the resonance region to the Gerasimov-Drell-Hearn sum rule for real and virtual photons has been evaluated. For the real photons this contribution accounts for a large fraction of the discrepancy between the sum rule expectations and the single pion photo-production analysis estimates.

  19. Research & Developments for Millimeter-Wave Dielectric Forsterite with Low Dielectric Constant, High Q, and Zero Temperature Coefficient of Resonant Frequency

    NASA Astrophysics Data System (ADS)

    Tsunooka, Tsutomu; Ando, Minato; Suzuki, Sadahiko; Yasufuku, Yoshitoyo; Ohsato, Hitoshi

    2013-09-01

    Forsterite Mg2SiO4 is a candidate for millimeter-wave dielectrics because of its high Q and low dielectric constant ɛr. Commercial forsterite has been improved with a high Q of 240,000 GHz using high-purity and fine raw materials, and the temperature coefficient of resonant frequency (TCf) can also be adjusted to near-zero ppm/°C by adding 24 wt % rutile compared with that in a previous study. In this study, the TCf, TCɛ, and ɛr of forsterite ceramics with rutile added are studied for the tuning conditions. Zero ppm/°C TCf of the forsterite with 30 and 25 wt % rutile added was achieved at 1200 °C for 2.5 and 2.25 h, respectively. The ɛr values of the near-zero TCf forsterite with 30 and 25 wt % rutile added are 11.3 and 10.2, respectively.

  20. Evaluation and optimization of quartz resonant-frequency retuned fork force sensors with high Q factors, and the associated electric circuits, for non-contact atomic force microscopy.

    PubMed

    Ooe, Hiroaki; Fujii, Mikihiro; Tomitori, Masahiko; Arai, Toyoko

    2016-02-01

    High-Q factor retuned fork (RTF) force sensors made from quartz tuning forks, and the electric circuits for the sensors, were evaluated and optimized to improve the performance of non-contact atomic force microscopy (nc-AFM) performed under ultrahigh vacuum (UHV) conditions. To exploit the high Q factor of the RTF sensor, the oscillation of the RTF sensor was excited at its resonant frequency, using a stray capacitance compensation circuit to cancel the excitation signal leaked through the stray capacitor of the sensor. To improve the signal-to-noise (S/N) ratio in the detected signal, a small capacitor was inserted before the input of an operational (OP) amplifier placed in an UHV chamber, which reduced the output noise from the amplifier. A low-noise, wideband OP amplifier produced a superior S/N ratio, compared with a precision OP amplifier. The thermal vibrational density spectra of the RTF sensors were evaluated using the circuit. The RTF sensor with an effective spring constant value as low as 1000 N/m provided a lower minimum detection limit for force differentiation. A nc-AFM image of a Si(111)-7 × 7 surface was produced with atomic resolution using the RTF sensor in a constant frequency shift mode; tunneling current and energy dissipation images with atomic resolution were also simultaneously produced. The high-Q factor RTF sensor showed potential for the high sensitivity of energy dissipation as small as 1 meV/cycle and the high-resolution analysis of non-conservative force interactions. PMID:26931855

  1. Evaluation and optimization of quartz resonant-frequency retuned fork force sensors with high Q factors, and the associated electric circuits, for non-contact atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Ooe, Hiroaki; Fujii, Mikihiro; Tomitori, Masahiko; Arai, Toyoko

    2016-02-01

    High-Q factor retuned fork (RTF) force sensors made from quartz tuning forks, and the electric circuits for the sensors, were evaluated and optimized to improve the performance of non-contact atomic force microscopy (nc-AFM) performed under ultrahigh vacuum (UHV) conditions. To exploit the high Q factor of the RTF sensor, the oscillation of the RTF sensor was excited at its resonant frequency, using a stray capacitance compensation circuit to cancel the excitation signal leaked through the stray capacitor of the sensor. To improve the signal-to-noise (S/N) ratio in the detected signal, a small capacitor was inserted before the input of an operational (OP) amplifier placed in an UHV chamber, which reduced the output noise from the amplifier. A low-noise, wideband OP amplifier produced a superior S/N ratio, compared with a precision OP amplifier. The thermal vibrational density spectra of the RTF sensors were evaluated using the circuit. The RTF sensor with an effective spring constant value as low as 1000 N/m provided a lower minimum detection limit for force differentiation. A nc-AFM image of a Si(111)-7 × 7 surface was produced with atomic resolution using the RTF sensor in a constant frequency shift mode; tunneling current and energy dissipation images with atomic resolution were also simultaneously produced. The high-Q factor RTF sensor showed potential for the high sensitivity of energy dissipation as small as 1 meV/cycle and the high-resolution analysis of non-conservative force interactions.

  2. Numerical study on localized defect modes in two-dimensional lattices: a high Q-resonant cavity

    NASA Astrophysics Data System (ADS)

    Moussa, R.; Salomon, L.; de Fornel, F.; Aourag, H.

    2003-10-01

    The spectral widths and the quality factors of defect modes localized for different defects structures formed in a 2D photonic crystal composed of a square lattice of circular rods of indium antimonide (InSb) are theoretically investigated. It is first shown that some factors such as the lattice nature, the line defect orientation, the nature and the defect width have a significant influence on the optical properties of the studied structures and can improve the Q factor and defect peak transmission intensity. Particularly, the transmission spectra of the defects calculated by means the transfer-matrix-method for a particular structure of eight line defects introduced in its center showed a high-quality factor which exceeded 4×10 5. This is an important issue for the fabrication of photonic crystals with such desired properties.

  3. Standardless multicomponent qNMR analysis of compounds with overlapped resonances based on the combination of ICA and PULCON.

    PubMed

    Monakhova, Yulia B; Lachenmeier, Dirk W; Kuballa, Thomas; Mushtakova, Svetlana P

    2015-10-01

    A fast and reliable nuclear magnetic resonance (NMR) method for quantitative analysis of targeted compounds with overlapped signals in complex mixtures has been established. The method is based on the combination of chemometric treatment for spectra deconvolution and the PULCON principle (pulse length based concentration determination) for quantification. Independent component analysis (ICA) (mutual information least dependent component analysis (MILCA) algorithm) was applied for spectra deconvolution in up to six component mixtures with known composition. The resolved matrices (independent components, ICs and ICA scores) were used for identification of analytes, calculating their relative concentrations and absolute integral intensity of selected resonances. The absolute analyte concentrations in multicomponent mixtures and authentic samples were then calculated using the PULCON principle. Instead of conventional application of absolute integral intensity in case of undisturbed signals, the multiplication of resolved IC absolute integral and its relative concentration in the mixture for each component was used. Correction factors that are required for quantification and are unique for each analyte were also estimated. The proposed method was applied for analysis of up to five components in lemon and orange juice samples with recoveries between 90% and 111%. The total duration of analysis is approximately 45 min including measurements, spectra decomposition and quantification. The results demonstrated that the proposed method is a promising tool for rapid simultaneous quantification of up to six components in case of spectral overlap and the absence of reference materials. PMID:26132651

  4. Earthquke-related variation in Schumann Resonance (SR) spectra and Q-bursts as simulated with a global TDTE Network

    NASA Astrophysics Data System (ADS)

    Yu, H.; Williams, E. R.

    2014-12-01

    The monitoring of earthquakes with SR has been reported by Nickolaenko and Hayakawa (Nickolaenko and Hayakawa 2014, 2006, Hayakawa 2005). Despite the presence of many SR observatories globally, the observation of SR anomalies caused by earthquakes is rare. And the physical mechanism for the SR anomaly is not clear. Further attention to methods for observing SR anomalies caused by earthquakes is needed. A simulation approach based on Nelson's 2DTelegraph Equation (TDTE) Network (Nelson, MIT doctoral thesis, 1967) is developed. The Earth-ionosphere cavity is discretized into 24×24 tesserae. This network approach is more flexible than an analytical model, especially for a model with day-night asymmetry. The relation of the magnitude of the anomaly and the geometrical arrangement among source, receiver and disturbed zone is discussed for the uniform model. The perturbed zone size is computed according to the estimated size of the earthquake preparation zone. For example, the radius of the perturbed zone is about 1000km when the earthquake magnitude is about Ms=7.0. The intensity variations for the first four SR modes are compared between perturbed and unperturbed models. In addition, the spectral characteristics at different distances between source and disturbed zone are analysed. Interestingly, the electric field shows different variation than the magnetic field in response to the localized perturbation. For the uniform model with single Q-burst source, when the height of the local ionosphere is decreased, the electric field is increased and reaches nearly 50% in intensity in the perturbed zone in the uniform model. However, in contrast, the magnetic response is far less pronounced. It shows almost no variation. But for multisource excitation, the electric field and magnetic field both show dramatic response which reaches nearly 100% variation for some special modes. And the big variation is not restricted to the perturbed zone. The variations show complicated

  5. Resonance

    NASA Astrophysics Data System (ADS)

    Perozzi, E.; Murdin, P.

    2000-11-01

    A resonance in CELESTIAL MECHANICS occurs when some of the quantities characterizing the motion of two or more celestial bodies can be considered as commensurable, i.e. their ratio is close to an integer fraction. In a simplified form, this can be expressed as ...

  6. Virtual Compton Scattering in the Resonance Region Up to the Deep Inelastic Region at Backward Angles and Momentum Transfer Squared of Q**2=1.0 GeV**2

    SciTech Connect

    Geraud Laveissiere; Natalie Degrande; Stephanie Jaminion; Christophe Jutier; Luminita Todor; Rachele Di Salvo; L. Van Hoorebeke; et. al.

    2004-06-01

    We have made the first measurements of the virtual Compton scattering process via the ep {yields} ep{gamma} exclusive reaction at Q{sup 2} = 1 GeV{sup 2} in the nucleon resonance region. The cross section is obtained at center of mass (CM) backward angle, in a range of total ({gamma}*p) CM energy W from the proton mass up to W = 1.91 GeV. The data show resonant structures in the first and second resonance regions, and are well reproduced at higher W by the Bethe-Heitler+Born cross section, including t-channel {pi}{sup 0}-exchange. At high W, our data, together with existing real photon data, show a striking Q{sup 2} independence. Our measurement of the ratio of H(e,e{prime}p){gamma} to H(e,e{prime}p){pi}{sup 0} cross sections is presented and compared to model predictions.

  7. Electroexcitation of the Roper resonance for 1.7<Q{sup 2}<4.5 GeV{sup 2} in e-vectorp{yields}en{pi}{sup +}

    SciTech Connect

    Aznauryan, I. G.; Burkert, V. D.; Avakian, H.; Carman, D. S.; Cords, D.; Degtyarenko, P. V.; Deur, A.; Elouadrhiri, L.; Guo, L.; Gyurjyan, V.; Heddle, D.; Ito, M. M.; Mecking, B. A.; Mestayer, M. D.; Niczyporuk, B. B.; Sharabian, Y. G.; Smith, E. S.; Stepanyan, S.; Weygand, D. P.; Wolin, E.

    2008-10-15

    The helicity amplitudes of the electroexcitation of the Roper resonance are extracted for 1.7<Q{sup 2}<4.5 GeV{sup 2} from recent high precision JLab-CLAS cross section and longitudinally polarized beam asymmetry data for {pi}{sup +} electroproduction on protons at W=1.15-1.69 GeV. The analysis is made using two approaches, dispersion relations and a unitary isobar model, which give consistent Q{sup 2} behavior of the helicity amplitudes for the {gamma}*p{yields}N(1440)P{sub 11} transition. It is found that the transverse helicity amplitude A{sub 1/2}, which is large and negative at Q{sup 2}=0, becomes large and positive at Q{sup 2}{approx_equal}2 GeV{sup 2}, and then drops slowly with Q{sup 2}. The longitudinal helicity amplitude S{sub 1/2}, which was previously found from CLAS e-vectorp{yields}ep{pi}{sup 0},en{pi}{sup +} data to be large and positive at Q{sup 2}=0.4,0.65 GeV{sup 2}, drops with Q{sup 2}. Available model predictions for {gamma}*p{yields}N(1440)P{sub 11} allow us to conclude that these results provide strong evidence in favor of N(1440)P{sub 11} as a first radial excitation of the 3q ground state. The results of the present paper also confirm the conclusion of our previous analysis for Q{sup 2}<1 GeV{sup 2} that the presentation of N(1440)P{sub 11} as a q{sup 3}G hybrid state is ruled out.

  8. Evaluation of Water Exchange Kinetics on [Ln(AAZTAPh-NO2)(H2O)q](x) Complexes Using Proton Nuclear Magnetic Resonance.

    PubMed

    Karimi, Shima; Tei, Lorenzo; Botta, Mauro; Helm, Lothar

    2016-06-20

    Water exchange kinetics on [Ln(AAZTAPh-NO2)(H2O)q](-) (Ln = Gd(3+), Dy(3+), or Tm(3+)) were determined by (1)H nuclear magnetic resonance (NMR) measurements. The number of inner-sphere water molecules was found to change from two to one when going from Dy(3+) to Tm(3+). The calculated water exchange rate constants obtained by variable-temperature proton transverse relaxation rates are 3.9 × 10(6), 0.46 × 10(6), and 0.014 × 10(6) s(-1) at 298 K for Gd(3+), Dy(3+), and Tm(3+), respectively. Variable-pressure measurements were used to assess the water exchange mechanism. The results indicate an associative and dissociative interchange mechanism for Gd(3+) and Dy(3+) complexes with ΔV(⧧) values of -1.4 and 1.9 cm(3) mol(-1), respectively. An associative activation mode (Ia or A mechanism) was obtained for the Tm(3+) complex (ΔV(⧧) = -5.6 cm(3) mol(-1)). Moreover, [Dy(AAZTAPh-NO2)(H2O)2](-) with a very high transverse relaxivity value was found as a potential candidate for negative contrast agents for high-field imaging applications. PMID:27227690

  9. Q-factor enhancement for self-actuated self-sensing piezoelectric MEMS resonators applying a lock-in driven feedback loop

    NASA Astrophysics Data System (ADS)

    Kucera, M.; Manzaneque, T.; Sánchez-Rojas, J. L.; Bittner, A.; Schmid, U.

    2013-08-01

    This paper presents a robust Q-control approach based on an all-electrical feedback loop enhancing the quality factor of a resonant microstructure by using the self-sensing capability of a piezoelectric thin film actuator made of aluminium nitride. A lock-in amplifier is used to extract the feedback signal which is proportional to the piezoelectric current. The measured real part is used to replace the originally low-quality and noisy feedback signal to modulate the driving voltage of the piezoelectric thin-film actuator. Since the lock-in amplifier reduces the noise in the feedback signal substantially, the proposed enhancement loop avoids the disadvantage of a constant signal-to-noise ratio, which an analogue feedback circuit usually suffers from. The quality factor was increased from the intrinsic value of 1766 to a maximum of 34 840 in air. These promising results facilitate precise measurements for self-actuated and self-sensing MEMS cantilevers even when operated in static viscous media.

