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Sample records for high precision calculation

  1. All-order approach to high-precision atomic calculation

    NASA Astrophysics Data System (ADS)

    Iskrenova-Tchoukova, Eugeniya

    High-precision atomic calculations combined with experiments of matching accuracy provide an excellent opportunity to test our understanding of atomic structure and properties as well as the many-body atomic theories. The relativistic all-order method, which is a linearized version of the coupled-cluster singles-doubles method, has proven to yield high precision results for a variety of atomic properties. In this thesis, we study the atomic properties of neutral atoms and ions by means of the relativistic all-order method. The lifetimes and ground state static polarizabilities of a singly ionized barium atom are studied in comparison with the isoelectronic neutral cesium atom and with a singly ionized calcium atom. The lifetimes of a number of excited states in atomic potassium, rubidium, and francium are theoretically calculated and compared with the available experimental data. The magnetic dipole hyperfine constant of the 9S1/2 state in 210Fr is calculated and the result is combined with the experimental one to extract the value of the 210Fr nuclear magnetic moment. Another part of the thesis work focuses on the development and implementation of an extension of the currently used all-order singles-doubles (SD) method to include all valence triple excitations in an iterative way, all-order SD+vT approximation. Some of the ideas and results presented in Chapters 4, 5, and 6 have been published and are subject to copyright laws. These publications are cited accordingly.

  2. Peculiarities of high-overtone transition probabilities in carbon monoxide revealed by high-precision calculation

    SciTech Connect

    Medvedev, Emile S.; Meshkov, Vladimir V.; Stolyarov, Andrey V.

    2015-10-21

    In the recent work devoted to the calculation of the rovibrational line list of the CO molecule [G. Li et al., Astrophys. J., Suppl. Ser. 216, 15 (2015)], rigorous validation of the calculated parameters including intensities was carried out. In particular, the Normal Intensity Distribution Law (NIDL) [E. S. Medvedev, J. Chem. Phys. 137, 174307 (2012)] was employed for the validation purposes, and it was found that, in the original CO line list calculated for large changes of the vibrational quantum number up to Δn = 41, intensities with Δn > 11 were unphysical. Therefore, very high overtone transitions were removed from the published list in Li et al. Here, we show how this type of validation is carried out and prove that the quadruple precision is indispensably required to predict the reliable intensities using the conventional 32-bit computers. Based on these calculations, the NIDL is shown to hold up for the 0 → n transitions till the dissociation limit around n = 83, covering 45 orders of magnitude in the intensity. The low-intensity 0 → n transition predicted in the work of Medvedev [Determination of a new molecular constant for diatomic systems. Normal intensity distribution law for overtone spectra of diatomic and polyatomic molecules and anomalies in overtone absorption spectra of diatomic molecules, Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka, 1984] at n = 5 is confirmed, and two additional “abnormal” intensities are found at n = 14 and 23. Criteria for the appearance of such “anomalies” are formulated. The results could be useful to revise the high-overtone molecular transition probabilities provided in spectroscopic databases.

  3. Peculiarities of high-overtone transition probabilities in carbon monoxide revealed by high-precision calculation

    NASA Astrophysics Data System (ADS)

    Medvedev, Emile S.; Meshkov, Vladimir V.; Stolyarov, Andrey V.; Gordon, Iouli E.

    2015-10-01

    In the recent work devoted to the calculation of the rovibrational line list of the CO molecule [G. Li et al., Astrophys. J., Suppl. Ser. 216, 15 (2015)], rigorous validation of the calculated parameters including intensities was carried out. In particular, the Normal Intensity Distribution Law (NIDL) [E. S. Medvedev, J. Chem. Phys. 137, 174307 (2012)] was employed for the validation purposes, and it was found that, in the original CO line list calculated for large changes of the vibrational quantum number up to Δn = 41, intensities with Δn > 11 were unphysical. Therefore, very high overtone transitions were removed from the published list in Li et al. Here, we show how this type of validation is carried out and prove that the quadruple precision is indispensably required to predict the reliable intensities using the conventional 32-bit computers. Based on these calculations, the NIDL is shown to hold up for the 0 → n transitions till the dissociation limit around n = 83, covering 45 orders of magnitude in the intensity. The low-intensity 0 → n transition predicted in the work of Medvedev [Determination of a new molecular constant for diatomic systems. Normal intensity distribution law for overtone spectra of diatomic and polyatomic molecules and anomalies in overtone absorption spectra of diatomic molecules, Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka, 1984] at n = 5 is confirmed, and two additional "abnormal" intensities are found at n = 14 and 23. Criteria for the appearance of such "anomalies" are formulated. The results could be useful to revise the high-overtone molecular transition probabilities provided in spectroscopic databases.

  4. Computational Calorimetry: High-Precision Calculation of Host–Guest Binding Thermodynamics

    PubMed Central

    2015-01-01

    We present a strategy for carrying out high-precision calculations of binding free energy and binding enthalpy values from molecular dynamics simulations with explicit solvent. The approach is used to calculate the thermodynamic profiles for binding of nine small molecule guests to either the cucurbit[7]uril (CB7) or β-cyclodextrin (βCD) host. For these systems, calculations using commodity hardware can yield binding free energy and binding enthalpy values with a precision of ∼0.5 kcal/mol (95% CI) in a matter of days. Crucially, the self-consistency of the approach is established by calculating the binding enthalpy directly, via end point potential energy calculations, and indirectly, via the temperature dependence of the binding free energy, i.e., by the van’t Hoff equation. Excellent agreement between the direct and van’t Hoff methods is demonstrated for both host–guest systems and an ion-pair model system for which particularly well-converged results are attainable. Additionally, we find that hydrogen mass repartitioning allows marked acceleration of the calculations with no discernible cost in precision or accuracy. Finally, we provide guidance for accurately assessing numerical uncertainty of the results in settings where complex correlations in the time series can pose challenges to statistical analysis. The routine nature and high precision of these binding calculations opens the possibility of including measured binding thermodynamics as target data in force field optimization so that simulations may be used to reliably interpret experimental data and guide molecular design. PMID:26523125

  5. High-precision calculation of the strange nucleon electromagnetic form factors

    SciTech Connect

    Green, Jeremy; Meinel, Stefan; Engelhardt, Michael G.; Krieg, Stefan; Laeuchli, Jesse; Negele, John W.; Orginos, Kostas; Pochinsky, Andrew; Syritsyn, Sergey

    2015-08-26

    We report a direct lattice QCD calculation of the strange nucleon electromagnetic form factors GsE and GsM in the kinematic range 0 ≤ Q2 ≤ 1.2GeV2. For the first time, both GsE and GsM are shown to be nonzero with high significance. This work uses closer-to-physical lattice parameters than previous calculations, and achieves an unprecented statistical precision by implementing a recently proposed variance reduction technique called hierarchical probing. We perform model-independent fits of the form factor shapes using the z-expansion and determine the strange electric and magnetic radii and magnetic moment. As a result, we compare our results to parity-violating electron-proton scattering data and to other theoretical studies.

  6. HOTB: High precision parallel code for calculation of four-particle harmonic oscillator transformation brackets

    NASA Astrophysics Data System (ADS)

    Stepšys, A.; Mickevicius, S.; Germanas, D.; Kalinauskas, R. K.

    2014-11-01

    This new version of the HOTB program for calculation of the three and four particle harmonic oscillator transformation brackets provides some enhancements and corrections to the earlier version (Germanas et al., 2010) [1]. In particular, new version allows calculations of harmonic oscillator transformation brackets be performed in parallel using MPI parallel communication standard. Moreover, higher precision of intermediate calculations using GNU Quadruple Precision and arbitrary precision library FMLib [2] is done. A package of Fortran code is presented. Calculation time of large matrices can be significantly reduced using effective parallel code. Use of Higher Precision methods in intermediate calculations increases the stability of algorithms and extends the validity of used algorithms for larger input values. Catalogue identifier: AEFQ_v4_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEFQ_v4_0.html Program obtainable from: CPC Program Library, Queen’s University of Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 Number of lines in programs, including test data, etc.: 1711 Number of bytes in distributed programs, including test data, etc.: 11667 Distribution format: tar.gz Program language used: FORTRAN 90 with MPI extensions for parallelism Computer: Any computer with FORTRAN 90 compiler Operating system: Windows, Linux, FreeBSD, True64 Unix Has the code been vectorized of parallelized?: Yes, parallelism using MPI extensions. Number of CPUs used: up to 999 RAM(per CPU core): Depending on allocated binomial and trinomial matrices and use of precision; at least 500 MB Catalogue identifier of previous version: AEFQ_v1_0 Journal reference of previous version: Comput. Phys. Comm. 181, Issue 2, (2010) 420-425 Does the new version supersede the previous version? Yes Nature of problem: Calculation of matrices of three-particle harmonic oscillator brackets (3HOB) and four-particle harmonic oscillator brackets (4HOB) in a more

  7. HOTB: High precision parallel code for calculation of four-particle harmonic oscillator transformation brackets

    NASA Astrophysics Data System (ADS)

    Stepšys, A.; Mickevicius, S.; Germanas, D.; Kalinauskas, R. K.

    2014-11-01

    This new version of the HOTB program for calculation of the three and four particle harmonic oscillator transformation brackets provides some enhancements and corrections to the earlier version (Germanas et al., 2010) [1]. In particular, new version allows calculations of harmonic oscillator transformation brackets be performed in parallel using MPI parallel communication standard. Moreover, higher precision of intermediate calculations using GNU Quadruple Precision and arbitrary precision library FMLib [2] is done. A package of Fortran code is presented. Calculation time of large matrices can be significantly reduced using effective parallel code. Use of Higher Precision methods in intermediate calculations increases the stability of algorithms and extends the validity of used algorithms for larger input values. Catalogue identifier: AEFQ_v4_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEFQ_v4_0.html Program obtainable from: CPC Program Library, Queen’s University of Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 Number of lines in programs, including test data, etc.: 1711 Number of bytes in distributed programs, including test data, etc.: 11667 Distribution format: tar.gz Program language used: FORTRAN 90 with MPI extensions for parallelism Computer: Any computer with FORTRAN 90 compiler Operating system: Windows, Linux, FreeBSD, True64 Unix Has the code been vectorized of parallelized?: Yes, parallelism using MPI extensions. Number of CPUs used: up to 999 RAM(per CPU core): Depending on allocated binomial and trinomial matrices and use of precision; at least 500 MB Catalogue identifier of previous version: AEFQ_v1_0 Journal reference of previous version: Comput. Phys. Comm. 181, Issue 2, (2010) 420-425 Does the new version supersede the previous version? Yes Nature of problem: Calculation of matrices of three-particle harmonic oscillator brackets (3HOB) and four-particle harmonic oscillator brackets (4HOB) in a more

  8. High-precision calculation of the branching ratio of the 40K decay constant.

    NASA Astrophysics Data System (ADS)

    Jourdan, F.

    2008-12-01

    40K is of great importance in Earth science, particularly for K/Ar, 40Ar/39Ar and K/Ca geochronology. The decay scheme of the 40K includes two different modes of decay, beta and electron capture followed by gamma-ray emission, which yield two different products, 40Ca* and 40Ar*. The relative probability that 40K decay following one of the two schemes is known as the branching ratio. An original method of calculation to obtain the value of the 40K branching ratio (λβ- /λtot) based on the K/Ar technique, is proposed. λβ- /λtot is obtained by combining the 40Ar*/40K value of Fish Canyon sanidine (FCs) secondary standard derived from four primary 40Ar/39Ar standards, with the current best estimates of the age of FCs and the value of the 40K total decay constant. The latest estimation of the 40K total decay constant and the age of FCs by Mundil et al. (2006), through comparison with U/Pb ages, yields a λβ- /λtot value of 89.59 ± 0.03% (1σ; relative error = ± 0.035%). Indirect measurement of the age of FCs by orbital tuning (Kuiper et al., 2008) combined with the value of 40K total decay constant measured by liquid scintillation counting by Kossert and Gunther (2004) yields a statistically indistinguishable value for the branching ratio of 89.61 ± 0.03%, with an average between the two values of 89.60 ± 0.04%. The method proposed here allows can easily be applied to further constrain the value of the 40K branching ratio as future refinements of the 40K decay constant and FCs age are produced, although it is expected that the adopted value will be close to λβ- /λtot = 89.60 ± 0.04%. Kossert and Gunther, 2004. Appl. Radiat. Isot. 60, 459-464. Kuiper et al., 2008. Science 320, 500-504. Mundil et al. 2006, Eos Trans. AGU, 87(52)

  9. Relativistic general-order coupled-cluster method for high-precision calculations: Application to the Al{sup +} atomic clock

    SciTech Connect

    Kallay, Mihaly; Nataraj, H. S.; Sahoo, B. K.; Das, B. P.; Visscher, Lucas

    2011-03-15

    We report the implementation of a general-order relativistic coupled-cluster method for performing high-precision calculations of atomic and molecular properties. As a first application, the black-body radiation shift of the Al{sup +} clock has been estimated precisely. The computed shift relative to the frequency of the 3s{sup 2} {sup 1}S{sub 0}{sup e}{yields}3s3p {sup 3}P{sub 0}{sup o} clock transition given by (-3.66{+-}0.60)x10{sup -18} calls for an improvement over the recent measurement with a reported result of (-9{+-}3)x10{sup -18}[Phys. Rev. Lett. 104, 070802 (2010)].

  10. High precision variational calculations for the Born-Oppenheimer energies of the ground state of the hydrogen molecule.

    PubMed

    Sims, James S; Hagstrom, Stanley A

    2006-03-01

    Born-Oppenheimer approximation Hylleraas variational calculations with up to 7034 expansion terms are reported for the 1sigma(g)+ ground state of neutral hydrogen at various internuclear distances. The nonrelativistic energy is calculated to be -1.174 475 714 220(1) hartree at R = 1.4 bohr, which is four orders of magnitude better than the best previous Hylleraas calculation, that of Wolniewicz [J. Chem. Phys. 103, 1792 (1995)]. This result agrees well with the best previous variational energy, -1.174 475 714 216 hartree, of Cencek (personal communication), obtained using explicitly correlated Gaussians (ECGs) [Cencek and Rychlewski, J. Chem. Phys. 98, 1252 (1993); Cencek et al., ibid. 95, 2572 (1995); Rychlewski, Adv. Quantum Chem. 31, 173 (1998)]. The uncertainty in our result is also discussed. The nonrelativistic energy is calculated to be -1.174 475 931 399(1) hartree at the equilibrium R = 1.4011 bohr distance. This result also agrees well with the best previous variational energy, -1.174 475 931 389 hartree, of Cencek and Rychlewski [Rychlewski, Handbook of Molecular Physics and Quantum Chemistry, edited by S. Wilson (Wiley, New York, 2003), Vol. 2, pp. 199-218; Rychlewski, Explicitly Correlated Wave Functions in Chemistry and Physics Theory and Applications, edited by J. Rychlewski (Kluwer Academic, Dordrecht, 2003), pp. 91-147.], obtained using ECGs. PMID:16526839

  11. High precision variational calculations for the Born-Oppenheimer energies of the ground state of the hydrogen molecule

    NASA Astrophysics Data System (ADS)

    Sims, James S.; Hagstrom, Stanley A.

    2006-03-01

    Born-Oppenheimer approximation Hylleraas variational calculations with up to 7034 expansion terms are reported for the Σg+1 ground state of neutral hydrogen at various internuclear distances. The nonrelativistic energy is calculated to be -1.174475714220(1)hartree at R =1.4bohr, which is four orders of magnitude better than the best previous Hylleraas calculation, that of Wolniewicz [J. Chem. Phys. 103, 1792 (1995)]. This result agrees well with the best previous variational energy, -1.174475714216hartree, of Cencek (personal communication), obtained using explicitly correlated Gaussians (ECGs) [Cencek and Rychlewski, J. Chem. Phys. 98, 1252 (1993); Cencek et al., ibid. 95, 2572 (1995); Rychlewski, Adv. Quantum Chem. 31, 173 (1998)]. The uncertainty in our result is also discussed. The nonrelativistic energy is calculated to be -1.174475931399(1)hartree at the equilibrium R =1.4011bohr distance. This result also agrees well with the best previous variational energy, -1.174475931389hartree, of Cencek and Rychlewski [Rychlewski, Handbook of Molecular Physics and Quantum Chemistry, edited by S. Wilson (Wiley, New York, 2003), Vol. 2, pp. 199-218; Rychlewski, Explicitly Correlated Wave Functions in Chemistry and Physics Theory and Applications, edited by J. Rychlewski (Kluwer Academic, Dordrecht, 2003), pp. 91-147.], obtained using ECGs.

  12. High Precision Electon Beam Polarimetry

    NASA Astrophysics Data System (ADS)

    Dutta, D.

    2016-02-01

    Over the last three decades high precision electron beam polarimetry has been at the fore-front of progress made in leveraging the spin degrees of freedom in nuclear and particle physics experiments. We review the three main types of polarimeters, Compton, Møller and Mott, that are typically used in experiments. We discuss some of the recent results in high precision electron polarimetry and some of the new ideas that are being explored for future application at current and proposed accelerators.

  13. Highly Parallel, High-Precision Numerical Integration

    SciTech Connect

    Bailey, David H.; Borwein, Jonathan M.

    2005-04-22

    This paper describes a scheme for rapidly computing numerical values of definite integrals to very high accuracy, ranging from ordinary machine precision to hundreds or thousands of digits, even for functions with singularities or infinite derivatives at endpoints. Such a scheme is of interest not only in computational physics and computational chemistry, but also in experimental mathematics, where high-precision numerical values of definite integrals can be used to numerically discover new identities. This paper discusses techniques for a parallel implementation of this scheme, then presents performance results for 1-D and 2-D test suites. Results are also given for a certain problem from mathematical physics, which features a difficult singularity, confirming a conjecture to 20,000 digit accuracy. The performance rate for this latter calculation on 1024 CPUs is 690 Gflop/s. We believe that this and one other 20,000-digit integral evaluation that we report are the highest-precision non-trivial numerical integrations performed to date.

  14. High-precision arithmetic in mathematical physics

    DOE PAGESBeta

    Bailey, David H.; Borwein, Jonathan M.

    2015-05-12

    For many scientific calculations, particularly those involving empirical data, IEEE 32-bit floating-point arithmetic produces results of sufficient accuracy, while for other applications IEEE 64-bit floating-point is more appropriate. But for some very demanding applications, even higher levels of precision are often required. Furthermore, this article discusses the challenge of high-precision computation, in the context of mathematical physics, and highlights what facilities are required to support future computation, in light of emerging developments in computer architecture.

  15. High-Precision Computation and Mathematical Physics

    SciTech Connect

    Bailey, David H.; Borwein, Jonathan M.

    2008-11-03

    At the present time, IEEE 64-bit floating-point arithmetic is sufficiently accurate for most scientific applications. However, for a rapidly growing body of important scientific computing applications, a higher level of numeric precision is required. Such calculations are facilitated by high-precision software packages that include high-level language translation modules to minimize the conversion effort. This paper presents a survey of recent applications of these techniques and provides some analysis of their numerical requirements. These applications include supernova simulations, climate modeling, planetary orbit calculations, Coulomb n-body atomic systems, scattering amplitudes of quarks, gluons and bosons, nonlinear oscillator theory, Ising theory, quantum field theory and experimental mathematics. We conclude that high-precision arithmetic facilities are now an indispensable component of a modern large-scale scientific computing environment.

  16. Verification of the MCU precision code and ROSFOND neutron data in application to the calculations of criticality of fast reactors with highly enriched uranium

    SciTech Connect

    Alekseev, N. I.; Kalugin, M. A.; Kulakov, A. S.; Novosel’tsev, A. P.; Sergeev, G. S.; Shkarovskiy, D. A.; Yudkevich, M. S.

    2014-12-15

    Calculation of 335 critical assemblies (benchmark experiments) with the core of highly enriched uranium and reflectors of various materials is performed. The statistical analysis of the results shows that, for all 16 materials studied, the absolute value of the most probable deviation of the calculated value of K{sub eff} from the experimental one does not exceed 0.005.

  17. Verification of the MCU precision code and ROSFOND neutron data in application to the calculations of criticality of fast reactors with highly enriched uranium

    NASA Astrophysics Data System (ADS)

    Alekseev, N. I.; Kalugin, M. A.; Kulakov, A. S.; Novosel'tsev, A. P.; Sergeev, G. S.; Shkarovskiy, D. A.; Yudkevich, M. S.

    2014-12-01

    Calculation of 335 critical assemblies (benchmark experiments) with the core of highly enriched uranium and reflectors of various materials is performed. The statistical analysis of the results shows that, for all 16 materials studied, the absolute value of the most probable deviation of the calculated value of K eff from the experimental one does not exceed 0.005.

  18. High Precision CCD Imaging Polarimetry

    NASA Astrophysics Data System (ADS)

    Magalhaes, A. M.; Rodrigues, C. V.; Margoniner, V. E.; Pereyra, A.; Heathcote, S.; Coyne, G. V.

    1994-12-01

    We describe a recent modification to the direct CCD Cameras at CTIO and LNA (Brazil) observatories in order to allow for high precision optical polarimetry. We make use of a rotating achromatic half-wave plate as a retarder and a Savart plate as analyser. Cancellation of sky polarization and independence of the CCD flat field correction are among the advantages of the arrangement. We show preliminary data that indicate the high polarimetric precision achievable with the method for non-extended sources. We give a brief description of the on-going observational programs employing the technique. Polarimetry of extended objects can be performed by using a Polaroid sheet in place of the Savart plate. Use of the Savart plate with such fields can also be valuable in the reduction, and analysis, of the extended source images as it provides polarization data on the non-extended objects in the field.

  19. High precision redundant robotic manipulator

    DOEpatents

    Young, K.K.D.

    1998-09-22

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space is disclosed. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degrees of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns. 3 figs.

  20. High precision redundant robotic manipulator

    DOEpatents

    Young, Kar-Keung David

    1998-01-01

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degreed of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns.

  1. Recent high precision surveys at PEP

    SciTech Connect

    Sah, R.C.

    1980-12-01

    The task of surveying and aligning the components of PEP has provided an opportunity to develop new instruments and techniques for the purpose of high precision surveys. The new instruments are quick and easy to use, and they automatically encode survey data and read them into the memory of an on-line computer. When measurements of several beam elements have been taken, the on-line computer analyzes the measured data, compares them with desired parameters, and calculates the required adjustments to beam element support stands.

  2. High precision anatomy for MEG.

    PubMed

    Troebinger, Luzia; López, José David; Lutti, Antoine; Bradbury, David; Bestmann, Sven; Barnes, Gareth

    2014-02-01

    Precise MEG estimates of neuronal current flow are undermined by uncertain knowledge of the head location with respect to the MEG sensors. This is either due to head movements within the scanning session or systematic errors in co-registration to anatomy. Here we show how such errors can be minimized using subject-specific head-casts produced using 3D printing technology. The casts fit the scalp of the subject internally and the inside of the MEG dewar externally, reducing within session and between session head movements. Systematic errors in matching to MRI coordinate system are also reduced through the use of MRI-visible fiducial markers placed on the same cast. Bootstrap estimates of absolute co-registration error were of the order of 1mm. Estimates of relative co-registration error were <1.5mm between sessions. We corroborated these scalp based estimates by looking at the MEG data recorded over a 6month period. We found that the between session sensor variability of the subject's evoked response was of the order of the within session noise, showing no appreciable noise due to between-session movement. Simulations suggest that the between-session sensor level amplitude SNR improved by a factor of 5 over conventional strategies. We show that at this level of coregistration accuracy there is strong evidence for anatomical models based on the individual rather than canonical anatomy; but that this advantage disappears for errors of greater than 5mm. This work paves the way for source reconstruction methods which can exploit very high SNR signals and accurate anatomical models; and also significantly increases the sensitivity of longitudinal studies with MEG. PMID:23911673

  3. High precision anatomy for MEG☆

    PubMed Central

    Troebinger, Luzia; López, José David; Lutti, Antoine; Bradbury, David; Bestmann, Sven; Barnes, Gareth

    2014-01-01

    Precise MEG estimates of neuronal current flow are undermined by uncertain knowledge of the head location with respect to the MEG sensors. This is either due to head movements within the scanning session or systematic errors in co-registration to anatomy. Here we show how such errors can be minimized using subject-specific head-casts produced using 3D printing technology. The casts fit the scalp of the subject internally and the inside of the MEG dewar externally, reducing within session and between session head movements. Systematic errors in matching to MRI coordinate system are also reduced through the use of MRI-visible fiducial markers placed on the same cast. Bootstrap estimates of absolute co-registration error were of the order of 1 mm. Estimates of relative co-registration error were < 1.5 mm between sessions. We corroborated these scalp based estimates by looking at the MEG data recorded over a 6 month period. We found that the between session sensor variability of the subject's evoked response was of the order of the within session noise, showing no appreciable noise due to between-session movement. Simulations suggest that the between-session sensor level amplitude SNR improved by a factor of 5 over conventional strategies. We show that at this level of coregistration accuracy there is strong evidence for anatomical models based on the individual rather than canonical anatomy; but that this advantage disappears for errors of greater than 5 mm. This work paves the way for source reconstruction methods which can exploit very high SNR signals and accurate anatomical models; and also significantly increases the sensitivity of longitudinal studies with MEG. PMID:23911673

  4. Precise calculation of the magnetosphere surface for a tilted dipole.

    NASA Technical Reports Server (NTRS)

    Choe, J. Y.; Beard, D. B.; Sullivan, E. C.

    1973-01-01

    The shape of the magnetosphere has been calculated self-consistently for inclinations of the earth's magnetic dipole from perpendicular to the solar wind. Inclination angles of 0-35 deg have been chosen in steps of 5 deg and various smooth trends in the surface characteristics with increasing inclination angle noted. The surface points and the complete field at the surface points have been calculated for the entire surfaces. The neutral point region has been given precise study in one degree steps and is found to be tangent to the solar wind velocity and to have a smooth continuous curvature.

  5. High precision triangular waveform generator

    DOEpatents

    Mueller, Theodore R.

    1983-01-01

    An ultra-linear ramp generator having separately programmable ascending and descending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

  6. New High Precision Linelist of H_3^+

    NASA Astrophysics Data System (ADS)

    Hodges, James N.; Perry, Adam J.; Markus, Charles; Jenkins, Paul A., II; Kocheril, G. Stephen; McCall, Benjamin J.

    2014-06-01

    As the simplest polyatomic molecule, H_3^+ serves as an ideal benchmark for theoretical predictions of rovibrational energy levels. By strictly ab initio methods, the current accuracy of theoretical predictions is limited to an impressive one hundredth of a wavenumber, which has been accomplished by consideration of relativistic, adiabatic, and non-adiabatic corrections to the Born-Oppenheimer PES. More accurate predictions rely on a treatment of quantum electrodynamic effects, which have improved the accuracies of vibrational transitions in molecular hydrogen to a few MHz. High precision spectroscopy is of the utmost importance for extending the frontiers of ab initio calculations, as improved precision and accuracy enable more rigorous testing of calculations. Additionally, measuring rovibrational transitions of H_3^+ can be used to predict its forbidden rotational spectrum. Though the existing data can be used to determine rotational transition frequencies, the uncertainties are prohibitively large. Acquisition of rovibrational spectra with smaller experimental uncertainty would enable a spectroscopic search for the rotational transitions. The technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy, or NICE-OHVMS has been previously used to precisely and accurately measure transitions of H_3^+, CH_5^+, and HCO^+ to sub-MHz uncertainty. A second module for our optical parametric oscillator has extended our instrument's frequency coverage from 3.2-3.9 μm to 2.5-3.9 μm. With extended coverage, we have improved our previous linelist by measuring additional transitions. O. L. Polyansky, et al. Phil. Trans. R. Soc. A (2012), 370, 5014--5027. J. Komasa, et al. J. Chem. Theor. Comp. (2011), 7, 3105--3115. C. M. Lindsay, B. J. McCall, J. Mol. Spectrosc. (2001), 210, 66--83. J. N. Hodges, et al. J. Chem. Phys. (2013), 139, 164201.

  7. Weighted Geometric Dilution of Precision Calculations with Matrix Multiplication

    PubMed Central

    Chen, Chien-Sheng

    2015-01-01

    To enhance the performance of location estimation in wireless positioning systems, the geometric dilution of precision (GDOP) is widely used as a criterion for selecting measurement units. Since GDOP represents the geometric effect on the relationship between measurement error and positioning determination error, the smallest GDOP of the measurement unit subset is usually chosen for positioning. The conventional GDOP calculation using matrix inversion method requires many operations. Because more and more measurement units can be chosen nowadays, an efficient calculation should be designed to decrease the complexity. Since the performance of each measurement unit is different, the weighted GDOP (WGDOP), instead of GDOP, is used to select the measurement units to improve the accuracy of location. To calculate WGDOP effectively and efficiently, the closed-form solution for WGDOP calculation is proposed when more than four measurements are available. In this paper, an efficient WGDOP calculation method applying matrix multiplication that is easy for hardware implementation is proposed. In addition, the proposed method can be used when more than exactly four measurements are available. Even when using all-in-view method for positioning, the proposed method still can reduce the computational overhead. The proposed WGDOP methods with less computation are compatible with global positioning system (GPS), wireless sensor networks (WSN) and cellular communication systems. PMID:25569755

  8. Exact-to-precision generalized perturbation for neutron transport calculation

    SciTech Connect

    Wang, C.; Abdel-Khalik, H. S.

    2013-07-01

    This manuscript extends the exact-to-precision generalized perturbation theory (E{sub P}GPT), introduced previously, to neutron transport calculation whereby previous developments focused on neutron diffusion calculation only. The E{sub P}GPT collectively denotes new developments in generalized perturbation theory (GPT) that place premium on computational efficiency and defendable accuracy in order to render GPT a standard analysis tool in routine design and safety reactor calculations. EPGPT constructs a surrogate model with quantifiable accuracy which can replace the original neutron transport model for subsequent engineering analysis, e.g. functionalization of the homogenized few-group cross sections in terms of various core conditions, sensitivity analysis and uncertainty quantification. This is achieved by reducing the effective dimensionality of the state variable (i.e. neutron angular flux) by projection onto an active subspace. Confining the state variations to the active subspace allows one to construct a small number of what is referred to as the 'active' responses which are solely dependent on the physics model rather than on the responses of interest, the number of input parameters, or the number of points in the state phase space. (authors)

  9. Towards High Precision Deuteron Polarimetry

    SciTech Connect

    Silva e Silva, M. da

    2009-08-04

    A finite electric dipole moment (EDM) in any fundamental system would constitute a signal for new physics. The deuteron presents itself as an optimal candidate both experimentally and theoretically. A new storage ring technique is being developed for which a small change in the vertical polarization would be a signal of a non-zero EDM. A novel polarimeter concept is under investigation. Besides being highly efficient, this polarimeter should continuously monitor the beam polarization, guaranteeing optimal sensitivity. Detailed studies on systematic error control, in addition to the measurement of cross sections and analyzing powers, were carried out at KVI-Groningen in The Netherlands. Measurements were conducted at COSY-Juelich in Germany yielding high efficiencies. The (statistics limited) ability to track changes in polarization at the level of a few hundred parts-per-million has been demonstrated. Further studies and developments to meet the final goal of sub-part-per-million sensitivity are in progress.

  10. High precision thermal neutron detectors

    SciTech Connect

    Radeka, V.; Schaknowski, N.A.; Smith, G.C.; Yu, B.

    1994-12-31

    Two-dimensional position sensitive detectors are indispensable in neutron diffraction experiments for determination of molecular and crystal structures in biology, solid-state physics and polymer chemistry. Some performance characteristics of these detectors are elementary and obvious, such as the position resolution, number of resolution elements, neutron detection efficiency, counting rate and sensitivity to gamma-ray background. High performance detectors are distinguished by more subtle characteristics such as the stability of the response (efficiency) versus position, stability of the recorded neutron positions, dynamic range, blooming or halo effects. While relatively few of them are needed around the world, these high performance devices are sophisticated and fairly complex, their development requires very specialized efforts. In this context, we describe here a program of detector development, based on {sup 3}He filled proportional chambers, which has been underway for some years at the Brookhaven National Laboratory. Fundamental approaches and practical considerations are outlined that have resulted in a series of high performance detectors with the best known position resolution, position stability, uniformity of response and reliability over time, for devices of this type.

  11. Precision Crystal Calorimeters in High Energy Physics

    ScienceCinema

    Ren-Yuan Zhu

    2010-01-08

    Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal?s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

  12. Calculation of precision satellite orbits with nonsingular elements /VOP formulation/

    NASA Technical Reports Server (NTRS)

    Velez, C. E.; Cefola, P. J.; Long, A. C.; Nimitz, K. S.

    1974-01-01

    Review of some results obtained in an effort to develop efficient, high-precision trajectory computation processes for artificial satellites by optimum selection of the form of the equations of motion of the satellite and the numerical integration method. In particular, the matching of a Gaussian variation-of-parameter (VOP) formulation is considered which is expressed in terms of equinoctial orbital elements and partially decouples the motion of the orbital frame from motion within the orbital frame. The performance of the resulting orbit generators is then compared with the popular classical Cowell/Gauss-Jackson formulation/integrator pair for two distinctly different orbit types - namely, the orbit of the ATS satellite at near-geosynchronous conditions and the near-circular orbit of the GEOS-C satellite at 1000 km.

  13. Cellular signalling effects in high precision radiotherapy

    NASA Astrophysics Data System (ADS)

    McMahon, Stephen J.; McGarry, Conor K.; Butterworth, Karl T.; Jain, Suneil; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

    2015-06-01

    Radiotherapy is commonly planned on the basis of physical dose received by the tumour and surrounding normal tissue, with margins added to address the possibility of geometric miss. However, recent experimental evidence suggests that intercellular signalling results in a given cell’s survival also depending on the dose received by neighbouring cells. A model of radiation-induced cell killing and signalling was used to analyse how this effect depends on dose and margin choices. Effective Uniform Doses were calculated for model tumours in both idealised cases with no delivery uncertainty and more realistic cases incorporating geometric uncertainty. In highly conformal irradiation, a lack of signalling from outside the target leads to reduced target cell killing, equivalent to under-dosing by up to 10% compared to large uniform fields. This effect is significantly reduced when higher doses per fraction are considered, both increasing the level of cell killing and reducing margin sensitivity. These effects may limit the achievable biological precision of techniques such as stereotactic radiotherapy even in the absence of geometric uncertainties, although it is predicted that larger fraction sizes reduce the relative contribution of cell signalling driven effects. These observations may contribute to understanding the efficacy of hypo-fractionated radiotherapy.

  14. Precision control of high temperature furnaces

    SciTech Connect

    Pollock, G.G.

    1994-12-31

    It is an object of the present invention to provide precision control of high temperature furnaces. It is another object of the present invention to combine the power of two power supplies of greatly differing output capacities in a single furnace. This invention combines two power supplies to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved. Further, this invention comprises a means for high speed measurement of temperature of the process by the method of measuring the amount of current flow in a deliberately induced charged particle current.

  15. High precision measurements in crustal dynamic studies

    NASA Technical Reports Server (NTRS)

    Wyatt, F.; Berger, J.

    1984-01-01

    The development of high-precision instrumentation for monitoring benchmark stability and evaluating coseismic strain and tilt signals is reviewed. Laser strainmeter and tilt observations are presented. Examples of coseismic deformation in several geographic locations are given. Evidence suggests that the Earth undergoes elastic response to abrupt faulting.

  16. High precision, rapid laser hole drilling

    DOEpatents

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2005-03-08

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  17. High precision, rapid laser hole drilling

    DOEpatents

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2013-04-02

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  18. High precision, rapid laser hole drilling

    DOEpatents

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2007-03-20

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  19. High Precision Pressure Measurement with a Funnel

    ERIC Educational Resources Information Center

    Lopez-Arias, T.; Gratton, L. M.; Oss, S.

    2008-01-01

    A simple experimental device for high precision differential pressure measurements is presented. Its working mechanism recalls that of a hydraulic press, where pressure is supplied by insufflating air under a funnel. As an application, we measure air pressure inside a soap bubble. The soap bubble is inflated and connected to a funnel which is…

  20. High precision Woelter optic calibration facility

    SciTech Connect

    Morales, R.I.; Remington, B.A.; Schwinn, T.

    1994-05-02

    We have developed an off-line facility for very precise characterization of the reflectance and spatial resolution of the grazing incidence Woelter Type 1 x-ray optics used at Nova. The primary component of the facility is a high brightness, ``point`` x-ray source consisting of a focussed DC electron beam incident onto a precision manipulated target/pinhole array. The data are recorded with a selection of detectors. For imaging measurements we use direct exposure x-ray film modules or an x-ray CCD camera. For energy-resolved reflectance measurements, we use lithium drifted silicon detectors and a proportional counter. An in situ laser alignment system allows precise location and rapid periodic alignment verification of the x-ray point source, the statically mounted Woelter optic, and the chosen detector.

  1. High bandwidth control of precision motion instrumentation

    NASA Astrophysics Data System (ADS)

    Bristow, Douglas A.; Dong, Jingyan; Alleyne, Andrew G.; Ferreira, Placid; Salapaka, Srinivas

    2008-10-01

    This article presents a high-bandwidth control design suitable for precision motion instrumentation. Iterative learning control (ILC), a feedforward technique that uses previous iterations of the desired trajectory, is used to leverage the repetition that occurs in many tasks, such as raster scanning in microscopy. Two ILC designs are presented. The first design uses the motion system dynamic model to maximize bandwidth. The second design uses a time-varying bandwidth that is particularly useful for nonsmooth trajectories such as raster scanning. Both designs are applied to a multiaxis piezoelectric-actuated flexure system and evaluated on a nonsmooth trajectory. The ILC designs demonstrate significant bandwidth and precision improvements over the feedback controller, and the ability to achieve precision motion control at frequencies higher than multiple system resonances.

  2. High-precision hydraulic Stewart platform

    NASA Astrophysics Data System (ADS)

    van Silfhout, Roelof G.

    1999-08-01

    We present a novel design for a Stewart platform (or hexapod), an apparatus which performs positioning tasks with high accuracy. The platform, which is supported by six hydraulic telescopic struts, provides six degrees of freedom with 1 μm resolution. Rotations about user defined pivot points can be specified for any axis of rotation with microradian accuracy. Motion of the platform is performed by changing the strut lengths. Servo systems set and maintain the length of the struts to high precision using proportional hydraulic valves and incremental encoders. The combination of hydraulic actuators and a design which is optimized in terms of mechanical stiffness enables the platform to manipulate loads of up to 20 kN. Sophisticated software allows direct six-axis positioning including true path control. Our platform is an ideal support structure for a large variety of scientific instruments that require a stable alignment base with high-precision motion.

  3. Portable high precision pressure transducer system

    DOEpatents

    Piper, Thomas C.; Morgan, John P.; Marchant, Norman J.; Bolton, Steven M.

    1994-01-01

    A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum florescent display.

  4. Portable high precision pressure transducer system

    DOEpatents

    Piper, T.C.; Morgan, J.P.; Marchant, N.J.; Bolton, S.M.

    1994-04-26

    A high precision pressure transducer system is described for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum fluorescent display. 2 figures.

  5. Fiber Scrambling for High Precision Spectrographs

    NASA Astrophysics Data System (ADS)

    Kaplan, Zachary; Spronck, J. F. P.; Fischer, D.

    2011-05-01

    The detection of Earth-like exoplanets with the radial velocity method requires extreme Doppler precision and long-term stability in order to measure tiny reflex velocities in the host star. Recent planet searches have led to the detection of so called "super-Earths” (up to a few Earth masses) that induce radial velocity changes of about 1 m/s. However, the detection of true Earth analogs requires a precision of 10 cm/s. One of the largest factors limiting Doppler precision is variation in the Point Spread Function (PSF) from observation to observation due to changes in the illumination of the slit and spectrograph optics. Thus, this stability has become a focus of current instrumentation work. Fiber optics have been used since the 1980's to couple telescopes to high-precision spectrographs, initially for simpler mechanical design and control. However, fiber optics are also naturally efficient scramblers. Scrambling refers to a fiber's ability to produce an output beam independent of input. Our research is focused on characterizing the scrambling properties of several types of fibers, including circular, square and octagonal fibers. By measuring the intensity distribution after the fiber as a function of input beam position, we can simulate guiding errors that occur at an observatory. Through this, we can determine which fibers produce the most uniform outputs for the severest guiding errors, improving the PSF and allowing sub-m/s precision. However, extensive testing of fibers of supposedly identical core diameter, length and shape from the same manufacturer has revealed the "personality” of individual fibers. Personality describes differing intensity patterns for supposedly duplicate fibers illuminated identically. Here, we present our results on scrambling characterization as a function of fiber type, while studying individual fiber personality.

  6. High precision radial velocities with GIANO spectra

    NASA Astrophysics Data System (ADS)

    Carleo, I.; Sanna, N.; Gratton, R.; Benatti, S.; Bonavita, M.; Oliva, E.; Origlia, L.; Desidera, S.; Claudi, R.; Sissa, E.

    2016-06-01

    Radial velocities (RV) measured from near-infrared (NIR) spectra are a potentially excellent tool to search for extrasolar planets around cool or active stars. High resolution infrared (IR) spectrographs now available are reaching the high precision of visible instruments, with a constant improvement over time. GIANO is an infrared echelle spectrograph at the Telescopio Nazionale Galileo (TNG) and it is a powerful tool to provide high resolution spectra for accurate RV measurements of exoplanets and for chemical and dynamical studies of stellar or extragalactic objects. No other high spectral resolution IR instrument has GIANO's capability to cover the entire NIR wavelength range (0.95-2.45 μm) in a single exposure. In this paper we describe the ensemble of procedures that we have developed to measure high precision RVs on GIANO spectra acquired during the Science Verification (SV) run, using the telluric lines as wavelength reference. We used the Cross Correlation Function (CCF) method to determine the velocity for both the star and the telluric lines. For this purpose, we constructed two suitable digital masks that include about 2000 stellar lines, and a similar number of telluric lines. The method is applied to various targets with different spectral type, from K2V to M8 stars. We reached different precisions mainly depending on the H-magnitudes: for H ˜ 5 we obtain an rms scatter of ˜ 10 m s-1, while for H ˜ 9 the standard deviation increases to ˜ 50 ÷ 80 m s-1. The corresponding theoretical error expectations are ˜ 4 m s-1 and 30 m s-1, respectively. Finally we provide the RVs measured with our procedure for the targets observed during GIANO Science Verification.

  7. High precision radial velocities with GIANO spectra

    NASA Astrophysics Data System (ADS)

    Carleo, I.; Sanna, N.; Gratton, R.; Benatti, S.; Bonavita, M.; Oliva, E.; Origlia, L.; Desidera, S.; Claudi, R.; Sissa, E.

    2016-03-01

    Radial velocities (RV) measured from near-infrared (NIR) spectra are a potentially excellent tool to search for extrasolar planets around cool or active stars. High resolution infrared (IR) spectrographs now available are reaching the high precision of visible instruments, with a constant improvement over time. GIANO is an infrared echelle spectrograph at the Telescopio Nazionale Galileo (TNG) and it is a powerful tool to provide high resolution spectra for accurate RV measurements of exoplanets and for chemical and dynamical studies of stellar or extragalactic objects. No other high spectral resolution IR instrument has GIANO's capability to cover the entire NIR wavelength range (0.95-2.45 μm) in a single exposure. In this paper we describe the ensemble of procedures that we have developed to measure high precision RVs on GIANO spectra acquired during the Science Verification (SV) run, using the telluric lines as wavelength reference. We used the Cross Correlation Function (CCF) method to determine the velocity for both the star and the telluric lines. For this purpose, we constructed two suitable digital masks that include about 2000 stellar lines, and a similar number of telluric lines. The method is applied to various targets with different spectral type, from K2V to M8 stars. We reached different precisions mainly depending on the H-magnitudes: for H ˜ 5 we obtain an rms scatter of ˜ 10 m s-1, while for H ˜ 9 the standard deviation increases to ˜ 50 ÷ 80 m s-1. The corresponding theoretical error expectations are ˜ 4 m s-1 and 30 m s-1, respectively. Finally we provide the RVs measured with our procedure for the targets observed during GIANO Science Verification.

  8. Note: High precision measurements using high frequency gigahertz signals

    NASA Astrophysics Data System (ADS)

    Jin, Aohan; Fu, Siyuan; Sakurai, Atsunori; Liu, Liang; Edman, Fredrik; Pullerits, Tõnu; Öwall, Viktor; Karki, Khadga Jung

    2014-12-01

    Generalized lock-in amplifiers use digital cavities with Q-factors as high as 5 × 108 to measure signals with very high precision. In this Note, we show that generalized lock-in amplifiers can be used to analyze microwave (giga-hertz) signals with a precision of few tens of hertz. We propose that the physical changes in the medium of propagation can be measured precisely by the ultra-high precision measurement of the signal. We provide evidence to our proposition by verifying the Newton's law of cooling by measuring the effect of change in temperature on the phase and amplitude of the signals propagating through two calibrated cables. The technique could be used to precisely measure different physical properties of the propagation medium, for example, the change in length, resistance, etc. Real time implementation of the technique can open up new methodologies of in situ virtual metrology in material design.

  9. High-precision spectroscopy of hydrogen molecular ions

    NASA Astrophysics Data System (ADS)

    Zhong, Zhen-Xiang; Tong, Xin; Yan, Zong-Chao; Shi, Ting-Yun

    2015-05-01

    In this paper, we overview recent advances in high-precision structure calculations of the hydrogen molecular ions ( and HD+), including nonrelativistic energy eigenvalues and relativistic and quantum electrodynamic corrections. In combination with high-precision measurements, it is feasible to precisely determine a molecular-based value of the proton-to-electron mass ratio. An experimental scheme is presented for measuring the rovibrational transition frequency (v,L) : (0,0) → (6,1) in HD+, which is currently underway at the Wuhan Institute of Physics and Mathematics. Project supported by the National Natural Science Foundation of China (Grants Nos. 11474316, 11004221, 10974224, and 11274348), the “Hundred Talent Program” of Chinese Academy of Sciences. Yan Zong-Chao was supported by NSERC, SHARCnet, ACEnet of Canada, and the CAS/SAFEA International Partnership Program for Creative Research Teams.

  10. High Precision Spectroscopy of Neutral Beryllium-9

    NASA Astrophysics Data System (ADS)

    Lau, Chui Yu; Williams, Will

    2015-05-01

    We report on the progress of high precision spectroscopy of the 2s2p singlet and triplet states in beryllium-9. Our goal is to improve the experimental precision on the energy levels of the 2s2p triplet J = 0, 1, and 2 states by a factor of 500, 100, and 500 respectively in order to delineate various theoretical predictions. The goal for the 2s2p singlet (J = 1) state is to improve the experimental precision on the energy level by a factor of 600 as a test of quantum electrodynamics. Our experimental setup consists of an oven capable of 1400 C that produces a collimated beam of neutral beryllium-9. The triplet states are probed with a 455 nm ECDL stabilized to a tellurium-210 line. The singlet state is probed with 235nm light from a frequency quadrupled titanium sapphire laser, where the frequency doubled light at 470 nm is stabilized to another tellurium-210 line. We also present our progress on improving the absolute accuracy of our frequency reference by using an ultrastable/low drift fiber coupled cavity.

  11. Precision mass measurements of highly charged ions

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Bale, J. C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Ettenauer, S.; Frekers, D.; Gallant, A. T.; Grossheim, A.; Lennarz, A.; Mane, E.; MacDonald, T. D.; Schultz, B. E.; Simon, M. C.; Simon, V. V.; Dilling, J.

    2012-10-01

    The reputation of Penning trap mass spectrometry for accuracy and precision was established with singly charged ions (SCI); however, the achievable precision and resolving power can be extended by using highly charged ions (HCI). The TITAN facility has demonstrated these enhancements for long-lived (T1/2>=50 ms) isobars and low-lying isomers, including ^71Ge^21+, ^74Rb^8+, ^78Rb^8+, and ^98Rb^15+. The Q-value of ^71Ge enters into the neutrino cross section, and the use of HCI reduced the resolving power required to distinguish the isobars from 3 x 10^5 to 20. The precision achieved in the measurement of ^74Rb^8+, a superallowed β-emitter and candidate to test the CVC hypothesis, rivaled earlier measurements with SCI in a fraction of the time. The 111.19(22) keV isomeric state in ^78Rb was resolved from the ground state. Mass measurements of neutron-rich Rb and Sr isotopes near A = 100 aid in determining the r-process pathway. Advanced ion manipulation techniques and recent results will be presented.

  12. Innovations in Calculating Precise Nutrient Intake of Hospitalized Patients

    PubMed Central

    Sullivan, Sheila Cox; Bopp, Melinda M.; Weaver, Dennis L.; Sullivan, Dennis H.

    2016-01-01

    Obtaining a detailed assessment of a hospitalized patient’s nutrient intake is often critically important to ensuring the patient’s successful recovery. However, this process is often laborious and prone to error. Inaccurate nutrient intake assessments result in the inability of the healthcare team to recognize patients with developing nutritional deficits that contribute to delayed recovery and prolonged lengths of stay. This paper describes an innovative, easy to use system designed to increase the precision of calorie count reports by using a combination of photography, direct observation, and a specially developed computer program. Although the system was designed specifically for use in a Department of Veterans Affairs Hospital, it has the potential to be adapted for use in other hospital environments. PMID:27384584

  13. Innovations in Calculating Precise Nutrient Intake of Hospitalized Patients.

    PubMed

    Sullivan, Sheila Cox; Bopp, Melinda M; Weaver, Dennis L; Sullivan, Dennis H

    2016-01-01

    Obtaining a detailed assessment of a hospitalized patient's nutrient intake is often critically important to ensuring the patient's successful recovery. However, this process is often laborious and prone to error. Inaccurate nutrient intake assessments result in the inability of the healthcare team to recognize patients with developing nutritional deficits that contribute to delayed recovery and prolonged lengths of stay. This paper describes an innovative, easy to use system designed to increase the precision of calorie count reports by using a combination of photography, direct observation, and a specially developed computer program. Although the system was designed specifically for use in a Department of Veterans Affairs Hospital, it has the potential to be adapted for use in other hospital environments. PMID:27384584

  14. Precision timing measurements for high energy photons

    NASA Astrophysics Data System (ADS)

    Anderson, Dustin; Apreysan, Artur; Bornheim, Adi; Duarte, Javier; Newman, Harvey; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Trevor, Jason; Xie, Si; Zhu, Ren-Yuan

    2015-07-01

    Particle colliders operating at high luminosities present challenging environments for high energy physics event reconstruction and analysis. We discuss how timing information, with a precision on the order of 10 ps, can aid in the reconstruction of physics events under such conditions. We present calorimeter based timing measurements from test beam experiments in which we explore the ultimate timing precision achievable for high energy photons or electrons of 10 GeV and above. Using a prototype calorimeter consisting of a 1.7×1.7×1.7 cm3 lutetium-yttrium oxyortho-silicate (LYSO) crystal cube, read out by micro-channel plate photomultipliers, we demonstrate a time resolution of 33.5±2.1 ps for an incoming beam energy of 32 GeV. In a second measurement, using a 2.5×2.5×20 cm3 LYSO crystal placed perpendicularly to the electron beam, we achieve a time resolution of 59±11 ps using a beam energy of 4 GeV. We also present timing measurements made using a shashlik-style calorimeter cell made of LYSO and tungsten plates, and demonstrate that the apparatus achieves a time resolution of 54±5 ps for an incoming beam energy of 32 GeV.

  15. Precision timing measurements for high energy photons

    SciTech Connect

    Anderson, Dustin; Apreysan, Artur; Bornheim, Adi; Duarte, Javier; Newman, Harvey; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Trevor, Jason; Xie, Si; Zhu, Ren-Yuan

    2014-11-21

    Particle colliders operating at high luminosities present challenging environments for high energy physics event reconstruction and analysis. We discuss how timing information, with a precision on the order of 10 ps, can aid in the reconstruction of physics events under such conditions. We present calorimeter based timing measurements from test beam experiments in which we explore the ultimate timing precision achievable for high energy photons or electrons of 10 GeV and above. Using a prototype calorimeter consisting of a 1.7×1.7×1.7 cm3 lutetium–yttrium oxyortho-silicate (LYSO) crystal cube, read out by micro-channel plate photomultipliers, we demonstrate a time resolution of 33.5±2.1 ps for an incoming beam energy of 32 GeV. In a second measurement, using a 2.5×2.5×20 cm3 LYSO crystal placed perpendicularly to the electron beam, we achieve a time resolution of 59±11 ps using a beam energy of 4 GeV. We also present timing measurements made using a shashlik-style calorimeter cell made of LYSO and tungsten plates, and demonstrate that the apparatus achieves a time resolution of 54±5 ps for an incoming beam energy of 32 GeV.

  16. High precision kinematic surveying with laser scanners

    NASA Astrophysics Data System (ADS)

    Gräfe, Gunnar

    2007-12-01

    The kinematic survey of roads and railways is becoming a much more common data acquisition method. The development of the Mobile Road Mapping System (MoSES) has reached a level that allows the use of kinematic survey technology for high precision applications. The system is equipped with cameras and laser scanners. For high accuracy requirements, the scanners become the main sensor group because of their geometric precision and reliability. To guarantee reliable survey results, specific calibration procedures have to be applied, which can be divided into the scanner sensor calibration as step 1, and the geometric transformation parameter estimation with respect to the vehicle coordinate system as step 2. Both calibration steps include new methods for sensor behavior modeling and multisensor system integration. To verify laser scanner quality of the MoSES system, the results are regularly checked along different test routes. It can be proved that a standard deviation of 0.004 m for height of the scanner points will be obtained, if the specific calibrations and data processing methods are applied. This level of accuracy opens new possibilities to serve engineering survey applications using kinematic measurement techniques. The key feature of scanner technology is the full digital coverage of the road area. Three application examples illustrate the capabilities. Digital road surface models generated from MoSES data are used, especially for road surface reconstruction tasks along highways. Compared to static surveys, the method offers comparable accuracy at higher speed, lower costs, much higher grid resolution and with greater safety. The system's capability of gaining 360 profiles leads to other complex applications like kinematic tunnel surveys or the precise analysis of bridge clearances.

  17. Pitch evaluation of high-precision gratings

    NASA Astrophysics Data System (ADS)

    Lu, Yancong; Zhou, Changhe; Wei, Chunlong; Jia, Wei; Xiang, Xiansong; Li, Yanyang; Yu, Junjie; Li, Shubin; Wang, Jin; Liu, Kun; Wei, Shengbin

    2014-11-01

    Optical encoders and laser interferometers are two primary solutions in nanometer metrology. As the precision of encoders depends on the uniformity of grating pitches, it is essential to evaluate pitches accurately. We use a CCD image sensor to acquire grating image for evaluating the pitches with high precision. Digital image correlation technique is applied to filter out the noises. We propose three methods for determining the pitches of grating with peak positions of correlation coefficients. Numerical simulation indicated the average of pitch deviations from the true pitch and the pitch variations are less than 0.02 pixel and 0.1 pixel for these three methods when the ideal grating image is added with salt and pepper noise, speckle noise, and Gaussian noise. Experimental results demonstrated that our method can measure the pitch of the grating accurately, for example, our home-made grating with 20μm period has 475nm peak-to-valley uniformity with 40nm standard deviation during 35mm range. Another measurement illustrated that our home-made grating has 40nm peak-to-valley uniformity with 10nm standard deviation. This work verified that our lab can fabricate high-accuracy gratings which should be interesting for practical application in optical encoders.

  18. Highly precise clocks to test fundamental physics

    NASA Astrophysics Data System (ADS)

    Bize, S.; Wolf, P.

    2012-12-01

    Highly precise atomic clocks and precision oscillators are excellent tools to test founding principles, such as the Equivalence Principle, which are the basis of modern physics. A large variety of tests are possible, including tests of Local Lorentz Invariance, of Local Position Invariance like, for example, tests of the variability of natural constants with time and with gravitation potential, tests of isotropy of space, etc. Over several decades, SYRTE has developed an ensemble of highly accurate atomic clocks and oscillators using a large diversity of atomic species and methods. The SYRTE clock ensemble comprises hydrogen masers, Cs and Rb atomic fountain clocks, Sr and Hg optical lattice clocks, as well as ultra stable oscillators both in the microwave domain (cryogenic sapphire oscillator) and in the optical domain (Fabry-Perot cavity stabilized ultra stable lasers) and means to compare these clocks locally or remotely (fiber links in the RF and the optical domain, femtosecond optical frequency combs, satellite time and frequency transfer methods). In this paper, we list the fundamental physics tests that have been performed over the years with the SYRTE clock ensemble. Several of these tests are done thanks to the collaboration with partner institutes including the University of Western Australia, the Max Planck Institut für Quantenoptik in Germany, and others.

  19. High precision innovative micropump for artificial pancreas

    NASA Astrophysics Data System (ADS)

    Chappel, E.; Mefti, S.; Lettieri, G.-L.; Proennecke, S.; Conan, C.

    2014-03-01

    The concept of artificial pancreas, which comprises an insulin pump, a continuous glucose meter and a control algorithm, is a major step forward in managing patient with type 1 diabetes mellitus. The stability of the control algorithm is based on short-term precision micropump to deliver rapid-acting insulin and to specific integrated sensors able to monitor any failure leading to a loss of accuracy. Debiotech's MEMS micropump, based on the membrane pump principle, is made of a stack of 3 silicon wafers. The pumping chamber comprises a pillar check-valve at the inlet, a pumping membrane which is actuated against stop limiters by a piezo cantilever, an anti-free-flow outlet valve and a pressure sensor. The micropump inlet is tightly connected to the insulin reservoir while the outlet is in direct communication with the patient skin via a cannula. To meet the requirement of a pump dedicated to closed-loop application for diabetes care, in addition to the well-controlled displacement of the pumping membrane, the high precision of the micropump is based on specific actuation profiles that balance effect of pump elasticity in low-consumption push-pull mode.

  20. Highly damped kinematic coupling for precision instruments

    DOEpatents

    Hale, Layton C.; Jensen, Steven A.

    2001-01-01

    A highly damped kinematic coupling for precision instruments. The kinematic coupling provides support while causing essentially no influence to its nature shape, with such influences coming, for example, from manufacturing tolerances, temperature changes, or ground motion. The coupling uses three ball-cone constraints, each combined with a released flexural degree of freedom. This arrangement enables a gain of higher load capacity and stiffness, but can also significantly reduce the friction level in proportion to the ball radius divided by the distance between the ball and the hinge axis. The blade flexures reduces somewhat the stiffness of the coupling and provides an ideal location to apply constrained-layer damping which is accomplished by attaching a viscoelastic layer and a constraining layer on opposite sides of each of the blade flexures. The three identical ball-cone flexures provide a damped coupling mechanism to kinematically support the projection optics system of the extreme ultraviolet lithography (EUVL) system, or other load-sensitive apparatus.

  1. High-Precision Computation: Mathematical Physics and Dynamics

    SciTech Connect

    Bailey, D. H.; Barrio, R.; Borwein, J. M.

    2010-04-01

    At the present time, IEEE 64-bit oating-point arithmetic is suficiently accurate for most scientic applications. However, for a rapidly growing body of important scientic computing applications, a higher level of numeric precision is required. Such calculations are facilitated by high-precision software packages that include high-level language translation modules to minimize the conversion e ort. This pa- per presents a survey of recent applications of these techniques and provides someanalysis of their numerical requirements. These applications include supernova simulations, climate modeling, planetary orbit calculations, Coulomb n-body atomic systems, studies of the one structure constant, scattering amplitudes of quarks, glu- ons and bosons, nonlinear oscillator theory, experimental mathematics, evaluation of orthogonal polynomials, numerical integration of ODEs, computation of periodic orbits, studies of the splitting of separatrices, detection of strange nonchaotic at- tractors, Ising theory, quantum held theory, and discrete dynamical systems. We conclude that high-precision arithmetic facilities are now an indispensable compo- nent of a modern large-scale scientic computing environment.

  2. High Precision Spectroscopy of CH_5^+ Using Nice-Ohvms

    NASA Astrophysics Data System (ADS)

    Hodges, James N.; Perry, Adam J.; McCall, Benjamin J.

    2013-06-01

    The elusive methonium ion, CH_5^+, is of great interest due to its highly fluxional nature. The only published high-resolution infrared spectrum remains completely unassigned to this date. The primary challenge in understanding the CH_5^+ spectrum is that traditional spectroscopic approaches rely on a molecule having only small (or even large) amplitude motions about a well-defined reference geometry, and this is not the case with CH_5^+. We are in the process of re-scanning Oka's spectrum, in the original Black Widow discharge cell, using the new technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS). The high precision afforded by optical saturation in conjunction with a frequency comb allows transition line centers to be determined with sub-MHz accuracy and precision -- a substantial improvement over the 90 MHz precision of Oka's work. With a high-precision linelist in hand, we plan to search for four line combination differences to directly determine the spacings between rotational energy levels. Such a search is currently infeasible due to the large number of false positives resulting from the relatively low precision and high spectral density of Oka's spectrum. The resulting combination differences, in conjunction with state-of-the-art theoretical calculations from Tucker Carrington, may provide the first insight into the rotational structure of this unique molecular system. E. T. White, J. Tang, T. Oka, Science (1999) 284, 135--137. B. M. Siller, et al. Opt. Express (2011), 19, 24822--24827. K. N. Crabtree, et al. Chem. Phys. Lett. (2012), 551, 1--6. X. Wang, T. Carrington, J. Chem. Phys., (2008), 129, 234102.

  3. Injection molded high precision freeform optics for high volume applications

    NASA Astrophysics Data System (ADS)

    Dick, Lars; Risse, Stefan; Tünnermann, Andreas

    2012-03-01

    Injection molding offers a cost-efficient method for manufacturing high precision plastic optics for high-volume applications. Optical surfaces such as flats, spheres and also aspheres are meanwhile state-of-the-art in the field of plastic optics. The demand for surfaces without symmetric properties, commonly referred to as freeform surfaces, continues to rise. Currently, new mathematical approaches are under consideration which allow for new complex optical designs. Such novel optical designs strongly encourage development of new manufacturing methods. Specifically, new surface descriptions without an axis of symmetry, new ultra precision machining methods and non-symmetrical shrinkage compensation strategies have to be developed to produce freeform optical surfaces with high precision for high-volume applications. This paper will illustrate a deterministic and efficient way for the manufacturing of ultra precision injection molding tool inserts with submicron precision and show the manufacturing of replicated freeform surfaces with micrometer range shape accuracy at diameters up to 40 mm with a surface roughness of approximately 2 nm.

  4. Aerodynamic window for high precision laser drilling

    NASA Astrophysics Data System (ADS)

    Sommer, Steffen; Dausinger, Friedrich; Berger, Peter; Hügel, Helmuth

    2007-05-01

    High precision laser drilling is getting more and more interesting for industry. Main applications for such holes are vaporising and injection nozzles. To enhance quality, the energy deposition has to be accurately defined by reducing the pulse duration and thereby reducing the amount of disturbing melting layer. In addition, an appropriate processing technology, for example the helical drilling, yields holes in steel at 1 mm thickness and diameters about 100 μm with correct roundness and thin recast layers. However, the processing times are still not short enough for industrial use. Experiments have shown that the reduction of the atmospheric pressure down to 100 hPa enhances the achievable quality and efficiency, but the use of vacuum chambers in industrial processes is normally quite slow and thus expensive. The possibility of a very fast evacuation is given by the use of an aerodynamic window, which produces the pressure reduction by virtue of its fluid dynamic features. This element, based on a potential vortex, was developed and patented as out-coupling window for high power CO II lasers by IFSW 1, 2, 3. It has excellent tightness and transmission properties, and a beam deflection is not detectable. The working medium is compressed air, only. For the use as vacuum element for laser drilling, several geometrical modifications had to be realized. The prototype is small enough to be integrated in a micromachining station and has a low gas flow. During the laser pulse, which is focussed through the potential flow, a very high fluence is reached, but the measurements have not shown any beam deflection or focal shifting. The evacuation time is below 300 ms so that material treatment with changing ambient pressure is possible, too. Experimental results have proven the positive effect of the reduced ambient pressure on the drilling process for the regime of nano- and picosecond laser pulses. Plasma effects are reduced and, because of the less absorption, the

  5. High precision optical surface metrology using deflectometry

    NASA Astrophysics Data System (ADS)

    Huang, Run

    Software Configurable Optical Test System (SCOTS) developed at University of Arizona is a highly efficient optical metrology technique based on the principle of deflectometry, which can achieve comparable accuracy with interferometry but with low-cost hardware. In a SCOTS test, an LCD display is used to generate structured light pattern to illuminate the test optics and the reflected light is captured by a digital camera. The surface slope of test optics is determined by triangulation of the display pixels, test optics, and the camera. The surface shape is obtained by the integration of the slopes. Comparing to interferometry, which has long served as an accurate non-contact optical metrology technology, SCOTS overcomes the limitation of dynamic range and sensitivity to environment. It is able to achieve high dynamic range slope measurement without requiring null optics. In this dissertation, the sensitivity and performance of the test system have been analyzed comprehensively. Sophisticated calibrations of system components have been investigated and implemented in different metrology projects to push this technology to a higher accuracy including low-order terms. A compact on-axis SCOTS system lowered the testing geometry sensitivity in the metrology of 1-meter highly aspheric secondary mirror of Large Binocular Telescope. Sub-nm accuracy was achieved in testing a high precision elliptical X-ray mirror by using reference calibration. A well-calibrated SCOTS was successfully constructed and is, at the time of writing this dissertation, being used to provide surface metrology feedback for the fabrication of the primary mirror of Daniel K. Inouye Solar Telescope which is a 4-meter off-axis parabola with more than 8 mm aspherical departure.

  6. High precision beam alignment of electromagnetic wigglers

    SciTech Connect

    Ben-Zvi, I.; Qiu, X.Z.

    1993-01-01

    The performance of Free-Electron Lasers depends critically on the quality of the alignment of the electron beam to the wiggler's magnetic axis and the deviation of this axis from a straight fine. The measurement of the electron beam position requires numerous beam position monitors in the wiggler, where space is at premium. The beam position measurement is used to set beam steerers for an orbit correction in the wiggler. The authors propose an alternative high precision alignment method in which one or two external Beam Position Monitors (BPM) are used. In this technique, the field in the electro-wiggler is modulated section by section and the beam position movement at the external BPM is detected in synchronism with the modulation. A beam offset at the modulated beam section will produce a modulation of the beam position at the detector that is a function of the of the beam offset and the absolute value of the modulation current. The wiggler errors produce a modulation that is a function of the modulation current. It will be shown that this method allows the detection and correction of the beam position at each section in the presence of wiggler errors with a good resolution. Furthermore, it allows one to measure the first and second integrals of the wiggler error over each wiggler section. Lastly, provided that wiggler sections can be degaussed effectively, one can test the deviation of the wiggler's magnetic axis from a straight line.

  7. High-Precision Motorcycle Trajectory Measurements Using GPS

    NASA Astrophysics Data System (ADS)

    Koyama, Yuichiro; Tanaka, Toshiyuki

    A method for measuring motorcycle trajectory using GPS is needed for simulating motorcycle dynamics. In GPS measurements of a motorcycle, both the declination of the motorcycle and obstacles near the course can cause problems. Therefore, we propose a new algorithm for GPS measurement of motorcycle trajectory. We interpolate the missing observation data within a few seconds using polynomial curves, and use a Kalman filter to smoothen position calculations. This results in obtaining trajectory with high accuracy and with sufficient continuity. The precision is equal to that of fixed point positioning, given a sufficient number of available satellites.

  8. [High Precision Spectral Calibration Method of Fourier Interferometric Spectrometer].

