Sample records for high precision experimental

  1. MEASUREMENT AND PRECISION, EXPERIMENTAL VERSION.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    THIS DOCUMENT IS AN EXPERIMENTAL VERSION OF A PROGRAMED TEXT ON MEASUREMENT AND PRECISION. PART I CONTAINS 24 FRAMES DEALING WITH PRECISION AND SIGNIFICANT FIGURES ENCOUNTERED IN VARIOUS MATHEMATICAL COMPUTATIONS AND MEASUREMENTS. PART II BEGINS WITH A BRIEF SECTION ON EXPERIMENTAL DATA, COVERING SUCH POINTS AS (1) ESTABLISHING THE ZERO POINT, (2)…

  2. Proton-proton bremsstrahlung calculation: Comparison with recent high-precision experimental results

    SciTech Connect

    Li Yi; Liou, M.K.; Schreiber, W.M. [Department of Physics and Institute for Nuclear Theory, Brooklyn College of the City University of New York, Brooklyn, New York 11210 (United States); Department of Physics, College of Staten Island of the City University of New York, Staten Island, New York 10314 (United States)

    2005-08-01

    Proton-proton bremsstrahlung cross sections and analyzing powers have been calculated at 190 MeV by using a one-boson-exchange model. The results are compared with the recently published high-precision Kernfysisch-Versneller-Instituut (KVI) data. Satisfactory agreement between theory and experiment has been found.

  3. Experimental access to higher-order Zeeman effects by precision spectroscopy of highly charged ions in a Penning trap

    E-print Network

    von Lindenfels, D; Glazov, D A; Volotka, A V; Sokolov, M M; Shabaev, V M; Plunien, G; Quint, W; Birkl, G; Martin, A; Vogel, M

    2013-01-01

    We present an experimental concept and setup for laser-microwave double-resonance spectroscopy of highly charged ions in a Penning trap. Such spectroscopy allows a highly precise measurement of the Zeeman splittings of fine- and hyperfine-structure levels due the magnetic field of the trap. We have performed detailed calculations of the Zeeman effect in the framework of quantum electrodynamics of bound states as present in such highly charged ions. We find that apart from the linear Zeeman effect, second- and third-order Zeeman effects also contribute to the splittings on a level of 10^-4 and 10^-8, respectively, and hence are accessible to a determination within the achievable spectroscopic resolution of the ARTEMIS experiment currently in preparation.

  4. High precision laser sclerostomy

    NASA Astrophysics Data System (ADS)

    Góra, W. S.; Urich, A.; McIntosh, L.; Carter, R. M.; Wilson, C. G.; Dhillon, B.; Hand, D. P.; Shephard, J. D.

    2015-03-01

    Ultrafast lasers offer a possibility of removing soft ophthalmic tissue without introducing collateral damage at the ablation site or in the surrounding tissue. The potential for using ultrashort pico- and femtosecond pulse lasers for modification of ophthalmic tissue has been reported elsewhere and has resulted in the introduction of new, minimally invasive procedures into clinical practice. Our research aims to define the most efficient parameters to allow for the modification of scleral tissue without introducing collateral damage. Our experiments were carried out on hydrated porcine sclera in vitro. Porcine sclera, which has similar collagen organization, histology and water content (~70%) to human tissue was used. Supporting this work we present a 2D finite element blow-off model which employs a one-step heating process. It is assumed that the incident laser radiation that is not reflected is absorbed in the tissue according to the Beer-Lambert law and transformed into heat energy. The experimental setup uses an industrial picosecond laser (TRUMPF TruMicro 5x50) with 5.9 ps pulses at 1030 nm, with pulse energies up to 125 ?J and a focused spot diameter of 35 ?m. Use of a beam steering scan head allows flexibility in designing complicated scanning patterns. In this study we have demonstrated that picosecond pulses are capable of removing scleral tissue without introducing any major thermal damage which offers a possible route for minimally invasive sclerostomy. In assessing this we have tested several different scanning patterns including single line ablation, square and circular cavity removal.

  5. 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…

  6. High precision laser forming for microactuation

    NASA Astrophysics Data System (ADS)

    Folkersma, Ger K. G. P.; Römer, G. R. B. E.; Brouwer, D. M.; Huis in't Veld, A. J.

    2014-03-01

    For assembly of micro-devices, such as photonic devices, the precision alignment of components is often critical for their performance. Laser forming, also known as laser-adjusting, can be used to create an integrated microactuator to align the components with sub-micron precision after bonding. In this paper a so-called three-bridge planar manipulator was used to study the laser-material interaction and thermal and mechanical behavior of the laser forming mechanism. A 3-D Finite Element Method (FEM) model and experiments are used to identify the optimal parameter settings for a high precision actuator. The goal in this paper is to investigate how precise the maximum occurring temperature and the resulting displacement are predicted by a 3-D FEM model by comparing with experimental results. A secondary goal is to investigate the resolution of the mechanism and the range of motion. With the experimental setup we measure the displacement and surface temperature in real-time. The time-dependent heat transfer FEM models match closely with experimental results, however the structural model can deviate more than 100% in absolute displacement. Experimentally, a positioning resolution of 0.1?m was achieved, with a total stroke exceeding 20?m. A spread of 10% in the temperature cycles between several experiments was found, which was attributed to a spread in the surface absorptivity. Combined with geometric tolerances, the spread in displacement can be as large as 20%. This implies that feedback control of the laser power, in combination with iterative learning during positioning, is required for high precision alignment. Even though the FEM models deviate substantially from the experiments, the 3-D FEM model predicts the trend in deformation sufficiently accurate to use it for design optimization of high precision 3-D actuators using laser adjusting.

  7. 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.

  8. Precision Experimental Verification of Special Relativity

    Microsoft Academic Search

    D. Newman; G. W. Ford; A. Rich; E. Sweetman

    1978-01-01

    We compare the results of precision electron g-factor experiments at low energy and at 110 keV. The agreement between these measurements constitutes the most precise laboratory confirmation to date of the predictions of special relativity. Relativistic electromagnetic theory and Thomas precession are verified in this test. We also consider limits on possible effects of acceleration.

  9. A Novel and High-Precision Optical Displacement Sensor

    Microsoft Academic Search

    A. Rostami; M. Noshad; H. Hedayati; A. Ghanbari; F. Janabi-Sharifi

    Summary In this paper, theoretical and experimental investigation of a novel compact and high-precision (0.2 nm) optical displacement sensor is presented. The sensor operation is based on optical intensity modulation due to diffraction. A circular disk, including a central transmitter and circumferential receivers (8 and 12 configurations), is considered as high precision displacement sensor. Effects of the number of receivers

  10. 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

  11. Evaluation of measurement precision in experimental methods

    Microsoft Academic Search

    Ljubomir Kubacek

    1965-01-01

    The above method for evaluating the precision of measurements used in medicine can be applied to a wider range of measurements. It has only been possible, owing to the limited size of the article, to include in it an analysis of measurement accuracy, without dealing with other important problems, such as a comparison of various methods for their accuracy.

  12. Detecting precise firing sequences in experimental data

    Microsoft Academic Search

    M. Abeles; I. Gat

    2001-01-01

    A precise firing sequence (PFS) is defined here as a sequence of three spikes with fixed delays (up to some time accuracy ?), that repeat excessively. This paper provides guidelines for detecting PFSs, verifying their significance through surrogate spike trains, and identifying existing PFSs. The method is based on constructing a three-fold correlation among spikes, estimating the expected shape of

  13. High precision triangular waveform generator

    DOEpatents

    Mueller, Theodore R. (Oak Ridge, TN)

    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.

  14. 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 20?m 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.

  15. 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 ?m to 2.5-3.9 ?m. 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.

  16. High Precision Nickel Isotopic Analyses in Meteorites

    NASA Astrophysics Data System (ADS)

    Chen, J. H.; Papanastassiou, D. A.; Wasserburg, G. J.

    2007-03-01

    We present high precision Ni isotope data on metal and sulfide from iron meteorites and chondrites and discuss the implications. We do not confirm large effects in sulfides from irons, reported earlier by others.

  17. High Precision Laser Range Sensor

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge (Inventor); Lay, Oliver P. (Inventor)

    2003-01-01

    The present invention is an improved distance measuring interferometer that includes high speed phase modulators and additional phase meters to generate and analyze multiple heterodyne signal pairs with distinct frequencies. Modulation sidebands with large frequency separation are generated by the high speed electro-optic phase modulators, requiring only a single frequency stable laser source and eliminating the need for a fist laser to be tuned or stabilized relative to a second laser. The combination of signals produced by the modulated sidebands is separated and processed to give the target distance. The resulting metrology apparatus enables a sensor with submicron accuracy or better over a multi- kilometer ambiguity range.

  18. High-Precision Computation and Mathematical Physics

    Microsoft Academic Search

    David H. Bailey; Jonathan M. Borwein

    2008-01-01

    At the present time, IEEE 64-bit floating-point arithmetic i s sufficiently accurate for most sci- entific applications. However, for a rapidly growing body of important scientific computing ap- plications, 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 min- imize the conversion effort. This paper

  19. Precision Crystal Calorimeters in High Energy Physics

    SciTech Connect

    Ren-Yuan Zhu

    2008-04-02

    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.

  20. 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.

  1. 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 ?m 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 drilling velocity is increased and widening effects are decreased. So the process is more efficient and precise. Furthermore, the necessary pulse energy for the drilling of a certain material thickness is reduced and so laser power can be saved.

  2. 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.

  3. Cellular signalling effects in high precision radiotherapy.

    PubMed

    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. PMID:25993091

  4. Highly Parallel, High-Precision Numerical Integration

    E-print Network

    Bailey, David H.

    of high-performance computing to research questions in math- ematics. In particular, high to very high accuracy (hundreds to thousands of digits) on highly parallel computer systems. Such schemes new identities. This paper presents performance results for 1-D and 2-D integral test suites on highly

  5. 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.

  6. High-Precision Photometry with the RCT

    NASA Astrophysics Data System (ADS)

    Everett, M.; Howell, S.; Davis, D.; McGruder, C. H., III; Gelderman, R.; Guinan, E.; Mattox, J. R.; Walter, D. K.

    2003-05-01

    We plan to conduct a high-precision photometric search for transitting extra-solar planets using the refurbished 1.3 m (50 inch) Robotically-Controlled Telescope (RCT) at Kitt Peak. The photometric capabilities and extra-solar planet search strategy for the RCT are discussed. Refurbishment of the RCT has been made possible by NASA grant NAG58762.

  7. 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.

  8. 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.

  9. 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.

  10. Design of a high precision microwave reflector

    Microsoft Academic Search

    E. W. Noller; J. L. Bauer

    1980-01-01

    Development of a high accuracy spherical microwave reflector to support contour RMS and pointing requirements for a new series of space instruments is reported. The reflector system is composed of precision machined aluminum tile reflectors supported from a eutectic coated graphite epoxy structure by flexures. Several basic technologies have been integrated into a manufacturing process that accommodates fabrication techniques of

  11. 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.

  12. Calibration of a high precision rotary table

    NASA Astrophysics Data System (ADS)

    Wang, Heyan; Xue, Zi; Shen, Ni; Huang, Yao

    2015-02-01

    In order to calibrate a high precision rotary table, a calibration system was established to measure the position error and repeatability of rotary table. The position error was measured with a polygon, an index table and an autocollimator to separate the angular error of the polygon from the position error of the rotary table, and the position error of rotary table was calculated using least square method. The rotary table was compensated and calibrated with the position error measured. The repeatability of the rotary table established through 10 times full circle rotations was 0.02 arc second. The measurement results indicated that the combination calibration method was suitable for the calibration of a high precision rotary table. It was found through the analysis that the angular measurement uncertainty was 0.08 arc second.

  13. 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.

  14. Adventures in High Precision Laser Spectroscopy

    SciTech Connect

    Theodor Haensch

    2009-01-29

    Optical frequency comb techniques are revolutionizing the art of measuring the frequency of light. The complex and highly specialized harmonic laser frequency chains of the past can now be replaced by a universal optical frequency comb synthesizer using just a single mode-locked femtosecond laser. After spectral broadening in a nonlinear optical fiber, such a laser emits a regular comb of hundred of thousands of evenly spaced sharp laser lines, extending throughout the visible and near infrared spectrum. The frequency of each line can be determined by radio frequency methods with extreme precision. Such frequency comb synthesizers are already revolutionizing precision laser spectroscopy, they provide the clock work for novel ultraprecise atomic clocks, based on optical transitions in atoms, ions or molecules, and they open new frontiers for stringent tests of fundamental physics laws.

  15. 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.

  16. 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.

  17. Nab: precise experimental study of unpolarized neutron beta decay

    NASA Astrophysics Data System (ADS)

    Pocanic, Dinko; Nab Collaboration

    2014-09-01

    Nab, a program of experimental study of unpolarized neutron decays at the Spallation Neutron Source, Oak Ridge, TN, aims to determine a, the electron-neutrino correlation with precision of ?a / a =10-3 , and b, the Fierz interference term, with uncertainty ?b ~= 3 ×10-3 . Neutron beta decay's simple theoretical description in the Standard Model (SM) is overconstrained by the set of available observables, providing opportunities to search for evidence of SM extensions. Planned Nab results will lead to a new precise determination of the ratio ? =GA /GV , and to significant reductions in the allowed limits for both right- and left-handed scalar and tensor currents. Alternatively, the experiment may detect a discrepancy from SM predictions consistent with certain realizations of supersymmetry. An optimized, asymmetric spectrometer has been designed to achieve the narrow proton momentum response function required to meet the physics goals of the experiment. The apparatus is to be used in a follow-up measurement (ABba) of asymmetry observables A and B in polarized neutron decay. Nab is funded, now in the construction stage, with planned beam readiness in 2016. We discuss the experiment's motivation, expected reach, design and method. Nab, a program of experimental study of unpolarized neutron decays at the Spallation Neutron Source, Oak Ridge, TN, aims to determine a, the electron-neutrino correlation with precision of ?a / a =10-3 , and b, the Fierz interference term, with uncertainty ?b ~= 3 ×10-3 . Neutron beta decay's simple theoretical description in the Standard Model (SM) is overconstrained by the set of available observables, providing opportunities to search for evidence of SM extensions. Planned Nab results will lead to a new precise determination of the ratio ? =GA /GV , and to significant reductions in the allowed limits for both right- and left-handed scalar and tensor currents. Alternatively, the experiment may detect a discrepancy from SM predictions consistent with certain realizations of supersymmetry. An optimized, asymmetric spectrometer has been designed to achieve the narrow proton momentum response function required to meet the physics goals of the experiment. The apparatus is to be used in a follow-up measurement (ABba) of asymmetry observables A and B in polarized neutron decay. Nab is funded, now in the construction stage, with planned beam readiness in 2016. We discuss the experiment's motivation, expected reach, design and method. Work supported by NSF grants PHY-1126683, 1205833, 1307328, and others.

  18. Precise antenna control design and its experimental verification

    NASA Astrophysics Data System (ADS)

    Kashiwase, Toshio; Yamada, Katsuhiko; Yamaguchi, Tetsuo; Awa, Yuji

    For inter-satellite communication, precise antenna pointing control with wide range and high scanning rate is required. Because structural vibration modes in the controller bandwidth degrade the performance of antenna pointing control and body attitude control, we need the antenna pointing control without excitation of the vibration modes. We propose here a new antenna control scheme with the function of active vibration control. Using a ground test setup, we verify the effectiveness of the control scheme as compared with the conventional proportional and integral (PI) control scheme.

  19. High-precision camera distortion measurements with a "calibration harp"

    E-print Network

    Paris-Sud XI, Université de

    High-precision camera distortion measurements with a "calibration harp" Z. Tang,1, R. Grompone von "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

  20. 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.

  1. 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.

  2. 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.

  3. Precision Density Measurements Near the Helium Lambda Transition Using High-Q Microwave Cavities

    Microsoft Academic Search

    D. M. Strayer; W. Jiang; N.-C. Yeh; N. Asplund

    1996-01-01

    A new experimental approach for high-precision density measurements of liquid helium near the lambda transition is proposed. Using a high-Q Nb microwave cavity (Q ~ 10^10) and the high-resolution thermometry (HRT), the changes in the density of helium that fills the cavity can be detected to high precision by accurate measurements of the resonant frequency shift (Delta f) as a

  4. 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.

  5. High-precision characterization of dynamic acoustic grating induced by stimulated Brillouin scattering in a high-birefringence optical fiber

    Microsoft Academic Search

    Weiwen Zou; Zuyuan He; Kazuo Hotate

    2008-01-01

    A novel experimental method is demonstrated to precisely characterize optical-frequency deviation within plusmn4 MHz between orthogonal axes in a high-birefringence fiber arising from the SBS-induced dynamic acoustic-grating. This precision means a birefringence accuracy of 3times10-8.

  6. High-Precision Platform Positioning with a Single GPS Receiver

    Microsoft Academic Search

    Sunil B. Bisnath; Richard B. Langley

    2001-01-01

    The goal of the research described in this paper is the design of a GPS data processing technique capable of producing high-precision positioning results, regardless of platform dynamics, utilising only a single, high-quality receiver. This is accomplished by combining two processing philosophies: point positioning - making use of precise GPS constellation ephemeris and clock offset information to estimation a single

  7. Faculty Position in Ultra High Precision Robotics & Manufacturing

    E-print Network

    Candea, George

    , manipulation and metrology systems targeting additive manufacturing; · New kinematics, quasi-perfect guidings, actuators, transmission systems, sensors and methods targeting ultra-high precision additive manufacturing. Specific areas include, but are not limited to: · Design of innovative ultra-high precision machining

  8. Cascade: hardware for high\\/variable precision arithmetic

    Microsoft Academic Search

    Tony M. Carter

    1989-01-01

    The Cascade hardware architecture for high\\/variable precision arithmetic is described. It uses a radix-16 redundant signed-digit number representation and directly supports single or multiple precision addition, subtraction, multiplication, division, extraction of the square root, and computation of the greatest divisor. It is object-oriented and implements an abstract class of objects, variable precision integers. It provides a complete suite of memory

  9. Analysis of quantization error in high-precision continuous-flow isotope ratio mass spectrometry

    Microsoft Academic Search

    Gavin L. Sacks; Christopher J. Wolyniak; J. Thomas Brenna

    2003-01-01

    High-precision isotope ratio mass spectrometry (IRMS) systems are equipped with digitizers that deliver effective maximum digitization depths of 16 to 24bits; however, there are no analyses of the proper board depth required to retain high precision in continuous-flow techniques. We report an experimental and theoretical evaluation of quantization error in continuous-flow IRMS (CF-IRMS). CO2 samples (100pmol–30nmol) were injected into a

  10. High-precision stereoscopic 3D mapping accuracy

    NASA Astrophysics Data System (ADS)

    Doerry, Armin W.

    2001-08-01

    The state-of-the-art in extremely versatile fine-resolution Synthetic Aperture Radar (SAR) systems allows incredibly fine resolution and accurate images to be formed over a wide range of imaging geometries (squint angles and depression angles). This capability in turn is allowing the fusion of multiple views of targets and scenes into very accurate 3-dimensional renderings of the same scenes and targets. With proper imaging geometry selections, relative height accuracy within a scene can easily be on the order of the resolution of the original SAR images, thereby rivaling the finest IFSARs even on the drawing boards, and without the height ambiguities typically associated with large-baseline IFSARs. Absolute accuracy is typically limited to the accuracy of SAR flight path knowledge, bounded typically by GPS performance. This paper presents the relationship of height accuracy to imaging geometry (flight path) selection, and illustrates conditions for optimum height estimates. Furthermore, height accuracy is related to 3-D position accuracy and precision over a variety of imaging geometries. Performance claims of height precision on the order of resolution are validated with experimental results that are also presented, using multiple aspects of a target scene collected from a high-performance single-phase-center SAR.

  11. 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.

  12. High Precision Measurements of Neutron Beta-Decay at LANSCE

    Microsoft Academic Search

    Mark Makela

    2009-01-01

    High precision measurements of neutron beta-decay can be used to study the standard model of particle physics by testing the unitarity condition of the CKM matrix. Precise measurements of the neutrons' lifetime and one of its angular correlations are needed to determine the necessary standard model parameters for a unitarity test from neutron decay alone. Several experiments are underway at

  13. High precision manufacturing cell for motor bearing components

    Microsoft Academic Search

    Keith Carlisle; Mike Pierse; Stephen Manley

    1999-01-01

    This paper briefly describes some of the advanced machine tool technology used in the design of an automated high precision manufacturing cell “DeltaTurn 40”, designed to meet the needs of the hard disc drive industry. Key features of the machine used to ensure lasting precision and speed of operation will be discussed. Results of extensive cutting trials on various ferrous

  14. High resolution GPR and its experimental study

    NASA Astrophysics Data System (ADS)

    Huang, Ling; Zeng, Zhaofa; Wang, Munan; Wang, Zhenjiang

    2007-12-01

    We develop a high resolution ground penetrating radar system (LANRCS-GPR) based on the E5071B Vector Network Analyzer (VNA). This system takes advantage of a wideband and adjustable frequency domain ground penetrating radar system and adds the characteristics of a network analyzer with ultra-wideband and high precision measurement. It adopts the LAN mode to concatenate system control that reduces construction cost and makes the system easy to expand. The high resolution ground penetrating radar system carries out real time imaging using F-K migration with high calculation efficiency. The experiment results of the system indicate that the LANRCS-GPR system provides high resolution and precision, high signal-to-noise ratio, and great dynamic range. Furthermore, the LANRCSGPR system is flexible and reliable to operate with easy to expand system functions. The research and development of the LANRCS-GPR provide the theoretical and experimental foundation for future frequency domain ground penetrating radar production and also can serve as an experimental platform with high data gathering precision, enormous information capability, wide application, and convenient operation for electromagnetic wave research and electromagnetic exploration

  15. High Precision Integer Multiplication with a GPU

    Microsoft Academic Search

    Niall Emmart; Charles Weems

    2011-01-01

    We have improved our prior implementation of Strassen's algorithm for high performance multiplication of very large integers on a general purpose graphics processor (GPU). A combination of algorithmic and implementation optimizations result in a factor of 2.3 speed improvement over our previous work, running on an NVIDIA 295. We have also reoptimized the implementation for an NVIDIA 480, from which

  16. High precision geodesy applied to CERN accelerators

    Microsoft Academic Search

    J. Gervaise; E. J. N. Wilson

    1987-01-01

    After examining the whys and wherefores of applied geodesy in high energy particle accelerator construction, the authors show how the transverse beam size and hence the dimension of the magnets are related to positional tolerances and review the methods and instruments developed for this purpose. Three accelerators have successively been built at CERN, the 28 GeV Proton Synchrotron (PS), The

  17. 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).