  10. Recoil polarization measurements for neutral pion electroproduction at Q{sup 2}=1(GeV/c){sup 2} near the {delta} resonance

    SciTech Connect

    Kelly, J. J.; Beise, E. J.; Breuer, H.; Chang, C. C.; Chant, N. S.; Roos, P. G.; Gayou, O.; Chai, Z.; Bertozzi, W.; Gilad, S.; Higinbotham, D. W.; Rvachev, M.; Sirca, S.; Suleiman, R.; Zheng, X.; Zhu, L.; Roche, R. E.; McAleer, S.; Meekins, D.; Jones, M. K.

    2007-02-15

    We measured angular distributions of differential cross section, beam analyzing power, and recoil polarization for neutral pion electroproduction at Q{sup 2}=1.0 (GeV/c){sup 2} in 10 bins of 1.17{<=}W{<=}1.35 GeV across the {delta} resonance. A total of 16 independent response functions were extracted, of which 12 were observed for the first time. Comparisons with recent model calculations show that response functions governed by real parts of interference products are determined relatively well near the physical mass, W=M{sub {delta}}{approx_equal}1.232 GeV, but the variation among models is large for response functions governed by imaginary parts, and for both types of response functions, the variation increases rapidly with W>M{sub {delta}}. We performed a multipole analysis that adjusts suitable subsets of l{sub {pi}}{<=}2 amplitudes with higher partial waves constrained by baseline models. This analysis provides both real and imaginary parts. The fitted multipole amplitudes are nearly model independent--there is very little sensitivity to the choice of baseline model or truncation scheme. By contrast, truncation errors in the traditional Legendre analysis of N{yields}{delta} quadrupole ratios are not negligible. Parabolic fits to the W dependence around M{sub {delta}} for the multiple analysis gives values for Re(S{sub 1+}/M{sub 1+})=(-6.61{+-}0.18)% and Re(E{sub 1+}/M{sub 1+})=(-2.87{+-}0.19)% for the p{pi}{sup 0} channel at W=1.232 GeV and Q{sup 2}=1.0 (GeV/c){sup 2} that are distinctly larger than those from the Legendre analysis of the same data. Similarly, the multipole analysis gives Re(S{sub 0+}/M{sub 1+})=(+7.1{+-}0.8)% at W=1.232 GeV, consistent with recent models, while the traditional Legendre analysis gives the opposite sign because its truncation errors are quite severe.

  11. The smallest resonator arrays in atmosphere by chip-size-grown nanowires with tunable Q-factor and frequency for subnanometer thickness detection.

    PubMed

    Jiang, Chengming; Tang, Chaolong; Song, Jinhui

    2015-02-11

    A chip-size vertically aligned nanowire (NW) resonator arrays (VNRs) device has been fabricated with simple one-step lithography process by using grown self-assembled zinc oxide (ZnO) NW arrays. VNR has cantilever diameter of 50 nm, which breakthroughs smallest resonator record (>100 nm) functioning in atmosphere. A new atomic displacement sensing method by using atomic force microscopy is developed to effectively identify the resonance of NW resonator with diameter 50 nm in atmosphere. Size-effect and half-dimensional properties of the NW resonator have been systematically studied. Additionally, VNR has been demonstrated with the ability of detecting nanofilm thickness with subnanometer (<10(-9)m) resolution. PMID:25575294

  12. Measurement of cross section and electron asymmetry of the p (e(pol), e-prime pi+) n reaction in the Delta(1232) and higher resonances for Q**2 <= 4.9-(GeV/c)**2

    SciTech Connect

    Kijun Park; Inna Aznauryan; Volker Burkert; Wooyoung Kim

    2006-06-01

    The cross section and beam asymmetry were measured in channel of (pol)ep --> e'pi^+n using 5.754 GeV electron beam with CEBAF Large Acceptance Spectrometer(CLAS). This measurement covers 4 pi angular coverage and high Q^2 up to 4.9 GeV^2 under various resonance mass regions. The structure functions sigmaT + epsilonLsigmaL, sigmaTT, sigmaLT and sigmaLT/ were extracted from fit angular distribution of cross section and asymmetry.

  13. Resonance production in. gamma gamma. collisions

    SciTech Connect

    Renard, F.M.

    1983-04-01

    The processes ..gamma gamma.. ..-->.. hadrons can be depicted as follows. One photon creates a q anti q pair which starts to evolve; the other photon can either (A) make its own q anti q pair and the (q anti q q anti q) system continue to evolve or (B) interact with the quarks of the first pair and lead to a modified (q anti q) system in interaction with C = +1 quantum numbers. A review of the recent theoretical activity concerning resonance production and related problems is given under the following headings: hadronic C = +1 spectroscopy (q anti q, qq anti q anti q, q anti q g, gg, ggg bound states and mixing effects); exclusive ..gamma gamma.. processes (generalities, unitarized Born method, VDM and QCD); total cross section (soft and hard contributions); q/sup 2/ dependence of soft processes (soft/hard separation, 1/sup +- +/ resonances); and polarization effects. (WHK)

  14. High-Q Hybrid Plasmon-Photon Modes in a Bottle Resonator Realized with a Silver-Coated Glass Fiber with a Varying Diameter

    NASA Astrophysics Data System (ADS)

    Rottler, Andreas; Harland, Malte; Bröll, Markus; Klingbeil, Matthias; Ehlermann, Jens; Mendach, Stefan

    2013-12-01

    We experimentally demonstrate that hybrid plasmon-photon modes exist in a silver-coated glass bottle resonator. The bottle resonator is realized in a glass fiber with a smoothly varying diameter, which is subsequently coated with a rhodamine 800-dye doped acryl-glass layer and a 30 nm thick silver layer. We show by means of photoluminescence experiments supported by electromagnetic simulations that the rhodamine 800 photoluminescence excites hybrid plasmon-photon modes in such a bottle resonator, which provide a plasmon-type field enhancement at the outer silver surface and exhibit quality factors as high as 1000.

  15. High-Q hybrid plasmon-photon modes in a bottle resonator realized with a silver-coated glass fiber with a varying diameter.

    PubMed

    Rottler, Andreas; Harland, Malte; Bröll, Markus; Klingbeil, Matthias; Ehlermann, Jens; Mendach, Stefan

    2013-12-20

    We experimentally demonstrate that hybrid plasmon-photon modes exist in a silver-coated glass bottle resonator. The bottle resonator is realized in a glass fiber with a smoothly varying diameter, which is subsequently coated with a rhodamine 800-dye doped acryl-glass layer and a 30 nm thick silver layer. We show by means of photoluminescence experiments supported by electromagnetic simulations that the rhodamine 800 photoluminescence excites hybrid plasmon-photon modes in such a bottle resonator, which provide a plasmon-type field enhancement at the outer silver surface and exhibit quality factors as high as 1000. PMID:24483745

  16. Q fever.

    PubMed

    Tissot-Dupont, Hervé; Raoult, Didier

    2008-09-01

    Q fever is a worldwide zoonosis caused by the pathogen Coxiella burnetii causing acute and chronic clinical manifestations. The name "Q fever" derives from "Query fever" and was given in 1935 following an outbreak of febrile illness in an abattoir in Queensland, Australia. C burnetii is considered a potential agent of bioterrorism (class B by the Centers for Disease Control). PMID:18755387

  17. Q fever

    MedlinePlus

    ... fever is antibiotics. For early-stage Q fever, doxycycline is the recommended antibiotic. If you have the ... fever. Your health care provider may prescribe both doxycycline and hydroxychloroquine. You may need to take antibiotics ...

  18. Q Fever

    PubMed Central

    Maurin, M.; Raoult, D.

    1999-01-01

    Q fever is a zoonosis with a worldwide distribution with the exception of New Zealand. The disease is caused by Coxiella burnetii, a strictly intracellular, gram-negative bacterium. Many species of mammals, birds, and ticks are reservoirs of C. burnetii in nature. C. burnetii infection is most often latent in animals, with persistent shedding of bacteria into the environment. However, in females intermittent high-level shedding occurs at the time of parturition, with millions of bacteria being released per gram of placenta. Humans are usually infected by contaminated aerosols from domestic animals, particularly after contact with parturient females and their birth products. Although often asymptomatic, Q fever may manifest in humans as an acute disease (mainly as a self-limited febrile illness, pneumonia, or hepatitis) or as a chronic disease (mainly endocarditis), especially in patients with previous valvulopathy and to a lesser extent in immunocompromised hosts and in pregnant women. Specific diagnosis of Q fever remains based upon serology. Immunoglobulin M (IgM) and IgG antiphase II antibodies are detected 2 to 3 weeks after infection with C. burnetii, whereas the presence of IgG antiphase I C. burnetii antibodies at titers of ≥1:800 by microimmunofluorescence is indicative of chronic Q fever. The tetracyclines are still considered the mainstay of antibiotic therapy of acute Q fever, whereas antibiotic combinations administered over prolonged periods are necessary to prevent relapses in Q fever endocarditis patients. Although the protective role of Q fever vaccination with whole-cell extracts has been established, the population which should be primarily vaccinated remains to be clearly identified. Vaccination should probably be considered in the population at high risk for Q fever endocarditis. PMID:10515901

  19. Single-frequency, injection-seeded Q-switched operation of resonantly pumped Er:YAG ceramic laser at 1645 nm

    NASA Astrophysics Data System (ADS)

    Ye, Qing; Gao, Chunqing; Wang, Shuo; Na, Quanxin; Shi, Yang; Wang, Qing; Gao, Mingwei; Zhang, Jian

    2016-07-01

    A single-frequency Q-switched Er:YAG polycrystalline ceramic laser is reported for the first time. The `Ramp-Hold-Fire' injection-seeding technique was employed to obtain single-frequency pulses, with an Er:YAG NPRO as a seed laser. Single-frequency laser operation was obtained with pulse energy of 4.7 mJ, pulse width of 250 ns and pulse repetition rate of 200 Hz.

  20. Josephson junction Q-spoiler

    DOEpatents

    Clarke, John; Hilbert, Claude; Hahn, Erwin L.; Sleator, Tycho

    1988-01-01

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  1. Josephson junction Q-spoiler

    DOEpatents

    Clarke, J.; Hilbert, C.; Hahn, E.L.; Sleator, T.

    1986-03-25

    An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

  2. Evanescent straight tapered-fiber coupling of ultra-high Q optomechanical micro-resonators in a low-vibration helium-4 exchange-gas cryostat

    NASA Astrophysics Data System (ADS)

    Rivière, R.; Arcizet, O.; Schliesser, A.; Kippenberg, T. J.

    2013-04-01

    We developed an apparatus to couple a 50-μm diameter whispering-gallery silica microtoroidal resonator in a helium-4 cryostat using a straight optical tapered-fiber at 1550 nm wavelength. On a top-loading probe specifically adapted for increased mechanical stability, we use a specifically-developed "cryotaper" to optically probe the cavity, allowing thus to record the calibrated mechanical spectrum of the optomechanical system at low temperatures. We then demonstrate excellent thermalization of a 63-MHz mechanical mode of a toroidal resonator down to the cryostat's base temperature of 1.65 K, thereby proving the viability of the cryogenic refrigeration via heat conduction through static low-pressure exchange gas. In the context of optomechanics, we therefore provide a versatile and powerful tool with state-of-the-art performances in optical coupling efficiency, mechanical stability, and cryogenic cooling.

  3. Single pi+ Electroproduction on the Proton in the First and Second Resonance Regions at 0.25GeV^2 < Q^2 < 0.65GeV^2 Using CLAS

    SciTech Connect

    H. Egiyan; I.G. Aznauryan; V.D. Burkert; K.A. Griffioen; K. Joo; R. Minehart; L.C. Smith

    2006-01-05

    The ep {yields} e'pi{sup +}n reaction was studied in the first and second nucleon resonance regions in the 0.25 GeV{sup 2} < Q{sup 2} < 0.65 GeV{sup 2} range using the CLAS detector at Thomas Jefferson National Accelerator Facility. For the first time the absolute cross sections were measured covering nearly the full angular range in the hadronic center-of-mass frame. The structure functions {sigma}{sub TL}, {sigma}{sub TT} and the linear combination {sigma}{sub T} + {epsilon}{sigma}{sub L} were extracted by fitting the {phi}-dependence of the measured cross sections, and were compared to the MAID and Sato-Lee models.

  4. Investigations of the radial propagation of blob-like structure in a non-confined electron cyclotron resonance heated plasma on Q-shu University Experiment with a Steady-State Spherical Tokamak

    SciTech Connect

    Ogata, R.; Liu, H. Q.; Ishiguro, M.; Ikeda, T.; Hanada, K.; Zushi, H.; Nakamura, K.; Fujisawa, A.; Idei, H.; Hasegawa, M.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Nishino, N.; Collaboration: QUEST Group

    2011-09-15

    A study of radial propagation and electric fields induced by charge separation in blob-like structures has been performed in a non-confined cylindrical electron cyclotron resonance heating plasma on Q-shu University Experiment with a Steady-State Spherical Tokamak using a fast-speed camera and a Langmuir probe. The radial propagation of the blob-like structures is found to be driven by E x B drift. Moreover, these blob-like structures were found to have been accelerated, and the property of the measured radial velocities agrees with the previously proposed model [C. Theiler et al., Phys. Rev. Lett. 103, 065001 (2009)]. Although the dependence of the radial velocity on the connection length of the magnetic field appeared to be different, a plausible explanation based on enhanced short-circuiting of the current path can be proposed.

  5. Induced proton polarization for {pi}{sup 0} electroproduction at Q{sup 2}=0.126 GeV{sup 2}/c{sup 2} around the {Delta}(1232) resonance

    SciTech Connect

    Alarcon, R.; Comfort, J.R.; Dolfini, S.; Mertz, C.; Young, A.; Gothe, R.W.; Kunz, C.; Epstein, M.; Liu, D.; Margaziotis, D.; Mukhopadhyay, S.; Armstrong, C.; Finn, J.M.; Jones, M.; McIntyre, J.I.; Perdrisat, C.; Woo, R.J.; Sarty, A.; Madey, R.; Van Verst, S.; Warren, G.A.; Bertozzi, W.; Chen, J.; Dodson, G.; Dow, K.; Farkhondeh, M.; Gilad, S.; Joo, K.; Kowalski, S.; Soong, S.; Tieger, D.; Tschalaer, C.; Turchinetz, W.; Punjabi, V.; Qin, L.; Ulmer, P.; Weinstein, L.B.; Rutt, P.; Burkert, V.; Chen, J.; Mitchell, J.; Karabarbounis, A.; Papanicolas, C.N.; Vellidis, C.; Williamson, S.; Dale, D.