    PubMed

    Lin, Jun; Shao, Jun; Song, Chao-yu; Li, Yun-wei; Lei, Yu-fei

    2015-12-01

    The Fourier interferometric spectrometer (FIS) acquires the interference data information of the spectrum and during the spectrum data processing, a series of spectrum reconstruction will be performed on the interference information to obtain the final spectrum information data. The spectral calibration is the key step to spectrum reconstruction of FIS, which directly determines accuracy and availability of the spectrum results. This paper introduces the basic ideas and calibration accuracy about the spectral calibration for the FIS and puts forward a new spectral calibration method based on calculating the precise value of the total optical path difference (TOPD). The TOPD of FIS is difficult to be precisely measured, but it is the core and key to the spectral calibration. In order to calculate the precise TOPD, this paper proposes the idea how to traverse the TOPD and analyzes the spectrum drift. During the calibration, all the possible values of the TOPD participate in the spectrum reconstruction flow to carry out spectrum recovery and analysis. Ultimately the TOPD with the minimum spectrum drift will be achieved, namely solution value of the TOPD. This method can accurately resolve the TOPD of the FIS and then calibrate the spectrum with high accuracy. In addition, the paper introduces the detailed and complete spectral calibration flow and obtains the center wavelength value of every band and wavenumber resolution. Moreover, the paper designs the main parameters of the typical FIS and generates its simulation interference data. Using the above method to calibrate the simulation data, the analysis and verification of the spectral calibration results proves that the calibration precision of wavenumber resolution achieves 0.000 25 cm⁻¹ or above. PMID:26964245

  9. Ultrastable Lasers and High-Precision Measurements

    NASA Astrophysics Data System (ADS)

    Chardonnet, Christian; Cohadon, Pierre-François Guellati-Khélifa, Saïda

    2015-10-01

    Lasers quickly escaped research laboratories to be included in just a few years' time into a large number of everyday life applications, but they remain a yet unrivaled tool for fundamental physics. This chapter presents the main characteristics of the lasers that physicists take advantage of in precision measurements, and a few examples of such measurements...

  10. High-precision positioning of radar scatterers

    NASA Astrophysics Data System (ADS)

    Dheenathayalan, Prabu; Small, David; Schubert, Adrian; Hanssen, Ramon F.

    2016-05-01

    Remote sensing radar satellites cover wide areas and provide spatially dense measurements, with millions of scatterers. Knowledge of the precise position of each radar scatterer is essential to identify the corresponding object and interpret the estimated deformation. The absolute position accuracy of synthetic aperture radar (SAR) scatterers in a 2D radar coordinate system, after compensating for atmosphere and tidal effects, is in the order of centimeters for TerraSAR-X (TSX) spotlight images. However, the absolute positioning in 3D and its quality description are not well known. Here, we exploit time-series interferometric SAR to enhance the positioning capability in three dimensions. The 3D positioning precision is parameterized by a variance-covariance matrix and visualized as an error ellipsoid centered at the estimated position. The intersection of the error ellipsoid with objects in the field is exploited to link radar scatterers to real-world objects. We demonstrate the estimation of scatterer position and its quality using 20 months of TSX stripmap acquisitions over Delft, the Netherlands. Using trihedral corner reflectors (CR) for validation, the accuracy of absolute positioning in 2D is about 7 cm. In 3D, an absolute accuracy of up to ˜ 66 cm is realized, with a cigar-shaped error ellipsoid having centimeter precision in azimuth and range dimensions, and elongated in cross-range dimension with a precision in the order of meters (the ratio of the ellipsoid axis lengths is 1/3/213, respectively). The CR absolute 3D position, along with the associated error ellipsoid, is found to be accurate and agree with the ground truth position at a 99 % confidence level. For other non-CR coherent scatterers, the error ellipsoid concept is validated using 3D building models. In both cases, the error ellipsoid not only serves as a quality descriptor, but can also help to associate radar scatterers to real-world objects.

  11. High-precision triangular-waveform generator

    DOEpatents

    Mueller, T.R.

    1981-11-14

    An ultra-linear ramp generator having separately programmable ascending and decending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

  12. High Precision Noise Measurements at Microwave Frequencies

    SciTech Connect

    Ivanov, Eugene; Tobar, Michael

    2009-04-23

    We describe microwave noise measurement system capable of detecting the phase fluctuations of rms amplitude of 2{center_dot}10{sup -11} rad/{radical}(Hz). Such resolution allows the study of intrinsic fluctuations in various microwave components and materials, as well as precise tests of fundamental physics. Employing this system we discovered a previously unknown phenomenon of down-conversion of pump oscillator phase noise into the low-frequency voltage fluctuations.

  13. High contrast gratings for high-precision metrology

    NASA Astrophysics Data System (ADS)

    Kroker, Stefanie; Steiner, Stefan; Käsebier, Thomas; Kley, Ernst-Bernhard; Tünnermann, Andreas

    2013-03-01

    Experiments in the field of high-precision optical metrology are crucially limited by thermal noise of the optical components such as mirrors or beam splitters. Amorphous coatings stacks are found to be a main source for these thermal fluctuations. In this contribution we present approaches to realize coating free optical components based on resonant high contrast gratings (HCGs) made of crystalline silicon. It is shown that beside classical cavity mirrors the concept of HCGs can also be used for reflective cavity couplers. We compare the advantages and challenges of these HCG reflectors with distributed Bragg reflectors made of crystalline coatings for applications in optical metrology.

  14. [IOL calculation for high ametropia].

    PubMed

    Haigis, W

    2008-11-01

    Long and short eyes are connected with high ametropia and constitute special problems for biometry and IOL calculations. Ultrasound measurements on these eyes, which often have altered geometries, are frequently more difficult than in normal eyes. This holds especially for long eyes, which significantly benefit from optical biometry. Measurement errors, IOL manufacturing tolerances and uncertainties regarding the effective lens position affect short eyes much more than normal eyes. The selection of a suitable IOL formula is of special importance for the refractive outcome. For short eyes, Holladay-2, HofferQ and Haigis are recommended, for long eyes Holladay-1, Holladay-2 and Haigis. In each case, optimized IOL constants must be used. If minus lenses for extremely long eyes are calculated with the same constants as plus lenses, a hyperopic refractive error is created, which can be avoided by a separate set of constants for minus lenses. For extremely short eyes the commonly used approximation of thinner lenses fails necessitating a thick lens calculation or raytracing. PMID:18998145

  15. High precision fabrication of antennas and sensors

    NASA Astrophysics Data System (ADS)

    Balčytis, A.; Seniutinas, G.; Urbonas, D.; Gabalis, M.; Vaškevičius, K.; Petruškevičius, R.; Molis, G.; Valušis, G. `.; Juodkazis, S.

    2015-02-01

    Electron and ion beam lithographies were used to fabricate and/or functionalize large scale - millimetre footprint - micro-optical elements: coupled waveguide-resonator structures on silicon-on-insulator (SOI) and THz antennas on low temperature grown LT-GaAs. Waveguide elements on SOI were made without stitching errors using a fixed beam moving stage approach. THz antennas were created using a three-step litography process. First, gold THz antennas defined by standard mask projection lithography were annealed to make an ohmic contact on LT-GaAs and post-processing with Ga-ion beam was used to define nano-gaps and inter digitised contacts for better charge collection. These approaches show the possibility to fabricate large footprint patterns with nanoscale precision features and overlay accuracy. Emerging 3D nanofabrication trends are discussed.

  16. High precision, high sensitivity distributed displacement and temperature measurements using OFDR-based phase tracking

    NASA Astrophysics Data System (ADS)

    Gifford, Dawn K.; Froggatt, Mark E.; Kreger, Stephen T.

    2011-05-01

    Optical Frequency Domain Reflectometry is used to measure distributed displacement and temperature change with very high sensitivity and precision by measuring the phase change of an optical fiber sensor as a function of distance with high spatial resolution and accuracy. A fiber containing semi-continuous Bragg gratings was used as the sensor. The effective length change, or displacement, in the fiber caused by small temperature changes was measured as a function of distance with a precision of 2.4 nm and a spatial resolution of 1.5 mm. The temperature changes calculated from this displacement were measured with precision of 0.001 C with an effective sensor gauge length of 12 cm. These results demonstrate that the method employed of continuously tracking the phase change along the length of the fiber sensor enables high resolution distributed measurements that can be used to detect very small displacements, temperature changes, or strains.

  17. High precision droplet based new form manufacturing

    SciTech Connect

    Aceves,S; Hadjiconstantinou, N; Miller, W O; Orme, M; Sahai, V; Shapiro, A B

    1999-09-16

    In collaboration with the University of California at Irvine (UCI), we are working on a new technology that relies on the precise deposition of nanoliter molten-metal droplets that are targeted onto a substrate by electrostatic charging and deflection. By this way, three-dimensional (3D) structural materials can be manufactured microlayer by microlayer. Because the volume of the droplets are small, they rapidly solidify on impact, bringing forth a material component with fine grain structures which lead to enhanced material properties (e.g., strength). UCI is responsible for an experimental investigation of the manufacturing feasibility of this process. LLNL has unique expertise in the computational modeling of 3D heat transfer and solid mechanics and has the large-scale computer resources necessary to model this large system. Process modeling will help move this technology from the bench-top to an industrial process. Applications at LLNL include rapid prototyping of metal parts and manufacturing new alloys by co-jetting different metals.

  18. New scheme of high-precision visual collimator

    NASA Astrophysics Data System (ADS)

    Ge, Zhaoxiang; Ying, Han; Chen, Lei

    1998-08-01

    Machine manufacture and installation, special constructional engineering and precision engineering surveying need a very high precision collimator. In the text, we discus a plane focusing visual collimator, which had been specially made for the synchrotron accelerator. Using an electronic spirit level as the reference element, CCD automatic aiming system, photoelectric readout device and computer processing technology, the new visual collimator has a much higher precision and can be used more quickly, more conveniently and more reliably.

  19. High precision applications of the global positioning system

    NASA Technical Reports Server (NTRS)

    Lichten, Stephen M.

    1991-01-01

    The Global Positioning System (GPS) is a constellation of U.S. defense navigation satellites which can be used for military and civilian positioning applications. A wide variety of GPS scientific applications were identified and precise positioning capabilities with GPS were already demonstrated with data available from the present partial satellite constellation. Expected applications include: measurements of Earth crustal motion, particularly in seismically active regions; measurements of the Earth's rotation rate and pole orientation; high-precision Earth orbiter tracking; surveying; measurements of media propagation delays for calibration of deep space radiometric data in support of NASA planetary missions; determination of precise ground station coordinates; and precise time transfer worldwide.

  20. Research on high precision equal-angle scanning method in rotary kiln temperature measurement system

    NASA Astrophysics Data System (ADS)

    Dai, Shaosheng; Guo, Zhongyuan; You, Changhui; Liu, Jinsong; Cheng, Yang; Tang, Huaming

    2016-05-01

    Aiming at traditional horizontal equal-angle scanning method's disadvantage of measurement error, a high precision equal-angle scanning method is proposed, the proposed method establishes a tilt scanning model by the following steps: introducing height variable, precisely calculating the viewing angle, building scanning model. The model is used to calculate scanning position on rotary kiln's surface, which helps to locate and track temperature variation. The experiment shows that the proposed method can effectively improve the precision of temperature spots' location on the rotary kiln surface.

  1. High precision defocused observations of planetary transits

    NASA Astrophysics Data System (ADS)

    Baştürk, Ö.; Hinse, T. C.; Özavcı, İ.; Tezcan, C. T.; Şenavcı, H. V.; Burdanov, A.; Y&örükoǧlu, O.; Orhan, R.; Selam, S. O.

    2014-03-01

    It is only possible to measure physical properties of extrasolar planets, if they transit their host stars. One can determine the masses and the radii of this kind of objects, and hence, have constraints on their chemical composition, internal structure, formation and evolution. The availability of high quality light curves of planetary transits is essential in determining these properties within a few percent. In order to obtain high-quality transit light curves, we apply the well-established defocus technique on meter and sub-meter class telescopes in our project. This technique allows longer integration times, and hence collecting more photons to build up a higher S/N ratio. In this study, we present our first photometric results with the 1m Turkish telescope (T100) located at TÜBİTAK National Observatory (TUG) of Turkey, which proved to be a well suited instrument to these observations with its large field of view. %

  2. Precision Timing Calorimeter for High Energy Physics

    DOE PAGESBeta

    Anderson, Dustin; Apresyan, Artur; Bornheim, Adolf; Duarte, Javier; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Trevor, Jason; Xie, Si

    2016-04-01

    Here, we present studies on the performance and characterization of the time resolution of LYSO-based calorimeters. Results for an LYSO sampling calorimeter and an LYSO-tungsten Shashlik calorimeter are presented. We also demonstrate that a time resolution of 30 ps is achievable for the LYSO sampling calorimeter. Timing calorimetry is described as a tool for mitigating the effects due to the large number of simultaneous interactions in the high luminosity environment foreseen for the Large Hadron Collider.

  3. A precise calculation of the nondimentional factor of the Wien constant

    NASA Astrophysics Data System (ADS)

    Geru, Ion I.; Geru Vitalie, I.

    It has been established that the precision of the calculation of the Wien fundamental constant b=hc/(kX1), (h-the Planck constant, c-the speed of the light), X1 -the solution of the equation Xe^X-5(e^X-1) is limited by the errors of the measurements of the constants k,h and c. The numerical values of X1 , obtained here by two various methods of calculation (the method of iterations and the method of the division of the inteval) give the same results. Using the IBM PCAT it has been established that the 10-th iteration of X1 become a constant with the numerical value X1= 4,9651142317442763, determined by a precision of 10^8 times greater than the speed of light.

  4. Bridging Calorimetry and Simulation through Precise Calculations of Cucurbituril–Guest Binding Enthalpies

    PubMed Central

    2015-01-01

    We used microsecond time scale molecular dynamics simulations to compute, at high precision, binding enthalpies for cucurbit[7]uril (CB7) with eight guests in aqueous solution. The results correlate well with experimental data from previously published isothermal titration calorimetry studies, and decomposition of the computed binding enthalpies by interaction type provides plausible mechanistic insights. Thus, dispersion interactions appear to play a key role in stabilizing these complexes, due at least in part to the fact that their packing density is greater than that of water. On the other hand, strongly favorable Coulombic interactions between the host and guests are compensated by unfavorable solvent contributions, leaving relatively modest electrostatic contributions to the binding enthalpies. The better steric fit of the aliphatic guests into the circular host appears to explain why their binding enthalpies tend to be more favorable than those of the more planar aromatic guests. The present calculations also bear on the validity of the simulation force field. Somewhat unexpectedly, the TIP3P water yields better agreement with experiment than the TIP4P-Ew water model, although the latter is known to replicate the properties of pure water more accurately. More broadly, the present results demonstrate the potential for computational calorimetry to provide atomistic explanations for thermodynamic observations. PMID:25221445

  5. High precision mass measurements for wine metabolomics

    NASA Astrophysics Data System (ADS)

    Roullier-Gall, Chloé; Witting, Michael; Gougeon, Régis; Schmitt-Kopplin, Philippe

    2014-11-01

    An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS². In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (Pinot noir) and white (Chardonnay) wines from various geographic origins in Burgundy.

  6. High precision mass measurements for wine metabolomics

    PubMed Central

    Roullier-Gall, Chloé; Witting, Michael; Gougeon, Régis D.; Schmitt-Kopplin, Philippe

    2014-01-01

    An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS2. In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (Pinot noir) and white (Chardonnay) wines from various geographic origins in Burgundy. PMID:25431760

  7. Precision timing calorimeter for high energy physics

    NASA Astrophysics Data System (ADS)

    Anderson, Dustin; Apresyan, Artur; Bornheim, Adolf; Duarte, Javier; Peña, Cristián; Spiropulu, Maria; Trevor, Jason; Xie, Si; Ronzhin, Anatoly

    2016-07-01

    Scintillator based calorimeter technology is studied with the aim to achieve particle detection with a time resolution on the order of a few 10 ps for photons and electrons at energies of a few GeV and above. We present results from a prototype of a 1.4×1.4×11.4 cm3 sampling calorimeter cell consisting of tungsten absorber plates and Cerium-doped Lutetium Yttrium Orthosilicate (LYSO) crystal scintillator plates. The LYSO plates are read out with wave lengths shifting fibers which are optically coupled to fast photo detectors on both ends of the fibers. The measurements with electrons were performed at the Fermilab Test Beam Facility (FTBF) and the CERN SPS H2 test beam. In addition to the baseline setup plastic scintillation counter and a MCP-PMT were used as trigger and as a reference for a time of flight measurement (TOF). We also present measurements with a fast laser to further characterize the response of the prototype and the photo sensors. All data were recorded using a DRS4 fast sampling digitizer. These measurements are part of an R&D program whose aim is to demonstrate the feasibility of building a large scale electromagnetic calorimeter with a time resolution on the order of 10 ps, to be used in high energy physics experiments.

  8. High precision predictions for exclusive VH production at the LHC

    DOE PAGESBeta

    Li, Ye; Liu, Xiaohui

    2014-06-04

    We present a resummation-improved prediction for pp → VH + 0 jets at the Large Hadron Collider. We focus on highly-boosted final states in the presence of jet veto to suppress the tt¯ background. In this case, conventional fixed-order calculations are plagued by the existence of large Sudakov logarithms αnslogm(pvetoT/Q) for Q ~ mV + mH which lead to unreliable predictions as well as large theoretical uncertainties, and thus limit the accuracy when comparing experimental measurements to the Standard Model. In this work, we show that the resummation of Sudakov logarithms beyond the next-to-next-to-leading-log accuracy, combined with the next-to-next-to-leading ordermore » calculation, reduces the scale uncertainty and stabilizes the perturbative expansion in the region where the vector bosons carry large transverse momentum. Thus, our result improves the precision with which Higgs properties can be determined from LHC measurements using boosted Higgs techniques.« less

  9. Developing and implementing a high precision setup system

    NASA Astrophysics Data System (ADS)

    Peng, Lee-Cheng

    The demand for high-precision radiotherapy (HPRT) was first implemented in stereotactic radiosurgery using a rigid, invasive stereotactic head frame. Fractionated stereotactic radiotherapy (SRT) with a frameless device was developed along a growing interest in sophisticated treatment with a tight margin and high-dose gradient. This dissertation establishes the complete management for HPRT in the process of frameless SRT, including image-guided localization, immobilization, and dose evaluation. The most ideal and precise positioning system can allow for ease of relocation, real-time patient movement assessment, high accuracy, and no additional dose in daily use. A new image-guided stereotactic positioning system (IGSPS), the Align RT3C 3D surface camera system (ART, VisionRT), which combines 3D surface images and uses a real-time tracking technique, was developed to ensure accurate positioning at the first place. The uncertainties of current optical tracking system, which causes patient discomfort due to additional bite plates using the dental impression technique and external markers, are found. The accuracy and feasibility of ART is validated by comparisons with the optical tracking and cone-beam computed tomography (CBCT) systems. Additionally, an effective daily quality assurance (QA) program for the linear accelerator and multiple IGSPSs is the most important factor to ensure system performance in daily use. Currently, systematic errors from the phantom variety and long measurement time caused by switching phantoms were discovered. We investigated the use of a commercially available daily QA device to improve the efficiency and thoroughness. Reasonable action level has been established by considering dosimetric relevance and clinic flow. As for intricate treatments, the effect of dose deviation caused by setup errors remains uncertain on tumor coverage and toxicity on OARs. The lack of adequate dosimetric simulations based on the true treatment coordinates from

  10. Galvanometer deflection: a precision high-speed system.

    PubMed

    Jablonowski, D P; Raamot, J

    1976-06-01

    An X-Y galvanometer deflection system capable of high precision in a random access mode of operation is described. Beam positional information in digitized form is obtained by employing a Ronchi grating with a sophisticated optical detection scheme. This information is used in a control interface to locate the beam to the required precision. The system is characterized by high accuracy at maximum speed and is designed for operation in a variable environment, with particular attention placed on thermal insensitivity. PMID:20165203

  11. System and method for high precision isotope ratio destructive analysis

    DOEpatents

    Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R

    2013-07-02

    A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

  12. High-precision camera distortion measurements with a ``calibration harp''

    NASA Astrophysics Data System (ADS)

    Tang, Zhongwei; Grompone von Gioi, Rafael; Monasse, Pascal; Morel, Jean-Michel

    2012-10-01

    This paper addresses the high precision measurement of the distortion of a digital camera from photographs. Traditionally, this distortion is measured from photographs of a flat pattern which contains aligned elements. Nevertheless, it is nearly impossible to fabricate a very flat pattern and to validate its flatness. This fact limits the attainable measurable precisions. In contrast, it is much easier to obtain physically very precise straight lines by tightly stretching good quality strings on a frame. Taking literally "plumb-line methods", we built a "calibration harp" instead of the classic flat patterns to obtain a high precision measurement tool, demonstrably reaching 2/100 pixel precisions. The harp is complemented with the algorithms computing automatically from harp photographs two different and complementary lens distortion measurements. The precision of the method is evaluated on images corrected by state-of-the-art distortion correction algorithms, and by popular software. Three applications are shown: first an objective and reliable measurement of the result of any distortion correction. Second, the harp permits to control state-of-the art global camera calibration algorithms: It permits to select the right distortion model, thus avoiding internal compensation errors inherent to these methods. Third, the method replaces manual procedures in other distortion correction methods, makes them fully automatic, and increases their reliability and precision.

  13. High speed high precision ablation from ms to fs

    NASA Astrophysics Data System (ADS)

    Poprawe, Reinhart; Gillner, Arnold; Hoffmann, Dieter; Gottmann, Jens; Wawers, Welf; Schulz, Wolfgang

    2008-05-01

    In recent years new generations of precision lasers have been demonstrated and are increasingly available on an industrial level. For example high beam quality and diffraction limited Fiber lasers, Slab lasers, Disk lasers and still Rod lasers are used very successfully. This paper focuses on - ns and μs drilling of shaped holes by helical drilling1 - drilling of extreme aspect ratios in dielectrics/glass by ns-slab lasers2 - nm-size periodic structuring of polymers by interferometric approaches - ablation by ns- and ps-pulses for metal moulds - generation of waveguide structures in glass by fs-pulses.3 On the laboratory scale a next generation of diffraction limited short pulse lasers is at the horizon.4 In particular, ps-lasers at multi-hundred watts of average power with repetition rates of several MHz,2 fs-lasers at 400W2 average power and green, frequency doubled lasers at 200W are under construction. At the short end of pulses, attosecond lasers have been demonstrated and themselves shall open a new domain of interaction of light and matter5.

  14. High precision framework for chaos many-body engine

    NASA Astrophysics Data System (ADS)

    Grossu, I. V.; Besliu, C.; Felea, D.; Jipa, Al.

    2014-04-01

    In this paper we present a C# 4.0 high precision framework for simulation of relativistic many-body systems. In order to benefit from the, previously developed, chaos analysis instruments, all new modules were integrated with Chaos Many-Body Engine (Grossu et al. 2010, 2013). As a direct application, we used 46 digits precision for analyzing the "Butterfly Effect" of the gravitational force in a specific relativistic nuclear collision toy-model.

  15. High precision spectroscopy and imaging in THz frequency range

    NASA Astrophysics Data System (ADS)

    Vaks, Vladimir L.

    2014-03-01

    Application of microwave methods for development of the THz frequency range has resulted in elaboration of high precision THz spectrometers based on nonstationary effects. The spectrometers characteristics (spectral resolution and sensitivity) meet the requirements for high precision analysis. The gas analyzers, based on the high precision spectrometers, have been successfully applied for analytical investigations of gas impurities in high pure substances. These investigations can be carried out both in absorption cell and in reactor. The devices can be used for ecological monitoring, detecting the components of chemical weapons and explosive in the atmosphere. The great field of THz investigations is the medicine application. Using the THz spectrometers developed one can detect markers for some diseases in exhaled air.

  16. Observation of Optical Chemical Shift by Precision Nuclear Spin Optical Rotation Measurements and Calculations.

    PubMed

    Shi, Junhui; Ikäläinen, Suvi; Vaara, Juha; Romalis, Michael V

    2013-02-01

    Nuclear spin optical rotation (NSOR) is a recently developed technique for detection of nuclear magnetic resonance via rotation of light polarization, instead of the usual long-range magnetic fields. NSOR signals depend on hyperfine interactions with virtual optical excitations, giving new information about the nuclear chemical environment. We use a multipass optical cell to perform the first precision measurements of NSOR signals for a range of organic liquids and find clear distinction between proton signals for different compounds, in agreement with our earlier theoretical predictions. Detailed first-principles quantum mechanical NSOR calculations are found to be in agreement with the measurements. PMID:26281737

  17. Computer-controlled high-precision Michelson wavemeter

    NASA Astrophysics Data System (ADS)

    Pedregosa-Gutierrez, J.; Guyomarc'h, D.; Vedel, M.; Champenois, C.; Knoop, M.

    2014-09-01

    The Michelson wavemeter is a popular instrument in many experiments where the high-precision measurement of a cw laser wavelength is required. In this paper, we describe a simple and inexpensive way to obtain high-precision measurements with this classical physicist's tool. We exploit the time stamp provided by the high-frequency clock present in modern data acquisition cards to measure the fractional uncertainty of the interference signal. The resulting relative uncertainty value for our current set-up is of the order of 10-8 and can be potentially improved by a factor of 100.

  18. High-precision thermal and electrical characterization of thermoelectric modules

    SciTech Connect

    Kolodner, Paul

    2014-05-15

    This paper describes an apparatus for performing high-precision electrical and thermal characterization of thermoelectric modules (TEMs). The apparatus is calibrated for operation between 20 °C and 80 °C and is normally used for measurements of heat currents in the range 0–10 W. Precision thermometry based on miniature thermistor probes enables an absolute temperature accuracy of better than 0.010 °C. The use of vacuum isolation, thermal guarding, and radiation shielding, augmented by a careful accounting of stray heat leaks and uncertainties, allows the heat current through the TEM under test to be determined with a precision of a few mW. The fractional precision of all measured parameters is approximately 0.1%.

  19. New technique of machining high precision mirror surface press roller

    NASA Astrophysics Data System (ADS)

    Hongsen, Deng

    1991-03-01

    High precision mirror surface press roller machining technique of corrosion and grinding proof is one of the key techniques that the production enterprises as well as the machining and manufacturing of the following industries sought to resolve for a long time: plastics, papermaking, rubber, film, and chip production. In Oct. 1984, a new comprehensive machining technique of metal brush coating, grinding with abrasive belt, as well as buffing was used to conduct nearly 20 experiments. In Jan. 1985, a pair of middle convex high precision mirror surface press rollers was successfully machined. The technical process is described.

  20. Research on high-precision hole measurement based on robot vision method

    NASA Astrophysics Data System (ADS)

    Song, Li-mei; Li, Da-peng; Qin, Ming-cui; Li, Zong-yan; Chang, Yu-lan; Xi, Jiang-tao

    2014-09-01

    A high-precision vision detection and measurement system using mobile robot is established for the industry field detection of motorcycle frame hole and its diameter measurement. The robot path planning method is researched, and the non-contact measurement method with high precision based on visual digital image edge extraction and hole spatial circle fitting is presented. The Canny operator is used to extract the edge of captured image, the Lagrange interpolation algorithm is utilized to determine the missing image edge points and calculate the centroid, and the least squares fitting method is adopted to fit the image edge points. Experimental results show that the system can be used for the high-precision real-time measurement of hole on motorcycle frame. The absolute standard deviation of the proposed method is 0.026 7 mm. The proposed method can not only improve the measurement speed and precision, but also reduce the measurement error.

  1. Ultrasonic detector for high precision measurements of carbon dioxide.

    PubMed

    Andersen, Peter C; Williford, Craig J; David, Donald E; Birks, John W

    2010-10-01

    A new instrument for monitoring atmospheric CO(2) has been developed based on the measurement of the speed of sound in air. The instrument uses a selective scrubber to yield highly precise and accurate measurements of CO(2) mixing ratios at ambient concentrations. The instrument has a precision of 0.3 ppmv (1σ) with a signal that is independent of pressure and requires a flow rate of only 30 mL/min. Laboratory measurements of atmospheric CO(2) showed excellent agreement with values obtained by nondispersive infrared absorption. The instrument has the advantage of collecting continuous, high-precision data every 25 s and can be modified for vertical profiling studies using kites, balloons, or light aircraft for the purpose of measuring landscape-scale fluxes. PMID:20822160

  2. Precision glass molding: an integrative approach for the production of high precision micro-optics

    NASA Astrophysics Data System (ADS)

    Hünten, Martin; Klocke, Fritz; Dambon, Olaf

    2010-02-01

    Miniaturization and integration are the dominating factors for the success of numerous optical devices. Conventional manufacturing processes for the fabrication of precise glass optics by means of grinding and polishing cannot cope the increasing demands in terms of precision, volume and costs. Here, precision glass molding is the enabling technology to meet these demands of the future optical products and applications. Since the market requests further miniaturization and integration of the micro optical components the possession of the entire sequence of processes is absolutely essential. With the accomplished and ongoing developments at the Fraunhofer IPT, the replication of double-sided (a)spherical and (a)cylindrical glass lenses with form accuracies of < 150 nm as well as lens arrays and even freeform optics could be realized. Therefore, a sequence of processes needs to be passed. The FEM-simulation of the molding process which was driven to a point capable to simulate even the molding of freeform optics is the first process step. Further on, new mold design concepts were generated to enable the replication of free formed optics. The research works focusing on the mold manufacturing led to sophisticated grinding process strategies able to realized complex mold geometries such as lens arrays. With regard to the coating of the molds, proceedings were developed assuring a defect free and uniform coating which enables the longevity of the molds and therewith helps reducing the final costs per lens. Thus, the precision glass molding becomes more and more interesting even for highly complex mid volume lots, characteristic for European or US optics manufacturer.

  3. Precision high voltage divider for the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Thümmler, Th; Marx, R.; Weinheimer, Ch

    2009-10-01

    The Karlsruhe Tritium Neutrino (KATRIN) experiment aims to determine the absolute mass of the electron antineutrino from a precise measurement of the tritium β-spectrum near its endpoint at 18.6 keV with a sensitivity of 0.2 eV c-2. KATRIN uses an electrostatic retardation spectrometer of MAC-E filter type for which it is crucial to monitor high voltages of up to 35 kV with a precision and long-term stability at the ppm level. Since devices capable of this precision are not commercially available, a new high voltage divider for direct voltages of up to 35 kV has been designed, following the new concept of the standard divider for direct voltages of up to 100 kV developed at the Physikalisch-Technische Bundesanstalt (PTB)PTB is the German National Metrology Institute providing scientific and technical services.. The electrical and mechanical design of the divider, the screening procedure for the selection of the precision resistors, and the results of the investigation and calibration at the PTB are reported here. During the latter, uncertainties at the low ppm level have been deduced for the new divider, thus qualifying it for the precision measurements of the KATRIN experiment.

  4. VIEW OF MICROMACHINING, HIGH PRECISION EQUIPMENT USED TO CUSTOM MAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF MICRO-MACHINING, HIGH PRECISION EQUIPMENT USED TO CUSTOM MAKE SMALL PARTS. LUMPS OF CLAY; SHOWN IN THE PHOTOGRAPH, WERE USED TO STABILIZE PARTS BEING MACHINED. (11/1/87) - Rocky Flats Plant, Stainless Steel & Non-Nuclear Components Manufacturing, Southeast corner of intersection of Cottonwood & Third Avenues, Golden, Jefferson County, CO

  5. GENERATION AND CONTROL OF HIGH PRECISION BEAMS AT LEPTON ACCELERATORS

    SciTech Connect

    Yu-Chiu Chao

    2007-06-25

    Parity violation experiments require precision manipulation of helicity-correlated beam coordinates on target at the nm/nrad-level. Achieving this unprecedented level of control requires a detailed understanding of the particle optics and careful tuning of the beam transport to keep anomalies from compromising the design adiabatic damping. Such efforts are often hindered by machine configuration and instrumentation limitations at the low energy end. A technique has been developed at CEBAF including high precision measurements, Mathematica-based analysis for obtaining corrective solutions, and control hardware/software developments for realizing such level of control at energies up to 5 GeV.

  6. Modeling of High Precision Neutron Nonelastic Cross Sections

    SciTech Connect

    Dietrich, F S; Anderson, J D; Bauer, R W; Grimes, S M; McNabb, D P

    2007-02-05

    A new method has been applied to the determination of neutron nonelastic cross sections for iron {sup 56}Fe and lead {sup 208}Pb for energies between 5 and 26 MeV. These data have estimated errors of only a few percent and do not suffer from the ambiguities encountered in earlier nonelastic data. We attempt to fit these high precision data using both a semiclassical single phase shift model (nuclear Ramsauer model) as well as a recent global optical model that well reproduces a wide body of neutron scattering observables. At the 5% uncertainty level, both models produce satisfactory fits. However, neither model gives satisfactory fits to these new precise data. We conclude that fitting precise data, i.e., data with errors of approximately 2% or less, may require a nuclear mass dependence of radii that reflects structure effects such as shell closures.

  7. The Mainz high-precision proton form factor measurement

    NASA Astrophysics Data System (ADS)

    Bernauer, Jan

    2011-04-01

    Form factors offer a direct approach to fundamental properties of the nucleons like the radius and charge distribution. Renewed interest was stirred up by the 5 sigma discrepancy between a recent determination of the proton radius from the Lamb shift in muonic hydrogen and preceding electron scattering results. The low-q shape of the form factors might also contain a direct signal of a pion cloud around the nucleus and is a strong test of hadron models. In my talk, I will discuss the electron scattering experiment performed with the 3-spectrometer-facility of the A1 collaboration at MAMI in Mainz, Germany. The data set covers the Q2-range from 0.004 to 1 (GeV / c) 2 and includes about 1400 separate cross section measurements, spanning the range of scattering angles from below 20° to above 120° at six beam energies between 180 and 855 MeV, with statistical uncertainties below 0.4%. The 3-spectrometer-setup allowed for a simultaneous monitoring of the luminosity and overlapping and redundant measurements of the cross section to achieve stringent control over systematic uncertainties. Beam stabilization systems and redundant current measurements further limit systematic effects. The measured cross sections were analyzed with the standard Rosenbluth separation technique and by employing direct fits of a large set of form factor models. The high redundancy of the data set allowed us to extract the form factors up to 0.6 (GeV / c) 2 with very small uncertainties and to give a new, precise value for the proton radius from electron scattering. From the form factors, the charge distribution and Zemach moments were calculated. The latter constitute important input for the theoretical corrections of the muonic Lamb shift experiment. However, the revised values can not explain the discrepancy. Further possible explanations include higher order QED-corrections, vacuum effects or even physics beyond the standard model.

  8. A precise calculation of delayed coincidence selection efficiency and accidental coincidence rate

    NASA Astrophysics Data System (ADS)

    Yu, Jing-Yi; Wang, Zhe; Chen, Shao-Min

    2015-05-01

    A precise background evaluation model is proposed to address the complex data structure of the delayed coincidence method, which is widely used in reactor electron-antineutrino oscillation experiments. In this model, effects from the muon veto, uncorrelated random background, and background are all studied analytically, simplifying the estimation of the systematic uncertainties of signal efficiency and accidental background rate. The results of the calculations are validated numerically with a number of simulation studies and also applied and validated in the recent Daya Bay hydrogen-capture based oscillation measurement. Supported by Ministry of Science and Technology of China (2013CB834302), National Natural Science Foundation of China (11235006, 11475093), Tsinghua University Initiative Scientific Research Program (2012Z02161), and Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education.

  9. High Precision Photometry for the K2 Mission

    NASA Astrophysics Data System (ADS)

    Huang, Xu; Soares-Furtado, Melinda; Penev, Kaloyan; Hartman, Joel; Bakos, Gaspar; Bhatti, Waqas; Domsa, Istvan; de Val-Borro, Miguel

    2015-12-01

    The two reaction wheel K2 mission brings new challenges for the data reduction processes. We developed a reduction pipeline for extracting high precision photometry from the K2 dataset and we use this pipeline to generate light curves for the K2 Campaign 0 super-stamps and K2 Campaign 1 target pixel dataset. Key to our reduction technique is the derivation of global astrometric solutions from the target stamps from which accurate centroids are passed on for high precision photometry extraction. We also implemented the image subtraction method to reduce the K2 Campaign 0 super-stamps containing open clusters M35 and NGC2158. We extract target light curvesfor sources from a combined UCAC4 and EPIC catalogue -- this includes not only primary targets of the K2 Mission, but also other stars that happen to fall on the pixel stamps. Our astrometric solutions achieve a median residual of ~0.127". For bright stars, our best 6.5 hour precision for raw light curves is ~20 parts per million (ppm). For our detrended light curves, the best 6.5 hour precision achieved is ~15 ppm. We show that our detrended light curves have fewer systematic effects (or trends, or red-noise) than light curves produced by other groups from the same observations. We highlight the measurements of rotation curves using the K2 light curves of stars within open cluster M35 and NGC2158.

  10. High-precision Photogrammetric Surface Figure Measurements under Cryogenic Environment

    NASA Astrophysics Data System (ADS)

    Lou, Z.; Qian, Y.; Fan, S. H.; Liu, C. R.; Wang, H. R.; Zuo, Y. X.; Cheng, J. Q.; Yang, J.

    2016-01-01

    Limited by the working temperature of the measurement equipments, most of the high-precision surface figure measurement techniques cannot be applied under a cryogenic environment. This paper reports the first attempt to measure the surface figure of a high-precision terahertz reflector panel under low temperatures based on photogrammetry. The measurement employs a high resolution industrial camera sitting on an automatic experimental platform which enables photos been taken in an automatic fashion inside a climate chamber. A repeatable accuracy of 2.1 μm rms is achieved under the cryogenic environment. Furthermore, surface figure measured by a three-coordinate measuring machine under room temperature is used to calibrate the thickness variation of the paper targets. By this technique, the surface figure of an aluminum prototype panel of the 5 meter Dome A Terahertz Telescope (DATE5) is measured from room temperature down to -55°C.

  11. Communication: High precision sub-Doppler infrared spectroscopy of the HeH{sup +} ion

    SciTech Connect

    Perry, Adam J.; Hodges, James N.; Markus, Charles R.; Kocheril, G. Stephen; McCall, Benjamin J.

    2014-09-14

    The hydrohelium cation, HeH{sup +}, serves as an important benchmark for ab initio calculations that take into account non-adiabatic, relativistic, and quantum electrodynamic effects. Such calculations are capable of predicting molecular transitions to an accuracy of ∼300 MHz or less. However, in order to continue to push the boundaries on these calculations, new measurements of these transitions are required. Here we measure seven rovibrational transitions in the fundamental vibrational band to a precision of ∼1 MHz using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy. These newly measured transitions are included in a fit to the rotation-vibration term values to derive refined spectroscopic constants in the v = 0 and v = 1 vibrational states, as well as to calculate rotation-vibration energy levels with high precision.

  12. Laser processing system development of large area and high precision

    NASA Astrophysics Data System (ADS)

    Park, Hyeongchan; Ryu, Kwanghyun; Hwang, Taesang

    2013-03-01

    As industry of PCB (Printed Circuit Board) and display growing, this industry requires an increasingly high-precision quality so current cutting process in industry is preferred laser machining than mechanical machining. Now, laser machining is used almost "step and repeat" method in large area, but this method has a problem such as cutting quality in the continuity of edge parts, cutting speed and low productivity. To solve these problems in large area, on-the-fly (stagescanner synchronized system) is gradually increasing. On-the-fly technology is able to process large area with high speed because of stage-scanner synchronized moving. We designed laser-based high precision system with on-the-fly. In this system, we used UV nano-second pulse laser, power controller and scanner with telecentric f-theta lens. The power controller is consisted of HWP(Half Wave Plate), thin film plate polarizer, photo diode, micro step motor and control board. Laser power is possible to monitor real-time and adjust precision power by using power controller. Using this machine, we tested cutting of large area coverlay and sheet type large area PCB by applying on-the-fly. As a result, our developed machine is possible to process large area without the problem of the continuity of edge parts and by high cutting speed than competitor about coverlay.

  13. Flight Test Performance of a High Precision Navigation Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Pierrottet, Diego; Amzajerdian, Farzin; Petway, Larry; Barnes, Bruce; Lockard, George

    2009-01-01

    A navigation Doppler Lidar (DL) was developed at NASA Langley Research Center (LaRC) for high precision velocity measurements from a lunar or planetary landing vehicle in support of the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. A unique feature of this DL is that it has the capability to provide a precision velocity vector which can be easily separated into horizontal and vertical velocity components and high accuracy line of sight (LOS) range measurements. This dual mode of operation can provide useful information, such as vehicle orientation relative to the direction of travel, and vehicle attitude relative to the sensor footprint on the ground. System performance was evaluated in a series of helicopter flight tests over the California desert. This paper provides a description of the DL system and presents results obtained from these flight tests.

  14. Strategy for Realizing High-Precision VUV Spectro-Polarimeter

    NASA Astrophysics Data System (ADS)

    Ishikawa, R.; Narukage, N.; Kubo, M.; Ishikawa, S.; Kano, R.; Tsuneta, S.

    2014-12-01

    Spectro-polarimetric observations in the vacuum ultraviolet (VUV) range are currently the only means to measure magnetic fields in the upper chromosphere and transition region of the solar atmosphere. The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) aims to measure linear polarization at the hydrogen Lyman- α line (121.6 nm). This measurement requires a polarization sensitivity better than 0.1 %, which is unprecedented in the VUV range. We here present a strategy with which to realize such high-precision spectro-polarimetry. This involves the optimization of instrument design, testing of optical components, extensive analyses of polarization errors, polarization calibration of the instrument, and calibration with onboard data. We expect that this strategy will aid the development of other advanced high-precision polarimeters in the UV as well as in other wavelength ranges.

  15. High-precision buffer circuit for suppression of regenerative oscillation

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Hare, David A.; Tcheng, Ping

    1995-01-01

    Precision analog signal conditioning electronics have been developed for wind tunnel model attitude inertial sensors. This application requires low-noise, stable, microvolt-level DC performance and a high-precision buffered output. Capacitive loading of the operational amplifier output stages due to the wind tunnel analog signal distribution facilities caused regenerative oscillation and consequent rectification bias errors. Oscillation suppression techniques commonly used in audio applications were inadequate to maintain the performance requirements for the measurement of attitude for wind tunnel models. Feedback control theory is applied to develop a suppression technique based on a known compensation (snubber) circuit, which provides superior oscillation suppression with high output isolation and preserves the low-noise low-offset performance of the signal conditioning electronics. A practical design technique is developed to select the parameters for the compensation circuit to suppress regenerative oscillation occurring when typical shielded cable loads are driven.

  16. High-precision Velocimetry Reveals δ Cephei's Secret Companion

    NASA Astrophysics Data System (ADS)

    Anderson, Richard I.; Sahlmann, Johannes; Holl, Berry; Eyer, Laurent

    2015-08-01

    The search for extra-solar planets has driven tremendous improvements in the precision of radial velocities measured with high-resolution echelle spectrographs. However, relatively few studies have as of yet exploited the present-day extreme (m/s) instrumental precision to study Cepheid variable stars.We have been observing the prototype of classical Cepheids, δ Cephei, since September 2011 using the HERMES spectrograph mounted to the Mercator telescope located at the Roque de los Muchachos Observatory on the island of La Palma. Being one of the most-studied variable stars, we originally chose δ Cephei as a maximum-precision reference for other Cepheids in our sample. To our great surprise however, we discovered a clear orbital signature in the homogeneous HERMES data. Adding in radial velocity data from the literature, we then determined δ Cephei's orbit (cf. Anderson et al. 2015, arXiv:1503.04116). The high orbital eccentricity (e=0.647) leads to close pericenter passages (rmin ~ 9.5 RδCep) which suggest an intriguing past that requires further study, since Cepheids are well-known magnifying glasses for stellar evolution (Kippenhahn & Weigert 1994). We furthermore determined a new parallax to δ Cephei (using Hipparcos data) that is in tension with previous estimates and shows that the orbit will have to be accounted for when measuring δ Cephei's parallax with Gaia.While some of our HERMES data are as precise as 9 m/s, we found correlated excess residuals when removing the reference pulsation model and orbital motion from the HERMES radial velocity data, leaving an RMS of 47 m/s. These higher-than-expected residuals are reminiscent of the "period-jitter" or "flickering" observed in high-precision photometry of Cepheids obtained with the Kepler and MOST satellites. This reveals a fortuitous synergy between variable stars studies and the field of exoplanet research and opens the window for a better understanding of Cepheid pulsations via high-precision

  17. High-Precision Twist-Controlled Bilayer and Trilayer Graphene.

    PubMed

    Chen, Xu-Dong; Xin, Wei; Jiang, Wen-Shuai; Liu, Zhi-Bo; Chen, Yongsheng; Tian, Jian-Guo

    2016-04-01

    Twist-controlled bilayer graphene (tBLG) and double-twisted trilayer graphene (DTTG) with high precision are fabricated and their controllable optoelectronic properties are investigated for the first time. The successful fabrication of tBLG and DTTG with designated θ provides an attractive starting point for systematic studies of interlayer coupling in misoriented few-layer graphene systems with well-defined geometry. PMID:26822255

  18. Some comments on high precision study of neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Bilenky, S. M.

    2015-07-01

    I discuss here some problems connected with the high precision study of neutrino oscillations. In the general case of n-neutrino mixing I derive a convenient expression for transition probability in which only independent terms (and mass-squared differences) enter. For three-neutrino mixing I discuss a problem of a definition of a large (atmospheric) neutrino mass-squared difference. I comment also possibilities to reveal the character of neutrino mass spectrum in future reactor neutrino experiments.

  19. High precision metrology of domes and aspheric optics

    NASA Astrophysics Data System (ADS)

    Murphy, Paul E.; Fleig, Jon; Forbes, Greg; Tricard, Marc

    2005-05-01

    Many defense systems have a critical need for high-precision, complex optics. However, fabrication of high quality, advanced optics is often seriously hampered by the lack of accurate and affordable metrology. QED's Subaperture Stitching Interferometer (SSI®) provides a breakthrough technology, enabling the automatic capture of precise metrology data for large and/or strongly curved (concave and convex) parts. QED"s SSI complements next-generation finishing technologies, such as Magnetorheological Finishing (MRF®), by extending the effective aperture, accuracy and dynamic range of a phase-shifting interferometer. This workstation performs automated sub-aperture stitching measurements of spheres, flats, and mild aspheres. It combines a six-axis precision stage system, a commercial Fizeau interferometer, and specially developed software that automates measurement design, data acquisition, and the reconstruction of the full-aperture figure error map. Aside from the correction of sub-aperture placement errors (such as tilts, optical power, and registration effects), our software also accounts for reference-wave error, distortion and other aberrations in the interferometer"s imaging optics. The SSI can automatically measure the full aperture of high numerical aperture surfaces (such as domes) to interferometric accuracy. The SSI extends the usability of a phase measuring interferometer and allows users with minimal training to produce full-aperture measurements of otherwise untestable parts. Work continues to extend this technology to measure aspheric shapes without the use of dedicated null optics. This SSI technology will be described, sample measurement results shown, and various manufacturing applications discussed.

  20. High precision damage-resistant multiple-pass ultraviolet reflectometer

    SciTech Connect

    Jolin, L.J.; Foltyn, S.R.

    1984-01-01

    A multiple-pass cell was reported by John White in 1942. Since them, it has been adapted for use as a high-precision reflectometer. The multiple-pass reflectometer has been studied and reported by Arnon and Baumeister. Here, a reflectometer which is similar is described. It utilizes a uv laser operating at lambda = 351 nm as the source and the White-cell mirrors are high-reflection dielectric coatings designed for that wavelength. Because of the low-loss reflectors used in the cell, a high number of traversals, reflections, can be achieved; R greater than or equal to 239. The use of dielectric mirrors also improves the damage resistance of the apparatus which is important when a uv laser beam is used. The results of reflectance measurements performed on several ultraviolet high reflectors are also reported. These include conventional dielectric coatings as well as a hybrid coating consisting of Al/sub 2/O/sub 3/, HfO/sub 2/, and SiO/sub 2/ layers. The Los Alamos optical damage laboratory has observed and defined several types of laser-induced damage to optical materials. In the case of high reflection, multi-layer, dielectric coatings, damage may be defined as any change in the coating layers or at the substrate interface which causes a measurable change in reflectance at its design wavelength. Since most dielectric high reflectors have reflectances approaching unity, and a change caused by laser irradiation can be minute, a precise method for measuring high reflectance must be utilized. A multiple-pass reflectometer based on the White cell was selected because of its demonstratd precision and high accuracy. It utilizes a laser as the source for reasons described later.

  1. Automated high precision secondary pH measurements

    NASA Astrophysics Data System (ADS)

    Bastkowski, F.; Jakobsen, P. T.; Stefan, F.; Kristensen, H. B.; Jensen, H. D.; Kawiecki, R.; Wied, C. E.; Kauert, A.; Seidl, B.; Spitzer, P.; Eberhardt, R.; Adel, B.

    2013-04-01

    A new setup for high precision, automated secondary pH measurements together with a reference measurement procedure has been developed and tested in interlaboratory comparisons using buffers pH 4.005, pH 7.000, and pH 10.012 at 25 °C and 37 °C. Using primary buffers as standards, a standard uncertainty in pH better than 0.005 can be reached. The central measuring device is a one piece, thermostatted cell of PFA (perfluoroalkoxy) with a built-in Hamilton® Single Pore™ Glass electrode. Due to its flow-through principle this device allows pH measurements with low consumption of measurement solutions. The very hydrophobic and smooth PFA as construction material facilitates complete emptying of the cell. Furthermore, the tempering unit affords very precise temperature control and hence contributes to the low target uncertainty of the produced secondary buffer solutions. Use of a symmetric measurement sequence and the two point calibration was sufficient to reach high precision and accuracy.

  2. Photonic systems for high precision radial velocity measurements

    NASA Astrophysics Data System (ADS)

    Halverson, Samuel

    2016-01-01

    I will discuss new instrumentation and techniques designed to maximize the Doppler radial velocity (RV) measurement precision of next generation exoplanet discovery instruments. These systems include a novel wavelength calibration device based on an all-fiber fabry-perot interferometer, a compact and efficient optical fiber image scrambler based on a single high-index ball lens, and a unique optical fiber mode mixer. These systems have been developed specifically to overcome three technological hurdles that have classically hindered high precision RV measurements in both the optical and near-infrared (NIR), namely: lack of available wavelength calibration sources, inadequate decoupling of the spectrograph from variable telescope illumination, and speckle-induced noise due to mode interference in optical fibers. The instrumentation presented here will be applied to the Habitable-zone Planet Finder, a NIR RV instrument designed to detect rocky planets orbiting in the habitable zones of nearby M-dwarfs, and represents a critical technological step towards the detection of potentially habitable Earth-like planets. While primarily focused in the NIR, many of these systems will be adapted to future optical RV instruments as well, such as NASA's new Extreme Precision Doppler Spectrometer for the WIYN telescope.

  3. High-precision position-specific isotope analysis

    PubMed Central

    Corso, Thomas N.; Brenna, J. Thomas

    1997-01-01

    Intramolecular carbon isotope distributions reflect details of the origin of organic compounds and may record the status of complex systems, such as environmental or physiological states. A strategy is reported here for high-precision determination of 13C/12C ratios at specific positions in organic compounds separated from complex mixtures. Free radical fragmentation of methyl palmitate, a test compound, is induced by an open tube furnace. Two series of peaks corresponding to bond breaking from each end of the molecule are analyzed by isotope ratio mass spectrometry and yield precisions of SD(δ-13C) < 0.4‰. Isotope labeling in the carboxyl, terminal, and methyl positions demonstrates the absence of rearrangement during activation and fragmentation. Negligible isotopic fractionation was observed as degree of fragmentation was adjusted by changing pyrolysis temperature. [1-13C]methyl palmitate with overall δ-13C = 4.06‰, yielded values of +457‰ for the carboxyl position, in agreement with expectations from the dilution, and an average of −27.95‰ for the rest of the molecule, corresponding to −27.46‰ for the olefin series. These data demonstrate the feasibility of automated high-precision position-specific analysis of carbon for molecules contained in complex mixtures. PMID:11038597

  4. Magnetic fields calculated by INTMAG compared with analytical solutions and precision measurements

    NASA Astrophysics Data System (ADS)

    Becker, Reinard

    1990-12-01

    The computer program INTMAG [R. Becker, Nucl. Instr. and Meth. B42 (1989) 303] calculates magnetostatic fields by integrating the contributions of real filaments, which result from splitting up solid windings, and of assumed filaments on the surface of iron pieces, in order to simulate the behaviour of the iron-air interface. The currents of the surface filaments are determined in succeeding steps by an iterative procedures, which saves memory at the expense of computing time, but allows to use as much as 999 filaments in a problem, even on a PC. Due to the integration calculus, the results are more accurate and much more "smooth" than from any finite difference or finite element method program. For the use in trajectory-optics programs such as EGN2 [W.B. Herrmannsfeldt, SLAC-331 (1988)], where radial expansion of axial data is a common procedure, the results of INTMAG do not need any "Maxwellisation", because they are exact solutions of Maxwell's equations. New features added to INTMAG comprise a finite permeability, rectangular coordinates, and mirroring to save numerical work in the case of mirror or angular symmetry as well as an improvement of the integration over the discretised boundary filaments. The PC versions of INTMAG is compiled with MS-Fortran 5.0 (Microsoft Corp., Redmont, WA, USA) which allows to use NAMELIST input, making the input file easy to read and easy to set up. Besides explaining the new features added, the emphasis of this paper is on the comparison of INTMAG calculations with analytical solutions, namely the magnetisation of iron ball and sphere in the case of axisymmetric coordinates and of iron rod and cylinder in rectangular coordinates for different values of permeability. As a further example in rectangular coordinates, a quadrupole is calculated, demonstrating the option of mirroring. Also a comparison is made with precision measurements (B. Langenbeck, private communication) in the gap of a bending magnet of the ESR [B. Franzke

  5. Testing of a high performance, precision-bore railgun

    NASA Astrophysics Data System (ADS)

    Peterson, D. R.; Weeks, D. A.; Zowarka, R. C., Jr.; Cook, R. W.; Weldon, W. F.

    1986-11-01

    Design features and diagnostic data are presented for a high pressure railgun, with emphasis on the effects of using high precision rails. The device featured a hoop-wound fiberglass/epoxy barrel with the rail held in place by the pressure exerted by a four-piece bolted steel sleave on the exterior of the barrel. A relatively large rail cross section was employed which tended to shear off at the interface with the barrel as the test firing continued and rail deflection occurred. Test firing showed that a finely-honed rail assembly consistently yielded higher muzzle velocities of the projectile and inhibited the occurrence of restrikes behind the projectile.

  6. Strategies for high-precision Global Positioning System orbit determination

    NASA Technical Reports Server (NTRS)

    Lichten, Stephen M.; Border, James S.

    1987-01-01

    Various strategies for the high-precision orbit determination of the GPS satellites are explored using data from the 1985 GPS field test. Several refinements to the orbit determination strategies were found to be crucial for achieving high levels of repeatability and accuracy. These include the fine tuning of the GPS solar radiation coefficients and the ground station zenith tropospheric delays. Multiday arcs of 3-6 days provided better orbits and baselines than the 8-hr arcs from single-day passes. Highest-quality orbits and baselines were obtained with combined carrier phase and pseudorange solutions.

  7. High-precision photometry for K2 Campaign 1

    NASA Astrophysics Data System (ADS)

    Huang, C. X.; Penev, K.; Hartman, J. D.; Bakos, G. Á.; Bhatti, W.; Domsa, I.; de Val-Borro, M.

    2015-12-01

    The two reaction wheel K2 mission promises and has delivered new discoveries in the stellar and exoplanet fields. However, due to the loss of accurate pointing, it also brings new challenges for the data reduction processes. In this paper, we describe a new reduction pipeline for extracting high-precision photometry from the K2 data set, and present public light curves for the K2 Campaign 1 target pixel data set. Key to our reduction is the derivation of global astrometric solutions from the target stamps, from which accurate centroids are passed on for high-precision photometry extraction. We extract target light curves for sources from a combined UCAC4 and EPIC catalogue - this includes not only primary targets of the K2 campaign 1, but also any other stars that happen to fall on the pixel stamps. We provide the raw light curves, and the products of various detrending processes aimed at removing different types of systematics. Our astrometric solutions achieve a median residual of ˜0.127 arcsec. For bright stars, our best 6.5 h precision for raw light curves is ˜20 parts per million (ppm). For our detrended light curves, the best 6.5 h precision achieved is ˜15 ppm. We show that our detrended light curves have fewer systematic effects (or trends, or red-noise) than light curves produced by other groups from the same observations. Example light curves of transiting planets and a Cepheid variable candidate, are also presented. We make all light curves public, including the raw and detrended photometry, at http://k2.hatsurveys.org.

  8. Thermal design and flight validation for high precision camera

    NASA Astrophysics Data System (ADS)

    Meng, Henghui; Sun, Lixia; Zhang, Chuanqiang; Geng, Liyin

    2015-10-01

    High precision camera, designed for advanced optical system, with a wide field of vision, high resolution and fast response, has a wild range of applications. As the main payload for spacecraft, the optical remote sensor is mounted exposed to the space, which means it should have a reliable optical performance in harsh space environment during lifetime. Because of the special optical characteristic, imaging path should be accurate, and less thermal deformation for the optical parts is required in the working process, so the high precision camera has a high level requirement for temperature. High resolution space camera is generally required to own the capability of adapting to space thermal environments. The flexible satellite's change of rolling attitude affects the temperature distribution of the camera and makes a difference to optical performance. The thermal control design of space camera is presented, and analysis the temperature data in orbit to prove the thermal design correct. It is proved that the rolling attitude has more influence on outer parts and less influence on inner parts, and active thermal control can weaken the influence of rolling attitude.

  9. High-Precision Floating-Point Arithmetic in ScientificComputation

    SciTech Connect

    Bailey, David H.

    2004-12-31

    At the present time, IEEE 64-bit floating-point arithmetic is sufficiently accurate for most scientific applications. However, for a rapidly growing body of important scientific computing applications, a higher level of numeric precision is required: some of these applications require roughly twice this level; others require four times; while still others require hundreds or more digits to obtain numerically meaningful results. Such calculations have been facilitated by new high-precision software packages that include high-level language translation modules to minimize the conversion effort. These activities have yielded a number of interesting new scientific results in fields as diverse as quantum theory, climate modeling and experimental mathematics, a few of which are described in this article. Such developments suggest that in the future, the numeric precision used for a scientific computation may be as important to the program design as are the algorithms and data structures.

  10. High Precision Polarimetry of the Epsilon Aurigae Eclipse

    NASA Astrophysics Data System (ADS)

    Wiktorowicz, Sloane

    2013-07-01

    Polarimetry of the epsilon Aurigae eclipse has the potential to discern the stellar latitude occulted by the companion's dusty disk, which may directly test interferometric results. In addition, the limb polarization of the primary star may be measured, which is an effect predicted by S. Chandrasekhar and verified by spatially resolved observations of the Sun. I will present B band, polarimetric observations of epsilon Aurigae taken over six nights in September and October 2009 using the POLISH high precision polarimeter at the Lick 3-m telescope. Polarimetric precision achieved during each night is of order 1 part in 10^5. Extensive post-eclipse observations have been taken with the significantly upgraded POLISH2 polarimeter at Lick Observatory. This instrument simultaneously measures all four Stokes parameters (I, Q, U, and V) and achieves precision within 2.0 times the photon shot noise limit over an entire observing run. This work is supported by a NExScI Sagan Fellowship, UC Lab Fees Research Grant, and UCO/Lick Observatory.

  11. High Precision U/Th Dating of First Polynesian Settlement

    PubMed Central

    Burley, David; Weisler, Marshall I.; Zhao, Jian-xin

    2012-01-01

    Previous studies document Nukuleka in the Kingdom of Tonga as a founder colony for first settlement of Polynesia by Lapita peoples. A limited number of radiocarbon dates are one line of evidence supporting this claim, but they cannot precisely establish when this event occurred, nor can they afford a detailed chronology for sequent occupation. High precision U/Th dates of Acropora coral files (abraders) from Nukuleka give unprecedented resolution, identifying the founder event by 2838±8 BP and documenting site development over the ensuing 250 years. The potential for dating error due to post depositional diagenetic alteration of ancient corals at Nukuleka also is addressed through sample preparation protocols and paired dates on spatially separated samples for individual specimens. Acropora coral files are widely distributed in Lapita sites across Oceania. U/Th dating of these artifacts provides unparalleled opportunities for greater precision and insight into the speed and timing of this final chapter in human settlement of the globe. PMID:23144962

  12. High-precision ground-based photometry of exoplanets

    NASA Astrophysics Data System (ADS)

    de Mooij, Ernst J. W.; Jayawardhana, Ray

    2013-04-01

    High-precision photometry of transiting exoplanet systems has contributed significantly to our understanding of the properties of their atmospheres. The best targets are the bright exoplanet systems, for which the high number of photons allow very high signal-to-noise ratios. Most of the current instruments are not optimised for these high-precision measurements, either they have a large read-out overhead to reduce the readnoise and/or their field-of-view is limited, preventing simultaneous observations of both the target and a reference star. Recently we have proposed a new wide-field imager for the Observatoir de Mont-Megantic optimised for these bright systems (PI: Jayawardhana). The instruments has a dual beam design and a field-of-view of 17' by 17'. The cameras have a read-out time of 2 seconds, significantly reducing read-out overheads. Over the past years we have obtained significant experience with how to reach the high precision required for the characterisation of exoplanet atmospheres. Based on our experience we provide the following advice: Get the best calibrations possible. In the case of bad weather, characterise the instrument (e.g. non-linearity, dome flats, bias level), this is vital for better understanding of the science data. Observe the target for as long as possible, the out-of-transit baseline is as important as the transit/eclipse itself. A short baseline can lead to improperly corrected systematic and mis-estimation of the red-noise. Keep everything (e.g. position on detector, exposure time) as stable as possible. Take care that the defocus is not too strong. For a large defocus, the contribution of the total flux from the sky-background in the aperture could well exceed that of the target, resulting in very strict requirements on the precision at which the background is measured.

  13. High-Precision Timing of Several Millisecond Pulsars

    NASA Astrophysics Data System (ADS)

    Ferdman, R. D.; Stairs, I. H.; Backer, D. C.; Ramachandran, R.; Demorest, P.; Nice, D. J.; Lyne, A. G.; Kramer, M.; Lorimer, D.; McLaughlin, M.; Manchester, D.; Camilo, F.; D'Amico, N.; Possenti, A.; Burgay, M.; Joshi, B. C.; Freire, P. C.

    2004-12-01

    The highest precision pulsar timing is achieved by reproducing as accurately as possible the pulse profile as emitted by the pulsar, in high signal-to-noise observations. The best profile reconstruction can be accomplished with several-bit voltage sampling and coherent removal of the dispersion suffered by pulsar signals as they traverse the interstellar medium. The Arecibo Signal Processor (ASP) and its counterpart the Green Bank Astronomical Signal Processor (GASP) are flexible, state-of-the-art wide-bandwidth observing systems, built primarily for high-precision long-term timing of millisecond and binary pulsars. ASP and GASP are in use at the 300-m Arecibo telescope in Puerto Rico and the 100-m Green Bank Telescope in Green Bank, West Virginia, respectively, taking advantage of the enormous sensitivities of these telescopes. These instruments result in high-precision science through 4 and 8-bit sampling and perform coherent dedispersion on the incoming data stream in real or near-real time. This is done using a network of personal computers, over an observing bandwidth of 64 to 128 MHz, in each of two polarizations. We present preliminary results of timing and polarimetric observations with ASP/GASP for several pulsars, including the recently-discovered relativistic double-pulsar binary J0737-3039. These data are compared to simultaneous observations with other pulsar instruments, such as the new "spigot card" spectrometer on the GBT and the Princeton Mark IV instrument at Arecibo, the precursor timing system to ASP. We also briefly discuss several upcoming observations with ASP/GASP.

  14. High precision photon flux determination for photon tagging experiments

    SciTech Connect

    Teymurazyan, A; Ahmidouch, A; Ambrozewicz, P; Asratyan, A; Baker, K; Benton, L; Burkert, V; Clinton, E; Cole, P; Collins, P; Dale, D; Danagoulian, S; Davidenko, G; Demirchyan, R; Deur, A; Dolgolenko, A; Dzyubenko, G; Ent, R; Evdokimov, A; Feng, J; Gabrielyan, M; Gan, L; Gasparian, A; Glamazdin, A; Goryachev, V; Hardy, K; He, J; Ito, M; Jiang, L; Kashy, D; Khandaker, M; Kolarkar, A; Konchatnyi, M; Korchin, A; Korsch, W; Kosinov, O; Kowalski, S; Kubantsev, M; Kubarovsky, V; Larin, I; Lawrence, D; Li, X; Martel, P; Matveev, V; McNulty, D; Mecking, B; Milbrath, B; Minehart, R; Miskimen, R; Mochalov, V; Nakagawa, I; Overby, S; Pasyuk, E; Payen, M; Pedroni, R; Prok, Y; Ritchie, B; Salgado, C; Shahinyan, A; Sitnikov, A; Sober, D; Stepanyan, S; Stevens, W; Underwood, J; Vasiliev, A; Vishnyakov, V; Wood, M; Zhou, S

    2014-07-01

    The Jefferson Laboratory PrimEx Collaboration has developed and implemented a method to control the tagged photon flux in photoproduction experiments at the 1% level over the photon energy range from 4.9 to 5.5 GeV. This method has been successfully implemented in a high precision measurement of the neutral pion lifetime. Here, we outline the experimental equipment and the analysis techniques used to accomplish this. These include the use of a total absorption counter for absolute flux calibration, a pair spectrometer for online relative flux monitoring, and a new method for post-bremsstrahlung electron counting.

  15. High precision photon flux determination for photon tagging experiments

    NASA Astrophysics Data System (ADS)

    Teymurazyan, A.; Ahmidouch, A.; Ambrozewicz, P.; Asratyan, A.; Baker, K.; Benton, L.; Burkert, V.; Clinton, E.; Cole, P.; Collins, P.; Dale, D.; Danagoulian, S.; Davidenko, G.; Demirchyan, R.; Deur, A.; Dolgolenko, A.; Dzyubenko, G.; Ent, R.; Evdokimov, A.; Feng, J.; Gabrielyan, M.; Gan, L.; Gasparian, A.; Glamazdin, A.; Goryachev, V.; Hardy, K.; He, J.; Ito, M.; Jiang, L.; Kashy, D.; Khandaker, M.; Kolarkar, A.; Konchatnyi, M.; Korchin, A.; Korsch, W.; Kosinov, O.; Kowalski, S.; Kubantsev, M.; Kubarovsky, V.; Larin, I.; Lawrence, D.; Li, X.; Martel, P.; Matveev, V.; McNulty, D.; Mecking, B.; Milbrath, B.; Minehart, R.; Miskimen, R.; Mochalov, V.; Nakagawa, I.; Overby, S.; Pasyuk, E.; Payen, M.; Pedroni, R.; Prok, Y.; Ritchie, B.; Salgado, C.; Shahinyan, A.; Sitnikov, A.; Sober, D.; Stepanyan, S.; Stevens, W.; Underwood, J.; Vasiliev, A.; Vishnyakov, V.; Wood, M.; Zhou, S.

    2014-12-01

    The Jefferson Laboratory PrimEx Collaboration has developed and implemented a method to control the tagged photon flux in photoproduction experiments at the 1% level over the photon energy range from 4.9 to 5.5 GeV. This method has been successfully implemented in a high precision measurement of the neutral pion lifetime. Here, we outline the experimental equipment and the analysis techniques used to accomplish this. These include the use of a total absorption counter for absolute flux calibration, a pair spectrometer for online relative flux monitoring, and a new method for post-bremsstrahlung electron counting.

  16. Globular Cluster Streams as Galactic High-Precision Scales

    NASA Astrophysics Data System (ADS)

    Küpper, Andreas H. W.; Balbinot, Eduardo; Bonaca, Ana; Johnston, Kathryn V.; Hogg, David W.; Kroupa, Pavel; Santiago, Basilio X.

    2016-08-01

    Tidal streams of globular clusters are ideal tracers of the Galactic gravitational potential. Compared to the few known, complex and diffuse dwarf-galaxy streams, they are kinematically cold, have thin morphologies and are abundant in the halo of the Milky Way. Their coldness and thinness in combination with potential epicyclic substructure in the vicinity of the stream progenitor turns them into high-precision scales. With the example of Palomar 5, we demonstrate how modeling of a globular cluster stream allows us to simultaneously measure the properties of the disrupting globular cluster, its orbital motion, and the gravitational potential of the Milky Way.

  17. Distributed high-precision time transfer through passive optical networks

    NASA Astrophysics Data System (ADS)

    Wu, Guiling; Hu, Liang; Zhang, Hao; Chen, Jianping

    2014-09-01

    We propose a one-point to multipoint distributed time transfer through passive optical networks using a time division multiple access (TDMA) based two-way time transfer. The clock at each clock user node is, in turn, compared with the high-precision reference clock at a master node by a two-way time transfer during assigned subperiods. The corresponding TDMA control protocol and time transfer units for the proposed scheme are designed and implemented. A 1×8 experimental system with a 20 km single-mode fiber in each subpath is demonstrated. The results show that a standard deviation of <60 ps can be reached in each comparison subperiod.