  18. Review of High Precision Theory and Experiment for Helium

    Microsoft Academic Search

    Gordon W. F. Drake

    Progress in obtaining essentially exact solutions to the nonrelativistic Schrödinger equation for the entire singly-excited\\u000a spectrum of helium and other three-body systems is reviewed, and a new upper bound for the ground state is presented. The\\u000a calculation of relativistic and quantum electrodynamic corrections is discussed, including high precision values for the Bethe\\u000a logarithm. The results are compared with high precision

  19. High-precision anemometer with thermal wave

    SciTech Connect

    Rachalski, Andrzej [Strata Mechanics Research Institute, Polish Academy of Sciences, uleja Reymonta 27, 30-112 Cracow (Poland)

    2006-09-15

    A new, highly accurate method of measurement of the gas flow velocity has been developed. The method employs the phenomenon of propagation of thermal waves in flowing gas. The probe consists of three thin wires. One of these is a hot wire and it is used to generate a thermal wave while the two remaining wires are used for wave detection. Since the phase shift of the wave between two points is proportional to the wave frequency, the flow velocity can be derived from the slope of the regression line. Signals from the wave detectors are sent via an analog to digital converter to the computer and processed. We report measurements of the laminar flow with the velocity between 30 and 200 cm/s. The accuracy of the velocity measurements is about 0.2 cm/s.

  20. 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.

  1. High precision geodesy applied to CERN accelerators

    NASA Astrophysics Data System (ADS)

    Gervaise, J.; Wilson, E. J. N.

    After examining the whys and wherefores of applied geodesy in high energy particle accelerator construction, the authors show how the transverse beam size and hence the dimension of the magnets are related to positional tolerances and review the methods and instruments developed for this purpose. Three accelerators have successively been built at CERN, the 28 GeV Proton Synchrotron (PS), The Intersecting Storage Rings (ISR), the Super Proton Synchrotron (SPS), and a fourth one is under construction, the Large Electron Positron Collider (LEP). Since 1954, date of the PS construction, many difficulties have been encountered and the authors show how applied geodesy has been able to overcome them. From the traditional geodetic methods available in the 1950's, used to build a 200-m diameter accelerator, up to the 1980's, many methods and instruments ranging from invar wire to Terrameter, have been developed. These have improved the reliability, accuracy and speed of the geodetic measurements and have given a philosophy and a strategy for the Applied Geodesy of a 27-km circumference collider such as LEP.

  2. High-precision broadband extinction measurements using differential solar occultation

    Microsoft Academic Search

    Larry L. Gordley; Benjamin T. Marshall; Mark E. Hervig; Martin J. McHugh; James M. Russell; John C. Kemp; Ellis E. Remsberg; R. Earl Thompson

    2002-01-01

    Solar occultation measurements from satellite have been very successful at sounding the upper atmosphere from cloud-top to well into the mesosphere (e.g. HALOE, ATMOS, SAGE, POAM). The HALOE instrument achieves transmission precision of 4 X10-6 at 2 arcminute resolution (1.6 Km at the Earth limb) with the differential gas correlation technique. With modern detectors, high precision tracking, better throughput and

  3. Precision forging processes for high-duty automotive components

    Microsoft Academic Search

    B.-A. Behrens; E. Doege; S. Reinsch; K. Telkamp; H. Daehndel; A. Specker

    2007-01-01

    Precision forging is defined as a flashless near net-shape forging operation which generates high quality parts concerning surface quality and dimensional accuracy. In the past, precision forging processes have been industrially established for axis-symmetric parts, e.g. gearwheels and steering pinions. Further development of the technology to more complex parts, e.g. helical gears, connecting rods and crankshafts is expected to lead

  4. EMCCD Technology in High Precision Photometry on Short Timescales

    Microsoft Academic Search

    Niall Smith; Alan Giltinan; Aidan O’Connor; Stephen O’Driscoll; Adrian Collins; Dylan Loughnan; Andreas Papageorgiou

    2008-01-01

    We discuss the advantages and limitations of Electron Multiplying CCD technology in high precision photometry on short timescales,\\u000a with special emphasis on probing the smallest structures in active galactic jets. Factors external to the EMCCD, rather than\\u000a the architecture of the EMCCD itself, most often limit the precision of photometry that can be reached with groundbased observations.\\u000a Although EMCCDs can

  5. Aroma extract dilution analysis. Precision and optimal experimental design.

    PubMed

    Ferreira, Vicente; Pet'ka, Ján; Aznar, Margarita

    2002-03-13

    The odor thresholds of 12 different compounds have been determined in an AEDA experiment using a panel composed of 8 individuals. Only in one case is the distribution of thresholds among judges significantly different from the log-normal. The cause of that departure from normality seems to be a cross adaptation rather than anosmia. The standard deviations (SD) range from 2(0.7) to 2(4.1), with 2(1.8) as average. If the AEDA is carried out at a dilution rate, R, and dilution R(P) (where P = 0, 1, 2.) is the last one at which a compound was detected by a judge, the flavor dilution (FD) factor that should be provided for that judge is R(P+0.5). In the case where several judges carry out the AEDA, the FD for a given compound should be the geometric mean of the FD provided by all the judges. The SD of the distribution of FDs is related to that of the distribution of odor thresholds, but is strongly influenced by the dilution rate, R, being higher with higher R values. The relationship between both SDs can be used to determine the expected precision (measured as the geometric length of the 95% confidence interval) of the result of an AEDA experiment as a function of the dilution rate, the number of judges, and the SD of the distribution of thresholds. Different simulations have shown that in most cases, a dilution rate of 10 is the best option, and that lower dilution rates are advantageous only if the analyzed solution contains compounds with a very narrow distribution of thresholds. PMID:11879029

  6. Experimental studies of adaptive structures for precision performance

    NASA Technical Reports Server (NTRS)

    Chen, G.-S.; Lurie, B. J.; Wada, B. K.

    1989-01-01

    An experimental study was made of the adaptive structure concept. Experimental data were obtained for a three-longeron, thirteen-bay truss-type test structure. This test structure can be softly suspended as well as rigidly clamped at the central bay. The load-carrying active member consists of a stack of concentric piezoelectric wafers, an eddy current displacement sensor, and a strain gage force sensor. A bridge (or compound) feedback technique developed in communication engineering is applied to the problem of active damping augmentation in adaptive structures. Using collocated force and velocity feedback around the active member, a desired output mechanical impedance can be implemented to maximize energy absorption by the active members. In addition, large gains can be implemented to linearize the active member's nonlinear behavior. Good agreements with linear finite element analysis was found for both static and dynamic structural responses. An 11 percent damping in the first bending mode was demonstrated in the closed-loop damping experiment.

  7. 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.

  8. Experimental setup for precise investigation of raindrop impacted thin water flows

    NASA Astrophysics Data System (ADS)

    Fister, Wolfgang; Kinnell, Peter I. A.; Greenwood, Philip; Kuhn, Nikolaus J.

    2015-04-01

    Experimental setups with rainfall simulators over soil flumes are a widely-used method to study laboratory-based erosion processes. Small scale processes, such as splash, sheet, and interrill erosion mechanisms, can be studied with a very high degree of precision and accuracy. However, a major problem when performing investigations on raindrop impacted thin water flows is that accurate measurements of key erosion variables are difficult to obtain. In many investigations, important values are, therefore, not directly measured, but inferred from easier to determine parameters. For example rainfall intensity, plot dimension, and flow discharge are recorded during an experiment to rather crudely estimate velocity and depth of flow. Since water depth and flow velocity vary spatially and temporally during experiments with non-controlled flow conditions, this lack of measurement accuracy clearly reduces the explanatory power of the experimental data. Another example for this imprecision is the use of pressure nozzles for this kind of high accuracy experiments. The main problem associated with spray-type nozzles is that they produce a wide spectrum of drop sizes. In order to characterise simulated rainfall from nozzles, certain parameters, such as mean volumetric drop diameter (d50), are generally used. Knowing that different drop sizes have different effects on particle detachment when impacting on thin water layers of certain depth, it is apparent that this parameter of average drop size is not suitable for the detection of precise relations of, for instance, drop size, flow depth, and particle detachment. Although simulated rainfall from nozzles has a more natural drop size distribution, this use of roughly calculated metadata, instead of accurately measured parameters, is one of the main reasons why it is still not possible to deduce exact physical formulas to precisely model soil erosion mechanisms. In order to be able to control and manipulate the key factors of the processes of raindrop impacted thin surface flows, an experimental setup and measurement protocol was designed. The main aims of this study are to present the setup of this newly-developed equipment and to explore the difficulties in designing specific parts of this instrumentation, and to provide guidance for other investigations on this topic. In addition, preliminary results using this experimental configuration are presented.

  9. High precision integer multiplication with a graphics processing unit

    Microsoft Academic Search

    Niall Emmart; Charles C. Weems

    2010-01-01

    In this paper we evaluate the potential for using an NVIDIA graphics processing unit (GPU) to accelerate high precision integer multiplication. The reported peak vector performance for a typical GPU appears to offer considerable potential for accelerating such a regular computation. Because of limitations in the on-chip memory, the high cost of kernel launches, and the particular nature of the

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

    SciTech Connect

    Kolodner, Paul [Bell Laboratories, Alcatel-Lucent, Inc., Murray Hill, New Jersey 07974 (United States)] [Bell Laboratories, Alcatel-Lucent, Inc., Murray Hill, New Jersey 07974 (United States)

    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%.

  11. High precision patterning of ITO using femtosecond laser annealing process

    NASA Astrophysics Data System (ADS)

    Cheng, Chung-Wei; Lin, Cen-Ying

    2014-09-01

    High precision patterning of crystalline indium tin oxide (c-ITO) patterns on amorphous ITO (a-ITO) thin films by femtosecond laser-induced crystallization with a Gaussian beam profile followed by chemical etching is demonstrated. In the proposed approach, the a-ITO thin film is selectively transformed into a c-ITO structure via a low heat affect zone and the well-defined thresholds (ablation and crystallization) supplied by the femtosecond laser pulse. The experimental results show that by careful control of the laser fluence above the crystallization threshold, c-ITO patterns with controllable line widths and ridge-free characteristics can be accomplished. By careful control of the laser fluence above the ablation threshold, fast fabrication of the two parallel sub-micro c-ITO line patterns using a single femtosecond laser beam and single scanning path can be achieved. Along-length sub-micro c-ITO line pattern is fabricated, and the feasibility of fabricating c-ITO patterns is confirmed, which are expected to be used in micro-electronics devices.

  12. An experimental assembly for precise measurement of thermal accommodation coefficients

    NASA Astrophysics Data System (ADS)

    Trott, Wayne M.; Castañeda, Jaime N.; Torczynski, John R.; Gallis, Michael A.; Rader, Daniel J.

    2011-03-01

    An experimental apparatus has been developed to determine thermal accommodation coefficients for a variety of gas-surface combinations. Results are obtained primarily through measurement of the pressure dependence of the conductive heat flux between parallel plates separated by a gas-filled gap. Measured heat-flux data are used in a formula based on Direct Simulation Monte Carlo (DSMC) simulations to determine the coefficients. The assembly also features a complementary capability for measuring the variation in gas density between the plates using electron-beam fluorescence. Surface materials examined include 304 stainless steel, gold, aluminum, platinum, silicon, silicon nitride, and polysilicon. Effects of gas composition, surface roughness, and surface contamination have been investigated with this system; the behavior of gas mixtures has also been explored. Without special cleaning procedures, thermal accommodation coefficients for most materials and surface finishes were determined to be near 0.95, 0.85, and 0.45 for argon, nitrogen, and helium, respectively. Surface cleaning by in situ argon-plasma treatment reduced coefficient values by up to 0.10 for helium and by ˜0.05 for nitrogen and argon. Results for both single-species and gas-mixture experiments compare favorably to DSMC simulations.

  13. High-precision static and dynamic angular measurements with a ring laser gyro

    Microsoft Academic Search

    Ludi Zheng; Quanan Tang; Xinyu Ma; Yanshen Zhang

    1996-01-01

    This presented paper describes a high-precision goniometer system with a ring laser gyro (RLG). The principle of the goniometer is introduced. The key techniques for improving the measuring accuracy are analyzed. As the central element of the goniometer, RLG is investigated, including its error items, such as scalefactor, bias and random walk coefficient. The experimental results are provided.

  14. 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 (1?) 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

  15. Contrast optimization in a high-precision interferometer

    NASA Astrophysics Data System (ADS)

    Simonova, Galina V.

    2004-12-01

    The accuracy of a high-precision interferometric experiment depends both on instrument errors and errors connected to interferograms processing. Both types of errors can be minimized by an optimum adjustment of the interferometer functions. The paper addresses the issue of the fringe pattern contrast optimization via the application of the electrochromic coating on the reference surface of the interferometer.

  16. Fiber optic synchronisation architecture for high precision GPS applications

    E-print Network

    Santerre, Rock

    Fiber optic synchronisation architecture for high precision GPS applications Daniel Macias and the receiver is monitored at the millimetre level [2]. These issues can be solved using optical fiber links), Université Laval, Québec, QC, G1V 0A6, Canada sophie.larochelle@gel.ulaval.ca Abstract: We propose a GPS-over-fiber

  17. High precision module for Chaos Many-Body Engine

    E-print Network

    Grossu, I V; Felea, D; Jipa, Al

    2014-01-01

    In this paper we present a C# high precision relativistic many-body module integrated with Chaos Many-Body Engine. As a direct application, we used it for estimating the butterfly effect involved by the gravitational force in a specific nuclear relativistic collision toy-model.

  18. A high precision Fabry-Perot cavity polarimeter at HERA

    Microsoft Academic Search

    S. Baudrand; M. Bouchel; V. Brisson; R. Chiche; M. Jacquet; S. Kurbasov; G. Li; C. Pascaud; A. Reboux; V. Soskov; Z. Zhang; F. Zomer; M. Beckingham; T. Behnke; N. Coppola; N. Meyners; D. Pitzl; S. Schmitt; M. Authier; P. Deck-Betinelli; Y. Queinec; L. Pinard

    2010-01-01

    A Fabry-Perot cavity polarimeter, installed in 2003 at HERA for the second phase of its operation, is described. The cavity polarimeter was designed to measure the longitudinal polarisation of the HERA electron beam with high precision for each electron bunch spaced with a time interval of 96 ns. Within the cavity the laser intensity was routinely enhanced up to a

  19. Long distance non-contact high precision measurements

    Microsoft Academic Search

    G. C. BAKOS; N. F. TSAGAS; J. LYGOURAS; J. LUCAS

    1993-01-01

    In recent times a great deal of interest has been shown the computer vision and robotics research community within the remote (non-contact) determination of configurations by using direct (active) range finding. The presently developed range finder is based upon the use of laser light and triangulation and aims at long distance high precision measurements. New image processing techniques are combined

  20. A High-Precision NDIR Gas Sensor for Automotive Applications

    Microsoft Academic Search

    Robert Frodl; Thomas Tille

    2006-01-01

    A new high-precision spectroscopic gas sensor measuring carbon dioxide (CO2) for harsh environmental conditions of automotive applications is presented. The carbon dioxide concentration is the primary parameter for sensing in cabin air quality, as well as an important safety parameter when R744 (carbon dioxide) is used as the refrigerant in the air conditioning system. The automotive environment challenges the potential

  1. 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.

  2. 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.

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

    SciTech Connect

    Heeger, Karsten M [Yale University

    2014-09-13

    This reports 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.

  4. 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.

  5. High precision calibration for 2D optical standard

    NASA Astrophysics Data System (ADS)

    Sun, Shuanghua; Gan, Xiaochuan; Xue, Zi; Ye, Xiaoyou; Wang, Heyan; Gao, Hongtang

    2012-10-01

    Photomask is a kind of 2-D optical standard with etched orthogonal coordinates made of a glass substrate chrominged or filmed with other metal. In order to solve the problems of measurement and traceability of ultra precision photomasks used in advanced manufacturing industry, 2-D photomask optical standard was calibrated in high precision laser two coordinate standard device. A high precision differential laser interferometer system was used for a length standard, a high magnification optical micro vision system was used for precision optical positioning feedback. In this paper, a image measurement model was purposed; A sampling window auto identification algorithm was designed. Grid stripe image could be identified and aimed at automatically by this algorithm. An edge detection method based on bidirection progressive scanning and 3-sigma rule for eliminating outliers in sampling window was found. Dirty point could be removed with effect. Edge detection error could be lowered. By this means, the measurement uncertainty of 2-D optical standard's ruling span was less than 0.3 micrometer (k=2).

  6. High Precision Digital Frequency Signal Source Based on FPGA

    NASA Astrophysics Data System (ADS)

    Yanbin, SHI; Jian, GUO; Ning, CUI

    The realization method of DDS technology is introduced, and its superior technical characteristics are analyzed in this paper. According to its characteristics, the high accuracy digital frequency signal source based on FPGA is designed. The simulation result indicated, compares with the traditional signal source, this type of signal source realized by the method of FPGA+DDS have many merits such as high precision and fast switch speed, which can satisfies the developing tendency of test facility.

  7. High-Precision Nonlinear, Adaptive, Robust Weapon Control Systems Design

    Microsoft Academic Search

    N. Coleman; M. Mattice; S. Banks; C. F. Lin; R. N. K. Loh; J. C. Juang; L. S. Shieh

    1992-01-01

    This paper summarizes the design objectives and approaches of the weapon control design presented in the Invited Session WA12 on Advanced Weapon Control Technology. To design a high-precision, high-bandwidth, and reliable weapon control system, several design approaches and their integration are investigated. This includes robust control design to account for unmodeled dynamics inherent in the gun-turrent system; adaptive-intelligent control to

  8. Analysis of quantization error in high-precision continuous-flow isotope ratio mass spectrometry.

    PubMed

    Sacks, Gavin L; Wolyniak, Christopher J; Brenna, J Thomas

    2003-12-12

    High-precision isotope ratio mass spectrometry (IRMS) systems are equipped with digitizers that deliver effective maximum digitization depths of 16 to 24 bits; however, there are no analyses of the proper board depth required to retain high precision in continuous-flow techniques. We report an experimental and theoretical evaluation of quantization error in continuous-flow IRMS (CF-IRMS). CO2 samples (100 pmol-30 nmol) were injected into a gas chromatography combustion IRMS system (GC-CIRMS). The analog signal was digitized by high precision, 24-bit ADC boards at 10 Hz, and was post-processed to simulate 12, 14, and 16-bit data sets. Delta13Cpdh values were calculated for all data sets by the conventional "summation" method or by curve-fitting the chromatographic peaks to the exponentially modified Gaussian (EMG) function. Benchmarks of S.D.(delta13Cpdh) = 0.3, 0.6, and 1.0/1000 were considered to assess precision. In the presence of significant quantization noise, curve-fitting required several-fold less CO2 than the summation method to reach a given benchmark. We derived an equation to describe the theoretical limitations of precision for the summation method as a function of CO2 admitted to the source and the step size of the boards. Theory was in close agreement with the observed lower limit of precision for the simulated 16-bit data set. Curve-fitting achieved a precision of S.D. <0.3/1000 for injections 20-fold smaller than summation for CO2 samples collected on an IRMS with 16-bit resolution. By mitigating the impact of quantization noise, curve-fitting expands the dynamic range within a single run to include lower analyte levels, and effectively reduces the need for high pumping capacities and high precision ADC boards. PMID:14661751

  9. High Efficiency Positron Accumulation for High-Precision Measurements

    E-print Network

    Hoogerheide, S Fogwell; Novitski, E; Gabrielse, G

    2015-01-01

    Positrons are accumulated within a Penning trap designed to make more precise measurements of the positron and electron magnetic moments. The retractable radioactive source used is weak enough to require no license for handling radioactive material and the radiation dosage one meter from the source gives an exposure several times smaller than the average radiation dose on the earth's surface. The 100 mK trap is mechanically aligned with the 4.2 K superconducting solenoid that produces a 6 tesla magnetic trapping field with a direct mechanical coupling.

  10. Experimental and numerical analysis of thermal forming processes for precision optics

    NASA Astrophysics Data System (ADS)

    Su, Lijuan

    Glass has been fabricated into different optical elements including aspherical lenses and freeform mirrors. However, aspherical lenses are very difficult to manufacture using traditional methods since they were specially developed for spherical lenses. On the other hand, large size mirrors are also difficult to make especially for high precision applications or if designed with complicated shapes. Recently developed two closely related thermal forming processes, i.e. compression molding and thermal slumping, have emerged as two promising methods for manufacturing aspherical lenses and freeform mirrors efficiently. Compression molding has already been used in industry to fabricate consumer products such as the lenses for digital cameras, while thermal slumping has been aggressively tested to create x-ray mirrors for space-based telescopes as well as solar panels. Although both process showed great potentials, there are a quite few technical challenges that prevent them from being readily implemented in industry for high volume production. This dissertation research seeks a fundamental understanding of the thermal forming processes for both precision glass lenses and freeform mirrors by using a combined experimental, analytical and numerical modeling approach. First, a finite element method (FEM) based methodology was presented to predict the refractive index change of glass material occurred during cooling. The FEM prediction was then validated using experimental results. Second, experiments were also conducted on glass samples with different cooling rates to study the refractive index variation caused by non-uniform cooling. A Shack-Hartmann Sensor (SHS) test setup was built to measure the index variations of thermally treated glass samples. Again, an FEM simulation model was developed to predict the refractive index variation. The prediction was compared with the experimental result, and the effects of different parameters were evaluated. In the last phase of this dissertation research, an FEM simulation model was developed to study the thin glass slumping processes on both concave and convex mandrels. Simulation of thin glass sheet slumping on convex mandrel was performed to study the effects of different process parameters, i.e. thickness of the glass sheet, cooling and heating rate, soaking time and soaking temperature. Finally, experiments of thermal slumping glass plates on a parabolic concave mandrel were performed to study the thickness effect on slumping process and the final surface contour of the upper surface of the glass plate. Simulation was again conducted to predict the surface contour. The comparison between simulation and experiments showed that the FEM simulation is adequate for predicting the surface contour if the glass was fully slumped. It was also discovered that for process conditions used, thinner glass sheets were not fully slumped.