    1998-12-01

    We present a measurement of the induced proton polarization P{sub n} in {pi}{sup 0} electroproduction on the proton around the {Delta} resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W=1231 MeV and Q{sup 2}=0.126 GeV{sup 2}/c{sup 2}, respectively. We measured a large induced polarization, P{sub n}={minus}0.397{plus_minus}0.055{plus_minus}0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model. {copyright} {ital 1998} {ital The American Physical Society}

  6. Q fever.

    PubMed Central

    Reimer, L G

    1993-01-01

    Q fever is an acute febrile illness first described in 1935 and now seen in many parts of the world. Human infection follows exposure to animals, especially domestic livestock. Recent outbreaks in metropolitan areas have implicated cats as the carrier of disease to humans. The etiologic agent, Coxiella burnetti, belongs to the family Rickettsiaceae, although it has distinct genetic characteristics and modes of transmission. Most recent attention has been focused on a number of large outbreaks of Q fever associated with medical research involving pregnant sheep. Although most infections are self-limited, some patients require prolonged treatment. Recent vaccines have had encouraging success in the prevention of disease in individuals at high risk of exposure. PMID:8358703

  7. Cross sections and beam asymmetries for $\\vev{e}p \\to en\\pi^+$ in the nucleon resonance region for $1.7 \\le Q^2 \\le 4.5 (GeV)^2$

    SciTech Connect

    K. Park; V.D. Burkert; W. Kim; CLAS Collaboration

    2008-01-01

    The exclusive electroproduction process $\\vec{e}p \\to e^\\prime n \\pi^+$ was measured in the range of the photon virtuality $Q^2 = 1.7 - 4.5 \\rm{GeV^2}$, and the invariant mass range for the $n\\pi^+$ system of $W = 1.15 - 1.7 \\rm{GeV}$ using the CEBAF Large Acceptance Spectrometer. For the first time, these kinematics are probed in exclusive $\\pi^+$ production from protons with nearly full coverage in the azimuthal and polar angles of the $n\\pi^+$ center-of-mass system. The $n\\pi^+$ channel has particular sensitivity to the isospin 1/2 excited nucleon states, and together with the $p\\pi^0$ final state will serve to determine the transition form factors of a large number of resonances. The largest discrepancy between these results and present modes was seen in the $\\sigma_{LT'}$ structure function. In this experiment, 31,295 cross section and 4,184 asymmetry data points were measured. Because of the large volume of data, only a reduced set of structure functions and Legendre polynomial moments can be presented that are obtained in model-independent fits to the differential cross sections.

  8. Interstitial deletion (6)q13q15

    SciTech Connect

    Gershoni-Baruch, R.; Mandel, H.; Bar El, H.; Bar-Nizan, N.; Borochowitz, Z.; Dar, Hanna

    1996-04-24

    We report on a 2-year-old child with psychomotor retardation, facial and urogenital anomalies. His chromosome constitution was 46,XY,del(6)(q13q15). This case further contributes to the karyotype-phenotype correlation of proximal deletion 6q syndromes. 18 refs., 3 figs., 1 tab.

  9. Analysis of Q burst waveforms

    NASA Astrophysics Data System (ADS)

    Ogawa, Toshio; Komatsu, Masayuki

    2007-04-01

    The electric field changes in ELF to VLF were observed with a ball antenna in fair weather at Kochi (latitude 33.3°N, longitude 133.4°E) during 2003-2004. Some 376 Q bursts were obtained, seven examples of which are analyzed in the present study. The continuous frequency spectra of the Q bursts and the background noises from 1.0 Hz to 11 kHz are compared, and it was found that the Q bursts prevail over the background in the frequency range from 1 to 300 Hz. The surplus is 20 dB (in amplitude) near the fundamental mode frequency. The "W"-type changes found in the initial portion of the Q burst waveforms are interpreted as the combined electromagnetic waveform of direct and antipodal waves from the causative lightning strokes. From the time intervals between the two waves, the source-receiver distances are estimated as far as 19 Mm. The pulses to excite the Schumann resonances in the Q bursts are clearly identified.

  10. Dynamically tuned high-Q AC-dipole implementation

    SciTech Connect

    Oddo, P.; Bai, M.; Dawson, W.C.; Meng, W.; Mernick, K.; Pai, C.; Roser, T.; Russo, T.

    2010-05-02

    AC-dipole magnets are typically implemented as a parallel LC resonant circuit. To maximize efficiency, it's beneficial to operate at a high Q. This, however, limits the magnet to a narrow frequency range. Current designs therefore operate at a low Q to provide a wider bandwidth at the cost of efficiency. Dynamically tuning a high Q resonant circuit tries to maintain a high efficiency while providing a wide frequency range. The results of ongoing efforts at BNL to implement dynamically tuned high-Q AC dipoles will be presented.

  11. Quantum codes from cyclic codes over F_q+uF_q+vF_q+uvF_q

    NASA Astrophysics Data System (ADS)

    Ashraf, Mohammad; Mohammad, Ghulam

    2016-07-01

    In this paper, we study quantum codes over F_q from cyclic codes over F_q+uF_q+vF_q+uvF_q, where u^2=u,~v^2=v,~uv=vu,~q=p^m , and p is an odd prime. We give the structure of cyclic codes over F_q+uF_q+vF_q+uvF_q and obtain self-orthogonal codes over F_q as Gray images of linear and cyclic codes over F_q+uF_q+vF_q+uvF_q . In particular, we decompose a cyclic code over F_q+uF_q+vF_q+uvF_q into four cyclic codes over F_q to determine the parameters of the corresponding quantum code.

  12. High Q factor bonding using natural resin for reduced thermal noise of test masses

    NASA Astrophysics Data System (ADS)

    Schediwy, S. W.; Gras, S.; Ju, L.; Blair, D. G.

    2005-02-01

    We show that a low acoustic loss resin enables composite mechanical structures to be bonded with minimal Q degradation. The resin is excreted from the Australian native grass tree Xanthorrhoea. This resin has traditionally been used as an adhesive by the Australian Aborigines. It is shown that the Q factor of the resin is greater than 300 for the 5180Hz resonance, which allows a high Q factor niobium resonator to be constructed with bonded mirrors while maintaining a Q of ˜106.

  13. SNAKE DEPLORIZING RESONANCE STUDY IN RHIC

    SciTech Connect

    BAI,M.; CAMERON, P.; LUCCIO, A.; HUANG, H.; PITISYN, V.; ET AL.

    2007-06-25

    Snake depolarizing resonances due to the imperfect cancellation of the accumulated perturbations on the spin precession between snakes were observed at the Relativistic Heavy Ion Collider (RHIC). During the RHIC 2005 and 2006 polarized proton runs, we mapped out the spectrum of odd order snake resonance at Q{sub y} = 7/10. Here, Q, is the beam vertical betatron tune. We also studied the beam polarization after crossing the 7/10th resonance as a function of resonance crossing rate. This paper reports the measured resonance spectrum as well as the results of resonance crossing.

  14. Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material

    DOEpatents

    Olsson, Roy H.; El-Kady; , Ihab F.; Ziaei-Moayyed, Maryam; Branch; , Darren W.; Su; Mehmet F.,; Reinke; Charles M.,

    2013-09-03

    A very high-Q, low insertion loss resonator can be achieved by storing many overtone cycles of a lateral acoustic wave (i.e., Lamb wave) in a lithographically defined suspended membrane comprising a low damping resonator material, such as silicon carbide. The high-Q resonator can sets up a Fabry-Perot cavity in a low-damping resonator material using high-reflectivity acoustic end mirrors, which can comprise phononic crystals. The lateral overtone acoustic wave resonator can be electrically transduced by piezoelectric couplers. The resonator Q can be increased without increasing the impedance or insertion loss by storing many cycles or wavelengths in the high-Q resonator material, with much lower damping than the piezoelectric transducer material.

  15. Coenzyme Q10 Therapy

    PubMed Central

    Garrido-Maraver, Juan; Cordero, Mario D.; Oropesa-Ávila, Manuel; Fernández Vega, Alejandro; de la Mata, Mario; Delgado Pavón, Ana; de Miguel, Manuel; Pérez Calero, Carmen; Villanueva Paz, Marina; Cotán, David; Sánchez-Alcázar, José A.

    2014-01-01

    For a number of years, coenzyme Q10 (CoQ10) was known for its key role in mitochondrial bioenergetics; later studies demonstrated its presence in other subcellular fractions and in blood plasma, and extensively investigated its antioxidant role. These 2 functions constitute the basis for supporting the clinical use of CoQ10. Also, at the inner mitochondrial membrane level, CoQ10 is recognized as an obligatory cofactor for the function of uncoupling proteins and a modulator of the mitochondrial transition pore. Furthermore, recent data indicate that CoQ10 affects the expression of genes involved in human cell signaling, metabolism and transport, and some of the effects of CoQ10 supplementation may be due to this property. CoQ10 deficiencies are due to autosomal recessive mutations, mitochondrial diseases, aging-related oxidative stress and carcinogenesis processes, and also statin treatment. Many neurodegenerative disorders, diabetes, cancer, and muscular and cardiovascular diseases have been associated with low CoQ10 levels as well as different ataxias and encephalomyopathies. CoQ10 treatment does not cause serious adverse effects in humans and new formulations have been developed that increase CoQ10 absorption and tissue distribution. Oral administration of CoQ10 is a frequent antioxidant strategy in many diseases that may provide a significant symptomatic benefit. PMID:25126052

  16. High Temperature Superconducting RF Resonators for Resonator Stabilized Oscillators

    NASA Astrophysics Data System (ADS)

    Goettee, Jeffrey David

    Electromagnetic resonators made of superconducting materials show unusually sharp resonances because resistive losses are minimized. The availability of high quality thin films of YB_2CU_3 O_{7-delta} (YBCO) with superconducting transitions at 92K has aroused interest in thin film resonators at microwave frequencies for use in filters and oscillators in communication and radar systems. I have investigated the design and radio frequency (rf) properties of superconducting resonators in microstrip geometries (in which the resonant element and a single ground plane are on opposite faces of the LaAlO_3 substrates). This monolithic approach minimizes vibration sensitivity, but exposes the resonators to interactions with the packaging structure. I used niobium (Nb) superconducting 2 GHz resonators at 4.2K to investigate the geometry dependence of the quality factor Q and the high frequency phase noise S_ {y}(f). Q's in excess of 250,000 and S_{y}(1 Hz) = -227 were achieved. Desirable geometries were then fabricated in YBCO thin films produced by coevaporation or sputtering. They typically showed Q's that are a factor of four lower than the comparable Nb resonator, but retained their usefulness to substantially higher temperatures ( ~60K). One of these YBCO resonators was successfully operated to stabilize an oscillator operating at 2 GHz with overall single-sideband phase noise }(1 Hz) = -30 dBc/Hz comparable to the best available competing technologies.

  17. Investigation of mechanically Q-switched lasers

    NASA Astrophysics Data System (ADS)

    Cole, Brian; Goldberg, Lew; Hough, Nathaniel; Nettleton, John

    2015-02-01

    Using a resonant scanner mirror Q-switch to provide a time varying change in cavity alignment, 1535nm lasers based on Er/Yb-doped glass and 1064nm lasers based on Nd:YAG were evaluated. Using a side pumping architecture, the Er/Yb glass laser used a compact mechanical Q-switch with a mirror rotation rate of 330 Rad/s, enabling generation of <3 mJ pulses with a pulse width of 16ns. The laser output was a diffraction limited TEM00 mode. A mechanical Q-switch based on a MEMS tilting mirror was also used; its performance in a laser cavity was found to be similar to the resonant mirror. The technique of mechanical Q-switching was also extended to a side pumped Nd:YAG laser (mirror sweep rate of 1300 Rad/s), enabling generation of Q-switched pulses of <30mJ and 25ns duration. The far-field divergence showed this laser to be highly multi-moded within the pump plane, with a measured beam-product-parameter greater than 30 mm-mRad.

  18. k and q Dedicated to Paul Callaghan

    NASA Astrophysics Data System (ADS)

    Blümich, Bernhard

    2016-06-01

    The symbols k and q denote wave numbers in scattering experiments as well as in NMR imaging. Their exploration in NMR is intimately linked to the legacy of Paul Callaghan with his books Magnetic Resonance Microscopy and Translational Dynamics & Magnetic Resonance (Oxford University Press, Oxford 1991 and 2011) placing their focus with their titles on k and q, respectively. Some aspects of k and q have been revisited in the Paul Callaghan lecture of the author at the ISMAR Conference in Shanghai in 2015, which are reviewed here. In particular, there are two definitions of q, one relating to diffusive displacement (q) and the other to coherent flow (qv). Concerning the latter, it turns out, that in the short gradient pulse limit, the common anti-phase pulsed field-gradient scheme can be replaced with schemes employing three and more gradient pulses, which derive from differentiation rules in numerical analysis. Practical gradient modulation schemes with finite gradient pulse widths follow from these to measure velocity with improved accuracy. This approach can be expanded to acceleration and higher order transport coefficients with applications to measurements of flow and potentially also restricted diffusion.

  19. k and q Dedicated to Paul Callaghan.

    PubMed

    Blümich, Bernhard

    2016-06-01

    The symbols k and q denote wave numbers in scattering experiments as well as in NMR imaging. Their exploration in NMR is intimately linked to the legacy of Paul Callaghan with his books Magnetic Resonance Microscopy and Translational Dynamics & Magnetic Resonance (Oxford University Press, Oxford 1991 and 2011) placing their focus with their titles on k and q, respectively. Some aspects of k and q have been revisited in the Paul Callaghan lecture of the author at the ISMAR Conference in Shanghai in 2015, which are reviewed here. In particular, there are two definitions of q, one relating to diffusive displacement (q) and the other to coherent flow (qv). Concerning the latter, it turns out, that in the short gradient pulse limit, the common anti-phase pulsed field-gradient scheme can be replaced with schemes employing three and more gradient pulses, which derive from differentiation rules in numerical analysis. Practical gradient modulation schemes with finite gradient pulse widths follow from these to measure velocity with improved accuracy. This approach can be expanded to acceleration and higher order transport coefficients with applications to measurements of flow and potentially also restricted diffusion. PMID:27067190

  20. Q fever - a review.

    PubMed

    Marrie, T J

    1990-08-01

    Q or "query" fever is a zoonosis caused by the organism Coxiella burnetii. Cattle, sheep and goats are the most common reservoirs of this organism. The placenta of infected animals contains high numbers (up to 10(9)/g) of C. burnetii. Aerosols occur at the time of parturition and man becomes infected following inhalation of the microorganism. The spectrum of illness in man is wide and consists of acute and chronic forms. Acute Q fever is most often a self-limited flu-like illness but may include pneumonia, hepatitis, or meningoencephalitis. Chronic Q fever almost always means endocarditis and rarely osteomyelitis. Chronic Q fever is not known to occur in animals other than man. An increased abortion and stillbirth rate are seen in infected domestic ungulates.Four provinces (Nova Scotia, New Brunswick, Ontario and Alberta) reported cases of Q fever in 1989.A vaccine for Q fever has recently been licensed in Australia. PMID:17423643

  1. The Q, Compound Q is Finally Deciphered

    PubMed Central

    Bhagi-Damodaran, Ambika; Lu, Yi

    2015-01-01

    Methane monooxygenases (MMOs) activate the high energy C-H bond of methane and convert it to methanol with high selectivity and under physiological conditions. Despite decades of efforts focusing on elucidating the structure, function and mechanism of soluble MMOs, the structure of a key intermediate (called compound Q) remained unknown. This article highlights a recent report by Banerjee et. al. which not only firmly establishes the core-structure of Q, but also provides significant insight into its formation, reaction with methane and eventual decay. PMID:26346336

  2. Large gauged Q balls

    NASA Astrophysics Data System (ADS)

    Anagnostopoulos, K. N.; Axenides, M.; Floratos, E. G.; Tetradis, N.