  18. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing.

    1993-01-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  19. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing

    1993-04-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  20. Design of a high-precision tunable double crystal monochromator

    SciTech Connect

    Shleifer, M.; Sharma, S.; Rotela, E.; Brite, C.

    1992-02-01

    The design of high-precision tunable double crystal monochromator is described. Each crystal of the monochromator can be aligned independently by a double-axis gimbal mechanism providing rotations about two perpendicular axes. Two orthogonal linear actuators operate the gimbal mechanism via a connecting bar. The exit beam height is controlled by separate linear actuators that change the distance between the crystals along the beam axis. Vertical separation between the crystals may also be adjusted. Thermal deformations are minimized in this compact UHV compatible design by water cooling of the first crystal. 7 refs.

  1. High-precision micro/nano-scale machining system

    DOEpatents

    Kapoor, Shiv G.; Bourne, Keith Allen; DeVor, Richard E.

    2014-08-19

    A high precision micro/nanoscale machining system. A multi-axis movement machine provides relative movement along multiple axes between a workpiece and a tool holder. A cutting tool is disposed on a flexible cantilever held by the tool holder, the tool holder being movable to provide at least two of the axes to set the angle and distance of the cutting tool relative to the workpiece. A feedback control system uses measurement of deflection of the cantilever during cutting to maintain a desired cantilever deflection and hence a desired load on the cutting tool.

  2. High-precision measurements of global stellar magnetic fields

    NASA Astrophysics Data System (ADS)

    Plachinda, S. I.

    2014-06-01

    This paper presents a brief history of the development of devices and techniques for high-precision measurements of stellar magnetic fields. Two main approaches for the processing of spectral-polarimetric observations are described: the method of least-squares deconvolution (LSD), which is used to find a mean-weighted average of the normalized polarization profile using a set of spectral lines, and a method in which each individual spectral line is used to determine the magnetic field, viz., the single line method (SL). The advantages and disadvantages of the LSD and SL methods are discussed.

  3. A High Precision Terahertz Wave Image Reconstruction Algorithm

    PubMed Central

    Guo, Qijia; Chang, Tianying; Geng, Guoshuai; Jia, Chengyan; Cui, Hong-Liang

    2016-01-01

    With the development of terahertz (THz) technology, the applications of this spectrum have become increasingly wide-ranging, in areas such as non-destructive testing, security applications and medical scanning, in which one of the most important methods is imaging. Unlike remote sensing applications, THz imaging features sources of array elements that are almost always supposed to be spherical wave radiators, including single antennae. As such, well-developed methodologies such as Range-Doppler Algorithm (RDA) are not directly applicable in such near-range situations. The Back Projection Algorithm (BPA) can provide products of high precision at the the cost of a high computational burden, while the Range Migration Algorithm (RMA) sacrifices the quality of images for efficiency. The Phase-shift Migration Algorithm (PMA) is a good alternative, the features of which combine both of the classical algorithms mentioned above. In this research, it is used for mechanical scanning, and is extended to array imaging for the first time. In addition, the performances of PMA are studied in detail in contrast to BPA and RMA. It is demonstrated in our simulations and experiments described herein that the algorithm can reconstruct images with high precision. PMID:27455269

  4. A High Precision Terahertz Wave Image Reconstruction Algorithm.

    PubMed

    Guo, Qijia; Chang, Tianying; Geng, Guoshuai; Jia, Chengyan; Cui, Hong-Liang

    2016-01-01

    With the development of terahertz (THz) technology, the applications of this spectrum have become increasingly wide-ranging, in areas such as non-destructive testing, security applications and medical scanning, in which one of the most important methods is imaging. Unlike remote sensing applications, THz imaging features sources of array elements that are almost always supposed to be spherical wave radiators, including single antennae. As such, well-developed methodologies such as Range-Doppler Algorithm (RDA) are not directly applicable in such near-range situations. The Back Projection Algorithm (BPA) can provide products of high precision at the the cost of a high computational burden, while the Range Migration Algorithm (RMA) sacrifices the quality of images for efficiency. The Phase-shift Migration Algorithm (PMA) is a good alternative, the features of which combine both of the classical algorithms mentioned above. In this research, it is used for mechanical scanning, and is extended to array imaging for the first time. In addition, the performances of PMA are studied in detail in contrast to BPA and RMA. It is demonstrated in our simulations and experiments described herein that the algorithm can reconstruct images with high precision. PMID:27455269

  5. High precision Hugoniot measurements of D2 near maximum compression

    NASA Astrophysics Data System (ADS)

    Benage, John; Knudson, Marcus; Desjarlais, Michael

    2015-11-01

    The Hugoniot response of liquid deuterium has been widely studied due to its general importance and to the significant discrepancy in the inferred shock response obtained from early experiments. With improvements in dynamic compression platforms and experimental standards these results have converged and show general agreement with several equation of state (EOS) models, including quantum molecular dynamics (QMD) calculations within the Generalized Gradient Approximation (GGA). This approach to modeling the EOS has also proven quite successful for other materials and is rapidly becoming a standard approach. However, small differences remain among predictions obtained using different local and semi-local density functionals; these small differences show up in the deuterium Hugoniot at ~ 30-40 GPa near the region of maximum compression. Here we present experimental results focusing on that region of the Hugoniot and take advantage of advancements in the platform and standards, resulting in data with significantly higher precision than that obtained in previous studies. These new data may prove to distinguish between the subtle differences predicted by the various density functionals. Results of these experiments will be presented along with comparison to various QMD calculations. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  6. High precision measurements of the diamond Hugoniot in and above the melt region

    SciTech Connect

    Hicks, D; Boehly, T; Celliers, P; Bradley, D; Eggert, J; McWilliams, R S; Collins, G

    2008-08-05

    High precision laser-driven shock wave measurements of the diamond principal Hugoniot have been made at pressures between 6 and 19 Mbar. Shock velocities were determined with 0.3-1.1% precision using a velocity interferometer. Impedance matching analysis, incorporating systematic errors in the equation-of-state of the quartz standard, was used to determine the Hugoniot with 1.2-2.7% precision in density. The results are in good agreement with published ab initio calculations which predict a small negative melt slope along the Hugoniot, but disagree with previous laser-driven shock wave experiments which had observed a large density increase in the melt region. In the extensive solid-liquid coexistence regime between 6 and 10 Mbar these measurements indicate that the mixed phase may be slightly more dense than would be expected from a simple interpolation between liquid and solid Hugoniots.

  7. High precision measurement system based on coplanar XY-stage

    NASA Astrophysics Data System (ADS)

    Fan, Kuang-Chao; Miao, Jin-Wei; Gong, Wei; Zhang, You-Liang; Cheng, Fang

    2011-12-01

    A coplanar XY-stage, together with a high precise measurement system, is presented in this paper. The proposed coplanar XY-stage fully conforms to the Abbe principle. The symmetric structural design is considered to eliminate the structure deformation due to force and temperature changes. For consisting of a high precise measurement system, a linear diffraction grating interferometer(LDGI) is employed as the position feedback sensor with the resolution to 1 nm after the waveform interpolation, an ultrasonic motor HR4 is used to generate both the long stroke motion and the nano positioning on the same stage. Three modes of HR4 are used for positioning control: the AC mode in continuous motion control for the long stroke; the gate mode to drive the motor in low velocity for the short stroke; and the DC mode in which the motor works as a piezo actuator, enabling accurate positioning of a few nanometers. The stage calibration is carried out by comparing the readings of LDGI with a Renishaw laser interferometer and repeated 5 times. Experimental results show the XY-stage has achieved positioning accuracy in less than 20nm after the compensation of systematic errors, and standard deviation is within 20 nm for travels up to 20 mm.

  8. Electronics design for a high precision image stabilization system

    NASA Astrophysics Data System (ADS)

    Casas, A.; Roma, D.; Carmona, M.; Gómez, J. M.; Bosch, J.; López, M.; Sabater, J.; Herms, A.; Maue, T.; Nakai, E.; Volkmer, R.; Schmidt, W.

    2014-07-01

    A very high precision Image Stabilization System has been designed for the Solar Orbiter mission. The different components that have been designed are the Correlation Tracking Camera (CTC), Tip-Tilt controller (TTC) and the system control in order to achieve the specified requirements. For the CTC, in order to achieve the required resolution of 12 bits and reduced power consumption, we used an external ADC. For the TTC, a special focus has been dedicated to a 55 V linear regulator in a QUASI-LDO configuration and a Tip-Tilt driver in a transconductance amplifier architecture. Results show that the full system reaches an attenuation of 1/10th of a pixel at 10Hz. The TTC provides a high voltage span, enough slew-rate and the needed stability levels.

  9. High-precision silicon nitride balls for bearings

    NASA Astrophysics Data System (ADS)

    Cundill, Robin T.

    1992-04-01

    Hybrid ceramic bearings are now commercially available for use in high performance applications where the properties of the ceramic balls give advantages in terms of higher operating speeds, increased stiffness, lower fraction and less heat generation. Most hybrid bearings are high precision angular contact ball bearings fitted with silicon nitride balls, which have to be finished to ISO dimensional grades 3 and 5. Ball diameter variation and deviation from the spherical form has to be less than 0.125 micrometers for Grade 5 balls and less than 0.08 micrometers for Grade 3 balls. Surface finish of silicon nitride balls is typically 0.003 - 0.010 micrometers Rq (0.002 - 0.008 micrometers Ra). At this level, the basic material microstructures is discernible which facilitates inspection for material and other faults.

  10. High Precision Assembly Line Synthesis for Molecules with Tailored Shapes

    PubMed Central

    Burns, Matthew; Essafi, Stephanie; Bame, Jessica R.; Bull, Stephanie P.; Webster, Matthew P.; Balieu, Sebastien; Dale, James W.; Butts, Craig P.; Harvey, Jeremy N.; Aggarwal, Varinder K.

    2014-01-01

    Molecular assembly lines, where molecules undergo iterative processes involving chain elongation and functional group manipulation are hallmarks of many processes found in Nature. We have sought to emulate Nature in the development of our own molecular assembly line through iterative homologations of boronic esters. Here we report a reagent (α-lithioethyl triispopropylbenzoate) which inserts into carbon-boron bonds with exceptionally high fidelity and stereocontrol. Through repeated iteration we have converted a simple boronic ester into a complex molecule (a carbon chain with ten contiguous methyl groups) with remarkably high precision over its length, its stereochemistry and therefore its shape. Different stereoisomers were targeted and it was found that they adopted different shapes (helical/linear) according to their stereochemistry. This work should now enable scientists to rationally design and create molecules with predictable shape, which could have an impact in all areas of molecular sciences where bespoke molecules are required. PMID:25209797

  11. Aspects of Precision Calculations of Nucleon Generalized Form Factors with Domain Wall Fermions on an Asqtad Sea

    SciTech Connect

    Bratt, Jonathan; Edwards, Robert; Engelhardt, Michael; Fleming, George; Hagler, Ph.; Lin, Meifeng; Meyer, Harvey; Musch, Bernhard; Negele, John; Orginos, Konstantinos; Pochinsky, Andrew; Procura, M.; Renner, Dru; Richards, David; Schroers, Wolfram; Syritsyn, Sergey

    2008-12-01

    In order to advance lattice calculations of moments of unpolarized, helicity, and transversity distributions, electromagnetic form factors, and generalized form factors of the nucleon to a new level of precision, this work investigates several key aspects of precision lattice calculations. We calculate the number of configurations required for constant statistical errors as a function of pion mass, describe the coherent sink method to help achieve these statistics, examine the statistical correlations between separate measurements, study correlations in the behavior of form factors at different momentum transfer, examine volume dependence, and compare mixed action results with those using comparable dynamical domain wall configurations. We also show selected form factor results and comment on the QCD evolution of our calculations of the flavor non-singlet nucleon angular momentum.

  12. High-precision analysis of the solar twin HIP 100963

    NASA Astrophysics Data System (ADS)

    Galarza, Jhon Yana; Meléndez, Jorge; Ramírez, Ivan; Yong, David; Karakas, Amanda I.; Asplund, Martin; Liu, Fan

    2016-04-01

    Context. HIP 100963 was one of the first solar twins identified. Although some high-precision analyses are available, a comprehensive high-precision study of chemical elements from different nucleosynthetic sources is still lacking from which to obtain potential new insights on planets, stellar evolution, and Galactic chemical evolution (GCE). Aims: We analyze and investigate the origin of the abundance pattern of HIP 100963 in detail, in particular the pattern of the light element Li, the volatile and refractory elements, and heavy elements from the s- and r-processes. Methods: We used the HIRES spectrograph on the Keck I telescope to acquire high-resolution (R ≈ 70 000) spectra with a high signal-to-noise ratio (S/N ≈ 400-650 per pixel) of HIP 100963 and the Sun for a differential abundance analysis. We measured the equivalent widths (EWs) of iron lines to determine the stellar parameters by employing the differential spectroscopic equilibrium. We determined the composition of volatile, refractory, and neutron-capture elements through a differential abundance analysis with respect to the Sun. Results: The stellar parameters we found are Teff = 5818 ± 4 K, log g = 4.49 ± 0.01 dex, vt = 1.03 ± 0.01km s-1, and [Fe/H] = -0.003 ± 0.004 dex. These low errors allow us to compute a precise mass (1.03+0.02-0.01 M⊙) and age (2.0 ± 0.4 Gyr), obtained using Yonsei-Yale isochrones. Using our [Y/Mg] ratio, we have determined an age of 2.1 ± 0.4 Gyr, in agreement with the age computed using isochrones. Our isochronal age also agrees with the age determined from stellar activity (2.4 ± 0.3 Gyr). We study the abundance pattern with condensation temperature (Tcond) taking corrections by the GCE into account. We show that the enhancements of neutron-capture elements are explained by contributions from both the s- and r-process. The lithium abundance follows the tight Li-age correlation seen in other solar twins. Conclusions: We confirm that HIP 100963 is a solar twin

  13. High-precision analysis of the solar twin HIP 100963

    NASA Astrophysics Data System (ADS)

    Galarza, Jhon Yana; Meléndez, Jorge; Ramírez, Ivan; Yong, David; Karakas, Amanda I.; Asplund, Martin; Liu, Fan

    2016-05-01

    Context. HIP 100963 was one of the first solar twins identified. Although some high-precision analyses are available, a comprehensive high-precision study of chemical elements from different nucleosynthetic sources is still lacking from which to obtain potential new insights on planets, stellar evolution, and Galactic chemical evolution (GCE). Aims: We analyze and investigate the origin of the abundance pattern of HIP 100963 in detail, in particular the pattern of the light element Li, the volatile and refractory elements, and heavy elements from the s- and r-processes. Methods: We used the HIRES spectrograph on the Keck I telescope to acquire high-resolution (R ≈ 70 000) spectra with a high signal-to-noise ratio (S/N ≈ 400-650 per pixel) of HIP 100963 and the Sun for a differential abundance analysis. We measured the equivalent widths (EWs) of iron lines to determine the stellar parameters by employing the differential spectroscopic equilibrium. We determined the composition of volatile, refractory, and neutron-capture elements through a differential abundance analysis with respect to the Sun. Results: The stellar parameters we found are Teff = 5818 ± 4 K, log g = 4.49 ± 0.01 dex, vt = 1.03 ± 0.01km s-1, and [Fe/H] = -0.003 ± 0.004 dex. These low errors allow us to compute a precise mass (1.03+0.02-0.01 M⊙) and age (2.0 ± 0.4 Gyr), obtained using Yonsei-Yale isochrones. Using our [Y/Mg] ratio, we have determined an age of 2.1 ± 0.4 Gyr, in agreement with the age computed using isochrones. Our isochronal age also agrees with the age determined from stellar activity (2.4 ± 0.3 Gyr). We study the abundance pattern with condensation temperature (Tcond) taking corrections by the GCE into account. We show that the enhancements of neutron-capture elements are explained by contributions from both the s- and r-process. The lithium abundance follows the tight Li-age correlation seen in other solar twins. Conclusions: We confirm that HIP 100963 is a solar twin

  14. Highly precise measurement of HIV DNA by droplet digital PCR.

    PubMed

    Strain, Matthew C; Lada, Steven M; Luong, Tiffany; Rought, Steffney E; Gianella, Sara; Terry, Valeri H; Spina, Celsa A; Woelk, Christopher H; Richman, Douglas D

    2013-01-01

    Deoxyribonucleic acid (DNA) of the human immunodeficiency virus (HIV) provides the most sensitive measurement of residual infection in patients on effective combination antiretroviral therapy (cART). Droplet digital PCR (ddPCR) has recently been shown to provide highly accurate quantification of DNA copy number, but its application to quantification of HIV DNA, or other equally rare targets, has not been reported. This paper demonstrates and analyzes the application of ddPCR to measure the frequency of total HIV DNA (pol copies per million cells), and episomal 2-LTR (long terminal repeat) circles in cells isolated from infected patients. Analysis of over 300 clinical samples, including over 150 clinical samples assayed in triplicate by ddPCR and by real-time PCR (qPCR), demonstrates a significant increase in precision, with an average 5-fold decrease in the coefficient of variation of pol copy numbers and a >20-fold accuracy improvement for 2-LTR circles. Additional benefits of the ddPCR assay over qPCR include absolute quantification without reliance on an external standard and relative insensitivity to mismatches in primer and probe sequences. These features make digital PCR an attractive alternative for measurement of HIV DNA in clinical specimens. The improved sensitivity and precision of measurement of these rare events should facilitate measurements to characterize the latent HIV reservoir and interventions to eradicate it. PMID:23573183

  15. Highly Precise Measurement of HIV DNA by Droplet Digital PCR

    PubMed Central

    Strain, Matthew C.; Lada, Steven M.; Luong, Tiffany; Rought, Steffney E.; Gianella, Sara; Terry, Valeri H.; Spina, Celsa A.; Woelk, Christopher H.; Richman, Douglas D.

    2013-01-01

    Deoxyribonucleic acid (DNA) of the human immunodeficiency virus (HIV) provides the most sensitive measurement of residual infection in patients on effective combination antiretroviral therapy (cART). Droplet digital PCR (ddPCR) has recently been shown to provide highly accurate quantification of DNA copy number, but its application to quantification of HIV DNA, or other equally rare targets, has not been reported. This paper demonstrates and analyzes the application of ddPCR to measure the frequency of total HIV DNA (pol copies per million cells), and episomal 2-LTR (long terminal repeat) circles in cells isolated from infected patients. Analysis of over 300 clinical samples, including over 150 clinical samples assayed in triplicate by ddPCR and by real-time PCR (qPCR), demonstrates a significant increase in precision, with an average 5-fold decrease in the coefficient of variation of pol copy numbers and a >20-fold accuracy improvement for 2-LTR circles. Additional benefits of the ddPCR assay over qPCR include absolute quantification without reliance on an external standard and relative insensitivity to mismatches in primer and probe sequences. These features make digital PCR an attractive alternative for measurement of HIV DNA in clinical specimens. The improved sensitivity and precision of measurement of these rare events should facilitate measurements to characterize the latent HIV reservoir and interventions to eradicate it. PMID:23573183

  16. Electronic Structure Calculations of Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    Bromley, Steve; Ziolkowski, Marcin; Marler, Joan

    2016-05-01

    Exotic systems like Highly Charged Ions (HCIs) are attracting more attention based on their properties and possible interactions. Abundance of HCIs in the solar wind and their interaction with the upper atmosphere puts them in the attention of astro- and atmospheric physicists. Also, their unique properties originating in the high charge make them an excellent candidate for precision measurements and the next generation of atomic clocks. For a better understanding of the dynamics of processes involving HCIs a combined theoretical and experimental effort is needed to study their basic properties and interactions. Both theory and experiment need to be combined due to the extreme nature of these systems. We present preliminary insight into electronic structure of light HCIs, their interactions with neutral atoms and dynamics of charge transfer processes.

  17. Scintillating crystals for precision crystal calorimetry in high energy physics

    SciTech Connect

    Zhu, R.

    1998-11-01

    Scintillating crystals in future high energy physics experiments face a new challenge to maintain its performance in a hostile radiation environment. This paper discusses the effects of radiation damage in scintillating crystals. The importance of maintaining crystal{close_quote}s light response uniformity and the feasibility to build a precision crystal calorimeter under radiation are elaborated. The mechanism of radiation damage in scintillating crystals is also discussed. While the damage in alkali halides is found to be caused by the oxygen/hydroxyl contamination, it is the structure defects, such as oxygen vacancies, cause damage in oxides. Material analysis used to reach these conclusions are presented in details. {copyright} {ital 1998 American Institute of Physics.}

  18. High-precision digital charge-coupled device TV system

    NASA Astrophysics Data System (ADS)

    Vishnevsky, Grigory I.; Ioffe, S. A.; Berezin, V. Y.; Rybakov, M. I.; Mikhaylov, A. V.; Belyaev, L. V.

    1991-06-01

    In certain test, measurement, and research applications of CCD TV systems, the greater accuracy than usual 8-bit frame-grabbers can provide is demanded without the system being too expensive. The paper presents the concept and features of the high-precision low-cost digital CCD TV system intended for obtaining 12-bit monochrome images of immobile or relatively slow moving objects. The increase in accuracy is achieved by the specific digitization procedure -- one column per frame, which combines the benefits of a slow A/D converter with real-time TV imaging compatibility. To reduce speed restrictions on sample- and-hold circuits, a zoomed pixel read out cycle, corresponding to the pixel to be digitized, is proposed. The system provides great flexibility in choice of integration times and readout rates by means of a programmable readout sequencer, and is easily adaptable to various user demands and CCDs types.

  19. Precision Viticulture from Multitemporal, Multispectral Very High Resolution Satellite Data

    NASA Astrophysics Data System (ADS)

    Kandylakis, Z.; Karantzalos, K.

    2016-06-01

    In order to exploit efficiently very high resolution satellite multispectral data for precision agriculture applications, validated methodologies should be established which link the observed reflectance spectra with certain crop/plant/fruit biophysical and biochemical quality parameters. To this end, based on concurrent satellite and field campaigns during the veraison period, satellite and in-situ data were collected, along with several grape samples, at specific locations during the harvesting period. These data were collected for a period of three years in two viticultural areas in Northern Greece. After the required data pre-processing, canopy reflectance observations, through the combination of several vegetation indices were correlated with the quantitative results from the grape/must analysis of grape sampling. Results appear quite promising, indicating that certain key quality parameters (like brix levels, total phenolic content, brix to total acidity, anthocyanin levels) which describe the oenological potential, phenolic composition and chromatic characteristics can be efficiently estimated from the satellite data.

  20. Fast and Adaptive Sparse Precision Matrix Estimation in High Dimensions

    PubMed Central

    Liu, Weidong; Luo, Xi

    2014-01-01

    This paper proposes a new method for estimating sparse precision matrices in the high dimensional setting. It has been popular to study fast computation and adaptive procedures for this problem. We propose a novel approach, called Sparse Column-wise Inverse Operator, to address these two issues. We analyze an adaptive procedure based on cross validation, and establish its convergence rate under the Frobenius norm. The convergence rates under other matrix norms are also established. This method also enjoys the advantage of fast computation for large-scale problems, via a coordinate descent algorithm. Numerical merits are illustrated using both simulated and real datasets. In particular, it performs favorably on an HIV brain tissue dataset and an ADHD resting-state fMRI dataset. PMID:25750463

  1. Superconducting Tunnel Junctions for High-Precision EUV Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ponce, F.; Carpenter, M. H.; Cantor, R.; Friedrich, S.

    2016-08-01

    We have characterized the photon response of superconducting tunnel junctions in the extreme ultraviolet energy range below 100 eV with a pulsed 355 nm laser. The detectors are operated at rates up to 5000 counts/s, are very linear in energy and have an energy resolution between 0.9 and 2 eV. We observe multiple peaks that correspond to an integer number of photons with a Poissonian probability distribution and that can be used for high-accuracy energy calibration. The uncertainty of the centroid depends on the detector resolution and the counting statistics and can be as low as 1 meV for well-separated peaks with >10^5 counts. We discuss the precision of the peak centroid as a function of detector resolution and total number of counts and the accuracy of the energy calibration.

  2. Ultra High Precision Laser Monitor for Oxygen Eddy Flux Measurements

    NASA Astrophysics Data System (ADS)

    Nelson, David; Herndon, Scott; McManus, Barry; Roscioli, Rob; Jervis, Dylan; Zahniser, Mark

    2016-04-01

    Atmospheric oxygen provides one of the most powerful tracers to study the carbon cycle through its close interaction with carbon dioxide. Keeling and co-workers demonstrated this at the global scale by using small variations in atmospheric oxygen content to disentangle oceanic and terrestrial carbon sinks. It would be very exciting to apply similar ideas at the ecosystem level to improve our understanding of biosphere-atmosphere exchange and our ability to predict the response of the biosphere and atmosphere to climate change. The eddy covariance technique is perhaps the most effective approach available to quantify the exchange of gases between these spheres. Therefore, eddy covariance flux measurements of oxygen would be extremely valuable. However, this requires a fast response (0.1 seconds), high relative precision (0.001% or 10 per meg) oxygen sensor. We report recent progress in developing such a sensor using a high resolution visible laser to probe the oxygen A-band electronic transition. We have demonstrated precision of 1 ppmv or 5 per meg for a 100 second measurement duration. This sensor will enable oxygen flux measurements using eddy covariance. In addition, we will incorporate a second laser in this instrument to simultaneously determine the fluxes of oxygen, carbon dioxide and water vapor within the same sampling cell. This will provide a direct, real time measurement of the ratio of the flux of oxygen to that of carbon dioxide. This ratio is expected to vary on short time scales and small spatial scales due to the differing stoichiometry of processes producing and consuming carbon dioxide. Thus measuring the variations in the ratio of oxygen and carbon dioxide fluxes will provide mechanistic information to improve our understanding of the crucial exchange of carbon between the atmosphere and biosphere.

  3. Fast, High-Precision Readout Circuit for Detector Arrays

    NASA Technical Reports Server (NTRS)

    Rider, David M.; Hancock, Bruce R.; Key, Richard W.; Cunningham, Thomas J.; Wrigley, Chris J.; Seshadri, Suresh; Sander, Stanley P.; Blavier, Jean-Francois L.

    2013-01-01

    The GEO-CAPE mission described in NASA's Earth Science and Applications Decadal Survey requires high spatial, temporal, and spectral resolution measurements to monitor and characterize the rapidly changing chemistry of the troposphere over North and South Americas. High-frame-rate focal plane arrays (FPAs) with many pixels are needed to enable such measurements. A high-throughput digital detector readout integrated circuit (ROIC) that meets the GEO-CAPE FPA needs has been developed, fabricated, and tested. The ROIC is based on an innovative charge integrating, fast, high-precision analog-to-digital circuit that is built into each pixel. The 128×128-pixel ROIC digitizes all 16,384 pixels simultaneously at frame rates up to 16 kHz to provide a completely digital output on a single integrated circuit at an unprecedented rate of 262 million pixels per second. The approach eliminates the need for off focal plane electronics, greatly reducing volume, mass, and power compared to conventional FPA implementations. A focal plane based on this ROIC will require less than 2 W of power on a 1×1-cm integrated circuit. The ROIC is fabricated of silicon using CMOS technology. It is designed to be indium bump bonded to a variety of detector materials including silicon PIN diodes, indium antimonide (InSb), indium gallium arsenide (In- GaAs), and mercury cadmium telluride (HgCdTe) detector arrays to provide coverage over a broad spectral range in the infrared, visible, and ultraviolet spectral ranges.

  4. Centroiding Experiment for Determining the Positions of Stars with High Precision

    NASA Astrophysics Data System (ADS)

    Yano, T.; Araki, H.; Hanada, H.; Tazawa, S.; Gouda, N.; Kobayashi, Y.; Yamada, Y.; Niwa, Y.

    2010-12-01

    We have experimented with the determination of the positions of star images on a detector with high precision such as 10 microarcseconds, required by a space astrometry satellite, JASMINE. In order to accomplish such a precision, we take the following two procedures. (1) We determine the positions of star images on the detector with the precision of about 0.01 pixel for one measurement, using an algorithm for estimating them from photon weighted means of the star images. (2) We determine the positions of star images with the precision of about 0.0001-0.00001 pixel, which corresponds to that of 10 microarcseconds, using a large amount of data over 10000 measurements, that is, the error of the positions decreases according to the amount of data. Here, we note that the procedure 2 is not accomplished when the systematic error in our data is not excluded adequately even if we use a large amount of data. We first show the method to determine the positions of star images on the detector using photon weighted means of star images. This algorithm, used in this experiment, is very useful because it is easy to calculate the photon weighted mean from the data. This is very important in treating a large amount of data. Furthermore, we need not assume the shape of the point spread function in deriving the centroid of star images. Second, we show the results in the laboratory experiment for precision of determining the positions of star images. We obtain that the precision of estimation of positions of star images on the detector is under a variance of 0.01 pixel for one measurement (procedure 1). We also obtain that the precision of the positions of star images becomes a variance of about 0.0001 pixel using about 10000 measurements (procedure 2).

  5. The interferometric method for measuring the generatrix straightness of high precision cone

    NASA Astrophysics Data System (ADS)

    Kang, Yanhui; Li, Huailu; Diao, Xiaofei; Zhang, Heng

    2015-10-01

    Cone parts are widely used in advanced manufacturing and precision mechanics, providing air proof, torque transmission and so on. The straightness of generatrix is one of the important parameters, and the required accuracy can be up to submicrometers. In order to realize the rapid and high precision generatrix measurement of smooth surface cone, a laser interferometric method is proposed based on the structure of typical Fizeau interferometer. The high precision optical flat is used for reference standard, and the surface of cone is the measured object. Two cylindrical lenses with different focal lengths realize unidirectional expansion of parallel beam, solving the problem of CCD camera fringe resolution. The interference fringes are curved because of the cone angle, and the peak is the basis for accurate determination of the generatrix. Two fringe processing techniques are described in detail, which are single-frame and phase-shifting methods. Single-frame method includes two steps, i.e. the calculation of integral part and decimal part. The advantage of this method is the simple measurement structure. Phase-shifting method needs piezoelectric transducer (PZT) to generate several steps for phase calculation, with the advantage of high accuracy. The experimental results show that the straightness measurement accuracy can be better than 0.2 μm.

  6. High-precision positioning system of four-quadrant detector based on the database query

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Deng, Xiao-guo; Su, Xiu-qin; Zheng, Xiao-qiang

    2015-02-01

    The fine pointing mechanism of the Acquisition, Pointing and Tracking (APT) system in free space laser communication usually use four-quadrant detector (QD) to point and track the laser beam accurately. The positioning precision of QD is one of the key factors of the pointing accuracy to APT system. A positioning system is designed based on FPGA and DSP in this paper, which can realize the sampling of AD, the positioning algorithm and the control of the fast swing mirror. We analyze the positioning error of facular center calculated by universal algorithm when the facular energy obeys Gauss distribution from the working principle of QD. A database is built by calculation and simulation with MatLab software, in which the facular center calculated by universal algorithm is corresponded with the facular center of Gaussian beam, and the database is stored in two pieces of E2PROM as the external memory of DSP. The facular center of Gaussian beam is inquiry in the database on the basis of the facular center calculated by universal algorithm in DSP. The experiment results show that the positioning accuracy of the high-precision positioning system is much better than the positioning accuracy calculated by universal algorithm.

  7. A simple high-precision Jacob's staff design for the high-resolution stratigrapher

    USGS Publications Warehouse

    Elder, W.P.

    1989-01-01

    The new generation of high-resolution stratigraphic research depends upon detailed bed-by-bed analysis to enhance regional correlation potential. The standard Jacob's staff is not an efficient and precise tool for measuring thin-bedded strata. The high-precision Jacob's staff design presented and illustrated in this paper meets the qualifications required of such an instrument. The prototype of this simple design consists of a sliding bracket that holds a Brunton-type compass at right angles to a ruled-off staff. This instrument provides rapid and accurate measurement of both thick- or thin-bedded sequences, thus decreasing field time and increasing stratigraphic precision. -Author

  8. Precision, high dose radiotherapy: helium ion treatment of uveal melanoma

    SciTech Connect

    Saunders, W.M.; Char, D.H.; Quivey, J.M.; Castro, J.R.; Chen, G.T.Y.; Collier, J.M.; Cartigny, A.; Blakely, E.A.; Lyman, J.T.; Zink, S.R.

    1985-02-01

    The authors report on 75 patients with uveal melanoma who were treated by placing the Bragg peak of a helium ion beam over the tumor volume. The technique localizes the high dose region very tightly around the tumor volume. This allows critical structures, such as the optic disc and the macula, to be excluded from the high dose region as long as they are 3 to 4 mm away from the edge of the tumor. Careful attention to tumor localization, treatment planning, patient immobilization and treatment verification is required. With a mean follow-up of 22 months (3 to 60 months) the authors have had only five patients with a local recurrence, all of whom were salvaged with another treatment. Pretreatment visual acuity has generally been preserved as long as the tumor edge is at least 4 mm away from the macula and optic disc. The only serious complication to date has been an 18% incidence of neovascular glaucoma in the patients treated at our highest dose level. Clinical results and details of the technique are presented to illustrate potential clinical precision in administering high dose radiotherapy with charged particles such as helium ions or protons.

  9. Design of a new high precision computer numerical control

    SciTech Connect

    Sweeney, D.J.; Weinert, G.F.

    1988-06-23

    The purpose of this project is to produce a generic high precision computer numerical controller (CNC) for use on microinch- and sub-microinch-resolution machine tools at the Lawrence Livermore National Laboratory. In order to fully utilize the potential of these machine tools, the CNC must include the ability to use multiple feedback sensors on each machine axis, incorporate corrections for quasistatic geometric errors (such as straightness, and squareness), be able to function over a relatively large range of motion (in excess of 60 inches per axis), and be able to produce motion updates at a rate sufficient to take advantage of the high bandwidth of the servo systems. At present, no commercially available CNC can presently meet all of the resolution, feed rate, and length of travel requirements of these machines. In order to minimize the complexity of the system, and thereby increase its reliability and maintainability, the programming was done in a high level language. The number of processors was kept as small as possible while still maintaining the performance requirements. We also used commercially available hardware in preference to building, in order to increase both reliability and maintainability. Special emphasis was given to making the CNC's operator interface as friendly as possible. We have completed a prototype control. We plan to install and test it in 1988. 4 figs.

  10. A new high-precision current supply for magnets

    SciTech Connect

    Wisnivesky, D. |; Lira, A.C.

    1995-08-01

    A new, high-precision, low-ripple current power supply (CPS) for magnets, based on a combination of an SCR converter and a single transistor switched mode power supply (SMPS) is described. The load power is primarily supplied by the SCR converter. The SMPS handles only a small fraction of the load power, and also, what is more significant, a very small part of the load current. In this paper, the topology and operating principle of the new power supply is discussed. A CPS, rated at 200 A at 45 V, was constructed and tested. The power supply energizes a family of quadrupole magnets at the Brazilian Synchrotron Light Source--LNLS. Making use of the current limit modulation (CLM) control method, magnetic field variations at full current are 5 ppm, with only 8 A passing through the switching transistor. The design and performance of the power supply under different operating conditions ar described. Variations of the proposed topology, suitable for high-current and high-voltage loads, are also discussed.

  11. Evaluation of High-Precision Sensors in Structural Monitoring

    PubMed Central

    Erol, Bihter

    2010-01-01

    One of the most intricate branches of metrology involves the monitoring of displacements and deformations of natural and anthropogenic structures under environmental forces, such as tidal or tectonic phenomena, or ground water level changes. Technological progress has changed the measurement process, and steadily increasing accuracy requirements have led to the continued development of new measuring instruments. The adoption of an appropriate measurement strategy, with proper instruments suited for the characteristics of the observed structure and its environmental conditions, is of high priority in the planning of deformation monitoring processes. This paper describes the use of precise digital inclination sensors in continuous monitoring of structural deformations. The topic is treated from two viewpoints: (i) evaluation of the performance of inclination sensors by comparing them to static and continuous GPS observations in deformation monitoring and (ii) providing a strategy for analyzing the structural deformations. The movements of two case study objects, a tall building and a geodetic monument in Istanbul, were separately monitored using dual-axes micro-radian precision inclination sensors (inclinometers) and GPS. The time series of continuous deformation observations were analyzed using the Least Squares Spectral Analysis Technique (LSSA). Overall, the inclinometers showed good performance for continuous monitoring of structural displacements, even at the sub-millimeter level. Static GPS observations remained insufficient for resolving the deformations to the sub-centimeter level due to the errors that affect GPS signals. With the accuracy advantage of inclination sensors, their use with GPS provides more detailed investigation of deformation phenomena. Using inclinometers and GPS is helpful to be able to identify the components of structural responses to the natural forces as static, quasi-static, or resonant. PMID:22163499

  12. Highly precise and robust packaging of optical components

    NASA Astrophysics Data System (ADS)

    Leers, Michael; Winzen, Matthias; Liermann, Erik; Faidel, Heinrich; Westphalen, Thomas; Miesner, Jörn; Luttmann, Jörg; Hoffmann, Dieter

    2012-03-01

    In this paper we present the development of a compact, thermo-optically stable and vibration and mechanical shock resistant mounting technique by soldering of optical components. Based on this technique a new generation of laser sources for aerospace applications is designed. In these laser systems solder technique replaces the glued and bolted connections between optical component, mount and base plate. Alignment precision in the arc second range and realization of long term stability of every single part in the laser system is the main challenge. At the Fraunhofer Institute for Laser Technology ILT a soldering and mounting technique has been developed for high precision packaging. The specified environmental boundary conditions (e.g. a temperature range of -40 °C to +50 °C) and the required degrees of freedom for the alignment of the components have been taken into account for this technique. In general the advantage of soldering compared to gluing is that there is no outgassing. In addition no flux is needed in our special process. The joining process allows multiple alignments by remelting the solder. The alignment is done in the liquid phase of the solder by a 6 axis manipulator with a step width in the nm range and a tilt in the arc second range. In a next step the optical components have to pass the environmental tests. The total misalignment of the component to its adapter after the thermal cycle tests is less than 10 arc seconds. The mechanical stability tests regarding shear, vibration and shock behavior are well within the requirements.

  13. Evaluation of high-precision sensors in structural monitoring.

    PubMed

    Erol, Bihter

    2010-01-01

    One of the most intricate branches of metrology involves the monitoring of displacements and deformations of natural and anthropogenic structures under environmental forces, such as tidal or tectonic phenomena, or ground water level changes. Technological progress has changed the measurement process, and steadily increasing accuracy requirements have led to the continued development of new measuring instruments. The adoption of an appropriate measurement strategy, with proper instruments suited for the characteristics of the observed structure and its environmental conditions, is of high priority in the planning of deformation monitoring processes. This paper describes the use of precise digital inclination sensors in continuous monitoring of structural deformations. The topic is treated from two viewpoints: (i) evaluation of the performance of inclination sensors by comparing them to static and continuous GPS observations in deformation monitoring and (ii) providing a strategy for analyzing the structural deformations. The movements of two case study objects, a tall building and a geodetic monument in Istanbul, were separately monitored using dual-axes micro-radian precision inclination sensors (inclinometers) and GPS. The time series of continuous deformation observations were analyzed using the Least Squares Spectral Analysis Technique (LSSA). Overall, the inclinometers showed good performance for continuous monitoring of structural displacements, even at the sub-millimeter level. Static GPS observations remained insufficient for resolving the deformations to the sub-centimeter level due to the errors that affect GPS signals. With the accuracy advantage of inclination sensors, their use with GPS provides more detailed investigation of deformation phenomena. Using inclinometers and GPS is helpful to be able to identify the components of structural responses to the natural forces as static, quasi-static, or resonant. PMID:22163499

  14. Extra precision docking, free energy calculation and molecular dynamics simulation studies of CDK2 inhibitors.

    PubMed

    Tripathi, Sunil Kumar; Muttineni, Ravikumar; Singh, Sanjeev Kumar

    2013-10-01

    Molecular docking, free energy calculation and molecular dynamics (MD) simulation studies have been performed, to explore the putative binding modes of 3,5-diaminoindazoles, imidazo(1,2-b)pyridazines and triazolo(1,5-a) pyridazines series of Cyclin-dependent kinase (CDK2) inhibitors. To evaluate the effectiveness of docking protocol in flexible docking, we have selected crystallographic bound compound to validate our docking procedure as evident from root mean square deviations (RMSDs). We found different binding sites namely catalytic, inhibitory phosphorylation, cyclin binding and CKS-binding site of the CDK2 contributing towards the binding of these compounds. Moreover, correlation between free energy of binding and biological activity yielded a statistically significant correlation coefficient. Finally, three representative protein-ligand complexes were subjected to molecular dynamics simulation to determine the stability of the predicted conformations. The low value of the RMSDs between the initial complex structure and the energy minimized final average complex structure suggests that the derived docked complexes are close to equilibrium. We suggest that the phenylacetyl type of substituents and cyclohexyl moiety make the favorable interactions with a number of residues in the active site, and show better inhibitory activity to improve the pharmacokinetic profile of compounds against CDK2. The structure-based drug design strategy described in this study will be highly useful for the development of new inhibitors with high potency and selectivity. PMID:23727278

  15. Calculation of the performance of magnetic lenses with limited machining precision.

    PubMed

    Sháněl, O; Zlámal, J; Oral, M

    2014-02-01

    To meet a required STEM resolution, the mechanical precision of the pole pieces of a magnetic lens needs to be determined. A tolerancing plugin in the EOD software is used to determine a configuration which both meets the optical specifications and is cost effective under the constraints of current manufacturing technologies together with a suitable combination of correction elements. PMID:24220249

  16. Sample Size Calculations for Precise Interval Estimation of the Eta-Squared Effect Size

    ERIC Educational Resources Information Center

    Shieh, Gwowen

    2015-01-01

    Analysis of variance is one of the most frequently used statistical analyses in the behavioral, educational, and social sciences, and special attention has been paid to the selection and use of an appropriate effect size measure of association in analysis of variance. This article presents the sample size procedures for precise interval estimation…

  17. High precision atomic data for halo nuclei and related nuclear structure

    SciTech Connect

    Noertershaeuser, Wilfried

    2013-07-11

    Nuclear charge radii of the lightest neutron-halo isotopes {sup 6,8}He, {sup 11}Li, and {sup 11}Be have been measured during the last decade using tailored laser-spectroscopic techniques for the needs of high-accuracy isotope shift measurements on millisecond-isotopes with very low production yields. Nuclear charge radii can be extracted using high-precision calculations of the mass-shift contribution and the electronic factor of the finite-nuclear-size effect. These results are important benchmarks for nuclear structure theory and give access to the correlations between halo neutrons and average distances of the halo neutrons from the core nucleus.

  18. High-Precision Studies of Compact Variable Stars

    NASA Astrophysics Data System (ADS)

    Bloemen, Steven

    2014-10-01

    This book, which is a reworked and updated version of Steven Bloemen's original PhD thesis, reports on several high-precision studies of compact variable stars. Its strength lies in the large variety of observational, theoretical and instrumentation techniques that are presented and used and paves the way towards new and detailed asteroseismic applications of single and binary subdwarf stars. Close binary stars are studied using high cadence spectroscopic datasets collected with state of the art electron multiplying CCDs and analysed using Doppler tomography visualization techniques. The work touches upon instrumentation, presenting the calibration of a new fast, multi-colour camera installed at the Mercator Telescope on La Palma. The thesis also includes theoretical work on the computation of the temperature range in which stellar oscillations can be driven in subdwarf B-stars. Finally, the highlight of the thesis is the measurement of velocities of stars using only photometric data from NASA's Kepler satellite. Doppler beaming causes stars to appear slightly brighter when they move towards us in their orbits, and this subtle effect can be seen in Kepler's brightness measurements. The thesis presents the first validation of such velocity measurements using independent spectroscopic measurements. Since the detection and validation of this Doppler beaming effect, it has been used in tens of studies to detect and characterize binary star systems, which are key calibrators in stellar astronomy.

  19. High precision zinc isotopic measurements applied to mouse organs.

    PubMed

    Moynier, Frédéric; Le Borgne, Marie

    2015-01-01

    We present a procedure to measure with high precision zinc isotope ratios in mouse organs. Zinc is composed of 5 stable isotopes ((64)Zn, (66)Zn, (67)Zn, (68)Zn and (70)Zn) which are naturally fractionated between mouse organs. We first show how to dissolve the different organs in order to free the Zn atoms; this step is realized by a mixture of HNO3 and H2O2. We then purify the zinc atoms from all the other elements, in particular from isobaric interferences (e.g., Ni), by anion-exchange chromatography in a dilute HBr/HNO3 medium. These first two steps are performed in a clean laboratory using high purity chemicals. Finally, the isotope ratios are measured by using a multi-collector inductively-coupled-plasma mass-spectrometer, in low resolution. The samples are injected using a spray chamber and the isotopic fractionation induced by the mass-spectrometer is corrected by comparing the ratio of the samples to the ratio of a standard (standard bracketing technique). This full typical procedure produces an isotope ratio with a 50 ppm (2 s.d.) reproducibility. PMID:26065372

  20. Calculation of measurement uncertainty in quantitative analysis of genetically modified organisms using intermediate precision--a practical approach.

    PubMed

    Zel, Jana; Gruden, Kristina; Cankar, Katarina; Stebih, Dejan; Blejec, Andrej

    2007-01-01

    Quantitative characterization of nucleic acids is becoming a frequently used method in routine analysis of biological samples, one use being the detection of genetically modified organisms (GMOs). Measurement uncertainty is an important factor to be considered in these analyses, especially where precise thresholds are set in regulations. Intermediate precision, defined as a measure between repeatability and reproducibility, is a parameter describing the real situation in laboratories dealing with quantitative aspects of molecular biology methods. In this paper, we describe the top-down approach to calculating measurement uncertainty, using intermediate precision, in routine GMO testing of food and feed samples. We illustrate its practicability in defining compliance of results with regulations. The method described is also applicable to other molecular methods for a variety of laboratory diagnostics where quantitative characterization of nucleic acids is needed. PMID:17474528

  1. Precision cosmology with time delay lenses: high resolution imaging requirements

    NASA Astrophysics Data System (ADS)

    Meng, Xiao-Lei; Treu, Tommaso; Agnello, Adriano; Auger, Matthew W.; Liao, Kai; Marshall, Philip J.

    2015-09-01

    Lens time delays are a powerful probe of cosmology, provided that the gravitational potential of the main deflector can be modeled with sufficient precision. Recent work has shown that this can be achieved by detailed modeling of the host galaxies of lensed quasars, which appear as ``Einstein Rings'' in high resolution images. The distortion of these arcs and counter-arcs, as measured over a large number of pixels, provides tight constraints on the difference between the gravitational potential between the quasar image positions, and thus on cosmology in combination with the measured time delay. We carry out a systematic exploration of the high resolution imaging required to exploit the thousands of lensed quasars that will be discovered by current and upcoming surveys with the next decade. Specifically, we simulate realistic lens systems as imaged by the Hubble Space Telescope (HST), James Webb Space Telescope (JWST), and ground based adaptive optics images taken with Keck or the Thirty Meter Telescope (TMT). We compare the performance of these pointed observations with that of images taken by the Euclid (VIS), Wide-Field Infrared Survey Telescope (WFIRST) and Large Synoptic Survey Telescope (LSST) surveys. We use as our metric the precision with which the slope γ' of the total mass density profile ρtotpropto r-γ' for the main deflector can be measured. Ideally, we require that the statistical error on γ' be less than 0.02, such that it is subdominant to other sources of random and systematic uncertainties. We find that survey data will likely have sufficient depth and resolution to meet the target only for the brighter gravitational lens systems, comparable to those discovered by the SDSS survey. For fainter systems, that will be discovered by current and future surveys, targeted follow-up will be required. However, the exposure time required with upcoming facilitites such as JWST, the Keck Next Generation Adaptive Optics System, and TMT, will only be of

  2. Precision cosmology with time delay lenses: High resolution imaging requirements

    SciTech Connect

    Meng, Xiao -Lei; Treu, Tommaso; Agnello, Adriano; Auger, Matthew W.; Liao, Kai; Marshall, Philip J.

    2015-09-28

    Lens time delays are a powerful probe of cosmology, provided that the gravitational potential of the main deflector can be modeled with sufficient precision. Recent work has shown that this can be achieved by detailed modeling of the host galaxies of lensed quasars, which appear as ``Einstein Rings'' in high resolution images. The distortion of these arcs and counter-arcs, as measured over a large number of pixels, provides tight constraints on the difference between the gravitational potential between the quasar image positions, and thus on cosmology in combination with the measured time delay. We carry out a systematic exploration of the high resolution imaging required to exploit the thousands of lensed quasars that will be discovered by current and upcoming surveys with the next decade. Specifically, we simulate realistic lens systems as imaged by the Hubble Space Telescope (HST), James Webb Space Telescope (JWST), and ground based adaptive optics images taken with Keck or the Thirty Meter Telescope (TMT). We compare the performance of these pointed observations with that of images taken by the Euclid (VIS), Wide-Field Infrared Survey Telescope (WFIRST) and Large Synoptic Survey Telescope (LSST) surveys. We use as our metric the precision with which the slope γ' of the total mass density profile ρtot∝ r–γ' for the main deflector can be measured. Ideally, we require that the statistical error on γ' be less than 0.02, such that it is subdominant to other sources of random and systematic uncertainties. We find that survey data will likely have sufficient depth and resolution to meet the target only for the brighter gravitational lens systems, comparable to those discovered by the SDSS survey. For fainter systems, that will be discovered by current and future surveys, targeted follow-up will be required. Furthermore, the exposure time required with upcoming facilitites such as JWST, the Keck Next Generation Adaptive Optics System, and TMT, will

  3. High-precision Mg isotopic systematics of bulk chondrites

    NASA Astrophysics Data System (ADS)

    Schiller, Martin; Handler, Monica R.; Baker, Joel A.

    2010-08-01

    Variations of the mass-independent abundance of 26Mg ( δ26Mg*) and stable Mg ( δ25Mg) isotope composition of chondrites are important because they constrain the homogeneity of 26Al and Mg isotopes in the proto-planetary disc and the validity of the short-lived 26Al-to- 26Mg chronometer applied to meteorites. We present high-precision Mg isotope data and Al/Mg ratios of chondrites representing nearly all major chondrite classes, including a step-leaching experiment on the CM2 chondrite Murchison. δ26Mg* variations in leachates of Murchison representing acid soluble material are ≤ 30 times smaller than reported for neutron-rich isotopes of Ti and Cr and do not reveal resolvable deficits in δ26Mg* (-0.002 to + 0.118‰). Very small variations in δ26Mg* anomalies in bulk chondrites (-0.006 to + 0.019‰) correlate with increasing 27Al/ 24Mg ratios and δ50Ti, reflecting the variable presence of calcium-aluminium-rich inclusions (CAIs) in some types of carbonaceous chondrites. Similarly, release of radiogenic 26Mg produced by 26Al decay from CAI material in the step-leaching of Murchison best explains the high δ26Mg* observed in the last, aggressive, leaching steps of this experiment. Overall, the observed variations in δ26Mg* are small and potential differences beyond that which result from the presence of CAI-like material cannot be detected within the analytical uncertainties of this study (± 0.004‰). The results do not allow radical heterogeneity of 26Al (≥±30%) or measurable Mg nucleosynthetic heterogeneity (≥±0.005‰) to have existed on a planetesimal scale in the proto-planetary disc. Combined with published δ26Mg* data for CAIs, the bulk chondrite data yield a precise initial ( 26Al/ 27Al) 0 = (5.21 ± 0.06) × 10 -5 and δ26Mg* = -0.0340 ± 0.0016‰ for the Solar System. However, it is not possible with the currently available data to determine with certainty whether CAIs and the material from which planetesimals accreted including

  4. Calculation and analysis for stiffness of the thrust aerostatic bearing of ultra-precision machine tools

    NASA Astrophysics Data System (ADS)

    Lu, Lihua; Zhao, Ziqiang; Liang, Yingchun; Zhang, Longjiang

    2010-10-01

    The single point diamond turning (SPDT) lathe of vertical flying cutting milling style is one important ultra-precision machining method for Large-aperture optics. To realize ultra-precision machining with SPDT technology, the turning spindle of the machine tools should be with higher stiffness and stability. In this paper, based on finite element method (FEM), an iterative procedure is proposed and implemented to solve the fluid dynamic model and structure model for simulation the couple of air pressure and structure flexibility. Simulation results show that pressure in the air gap makes the plate deform and this deformation produced by the pressure adversely modifies the pressure distribution. Experimental results indicate that the method can predict the aerostatic spindle stiffness accurately, the prediction error is about 2.04%. These results show a relevant influence of the structural flexibility of the bearing on its static performance.

  5. Progress Towards a High-Precision Infrared Spectroscopic Survey of the H_3^+ Ion

    NASA Astrophysics Data System (ADS)

    Perry, Adam J.; Hodges, James N.; Markus, Charles R.; Kocheril, G. Stephen; Jenkins, Paul A., II; McCall, Benjamin J.

    2015-06-01

    The trihydrogen cation, H_3^+, represents one of the most important and fundamental molecular systems. Having only two electrons and three nuclei, H_3^+ is the simplest polyatomic system and is a key testing ground for the development of new techniques for calculating potential energy surfaces and predicting molecular spectra. Corrections that go beyond the Born-Oppenheimer approximation, including adiabatic, non-adiabatic, relativistic, and quantum electrodynamic corrections are becoming more feasible to calculate. As a result, experimental measurements performed on the H_3^+ ion serve as important benchmarks which are used to test the predictive power of new computational methods. By measuring many infrared transitions with precision at the sub-MHz level it is possible to construct a list of the most highly precise experimental rovibrational energy levels for this molecule. Until recently, only a select handful of infrared transitions of this molecule have been measured with high precision (˜ 1 MHz). Using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy, we are aiming to produce the largest high-precision spectroscopic dataset for this molecule to date. Presented here are the current results from our survey along with a discussion of the combination differences analysis used to extract the experimentally determined rovibrational energy levels. O. Polyansky, et al., Phil. Trans. R. Soc. A (2012), 370, 5014. M. Pavanello, et al., J. Chem. Phys. (2012), 136, 184303. L. Diniz, et al., Phys. Rev. A (2013), 88, 032506. L. Lodi, et al., Phys. Rev. A (2014), 89, 032505. J. Hodges, et al., J. Chem. Phys (2013), 139, 164201.

  6. Closed loop high precision position control system with optical scale

    NASA Astrophysics Data System (ADS)

    Ge, Cheng-liang; Liao, Yuan; He, Zhong-wu; Luo, Zhong-xiang; Huang, Zhi-wei; Wan, Min; Hu, Xiao-yang; Fan, Guo-bin; Liang, Zheng

    2008-03-01

    With the developments of science of art, there are more and more demands on the high resolution control of position of object to be controlled, such as lathe, product line, elements in the optical resonant cavity, telescope, and so on. As one device with high resolution, the optical scale has more and more utility within the industrial and civil applications. With one optical scale and small DC servo motor, one closed loop high resolution position control system is constructed. This apparatus is used to control the position of the elements of optical system. The optical scale is attached on the object or reference guide way. The object position is sampled by a readhead of non-contact optical encoder. Control system processes the position information and control the position of object through the motion control of servo DC motor. The DC motor is controlled by one controller which is connected to an industrial computer. And the micro frictionless slide table does support the smooth motion of object to be controlled. The control algorithm of system is PID (Proportional-Integral-Differential) methods. The PID control methods have well ROBUST. The needed data to control are position, velocity and acceleration of the object. These three parameters correspond to the PID characters respectively. After the accomplishments of hardware, GUI (Graphical user interface), that is, the software of control system is also programmed. The whole system is assembled by specialized worker. Through calibration experiments, the coefficients of PID are obtained respectively. And then the precision of position control of the system is about 0.1μm.

  7. Laser interferometric high-precision angle monitor for JASMINE

    NASA Astrophysics Data System (ADS)

    Niwa, Yoshito; Arai, Koji; Sakagami, Masaaki; Gouda, Naoteru; Kobayashi, Yukiyasu; Yamada, Yoshiyuki; Yano, Taihei

    2006-06-01

    The JASMINE instrument uses a beam combiner to observe two different fields of view separated by 99.5 degrees simultaneously. This angle is so-called basic angle. The basic angle of JASMINE should be stabilized and fluctuations of the basic angle should be monitored with the accuracy of 10 microarcsec in root-mean-square over the satellite revolution period of 5 hours. For this purpose, a high-precision interferometric laser metrogy system is employed. One of the available techniques for measuring the fluctuations of the basic angle is a method known as the wave front sensing using a Fabry-Perot type laser interferometer. This technique is to detect fluctuations of the basic angle as displacement of optical axis in the Fabry-Perot cavity. One of the advantages of the technique is that the sensor is made to be sensitive only to the relative fluctuations of the basic angle which the JASMINE wants to know and to be insensitive to the common one; in order to make the optical axis displacement caused by relative motion enhanced the Fabry-Perot cavity is formed by two mirrors which have long radius of curvature. To verify the principle of this idea, the experiment was performed using a 0.1m-length Fabry-Perot cavity with the mirror curvature of 20m. The mirrors of the cavity were artificially actuated in either relative way or common way and the resultant outputs from the sensor were compared.

  8. Two-dimensional, high flow, precisely controlled monodisperse drop source

    NASA Astrophysics Data System (ADS)

    Dressler, John L.

    1993-03-01

    A versatile acoustically-driven fluid atomizer was designed and operated that creates precise monodisperse sprays by Rayleigh breakup or polydisperse sprays by the acoustic driving of amplitude dependent instabilities. The atomizer forms a cylindrical, conical, or flat (sheet) liquid jet by means of a photofabricated nozzle. The spray pattern and spray volume are altered by changing the nozzle. A piezoelectric driver, constructed to efficiently couple energy to the liquid, modulates the fluid velocity. When operated at low power, the drop generator can produce arrays of monodisperse drops as small as 15 microns in diameter. Operating the piezoelectric driver at high power produces perturbations with sufficient energy to break the liquid jets into drops, with a net increase in surface energy. The resulting drop sizes are influenced by the frequency and amplitude of the driving signal and nozzle size. The spatial distribution of the spray is controlled by the spacing and geometry of the holes in the nozzle plate, the amplitude of the acoustic signal, and the swirl in the fluid manifold. This device is more robust than the typical acoustic drop generator because small drops can be made from large holes, reducing the plugging problem. No air flow is used.

  9. Report on APMP supplementary comparison: high precision roundness measurement

    NASA Astrophysics Data System (ADS)

    Buajarern, J.; Naoi, K.; Baker, A.; Zi, X.; Tsai, C.-L.; Eom, T. B.; Leng, T. S.; Kruger, O.

    2016-01-01

    A regional supplementary comparison, APMP.L-S4, was held in 2012 to demonstrate the equivalence of routine calibration services offered by NMIs to clients. Participants in this APMP.L-S4 comparison agreed to apply multi-step method for spidle error separation in order to yield the high precision roundness measurement. Eight laboratories from NMIs participated in this supplementary comparison; NIMT, NMIJ, NMIA, NIM, CMS/ITRI, KRISS, NMC/A*STAR and NMISA. This report describes the measurement results of 2 glass hemispheres and 2 softgauges. The calibrations of this comparison were carried out by participants during the period from March 2012 to May 2013. The results show that there is a degree of equivalence within 0.8 for all measurands. Hence, there is a close agreement between the measurements. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. Smart sensors and calibration standards for high precision metrology

    NASA Astrophysics Data System (ADS)

    Brand, Uwe; Gao, Sai; Doering, Lutz; Li, Zhi; Xu, Min; Buetefisch, Sebastian; Peiner, Erwin; Fruehauf, Joachim; Hiller, Karla

    2015-05-01

    The paper summarize the PTB activities in the field of silicon sensors for dimensional metrology especially roughness measurements and silicon calibration standards developed during the past ten years. A focus lies in the development of 2D silicon microprobes which enable roughness measurements in nozzles as small as 100 μm in diameter. Moreover these microprobes offer the potential for very fast tactile measurements up to 15 mm/s due to their tiny mass and therefore small dynamic forces. When developing high precision tactile sensors care has to be taken, not to scratch the often soft surfaces. Small probing forces and well defined tip radii have to be used to avoid surface destruction. Thus probing force metrology and methods to determine the radius and form of probing tips have been developed. Silicon is the preferred material for the calibration of topography measuring instruments due to its excellent mechanical and thermal stability and due to the fabrication and structuring possibilities of silicon microtechnology. Depth setting standards, probing force setting standards, tip radius and tip form standards, reference springs and soft material testing artefacts will be presented.

  11. Interferometric apparatus for ultra-high precision displacement measurement

    NASA Technical Reports Server (NTRS)

    Zhao, Feng (Inventor)

    2004-01-01

    A high-precision heterodyne interferometer measures relative displacement by creating a thermally-insensitive system generally not subject to polarization leakage. By using first and second light beams separated by a small frequency difference (.DELTA.f), beams of light at the first frequency (f.sub.0) are reflected by co-axial mirrors, the first mirror of which has a central aperture through which the light is transmitted to and reflected by the second mirror. Prior to detection, the light beams from the two mirrors are combined with light of the second and slightly different frequency. The combined light beams are separated according to the light from the mirrors. The change in phase (.DELTA..phi.) with respect to the two signals is proportional to the change in distance of Fiducial B by a factor of wavelength (.lambda.) divided by 4.pi. (.DELTA.L=.lambda..DELTA..phi.1/(4.pi.)). In a second embodiment, a polarizing beam splitting system can be used.

  12. High-precision impedance spectroscopy: a strategy demonstrated on PZT.

    PubMed

    Boukamp, Bernard A; Blank, Dave H A

    2011-12-01

    Electrochemical impedance spectroscopy (EIS) has been recognized as a very powerful tool for studying charge and mass transport and transfer in a wide variety of electrically or electrochemically active systems. Sophisticated modeling programs make it possible to extract parameters from the impedance data, thus contributing to a better understanding of the system or material properties. For an accurate analysis, a correct modeling function is needed; this is often in the form of an equivalent circuit. It is not always possible to define the modeling function from visual inspection of the impedance dispersion. Small contributions to the overall dispersion can be masked, and hence overlooked. In this publication, a strategy is presented for high-precision impedance data analysis. A Kramers-Kronig test is used for the essential data validation. An iterative process of partial analysis and subtraction assists in deconvoluting the impedance spectrum, yielding both a vi- able model function and a set of necessary starting values for the full complex nonlinear least squares (CNLS) modeling. The advantage and possibilities of this strategy are demonstrated with an analysis of the ionic and electronic conductivity of lead zirconate titanate (PZT) as functions of temperature and oxygen partial pressure. PMID:23443688

  13. High Precision 40K/39K Ratio Determination

    NASA Astrophysics Data System (ADS)

    Naumenko, M. O.; Mezger, K.; Nagler, T. F.; Villa, I. M.

    2012-12-01

    Potassium is one of the eight most abundant chemical elements in the Earth's crust and a major element in many rock-forming minerals. The isotope 40K is radioactive and undergoes β- decay to 40Ca (ca. 89.3%) and electron capture to 40Ar (ca. 10.7%). Both decays can potentially be used as dating systems. The most commonly used branch is the decay of 40K to 40Ar because it can yield highly precise ages. Both decay schemes rely on the knowledge of the 40K branching ratio and the natural 40K abundance. A 40K abundance of 0.011672±41 % was measured on terrestrial material [1]. The relative uncertainty of 0.35 % has not been improved since. Recent improvements in the precision of mass spectrometric measurements have led to the situation that the uncertainties on the K decay constant and the abundance of 40K are a major source of uncertainty on the measured ages. A more precise definition of the 40K decay constant was attempted by different research groups within the last decade [2-9] but the goal of obtaining 0.1 % relative uncertainty on K-Ar ages for geological materials, as requested by the EARTHtime initiative, has not been achieved yet. In order to improve on this situation we studied the abundances of the K isotopes in terrestrial standards. A ThermoFischer Triton+ thermal ionisation mass spectrometer was used for K isotope ratio measurements of the NIST SRM 918b K standard loaded on Ta filaments with 0.1M phosphoric acid. Three techniques were applied: (A) dynamic measurement with in-run normalisation to the IUPAC value 41K/39K=0.072168; (B) a simple total evaporation procedure; (C) the "NBL-modified" total evaporation [10]. The 40K ion beam was measured in a Faraday cup with a 1E12 Ω resistor; 39K and 41K were collected in Faraday cups with 1E11 Ω resistors. Amplifier gains were intercalibrated by supplying fixed voltages off-line. Different measurement techniques were combined with different loading procedures. We also tested ionisation yields for the

  14. French Meteor Network for High Precision Orbits of Meteoroids

    NASA Technical Reports Server (NTRS)

    Atreya, P.; Vaubaillon, J.; Colas, F.; Bouley, S.; Gaillard, B.; Sauli, I.; Kwon, M. K.

    2011-01-01

    There is a lack of precise meteoroids orbit from video observations as most of the meteor stations use off-the-shelf CCD cameras. Few meteoroids orbit with precise semi-major axis are available using film photographic method. Precise orbits are necessary to compute the dust flux in the Earth s vicinity, and to estimate the ejection time of the meteoroids accurately by comparing them with the theoretical evolution model. We investigate the use of large CCD sensors to observe multi-station meteors and to compute precise orbit of these meteoroids. An ideal spatial and temporal resolution to get an accuracy to those similar of photographic plates are discussed. Various problems faced due to the use of large CCD, such as increasing the spatial and the temporal resolution at the same time and computational problems in finding the meteor position are illustrated.

  15. Precise Calculation of a Bond Percolation Transition and Survival Rates of Nodes in a Complex Network

    PubMed Central

    Kawamoto, Hirokazu; Takayasu, Hideki; Jensen, Henrik Jeldtoft; Takayasu, Misako

    2015-01-01

    Through precise numerical analysis, we reveal a new type of universal loopless percolation transition in randomly removed complex networks. As an example of a real-world network, we apply our analysis to a business relation network consisting of approximately 3,000,000 links among 300,000 firms and observe the transition with critical exponents close to the mean-field values taking into account the finite size effect. We focus on the largest cluster at the critical point, and introduce survival probability as a new measure characterizing the robustness of each node. We also discuss the relation between survival probability and k-shell decomposition. PMID:25885791

  16. Precision optical slit for high heat load or ultra high vacuum

    DOEpatents

    Andresen, N.C.; DiGennaro, R.S.; Swain, T.L.

    1995-01-24

    This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochromators for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line. 21 figures.

  17. Precision optical slit for high heat load or ultra high vacuum

    DOEpatents

    Andresen, Nord C.; DiGennaro, Richard S.; Swain, Thomas L.

    1995-01-01

    This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochrometers for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line.

  18. Retrieving High Precision River Stages and Slopes from Space

    NASA Astrophysics Data System (ADS)

    Rodriguez, E.; Moller, D.

    2005-12-01

    Conventional radar altimetry has been successful in retrieving water level measurements at altimeter crossings with an accuracy of 10cm to 20cm. Although promising, this measurement accuracy is insufficient to provide global monitoring of fresh water bodies, as has been proposed by the WatER mission, for instance. In this paper we examine in detail the error sources that a near-nadir synthetic aperture radar interferometer, such as the KaRIN instrument proposed to meet the WatER requirements, will be subject to and demonstrate that with appropriate calibration techniques, measurements of river stage with an accuracy of approximately 5 cm and river slope with an accuracy of 1 cm/1km can be obtained. In the first part, we examine the main error contributors to the height measurements and quantify the expected magnitude of the errors. The errors sources examined include tropospheric effects, spacecraft orbit and attitude stability, the effect of vegetation, and the effect of topographic lay-over. These sources of error are examined analytically and also with the help of an instrument simulation which includes all error sources to generate simulated measurements. Simulated performance results will be presented for the Ohio river basin and for the Amazon basin at the Solimoes/Puros confluence. In the second part, we examine calibration techniques to mitigate the errors mentioned above and demonstrate the feasibility of achieving the height and slope performance given in the first paragraph. Simulated calibration results will be presented for both Ohio and Amazon basins. Finally, we propose a method for processing the interferometer data to optimally filter random measurement noise and provide high precision estimates of river stage and slope which can be assimilated simply into hydrologic models or used in conjunction with ancillary data or physical assumptions to provide estimates of river discharge.