  11. 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.

  12. Experimental verification of quantum precision limit in adaptive qubit state tomography

    E-print Network

    Zhibo Hou; Huangjun Zhu; Guo-Yong Xiang; Chuan-Feng Li; Guang-Can Guo

    2015-03-01

    The precision limit in quantum state tomography is of great interest not only to practical applications but also to foundational studies. However, little is known about this subject in the multiparameter setting even theoretically due to the subtle information tradeoff among incompatible observables. In the case of a qubit, the theoretic precision limit was determined by Hayashi as well as Gill and Massar, but attaining the precision limit in experiments has remained a challenging task. Here we report the first experimental verification of this precision limit in adaptive quantum state tomography on optical polarization qubits. The two-step adaptive strategy employed in our experiment is very easy to implement in practice. Yet it is surprisingly powerful in optimizing most figures of merit of practical interest. Our study may have significant implications for multiparameter quantum estimation problems, such as quantum metrology. Meanwhile, it may promote our understanding about the complementarity principle and uncertainty relations from the information theoretic perspective.

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

    E-print Network

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

    2015-01-01

    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. 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 $\\gamma'$ of the...

  14. A High Precision Fabry-Perot Cavity Polarimeter at HERA

    E-print Network

    S. Baudrand; M. Bouchel; V. Brisson; R. Chiche; M. Jacquet; S. Kurbasov; G. Li; C. Pascaud; A. Reboux; V. Soskov; Z. Zhang; F. Zomer; M. Beckingham; T. Behnke; N. Coppola; N. Meyners; D. Pitzl; S. Schmitt; M. Authier; P. Deck-Betinelli; Y. Queinec; L. Pinard

    2010-06-28

    A Fabry-Perot cavity polarimeter, installed in 2003 at HERA for the second phase of its operation, is described. The cavity polarimeter was designed to measure the longitudinal polarisation of the HERA electron beam with high precision for each electron bunch spaced with a time interval of 96ns. Within the cavity the laser intensity was routinely enhanced up to a few kW from its original value of 0.7W in a stable and controllable way. By interacting such a high intensity laser beam with the HERA electron beam it is possible to measure its polarisation with a relative statistical precision of 2% per bunch per minute. Detailed systematic studies have also been performed resulting in a systematic uncertainty of 1%.

  15. 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.

  16. High-precision torque control of reluctance motors

    Microsoft Academic Search

    Nobuyuki Matsui; Norihiko Akao; Tomoo Wakino

    1991-01-01

    The high-precision torque control of a reluctance motor for servo applications is described. The prototype is a three-phase, eight-pole reluctance motor driven by a MOSFET inverter. The current control and the speed control are performed by software of the digital signal processor TMS 32010. The motor is supplied by sinusoidal current, and two current control methods are proposed. One is

  17. High-precision reflectivity measurements: improvements in the calibration procedure

    NASA Astrophysics Data System (ADS)

    Jupe, Marco; Grossmann, Florian; Starke, Kai; Ristau, Detlev

    2003-05-01

    The development of high quality optical components is heavily depending on precise characterization procedures. The reflectance and transmittance of laser components are the most important parameters for advanced laser applications. In the industrial fabrication of optical coatings, quality management is generally insured by spectral photometric methods according to ISO/DIS 15386 on a medium level of accuracy. Especially for high reflecting mirrors, a severe discrepancy in the determination of the absolute reflectivity can be found for spectral photometric procedures. In the first part of the CHOCLAB project, a method for measuring reflectance and transmittance with an enhanced precision was developed, which is described in ISO/WD 13697. In the second part of the CHOCLAB project, the evaluation and optimization for the presented method is scheduled. Within this framework international Round-Robin experiment is currently in progress. During this Round-Robin experiment, distinct deviations could be observed between the results of high precision measurement facilities of different partners. Based on the extended experiments, the inhomogeneity of the sample reflectivity was identified as one important origin for the deviation. Consequently, this inhomogeneity is also influencing the calibration procedure. Therefore, a method was developed that allows the calibration of the chopper blade using always the same position on the reference mirror. During the investigations, the homogeneity of several samples was characterized by a surface mapping procedure for 1064 nm. The measurement facility was extended to the additional wavelength 532 nm and a similar set-up was assembled at 10.6 ?m. The high precision reflectivity procedure at the mentioned wavelengths is demonstrated for exemplary measurements.

  18. OPTIMIZING THE PRECISION OF TOXICITY THRESHOLD ESTIMATION USING A TWO-STAGE EXPERIMENTAL DESIGN

    EPA Science Inventory

    An important consideration for risk assessment is the existence of a threshold, i.e., the highest toxicant dose where the response is not distinguishable from background. We have developed methodology for finding an experimental design that optimizes the precision of threshold mo...

  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 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.

  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. Precision absolute measurements of strong and highly inhomogeneous magnetic fields.

    PubMed

    Honig, A; Moroz, M

    1978-02-01

    The low-temperature ([similar or less than]4 K) dependence of the photoconductance in n-type silicon on the conduction electron and bound donor electron spin state serves as the basis of a high-precision, wide-range magnetic field measuring probe, which by virtue of its very small dimensions is well suited for spatial mapping of highly inhomogeneous fields produced by superconducting magnets. The probe may also be adapted to power and frequency measurement of microwave sources operating at approximately mW power levels and frequencies up to approximately 500 GHz. PMID:18699056

  3. 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.

  4. 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.

  5. High-precision branching ratio measurement for the superallowed {beta}{sup +} emitter {sup 62}Ga

    SciTech Connect

    Finlay, P.; Svensson, C. E.; Bandyopadhyay, D.; Grinyer, G. F.; Hyland, B.; Leach, K. G.; Phillips, A. A.; Schumaker, M. A.; Wong, J. [Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Ball, G. C.; Chakrawarthy, R. S.; Hackman, G.; Kanungo, R.; Morton, A. C.; Pearson, C. J.; Savajols, H. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Leslie, J. R.; Towner, I. S. [Department of Physics, Queen's University, Kingston, Ontario K7L 3N6 (Canada); Austin, R. A. E.; Chaffey, A. [Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3 (Canada)] (and others)

    2008-08-15

    A high-precision branching ratio measurement for the superallowed {beta}{sup +} decay of {sup 62}Ga was performed at the Isotope Separator and Accelerator (ISAC) radioactive ion beam facility. The 8{pi} spectrometer, an array of 20 high-purity germanium detectors, was employed to detect the {gamma} rays emitted following Gamow-Teller and nonanalog Fermi {beta}{sup +} decays of {sup 62}Ga, and the SCEPTAR plastic scintillator array was used to detect the emitted {beta} particles. Thirty {gamma} rays were identified following {sup 62}Ga decay, establishing the superallowed branching ratio to be 99.858(8)%. Combined with the world-average half-life and a recent high-precision Q-value measurement for {sup 62}Ga, this branching ratio yields an ft value of 3074.3{+-}1.1 s, making {sup 62}Ga among the most precisely determined superallowed ft values. Comparison between the superallowed ft value determined in this work and the world-average corrected Ft value allows the large nuclear-structure-dependent correction for {sup 62}Ga decay to be experimentally determined from the CVC hypothesis to better than 7% of its own value, the most precise experimental determination for any superallowed emitter. These results provide a benchmark for the refinement of the theoretical description of isospin-symmetry breaking in A{>=}62 superallowed decays.

  6. Selection and use of TLDS for high precision NERVA shielding measurements

    NASA Technical Reports Server (NTRS)

    Woodsum, H. C.

    1972-01-01

    An experimental evaluation of thermoluminescent dosimeters was performed in order to select high precision dosimeters for a study whose purpose is to measure gamma streaming through the coolant passages of a simulated flight type internal NERVA reactor shield. Based on this study, the CaF2 chip TLDs are the most reproducible dosimeters with reproducibility generally within a few percent, but none of the TLDs tested met the reproducibility criterion of plus or minus 2%.

  7. High precision, accuracy, and resolution of 3D laser scanner employing pulsed time-of-flight measurement

    Microsoft Academic Search

    Martin Pfennigbauer; Andreas Ullrich; João Pereira Do Carmo

    2011-01-01

    We present experimental results of a high-speed 3-D laser scanner developed for the European Space Agency within an activity dealing with a high precision relative attitude control sensor for formation flying. By employing pulsed-time-offlight measurement, we demonstrated sub-mm accuracy and precision as well as unprecedented resolution of single-shot measurements to natural targets at distances up to 150 m. The instrument

  8. 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

  9. 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.

  10. High Precision Laser and Microwave Spectroscopy of Antiprotonic Helium

    E-print Network

    E. Widmann

    2002-10-29

    This talk gives an overview of the recent results on the precision spectroscopy of antiprotonic helium which was performed by the ASACUSA collaboration at the Antiproton Decelerator of CERN. The laser spectroscopy of energy levels of the antiproton has reached a relative accuracy of $\\sim 10^{-7}$, and by comparing the experimental value for the transition wavelengths with theoretical calculations, a CPT test on the equality of proton and antiproton charge and mass of $<6\\times10^{-8}$ has been obtained. In a recent experiment, the hyperfine structure of the $(n,l)=(37,35)$ state of antiprotonic helium has been measured for the first time with an accuracy of $3 \\times 10^{-5}$.

  11. Test results of high-precision large cryogenic lens holders

    NASA Astrophysics Data System (ADS)

    Gal, C.; Reutlinger, A.; Boesz, A.; Leberle, T.; Mottaghibonab, A.; Eckert, P.; Dubowy, M.; Gebler, H.; Grupp, F.; Geis, N.; Bode, A.; Katterloher, R.; Bender, R.

    2012-09-01

    For the Euclid mission a Pre-Development phase is implemented to prove feasibility of individual components of the system [1]. The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision large lens holders (?170 mm) at cryogenic temperatures (150K). The four lenses of the optical system are made of different materials: fused silica, CaF2, and LF5G15 that are mounted in a separate lens barrel design. Each lens has its separate mechanical interface to the lens barrel, the so called adaption ring. The performance of the lens holder design is verified by adapted test equipment and test facility including an optical metrology system. The characterization of the lens deformation and displacement (decenter, tilt) due to mechanical loads of the holder itself as well as thermally induced loads are driven by the required submicron precision range and the operational thermal condition. The surface deformation of the lens and its holder is verified by interferometric measurements, while tilt and position accuracy are measured by in-situ fibre based distance sensors. The selected distance measurement sensors have the capability to measure in a few mm range with submicron resolution in ultra high vacuum, in vibration environments and at liquid nitrogen temperatures and below. The calibration of the measurement system is of crucial importance: impacts such as temperature fluctuation, surface roughness, surface reflectivity, straylight effects, etc. on the measured distance are carefully calibrated. Inbuilt thermal expansion effects of the fibre sensors are characterized and proven with lens dummy with quasi zero CTE. The paper presents the test results and measured performance of the high precision large cryogenic lens holders attained by the metrology system. These results are presented on behalf of the EUCLID consortium.

  12. 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.

  13. 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.

  14. Experimental Study on the Precise Orbit Determination of the BeiDou Navigation Satellite System

    PubMed Central

    He, Lina; Ge, Maorong; Wang, Jiexian; Wickert, Jens; Schuh, Harald

    2013-01-01

    The regional service of the Chinese BeiDou satellite navigation system is now in operation with a constellation including five Geostationary Earth Orbit satellites (GEO), five Inclined Geosynchronous Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Besides the standard positioning service with positioning accuracy of about 10 m, both precise relative positioning and precise point positioning are already demonstrated. As is well known, precise orbit and clock determination is essential in enhancing precise positioning services. To improve the satellite orbits of the BeiDou regional system, we concentrate on the impact of the tracking geometry and the involvement of MEOs, and on the effect of integer ambiguity resolution as well. About seven weeks of data collected at the BeiDou Experimental Test Service (BETS) network is employed in this experimental study. Several tracking scenarios are defined, various processing schemata are designed and carried out; and then, the estimates are compared and analyzed in detail. The results show that GEO orbits, especially the along-track component, can be significantly improved by extending the tracking network in China along longitude direction, whereas IGSOs gain more improvement if the tracking network extends in latitude. The involvement of MEOs and ambiguity-fixing also make the orbits better. PMID:23529116

  15. High Resolution, High Precision I-Line Stepper Processing

    NASA Astrophysics Data System (ADS)

    Yanazawa, H.; Hasegawa, N.; Kurosaki, T.; Hashimoto, N.; Nonogaki, S.

    1985-06-01

    Currently, the integrated MOS dynamic RAM has as many as 256 thousand memory cells per chip based on 2 pm photolithography. Figure 1 shows the history and the prospects for progress in microfabrication technology. Feature size versus year, as reported by Bossung in 1978, is shown, as developed from independent analysis by Moore, Noyce and Gnostic concept. Circles numbered 1 and 2 show that 64K- and 256K-bit RAMs were developed in 1981 and 1984, and that their feature sizes were 3?m and 2?m, respectively. It is significant that the predictions and the real developments are so close. Furthermore, since the basic process for 3 M-bit RAMs based on 1.3?m microlithography has already been reported in conference, it is highly likely that they will become commercially available around 1987, as predicted by the circle numbered 3 based on 1.3?m microlithography.

  16. 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 (?-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

  17. High Precision Isotope Petrography by Secondary Ion Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Yurimoto, H.

    2009-12-01

    Since Shimizu et al. (GCA 1978) have demonstrated that in-situ micro-scale analyses of isotopes and trace elements in minerals were succeeded by secondary ion mass spectrometry (SIMS), geochemists develop the SIMS methods towards isotope mapping with spatial resolution of electron microscopy level. At present, high spatial resolution imaging by SIMS has been succeeded by scanning methods using ion-probe and by projection methods using stigmatic secondary ion optics. For high precision isotope analysis with high spatial resolution, intense secondary ions are indispensable for each pixel in the image. However, one of the major instrumental problems is that there were no adequate detectors for this purpose. In order to solve the problem, we proposed a two-dimensional solid-state ion detector called SCAPS (Takayanagi et al., IEEE Trans. 2003). The development is still continued and performances of recent SCAPS detector is achieved to: (1) direct sensitive for ions from single ion, (2) no dead time, and (3) perfect linearity of five orders of magnitude dynamic range. Installing the SCAPS detector into a stigmatic SIMS of Cameca ims-1270, we obtained oxygen isotope (delta-O-17 and delta-O-18) images of about 100 micrometer field with ~500 nm resolution and ~5 permil precision. The performance of high precision isotope imaging have might not be matured, but overcome a hurdle towards isotope petrography (Isotopography). We apply this isotopography to research fields of (a) survey of isotope anomalous micrograins and (b) isotope micro-distribution in rocks and minerals. In the application (a), we found in-situ presolar grains in meteorites (Nagashima et al., Nature 2004) and cosmic symplectite (COS) from a meteorite (Sakamoto et al., Science 2007). In the application (b), we showed how distribute oxygen isotopic compositions in micro-scale within CAI minerals (Yurimoto et al., Rev. Mineral. 2008; Fagan et al., in prep.). In combination fields of (a) and (b), we demonstrated how preserves Martian water and how contaminates terrestrial water in Martian meteorites (Greenwood et al., GRL 2008). These new knowledge from isotopography provides novel perspective of earth and planetary sciences.

  18. 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

  19. High precision object geo-localization and visualization in sensor networks

    NASA Astrophysics Data System (ADS)

    Lemaire, Simon; Bodensteiner, Christoph; Arens, Michael

    2013-10-01

    The wide availability of previously acquired, geo-referenced imagery enables automatic video based solutions for high precision object geo-localization and cooperative visualization. We present a system which geo-references objects seen in UAV video streams, distributes this information in a sensor network and visualizes them on modern smartphones using augmented reality techniques. The feasibility of the approach was experimentally validated using Mini-UAV ("MD-400") and high altitude UAV video footage in combination with modern off-the-shelve smartphones. Applications are widespread and include for instance crisis and disaster management or military applications.

  20. High precision surface metrology using a phase retrieval method

    NASA Astrophysics Data System (ADS)

    Modi, Mohammed H.; Mercere, Pascal; Idir, Mourad

    2009-09-01

    At wavelength metrology offers a unique opportunity to characterize ultra high quality optics of diffraction limited performance. This technique is based on a coherent interaction of incident wave fields reflected from different surface positions. The mirror surface acts as a phase object which introduces a phase error in the outgoing wave fields. Resultant aberrated wavefront modulates the intensity near the focal plane. The modulated intensity profile can be used to retrieve the mirror shape profile using a numerical phase retrieval method which is developed in the present work. This at-wavelength metrology gives a precise shape information of a mirror having a figure error < 1nm which is extremely difficult to measure with conventional metrology tools.

  1. High-Precision Mass Measurements of Radionuclides with Penning Traps

    NASA Astrophysics Data System (ADS)

    Block, Michael

    The mass of an atom is directly related to the binding energy of all its constituents. Thus, it provides information about all the interactions inside the atom. High-precision mass measurements hence allow studies of fundamental interactions and are of great importance in many different fields in physics. The masses of radionuclides provide information on their stability and their structure and are therefore of particular interest for nuclear structure investigations and as input for nucleosynthesis models in nuclear astrophysics. Penning trap mass spectrometry provides masses of radionuclides with unprecedented accuracies on the order of 10^{-8} and can nowadays be applied even to nuclides with short half-lives and low production rates. Utilizing advanced ion manipulation techniques radionuclides from essentially all elements produced in a broad range of nuclear reactions can be accessed. In this chapter the standard procedures of on-line Penning trap mass spectrometry are introduced and some representative examples of recent mass measurements are given.

  2. 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.

  3. 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.

  4. Design Of A New High Precision Computer Numerical Control

    NASA Astrophysics Data System (ADS)

    Sweeney, Douglas J.; Weinert, George F.

    1989-01-01

    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.

  5. 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.

  6. 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

  7. 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

  8. High-precision heliostat for long-path light tracking

    NASA Astrophysics Data System (ADS)

    Hawat, Tom; Stephen, Thomas M.; DeMaziere, Martine M.; Neefs, Eddy

    2003-08-01

    A heliostat has been designed and built for use in optical remote sensing of the atmosphere. The heliostat uses two flat mirrors to track the sun and direct the sunlight to optical instruments. A stepper motor driven horizontal turntable is used to track the sun in azimuth and support an elevation assembly and a mechanical tower. The stepper motor driven elevation assembly drives an acquisition mirror that tracks the sun in elevation. This mirror directs the solar beam to a secondary mirror fixed on the mechanical tower. The secondary mirror then directs the solar beam along the axis of the tracker for use in measurements. A sensitive, high resolution CCD camera, receives a small part of the solar beam to analyze for fine servo-control. Ground based tests have demonstrated this instrument"s tracking capability for the sun, the moon, stars and for long pathlength sources. Presently, this system is coupled with a high-resolution Brucker 120M spectrometer used to obtain solar absorption spectra. The heliostat directs the solar radiation along the spectrometer optical axis. The pointing precision was measured to be better than 0.5 arcsec. A description of the heliostat is presented, as well as the results of ground tests.

  9. 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.

  10. Silicon avalanche pixel sensor for high precision tracking

    NASA Astrophysics Data System (ADS)

    D'Ascenzo, N.; Marrocchesi, P. S.; Moon, C. S.; Morsani, F.; Ratti, L.; Saveliev, V.; Savoy Navarro, A.; Xie, Q.

    2014-03-01

    The development of an innovative position sensitive pixelated sensor to detect and measure with high precision the coordinates of the ionizing particles is proposed. The silicon avalanche pixel sensors (APiX) is based on the vertical integration of avalanche pixels connected in pairs and operated in coincidence in fully digital mode and with the processing electronics embedded on the chip. The APiX sensor addresses the need to minimize the material budget and related multiple scattering effects in tracking systems requiring a high spatial resolution in the presence of the large track occupancy. The expected operation of the new sensor features: low noise, low power consumption and suitable radiation tolerance. The APiX device provides on-chip digital information on the position of the coordinate of the impinging charged particle and can be seen as the building block of a modular system of pixelated arrays, implementing a sparsified readout. The technological challenges are the 3D integration of the device under CMOS processes and integration of processing electronics.

  11. Ramsey Method of Separated Oscillatory Fields for High-Precision Penning Trap Mass Spectrometry

    SciTech Connect

    George, S.; Blaum, K. [GSI, Planckstrasse 1, 64291 Darmstadt (Germany); Institut fuer Physik, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Baruah, S.; Breitenfeldt, M.; Schweikhard, L. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Blank, B. [Centre d'Etudes Nucleaires de Bordeaux-Gradignan, 33175 Gradignan Cedex (France); Hager, U. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), 40014 Jyvaeskylae (Finland); Herfurth, F.; Savreux, R.; Yazidjian, C. [GSI, Planckstrasse 1, 64291 Darmstadt (Germany); Herlert, A. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Kellerbauer, A. [Max-Planck Institut fuer Kernphysik, 69117 Heidelberg (Germany); Kluge, H.-J. [GSI, Planckstrasse 1, 64291 Darmstadt (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Kretzschmar, M. [Institut fuer Physik, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Lunney, D. [CSNSM-IN2P3-CNRS, 91405 Orsay-Campus (France); Schwarz, S. [NSCL, Michigan State University, East Lansing, Michigan 48824-1321 (United States)

    2007-04-20

    Ramsey's method of separated oscillatory fields is applied to the excitation of the cyclotron motion of short-lived ions in a Penning trap to improve the precision of their measured mass values. The theoretical description of the extracted ion-cyclotron-resonance line shape is derived and its correctness demonstrated experimentally by measuring the mass of the short-lived {sup 38}Ca nuclide with an uncertainty of 1.1x10{sup -8} using the Penning trap mass spectrometer ISOLTRAP at CERN. The mass of the superallowed beta emitter {sup 38}Ca contributes for testing the theoretical corrections of the conserved-vector-current hypothesis of the electroweak interaction. It is shown that the Ramsey method applied to Penning trap mass measurements yields a statistical uncertainty similar to that obtained by the conventional technique but 10 times faster. Thus the technique is a new powerful tool for high-precision mass measurements.