    2001-12-01

    We study Q balls associated with local U(1) symmetries. Such Q balls are expected to become unstable for large values of their charge because of the repulsion mediated by the gauge force. We consider the possibility that the repulsion is eliminated through the presence in the interior of the Q ball of fermions with charge opposite to that of the scalar condensate. Another possibility is that two scalar condensates of opposite charge form in the interior. We demonstrate that both these scenarios can lead to the existence of classically stable, large, gauged Q balls. We present numerical solutions, as well as an analytical treatment of the ``thin-wall'' limit.

  3. Resonances and resonance widths

    SciTech Connect

    Collins, T.

    1986-05-01

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

  4. The symmetric q-oscillator algebra: q-coherent states, q-Bargmann-Fock realization and continuous q-Hermite polynomials with 0 < q < 1

    NASA Astrophysics Data System (ADS)

    Fakhri, H.; Hashemi, A.

    2016-01-01

    The symmetric q-analysis is used to construct a type of minimum-uncertainty q-coherent states in the Fock representation space of the symmetric q-oscillator ∗-algebra with 0 < q < 1. Then, its corresponding q-Hermite polynomials are derived by using the q-Bargmann-Fock realization of the symmetric q-oscillator algebra.

  5. Coenzyme Q10 (PDQ)

    MedlinePlus

    ... and use of CoQ10 as a complementary or alternative treatment for cancer? CoQ10 was first identified in 1957. Its chemical ... of CAM therapies originally considered to be purely alternative approaches are finding a place in cancer treatment—not as cures, but as complementary therapies that ...

  6. Extended ultrahigh-Q-cavity diode laser.

    PubMed

    Xie, Zhenda; Liang, Wei; Savchenkov, Anatoliy A; Lim, Jinkang; Burkhart, Jan; McDonald, Mickey; Zelevinsky, Tanya; Ilchenko, Vladimir S; Matsko, Andrey B; Maleki, Lute; Wong, Chee Wei

    2015-06-01

    We report on a study of a 698 nm extended cavity semiconductor laser with intracavity narrowband optical feedback from a whispering gallery mode resonator. This laser comprises an ultrahigh-Q (>10(10)) resonator supporting stimulated Rayleigh scattering, a diffraction grating wavelength preselector, and a reflective semiconductor amplifier. Single longitudinal mode lasing is characterized with sub-kilohertz linewidth and a 9 nm coarse tuning range. The laser has a potential application for integration with the 1S0-3P0 strontium transition to create compact precision atomic clocks. PMID:26030566

  7. Experimental determination of a betatron difference resonance

    SciTech Connect

    Ellison, M.; Ball, M.; Brabson, B.

    1993-06-01

    The betatron difference resonance, Q{sub z} {minus} 2Q{sub z} = {minus}6, where Q{sub x,z} are the number of betatron oscillations per turn, was studied at the Indiana University Cyclotron Facility (IUCF) cooler ring. The position of the beam was measured in both the horizontal and vertical planes of oscillation after a pulsed kicker magnet was fired to produce coherent motion. The effect of the coupling resonance was clearly observed and it was found that the subsequent particle motion could be described by a simple Hamiltonian. The resonance strength and tune shift as a function of betatron amplitude were measured.

  8. Electroexcitation of nucleon resonances

    SciTech Connect

    Inna Aznauryan, Volker D. Burkert

    2012-01-01

    We review recent progress in the investigation of the electroexcitation of nucleon resonances, both in experiment and in theory. The most accurate results have been obtained for the electroexcitation amplitudes of the four lowest excited states, which have been measured in a range of Q2 up to 8 and 4.5 GeV2 for the Delta(1232)P33, N(1535)S11 and N(1440)P11, N(1520)D13, respectively. These results have been confronted with calculations based on lattice QCD, large-Nc relations, perturbative QCD (pQCD), and QCD-inspired models. The amplitudes for the Delta(1232) indicate large pion-cloud contributions at low Q2 and don't show any sign of approaching the pQCD regime for Q2<7 GeV2. Measured for the first time, the electroexcitation amplitudes of the Roper resonance, N(1440)P11, provide strong evidence for this state as a predominantly radial excitation of a three-quark (3q) ground state, with additional non-3-quark contributions needed to describe the low Q2 behavior of the amplitudes. The longitudinal transition amplitude for the N(1535)S11 was determined and has become a challenge for quark models. Explanations may require large meson-cloud contributions or alternative representations of this state. The N(1520)D13 clearly shows the rapid changeover from helicity-3/2 dominance at the real photon point to helicity-1/2 dominance at Q2 > 0.5 GeV2, confirming a long-standing prediction of the constituent quark model. The interpretation of the moments of resonance transition form factors in terms of transition transverse charge distributions in infinite momentum frame is presented.

  9. Q-branes

    NASA Astrophysics Data System (ADS)

    Abel, Steven; Kehagias, Alex

    2015-11-01

    Non-topological solitons (Q-balls) are discussed in some stringy settings. Our main result is that the dielectric D-brane system of Myers admits non-abelian Q-ball solutions on their world-volume, in which N D p-branes relax to the standard dielectric form outside the Q-ball, but assume a more diffuse configuration at its centre. We also consider how Q-balls behave in the bulk of extra-dimensional theories, or on wrapped branes. We demonstrate that they carry Kaluza-Klein charge and possess a corresponding Kaluza-Klein tower of states just as normal particles, and we discuss surface energy effects by finding exact Q-ball solutions in models with a specific logarithmic potential.

  10. Fabrication of a microtoroidal resonator with picometer precise resonant wavelength.

    PubMed

    Liu, Xiao-Fei; Lei, Fuchuan; Gao, Ming; Yang, Xu; Qin, Guo-Qing; Long, Gui-Lu

    2016-08-01

    Fabricating an optical microresonator with precise resonant wavelength is of significant importance for fundamental research and practical applications. Here, we develop an effective method to fabricate ultra-high Q microtoroid with picometer-precise resonant wavelength. Our method adds a tuning reflow process, using low-power CO2 laser pulses, to the traditional fabrication process. It can tailor resonant wavelength to a red or blue direction by choosing a proper laser power. Also, this shift can be controlled by the exposure time. Meanwhile, quality factor remains nearly unchanged during this tailoring process. Our method can greatly reduce the difficulties of experiments where precise resonances are required. PMID:27472629

  11. Compact Q-balls

    NASA Astrophysics Data System (ADS)

    Bazeia, D.; Losano, L.; Marques, M. A.; Menezes, R.; da Rocha, R.

    2016-07-01

    In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  12. Q fever - early

    MedlinePlus

    ... burnetii , which live in domestic animals such as cattle, sheep, goats, birds, and cats. Some wild animals and ticks also carry the bacteria. You can get Q fever by drinking raw (unpasteurized) milk, or after breathing ...

  13. Popular Chat Day Q & A

    MedlinePlus

    ... Day / Popular Chat Day Q & A Popular Chat Day Q & A Print Read students’ most popular questions ... Cool Order Free Materials National Drugs & Alcohol Chat Day Chat Day Participant FAQs Popular Chat Day Q & ...

  14. DIGITAL Q METER

    DOEpatents

    Briscoe, W.L.

    1962-02-13

    A digital Q meter is described for measuring the Q of mechanical or electrical devices. The meter comprises in combination a transducer coupled to an input amplifier, and an upper and lower level discriminator coupled to the amplifier and having their outputs coupled to an anticoincidence gate. The output of the gate is connected to a scaler. The lower level discriminator is adjusted to a threshold level of 36.8 percent of the operating threshold level of the upper level discriminator. (AEC)

  15. Deletion (2)(q37)

    SciTech Connect

    Stratton, R.F.; Tolworthy, J.A.; Young, R.S.

    1994-06-01

    We report on a 5-month-old girl with widely spaced nipples, redundant nuchal skin, coarctation of the aorta, anal atresia with distal fistula, postnatal growth retardation, hypotonia, and sparse scalp hair. Initial clinical assessment suggested the diagnosis of Ullrich-Turner syndrome. Chromosome analysis showed a 46,XX,del(2)(q37) karyotype in peripheral lymphocytes. We compare her findings to those of other reported patients with terminal deletions of 2q. 8 refs., 2 figs., 1 tab.

  16. A random Q-switched fiber laser.

    PubMed

    Tang, Yulong; Xu, Jianqiu

    2015-01-01

    Extensive studies have been performed on random lasers in which multiple-scattering feedback is used to generate coherent emission. Q-switching and mode-locking are well-known routes for achieving high peak power output in conventional lasers. However, in random lasers, the ubiquitous random cavities that are formed by multiple scattering inhibit energy storage, making Q-switching impossible. In this paper, widespread Rayleigh scattering arising from the intrinsic micro-scale refractive-index irregularities of fiber cores is used to form random cavities along the fiber. The Q-factor of the cavity is rapidly increased by stimulated Brillouin scattering just after the spontaneous emission is enhanced by random cavity resonances, resulting in random Q-switched pulses with high brightness and high peak power. This report is the first observation of high-brightness random Q-switched laser emission and is expected to stimulate new areas of scientific research and applications, including encryption, remote three-dimensional random imaging and the simulation of stellar lasing. PMID:25797520

  17. Measurement Of Differential Cross Sections Of p(e,e'{pi}{sup +})n For High-Lying Resonances At Q{sup 2} < 5 GeV{sup 2}

    SciTech Connect

    Park, Kijun

    2014-01-01

    The exclusive electro-production process ep -> e'n{pi}{sup +} was measured in the range of the invariant mass for n{pi}{sup +} system 1.6 GeV <= W <= 2.0 GeV, and the photon virtuality 1.8 GeV{sup 2} <= Q{sup 2} <= 4.0 GeV{sup 2} using CLAS. For the first time, these kinematics are probed in exclusive {pi}{sup +} production from the protons with nearly full coverage in the azimuthal and polar angles of the n{pi}{sup +} center-of-mass system. In this experiment, approximately 39,000 differential cross-section data points were measured. In this proceeding, preliminary results of our latest analysis work are presented on differential cross sections and structure functions as well as Legendre Moments.

  18. Backward electroproduction of pi{sup 0} mesons on protons in the region of nucleon resonances at four momentum transfer squared Q2 = 1.0 GeV2

    SciTech Connect

    Laveissiere, G; Degrande, N; Jaminion, S; Jutier, C; Todor, L; Salvo, R Di; Hoorebeke, L Van

    2004-04-01

    Exclusive electroproduction of pi{sup 0} mesons on protons in the backward hemisphere has been studied at Q2 = 1.0 GeV2 by detecting protons in the forward direction in coincidence with scattered electrons from the 4 GeV electron beam in Jefferson Lab's Hall A. The data span the range of the total (gamma*p) center-of-mass energy W from the pion production threshold to W = 2.0 GeV. The differential cross sections sigma{sub T} + epsilon sigma{sub L}, sigma{sub TL}, and sigma{sub TT} were separated from the azimuthal distribution and are presented together with the MAID and SAID parameterizations.

  19. Three-region specific microdissection libraries for the long arm of human chromosome 2, regions q33-q35, q31-q32, and q23-q24

    SciTech Connect

    Yu, J.; Tong, S.; Whittier, A.

    1995-09-01

    Three region-specific libraries have been constructed from the long arm of human chromosome 2, including regions 2q33-35 (2Q2 library), 2q31-32 (2Q3) and 2q23-24 (2Q4). Chromosome microdissection and the MboI linker-adaptor microcloning techniques were used in constructing these libraries. The libraries comprised hundreds of thousands of microclones in each library. Approximately half of the microclones in the library contained unique or low-copy number sequence inserts. The insert sizes ranged between 50 and 800 bp, with a mean of 130-190 bp. Southern blot analysis of individual unique sequence microclones showed that 70-94% of the microclones were derived from the dissected region. 31 unique sequence microclones from the 2Q2 library, 31 from 2Q3, and 30 from 2Q4, were analyzed for insert sizes, the hybridizing genomic HindIII fragment sizes, and cross-hybridization to rodent species. These libraries and the short insert microclones derived from the libraries should be useful for high resolution physical mapping, sequence-ready reagents for large scale genomic sequencing, and positional cloning of disease-related genes assigned to these regions, e.g. the recessive familial amyotrophic lateral sclerosis assigned to 2q33-q35, and a type I diabetes susceptibility gene to 2q31-q33. 17 refs., 5 figs., 2 tabs.

  20. Wavelength-tunable optical ring resonators

    DOEpatents

    Watts, Michael R.; Trotter, Douglas C.; Young, Ralph W.; Nielson, Gregory N.

    2009-11-10

    Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

  1. Wavelength-tunable optical ring resonators

    DOEpatents

    Watts, Michael R.; Trotter, Douglas C.; Young, Ralph W.; Nielson, Gregory N.

    2011-07-19

    Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

  2. Wave Phenomena in an Acoustic Resonant Chamber

    ERIC Educational Resources Information Center

    Smith, Mary E.; And Others

    1974-01-01

    Discusses the design and operation of a high Q acoustical resonant chamber which can be used to demonstrate wave phenomena such as three-dimensional normal modes, Q values, densities of states, changes in the speed of sound, Fourier decomposition, damped harmonic oscillations, sound-absorbing properties, and perturbation and scattering problems.…

  3. Miniature Sapphire Acoustic Resonator - MSAR

    NASA Technical Reports Server (NTRS)

    Wang, Rabi T.; Tjoelker, Robert L.

    2011-01-01

    A room temperature sapphire acoustics resonator incorporated into an oscillator represents a possible opportunity to improve on quartz ultrastable oscillator (USO) performance, which has been a staple for NASA missions since the inception of spaceflight. Where quartz technology is very mature and shows a performance improvement of perhaps 1 dB/decade, these sapphire acoustic resonators when integrated with matured quartz electronics could achieve a frequency stability improvement of 10 dB or more. As quartz oscillators are an essential element of nearly all types of frequency standards and reference systems, the success of MSAR would advance the development of frequency standards and systems for both groundbased and flight-based projects. Current quartz oscillator technology is limited by quartz mechanical Q. With a possible improvement of more than x 10 Q with sapphire acoustic modes, the stability limit of current quartz oscillators may be improved tenfold, to 10(exp -14) at 1 second. The electromagnetic modes of sapphire that were previously developed at JPL require cryogenic temperatures to achieve the high Q levels needed to achieve this stability level. However sapphire fs acoustic modes, which have not been used before in a high-stability oscillator, indicate the required Q values (as high as Q = 10(exp 8)) may be achieved at room temperature in the kHz range. Even though sapphire is not piezoelectric, such a high Q should allow electrostatic excitation of the acoustic modes with a combination of DC and AC voltages across a small sapphire disk (approximately equal to l mm thick). The first evaluations under this task will test predictions of an estimated input impedance of 10 kilohms at Q = 10(exp 8), and explore the Q values that can be realized in a smaller resonator, which has not been previously tested for acoustic modes. This initial Q measurement and excitation demonstration can be viewed similar to a transducer converting electrical energy to

  4. Q-instantons

    NASA Astrophysics Data System (ADS)

    Bergshoeff, E. A.; Hartong, J.; Ploegh, A.; Sorokin, D.