  19. High-precision photometry of WASP-12 b transits

    NASA Astrophysics Data System (ADS)

    Maciejewski, G.; Errmann, R.; Raetz, St.; Seeliger, M.; Spaleniak, I.; Neuhäuser, R.

    2011-04-01

    Aims: The transiting extrasolar planet WASP-12 b was found to be one of the most intensely irradiated exoplanets. It is unexpectedly bloated and is losing mass that may accrete into the host star. Our aim was to refine the parameters of this intriguing system and search for signs of transit timing variations. Methods: We gathered high-precision light curves for two transits of WASP-12 b. Assuming various limb-darkening laws, we generated best-fitting models and redetermined the parameters of the system. Error estimates were derived by the prayer-bead method and Monte Carlo simulations. Results: System parameters obtained by us are found to agree with previous studies within one sigma. Use of the non-linear limb-darkening laws results in the best-fitting models. With two new mid-transit times, the ephemeris was refined to BJDTDB = (2 454 508.97682 ± 0.00020) + (1.09142245 ± 0.00000033)E. Interestingly, indications of transit timing variation are detected at the level of 3.4 sigma. This signal can be induced by an additional planet in the system. Simplified numerical simulations show that a perturber could be a terrestrial-type planet if both planets are in a low-order orbital resonance. However, we emphasise that further observations are needed to confirm variation and to constrain properties of the perturber. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA), operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofisica de Andalucia (CSIC).Photometric data are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/528/A65

  20. Derivative properties from high-precision equations of state.

    PubMed

    Haghbakhsh, Reza; Konttorp, Morten; Raeissi, Sona; Peters, Cor J; O'Connell, John P

    2014-12-11

    In this study, the behavior of derivative properties estimated by equations of state, including isochoric heat capacity, isobaric heat capacity, speed of sound, and the Joule-Thomson coefficient for pure compounds and a mixture, has been investigated. The Schmidt-Wagner and Jacobsen-Stewart equations of state were used for predictions of derivative properties of 10 different pure compounds from various nonpolar hydrocarbons, nonpolar cyclic hydrocarbons, polar compounds, and refrigerants. The estimations were compared to experimental data. To evaluate the behavior of mixtures, the extended corresponding states principle (ECS) was studied. Analytical relationships were derived for isochoric heat capacity, isobaric heat capacity, the Joule-Thomson coefficient, and the speed of sound. The ECS calculations were compared to the reference surface data of methane + ethane. The ECS principle was found to generate data of high quality. PMID:25347617

  1. High Precision Prediction of Functional Sites in Protein Structures

    PubMed Central

    Buturovic, Ljubomir; Wong, Mike; Tang, Grace W.; Altman, Russ B.; Petkovic, Dragutin

    2014-01-01

    We address the problem of assigning biological function to solved protein structures. Computational tools play a critical role in identifying potential active sites and informing screening decisions for further lab analysis. A critical parameter in the practical application of computational methods is the precision, or positive predictive value. Precision measures the level of confidence the user should have in a particular computed functional assignment. Low precision annotations lead to futile laboratory investigations and waste scarce research resources. In this paper we describe an advanced version of the protein function annotation system FEATURE, which achieved 99% precision and average recall of 95% across 20 representative functional sites. The system uses a Support Vector Machine classifier operating on the microenvironment of physicochemical features around an amino acid. We also compared performance of our method with state-of-the-art sequence-level annotator Pfam in terms of precision, recall and localization. To our knowledge, no other functional site annotator has been rigorously evaluated against these key criteria. The software and predictive models are incorporated into the WebFEATURE service at http://feature.stanford.edu/wf4.0-beta. PMID:24632601

  2. Precision calculation of radiative n-p capture for big-bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Rupak, Gautam

    2000-04-01

    An effective field theory calculation of the n parrow d+γ cross section accurate to 1% for center of mass energy E up to 1 MeV is presented. At these energies, which are relevant for big-bang nucleosynthesis, isovector magnetic transitions M1 and isovector electric transitions E1 give the dominant contributions. The M1 amplitude is calculated up to next-to-next-to-leading order (NNLO) and the contribution from the associated four-nucleon-one-photon operator is determined from the cold neutron capture rate. The E1 amplitude is calculated up to NNNNLO. The four-nucleon-one-photon operator contribution to E1 is determined from the related deuteron photodisintegration reaction γ darrow np.

  3. Precision of Porosity Calculation from "Material Stopping Power" Using Neutron Radiography

    NASA Astrophysics Data System (ADS)

    Nshimirimana, Robert; Radebe, Mabuti; de Beer, Frikkie

    The ability of digital neutron radiography to determine several important physical properties (e.g. porosity) of porous media and to identify the location of constituencies inside the sample in a non-destructive manner, are of great important in the fields of nuclear waste encapsulation and -shielding, civil engineering and geological studies. Unfortunately material thickness and radiation scatter hamper the accuracy and precision ofmeasurements. Correction methods are used to minimize the effect of neutron scattering in quantitative analysis neutron radiography experiment. To further minimize the error due to neutron scattering, it is advisable to position the sample as far away as possible from the neutron detector when perform quantitative neutron radiography. That requires the trade between sharpness and neutron scattering. In this work the neutron radiographyquantitative experiments were performed when the samples are placed too close (≈ 0.1 cm) to the detector; and accurate results of porosity measurement were obtained without applying any neutron scattering correction tool or method.

  4. High-precision measurement of chlorine stable isotope ratios

    USGS Publications Warehouse

    Long, A.; Eastoe, C.J.; Kaufmann, R.S.; Martin, J.G.; Wirt, L.; Finley, J.B.

    1993-01-01

    We present an analysis procedure that allows stable isotopes of chlorine to be analyzed with precision sufficient for geological and hydrological studies. The total analytical precision is ?????0.09%., and the present known range of chloride in the surface and near-surface environment is 3.5???. As Cl- is essentially nonreactive in natural aquatic environments, it is a conservative tracer and its ??37Cl is also conservative. Thus, the ??37Cl parameter is valuable for quantitative evaluation of mixing of different sources of chloride in brines and aquifers. ?? 1993.

  5. Seismicity analysis in Indonesia region from high precision hypocenter location

    NASA Astrophysics Data System (ADS)

    Nugraha, Andri; Shiddiqi, Hasbi; Widiyantoro, Sri; Ramdhan, Mohamad; Wandono, Wandono

    2015-04-01

    As a complex tectonic region, Indonesia has a high seismicity rate which is related to subduction and collision as well as strike-slip fault. High-precision earthquake locations with adequate relocation method and proper velocity model are necessary for seismicity analysis. We used nearly 25,000 earthquakes that were relocated using double-difference method. In our relocation process, we employed teleseismic, regional, and local P-wave arrival times. Furthermore, we employed regional-global nested velocity models that take into account the subduction slab in the study region by using a 3D model for area inside and a 1D model for area outside Indonesia. Relocation results show shifted hypocenters that are generally perpendicular to the trench. Beneath western Sunda arc, the Wadati-Benioff Zone (WBZ) extents to a depth of about 300 km and depicts a gently dipping slab. The WBZ beneath eastern Sunda arc extends deeper to about 500 km and depicts a steep slab geometry. In the Sunda-Banda transition zone, we found anomalously low seismicity beneath the oceanic-continental transition region. The WBZ of the severely curved Banda arc extends to a depth of about 600 km and depicts a two-slab model. In the Molucca collision zone, seismicity clearly depicts two opposing slabs of the Molucca sea plate, i.e. to the east and to the west. Around Sulawesi region, most earthquakes are related to the north Sulawesi trench and depict subducted slab beneath the northern part of the island. In Sumatra region, we identified a seismic gap in the WBZ between 70 km and 150 km. Seismicity gaps are also detected beneath particular regions, e.g. Mentawai region, and several parts along the subducted slab. Similar to the Sumatra region, beneath eastern Sunda arc, seismic gap in WBZ is also detected but deeper, i.e. at depths of 150 km to 250 km. Furthermore, we used global centroid moment tensor catalog data available for earthquakes with magnitude 5.0 or greater. In general, focal mechanism

  6. Hybrid method for the precise calculation of the general dyadic Greens functions for SAW and leaky wave substrates.

    SciTech Connect

    Branch, Darren W.

    2008-05-01

    Recently, the generalized method for calculation of the 16-element Green's function for analysis of surface acoustic waves has proven crucial to develop more sophisticated transducers. The generalized Green's function provides a precise relationship between the acoustic stresses and electric displacement on the three mechanical displacements and electric potential. This generalized method is able to account for mass loading effects which is absent in the effective permittivity approach. However, the calculation is numerically intensive and may lead to numerical instabilities when solving for both the eigenvalues and eigenvectors simultaneously. In this work, the general eigenvalue problem was modified to eliminate the numerical instabilities in the solving procedure. An algorithm is also presented to select the proper eigenvalues rapidly to facilitate analysis for all types of acoustic propagation. The 4 x 4 Green's functions and effective permittivities were calculated for materials supporting Rayleigh, leaky, and leaky longitudinal waves as demonstration of the method.

  7. New Insights for High-precision Asteroseismology: Acoustic Radius of KIC 6225718

    NASA Astrophysics Data System (ADS)

    Wu, Tao; Li, Yan

    2016-02-01

    Asteroseismology is a powerful tool for probing stellar interiors and determining stellar fundamental parameters. In previous works, the {χ }2-minimization method is usually used to find the best-matching model to characterize observations. In this Letter, we adopt the {χ }2-minimization method but only use the observed high-precision oscillation to constrain theoretical models for solar-like oscillating star KIC 6225718, which is observed by the Kepler satellite. We also take into account the influence of model precision. Finally, we find that the time resolution of stellar evolution cannot be ignored in high-precision asteroseismic analysis. Based on this, we find the acoustic radius {τ }0 is the only global parameter that can be accurately measured by the {χ }ν 2-matching method between observed frequencies and theoretical model calculations. We obtain {τ }0={4601.5}-8.3+4.4 s. In addition, we analyze the distribution of {χ }ν 2-minimization models (CMMs) and find that the distribution range of CMMs is slightly enlarged by some extreme cases, which possess both a larger mass and a higher (or lower) heavy element abundance, at the lower acoustic radius end.

  8. On the use of an analytic source model for dose calculations in precision image-guided small animal radiotherapy

    NASA Astrophysics Data System (ADS)

    Granton, Patrick V.; Verhaegen, Frank

    2013-05-01

    Precision image-guided small animal radiotherapy is rapidly advancing through the use of dedicated micro-irradiation devices. However, precise modeling of these devices in model-based dose-calculation algorithms such as Monte Carlo (MC) simulations continue to present challenges due to a combination of very small beams, low mechanical tolerances on beam collimation, positioning and long calculation times. The specific intent of this investigation is to introduce and demonstrate the viability of a fast analytical source model (AM) for use in either investigating improvements in collimator design or for use in faster dose calculations. MC models using BEAMnrc were developed for circular and square fields sizes from 1 to 25 mm in diameter (or side) that incorporated the intensity distribution of the focal spot modeled after an experimental pinhole image. These MC models were used to generate phase space files (PSFMC) at the exit of the collimators. An AM was developed that included the intensity distribution of the focal spot, a pre-calculated x-ray spectrum, and the collimator-specific entrance and exit apertures. The AM was used to generate photon fluence intensity distributions (ΦAM) and PSFAM containing photons radiating at angles according to the focal spot intensity distribution. MC dose calculations using DOSXYZnrc in a water and mouse phantom differing only by source used (PSFMC versus PSFAM) were found to agree within 7% and 4% for the smallest 1 and 2 mm collimator, respectively, and within 1% for all other field sizes based on depth dose profiles. PSF generation times were approximately 1200 times faster for the smallest beam and 19 times faster for the largest beam. The influence of the focal spot intensity distribution on output and on beam shape was quantified and found to play a significant role in calculated dose distributions. Beam profile differences due to collimator alignment were found in both small and large collimators sensitive to shifts of 1

  9. How to Compute a Slot Marker - Calculation of Controller Managed Spacing Tools for Efficient Descents with Precision Scheduling

    NASA Technical Reports Server (NTRS)

    Prevot, Thomas

    2012-01-01

    This paper describes the underlying principles and algorithms for computing the primary controller managed spacing (CMS) tools developed at NASA for precisely spacing aircraft along efficient descent paths. The trajectory-based CMS tools include slot markers, delay indications and speed advisories. These tools are one of three core NASA technologies integrated in NASAs ATM technology demonstration-1 (ATD-1) that will operationally demonstrate the feasibility of fuel-efficient, high throughput arrival operations using Automatic Dependent Surveillance Broadcast (ADS-B) and ground-based and airborne NASA technologies for precision scheduling and spacing.

  10. Use precise calculation models to operate or design refinery gas treating systems

    SciTech Connect

    1996-07-01

    Amine simulators using rate-based calculation methodology can show refinery operators how to treat more acid gas with existing equipment. These simulators can rate the performance and design of an existing unit by evaluating tray size, downcomer configuration, column diameter, wier height, tray depth and operation with a particular solvent. In addition, these simulators can optimize plant designers` solvent selection and equipment sizing in grassroots applications.

  11. An automatic high precision registration method between large area aerial images and aerial light detection and ranging data

    NASA Astrophysics Data System (ADS)

    Du, Q.; Xie, D.; Sun, Y.

    2015-06-01

    The integration of digital aerial photogrammetry and Light Detetion And Ranging (LiDAR) is an inevitable trend in Surveying and Mapping field. We calculate the external orientation elements of images which identical with LiDAR coordinate to realize automatic high precision registration between aerial images and LiDAR data. There are two ways to calculate orientation elements. One is single image spatial resection using image matching 3D points that registered to LiDAR. The other one is Position and Orientation System (POS) data supported aerotriangulation. The high precision registration points are selected as Ground Control Points (GCPs) instead of measuring GCPs manually during aerotriangulation. The registration experiments indicate that the method which registering aerial images and LiDAR points has a great advantage in higher automation and precision compare with manual registration.

  12. Precise Electromagnetic Tests of Ab Initio Calculations of Light Nuclei: States in {sup 10}Be

    SciTech Connect

    McCutchan, E. A.; Lister, C. J.; Wiringa, R. B.; Pieper, Steven C.; Seweryniak, D.; Greene, J. P.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Zhu, S.; Chiara, C. J.; Stefanescu, I.

    2009-11-06

    In order to test ab initio calculations of light nuclei, we have remeasured lifetimes in {sup 10}Be using the Doppler shift attenuation method (DSAM) following the {sup 7}Li({sup 7}Li,alpha){sup 10}Be reaction at 8 and 10 MeV. The new experiments significantly reduce systematic uncertainties in the DSAM technique. The J{sup p}i=2{sub 1}{sup +} state at 3.37 MeV has tau=205+-(5){sub stat}+-(7){sub sys} fs corresponding to a B(E2arrow down) of 9.2(3)e{sup 2} fm{sup 4} in broad agreement with many calculations. The J{sup p}i=2{sub 2}{sup +} state at 5.96 MeV was found to have a B(E2arrow down) of 0.11(2)e{sup 2} fm{sup 4} and provides a more discriminating test of nuclear models. New Green's function Monte Carlo calculations for these states and transitions with a number of Hamiltonians are also reported and compared to experiment.

  13. Evaluation of the Precision of Return Period calculated by GSMaP data

    NASA Astrophysics Data System (ADS)

    Taguchi, R.; Seto, S.

    2015-12-01

    A heavy rain by Typhoon1326 was generated over IzuOshima Island on October 17, 2013. As for nine rain gauges in IzuOshima Island, precipitation amount exceeded the threshold of the special warning for 3 hours. However, the special warning was not announced because it did not satisfy "heavy rainfall over the threshold value is recorded at more than 10 points". It is suggested that the special warning at islands is hard to be announced. Therefore we propose to apply GSMaP which can be used not only over land but over ocean for the special warning. We calculated the threshold of the special warning by using GSMaP data and compared it with that by Japan Meteorological Agency (JMA). GSMaP has the following characteristics. ・GSMaP estimates precipitation every hour with the resolution of 0.1 degrees grid. ・GSMaP is not good at orographic rainfall , but it is good at rainfall over the Tropics and ocean. ・GSMaP covers almost all over the world between 60 degrees north and south. The standard of JMA is as follows. ・The amount of rainfall in 3 hours exceed 50-year value at 10 points in the spread of the prefecture degree. ・The amount of rainfall in 48 hours exceed 50-year value at 50 points in the spread of the prefecture degree. We calculated the amount of 50-year rainfall by GSMaP and compared it with the threshold value of JMA. But there are only 9-year GSMaP data used in this study. The number of sample is too little to calculate return period. We have also added the data at the surrounding grids. We tried to increase the number of samples in this way. GSMaP has several problems. One of that's GSMaP mistakes snow for rainfall. So we grasped the characteristics of such case. And we made the mask to take such case. When we calculate with the mask, the abnormal values has decreased. We improved stability of calculation return period with these ways.

  14. Preliminary design approach for large high precision segmented reflectors

    NASA Technical Reports Server (NTRS)

    Mikulas, Martin M., Jr.; Collins, Timothy J.; Hedgepeth, John M.

    1990-01-01

    A simplified preliminary design capability for erectable precision segmented reflectors is presented. This design capability permits a rapid assessment of a wide range of reflector parameters as well as new structural concepts and materials. The preliminary design approach was applied to a range of precision reflectors from 10 meters to 100 meters in diameter while considering standard design drivers. The design drivers considered were: weight, fundamental frequency, launch packaging volume, part count, and on-orbit assembly time. For the range of parameters considered, on-orbit assembly time was identified as the major design driver. A family of modular panels is introduced which can significantly reduce the number of reflector parts and the on-orbit assembly time.

  15. Results of Propellant Mixing Variable Study Using Precise Pressure-Based Burn Rate Calculations

    NASA Technical Reports Server (NTRS)

    Stefanski, Philip L.

    2014-01-01

    A designed experiment was conducted in which three mix processing variables (pre-curative addition mix temperature, pre-curative addition mixing time, and mixer speed) were varied to estimate their effects on within-mix propellant burn rate variability. The chosen discriminator for the experiment was the 2-inch diameter by 4-inch long (2x4) Center-Perforated (CP) ballistic evaluation motor. Motor nozzle throat diameters were sized to produce a common targeted chamber pressure. Initial data analysis did not show a statistically significant effect. Because propellant burn rate must be directly related to chamber pressure, a method was developed that showed statistically significant effects on chamber pressure (either maximum or average) by adjustments to the process settings. Burn rates were calculated from chamber pressures and these were then normalized to a common pressure for comparative purposes. The pressure-based method of burn rate determination showed significant reduction in error when compared to results obtained from the Brooks' modification of the propellant web-bisector burn rate determination method. Analysis of effects using burn rates calculated by the pressure-based method showed a significant correlation of within-mix burn rate dispersion to mixing duration and the quadratic of mixing duration. The findings were confirmed in a series of mixes that examined the effects of mixing time on burn rate variation, which yielded the same results.

  16. Design of a high-precision double crystal tunable monochromator

    SciTech Connect

    Shleifer, M.; Sharma, S.; Woodle, M.; Rotela, E.; Brite, C.

    1993-11-01

    This paper describes a UHV-compatible double crystal monochromator with independent drives for 2 linear and 2 angular crystal motions. Precise angular crystal positioning is achieved by using a spindle with a double gimbal mechanism, which converts linear motion of 0.1 micron to an angular motion of 0.042 arcsec. In order to decrease thermal distortions, the crystal intercepting white beam, is watercooled.

  17. Ion source for high-precision mass spectrometry

    DOEpatents

    Todd, Peter J.; McKown, Henry S.; Smith, David H.

    1984-01-01

    The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit.

  18. Ion source for high-precision mass spectrometry

    DOEpatents

    Todd, P.J.; McKown, H.S.; Smith, D.H.

    1982-04-26

    The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit. 2 figures, 3 tables.

  19. Gauges for Highly Precise Metrology of a Compound Mirror

    NASA Technical Reports Server (NTRS)

    Gursel, Yekta

    2005-01-01

    Three optical gauges have been developed for guiding the assembly and measuring precisely the reflecting surfaces of a compound mirror that comprises a corner-cube retroreflector glued in a hole on a flat mirror. In the specific application for which the gauges were developed, the compound mirror is part of a siderostat in a stellar interferometer. The flat-mirror portion of the compound mirror is the siderostat mirror; the retroreflector portion of the compound mirror is to be used, during operation of the interferometer, to monitor the location of the siderostat mirror surface relative to other optical surfaces of the interferometer. Nominally, the optical corner of the retroreflector should lie precisely on the siderostat mirror surface, but this precision cannot be achieved in fabrication: in practice, there remains some distance between the optical corner and the siderostat mirror surface. For proper operation of the interferometer, it is required to make this distance as small as possible and to know this distance within 1 nm. The three gauges make it possible to satisfy these requirements.

  20. Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos

    SciTech Connect

    Heeger, Karsten M.

    2014-09-13

    This report presents experimental research at the intensity frontier of particle physics with particular focus on the study of reactor antineutrinos and the precision measurement of neutrino oscillations. The experimental neutrino physics group of Professor Heeger and Senior Scientist Band at Yale University has had leading responsibilities in the construction and operation of the Daya Bay Reactor Antineutrino Experiment and made critical contributions to the discovery of non-zero$\\theta_{13}$. Heeger and Band led the Daya Bay detector management team and are now overseeing the operations of the antineutrino detectors. Postdoctoral researchers and students in this group have made leading contributions to the Daya Bay analysis including the prediction of the reactor antineutrino flux and spectrum, the analysis of the oscillation signal, and the precision determination of the target mass yielding unprecedented precision in the relative detector uncertainty. Heeger's group is now leading an R\\&D effort towards a short-baseline oscillation experiment, called PROSPECT, at a US research reactor and the development of antineutrino detectors with advanced background discrimination.

  1. High-precision mass measurements of 25Al and 30P at JYFLTRAP

    NASA Astrophysics Data System (ADS)

    Canete, L.; Kankainen, A.; Eronen, T.; Gorelov, D.; Hakala, J.; Jokinen, A.; Kolhinen, V. S.; Koponen, J.; Moore, I. D.; Reinikainen, J.; Rinta-Antila, S.

    2016-05-01

    The masses of the astrophysically relevant nuclei 25Al and 30P have been measured with a Penning trap for the first time. The mass-excess values for 25Al ( Δ = -8915.962(63) keV) and 30P ( Δ = -20200.854(64) keV) obtained with the JYFLTRAP double Penning trap mass spectrometer are in good agreement with the Atomic Mass Evaluation 2012 values but ≈ 5-10 times more precise. A high precision is required for calculating resonant proton-capture rates of astrophysically important reactions 25Al ( p, γ)26Si and 30P( p, γ)31S . In this work, Q_{(p,γ)} = 5513.99(13) keV and Q_{(p,γ)} = 6130.64(24) keV were obtained for 25Al and 30P , respectively. The effect of the more precise values on the resonant proton-capture rates has been studied. In addition to nuclear astrophysics, the measured QEC value of 25Al , 4276.805(45) keV, is relevant for studies of T = 1/2 mirror beta decays which have a potential to be used to test the Conserved Vector Current hypothesis.

  2. High-precision simulations of the weak lensing effect on cosmic microwave background polarization

    NASA Astrophysics Data System (ADS)

    Fabbian, Giulio; Stompor, Radek

    2013-08-01

    We studied the accuracy, robustness, and self-consistency of pixel-domain simulations of the gravitational lensing effect on the primordial cosmic microwave background (CMB) anisotropies due to the large-scale structure of the Universe. In particular, we investigated the dependence of the precision of the results precision on some crucial parameters of these techniques and propose a semi-analytic framework to determine their values so that the required precision is a priori assured and the numerical workload simultaneously optimized. Our focus was on the B-mode signal, but we also discuss other CMB observables, such as the total intensity, T, and E-mode polarization, emphasizing differences and similarities between all these cases. Our semi-analytic considerations are backed up by extensive numerical results. Those are obtained using a code, nicknamed lenS2HAT - for lensing using scalable spherical harmonic transforms (S2HAT) - which we have developed in the course of this work. The code implements a version of the previously described pixel-domain approach and permits performing the simulations at very high resolutions and data volumes, thanks to its efficient parallelization provided by the S2HAT library - a parallel library for calculating of the spherical harmonic transforms. The code is made publicly available.

  3. Vibration-rotation variational calculations - Precise results on HCN up to 25,000/cm

    NASA Astrophysics Data System (ADS)

    Carter, Stuart; Mills, Ian M.; Handy, Nicholas C.

    1993-09-01

    Variation calculations of the vibration-rotation energy levels of many isotopomers of HCN are reported, for J = 0, 1, and 2, extending up to approximately 8 quanta of each of the stretching vibrations and 14 quanta of the bending mode. The force field, which is represented as a polynomial expansion in Morse coordinates for the bond stretches and even powers of the angle bend, has been refined by least squares to fit simultaneously all observed data on the Sigma and Pi state vibrational energies, and the Sigma state rotational constants, for both HCN and DCN. The observed vibrational energies are fitted to roughly +/- 0.5/cm, and the rotational constants to roughly +/- 0.0001/cm. The force field has been used to predict the vibration rotation spectra of many isotopomers of HCN up to 25,000/cm.

  4. Progress in high-lift aerodynamic calculations

    NASA Technical Reports Server (NTRS)

    Rogers, Stuart E.

    1993-01-01

    The current work presents progress in the effort to numerically simulate the flow over high-lift aerodynamic components, namely, multi-element airfoils and wings in either a take-off or a landing configuration. The computational approach utilizes an incompressible flow solver and an overlaid chimera grid approach. A detailed grid resolution study is presented for flow over a three-element airfoil. Two turbulence models, a one-equation Baldwin-Barth model and a two equation k-omega model are compared. Excellent agreement with experiment is obtained for the lift coefficient at all angles of attack, including the prediction of maximum lift when using the two-equation model. Results for two other flap riggings are shown. Three-dimensional results are presented for a wing with a square wing-tip as a validation case. Grid generation and topology is discussed for computing the flow over a T-39 Sabreliner wing with flap deployed and the initial calculations for this geometry are presented.

  5. High-precision analysis of SF6 at ambient level

    NASA Astrophysics Data System (ADS)

    Lim, J. S.; Moon, D. M.; Kim, J. S.; Yun, W.-T.; Lee, J.

    2013-09-01

    This work reports on the development of a technique for the precise analysis of ambient SF6. This technique, which involves a gas chromatograph/electron capture detector (GC-ECD) coupled with an Activated Alumina-F1 (AA-F1) column, performed well in the measurements, particularly in terms of accuracy, which complies with the World Meteorological Organization (WMO)-recommended compatibility of 0.02 ppt. Compared to the Porapak Q technique, we observed a sharper peak shape for the SF6 stream, which substantiates the improvement in the analytical precision. The traceability to the WMO scale was tested by calibrating the GC-ECD/AA-F1 analyser using five SF6 standards provided by the WMO/Global Atmosphere Watch (GAW) Central Calibration Laboratory (CCL) for SF6 (NOAA, United States of America). After calibration by various methods, the GC-ECD/AA-F1 accurately estimated the mole fraction of SF6 in the working standard prepared by the World Calibration Centre for SF6 operated by the Korea Meteorological Administration (KMA)/Korea Research Institute of Standards and Science (KRISS). Among the calibration methods, the two-point calibration method emerged to be the most economical procedure in terms of the data quality and measurement time. It was found that the KRISS scale of SF6/N2 was biased by 0.13 ppt when compared to the WMO scale of SF6/air; this bias is probably due to a different matrix.

  6. High-precision gamma-ray spectroscopy for enhancing production and application of medical isotopes

    NASA Astrophysics Data System (ADS)

    McCutchan, E. A.; Sonzogni, A. A.; Smith, S. V.; Muench, L.; Nino, M.; Greene, J. P.; Carpenter, M. P.; Zhu, S.; Chillery, T.; Chowdhury, P.; Harding, R.; Lister, C. J.

    2015-10-01

    Nuclear medicine is a field which requires precise decay data for use in planning radionuclide production and in imaging and therapeutic applications. To address deficiencies in decay data, sources of medical isotopes were produced and purified at the Brookhaven Linear Isotope Producer (BLIP) then shipped to Argonne National Laboratory where high-precision, gamma-ray measurements were performed using Gammasphere. New decay schemes for a number of PET isotopes and the impact on dose calculations will be presented. To investigate the production of next-generation theranostic or radiotherapeutic isotopes, cross section measurements with high energy protons have also been explored at BLIP. The 100-200 MeV proton energy regime is relatively unexplored for isotope production, thus offering high discovery potential but at the same time a challenging analysis due to the large number of open channels at these energies. Results of cross sections deduced from Compton-suppressed, coincidence gamma-ray spectroscopy performed at Lowell will be presented, focusing on the production of platinum isotopes by irradiating natural platinum foils with 100 to 200 MeV protons. DOE Isotope Program is acknowledged for funding ST5001030. Work supported by the US DOE under Grant DE-FG02-94ER40848 and Contracts DE-AC02-98CH10946 and DE-AC02-06CH11357.

  7. High-precision photometry by telescope defocusing - VII. The ultrashort period planet WASP-103

    NASA Astrophysics Data System (ADS)

    Southworth, John; Mancini, L.; Ciceri, S.; Budaj, J.; Dominik, M.; Figuera Jaimes, R.; Haugbølle, T.; Jørgensen, U. G.; Popovas, A.; Rabus, M.; Rahvar, S.; von Essen, C.; Schmidt, R. W.; Wertz, O.; Alsubai, K. A.; Bozza, V.; Bramich, D. M.; Calchi Novati, S.; D'Ago, G.; Hinse, T. C.; Henning, Th.; Hundertmark, M.; Juncher, D.; Korhonen, H.; Skottfelt, J.; Snodgrass, C.; Starkey, D.; Surdej, J.

    2015-02-01

    We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to establish a high-precision reference epoch for transit timing studies. The time of the reference transit mid-point is now measured to an accuracy of 4.8 s, versus 67.4 s in the discovery paper, aiding future searches for orbital decay. With the help of published spectroscopic measurements and theoretical stellar models, we determine the physical properties of the system to high precision and present a detailed error budget for these calculations. The planet has a Roche lobe filling factor of 0.58, leading to a significant asphericity; we correct its measured mass and mean density for this phenomenon. A high-resolution Lucky Imaging observation shows no evidence for faint stars close enough to contaminate the point spread function of WASP-103. Our data were obtained in the Bessell RI and the SDSS griz passbands and yield a larger planet radius at bluer optical wavelengths, to a confidence level of 7.3σ. Interpreting this as an effect of Rayleigh scattering in the planetary atmosphere leads to a measurement of the planetary mass which is too small by a factor of 5, implying that Rayleigh scattering is not the main cause of the variation of radius with wavelength.

  8. Design and Calibration of a High-Precision Density Gauge for Firn and Ice Cores

    NASA Astrophysics Data System (ADS)

    Breton, Daniel; Hamilton, Gordon

    2009-10-01

    The Maine Automated Density Gauge Experiment (MADGE) is a field deployable gamma-ray density gauging instrument designed to provide high resolution (3.3 mm) and high precision (±0.004 g cm-3) density profiles of polar firn and ice cores at a typical throughput of 1.5 m h-1. The resulting density profiles are important in ice sheet mass balance and paleoclimate studies, as well as the modeling electromagnetic wave propagation in firn and ice for remote sensing and ground penetrating radar applications. This study describes the design (optimal gamma-ray energy selection, measurement uncertainty analysis, dead-time corrections) and calibration (mass-attenuation coefficient and absolute density calibrations) of the instrument, and discusses the results of additional experiments to verify the calculated measurement uncertainty. Data collected from firn cores drilled on the recent 2006-2007 U.S. Internation Trans-Antarctic Scientific Expedition are also shown and discussed.

  9. High Precision Measurement of Stellar Radial Velocity Variations

    NASA Technical Reports Server (NTRS)

    Cochran, W. D.

    1984-01-01

    A prototype instrument for measurement of stellar radial velocity variations to a precision of a few meters per second is discussed. The instrument will be used to study low amplitude stellar non-radial oscillations, to search for binary systems with large mass ratios, and ultimately to search for extrasolar planetary systems. The instrument uses a stable Fabry-Perot etalon, in reflection, to impose a set of fixed reference absorption lines on the stellar spectrum before it enters the coude spectrograph of the McDonald Observatory 2.7-m telescope. The spectrum is recorded on the Octicon detector, which consists of eight Reticon arrays placed end to end. Radial velocity variations of the star are detected by measuring the shift of the stellar lines with respect the artificial Fabry-Perot lines, and correcting for the known motions in the solar system.

  10. Application of GPS in a high precision engineering survey network

    NASA Astrophysics Data System (ADS)

    Ruland, R.; Leick, A.

    A global positioning system (GPS) satellite survey was conducted with the Macrometer to support construction at the standard linear accelerator center (SLAC). The network consists of 16 stations of which 9 stations were part of the Macrometer network. The horizontal accuracy of the terrestrial survey, consisting of angles and distances, equals that of the GPS survey only in the loop portion of the network. All stations are part of the precise level network. The elliposoidal heights obtained from the GPS survey and the orthometric heights of the level network are used to compute geoid undulations. The profile agreed with the observed geoid within the standard deviation of the GPS survey. Angles and distances were adjusted together (TERRA), and all terrestrial observations were combined with the GPS vector observations in a combination adjustment (COMB). A comparison of COMB and TERRA revealed systematic errors in the terrestrial solution.

  11. Aerospace Laser Ignition/Ablation Variable High Precision Thruster

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan W. (Inventor); Edwards, David L. (Inventor); Campbell, Jason J. (Inventor)

    2015-01-01

    A laser ignition/ablation propulsion system that captures the advantages of both liquid and solid propulsion. A reel system is used to move a propellant tape containing a plurality of propellant material targets through an ignition chamber. When a propellant target is in the ignition chamber, a laser beam from a laser positioned above the ignition chamber strikes the propellant target, igniting the propellant material and resulting in a thrust impulse. The propellant tape is advanced, carrying another propellant target into the ignition chamber. The propellant tape and ignition chamber are designed to ensure that each ignition event is isolated from the remaining propellant targets. Thrust and specific impulse may by precisely controlled by varying the synchronized propellant tape/laser speed. The laser ignition/ablation propulsion system may be scaled for use in small and large applications.

  12. A high precision, compact electromechanical ground rotation sensor

    SciTech Connect

    Dergachev, V.; DeSalvo, R.; Asadoor, M.; Bhawal, A.; Gong, P.; Kim, C.; Lottarini, A.; Minenkov, Y.; Murphy, C.; O'Toole, A.; Peña Arellano, F. E.; and others

    2014-05-15

    We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of 1 × 10{sup −11}m/√( Hz ). We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10{sup −9} rad /√( Hz ) at 10 mHz and 6.4 × 10{sup −10} rad /√( Hz ) at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.

  13. A high precision, compact electromechanical ground rotation sensor.

    PubMed

    Dergachev, V; DeSalvo, R; Asadoor, M; Bhawal, A; Gong, P; Kim, C; Lottarini, A; Minenkov, Y; Murphy, C; O'Toole, A; Peña Arellano, F E; Rodionov, A V; Shaner, M; Sobacchi, E

    2014-05-01

    We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of 1 × 10⁻¹¹ m/√Hz. We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10⁻⁹ rad/√Hz at 10 mHz and 6.4 × 10⁻¹⁰ rad/√Hz at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality. PMID:24880388

  14. HIGH-PRECISION DYNAMICAL MASSES OF VERY LOW MASS BINARIES

    SciTech Connect

    Konopacky, Q. M.; Ghez, A. M.; McLean, I. S.; Barman, T. S.; Rice, E. L.; Bailey, J. I.; White, R. J.; Duchene, G. E-mail: ghez@astro.ucla.ed E-mail: barman@lowell.ed E-mail: white@chara.gsu.ed

    2010-03-10

    We present the results of a three year monitoring program of a sample of very low mass (VLM) field binaries using both astrometric and spectroscopic data obtained in conjunction with the laser guide star adaptive optics system on the W. M. Keck II 10 m telescope. Among the 24 systems studied, 15 have undergone sufficient orbital motion, allowing us to derive their relative orbital parameters and hence their total system mass. These measurements more than double the number of mass measurements for VLM objects, and include the most precise mass measurement to date (<2%). Among the 11 systems with both astrometric and spectroscopic measurements, six have sufficient radial velocity variations to allow us to obtain individual component masses. This is the first derivation of the component masses for five of these systems. Altogether, the orbital solutions of these low mass systems show a correlation between eccentricity and orbital period, consistent with their higher mass counterparts. In our primary analysis, we find that there are systematic discrepancies between our dynamical mass measurements and the predictions of theoretical evolutionary models (TUCSON and LYON) with both models either underpredicting or overpredicting the most precisely determined dynamical masses. These discrepancies are a function of spectral type, with late-M through mid-L systems tending to have their masses underpredicted, while one T-type system has its mass overpredicted. These discrepancies imply that either the temperatures predicted by evolutionary and atmosphere models are inconsistent for an object of a given mass, or the mass-radius relationship or cooling timescales predicted by the evolutionary models are incorrect. If these spectral-type trends are correct and hold into the planetary mass regime, the implication is that the masses of directly imaged extrasolar planets are overpredicted by the evolutionary models.

  15. High precision quantum-chemical treatment of adsorption: Benchmarking physisorption of molecular hydrogen on graphane

    NASA Astrophysics Data System (ADS)

    Usvyat, Denis

    2015-09-01

    A multilevel hierarchical ab initio protocol for calculating adsorption on non-conducting surfaces is presented. It employs fully periodic treatment, which reaches local Møller-Plesset perturbation theory of second order (MP2) with correction for the basis set incompleteness via the local F12 technique. Post-MP2 corrections are calculated using finite clusters. That includes the coupled cluster treatment in the local and canonical frameworks (up to perturbative quadruples) and correlated core (with MP2). Using this protocol, the potential surface of hydrogen molecules adsorbed on graphane was computed. According to the calculations, hydrogen molecules are adsorbed on graphane in a perpendicular to the surface orientation with the minimum of the potential surface of around -3.6 kJ/mol located at the distance of 3.85 Å between the bond center of the hydrogen molecule and the mid-plane of graphane. The adsorption sites along the path from the downward-pointing carbon to the ring center of the graphane are energetically virtually equally preferable, which can enable nearly free translations of hydrogen molecules along these paths. Consequently, the hydrogen molecules on graphane most likely form a non-commensurate monolayer. The analysis of the remaining errors reveals a very high accuracy of the computed potential surface with an error bar of a few tenths of a kJ/mol. The obtained results are a high-precision benchmark for further theoretical and experimental studies of hydrogen molecules interacting with graphane.

  16. High precision quantum-chemical treatment of adsorption: Benchmarking physisorption of molecular hydrogen on graphane

    SciTech Connect

    Usvyat, Denis

    2015-09-14

    A multilevel hierarchical ab initio protocol for calculating adsorption on non-conducting surfaces is presented. It employs fully periodic treatment, which reaches local Møller-Plesset perturbation theory of second order (MP2) with correction for the basis set incompleteness via the local F12 technique. Post-MP2 corrections are calculated using finite clusters. That includes the coupled cluster treatment in the local and canonical frameworks (up to perturbative quadruples) and correlated core (with MP2). Using this protocol, the potential surface of hydrogen molecules adsorbed on graphane was computed. According to the calculations, hydrogen molecules are adsorbed on graphane in a perpendicular to the surface orientation with the minimum of the potential surface of around −3.6 kJ/mol located at the distance of 3.85 Å between the bond center of the hydrogen molecule and the mid-plane of graphane. The adsorption sites along the path from the downward-pointing carbon to the ring center of the graphane are energetically virtually equally preferable, which can enable nearly free translations of hydrogen molecules along these paths. Consequently, the hydrogen molecules on graphane most likely form a non-commensurate monolayer. The analysis of the remaining errors reveals a very high accuracy of the computed potential surface with an error bar of a few tenths of a kJ/mol. The obtained results are a high-precision benchmark for further theoretical and experimental studies of hydrogen molecules interacting with graphane.

  17. High precision (14 bit), high density (octal) analog to digital converter for spectroscopy applications.

    PubMed

    Subramaniam, E T; Jain, Mamta; Bhowmik, R K; Tripon, Michel

    2008-10-01

    Nuclear and particle physics experiments with large number of detectors require signal processing and data collection strategies that call for the ability to collect large amount of data while not sacrificing the precision and accuracy of the data being collected. This paper deals with the development of a high precision pulse peak detection, analog to digital converter (ADC) module with eight independent channels in plug-in daughter card motherboard model, best suited for spectroscopy experiments. This module provides multiple channels without cross-talk and of 14 bit resolution, while maintaining high density (each daughter card has an area of just 4.2(")x0.51(")) and exhibiting excellent integral nonlinearity (< or = +/-2 mV or +/-0.02% full scale reading) and differential nonlinearity (< or = +/-1%). It was designed, developed and tested, in house, and gives added advantages of cost effectiveness and ease of maintenance. PMID:19044710

  18. High precision (14 bit), high density (octal) analog to digital converter for spectroscopy applications

    NASA Astrophysics Data System (ADS)

    Subramaniam, E. T.; Jain, Mamta; Bhowmik, R. K.; Tripon, Michel

    2008-10-01

    Nuclear and particle physics experiments with large number of detectors require signal processing and data collection strategies that call for the ability to collect large amount of data while not sacrificing the precision and accuracy of the data being collected. This paper deals with the development of a high precision pulse peak detection, analog to digital converter (ADC) module with eight independent channels in plug-in daughter card motherboard model, best suited for spectroscopy experiments. This module provides multiple channels without cross-talk and of 14 bit resolution, while maintaining high density (each daughter card has an area of just 4.2″×0.51″) and exhibiting excellent integral nonlinearity (≤±2 mV or ±0.02% full scale reading) and differential nonlinearity (≤±1%). It was designed, developed and tested, in house, and gives added advantages of cost effectiveness and ease of maintenance.

  19. A High Precision Position Sensor Design and Its Signal Processing Algorithm for a Maglev Train

    PubMed Central

    Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

    2012-01-01

    High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run. PMID:22778582

  20. A high-precision sampling scheme to assess persistence and transport characteristics of micropollutants in rivers.

    PubMed

    Schwientek, Marc; Guillet, Gaëlle; Rügner, Hermann; Kuch, Bertram; Grathwohl, Peter

    2016-01-01

    Increasing numbers of organic micropollutants are emitted into rivers via municipal wastewaters. Due to their persistence many pollutants pass wastewater treatment plants without substantial removal. Transport and fate of pollutants in receiving waters and export to downstream ecosystems is not well understood. In particular, a better knowledge of processes governing their environmental behavior is needed. Although a lot of data are available concerning the ubiquitous presence of micropollutants in rivers, accurate data on transport and removal rates are lacking. In this paper, a mass balance approach is presented, which is based on the Lagrangian sampling scheme, but extended to account for precise transport velocities and mixing along river stretches. The calculated mass balances allow accurate quantification of pollutants' reactivity along river segments. This is demonstrated for representative members of important groups of micropollutants, e.g. pharmaceuticals, musk fragrances, flame retardants, and pesticides. A model-aided analysis of the measured data series gives insight into the temporal dynamics of removal processes. The occurrence of different removal mechanisms such as photooxidation, microbial degradation, and volatilization is discussed. The results demonstrate, that removal processes are highly variable in time and space and this has to be considered for future studies. The high precision sampling scheme presented could be a powerful tool for quantifying removal processes under different boundary conditions and in river segments with contrasting properties. PMID:26283620

  1. High-precision work distributions for extreme non-equilibrium processes in large systems

    NASA Astrophysics Data System (ADS)

    Hartmann, Alexander

    2014-03-01

    The distributions of work for strongly non-equilibrium processes are studied using a very general form of a large-deviation approach, which allows one to study distributions down to extremely small probabilities of almost arbitrary quantities of interest for equilibrium, non-equilibrium stationary and even non-stationary processes. The method is applied to varying quickly the external field in a wide range B = 3 <--> 0 for critical (T = 2 . 269) two-dimensional Ising system of size L × L = 128 × 128 . To obtain free energy differences from the work distributions, they must be studied in ranges where the probabilities are as small as 10-240, which is not possible using direct simulation approaches. By comparison with the exact free energies, one sees that the present approach allows one to obtain the free energy with a very high relative precision of 10-4. This works well also for non-zero field, i.e., for a case where standard umbrella-sampling methods seem to be not so efficient to calculate free energies. Furthermore, for the present case it is verified that the resulting distributions of work fulfill Crooks theorem with high precision. Finally, the free energy for the Ising magnet as a function of the field strength is obtained.

  2. A high precision position sensor design and its signal processing algorithm for a maglev train.

    PubMed

    Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

    2012-01-01

    High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run. PMID:22778582

  3. First results for electromagnetic three-nucleon form factors from high-precision two-nucleon interactions

    SciTech Connect

    Sergio Alexandre Pinto; Stadler, Alfred; Gross, Franz L.

    2010-01-01

    The electromagnetic form factors of the three-nucleon bound states were calculated in Complete Impulse Approximation in the framework of the Covariant Spectator Theory for the new high-precision two-nucleon interaction models WJC-1 and WJC-2. The calculations use an approximation for the three-nucleon vertex functions with two nucleons off mass shell. The form factors with WJC-2 are close to the ones obtained with the older model W16 and to nonrelativistic potential calculations with lowest-order relativistic corrections, while the form factors with the most precise two-nucleon model WJC-1 exhibit larger differences. These results can be understood when the effect of the different types of pion-nucleon coupling used in the various models is examined.

  4. High-precision timeline for Earth's most severe extinction.

    PubMed

    Burgess, Seth D; Bowring, Samuel; Shen, Shu-zhong

    2014-03-01

    The end-Permian mass extinction was the most severe loss of marine and terrestrial biota in the last 542 My. Understanding its cause and the controls on extinction/recovery dynamics depends on an accurate and precise age model. U-Pb zircon dates for five volcanic ash beds from the Global Stratotype Section and Point for the Permian-Triassic boundary at Meishan, China, define an age model for the extinction and allow exploration of the links between global environmental perturbation, carbon cycle disruption, mass extinction, and recovery at millennial timescales. The extinction occurred between 251.941 ± 0.037 and 251.880 ± 0.031 Mya, an interval of 60 ± 48 ka. Onset of a major reorganization of the carbon cycle immediately precedes the initiation of extinction and is punctuated by a sharp (3‰), short-lived negative spike in the isotopic composition of carbonate carbon. Carbon cycle volatility persists for ∼500 ka before a return to near preextinction values. Decamillenial to millennial level resolution of the mass extinction and its aftermath will permit a refined evaluation of the relative roles of rate-dependent processes contributing to the extinction, allowing insight into postextinction ecosystem expansion, and establish an accurate time point for evaluating the plausibility of trigger and kill mechanisms. PMID:24516148

  5. Application of GPS in a high precision engineering survey network

    SciTech Connect

    Ruland, R.; Leick, A.

    1985-04-01

    A GPS satellite survey was carried out with the Macrometer to support construction at the Stanford Linear Accelerator Center (SLAC). The network consists of 16 stations of which 9 stations were part of the Macrometer network. The horizontal and vertical accuracy of the GPS survey is estimated to be 1 to 2 mm and 2 to 3 mm respectively. The horizontal accuracy of the terrestrial survey, consisting of angles and distances, equals that of the GPS survey only in the ''loop'' portion of the network. All stations are part of a precise level network. The ellipsoidal heights obtained from the GPS survey and the orthometric heights of the level network are used to compute geoid undulations. A geoid profile along the linac was computed by the National Geodetic Survey in 1963. This profile agreed with the observed geoid within the standard deviation of the GPS survey. Angles and distances were adjusted together (TERRA), and all terrestrial observations were combined with the GPS vector observations in a combination adjustment (COMB). A comparison of COMB and TERRA revealed systematic errors in the terrestrial solution. A scale factor of 1.5 ppM +- .8 ppM was estimated. This value is of the same magnitude as the over-all horizontal accuracy of both networks. 10 refs., 3 figs., 5 tabs.

  6. High-Precision Nucleation Rate Measurements for Higher Melting Metals

    NASA Astrophysics Data System (ADS)

    Bokeloh, Joachim; Wilde, Gerhard

    2014-08-01

    Nucleation of a crystal in undercooled melts of higher melting face-centered-cubic-metals has often been studied in the past. However, the data available were not of sufficient accuracy and only covered nucleation rates in too small of a range to allow precise conclusions concerning the nature of the underlying process as well as concerning important parameters such as the solid-liquid interface free energy that can in principle be deducted from such analyses. One way to circumvent ambiguities and analyze nucleation kinetics under well-defined conditions experimentally is given by performing statistically significant numbers of repeated single droplet experiments. Application of proper statistics analyses yields nucleation rates that are independent of a specific nucleation model. The first studies that were conducted in accordance with this approach on pure model materials revealed that the approach is valid. The results are comparable to those obtained by classic nucleation theory applied to experimental data, and it was shown that one might need to rethink the common assumption that heterogeneous nucleation is almost always responsible for solidification initiation. The current results also show that often-used models for the solid-liquid interface free energy might lead to overestimated values.

  7. High-speed precision weighing of pharmaceutical capsules

    NASA Astrophysics Data System (ADS)

    Bürmen, Miran; Pernuš, Franjo; Likar, Boštjan

    2009-11-01

    In this paper, we present a cost-effective method for fast and accurate in-line weighing of hard gelatin capsules based on the optimized capacitance sensor and real-time processing of the capsule capacitance profile resulting from 5000 capacitance measurements per second. First, the effect of the shape and size of the capacitive sensor on the sensitivity and stability of the measurements was investigated in order to optimize the performance of the system. The method was tested on two types of hard gelatin capsules weighing from 50 mg to 650 mg. The results showed that the capacitance profile was exceptionally well correlated with the capsule weight with the correlation coefficient exceeding 0.999. The mean precision of the measurements was in the range from 1 mg to 3 mg, depending on the size of the capsule and was significantly lower than the 5% weight tolerances usually used by the pharmaceutical industry. Therefore, the method was found feasible for weighing pharmaceutical hard gelatin capsules as long as certain conditions are met regarding the capsule fill properties and environment stability. The proposed measurement system can be calibrated by using only two or three sets of capsules with known weight. However, for most applications it is sufficient to use only empty and nominally filled capsules for calibration. Finally, a practical application of the proposed method showed that a single system is capable of weighing around 75 000 capsules per hour, while using multiple systems could easily increase the inspection rate to meet almost any requirements.

  8. New Insights into Stellar Astrophysics from High-Precision Photometry

    NASA Astrophysics Data System (ADS)

    Soderblom, David R.

    2013-01-01

    The rich harvest of information on the occurrence and nature of planets around solar-type stars is why Kepler was built, but equally profound from this mission are the insights and quantitative physical studies of stars. The Kepler sample is dominated by the ~100,000 stars that are like the Sun, yet the Kepler field includes examples of nearly every stellar type. Kepler's exquisite photometry - continuously over an extended time - has enabled the detection of new phenomena and has provided critical tests of stellar models. In this brief review I will summarize some of the exciting new findings that Kepler has made possible, including: Stellar surface granulation in late-type stars; Evidence for rapid rotation of the cores of some evolved stars; Flares on G, K and M stars; Precise ages for older solar-type stars; Evidence for "mixed" modes in evolved stars that couple p-modes to interior g-modes; Stellar differential rotation; Detection of stellar activity cycles from asteroseismology; Mixing processes in stars; Detailed studies of eclipsing binaries; A comparison of the Sun to similar stars; Pulsating stars; Stellar surface features revealed by planet transits.

  9. High precision determination of the terrestrial 40K abundance

    NASA Astrophysics Data System (ADS)

    Naumenko, Maria O.; Mezger, Klaus; Nägler, Thomas F.; Villa, Igor M.

    2013-12-01

    Recent improvements in the precision of mass spectrometric measurements have reduced the uncertainty of K-Ar and 39Ar-40Ar ages measured on geological materials. Now the major sources of uncertainty are the uncertainties on the 40K decay constant and the absolute abundance of 40K. In order to improve on this situation we determined the abundance of the 40K isotope in terrestrial standards. A ThermoFischer Triton+ thermal ionization mass spectrometer was used for K isotope ratio measurements of the NIST K standard reference materials SRM 918b and SRM 985. Ion beams were measured in Faraday cups with amplifiers equipped with 1010, 1011 and 1012 Ω resistors. Three measurement protocols were used: (A) dynamic measurement with in-run fractionation correction by normalization to the IUPAC recommended isotope ratio 41K/39K = 0.072 1677; (B) total evaporation; (C) a modified total evaporation with interblock baseline measurements. Different measurement protocols were combined with different loading procedures. The best results were obtained by loading samples on single oxidized tantalum filaments with 0.1 M H3PO4. The total ion yields (ionization + transmission) were tested for the evaporation procedures (B) and (C) and ranged up to 48%. The resulting best estimate for the 40K/39K ratio is 0.000 125 116 ± 57 (2σ), corresponding to an isotopic abundance 40K/K = (1.1668 ± 8) × 10-4.

  10. High Precision Photometry of Bright Transiting Exoplanet Hosts

    NASA Astrophysics Data System (ADS)

    Wilson, Maurice; Eastman, Jason; Johnson, John A.

    2016-01-01

    Within the past two decades, the successful search for exoplanets and the characterization of their physical properties have shown the immense progress that has been made towards finding planets with characteristics similar to Earth. For most exoplanets with a radius about the size of Earth, evaluating their physical properties, such as the mass, radius and equilibrium temperature, cannot be determined with satisfactory precision. The MINiature Exoplanet Radial Velocity Array (MINERVA) was recently built to obtain spectroscopic and photometric measurements to find, confirm, and characterize Earth-like exoplanets. MINERVA's spectroscopic survey targets the brightest, nearby stars which are well-suited to the array's capabilities, while its primary photometric goal is to search for transits around these bright targets. Typically, it is difficult to find satisfactory comparison stars within a telescope's field of view when the primary target is very bright. This issue is resolved by using one of MINERVA's telescopes to observe the primary bright star while the other telescopes observe a distinct field of view that contains satisfactory bright comparison stars. We describe the code used to identify nearby comparison stars, schedule the four telescopes, produce differential photometry from multiple telescopes, and show the first results from this effort.This work has been funded by the Ronald E. McNair Post-Baccalaureate Achievement Program, the ERAU Honors Program, the ERAU Undergraduate Research Spark Fund, and the Banneker Institute at the Harvard-Smithsonian Center for Astrophysics.

  11. Electronic solar compass for high precision orientation on any planet

    NASA Astrophysics Data System (ADS)

    Flora, F.; Bollanti, S.; De Meis, D.; Di Lazzaro, P.; Gallerano, G. P.; Mezi, L.; Murra, D.; Torre, A.; Vicca, D.

    2016-07-01

    A compact, fully automatic electronic solar compass has been developed at the ENEA Frascati Laboratories. The compass is inspired to ``camera obscura'' sundials like those inside churches. Sun ephemerides are calculated using an approximate but effective analytical solution of Kepler's laws, where the Earth (or other planets) orbit main parameters are introduced. The instrument is light, cheap and it has an accuracy better than 1 arcmin. Some examples of application of the device as well as the possibility to use it on Mars are presented.

  12. A Highly Accurate Stress Measurement System for Producing Precise X-Ray Masks

    NASA Astrophysics Data System (ADS)

    Oda, Masatoshi; Une, Atsunobu; Okada, Ikuo; Shinohara, Shinji; Nakayama, Yasuo; Yoshihara, Hideo

    1995-12-01

    A new system that measures stress in film deposited on Si wafers has been developed to produce highly accurate X-ray masks. The system consists of very rigid air sliders, an electrostatic sensor, and a soft-handling wafer chuck. With the system, wafer warp is precisely measured before and after film deposition, and the stress distribution is calculated from those measurements. Wafer warps can be measured with a repeatability of a few nanometers by this system. The stress distribution of absorber film on 2-mm-thick Si wafers can be determined with an accuracy of ±5 MPa. The stress distribution agrees well with the pattern position shifts in the membrane.

  13. High Precision Measurement of the Proton Elastic Form Factor Ratio at Low Q2

    SciTech Connect

    Xiaohui Zhan

    2009-12-01

    A high precision measurement of the proton elastic form factor ratio µpGEp/GMp in the range Q2 = 0.3–0.7 GeV2/c2 was performed using recoil polarimetry in Jefferson Lab Hall A. In this low Q2 range, previous data from LEDEX [5] along with many fits and calculations [2, 3, 4] indicate substantial deviations of the ratio from unity. In this new measurement, with 80% polarized electron beam for 24 days, we are able to achieve <1% statistical uncertainty. Preliminary results are a few percent lower than expected from previous world data and fits, indicating a smaller GEp at this region. Beyond the intrinsic interest in nucleon structure, the improved form factor measurements also have implications for DVCS, determinations of the proton Zemach radius and strangeness form factors through parity violation experiments.

  14. A novel algorithm combining oversampling and digital lock-in amplifier of high speed and precision

    NASA Astrophysics Data System (ADS)

    Li, Gang; Zhou, Mei; He, Feng; Lin, Ling

    2011-09-01

    Because of a large amount of arithmetic in the standard digital lock-in detection, a high performance processor is needed to implement the algorithm in real time. This paper presents a novel algorithm that integrates oversampling and high-speed lock-in detection. The algorithm sets the sampling frequency as a whole-number multiple of four of the input signal frequency, and then uses the common downsampling technology to lower the sampling frequency to four times of the input signal frequency. It could effectively remove the noise interference and improve the detection accuracy. After that the phase sensitive detector is implemented. It simply does the addition and subtraction on four points in the period of same phase and replaces almost all the multiplication operations to speed up digital lock-in detection calculation substantially. Furthermore, the correction factor is introduced to improve the calculation accuracy of the amplitude, and an error caused by the algorithm in theory can be eliminated completely. The results of the simulation and actual experiments show that the novel algorithm combining digital lock-in detection and oversampling not only has the high precision, but also has the unprecedented speed. In our work, the new algorithm is suitable for the real-time weak signal detection in the general microprocessor not just digital signal processor.

  15. Instrument for measuring moment of inertia with high precision

    NASA Astrophysics Data System (ADS)

    Zheng, Yongjun; Lin, Min; Guo, Bin

    2010-08-01

    Accurate calculation of the moment of inertia of an irregular body is made difficult by the large number of quantities. A popular method is to use a trifilar suspension system to measure the period of oscillation of the body in the horizontal plane. In this paper, an instrument for measuring the moment of inertia based on trifilar pendulum is designed; some sources of error are discussed; three metal disks with known moments of inertia are used to calibrate the instrument, the other metal disks with known moments of inertia are used to test the accuracy of the instrument. The results are consistent when compared with calculated moment of inertia of the metal disks. In addition, the instrument could be used to measure the moment of inertia of other irregular objects. The period of oscillation is acquired by the capture mode of MSP430 microprocessor, the mass is obtained by the Electronic Balance and the data is transferred to the MSP430 via serial port.

  16. Design and development of a high-precision, high-payload telescope dual-drive system

    NASA Astrophysics Data System (ADS)

    Worthington, Michael S.; Beets, Timothy A.; Beno, Joseph H.; Mock, Jason R.; Murphy, Brian T.; South, Brian J.; Good, John M.

    2010-07-01

    A high precision, dual drive system has been designed and developed for the Wide Field Upgrade to the Hobby-Eberly Telescope* at McDonald Observatory in support of the Hobby-Eberly Telescope Dark Energy Experiment‡. Analysis, design and controls details will be of interest to designers of large scale, high precision robotic motion devices. The drive system positions the 19,000 kg star tracker to a precision of less than 5 microns along its 4-meter travel. While positioning requirements remain essentially equal to the existing HET, tracker mass increases by a factor greater than 5. The 10.5-meter long tracker is driven at each end by planetary roller screws, each having two distinct drive sources dictated by the desired operation: one slowly rotates the screw when tracking celestial objects and the second rotates the nut for rapid displacements. Key results of the roller screw rotordynamics analysis are presented. A description of the complex bearing arrangement providing required degrees of freedom as well as the impact of a detailed Failure Modes and Effects Analysis addressing necessary safety systems is also presented. Finite element analysis results demonstrate how mechanical springs increase the telescope's natural frequency response by 22 percent. The critical analysis and resulting design is provided.

  17. High channel count and high precision channel spacing multi-wavelength laser array for future PICs.

    PubMed

    Shi, Yuechun; Li, Simin; Chen, Xiangfei; Li, Lianyan; Li, Jingsi; Zhang, Tingting; Zheng, Jilin; Zhang, Yunshan; Tang, Song; Hou, Lianping; Marsh, John H; Qiu, Bocang

    2014-01-01

    Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%. PMID:25488111

  18. High channel count and high precision channel spacing multi-wavelength laser array for future PICs

    PubMed Central

    Shi, Yuechun; Li, Simin; Chen, Xiangfei; Li, Lianyan; Li, Jingsi; Zhang, Tingting; Zheng, Jilin; Zhang, Yunshan; Tang, Song; Hou, Lianping; Marsh, John H.; Qiu, Bocang

    2014-01-01

    Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%. PMID:25488111

  19. A novel power source for high-precision, highly efficient micro w-EDM

    NASA Astrophysics Data System (ADS)

    Chen, Shun-Tong; Chen, Chi-Hung

    2015-07-01

    The study presents the development of a novel power source for high-precision, highly efficient machining of micropart microstructures using micro wire electrical discharge machining (w-EDM). A novel power source based on a pluri resistance-capacitance (pRC) circuit that can generate a high-frequency, high-peak current with a short pulse train is proposed and designed to enhance the performance of micro w-EDM processes. Switching between transistors is precisely controlled in the designed power source to create a high-frequency short-pulse train current. Various microslot cutting tests in both aluminum and copper alloys are conducted. Experimental results demonstrate that the pRC power source creates instant spark erosion resulting in markedly less material for removal, diminishing discharge crater size, and consequently an improved surface finish. A new evaluation approach for spark erosion ability (SEA) to assess the merits of micro EDM power sources is also proposed. In addition to increasing the speed of micro w-EDM by increasing wire feed rates by 1.6 times the original feed rate, the power source is more appropriate for machining micropart microstructures since there is less thermal breaking. Satisfactory cutting of an elaborate miniature hook-shaped structure and a high-aspect ratio microstructure with a squared-pillar array also reveal that the developed pRC power source is effective, and should be very useful in the manufacture of intricate microparts.

  20. High precision study of muon catalyzed fusion in D2 and HD gas

    NASA Astrophysics Data System (ADS)

    Balin, D. V.; Ganzha, V. A.; Kozlov, S. M.; Maev, E. M.; Petrov, G. E.; Soroka, M. A.; Schapkin, G. N.; Semenchuk, G. G.; Trofimov, V. A.; Vasiliev, A. A.; Vorobyov, A. A.; Voropaev, N. I.; Petitjean, C.; Gartner, B.; Lauss, B.; Marton, J.; Zmeskal, J.; Case, T.; Crowe, K. M.; Kammel, P.; Hartmann, F. J.; Faifman, M. P.

    2011-03-01

    Muon catalyzed dd fusion in D2 and HD gases in the temperature range from 28 to 350 K was investigated in a series of experiments based on a time-projection ionization chamber operating with pure hydrogen. All main observables in this reaction chain were measured with high absolute precision including the resonant and non-resonant ddμ formation rates, the rate for hyperfine transitions in dμ atoms, the branching ratio of the two charge symmetric fusion channels 3He + n and t + p and the muon sticking probability. The report presents the final analysis of the data together with a comprehensive comparison with calculations based on recent μCF theories. The energy of the loosely bound ddμ state with quantum numbers J = 1, ν = 1, which is central to the mechanism of resonant molecule formation, is extracted with precision ɛ11(fit) = -1.9651(7) eV. in impressive agreement with the latest theoretical results ɛ11(theory) = -1.9646 eV.

  1. Calculation of the vacuum Green's function valid for high toroidal mode number in tokamaks.

    NASA Astrophysics Data System (ADS)

    Chance, Morrell; Turnbull, Alan

    2005-10-01

    The present evaluation of the Green's function used for the magmetic scalar potential in vacuum calculations for axisymmetric geometry in the vacuum segments of gato, pest and other mhd stability codes has been found to be deficient for moderately high toroidal mode numbers. This was due to the loss of numerical precision arising from the upward recursion relation used for generating the functions to high mode numbers. The recursion is initiated from the complete elliptic integrals of the first and second kinds. To ameliorate this, a direct integration of the integral representation of the function was crafted to achieve the necessary high accuracy for moderately high mode numbers. At very high mode numbers the loss of numerical precision due to the oscillatory behavior of the integrand is further avoided by judiciously deforming the integration contour in the complex plane. Machine precision, roughly 14 -- 16 digits, accuracy can be achieved by using a combination of both these techniques.

  2. A Precise Calibration Technique for Measuring High Gas Temperatures

    NASA Technical Reports Server (NTRS)

    Gokoglu, Suleyman A.; Schultz, Donald F.

    1999-01-01

    A technique was developed for direct measurement of gas temperatures in the range of 2050 K - 2700 K with improved accuracy and reproducibility. The technique utilized the low-emittance of certain fibrous Materials, and the uncertainty of the technique was limited by the uncertainty in the melting points of the materials, i.e., +/- 15 K. The materials were pure, thin, metal-oxide fibers whose diameters varied from 60 mm to 400 mm in the experiments. The sharp increase in the emittance of the fibers upon melting was utilized as indication of reaching a known gas temperature. The accuracy of the technique was confirmed by both calculated low emittance values of transparent fibers, of order 0.01, up to a few degrees below their melting point and by the fiber-diameter independence of the results. This melting-point temperature was approached by increments not larger than 4 K, which was accomplished by controlled increases of reactant flow rates in hydrogen-air and/or hydrogen- oxygen flames. As examples of the applications of the technique, the gas-temperature measurements were used (a) for assessing the uncertainty in infering gas temperatures from thermocouple measurements, and (b) for calibrating an IR camera to measure gas temperatures. The technique offers an excellent calibration reference for other gas-temperature measurement methods to improve their accuracy and reliably extending their temperature range of applicability.

  3. A Precise Calibration Technique for Measuring High Gas Temperatures

    NASA Technical Reports Server (NTRS)

    Gokoglu, Suleyman A.; Schultz, Donald F.

    2000-01-01

    A technique was developed for direct measurement of gas temperatures in the range of 2050 K 2700 K with improved accuracy and reproducibility. The technique utilized the low-emittance of certain fibrous materials, and the uncertainty of the technique was United by the uncertainty in the melting points of the materials, i.e., +/-15 K. The materials were pure, thin, metal-oxide fibers whose diameters varied from 60 microns to 400 microns in the experiments. The sharp increase in the emittance of the fibers upon melting was utilized as indication of reaching a known gas temperature. The accuracy of the technique was confirmed by both calculated low emittance values of transparent fibers, of order 0.01, up to a few degrees below their melting point and by the fiber-diameter independence of the results. This melting-point temperature was approached by increments not larger than 4 K, which was accomplished by controlled increases of reactant flow rates in hydrogen-air and/or hydrogen-oxygen flames. As examples of the applications of the technique, the gas-temperature measurements were used: (a) for assessing the uncertainty in inferring gas temperatures from thermocouple measurements, and (b) for calibrating an IR camera to measure gas temperatures. The technique offers an excellent calibration reference for other gas-temperature measurement methods to improve their accuracy and reliably extending their temperature range of applicability.

  4. HYDRA: High Speed Simulation Architecture for Precision Spacecraft Formation Flying

    NASA Technical Reports Server (NTRS)

    Martin, Bryan J.; Sohl, Garett A.

    2003-01-01

    This viewgraph presentation describes HYDRA, which is architecture to facilitate high-fidelity and real-time simulation of formation flying missions. The contents include: 1) Motivation; 2) Objective; 3) HYDRA-Description and Overview; 4) HYDRA-Hierarchy; 5) Communication in HYDRA; 6) Simulation Specific Concerns in HYDRA; 7) Example application (Formation Acquisition); and 8) Sample Problem Results.

  5. Pointing Control System for a High Precision Flight Telescope

    SciTech Connect

    BENTLEY,ANTHONY E.; WILCOXEN,JEFFREY LEE

    2000-12-01

    A pointing control system is developed and tested for a flying gimbaled telescope. The two-axis pointing system is capable of sub-microradian pointing stability and high accuracy in the presence of large host vehicle jitter. The telescope also has high agility--it is capable of a 50-degree retarget (in both axes simultaneously) in less than 2 seconds. To achieve the design specifications, high-accuracy, high-resolution, two-speed resolvers were used, resulting in gimbal-angle measurements stable to 1.5 microradians. In addition, on-axis inertial angle displacement sensors were mounted on the telescope to provide host-vehicle jitter cancellation. The inertial angle sensors are accurate to about 100 nanoradians, but do not measure low frequency displacements below 2 Hz. The gimbal command signal includes host-vehicle attitude information, which is band-limited. This provides jitter data below 20 Hz, but includes a variable latency between 15 and 25 milliseconds. One of the most challenging aspects of this design was to combine the inertial-angle-sensor data with the less perfect information in the command signal to achieve maximum jitter reduction. The optimum blending of these two signals, along with the feedback compensation were designed using Quantitative Feedback Theory.