  12. A new method to eliminate the noise of vacuum microelectronic high precision accelerometer

    Microsoft Academic Search

    Hai-Tao Liu; Zhi-Yu Wen; Li Chen; Zhong-Quan Wen; Xue-Feng He

    2011-01-01

    The vacuum microelectronic high precision accelerometer was developed based on the vacuum field emission theory; it has many advantages such as high precision, good linearity in theory, but the inherent low frequency such as 1\\/f noise of the accelerometer decreases the signal-to-noise ratio greatly, and it is the main influencing factors to precision and linearity of accelerometer. In this paper

  13. TOWARDS HIGH-PRECISION AMS: PROGRESS AND LIMITATIONS

    Microsoft Academic Search

    Christopher Bronk Ramsey; Thomas HighamPhilip Leach

    Precision and accuracy in accelerator mass spectrometry (AMS) dating relies on the systematic reduction of errors at all stages of the dating process, from sampling to AMS measurement. With new AMS systems providing much better precision and accuracy for the final stage of the process, we need to review the process as a whole to test the accuracy of reported

  14. New linear piezomotors for high-force precise positioning applications

    NASA Astrophysics Data System (ADS)

    Le Letty, Ronan; Claeyssen, Frank; Barillot, Francois; Six, Marc F.; Bouchilloux, Philippe

    1998-07-01

    Piezomotors are an increasingly competitive alternative to electromagnetic stepper motors, especially in applications where large bandwidths and/or precise positioning control are desired. Piezomotors use a combination of electromechanical and frictional forces and, compared to conventional electromagnetic motors, have the advantages that no power supply is required to maintain the motor in position and no lubrication is necessary in the device. The operating principle of these motors relies on the use of an ultrasonic vibration, which is created via the piezoelectric effect (at resonance in most cases), in order to generate vibration forces at the `stator/rotor' contact interface. A mechanical preload is also applied at this contact interface and is responsible for the motor's holding force at rest. To meet the specifications of an aerospace application, we developed a new design of Linear PiezoMotors (LPMs). The first prototype we built shows very promising results, and makes the LPM a serious candidate to replace conventional stepper motors. The LPM features the following characteristics: a standing force of 100 N, a blocked force of 37 N, a maximum actuation speed of 23 mm/s, a maximum run of 10 mm, a mass of 500 g, an electrical power of 2.2 W, and a position accuracy superior to 1 micrometers . To our knowledge, the driving force delivered by the LPM has never before been achieved in resonant devices. This paper describes the physical operating principles of the LPM, as well as the modeling tools and experimental techniques we used for its development. Several implementation schemes are also presented and show the wide range of possible applications offered by the linear piezomotor.

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

    DOEpatents

    Andresen, Nord C. (Hayward, CA); DiGennaro, Richard S. (Albany, CA); Swain, Thomas L. (Richmond, CA)

    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.

  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. 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 0.1?m.

  18. Toward the robust control of high-bandwidth high-precision flexible optical systems

    Microsoft Academic Search

    Kenneth Wayne Barker

    1991-01-01

    It is well known that control-structure-interaction (CSI) phenomena limit the stability and performance of controlled flexible structures. Most CSI research focuses on rigid body control of flexible structures with relatively low closed loop control bandwidths. This research examines the CSI phenomena associated with high bandwidth high precision control of a reaction actuator mounted to a flexible support structure. In particular,

  19. The Belle II pixel detector: High precision with low material

    NASA Astrophysics Data System (ADS)

    Marinas, C.

    2013-12-01

    An upgrade of the existing Japanese flavor factory (KEKB in Tsukuba, Japan) is under construction, and foreseen for commissioning by the end of 2014. This new e+e- machine (“SuperKEKB”) will deliver an instantaneous luminosity of 8×1035 cm-2 s-1, which is 40 times higher than the world record set by KEKB. In order to be able to fully exploit the increased number of events and provide high precision measurements of the decay vertex of the B meson systems in such a harsh environment, the Belle detector will be upgraded (“Belle II”) and a new silicon vertex detector, based on the DEPFET technology, will be designed and constructed. The new pixel detector, close to the interaction point, will consist on two layers of DEPFET active pixel sensors. This technology combines the detection together with the in-pixel amplification by the integration, on every pixel, of a field effect transistor into a fully depleted silicon bulk. In Belle II, DEPFET sensors thinned down to 75 ?m with low power consumption and low intrinsic noise will be used.

  20. High precision $^{89}$Y($?$,$?$)$^{89}$Y scattering at low energies

    E-print Network

    G. G. Kiss; P. Mohr; Zs. \\; Fülöp; D. Galaviz; Gy. Gyürky; Z. Elekes; E. Somorjai; A. Kretschmer; K. Sonnabend; A. Zilges; M. Avrigeanu

    2010-12-10

    Elastic scattering cross sections of the $^{89}$Y($\\alpha$,$\\alpha$)$^{89}$Y reaction have been measured at energies E$_{c.m.}$ = 15.51 and 18.63 MeV. The high precision data for the semi-magic $N = 50$ nucleus $^{89}$Y are used to derive a local potential and to evaluate the predictions of global and regional $\\alpha$-nucleus potentials. The variation of the elastic alpha scattering cross sections along the $N = 50$ isotonic chain is investigated by a study of the ratios of angular distributions for $^{89}$Y($\\alpha$,$\\alpha$)$^{89}$Y and $^{92}$Mo($\\alpha$,$\\alpha$)$^{92}$Mo at E$_{c.m.} \\approx$ 15.51 and 18.63 MeV. This ratio is a very sensitive probe at energies close to the Coulomb barrier, where scattering data alone is usually not enough to characterize the different potentials. Furthermore, $\\alpha$-cluster states in $^{93}$Nb = $^{89}$Y $\\otimes$ $\\alpha$ are investigated.

  1. 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 ?- 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 ? resistor; 39K and 41K were collected in Faraday cups with 1E11 ? 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 evaporation procedures (B) and (C). Our measured 40K/39K ratios are statistically indistinguishable from those reported by [1] but have lower uncertainties. Techniques A, B and C gave 1 standard error of 0.07 %, 0.2 %, and 0.14 %, respectively. 1. Garner E.L. et al. (1975) J.Res.Natl.Bur.Stand.79A, 713-725. 2. Grau Malonda A., Grau Carles A. (2002) Appl. Radiat. Isot. 56, 153-156. 3. Kossert K., Günter E. (2004) Appl.Radiat.Isot.60, 459-464. 4. Krumrei T.V. et al. (2006) Chem.Geol. 227, 258-273. 5. Kwon J. et al. (2002) Math.Geol. 34, 457-475. 6. Min K. et al. (2000) Geochim. Cosmochim. Acta 64, 73-98. 7. Nägler T.F., Villa I.M. (2000) Chem. Geol. 169, 5-16. 8. Renne P.R. et al. (2010) Geochim. Cosmochim. Acta 74, 5349-5367. 9. Schwarz W.H. et al. (2011) Geochim. Cosmochim. Acta 75, 5094-5096. 10. Richter S., Goldberg S.A. (2003) Int. J. Mass Spect. 229, 181-197.

  2. 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.

  3. Radio emission from Supernovae and High Precision Astrometry

    NASA Astrophysics Data System (ADS)

    Perez-Torres, M. A.

    1999-11-01

    The present thesis work makes contributions in two scientific fronts: differential astrometry over the largest angular scales ever attempted (approx. 15 arcdegrees) and numerical simulations of radio emission from very young supernovae. In the first part, we describe the results of the use of very-long-baseline interferometry (VLBI) in one experiment designed to measure with very high precision the angular distance between the radio sources 1150+812 (QSO) and 1803+784 (BL Lac). We observed the radio sources on 19 November 1993 using an intercontinental array of radio telescopes, which simultaneously recorded at 2.3 and 8.4 GHz. VLBI differential astrometry is capable, Nature allowing, of yielding source positions with precisions well below the milliarcsecond level. To achieve this precision, we first had to accurately model the rotation of the interferometric fringes via the most precise models of Earth Orientation Parameters (EOP; precession, polar motion and UT1, nutation). With this model, we successfully connected our phase delay data at both frequencies and, using difference astrometric techniques, determined the coordinates of 1803+784 relative to those of 1150+812-within the IERS reference frame--with an standard error of about 0.6 mas in each coordinate. We then corrected for several effects including propagation medium (mainly the atmosphere and ionosphere), and opacity and source-structure effects within the radio sources. We stress that our dual-frequency measurements allowed us to accurately subtract the ionosphere contribution from our data. We also used GPS-based TEC measurements to independently find the ionosphere contribution, and showed that these contributions agree with our dual-frequency measurements within about 2 standard deviations in the less favorables cases (the longest baselines), but are usually well within one standard deviation. Our estimates of the relative positions, whether using dual-frequency-based or GPS-based ionosphere corrections, agree well within one standard deviation. In summary, our astrometric results demonstrate the feasibility of using phase-delay difference techniques (single-frequency or dual-frequency) for sources separated by as far as 15(deg) on the sky. This opens the avenue for the extension of the technique on a global scale with the aim of building up a quasi-inertial reference frame (of submilliarcsecond accuracy) based on extragalactic radio sources. The second part of this thesis is devoted to the study of the radio emission of the Type II supernova SN 1993J, whose relative proximity (it exploded in the Galaxy M81, at a distance of 10 million of light-years) has allowed us to observe it with VLBI at different radio frequency bands since June 1993. This radio supernova is the best studied one so far and thus a perfect laboratory to test supernova radio emission models. Early VLBI observations of this supernova by our group allowed us to discover the shell structure of SN 1993J--likely common to all supernovae--the youngest ever discovered in a supernova. Subsequently, our VLBI observations showed SN 1993J to be self-similarly expanding and, more recently, we used our VLBI observations at 3.6 and 6 cm in the period 6 through 42 months after explosion to show that the supernova expansion is decelerating, its size following a power-law with time (R t^m; m=0.86 +- 0.02). Our measurement of the expansion index yields estimates of the density of both supernova ejecta and circumstellar material in standard supernova explosion models. In particular, the density of the circumstellar material seems to be following a power-law less steep than usual (rhocs r^{-s}, with s approx. 1.66 instead of the standard s=2). Our VLBI observations also showed that the supernova radio emission comes from a shell of width 30% of the outer radius. In this thesis, we describe a numerical code that simulates synchrotron radio emission from a supernova. We assume that the supernova is self-similarly and spherically symmetric expanding, and that the radio emission comes only from its shell. We

  4. 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.

  5. Calibration of geometrical systematic error in high-precision spherical surface measurement

    NASA Astrophysics Data System (ADS)

    Wang, Daodang; Yang, Yongying; Chen, Chen; Zhuo, Yongmo

    2011-08-01

    Geometric aberrations in interferometric testing system can significantly influence the measurement results in the case of high-numerical-aperture test spherical surface, in which obvious high-order aberrations introduced by wavefront defocus could be observed and they cannot be removed with the traditional calibration method. A technique based on the rigorous model for the analysis of geometric aberrations introduced by wavefront tilt and defocus, is presented for the calibration of the corresponding geometrical systematic error. The calibration method can be carried out either with or without a prior knowledge of the spherical surface under test. The feasibility of the proposed method has been demonstrated by computer simulation, and the residual error less than 0.001? is obtained. Experimental validation is carried out by testing a high-numerical-aperture spherical surface with the ZYGO interferometer, and an accuracy RMS about 0.003? with the proposed calibration technique is achieved. The effect of geometric aberrations on the measurement is discussed in detail. The proposed calibration method provides a feasible way to lower the requirement on the adjusting precision of mechanical device, and is of great practicality for the high-precision measurement of high-numerical-aperture spherical surface.

  6. High-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global

    E-print Network

    Jin, Deborah

    High-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global Descriptions of Hyper-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global Descriptions of Hyper

  7. 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 solutions for large earthquakes around the Indonesian region are thrusting that is related to subduction processes. However, large strike-slip earthquakes are also present in this region and are related to major strike-slip faults, e.g. Sumatra and Sorong faults. We also analysed the distribution of P- and T-axes of these solutions, and found that most of subducted slabs are under compression, where P-axes are perpendicular to the trench.

  8. High precision quantum control of single donor spins in silicon

    E-print Network

    Rajib Rahman; Cameron J. Wellard; Forrest R. Bradbury; Marta Prada; Jared H. Cole; Gerhard Klimeck; Lloyd C. L. Hollenberg

    2007-05-15

    The Stark shift of the hyperfine coupling constant is investigated for a P donor in Si far below the ionization regime in the presence of interfaces using Tight-binding and Band Minima Basis approaches and compared to the recent precision measurements. The TB electronic structure calculations included over 3 million atoms. In contrast to previous effective mass based results, the quadratic Stark coefficient obtained from both theories agrees closely with the experiments. This work represents the most sensitive and precise comparison between theory and experiment for single donor spin control. It is also shown that there is a significant linear Stark effect for an impurity near the interface, whereas, far from the interface, the quadratic Stark effect dominates. Such precise control of single donor spin states is required particularly in quantum computing applications of single donor electronics, which forms the driving motivation of this work.

  9. 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.

  10. High precision survey and alignment techniques in accelerator construction

    Microsoft Academic Search

    J Gervaise

    1974-01-01

    Basic concepts of precision surveying are briefly reviewed, and an historical account is given of instruments and techniques used during the construction of the Proton Synchrotron (1954-59), the Intersecting Storage Rings (1966-71), and the Super Proton Synchrotron (1971). A nylon wire device, distinvar, invar wire and tape, and recent automation of the gyrotheodolite and distinvar as well as auxiliary equipment

  11. High precision silicon piezo resistive SMART pressure sensor

    Microsoft Academic Search

    Rod Brown

    2005-01-01

    Instruments for test and calibration require a pressure sensor that is precise and stable. Market forces also dictate a move away from single measurand test equipment and, certainly in the case of pressure, away from single range equipment. A pressure `module' is required which excels in pressure measurement but is interchangble with sensors for other measurands. A communications interface for

  12. High-precision isotopic analysis of nanogram quantities of plutonium

    SciTech Connect

    Perrin, R.E.; Knobeloch, G.W.; Armijo, V.M.; Efurd, D.W.

    1984-06-01

    A surface ionization-diffusion-type ionization source that uses a rhenium filament overplated with platinum has been developed and optimized for 0.5- to 2-ng plutonium samples. This source is capable of measuring the /sup 240/Pu//sup 239/Pu atom ratio in nuclear-test-debris samples to 0.15% precision and accuracy at the 95% confidence level.

  13. Experimental High Energy Neutrino Astrophysics

    SciTech Connect

    Distefano, Carla [Laboratori Nazionali del Sud, Catania (Italy)

    2005-10-12

    Neutrinos are considered promising probes for high energy astrophysics. More than four decades after deep water Cerenkov technique was proposed to detect high energy neutrinos. Two detectors of this type are successfully taking data: BAIKAL and AMANDA. They have demonstrated the feasibility of the high energy neutrino detection and have set first constraints on TeV neutrino production astrophysical models. The quest for the construction of km3 size detectors have already started: in the South Pole, the IceCube neutrino telescope is under construction; the ANTARES, NEMO and NESTOR Collaborations are working towards the installation of a neutrino telescope in the Mediterranean Sea.

  14. A New High Precision Differential Spectrometer: Construction, Characteristics, And Capabilities

    NASA Astrophysics Data System (ADS)

    Stephens, R. B.; Sorensen, G. K.

    1981-04-01

    A unique differential spectrometer has been developed for the quantitative examination of surfaces. It combines a tuneable pulsed dye laser light source, a flexible precision sample holder, silicon photodiode-in-integrating sphere detectors, and a desktop computer controller/analyzer. This combination enables very precise measurements--twiddlel% systematic errors and twiddle.02% random errors in reflection and transmission measurements. The spectrome-ter has been applied to the investigation of the structure of various component films used in semiconductor devices and in a basic study of the molecular-molecular interactions of dyes adsorbed on surfaces. With only minor modifications, this device can make transient spectroscopy measurements with a resolution of twiddle 10 nsec. It can also be used for a variety of modulation spectroscopies. We will be exploring those areas in the future.

  15. 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.

  16. Calculated thermal behavior of ventilated high precision radio telescopes

    Microsoft Academic Search

    A. Greve; M. Bremer

    2006-01-01

    Radio telescopes that operate at millimeter and sub-millimeter wavelengths need a reflector-surface precision of a few tens of microns and a pointing accuracy of a few arcseconds. When built in a conventional way from steel and aluminum, as in the case of larger-diameter telescopes, thermal control must be applied to reduce temperature-induced deformations, in particular of the reflector backup structure.

  17. 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.

  18. High-Precision UPb Zircon Dates as Benchmarks in Absolute Time

    Microsoft Academic Search

    M. D. Schmitz; S. A. Bowring; B. Schoene

    2003-01-01

    High-precision IDTIMS U-Pb zircon dates provide the most precise and accurate isotopic benchmarks in absolute time, due to the concordancy check of the paired U-Pb decay schemes, the precisely measured 235U and 238U decay constants, very high initial parent\\/daughter ratios, and the robust nature of zircon to loss or gain of U and Pb over geologic time. However, caveats to

  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. High Precision Measurements of the Pion Proton Differential Cross Section

    E-print Network

    EPECUR Collaboration; I. G. Alekseev; V. A. Andreev; I. G. Bordyuzhin; D. A. Fedin; Ye. A. Filimonov; V. V. Golubev; A. B. Gridnev; V. P. Kanavets; E. A. Konovalova; L. I. Koroleva; A. I. Kovalev; N. G. Kozlenko; V. S. Kozlov; A. G. Krivshich; B. V. Morozov; V. M. Nesterov; D. V. Novinsky; V. V. Ryltsov; M. Sadler; A. D. Sulimov; V. V. Sumachev; D. N. Svirida; V. I. Tarakanov; V. Yu. Trautman

    2012-04-28

    Study of the elastic scattering can produce a rich information on the dynamics of the strong interaction. The EPECUR collaboration is aimed at the research of baryon resonances in the second resonance region via pion-proton elastic scattering and kaon-lambda production. The experiment features high statistics and better than 1 MeV resolution in the invariant mass thus allowing searches for narrow resonances with the coupling to the pi p channel as low as 5%. The experiment is of "formation" type, i.e. the resonances are produced in s-channel and the scan over the invariant mass is done by the variation of the incident pion momentum which is measured with the accuracy of 0.1% with a set of 1 mm pitch proportional chambers located in the first focus of the beam line. The reaction is identified by a magnetless spectrometer based on wire drift chambers with a hexagonal structure. Background suppression in this case depends on the angular resolution, so the amount of matter in the chambers and the setup was minimized to reduce multiple scattering. The measurements started in 2009 with the setup optimized for elastic pion-proton scattering. With 3 billions of triggers already recorded the differential cross section of the elastic pi p-scattering on a liquid hydrogen target in the region of the diffraction minimum is measured with statistical accuracy about 1% in 1 MeV steps in terms of the invariant mass. The paper covers the experimental setup, current status and some preliminary results.

  1. Design and realization of high precision FBG rain gauge based on triangle cantilever beam and its performance research

    NASA Astrophysics Data System (ADS)

    Lan, Ruo-ming; Cao, Yu-qiang

    2015-05-01

    A novel fiber Bragg grating (FBG) rain gauge is proposed in this paper to achieve high precision rainfall measurement. One core sensitive FBG, a temperature compensation FBG and a mechanical transition system construct this novel FBG rain gauge. Sensing principle of this FBG rain gauge is explained in detail, and its theoretical calculation model is also established, which shows that the relationship between center wavelength of sensitive FBG and external rainfall has very good linearity. To verify its detection performance, the calibration experiment on one prototype of this FBG rain gauge is carried out. After experiment data analysis, the detection precision of this FBG rain gauge is 15.4 ?m which is almost two orders of magnitude higher than that of the existing rainfall measurement device. The experimental data confirm that this FBG rain gauge can achieve rainfall measurement with high precision.

  2. High-precision distribution of highly stable optical pulse trains with 8.8 × 10?¹? instability.

    PubMed

    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

  3. Network Intrusion Detection Method Based on High Speed and Precise Genetic Algorithm Neural Network

    Microsoft Academic Search

    Jingwen Tian; Meijuan Gao

    2009-01-01

    Aimed at the network intrusion behaviors are characterized with uncertainty, complexity, diversity and dynamic tendency and the advantages of neural network, an intrusion detection method based on high speed and precise genetic algorithm neural network is presented in this paper. The high speed and precise genetic algorithm neural network is combined the adaptive and floating-point code genetic algorithm with BP

  4. Adjustment Procedure of a High Precision Deployable Mesh Antenna for MUSES-B Spacecraft

    Microsoft Academic Search

    Masaki Tabata; M. C. Natori; Takanori Tashima; Toshio Inoue

    1997-01-01

    In this paper, a precise on-ground adjustment procedure of a high precision deployable space antenna which has to keep the required surface accuracy in space environment, such as zero gravity, high vacuum, etc., is investigated. For space structure systems in the relatively near future the active shape control technology in orbits is still not matured, and it is important to

  5. Master Thesis ICT/ECS 2007 19 High Precision Motor and Servo

    E-print Network

    Jantsch, Axel

    Master Thesis ICT/ECS ­ 2007 ­ 19 High Precision Motor and Servo Controller For Unmanned Micro life organized. #12;II #12;ABSTRACT III High Precision Motor and Servo Controller For Unmanned Micro is an electrical propelled vehicle. The involved parts are DC-motors and digital servos which are individually

  6. 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

  7. 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.