    2008-06-01

    We construct the half-supersymmetric instanton solutions that are electric-magnetically dual to the recently discussed half-supersymmetric Q7-branes. We call these instantons ``Q-instantons''. Whereas the D-instanton is most conveniently described using the RR axion χ and the dilaton phi, the Q-instanton is most conveniently described using a different set of fields (χ',T), where χ' is an axionic scalar. The real part of the Q-instanton on-shell action is a function of T and the imaginary part is linear in χ'. Discrete shifts of the axion χ' correspond to PSL(2, Bbb Z) transformations that are of finite order. These are e.g. pure S-duality transformations relating weak and strongly coupled regimes. We argue that near each orbifold point of the quantum axion-dilaton moduli space {τ mid τ in PSL(2, Bbb R)/(SO(2) × PSL(2, Bbb Z))} the higher order Script R4 terms in the string effective action contain contributions from an infinite sum of single multiply-charged instantons with the Q-instantons corresponding to the orbifold points τ = i, ρ.

  5. Tandem duplication of chromosome 14 (q12q13).

    PubMed

    Verma, R S; Kleyman, S M; Conte, R A; Laqui-Pili, C; Bennett, H

    1997-01-01

    A nine-years-old Egyptian boy was referred for speech and language delay. He has an I.Q. of 35 which is in the moderately to severely delayed range. Routine cytogenetic and FISH-techniques revealed a de novo tandem duplication of chromosome 14 bands q12 and q13, i.e., 46, XY, dup (14)(q12q13) and there are no investigations reporting a direct de novo duplication for this region. PMID:9526614

  6. Simulation and fabrication of thin film bulk acoustic wave resonator

    NASA Astrophysics Data System (ADS)

    Xixi, Han; Yi, Ou; Zhigang, Li; Wen, Ou; Dapeng, Chen; Tianchun, Ye

    2016-07-01

    In this paper, we present the simulation and fabrication of a thin film bulk acoustic resonator (FBAR). In order to improve the accuracy of simulation, an improved Mason model was introduced to design the resonator by taking the coupling effect between electrode and substrate into consideration. The resonators were fabricated by the eight inch CMOS process, and the measurements show that the improved Mason model is more accurate than a simple Mason model. The Q s (Q at series resonance), Q p (Q at parallel resonance), Q max and k t 2 of the FBAR were measured to be 695, 814, 1049, and 7.01% respectively, showing better performance than previous reports. Project supported by the National Natural Science Foundation of China (Nos. 61274119, 61306141, 61335008) and the Natural Science Foundation of Jiangsu Province (No. BK20131099).

  7. Coenzyme Q and Mitochondrial Disease

    ERIC Educational Resources Information Center

    Quinzii, Catarina M.; Hirano, Michio

    2010-01-01

    Coenzyme Q[subscript 10] (CoQ[subscript 10]) is an essential electron carrier in the mitochondrial respiratory chain and an important antioxidant. Deficiency of CoQ[subscript 10] is a clinically and molecularly heterogeneous syndrome, which, to date, has been found to be autosomal recessive in inheritance and generally responsive to CoQ[subscript…

  8. Pushing the Limits: RF Field Control at High Loaded Q

    SciTech Connect

    M. Liepe; S.A. Belomestnykh; J. Dobbins; R.P.K. Kaplan; C.R. Strohman; B.K. Stuhl; C. Hovater; T. Plawski

    2005-05-16

    The superconducting cavities in an Energy-Recovery-Linac will be operated with a high loaded Q of several 10{sup 7}, possible up to 10{sup 8}. Not only has no prior control system ever stabilized the RF field in a linac cavity with such high loaded Q, but also highest field stability in amplitude and phase is required at this high loaded Q. Because of a resulting bandwidth of the cavity of only a few Hz, this presents a significant challenge: the field in the cavity extremely sensitive to any perturbation of the cavity resonance frequency due to microphonics and Lorentz force detuning. To prove that the RF field in a high loaded Q cavity can be stabilized, and that Cornell's newly developed digital control system is able to achieve this, the system was connected to a high loaded Q cavity at the JLab IR-FEL. Excellent cw field stability--about 10{sup -4} rms in relative amplitude and 0.02 deg rms in phase--was achieved at a loaded Q of 2.1 x 10{sup 7} and 1.2 x 10{sup 8}, setting a new record in high loaded Q operation of a linac cavity. Piezo tuner based cavity frequency control proved to be very effective in keeping the cavity on resonance and allowed reliable to ramp up to high gradients in less than 1 second.

  9. The q-harmonic oscillators, q-coherent states and the q-symplecton

    NASA Technical Reports Server (NTRS)

    Biedenharn, L. C.; Lohe, M. A.; Nomura, Masao

    1993-01-01

    The recently introduced notion of a quantum group is discussed conceptually and then related to deformed harmonic oscillators ('q-harmonic oscillators'). Two developments in applying q-harmonic oscillators are reviewed: q-coherent states and the q-symplecton.

  10. Big Brother I. Q.

    ERIC Educational Resources Information Center

    Gilliatt, Michael T.

    1977-01-01

    Lists four harmful consequences that critics suggest educational testing may have, and in discussing the danger that I.Q. testing may place an indelible stamp of inferiority upon students, this research re-examines the purpose of testing. (Author/RK)

  11. Exact Tuning of High-Q Optical Microresonators by Use of UV

    NASA Technical Reports Server (NTRS)

    Savchankov, Anaotliy; Maleki, Lute; Iltchenko, Vladimir; Handley, Timothy

    2006-01-01

    In one of several alternative approaches to the design and fabrication of a "whispering-gallery" optical microresonator of high resonance quality (high Q), the index of refraction of the resonator material and, hence, the resonance frequencies. In this approach, a microresonator structure is prepared by forming it from an ultraviolet-sensitive material. Then the structure is subjected to controlled exposure to UV light while its resonance frequencies are monitored.

  12. q-bosons and the q-analogue quantized field

    NASA Technical Reports Server (NTRS)

    Nelson, Charles A.

    1995-01-01

    The q-analogue coherent states are used to identify physical signatures for the presence of a 1-analogue quantized radiation field in the q-CS classical limits where the absolute value of z is large. In this quantum-optics-like limit, the fractional uncertainties of most physical quantities (momentum, position, amplitude, phase) which characterize the quantum field are O(1). They only vanish as O(1/absolute value of z) when q = 1. However, for the number operator, N, and the N-Hamiltonian for a free q-boson gas, H(sub N) = h(omega)(N + 1/2), the fractional uncertainties do still approach zero. A signature for q-boson counting statistics is that (Delta N)(exp 2)/ (N) approaches 0 as the absolute value of z approaches infinity. Except for its O(1) fractional uncertainty, the q-generalization of the Hermitian phase operator of Pegg and Barnett, phi(sub q), still exhibits normal classical behavior. The standard number-phase uncertainty-relation, Delta(N) Delta phi(sub q) = 1/2, and the approximate commutation relation, (N, phi(sub q)) = i, still hold for the single-mode q-analogue quantized field. So, N and phi(sub q) are almost canonically conjugate operators in the q-CS classical limit. The q-analogue CS's minimize this uncertainty relation for moderate (absolute value of z)(exp 2).

  13. Jupiter's Tidal Q: The Range of Uncertainty

    NASA Astrophysics Data System (ADS)

    Greenberg, Richard; Barnes, R.; Jackson, B.

    2008-09-01

    Jupiter's Q, which quantifies the net effect of poorly understood dissipative processes, is central to the physical and orbital history of the Galilean satellites and to studies of extra-solar planets. A standard procedure for determining orbits from observations of extra-solar planets is to estimate e-damping times, using for Q a "commonly accepted value” 105-106, based on supposed constraints on Jupiter's Q: If the damping time is short, orbits are assumed circular; if the data nevertheless require a finite e, it is attributed to perturbations by unseen planets. But those now-standard procedures are flawed because, in fact, there are no firm constraints on Jupiter's Q. Given the dynamics of the system and its Laplace resonance, knowledge of the tidal dissipation rate in Io (from heat flux) and of Io's orbital acceleration dn1/dt (from mutual occultations and eclipses) should determine the effective value of QJ. If the Laplace resonance were in an equilibrium steady-state, then either one of those measured values yield QJ. Aksnes and Franklin's ("A&F's” 2001) solution for dn1/dt of 3.6x10-10/yr and McEwen et al.'s (1992) Io heat flux 1.3x1014W, gives QJ=2x105, the solution A&F highlighted. However, slight changes from those measured values, well within the uncertainty range, would yield infinite QJ. Another fit to the mutual event data allowed dn1/dt=0, but A&F rejected this result because the implied QJ ( 3x104) was outside the conventionally accepted range. In fact, that range is based on the steady-state condition of the resonance (placing an upper limit on QJ) and on the assumption that dn1/dt<0; (which gives a lower limit), both of which are ruled out by A&F's results. Our study of tidal evolution of "hot Jupiters” (Jackson et al. 2008) suggests typical Q values of 106.5, somewhat above the widely assumed range, but below the real upper limit (infinity) for Jupiter.

  14. Back to 1974: The Q-onium

    NASA Astrophysics Data System (ADS)

    Kamenik, Jernej F.; Redi, Michele

    2016-09-01

    We show that the 750 GeV di-photon excess could be explained by the Q-onium system of a new QCD-like theory with fermions vectorial under the SM. Beside the spin-0 di-photon singlet this scenario predicts almost degenerate colored scalars and spin-1 resonances analogous to the J / Ψ in QCD. All these states are within the reach of the LHC. An apparent large width can be explained as due to production of excited states with splitting Δm ∼ Γ.

  15. Disappearing Q operator

    NASA Astrophysics Data System (ADS)

    Jones, H. F.; Rivers, R. J.

    2007-01-01

    In the Schrödinger formulation of non-Hermitian quantum theories a positive-definite metric operator η≡e-Q must be introduced in order to ensure their probabilistic interpretation. This operator also gives an equivalent Hermitian theory, by means of a similarity transformation. If, however, quantum mechanics is formulated in terms of functional integrals, we show that the Q operator makes only a subliminal appearance and is not needed for the calculation of expectation values. Instead, the relation to the Hermitian theory is encoded via the external source j(t). These points are illustrated and amplified for two non-Hermitian quantum theories: the Swanson model, a non-Hermitian transform of the simple harmonic oscillator, and the wrong-sign quartic oscillator, which has been shown to be equivalent to a conventional asymmetric quartic oscillator.

  16. Disappearing Q operator

    SciTech Connect

    Jones, H. F.; Rivers, R. J.

    2007-01-15

    In the Schroedinger formulation of non-Hermitian quantum theories a positive-definite metric operator {eta}{identical_to}e{sup -Q} must be introduced in order to ensure their probabilistic interpretation. This operator also gives an equivalent Hermitian theory, by means of a similarity transformation. If, however, quantum mechanics is formulated in terms of functional integrals, we show that the Q operator makes only a subliminal appearance and is not needed for the calculation of expectation values. Instead, the relation to the Hermitian theory is encoded via the external source j(t). These points are illustrated and amplified for two non-Hermitian quantum theories: the Swanson model, a non-Hermitian transform of the simple harmonic oscillator, and the wrong-sign quartic oscillator, which has been shown to be equivalent to a conventional asymmetric quartic oscillator.

  17. Nonclassical properties of the q -coherent and q -cat states of the Biedenharn-Macfarlane q oscillator with q >1

    NASA Astrophysics Data System (ADS)

    Fakhri, H.; Hashemi, A.

    2016-01-01

    This paper has been motivated by a recent paper by Dey [Phys. Rev. D 91, 044024 (2015), 10.1103/PhysRevD.91.044024] on the known Arik-Coon q oscillator. We construct q coherent, even and odd q -cat states in Fock representation for the Biedenharn-Macfarlane q oscillator with q >1 and study their nonclassical properties. The q -coherent states minimize the Heisenberg uncertainty relation between the generalized position and momentum operators as well as the x and y components of a q -deformed su(1 ,1 ) algebra in the Schwinger boson representation. The latter is also minimized by the even and odd q -cat states. We show that, contrary to the undeformed harmonic oscillator, the squeezing effect in both position and momentum operators can be exhibited by odd q -cat states. It is also violated by even q -cat states. Furthermore, it is shown that the antibunching effect and sub-Poissonian or super-Poissonian statistics can simultaneously appear by each of the even or odd q -cat states. Finally, a unitary Fock representation of the q -deformed su(1 ,1 ) algebra is obtained by the q -deformed Bargmann-Fock realization.

  18. Progress toward high-Q perfect absorption: A Fano antilaser

    NASA Astrophysics Data System (ADS)

    Yu, Sunkyu; Piao, Xianji; Hong, Jiho; Park, Namkyoo

    2015-07-01

    Here we propose a route to the high-Q perfect absorption of light by introducing the concept of a Fano antilaser. Based on the drastic spectral variation of the optical phase in a Fano-resonant system, a spectral singularity for scatter-free perfect absorption can be achieved with an order of magnitude smaller material loss. By applying temporal coupled mode theory to a Fano-resonant waveguide platform, we reveal that the required material loss and following absorption Q factor are ultimately determined by the degree of Fano spectral asymmetry. The feasibility of the Fano antilaser is confirmed using a photonic crystal platform, to demonstrate spatiospectrally selective heating. Our results utilizing the phase-dependent control of device bandwidths derive a counterintuitive realization of high-Q perfect conversion of light into internal energy, and thus pave the way for a new regime of absorption-based devices, including switches, sensors, thermal imaging, and optothermal emitters.

  19. Ultrasonic attenuation - Q measurements on 70215,29. [lunar rock

    NASA Technical Reports Server (NTRS)

    Warren, N.; Trice, R.; Stephens, J.

    1974-01-01

    Ultrasonic attenuation measurements have been made on an aluminum alloy, obsidian, and rock samples including lunar sample 70215,29. The measurement technique is based on a combination of the pulse transmission method and the forced resonance method. The technique is designed to explore the problem of defining experimentally, the Q of a medium or sample in which mode conversion may occur. If modes are coupled, the measured attenuation is strongly dependent on individual modes of vibration, and a range of Q-factors may be measured over various resonances or from various portions of a transient signal. On 70215,29, measurements were made over a period of a month while the sample outgassed in hard varuum. During this period, the highest measured Q of this sample increased from a few hundred into the range of 1000-1300.