  6. High-Precision Sub-Doppler Infrared Spectroscopy of HeH^+

    NASA Astrophysics Data System (ADS)

    Perry, Adam J.; Hodges, James N.; Markus, Charles; Kocheril, G. Stephen; Jenkins, Paul A., II; McCall, Benjamin J.

    2014-06-01

    The helium hydride ion, HeH^+, is the simplest heteronuclear diatomic, and is composed of the two most abundant elements in the universe. It is widely believed that this ion was among the first molecules to be formed; thus it has been of great interest to scientists studying the chemistry of the early universe. HeH^+ is also isoelectronic to H_2 which makes it a great target ion for theorists to include adiabatic and non-adiabatic corrections to its Born-Oppenheimer potential energy surface. The accuracy of such calculations is further improved by incorporating electron relativistic and quantum electrodynamic effects. Using the highly sensitive spectroscopic technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS) we are able to perform sub-Doppler spectroscopy on ions of interest. When combined with frequency calibration from an optical frequency comb we fit line centers with sub-MHz precision as has previously been shown for the H3^+, HCO+, and CH5+ ions. Here we report a list of the most precisely measured rovibrational transitions of HeH^+ to date. These measurements should allow theorists to continue to push the boundaries of ab initio calculations in order to further study this important fundamental species. S. Lepp, P. C. Stancil, A. Dalgarno J. Phys. B (2002), 35, R57. S. Lepp, Astrophys. Space Sci. (2003), 285, 737. K. Pachucki, J. Komasa, J. Chem. Phys (2012), 137, 204314. J. N. Hodges, A. J. Perry, P. A. Jenkins II, B. M. Siller, B. J. McCall J. Chem. Phys. (2013), 139, 164201.

  7. Development of a High Precision Body Surface Electrocardiogram

    NASA Astrophysics Data System (ADS)

    Inui, Shigeru; Toyosu, Yasushi; Akutagawa, Masatake; Kinouchi, Yosuke

    In the 12-lead electrocardiograph currently being used general medical practice, electrodes are positioned at 6 locations in the chest region and the cardiac potential is measured. This research increases the number of electrode to 124 at evenly-spaced intervals over the body surface of the chest, side and back. The commonly used band elimination filter is not used as a countermeasure for exclusion of the noise from such electrodes, and a body surface electrocardiograph has been developed that makes it possible to perform high-speed sampling of the cardiac potential at 80-100 times the conventional rate. From the sampling data obtained with high spatial resolution, maps and animations of the body surface potential distribution are created and displayed from the 1dimension waveform as well as from the 2dimensions/3dimensions waveforms.

  8. Precision Experiments With Stored And Cooled Highly Charged Ions

    NASA Astrophysics Data System (ADS)

    Kluge, H.-Jürgen

    2006-11-01

    Accumulation, storing and cooling techniques play an increasingly important role in many areas of science. These procedures can be applied in Penning traps and storage rings to ions. In this way, quantum electrodynamics can be tested in extreme electromagnetic fields by measuring hyperfine structure splittings. Lamb shifts, or g-factors in hydrogen-like heavy systems such as U91+ or Pb81+. In addition, fundamental constants or nuclear properties like the atomic mass can be determined. In the case of a radioactive ion, the fate of an individual ion, undergoing a nuclear decay, can be studied in detail by observing the disappearance of the signal of the mother and the appearance of that of the daughter isotope. Presently, the Highly-charged Ion TRAP (HITRAP) facility is being built up at GSI. Stable or radioactive highly charged ions are produced by colliding relativistic ions with a target. After electron cooling and deceleration in the storage ring ESR at GSI, these ions are ejected, decelerated further, and injected into a Penning trap where cooling to 4 K takes place. From there, the cooled highly charged ions such as hydrogen-like uranium are transferred at low energy to different experimental set-ups which are being built up by the international HITRAP Collaboration.

  9. High Precision SC Cavity alignment Measurements with Higher Order Modes

    SciTech Connect

    Molloy, Stephen; Frisch, Josef; Hendrickson, Linda; McCormick, Douglas; May, Justin; Ross, Marc; Smith, Tonee; Eddy, Nathan; Nagaitsev, Sergei; Baboi, Nicoleta; Hensler, Olaf; Petrosyan, Lyudvig; Napoly, Olivier; Paparella, Rita; Simon, Claire; /DSM, DAPNIA, Saclay

    2007-06-14

    Experiments at the FLASH linac at DESY have demonstrated that the higher order modes (HOMs) induced in superconducting cavities can be used to provide a variety of beam and cavity diagnostics. The centers of the cavities can be determined from the beam orbit which produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used as a high resolution beam position monitor. For most superconducting accelerators, the existing HOM couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional BPM.

  10. A high-precision pulse-width modulator source.

    SciTech Connect

    Lenkszus, F.; Laird, R.

    1999-09-30

    A novel high-resolution pulse-width modulator (PWM) is being developed for a new digital regulator for the Advanced Photon Source power converters. The circuit features 82-ps setability over an 80-{micro}s range. Our application requires a 50-{micro}s fill-scale range; therefore the 82-ps setability is equivalent to better than 19 bits. The circuit is presently implemented as a VME module and is an integral part of the digital regulator prototype. The design concept and performance results will be presented.

  11. High speed precision motion strategies for lightweight structures

    NASA Technical Reports Server (NTRS)

    Book, Wayne J.

    1987-01-01

    Work during the recording period proceeded along the lines of the proposal, i.e., three aspects of high speed motion planning and control of flexible structures were explored: fine motion control, gross motion planning and control, and automation using light weight arms. In addition, modeling the large manipulator arm to be used in experiments and theory has lead to some contributions in that area. These aspects are reported below. Conference, workshop and journal submissions, and presentations related to this work were seven in number, and are listed. Copies of written papers and abstracts are included.

  12. Spectral band passes for a high precision satellite sounder

    NASA Technical Reports Server (NTRS)

    Kaplan, L. D.; Chahine, M. T.; Susskind, J.; Searl, J. E.

    1977-01-01

    Atmospheric temperature soundings with significantly improved vertical resolution can be obtained from carefully chosen narrow band-pass measurements in the 4.3-micron band of CO2 by taking advantage of the variation of the absorption coefficients, and thereby the weighting functions, with pressure and temperature. A set of channels has been found in the 4.2-micron region that is capable of yielding about 2-km vertical resolution in the troposphere. The concept of a complete system is presented for obtaining high resolution retrievals of temperature and water vapor distribution, as well as surface and cloud top temperatures, even in the presence of broken clouds.

  13. Combination spindle-drive system for high precision machining

    DOEpatents

    Gerth, Howard L.

    1977-07-26

    A combination spindle-drive is provided for fabrication of optical quality surface finishes. Both the spindle-and-drive utilize the spindle bearings for support, thereby removing the conventional drive-means bearings as a source of vibration. An airbearing spindle is modified to carry at the drive end a highly conductive cup-shaped rotor which is aligned with a stationary stator to produce torque in the cup-shaped rotor through the reaction of eddy currents induced in the rotor. This arrangement eliminates magnetic attraction forces and all force is in the form of torque on the cup-shaped rotor.

  14. High precision moving magnet chopper for variable operation conditions

    NASA Technical Reports Server (NTRS)

    Aicher, Winfried; Schmid, Manfred

    1994-01-01

    In the context of an ESTEC technology contract, a Chopping Mechanism was developed and built with the Far Infrared and Submillimeter Telescope (FIRST) astronomy mission as a reference. The task of the mechanism is to tilt the subreflector of the telescope with an assumed mass of 2.5 kg about one chopping axis at nominal frequencies of up to 5 Hz and chopping angles of up to +/- 11.25 mrad with high efficiency (minimum time for position change). The chopping axis is required to run through the subreflector vertex. After performing a concept trade-off also considering the low operational temperatures in the 130 K range, a design using moving magnet actuators was found to be the favorite one. In addition, a bearing concept using flexible pivots was chosen to meet the high chopping accuracy required. With this approach, a very reliable design could be realized, since the actuators work without any mechanical contact between its moving and fixed parts, and the only bearings used are two flexible pivots supporting the subreflector mounting interface. The mechanism was completely built in titanium in a lightweight and stiff design. The moving magnet actuators were designed to meet the stringent requirements for minimum risetime (time necessary to move from one angular position to a new one) in the 20 msec range. The angular position and the corresponding chopping frequency as well can be arbitrarily selected by the user.

  15. High precision moving magnet chopper for variable operation conditions

    NASA Astrophysics Data System (ADS)

    Aicher, Winfried; Schmid, Manfred

    1994-05-01

    In the context of an ESTEC technology contract, a Chopping Mechanism was developed and built with the Far Infrared and Submillimeter Telescope (FIRST) astronomy mission as a reference. The task of the mechanism is to tilt the subreflector of the telescope with an assumed mass of 2.5 kg about one chopping axis at nominal frequencies of up to 5 Hz and chopping angles of up to +/- 11.25 mrad with high efficiency (minimum time for position change). The chopping axis is required to run through the subreflector vertex. After performing a concept trade-off also considering the low operational temperatures in the 130 K range, a design using moving magnet actuators was found to be the favorite one. In addition, a bearing concept using flexible pivots was chosen to meet the high chopping accuracy required. With this approach, a very reliable design could be realized, since the actuators work without any mechanical contact between its moving and fixed parts, and the only bearings used are two flexible pivots supporting the subreflector mounting interface. The mechanism was completely built in titanium in a lightweight and stiff design. The moving magnet actuators were designed to meet the stringent requirements for minimum risetime (time necessary to move from one angular position to a new one) in the 20 msec range. The angular position and the corresponding chopping frequency as well can be arbitrarily selected by the user.

  16. A high-precision mechanical absolute-rotation sensor.

    PubMed

    Venkateswara, Krishna; Hagedorn, Charles A; Turner, Matthew D; Arp, Trevor; Gundlach, Jens H

    2014-01-01

    We have developed a mechanical absolute-rotation sensor capable of resolving ground rotation angle of less than 1 nrad/√Hz above 30 mHz and 0.2 nrad/√Hz above 100 mHz about a single horizontal axis. The device consists of a meter-scale beam balance, suspended by a pair of flexures, with a resonance frequency of 10.8 mHz. The center of mass is located 3 μm above the pivot, giving an excellent horizontal displacement rejection of better than 3 × 10(-5) rad/m. The angle of the beam is read out optically using a high-sensitivity autocollimator. We have also built a tiltmeter with better than 1 nrad/√Hz sensitivity above 30 mHz. Co-located measurements using the two instruments allowed us to distinguish between background rotation signal at low frequencies and intrinsic instrument noise. The rotation sensor is useful for rotational seismology and for rejecting background rotation signal from seismometers in experiments demanding high levels of seismic isolation, such as Advanced Laser Interferometer Gravitational-wave Observatory. PMID:24517804

  17. Creating high-stability high-precision bipolar trim power supply

    SciTech Connect

    Chen, Zhe; Merz, William A.

    2012-07-01

    Thomas Jefferson National Accelerator Facility (TJNAF) is founded by the US Department of Energy (DOE) office of science for the technology advancement and physics research in electron beam accelerator. This facility has the state of the art technology to carry out world-class cutting-edge experiments for the nucleus composition and atomic characteristics identification and exploration for the nature of the matter in the universe. A continuous wave electron beam is featured for such experiments, thus precise and stable trim power supply is required to meet such purpose. This paper demonstrates the challenges and solutions to design, assemble, fabrication and test such high-precision high-stability power supplies. This paper presents the novel design and first article test of the ±20A ±75V bipolar, 100ppm stability level current-regulated high-power trim power supplies for the beam manipulation. This special design can provide valuable documentation and reference values for future designs and special applications in particle accelerator power supply creation.

  18. High range precision laser radar system using a Pockels cell and a quadrant photodiode

    NASA Astrophysics Data System (ADS)

    Jo, Sungeun; Kong, Hong Jin; Bang, Hyochoong; Kim, Jae-Wan; Jeon, Byoung Goo

    2016-05-01

    We have proposed and demonstrated a novel technique to measure distance with high range precision. To meet the stringent requirements of a variety of applications, range precision is an important specification for laser radar systems. Range precision in conventional laser radar systems is limited by several factors, namely laser pulse width, the bandwidth of a detector, the timing resolution of the time to digital converter, shot noise and timing jitters generated by electronics. The proposed laser radar system adopts a Pockels cell and a quadrant photodiode and only measures the energy of a laser pulse to obtain range so that the effect of those factors is reduced in comparison to conventional systems. In the proposed system, the measured range precision was 5.7 mm with 100 laser pulses. The proposed method is expected to be an alternative method for laser radar system requiring high range precision in many applications.

  19. High Precision Assembly of Thin Mirror X-ray Telescopes

    NASA Astrophysics Data System (ADS)

    Schattenburg, Mark

    Lightweight high resolution x-ray telescope optics are one of the key technologies under development for next-generation x-ray telescopes. The ultimate goal of this effort is to realize optics with spatial resolution rivaling Chandra (<1 arc-sec) but with collecting areas that are larger by orders of magnitude. In the USA several institutions, including GSFC, MSFC, Harvard-SAO, MIT and Northwest University are working on a variety of approaches to this problem. An excellent example is the NuSTAR x-ray telescope, which teamed Cal Tech, GSFC, Columbia University and LLNL to produce a superb set of hard x-ray optics. The telescope was composed of thousands of 0.2 mm-thick glass mirrors which were epoxied into place around a spindle structure. While very light weight, this process resulted in ~1 arc min resolution. We want to achieve ~100 times better with similar mass. A group at NASA GSFC has recently demonstrated an alternative thin-glass assembly procedure that has achieved ~7 arc sec resolution with x-ray tests. Further progress towards 1 arc-sec will require mirrors with improved figure, lower stress coatings, improved alignment, better metrology, and low stress bonding. Many of the difficulties with current mirror assembly practice stem from the use of epoxy as a bonding agent. Epoxy has many disadvantages, including high shrinkage, large CTE and creep, resin aging effects, water absorption, outgassing, low tensile strength, exothermicity, and requiring large amounts of time and/or heat to cure. These effects can cause errors that become â€oefrozen in― to the bond with no possibility of correction. We propose to investigate replacing epoxy with low temperature, low shrinkage solder alloys. We use these solders in conjunction with high power, millisec-long pulses from a fiber IR laser to deliver controlled amounts of heat into the bond area. We have demonstrated that laser pulses can be used to actuate carefully designed bonds by permanently compressing

  20. Precision high energy liner implosion experiments PHELIX [1

    SciTech Connect

    Reass, William A; Baca, David M; Griego, Jeffrey R; Reinovsky, Robert E; Rousculp, Christopher L; Turchi, Peter J

    2009-01-01

    This paper describes the hardware design of a small megajoule sized transformer coupled pulse power system utilized to drive hydrodynamic liner experiments with a nominal current capability of 10 megAmperes. The resulting liner velocities and characteristics provide properties of physics interest. The capacitor banks utilize the ''Atlas'' plastic cased 60 kV, 60 kJ capacitors [2] and railgaps [3]. The air insulated marx'S are configured to dive a multi-filar toroidal transformer. The 4:1 multi-filar toroidal transformer is mechanically part of a circular disc line and this feature results in an attractive inductance budget. Because of the compact size, re-usable transformer, and resulting low maintenance cost, shot rates can be high compared to other ''large'' machines or explosively driven hydrodynamic methods. The PHELIX modeling, construction status, and test results will also be provided.

  1. High Precision Superconducting Cavity Diagnostics With Higher Order Mode Measurements

    SciTech Connect

    Molloy, S.; Frisch, J.; McCormick, D.; May, J.; Ross, M.; Smith, T.; Baboi, N.; Hensler, O.; Petrosian, L.; Napoly, O.; Paparella, R.C.; Simon, C.; Eddy, N.; Nagaitsev, S.; Wendt, M.; /Fermilab

    2007-02-12

    Experiments at the FLASH facility at DESY have demonstrated that the higher order modes induced in superconducting cavities can be used to provide a variety of beam and cavity diagnostics. The axes of the modes can be determined from the beam orbit that produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used to obtain high resolution beam position information, and the phase of the monopole modes to measure the beam phase relative to the accelerator rf. For most superconducting accelerators, the existing higher order mode couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional beam position monitor.

  2. A high precision calorimeter for the SOX experiment

    NASA Astrophysics Data System (ADS)

    Papp, L.; Agostini, M.; Altenmüller, K.; Appel, S.; Caminata, A.; Cereseto, R.; Di Noto, L.; Farinon, S.; Musenich, R.; Neumair, B.; Oberauer, L.; Pallavicini, M.; Schönert, S.; Testera, G.; Zavatarelli, S.

    2016-07-01

    The SOX (Short distance neutrino Oscillations with BoreXino) experiment is being built to discover or reject eV-scale sterile neutrinos by observing short baseline oscillations of active-to-sterile neutrinos [1]. For this purpose, a 100 kCi 144Ce-144Pr antineutrino generator (CeSOX) will be placed under the BOREXINO detector at the Laboratori Nazionali del Gran Sasso. Thanks to its large size and very low background, BOREXINO is an ideal detector to discover or reject eV-scale sterile neutrinos. To reach the maximal sensitivity, we aim at determining the neutrino flux emitted by the antineutrino generator with a < 1 % accuracy. With this goal, TU München and INFN Genova are developing a vacuum calorimeter, which is designed to measure the source-generated heat with high accuracy.

  3. High precision pointing with a multiline spectrometer at the VTT

    NASA Astrophysics Data System (ADS)

    Staiger, J.

    2012-12-01

    We are investigating the pointing quality of the VTT, Tenerife under the aspect of suitability for long-term heliosesimological observations. Tests have shown that thermal and mechanical loads within the telescope may create spurious image drifts with shift rates of up to 5 arcsec per hour. During daylong recordings this will reduce significantly the effective size of the field-of-view and may infer artificial lateral movements into the data. The underlying problem that not all image position offsets developing during a measurement may be compensated for is common to most high-resolution solar telescopes independently of the type of pointing system used. We are developing new approaches to address this problem which are to be tested in the near future at the VTT. The simulations established so far show that the problem may be reduced by more than 90 %.

  4. High Precision SC Cavity Diagnostics with HOM Measurements

    SciTech Connect

    Frisch, Josef; Hendrickson, Linda; McCormick, Douglas; May, Justin; Molloy, Stephen; Ross, Marc; /SLAC

    2006-08-18

    Experiments at the FLASH linac at DESY have demonstrated that the Higher Order Modes induced in Superconducting Cavities can be used to provide a variety of beam and cavity diagnostics. The centers of the cavities can be determined from the beam orbit which produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used as a high resolution beam position monitor, and the phase of the monopole modes to measure the beam phase relative to the accelerator RF. Beam orbit feedback which minimizes the dipole HOM power in a set of structures has been demonstrated. For most SC accelerators, the existing HOM couplers provide the necessary signals, and the down mix and digitizing electronics are straightforward, similar to those for a conventional BPM.

  5. Development of Large Current High Precision Pulse Power Supply

    NASA Astrophysics Data System (ADS)

    Takayanagi, Tomohiro; Koseki, Shoichiro; Kubo, Hiroshi; Katoh, Shuji; Ogawa, Shinichi

    JAEA and KEK are jointly constructing a high intensity proton accelerator project J-PARC. Its main accelerator is 3GeV synchrotron. Its injection bump magnets, especially horizontal paint bump magnets, are excited by large pulse currents. Their rated currents are over 10kA and pulse widths are about 1ms. Tracking errors are required to be less than 1%. Multiple connected two-quadrant IGBT choppers are adopted for their power supplies. Their output currents are controlled by feedback control with minor loop voltage control (m-AVR). When output current of a chopper intermits at small current, its output voltage rises up and current control becomes difficult. In this paper response of m-AVR and output voltage characteristics at current intermittent region are studied and an improved control scheme is proposed. The performance is confirmed by a test.

  6. Proton radii of {sup 4,6,8}He isotopes from high-precision nucleon-nucleon interactions

    SciTech Connect

    Caurier, E.; Navratil, P.

    2006-02-15

    Recently, precision laser spectroscopy on {sup 6}He atoms determined accurately the isotope shift between {sup 4}He and {sup 6}He and, consequently, the charge radius of {sup 6}He. A similar experiment for {sup 8}He is under way. We have performed large-scale ab initio calculations for {sup 4,6,8}He isotopes using high-precision nucleon-nucleon (NN) interactions within the no-core shell model (NCSM) approach. With the CD-Bonn 2000 NN potential we found point-proton root-mean-square (rms) radii of {sup 4}He and {sup 6}He 1.45(1) fm and 1.89(4), respectively, in agreement with experiment and predict the {sup 8}He point-proton rms radius to be 1.88(6) fm. At the same time, our calculations show that the recently developed nonlocal INOY NN potential gives binding energies closer to experiment, but underestimates the charge radii.

  7. A high precision method for mapping phase to amplitude in direct digital synthesis and its hardware implementation

    NASA Astrophysics Data System (ADS)

    Cao, Zhang; Song, Wei; Peng, Zhicong; Xu, Lijun

    2014-11-01

    There exist a number of algorithms to map the phase to amplitude in direct digital synthesis (DDS). For DDS with more than 14 output bits, the Coordinate Rotation Digital Computer (CORDIC) algorithm is well known for its high precision. Also, it is effective in solutions where there is the need of in-phase and quadrature components simultaneously because the algorithm calculates both. In this paper, a Taylor expansion based method was proposed to calculate both in-phase and quadrature at the same time. Numerical simulations for different data format, e.g., double and finite bits, were carried out in Matlab and Quartus, which were followed by the hardware implementation in Field Programmable Gate Array. The results demonstrated that the proposed method possessed higher precision and exhausted less logic elements than the CORDIC algorithm.

  8. A high precision method for mapping phase to amplitude in direct digital synthesis and its hardware implementation.

    PubMed

    Cao, Zhang; Song, Wei; Peng, Zhicong; Xu, Lijun

    2014-11-01

    There exist a number of algorithms to map the phase to amplitude in direct digital synthesis (DDS). For DDS with more than 14 output bits, the Coordinate Rotation Digital Computer (CORDIC) algorithm is well known for its high precision. Also, it is effective in solutions where there is the need of in-phase and quadrature components simultaneously because the algorithm calculates both. In this paper, a Taylor expansion based method was proposed to calculate both in-phase and quadrature at the same time. Numerical simulations for different data format, e.g., double and finite bits, were carried out in Matlab and Quartus, which were followed by the hardware implementation in Field Programmable Gate Array. The results demonstrated that the proposed method possessed higher precision and exhausted less logic elements than the CORDIC algorithm. PMID:25430130

  9. High Precision Ti stable Isotope Measurement of Terrestrial Rocks

    NASA Astrophysics Data System (ADS)

    Millet, M. A.; Dauphas, N.; Williams, H. M.; Burton, K. W.; Nowell, G. M.

    2014-12-01

    Advances in multi-collection plasma source mass spectrometry have allowed the determination of stable isotope composition of transition metals to address questions relevant to both high and low temperature geochemistry. However, titanium has received only very limited attention. Here we present a new technique allowing the determination of the stable isotope composition of titanium in geological samples (d49Ti or deviation of the 49Ti/47Ti ratio from the OL-Ti in-house standard of reference) using double-spike methodology and high-resolution MC-ICP-MS. We have carried out a range analytical tests for a wide spectrum of samples matrices to demonstrate a external reproducibility of ±0.02‰ on the d49Ti while using as little as 150ng of natural Ti for a single analysis. We have analysed a comprehensive selection of mantle-derived samples covering a range of geodynamic contexts (MORB, IAB, OIB, adakites, eclogites, serpentines) and geographical distribution (MORB: Mid-Atlantic Ridge, Southwest Indian Ridge and Eastern Pacific Ridge; IAB: New Britain reference suite and Marianas Arc). The samples show a very limited range from -0.06‰ to +0.04‰ with a main mode at +0.004‰ relative to the OL-Ti standard. Average values for MORB, IAB and eclogites are similar within uncertainty and thus argue for limited mobility of Ti during subduction zone processes and homogeneity of the Ti stable isotope composition of the upper mantle. However, preliminary data for more evolved igneous rocks suggest that they display heavier Ti stable isotope compositions, which may reflect the removal of isotopically light Ti as a function of Fe-Ti oxide crystallisation. This is in good agreement with Ti being present in 5-fold and 6-fold coordination in basaltic melts and preferential uptake of 6-folded Ti by Ti-bearing oxides [1]. This dataset will be complemented by analysis of abyssal peridotites to confirm the homogeneity of the mantle as well as data for a range of ferromanganese crusts

  10. High-Precision Measurements of the Brightness Variation of Nereid

    NASA Astrophysics Data System (ADS)

    Terai, Tsuyoshi; Itoh, Yoichi

    2013-04-01

    Nereid, the outer satellite of Neptune, has a highly eccentric prograde orbit with a semimajor axis of larger than 200 in units of Neptune's radius, and is classified as an irregular satellite. Although the capture origin of irregular satellites has been widely accepted, several previous studies suggest that Nereid was formed in the circumplanetary disk of Neptune and ejected outward to the present location by Triton. A series of our photometric observations confirm that Nereid's rotation period, 11.5 hr, is stable and nonchaotic, as indicated by Grav, Holman, and Kavelaars (2003, ApJ, 591, L71). The optical colors of Nereid are indistinguishable from those of trans-Neptunian objects and Centaurs, especially from these objects with neutral colors. We also found the consistency of Nereid's rotation period based on the size-rotation distribution of small outer bodies. It is likely that Nereid originated as an immigrant body captured from the heliocentric orbit that was 4-5 AU away from Neptune's orbit.

  11. High Resolution Airborne Digital Imagery for Precision Agriculture

    NASA Technical Reports Server (NTRS)

    Herwitz, Stanley R.

    1998-01-01

    The Environmental Research Aircraft and Sensor Technology (ERAST) program is a NASA initiative that seeks to demonstrate the application of cost-effective aircraft and sensor technology to private commercial ventures. In 1997-98, a series of flight-demonstrations and image acquisition efforts were conducted over the Hawaiian Islands using a remotely-piloted solar- powered platform (Pathfinder) and a fixed-wing piloted aircraft (Navajo) equipped with a Kodak DCS450 CIR (color infrared) digital camera. As an ERAST Science Team Member, I defined a set of flight lines over the largest coffee plantation in Hawaii: the Kauai Coffee Company's 4,000 acre Koloa Estate. Past studies have demonstrated the applications of airborne digital imaging to agricultural management. Few studies have examined the usefulness of high resolution airborne multispectral imagery with 10 cm pixel sizes. The Kodak digital camera integrated with ERAST's Airborne Real Time Imaging System (ARTIS) which generated multiband CCD images consisting of 6 x 106 pixel elements. At the designated flight altitude of 1,000 feet over the coffee plantation, pixel size was 10 cm. The study involved the analysis of imagery acquired on 5 March 1998 for the detection of anomalous reflectance values and for the definition of spectral signatures as indicators of tree vigor and treatment effectiveness (e.g., drip irrigation; fertilizer application).

  12. A research of a high precision multichannel data acquisition system

    NASA Astrophysics Data System (ADS)

    Zhong, Ling-na; Tang, Xiao-ping; Yan, Wei

    2013-08-01

    The output signals of the focusing system in lithography are analog. To convert the analog signals into digital ones which are more flexible and stable to process, a desirable data acquisition system is required. The resolution of data acquisition, to some extent, affects the accuracy of focusing. In this article, we first compared performance between the various kinds of analog-to-digital converters (ADC) available on the market at the moment. Combined with the specific requirements (sampling frequency, converting accuracy, numbers of channels etc) and the characteristics (polarization, amplitude range etc) of the analog signals, the model of the ADC to be used as the core chip in our hardware design was determined. On this basis, we chose other chips needed in the hardware circuit that would well match with ADC, then the overall hardware design was obtained. Validation of our data acquisition system was verified through experiments and it can be demonstrated that the system can effectively realize the high resolution conversion of the multi-channel analog signals and give the accurate focusing information in lithography.

  13. In-plane laser forming for high precision alignment

    NASA Astrophysics Data System (ADS)

    Folkersma, Ger; Römer, Gert-Willem; Brouwer, Dannis; Veld, Bert Huis in't.

    2014-12-01

    Laser microforming is extensively used to align components with submicrometer accuracy, often after assembly. While laser-bending sheet metal is the most common laser-forming mechanism, the in-plane upsetting mechanism is preferred when a high actuator stiffness is required. A three-bridge planar actuator made out of Invar 36 sheet was used to characterize this mechanism by experiments, finite element method modeling, and a fast-reduced model. The predictions of the thermal models agree well with the temperature measurements, while the final simulated displacement after 15 pulses deviates up to a factor of 2 from the measurement, using standard isotropic hardening models. Furthermore, it was found from the experiments and models that a small bridge width and a large bridge thickness are beneficial to decrease the sensitivity to disturbances in the process. The experiments have shown a step size as small as 0.1 μm, but with a spread of 20%. This spread is attributed to scattering in surface morphology, which affects the absorbed laser power. To decrease the spread and increase the positioning accuracy, an adapted closed-loop learning algorithm is proposed. Simulations using the reduced model showed that 78% of the alignment trials were within the required accuracy of ±0.1 μm.

  14. High Precision Cosmology with the Cosmic Background Radiation

    NASA Astrophysics Data System (ADS)

    Farhang, Marzieh

    around the fiducial model of the standard recombination scenario. Though theoretically well studied, the detailed assumptions in the recombination history, based on standard atomic physics, have never been directly tested. However, for our CMB-based cosmological inferences to be reliable, the recombination scenario needs to be observationally verified. We approach this problem in a model-independent way and construct rank-ordered parameter eigen-modes with the highest power to probe Xe. We study various properties of these modes, including their convergence, fiducial model-dependence, dataset dependence, and the eigen-modes response to marginalization over different standard parameters. We demonstrate that, if enough modes are included, the eigen-modes form a practically complete set of basis function for expanding different physically motivated Xe perturbations. We also develop an information-based criterion to truncate the eigen-mode hierarchy, which can be used in similar hierarchical model selections as well. We show how our measurements of cosmic parameters will be affected if possible deviations in the recombination history are ignored. The method is applied to simulations of Planck+ACTPol and a cosmic variance limited survey with differing simulated recombination histories and the recovered Xe trajectories are constructed. We also apply the method to the best currently available CMB datasets, WMAP9+ACT/SPT. The first constructed eigen-mode turns out to be a direct measure of the damping envelope. Its current measurement with SPT slightly indicates a damping tail anomaly, while ACT data agree well with the standard scenario. High resolution Planck data will resolve this tension with high significance.

  15. High precision predictions for exclusive VH production at the LHC

    SciTech Connect

    Li, Ye; Liu, Xiaohui

    2014-06-04

    We present a resummation-improved prediction for pp → VH + 0 jets at the Large Hadron Collider. We focus on highly-boosted final states in the presence of jet veto to suppress the tt¯ background. In this case, conventional fixed-order calculations are plagued by the existence of large Sudakov logarithms αnslogm(pvetoT/Q) for Q ~ mV + mH which lead to unreliable predictions as well as large theoretical uncertainties, and thus limit the accuracy when comparing experimental measurements to the Standard Model. In this work, we show that the resummation of Sudakov logarithms beyond the next-to-next-to-leading-log accuracy, combined with the next-to-next-to-leading order calculation, reduces the scale uncertainty and stabilizes the perturbative expansion in the region where the vector bosons carry large transverse momentum. Thus, our result improves the precision with which Higgs properties can be determined from LHC measurements using boosted Higgs techniques.

  16. High Precision Pulsar Timing: Effects of ISM Correction Schemes

    NASA Astrophysics Data System (ADS)

    Kunert, Willie; Verbiest, J. P. W.; Shannon, R.; Stinebring, D.

    2012-01-01

    Pulsar timing arrays are one of the leading methods in the search for gravitational waves (GWs). However a significant issue facing this method is the effect of the interstellar medium (ISM). There are multiple methodologies being used to correct for these effects but their efficacy has not been carefully studied. We conducted an initial study of biases induced by correcting for the interstellar medium. We simulated times of arrival (TOAs) with white noise and added ISM delays. We measure the ISM effects as is done with normal data, and created a model of these effects using polynomial fitting. This modeling method is most commonly used in the European Pulsar Timing Array. We then remove these measured ISM effects and compare final and initial TOAs. Ideally they should be the same; however, the differences between the 'corrected' TOAs and original TOAs reveal the weaknesses of this method. In preliminary results we concluded that the higher order polynomials do a better job, yet there is a limit as to how high an order one can use. We also found no significant systematic parameter bias induced by using this method. However, it is clear that certain parameters are more affected by this process of correction. The parameters most affected were the frequency and frequency derivative of the pulsar, but biases in these parameters are not important because the power due to them gets removed in the standard timing analysis. We are continuing this research by comparing and contrasting ISM correction schemes, as well as studying the actual behavior of the ISM in more detail. This research is supported by an NSF-PIRE and an NSF-AST grant.

  17. A comprehensive filtering scheme for high-resolution estimation of the water balance components from high-precision lysimeters

    NASA Astrophysics Data System (ADS)

    Hannes, M.; Wollschlager, U.; Schrader, F.; Durner, W.; Gebler, S.; Putz, T.; Fank, J.; von Unold, G.; Vogel, H.-J.

    2015-08-01

    Large weighing lysimeters are currently the most precise method to directly measure all components of the terrestrial water balance in parallel via the built-in weighing system. As lysimeters are exposed to several external forces such as management practices or wind influencing the weighing data, the calculated fluxes of precipitation and evapotranspiration can be altered considerably without having applied appropriate corrections to the raw data. Therefore, adequate filtering schemes for obtaining most accurate estimates of the water balance components are required. In this study, we use data from the TERENO (TERrestrial ENvironmental Observatories) SoilCan research site in Bad Lauchstadt to develop a comprehensive filtering procedure for high-precision lysimeter data, which is designed to deal with various kinds of possible errors starting from the elimination of large disturbances in the raw data resulting e.g., from management practices all the way to the reduction of noise caused e.g., by moderate wind. Furthermore, we analyze the influence of averaging times and thresholds required by some of the filtering steps on the calculated water balance and investigate the ability of two adaptive filtering methods (the adaptive window and adaptive threshold filter (AWAT filter; Peters et al., 2014), and a new synchro filter applicable to the data from a set of several lysimeters) to further reduce the filtering error. Finally, we take advantage of the data sets of all 18 lysimeters running in parallel at the Bad Lauchstadt site to evaluate the performance and accuracy of the proposed filtering scheme. For the tested time interval of 2 months, we show that the estimation of the water balance with high temporal resolution and good accuracy is possible. The filtering code can be downloaded from the journal website as Supplement to this publication.

  18. Ultrastable mirrors made from diamond reinforced SiC composites for high precision and power applications

    NASA Astrophysics Data System (ADS)

    Akbas, M. A.; Mastrobattisto, D.; Vance, W.; Jurgaitis, P.; Aghajanian, M. K.

    2012-10-01

    Diamond reinforced reaction bonded silicon carbide composites have unique properties such as very high stiffness, low density, low thermal expansion coefficient and high thermal conductivity making them attractive materials for high precision optical and structural components. However, their use in high precision equipments was limited due to significant difficulties in high tolerance machining of these super hard composites. In this present work, machineable diamond reinforced SiC composites were fabricated through forming hybrid monolithic microstructures with diamond free machineable surfaces. The resulting machineable composites were used to produce ultra-stable mirror substrates with optional internal cooling channels for high power laser optic applications.

  19. Precision calculation of 1/4-BPS Wilson loops in AdS5×S5

    NASA Astrophysics Data System (ADS)

    Forini, V.; Puletti, V. Giangreco M.; Griguolo, L.; Seminara, D.; Vescovi, E.

    2016-02-01

    We study the strong coupling behaviour of 1/4-BPS circular Wilson loops (a family of "latitudes") in {N}=4 Super Yang-Mills theory, computing the one-loop corrections to the relevant classical string solutions in AdS5 ×S5. Supersymmetric localization provides an exact result that, in the large 't Hooft coupling limit, should be reproduced by the sigma-model approach. To avoid ambiguities due to the absolute normalization of the string partition function, we compare the ratio between the generic latitude and the maximal 1/2-BPS circle: any measure-related ambiguity should simply cancel in this way. We use the Gel'fand-Yaglom method with Dirichlet boundary conditions to calculate the relevant functional determinants, that present some complications with respect to the standard circular case. After a careful numerical evaluation of our final expression we still find disagreement with the localization answer: the difference is encoded into a precise "remainder function". We comment on the possible origin and resolution of this discordance.

  20. Method of high precision interval measurement in pulse laser ranging system

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong

    2013-09-01

    Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.

  1. Generation of High Resolution and High Precision Orthorectified Road Imagery from Mobile Mapping System

    NASA Astrophysics Data System (ADS)

    Sakamoto, M.; Tachibana, K.; Shimamura, H.

    2012-07-01

    In this paper, a novel technique to generate a high resolution and high precision Orthorectified Road Imagery (ORI) by using spatial information acquired from a Mobile Mapping System (MMS) is introduced. The MMS was equipped with multiple sensors such as GPS, IMU, odometer, 2-6 digital cameras and 2-4 laser scanners. In this study, a Triangulated Irregular Network (TIN) based approach, similar to general aerial photogrammetry, was adopted to build a terrain model in order to generate ORI with high resolution and high geometric precision. Compared to aerial photogrammetry, there are several issues that are needed to be addressed. ORI is generated by merging multiple time sequence images of a short section. Hence, the influence of occlusion due to stationary objects, such as telephone poles, trees, footbridges, or moving objects, such as vehicles, pedestrians are very significant. Moreover, influences of light falloff at the edges of cameras, tone adjustment among images captured from different cameras or a round trip data acquisition of the same path, and time lag between image exposure and laser point acquisition also need to be addressed properly. The proposed method was applied to generate ORI with 1 cm resolution, from the actual MMS data sets. The ORI generated by the proposed technique was more clear, occlusion free and with higher resolution compared to the conventional orthorectified coloured point cloud imagery. Moreover, the visual interpretation of road features from the ORI was much easier. In addition, the experimental results also validated the effectiveness of proposed radiometric corrections. In occluded regions, the ORI was compensated by using other images captured from different angles. The validity of the image masking process, in the occluded regions, was also ascertained.

  2. High precision numerical simulation of the trans-pacific tsunami caused by the 2011 Tohoku earthquake

    NASA Astrophysics Data System (ADS)

    Baba, T.; Allgeyer, S.; Hossen, M. J.; Cummins, P. R.; Tsushima, H.; Hayashi, Y.; Imai, K.; Kato, T.

    2015-12-01

    For high-precision simulations of the trans-pacific tsunamis, we would have to include additional effects on the conventional long-wave theory. Water waves with different wavelengths travel at different speeds so that frequency dispersion is not negligible in the far-field tsunamis. It can be modelled with Boussinesq equations. Baba et al. (2015) developed a high-speed code solving the Boussinesq equations. Recently, importance of effects of small elastic deformation of the Earth loaded by tsunami and seawater density vertical stratification were shown in many studies for the 2010 Chile and 2011 Tohoku far-field tsunamis. Allgeyer and Cummins (2014) successfully suggested a practical method to add these effects in the conventional numerical scheme. However, we don't have yet a simulation code the all effects incorporated simultaneously. This study combined the module of Allgeyer and Cummins (2014) with the Baba's (2015) code. Also here the elastic loading model was improved by considering the gravitational potential change during the tsunami propagation. Calculation with these all effects incur a huge computational cost, so we used a high performance vector computer, Earth Simulator 3, installed in JAMSTEC this year. With the new code on the new computer, we simulated the trans-pacific tsunami by giving a time-dependent sea surface development during the 2011 Tohoku earthquake estimated by the multi-time window tsunami inversion method that used dispersive Green's functions. Our calculation provided a good agreement with the deep-ocean observations at the whole Pacific Ocean. We also found that the three effects, Boussinesq, elastic loading and sea water stratification are equally important simulating the tsunami waveforms in far-field.

  3. Classification of LIDAR Data for Generating a High-Precision Roadway Map

    NASA Astrophysics Data System (ADS)

    Jeong, J.; Lee, I.

    2016-06-01

    Generating of a highly precise map grows up with development of autonomous driving vehicles. The highly precise map includes a precision of centimetres level unlike an existing commercial map with the precision of meters level. It is important to understand road environments and make a decision for autonomous driving since a robust localization is one of the critical challenges for the autonomous driving car. The one of source data is from a Lidar because it provides highly dense point cloud data with three dimensional position, intensities and ranges from the sensor to target. In this paper, we focus on how to segment point cloud data from a Lidar on a vehicle and classify objects on the road for the highly precise map. In particular, we propose the combination with a feature descriptor and a classification algorithm in machine learning. Objects can be distinguish by geometrical features based on a surface normal of each point. To achieve correct classification using limited point cloud data sets, a Support Vector Machine algorithm in machine learning are used. Final step is to evaluate accuracies of obtained results by comparing them to reference data The results show sufficient accuracy and it will be utilized to generate a highly precise road map.

  4. High Sensitive Precise 3D Accelerometer for Solar System Exploration with Unmanned Spacecrafts

    NASA Astrophysics Data System (ADS)

    Savenko, Y. V.; Demyanenko, P. O.; Zinkovskiy, Y. F.

    Solutions of several space and geophysical tasks require creating high sensitive precise accelerometers with sensitivity in order of 10 -13 g. These several tasks are following: inertial navigation of the Earth and Space; gravimetry nearby the Earth and into Space; geology; geophysics; seismology etc. Accelerometers (gravimeters and gradientmeters) with required sensitivity are not available now. The best accelerometers in the world have sensitivity worth on 4-5 orders. It has been developed a new class of fiber-optical sensors (FOS) with light pulse modulation. These sensors have super high threshold sensitivity and wide (up to 10 orders) dynamic range, and can be used as a base for creating of measurement units of physical values as 3D superhigh sensitive precise accelerometers of linear accelerations that is suitable for highest requirements. The principle of operation of the FOS is organically combined with a digital signal processing. It allows decreasing hardware of the accelerometer due to using a usual air-borne or space-borne computer; correcting the influence of natural, design, technological drawbacks of FOS on measured results; neutralising the influence of extraordinary situations available during using of FOS; decreasing the influence of internal and external destabilising factors (as for FOS), such as oscillation of environment temperature, instability of pendulum cycle frequency of sensitive element of the accelerometer etc. We were conducted a quantitative estimation of precise opportunities of analogue FOS in structure of fiber optical measuring devices (FOMD) for elementary FOMD with analogue FOS built on modern element basis of fiber optics (FO), at following assumptions: absolute parameter stability of devices of FOS measuring path; single transmission band of registration path; maximum possible inserted in optical fiber (OF) a radiated power. Even at such idealized assumptions, a calculated value in limit reached minimum inaccuracy of

  5. High-Precision Measurement of Surface Wave Phase and Amplitude Across a Dense Seismic Array

    NASA Astrophysics Data System (ADS)

    Jin, G.; Gaherty, J. B.

    2010-12-01

    The accurate characterization of seismic surface wavefields across an array of seismic stations provides exceptional constraints on crustal and mantle shear velocities and anisotropic fabric directly beneath the array. By taking advantage of the similarity of the surface wavefield at nearby seismic stations, we have developed a new technique to automatically estimate the relative phase and amplitude of the wavefield with greater precision than in standard methodologies. We calculate the multi-channel cross-correlation of broadband (20-200 s) Rayleigh waveforms between the nearby stations. We then narrow-band filter the interstation correlation functions, and fit the filtered correlation waveforms with a five-parameter controlled wavelet to obtain frequency-dependent phase delay and amplitude variations between multiple station pairs. We reduce the manual interaction so that the measurement can be done more objectively and efficiently, establishing a set of standards to automatically evaluate each measurement and select the most robust ones. Because the correlation function is periodic, the phase delay measurement can cycle skip by one or more integral periods. We address this problem by evaluating each observations using three independent grades, based on the magnitude of the delay time relative to that predicted for a reference model, the continuity of the dispersion curve, and and the agreement between measurements taken at nearby stations, respectively. The weight between these grades is adjusted to get the most coherent set of delay times across the array. We applied this technique to surface waves recorded across EarthScope’s Transportable Array (TA) in 2006 and 2007. These data provide excellent coverage of the upper mantle beneath and along the San Andreas fault in California. The highly localized, precise interstation delay times evalulated at a variety of source-receiver azimuths provide a unique new constraint on upper-mantle anisotropy associated with

  6. Effective theory for the nonrigid rotor in an electromagnetic field: Toward accurate and precise calculations of E2 transitions in deformed nuclei

    DOE PAGESBeta

    Coello Pérez, Eduardo A.; Papenbrock, Thomas F.

    2015-07-27

    In this paper, we present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant nonminimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoreticalmore » uncertainties at leading order. To probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading-order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. In addition, we study the faint interband transitions within the effective theory and focus on the E2 transitions from the 02+ band (the “β band”) to the ground-state band. Here the predictions from the effective theory are consistent with data for several nuclei, thereby proposing a solution to a long-standing challenge.« less

  7. Effective theory for the nonrigid rotor in an electromagnetic field: Toward accurate and precise calculations of E2 transitions in deformed nuclei

    SciTech Connect

    Coello Pérez, Eduardo A.; Papenbrock, Thomas F.

    2015-07-27

    In this paper, we present a model-independent approach to electric quadrupole transitions of deformed nuclei. Based on an effective theory for axially symmetric systems, the leading interactions with electromagnetic fields enter as minimal couplings to gauge potentials, while subleading corrections employ gauge-invariant nonminimal couplings. This approach yields transition operators that are consistent with the Hamiltonian, and the power counting of the effective theory provides us with theoretical uncertainty estimates. We successfully test the effective theory in homonuclear molecules that exhibit a large separation of scales. For ground-state band transitions of rotational nuclei, the effective theory describes data well within theoretical uncertainties at leading order. To probe the theory at subleading order, data with higher precision would be valuable. For transitional nuclei, next-to-leading-order calculations and the high-precision data are consistent within the theoretical uncertainty estimates. In addition, we study the faint interband transitions within the effective theory and focus on the E2 transitions from the 02+ band (the “β band”) to the ground-state band. Here the predictions from the effective theory are consistent with data for several nuclei, thereby proposing a solution to a long-standing challenge.

  8. High-precision three-dimensional coordinate measurement with subwavelength-aperture-fiber point diffraction interferometer

    NASA Astrophysics Data System (ADS)

    Wang, Daodang; Xu, Yangbo; Chen, Xixi; Wang, Fumin; Kong, Ming; Zhao, Jun

    2014-11-01

    To overcome the accuracy limitation due to the machining error of standard parts in measurement system, a threedimensional coordinate measurement method with subwavelength-aperture-fiber point diffraction interferometer (PDI) is proposed, in which the high-precision measurement standard is obtained from the ideal point-diffracted spherical wavefront instead of standard components. On the basis of the phase distribution demodulated from point-diffraction interference field, high-precision three-dimensional coordinate measurement is realized with numerical iteration optimization algorithm. The subwavelength-aperture fiber is used as point-diffraction source to get precise and highenergy spherical wavefront within high aperture angle range, by which the conflict between diffraction wave angle and energy in traditional PDI can be avoided. Besides, a double-iterative method based on Levenbery-Marquardt algorithm is proposed to realize precise reconstruct three-dimensional coordinate. The analysis shows that the proposed method can reach the measurement precision better than microns within a 200×200×300 (in unit of mm) working volume. This measurement method does not rely on the initial iteration value in numerical coordinate reconstruction, and also has high measurement precision, large measuring range, fast processing speed and preferable anti-noise ability. It is of great practicality for measurement of three-dimensional coordinate and calibration of measurement system.

  9. High-precision B (E2) measurements of semi-magic Ni58,60,62,64 by Coulomb excitation

    NASA Astrophysics Data System (ADS)

    Allmond, J. M.; Brown, B. A.; Stuchbery, A. E.; Galindo-Uribarri, A.; Padilla-Rodal, E.; Radford, D. C.; Batchelder, J. C.; Howard, M. E.; Liang, J. F.; Manning, B.; Varner, R. L.; Yu, C.-H.

    2014-09-01

    High-precision reduced electric-quadrupole transition probabilities B (E2;01+→21+) have been measured from single-step Coulomb excitation of semi-magic Ni58,60,62,64 (Z=28) beams at 1.8 MeV per nucleon on a natural carbon target. The energy loss of the nickel beams through the carbon target were directly measured with a zero-degree Bragg detector and the absolute B (E2) values were normalized by Rutherford scattering. The B (E2) values disagree with recent lifetime studies that employed the Doppler-shift attenuation method. The present high-precision B (E2) values reveal an asymmetry about Ni62, midshell between N =28 and 40, with larger values towards Ni56 (Z =N=28). The experimental B (E2) values are compared with shell-model calculations in the full pf model space and the results indicate a soft Ni56 core.

  10. A High-Precision, Optical Polarimeter to Measure Inclinations of High Mass X-Ray Binaries

    NASA Astrophysics Data System (ADS)

    Wiktorowicz, Sloane; Matthews, K.; Kulkarni, S. R.

    2007-12-01

    While most astrophysical objects require many parameters in order to be fully described, black holes are unique in that only three parameters are required: mass, spin, and charge. Of these, mass and spin are enough to describe the black hole's gravitational field and event horizon location. Therefore, theory and observation may jointly pursue one or two quantities to uncover the progenitor star's history. Constraints on black hole mass exist for high mass X-ray binaries, such as Cygnus X-1, which is thought to consist of a 40 ± 10 solar mass O9.7Iab star and a 13.5-29 solar mass black hole (Ziolkowski 2005). While the constraints on the mass of the compact object are tight enough to declare that it is a black hole, they are sufficiently loose as to prohibit precise modeling of the progenitor star's mass. We have built an optical polarimeter for the Hale 5-m telescope at Mt. Palomar to provide an independent method for determining black hole mass. Degree of polarization will vary for an edge-on system, while position angle of net polarization will vary for a face-on system. Therefore, by monitoring the linear polarimetric variability of the binary, inclination can be estimated. Coupled with the known mass function of the binary from radial velocity work (Gies et al. 2003), inclination estimates constrain the mass of the black hole. Our polarimeter, POLISH (POLarimeter for Inclination Studies of High mass x-ray binaries), has achieved linear polarimetric precision of less than 10 parts per million on bright, unpolarized standard stars. We will also present results for polarized standard stars and Cygnus X-1 itself. This instrument has been funded by an endowment from the Moore Foundation.

  11. Precision Spectroscopy on Highly-Excited Vibrational Levels of H_2

    NASA Astrophysics Data System (ADS)

    Niu, Ming Li; Salumbides, Edcel John; Ubachs, Wim

    2015-06-01

    The ground electronic energy levels of H_2 have been used as a benchmark system for the most precise comparisons between ab initio calculations and experimental investigations. Recent examples include the determinations of the ionization energy [1], fundamental vibrational energy splitting [2], and rotational energy progression extending to J=16 [3]. In general, the experimental and theoretical values are in excellent agreement with each other. The energy calculations, however, reduce in accuracy with the increase in rotational and vibrational excitation, limited by the accuracy of non-Born Oppenheimer corrections, as well as the higher-order QED effects. While on the experimental side, it remains difficult to sufficiently populate these excited levels in the ground electronic state. We present here our high-resolution spectroscopic study on the X ^1σ^+_g electronic ground state levels with very high vibrational quanta (ν=10,11,12). Vibrationally-excited H_2 are produced from the photodissociation of H_2S [4], and subsequently probed by a narrowband pulsed dye laser system. The experimental results are consistent with and more accurate than the best theoretical values [5]. These vibrationally-excited level energies are also of interest to studies that extract constraints on the possible new interactions that extend beyond the Standard Model [6]. [1] J. Liu et al., J. Chem. Phys. 130, 174306 (2009). [2] G. Dickenson et al., Phys. Rev. Lett. 110, 193601 (2013). [3] E.J. Salumbides et al., Phys. Rev. Lett. 107, 143005 (2011). [4] J. Steadman and T. Baer, J. Chem. Phys. 91, 6113 (1989). [5] J. Komasa et al., J. Chem. Theory Comp. 7, 3105 (2011). [6] E.J. Salumbides et al., Phys. Rev. D 87, 112008 (2013).

  12. Machine Vision for High Precision Volume Measurement Applied to Levitated Containerless Materials Processing

    NASA Technical Reports Server (NTRS)

    Bradshaw, R. C.; Schmidt, D. P.; Rogers, J. R.; Kelton, K. F.; Hyers, R. W.

    2005-01-01

    By combining the best practices in optical dilatometry with new numerical methods, a high-speed and high precision technique has been developed to measure volume of levitated, containerlessly processed samples with sub- pixel resolution. Containerless processing provides the ability to study highly reactive materials without the possibility of contamination affecting thermo-physical properties. Levitation is a common technique used to isolate a sample as it is being processed. Noncontact optical measurement of thermo-ophysical properties is very important as traditional measuring methods cannot be used. Modern, digitally recorded images require advanced numerical routines to recover the sub-pixel locations of sample edges and, in turn produce high precision measurements.

  13. Use of Terrestrial Laser Scanning Technology for Long Term High Precision Deformation Monitoring

    PubMed Central

    Vezočnik, Rok; Ambrožič, Tomaž; Sterle, Oskar; Bilban, Gregor; Pfeifer, Norbert; Stopar, Bojan

    2009-01-01

    The paper presents a new methodology for high precision monitoring of deformations with a long term perspective using terrestrial laser scanning technology. In order to solve the problem of a stable reference system and to assure the high quality of possible position changes of point clouds, scanning is integrated with two complementary surveying techniques, i.e., high quality static GNSS positioning and precise tacheometry. The case study object where the proposed methodology was tested is a high pressure underground pipeline situated in an area which is geologically unstable. PMID:22303152

  14. High-precision measurements of π p elastic differential cross sections in the second resonance region

    NASA Astrophysics Data System (ADS)

    Alekseev, I. G.; Andreev, V. A.; Bordyuzhin, I. G.; Briscoe, W. J.; Filimonov, Ye. A.; Golubev, V. V.; Gridnev, A. B.; Kalinkin, D. V.; Koroleva, L. I.; Kozlenko, N. G.; Kozlov, V. S.; Krivshich, A. G.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Sadler, M.; Shurygin, B. M.; Strakovsky, I. I.; Sulimov, A. D.; Sumachev, V. V.; Svirida, D. N.; Tarakanov, V. I.; Trautman, V. Yu.; Workman, R. L.; Epecur Collaboration; Gw Ins Data Analysis Center

    2015-02-01

    Cross sections for π±p elastic scattering have been measured to high precision by the EPECUR Collaboration for beam momenta between 800 and 1240 MeV/c using the ITEP proton synchrotron. The data precision allows comparisons of the existing partial-wave analyses on a level not possible previously. These comparisons imply that over the covered energy range, the Carnegie-Mellon-Berkeley analysis is significantly more predictive when compared to versions of the Karlsruhe-Helsinki analyses.

  15. Precise calculations of the influence of HF EM forces on the melt hydrodynamics for FZ silicon single crystal growth

    NASA Astrophysics Data System (ADS)

    Dadzis, K.; Muiznieks, A.; Rudevics, A.; Ratnieks, G.

    2005-06-01

    During the floating zone silicon single crystal growth by the needle-eye technique, the melting of the polycrystalline feed rod is ensured by a high-frequency inductor. It gives rise to electromagnetic (EM) forces in the skin layer at the free surface of the molten zone, which may influence the melt flow very distinctly. In the present paper two approaches to the numerical modelling of the EM forces in the case of a very distinct skin-effect are compared and applied to hydrodynamic calculations for a specific 2'' floating zone growth system. Figs 22, Refs 3.

  16. Telluric Line Effect on High Precision Radial Velocity Survey of K and M Dwarfs

    NASA Astrophysics Data System (ADS)

    Sithajan, Sirinrat; Ge, Jian; Wang, Ji

    2016-01-01

    The red and NIR region, where K and M dwarfs emit most of light, is the desirable region for radial velocity (RV) measurements for detecting low mass planets, but this wavelength region is heavily contaminated with telluric absorption lines. Variation in the telluric line depths and centroids can result in large RV measurement uncertainties, limiting the sensitivity to detect low mass planets. Here we use simulations to study effect of telluric removal and the residuals on RV measurements and determine the level of correction needed to minimize the effect. Simulated spectra from three representative spectrographs with spectral resolutions, R=60K, 80K, 100K and 120K for wavelength coverage at 0.38-0.62 μm (called the optical spectrograph), 0.38-0.90 μm (called the broad optical spectrograph) and 0.90-2.4 μm (called the NIR spectrograph), have been studied. Two methods are used to study the RV effect by the telluric lines. The first one is a 'Masking' method, in which the telluric lines are identified and removed from RV calculation. The other method is a 'Removal' method, in which all heavily saturated lines are masked out and the remaining lines are subtracted by synthetic atmospheric spectra to a desired level. Our results show that, in case of late M dwarfs, the broad optical spectrograph can gain additional RV sensitivity over the optical spectrograph if telluric lines can be modeled and subtracted to better than 10%, or all lines deeper than 5% are masked out from RV calculation. For the earlier type stars, it requires better than 2% modeling and subtracting precision with the broad optical spectrograph to gain additional Doppler sensitivity over the optical spectrograph. Besides the photon gain with the NIR spectrograph over the optical spectrograph for late M dwarf observations, the NIR can gain additional advantage of Doppler sensitivity over the optical tool for late M dwarfs when telluric residuals can be subtracted to below 1%. However, it is never

  17. A Simple, High-Precision, High-Sensitivity Tracer Assay for N(inf2) Fixation

    PubMed Central

    Montoya, J. P.; Voss, M.; Kahler, P.; Capone, D. G.

    1996-01-01

    We describe a simple, precise, and sensitive experimental protocol for direct measurement of N(inf2) fixation using the conversion of (sup15)N(inf2) to organic N. Our protocol greatly reduces the limit of detection for N(inf2) fixation by taking advantage of the high sensitivity of a modern, multiple-collector isotope ratio mass spectrometer. This instrument allowed measurement of N(inf2) fixation by natural assemblages of plankton in incubations lasting several hours in the presence of relatively low-level (ca. 10 atom%) tracer additions of (sup15)N(inf2) to the ambient pool of N(inf2). The sensitivity and precision of this tracer method are comparable to or better than those associated with the C(inf2)H(inf2) reduction assay. Data obtained in a series of experiments in the Gotland Basin of the Baltic Sea showed excellent agreement between (sup15)N(inf2) tracer and C(inf2)H(inf2) reduction measurements, with the largest discrepancies between the methods occurring at very low fixation rates. The ratio of C(inf2)H(inf2) reduced to N(inf2) fixed was 4.68 (plusmn) 0.11 (mean (plusmn) standard error, n = 39). In these experiments, the rate of C(inf2)H(inf2) reduction was relatively insensitive to assay volume. Our results, the first for planktonic diazotroph populations of the Baltic, confirm the validity of the C(inf2)H(inf2) reduction method as a quantitative measure of N(inf2) fixation in this system. Our (sup15)N(inf2) protocols are comparable to standard C(inf2)H(inf2) reduction procedures, which should promote use of direct (sup15)N(inf2) fixation measurements in other systems. PMID:16535283

  18. Flexible, non-contact and high-precision measurements of optical components

    NASA Astrophysics Data System (ADS)

    Beutler, A.

    2016-06-01

    A high-accuracy cylindrical coordinate measuring instrument developed for the measurement of optical components is presented. It is equipped with an optical point sensor system including a high aperture probe. This setup allows measurements to be performed with high accuracy in a flexible way. Applications include the measurement of the topography of high-precision aspheric and freeform lenses and diffractive structures. High measuring speeds guarantee the implementation in a closed-loop production process.

  19. Design of a double Penning-trap mass spectrometer for high-precision mass measurements

    NASA Astrophysics Data System (ADS)

    Ratnayake, Ishara; Bryce, Richard; Hawks, Paul; Hunt, Curtis; Redshaw, Matthew

    2014-05-01

    The mass of an atom plays an important role in various fields throughout science. As such, there is a need for precise mass determinations on a wide range of isotopes. At Central Michigan University we are developing a Penning trap to focus on ultra-high precision measurements of long-lived radioactive isotopes and isotopes that have low natural abundances. The Penning trap we are constructing will consist of a double precision measurement trap structure for simultaneous cyclotron frequency comparisons to eliminate the effect of magnetic field fluctuations. An additional, cylindrical Penning trap will be used to capture ions from external ion sources, eliminate contaminant ions and transfer the ions of interest to the precision traps. In this poster we will present the design of the Penning trap system, and report on the current status of the project. This work supported in part by NSF award no. 1307233.

  20. Methods for high precision 14C AMS measurement of atmospheric CO2 at LLNL

    SciTech Connect

    Graven, H D; Guilderson, T P; Keeling, R F

    2006-10-18

    Development of {sup 14}C analysis with precision better than 2{per_thousand} has the potential to expand the utility of {sup 14}CO{sub 2} measurements for carbon cycle investigations as atmospheric gradients currently approach traditional measurement precision of 2-5{per_thousand}. The AMS facility at the Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, produces high and stable beam currents that enable efficient acquisition times for large numbers of {sup 14}C counts. One million {sup 14}C atoms can be detected in approximately 25 minutes, suggesting that near 1{per_thousand} counting precision is economically feasible at LLNL. The overall uncertainty in measured values is ultimately determined by the variation between measured ratios in several sputtering periods of the same sample and by the reproducibility of replicate samples. Experiments on the collection of one million counts on replicate samples of CO{sub 2} extracted from a whole air cylinder show a standard deviation of 1.7{per_thousand} in 36 samples measured over several wheels. This precision may be limited by the reproducibility of Oxalic Acid I standard samples, which is considerably poorer. We outline the procedures for high-precision sample handling and analysis that have enabled reproducibility in the cylinder extraction samples at the <2{per_thousand} level and describe future directions to continue increasing measurement precision at LLNL.

  1. A high precision apparatus for intracellular thermal response at single-cell level

    NASA Astrophysics Data System (ADS)

    Tian, Wenjuan; Wang, Cangling; Wang, Jianqing; Chen, Qiuhua; Sun, Jianfei; Li, Can; Wang, Xing; Gu, Ning

    2015-09-01

    In this work, a nanoprobe that is highly thermo-sensitive to tiny temperature changes was prepared based on a thermocouple metal junction. A series of electro-element apparatuses were integrated to accomplish single-cell temperature measurement. The temperature measurement probe (TMP) was constructed by tungsten (W), polyurethane (PU), and platinum (Pt). The tip size of TMP was characterized at less than 500 nm, and the tip angle was between 10 and 20° with the resistance in the range of 500 to 1500 Ω. The single-cell temperature measurement probes were calibrated and calculated with a Seebeck coefficient ranging from 6 to 8 μV °C-1 at a precision of 0.1 °C. Monitoring the temperature at a single-cell level by inserting the TMP in marine lung epithelia (MLE)-12 cells displayed that the stimulation of lipopolysaccharide (LPS) and cobalt chloride induced different single-cell temperature fluctuation. This investigation could help reveal complex cellular functions and develop novel diagnoses.

  2. A high precision apparatus for intracellular thermal response at single-cell level.

    PubMed

    Tian, Wenjuan; Wang, Cangling; Wang, Jianqing; Chen, Qiuhua; Sun, Jianfei; Li, Can; Wang, Xing; Gu, Ning

    2015-09-01

    In this work, a nanoprobe that is highly thermo-sensitive to tiny temperature changes was prepared based on a thermocouple metal junction. A series of electro-element apparatuses were integrated to accomplish single-cell temperature measurement. The temperature measurement probe (TMP) was constructed by tungsten (W), polyurethane (PU), and platinum (Pt). The tip size of TMP was characterized at less than 500 nm, and the tip angle was between 10 and 20° with the resistance in the range of 500 to 1500 Ω. The single-cell temperature measurement probes were calibrated and calculated with a Seebeck coefficient ranging from 6 to 8 μV °C(-1) at a precision of 0.1 °C. Monitoring the temperature at a single-cell level by inserting the TMP in marine lung epithelia (MLE)-12 cells displayed that the stimulation of lipopolysaccharide (LPS) and cobalt chloride induced different single-cell temperature fluctuation. This investigation could help reveal complex cellular functions and develop novel diagnoses. PMID:26267315

  3. HIGH-PRECISION MACLAURIN-BASED MODELS OF ROTATING LIQUID PLANETS

    SciTech Connect

    Hubbard, W. B.

    2012-09-01

    We present an efficient numerical self-consistent field method for calculating a gravitational model of a rotating liquid planet to spherical harmonic degree {approx}30 and a precision {approx}10{sup -12} in the external gravity field. The method's accuracy is validated by comparing results, for Jupiter rotation parameters, with the exact Maclaurin constant-density solution. The method can be generalized to non-constant density.

  4. Introducing SummerTime: A package for high-precision computation of sums appearing in DRA1 method

    NASA Astrophysics Data System (ADS)

    Lee, Roman N.; Mingulov, Kirill T.

    2016-06-01

    We present the Mathematica  package SummerTime  for arbitrary-precision computation of sums appearing in the results of DRA method (Lee, 2010). So far these results include the following families of the integrals: 3-loop onshell massless vertices, 3-loop onshell mass operator type integrals, 4-loop QED-type tadpoles, 4-loop massless propagators (Lee et al., 2010; Lee and Smirnov, 2011; Lee et al., 2011, 2012). The package can be used for high-precision numerical computation of the expansion of the integrals from the above families around arbitrary space-time dimension. In addition, this package contains convenient tools for the calculation of multiple zeta values, harmonic polylogarithms and other transcendental numbers expressed in terms of nested sums with factorized summand.

  5. Precision of FLEET Velocimetry Using High-speed CMOS Camera Systems

    NASA Technical Reports Server (NTRS)

    Peters, Christopher J.; Danehy, Paul M.; Bathel, Brett F.; Jiang, Naibo; Calvert, Nathan D.; Miles, Richard B.

    2015-01-01

    Femtosecond laser electronic excitation tagging (FLEET) is an optical measurement technique that permits quantitative velocimetry of unseeded air or nitrogen using a single laser and a single camera. In this paper, we seek to determine the fundamental precision of the FLEET technique using high-speed complementary metal-oxide semiconductor (CMOS) cameras. Also, we compare the performance of several different high-speed CMOS camera systems for acquiring FLEET velocimetry data in air and nitrogen free-jet flows. The precision was defined as the standard deviation of a set of several hundred single-shot velocity measurements. Methods of enhancing the precision of the measurement were explored such as digital binning (similar in concept to on-sensor binning, but done in post-processing), row-wise digital binning of the signal in adjacent pixels and increasing the time delay between successive exposures. These techniques generally improved precision; however, binning provided the greatest improvement to the un-intensified camera systems which had low signal-to-noise ratio. When binning row-wise by 8 pixels (about the thickness of the tagged region) and using an inter-frame delay of 65 micro sec, precisions of 0.5 m/s in air and 0.2 m/s in nitrogen were achieved. The camera comparison included a pco.dimax HD, a LaVision Imager scientific CMOS (sCMOS) and a Photron FASTCAM SA-X2, along with a two-stage LaVision High Speed IRO intensifier. Excluding the LaVision Imager sCMOS, the cameras were tested with and without intensification and with both short and long inter-frame delays. Use of intensification and longer inter-frame delay generally improved precision. Overall, the Photron FASTCAM SA-X2 exhibited the best performance in terms of greatest precision and highest signal-to-noise ratio primarily because it had the largest pixels.

  6. Precision of FLEET Velocimetry Using High-Speed CMOS Camera Systems

    NASA Technical Reports Server (NTRS)

    Peters, Christopher J.; Danehy, Paul M.; Bathel, Brett F.; Jiang, Naibo; Calvert, Nathan D.; Miles, Richard B.