  8. Light time calculations in high precision deep space navigation

    E-print Network

    Bertone, Stefano; Lainey, Valéry

    2013-01-01

    During the last decade, the precision in the tracking of spacecraft has constantly improved. With the recent discovery of few astrometric anomalies, such as the Pioneer and Earth flyby anomalies, it becomes important to deeply analyze the operative modeling currently adopted in Deep Space Navigation (DSN). Our study shows that some traditional approximations can lead to neglect tiny terms that could have consequences in the orbit determination of a probe in specific configurations such as during an Earth flyby. Here we suggest a way to improve the light time calculation used for probe tracking.

  9. High precision survey and alignment techniques in accelerator construction

    E-print Network

    Gervaise, J

    1974-01-01

    Basic concepts of precision surveying are briefly reviewed, and an historical account is given of instruments and techniques used during the construction of the Proton Synchrotron (1954-59), the Intersecting Storage Rings (1966-71), and the Super Proton Synchrotron (1971). A nylon wire device, distinvar, invar wire and tape, and recent automation of the gyrotheodolite and distinvar as well as auxiliary equipment (polyurethane jacks, Centipede) are discussed in detail. The paper ends summarizing the present accuracy in accelerator metrology, giving an outlook of possible improvement, and some aspects of staffing for the CERN Survey Group. (0 refs).

  10. Applied high resolution digital control for universal precision systems

    E-print Network

    Gawlik, Aaron John

    2008-01-01

    This thesis describes the design and characterization of a high-resolution analog interface for dSPACE digital control systems and a high-resolution, high-speed data acquisition and control system. These designs are intended ...

  11. A High Precision Feature Based on LBP and Gabor Theory for Face Recognition

    PubMed Central

    Xia, Wei; Yin, Shouyi; Ouyang, Peng

    2013-01-01

    How to describe an image accurately with the most useful information but at the same time the least useless information is a basic problem in the recognition field. In this paper, a novel and high precision feature called BG2D2LRP is proposed, accompanied with a corresponding face recognition system. The feature contains both static texture differences and dynamic contour trends. It is based on Gabor and LBP theory, operated by various kinds of transformations such as block, second derivative, direct orientation, layer and finally fusion in a particular way. Seven well-known face databases such as FRGC, AR, FERET and so on are used to evaluate the veracity and robustness of the proposed feature. A maximum improvement of 29.41% is achieved comparing with other methods. Besides, the ROC curve provides a satisfactory figure. Those experimental results strongly demonstrate the feasibility and superiority of the new feature and method. PMID:23552103

  12. High-precision control of LSRM based X-Y table for industrial applications.

    PubMed

    Pan, J F; Cheung, Norbert C; Zou, Yu

    2013-01-01

    The design of an X-Y table applying direct-drive linear switched reluctance motor (LSRM) principle is proposed in this paper. The proposed X-Y table has the characteristics of low cost, simple and stable mechanical structure. After the design procedure is introduced, an adaptive position control method based on online parameter identification and pole-placement regulation scheme is developed for the X-Y table. Experimental results prove the feasibility and its priority over a traditional PID controller with better dynamic response, static performance and robustness to disturbances. It is expected that the novel two-dimensional direct-drive system find its applications in high-precision manufacture area. PMID:22981303

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

    Microsoft Academic Search

    D. G. Hicks; T. R. Boehly; P. M. Celliers; D. K. Bradley; J. H. Eggert; R. S. McWilliams; G Collins

    2008-01-01

    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

  14. High Performance Computing Meets Experimental Mathematics

    E-print Network

    Bailey, David H.

    High Performance Computing Meets Experimental Mathematics David H. Bailey Lawrence Berkeley. Two of these computations were performed on highly parallel computers, since they are not feasible large, high-performance computer systems. What's more, in these new appli- cations the computer

  15. High Performance Computing Meets Experimental Mathematics #

    E-print Network

    Li, Xiaoye Sherry

    High Performance Computing Meets Experimental Mathematics # David H. Bailey Lawrence Berkeley. Two of these computations were performed on highly parallel computers, since they are not feasible large, high­performance computer systems. What's more, in these new appli­ cations the computer

  16. BAM: A metrology device for a high precision astrometric mission

    NASA Astrophysics Data System (ADS)

    Riva, A.; Gai, M.; Lattanzi, M. G.; Russo, F.; Buzzi, R.

    2014-12-01

    Gaia is ESA next-generation astrometric space mission, that will be launched in December 2013. The main objective of Gaia is to produce an astrometric census of one billion objects down to the 20th magnitude. The level of astrometric precision will be around the 10 microarcseconds. In order to achieve such demanding performances, the complexity of the satellite is huge, and a proper fully automated operation must be adopted. One of the essential parts of the satellite is the BAM instrument, an interferometric device with the task of monitoring the variation of the Basic Angle between the two telescope that compose the payload. In this paper we describe the main features of this sub-instrument and its performances.

  17. Decade-spanning high-precision terahertz frequency comb.

    PubMed

    Finneran, Ian A; Good, Jacob T; Holland, Daniel B; Carroll, P Brandon; Allodi, Marco A; Blake, Geoffrey A

    2015-04-24

    The generation and detection of a decade-spanning terahertz (THz) frequency comb is reported using two Ti:sapphire femtosecond laser oscillators and asynchronous optical sampling THz time-domain spectroscopy. The comb extends from 0.15 to 2.4 THz, with a tooth spacing of 80 MHz, a linewidth of 3.7 kHz, and a fractional precision of 1.8×10^{-9}. With time-domain detection of the comb, we measure three transitions of water vapor at 10 mTorr between 1-2 THz with an average Doppler-limited fractional accuracy of 6.1×10^{-8}. Significant improvements in bandwidth, resolution, and sensitivity are possible with existing technologies. PMID:25955051

  18. A high precision, compact electromechanical ground rotation sensor

    SciTech Connect

    Dergachev, V., E-mail: volodya@caltech.edu [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); DeSalvo, R. [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States) [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); University of Sannio, C.so Garibaldi 107, Benevento 82100 (Italy); Asadoor, M. [Mayfield Senior School, 500 Bellefontaine Street, Pasadena, California 91105 (United States) [Mayfield Senior School, 500 Bellefontaine Street, Pasadena, California 91105 (United States); Oklahoma State University, 219 Student Union, Stillwater, Oklahoma 74074 (United States); Bhawal, A. [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States) [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States); Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Gong, P. [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China) [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China); School of Industrial and System Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0205 (United States); Kim, C. [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States); Lottarini, A. [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy) [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Department of Computer Science, Columbia University, 1214 Amsterdam Avenue, New York, New York 10027 (United States); Minenkov, Y. [Sezione INFN Tor Vergata, via della Ricerca Scientifica  1, 00133 Roma (Italy)] [Sezione INFN Tor Vergata, via della Ricerca Scientifica  1, 00133 Roma (Italy); Murphy, C. [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia) [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia); University of Melbourne Grattan Street, Parkville VIC 3010 (Australia); O'Toole, A. [University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States) [University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States); Michigan Technological University, 1400 Townsend Dr, Houghton, Michigan 49931 (United States); Peña Arellano, F. E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); 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.

  19. 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.

  20. High precision Monte Carlo event generation for particle colliders

    NASA Astrophysics Data System (ADS)

    Berggren, Calvin James

    Matrix-element calculations and parton shower programs are both crucial tools in the analysis of data at modern particle physics experiments at colliders. Finding the most effective ways to combine these complementary, but sometimes conflicting, approaches to simulating physical events has been the subject of much work in the recent decade. This thesis investigates state-of-the-art ways in which the precision of the matrix elements can be extended in combination with the parton shower. We identify three dimensions along which precision can be improved and describe how progress can be made along each one. First, we present a general method to match fully differential next-to-next-to-leading-order (NNLO) calculations to parton shower (PS) programs, which represents an extension of the successful LO+PS (leading order) and NLO+PS (next-to-leading order) frameworks to NNLO+PS. We discuss in detail the perturbative accuracy criteria a complete NNLO+PS matching has to satisfy, and we give an explicit and general construction of the input "Monte Carlo cross sections" satisfying all required criteria. Next, we describe how augmenting an NLO calculation with higher-order resummation of large Sudakov logarithms allows one to extend the lowest-order matching of tree-level matrix elements with parton showers to give a complete description at the next higher perturbative accuracy in alphas, at both small and large jet resolutions. As a byproduct, this combination naturally leads to a smooth connection of the NLO calculations for different jet multiplicities. We focus on the general construction of our method and present results of an implementation in the GENEVA Monte Carlo framework. For leptonic collisions, we apply our construction to e+e - ? jets and obtain good agreement with LEP data for a variety of 2-jet observables. For hadronic collisions, we look at Drell-Yan production.

  1. Advanced Tool Edge Geometry for High Precision Hard Turning

    Microsoft Academic Search

    F. Klocke; H. Kratz

    2005-01-01

    The hard turning process has been attracting interest in different industrial sectors for finishing operations of hard materials. However, it still presents disadvantages with respect to process capability and reliability. In this paper the impact of PcBN tool edge geometry is investigated based on a modelling as well as an experimental approach. The hard turning process is described by means

  2. High Precision Half-Life Measurement of ^38Ca

    Microsoft Academic Search

    H. I. Park; J. C. Hardy; V. E. Iacob; L. Chen; J. Goodwin; V. Horvat; N. Nica; L. Trache; R. E. Tribble

    2010-01-01

    The measured ft values for superallowed 0^+ -> 0^+ nuclear beta decay can be used to test the Conserved Vector Current (CVC) hypothesis and the unitarity of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. One of the essential elements of this test is the calculated radiative and isospin-symmetry breaking corrections that must be applied to experimental data [1]. Some of these corrections depend

  3. High precision and stable structures for particle detectors

    Microsoft Academic Search

    Suzana da Mota Silva; Rui Ribeiro; Claude Hauviller

    1999-01-01

    We are studying structures in CFRP with bonded piezoelectric sensors and actuators, able to monitor and compensate the vibrations affecting the performance of these systems. In this paper a detailed description of the simulation model is presented and the results compared with the experimental measurements. The transient response of a plate structure under vibrations with and without feedback control are

  4. The accuracy and precision of the experimental ?-determination in the 1\\/E 1+? epithermal reactor-neutron spectrum

    Microsoft Academic Search

    F. De Corte; K. Sordo-El Hammami; L. Moens; A. Simonits; A. De Wispelaere; J. Hoste

    1981-01-01

    Some methods for the experimental ?-determination in the 1\\/E1+? epithermal reactorneutron spetrum are critically compared with respect to their accuracy and precision. The analysis is based\\u000a on the error propagation theory. Besides the general formulae numerical examples are elaborated for specific conditions in\\u000a the Thetis reactor (Gent) and the WWR-M reactor (Budapest).

  5. Mold, flow, and economic considerations in high temperature precision casting

    E-print Network

    Humbert, Matthew S

    2013-01-01

    Casting high temperature alloys that solidify through a noticeable two phase region, specifically platinum-ruthenium alloys, is a particularly challenging task due to their high melting temperature and this necessitates ...

  6. High-precision CO2 isotopologue spectrometer with a difference-frequency-generation laser source

    E-print Network

    High-precision CO2 isotopologue spectrometer with a difference-frequency-generation laser source for Atmospheric Research, 3450 Mitchell Lane, Boulder, Colorado 80301, USA 2 School of Medicine, University A precision laser spectrometer for the detection of CO2 isotopes is reported. The spectrometer measures

  7. Secure tunneling of high-precision clock synchronization protocols and other time-stamped data

    Microsoft Academic Search

    Albert Treytl; Bernd Hirschler; Thilo Sauter

    2010-01-01

    This article analyzes the viability of secure tunneling for clock synchronization protocols with special respect to high-precision clock synchronization requiring hardware timestamping. It investigates whether security mechanisms introduced to protect timing information have an impact on the precision of clock synchronization. Two reference designs - one for an MII-based and one for a MAC-based time stamper - are used together

  8. High precision pressure control system of cubic press based on ARM

    Microsoft Academic Search

    Shaojia He; Jinhai Mo; Shouqi Wei; Dao Huang

    2008-01-01

    High control precision of pressure is one of the most important factor to guarantee the quality and quantity of synthetic diamond. But the pressure control system of cubic press in common use has the disadvantages of large zero drift, poor repeatability, and low control precision. To handle these problems, a novel pressure control system of cubic press has been developed.

  9. Experimental assessment of the time transfer capability of precise point positioning (PPP)

    Microsoft Academic Search

    Diego Orgiazzi; Patrizia Tavella; François Lahaye

    2005-01-01

    In recent years, many national timing laboratories have installed geodetic global positioning system (GPS) receivers together with their traditional GPS\\/GLONASS common view (CV) receivers and two way satellite time and frequency transfer (TWSTFT) equipment. A method called precise point positioning (PPP) is in use in the geodetic community allowing precise recovery of geodetic GPS receiver position, clock phase and tropospheric

  10. 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 ? 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 (2?), corresponding to an isotopic abundance 40K/K = (1.1668 ± 8) × 10-4.

  11. 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

  12. High-precision pepper-pot technique for a low-emittance electron beam

    Microsoft Academic Search

    Y. Yamazaki; T. Kurihara; H. Kobayashi; I. Sato; A. Asami

    1992-01-01

    An emittance measurement system employing a high-precision pepper-pot technique has been developed for an electron beam with low emittance, less than pi mm mrad. Since luminous spots on a scintillator are very small, each one was magnified and observed individually with high spatial resolution by scanning an optical system mounted on a precise movable platform. The beam from a high-brightness

  13. High-precision pepper-pot technique for a low-emittance electron beam

    NASA Astrophysics Data System (ADS)

    Yamazaki, Y.; Kurihara, T.; Kobayashi, H.; Sato, I.; Asami, A.

    1992-11-01

    An emittance measurement system employing a high-precision pepper-pot technique has been developed for an electron beam with low emittance, less than ? mm mrad. Since luminous spots on a scintillator are very small, each one was magnified and observed individually with high spatial resolution by scanning an optical system mounted on a precise movable platform. The beam from a high-brightness electron gun was evaluated using this system.

  14. High-temperature precision forming of titanium blades

    SciTech Connect

    Ermachenko, A.G.; Karavayeva, M.V. [Russian Academy of Sciences, Ufa (Russian Federation). Inst. for Metals Superplasticity Problems

    1996-10-01

    Based on the experimental study of superplastic deformation parameters, a technology was developed for producing near-net-shape compressor blade forgings for gas turbine units from Ti-6.2Al-2.5Mo-1.5Cr-0.2Si-0.5Fe. The mechanical properties of these blades are higher than those of blades produced by conventional methods, and the anisotropy coefficient is reduced. The improved properties of the blades can be attributed to the isotropy of mechanical properties resulting from the homogeneous fine-grained equiaxed structure produced throughout the blade volume.

  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 [Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands); Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747AA Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands); Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands)

    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 the irradiation of cell samples with the specified accuracy. Measurements of the transverse and longitudinal dose distribution showed that the dose variation over the sample volume was {+-}0.8% and {+-}0.7% in the lateral and longitudinal directions, respectively. The track-averaged LET of 132{+-}10 keV/{mu}m and dose-averaged LET of 189{+-}15 keV/{mu}m at the position of the sample were obtained from a GEANT4 simulation, which was validated experimentally. Three separately measured cell-survival curves yielded nearly identical results. Conclusions: With the new facility, high-precision carbon-ion irradiations of biological samples can be performed with highly reproducible results.

  16. Friction models incorporating thermal effects in highly precision actuators

    NASA Astrophysics Data System (ADS)

    Li, J. W.; Chen, X. B.; An, Q.; Tu, S. D.; Zhang, W. J.

    2009-04-01

    This paper presents two models based on the LuGre model for friction with consideration of thermal effects. In Model I, parameters in the LuGre model are considered as temperature dependent. In Model II, parameters in the LuGre model are considered as temperature independent; while a temperature-dependent function is added to the temperature-independent LuGre model. Both models are experimentally evaluated, which shows that both can effectively incorporate thermal effects but Model II has better accuracy. Since these models are developed in the context of the motion system, they should be readily incorporated in motion control algorithms for effective control of motion systems with friction if temperature rise is significant in these systems.

  17. High-precision tungsten isotope measurements of iron meteorites

    NASA Astrophysics Data System (ADS)

    Qin, Liping

    A new procedure was developed to accurately measure the W isotopic compositions of iron meteorites with a precision of better than ± 0.1 on epsilon W-182 and epsilon W-184. The W isotopic compositions of 33 iron meteorites from both magmatic and non-magmatic groups were determined. Deficits of ~0.1 part per ten thousand in the abundance of non-radiogenic W-184 in group IVB iron meteorites relative to the silicate Earth were reported for the first time. These are most likely due to incomplete mixing at the planetesimal scale (2-4 km radius bodies) of the products of slow ( s ) and rapid ( r ) neutron capture nucleosynthesis in the solar nebula. The correction that must be applied to the Hf-W model age of core formation in IVB irons due to the presence of these nuclear anomalies is -0.5 Myr. Tentative nuclear anomalies in W-180 were also found for IVBs, but more work needs to be done to validate these results. Epsilon W-182 results from this study are generally consistent with previous studies. The more negative epsilon W-182 values in some iron meteorites than the initial value in CAIs, and variations in epsilon W-182 values within individual magmatic iron meteorite groups are most easily explained as a result of exposure to galactic cosmic rays in space. A correction method was applied to estimate the pre-exposure epsilon W-182 for individual magmatic iron meteorite groups. The corrected epsilon W-182 shows that metal-silicate differentiation occurred very early (within first 2 Myr) for most magmatic groups. A numerical model was developed to simulate the thermal histories of iron meteorite parent bodies. For the first time, such a thermal model was combined with the Hf-W metal-silicate differentiation age and the parent body size, to constrain the accretion time scale. The estimated accretion time is within 1.5 Myr for most magmatic iron groups, and could be as early as 0.2 Myr for IVB. This is consistent with a recent study by Bottke et al. (2006), showing that the iron meteorite parent bodies may have originated in the region of terrestrial planets where the accretion rates are fast. We also provide W isotopic constraints on the formation mechanism of non- magmatic irons. The homogeneous epsilon W-182 in IAB-IIICD support the model of formation of metal pools in a chondritic reservoir by a late impact event dated at 4-7 Myr after the condensation of CAIs.

  18. High-precision position control of a heavy-lift manipulator in a dynamic environment

    E-print Network

    Garretson, Justin R. (Justin Richard)

    2005-01-01

    This thesis considers the control of a heavy-lift serial manipulator operating on the deck of a large ocean vessel. This application presents a unique challenge for high- precision control because the system must contend ...

  19. High precision VSS motion control of servo drives

    Microsoft Academic Search

    Karel Jezernik

    2008-01-01

    In this paper we investigate the advantages and feasibility of motor control using very fast (MHz) switching in place of traditional amplifiers. We also propose integrated motion-control architecture based on a sliding mode control to be implemented in digital logic at an equally high rate. A switching controller combines the current and motion feedback paths into a single loop. A

  20. 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.

  1. Measuring the Verdet constant: a simple, high precision, automatic device

    Microsoft Academic Search

    O. Brevet-Philibert; R. Brunetton; J. Monin

    1988-01-01

    An instrument is described that allows the automatic measurement of the Verdet constant. The measuring cell, especially suited for liquids, is of original design. Using a multipass of the light beam, it provides high Faraday rotation with a low magnetic field. The rotation of the polarisation is measured automatically by a novel technique. Systematic errors are very small and the

  2. PARTICLES AND FIELDS: Study of the data taking strategy for a high precision ? mass measurement

    NASA Astrophysics Data System (ADS)

    Wang, You-Kai; Zhang, Jian-Yong; Mo, Xiao-Hu; Yuan, Chang-Zheng

    2009-07-01

    To achieve a high precision ? mass measurement at the high luminosity experiment BESIII, Monte Carlo simulation and sampling technique are utilized to simulate various data taking cases for single and multi-parameter fits by virtue of which the optimal scheme is determined. The optimized proportion of luminosity distributed at selected points and the relation between precision and luminosity are obtained. In addition, the optimization of the fit scheme is confirmed by scrutinizing a variety of fit possibilities.

  3. High-precision wavelength-flexible frequency division for metrology

    SciTech Connect

    Gross, Petra; Boller, Klaus-Jochen; Klein, Marvin E. [Department of Applied Physics, University of Twente, 7500 AE Enschede (Netherlands); Art Innovation b.v., Zutphenstraat 25, 7575 EJ Oldenzaal (Netherlands)

    2005-04-01

    We realize and investigate wavelength-flexible phase-coherent all-optical frequency division by 2. Frequency division is obtained via self-phase-locking in a degenerate continuous-wave (cw) optical parametric oscillator (OPO). The wavelength flexibility of the divider is based on the use of quasi-phase-matching with perpendicular polarizations of the OPO output waves (type II). Mutual injection of the subharmonic waves is achieved by using an intracavity quarter-wave plate. A locking range of up to 160 MHz is observed experimentally, and a stable, self-phase-locked operation of the OPO is achieved over typically 15 min. For the first time, we measure the frequency stability of the divider by recording the relative phases of the subharmonic waves as a function of time. For a measurement time interval of 40 s, we measure a residual frequency instability of the divider of 8x10{sup -18}. We demonstrate a full control of the OPO's output-wave phase difference and observe the related change in power ratio of the subharmonic waves in agreement with the theoretically expected behavior. We propose that this possibility to monitor the divider's drift within the locking range via the power ratio can be used for stabilizing that drift in order to achieve a significant improvement of the long-term stability of the divide-by-2 OPO.