  20. Q Fever Update, Maritime Canada

    PubMed Central

    Marrie, Thomas J.; Campbell, Nancy; McNeil, Shelly A.; Webster, Duncan

    2008-01-01

    Since the 1990s, reports of Q fever in Nova Scotia, Canada, have declined. Passive surveillance for Q fever in Nova Scotia and its neighboring provinces in eastern Canada indicates that the clinical manifestation of Q fever in the Maritime provinces is pneumonia and that incidence of the disease may fluctuate. PMID:18258080

  1. What happens to Q balls if Q is so large?

    NASA Astrophysics Data System (ADS)

    Sakai, Nobuyuki; Tamaki, Takashi

    2012-05-01

    In the system of a gravitating Q ball, there is a maximum charge Qmax⁡ inevitably, while in flat spacetime there is no upper bound on Q in typical models such as the Affleck-Dine model. Theoretically, the charge Q is a free parameter, and phenomenologically it could increase by charge accumulation. We address a question of what happens to Q balls if Q is close to Qmax⁡. First, without specifying a model, we show analytically that inflation cannot take place in the core of a Q ball, contrary to the claim of previous work. Next, for the Affleck-Dine model, we analyze perturbation of equilibrium solutions with Q≈Qmax⁡ by numerical analysis of dynamical field equations. We find that the extremal solution with Q=Qmax⁡ and unstable solutions around it are “critical solutions,” which means the threshold of black-hole formation.

  2. Cautionary tale of mismeasured tails from q /g bias

    NASA Astrophysics Data System (ADS)

    Martin, Adam; Roy, Tuhin S.

    2016-07-01

    Jet substructure techniques such as subjet pT-asymmetry, mass-drop, and grooming have become powerful and widely used tools in experimental searches at the LHC. While these tools provide much-desired handles to separate signal from background, they can introduce unexpected mass scales into the analysis. These scales may be misinterpreted as excesses if these are not correctly incorporated into background modeling. As an example, we study the ATLAS hadronic di-W /Z resonance search. There, we find that the substructure analysis—in particular the combination of a subjet asymmetry cut with the requirement on the number of tracks within a jet—induces a mass scale where the dominant partonic subprocess in the background changes from p p →g +q /q ¯ to p p →q q ¯. In light of this scale, modeling the QCD background using a simple smooth function with monotonically decreasing slope appears insufficient.

  3. Measurement of the Proton Spin Function g1(x,Q2) for Q2 from 0.15 to 1.6 GeV with CLAS

    SciTech Connect

    Renee Fatemi; Alexander Skabelin; Volker Burkert; Donald Crabb; Raffaella De Vita; Sebastian Kuhn; Ralph Minehart

    2003-11-01

    Double-polarization asymmetries for inclusive ep scattering were measured at Jefferson Lab using 2.6 and 4.3 GeV longitudinally polarized electrons incident on a longitudinally polarized NH{sub 3} target in the CLAS detector. The polarized structure function g{sub 1}(x,Q{sup 2}) was extracted throughout the nucleon resonance region and into the deep inelastic regime, for Q{sup 2} = 0.15-1.64 GeV{sup 2}. The contributions to the first moment {Gamma}{sub 1}(Q{sup 2}) = g{sub 1}(x,Q{sup 2})dx were determined up to Q{sup 2}=1.2 GeV{sup 2}. Using a parameterization for g{sub 1} in the unmeasured low x regions, the complete first moment was estimated over this Q{sup 2} region. A rapid change in {Gamma}{sub 1} is observed for Q{sup 2} < 1 GeV{sup 2}, with a sign change near Q{sup 2} = 0.3 GeV{sup 2}, indicating dominant contributions from the resonance region. At Q{sup 2}=1.2 GeV{sup 2} our data are below the pQCD evolved scaling value.

  4. Tailored Asymmetry for Enhanced Coupling to WGM Resonators

    NASA Technical Reports Server (NTRS)

    Mohageg, Makan; Maleki, Lute

    2008-01-01

    Coupling of light into and out of whispering- gallery-mode (WGM) optical resonators can be enhanced by designing and fabricating the resonators to have certain non-axisymmetric shapes (see figure). Such WGM resonators also exhibit the same ultrahigh values of the resonance quality factor (Q) as do prior WGM resonators. These WGM resonators are potentially useful as tunable narrow-band optical filters having throughput levels near unity, high-speed optical switches, and low-threshold laser resonators. These WGM resonators could also be used in experiments to investigate coupling between high-Q and chaotic modes within the resonators. For a WGM resonator made of an optically nonlinear material (e.g., lithium niobate) or another material having a high index of refraction, a prism made of a material having a higher index of refraction (e.g., diamond) must be used as part of the coupling optics. For coupling of a beam of light into (or out of) the high-Q resonator modes, the beam must be made to approach (or recede from) the resonator at a critical angle determined by the indices of refraction of the resonator and prism materials. In the case of a lithium niobate/diamond interface, this angle is approximately 22 .

  5. Whispering Gallery Mode Optomechanical Resonator

    NASA Technical Reports Server (NTRS)

    Aveline, David C.; Strekalov, Dmitry V.; Yu, Nan; Yee, Karl Y.

    2012-01-01

    Great progress has been made in both micromechanical resonators and micro-optical resonators over the past decade, and a new field has recently emerged combining these mechanical and optical systems. In such optomechanical systems, the two resonators are strongly coupled with one influencing the other, and their interaction can yield detectable optical signals that are highly sensitive to the mechanical motion. A particularly high-Q optical system is the whispering gallery mode (WGM) resonator, which has many applications ranging from stable oscillators to inertial sensor devices. There is, however, limited coupling between the optical mode and the resonator s external environment. In order to overcome this limitation, a novel type of optomechanical sensor has been developed, offering great potential for measurements of displacement, acceleration, and mass sensitivity. The proposed hybrid device combines the advantages of all-solid optical WGM resonators with high-quality micro-machined cantilevers. For direct access to the WGM inside the resonator, the idea is to radially cut precise gaps into the perimeter, fabricating a mechanical resonator within the WGM. Also, a strategy to reduce losses has been developed with optimized design of the cantilever geometry and positions of gap surfaces.

  6. High-Q filters with complete transports using quasiperiodic rings with spin-orbit interaction

    SciTech Connect

    Qiu, R. Z.; Chen, C. H.; Tsao, C. W.; Hsueh, W. J.

    2014-09-15

    A high Q filter with complete transports is achieved using a quasiperiodic Thue-Morse array of mesoscopic rings with spin-orbit interaction. As the generation order of the Thue-Morse array increases, not only does the Q factor of the resonance peak increase exponentially, but the number of sharp resonance peaks also increases. The maximum Q factor for the electronic filter of a Thue-Morse array is much greater than that in a periodic array, for the same number of the rings.

  7. Optical Microspherical Resonators for Biomedical Sensing

    PubMed Central

    Soria, Silvia; Berneschi, Simone; Brenci, Massimo; Cosi, Franco; Conti, Gualtiero Nunzi; Pelli, Stefano; Righini, Giancarlo C.

    2011-01-01

    Optical resonators play an ubiquitous role in modern optics. A particular class of optical resonators is constituted by spherical dielectric structures, where optical rays are total internal reflected. Due to minimal reflection losses and to potentially very low material absorption, these guided modes, known as whispering gallery modes, can confer the resonator an exceptionally high quality factor Q, leading to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. These attractive characteristics make these miniaturized optical resonators especially suited as laser cavities and resonant filters, but also as very sensitive sensors. First, a brief analysis is presented of the characteristics of microspherical resonators, of their fabrication methods, and of the light coupling techniques. Then, we attempt to overview some of the recent advances in the development of microspherical biosensors, underlining a number of important applications in the biomedical field. PMID:22346603

  8. Nonlinear optics and crystalline whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey B.; Savchenkov, Anatoliy A.; Ilchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We report on our recent results concerning fabrication of high-Q whispering gallery mode (WGM) crystalline resonators, and discuss some possible applications of lithium niobate WGM resonators in nonlinear optics and photonics. In particular, we demonstrate experimentally a tunable third-order optical filter fabricated from the three metalized resonators; and report observation of parametric frequency dobuling in a WGM resonator made of periodically poled lithium niobate (PPLN).

  9. Gauged Q-balls

    NASA Technical Reports Server (NTRS)

    Lee, Kimyeong; Stein-Schabes, Jaime A.; Watkins, Richard; Widrow, Lawrence M.

    1988-01-01

    Classical non-topological soliton configurations are considered within the theory of a complex scalar field with a gauged U symmetry. Their existence and stability against dispersion are demonstrated and some of their properties are investigated analytically and numerically. The soliton configuration is such that inside the soliton the local U symmetry is broken, the gauge field becomes massive and for a range of values of the coupling constants the soliton becomes a superconductor pushing the charge to the surface. Furthermore, because of the repulsive Coulomb force, there is a maximum size for these objects, making impossible the existence of Q-matter in bulk form. Also briefly discussed are solitons with fermions in a U gauge theory.

  10. Optical resonator

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

  11. Q fever — a review

    PubMed Central

    Marrie, Thomas J.

    1990-01-01

    Q or “query” fever is a zoonosis caused by the organism Coxiella burnetii. Cattle, sheep and goats are the most common reservoirs of this organism. The placenta of infected animals contains high numbers (up to 109/g) of C. burnetii. Aerosols occur at the time of parturition and man becomes infected following inhalation of the microorganism. The spectrum of illness in man is wide and consists of acute and chronic forms. Acute Q fever is most often a self-limited flu-like illness but may include pneumonia, hepatitis, or meningoencephalitis. Chronic Q fever almost always means endocarditis and rarely osteomyelitis. Chronic Q fever is not known to occur in animals other than man. An increased abortion and stillbirth rate are seen in infected domestic ungulates. Four provinces (Nova Scotia, New Brunswick, Ontario and Alberta) reported cases of Q fever in 1989. A vaccine for Q fever has recently been licensed in Australia. ImagesFigure 1. PMID:17423643

  12. Resonance scraping

    SciTech Connect

    Collins, T.

    1986-06-01

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

  13. YBCO superconducting ring resonators at millimeter-wave frequencies

    NASA Technical Reports Server (NTRS)

    Chorey, Christopher M.; Kong, Keon-Shik; Bhasin, Kul B.; Warner, J. D.; Itoh, Tatsuo

    1991-01-01

    Microstrip ring resonators operating at 35 GHz were fabricated from laser ablated YBCO films deposited on lanthanum aluminate substrates. They were measured over a range of temperatures and their performances compared to identical resonators made of evaporated gold. Below 60 Kelvin the superconducting strip performed better than the gold, reaching an unloaded Q approximately 1.5 times that of gold at 25 K. A shift in the resonant frequency follows the form predicted by the London equations. The Phenomenological Loss Equivalence Method is applied to the ring resonator and the theoretically calculated Q values are compared to the experimental results.

  14. Tunable filters using wideband elastic resonators.

    PubMed

    Kadota, Michio; Ogami, Takashi; Kimura, Tetsuya; Daimon, Katsuya

    2013-10-01

    Currently, an ultra-wideband resonator is greatly needed to realize a tunable filter with a wide tunable range, because mobile phones with multiple bands and cognitive radio systems require such tunable filters to simplify their circuits. Although tunable filters have been studied using SAW resonators, their tunable range was insufficient for the filters even when wideband SAW resonators with a bandwidth of 17% were used. Therefore, the fabrication of wider-bandwidth resonators has been attempted with the goal of realizing tunable filters with wide tunable ranges. In this study, an SH0- mode plate wave resonator in a 27.5°YX-LiNbO3 plate with an ultra-wide bandwidth of 29.1%, a high impedance ratio of 98 dB, and a high Q (Q(r) = 700 and Q(a) = 720) was realized. Two types of tunable filters were constructed using such SH0-mode resonators and capacitors. As a result, tunable ranges (bands) of 13% to 19% were obtained. The possibility of applying the SH0-mode resonator in the high-frequency gigahertz range is discussed. PMID:24081261

  15. Nonlinear optics and crystalline whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey; Savchenkov, Anatoliy; Ilchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We report on our recent results concerning fabrication of high-Q whispering gallery mode crystalline resonaors, and discuss some possible applications of lithium niobate WGM resonators in nonlinear optics and photonics.

  16. An Open Resonator for Physical Studies

    NASA Astrophysics Data System (ADS)

    Kuzmichev, I. K.; Melezhik, P. N.; Poyedinchuk, A. Ye.

    2006-06-01

    The excitation efficency of the TEM01 q oscillation of an two-mirror hemispherical open resonator (OR) is studied. The resonator is excited by the TE01 wave of a circular waveguide joined in the middle of the OR plane mirror. Given the waveguide optimum size, the TEM01 q mode excitation efficiency reaches 78%. Analysis of the resonant system spectrum in the 4-mm wave region shows that this waveguide-OR system offers a single mode resonance curve across almost a 10-GHz tuning range. The TEM0110 mode field distribution with and without the circular waveguide in the middle of the OR plane mirror is available due to the small scatterer method. It is shown that the considered open system is suitable for measuring electromagnetic characteristics of high-loss substances and metamaterials in the short-wave end of the millimeter (mm) region as well as in the submillimeter (submm) wave region.

  17. Superconducting Resonators with Parasitic Electromagnetic Environments

    NASA Astrophysics Data System (ADS)

    Hornibrook, John; Mitchell, Emma; Reilly, David

    2012-02-01

    Microwave losses in niobium superconducting resonators are investigated at milli-Kelvin temperatures and with low drive power. In addition to the well-known suppression of Q-factor that arises from coupling between the resonator and two-level defects in the dielectric substrate [1-4], we report strong dependence of the loaded Q-factor and resonance line-shape on the electromagnetic environment. Methods to suppress parasitic coupling between the resonator and its environment are demonstrated.[4pt] [1] Day, P.K. et al., Nature 425, 817-821 (2003).[0pt] [2] Wallraff, A. et. al., Nature 451, 162-167 (2004).[0pt] [3] Macha, P. et. al., Appl. Phys. Lett., 96, 062503 (2010).[0pt] [4] O'Connell, A.D. et. al., Appl. Phys. Lett., 92, 112903 (2008).

  18. THE Q-BIOTYPE WHITEFLY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2004, the Q-biotype of the sweetpotato whitefly, Bemisia tabaci, was identified in the U.S. for the first time. The level of insecticide resistance to pyriproxyfen (Distance) and imidacloprid (Marathon) of the Q-biotype was higher than any U.S. population of B-biotype whiteflies (silverleaf white...

  19. Linear and nonlinear behavior of crystalline optical whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy A.; Matsko, Andrey B.; Ilchenko, Vladimir S.; Maleki, Lute

    2004-01-01

    We demonstrate strong nonlinear behavior of high-Q whispering gallery mode (WGM) resonators made out of various crystals adn devices based on the resonators. The maximum WGM optical Q-fact or achieved at room temperature exceeds 2X10 to the tenth power.