    2015-01-01

    Femtosecond laser electronic excitation tagging (FLEET) is an optical measurement technique that permits quantitative velocimetry of unseeded air or nitrogen using a single laser and a single camera. In this paper, we seek to determine the fundamental precision of the FLEET technique using high-speed complementary metal-oxide semiconductor (CMOS) cameras. Also, we compare the performance of several different high-speed CMOS camera systems for acquiring FLEET velocimetry data in air and nitrogen free-jet flows. The precision was defined as the standard deviation of a set of several hundred single-shot velocity measurements. Methods of enhancing the precision of the measurement were explored such as digital binning (similar in concept to on-sensor binning, but done in post-processing), row-wise digital binning of the signal in adjacent pixels and increasing the time delay between successive exposures. These techniques generally improved precision; however, binning provided the greatest improvement to the un-intensified camera systems which had low signal-to-noise ratio. When binning row-wise by 8 pixels (about the thickness of the tagged region) and using an inter-frame delay of 65 microseconds, precisions of 0.5 meters per second in air and 0.2 meters per second in nitrogen were achieved. The camera comparison included a pco.dimax HD, a LaVision Imager scientific CMOS (sCMOS) and a Photron FASTCAM SA-X2, along with a two-stage LaVision HighSpeed IRO intensifier. Excluding the LaVision Imager sCMOS, the cameras were tested with and without intensification and with both short and long inter-frame delays. Use of intensification and longer inter-frame delay generally improved precision. Overall, the Photron FASTCAM SA-X2 exhibited the best performance in terms of greatest precision and highest signal-to-noise ratio primarily because it had the largest pixels.

  7. Research on high precision centering assembly method of roll edge optical elements

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Liu, Xiaomei

    2015-08-01

    In order to improve the imaging quality of target imaging optical system, in the special environment of large temperature difference, the centering assembly precision of roll edge optical elements was studied. According to the hole-axis coordinate error theory of mechanics, by analyzing the factors affected the precision of mechanical heating surface, combining with the existing method to eliminate error and centering assembly process, a new kind of high precision centering assembly method was put forward. Using additional grinding device to grinding roll edge of optical element, eliminate the machining error on the surface of the mechanical hot working, thus improve the centering assembly precision between the roll edge optical element and lens tube. The result of experiment shows that the centering precision can reach less than 3μm when assembled optical element after roll edge using new centering assembly method, and improved by 25% compared to the traditional method of roll edge optical elements are assembled directly after hot working. New assembly method with additional grinding device can improve the centering assembly precision of roll edge optical elements, and greatly reduce the difficulty of optical design of such optical imaging system using in large temperature difference environment, when meet the same image quality.

  8. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi

    2013-11-01

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 {+-} 0.0007 fm was extracted which is 7{sigma} smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these "electronic" determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup -4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  9. Fabrication and Assembly of High-Precision Hinge and Latch Joints for Deployable Optical Instruments

    NASA Technical Reports Server (NTRS)

    Phelps, James E.

    1999-01-01

    Descriptions are presented of high-precision hinge and latch joints that have been co-developed, for application to deployable optical instruments, by NASA Langley Research Center and Nyma/ADF. Page-sized versions of engineering drawings are included in two appendices to describe all mechanical components of both joints. Procedures for assembling the mechanical components of both joints are also presented. The information herein is intended to facilitate the fabrication and assembly of the high-precision hinge and latch joints, and enable the incorporation of these joints into the design of deployable optical instrument systems.

  10. Towards high precision measurements of nuclear g-factors for the Be isotopes

    NASA Astrophysics Data System (ADS)

    Takamine, A.; Wada, M.; Okada, K.; Ito, Y.; Schury, P.; Arai, F.; Katayama, I.; Imamura, K.; Ichikawa, Y.; Ueno, H.; Wollnik, H.; Schuessler, H. A.

    2016-06-01

    We describe the present status of future high-precision measurements of nuclear g-factors utilizing laser-microwave double and laser-microwave-rf triple resonance methods for online-trapped, laser-cooled radioactive beryllium isotope ions. These methods have applicability to other suitably chosen isotopes and for beryllium show promise in deducing the hyperfine anomaly of 11Be with a sufficiently high precision to study the nuclear magnetization distribution of this one-neutron halo nucleus in a nuclear-model-independent manner.

  11. A high precision attitude determination and control system for the UYS-1 nanosatellite

    NASA Astrophysics Data System (ADS)

    Chaurais, J. R.; Ferreira, H. C.; Ishihara, J. Y.; Borges, R. A.; Kulabukhov, A. M.; Larin, V. A.; Belikov, V. V.

    This paper presents the design of a high precision attitude determination and control system for the UYS-1 Ukrainian nanosatellite. Its main task is the 3-axis stabilization with less than 0.5° angle errors, so the satellite may take high precision photos of Earth's surface. To accomplish this task, this system comprises a star tracker and three reaction wheels. To avoid external disturbances and actuators faults, a PD-type and a PID-type robust controllers are simulated and the results are compared to an empirically adjusted PD controller.

  12. High-Precision U-Pb Geochronology of Ice River Perovskite: A Possible Interlaboratory and Intertechnique EARTHTIME Standard

    NASA Astrophysics Data System (ADS)

    Burgess, S. D.; Bowring, S. A.; Heaman, L. M.

    2012-12-01

    Accurate and precise U-Pb geochronology of accessory phases other than zircon are required for dating some LIP basalts or determining the temporal patterns of kimberlite pipes, for example. Advances in precision and accuracy lead directly to an increase in the complexity of questions that can be posed. U-Pb geochronology of perovskite (CaTiO3) has been applied to silica-undersaturated basalts, carbonatites, alkaline igneous rocks, and kimberlites. Most published IDTIMS perovskite dates have 2-sigma precisions at the ~0.2% level for weighted mean 206Pb/238U dates, much less than possible with IDTIMS analyses of zircons, which limits the applicability of perovskite in high-precision applications. Precision on perovskite dates is lower than zircon because of common Pb, which in some cases can be up to 50% of the total Pb and must be corrected for and accurately partitioned between blank and initial. Relatively small changes in the composition of common Pb can result in inaccurate but precise dates. In many cases minerals with significant common Pb are corrected using Stacey and Kramers (1975) two stage Pb evolution model. This can be done without serious consequence to the final date for minerals with high U/Pb ratios. In the more common case where U/Pb ratios are relatively low and the proportion of common Pb is large, applying a model-derived Pb isotopic composition rather than measuring it directly can introduce percent-level inaccuracy to dates calculated with precisely known U/Pb ratios. Direct measurement of the common Pb composition can be done on a U-poor mineral that co-crystallized with perovskite; feldspar and clinopyroxene are commonly used. Clinopyroxene can contain significant in-grown radiogenic Pb and our experiments indicate that it is not eliminated by aggressive step-wise leaching. The U/Pb ratio in clinopyroxene is generally low (20 < mu < 50) but significant. Other workers (e.g. Kamo et al., 2003; Corfu and Dahlgren, 2008), have used two methods

  13. Capability study for ozone high-precision retrieval with JEM/SMILES

    NASA Astrophysics Data System (ADS)

    Takahashi, Chikako; Suzuki, Makoto; Ochiai, Satoshi; Takayanagi, Masahiro

    One of the most unique characteristics of JEM/SMILES observation is its high sensitivity (500K system noise by employing 4K cooled SIS mixer) in detecting atmospheric limb emission in the submillimeter wave range, which are band A (624.3-625.5 GHz), band B (625.1-626.3 GHz), and band C (649.1-650.3 GHz). It observes limb emission from atmospheric minor constituents in the stratosphere, such as O3 , ClO, HCl, HNO3 , HOCl, CH3 CN, HO2 , BrO, O3 isotopes etc. The JEM/SMILES mission is mainly devoted to studying precise halogen chemistry related to ozone destruction. Spatial coverage is near global, that is the nominal latitude coverage is 38S - 65N owing to tilting the antenna beam to 45 degree left from the direction of orbital motion. It is highly expected that SMILES observation path encounters the atmosphere in the elongated polar voltex toward lower latitude in the northern hemisphere. The sensitivity of SMILES can be utilized for its unique observations, one is the detection of trace species which has never been observed in acceptable precision, and the other is high precision observation of major species such as O3 and HCl. This paper discusses how the ozone high-precision retrieval with the JEM/SMILES can be achieved based on the operational retrieval algorithm. The JEM/SMILES observes ozone absorption line at 625.37GHz in lower observation bands, band A and band B. As the JEM/SMILES is a high sensitive sensor, the high-precision retrieval is expected, the minimum precision of retrieved ozone height profile is 0.5% at about 30km under ideal condition, which is better than existing similar sensors, such as Aura/MLS and Odin/SMR. It is also discussed height resolutions (3.5-4.1 km nominally determined by the instrument) as trade off with precision. Thus these two factors should be decided by a kind of trade-off considering scientific requirements. The information content is used to optimize these factors and we clarify the precision, the height resolution, and

  14. Remote and high precision step height measurement with an optical fiber multiplexing interferometric system

    NASA Astrophysics Data System (ADS)

    Wang, Yunzhi; Xie, Fang; Ma, Sen; Chen, Liang

    2015-03-01

    An optical fiber multiplexing low coherence and high coherence interferometric system, which includes a Fizeau interferometer as the sensing element and a Michelson interferometer as the demodulating element, is designed for remote and high precision step height measurement. The Fizeau interferometer is placed in the remote field for sensing the measurand, while the Michelson interferometer which works in both modes of low coherence interferometry and high coherence interferometry is employed for demodulating the measurand. The range of the step height is determined by the low coherence interferometry and the value of it is measured precisely by the high coherence interferometry. High precision has been obtained by searching precisely the peak of the low coherence interferogram symmetrically from two sides of the low coherence interferogram and stabilizing the Michelson interferometer with a feedback loop. The maximum step height that could be measured is 6 mm while the measurement resolution is less than 1 nm. The standard deviation of 10 times measurement results of a step height of 1 mm configurated with two gauge blocks is 0.5 nm.

  15. Application of high-precision two-way ranging to Galileo Earth-1 encounter navigation

    NASA Technical Reports Server (NTRS)

    Pollmeier, V. M.; Thurman, S. W.

    1992-01-01

    The application of precision two-way ranging to orbit determination with relatively short data arcs is investigated for the Galileo spacecraft's approach to its first Earth encounter (December 8, 1990). Analysis of previous S-band (2.3-GHz) ranging data acquired from Galileo indicated that under good signal conditions submeter precision and 10-m ranging accuracy were achieved. It is shown that ranging data of sufficient accuracy, when acquired from multiple stations, can sense the geocentric angular position of a distant spacecraft. A range data filtering technique, in which explicit modeling of range measurement bias parameters for each station pass is utilized, is shown to largely remove the systematic ground system calibration errors and transmission media effects from the Galileo range measurements, which would otherwise corrupt the angle-finding capabilities of the data. The accuracy of the Galileo orbit solutions obtained with S-band Doppler and precision ranging were found to be consistent with simple theoretical calculations, which predicted that angular accuracies of 0.26-0.34 microrad were achievable. In addition, the navigation accuracy achieved with precision ranging was marginally better than that obtained using delta-differenced one-way range (delta DOR), the principal data type that was previously used to obtain spacecraft angular position measurements operationally.

  16. High-precision laser and rf spectroscopy of atomic, molecular, and slow ion beams

    SciTech Connect

    Childs, W.J.; Goodman, L.S.; Sen, A.

    1987-01-01

    Interesting new results were obtained in 1986 in high-precision Laser-rf studies of neutral atoms, neutral molecules, and atomic ions. Because of their novelty, the ionic results are discussed at some length and then summarize briefly results in the other two areas.

  17. High precision elastic α scattering on the even-odd 115In nucleus at low energies

    NASA Astrophysics Data System (ADS)

    Kiss, G. G.; Szücs, T.; Mohr, P.; Fülöp, Zs; Gyürky, Gy; Halász, Z.; Soha, R. F.; Somorjai, E.; Ornelas, A.; Galaviz, D.; Yalçın, C.; Güray, R. T.; Özkan, N.

    2016-01-01

    Elastic alpha scattering cross sections on the even-odd 115In nucleus have been measured at energies Elab. = 16.15 MeV and 19.50 MeV. The high precision experimental data are used to derive the parameters of a local a nucleus optical potential.

  18. An optical fiber multiplexing interferometric system for measuring remote and high precision step height

    NASA Astrophysics Data System (ADS)

    Wang, Yunzhi; Xie, Fang; Ma, Sen; Chen, Liang

    2015-02-01

    In this paper, an optical fiber multiplexing interferometric system including a Fizeau interferometer and a Michelson interferometer is designed for remote and high precision step height measurement. The Fizeau interferometer which is inserted in the remote sensing field is used for sensing the measurand, while the Michelson interferometer which is stabilized by a feedback loop works in both modes of low coherence interferometry and high coherence interferometry to demodulate the measurand. The range of the step height is determined by the low coherence interferometry and the value of it is measured precisely by the high coherence interferometry. High precision has been obtained by using the symmetrical peak-searching method to address the peak of the low coherence interferogram precisely and stabilizing the Michelson interferometer with a feedback loop. The maximum step height that could be measured is 6 mm while the measurement resolution is less than 1 nm. The standard deviation of 10 times measurement results of a step height of 1 mm configurated with two gauge blocks is 0.5 nm.

  19. High-Precise Spectrometry of the Terahertz Frequency Range: The Methods, Approaches and Applications

    NASA Astrophysics Data System (ADS)

    Vaks, Vladimir

    2012-01-01

    In the paper we present a high precise THz technique (frequency synthesizers and spectrometer) and its applications for noninvasive medical diagnostics and security systems. The cornerstone of the presented devices is multipliers and mixers based on quantum superlattice structures. The multipliers based on superlattice structures are shown to be more effective than Schottky diodes and provide THz radiation up to 8.1 THz.

  20. High precision semiautomated computed tomography measurement of lumbar disk and vertebral heights

    PubMed Central

    Tan, Sovira; Yao, Jianhua; Yao, Lawrence; Ward, Michael M.

    2013-01-01

    Purpose: Evaluation of treatments of many spine disorders requires precise measurement of the heights of vertebral bodies and disk spaces. The authors present a semiautomated computer algorithm measuring those heights from spine computed tomography (CT) scans and evaluate its precision. Methods: Eight patients underwent two spine CT scans in the same day. In each scan, five thoracolumbar vertebral heights and four disk heights were estimated using the algorithm. To assess precision, the authors computed the differences between the height measurements in the two scans, coefficients of variation (CV), and 95% limits of agreement. Intraoperator and interoperator precisions were evaluated. For local vertebral and disk height measurement (anterior, middle, posterior) the algorithm was compared to a manual mid-sagittal plane method. Results: The mean (standard deviation) interscan difference was as low as 0.043 (0.031) mm for disk heights and 0.044 (0.043) mm for vertebral heights. The corresponding 95% limits of agreement were [−0.085, 0.11] and [−0.10, 0.12] mm, respectively. Intraoperator and interoperator precision was high, with a maximal CV of 0.30%. For local vertebral and disk heights, the algorithm improved upon the precision of the manual mid-sagittal plane measurement by as much as a factor of 6 and 4, respectively. Conclusions: The authors evaluated the precision of a novel computer algorithm for measuring vertebral body heights and disk heights using short term repeat CT scans of patients. The 95% limits of agreement indicate that the algorithm can detect small height changes of the order of 0.1 mm. PMID:23298096

  1. High-precision spectroscopy of ultracold molecules in an optical lattice

    NASA Astrophysics Data System (ADS)

    McGuyer, B. H.; McDonald, M.; Iwata, G. Z.; Tarallo, M. G.; Grier, A. T.; Apfelbeck, F.; Zelevinsky, T.

    2015-05-01

    The study of ultracold molecules tightly trapped in an optical lattice can expand the frontier of precision measurement and spectroscopy, and provide a deeper insight into molecular and fundamental physics. Here we create, probe, and image microkelvin 88Sr2 molecules in a lattice, and demonstrate precise measurements of molecular parameters as well as coherent control of molecular quantum states using optical fields. We discuss the sensitivity of the system to dimensional effects, a new bound-to-continuum spectroscopy technique for highly accurate binding energy measurements, and prospects for new physics with this rich experimental system.

  2. Generalized lock-in amplifier for precision measurement of high frequency signals

    NASA Astrophysics Data System (ADS)

    Fu, Siyuan; Sakurai, Atsunori; Liu, Liang; Edman, Fredrik; Pullerits, Tõnu; Öwall, Viktor; Karki, Khadga Jung

    2013-11-01

    We herein formulate the concept of a generalized lock-in amplifier for the precision measurement of high frequency signals based on digital cavities. Accurate measurement of signals higher than 200 MHz using the generalized lock-in is demonstrated. The technique is compared with a traditional lock-in and its advantages and limitations are discussed. We also briefly point out how the generalized lock-in can be used for precision measurement of giga-hertz signals by using parallel processing of the digitized signals.

  3. Development and Utilization of High Precision Digital Elevation Data taken by Airborne Laser Scanner

    NASA Astrophysics Data System (ADS)

    Akutsu, Osamu; Ohta, Masataka; Isobe, Tamio; Ando, Hisamitsu, Noguchi, Takahiro; Shimizu, Masayuki

    2005-03-01

    Disasters caused by heavy rain in urban areas bring a damage such as chaos in the road and railway transport systems, power failure, breakdown of the telephone system and submersion of built up areas, subways and underground shopping arcades, etc. It is important to obtain high precision elevation data which shows the detailed landform because a slight height difference affects damages by flood very considerably. Therefore, The Geographical Survey Institute (GSI) is preparing 5m grid digital terrain model (DTM) based on precise ground elevation data taken by using airborne laser scanner. This paper describes the process and an example of the use of a 5m grid digital data set.

  4. Acoustic grating fringe projector for high-speed and high-precision three-dimensional shape measurements

    SciTech Connect

    Yin Xuebing; Zhao Huijie; Zeng Junyu; Qu Yufu

    2007-05-20

    A new acoustic grating fringe projector (AGFP) was developed for high-speed and high-precision 3D measurement. A new acoustic grating fringe projection theory is also proposed to describe the optical system. The AGFP instrument can adjust the spatial phase and period of fringes with unprecedented speed and accuracy. Using rf power proportional-integral-derivative (PID) control and CCD synchronous control, we obtain fringes with fine sinusoidal characteristics and realize high-speed acquisition of image data. Using the device, we obtained a precise phase map for a 3D profile. In addition, the AGFP can work in running fringe mode, which could be applied in other measurement fields.

  5. Status and outlook of CHIP-TRAP: The Central Michigan University high precision Penning trap

    NASA Astrophysics Data System (ADS)

    Redshaw, M.; Bryce, R. A.; Hawks, P.; Gamage, N. D.; Hunt, C.; Kandegedara, R. M. E. B.; Ratnayake, I. S.; Sharp, L.

    2016-06-01

    At Central Michigan University we are developing a high-precision Penning trap mass spectrometer (CHIP-TRAP) that will focus on measurements with long-lived radioactive isotopes. CHIP-TRAP will consist of a pair of hyperbolic precision-measurement Penning traps, and a cylindrical capture/filter trap in a 12 T magnetic field. Ions will be produced by external ion sources, including a laser ablation source, and transported to the capture trap at low energies enabling ions of a given m / q ratio to be selected via their time-of-flight. In the capture trap, contaminant ions will be removed with a mass-selective rf dipole excitation and the ion of interest will be transported to the measurement traps. A phase-sensitive image charge detection technique will be used for simultaneous cyclotron frequency measurements on single ions in the two precision traps, resulting in a reduction in statistical uncertainty due to magnetic field fluctuations.

  6. High precision astrometry with HST/WFC3 Scanning mode: parallaxes of two Galactic Cepheids

    NASA Astrophysics Data System (ADS)

    Casertano, Stefano; Riess, Adam G.

    2016-01-01

    We present astrometric results obtained by using the spatial scan capability of HST/WFC3. By scanning the telescope during an observation, we are able to measure the relative position of sources in the direction perpendicular to the scan with precision of 0.5 milli-pixels (about 20 micro-arcseconds). We will use this capability to measure the trigonometric parallax of eighteen Galactic Cepheids with periods long enough to serve as calibrators of the Period-Luminosity relation. This calibration will support a determination of the Hubble Constant with an expected accuracy of 2 percent. We present the measurements of the first two of these Cepheids, SS CMa and VY Car, with an accuracy of 30 micro-arcseconds each. We also discuss some of the difficulties inherent in milli-pixel precision measurements, and the requirements for high-precision astrometry with HST.

  7. High precision methods for locating the celestial intermediate pole and origin

    NASA Astrophysics Data System (ADS)

    Capitaine, N.; Wallace, P. T.

    2006-05-01

    Context: .The precession-nutation transformation describes the changing directions on the celestial sphere of the Earth's pole and an adopted origin of right ascension. The coordinate system for the celestial sphere is the geocentric celestial reference system, and the two directions are the celestial intermediate pole (CIP) and the celestial intermediate origin (CIO), the latter having supplanted the equinox for this purpose following IAU resolutions in 2000. The celestial coordinate triad based on the CIP and CIO is called the celestial intermediate reference system; the prediction of topocentric directions additionally requires the Earth rotation angle (ERA), the counterpart of Greenwich sidereal time (GST) in the former equinox based system. Aims: .The purpose of this paper is to review the different ways of calculating the CIP and CIO directions to precisions of a few microarcseconds over a time span of several centuries, meeting the requirements of high-accuracy applications. Methods: .Various implementations are described, their theoretical bases compared and the relationships between the expressions for the relevant parameters are provided. Semi-analytical and numerical comparisons have been made, based on the P03 precession and the IAU 2000A nutation, with slight modifications to the latter to make it consistent with P03. Results: .We have identified which transformations between celestial and terrestrial coordinates involve a minimum number of variables and coefficients for given accuracy objectives. The various methods are consistent at the level of a few microarcseconds over several centuries, and equal accuracy is achievable using both the equinox/GST paradigm and the CIO/ERA paradigm. Given existing nutation models, the most concise expressions for locating the CIP are based on the Fukushima-Williams bias-precession-nutation angles. The CIO can be located to a few microarcseconds using the CIO locator s. The equation of the origins (EO) is sensitive

  8. Development of high precision laser measurement to Space Debris and Applications in SHAO

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongping; Chen, Juping; Xiong, Yaoheng; Han, Xingwei

    2016-07-01

    Artificial space debris has become the focus during the space exploration because of producing the damage for the future active spacecrafts and high precision measurement for space debris are required for debris surveillance and collision avoidance. Laser ranging technology is inherently high accurate and will play an important role in precise orbit determination, accurate catalog of space debris. Shanghai Astronomical Observatory (SHAO) of CAS, has been developing the technology of laser measurement to space debris for several years. According to characteristics of laser echoes from space debris and the experiences of relevant activities, high repetition rate, high power laser system and low dark noise APD detector with high quantum efficiency and high transmissivity of narrow bandwidth spectral filter are applied to laser measurement to space debris in SHAO. With these configurations, great achievements of laser measurement to space debris are made with hundreds of passes of laser data from space debris in the distance between 500km and 2500km with Radar Cross Section (RCS) of more than 10 m^{2} to less than 0.5m^{2} at the measuring precision of less than 1m (RMS). For better application of laser ranging technology, Chinese Space Debris Observation network, consisting of Shanghai, Changchun and Kunming station, has been preliminary developed and the coordinated observation has been performed to increase the measuring efficiency for space debris. It is referred from data that laser ranging technology can be as the essential high accuracy measurement technology in the study of space debris.

  9. Method of curved surface abnormal holes vision measurement based on high precision turntable

    NASA Astrophysics Data System (ADS)

    Lyu, Laipeng; Bi, Chao; Fang, Jianguo; Zhu, Yong; Wang, Liping

    2015-10-01

    For solving the difficult problem that there is no effective way to measure abnormal holes located at blade erection loop of aero-engine case, an image measurement system based on high precision air-bearing turntable is established in this paper. The issue that monocular vision can't measure curved surface has overcome by using high precision turntable to make sure high positioning accuracy of the surface abnormal holes and high-resolution microscope lens which is used to image local tiny features. Besides, an algorithm of determining the boundary points of a trailing edge on the contour of abnormal hole is proposed to achieve a rapid fitting and accuracy. After experiments and analysis, results show that the system can be used to measure local tiny features on curved surfaces validly and efficiently.

  10. PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION

    SciTech Connect

    J.A. Ziegler

    2000-11-20

    The purpose of this calculation is to provide a dose consequence analysis of high-level waste (HLW) consisting of plutonium immobilized in vitrified HLW to be handled at the proposed Monitored Geologic Repository at Yucca Mountain for a beyond design basis event (BDBE) under expected conditions using best estimate values for each calculation parameter. In addition to the dose calculation, a plutonium respirable particle size for dose calculation use is derived. The current concept for this waste form is plutonium disks enclosed in cans immobilized in canisters of vitrified HLW (i.e., glass). The plutonium inventory at risk used for this calculation is selected from Plutonium Immobilization Project Input for Yucca Mountain Total Systems Performance Assessment (Shaw 1999). The BDBE examined in this calculation is a nonmechanistic initiating event and the sequence of events that follow to cause a radiological release. This analysis will provide the radiological releases and dose consequences for a postulated BDBE. Results may be considered in other analyses to determine or modify the safety classification and quality assurance level of repository structures, systems, and components. This calculation uses best available technical information because the BDBE frequency is very low (i.e., less than 1.0E-6 events/year) and is not required for License Application for the Monitored Geologic Repository. The results of this calculation will not be used as part of a licensing or design basis.

  11. High-precision spectroscopy of late-type stars with three-dimensional model stellar atmospheres

    NASA Astrophysics Data System (ADS)

    Collet, Remo

    2015-08-01

    Classical spectroscopic analyses of late-type stars generally rely on the use of synthetic spectra computed with stationary, one-dimensional (1D), hydrostatic model stellar atmospheres to quantitatively interpret observations. Recent years, however, have seen a rapid development in the field of three-dimensional (3D) hydrodynamical modelling of stellar atmospheres and stellar spectra.In this contribution, I will present results from realistic, time-dependent, hydrodynamical 3D simulations of stellar atmospheres of solar- and late-type stars, covering a wide range of stellar parameters and compositions, from main sequence to red giant branch and with metallicities from [Fe/H]=+0.5 down to [Fe/H]=-4. These 3D model atmospheres have been generated using a custom version of the radiation-magnetohydrodynamics Stagger-Code which implements state-of-the-art input micro-physics, equation of state and opacity data, and a realistic treatment of non-grey radiative transfer.I will describe the main properties of the simulations and discuss the application of 3D model atmospheres to spectral line-formation calculations and high-precision spectroscopy of late-type stars. I will illustrate the main effects of 3D modelling of stellar atmospheres and stellar spectra on the predicted strengths and shapes of spectral lines, highlighting the systematic differences with respect to calculations based on classical, 1D, hydrostatic models.In particular, I will present the results of spectroscopic carbon, nitrogen and oxygen abundance determinations based on the analysis of CH, NH, CN and OH molecular bands with 3D model stellar atmospheres. I will show that the differences with respect to classical analyses based on 1D models can be significant and of the order of 0.5 to 1 dex in terms of logarithmic abundances of these important elements.Finally, I will also discuss the application of 3D models to the analysis and interpretation of data from large-scale space-born and ground

  12. Real-space electronic structure calculations with full-potential all-electron precision for transition metals

    NASA Astrophysics Data System (ADS)

    Ono, Tomoya; Heide, Marcus; Atodiresei, Nicolae; Baumeister, Paul; Tsukamoto, Shigeru; Blügel, Stefan

    2010-11-01

    We have developed an efficient computational scheme utilizing the real-space finite-difference formalism and the projector augmented-wave (PAW) method to perform precise first-principles electronic-structure simulations based on the density-functional theory for systems containing transition metals with a modest computational effort. By combining the advantages of the time-saving double-grid technique and the Fourier-filtering procedure for the projectors of pseudopotentials, we can overcome the egg box effect in the computations even for first-row elements and transition metals, which is a problem of the real-space finite-difference formalism. In order to demonstrate the potential power in terms of precision and applicability of the present scheme, we have carried out simulations to examine several bulk properties and structural energy differences between different bulk phases of transition metals and have obtained excellent agreement with the results of other precise first-principles methods such as a plane-wave-based PAW method and an all-electron full-potential linearized augmented plane-wave (FLAPW) method.

  13. A near infrared laser frequency comb for high precision Doppler planet surveys

    NASA Astrophysics Data System (ADS)

    Osterman, S.; Diddams, S.; Quinlan, F.; Bally, J.; Ge, J.; Ycas, G.

    2011-07-01

    Perhaps the most exciting area of astronomical research today is the study of exoplanets and exoplanetary systems, engaging the imagination not just of the astronomical community, but of the general population. Astronomical instrumentation has matured to the level where it is possible to detect terrestrial planets orbiting distant stars via radial velocity (RV) measurements, with the most stable visible light spectrographs reporting RV results the order of 1 m/s. This, however, is an order of magnitude away from the precision needed to detect an Earth analog orbiting a star such as our sun, the Holy Grail of these efforts. By performing these observations in near infrared (NIR) there is the potential to simplify the search for distant terrestrial planets by studying cooler, less massive, much more numerous class M stars, with a tighter habitable zone and correspondingly larger RV signal. This NIR advantage is undone by the lack of a suitable high precision, high stability wavelength standard, limiting NIR RV measurements to tens or hundreds of m/s [1, 2]. With the improved spectroscopic precision provided by a laser frequency comb based wavelength reference producing a set of bright, densely and uniformly spaced lines, it will be possible to achieve up to two orders of magnitude improvement in RV precision, limited only by the precision and sensitivity of existing spectrographs, enabling the observation of Earth analogs through RV measurements. We discuss the laser frequency comb as an astronomical wavelength reference, and describe progress towards a near infrared laser frequency comb at the National Institute of Standards and Technology and at the University of Colorado where we are operating a laser frequency comb suitable for use with a high resolution H band astronomical spectrograph.

  14. High Precision Isotope Analyses Using Multi-Collector SIMS: Applications to Earth and Planetary Science.

    NASA Astrophysics Data System (ADS)

    Kita, N. T.; Ushikubo, T.; Valley, J. W.

    2008-05-01

    The CAMECA IMS-1280 large radius, multicollector ion microprobe at the Wisc-SIMS National Facility is capable of high accuracy and precision for in situ analysis of isotope ratios. With improved hardware stability and software capability, high precision isotope analyses are routinely performed, typically 5 min per spot. We have developed analytical protocols for stable isotope analyses of oxygen, carbon, Mg, Si and Sulfur using multi-collector Faraday Cups (MCFC) and achieved precision of 0.1-0.2 ‰ (1SD) from a typically 10μm spot analyses. A number of isotopically homogeneous mineral standards have been prepared and calibrated in order to certify the accuracy of analyses in the same level. When spatial resolution is critical, spot size is reduced down to sub- μm for δ 18O to obtain better than 0.5‰ (1SD) precision by using electron multiplier (EM) on multi-collection system. Multi-collection EM analysis is also applied at 10 ppm level to Li isotope ratios in zircon with precision better than 2‰ (1SD). A few applications will be presented. (1) Oxygen three isotope analyses of chondrules in ordinary chondrites revealed both mass dependent and mass independent oxygen isotope fractionations among chondrules as well as within individual chondrules. The results give constraints on the process of chondrule formation and origin of isotope reservoirs in the early solar system. (2) High precision 26Al-26Mg (half life of 0.73 Ma) chronology is applied to zoned melilite and anorthite from Ca, Al-rich inclusions (CAI) in Leoville meteorite, and a well-defined internal isochron is obtained. The results indicate the Al- Mg system was remained closed within 40ky of the crystallization of melilite and anorthite in this CAI. (3) Sub- μm spot analyses of δ18O in isotopically zoned zircon from high-grade metamorphism reveals a diffusion profile of ~6‰ over 2μm, indicating slow diffusion of oxygen in zircon. This result also implies that old Archean detrital zircons (> 4

  15. Precisely Controlled Ultrathin Conjugated Polymer Films for Large Area Transparent Transistors and Highly Sensitive Chemical Sensors.

    PubMed

    Khim, Dongyoon; Ryu, Gi-Seong; Park, Won-Tae; Kim, Hyunchul; Lee, Myungwon; Noh, Yong-Young

    2016-04-01

    A uniform ultrathin polymer film is deposited over a large area with molecularlevel precision by the simple wire-wound bar-coating method. The bar-coated ultrathin films not only exhibit high transparency of up to 90% in the visible wavelength range but also high charge carrier mobility with a high degree of percolation through the uniformly covered polymer nanofibrils. They are capable of realizing highly sensitive multigas sensors and represent the first successful report of ethylene detection using a sensor based on organic field-effect transistors. PMID:26849096

  16. Analytical modeling of high precision measurement of thermal heat transfer by laser heating

    NASA Astrophysics Data System (ADS)

    Jain, Abhishek

    2005-04-01

    Study of precise thermal heat transfer due to laser heating of metals and other structures has been found to be of great use in different applications ranging from MEMS, nanostructures and biomedical devices. In this paper an analytical modeling of measuring the temperature at a junction of the thermocouple and the metal surface is done. Analytical treatment is also done to calculate the temperature distribution inside the metal assuming the laser as a point heat source. The metal in consideration is stainless steel and is heated using laser. When a thermocouple is mounted on the metal surface there is a fall in the junction temperature due to the depression of the thermocouple inside the metal, which results in the error in the final measurement. In the present study an analytical investigation is done to measure the error generated due to this depression. Temperature distribution inside the block is also calculated based on heat diffusion equation in cylindrical coordinates.

  17. Performance calculation and simulation system of high energy laser weapon

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Liu, Min; Su, Yu; Zhang, Ke

    2014-12-01

    High energy laser weapons are ready for some of today's most challenging military applications. Based on the analysis of the main tactical/technical index and combating process of high energy laser weapon, a performance calculation and simulation system of high energy laser weapon was established. Firstly, the index decomposition and workflow of high energy laser weapon was proposed. The entire system was composed of six parts, including classical target, platform of laser weapon, detect sensor, tracking and pointing control, laser atmosphere propagation and damage assessment module. Then, the index calculation modules were designed. Finally, anti-missile interception simulation was performed. The system can provide reference and basis for the analysis and evaluation of high energy laser weapon efficiency.

  18. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Chen, H.; Yu, T.; Li, B.

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  19. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage.

    PubMed

    Yang, Z; Chen, H; Yu, T; Li, B

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage. PMID:27587158

  20. A high-precision apparatus for the characterization of thermal interface materials.

    PubMed

    Kempers, R; Kolodner, P; Lyons, A; Robinson, A J

    2009-09-01

    An apparatus has been designed and constructed to characterize thermal interface materials with unprecedented precision and sensitivity. The design of the apparatus is based upon a popular implementation of ASTM D5470 where well-characterized meter bars are used to extrapolate surface temperatures and measure heat flux through the sample under test. Measurements of thermal resistance, effective thermal conductivity, and electrical resistance can be made simultaneously as functions of pressure or sample thickness. This apparatus is unique in that it takes advantage of small, well-calibrated thermistors for precise temperature measurements (+/-0.001 K) and incorporates simultaneous measurement of electrical resistance of the sample. By employing precision thermometry, low heater powers and minimal temperature gradients are maintained through the meter bars, thereby reducing uncertainties due to heat leakage and changes in meter-bar thermal conductivity. Careful implementation of instrumentation to measure thickness and force also contributes to a low overall uncertainty. Finally, a robust error analysis provides uncertainties for all measured and calculated quantities. Baseline tests were performed to demonstrate the sensitivity and precision of the apparatus by measuring the contact resistance of the meter bars in contact with each other as representative low specific thermal resistance cases. A minimum specific thermal resistance of 4.68x10(-6) m(2) K/W was measured with an uncertainty of 2.7% using a heat transfer rate of 16.8 W. Additionally, example measurements performed on a commercially available graphite thermal interface material demonstrate the relationship between thermal and electrical contact resistance. These measurements further demonstrate repeatability in measured effective thermal conductivity of approximately 1%. PMID:19791968

  1. High-precision, automated integration of multiple isothermal titration calorimetric thermograms: new features of NITPIC.

    PubMed

    Scheuermann, Thomas H; Brautigam, Chad A

    2015-04-01

    Isothermal titration calorimetry (ITC) has become a standard and widely available tool to measure the thermodynamic parameters of macromolecular associations. Modern applications of the method, including global analysis and drug screening, require the acquisition of multiple sets of data; sometimes these data sets number in the hundreds. Therefore, there is a need for quick, precise, and automated means to process the data, particularly at the first step of data analysis, which is commonly the integration of the raw data to yield an interpretable isotherm. Herein, we describe enhancements to an algorithm that previously has been shown to provide an automated, unbiased, and high-precision means to integrate ITC data. These improvements allow for the speedy and precise serial integration of an unlimited number of ITC data sets, and they have been implemented in the freeware program NITPIC, version 1.1.0. We present a comprehensive comparison of the performance of this software against an older version of NITPIC and a current version of Origin, which is commonly used for integration. The new methods recapitulate the excellent performance of the previous versions of NITPIC while speeding it up substantially, and their precision is significantly better than that of Origin. This new version of NITPIC is therefore well suited to the serial integration of many ITC data sets. PMID:25524420

  2. High-precision image aided inertial navigation with known features: observability analysis and performance evaluation.

    PubMed

    Jiang, Weiping; Wang, Li; Niu, Xiaoji; Zhang, Quan; Zhang, Hui; Tang, Min; Hu, Xiangyun

    2014-01-01

    A high-precision image-aided inertial navigation system (INS) is proposed as an alternative to the carrier-phase-based differential Global Navigation Satellite Systems (CDGNSSs) when satellite-based navigation systems are unavailable. In this paper, the image/INS integrated algorithm is modeled by a tightly-coupled iterative extended Kalman filter (IEKF). Tightly-coupled integration ensures that the integrated system is reliable, even if few known feature points (i.e., less than three) are observed in the images. A new global observability analysis of this tightly-coupled integration is presented to guarantee that the system is observable under the necessary conditions. The analysis conclusions were verified by simulations and field tests. The field tests also indicate that high-precision position (centimeter-level) and attitude (half-degree-level)-integrated solutions can be achieved in a global reference. PMID:25330046

  3. Determination of the half-life of 213Fr with high precision

    NASA Astrophysics Data System (ADS)

    Fisichella, M.; Musumarra, A.; Farinon, F.; Nociforo, C.; Del Zoppo, A.; Figuera, P.; La Cognata, M.; Pellegriti, M. G.; Scuderi, V.; Torresi, D.; Strano, E.

    2013-07-01

    High-precision measurement of half-life and Qα value of neutral and highly charged α emitters is a major subject of investigation currently. In this framework, we recently pushed half-life measurements of neutral emitters to a precision of a few per mil. This result was achieved by using different techniques and apparatuses at Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS) and GSI Darmstadt. Here we report on 213Fr half-life determination [T1/2(213Fr) = 34.14±0.06 s] at INFN-LNS, detailing the measurement protocol used. Direct comparison with the accepted value in the literature shows a discrepancy of more than three sigma. We propose this new value as a reference, discussing previous experiments.

  4. Optical timing receiver for the NASA laser ranging system. Part 2: High precision time interval digitizer

    NASA Technical Reports Server (NTRS)

    Leskovar, B.; Turko, B.

    1977-01-01

    The development of a high precision time interval digitizer is described. The time digitizer is a 10 psec resolution stop watch covering a range of up to 340 msec. The measured time interval is determined as a separation between leading edges of a pair of pulses applied externally to the start input and the stop input of the digitizer. Employing an interpolation techniques and a 50 MHz high precision master oscillator, the equivalent of a 100 GHz clock frequency standard is achieved. Absolute accuracy and stability of the digitizer are determined by the external 50 MHz master oscillator, which serves as a standard time marker. The start and stop pulses are fast 1 nsec rise time signals, according to the Nuclear Instrument means of tunnel diode discriminators. Firing level of the discriminator define start and stop points between which the time interval is digitized.

  5. High-Precision Image Aided Inertial Navigation with Known Features: Observability Analysis and Performance Evaluation

    PubMed Central

    Jiang, Weiping; Wang, Li; Niu, Xiaoji; Zhang, Quan; Zhang, Hui; Tang, Min; Hu, Xiangyun

    2014-01-01

    A high-precision image-aided inertial navigation system (INS) is proposed as an alternative to the carrier-phase-based differential Global Navigation Satellite Systems (CDGNSSs) when satellite-based navigation systems are unavailable. In this paper, the image/INS integrated algorithm is modeled by a tightly-coupled iterative extended Kalman filter (IEKF). Tightly-coupled integration ensures that the integrated system is reliable, even if few known feature points (i.e., less than three) are observed in the images. A new global observability analysis of this tightly-coupled integration is presented to guarantee that the system is observable under the necessary conditions. The analysis conclusions were verified by simulations and field tests. The field tests also indicate that high-precision position (centimeter-level) and attitude (half-degree-level)-integrated solutions can be achieved in a global reference. PMID:25330046

  6. High-precision measurement of pixel positions in a charge-coupled device.

    PubMed

    Shaklan, S; Sharman, M C; Pravdo, S H

    1995-10-10

    The high level of spatial uniformity in modern CCD's makes them excellent devices for astrometric instruments. However, at the level of accuracy envisioned by the more ambitious projects such as the Astrometric Imaging Telescope, current technology produces CCD's with significant pixel registration errors. We describe a technique for making high-precision measurements of relative pixel positions. We measured CCD's manufactured for the Wide Field Planetary Camera II installed in the Hubble Space Telescope. These CCD's are shown to have significant step-and-repeat errors of 0.033 pixel along every 34th row, as well as a 0.003-pixel curvature along 34-pixel stripes. The source of these errors is described. Our experiments achieved a per-pixel accuracy of 0.011 pixel. The ultimate shot-noise limited precision of the method is less than 0.001 pixel. PMID:21060522

  7. All low voltage lateral junction scanning tunneling microscope with very high precision and stability

    NASA Astrophysics Data System (ADS)

    Hou, Yubin; Wang, Jihui; Lu, Qingyou

    2008-11-01

    We describe the first lateral junction and fully low voltage scanning tunneling microscope, featuring very high precision, stability, compactness, and image quality (highly oriented pyrolytic graphite atomic resolution images). In its core, the tip and sample each sit on one of two parallel-mounted piezoelectric tube scanners so that the tip-sample gap is regulated along the scanners' pairing direction. The scanner's large lateral deflection provides a large gap regulation range even under low voltages, allowing exclusively using only low voltage (less than ±15 V) operational amplifiers to precisely implement the coarse (inertial slider) and fine approach, feedback control, and hence the entire electronics. Because the scanners are identical and adjacent, thermal drifts are minimal.

  8. A novel high precision adaptive equalizer in digital coherent optical receivers

    NASA Astrophysics Data System (ADS)

    Ma, Xiurong; Xu, Yujun; Wang, Xiao; Ding, Zhaocai

    2015-10-01

    A novel high precision adaptive equalization method is introduced and applied to dynamic equalization for quadrature phase shift keying (QPSK) coherent optical communication system in this paper. A frequency-domain constant modulus algorithm (CMA) method is used to equalize the received signal roughly. Then, some non-ideal output signals will be picked out through the error measurement, and they will be equalized accurately further in a fixed time-domain CMA equalizer. This high precision equalization method can decrease the equalization error, then it can reduce the bit error ratio (BER) of coherent communication system. Simulation results show that there is a 6% decrease for computation complexity by proposed scheme when compared with time-domain CMA. Furthermore, compared with time-domain CMA and frequency-domain CMA, about 2 dB and 2.2 dB in OSNR improvement can be obtained by proposed scheme at the BER value of 1e-3, respectively.

  9. Laser interferometric high-precision geometry (angle and length) monitor for JASMINE

    NASA Astrophysics Data System (ADS)

    Niwa, Y.; Arai, K.; Ueda, A.; Sakagami, M.; Gouda, N.; Kobayashi, Y.; Yamada, Y.; Yano, T.

    2008-07-01

    The telescope geometry of JASMINE should be stabilized and monitored with the accuracy of about 10 to 100 pm or 10 to 100 prad of rms over about 10 hours. For this purpose, a high-precision interferometric laser metrology system is employed. Useful techniques for measuring displacements on extremely small scales are the wave-front sensing method and the heterodyne interferometrical method. Experiments for verification of measurement principles are well advanced.

  10. A high precision gamma-ray spectrometer for the Mars-94 mission

    SciTech Connect

    Mitrofanov, I.G.; Anfimov, D.S.; Chernenko, A.M.

    1994-06-01

    The high precision gamma-ray spectrometer (PGS) is scheduled to be launched on the Mars-94 mission in October 1994, and to go into an elliptical polar orbit around Mars. The PGS consists of two high-purity germanium (Ge) detectors, associated electronics, and a passive cooler and will be mounted on one of the solar panels. The PGS will measure nuclear gamma-ray emissions from the martian surface, cosmic gamma-ray bursts, and the high-energy component of solar flares in the broad energy range from 50 KeV to 8 MeV using 4096 energy channels.

  11. The high precision control of the satellites formation for diffraction imaging

    NASA Astrophysics Data System (ADS)

    Yang, Guang; He, Liang; Song, Ting; Sun, Binglei; Hao, Tianwei

    2016-01-01

    To satisfy need of high resolution observation from space. This article elaborates a method of high precision spacecraft formation control based on file diffraction theory. Improving the spacecraft control accuracy to millimeter is a challenge. With the method in this article this challenge can be solved. The algorithm in this article concerning the vibration of spacecraft and based on dynamic modeling of even relative quaternion theory deduced a method of attitude and orbit integrated control. Using this control algorithm to simulation can get the result that it can make the spacecraft integrate formation control as the technical basis of space high resolution observation.

  12. High Resolution Mass Spectra Analysis with a Programmable Calculator.

    ERIC Educational Resources Information Center

    Holdsworth, David K.

    1980-01-01

    Highlighted are characteristics of programs written for a pocket-sized programmable calculator to analyze mass spectra data (such as displaying high resolution masses for formulas, predicting whether formulas are stable molecules or molecular ions, determining formulas by isotopic abundance measurement) in a laboratory or classroom. (CS)

  13. Accurate time delay technology in simulated test for high precision laser range finder

    NASA Astrophysics Data System (ADS)

    Chen, Zhibin; Xiao, Wenjian; Wang, Weiming; Xue, Mingxi

    2015-10-01

    With the continuous development of technology, the ranging accuracy of pulsed laser range finder (LRF) is higher and higher, so the maintenance demand of LRF is also rising. According to the dominant ideology of "time analog spatial distance" in simulated test for pulsed range finder, the key of distance simulation precision lies in the adjustable time delay. By analyzing and comparing the advantages and disadvantages of fiber and circuit delay, a method was proposed to improve the accuracy of the circuit delay without increasing the count frequency of the circuit. A high precision controllable delay circuit was designed by combining the internal delay circuit and external delay circuit which could compensate the delay error in real time. And then the circuit delay accuracy could be increased. The accuracy of the novel circuit delay methods proposed in this paper was actually measured by a high sampling rate oscilloscope actual measurement. The measurement result shows that the accuracy of the distance simulated by the circuit delay is increased from +/- 0.75m up to +/- 0.15m. The accuracy of the simulated distance is greatly improved in simulated test for high precision pulsed range finder.

  14. High precision U-PB geochronology and implications for the tectonic evolution of the Superior Province

    NASA Technical Reports Server (NTRS)

    Davis, D. W.; Corfu, F.; Krogh, T. E.

    1986-01-01

    The underlying mechanisms of Archean tectonics and the degree to which modern plate tectonic models are applicable early in Earth's history continue to be a subject of considerable debate. A precise knowledge of the timing of geological events is of the utmost importance in studying this problem. The high precision U-Pb method has been applied in recent years to rock units in many areas of the Superior Province. Most of these data have precisions of about + or - 2-3 Ma. The resulting detailed chronologies of local igneous development and the regional age relationships furnish tight constraints on any Archean tectonic model. Superior province terrains can be classified into 3 types: (1) low grade areas dominated by meta-volcanic rocks (greenstone belts); (2) high grade, largely metaplutonic areas with abundant orthogneiss and foliated to massive I-type granitoid bodies; and (3) high grade areas with abundant metasediments, paragneiss and S-type plutons. Most of the U-Pb age determinations have been done on type 1 terrains with very few having been done in type 3 terrains. A compilation of over 120 ages indicates that the major part of igneous activity took place in the period 2760-2670 Ma, known as the Kenoran event. This event was ubiquitous throughout the Superior Province.

  15. "Modal Noise" in Single-mode Fibers: A Cautionary Note for High Precision Radial Velocity Instruments

    NASA Astrophysics Data System (ADS)

    Halverson, Samuel; Roy, Arpita; Mahadevan, Suvrath; Schwab, Christian

    2015-12-01

    Exploring the use of single-mode fibers (SMFs) in high precision Doppler spectrometers has become increasingly attractive since the advent of diffraction-limited adaptive optics systems on large-aperture telescopes. Spectrometers fed with these fibers can be made significantly smaller than typical “seeing-limited” instruments, greatly reducing cost and overall complexity. Importantly, classical mode interference and speckle issues associated with multi-mode fibers, also known as “modal noise,” are mitigated when using SMFs, which also provide perfect radial and azimuthal image scrambling. However, SMFs do support multiple polarization modes, an issue that is generally ignored for larger-core fibers given the large number of propagation modes. Since diffraction gratings used in most high resolution astronomical instruments have dispersive properties that are sensitive to incident polarization changes, any birefringence variations in the fiber can cause variations in the efficiency profile, degrading illumination stability. Here we present a cautionary note outlining how the polarization properties of SMFs can affect the radial velocity (RV) measurement precision of high resolution spectrographs. This work is immediately relevant to the rapidly expanding field of diffraction-limited, extreme precision RV spectrographs that are currently being designed and built by a number of groups.

  16. Next generation KATRIN high precision voltage divider for voltages up to 65kV

    NASA Astrophysics Data System (ADS)

    Bauer, S.; Berendes, R.; Hochschulz, F.; Ortjohann, H.-W.; Rosendahl, S.; Thümmler, T.; Schmidt, M.; Weinheimer, C.

    2013-10-01

    The KATRIN (KArlsruhe TRItium Neutrino) experiment aims to determine the mass of the electron antineutrino with a sensitivity of 200 meV by precisely measuring the electron spectrum of the tritium beta decay. This will be done by the use of a retarding spectrometer of the MAC-E-Filter type. To achieve the desired sensitivity the stability of the retarding potential of -18.6 kV has to be monitored with a precision of 3 ppm over at least two months. Since this is not feasible with commercial devices, two ppm-class high voltage dividers were developed, following the concept of the standard divider for DC voltages of up to 100 kV of the Physikalisch-Technische Bundesanstalt (PTB). In order to reach such high accuracies different effects have to be considered. The two most important ones are the temperature dependence of resistance and leakage currents, caused by insulators or corona discharges. For the second divider improvements were made concerning the high-precision resistors and the thermal design of the divider. The improved resistors are the result of a cooperation with the manufacturer. The design improvements, the investigation and the selection of the resistors, the built-in ripple probe and the calibrations at PTB will be reported here. The latter demonstrated a stability of about 0.1 ppm/month over a period of two years.

  17. Development of a mobile and high-precision atmospheric CO2 monitoring station

    NASA Astrophysics Data System (ADS)

    Molnár, M.; Haszpra, L.; Major, I.; Svingor, É.; Veres, M.

    2009-04-01

    consisting of 2 min flushing and 20 sec signal integration. The usual change of the response function is below 0.2 ppm after 2 hours following a previous calibration. The analyser measures the CO2 mixing ratio in the sample gas in every 3 seconds. Output data are registered by a data logger developed for this application (Special Control Devices). The overall uncertainty of our atmospheric CO2 mixing ratio measurements is < 0.5 ppm (< 0,2 %). This level of error is acceptable for fossil fuel CO2 calculations as the uncertainty of the other required parameter radiocarbon content of atmospheric CO2 is usually 0.3-0.5%. Using the developed mobile and high-precision atmospheric CO2 monitoring station we plan to determine the fossil fuel CO2 amount in the air of different cities and other average industrial regions in Hungary. This research project was supported by Hungarian NSF (Ref No. F69029).

  18. GNSS tropospheric gradients with high temporal resolution and their effect on precise positioning

    NASA Astrophysics Data System (ADS)

    Lu, Cuixian; Li, Xingxing; Li, Zhenhong; Heinkelmann, Robert; Nilsson, Tobias; Dick, Galina; Ge, Maorong; Schuh, Harald

    2016-01-01

    The tropospheric horizontal gradients with high spatiotemporal resolutions provide important information to describe the azimuthally asymmetric delays and significantly increase the ability of ground-based GNSS (Global Navigation Satellite Systems) within the field of meteorological studies, like the nowcasting of severe rainfall events. The recent rapid development of multi-GNSS constellations has potential to provide such high-resolution gradients with a significant degree of accuracy. In this study, we develop a multi-GNSS process for the precise retrieval of high-resolution tropospheric gradients. The tropospheric gradients with different temporal resolutions, retrieved from both single-system and multi-GNSS solutions, are validated using independent numerical weather models (NWM) data and water vapor radiometer (WVR) observations. The benefits of multi-GNSS processing for the retrieval of tropospheric gradients, as well as for the improvement of precise positioning, are demonstrated. The multi-GNSS high-resolution gradients agree well with those derived from the NWM and WVR, especially for the fast-changing peaks, which are mostly associated with synoptic fronts. The multi-GNSS gradients behave in a much more stable manner than the single-system estimates, especially in cases of high temporal resolution, benefiting from the increased number of observed satellites and improved observation geometry. The high-resolution multi-GNSS gradients show higher correlation with the NWM and WVR gradients than the low-resolution gradients. Furthermore, the precision of station positions can also be noticeably improved by multi-GNSS fusion, and enhanced results can be achieved if the high-resolution gradient estimation is performed, instead of the commonly used daily gradient estimation in the multi-GNSS data processing.

  19. Aeroelastic Calculations of Quiet High- Speed Fan Performed

    NASA Technical Reports Server (NTRS)

    Bakhle, Milind A.; Srivastava, Rakesh; Mehmed, Oral; Min, James B.

    2002-01-01

    An advanced high-speed fan was recently designed under a cooperative effort between the NASA Glenn Research Center and Honeywell Engines & Systems. The principal design goals were to improve performance and to reduce fan noise at takeoff. Scale models of the Quiet High-Speed Fan were tested for operability, performance, and acoustics. During testing, the fan showed significantly improved noise characteristics, but a self-excited aeroelastic vibration known as flutter was encountered in the operating range. Flutter calculations were carried out for the Quiet High-Speed Fan using a three-dimensional, unsteady aerodynamic, Reynolds-averaged Navier-Stokes turbomachinery code named "TURBO." The TURBO code can accurately model the viscous flow effects that can play an important role in various aeroelastic problems such as flutter with flow separation, flutter at high loading conditions near the stall line (stall flutter), and flutter in the presence of shock and boundary-layer interaction. Initially, calculations were performed with no blade vibrations. These calculations were at a constant rotational speed and a varying mass flow rate. The mass flow rate was varied by changing the backpressure at the exit boundary of the computational domain. These initial steady calculations were followed by aeroelastic calculations in which the blades were prescribed to vibrate harmonically in a natural mode, at a natural frequency, and with a fixed interblade phase angle between adjacent blades. The AE-prep preprocessor was used to interpolate the in-vacuum mode shapes from the structural dynamics mesh onto the computational fluid dynamics mesh and to smoothly propagate the grid deformations from the blade surface to the interior points of the grid. The aeroelastic calculations provided the unsteady aerodynamic forces on the blade surface due to blade vibrations. These forces were vector multiplied with the structural dynamic mode shape to calculate the work done on the blade during

  20. Development and Validation of High Precision Thermal, Mechanical, and Optical Models for the Space Interferometry Mission

    NASA Technical Reports Server (NTRS)

    Lindensmith, Chris A.; Briggs, H. Clark; Beregovski, Yuri; Feria, V. Alfonso; Goullioud, Renaud; Gursel, Yekta; Hahn, Inseob; Kinsella, Gary; Orzewalla, Matthew; Phillips, Charles

    2006-01-01

    SIM Planetquest (SIM) is a large optical interferometer for making microarcsecond measurements of the positions of stars, and to detect Earth-sized planets around nearby stars. To achieve this precision, SIM requires stability of optical components to tens of picometers per hour. The combination of SIM s large size (9 meter baseline) and the high stability requirement makes it difficult and costly to measure all aspects of system performance on the ground. To reduce risks, costs and to allow for a design with fewer intermediate testing stages, the SIM project is developing an integrated thermal, mechanical and optical modeling process that will allow predictions of the system performance to be made at the required high precision. This modeling process uses commercial, off-the-shelf tools and has been validated against experimental results at the precision of the SIM performance requirements. This paper presents the description of the model development, some of the models, and their validation in the Thermo-Opto-Mechanical (TOM3) testbed which includes full scale brassboard optical components and the metrology to test them at the SIM performance requirement levels.

  1. High Precision Oxygen Three Isotope Analysis of Wild-2 Particles and Anhydrous Chondritic Interplanetary Dust Particles

    NASA Technical Reports Server (NTRS)

    Nakashima, D.; Ushikubo, T.; Zolensky, Michael E.; Weisberg, M. K.; Joswiak, D. J.; Brownlee, D. E.; Matrajt, G.; Kita, N. T.

    2011-01-01

    One of the most important discoveries from comet Wild-2 samples was observation of crystalline silicate particles that resemble chondrules and CAIs in carbonaceous chondrites. Previous oxygen isotope analyses of crystalline silicate terminal particles showed heterogeneous oxygen isotope ratios with delta(sup 18)O to approx. delta(sup 17)O down to -50% in the CAI-like particle Inti, a relict olivine grain in Gozen-sama, and an olivine particle. However, many Wild-2 particles as well as ferromagnesian silicates in anhydrous interplanetary dust particles (IDPs) showed Delta(sup 17)O values that cluster around -2%. In carbonaceous chondrites, chondrules seem to show two major isotope reservoirs with Delta(sup 17)O values at -5% and -2%. It was suggested that the Delta(sup 17)O = -2% is the common oxygen isotope reservoir for carbonaceous chondrite chondrules and cometary dust, from the outer asteroid belt to the Kuiper belt region. However, a larger dataset with high precision isotope analyses (+/-1-2%) is still needed to resolve the similarities or distinctions among Wild-2 particles, IDPs and chondrules in meteorites. We have made signifi-cant efforts to establish routine analyses of small particles (< or =10micronsm) at 1-2% precision using IMS-1280 at WiscSIMS laboratory. Here we report new results of high precision oxygen isotope analyses of Wild-2 particles and anhydrous chondritic IDPs, and discuss the relationship between the cometary dust and carbonaceous chondrite chondrules.

  2. A flexile and high precision calibration method for binocular structured light scanning system.

    PubMed

    Yuan, Jianying; Wang, Qiong; Li, Bailin

    2014-01-01

    3D (three-dimensional) structured light scanning system is widely used in the field of reverse engineering, quality inspection, and so forth. Camera calibration is the key for scanning precision. Currently, 2D (two-dimensional) or 3D fine processed calibration reference object is usually applied for high calibration precision, which is difficult to operate and the cost is high. In this paper, a novel calibration method is proposed with a scale bar and some artificial coded targets placed randomly in the measuring volume. The principle of the proposed method is based on hierarchical self-calibration and bundle adjustment. We get initial intrinsic parameters from images. Initial extrinsic parameters in projective space are estimated with the method of factorization and then upgraded to Euclidean space with orthogonality of rotation matrix and rank 3 of the absolute quadric as constraint. Last, all camera parameters are refined through bundle adjustment. Real experiments show that the proposed method is robust, and has the same precision level as the result using delicate artificial reference object, but the hardware cost is very low compared with the current calibration method used in 3D structured light scanning system. PMID:25202736

  3. High-precision astrometry with VVV - I. An independent reduction pipeline for VIRCAM@VISTA

    NASA Astrophysics Data System (ADS)

    Libralato, M.; Bellini, A.; Bedin, L. R.; Anderson, J.; Piotto, G.; Nascimbeni, V.; Platais, I.; Minniti, D.; Zoccali, M.

    2015-06-01

    We present a new reduction pipeline for the VIRCAM@VISTA detector and describe the method developed to obtain high-precision astrometry with the VISTA Variables in the Vía Láctea (VVV) data set. We derive an accurate geometric-distortion correction using as calibration field the globular cluster NGC 5139, and showed that we are able to reach a relative astrometric precision of about 8 mas per coordinate per exposure for well-measured stars over a field of view of more than 1 deg2. This geometric-distortion correction is made available to the community. As a test bed, we chose a field centred around the globular cluster NGC 6656 from the VVV archive and computed proper motions for the stars within. With 45 epochs spread over four years, we show that we are able to achieve a precision of 1.4 mas yr-1 and to isolate each population observed in the field (cluster, Bulge and Disc) using proper motions. We used proper-motion-selected field stars to measure the motion difference between Galactic disc and bulge stars. Our proper-motion measurements are consistent with UCAC4 and PPMXL, though our errors are much smaller. Models have still difficulties in reproducing the observations in this highly reddened Galactic regions.

  4. High-precision Pb Isotopes Reveal Two Small Magma Bodies Beneath the Summit of Kilauea Volcano

    NASA Astrophysics Data System (ADS)

    Pietruszka, A. J.; Heaton, D. E.; Marske, J. P.; Garcia, M. O.

    2013-12-01

    The summit magma storage reservoir of Kilauea Volcano is one of the most important components of the volcano's magmatic plumbing system, but its geometry is poorly known. High-precision Pb isotopic analyses of Kilauea summit lavas (1959-1982) define the minimum number of magma bodies within the summit reservoir and their volumes. The 206Pb/204Pb ratios of these lavas display a temporal decrease due to changes in the composition of the parental magma delivered to the volcano. Analyses of multiple lavas from some individual eruptions reveal small but significant differences in 206Pb/204Pb. The extra-caldera lavas from Aug. 1971 and Jul. 1974 display lower Pb isotope ratios and higher MgO contents (10 wt. %) than the intra-caldera lavas (MgO ~7-8 wt. %) from each eruption. From 1971 to 1982, the 206Pb/204Pb ratios of the lavas define two separate decreasing temporal trends. The intra-caldera lavas from 1971, 1974, 1975, Apr. 1982 and the lower MgO lavas from Sep. 1982 have higher 206Pb/204Pb ratios at a given time (compared to the extra-caldera lavas and the higher MgO lavas from Sep. 1982). These trends require that the intra- and extra-caldera lavas (and the Sep. 1982 lavas) were supplied from two separate, partially isolated magma bodies. Numerous studies (Fiske and Kinoshita, 1969; Klein et al., 1987) have long identified the locus of Kilauea's summit reservoir ~2 km southeast of Halemaumau (HMM) at a depth of ~2-7 km, but more recent investigations have discovered a second magma body located <1 km below the east rim of HMM (Battaglia et al., 2003; Johnson et al., 2010). The association between the vent locations of the extra-caldera lavas near the southeast rim of the caldera and their higher MgO contents suggests that these lavas tapped the deeper magma body. In contrast, the lower MgO intra-caldera lavas were likely derived from the shallow magma body beneath HMM. Residence time modeling based on the Pb isotope ratios of the lavas suggests that the magma volume

  5. Design of a Laser Ablation Ion Source for High-Precision Penning Trap Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Hunt, Curtis; Ratnayake, Ishara; Hawks, Paul; Bryce, Richard; Redshaw, Matthew

    2014-05-01

    High-precision atomic mass measurements provide important data for a wide range of fields including atomic, nuclear and neutrino physics, determination of fundamental constants, and metrology. At Central Michigan University we are building a Penning trap system that will utilize ions produced by external ion sources to allow access to a wide range of isotopes, including long-lived radioactive isotopes and isotopes with low natural abundances. The ions will be transported to a ``capture'' trap, before being transferred to double precision-measurement trap structure. In this poster we will present the design of a laser ablation ion source and the ion extraction and transport optics. We will report on the current status of the construction and operation of the ion source and the CMU Penning trap. This work supported in part by NSF award no. 1307233.

  6. High-precision masses of neutron-deficient rubidium isotopes using a Penning trap mass spectrometer

    SciTech Connect

    Kellerbauer, A.; Audi, G.; Guenaut, C.; Lunney, D.; Beck, D.; Herfurth, F.; Kluge, H.-J.; Weber, C.; Yazidjian, C.; Blaum, K.; Bollen, G.; Schwarz, S.; Herlert, A.; Schweikhard, L.

    2007-10-15

    The atomic masses of the neutron-deficient radioactive rubidium isotopes {sup 74-77,79,80,83}Rb have been measured with the Penning trap mass spectrometer ISOLTRAP. Using the time-of-flight cyclotron resonance technique, relative mass uncertainties ranging from 1.6x10{sup -8} to 5.6x10{sup -8} were achieved. In all cases, the mass precision was significantly improved as compared with the prior Atomic-Mass Evaluation; no significant deviations from the literature values were observed. The exotic nuclide {sup 74}Rb, with a half-life of only 65 ms, is the shortest-lived nuclide on which a high-precision mass measurement in a Penning trap has been carried out. The significance of these measurements for a check of the conserved-vector-current hypothesis of the weak interaction and the unitarity of the Cabibbo-Kobayashi-Maskawa matrix is discussed.

  7. The design of a stepper motor control-based high-precision varifocal imaging optical system

    NASA Astrophysics Data System (ADS)

    Xiang, Bai

    2012-11-01

    This study, while introducing the theories and makeup of conventional cam varifocal system, indicates the two faults stemming from their inherent mechanism and potentiometer-based focal-length measurement: 1) inability to stop optic axis vibration and 2) considerable error in real-time output of focal-length value. As a result, a stepper motor, instead of cam mechanism, was employed to control mirrors of variofocus and mirrors of compensation in moving accurately along straight-ling rails so that continuous focal-length variation and surface image positioning were accomplished; a linear encoder was substituted for potentiometer in realizing real-time output of focal-length value and also in closed-loop control of stepper motor. Compared with the cam mechanism, this system provides 90% less vibration and 80% more positioning precision, thereby basically solving the problems of the cam system and enabling the high-precision angular measurement.

  8. A modular high precision digital system for hypervelocity projectile performance measurements

    NASA Astrophysics Data System (ADS)

    Nagarkar, Vivek V.; Singh, Bipin; Miller, Stuart; Campbell, Larry; Bishel, Ron; Rushing, Rick

    2008-04-01

    The performance measurement of hypervelocity projectiles in flight is critical in ensuring proper projectile operation, for designing new long-range missile systems with improved accuracy, and for assessing damage to the target upon impact to determine the projectile's lethality. We are developing a modular, low cost, digital X-ray imaging system to measure hypervelocity projectile parameters with high precision and to almost instantaneously map its trajectory in 3D space to compute its pitch, yaw, displacement from its path, and velocity. The preliminary data suggest that this system can render an accuracy of 0.25° in measuring pitch and yaw, an accuracy of 0.03" in estimating displacement from the centerline, and a precision of +/-0.0001% in measuring velocity, which is well beyond the capability of any existing system.

  9. Calculating High Speed Centrifugal Compressor Performance from Averaged Measurements

    NASA Astrophysics Data System (ADS)

    Lou, Fangyuan; Fleming, Ryan; Key, Nicole L.

    2012-12-01

    To improve the understanding of high performance centrifugal compressors found in modern aircraft engines, the aerodynamics through these machines must be experimentally studied. To accurately capture the complex flow phenomena through these devices, research facilities that can accurately simulate these flows are necessary. One such facility has been recently developed, and it is used in this paper to explore the effects of averaging total pressure and total temperature measurements to calculate compressor performance. Different averaging techniques (including area averaging, mass averaging, and work averaging) have been applied to the data. Results show that there is a negligible difference in both the calculated total pressure ratio and efficiency for the different techniques employed. However, the uncertainty in the performance parameters calculated with the different averaging techniques is significantly different, with area averaging providing the least uncertainty.