  4. High-precision delay testing of Virtex-4 FPGA designs

    Microsoft Academic Search

    Jack Smith; Tian Xia

    2007-01-01

    We present a new method of performing high-resolution path delay testing on designs targeted to Xilinx Virtex-4 field-programmable gate arrays (FPGAs). Our built-in self-test architecture uses an on-chip delay line to set the launch time of test pattern generators to their optimum point for stressing paths in the chip. Consequently, it catches delay defects as small as 78 ps and

  5. Strong interaction corrections to the neutron beta decay and high precision

    Microsoft Academic Search

    A. García; J. L. García-Luna

    2000-01-01

    We present, in the neutron beta decay, expressions for the decay rate and the electron asymmetry that contain the theoretical effects at the 10-4 level. This accuracy is better than the current experimental precision that experiments allow. We consider the effects of the second class current and the radiative corrections. We compare the values of the CKM matrix element |Vud|

  6. Strong interaction corrections to the neutron beta decay and high precision

    Microsoft Academic Search

    A. Garc?´a; J. L. Garc?´a-Luna

    2000-01-01

    We present, in the neutron beta decay, expressions for the decay rate and the electron asymmetry that contain the theoretical effects at the 10?4 level. This accuracy is better than the current experimental precision that experiments allow. We consider the effects of the second class current and the radiative corrections. We compare the values of the CKM matrix element |Vud|

  7. Precision Crystal Calorimeters in High Energy Physics: Past, Present and Future

    SciTech Connect

    Zhu Renyuan [California Institute of Technology, Pasadena, CA 91125 (United States)

    2006-10-27

    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.

  8. Precision Crystal Calorimeters in High Energy Physics: Past, Present, and Future

    SciTech Connect

    Zhu, Ren-Yuan (Caltech) [Caltech

    2008-04-02

    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.

  9. High-precision gas chromatography-combustion isotope ratio mass spectrometry at low signal levels.

    PubMed

    Goodman, K J; Brenna, J T

    1995-01-01

    Precision and accuracy of gas chromatography-combustion isotope ratio mass spectrometry are investigated for sample levels down to about 5 pmol C in fatty acid methyl ester mixtures spanning 1000-fold in concentration. Precision and accuracy of isotope ratios diverge rapidly for conventional summation methods, and become unusable below 30 pmol material on column. At lower levels, mean isotope ratios were statistically different from reference values indicating bias as well as poor precision. In contrast, curve fitting, using the exponentially modified Gaussian line shape, gives improved precision for most peaks and useful results down to 3 pmol. The curve-fitting algorithm was also less sensitive to signal integration time than the summation method. These data indicate that curve fitting may be the method of choice for integration of noisy data when high-precision isotope ratios are desired. PMID:7881535

  10. Charge Breeding Techniques in an Electron Beam Ion Trap for High Precision Mass Spectrometry at TITAN

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    Penning trap mass spectrometry is the most accurate and precise method available for performing atomic mass measurements. TRIUMF's Ion Trap for Atomic and Nuclear science is currently the only facility to couple its Penning trap to a rare isotope facility and an electron beam ion trap (EBIT). The EBIT is a valuable tool for beam preparation: since the precision scales linearly with the charge state, it takes advantage of the precision gained by using highly charged ions. However, this precision gain is contingent on fast and efficient charge breeding. An optimization algorithm has been developed to identify the optimal conditions for running the EBIT. Taking only the mass number and half-life of the isotope of interest as inputs, the electron beam current density, charge breeding time, charge state, and electron beam energy are all specified to maximize this precision. An overview of the TITAN charge breeding program, and the results of charge breeding simulations will be presented.

  11. Controller design and implementation for a 6-degree-of-freedom magnetically levitated positioner with high precision 

    E-print Network

    Yu, Ho

    2005-11-01

    This thesis presents the controller design and implementation of a high-precision 6-degree-of-freedom (6-DOF) magnetically levitated (maglev) positioner. This high-precision positioning system consists of a novel ...

  12. Controller design and implementation for a 6-degree-of-freedom magnetically levitated positioner with high precision

    E-print Network

    Yu, Ho

    2005-11-01

    This thesis presents the controller design and implementation of a high-precision 6-degree-of-freedom (6-DOF) magnetically levitated (maglev) positioner. This high-precision positioning system consists of a novel concentrated-field magnet matrix...

  13. 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.

  14. Precision high energy liner implosion experiments PHELIX [1

    SciTech Connect

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

    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.

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

    SciTech Connect

    Molloy, S.; Frisch, J.; McCormick, D.; May, J.; Ross, M.; Smith, T.; /SLAC; Baboi, N.; Hensler, O.; Petrosian, L.; /DESY; Napoly, O.; Paparella, R.C.; Simon, C.; /Saclay; 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.

  16. Calibration, registration, and synchronization for high precision augmented reality haptics.

    PubMed

    Harders, Matthias; Bianchi, Gérald; Knoerlein, Benjamin; Székely, Gábor

    2009-01-01

    In our current research we examine the application of visuo-haptic augmented reality setups in medical training. To this end, highly accurate calibration, system stability, and low latency are indispensable prerequisites. These are necessary to maintain user immersion and avoid breaks in presence which potentially diminish the training outcome. In this paper we describe the developed calibration methods for visuo-haptic integration, the hybrid tracking technique for stable alignment of the augmentation, and the distributed framework ensuring low latency and component synchronization. Finally, we outline an early prototype system based on the multimodal augmented reality framework. The latter allows colocated visuo-haptic interaction with real and virtual scene components in a simplified open surgery setting. PMID:19008561

  17. 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 %.

  18. 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).

  19. High Precision Measurements of the Pion Proton Differential Cross Section

    E-print Network

    Andreev, V A; Golubev, V V; Gridnev, A B; Konovalova, E A; Kovalev, A I; Kozlenko, N G; Kozlov, V S; Krivshich, A G; Novinsky, D V; Sadler, M; Sumachev, V V; Tarakanov, V I; Trautman, V Yu

    2012-01-01

    Study of the elastic scattering can produce a rich information on the dynamics of the strong interaction. The EPECUR collaboration is aimed at the research of baryon resonances in the second resonance region via pion-proton elastic scattering and kaon-lambda production. The experiment features high statistics and better than 1 MeV resolution in the invariant mass thus allowing searches for narrow resonances with the coupling to the pi p channel as low as 5%. The experiment is of "formation" type, i.e. the resonances are produced in s-channel and the scan over the invariant mass is done by the variation of the incident pion momentum which is measured with the accuracy of 0.1% with a set of 1 mm pitch proportional chambers located in the first focus of the beam line. The reaction is identified by a magnetless spectrometer based on wire drift chambers with a hexagonal structure. Background suppression in this case depends on the angular resolution, so the amount of matter in the chambers and the setup was minimi...

  20. High-precision and high-accuracy rovibrational spectroscopy of molecular ions

    NASA Astrophysics Data System (ADS)

    Hodges, James N.; Perry, Adam J.; Jenkins, Paul A.; Siller, Brian M.; McCall, Benjamin J.

    2013-10-01

    We present a versatile new instrument capable of measuring rovibrational transition frequencies of molecular ions with sub-MHz accuracy and precision. A liquid-nitrogen cooled positive column discharge cell, which can produce large column densities of a wide variety of molecular ions, is probed with sub-Doppler spectroscopy enabled by a high-power optical parametric oscillator locked to a moderate finesse external cavity. Frequency modulation (heterodyne) spectroscopy is employed to reduce intensity fluctuations due to the cavity lock, and velocity modulation spectroscopy permits ion-neutral discrimination. The relatively narrow Lamb dips are precisely and accurately calibrated using an optical frequency comb. This method is completely general as it relies on the direct measurement of absorption or dispersion of rovibrational transitions. We expect that this new approach will open up many new possibilities: from providing new benchmarks for state-of-the-art ab initio calculations to supporting astronomical observations to helping assign congested spectra by combination differences. Herein, we describe the instrument in detail and demonstrate its performance by measuring ten R-branch transitions in the ?2 band of H_3^+, two transitions in the ?1 band of HCO+, and the first sub-Doppler transition of CH_5^+.

  1. 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.

  2. High-precision nuclear structure calculations using Spline-Galerkin lattices

    NASA Astrophysics Data System (ADS)

    Oberacker, V. E.; Kegley, D. R.; Umar, A. S.; Strayer, M. R.

    1996-10-01

    In connection with new experimental facilities such as HRIBF, we are carrying out high-precision nuclear structure calculations to study nuclei far from stability. Our goal is to use the data obtained by HRIBF to provide a better parametrization of the effective N-N force. This would entail the reproduction of binding energies, charge radii, fission barriers and other observables for several chains of isotopes. The properties of these nuclei are also crucial for various astrophysical nucleosynthesis processes. The main challenge in the theory of exotic nuclei near the proton or neutron drip line is that the outermost nucleons are weakly bound and that these states are close to the particle continuum. Because of the large spatial extent of the weakly bound states, the traditional basis expansion methods fail to converge. We overcome these problems by representing the nuclear Hamiltonian on a coordinate space lattice; very high accuracy is achieved utilizing our recently developed Spline-Galerkin method (D.R. Kegley, Ph.D. thesis, Vanderbilt U. (1996)). First calculations using this method for axially symmetric nuclei will be presented. In particular, we will discuss deformed shell model, HF+BCS and HFB implementations of the method.

  3. 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.

  4. An experimental study of highly lazy plumes

    NASA Astrophysics Data System (ADS)

    Kaye, Nigel; Hunt, Gary

    2006-11-01

    We present results from an experimental study of highly lazy turbulent plumes, i.e. plumes with relatively low source momentum flux, or equivalently very large source Richardson numbers. Experimental observations indicate that the plumes contract as they move vertically away from the source and that the extent of the contraction is independent of the source Richardson number (consistent with previous experimental studies). Using the experimental technique developed by Baines (1983), we made volume flux measurements in the near source region of the plume. Our experimental results indicate that the volume flux increases linearly with distance from the source and scales with the source Richardson number to the one third power. This result is discussed in relation to existing entrainment models for forced plumes (low source Richardson number) and we demonstrate that these do not adequately describe the near source region of highly lazy plumes. It is also noted that the near source behaviour is similar to that of a line plume and a possible explanation for this behaviour is presented. Baines, W.D. (1983), ``A technique for the direct measurement of volume flux of a plume,'' J. Fluid Mech. 132, 247--256.

  5. Experimental study on process of precision forging of an aluminium-alloy rotor

    Microsoft Academic Search

    Debin Shan; Fang Liu; Wenchen Xu; Yan Lu

    2005-01-01

    This paper describes the process of precision forging of an aluminium-alloy rotor with 23 radial twist blades. Fully-enclosed die forging with isothermal condition was carried out to form the complexity shape rotor. A combined female die was designed to solve the die releasing. Several forming schemes were employed to reduce the forging pressure or to improve the die fill in

  6. High-precision measurements of ? 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 ?±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.

  7. High-precision wavelength calibration of astronomical spectrographs with laser frequency combs

    Microsoft Academic Search

    M. T. Murphy; Th. Udem; R. Holzwarth; A. Sizmann; L. Pasquini; C. Araujo-Hauck; H. Dekker; S. D'Odorico; M. Fischer; T. W. Hänsch; A. Manescau

    2007-01-01

    We describe a possible new technique for precise wavelength calibration of high-resolution astronomical spectrographs using femtosecond-pulsed mode-locked lasers controlled by stable oscillators such as atomic clocks. Such `frequency combs' provide a series of narrow modes which are uniformly spaced according to the laser's pulse repetition rate and whose absolute frequencies are known a priori with relative precision better than 10-12.

  8. Research on machining error compensation in high-precision surface grinding machine for optical aspheric elements

    NASA Astrophysics Data System (ADS)

    Ke, Xiaolong; Guo, Yinbiao; Zhang, Shihan; Huang, Hao

    2010-10-01

    Using aspheric component in optical system can correct optical aberration, acquire high imaging quality, improve the optical characteristic, simplify system structure, and reduce system volume. Nowadays, high-precision surface grinding machine is an important approach to processing optical aspheric elements. However, because of the characteristics of optical aspheric elements, the processing method makes a higher demand to whole performance of surface grinding machine, and hardly to achieve ideal machining effect. Taking high generality and efficiency into account, this paper presents a compensation method for machining errors of high-precision surface grinding machine, which bases on optical aspheric elements, to achieve high-precision machining for all kinds of optical aspheric elements. After compensation, the machining accuracy of grinding machine could reach 2um/200×200mm. The research bases on NC surface grinding machine which is self developed. First of all, this paper introduces machining principle for optical aspheric elements on the grinding machine. And then error sources which producing errors are analyzed. By contacting and non-contacting measurement sensors, measurement software which is self designed realizes on-position measure for grinded workpiece, then fits surface precision and machining errors. Through compensation software for machining error which is self designed, compensation algorithm is designed and translated compensation data into G-code for the high-precision grinding machine to achieve compensation machining. Finally, by comparison between machining error compensation before and after processing, the experiments for this purpose are done to validate the compensation machining accuracy.

  9. High-precision thickness setting models for titanium alloy plate cold rolling without tension

    NASA Astrophysics Data System (ADS)

    Wang, Xiaochen; Yang, Quan; He, Fei; Sun, Youzhao; Xiao, Huifang

    2015-03-01

    Due to its highly favorable physical and chemical properties, titanium and titanium alloy are widely used in a variety of industries. Because of the low output of a single batch, plate cold rolling without tension is the most common rolling production method for titanium alloy. This method is lack of on-line thickness closed-loop control, with carefully thickness setting models for precision. A set of high-precision thickness setting models are proposed to suit the production method. Because of frequent variations in rolling specification, a model structural for the combination of analytical models and statistical models is adopted to replace the traditional self-learning method. The deformation resistance and friction factor, the primary factors which affect model precision, are considered as the objectives of statistical modeling. Firstly, the coefficient fitting of deformation resistance analytical model based on over-determined equations set is adopted. Additionally, a support vector machine(SVM) is applied to the modeling of the deformation resistance and friction factor. The setting models are applied to a 1450 plate-coiling mill for titanium alloy plate rolling, and then thickness precision is found consistently to be within 3%, exceeding the precision of traditional setting models with a self-learning method based on a large number of stable rolling data. Excellent application performance is obtained. The proposed research provides a set of high-precision thickness setting models which are well adapted to the characteristics of titanium alloy plate cold rolling without tension.

  10. High Precision HalfWave Rectifier Circuit In Dual Phase Output Mode

    E-print Network

    Jamjaem, Theerayut

    2010-01-01

    This paper present high precision halfwave rectifier circuit in dual phase output mode by 0.5 micrometer CMOS technology, plus or minus 1.5 V low voltage, it has received input signal and sent output current signal, respond in high frequency. The main structure compound with CMOS inverter circuit, common source circuit, and current mirror circuit. Simulation and confirmation quality of working by PSpice program, then it able to operating at maximum frequency about 100 MHz, maximum input current range about 400 \\mu Ap p, high precision output signal, low power dissipation, and uses a little transistor.

  11. 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-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. This accuracy limit is important for fundamental interaction tests, but also allows for the study of the fine structure of the nuclear mass surface with unprecedented accuracy, whenever required. The use of the FT-ICR technique provides true single ion sensitivity. This is essential to access isotopes that are produced with minimum rates which are very often the most interesting ones. Instead of pushing for highest accuracy, the high charge state of the ions can also be used to reduce the storage time of the ions, hence making measurements on even shorter-lived isotopes possible. Decay studies in ion traps will become possible with MATS. Novel spectroscopic tools for in-trap high-resolution conversion-electron and charged-particle spectroscopy from carrier-free sources will be developed, aiming e.g. at the measurements of quadrupole moments and E0 strengths. With the possibility of both high-accuracy mass measurements of the shortest-lived isotopes and decay studies, the high sensitivity and accuracy potential of MATS is ideally suited for the study of very exotic nuclides that will only be produced at the FAIR facility.Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The dependencies of the hyperfine splitting and isotope shift on the nuclear moments and mean square nuclear charge radii are well known and the theoretical framework for the extraction of nuclear parameters is well established. These extracted parameters provide fundamental information on the structure of nuclei at the limits of stability. Vital information on both bulk and valence nuclear properties are derived and an exceptional sensitivity to changes in nuclear def

  12. Natural Vs. Precise Concise Languages for Human Operation of Computers: Research Issues and Experimental Approaches

    Microsoft Academic Search

    Ben Shneiderman

    1980-01-01

    This paper raises concerns that natural language front ends for computer systems can limit a researcher's scope of thinking, yield inappropriately complex systems, and exaggerate public fear of computers. Alternative modes of computer use are suggested and the role of psychologically oriented controlled experimentation is emphasized. Research methods and recent experimental results are briefly reviewed.

  13. Innovative High-Precision Position Sensor Systems for Robotic and Automotive Applications

    Microsoft Academic Search

    M. R. Kirchhoff; C. Boese; J. Güttler; M. Feldmann; S. Büttgenbach

    2009-01-01

    Easily integrated high-precision position sensor systems manufactured by means of MEMS technologies are presented in this work. Two contactless working principles, inductive and capacitive, have been brought in operation successfully. The inductive sensors detect the direction of vector magnetic fields. Combined with permanent magnets, they are optimized for high-resolution angular measurements within the joints of parallel robots. The capacitive linear

  14. Precision Measurements of the Ionization Energy and Its Temperature Variation in High Purity Silicon Radiation Detectors

    Microsoft Academic Search

    R. D. Ryan

    1973-01-01

    High precision absolute measurements of the ionization energy (¿) for alpha particles and electrons have been made in two thick high purity silicon guard ring detectors between 100 K and 250 K. At a fixed energy (E) both ¿¿ and ¿e- were found to vary linearly (r = 0.999) with the band gap (WG). ¿¿ and ¿e- also increased with

  15. 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.

  16. A Phase Sensitive Voltmeter For A High-speed, High-precision Electrical Impedance Tomograph

    Microsoft Academic Search

    Raymond D. Cook; Gary J. Saulnier; John C. Goble

    1991-01-01

    Many potential applications for Electrical Impedance Tomography (EIT) have been investigated, many of which are particularly suited to real-time imaging [I]. The ill-posedness of the inverse problem of reconstructing the interior impedance distribution from boundary measurements requires that the boundary data be measured with great precision. As speed and precision are in general conflicting requirements, the construction of an instrument

  17. Adjusting for High-dimensional Covariates in Sparse Precision Matrix Estimation by ?1-Penalization.

    PubMed

    Yin, Jianxin; Li, Hongzhe

    2013-04-01

    Motivated by the analysis of genetical genomic data, we consider the problem of estimating high-dimensional sparse precision matrix adjusting for possibly a large number of covariates, where the covariates can affect the mean value of the random vector. We develop a two-stage estimation procedure to first identify the relevant covariates that affect the means by a joint ?1 penalization. The estimated regression coefficients are then used to estimate the mean values in a multivariate sub-Gaussian model in order to estimate the sparse precision matrix through a ?1-penalized log-determinant Bregman divergence. Under the multivariate normal assumption, the precision matrix has the interpretation of a conditional Gaussian graphical model. We show that under some regularity conditions, the estimates of the regression coefficients are consistent in element-wise ?? norm, Frobenius norm and also spectral norm even when p ? n and q ? n. We also show that with probability converging to one, the estimate of the precision matrix correctly specifies the zero pattern of the true precision matrix. We illustrate our theoretical results via simulations and demonstrate that the method can lead to improved estimate of the precision matrix. We apply the method to an analysis of a yeast genetical genomic data. PMID:23687392

  18. Investigation of high-precision {Lambda} hypernuclear spectroscopy via the (e,e'K{sup +}) reaction

    SciTech Connect

    Kawama, Daisuke

    2012-03-31

    The study of {Lambda} hypernuclear structure is very interesting in point of the understanding of the interaction between {Lambda} and nucleon ({Lambda}-N interaction) and its ?strange? structure itself due to the containment of a {Lambda} hyperon which has a strangeness as a new degree of freedom. In the several way to study the Lamda hypernuclei, the (e,e'K{sup +}) reaction spectroscopy is a powerful tool for the precise investigation of {Lamda} hypernuclear structure. The purpose of the preset thesis is the establishment of the experimental design with the efficient data analysis method for the (e,e'K{sup +}) hypernuclear spectroscopic experiment in the wide mass region (from A=7 to A=52). It is very challenging to perform the (e,e'K{sup +}) spectroscopic experiment with such a heavy target, because of the huge electron background due to the bremsstrahlung process. In the experiment, it is required to obtain the necessary hypernuclear yield, suppressing the background event ratio. We achieved these requirements by newly constructing the high resolution electron spectrometer (HES) and splitter magnet (SPL) dedicated to the (e,e'K{sup +}) spectroscopic experiment. The HES consists of two quadrupole magnets and a dipole magnets (Q-Q-D) with a momentum resolution of dp/p = 3x10^-4 at p = 0.84 GeV/c. It was used being vertically tilted by 6.5 degree so as to optimize signal to noise ratio and hypernuclear yield. The SPL is a dipole magnet. The experimental target was placed at the entrance of this magnet. The role of the SPL is to separate four kind of particles; scattered kaons, photons created by the bremsstrahlung, the post beam and scattered electrons. In addition, since the SPL is a part of the kaon and electron spectrometers. We designed the magnet shape carefully considering these points. The experiment was performed with 2.344 GeV/c electron beam from CEBAF at Jefferson Lab. The experimental setup consists of the HES, SPL and HKS (high momentum resolution kaon spectrometer). The HKS is also a Q-Q-D type spectrometer with the momentum resolution of dp/p = 2x10^-4 at p = 1.2 GeV/c. In the data analysis, the particle momentum calibration was the most important procedure. At the initial point, the particle momentum was obtained from the calculated magnetic field map of the spectrometer whose accuracy is an order of 10^-2. The initial momentum was calibrated by two step, the the magnetic field map improvement and the calibration with known masses of {Lambda}/{Sigma}{sup 0} which were observed by the CH{sub 2} target data. As a result of the calibration, the momentum resolutions of HKS and HES were estimated as 4x10^-4 and 6x10^-4, respectively. Though these values are the double of the designed value, it was achieved to obtain the {Lambda}/{Sigma}{sup 0} peaks with the same order of the designed energy from the original calculated magnetic field. The cross section was calculated with the several estimated factors. The averaged p({gamma}*, K{sup +}){Lamda} cross section in the HKS acceptance, (0.90 < cos({theta}^CM_K{sup +}) < 1.0) was calculated as 227 ± 12 ±26 [nb/sr], which is consistent within the error bar with the other experiment results of p({gamma}, K{sup +}){Lamda}. The obtained yield of the peak was almost same as the designed value with the considered detector efficiencies. The observed hypernuclear spectrum of ^12_{Lambda} B was also consistent with the other experimental results. These analysis result represents that the experimental setup including the newly constructed HES and SPL worked and the calibration procedure of this unique experimental setup is basically established.