  20. New insights into the chemistry of Coenzyme Q-0: A voltammetric and spectroscopic study.

    PubMed

    Gulaboski, Rubin; Bogeski, Ivan; Kokoskarova, Pavlinka; Haeri, Haleh H; Mitrev, Sasa; Stefova, Marina; Stanoeva, Jasmina Petreska; Markovski, Velo; Mirčeski, Valentin; Hoth, Markus; Kappl, Reinhard

    2016-10-01

    Coenzyme Q-0 (CoQ-0) is the only Coenzyme Q lacking an isoprenoid group on the quinoid ring, a feature important for its physico-chemical properties. Here, the redox behavior of CoQ-0 in buffered and non-buffered aqueous media was examined. In buffered aqueous media CoQ-0 redox chemistry can be described by a 2-electron-2-proton redox scheme, characteristic for all benzoquinones. In non-buffered media the number of electrons involved in the electrode reaction of CoQ-0 is still 2; however, the number of protons involved varies between 0 and 2. This results in two additional voltammetric signals, attributed to 2-electrons-1H(+) and 2-electrons-0H(+) redox processes, in which mono- and di-anionic compounds of CoQ-0 are formed. In addition, CoQ-0 exhibits a complex chemistry in strong alkaline environment. The reaction of CoQ-0 and OH(-) anions generates several hydroxyl derivatives as products. Their structures were identified with HPLC/MS. The prevailing radical reaction mechanism was analyzed by electron paramagnetic resonance spectroscopy. The hydroxyl derivatives of CoQ-0 have a strong antioxidative potential and form stable complexes with Ca(2+) ions. In summary, our results allow mechanistic insights into the redox properties of CoQ-0 and its hydroxylated derivatives and provide hints on possible applications. PMID:27268099

  1. Low-loss coupling to dielectric resonators

    NASA Technical Reports Server (NTRS)

    Hearn, C. P.; Bradshaw, E. S.; Trew, R. J.; Hefner, B. B., Jr.

    1991-01-01

    A compilation is presented of experimental observations and arguments concerning the use of dielectric resonators in applications requiring both tight coupling (beta greater than 10) and high unloaded Q, such as low loss bandpass filters. The microstrip coupled dielectric resonator is the primary focus, but an alternative coupling technique is discussed and comparatively evaluated. It is concluded that coupling factors as large as 65 are achievable.

  2. Electroelastic effect of thickness mode langasite resonators.

    PubMed

    Zhang, Haifeng; Turner, Joseph A; Yang, Jiashi; Kosinski, John A

    2007-10-01

    Langasite is a very promising material for resonators due to its good temperature behavior and high piezoelectric coupling, low acoustic loss, and high Q factor. The biasing effect for langasite resonators is crucial for resonator design. In this article, the resonant frequency shift of a thickness-mode langasite resonator is analyzed with respect to a direct current (DC) electric field applied in the thickness direction. The vibration modes of a thin langasite plate fully coated with an electrode are analyzed. The analysis is based on the theory for small fields superposed on a bias in electroelastic bodies and the first-order perturbation integral theory. The electroelastic effect of the resonator is analyzed by both analytical and finite-element methods. The complete set of nonlinear elastic, piezoelectric, dielectric permeability, and electrostrictive constants of langasite is used in the theoretical and numerical analysis. The sensitivity of electroelastic effect to nonlinear material constants is analyzed. PMID:18019250

  3. Q-switched Nd:YAG optical vortex lasers.

    PubMed

    Kim, D J; Kim, J W; Clarkson, W A

    2013-12-01

    Q-switched operation of a high-quality Nd:YAG optical vortex laser with the first order Laguerre-Gaussian mode and well-determined helical wavefronts using a fiber-based pump beam conditioning scheme is reported. A simple two-mirror resonator incorporating an acousto-optic Q-switch was employed, along with an etalon and a Brewster plate to enforce the particular helicity of the output. The laser yielded Q-switched pulses with ~250 μJ pulse energy and ~33 ns pulse duration (FWHM) at a 0.1 kHz repetition rate for 5.1 W of absorbed pump power. The handedness of the helical wavefronts was preserved regardless of the repetition rates. The prospects of further power scaling and improved laser performance are discussed. PMID:24514499

  4. 100-megawatt power Q-switched Er-glass laser

    NASA Astrophysics Data System (ADS)

    Taboada, John; Taboada, John M.; Stolarski, David J.; Zohner, Justin J.; Chavey, Lucas J.; Hodnett, Harvey M.; Noojin, Gary D.; Thomas, Robert J.; Kumru, Semih S.; Cain, Clarence P.

    2006-02-01

    A very high energy Q-switched Er-glass laser is reported. We incorporated a rotating, resonant mirror/Porro-cavity reflector optical arrangement to achieve very high shutter speeds on the cavity Q of a laser designed for energetic, flashlamp-pumped, 600-μs, 1540-nm pulses. Reproducible 3.75-J, 35-ns, 1533-nm laser pulses were obtained at a repetition rate less than 1 minute. Our work shows that reliable, very high energy, Q-switched, Er-glass laser pulses at 1533 nm can be generated mechanically with no apparent damage to laser cavity components. We demonstrate the applications of this "eye safe" wavelength to energetic processes such as LIBS and materials processing. The laser could also serve as a new tool for bioeffects studies and targeting applications.

  5. Unusual variant of holoprosencephaly in monosomy 13q.

    PubMed

    Marcorelles, Pascale; Loget, Philippe; Fallet-Bianco, Catherine; Roume, Joëlle; Encha-Razavi, Ferechte; Delezoide, Anne-Lise

    2002-01-01

    The clinical phenotype related to the terminal deletion of the long arm of the chromosome 13 (the so-called 13q- syndrome) includes a considerable number of malformations, especially of the brain. This report describes five cases of a cerebral midline anomaly that leads to a particular clover-shaped type of holoprosencephaly in 13q- fetuses at different stages of the second and third trimesters of gestation. Our cases are compared to those in literature reviews. This malformation has only been described by computer tomography and magnetic resonance imaging in eight children of various ages and has been called "middle interhemispheric fusion" or syntelencephaly. Recently, the human gene ZIC2, the mutation of which leads to holoprosencephaly, has been mapped to the long arm of chromosome 13. on band q32. These findings suggest that this particular type of holoprosencephaly may be related to ZIC2 gene loss of function. PMID:11910512

  6. R248Q mutation--Beyond p53-DNA binding.

    PubMed

    Ng, Jeremy W K; Lama, Dilraj; Lukman, Suryani; Lane, David P; Verma, Chandra S; Sim, Adelene Y L

    2015-12-01

    R248 in the DNA binding domain (DBD) of p53 interacts directly with the minor groove of DNA. Earlier nuclear magnetic resonance (NMR) studies indicated that the R248Q mutation resulted in conformation changes in parts of DBD far from the mutation site. However, how information propagates from the mutation site to the rest of the DBD is still not well understood. We performed a series of all-atom molecular dynamics (MD) simulations to dissect sterics and charge effects of R248 on p53-DBD conformation: (i) wild-type p53 DBD; (ii) p53 DBD with an electrically neutral arginine side-chain; (iii) p53 DBD with R248A; (iv) p53 DBD with R248W; and (v) p53 DBD with R248Q. Our results agree well with experimental observations of global conformational changes induced by the R248Q mutation. Our simulations suggest that both charge- and sterics are important in the dynamics of the loop (L3) where the mutation resides. We show that helix 2 (H2) dynamics is altered as a result of a change in the hydrogen bonding partner of D281. In turn, neighboring L1 dynamics is altered: in mutants, L1 predominantly adopts the recessed conformation and is unable to interact with the major groove of DNA. We focused our attention the R248Q mutant that is commonly found in a wide range of cancer and observed changes at the zinc-binding pocket that might account for the dominant negative effects of R248Q. Furthermore, in our simulations, the S6/S7 turn was more frequently solvent exposed in R248Q, suggesting that there is a greater tendency of R248Q to partially unfold and possibly lead to an increased aggregation propensity. Finally, based on the observations made in our simulations, we propose strategies for the rescue of R248Q mutants. PMID:26442703

  7. E{sub 1+}/M{sub 1+} and S{sub 1+}/M{sub 1+} from an analysis of p(e,e{prime}p){pi}{sup 0} in the region of the {Delta}(1232) resonance at Q{sup 2} = 3.2 (GeV/c){sup 2}

    SciTech Connect

    V. Burkert; L. Elouadrhiri

    1995-10-01

    In this paper the authors present an analysis of exclusive p(e,e{prime}p){pi}{sup 0} data to determine the electromagnetic and scalar transition multipoles in the mass region of the {Delta}(1232) at the highest Q{sup 2} value where data exist, Q{sup 2} = 3.2(GeV/c){sup 2}.

  8. Resonance IR: a coherent multidimensional analogue of resonance Raman.

    PubMed

    Boyle, Erin S; Neff-Mallon, Nathan A; Handali, Jonathan D; Wright, John C

    2014-05-01

    This work demonstrates the use of triply resonant sum frequency (TRSF) spectroscopy as a "resonance IR" analogue to resonance Raman spectroscopy. TRSF is a four-wave-mixing process where three lasers with independent frequencies interact coherently with a sample to generate an output at their triple summation frequency. The first two lasers are in the infrared and result in two vibrational excitations, while the third laser is visible and induces a two-quantum anti-Stokes resonance Raman transition. The signal intensity grows when the laser frequencies are all in resonance with coupled vibrational and electronic states. The method therefore provides electronic enhancement of IR-active vibrational modes. These modes may be buried beneath solvent in the IR spectrum and also be Raman-inactive and therefore inaccessible by other techniques. The method is presented on the centrosymmetric complex copper phthalocyanine tetrasulfonate. In this study, the two vibrational frequencies were scanned across ring-breathing modes, while the visible frequency was left in resonance with the copper phthalocyanine tetrasulfonate Q band, resulting in a two-dimensional infrared plot that also reveals coupling between vibrational states. TRSF has the potential to be a very useful probe of structurally similar biological motifs such as hemes, as well as synthetic transition-metal complexes. PMID:24707979

  9. Composite Resonator Surface Emitting Lasers

    SciTech Connect

    FISCHER,ARTHUR J.; CHOQUETTE,KENT D.; CHOW,WENG W.; ALLERMAN,ANDREW A.; GEIB,KENT M.

    2000-05-01

    The authors have developed electrically-injected coupled-resonator vertical-cavity lasers and have studied their novel properties. These monolithically grown coupled-cavity structures have been fabricated with either one active and one passive cavity or with two active cavities. All devices use a selectively oxidized current aperture in the lower cavity, while a proton implant was used in the active-active structures to confine current in the top active cavity. They have demonstrated optical modulation from active-passive devices where the modulation arises from dynamic changes in the coupling between the active and passive cavities. The laser intensity can be modulated by either forward or reverse biasing the passive cavity. They have also observed Q-switched pulses from active-passive devices with pulses as short as 150 ps. A rate equation approach is used to model the Q-switched operation yielding good agreement between the experimental and theoretical pulseshape. They have designed and demonstrated the operation of active-active devices which la.se simultaneously at both longitudinal cavity resonances. Extremely large bistable regions have also been observed in the light-current curves for active-active coupled resonator devices. This bistability can be used for high contrast switching with contrast ratios as high as 100:1. Coupled-resonator vertical-cavity lasers have shown enhanced mode selectivity which has allowed devices to lase with fundamental-mode output powers as high as 5.2 mW.

  10. Efficient telecom to visible wavelength conversion in doubly resonant gallium phosphide microdisks

    NASA Astrophysics Data System (ADS)

    Lake, David P.; Mitchell, Matthew; Jayakumar, Harishankar; dos Santos, Laís Fujii; Curic, Davor; Barclay, Paul E.

    2016-01-01

    Resonant second harmonic generation between 1550 nm and 775 nm with normalized outside efficiency > 3.8 × 10 - 4 mW - 1 is demonstrated in a gallium phosphide microdisk supporting high-Q modes at visible ( Q ˜ 10 4 ) and infrared ( Q ˜ 10 5 ) wavelengths. The double resonance condition is satisfied for a specific pump power through intracavity photothermal temperature tuning using ˜ 360 μ W of 1550 nm light input to a fiber taper and coupled to a microdisk resonance. Power dependent efficiency consistent with a simple model for thermal tuning of the double resonance condition is observed.

  11. q-quaternions and q-deformed su(2) instantons

    SciTech Connect

    Fiore, Gaetano

    2007-10-15

    We construct (anti-)instanton solutions of a would-be q-deformed su(2) Yang-Mills theory on the quantum Euclidean space R{sub q}{sup 4} [the SO{sub q}(4)-covariant noncommutative space] by reinterpreting the function algebra on the latter as a q-quaternion bialgebra. Since the (anti-)self-duality equations are covariant under the quantum group of deformed rotations, translations, and scale change, by applying the latter we can generate new solutions from the one centered at the origin and with unit size. We also construct multi-instanton solutions. As they depend on noncommuting parameters playing the roles of 'sizes' and 'coordinates of the centers' of the instantons, this indicates that the moduli space of a complete theory should be a noncommutative manifold. Similarly, gauge transformations should be allowed to depend on additional noncommutative parameters.

  12. Deletion (11)(q14.1q21)

    SciTech Connect

    Stratton, R.F.; Lazarus, K.H.; Ritchie, E.J.L.; Bell, A.M.

    1994-02-01

    The authors report on a 4-year-old girl with moderate development delay, horseshoe kidney, bilateral duplication of the ureters with right upper pole obstruction, hydronephrosis and nonfunction, and subsequent Wilms tumor of the right lower pole. She had an interstitial deletion of the long arm of chromosome 11 involving the region 11(q14.1q21). 22 refs., 2 figs., 1 tab.

  13. Q-switched Ho:Lu2O3 laser at 2.12 μm.

    PubMed

    Lamrini, Samir; Koopmann, Philipp; Scholle, Karsten; Fuhrberg, Peter

    2013-06-01

    We report on a Q-switched Ho:Lu2O3 laser resonantly pumped by a GaSb-based laser diode stack at 1.9 μm. The maximum output energy extracted from the compact plano-plano acousto-optically Q-switched resonator was 8 mJ at a 100 Hz pulse repetition rate, while the peak power was 40 kW. The laser wavelength was 2.124 μm. PMID:23722799

  14. Complex multireference configuration interaction calculations for the K-vacancy Auger states of N(q+) (q = 2-5) ions.

    PubMed

    Peng, Yi-Geng; Wu, Yong; Zhu, Lin-Fan; Zhang, Song Bin; Wang, Jian-Guo; Liebermann, H-P; Buenker, R J

    2016-02-01

    K-vacancy Auger states of N(q+) (q = 2-5) ions are studied by using the complex multireference single- and double-excitation configuration interaction (CMRD-CI) method. The calculated resonance parameters are in good agreement with the available experimental and theoretical data. It shows that the resonance positions and widths converge quickly with the increase of the atomic basis sets in the CMRD-CI calculations; the standard atomic basis set can be employed to describe the atomic K-vacancy Auger states well. The strong correlations between the valence and core electrons play important roles in accurately determining those resonance parameters, Rydberg electrons contribute negligibly in the calculations. Note that it is the first time that the complex scaling method has been successfully applied for the B-like nitrogen. CMRD-CI is readily extended to treat the resonance states of molecules in the near future. PMID:26851920

  15. Sigma model Q-balls and Q-stars

    SciTech Connect

    Verbin, Y.