  10. High precision differential measurement of surface photovoltage transients on ultrathin CdS layers.

    PubMed

    Dittrich, Th; Bönisch, S; Zabel, P; Dube, S

    2008-11-01

    Time-resolved surface photovoltage (SPV) is an important method for studying charge separation, for example, in nanostructured semiconductors. High precision differential measurement of SPV transients was realized with two identical measurement capacitors and high-impedance buffers. In addition, logarithmic readout and averaging procedures were implemented for single transients over eight magnitudes in time. As a model system ultrathin CdS layers were investigated. The thickness dependencies of the SPV amplitudes and that of the dominating relaxation mechanisms are demonstrated and discussed. PMID:19045899

  11. Lightweight Metal Matrix Composite Segmented for Manufacturing High-Precision Mirrors

    NASA Technical Reports Server (NTRS)

    Vudler, Vladimir

    2012-01-01

    High-precision mirrors for space applications are traditionally manufactured from one piece of material, such as lightweight glass sandwich or beryllium. The purpose of this project was to develop and test the feasibility of a manufacturing process capable of producing mirrors out of welded segments of AlBeMet(Registered Trademark) (AM162H). AlBeMet(Registered Trademark) is a HIP'd (hot isostatic pressed) material containing approximately 62% beryllium and 38% aluminum. As a result, AlBeMet shares many of the benefits of both of those materials for use in high performance mirrors, while minimizing many of their weaknesses.

  12. High precision Faraday collector MC-ICPMS thorium isotope ratio determination

    NASA Astrophysics Data System (ADS)

    Potter, Emma-Kate; Stirling, Claudine H.; Andersen, Morten B.; Halliday, Alex N.

    2005-12-01

    Uranium-series dating of carbonate materials requires precise determination of the spike sample thorium isotope ratio, 230Th/229Th. This ratio is commonly measured using ion counting techniques, however the precision of analyses using ion counting devices suffers from beam intensity limitations, drift in multiplier gain and non-linearities in electron multiplier response. Here, we describe the application of multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) to determine thorium isotope ratios at hitherto unattained precision. For the first time, thorium isotope analyses were performed using only Faraday collectors coupled to 1011 [Omega] feedback resistors in the amplifier system. Spiked thorium solutions were concentrated to produce 230Th and 229Th signal intensities of around 50 mV and 100 mV, respectively (across a 1011 [Omega] resistor) and are run at high intensity for a short period of time (~1 min). These analyses yield a 230Th/229Th external reproducibility of better than 0.3[per mille sign] for ~25-30 pg of consumed 230Th. This is a factor of two better than the best published thermal ionisation mass spectrometry (TIMS) and MC-ICPMS techniques for similar sample sizes, and represents up to an order of magnitude improvement over many other established protocols. Combined with new techniques for high precision Faraday measurement of uranium isotopic composition [1], this permits improvements in the uncertainty of U-series ages to better than 0.1 thousand years (ka) at 100 ka and 1 ka at 300 ka. It should also be possible to resolve events to ~14 ka at 600 ka. Using these techniques, the U-series dating limit can be extended from 500-600 ka to 800 ka enabling a more detailed study of the frequency of late Pleistocene climate events.

  13. [Automated recording of precision profiles for the radioimmunological determination of T4 using a pocket calculator of the HP-41 CV type].

    PubMed

    Ditu, M; Waud, J M; Hamilton, R G; Wagner, H N

    1984-01-01

    Precision profiles as useful tool for assurance of assay quality in 10 independent T4RIAs have been automatically obtained using a small programmable pocket calculator HP-41 CV. For each T4 assay batch, the within-assay coefficient of variation varied from 7 to 11% in the hormone concentration range of 2 to 20 micrograms/dl. The difference in coefficient of variation for all the 10 successive assay batches of T4, never exceeded 1% in the same hormone concentrations regions. All the above findings demonstrate that the precision profile can be used as a powerful tool for assessing the assay quality and consistency of overall random error between successive assay batches. PMID:6536211

  14. Precise electromagnetic tests of ab-initio calculations of light nucle i: states in {sup10}Be.

    SciTech Connect

    McCutchan, E. A.; Lister, C. J.; Wiringa, R. B.; Pieper, S. C.; Seweryniak, D.; Greene, J. P.; Carpenter, M. P.; Chiara, C. J.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Stefanescu, I.; Zhu, S.; Physics; Univ. of Maryland

    2009-01-01

    In order to test ab initio calculations of light nuclei, we have remeasured lifetimes in {sup 10}Be using the Doppler shift attenuation method (DSAM) following the {sup 7}Li({sup 7}Li,{alpha}){sup 10}Be reaction at 8 and 10 MeV. The new experiments significantly reduce systematic uncertainties in the DSAM technique. The J{sup TT} = 2{sub 1}{sup +} state at 3.37 MeV has T = 205 {+-} (5){sub stat}{+-}(7){sub sys} fs corresponding to a B(E2{down_arrow}) of 9.2(3)e{sup 2}fm{sup 4} in broad agreement with many calculations. The J{sup TT} = 2{sub 2}{sup +} state at 5.96 MeV was found to have a B(E2{down_arrow}) of 0.11(2)e{sup 2}fm{sup 4} and provides a more discriminating test of nuclear models. New Green's function Monte Carlo calculations for these states and transitions with a number of Hamiltonians are also reported and compared to experiment.

  15. Fast and precise algorithms for calculating offset correction in single photon counting ASICs built in deep sub-micron technologies

    NASA Astrophysics Data System (ADS)

    Maj, P.

    2014-07-01

    An important trend in the design of readout electronics working in the single photon counting mode for hybrid pixel detectors is to minimize the single pixel area without sacrificing its functionality. This is the reason why many digital and analog blocks are made with the smallest, or next to smallest, transistors possible. This causes a problem with matching among the whole pixel matrix which is acceptable by designers and, of course, it should be corrected with the use of dedicated circuitry, which, by the same rule of minimizing devices, suffers from the mismatch. Therefore, the output of such a correction circuit, controlled by an ultra-small area DAC, is not only a non-linear function, but it is also often non-monotonic. As long as it can be used for proper correction of the DC operation points inside each pixel, it is acceptable, but the time required for correction plays an important role for both chip verification and the design of a big, multi-chip system. Therefore, we present two algorithms: a precise one and a fast one. The first algorithm is based on the noise hits profiles obtained during so called threshold scan procedures. The fast correction procedure is based on the trim DACs scan and it takes less than a minute in a SPC detector systems consisting of several thousands of pixels.

  16. A New High-precision Correction Method of Temperature Distribution in Model Stellar Atmospheres

    NASA Astrophysics Data System (ADS)

    Sapar, A.; Poolamäe, R.; Sapar, L.

    The main features of the temperature correction methods, suggested and used in modeling of plane-parallel stellar atmospheres, are discussed. The main features of the new method are described. Derivation of the formulae for a version of the Unsöld-Lucy method, used by us in the SMART (Stellar Model Atmospheres and Radiative Transport) software for modeling stellar atmospheres, is presented. The method is based on a correction of the model temperature distribution based on minimizing differences of flux from its accepted constant value and on the requirement of the lack of its gradient, meaning that local source and sink terms of radiation must be equal. The final relative flux constancy obtainable by the method with the SMART code turned out to have the precision of the order of 0.5 %. Some of the rapidly converging iteration steps can be useful before starting the high-precision model correction. The corrections of both the flux value and of its gradient, like in Unsöld-Lucy method, are unavoidably needed to obtain high-precision flux constancy. A new temperature correction method to obtain high-precision flux constancy for plane-parallel LTE model stellar atmospheres is proposed and studied. The non-linear optimization is carried out by the least squares, in which the Levenberg-Marquardt correction method and thereafter additional correction by the Broyden iteration loop were applied. Small finite differences of temperature (δ T/T=10-3) are used in the computations. A single Jacobian step appears to be mostly sufficient to get flux constancy of the order 10-2 %. The dual numbers and their generalization -- the dual complex numbers (the duplex numbers) -- enable automatically to get the derivatives in the nilpotent part of the dual numbers. A version of the SMART software is in the stage of refactorization to dual and duplex numbers, what enables to get rid of the finite differences, as an additional source of lowering precision of the computed results.

  17. Flux Leakage Measurements for Defect Characterization Using a High Precision 3-AXIAL Gmr Magnetic Sensor

    NASA Astrophysics Data System (ADS)

    Pelkner, M.; Blome, M.; Reimund, V.; Thomas, H.-M.; Kreutzbruck, M.

    2011-06-01

    High-precision magnetic field sensors are of increasing interest in non destructive testing (NDT). In particular GMR-sensors (giant magneto resistance) are qualified because of their high sensitivity, high signal-to-noise ratio and high spatial resolution. With a GMR-gradiometer and a 3D-GMR-magnetometer we performed magnetic flux leakage measurements of artificial cracks and cracks of a depth of ≤50 μm still could be dissolved with a sufficient high signal-to-noise ratio. A semi-analytic magnetic dipole model that allows realistic GMR sensor characteristics to be incorporated is used for swiftly predicting magnetic stray fields. The reliable reconstruction based on measurements of artificial rectangular-shaped defects is demonstrated.

  18. High-precision measurements of the 87Rb D -line tune-out wavelength

    NASA Astrophysics Data System (ADS)

    Leonard, R. H.; Fallon, A. J.; Sackett, C. A.; Safronova, M. S.

    2015-11-01

    We report an experimental measurement of a light wavelength at which the ac electric polarizability equals zero for 87Rb atoms in the F =2 ground hyperfine state. The experiment uses a condensate interferometer both to find this "tune-out" wavelength and to accurately determine the light polarization for it. The wavelength lies between the D 1 and D 2 spectral lines at 790.032388(32) nm. The measurement is sensitive to the tensor contribution to the polarizability, which has been removed so that the reported value is the zero of the scalar polarizability. The precision is 50 times better than previous tune-out wavelength measurements. Our result can be used to determine the ratio of matrix elements |<5 P3 /2||d ||5 S1 /2>/<5 P1 /2||d ||5 S1 /2>|2=1.99221 (3 ) , a 100-fold improvement over previous experimental values. New theoretical calculations for the tune-out wavelength and matrix element ratio are presented. The results are consistent with the experiment, with uncertainty estimates for the theory about an order of magnitude larger than the experimental precision.

  19. High-precision orbit determination for high-earth elliptical orbiters using the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Lichten, S. M.; Estefan, J. A.

    1990-01-01

    Orbit covariance analyses pertaining to the Japanese VLBI Space Observatory Program (VSOP) MUSES-B satellite and to the International VLBI Satellite are presented. It is determined that a combination of Doppler and GPS measurements can provide the orbit accuracy required to support advanced radio interferometric experiments. For the VSOP, the required orbit accuracy of 130 m is easily met with two-way Doppler as the primary type of data; the 0.4 cm/s VSOP velocity requirement is also feasible provided that precise ground calibrations of tropospheric delays and station coordinates are available. It is concluded that combining the data from a VSOP GPS flight instrument with the ground GPS and two-way Doppler data will significantly enhance orbit determination accuracy in position and velocity.

  20. ACT3: A High-speed, High-Precision Electrical Impedance Tomograph

    PubMed Central

    Cook, Raymond D.; Saulnier, Gary J.; Gisser, David G.; Goble, John C.; Newell, JC.; Isaacson, David

    2016-01-01

    This paper presents the design, implementation, and performance of Rensselaer’s third-generation Adaptive Current Tomograph, ACT3. This system uses 32 current sources and 32 phase-sensitive voltmeters to make a 32-electrode system that is capable of applying arbitrary spatial patterns of current. The instrumentation provides 16 b precision on both the current values and the real and reactive voltage readings and can collect the data for a single image in 133 ms. Additionally, the instrument is able to automatically calibrate its voltmeters and current sources and adjust the current source output impedance under computer control. The major system components are discussed in detail and performance results are given. Images obtained using stationary agar targets and a moving pendulum in a phantom as well as in vivo resistivity profiles showing human respiration are shown. PMID:7927393

  1. High speed inlet calculations with real gas effects

    NASA Technical Reports Server (NTRS)

    Coirier, William J.

    1988-01-01

    A 2-D steady-state Navier-Stokes solver has been upgraded to include the effects of frozen and equilibrium air chemistry for applications to high speed flight vehicles. To provide a computationally economical first order approximation to the high temperature physics, variable thermodynamic data is used for the chemically frozen mode to allow for a variation with temperature of the air specific heats and enthalpy. For calculations involving air in chemical equilibrium, a specially modified version of the NASA Lewis Chemical Equilibrium Code, CEC, is used to compute the chemical composition and resultant thermochemical properties. The upgraded solver is demonstrated by comparing results from calorically perfect (C sub p=constant), thermally perfect (frozen) and equilibrium air calculations for a variety of geometries, and flight Mach numbers.

  2. High precision thermal stress study on flip chips by synchrotron polychromatic x-ray microdiffraction

    SciTech Connect

    Chen, Kai; Tamura, Nobumichi; Tang, Wei; Kunz, Martin; Chou, Yi-Chia; Tu, King-Ning; Lai, Yi-Shao

    2010-01-01

    The bending and residual stress of flip chips caused by the mismatch of thermal expansion between the chip and the substrate have been measured by polychromatic microfocused synchrotron x-ray beam. Precise orientation information as a function of position on the chip was obtained from Laue diffraction patterns, so that the bending angle with respect to a reference position at the center of the chip can be calculated at each position. This in turn allows deducing the local curvature of the entire flip chip. Local stress distribution was then mapped by applying a modified Stoney's stress-strain equation to the measured curvature. Our study shows that thermal stress on the circuits and the solder joints in a flip chip strongly depend on temperature and the distance from the center of the chip, indicating that interconnects at the corner and edge of a flip chip are of reliability concerns.

  3. Proceedings, High-Precision $\\alpha_s$ Measurements from LHC to FCC-ee

    SciTech Connect

    d'Enterria, David; Skands, Peter Z.

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experimental uncertainties associated to each extraction method, the improvements expected from LHC data in the coming years, and future perspectives achievable in $e^+e^-$ collisions at the Future Circular Collider (FCC-ee) with $\\cal{O}$(1--100 ab$^{-1}$) integrated luminosities yielding 10$^{12}$ Z bosons and jets, and 10$^{8}$ W bosons and $\\tau$ leptons, are thoroughly reviewed. The current uncertainty of the (preliminary) 2015 strong coupling world-average value, $\\alpha_s(m_Z)$ = 0.1177 $\\pm$ 0.0013, is about 1\\%. Some participants believed this may be reduced by a factor of three in the near future by including novel high-precision observables, although this opinion was not universally shared. At the FCC-ee facility, a factor of ten reduction in the $\\alpha_s$ uncertainty should be possible, mostly thanks to the huge Z and W data samples available.

  4. A High Precision Method for Quantitative Measurements of Reactive Oxygen Species in Frozen Biopsies

    PubMed Central

    Lindgren, Mikael; Gustafsson, Håkan

    2014-01-01

    Objective An electron paramagnetic resonance (EPR) technique using the spin probe cyclic hydroxylamine 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH) was introduced as a versatile method for high precision quantification of reactive oxygen species, including the superoxide radical in frozen biological samples such as cell suspensions, blood or biopsies. Materials and Methods Loss of measurement precision and accuracy due to variations in sample size and shape were minimized by assembling the sample in a well-defined volume. Measurement was carried out at low temperature (150 K) using a nitrogen flow Dewar. The signal intensity was measured from the EPR 1st derivative amplitude, and related to a sample, 3-carboxy-proxyl (CP•) with known spin concentration. Results The absolute spin concentration could be quantified with a precision and accuracy better than ±10 µM (k = 1). The spin concentration of samples stored at −80°C could be reproduced after 6 months of storage well within the same error estimate. Conclusion The absolute spin concentration in wet biological samples such as biopsies, water solutions and cell cultures could be quantified with higher precision and accuracy than normally achievable using common techniques such as flat cells, tissue cells and various capillary tubes. In addition; biological samples could be collected and stored for future incubation with spin probe, and also further stored up to at least six months before EPR analysis, without loss of signal intensity. This opens for the possibility to store and transport incubated biological samples with known accuracy of the spin concentration over time. PMID:24603936

  5. High-precision molecular dynamics simulation of UO2-PuO2: Anion self-diffusion in UO2

    NASA Astrophysics Data System (ADS)

    Potashnikov, S. I.; Boyarchenkov, A. S.; Nekrasov, K. A.; Kupryazhkin, A. Ya.

    2013-02-01

    Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the approximation of rigid ions and pair interactions (RIPI) using high-performance graphics processors (GPU). In this article we study self-diffusion mechanisms of oxygen anions in uranium dioxide (UO2) with the 10 recent and widely used sets of interatomic pair potentials (SPP) under periodic (PBC) and isolated (IBC) boundary conditions. Wide range of measured diffusion coefficients (from 10-3 cm2/s at melting point down to 10-12 cm2/s at 1400 K) made possible a direct comparison (without extrapolation) of the simulation results with the experimental data, which have been known only at low temperatures (T < 1500 K). A highly detailed (with the temperature step of 1 K) calculation of the diffusion coefficient allowed us to plot temperature dependences of the diffusion activation energy and its derivative, both of which show a wide (˜1000 K) superionic transition region confirming the broad λ-peaks of heat capacity obtained by us earlier. It is shown that regardless of SPP the anion self-diffusion in model crystals without surface or artificially embedded defects goes on via exchange mechanism, rather than interstitial or vacancy mechanisms suggested by the previous works. The activation energy of exchange diffusion turned out to coincide with the anti-Frenkel defect formation energy calculated by the lattice statics.

  6. Research on a kind of high precision and fast signal processing algorithm for FM/CW laser radar

    NASA Astrophysics Data System (ADS)

    Xu, Xinke; Liu, Guodong; Chen, Fengdong; Liu, Bingguo; Zhuang, Zhitao; Lu, Cheng; Gan, Yu

    2014-12-01

    Range accuracy and efficiency are two important indicators for Frequency modulated continuous wave (FM/CW) laser radar, improving the accuracy and efficiency of extracting beat frequency are key factors for them. Multiple Modulation Zoom Spectrum Analysis (ZFFT) and the Chirp-Z Transform (CZT) are two widely used methods for improving frequency estimation. The paper through analyze advantages and disadvantages of these methods, proposes a high accuracy and fast signal processing method which is ZFFT-CZT, it combines advantages that ZFFT can reduce data size, and CZT can zoom in frequency of any interested band. The processing of ZFFT-CZT is following: firstly ZFFT is conducted by conducting Fourier transform on short time signal to calculate amount of frequency shift, and transforming high-frequency signal into low-frequency signal of long time sampling, then CZT is conducted by choosing any interested band to continue subdividing the spectral peaks, which can reduce picket fence effect. By simulate experiment based on ZFFT-CZT method, two closed targets at distance of 50m and 50.001m are measured, and the measurement errors are 40μm and 34μm respectively. It proved that ZFFT-CZT has a small amount of calculation, which can meet the requirement of high precision frequency extraction.

  7. Indirect Terahertz Spectroscopy of Molecular Ions Using Highly Accurate and Precise Mid-Ir Spectroscopy

    NASA Astrophysics Data System (ADS)

    Mills, Andrew A.; Ford, Kyle B.; Kreckel, Holger; Perera, Manori; Crabtree, Kyle N.; McCall, Benjamin J.

    2009-06-01

    With the advent of Herschel and SOFIA, laboratory methods capable of providing molecular rest frequencies in the terahertz and sub-millimeter regime are increasingly important. As of yet, it has been difficult to perform spectroscopy in this wavelength region due to the limited availability of radiation sources, optics, and detectors. Our goal is to provide accurate THz rest frequencies for molecular ions by combining previously recorded microwave transitions with combination differences obtained from high precision mid-IR spectroscopy. We are constructing a Sensitive Resolved Ion Beam Spectroscopy setup which will harness the benefits of kinematic compression in a molecular ion beam to enable very high resolution spectroscopy. This ion beam is interrogated by continuous-wave cavity ringdown spectroscopy using a home-made widely tunable difference frequency laser that utilizes two near-IR lasers and a periodically-poled lithium niobate crystal. Here, we report our efforts to optimize our ion beam spectrometer and to perform high-precision and high-accuracy frequency measurements using an optical frequency comb. footnote

  8. Thermoresponsive Ultrathin Membranes with Precisely Tuned Nanopores for High-Flux Separation.

    PubMed

    Zhu, Yuzhang; Gao, Shoujian; Hu, Liang; Jin, Jian

    2016-06-01

    With the growing demand for small- and large-scale bioprocesses, advanced membranes with high energy efficiency are highly required. However, conventional polymer-based membranes often have to sacrifice selectivity for permeability. In this work, we report the fabrication of a thermoresponsive composite ultrathin membrane with precisely controlled nanopores for high-throughput separation. The composite membrane is made by grafting a PEG analogue thermoresponsive copolymer onto an ultrathin single-wall carbon nanotubes (SWCNTs) membrane via π-π interaction with no use of the common "grafting from" synthesis approach. The composite membrane exhibits ultrahigh water permeation flux as high as 6430 L m(-2) h(-1) at 40 °C, and more importantly, the pore size of the membrane could be finely adjusted by utilizing the thermoresponsive property of the grafted copolymer. With the temperature changing below and above the lower critical solution temperature (LCST) of the copolymer, the effective pore size of the membrane can be tuned precisely between approximately 12 and 14 nm, which could be applied to effectively separate materials with very small size differences through size sieving. PMID:27177239

  9. Novel technique for high-precision Bragg-angle determination in crystal x-ray spectroscopy

    SciTech Connect

    Braun, J.; Bruhns, H.; Trinczek, M.; Lopez-Urrutia, J. R. Crespo; Ullrich, J.

    2005-07-15

    A novel technique for a high-precision large acceptance determination of the Bragg angle in crystal x-ray spectroscopy is presented and demonstrated. The method exploits visible light beams as fiducials reflected on the x-ray crystal's surface to ensure exact knowledge of the position on the crystal at which the x rays are reflected, replacing entrance slits, thus making flat crystals suitable for low x-ray fluxes. It can be shown that many error sources arising from uncertainties in the determination of geometrical properties are eliminated in this way. A flat crystal x-ray spectrometer based on this technique has been designed, built, and tested using the most precisely known wavelengths emitted by highly charged ions, namely H- and He-like argon. The result for the 1s2p {sup 1}P{sub 1}{yields}1s{sup 2} {sup 1}S{sub 0} w-line of He-like argon exhibits a statistical uncertainty of 3.8 ppm and an estimated systematic error of about 3 ppm, thus becoming the most accurate measurement of the He-like resonance transition in highly charged ions. It is shown that achieving a systematic error of below 1 ppm is feasible with this method. Therefore, our technique should allow reaching total accuracies approaching 1 ppm on transitions of mid-Z highly charged ions, which would provide challenging tests for state-of-the-art theoretical predictions.

  10. High-precision determination of iron oxidation state in silicate glasses using XANES

    SciTech Connect

    Cottrell, Elizabeth; Kelley, Katherine A.; Lanzirotti, Antonio; Fischer, Rebecca A.

    2009-11-04

    Fe K-edge X-ray absorption near-edge structure (XANES) and Moessbauer spectra were collected on natural basaltic glasses equilibrated over a range of oxygen fugacity (QFM - 3.5 to QFM + 4.5). The basalt compositions and fO{sub 2} conditions were chosen to bracket the natural range of redox conditions expected for basalts from mid-ocean ridge, ocean island, back-arc basin, and arc settings, in order to develop a high-precision calibration for the determination of Fe{sup 3+}/{Sigma}Fe in natural basalts. The pre-edge centroid energy, corresponding to the 1s {yields} 3d transition, was determined to be the most robust proxy for Fe oxidation state, affording significant advantages compared to the use of other spectral features. A second-order polynomial models the correlation between the centroid and Fe{sup 3+}/{Sigma}Fe, yielding a precision of {+-} 0.0045 in Fe{sup 3+}/{Sigma}Fe for glasses with Fe{sup 3+}/{Sigma}Fe > 8%, which is comparable to the precision of wet chemistry. This high precision relies on a Si (311) monochromator to better define the Fe{sup 2+} and Fe{sup 3+} transitions, accurate and robust modeling of the pre-edge feature, dense fO{sub 2}-coverage and compositional appropriateness of reference glasses, and application of a non-linear drift correction. Through re-analysis of the reference glasses across three synchrotron beam sessions, we show that the quoted precision can be achieved (i.e., analyses are reproducible) across multiple synchrotron beam sessions, even when spectral collection conditions (detector parameters or sample geometry) change. Rhyolitic glasses were also analyzed and yield a higher centroid energy at a given Fe{sup 3+}/{Sigma}Fe than basalts, implying that major variations in melt structure affect the relationship between centroid position and Fe{sup 3+}/{Sigma}Fe, and that separate calibrations are needed for the determination of oxidation state in basalts and rhyolites.

  11. Cygnus OB2 DANCe: A high-precision proper motion study of the Cygnus OB2 association

    NASA Astrophysics Data System (ADS)

    Wright, Nicholas J.; Bouy, Herve; Drew, Janet E.; Sarro, Luis Manuel; Bertin, Emmanuel; Cuillandre, Jean-Charles; Barrado, David

    2016-08-01

    We present a high-precision proper motion study of 873 X-ray and spectroscopically selected stars in the massive OB association Cygnus OB2 as part of the DANCe project. These were calculated from images spanning a 15 yr baseline and have typical precisions <1 mas yr-1. We calculate the velocity dispersion in the two axes to be σ _α (c) = 13.0^{+0.8}_{-0.7} and σ _δ (c) = 9.1^{+0.5}_{-0.5} km s-1, using a two-component, two-dimensional model that takes into account the uncertainties on the measurements. This gives a three-dimensional velocity dispersion of σ3D = 17.8 ± 0.6 km s-1 implying a virial mass significantly larger than the observed stellar mass, confirming that the association is gravitationally unbound. The association appears to be dynamically unevolved, as evidenced by considerable kinematic substructure, non-isotropic velocity dispersions and a lack of energy equipartition. The proper motions show no evidence for a global expansion pattern, with approximately the same amount of kinetic energy in expansion as there is in contraction, which argues against the association being an expanded star cluster disrupted by process such as residual gas expulsion or tidal heating. The kinematic substructures, which appear to be close to virial equilibrium and have typical masses of 40-400 M⊙, also do not appear to have been affected by the expulsion of the residual gas. We conclude that Cyg OB2 was most likely born highly substructured and globally unbound, with the individual subgroups born in (or close to) virial equilibrium, and that the OB association has not experienced significant dynamical evolution since then.

  12. Cygnus OB2 DANCe: A high-precision proper motion study of the Cygnus OB2 association

    NASA Astrophysics Data System (ADS)

    Wright, Nicholas J.; Bouy, Herve; Drew, Janet E.; Sarro, Luis Manuel; Bertin, Emmanuel; Cuillandre, Jean-Charles; Barrado, David

    2016-08-01

    We present a high-precision proper motion study of 873 X-ray and spectroscopically selected stars in the massive OB association Cygnus OB2 as part of the DANCe project. These were calculated from images spanning a 15 year baseline and have typical precisions < 1 mas/yr. We calculate the velocity dispersion in the two axes to be $\\sigma_\\alpha(c) = 13.0^{+0.8}_{-0.7}$ and $\\sigma_\\delta(c) = 9.1^{+0.5}_{-0.5}$ km/s, using a 2-component, 2-dimensional model that takes into account the uncertainties on the measurements. This gives a 3-dimensional velocity dispersion of $\\sigma_{3D} = 17.8 \\pm 0.6$ km/s implying a virial mass significantly larger than the observed stellar mass, confirming that the association is gravitationally unbound. The association appears to be dynamically unevolved, as evidenced by considerable kinematic substructure, non-isotropic velocity dispersions and a lack of energy equipartition. The proper motions show no evidence for a global expansion pattern, with approximately the same amount of kinetic energy in expansion as there is in contraction, which argues against the association being an expanded star cluster disrupted by process such as residual gas expulsion or tidal heating. The kinematic substructures, which appear to be close to virial equilibrium and have typical masses of 40-400 M$_\\odot$, also do not appear to have been affected by the expulsion of the residual gas. We conclude that Cyg OB2 was most likely born highly substructured and globally unbound, with the individual subgroups born in (or close to) virial equilibrium, and that the OB association has not experienced significant dynamical evolution since then.

  13. High-Precision Distribution of Highly Stable Optical Pulse Trains with 8.8 × 10-19 instability

    NASA Astrophysics Data System (ADS)

    Ning, B.; Zhang, S. Y.; Hou, D.; Wu, J. T.; Li, Z. B.; Zhao, J. Y.

    2014-05-01

    The high-precision distribution of optical pulse trains via fibre links has had a considerable impact in many fields. In most published work, the accuracy is still fundamentally limited by unavoidable noise sources, such as thermal and shot noise from conventional photodiodes and thermal noise from mixers. Here, we demonstrate a new high-precision timing distribution system that uses a highly precise phase detector to obviously reduce the effect of these limitations. Instead of using photodiodes and microwave mixers, we use several fibre Sagnac-loop-based optical-microwave phase detectors (OM-PDs) to achieve optical-electrical conversion and phase measurements, thereby suppressing the sources of noise and achieving ultra-high accuracy. The results of a distribution experiment using a 10-km fibre link indicate that our system exhibits a residual instability of 2.0 × 10-15 at1 s and8.8 × 10-19 at 40,000 s and an integrated timing jitter as low as 3.8 fs in a bandwidth of 1 Hz to 100 kHz. This low instability and timing jitter make it possible for our system to be used in the distribution of optical-clock signals or in applications that require extremely accurate frequency/time synchronisation.

  14. High-Precision Distribution of Highly Stable Optical Pulse Trains with 8.8 × 10−19 instability

    PubMed Central

    Ning, B.; Zhang, S. Y.; Hou, D.; Wu, J. T.; Li, Z. B.; Zhao, J. Y.

    2014-01-01

    The high-precision distribution of optical pulse trains via fibre links has had a considerable impact in many fields. In most published work, the accuracy is still fundamentally limited by unavoidable noise sources, such as thermal and shot noise from conventional photodiodes and thermal noise from mixers. Here, we demonstrate a new high-precision timing distribution system that uses a highly precise phase detector to obviously reduce the effect of these limitations. Instead of using photodiodes and microwave mixers, we use several fibre Sagnac-loop-based optical-microwave phase detectors (OM-PDs) to achieve optical-electrical conversion and phase measurements, thereby suppressing the sources of noise and achieving ultra-high accuracy. The results of a distribution experiment using a 10-km fibre link indicate that our system exhibits a residual instability of 2.0 × 10−15 at1 s and8.8 × 10−19 at 40,000 s and an integrated timing jitter as low as 3.8 fs in a bandwidth of 1 Hz to 100 kHz. This low instability and timing jitter make it possible for our system to be used in the distribution of optical-clock signals or in applications that require extremely accurate frequency/time synchronisation. PMID:24870442

  15. Low phase noise high power handling InGaAs photodiodes for precise timing applications

    NASA Astrophysics Data System (ADS)

    Datta, Shubhashish; Joshi, Abhay; Becker, Don

    2009-05-01

    Time is the most precisely measured physical quantity. Such precision is achieved by optically probing hyperfine atomic transitions. These high Q-factor resonances demonstrate frequency instability of ~10-18 over 1 s observation time. Conversion of such a stable optical clock signal to an electrical clock through photodetection introduces additional phase noise, thereby resulting in a significant degradation in the frequency stability. This excess phase noise is primarily caused by the conversion of optical intensity noise into electrical phase noise by the phase non-linearity of the photodetector, characterized by its power-to-phase conversion factor. It is necessary to minimize this phase nonlinearity in order to develop the next generation of ultra-high precision electronic clocks. Reduction in excess phase noise must be achieved while ensuring a large output RF signal generated by the photodetector. The phase linearity in traditional system designs that employ a photoreceiver, namely a photodiode followed by a microwave amplifier, is limited by the phase non-linearity of the amplifier. Utilizing high-power handling photodiodes eliminates the need of microwave amplifiers. In this work, we present InGaAs p-i-n photodiodes that display a power-to-phase conversion factor <6 rad/W at a peak-to-peak RF output amplitude of 2 V. In comparison, the photodiode coupled to a transimpedance amplifier demonstrates >44 rad/W at a peak-to-peak RF output amplitude of 0.5 V. These results are supported by impulse response measurements at 1550 nm wavelength at 1 GHz repetition rate. These photodiodes are suitable of applications such as optical clock distribution networks, photonic analog-to-digital converters, and phased array radars.

  16. High-Precision Dispensing of Nanoliter Biofluids on Glass Pedestal Arrays for Ultrasensitive Biomolecule Detection.

    PubMed

    Chen, Xiaoxiao; Liu, Yang; Xu, QianFeng; Zhu, Jing; Poget, Sébastien F; Lyons, Alan M

    2016-05-01

    Precise dispensing of nanoliter droplets is necessary for the development of sensitive and accurate assays, especially when the availability of the source solution is limited. Conventional approaches are limited by imprecise positioning, large shear forces, surface tension effects, and high costs. To address the need for precise and economical dispensing of nanoliter volumes, we developed a new approach where the dispensed volume is dependent on the size and shape of defined surface features, thus freeing the dispensing process from pumps and fine-gauge needles requiring accurate positioning. The surface we fabricated, called a nanoliter droplet virtual well microplate (nVWP), achieves high-precision dispensing (better than ±0.5 nL or ±1.6% at 32 nL) of 20-40 nL droplets using a small source drop (3-10 μL) on isolated hydrophilic glass pedestals (500 μm on a side) bonded to arrays of polydimethylsiloxane conical posts. The sharp 90° edge of the glass pedestal pins the solid-liquid-vapor triple contact line (TCL), averting the wetting of the glass sidewalls while the fluid is prevented from receding from the edge. This edge creates a sufficiently large energy barrier such that microliter water droplets can be poised on the glass pedestals, exhibiting contact angles greater >150°. This approach relieves the stringent mechanical alignment tolerances required for conventional dispensing techniques, shifting the control of dispensed volume to the area circumscribed by the glass edge. The effects of glass surface chemistry and dispense velocity on droplet volume were studied using optical microscopy and high-speed video. Functionalization of the glass pedestal surface enabled the selective adsorption of specific peptides and proteins from synthetic and natural biomolecule mixtures, such as venom. We further demonstrate how the nVWP dispensing platform can be used for a variety of assays, including sensitive detection of proteins and peptides by fluorescence

  17. A novel approach for high precision rapid potentiometric titrations: Application to hydrazine assay

    NASA Astrophysics Data System (ADS)

    Sahoo, P.; Malathi, N.; Ananthanarayanan, R.; Praveen, K.; Murali, N.

    2011-11-01

    We propose a high precision rapid personal computer (PC) based potentiometric titration technique using a specially designed mini-cell to carry out redox titrations for assay of chemicals in quality control laboratories attached to industrial, R&D, and nuclear establishments. Using this technique a few microlitre of sample (50-100 μl) in a total volume of ˜2 ml solution can be titrated and the waste generated after titration is extremely low comparing to that obtained from the conventional titration technique. The entire titration including online data acquisition followed by immediate offline analysis of data to get information about concentration of unknown sample is completed within a couple of minutes (about 2 min). This facility has been created using a new class of sensors, viz., pulsating sensors developed in-house. The basic concept in designing such instrument and the salient features of the titration device are presented in this paper. The performance of the titration facility was examined by conducting some of the high resolution redox titrations using dilute solutions--hydrazine against KIO3 in HCl medium, Fe(II) against Ce(IV) and uranium using Davies-Gray method. The precision of titrations using this innovative approach lies between 0.048% and 1.0% relative standard deviation in different redox titrations. With the evolution of this rapid PC based titrator it was possible to develop a simple but high precision potentiometric titration technique for quick determination of hydrazine in nuclear fuel dissolver solution in the context of reprocessing of spent nuclear fuel in fast breeder reactors.

  18. Precision equation of state measurements on hydrocarbons in the high energy density regime

    NASA Astrophysics Data System (ADS)

    Barrios Garcia, Maria Alejandra

    The equation of state (EOS) of materials at extreme temperatures and pressures is of interest to astrophysics, high-energy-density physics, and inertial confinement fusion (ICF). The behavior of hydrocarbon materials at high-pressures (>1 Mbar) is essential to the understanding of ablator materials for ICF ignition targets. The EOS measurements on CHX presented here provide benchmark behavior of hydrocarbons under extreme conditions and the effect of stoichiometry (i.e. C:H ratio) on that behavior. Advances in diagnostics and analysis have made it possible to perform highly accurate measurements of shock velocity to ˜1% precision in transparent materials. This refines the impedance-match (IM) technique for laser-driven shock experiments producing precise EOS data at extreme pressures using a transparent standard such as alpha-quartz. The OMEGA laser was used to produce principal (single-shock) Hugoniot EOS measurements on polystyrene (CH), polypropylene (CH2), Glow-Discharge-Polymer (GDP) (C43H56O), and Germanium-doped GDP at shock pressures of 1--10 Mbar, with an alpha-quartz standard. This precision data tightly constrains the Hugoniot behavior of these hydrocarbons, even with the inclusion of systematic uncertainties inherent in the IM technique. A novel target design providing double-shock (re-shock) measurements along with principal Hugoniot data is presented. Results of the single-and double-shock experiments on these hydrocarbons are presented and compared to various EOS models. Temperature measurements are presented for CH and CH2; measuring both the thermal and kinematic behavior of these materials provides their complete shock EOS. Reflectance measurements on CH and CH2 show that both hydrocarbons transition from transparent insulators to reflecting conductors at pressures of 1 to 2 Mbar.

  19. Real-space method for highly parallelizable electronic transport calculations

    NASA Astrophysics Data System (ADS)

    Feldman, Baruch; Seideman, Tamar; Hod, Oded; Kronik, Leeor

    2014-07-01

    We present a real-space method for first-principles nanoscale electronic transport calculations. We use the nonequilibrium Green's function method with density functional theory and implement absorbing boundary conditions (ABCs, also known as complex absorbing potentials, or CAPs) to represent the effects of the semi-infinite leads. In real space, the Kohn-Sham Hamiltonian matrix is highly sparse. As a result, the transport problem parallelizes naturally and can scale favorably with system size, enabling the computation of conductance in relatively large molecular junction models. Our use of ABCs circumvents the demanding task of explicitly calculating the leads' self-energies from surface Green's functions, and is expected to be more accurate than the use of the jellium approximation. In addition, we take advantage of the sparsity in real space to solve efficiently for the Green's function over the entire energy range relevant to low-bias transport. We illustrate the advantages of our method with calculations on several challenging test systems and find good agreement with reference calculation results.

  20. High precision measurements of the neutron spin structure in Hall A at Jlab

    SciTech Connect

    Annand, R M; Cates, G; Cisbani, E; Franklin, G B; Liyanage, N; Puckett, A; Rosner, G; Wojtsekhowski, B; Zheng, X

    2012-04-01

    Conclusions of this presentation are: (1) JLab energy upgrade will offer new exciting opportunities to study the nucleon (spin) structure such as high precision, unexplored phase space, flavor decomposition; (2) Large technological efforts is in progress to optimally exploit these opportunities; (3) HallA will be the first hall to get the new beam, first experiment expected to run in 2014; (4) A1n likely one of the first experiments to take data in the new 12 GeV era; and (5) SIDIS exp. will follow in couple of years.

  1. Development of laser interferometric high-precision geometry monitor for JASMINE

    NASA Astrophysics Data System (ADS)

    Niwa, Yoshito; Arai, Koji; Ueda, Akitoshi; Sakagami, Masaaki; Gouda, Naoteru; Kobayashi, Yukiyasu; Yamada, Yoshiyuki; Yano, Taihei

    2008-07-01

    The telescope geometry of JASMINE should be stabilized and monitored with the accuracy of about 10 to 100 picometer or 10 to 100 picoradian in root-mean-square over about 10 hours. For this purpose, a high-precision interferometric laser metrology system is employed. One of useful techniques for measuring displacements in extremely minute scales is the heterodyne interferometrical method. Experiment for verification of multi degree of freedom measurement was performed and mirror motions were successfully monitored with three degree of freedom.

  2. A High Precision Scanning Control System For A VUV Fourier Transform Spectrometer

    SciTech Connect

    De Oliveira, N.; Nahon, L.; Polack, F.; Joyeux, D.; Phalippou, D.; Rodier, J. C.; Vervloeet, M.

    2007-01-19

    A VUV Fourier transform spectrometer based on a wavefront division interferometer has been built. Our ultimate goal is to provide a high resolution absorption spectrometer in the 140 - 40 nm range using the new third generation French synchrotron source Soleil as the background continuum. Here, we present the design and latest performance of the instrument scanning control system. It is based on multiple reflections of a monomode, frequency-stabilized HeNe laser between two plane mirrors allowing the required sensitivity on the displacement of the interferometer mobile arm. The experimental results on the sampling precision show an rms error below 5 nm for a travel length of 7.5 mm.

  3. Improving suppression ratio of microwave photonic filters using high-precision spectral shaping

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Li, Shangyuan; Liao, Jinxin; Zheng, Xiaoping; Zhang, Hanyi; Zhou, Bingkun

    2015-05-01

    The main-to-sidelobe suppression ratio (MSSR) is significant to filters. The tap weight errors worsen the MSSR of the finite impulse response (FIR) microwave photonic filters (MPFs). The MSSR can be improved by shaping the multicarrier optical source spectra with high precision. By compensating the errors with an iteration method, the sidelobes of the amplitude response can be optimized to increase the MSSR. Such a method is simple, effective, and compatible with all FIR MPF approaches. In the experiment, optical spectra of Gaussian profiles were taken as an example, and an MSSR improvement from 50 to 63 dB was demonstrated.

  4. Asynchronous RTK precise DGNSS positioning method for deriving a low-latency high-rate output

    NASA Astrophysics Data System (ADS)

    Liang, Zhang; Hanfeng, Lv; Dingjie, Wang; Yanqing, Hou; Jie, Wu

    2015-07-01

    Low-latency high-rate (1 Hz) precise real-time kinematic (RTK) can be applied in high-speed scenarios such as aircraft automatic landing, precise agriculture and intelligent vehicle. The classic synchronous RTK (SRTK) precise differential GNSS (DGNSS) positioning technology, however, is not able to obtain a low-latency high-rate output for the rover receiver because of long data link transmission time delays (DLTTD) from the reference receiver. To overcome the long DLTTD, this paper proposes an asynchronous real-time kinematic (ARTK) method using asynchronous observations from two receivers. The asynchronous observation model (AOM) is developed based on undifferenced carrier phase observation equations of the two receivers at different epochs with short baseline. The ephemeris error and atmosphere delay are the possible main error sources on positioning accuracy in this model, and they are analyzed theoretically. In a short DLTTD and during a period of quiet ionosphere activity, the main error sources decreasing positioning accuracy are satellite orbital errors: the "inverted ephemeris error" and the integration of satellite velocity error which increase linearly along with DLTTD. The cycle slip of asynchronous double-differencing carrier phase is detected by TurboEdit method and repaired by the additional ambiguity parameter method. The AOM can deal with synchronous observation model (SOM) and achieve precise positioning solution with synchronous observations as well, since the SOM is only a specific case of AOM. The proposed method not only can reduce the cost of data collection and transmission, but can also support the mobile phone network data link transfer mode for the data of the reference receiver. This method can avoid data synchronizing process besides ambiguity initialization step, which is very convenient for real-time navigation of vehicles. The static and kinematic experiment results show that this method achieves 20 Hz or even higher rate output in

  5. On the recovery of gravity anomalies from high precision altimeter data

    NASA Technical Reports Server (NTRS)

    Lelgemann, D.

    1976-01-01

    A model for the recovery of gravity anomalies from high precision altimeter data is derived which consists of small correction terms to the inverse Stokes' formula. The influence of unknown sea surface topography in the case of meandering currents such as the Gulf Stream is discussed. A formula was derived in order to estimate the accuracy of the gravity anomalies from the known accuracy of the altimeter data. It is shown that for the case of known harmonic coefficients of lower order the range of integration in Stokes inverse formula can be reduced very much.

  6. Graphic overlays in high-precision teleoperation: Current and future work at JPL

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.; Venema, Steven C.

    1989-01-01

    In space teleoperation additional problems arise, including signal transmission time delays. These can greatly reduce operator performance. Recent advances in graphics open new possibilities for addressing these and other problems. Currently a multi-camera system with normal 3-D TV and video graphics capabilities is being developed. Trained and untrained operators will be tested for high precision performance using two force reflecting hand controllers and a voice recognition system to control two robot arms and up to 5 movable stereo or non-stereo TV cameras. A number of new techniques of integrating TV and video graphics displays to improve operator training and performance in teleoperation and supervised automation are evaluated.

  7. Design of a fast and high-precision polygonal scanner for HDTV

    NASA Astrophysics Data System (ADS)

    Risse, Stefan; Guyenot, Volker

    1997-07-01

    With the continuing development of laser-display-technology, a new possibility for the production high level image projection is forwarded and with it the beginning of a new era in television: TV picture formats previously thought impossible, the sharpness, color intensity and unsurpassed resolution of which make the dream of home cinema a reality. The key to this experience is visible laser light in red, green and blue, projected on a screen with the aid of horizontal and vertical deflection units. In this paper, a primarily horizontal deflection system in the form of a rotating polygonal scanner is described. The design of this scanner assembly combines a double spherical air bearing with an integrated polygonal mirror for deflection and a high torque inside drive for quickly reaching high rotation. The Fraunhofer Institute of Applied Optics and Precision Engineering (IOF Jena) develops, from conception to assembled prototype, new self-acting precision bearing systems. This new scanner solution developed out of IOF's previous developments resulting in the first ever sealed, minimal-maintenance, self- acting bearing.

  8. Diode laser-based sensor for high precision measurements of ambient CO2 in network applications

    NASA Astrophysics Data System (ADS)

    Sonnenfroh, D.; Parameswaran, K.

    2011-02-01

    The increasing need for better spatial and temporal measurements of greenhouse gases, especially CO2, to support global climate change modeling is driving the expansion of monitoring networks. Currently, networks making ambient CO2 measurements use environmentally stabilized sensors based on non-dispersive infrared absorption spectroscopy. To expand both measurement capability and coverage, much work is underway to develop highly accurate, reliable yet economical sensors for the greenhouse gases. The US Department of Energy has created specifications for a new sensor that has high performance but at a cost that permits widespread deployment. We report on a sensor designed to meet this need. We have demonstrated a compact, automated, high precision sensor for ambient CO2 that offers good performance in an economical package. The sensor is a near-IR diode laser-based absorption spectrometer operating near 2 μm and using Integrated Cavity Output Spectroscopy (ICOS). Field demonstrations were carried out at both the UNH/AirMap Thompson Farm Observatory and the NOAA Boulder Atmospheric Observatory. The sensor has a demonstrated precision of between 0.090 and 0.125 ppmv for a 30 sec acquisition, or 1 part in 3000 to 4000.

  9. Optimization design about gimbal structure of high-precision autonomous celestial navigation tracking mirror system

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Zhang, Jing; Xie, Mei-lin; Yue, Peng

    2016-01-01

    High precision tracking platform of celestial navigation with control mirror servo structure form, to solve the disadvantages of big volume and rotational inertia, slow response speed, and so on. It improved the stability and tracking accuracy of platform. Due to optical sensor and mirror are installed on the middle-gimbal, stiffness and resonant frequency requirement for high. Based on the application of finite element modality analysis theory, doing Research on dynamic characteristics of the middle-gimbal, and ANSYS was used for the finite element dynamic emulator analysis. According to the result of the computer to find out the weak links of the structure, and Put forward improvement suggestions and reanalysis. The lowest resonant frequency of optimization middle-gimbal avoid the bandwidth of the platform servo mechanism, and much higher than the disturbance frequency of carrier aircraft, and reduces mechanical resonance of the framework. Reaching provides a theoretical basis for the whole machine structure optimization design of high-precision of autonomous Celestial navigation tracking mirror system.

  10. High precision radially-polarized-light pupil-filtering differential confocal measurement

    NASA Astrophysics Data System (ADS)

    Wang, Yun; Qiu, Lirong; Zhao, Weiqian

    2016-08-01

    A new method, high precision radially-polarized light pupil-filtering differential confocal measurement (RPDCM), is proposed to improve the 3D measurement resolution of confocal system. SPDCM uses the property that the radially-polarized-light can produce a strong longitudinal field component after being focused by a high numerical aperture objective to reduce the lateral size of the focus spot, and relies on the pupil-filtering technique to optimize the pupil function of the optical system by the designed pupil filter, which therefore improves the lateral resolution of confocal system, and it uses the differential confocal technology to improve the axial measurement resolution of the confocal system, thereby improves the 3D measurement resolution of the confocal system. Based on RPDCM, we developed a high precision radially-polarized light pupil-filtering differential confocal setup, and use it to verify the effectiveness of RPDCM by experiments. The theoretical analysis and experimental results show that the RPDCM can reach the lateral and axial measurement resolutions of 150 nm and 1 nm, respectively, which are an improvement of 20-32% and 3.7 times compared with a confocal system.

  11. Precision Higgs Physics

    NASA Astrophysics Data System (ADS)

    Boughezal, Radja

    2015-04-01

    The future of the high energy physics program will increasingly rely upon precision studies looking for deviations from the Standard Model. Run I of the Large Hadron Collider (LHC) triumphantly discovered the long-awaited Higgs boson, and there is great hope in the particle physics community that this new state will open a portal onto a new theory of Nature at the smallest scales. A precision study of Higgs boson properties is needed in order to test whether this belief is true. New theoretical ideas and high-precision QCD tools are crucial to fulfill this goal. They become even more important as larger data sets from LHC Run II further reduce the experimental errors and theoretical uncertainties begin to dominate. In this talk, I will review recent progress in understanding Higgs properties,including the calculation of precision predictions needed to identify possible physics beyond the Standard Model in the Higgs sector. New ideas for measuring the Higgs couplings to light quarks as well as bounding the Higgs width in a model-independent way will be discussed. Precision predictions for Higgs production in association with jets and ongoing efforts to calculate the inclusive N3LO cross section will be reviewed.

  12. Neutronic calculations for a new high flux reactor

    SciTech Connect

    Difilippo, F.C.; Worley, B.A.; Vondy, D.R.

    1985-01-01

    The Oak Ridge National Laboratory has begun the design of a new high flux reactor to be used for basic research, isotope production, and material irradiation. One of the principal goals of the design is the production of a thermal flux peak in the reflector larger than 5 x 10/sup 15//cm/sup 2/sec. A theoretical analysis of the slowing-down and diffusion of neutrons produced by a spherical fission source immersed in a moderator shows that the flux per unit power is maximized by combining a very undermoderated core with a very low absorbing reflector. The theoretical model interrelates total power, power density and transport properties with the thermal flux allowing very inexpensive scoping calculations. Full scale and detailed calculations were made with a numerical model which uses the Bold Venture code system. Calculations show that a highly enriched /sup 235/U reactor with D/sub 2/O as moderator and reflector would produce the desired peak flux, and the reactor would have a reasonable core life.

  13. Accelerating experimental high-order spatial statistics calculations using GPUs

    NASA Astrophysics Data System (ADS)

    Li, Xue; Huang, Tao; Lu, De-Tang; Niu, Cong

    2014-09-01

    High-order spatial statistics have been widely used to describe the spatial phenomena in the field of geology science. Spatial statistics are subject to extremely heavy computational burden for large geostatistical models. To improve the computational efficiency, a parallel approach based on GPU (Graphics Processing Unit) is proposed for the calculation of high-order spatial statistics. The parallel scheme is achieved by utilizing a two-stage method to calculate the replicate of a moment for a given template simultaneously termed as the node-stage parallelism, and transform the spatial moments to cumulants for all lags of a template simultaneously termed as the template-stage parallelism. Also, a series of optimization strategies are proposed to take full advantage of the computational capabilities of GPUs, including the appropriate task allocation to the CUDA (Compute Unified Device Architecture) threads, proper organization of the GPU physical memory, and optimal improvement of the existed parallel routines. Tests are carried out on two training images to compare the performance of the GPU-based method with that of the serial implementation. Error analysis results indicate that the proposed parallel method can generate accurate cumulant maps, and the performance comparisons on various examples show that all the speedups for third-order, fourth-order and fifth-order cumulants calculation are over 17 times.

  14. Calculates Neutron Production in Canisters of High-level Waste

    Energy Science and Technology Software Center (ESTSC)

    1993-01-15

    ALPHN calculates the (alpha,n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the (alpha,n) neutron production of each actinide in neutrons per second and the total for the canister. The (alpha,n) neutron production rates are source terms only; that is, they are production rates within the glass andmore » do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister.« less

  15. High-precision comparison of the antiproton-to-proton charge-to-mass ratio.

    PubMed

    Ulmer, S; Smorra, C; Mooser, A; Franke, K; Nagahama, H; Schneider, G; Higuchi, T; Van Gorp, S; Blaum, K; Matsuda, Y; Quint, W; Walz, J; Yamazaki, Y

    2015-08-13

    Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H(-)) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q/m)p- to that for the proton (q/m)p and obtain (q/m)p-/(q/m)p − 1 =1(69) × 10(-12). The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of <720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of |α − 1| < 8.7 × 10(-7). PMID:26268189

  16. First high-precision differential abundance analysis of extremely metal-poor stars

    NASA Astrophysics Data System (ADS)

    Reggiani, Henrique; Meléndez, Jorge; Yong, David; Ramírez, Ivan; Asplund, Martin

    2016-02-01

    Context. Studies of extremely metal-poor stars indicate that chemical abundance ratios [X/Fe] have a root mean square scatter as low as 0.05 dex (12%). It remains unclear whether this reflects observational uncertainties or intrinsic astrophysical scatter arising from physical conditions in the interstellar medium at early times. Aims: We measure differential chemical abundance ratios in extremely metal-poor stars to investigate the limits of precision and to understand whether cosmic scatter or observational errors are dominant. Methods: We used high-resolution (R ~ 95 000) and high signal-to-noise (S/N = 700 at 5000 Å) HIRES/Keck spectra to determine high-precision differential abundances between two extremely metal-poor stars through a line-by-line differential approach. We determined stellar parameters for the star G64-37 with respect to the standard star G64-12. We performed EW measurements for the two stars for the lines recognized in both stars and performed spectral synthesis to study the carbon abundances. Results: The differential approach allowed us to obtain errors of σ(Teff) = 27 K, σ(log g) = 0.06 dex, σ( [Fe/H] ) = 0.02 dex and σ(vt) = 0.06 km s-1. We estimated relative chemical abundances with a precision as low as σ([X/Fe]) ≈ 0.01 dex. The small uncertainties demonstrate that there are genuine abundance differences larger than the measurement errors. The observed Li difference cannot be explained by the difference in mass because the less massive star has more Li. Conclusions: It is possible to achieve an abundance precision around ≈ 0.01-0.05 dex for extremely metal-poor stars, which opens new windows on the study of the early chemical evolution of the Galaxy. Table A.1 is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/586/A67

  17. A low noise and high precision linear power supply with thermal foldback protection

    NASA Astrophysics Data System (ADS)

    Carniti, P.; Cassina, L.; Gotti, C.; Maino, M.; Pessina, G.

    2016-05-01

    A low noise and high precision linear power supply was designed for use in rare event search experiments with macrobolometers. The circuit accepts at the input a "noisy" dual supply voltage up to ±15 V and gives at the output precise, low noise, and stable voltages that can be set between ±3.75 V and ±12.5 V in eight 1.25 V steps. Particular care in circuit design, component selection, and proper filtering results in a noise spectral density of 50 nV / √{ Hz } at 1 Hz and 20 nV / √{ Hz } white when the output is set to ±5 V. This corresponds to 125 nV RMS (0.8 μV peak to peak) between 0.1 Hz and 10 Hz, and 240 nV RMS (1.6 μV peak to peak) between 0.1 Hz and 100 Hz. The power supply rejection ratio (PSRR) of the circuit is 100 dB at low frequency, and larger than 40 dB up to high frequency, thanks to a proper compensation design. Calibration allows to reach a precision in the absolute value of the output voltage of ±70 ppm, or ±350 μV at ±5 V, and to reduce thermal drifts below ±1 ppm/∘C in the expected operating range. The maximum peak output current is about 6 A from each output. An original foldback protection scheme was developed that dynamically limits the maximum output current to keep the temperature of the output transistors within their safe operating range. An add-on card based on an ARM Cortex-M3 microcontroller is devoted to the monitoring and control of all circuit functionalities and provides remote communication via CAN bus.

  18. Optical test bench for high precision metrology and alignment of zoom sub-assembly components

    NASA Astrophysics Data System (ADS)

    Leprêtre, F.; Levillain, E.; Wattellier, B.; Delage, P.; Brahmi, D.; Gascon, A.

    2013-09-01

    Thales Angénieux (TAGX) designs and manufactures zoom lens assemblies for cinema applications. These objectives are made of mobile lens assemblies. These need to be precisely characterized to detect alignment, polishing or glass index homogeneity errors, which amplitude may range to a few hundreds of nanometers. However these assemblies are highly aberrated with mainly spherical aberration (>30 μm PV). PHASICS and TAGX developed a solution based on the use of a PHASICS SID4HR wave front sensor. This is based on quadri-wave lateral shearing interferometry, a technology known for its high dynamic range. A 100-mm diameter He:Ne source illuminates the lens assembly entrance pupil. The transmitted wave front is then directly measured by the SID4- HR. The measured wave front (WFmeas) is then compared to a simulation from the lens sub-assembly optical design (WFdesign). We obtain a residual wave front error (WFmanufactured), which reveals lens imperfections due to its manufacturing. WFmeas=WFdesign+(WFEradius+WFEglass+WFEpolish)=WF design + WFmanufactured The optical test bench was designed so that this residual wave front is measured with a precision below 100 nm PV. The measurement of fast F-Number lenses (F/2) with aberrations up to 30 μm, with a precision of 100 nm PV was demonstrated. This bench detects mismatches in sub-assemblies before the final integration step in the zoom. Pre-alignment is also performed in order to overpass the mechanical tolerances. This facilitates the completed zoom alignment. In final, productivity gains are expected due to alignment and mounting time savings.

  19. A low noise and high precision linear power supply with thermal foldback protection.

    PubMed

    Carniti, P; Cassina, L; Gotti, C; Maino, M; Pessina, G

    2016-05-01

    A low noise and high precision linear power supply was designed for use in rare event search experiments with macrobolometers. The circuit accepts at the input a "noisy" dual supply voltage up to ±15 V and gives at the output precise, low noise, and stable voltages that can be set between ±3.75 V and ±12.5 V in eight 1.25 V steps. Particular care in circuit design, component selection, and proper filtering results in a noise spectral density of 50nV/Hz at 1 Hz and 20nV/Hz white when the output is set to ±5 V. This corresponds to 125 nV RMS (0.8 μV peak to peak) between 0.1 Hz and 10 Hz, and 240 nV RMS (1.6 μV peak to peak) between 0.1 Hz and 100 Hz. The power supply rejection ratio (PSRR) of the circuit is 100 dB at low frequency, and larger than 40 dB up to high frequency, thanks to a proper compensation design. Calibration allows to reach a precision in the absolute value of the output voltage of ±70 ppm, or ±350 μV at ±5 V, and to reduce thermal drifts below ±1 ppm/(∘)C in the expected operating range. The maximum peak output current is about 6 A from each output. An original foldback protection scheme was developed that dynamically limits the maximum output current to keep the temperature of the output transistors within their safe operating range. An add-on card based on an ARM Cortex-M3 microcontroller is devoted to the monitoring and control of all circuit functionalities and provides remote communication via CAN bus. PMID:27250450

  20. Active Focal Zone Sharpening for High-Precision Treatment Using Histotripsy

    PubMed Central

    Wang, Tzu-Yin; Xu, Zhen; Hall, Timothy L.; Fowlkes, J. Brian; Roberts, William W.; Cain, Charles A.

    2011-01-01

    The goal of this study is to develop a focal zone sharpening strategy that produces more precise lesions for pulsed cavitational ultrasound therapy, or histotripsy. Precise and well-confined lesions were produced by locally suppressing cavitation in the periphery of the treatment focus without affecting cavitation in the center. The local suppression of cavitation was achieved using cavitation nuclei preconditioning pulses to actively control cavitation in the periphery of the focus. A 1-MHz 513-element therapeutic array was used to generate both the therapy and the nuclei preconditioning pulses. For therapy, 10-cycle bursts at 100-Hz pulse repetition frequency with P−/P+ pressure of 21/76 MPa were delivered to the geometric focus of the therapeutic array. For nuclei preconditioning, a different pulse was delivered to an annular region immediately surrounding the focus before each therapy pulse. A parametric study on the effective pressure, pulse duration, and delivery time of the preconditioning pulse was conducted in red blood cell-gel phantoms, where cavitational damage was indicated by the color change resulting from local cell lysis. Results showed that a short-duration (20 µs) preconditioning pulse at a medium pressure (P−/P+ pressure of 7.2/13.6 MPa) delivered shortly before (30 µs) the therapy pulse substantially suppressed the peripheral damage by 77 ± 13% while complete fractionation in the focal center was maintained. High-speed imaging of the bubble cloud showed a substantial decrease in the maximum width of the bubble cloud by 48 ± 24% using focal zone sharpening. Experiments in ex vivo livers confirmed that highly confined lesions were produced in real tissues as well as in the phantoms. This study demonstrated the feasibility of active focal zone sharpening using cavitation nuclei preconditioning, allowing for increased treatment precision compared with the natural focal width of the therapy transducer. PMID:21342816

  1. The research of the high precision universal stable reconnaissance platform in near space

    NASA Astrophysics Data System (ADS)

    Yang, Hong-tao; Cao, Jian-zhong; Fan, Zhe-yuan; Chen, Wei-ning

    2011-08-01

    The appliance of military was recognized more and more ,It is important that pod can bear the weight of the availability payload achieve the observation to the earth in 20km-100km area and work in the all-weather. The stable platform can load high imaging spectrometer, the thermal infrared imager, the infrared radiometer, the millimeter waves radar, the laser weapon and so on,in order to realize reconnaissance and attacking integrative and warning the long-distant missile. The stabilization accuracy of platform is prior to 20μrad and burden heavy load to the best of one's abilities. It used high precision velocity and acceleration gyroscope to fulfill the stabilization of the platform. Light-weight design by using new composite material and optimizing design. It was adapt to the near space environment better by structure design and simulation analysis.Enhance its basic frequency and sure the rigid of the frame platform .In addition, the structure of platform apply the two-axis and four-frame and use the method of FEA to fulfill the optimum design in order to attain the object of light-weight.In consider to the precision of the platform I establish the math model and make use of the monte carlo method to appraise and analysis the error that affect the precision of the platform. After emulating by the software of the Matlab to verify the results. It is apply the method that link the platform and aerocraft by mounting the no angular displacement shock absorbers on the elevator mechanism. This kind of design insulate the angular vibration and minish the linear vibration to ensure the image quality.

  2. Dichroism in the pseudogap phase observed through high precision Sagnac interferometry

    NASA Astrophysics Data System (ADS)

    Schemm, Elizabeth

    2008-03-01

    Polar Kerr effect in the high-Tc superconductor YBa2Cu3O6+xootnotetextJing Xia, Elizabeth Schemm, G. Deutscher, S. A. Kivelson, D. A. Bonn, W. N. Hardy, R. Liang, W. Siemons, G. Koster, M. M. Fejer, and A. Kapitulnik, arXiv:0711.2494 (2007). was measured at zero magnetic field with high precision using a cryogenic Sagnac fiber interferometer. We observed non-zero Kerr rotations on the order of ˜ 1 μrad appearing near the pseudogap temperature T^*, and marking what appears to be a true phase transition. Anomalous magnetic behavior in magnetic-field training of the effect suggests that time reversal symmetry is already broken above room temperature. We will show results from single crystals and oriented films. Preliminary results on other high-temperature superconductors will also be discussed. Work done in collaboration with Jing Xia and Aharon Kapitulnik.

  3. First measurement of efficiency and precision of CCD detectors for high energy physics

    NASA Astrophysics Data System (ADS)

    Bailey, R.; Damerell, C. J. S.; English, R. L.; Gillman, A. R.; Lintern, A. L.; Watts, S. J.; Wickens, F. J.

    1983-08-01

    It has been known for some time that a 2-dimensional charge-coupled device (CCD) might be used for detecting high energy particles with high precision and excellent 2-track resolution. Such detectors could be used to distinguish between prompt tracks and decay products in events producing short-lived particles (heavy leptons, charm, beauty etc.). We now present results in which (for the first time) a telescope of CCD detectors has been operated in a beam of high energy particles. The main results are that even these early detectors have excellent performance characteristics, namely efficiency for track detection of 98±2% per plane, spatial resolution of 4.3 μm and 6.1 μm in two orthogonal directions and 2-track resolution of 40 μm in space.

  4. Improved GPS-based coseismic displacement monitoring using high-precision oscillators

    NASA Astrophysics Data System (ADS)

    Weinbach, U.; Schön, S.

    2015-05-01

    The determination of high-frequency displacements using Global Navigation Satellite Systems (GNSS) observations with sampling frequencies > 1 Hz has attracted much interest in recent years, e.g., in seismology. We propose a new concept for GPS Precise Point Positioning (PPP) that takes advantage of a highly stable oscillator connected to the GPS receiver by modeling its behavior. We show that the high-frequency noise of kinematic GPS height estimates can be reduced by a factor of up to 4 to the level of 2-3 mm and the overall standard deviation including systematic long periodic errors by a factor of up to 2 to the 1 cm level. Consequently, valuable small and currently hidden vertical displacements can be detected that are not visible with classical PPP. Using data of the 2010 Chile earthquake, we demonstrate that coseismic vertical displacements with an amplitude of only 5 mm can be recovered using PPP with the proposed clock modeling strategy.

  5. A numerical method for determining highly precise electron energy distribution functions from Langmuir probe characteristics

    SciTech Connect

    Bang, Jin-Young; Chung, Chin-Wook

    2010-12-15

    Electron energy distribution functions (EEDFs) were determined from probe characteristics using a numerical ac superimposed method with a distortion correction of high derivative terms by varying amplitude of a sinusoidal perturbation voltage superimposed onto the dc sweep voltage, depending on the related electron energy. Low amplitude perturbation applied around the plasma potential represented the low energy peak of the EEDF exactly, and high amplitude perturbation applied around the floating potential was effective to suppress noise or distortion of the probe characteristic, which is fatal to the tail electron distribution. When a small random noise was imposed over the stabilized prove characteristic, the numerical differentiation method was not suitable to determine the EEDF, while the numerical ac superimposed method was able to obtain a highly precise EEDF.

  6. A novel approach for pulse width measurements with a high precision (8 ps RMS) TDC in an FPGA

    NASA Astrophysics Data System (ADS)

    Ugur, C.; Linev, S.; Michel, J.; Schweitzer, T.; Traxler, M.

    2016-01-01

    High precision time measurements are a crucial element in particle identification experiments, which likewise require pulse width information for Time-over-Threshold (ToT) measurements and charge measurements (correlated with pulse width). In almost all of the FPGA-based TDC applications, pulse width measurements are implemented using two of the TDC channels for leading and trailing edge time measurements individually. This method however, requires twice the number of resources. In this paper we present the latest precision improvements in the high precision TDC (8 ps RMS) developed before [1], as well as the novel way of measuring ToT using a single TDC channel, while still achieving high precision (as low as 11.7 ps RMS). The effect of voltage, generated by a DC-DC converter, over the precision is also discussed. Finally, the outcome of the temperature change over the pulse width measurement is shown and a correction method is suggested to limit the degradation.

  7. Precision calculation of threshold πd scattering, πN scattering lengths, and the GMO sum rule

    NASA Astrophysics Data System (ADS)

    Baru, V.; Hanhart, C.; Hoferichter, M.; Kubis, B.; Nogga, A.; Phillips, D. R.

    2011-12-01

    We use chiral perturbation theory (ChPT) to calculate the πd scattering length with an accuracy of a few percent, including isospin-violating corrections in both the two- and three-body sectors. In particular, we provide the technical details of a recent letter (Baru et al., 2011) [1], where we used data on pionic deuterium and pionic hydrogen atoms to extract the isoscalar and isovector pion-nucleon scattering lengths a and a. We study isospin-breaking contributions to the three-body part of a due to mass differences, isospin violation in the πN scattering lengths, and virtual photons. This last class of effects is ostensibly infrared enhanced due to the smallness of the deuteron binding energy. However, we show that the leading virtual-photon effects that might undergo such enhancement cancel, and hence the standard ChPT counting provides a reliable estimate of isospin violation in a due to virtual photons. Finally, we discuss the validity of the Goldberger-Miyazawa-Oehme sum rule in the presence of isospin violation, and use it to determine the charged-pion-nucleon coupling constant.

  8. High Precision UV Measurements in CO, Towards a Laboratory Test of the Time-Invariance of μ.

    NASA Astrophysics Data System (ADS)

    de Nijs, Adrian J.; Eikema, Kjeld S. E.; Ubachs, Wim; Bethlem, Hendrick L.