  19. Experimental approaches for addressing fundamental biological questions in living, functioning cells with single molecule precision

    PubMed Central

    Lenn, Tchern; Leake, Mark C.

    2012-01-01

    In recent years, single molecule experimentation has allowed researchers to observe biological processes at the sensitivity level of single molecules in actual functioning, living cells, thereby allowing us to observe the molecular basis of the key mechanistic processes in question in a very direct way, rather than inferring these from ensemble average data gained from traditional molecular and biochemical techniques. In this short review, we demonstrate the impact that the application of single molecule bioscience experimentation has had on our understanding of various cellular systems and processes, and the potential that this approach has for the future to really address very challenging and fundamental questions in the life sciences. PMID:22773951

  20. Experimental tomography of high-NOON states

    E-print Network

    Yonatan Israel; Itai Afek; Shamir Rosen; Oron Ambar; Yaron Silberberg

    2011-12-19

    We have performed experimental quantum state tomography of NOON states with up to four photons. The measured states are generated by mixing a classical coherent state with spontaneous parametric down-conversion. We show that this method produces states which exhibit a high fidelity with ideal NOON states. The fidelity is limited by the overlap of the two-photon down-conversion state with any two photons originating from the coherent state, for which we introduce and measure a figure of merit. A second limitation on the fidelity set by the total setup transmission is discussed. We also apply the same tomography procedure for characterizing correlated photon hole states.

  1. [Experimental and theoretical high energy physics program

    SciTech Connect

    Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

    1993-04-01

    Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac{endash}Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e{sup +}e{sup {minus}} collisions at CERN; {bar p}{endash}p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab. (RWR)

  2. High-Precision Measurements of the Superallowed Beta+ Decays of 38Ca and 46V 

    E-print Network

    Park, Hyo-In

    2012-10-19

    depended on beta-delayed gamma-ray intensities being measured with a high-purity germanium detector calibrated for absolute efficiency to 0.2% precision. This branching-ratio result represents our first step in bringing the ft value for the superallowed ³?...

  3. High Precision Eccentricity Measurement of Accelerating Cavities by Use of the Small Perturbation Theory

    Microsoft Academic Search

    A. Labanc

    2007-01-01

    The TESLA-type superconducting accelerating cavities are designed for use in high gradient linear accelerators - operating free electron laser in Hamburg (FLASH) and the future projects X-ray free electron laser (XFEL) and international linear collider (ILC). The cells of these cavities must be precisely aligned to the beam trajectory in order to minimize its unwanted interaction with the acceleration mode

  4. High-precision computation of two-loop Feynman diagrams with Wilson fermions

    E-print Network

    Stefano Capitani; Sergio Caracciolo; Andrea Pelissetto; Giancarlo Rossi

    1997-10-22

    We apply the coordinate-space method by Luescher and Weisz to the computation of two-loop diagrams in full QCD with Wilson fermions on the lattice. The essential ingredient is the high-precision determination of mixed fermionic-bosonic propagators.

  5. Using Automated, High-precision Repicking to Improve Delineation of Microseismic Structures

    E-print Network

    Rowe, Charlotte

    Using Automated, High-precision Repicking to Improve Delineation of Microseismic Structures at the Soultz Geothermal Reservoir C. A. ROWE,*1 R. C. ASTER,1 W. S. PHILLIPS,2 R. H. JONES,3 B. BORCHERS 4 picks in large digital seismic data sets provides signi®cant improvement in resolution of microseismic

  6. High-Precision Absolute Positioning of Medical Instruments in MRI Systems

    Microsoft Academic Search

    Eric Aboussouan; Sylvain Martel

    2006-01-01

    An absolute positioning technique has been developed for ferromagnetic markers in medical instruments and untethered devices operating in a magnetic resonance imaging (MRI) system. This technique allows high precision 3D readings of the location of the device with respect to the absolute center of the MRI bore. The local magnetic field induced by the device is used as a signature

  7. Development of high precision and multifunctional timing system using integrated GPS\\/BD receiver

    Microsoft Academic Search

    Li Gun; Wu Fu-ping; Wei Jing-fa; Huang Xian-he

    2008-01-01

    A highly precise and multifunctional timing system using the self development integrated GPS\\/BD time receiver is presented in this paper. The authors firstly designed an integrated GPS\\/BD (compass or Beidou navigation system of China) time receiver for time and frequency synchronization in a local network, and describing the main issues and the solution of the receiver implement in detail, and

  8. HIGH PRECISION KINEMATIC POSITIONING USING SINGLE DUAL-FREQUENCY GPS RECEIVER

    Microsoft Academic Search

    Y. Gao; A. Wojciechowski

    Currently, high precision kinematic GPS positioning with centimetre level accuracy can only be carried out using differential GPS (DGPS) positioning techniques which require the deployment of base receiver stations. The requirement to deploy base receiver sta- tions, however, spatially limits the operating range of the rover receiver to about 20 km from the base stations. As a result, it not

  9. High Precision Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard for

    E-print Network

    Jin, Deborah

    High Precision Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard for Frequency and Time Thesis directed atomic clock states equally, such that the transition frequency is unchanged. Strontium is a natural

  10. Design and optimzation of high precision CMOS voltage reference using Taguchi orthogonal array technique

    Microsoft Academic Search

    Hande Vinayak; Maryam Shojaei Baghini; Prakash Apte

    2011-01-01

    A CMOS voltage reference, which is based on the weighted compensation of thermal voltage and threshold voltage temperature variations is presented. Subthreshold NMOS transistors and resistive divider configuration are used to achieve reference voltage with low temperature coefficient. Taguchi orthogonal array technique is presented to optimize the circuit to attain precise reference voltage with high PSRR. The proposed voltage reference

  11. A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes of carbon dioxide

    E-print Network

    Saleska, Scott

    A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes problem opens the possibility of field worthy rapid response isotopic instrumentation and attests to the maturity of these lasers as spectroscopic sources. 1. Introduction The measurement of isotopic ratios

  12. High-precision osmium isotopes in enstatite and Rumuruti David van Acken a,b,

    E-print Network

    Weston, Ken

    High-precision osmium isotopes in enstatite and Rumuruti chondrites David van Acken a,b, , Alan D in revised form 21 April 2011; available online 29 April 2011 Abstract Isotopic heterogeneity within meteorites in terms of oxidation state, and might thus also present extremes if there is significant isotopic

  13. J-RAS: A high precision reference for the isotopic composition of CO2 in air

    E-print Network

    J-RAS: A high precision reference for the isotopic composition of CO2 in air W. A. Brand, M carbon cycle and the stable isotopes of CO2 in air o The referencing concept and the ARAMIS line · First J-RAS intercomparison results and outlook Outline: *J-RAS = 'Jena-Reference Air Set' GASIR annual

  14. Total dose radiation effect simulations on a high-precision data acquisition system

    Microsoft Academic Search

    Esko Mikkola; Bert Vermeire; Terence Chiu; Hugh Barnaby; H. G. Parks

    2007-01-01

    A novel method to evaluate total dose radiation response on large mixed signal circuits is described. The method is based on partly behavioral, partly structural simulation on the VHDL-AMS language. Results obtained with the developed simulation method are compared to total dose testing results of an embedded high-precision data acquisition system. The system was total dose tested until functional failure

  15. A High-Performance Double Precision Accumulator Krishna K. Nagar and Jason D. Bakos

    E-print Network

    Bakos, Jason D.

    it is based. In this paper we present a design for a double precision accumulator that achieves high this by integrating a coalescing reduction circuit within the low-level design of a base-converting floating-point adder. When implemented on our Virtex-2 Pro 100 FPGA, our design achieves a speed of 170 MHz. I

  16. High precision multi-genome scale reannotation of enzyme function by EFICAz

    Microsoft Academic Search

    Adrian K Arakaki; Weidong Tian; Jeffrey Skolnick

    2006-01-01

    BACKGROUND: The functional annotation of most genes in newly sequenced genomes is inferred from similarity to previously characterized sequences, an annotation strategy that often leads to erroneous assignments. We have performed a reannotation of 245 genomes using an updated version of EFICAz, a highly precise method for enzyme function prediction. RESULTS: Based on our three-field EC number predictions, we have

  17. Methodology for developing a high-precision ultrasound flow meter and fluid velocity profile reconstruction

    Microsoft Academic Search

    Emmanuelle Mandard; Denis Kouame; Rodolphe Battault; Jean-Pierre Remenieras; F. Patat

    2008-01-01

    This article reports the methodology used to develop a high-precision ultrasound transit time flow meter dedicated to liquid hydrocarbons. This kind of flow meter is designed for custody transfer applications requiring accuracy better than 0.15% of reading. We focus here on certain specific points to achieve this accuracy. The transit time method needs to estimate accurately the time delay between

  18. 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.

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

    PubMed

    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. PMID:24289431

  20. Research on the realization of high precision RC array through IC thin film technology

    NASA Astrophysics Data System (ADS)

    Sun, Fangkui; Jiang, Wei; Wu, Di; Zhang, Shoutao

    2008-02-01

    This paper discusses some advantages of IC thin film technology in realizing RC array that traditional thick film technology does not have, which make IC thin film technology the mainstream in realizing RC array devices. Then it focuses on how to use IC thin film technology to realize high precision RC array, some practical techniques are put forward, based on our experiments and experience in layout design and fabrication. These techniques are demonstrated separately according to the respective characteristics of resistor and capacitor. Finally, the different ranges of precision of the devices tested in different ways through specific experiments are given.

  1. 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

  2. High-Precision Tuning of State for Memristive Devices by Adaptable Variation-Tolerant Algorithm

    E-print Network

    Alibart, Fabien; Hoskins, Brian; Strukov, Dmitri

    2011-01-01

    Using memristive properties common for the titanium dioxide thin film devices, we designed a simple write algorithm to tune device conductance at a specific bias point to 1% relative accuracy (which is roughly equivalent to 7-bit precision) within its dynamic range even in the presence of large variations in switching behavior. The high precision state is nonvolatile and the results are likely to be sustained for nanoscale memristive devices because of the inherent filamentary nature of the resistive switching. The proposed functionality of memristive devices is especially attractive for analog computing with low precision data. As one representative example we demonstrate hybrid circuitry consisting of CMOS summing amplifier and two memristive devices to perform analog multiply and accumulate computation, which is a typical bottleneck operation in information processing.

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

    SciTech Connect

    Hicks, D. G.; Celliers, P. M.; Bradley, D. K.; Eggert, J. H.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Boehly, T. R. [Laboratory for Laser Energetics, University of Rochester, New York 14623 (United States); McWilliams, R. S. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); University of California, Berkeley, California 94720 (United States); Jeanloz, R. [University of California, Berkeley, California 94720 (United States)

    2008-11-01

    High-precision 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 uncertainties 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, the present measurements indicate that the mixed phase is a few percent more dense than what would be expected from a simple interpolation between liquid and solid Hugoniots.

  4. Experimental Characterization of Hysteresis in a Revolute Joint for Precision Deployable Structures

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Fung, Jimmy; Gloss, Kevin; Liechty, Derek S.

    1997-01-01

    Recent studies of the micro-dynamic behavior of a deployable telescope metering truss have identified instabilities in the equilibrium shape of the truss in response to low-energy dynamic loading. Analyses indicate that these micro-dynamic instabilities arise from stick-slip friction within the truss joints (e.g., hinges and latches). The present study characterizes the low-magnitude quasi-static load cycle response of the precision revolute joints incorporated in the deployable telescope metering truss, and specifically, the hysteretic response of these joints caused by stick-slip friction within the joint. Detailed descriptions are presented of the test setup and data reduction algorithms, including discussions of data-error sources and data-filtering techniques. Test results are presented from thirteen specimens, and the effects of joint preload and manufacturing tolerances are investigated. Using a simplified model of stick-slip friction, a relationship is made between joint load-cycle behavior and micro-dynamic dimensional instabilities in the deployable telescope metering truss.

  5. High-precision pressure shifting measurement technique using frequency-stabilized cavity ring-down spectroscopy

    Microsoft Academic Search

    David J. Robichaud; Joseph T. Hodges; Daniel Lisak; Charles E. Miller; Mitchio Okumura

    2008-01-01

    We describe a high-precision method for measuring pressure shifting of absorption lines. The technique involves the acquisition of high-resolution spectra using a cavity ring-down spectrometer whose length is continuously locked to a frequency-stabilized reference laser over a range of sample pressures. We discuss a relatively large correction arising from the pressure-dependence of dispersion in the cavity modes, and we demonstrate

  6. Near real-time high-resolution airborne camera, AEROCam, for precision agriculture

    Microsoft Academic Search

    Xiaodong Zhang; Ho Jin Kim; Clinton Streeter; David A. Claypool; Ramesh Sivanpillai; Santhosh Seelan

    2011-01-01

    Precision agriculture often relies on high-resolution imagery to delineate the variability within a field. Airborne Environmental Research Observational Camera (AEROCam) was designed to meet the needs of agriculture producers, ranchers, and researchers, who require high-resolution imagery in a near real-time environment for rapid decision support. AEROCam was developed and operated through a unique collaboration between several departments at the University

  7. High-precision two-dimensional atom localization via quantum interference in a tripod-type system

    NASA Astrophysics Data System (ADS)

    Wang, Zhiping; Yu, Benli

    2014-03-01

    A scheme is proposed for high-precision two-dimensional atom localization in a four-level tripod-type atomic system via measurement of the excited state population. It is found that because of the position-dependent atom–field interaction, the precision of 2D atom localization can be significantly improved by appropriately adjusting the system parameters. Our scheme may be helpful in laser cooling or atom nanolithography via high-precision and high-resolution atom localization.

  8. High Precision Tracking Control based on Pseudo-Inverse Feedforward Control System for Next-Generation Optical Disks

    NASA Astrophysics Data System (ADS)

    Ogata, Tokoku; Nakazaki, Tatsuya; Sakimura, Naohide; Ohishi, Kiyoshi; Miyazaki, Toshimasa; Koide, Daiichi; Tokumaru, Haruki; Takano, Yoshimichi

    2012-08-01

    Optical disk drive systems must realize high-precision tracking control. For this purpose, we have already proposed a tracking control system that is composed of a high gain servo controller (HGSC) and a perfect tracking controller (PTC). The conventional feedforward tracking control system adequately suppresses the tracking error caused by track eccentricity. However, the PTC system in the conventional system is complicated. Therefore, the PTC system embedded on a digital signal processor (DSP) cannot realize fast sampling time and the conventional system has a speedup limitation in the optical disk tracking control system. Hence, in this paper, we propose a new high-speed and high-precision feedforward tracking control system that uses a pseudo-inverse matrix. The proposed system consists of the pseudo-inverse feedforward control (P-IFFC). The proposed system realizes simple and quick execution in a digital signal processor software servo. Our experimental results confirm that the proposed system effectively suppresses the tracking error under a condition of the 7200 rpm disk rotation speed of DVD+R. In addition, the conventional systems and the proposed system with a pseudo-inverse matrix are compared in terms of processing time and tracking error.

  9. DESIGN & EXPERIMENTATION OF HIGH CURRENT DENSITY DC MAGNETOHYDRODYNAMIC (MHD) MICROPUMP

    E-print Network

    Kassegne, Samuel Kinde

    DESIGN & EXPERIMENTATION OF HIGH CURRENT DENSITY DC MAGNETOHYDRODYNAMIC (MHD) MICROPUMP Nguyen: Design, Fabrication, & Experimentation of DC MHD Micropump OF THE THESIS Design, Fabrication, & Experimentation of DC MHD Micropump by Bao Thanh Nguyen Master of Science

  10. High-Precision U-Pb Zircon Dates as Benchmarks in Absolute Time

    NASA Astrophysics Data System (ADS)

    Schmitz, M. D.; Bowring, S. A.; Schoene, B.

    2003-12-01

    High-precision IDTIMS U-Pb zircon dates provide the most precise and accurate isotopic benchmarks in absolute time, due to the concordancy check of the paired U-Pb decay schemes, the precisely measured 235U and 238U decay constants, very high initial parent/daughter ratios, and the robust nature of zircon to loss or gain of U and Pb over geologic time. However, caveats to the use of such zircon dates include the accurate assessment and minimization of random and systematic errors in the analytical methods, and decay constant uncertainties. Unfortunately, there exists little consensus within the U-Pb geochronological community regarding an international zircon standard for the external assessment of interlaboratory reproducibility, while residual questions remain regarding the potential for systematic error in the single available high-precision counting experiment of the U decay constants1. Stringent criteria are imposed on candidates for zircon geochronology standards including the absence of inheritance and Pb-loss at both the single grain scale and the resolution of microbeam techniques. We present an example of the potential and limitations of a possible zircon standard, AS3, from the Duluth Complex, North American Midcontinent Rift2. New data for 27 single zircons are indistinguishable from prior results, with 207Pb/206Pb and upper intercept dates identical within error to a U-Pb concordia date of 1099.1+/-0.2 Ma (+/-1.2 Ma with systematic errors) based on 12 concordant and equivalent analyses. However, we must reiterate that a zircon population exhibiting consistent concordancy remains elusive, as AS3 and all Paleozoic and older standard candidates so far examined contain grains exhibiting Pb-loss, although rigorous selection and preparation of zircons through diamagnetic separation and aggressive abrasion can mitigate this phenomenon. The continued screening of candidate standards by both IDTIMS and SHRIMP techniques should be an organized, international endeavor involving all high-precision geochronology laboratories. Under the single assumption that the equivalent data represent the approach to closed system behavior, the correspondence of the AS3 zircons with the presently defined concordia curve suggests the accuracy of the ratio of the presently accepted decay constants1 to within their 0.1% (2? ) counting errors. While a proposed revision of the 235U decay constant3 is apparently unnecessary, additional high-precision, high n, statistically equivalent zircon population samplings are necessary to further evaluate decay constants and their uncertainties at the per mil level. When measured on appropriate lithologies, high-precision U-Pb dates also become powerful tools for the intercalibration of other radioisotope decay rates more difficult to measure through counting or accumulation (e.g. 40K, 176Lu, 187Re). We will present several new high-precision data sets for quickly cooled Oligocene to Archean extrusive and intrusive rocks, and assess their usefulness as benchmarks for the intercalibration of radiometric time; a growing number of high-precision U-Pb zircon and 40Ar/39Ar feldspar, biotite or hornblende pairs spanning more than 3 Ga in absolute time indicate a consistently younger bias in 40Ar/39Ar dates of between 0.7 and 1%. 1Jaffey et al. (1974) Phys Rev C 4:1889-1906; 2Paces and Miller (1993) J Geophys Res 98:13997-14013; 3Mattinson (2000) EOS 81:S444

  11. High precision Penning trap mass spectrometry of rare isotopes produced by projectile fragmentation

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, Anna; Bachelet, C.; Barquest, B. R.; Bollen, G.; Campbell, C. M.; Ferrer, R.; Guenaut, C.; Lincoln, D.; Morrissey, D. J.; Pang, G. K.; Prinke, A. M.; Ringle, R.; Savory, J.; Schwarz, S.; Block, M.; Schury, P.; Folden, C. M., III; Melconian, D.; Sjue, S. K. J.

    2009-10-01

    The Low Energy Beam and Ion Trap (LEBIT) facility combines high precision Penning trap mass spectrometry with fast beam projectile fragmentation and high pressure gas stopping techniques. Advanced ion manipulation, such as high efficiency continuous mass selection in an ion-guide and radio-frequency ion accumulation and bunching, are used to purify, cool, and pulse the beam. Recent mass measurements include ^63-66Fe, ^66As, and ^32Si. The neutron-rich iron isotopes access the N = 40 subshell closure. The new significantly lower mass uncertainty makes ^66As a candidate to test the CVC hypothesis. ^32Si, member of the A = 32, T = 2 quintet, provides the most precise test of the isobaric multiplet mass equation . An overview of the various aspects of ion manipulation and some of the resulting measurements will be presented.

  12. Charge breeding rare isotopes for high precision mass measurements: challenges and opportunities

    NASA Astrophysics Data System (ADS)

    Simon, M. C.; Macdonald, T. D.; Bale, J. C.; Chowdhury, U.; Eberhardt, B.; Eibach, M.; Gallant, A. T.; Jang, F.; Lennarz, A.; Luichtl, M.; Ma, T.; Robertson, D.; Simon, V. V.; Andreoiu, C.; Brodeur, M.; Brunner, T.; Chaudhuri, A.; Crespo López-Urrutia, J. R.; Delheij, P.; Ettenauer, S.; Frekers, D.; Grossheim, A.; Gwinner, G.; Kwiatkowski, A. A.; Lapierre, A.; Mané, E.; Pearson, M. R.; Ringle, R.; Schultz, B. E.; Dilling, J.

    2013-09-01

    Ion charge breeding for Penning-trap mass spectrometry has been established as providing a precision increase that scales linearly with the charge state of the ion. Fast and efficient charge breeding is a precondition for the application of this approach to rare isotopes. However, in view of low yields and short half-lives the precision boost is partly compromised by unavoidable ion losses inherent to the charge breeding process. The mass spectrometer TRIUMFs ion trap for atomic and nuclear science is pioneering this field by coupling a Penning trap and an electron beam ion trap to the rare-isotope beam facility ISAC at TRIUMF. Here we present simulations that calculate and maximize the effective precision gain of time-of-flight ion-cyclotron-resonance measurements with highly charged ions of short-lived nuclides. In addition we compare the characteristics of measurements with singly and highly charged ions, and we summarize recent results that explored benefits of charge breeding that go beyond the precision increase.

  13. 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 (? 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.