    2007-10-15

    A new kind of Q-balls is found: Q-balls in a nonlinear sigma model. Their main properties are presented together with those of their self-gravitating generalization, sigma model Q-stars. A simple special limit of solutions which are bound by gravity alone ('sigma stars') is also discussed briefly. The analysis is based on calculating the mass, global U(1) charge and binding energy for families of solutions parametrized by the central value of the scalar field. Two kinds (differing by the potential term) of the new sigma model Q-balls and Q-stars are analyzed. They are found to share some characteristics while differing in other respects like their properties for weak central scalar fields which depend strongly on the form of the potential term. They are also compared with their ordinary counterparts and although similar in some respects, significant differences are found like the existence of an upper bound on the central scalar field. A special subset of the sigma model Q-stars contains those which do not possess a flat space limit. Their relation with sigma star solutions is discussed.

  16. Q Fever in French Guiana

    PubMed Central

    Eldin, Carole; Mahamat, Aba; Demar, Magalie; Abboud, Philippe; Djossou, Félix; Raoult, Didier

    2014-01-01

    Coxiella burnetii, the causative agent of Q fever, is present worldwide. Recent studies have shown that this bacterium is an emerging pathogen in French Guiana and has a high prevalence (24% of community-acquired pneumonia). In this review, we focus on the peculiar epidemiology of Q fever in French Guiana. We place it in the context of the epidemiology of the disease in the surrounding countries of South America. We also review the clinical features of Q fever in this region, which has severe initial presentation but low mortality rates. These characteristics seem to be linked to a unique genotype (genotype 17). Finally, we discuss the issue of the animal reservoir of C. burnetii in French Guiana, which is still unknown. Further studies are necessary to identify this reservoir. Identification of this reservoir will improve the understanding of the Q fever epidemic in French Guiana and will provide new tools to control this public health problem. PMID:25092817

  17. Q (Alpha) Function and Squeezing Effect

    NASA Technical Reports Server (NTRS)

    Yunjie, Xia; Xianghe, Kong; Kezhu, Yan; Wanping, Chen

    1996-01-01

    The relation of squeezing and Q(alpha) function is discussed in this paper. By means of Q function, the squeezing of field with gaussian Q(alpha) function or negative P(a)function is also discussed in detail.

  18. Decoding Gαq signaling.

    PubMed

    Litosch, Irene

    2016-05-01

    q signals with phospholipase C-β (PLC-β) to modify behavior in response to an agonist-bound GPCR. While the fundamental steps which prime Gαq to interact with PLC-β have been identified, questions remain concerning signal strength with PLC-β and other effectors. Gαq is generally viewed to function as a simple ON and OFF switch for its effector, dependent on the binding of GTP or GDP. However, Gαq does not have a single effector, Gαq has many different effectors. Furthermore, select effectors also regulate Gαq activity. PLC-β is a lipase and a GTPase activating protein (GAP) selective for Gαq. The contribution of G protein regulating activity to signal amplitude remains unclear. The unique PLC-β coiled-coil domain is essential for maximum Gαq response, both lipase and GAP. Nonetheless, coiled-coil domain associations necessary to maximum response have not been revealed by the structural approach. This review discusses progress towards understanding the basis for signal strength with PLC-β and other effectors. Shared and effector-specific interactions have been identified. Finally, the evidence for allosteric regulation of lipase stimulation by protein kinase C, the membrane, phosphatidic acid, phosphatidylinositol-4, 5-bisphosphate and GPCR is explored. Endogenous allosteric regulators can suppress or enhance maximum lipase stimulation dependent on the PLC-β coiled-coil domain. A better understanding of allosteric modulation may therefore identify a wealth of new targets to regulate signal strength and behavior. PMID:27012764

  19. Default mode network connectivity and reciprocal social behavior in 22q11.2 deletion syndrome

    PubMed Central

    Schreiner, Matthew J.; Karlsgodt, Katherine H.; Uddin, Lucina Q.; Chow, Carolyn; Congdon, Eliza; Jalbrzikowski, Maria

    2014-01-01

    22q11.2 deletion syndrome (22q11DS) is a genetic mutation associated with disorders of cortical connectivity and social dysfunction. However, little is known about the functional connectivity (FC) of the resting brain in 22q11DS and its relationship with social behavior. A seed-based analysis of resting-state functional magnetic resonance imaging data was used to investigate FC associated with the posterior cingulate cortex (PCC), in (26) youth with 22qDS and (51) demographically matched controls. Subsequently, the relationship between PCC connectivity and Social Responsiveness Scale (SRS) scores was examined in 22q11DS participants. Relative to 22q11DS participants, controls showed significantly stronger FC between the PCC and other default mode network (DMN) nodes, including the precuneus, precentral gyrus and left frontal pole. 22q11DS patients did not show age-associated FC changes observed in typically developing controls. Increased connectivity between PCC, medial prefrontal regions and the anterior cingulate cortex, was associated with lower SRS scores (i.e. improved social competence) in 22q11DS. DMN integrity may play a key role in social information processing. We observed disrupted DMN connectivity in 22q11DS, paralleling reports from idiopathic autism and schizophrenia. Increased strength of long-range DMN connectivity was associated with improved social functioning in 22q11DS. These findings support a ‘developmental-disconnection’ hypothesis of symptom development in this disorder. PMID:23912681

  20. Applications and Methods of Operating a Three-dimensional Nano-electro-mechanical Resonator and Related Devices

    NASA Technical Reports Server (NTRS)

    Kaul, Anupama B. (Inventor); Epp, Larry W. (Inventor); Bagge, Leif (Inventor)

    2013-01-01

    Carbon nanofiber resonator devices, methods for use, and applications of said devices are disclosed. Carbon nanofiber resonator devices can be utilized in or as high Q resonators. Resonant frequency of these devices is a function of configuration of various conducting components within these devices. Such devices can find use, for example, in filtering and chemical detection.

  1. The study of piezoelectric lateral-electric-field-excited resonator.

    PubMed

    Zaitsev, Boris; Kuznetsova, Iren; Shikhabudinov, Alexander; Teplykh, Andrey; Borodina, Irina

    2014-01-01

    The piezoelectric lateral-electric-field-excited resonator based on an X-cut lithium niobate plate has been investigated. Two rectangular electrodes were applied on one side of the plate so that the lateral electric field components were parallel to the crystallographic Y-axis and excited the longitudinal wave in the gap between the electrodes. The region around the electrodes was covered with a special absorbing varnish to suppress the spurious oscillations. The effect of the absorbing coating width on the resonant frequency and Q-factor of the lateral field-excited resonator was studied in detail with the series and parallel resonances for different width of the gap between the electrodes. As a result, we found experimentally the parameter regions of pure resonances and the boundaries of value variation for resonance frequency, Q-factor, and effective electromechanical coupling coefficient. PMID:24402903

  2. Measurement and analysis of cryogenic sapphire dielectric resonators and DROs

    NASA Technical Reports Server (NTRS)

    Dick, G. J.

    1987-01-01

    Presented are the experimental and computational results of a study on a new kind of dielectric resonator oscillator (DRO). It consists of a cooled, cylindrically symmetric sapphire resonator surrounded by a metallic shield and is capable of higher Q's than any other dielectric resonator. Isolation of fields to the sapphire by the special nature of the electromagnetic mode allows the very low loss of the sapphire itself to be expressed. Calculations show that the plethora of modes in such resonators can be effectively reduced through the use of a ring resonator with appropriate dimensions. Experimental results show Q's ranging from 3 x 10 to the 8th at 77 K to 10 to the 9th at 4.2 K. Performance is estimated for several types of DROs incorporating these resonators. Phase noise reductions in X-band sources are indicated at values substantially lower than those previously available.

  3. Interstitial deletions 4q21.1q25 and 4q25q27: Phenotypic variability and relation to Rieger anomaly

    SciTech Connect

    Kulharya, A.S.; Schneider, N.R.; Tonk, V.

    1995-01-16

    We describe clinical and chromosomal findings in two patients with del(4q). Patient 1, with interstitial deletion (4)(q21.1q25), had craniofacial and skeletal anomalies and died at 8 months hydrocephalus. Patient 2, with interstitial deletion (4)(q25q27), had craniofacial and skeletal anomalies with congenital hypotonia and developmental delay. These patients shared certain manifestations with other del(4q) patients but did not have Rieger anomaly. Clinical variability among patients with interstitial deletions of 4q may be related to variable expression, variable deletion, or imprinting of genes within the 4q region. 15 refs., 4 figs., 1 tab.

  4. Experimental study of electro-optical Q-switched pulsed Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    A, Maleki; M Kavosh, Tehrani; H, Saghafifar; M, H. Moghtader Dindarlu

    2016-03-01

    We report the specification of a compact and stable side diode-pumped Q-switched pulsed Nd:YAG laser. We experimentally study and compare the performance of the pulsed Nd:YAG laser in the free-running and Q-switched modes at different pulse repetition rates from 1 Hz to 100 Hz. The laser output energy is stabilized by using a special configuration of the optical resonator. In this laser, an unsymmetrical concave-concave resonator is used and this structure helps the mode volume to be nearly fixed when the pulse repetition rate is increased. According to the experimental results in the Q-switched operation, the laser output energy is nearly constant around 70 mJ with an FWHM pulse width of 7 ns at 100 Hz. The optical-to-optical conversion efficiency in the Q-switched regime is 17.5%.

  5. Apex-angle-dependent resonances in triangular split-ring resonators

    NASA Astrophysics Data System (ADS)

    Burnett, Max A.; Fiddy, Michael A.

    2016-02-01

    Along with other frequency selective structures (Pendry et al. in IEEE Trans Microw Theory Tech 47(11):2075-2084, 1999) (circles and squares), triangular split-ring resonators (TSRRs) only allow frequencies near the center resonant frequency to propagate. Further, TSRRs are attractive due to their small surface area (Vidhyalakshmi et al. in Stopband characteristics of complementary triangular split ring resonator loaded microstrip line, 2011), comparatively, and large quality factors ( Q) as previously investigated by Gay-Balmaz et al. (J Appl Phys 92(5):2929-2936, 2002). In this work, we examine the effects of varying the apex angle on the resonant frequency, the Q factor, and the phase shift imparted by the TSRR element within the GHz frequency regime.

  6. Microspherical photonics: Sorting resonant photonic atoms by using light

    SciTech Connect

    Maslov, Alexey V.; Astratov, Vasily N.

    2014-09-22

    A method of sorting microspheres by resonant light forces in vacuum, air, or liquid is proposed. Based on a two-dimensional model, it is shown that the sorting can be realized by allowing spherical particles to traverse a focused beam. Under resonance with the whispering gallery modes, the particles acquire significant velocity along the beam direction. This opens a unique way of large-volume sorting of nearly identical photonic atoms with 1/Q accuracy, where Q is the resonance quality factor. This is an enabling technology for developing super-low-loss coupled-cavity structures and devices.

  7. Structure functions at low Q^2: higher twists and target mass effects

    SciTech Connect

    Wally Melnitchouk

    2006-05-22

    We review the physics of structure functions at low Q{sup 2}, focusing on the phenomenon of quark-hadron duality and the resonance-scaling transition, both phenomenologically and in the context of quark models. We also present a new implementation of target mass corrections to nucleon structure functions which, unlike existing treatments, has the correct kinematic threshold behavior at finite Q{sup 2} in the x -> 1 limit.

  8. Dielectric microwave resonators in TE011 cavities for electron paramagnetic resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Mett, Richard R.; Sidabras, Jason W.; Golovina, Iryna S.; Hyde, James S.

    2008-09-01

    The coupled system of the microwave cylindrical TE011 cavity and the TE01δ dielectric modes has been analyzed in order to determine the maximum achievable resonator efficiency parameter of a dielectric inserted into a cavity, and whether this value can exceed that of a dedicated TE01δ mode dielectric resonator. The frequency, Q value, and resonator efficiency parameter Λ for each mode of the coupled system were calculated as the size of the dielectric was varied. Other output parameters include the relative field magnitudes and phases. Two modes are found: one with fields in the dielectric parallel to the fields in the cavity center and the other with antiparallel fields. Results closely match those from a computer program that solves Maxwell's equations by finite element methods. Depending on the relative natural resonance frequencies of the cavity and dielectric, one mode has a higher Q value and correspondingly lower Λ than the other. The mode with the higher Q value is preferentially excited by a coupling iris or loop in or near the cavity wall. However, depending on the frequency separation between modes, either can be excited in this way. A relatively narrow optimum is found for the size of the insert that produces maximum signal for both modes simultaneously. It occurs when the self-resonance frequencies of the two resonators are nearly equal. The maximum signal is almost the same as that of the dedicated TE01δ mode dielectric resonator alone, Λ ≅40 G/W1/2 at X-band for a KTaO3 crystal. The cavity is analogous to the second stage of a two-stage coupler. In general, there is no electron paramagnetic resonance (EPR) signal benefit by use of a second stage. However, there is a benefit of convenience. A properly designed sample-mounted resonator inserted into a cavity can give EPR signals as large as what one would expect from the dielectric resonator alone.

  9. Dielectric microwave resonators in TE(011) cavities for electron paramagnetic resonance spectroscopy.

    PubMed

    Mett, Richard R; Sidabras, Jason W; Golovina, Iryna S; Hyde, James S

    2008-09-01

    The coupled system of the microwave cylindrical TE(011) cavity and the TE(01delta) dielectric modes has been analyzed in order to determine the maximum achievable resonator efficiency parameter of a dielectric inserted into a cavity, and whether this value can exceed that of a dedicated TE(01delta) mode dielectric resonator. The frequency, Q value, and resonator efficiency parameter Lambda for each mode of the coupled system were calculated as the size of the dielectric was varied. Other output parameters include the relative field magnitudes and phases. Two modes are found: one with fields in the dielectric parallel to the fields in the cavity center and the other with antiparallel fields. Results closely match those from a computer program that solves Maxwell's equations by finite element methods. Depending on the relative natural resonance frequencies of the cavity and dielectric, one mode has a higher Q value and correspondingly lower Lambda than the other. The mode with the higher Q value is preferentially excited by a coupling iris or loop in or near the cavity wall. However, depending on the frequency separation between modes, either can be excited in this way. A relatively narrow optimum is found for the size of the insert that produces maximum signal for both modes simultaneously. It occurs when the self-resonance frequencies of the two resonators are nearly equal. The maximum signal is almost the same as that of the dedicated TE(01delta) mode dielectric resonator alone, Lambda congruent with40 G/W(1/2) at X-band for a KTaO(3) crystal. The cavity is analogous to the second stage of a two-stage coupler. In general, there is no electron paramagnetic resonance (EPR) signal benefit by use of a second stage. However, there is a benefit of convenience. A properly designed sample-mounted resonator inserted into a cavity can give EPR signals as large as what one would expect from the dielectric resonator alone. PMID:19044441

  10. Discrete resonances

    NASA Astrophysics Data System (ADS)

    Vivaldi, Franco

    2015-12-01

    The concept of resonance has been instrumental to the study of Hamiltonian systems with divided phase space. One can also define such systems over discrete spaces, which have a finite or countable number of points, but in this new setting the notion of resonance must be re-considered from scratch. I review some recent developments in the area of arithmetic dynamics which outline some salient features of linear and nonlinear stable (elliptic) orbits over a discrete space, and also underline the difficulties that emerge in their analysis.