    2011-06-01

    The metastable a^3Π state of CO has favourable properties for testing the time-invariance of physical constants. Due to an incidental near-degeneracy between the Ω=0, J=8 and the Ω=0, J=6 the 2-photon microwave transition connecting these two states is highly sensitive to a possible time variation of physical constants, with a sensitivity coefficient ranging from ≈ -300 to ≈ +150 for different isotopes. We are planning a molecular beam experiment to measure these transitions. As a first step, spectroscopic measurements have been performed on the X^1Σ^+ → a^3Π transition around 206 nm. We have recorded a total of 40 optical transitions in the six most abundant isotopes. For these measurements, we have used the fourth harmonic of an injection-seeded titanium:sapphire pulsed oscillator. A frequency comb laser referenced to a Rb-clock was used for the absolute calibration of the seed laser. An absolute accuracy of a few MHz was reached. The optical data for 12C16O, together with published RF and MW data, was fitted to an effective Hamiltonian. The precision of a number of molecular parameters was significantly increased. The obtained parameters were isotope scaled to calculate the optical transition frequencies in other isotopes. These frequencies typically agree with the measurements within 10 MHz. These calculations confirm the high sensitivity of the near degeneracies to variations of μ. H.L. Bethlem and W. Ubachs, Faraday Discussions 142, 25-36 (2009)

  9. Digital signal processor-based high-precision on-line Voigt lineshape fitting for direct absorption spectroscopy.

    PubMed

    Xu, Lijun; Liu, Chang; Zheng, Deyan; Cao, Zhang; Cai, Weiwei

    2014-12-01

    To realize on-line high-accuracy measurement in direct absorption spectroscopy (DAS), a system-on-chip, high-precision digital signal processor-based on-line Voigt lineshape fitting implementation is introduced in this paper. Given that the Voigt lineshape is determined by the Gauss full width at half maximum (FWHM) and Lorentz FWHM, a look-up table, which covers a range of combinations of both, is first built to achieve rapid and accurate calculation of Voigt lineshape. With the look-up table and raw absorbance data in hand, Gauss-Newton nonlinear fitting module is implemented to obtain the parameters including both the Gauss and Lorentz FWHMs, which can be used to calculate the integrated absorbance. To realize the proposed method in hardware, a digital signal processor (DSP) is adopted to fit the Voigt lineshape in a real-time DAS measurement system. In experiment, temperature and H2O concentration of a flat flame are recovered from the transitions of 7444.36 cm(-1) and 7185.6 cm(-1) by the DSP-based on-line Voigt lineshape fitting and on-line integral of the raw absorbance, respectively. The results show that the proposed method can not only fit the Voigt lineshape on-line but also improve the measurement accuracy compared with those obtained from the direct integral of the raw absorbance. PMID:25554273

  10. Digital signal processor-based high-precision on-line Voigt lineshape fitting for direct absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Xu, Lijun; Liu, Chang; Zheng, Deyan; Cao, Zhang; Cai, Weiwei

    2014-12-01

    To realize on-line high-accuracy measurement in direct absorption spectroscopy (DAS), a system-on-chip, high-precision digital signal processor-based on-line Voigt lineshape fitting implementation is introduced in this paper. Given that the Voigt lineshape is determined by the Gauss full width at half maximum (FWHM) and Lorentz FWHM, a look-up table, which covers a range of combinations of both, is first built to achieve rapid and accurate calculation of Voigt lineshape. With the look-up table and raw absorbance data in hand, Gauss-Newton nonlinear fitting module is implemented to obtain the parameters including both the Gauss and Lorentz FWHMs, which can be used to calculate the integrated absorbance. To realize the proposed method in hardware, a digital signal processor (DSP) is adopted to fit the Voigt lineshape in a real-time DAS measurement system. In experiment, temperature and H2O concentration of a flat flame are recovered from the transitions of 7444.36 cm-1 and 7185.6 cm-1 by the DSP-based on-line Voigt lineshape fitting and on-line integral of the raw absorbance, respectively. The results show that the proposed method can not only fit the Voigt lineshape on-line but also improve the measurement accuracy compared with those obtained from the direct integral of the raw absorbance.

  11. An Approach for High-precision Stand-alone Positioning in a Dynamic Environment

    NASA Astrophysics Data System (ADS)

    Halis Saka, M.; Metin Alkan, Reha; Ozpercin, Alişir

    2015-04-01

    In this study, an algorithm is developed for precise positioning in dynamic environment utilizing a single geodetic GNSS receiver using carrier phase data. In this method, users should start the measurement on a known point near the project area for a couple of seconds making use of a single dual-frequency geodetic-grade receiver. The technique employs iono-free carrier phase observations with precise products. The equation of the algorithm is given below; Sm(t(i+1))=SC(ti)+[ΦIF (t(i+1) )-ΦIF (ti)] where, Sm(t(i+1)) is the phase-range between satellites and the receiver, SC(ti) is the initial range computed from the initial known point coordinates and the satellite coordinates and ΦIF is the ionosphere-free phase measurement (in meters). Tropospheric path delays are modelled using the standard tropospheric model. To accomplish the process, an in-house program was coded and some functions were adopted from Easy-Suite available at http://kom.aau.dk/~borre/easy. In order to assess the performance of the introduced algorithm in a dynamic environment, a dataset from a kinematic test measurement was used. The data were collected from a kinematic test measurement in Istanbul, Turkey. In the test measurement, a geodetic dual-frequency GNSS receiver, Ashtech Z-Xtreme, was set up on a known point on the shore and a couple of epochs were recorded for initialization. The receiver was then moved to a vessel and data were collected for approximately 2.5 hours and the measurement was finalized on a known point on the shore. While the kinematic measurement on the vessel were carried out, another GNSS receiver was set up on a geodetic point with known coordinates on the shore and data were collected in static mode to calculate the reference trajectory of the vessel using differential technique. The coordinates of the vessel were calculated for each measurement epoch with the introduced method. With the purpose of obtaining more robust results, all coordinates were calculated

  12. CP Violation and Beauty Decays - A Case Study of High Impact, High Sensitivity and Even High Precision Physics

    NASA Astrophysics Data System (ADS)

    Bigi, I. I.

    The narrative of these lectures contains three main threads: (i) CP violation despite having so far been observed only in the decays of neutral kaons has been recognized as a phenomenon of truly fundamental importance. The KM ansatz constitutes the minimal implementation of CP violation: without requiring unknown degrees of freedom it can reproduce the known CP phenomenology in a nontrivial way. (ii) The physics of beauty hadrons - in particular their weak decays - opens a novel window onto fundamental dynamics: they usher in a new quark family (presumably the last one); they allow us to determine fundamental quantities of the Standard Model like the b quark mass and the CKM parameters V(cb), V(ub), V(ts) and V(td); they exhibit speedy or even rapid B0 - ¯ B0 oscillations. (iii) Heavy Quark Expansions allow us to treat B decays with an accuracy that would not have been thought possible a mere decade ago. These three threads are joined together in the following manner: (a) Huge CP asymmetries are predicted in B decays, which represents a decisive test of the KM paradigm for CP violation. (b) Some of these predictions are made with high parametric reliability, which (c) can be translated into numerical precision through the judicious employment of novel theoretical technologies. (d) Beauty decays thus provide us with a rich and promising field to search for New Physics and even study some of its salient features. At the end of it there might quite possibly be a New Paradigm for High Energy Physics. There will be some other threads woven into this tapestry: electric dipole moments, and CP violation in other strange and in charm decays.

  13. Aspects of ultra-high-precision diamond machining of RSA 443 optical aluminium

    NASA Astrophysics Data System (ADS)

    Mkoko, Z.; Abou-El-Hossein, K.

    2015-08-01

    Optical aluminium alloys such as 6061-T6 are traditionally used in ultra-high precision manufacturing for making optical mirrors for aerospace and other applications. However, the optics industry has recently witnessed the development of more advanced optical aluminium grades that are capable of addressing some of the issues encountered when turning with single-point natural monocrystalline diamond cutters. The advent of rapidly solidified aluminium (RSA) grades has generally opened up new possibilities for ultra-high precision manufacturing of optical components. In this study, experiments were conducted with single-point diamond cutters on rapidly solidified aluminium RSA 443 material. The objective of this study is to observe the effects of depth of cut and feed rate at a fixed rotational speed on the tool wear rate and resulting surface roughness of diamond turned specimens. This is done to gain further understanding of the rate of wear on the diamond cutters versus the surface texture generated on the RSA 443 material. The diamond machining experiments yielded machined surfaces which are less reflective but with consistent surface roughness values. Cutting tools were observed for wear through scanning microscopy; relatively low wear pattern was evident on the diamond tool edge. The highest tool wear were obtained at higher depth of cut and increased feed rate.

  14. Adaptive sliding mode control on inner axis for high precision flight motion simulator

    NASA Astrophysics Data System (ADS)

    Fu, Yongling; Niu, Jianjun; Wang, Yan

    2008-10-01

    Discrete adaptive sliding mode control (ASMC) with exponential reaching law is proposed to alleviate the influence of the factors such as the periodical fluctuation torque of motor, nonlinear friction, and other disturbance which will deteriorate the tracking performance of a DC torque motor driven inner axis for a high precision flight motion simulator, considering the limited compensating ability of the ASMC for these uncertainty, an equivalent friction advance compensator based on Stribeck model is also presented for extra-low speed servo of the system. Firstly, the way direct using the available parts of the inner axis itself to ascertain the parameters for Stribeck model is listed. Secondly, adaptive approach is used to overcome the difficulty of choice the key parameter for exponential reaching law, and the stability of the algorithm is analyzed. Lastly, comparable experiments are carried out to verify the valid of the combined approach. The experiments results show with a stable 0.00006°/s speed response, 95% of time the tracking error is within 0.0002°, other servos such as sine wave tracking are also with high precision.

  15. Fabrication of micro-optical components by high-precision embossing

    NASA Astrophysics Data System (ADS)

    Otto, Thomas; Schubert, Andreas; Boehm, Juliana; Gessner, Thomas

    2000-08-01

    Optical components, such as miniature spectrometer gratings working in the infrared range for environmental monitoring or physical analytics, contribute appeciably to the price of Micro Electro Opto Mechanical Systems (MOEMS). These optical components could be a part of a miniature functional package produced with an alternative fabrication technology based on cold forming metals. The cost-efficient fabrication of these components, for example by implementation of forming technology, appears promising. With this technology, high quality embossing of optical structures for high precision requirements in a batch process is possible. In this way the system costs can be reduced. In this paper aluminum forming by cold embossed grating for the fabrication of gratings was investigated. Experiments with different geometries of the embossed grating were carried out. The quality of the embossed structures is primarily determined by the precision and surface quality of the die. Therefore we used a single crystalline silicon tool made by etching as a die. Quality criteria for the review of the formed optical grating were the geometry of surfaces and the surface roughness as well as optical properties of the total structure.

  16. High-precision micro-through-hole array in quartz glass machined by infrared picosecond laser

    NASA Astrophysics Data System (ADS)

    Ji, Lingfei; Hu, Yan; Li, Jian; Wang, Wenhao; Jiang, Yijian

    2015-11-01

    Circle and triangle micro-through-hole arrays without cracks, chips, and debris were machined in 0.3-mm-thick quartz glass by picosecond laser (wavelength = 1064 nm, pulse width ~12 ps) in air ambient. The diameter of each circle through-hole was 550 μm, and the side length of each triangle hole is 500 μm; 30 μm spacing between the adjacent hole edges and the smooth machined surface with R a = 0.8 μm roughness depicted the high precision of the high-density micro-through-hole arrays. The fundamental properties of the ps laser processing of quartz glass were investigated. The laser ablation threshold fluence of the quartz glass was determined as 3.49 J/cm2. Based on the fundamental investigation, a quantitative design of the cutting path for micro-machining of the through-holes with various geometries in quartz glass was developed. The work presents a more practical ps laser micro-machining technique for micro-through-hole arrays in glass-like materials for industrial application due to the precise quality, flexibility in geometries, ease of manipulation, and large-scale application.

  17. Ultrathin Silica Membranes with Highly Ordered and Perpendicular Nanochannels for Precise and Fast Molecular Separation.

    PubMed

    Lin, Xingyu; Yang, Qian; Ding, Longhua; Su, Bin

    2015-11-24

    Membranes with the ability of molecular/ionic separation offer potential in many processes ranging from molecular purification/sensing, to nanofluidics and to mimicking biological membranes. In this work, we report the preparation of a perforative free-standing ultrathin silica membrane consisting of straight and parallel nanochannels with a uniform size (∼2.3 nm) for precise and fast molecular separation. Due to its small and uniform channel size, the membrane exhibits a precise selectivity toward molecules based on size and charge, which can be tuned by ionic strength, pH or surface modification. Furthermore, the ultrasmall thickness (10-120 nm), vertically aligned channels, and high porosity (4.0 × 10(12) pores cm(-2)) give rise to a significantly high molecular transport rate. In addition, the membrane also displays excellent stability and can be consecutively reused for a month after washing or calcination. More importantly, the membrane fabrication is convenient, inexpensive, and does not rely on sophisticated facilities or conditions, providing potential applications in both separation science and micro/nanofluidic chip technologies. PMID:26458217

  18. Study of highly precise outdoor characterization technique for photovoltaic modules in terms of reproducibility

    NASA Astrophysics Data System (ADS)

    Fukabori, Akihiro; Takenouchi, Takakazu; Matsuda, Youji; Tsuno, Yuki; Hishikawa, Yoshihiro

    2015-08-01

    In this study, novel outdoor measurements were conducted for highly precise characterization of photovoltaic (PV) modules by measuring current-voltage (I-V) curves with fast sweep speeds and module’s temperature, and with a PV sensor for reference. Fast sweep speeds suppressed the irradiance variation. As a result, smooth I-V curves were obtained and the PV parameter deviation was suppressed. The module’s temperature was measured by attaching resistive temperature detector sensors on the module’s backsheet. The PV sensor was measured synchronously with the PV module. The PV parameters including Isc, Pmax, Voc, and FF were estimated after correcting the I-V curves using the IEC standards. The reproducibility of Isc, Pmax, Voc, and FF relative to the outdoor fits was evaluated as 0.43, 0.58, 0.24, and 0.23%, respectively. The results demonstrate that highly precise measurements are possible using a PV measurement system with the three above-mentioned features.

  19. High-precision temporal constraints on intrusive magmatism of the Siberian Traps

    NASA Astrophysics Data System (ADS)

    Burgess, Seth; Bowring, Sam; Pavlov, Volodia E.; Veselovsky, Roman V.

    2014-05-01

    The broad temporal coincidence between large igneous province magmatism and some of the most severe biotic/environmental crises in Earth history has led many to infer a causal connection between the two. Notable examples include the end-Permian mass extinction and eruption/emplacement of the Siberian Traps large igneous province (LIP) and the end-Triassic mass extinction and the Central Atlantic Magmatic Province. In models proposing a causal connection between LIP magmatism and the environmental changes that lead to mass extinction, gases and particulates injected into the atmosphere are thought to cause abrupt changes in climate and ocean chemistry sufficient to drive mass extinction of marine and terrestrial biota. Magmatism has been proposed to cause voluminous volatile release via contact metamorphism of the sedimentary rocks. In the case of the Siberian Traps LIP, the compositions of sedimentary rocks (carbonates, evaporates, organic-rich shales) that host sills and dikes are ideal for greenhouse gas generation. When coupled with the enormous volume of Siberian LIP intrusive rocks, there is the potential for volatile generation on a scale necessary to drive environmental changes and mass extinction. This model must be tested by comparing the timing of intrusive magmatism with that of the mass extinction. Coupled high-precision geochronology and astrochronology have constrained the timing of biotic crisis and associated environmental perturbations from the deca-millennial to sub-millennial timescale, suggesting that the biotic crisis was abrupt, occurring over < 100 ka. Published geochronology on sills and dikes from the LIP are sparse and lack the necessary precision to resolve the relative timing of the two events outside of age uncertainty. We present new high-precision U-Pb zircon geochronology on seventeen gabbroic sills from throughout the magmatic province. This includes samples from the mineralized and differentiated intrusions in the Noril'sk region

  20. Non-contact profiling for high precision fast asphere topology measurement

    NASA Astrophysics Data System (ADS)

    Petter, Jürgen; Berger, Gernot

    2013-04-01

    Quality control in the fabrication of high precision optics these days needs nanometer accuracy. However, the fast growing number of optics with complex aspheric shapes demands an adapted measurement method as existing metrology systems more and more reach their limits. In this contribution the authors present a unique and highly flexible approach for measuring spheric and aspheric optics with diameters from 2mm up to 420mm and with almost unlimited spheric departures. Based on a scanning point interferometer the system combines the high precision and the speed of an optical interferometer with the high form flexibility of a classical tactile scanning system. This enables the measurement of objects with steep or strongly changing slopes such as "pancake" or "gull wing" objects. The high accuracy of ±50nm over the whole surface is achieved by using a full reference concept ensuring the position control even over long scanning paths. The core of the technology is a multiwavelength interferometer (MWLI); by use of several wavelengths this sensor system allows for the measurement of objects with polished as well as with ground surfaces. Furthermore, a large absolute measurement range facilitates measuring surfaces with steps or discontinuities like diffractive structures or even segmented objects. As all the measurements can be done using one and the same system, a direct comparison is possible during production and after finishing an object. The contribution gives an insight into the functionality of the MWLI-sensor as well as into the concept of the reference system of the scanning metrology system. Furthermore, samples of application are discussed.

  1. Development of a High Precision and Stability Ambient N2O and CO Analyzer

    NASA Astrophysics Data System (ADS)

    Zhou, Jingang; Hoffnagle, John; Tan, Sze; Dong, Feng; Fleck, Derek; Yiu, John; Huang, Kuan; Leggett, Graham; He, Yonggang

    2016-04-01

    With a global warming potential of nearly 300, N2O is a critically important greenhouse gas, contributing about 5 % of the US total GHG emissions. Agriculture soil management practices are the dominant source of anthropogenic N2O emissions, contributing nearly 75 % of US N2O emissions. In urban areas, vehicle tailpipe emissions and waste water treatment plants are significant sources of N2O. We report here a new mid-infrared laser-based cavity ring-down spectrometer (Picarro G5310) that was recently developed to simultaneously measure sub-ppb ambient concentrations of two key greenhouse gas species, N2O and CO, while measuring H2O as well. It combines a quantum cascade laser with a proprietary 3-mirror optical cavity. The ambient N2O and CO measurement precisions are 0.1ppb (10sec), 0.014ppb (600sec), and 0.006ppb (3000sec); and the measurements could even be averaged down over 3 hours, giving measurement precisions of 0.003ppb. The measurable N2O and CO ranges have been tested up to 2.5ppm. With the high precision and unparalleled stability, G5310 is believed a promising tool for long-term monitoring in atmospheric sciences. The new optical analyzer was set up to monitor N2O and CO (G5310), along with CO2 and CH4(G4301), in ambient air obtained from a 10 meter tower in Santa Clara, California. Evidence of contributions from traffic and a nearby sewage treatment facility were expected in the measurement data.

  2. A demonstration of high precision GPS orbit determination for geodetic applications

    NASA Technical Reports Server (NTRS)

    Lichten, S. M.; Border, J. S.

    1987-01-01

    High precision orbit determination of Global Positioning System (GPS) satellites is a key requirement for GPS-based precise geodetic measurements and precise low-earth orbiter tracking, currently under study at JPL. Different strategies for orbit determination have been explored at JPL with data from a 1985 GPS field experiment. The most successful strategy uses multi-day arcs for orbit determination and includes fine tuning of spacecraft solar pressure coefficients and station zenith tropospheric delays using the GPS data. Average rms orbit repeatability values for 5 of the GPS satellites are 1.0, 1.2, and 1.7 m in altitude, cross-track, and down-track componenets when two independent 5-day fits are compared. Orbit predictions up to 24 hours outside the multi-day arcs agree within 4 m of independent solutions obtained with well tracked satellites in the prediction interval. Baseline repeatability improves with multi-day as compared to single-day arc orbit solutions. When tropospheric delay fluctuations are modeled with process noise, significant additional improvement in baseline repeatability is achieved. For a 246-km baseline, with 6-day arc solutions for GPS orbits, baseline repeatability is 2 parts in 100 million (0.4-0.6 cm) for east, north, and length components and 8 parts in 100 million for the vertical component. For 1314 and 1509 km baselines with the same orbits, baseline repeatability is 2 parts in 100 million for the north components (2-3 cm) and 4 parts in 100 million or better for east, length, and vertical components.

  3. End of Frustration: Catalytic Precision Polymerization with Highly Interacting Lewis Pairs.

    PubMed

    Knaus, Maximilian G M; Giuman, Marco M; Pöthig, Alexander; Rieger, Bernhard

    2016-06-22

    Herein we report on the catalytic polymerization of diverse Michael-type monomers with high precision by using simple but highly active combinations of phosphorus-containing Lewis bases and organoaluminum compounds. The interacting Lewis pair catalysts enable the control of molecular weight and microstructure of the produced polymers. The reactions show a linear Mn vs consumption plot thus proving a living type polymerization. The initiation has been investigated by end-group analysis with ESI mass spectrometric analysis. With these main-group element Lewis acid base pairs, it is not only possible to polymerize sterically demanding, functionalized as well as heteroatom containing monomers but also, for the first time, to catalytically polymerize extended Michael systems, like 4-vinylpyridine. PMID:27254134

  4. Note: High precision angle generator using multiple ultrasonic motors and a self-calibratable encoder

    NASA Astrophysics Data System (ADS)

    Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan; Bong Eom, Tae

    2011-11-01

    We present an angle generator with high resolution and accuracy, which uses multiple ultrasonic motors and a self-calibratable encoder. A cylindrical air bearing guides a rotational motion, and the ultrasonic motors achieve high resolution over the full circle range with a simple configuration. The self-calibratable encoder can compensate the scale error of a divided circle (signal period: 20″) effectively by applying the equal-division-averaged method. The angle generator configures a position feedback control loop using the readout of the encoder. By combining the ac and dc operation mode, the angle generator produced stepwise angular motion with 0.005″ resolution. We also evaluated the performance of the angle generator using a precision angle encoder and an autocollimator. The expanded uncertainty (k = 2) in the angle generation was estimated less than 0.03″, which included the calibrated scale error and the nonlinearity error.

  5. Flow-Based Systems for Rapid and High-Precision Enzyme Kinetics Studies

    PubMed Central

    Hartwell, Supaporn Kradtap; Grudpan, Kate

    2012-01-01

    Enzyme kinetics studies normally focus on the initial rate of enzymatic reaction. However, the manual operation of steps of the conventional enzyme kinetics method has some drawbacks. Errors can result from the imprecise time control and time necessary for manual changing the reaction cuvettes into and out of the detector. By using the automatic flow-based analytical systems, enzyme kinetics studies can be carried out at real-time initial rate avoiding the potential errors inherent in manual operation. Flow-based systems have been developed to provide rapid, low-volume, and high-precision analyses that effectively replace the many tedious and high volume requirements of conventional wet chemistry analyses. This article presents various arrangements of flow-based techniques and their potential use in future enzyme kinetics applications. PMID:22577614

  6. High precision tune and coupling measurements and tune/coupling feedback in RHIC

    SciTech Connect

    Minty, M.; Curcio, A.; Dawson, C.; Degen, C.; Luo, Y.; Marr, G.; Martin, B.; Marusic, A.; Mernick, K.; Oddo, P.; Russo, T.; Schoefer, V.; Schroeder, R.; Schulthiess, C.; Wilinski, M.

    2010-08-01

    Precision measurement and control of the betatron tunes and betatron coupling in RHIC are required for establishing and maintaining both good operating conditions and, particularly during the ramp to high beam energies, high proton beam polarization. While the proof-of-principle for simultaneous tune and coupling feedback was successfully demonstrated earlier, routine application of these systems has only become possible recently. Following numerous modifications for improved measurement resolution and feedback control, the time required to establish full-energy beams with the betatron tunes and coupling regulated by feedback was reduced from several weeks to a few hours. A summary of these improvements, select measurements benefitting from the improved resolution and a review of system performance are the subject of this report.

  7. The first high-precision gravity survey in the North Pole region

    NASA Astrophysics Data System (ADS)

    Sokolov, A. V.; Krasnov, A. A.; Koneshov, V. N.; Glazko, V. V.

    2016-03-01

    The experience with conducting a marine gravity survey onboard a surface vessel under complicated ice conditions at high latitude is described. In 2014, a high-precision marine gravity survey with two modifications of the Chekan-AM gravimeter was carried out in the North Pole region. The measurements were conducted during two months from aboard the Akademik Fedorov research vessel on a given grid with a total length of 10000 km of the routes. As a result, 70000 gravity points at Arctic latitudes including the region of the geographical North Pole itself are acquired. In this paper, we discuss the methodical aspects of conducting the survey and present the accuracy estimates of the gravity measurements. The comparison of the obtained results with the Earth's gravity models demonstrates the absence of systematic errors and the higher spatial resolution of the measurements with the Chekan-AM gravimeters.

  8. High-precision optomechanical lens system for space applications assembled by a local soldering technique

    NASA Astrophysics Data System (ADS)

    Pleguezuelo, Pol Ribes; Koechlin, Charlie; Hornaff, Marcel; Kamm, Andreas; Beckert, Erik; Fiault, Guillaume; Eberhardt, Ramona; Tünnermann, Andreas

    2016-06-01

    Soldering using metallic solder alloys is an alternative to adhesive bonding. Laser-based soldering processes are especially well suited for the joining of optical components made of fragile and brittle materials such as glass, ceramics, and optical crystals. This is due to a localized and minimized input of thermal energy. Solderjet bumping technology has been used to assemble a lens mount breadboard using specifications and requirements found for the optical beam expander for the European Space Agency EarthCare Mission. The silica lens and a titanium barrel have been designed and assembled with this technology in order to withstand the stringent mission demands of handling high mechanical and thermal loads without losing the optical performance. Finally, a high-precision optomechanical lens mount has been assembled with minimal localized stress (<1 MPa) showing outstanding performance in terms of wave-front error and beam depolarization ratio before and after environmental tests.

  9. Versatile, kinetically controlled, high precision electrohydrodynamic writing of micro/nanofibers

    PubMed Central

    Huang, YongAn; Duan, Yongqing; Ding, Yajiang; Bu, Ningbin; Pan, Yanqiao; Lu, Nanshu; Yin, Zhouping

    2014-01-01

    Direct writing of hierarchical micro/nanofibers have recently gained popularity in flexible/stretchable electronics due to its low cost, simple process and high throughput. A kinetically controlled mechanoelectrospinning (MES) is developed to directly write diversified hierarchical micro/nanofibers in a continuous and programmable manner. Unlike conventional near-field electrospinning, our MES method introduces a mechanical drawing force, to simultaneously enhance the positioning accuracy and morphology controllability. The MES is predominantly controlled by the substrate speed, the nozzle-to-substrate distance, and the applied voltage. As a demonstration, smooth straight, serpentine, self-similar, and bead-on-string structures are direct-written on silicon/elastomer substrates with a resolution of 200 nm. It is believed that MES can promote the low-cost, high precision fabrication of flexible/stretchable electronics or enable the direct writing of the sacrificial structures for nanoscale lithography. PMID:25091829

  10. High-precision photometry by telescope defocussing - VI. WASP-24, WASP-25 and WASP-26

    NASA Astrophysics Data System (ADS)

    Southworth, John; Hinse, T. C.; Burgdorf, M.; Calchi Novati, S.; Dominik, M.; Galianni, P.; Gerner, T.; Giannini, E.; Gu, S.-H.; Hundertmark, M.; Jørgensen, U. G.; Juncher, D.; Kerins, E.; Mancini, L.; Rabus, M.; Ricci, D.; Schäfer, S.; Skottfelt, J.; Tregloan-Reed, J.; Wang, X.-B.; Wertz, O.; Alsubai, K. A.; Andersen, J. M.; Bozza, V.; Bramich, D. M.; Browne, P.; Ciceri, S.; D'Ago, G.; Damerdji, Y.; Diehl, C.; Dodds, P.; Elyiv, A.; Fang, X.-S.; Finet, F.; Figuera Jaimes, R.; Hardis, S.; Harpsøe, K.; Jessen-Hansen, J.; Kains, N.; Kjeldsen, H.; Korhonen, H.; Liebig, C.; Lund, M. N.; Lundkvist, M.; Mathiasen, M.; Penny, M. T.; Popovas, A.; Prof., S.; Rahvar, S.; Sahu, K.; Scarpetta, G.; Schmidt, R. W.; Schönebeck, F.; Snodgrass, C.; Street, R. A.; Surdej, J.; Tsapras, Y.; Vilela, C.

    2014-10-01

    We present time series photometric observations of 13 transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, WASP-24 and WASP-26 have been observed with Spitzer, and WASP-25 was previously comparatively neglected. Our light curves were obtained using the telescope-defocussing method and have scatters of 0.5-1.2 mmag relative to their best-fitting geometric models. We use these data to measure the physical properties and orbital ephemerides of the systems to high precision, finding that our improved measurements are in good agreement with previous studies. High-resolution Lucky Imaging observations of all three targets show no evidence for faint stars close enough to contaminate our photometry. We confirm the eclipsing nature of the star closest to WASP-24 and present the detection of a detached eclipsing binary within 4.25 arcmin of WASP-26.

  11. Precision high-value resistance scaling with a two-terminal cryogenic current comparator

    NASA Astrophysics Data System (ADS)

    Hernandez-Marquez, F. L.; Bierzychudek, M. E.; Jones, G. R.; Elmquist, R. E.

    2014-04-01

    We describe a cryogenic two-terminal high-resistance bridge and its application in precision resistance scaling from the quantized Hall resistance (QHR) at RH = RK/2 = 12 906.4035 Ω to decade resistance standards with values between 1 MΩ and 1 GΩ. The design minimizes lead resistance errors with multiterminal connections to the QHR device. A single variable voltage source and resistive ratio windings are utilized to achieve excellent dynamic stability, which is not readily obtained in low-current measurements with conventional cryogenic current comparators (CCCs). Prototypes of this bridge have been verified by a successful international comparison of high-resistance scaling using two-terminal CCCs in the national metrology institutes of Argentina, Mexico, and the United States.

  12. A Lightweight, Precision-Deployable, Optical Bench for High Energy Astrophysics Missions

    NASA Astrophysics Data System (ADS)

    Danner, Rolf; Dailey, D.; Lillie, C.

    2011-09-01

    The small angle of total reflection for X-rays, forcing grazing incidence optics with large collecting areas to long focal lengths, has been a fundamental barrier to the advancement of high-energy astrophysics. Design teams around the world have long recognized that a significant increase in effective area beyond Chandra and XMM-Newton requires either a deployable optical bench or separate X-ray optics and instrument module on formation flying spacecraft. Here, we show that we have in hand the components for a lightweight, precision-deployable optical bench that, through its inherent design features, is the affordable path to the next generation of imaging high-energy astrophysics missions. We present our plans for a full-scale engineering model of a deployable optical bench for Explorer-class missions. We intend to use this test article to raise the technology readiness level (TRL) of the tensegrity truss for a lightweight, precision-deployable optical bench for high-energy astrophysics missions from TRL 3 to TRL 5 through a set of four well-defined technology milestones. The milestones cover the architecture's ability to deploy and control the focal point, characterize the deployed dynamics, determine long-term stability, and verify the stowed load capability. Our plan is based on detailed design and analysis work and the construction of a first prototype by our team. Building on our prior analysis and the high TRL of the architecture components we are ready to move on to the next step. The key elements to do this affordably are two existing, fully characterized, flight-quality, deployable booms. After integrating them into the test article, we will demonstrate that our architecture meets the deployment accuracy, adjustability, and stability requirements. The same test article can be used to further raise the TRL in the future.

  13. High precision differential abundance measurements in globular clusters: chemical inhomogeneities in NGC 6752

    NASA Astrophysics Data System (ADS)

    Yong, David; Meléndez, Jorge; Grundahl, Frank; Roederer, Ian U.; Norris, John E.; Milone, A. P.; Marino, A. F.; Coelho, P.; McArthur, Barbara E.; Lind, K.; Collet, R.; Asplund, Martin

    2013-10-01

    We report on a strictly differential line-by-line analysis of high-quality UVES spectra of bright giants in the metal-poor globular cluster NGC 6752. We achieved high precision differential chemical abundance measurements for Fe, Na, Si, Ca, Ti, Cr, Ni, Zn, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy with uncertainties as low as ˜0.01 dex (˜2 per cent). We obtained the following main results. (1) The observed abundance dispersions are a factor of ˜2 larger than the average measurement uncertainty. (2) There are positive correlations, of high statistical significance, between all elements and Na. (3) For any pair of elements, there are positive correlations of high statistical significance, although the amplitudes of the abundance variations are small. Removing abundance trends with effective temperature and/or using a different pair of reference stars does not alter these results. These abundance variations and correlations may reflect a combination of (a) He abundance variations and (b) inhomogeneous chemical evolution in the pre- or protocluster environment. Regarding the former, the current constraints on ΔY from photometry likely preclude He as being the sole explanation. Regarding the latter, the nucleosynthetic source(s) must have synthesized Na, α, Fe-peak and neutron-capture elements and in constant amounts for species heavier than Si; no individual object can achieve such nucleosynthesis. We speculate that other, if not all, globular clusters may exhibit comparable abundance variations and correlations to NGC 6752 if subjected to a similarly precise analysis.

  14. The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

    PubMed Central

    Carbone, Ludovico; Fulda, Paul; Bond, Charlotte; Brueckner, Frank; Brown, Daniel; Wang, Mengyao; Lodhia, Deepali; Palmer, Rebecca; Freise, Andreas

    2013-01-01

    Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light. We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry. PMID:23962813

  15. Development of a facility for high-precision irradiation of cells with carbon ions

    SciTech Connect

    Goethem, Marc-Jan van; Niemantsverdriet, Maarten; Brandenburg, Sytze; Langendijk, Johannes A.; Coppes, Robert P.; Luijk, Peter van

    2011-01-15

    Purpose: Compared to photons, using particle radiation in radiotherapy reduces the dose and irradiated volume of normal tissues, potentially reducing side effects. The biological effect of dose deposited by particles such as carbon ions, however, differs from that of dose deposited by photons. The inaccuracy in models to estimate the biological effects of particle radiation remains the most important source of uncertainties in particle therapy. Improving this requires high-precision studies on biological effects of particle radiation. Therefore, the authors aimed to develop a facility for reproducible and high-precision carbon-ion irradiation of cells in culture. The combined dose nonuniformity in the lateral and longitudinal direction should not exceed {+-}1.5%. Dose to the cells from particles than other carbon ions should not exceed 5%. Methods: A uniform lateral dose distribution was realized using a single scatter foil and quadrupole magnets. A modulator wheel was used to create a uniform longitudinal dose distribution. The choice of beam energy and the optimal design of these components was determined using GEANT4 and SRIM Monte Carlo simulations. Verification of the uniformity of the dose distribution was performed using a scintillating screen (lateral) and a water phantom (longitudinal). The reproducibility of dose delivery between experiments was assessed by repeated measurements of the spatial dose distribution. Moreover, the reproducibility of dose-response measurements was tested by measuring the survival of irradiated HEK293 cells in three independent experiments. Results: The relative contribution of dose from nuclear reaction fragments to the sample was found to be <5% when using 90 MeV/u carbon ions. This energy still allows accurate dosimetry conforming to the IAEA Report TRS-398, facilitating comparison to dose-effect data obtained with other radiation qualities. A 1.3 mm long spread-out Bragg peak with a diameter of 30 mm was created, allowing

  16. High-precision percolation thresholds and Potts-model critical manifolds from graph polynomials

    NASA Astrophysics Data System (ADS)

    >Jesper Lykke Jacobsen,

    2014-04-01

    The critical curves of the q-state Potts model can be determined exactly for regular two-dimensional lattices G that are of the three-terminal type. This comprises the square, triangular, hexagonal and bow-tie lattices. Jacobsen and Scullard have defined a graph polynomial PB(q, v) that gives access to the critical manifold for general lattices. It depends on a finite repeating part of the lattice, called the basis B, and its real roots in the temperature variable v = eK - 1 provide increasingly accurate approximations to the critical manifolds upon increasing the size of B. Using transfer matrix techniques, these authors computed PB(q, v) for large bases (up to 243 edges), obtaining determinations of the ferromagnetic critical point vc > 0 for the (4, 82), kagome, and (3, 122) lattices to a precision (of the order 10-8) slightly superior to that of the best available Monte Carlo simulations. In this paper we describe a more efficient transfer matrix approach to the computation of PB(q, v) that relies on a formulation within the periodic Temperley-Lieb algebra. This makes possible computations for substantially larger bases (up to 882 edges), and the precision on vc is hence taken to the range 10-13. We further show that a large variety of regular lattices can be cast in a form suitable for this approach. This includes all Archimedean lattices, their duals and their medials. For all these lattices we tabulate high-precision estimates of the bond percolation thresholds pc and Potts critical points vc. We also trace and discuss the full Potts critical manifold in the (q, v) plane, paying special attention to the antiferromagnetic region v < 0. Finally, we adapt the technique to site percolation as well, and compute the polynomials PB(p) for certain Archimedean and dual lattices (those having only cubic and quartic vertices), using very large bases (up to 243 vertices). This produces the site percolation thresholds pc to a precision of the order of 10-9.

  17. Development of high-precision high-frequency phase-shifting circuit

    NASA Astrophysics Data System (ADS)

    Ye, Shuliang; Song, Jiaying; Zhang, Baowu; Qiu, Jian

    2010-08-01

    Phase-locked frequency multiplying technology is utilized to amplify 10MHz signal to 640MHz. Pulse inhibition method is then exploited to make high-frequency signal have a phase shift of 2π. 20MHz signal with 2π / 32 phase shift is output after 5 times flip frequency division. In order to optimize electromagnetic compatibility, signal integrity and power integrity of a high-speed circuit, system simulation is performed using HyperLynx, a specially EDA simulation software. A whole printed circuit board (PCB) was made under the guide of optimized simulation results. Phase-shift experiments show that the output of high-frequency phase-shifting circuit system is two-way signals with a frequency of 20.0001 MHz with 1.8ns time difference, i.e. two signals with 12.96°phase difference are obtained.

  18. Predicting Novel Bulk Metallic Glasses via High- Throughput Calculations

    NASA Astrophysics Data System (ADS)

    Perim, E.; Lee, D.; Liu, Y.; Toher, C.; Gong, P.; Li, Y.; Simmons, W. N.; Levy, O.; Vlassak, J.; Schroers, J.; Curtarolo, S.

    Bulk metallic glasses (BMGs) are materials which may combine key properties from crystalline metals, such as high hardness, with others typically presented by plastics, such as easy processability. However, the cost of the known BMGs poses a significant obstacle for the development of applications, which has lead to a long search for novel, economically viable, BMGs. The emergence of high-throughput DFT calculations, such as the library provided by the AFLOWLIB consortium, has provided new tools for materials discovery. We have used this data to develop a new glass forming descriptor combining structural factors with thermodynamics in order to quickly screen through a large number of alloy systems in the AFLOWLIB database, identifying the most promising systems and the optimal compositions for glass formation. National Science Foundation (DMR-1436151, DMR-1435820, DMR-1436268).

  19. Highly Accurate Calculations of the Phase Diagram of Cold Lithium

    NASA Astrophysics Data System (ADS)

    Shulenburger, Luke; Baczewski, Andrew

    The phase diagram of lithium is particularly complicated, exhibiting many different solid phases under the modest application of pressure. Experimental efforts to identify these phases using diamond anvil cells have been complemented by ab initio theory, primarily using density functional theory (DFT). Due to the multiplicity of crystal structures whose enthalpy is nearly degenerate and the uncertainty introduced by density functional approximations, we apply the highly accurate many-body diffusion Monte Carlo (DMC) method to the study of the solid phases at low temperature. These calculations span many different phases, including several with low symmetry, demonstrating the viability of DMC as a method for calculating phase diagrams for complex solids. Our results can be used as a benchmark to test the accuracy of various density functionals. This can strengthen confidence in DFT based predictions of more complex phenomena such as the anomalous melting behavior predicted for lithium at high pressures. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  20. High-precision automatic online measurement system of engine block top surface holes

    NASA Astrophysics Data System (ADS)

    Yongqiang, Shi; Changku, Sun; Yukun, Ma; Hongxu, Duan; Peng, Wang

    2012-05-01

    The measurement of holes in the engine block top surface determines the general coupling effect of the engine. All of these holes are strictly restricted by the requirements of the dimensional tolerance and the geometrical tolerance, which determines the final engine quality. At present, these holes are measured mostly by the coordinate measuring machine (CMM) in the production line, and meeting the industry demands of automation, rapidity, and online testing with the method is difficult. A new rapid solution measuring the holes in the engine block top surface is proposed, which is based on the combination of multiple visual sensors. The flexible location method of the block is designed, and the global data fusion model based on multiple visual sensors is studied. Finally, the unified correction model of the lens distortion and the system inclination is proposed, and a revised system model with more precision is researched. The CMM measures the holes sizes and the spatial relationship between holes, and the data obtained are substituted into the global data fusion model to complete the system on-site rapid calibration. The experimental results show that the scheme is feasible. The measurement system can meet the production line needs of intelligence, rapidity, and high precision.

  1. Two Fabry-Perot interferometers for high precision wavelength calibration in the near-infrared

    NASA Astrophysics Data System (ADS)

    Schäfer, Sebastian; Reiners, Ansgar

    2012-09-01

    The most frequently used standard light sources for spectroscopic high precision wavelength calibration are hollow cathode lamps. These lamps, however, do not provide homogeneous line distribution and intensities. Particularly in the infrared, the number of useful lines is severely limited and the spectrum is contaminated by lines of the filler gas. With the goal of achieving sub m/s stability in the infrared, as required for detecting earthlike extra-solar planets, we are developing two passively stabilized Fabry-Perot interferometers for the red visible (600-1050nm) and near infrared wavelength regions (900-1350nm). Each of the two interferometers can produce ~15,000 lines of nearly constant brightness. The Fabry-Perot interferometers aim at a RV calibration precision of 10cm/s and are optimized in line shape and spacing for the infrared planet hunting CARMENES spectrograph that is currently being built for the Calar Alto 3.5m telescope. Here we present the first results of our work.

  2. Artificial Incoherent Speckles Enable Precision Astrometry and Photometry in High-contrast Imaging

    NASA Astrophysics Data System (ADS)

    Jovanovic, N.; Guyon, O.; Martinache, F.; Pathak, P.; Hagelberg, J.; Kudo, T.

    2015-11-01

    State-of-the-art coronagraphs employed on extreme adaptive optics enabled instruments are constantly improving the contrast detection limit for companions at ever-closer separations from the host star. In order to constrain their properties and, ultimately, compositions, it is important to precisely determine orbital parameters and contrasts with respect to the stars they orbit. This can be difficult in the post-coronagraphic image plane, as by definition the central star has been occulted by the coronagraph. We demonstrate the flexibility of utilizing the deformable mirror in the adaptive optics system of the Subaru Coronagraphic Extreme Adaptive Optics system to generate a field of speckles for the purposes of calibration. Speckles can be placed up to 22.5 λ/D from the star, with any position angle, brightness, and abundance required. Most importantly, we show that a fast modulation of the added speckle phase, between 0 and π, during a long science integration renders these speckles effectively incoherent with the underlying halo. We quantitatively show for the first time that this incoherence, in turn, increases the robustness and stability of the adaptive speckles, which will improve the precision of astrometric and photometric calibration procedures. This technique will be valuable for high-contrast imaging observations with imagers and integral field spectrographs alike.

  3. High precision optical cavity length and width measurements using double modulation.

    PubMed

    Staley, A; Hoak, D; Effler, A; Izumi, K; Dwyer, S; Kawabe, K; King, E J; Rakhmanov, M; Savage, R L; Sigg, D

    2015-07-27

    We use doubly phase modulated light to measure both the length and the linewidth of an optical resonator with high precision. The first modulation is at RF frequencies and is set near a multiple of the free spectral range, whereas the second modulation is at audio frequencies to eliminate offset errors at DC. The light in transmission or in reflection of the optical resonator is demodulated while sweeping the RF frequency over the optical resonance. We derive expressions for the demodulated power in transmission, and show that the zero crossings of the demodulated signal in transmission serve as a precise measure of the cavity linewidth at half maximum intensity. We demonstrate the technique on two resonant cavities, with lengths 16 m and a 4 km, and achieve an absolute length accuracy as low as 70 ppb. The cavity width for the 16 m cavity was determined with an accuracy of approximately 6000 ppm. Through an analysis of the systematic errors we show that this result could be substantially improved with the reduction of technical sources of uncertainty. PMID:26367601

  4. A conceptual high-resolution MR encoder and torque transducer for precision actuators

    NASA Astrophysics Data System (ADS)

    Nowak, Brent Michael

    This dissertation analytically and experimentally demonstrated a conceptual solution for the high- resolution position sensing, and torque sensing requirements of precision, intelligent machines. The method included an evaluation of the advanced actuators non-linearities and parametric coupling. An analysis of current industrial and research-level sensing practices in robots will be conducted. The purpose of this analysis established the degree to which current practices adequately address the precision requirements of advanced machines. Subsequently, based on this need and relevance, an investigation and analysis of the primary actuator level sensors was conducted. The physics and technologies were identified and measured relative each other and the actuator requirements. A select down of the technologies was conducted. The magnetoresistive phenomenon was investigated in- depth. The performance of the magnetic recording channel has been analyzed relative to the rotary encoder requirements of the advanced actuator. Based on this investigation, through the application of a set of governing design equations, a MR encoder model has been developed. This model includes system non-linearities and noise sources. Both the MR encoder and MR torque sensor conceptual designs have been presented. Limitations in current technology have been identified and proposed alternatives proposed. Finally, the MR encoder concept has been simulated. An experimental test-bed has been developed to collect actual MR read head signals and incorporated into the model. The data has been summarized and the future research identified.

  5. High-precision laser-assisted absolute determination of x-ray diffraction angles

    SciTech Connect

    Kubicek, K.; Braun, J.; Bruhns, H.; Crespo Lopez-Urrutia, J. R.; Mokler, P. H.; Ullrich, J.

    2012-01-15

    A novel technique for absolute wavelength determination in high-precision crystal x-ray spectroscopy recently introduced has been upgraded reaching unprecedented accuracies. The method combines visible laser beams with the Bond method, where Bragg angles ({theta} and -{theta}) are determined without any x-ray reference lines. Using flat crystals this technique makes absolute x-ray wavelength measurements feasible even at low x-ray fluxes. The upgraded spectrometer has been used in combination with first experiments on the 1s2p {sup 1}P{sub 1}{yields} 1s{sup 2} {sup 1}S{sub 0} w-line in He-like argon. By resolving a minute curvature of the x-ray lines the accuracy reaches there the best ever reported value of 1.5 ppm. The result is sensitive to predicted second-order QED contributions at the level of two-electron screening and two-photon radiative diagrams and will allow for the first time to benchmark predicted binding energies for He-like ions at this level of precision.

  6. A new, high-precision measurement of the X-ray Cu K α spectrum

    NASA Astrophysics Data System (ADS)

    Mendenhall, Marcus H.; Cline, James P.; Henins, Albert; Hudson, Lawrence T.; Szabo, Csilla I.; Windover, Donald

    2016-03-01

    One of the primary measurement issues addressed with NIST Standard Reference Materials (SRMs) for powder diffraction is that of line position. SRMs for this purpose are certified with respect to lattice parameter, traceable to the SI through precise measurement of the emission spectrum of the X-ray source. Therefore, accurate characterization of the emission spectrum is critical to a minimization of the error bounds on the certified parameters. The presently accepted sources for the SI traceable characterization of the Cu K α emission spectrum are those of Härtwig, Hölzer et al., published in the 1990s. The structure of the X-ray emission lines of the Cu K α complex has been remeasured on a newly commissioned double-crystal instrument, with six-bounce Si (440) optics, in a manner directly traceable to the SI definition of the meter. In this measurement, the entire region from 8020 eV to 8100 eV has been covered with a highly precise angular scale and well-defined system efficiency, providing accurate wavelengths and relative intensities. This measurement is in modest disagreement with reference values for the wavelength of the Kα1 line, and strong disagreement for the wavelength of the Kα2 line.

  7. High-precision magnetic field measurements of Ap and Bp stars

    NASA Astrophysics Data System (ADS)

    Wade, G. A.; Donati, J.-F.; Landstreet, J. D.; Shorlin, S. L. S.

    2000-04-01

    In this paper we describe a new approach for measuring the mean longitudinal magnetic field and net linear polarization of Ap and Bp stars. As was demonstrated by Wade et al., least-squares deconvolution (LSD; Donati et al.) provides a powerful technique for detecting weak Stokes V, Q and U Zeeman signatures in stellar spectral lines. These signatures have the potential to apply strong new constraints to models of stellar magnetic field structure. Here we point out two important uses of LSD Stokes profiles. First, they can provide very precise determinations of the mean longitudinal magnetic field. In particular, this method allows one frequently to obtain 1σ error bars better than 50G, and smaller than 20G in some cases. This method is applicable to both broad- and sharp-lined stars, with both weak and strong magnetic fields, and effectively redefines the quality standard of longitudinal field determinations. Secondly, LSD profiles can in some cases provide a measure of the net linear polarization, a quantity analogous to the broad-band linear polarization recently used to derive detailed magnetic field models for a few stars (e.g. Leroy et al.). In this paper we report new high-precision measurements of the longitudinal fields of 14 magnetic Ap/Bp stars, as well as net linear polarization measurements for four of these stars, derived from LSD profiles.

  8. A complex programmable logic device-based high-precision electrical capacitance tomography system

    NASA Astrophysics Data System (ADS)

    Zhou, Haili; Xu, Lijun; Cao, Zhang; Liu, XiaoLei; Liu, Shi

    2013-07-01

    In this paper, a high-precision measurement system for electrical capacitance tomography (ECT) is presented. A low-cost complex programmable logic device (CPLD) is employed to accomplish logic control, signal generation, data acquisition, digital demodulation and communication with the aid of external components. By adopting a simple digital demodulator recently developed by the authors, the demodulation to ac signals becomes rather simple and resource-saving. A double-T-switches configuration is developed to improve the precision and lower the limit of multi-channel capacitance measurement. A capacitance network is constructed for system calibration. A square ECT sensor with 16 electrodes is constructed to test the practical performance of the measurement system. With a data acquisition rate of 185 frame s-1, the signal-to-noise ratio and standard deviation of capacitance measurement can reach up to 70 dB and 0.09 fF, respectively. Image reconstruction experiment has validated the CPLD-based ECT system.

  9. High precision carbon-interspaced antiscatter grids: Performance testing and moiré pattern analysis

    NASA Astrophysics Data System (ADS)

    Lee, S. J.; Cho, H. S.; Oh, J. E.; Choi, S. I.; Cho, H. M.; Park, Y. O.; Hong, D. K.; Lee, M. S.; Yang, Y. J.; Je, U. K.; Kim, D. S.; Lee, H. K.

    2011-10-01

    Recently, we have developed high precision carbon-interspaced antiscatter grids to be suitable for digital radiography (DR) adopting a precise sawing process. For systematic evaluation of the grid performance, we prepared several sample grids having different grid frequencies (4.0-8.5 lines/mm) and grid ratios (5:1-10:1) and established a well-controlled test condition based upon the IEC standard. In this paper, we presented the performance characteristics of the carbon-interspaced grids in terms of the transmission of primary radiation ( Tp), the transmission of scattered radiation ( Ts), the transmission of total radiation ( Tt), contrast improvement factor ( Cif), and Bucky factor ( B). We also described the grid line artifact, known as a moiré pattern, which may be the most critical problem to be solved for the successful grid use in DR. We examined the factors that affect the moiré pattern by integrating the sample grids with an a-Se based flat panel detector having a 139 μm×139 μm pixel size.

  10. High-precision radiocarbon dating and historical biblical archaeology in southern Jordan.

    PubMed

    Levy, Thomas E; Higham, Thomas; Bronk Ramsey, Christopher; Smith, Neil G; Ben-Yosef, Erez; Robinson, Mark; Münger, Stefan; Knabb, Kyle; Schulze, Jürgen P; Najjar, Mohammad; Tauxe, Lisa

    2008-10-28

    Recent excavations and high-precision radiocarbon dating from the largest Iron Age (IA, ca. 1200-500 BCE) copper production center in the southern Levant demonstrate major smelting activities in the region of biblical Edom (southern Jordan) during the 10th and 9th centuries BCE. Stratified radiocarbon samples and artifacts were recorded with precise digital surveying tools linked to a geographic information system developed to control on-site spatial analyses of archaeological finds and model data with innovative visualization tools. The new radiocarbon dates push back by 2 centuries the accepted IA chronology of Edom. Data from Khirbat en-Nahas, and the nearby site of Rujm Hamra Ifdan, demonstrate the centrality of industrial-scale metal production during those centuries traditionally linked closely to political events in Edom's 10th century BCE neighbor ancient Israel. Consequently, the rise of IA Edom is linked to the power vacuum created by the collapse of Late Bronze Age (LB, ca. 1300 BCE) civilizations and the disintegration of the LB Cypriot copper monopoly that dominated the eastern Mediterranean. The methodologies applied to the historical IA archaeology of the Levant have implications for other parts of the world where sacred and historical texts interface with the material record. PMID:18955702

  11. Application of the spherical harmonic gravity model in high precision inertial navigation systems

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Yang, Gongliu; Li, Xiangyun; Zhou, Xiao

    2016-09-01

    The spherical harmonic gravity model (SHM) may, in general, be considered as a suitable alternative to the normal gravity model (NGM), because it represents the Earth’s gravitational field more accurately. However, the high-resolution SHM has never been used in current inertial navigation systems (INSs) due to its extremely complex expression. In this paper, the feasibility and accuracy of a truncated SHM are discussed for application in a real-time free-INS with a precision demand better than 0.8 nm h‑1. In particular, the time and space complexity are analyzed mathematically to verify the feasibility of the SHM. Also, a test on a typical navigation computer shows a storable range of cut-off degrees. To further evaluate the appropriate degree and accuracy of the truncated SHM, analyses of covariance and truncation error are proposed. Finally, a SHM of degree 12 is demonstrated to be the appropriate model for routine INSs in the precision range of 0.4–0.75 nm h‑1. Flight simulations and road tests show its outstanding performance over the traditional NGM.

  12. High-precision correlative fluorescence and electron cryo microscopy using two independent alignment markers☆

    PubMed Central

    Schellenberger, Pascale; Kaufmann, Rainer; Siebert, C. Alistair; Hagen, Christoph; Wodrich, Harald; Grünewald, Kay

    2014-01-01

    Correlative light and electron microscopy (CLEM) is an emerging technique which combines functional information provided by fluorescence microscopy (FM) with the high-resolution structural information of electron microscopy (EM). So far, correlative cryo microscopy of frozen-hydrated samples has not reached better than micrometre range accuracy. Here, a method is presented that enables the correlation between fluorescently tagged proteins and electron cryo tomography (cryoET) data with nanometre range precision. Specifically, thin areas of vitrified whole cells are examined by correlative fluorescence cryo microscopy (cryoFM) and cryoET. Novel aspects of the presented cryoCLEM workflow not only include the implementation of two independent electron dense fluorescent markers to improve the precision of the alignment, but also the ability of obtaining an estimate of the correlation accuracy for each individual object of interest. The correlative workflow from plunge-freezing to cryoET is detailed step-by-step for the example of locating fluorescence-labelled adenovirus particles trafficking inside a cell. PMID:24262358

  13. High-precision correlative fluorescence and electron cryo microscopy using two independent alignment markers.

    PubMed

    Schellenberger, Pascale; Kaufmann, Rainer; Siebert, C Alistair; Hagen, Christoph; Wodrich, Harald; Grünewald, Kay

    2014-08-01

    Correlative light and electron microscopy (CLEM) is an emerging technique which combines functional information provided by fluorescence microscopy (FM) with the high-resolution structural information of electron microscopy (EM). So far, correlative cryo microscopy of frozen-hydrated samples has not reached better than micrometre range accuracy. Here, a method is presented that enables the correlation between fluorescently tagged proteins and electron cryo tomography (cryoET) data with nanometre range precision. Specifically, thin areas of vitrified whole cells are examined by correlative fluorescence cryo microscopy (cryoFM) and cryoET. Novel aspects of the presented cryoCLEM workflow not only include the implementation of two independent electron dense fluorescent markers to improve the precision of the alignment, but also the ability of obtaining an estimate of the correlation accuracy for each individual object of interest. The correlative workflow from plunge-freezing to cryoET is detailed step-by-step for the example of locating fluorescence-labelled adenovirus particles trafficking inside a cell. PMID:24262358

  14. High-precision radiocarbon dating and historical biblical archaeology in southern Jordan

    PubMed Central

    Levy, Thomas E.; Higham, Thomas; Bronk Ramsey, Christopher; Smith, Neil G.; Ben-Yosef, Erez; Robinson, Mark; Münger, Stefan; Knabb, Kyle; Schulze, Jürgen P.; Najjar, Mohammad; Tauxe, Lisa

    2008-01-01

    Recent excavations and high-precision radiocarbon dating from the largest Iron Age (IA, ca. 1200–500 BCE) copper production center in the southern Levant demonstrate major smelting activities in the region of biblical Edom (southern Jordan) during the 10th and 9th centuries BCE. Stratified radiocarbon samples and artifacts were recorded with precise digital surveying tools linked to a geographic information system developed to control on-site spatial analyses of archaeological finds and model data with innovative visualization tools. The new radiocarbon dates push back by 2 centuries the accepted IA chronology of Edom. Data from Khirbat en-Nahas, and the nearby site of Rujm Hamra Ifdan, demonstrate the centrality of industrial-scale metal production during those centuries traditionally linked closely to political events in Edom's 10th century BCE neighbor ancient Israel. Consequently, the rise of IA Edom is linked to the power vacuum created by the collapse of Late Bronze Age (LB, ca. 1300 BCE) civilizations and the disintegration of the LB Cypriot copper monopoly that dominated the eastern Mediterranean. The methodologies applied to the historical IA archaeology of the Levant have implications for other parts of the world where sacred and historical texts interface with the material record. PMID:18955702

  15. Precise color images a high-speed color video camera system with three intensified sensors

    NASA Astrophysics Data System (ADS)

    Oki, Sachio; Yamakawa, Masafumi; Gohda, Susumu; Etoh, Takeharu G.

    1999-06-01

    High speed imaging systems have been used in a large field of science and engineering. Although the high speed camera systems have been improved to high performance, most of their applications are only to get high speed motion pictures. However, in some fields of science and technology, it is useful to get some other information, such as temperature of combustion flame, thermal plasma and molten materials. Recent digital high speed video imaging technology should be able to get such information from those objects. For this purpose, we have already developed a high speed video camera system with three-intensified-sensors and cubic prism image splitter. The maximum frame rate is 40,500 pps (picture per second) at 64 X 64 pixels and 4,500 pps at 256 X 256 pixels with 256 (8 bit) intensity resolution for each pixel. The camera system can store more than 1,000 pictures continuously in solid state memory. In order to get the precise color images from this camera system, we need to develop a digital technique, which consists of a computer program and ancillary instruments, to adjust displacement of images taken from two or three image sensors and to calibrate relationship between incident light intensity and corresponding digital output signals. In this paper, the digital technique for pixel-based displacement adjustment are proposed. Although the displacement of the corresponding circle was more than 8 pixels in original image, the displacement was adjusted within 0.2 pixels at most by this method.

  16. Spatial dependent diffusion of cosmic rays and the excess of primary electrons derived from high precision measurements by AMS-02

    NASA Astrophysics Data System (ADS)

    Jin, Chao; Guo, Yi-Qing; Hu, Hong-Bo

    2016-01-01

    The precise spectra of Cosmic Ray (CR) electrons and positrons have been published by the measurement of AMS-02. It is reasonable to regard the difference between the electron and positron spectra (ΔΦ = Φe- -Φe+) as being dominated by primary electrons. The resulting electron spectrum shows no sign of spectral softening above 20 GeV, which is in contrast with the prediction of the standard model of CR propagation. In this work, we generalize the analytic one-dimensional two-halo model of diffusion to a three-dimensional realistic calculation by implementing spatial variant diffusion coefficients in the DRAGON package. As a result, we can reproduce the spectral hardening of protons observed by several experiments, and predict an excess of high energy primary electrons which agrees with the measurement reasonably well. Unlike the break spectrum obtained for protons, the model calculation predicts a smooth electron excess and thus slightly over-predicts the flux from tens of GeV to 100 GeV. To understand this issue, further experimental and theoretical studies are necessary. Supported by Natural Sciences Foundation of China (11135010)

  17. Fabrication and testing of a high-precision concave spherical mirror

    NASA Astrophysics Data System (ADS)

    Burke, Jan; Green, Katie; Stuart, Wayne; Puhanic, Edita; Leistner, Achim; Oreb, Bob

    2008-08-01

    CSIRO's Australian Centre for Precision Optics has recently finished the production of a high-precision concave spherical mirror. The specifications were very ambitious: numerical aperture 0.75; asphericity below 5.5 nm rms and 27.3 nm P-V. The available reference transmission sphere had to be calibrated to enable adequate accuracy. Due to the high numerical aperture of the mirror, sub-aperture measurements had to be stitched together to form a complete surface map of the mirror. Phase-shifting interferometry at high numerical aperture suffers from phase-step non-uniformity because of the large off-axis angles. We present what we believe to be a new interpretation of this phenomenon as a focus error, which clarifies where in the interferometer the phase-shift error occurs. We discuss the ball-averaging method for calibrating the reference transmission sphere and present results from the averaging process to ensure an uncertainty commensurate with the certification requirement. For carrying out the sub-aperture measurements, we constructed a two-axis gimbal mount to swivel the mirror around the focus of the test wavefront. If the centers of curvature of the transmission sphere and the mirror coincide, the mirror can be tilted without losing the interferogram. We present a simple and effective alignment method, which can be generally applied to optical tests where the wavefront comes to a focus. The mirror was coated with protected aluminum and tested in its mount. No effect on the sphericity error from the coating was found, and the specifications were exceeded by approximately 30%. We discuss subtleties of the stitching process on curved surfaces and report final results.

  18. High precision series solutions of differential equations: Ordinary and regular singular points of second order ODEs

    NASA Astrophysics Data System (ADS)

    Noreen, Amna; Olaussen, Kåre

    2012-10-01

    A subroutine for a very-high-precision numerical solution of a class of ordinary differential equations is provided. For a given evaluation point and equation parameters the memory requirement scales linearly with precision P, and the number of algebraic operations scales roughly linearly with P when P becomes sufficiently large. We discuss results from extensive tests of the code, and how one, for a given evaluation point and equation parameters, may estimate precision loss and computing time in advance. Program summary Program title: seriesSolveOde1 Catalogue identifier: AEMW_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMW_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 991 No. of bytes in distributed program, including test data, etc.: 488116 Distribution format: tar.gz Programming language: C++ Computer: PC's or higher performance computers. Operating system: Linux and MacOS RAM: Few to many megabytes (problem dependent). Classification: 2.7, 4.3 External routines: CLN — Class Library for Numbers [1] built with the GNU MP library [2], and GSL — GNU Scientific Library [3] (only for time measurements). Nature of problem: The differential equation -s2({d2}/{dz2}+{1-ν+-ν-}/{z}{d}/{dz}+{ν+ν-}/{z2})ψ(z)+{1}/{z} ∑n=0N vnznψ(z)=0, is solved numerically to very high precision. The evaluation point z and some or all of the equation parameters may be complex numbers; some or all of them may be represented exactly in terms of rational numbers. Solution method: The solution ψ(z), and optionally ψ'(z), is evaluated at the point z by executing the recursion A(z)={s-2}/{(m+1+ν-ν+)(m+1+ν-ν-)} ∑n=0N Vn(z)A(z), ψ(z)=ψ(z)+A(z), to sufficiently large m. Here ν is either ν+ or ν-, and Vn(z)=vnz. The recursion is initialized by A(z)=δzν,for n

  19. MATS and LaSpec: High-precision experiments using ion traps and lasers at FAIR

    NASA Astrophysics Data System (ADS)

    Rodríguez, D.; Blaum, K.; Nörtershäuser, W.; Ahammed, M.; Algora, A.; Audi, G.; Äystö, J.; Beck, D.; Bender, M.; Billowes, J.; Block, M.; Böhm, C.; Bollen, G.; Brodeur, M.; Brunner, T.; Bushaw, B. A.; Cakirli, R. B.; Campbell, P.; Cano-Ott, D.; Cortés, G.; Crespo López-Urrutia, J. R.; Das, P.; Dax, A.; de, A.; Delheij, P.; Dickel, T.; Dilling, J.; Eberhardt, K.; Eliseev, S.; Ettenauer, S.; Flanagan, K. T.; Ferrer, R.; García-Ramos, J.-E.; Gartzke, E.; Geissel, H.; George, S.; Geppert, C.; Gómez-Hornillos, M. B.; Gusev, Y.; Habs, D.; Heenen, P.-H.; Heinz, S.; Herfurth, F.; Herlert, A.; Hobein, M.; Huber, G.; Huyse, M.; Jesch, C.; Jokinen, A.; Kester, O.; Ketelaer, J.; Kolhinen, V.; Koudriavtsev, I.; Kowalska, M.; Krämer, J.; Kreim, S.; Krieger, A.; Kühl, T.; Lallena, A. M.; Lapierre, A.; Le Blanc, F.; Litvinov, Y. A.; Lunney, D.; Martínez, T.; Marx, G.; Matos, M.; Minaya-Ramirez, E.; Moore, I.; Nagy, S.; Naimi, S.; Neidherr, D.; Nesterenko, D.; Neyens, G.; Novikov, Y. N.; Petrick, M.; Plaß, W. R.; Popov, A.; Quint, W.; Ray, A.; Reinhard, P.-G.; Repp, J.; Roux, C.; Rubio, B.; Sánchez, R.; Schabinger, B.; Scheidenberger, C.; Schneider, D.; Schuch, R.; Schwarz, S.; Schweikhard, L.; Seliverstov, M.; Solders, A.; Suhonen, M.; Szerypo, J.; Taín, J. L.; Thirolf, P. G.; Ullrich, J.; van Duppen, P.; Vasiliev, A.; Vorobjev, G.; Weber, C.; Wendt, K.; Winkler, M.; Yordanov, D.; Ziegler, F.

    2010-05-01

    Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. The mass and its inherent connection with the nuclear binding energy is a fundamental property of a nuclide, a unique “fingerprint”. Thus, precise mass values are important for a variety of applications, ranging from nuclear-structure studies like the investigation of shell closures and the onset of deformation, tests of nuclear mass models and mass formulas, to tests of the weak interaction and of the Standard Model. The required relative accuracy ranges from 10-5 to below 10-8 for radionuclides, which most often have half-lives well below 1 s. Substantial progress in Penning trap mass spectrometry has made this method a prime choice for precision measurements on rare isotopes. The technique has the potential to provide high accuracy and sensitivity even for very short-lived nuclides. Furthermore, ion traps can be used for precision decay studies and offer advantages over existing methods. With MATS (Precision Measurements of very short-lived nuclei using an A_dvanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10-9 can be reached by employing highly-charged ions and a non

  20. Evaluation of a Metric Camera System Tailored for High Precision Uav Applications

    NASA Astrophysics Data System (ADS)

    Kraft, T.; Geßner, M.; Meißner, H.; Cramer, M.; Gerke, M.; Przybilla, H. J.

    2016-06-01

    In this paper we present the further evaluation of DLR's modular airborne camera system MACS-Micro for small unmanned aerial vehicle (UAV). The main focus is on standardized calibration procedures and on photogrammetric workflows. The current prototype consists of an industrial grade frame imaging camera with 12 megapixel resolutions and a compact GNSS/IMU solution which are operated by an embedded computing unit (CPU). The camera was calibrated once pre-flight and several times post-flight over a period of 5 month using a three dimensional test field. The verification of the radiometric quality of the acquired images has been done under controlled static conditions and kinematic conditions testing different demosaicing methods. The validation of MACS-Micro is done by comparing a traditional photogrammetric evaluation with the workflows of Agisoft Photoscan and Pix4D Mapper. The analyses are based on an aerial survey of an urban environment using precise ground control points and acquired GNSS observations. Aerial triangulations with different configuratrions of ground control points (GCP's) had been calculated, comparing the results of using a camera self-calibration and introducing fixed interior orientation parameters for Agisoft and Pix4D. The results are promising concerning the metric characteristics of the used camera and achieved accuracies in this test case. Further aspects have to be evaluated by further expanded test scenarios.