  14. Experimental high-velocity missile head injury.

    PubMed

    Allen, I V; Scott, R; Tanner, J A

    1982-09-01

    A standardized experimental high-velocity penetrating head-injury model has been produced in which pathological lesions were observed, not only in the wound track but at sites more remote from the track in the hypothalamus, brain stem and cerebellum. Diffuse subarachnoid haemorrhage was common and intraventricular haemorrhage was a constant feature. Other constant histological abnormalities were:L 1. Perivascular "ring' haemorrhages. 2. Perivascular haemorrhage with a surrounding zone of decreased staining intensity. 3. Perivascular increased staining intensity. 4. Areas of decreased staining intensity apparently dissociated from areas of haemorrhage. The pathogenesis of the perivascular lesions is discussed and preliminary studies suggest that these may be the site of early oedema. The implications of this experiment for military surgery and for ballistic protection of the head are discussed. PMID:6183206

  15. Speed-stabilization control of a high-speed PM synchronous motor without high-precision sensors

    Microsoft Academic Search

    Zou Jibin; Xu Yongxiang; Shang Jing; Liang Weiyan

    2002-01-01

    Speed-stabilization control of a 30000 rpm highspeed PMSM (permanent magnet synchronous motor) is achieved without speed sensors. The rotor position of the PMSM is detected by a discrete Hall sensor with the resolution of ±90 electrical degrees. Circuits based on phase locked loop (PLL) are designed to obtain the speed signal and high-precision rotor position signal. Two filters with different

  16. High-Precision Radiosurgical Dose Delivery by Interlaced Microbeam Arrays of High-Flux Low-Energy Synchrotron

    E-print Network

    Paris-Sud XI, Université de

    , Switzerland Abstract Microbeam Radiation Therapy (MRT) is a preclinical form of radiosurgery dedicated those described in any other conventional radiation therapy. Citation: Serduc R, Bra¨uer-Krisch EHigh-Precision Radiosurgical Dose Delivery by Interlaced Microbeam Arrays of High-Flux Low

  17. Using long-baseline interferometric gravitational waves detectors for high precision measures of the gravitational acceleration

    E-print Network

    Christian Corda

    2007-01-25

    A derivation of the optical axis lenght fluctations due by tilts of the mirrors of the Fabry-Perot cavity of long-baseline interferometers for the detection of gravitational waves in presence of the gravitational field of the earth is discussed. By comparing with the typical tilt-induced noises it is shown that this potential signal, which is considered a weak source of noise, is negligible for the first generation of gravitational waves interferometers, but, in principle, this effect could be used for high precision measures of the gravitational acceleration if advanced projects will achieve an high sensitivity. In that case the precision of the misure could be higher than the gravimeter realized by the Istituto di Metrologia ``Gustavo Colonnetti''.

  18. Using femtosecond laser to fabricate highly precise interior three-dimensional microstructures in polymeric flow chip

    PubMed Central

    Lee, Chia-Yu; Chang, Ting-Chou; Wang, Shau-Chun; Chien, Chih-Wei; Cheng, Chung-Wei

    2010-01-01

    This paper reports using femtosecond laser marker to fabricate the three-dimensional interior microstructures in one closed flow channel of plastic substrate. Strip-like slots in the dimensions of 800 ?m×400 ?m×65 ?m were ablated with pulse Ti:sapphire laser at 800 nm (pulse duration of ?120 fs with 1 kHz repetition rate) on acrylic slide. After ablation, defocused beams were used to finish the surface of microstructures. Having finally polished with sonication, the laser fabricated structures are highly precise with the arithmetic roughness of 1.5 and 4.5 nm. Fabricating such highly precise microstructures cannot be accomplished with nanosecond laser marking or other mechanical drilling methods. In addition, since laser ablation can directly engrave interior microstructures in one closed chip, glue smearing problems to damage molded microstructures possibly to occur during the chip sealing procedures can be avoided too. PMID:21079695

  19. Direct high-precision measurement of the magnetic moment of the proton.

    PubMed

    Mooser, A; Ulmer, S; Blaum, K; Franke, K; Kracke, H; Leiteritz, C; Quint, W; Rodegheri, C C; Smorra, C; Walz, J

    2014-05-29

    One of the fundamental properties of the proton is its magnetic moment, µp. So far µp has been measured only indirectly, by analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in terms of the nuclear magneton: ?p = 2.792847350(9)?N. This measurement outperforms previous Penning-trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty-year-old indirect measurement, in which significant theoretical bound state corrections were required to obtain µp, by a factor of 3. By application of this method to the antiproton magnetic moment, the fractional precision of the recently reported value can be improved by a factor of at least 1,000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons. PMID:24870545

  20. Reliable and integrated technique for determining resonant frequency in radio frequency resonators. Application to a high-precision resonant cavity-based displacement sensor.

    PubMed

    Jauregui, Rigoberto; Asua, Estibaliz; Portilla, Joaquin; Etxebarria, Victor

    2015-03-01

    This paper presents a reliable and integrated technique for determining the resonant frequency of radio frequency resonators, which can be of interest for different purposes. The approach uses a heterodyne scheme as phase detector coupled to a voltage-controlled oscillator. The system seeks the oscillator frequency that produces a phase null in the resonator, which corresponds to the resonant frequency. A complete explanation of the technique to determine the resonant frequency is presented and experimentally tested. The method has been applied to a high-precision displacement sensor based on resonant cavity, obtaining a theoretical nanometric precision. PMID:25832260

  1. MEMS - Frequency Agile High Precision Ranging under the Dual Use Applications Program (DUAP)

    Microsoft Academic Search

    Paul Bauhahn

    2001-01-01

    The objective of this program was laboratory demonstration of a low cost, jamming resistant, precision ranging system (radar) for proximity fuze and short-range measurement systems. Two approaches were envisioned: (1) The baseline-a baseband system directly radiating and detecting a random sequence of short pulses and (2) A higher risk design based on a transmitter using high-speed modulation of a micro-electromechanical

  2. High-precision Timing of Five Millisecond Pulsars: Space Velocities, Binary Evolution, and Equivalence Principles

    Microsoft Academic Search

    M. E. Gonzalez; I. H. Stairs; R. D. Ferdman; P. C. C. Freire; D. J. Nice; P. B. Demorest; S. M. Ransom; M. Kramer; F. Camilo; G. Hobbs; R. N. Manchester; A. G. Lyne

    2011-01-01

    We present high-precision timing of five millisecond pulsars (MSPs) carried out for more than seven years; four pulsars are in binary systems and one is isolated. We are able to measure the pulsars' proper motions and derive an estimate for their space velocities. The measured two-dimensional velocities are in the range 70-210 km s-1, consistent with those measured for other

  3. Thermo-optic noise in coated mirrors for high-precision optical measurements

    E-print Network

    M. Evans; S. Ballmer; M. Fejer; P. Fritschel; G. Harry; G. Ogin

    2008-07-30

    Thermal fluctuations in the coatings used to make high-reflectors are becoming significant noise sources in precision optical measurements and are particularly relevant to advanced gravitational wave detectors. There are two recognized sources of coating thermal noise, mechanical loss and thermal dissipation. Thermal dissipation causes thermal fluctuations in the coating which produce noise via the thermo-elastic and thermo-refractive mechanisms. We treat these mechanisms coherently, give a correction for finite coating thickness, and evaluate the implications for Advanced LIGO.

  4. Silicon-micromachined micromirrors with integrated high-precision actuators for external-cavity semiconductor lasers

    Microsoft Academic Search

    Meng-Hsiung Kiang; Olav Solgaard; Richard S. Muller; Kam Y. Lau

    1996-01-01

    We present an actuated silicon-micromachined micromirror with continuous and highly accurate position adjustment designed to be used in the construction of external-cavity semiconductor-laser modules. In our initial design, a positioning accuracy better than ±0.2 ?m for the actuated micromirrors is obtained. The mechanical robustness, small size, and fine-positional precision of the actuated micromirrors are sufficient for external-cavity-laser applications. In production,

  5. High precision planar waveguide propagation loss measurement technique using a Fabry-Perot cavity

    Microsoft Academic Search

    Thomas Feuchter; Carsten Thirstrup

    1994-01-01

    A high precision measurement technique for characterizing the propagation loss in silica low-loss optical waveguides, based on measuring the contrast of a Fabry-Perot cavity, is demonstrated. The cavity consists of the waveguide coupled to two polarization-maintaining fibers, each end facet coated with dielectric mirrors, leaving the reflectivity as an adjustable parameter. The contrast is measured by modulating the cavity length

  6. Development of a high-precision straightness measuring system with DVD pick-up head

    Microsoft Academic Search

    Kuang-Chao Fan; Chih-Liang Chu; Jarn-Lien Liao; Jong-I. Mou

    2003-01-01

    A low-cost and high-precision straightness measurement system using a DVD pick-up head has been developed in this research. By removing its objective lens the pick-up head of a commercial DVD player possesses excellent properties of stable laser power, collimated laser beam, circular Gaussian distribution and sensitive photodetectors. A moving knife-edge piece is placed between the pick-up head and a plane

  7. High-precision gravity network to monitor temporal variations in gravity across Yucca Mountain, Nevada

    SciTech Connect

    Harris, R.N.; Ponce, D.A.

    1988-12-31

    Repeatable high-precision gravity surveys provide a method of monitoring temporal variations in the gravity field. Fluctuations in the gravity field may indicate water table changes, crustal deformation, or precursors to volcanism and earthquakes. This report describes a high-precision gravity loop which has been established across Yucca Mountain, Nevada in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) program. The purpose of this gravity loop is to monitor temporal variations in gravity across Yucca Mountain in an effort to interpret and predict the stability of the tectonic framework and changes in the subsurface density field. Studies of the tectonic framework which include volcanic hazard seismicity, and faulting studies are in progress. Repeat high-precision gravity surveys are less expensive and can be made more rapidly than a corresponding leveling survey. High-precision gravity surveys are capable of detecting elevation changes of 3 to 5 cm, and thus can be employed as an efficient tool for monitoring vertical crustal movements while supplementing or partially replacing leveling data. The Yucca Mountain gravity network has been tied to absolute gravity measurements established in southern Nevada. These ties provide an absolute datum for comparing repeat occupations of the gravity network, and provide a method of monitoring broad-scale changes in gravity. Absolute gravity measurements were also made at the bottom and top of the Charleston Peak calibration loop in southern Nevada. These absolute gravity measurements provide local control of calibrating gravity meters over the gravity ranges observed at Yucca Mountain. 13 refs., 7 figs., 3 tabs.

  8. High-precision photometry by telescope defocusing - I. The transiting planetary system WASP5

    Microsoft Academic Search

    John Southworth; T. C. Hinse; U. G. Jørgensen; M. Dominik; D. Ricci; M. J. Burgdorf; A. Hornstrup; P. J. Wheatley; T. Anguita; V. Bozza; S. Calchi Novati; K. Harpsøe; P. Kjærgaard; C. Liebig; L. Mancini; G. Masi; M. Mathiasen; S. Rahvar; G. Scarpetta; C. Snodgrass; J. Surdej; C. C. Thöne; M. Zub

    2009-01-01

    We present high-precision photometry of two transit events of the extrasolar planetary system WASP-5, obtained with the Danish 1.54-m telescope at European Southern Obseratory La Silla. In order to minimize both random and flat-fielding errors, we defocused the telescope so its point spread function approximated an annulus of diameter 40 pixel (16 arcsec). Data reduction was undertaken using standard aperture

  9. A comparative study of integrators for constructing ephemerides with high precision.

    NASA Astrophysics Data System (ADS)

    Huang, Tian-Yi

    1990-09-01

    There are four indexes for evaluating various integrators. They are the local truncation error, the numerical stability, the complexity of computation and the quality of adaptation. A review and a comparative study of several numerical integration methods, such as Adams, Cowell, Runge-Kutta-Fehlberg, Gragg-Bulirsch-Stoer extrapolation, Everhart, Taylor series and Krogh, which are popular for constructing ephemerides with high precision, has been worked out.

  10. Detuned Twin-Signal-Recycling for ultra-high precision interferometers

    E-print Network

    Andre Thuering; Roman Schnabel; Harald Lueck; Karsten Danzmann

    2007-07-03

    We propose a new interferometer technique for high precision phase measurements such as those in gravitational wave detection. The technique utilizes a pair of optically coupled resonators that provides identical resonance conditions for the upper as well the lower phase modulation signal sidebands. This symmetry significantly reduces the noise spectral density in a wide frequency band compared with single sideband recycling topologies of current and planned gravitational wave detectors. Furthermore the application of squeezed states of light becomes less demanding.

  11. An EtherCAT-based motor drive for high precision motion systems

    Microsoft Academic Search

    Minyoung Sung; Kanghee Kim; Hyun-Wook Jin; Taehyoun Kim

    2011-01-01

    Industrial Ethernet-based motor drives offer many advantages for motion applications. This paper presents the implementation and analysis of a motor drive with the EtherCAT, an open real-time Ethernet standard, for high-precision motion systems. Considering the characteristics of the multitasked soft- ware and the network interface, we analyze the delay in actuating the motor in response to a command from the

  12. Construction of the new high-precision Earth rotation series at long time intervals

    NASA Astrophysics Data System (ADS)

    Pashkevich, V.

    2014-12-01

    In the previous investigation (Pashkevich, 2013) the high-precision Rigid Earth Rotation Series (designated RERS2012) dynamically adequate to the JPL DE406/LE406 (Standish, 1998) ephemeris over 2000 and 6000 years were constructed. The main aim of present research is improvement of the Rigid Earth Rotation Series RERS2012 by using the JPL DE422/LE422 (Folkner, 2011) ephemeris, and as a result of the construction of the new high-precision Rigid Earth Rotation Series dynamically adequate to the JPL DE422/LE422 ephemeris over 2000 and 6000 years. The discrepancies between the high-precision numerical solutions and the semi-analytical solutions of the rigid Earth rotation problem with respect to the fixed ecliptic of epoch J2000 are investigated by the least-squares method and by the spectral analysis methods. The problem is solved only for the relativistic (Kinematical) case in which the geodetic perturbations (the most essential relativistic perturbations) in the Earth rotation are taken into account.

  13. Remote Measurement of Breathing Rate in Real Time Using a High Precision, Single-Point Infrared Temperature Sensor

    E-print Network

    O'Kane, Jason

    a high precision, single-point infrared sensor. Remote breathing detec- tion is especially useful-nasal region of the face, continuously targeting and sampling the infrared sensor. The breathing rateRemote Measurement of Breathing Rate in Real Time Using a High Precision, Single-Point Infrared

  14. Precision and broadband frequency swept laser source based on high-order modulation-sideband injection-locking.

    PubMed

    Wei, Fang; Lu, Bin; Wang, Jian; Xu, Dan; Pan, Zhengqing; Chen, Dijun; Cai, Haiwen; Qu, Ronghui

    2015-02-23

    A precision and broadband laser frequency swept technique is experimentally demonstrated. Using synchronous current compensation, a slave diode laser is dynamically injection-locked to a specific high-order modulation-sideband of a narrow-linewidth master laser modulated by an electro-optic modulator (EOM), whose driven radio frequency (RF) signal can be agilely, precisely controlled by a frequency synthesizer, and the high-order modulation-sideband enables multiplied sweep range and tuning rate. By using 5th order sideband injection-locking, the original tuning range of 3 GHz and tuning rate of 0.5 THz/s is multiplied by 5 times to 15 GHz and 2.5 THz/s respectively. The slave laser has a 3 dB-linewidth of 2.5 kHz which is the same to the master laser. The settling time response of a 10 MHz frequency switching is 2.5 µs. By using higher-order modulation-sideband and optimized experiment parameters, an extended sweep range and rate could be expected. PMID:25836532

  15. A Flexile and High Precision Calibration Method for Binocular Structured Light Scanning System

    PubMed Central

    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

  16. 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.

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

    SciTech Connect

    Noertershaeuser, Wilfried [Technische Universitaet Darmstadt (Germany); Johannes Gutenberg-Universitaet Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

    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. Studies Of Submicron 3He Slabs Using A High Precision Torsional Oscillator

    SciTech Connect

    Corcoles, Antonio; Casey, Andrew; Cowan, Brian; Saunders, John [Department of Physics, Royal Holloway University of London, Egham, Surrey, TW20 0EX (United Kingdom); Parpia, Jeevak [LASSP, Department of Physics, Clark Hall, Cornell University, Ithaca, NY 14853 (United States); Bowley, Roger [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

    2006-09-07

    A high precision torsional oscillator has been used to study 3He films of thickness in the range 100 to 350 nm. In previous work we found that the films decoupled from the oscillator motion below 60 mK, in the Knudsen limit. This precluded observation of the superfluid transition. Here we report measurements using a torsional oscillator whose highly polished inner surfaces have been decorated with a low density of silver particles to act as random elastic scattering centres. This modification locks the normal film to the surface. A superfluid transition of the film is observed.

  19. High-Precision Double-Spike Sr Isotope Measurements: Applications to Geochemistry and Cosmochemistry

    NASA Astrophysics Data System (ADS)

    Parkinson, I. J.; Burton, K. W.; Mokadem, F.; Charlier, B. L.

    2007-12-01

    Strontium isotope systematics consist of the stable 88Sr/86Sr ratio, the radiogenic 87Sr/86Sr ratio and the 84Sr/86Sr ratio which is stable in terrestrial materials and may vary due to nuclear- synthetic processes in some meteorites [1]. Growing interest in natural mass dependent 88Sr/86Sr variations indicate that terrestrial samples vary by ~500 ppm and have been measured to a precision of 50-70 ppm by MC-ICP-MS [2, 3]. However, the precision is large relative to the likely variation in many terrestrial systems. Furthermore, 84Sr/86Sr ratios are poorly determined due to spectral interferences and therefore MC-ICP-MS techniques are not appropriate for high-precision analyses of all the Sr isotope ratios. Recent advances in TIMS allow 87Sr/86Sr and 84Sr/86Sr ratios to be measured to an external precision of ~5 and 60 ppm respectively with instrumental fractionation being corrected by internal normalisation to a constant 88Sr/86Sr ratio. Following on from the pioneering work of [4] we use an 84Sr- 87Sr double-spike coupled with TIMS analyses. Optimal spiking, extended ion collection times and a 25-fold improvement in the determination of the spike composition compared to [4] allow us to measure 87Sr/86Sr and 88Sr/86Sr ratios to better than 10 ppm external precision. The double-spike determination consists of an un-spiked and spiked measurement, with spiking prior to chemical separation because column separation produces a consistent and resolvable light fractionation effect of 21 to 93 ppm. The un-spiked run allows us to assess any non-mass dependent fractionation effects. Double-spike deconvolution is performed in 87Sr denominator space. Our preliminary high-precision data allows us to resolve small (25 ppm) mass-dependent shifts in seawater 88Sr/86Sr, which may reflect short-timescale Sr fluxes in the oceans. References [1] D.A. Papanastassiou, G.J. Wasserburg, Geophys. Res. Lett. 5 (1978) 361-376. [2] J. Fietzke, A. Eisenhauer, Geochem. Geophys. Geosyst., 7, (2006) Q08009, doi:10.1029/2006GC001243. [3] G.M. Nowell, et al., Geochim. Cosmochim. Acta. 71 (2007) A725. [4] P.J. Patchett, Nature, 283 (1980b) 438-441.

  20. 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 [Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); McCall, Benjamin J., E-mail: bjmccall@illinois.edu [Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); Departments of Astronomy and Physics, University of Illinois, Urbana, Illinois 61801 (United States)

    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.

  1. Communication: High precision sub-Doppler infrared spectroscopy of the HeH? ion.

    PubMed

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

    2014-09-14

    The hydrohelium cation, HeH(+), 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. PMID:25217893

  2. Interacting sources for high-precision atom interferometry - a theoretical study

    NASA Astrophysics Data System (ADS)

    Posso Trujillo, Katerine; Ahlers, Holger; Schubert, Christian; Ertmer, Wolfgang; Rasel, Ernst; Gaaloul, Naceur

    2014-05-01

    We theoretically study the possibilities to use binary quantum mixtures as sources for high-precision atom interferometers with interferometry times ranging over several seconds. Such schemes are of timely interest in the context of inertial navigation or fundamental physics laws tests. The mixture expansion dynamics are solved by integrating a set of two coupled Gross-Pitaevskii equations. In order to satisfy the severe requirements of a precise differential interferometer, a common delta-kick cooling stage is applied to the two ensembles simultaneously to induce ultra-slow expansion (~ 50 pk regime). Other systematic effects are analysed and mitigation strategies identified. To illustrate this study, we consider the case of three mixtures of 87Rb/85Rb, 87Rb/39Kand87Rb/41K widely used in atom interferometry measurements. The advantages and drawbacks of every pair are highlighted and discussed. K. Posso-Trujillo. thanks the German Academic Exchange Service - DAAD (research grant No. A/10/74250).

  3. 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 ?m 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.

  4. High efficiency positron accumulation for high-precision magnetic moment experiments.

    PubMed

    Fogwell Hoogerheide, S; Dorr, J C; Novitski, E; Gabrielse, G

    2015-05-01

    Positrons are accumulated within a Penning trap designed to make more precise measurements of the positron and electron magnetic moments. The retractable radioactive source used is weak enough to require no license for handling radioactive material, and the radiation dosage 1 m from the source gives an exposure several times smaller than the average radiation dose on the earth's surface. The 100 mK trap is mechanically aligned with the 4.2 K superconducting solenoid that produces a 6 T magnetic trapping field with a direct mechanical coupling. PMID:26026516

  5. 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

  6. 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. [Max-Planck-Institute for Nuclear Physics, D-69117 Heidelberg (Germany)

    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.

  7. An efficient, compact, and versatile fiber double scrambler for high precision radial velocity instruments

    E-print Network

    Halverson, Samuel; Mahadevan, Suvrath; Ramsey, Lawrence; Levi, Eric; Schwab, Christian; Hearty, Fred; MacDonald, Nick

    2015-01-01

    We present the design and test results of a compact optical fiber double-scrambler for high-resolution Doppler radial velocity instruments. This device consists of a single optic: a high-index $n$$\\sim$2 ball lens that exchanges the near and far fields between two fibers. When used in conjunction with octagonal fibers, this device yields very high scrambling gains and greatly desensitizes the fiber output from any input illumination variations, thereby stabilizing the instrument profile of the spectrograph and improving the Doppler measurement precision. The system is also highly insensitive to input pupil variations, isolating the spectrograph from telescope illumination variations and seeing changes. By selecting the appropriate glass and lens diameter the highest efficiency is achieved when the fibers are practically in contact with the lens surface, greatly simplifying the alignment process when compared to classical double-scrambler systems. This prototype double-scrambler has demonstrated significant pe...

  8. Optical vortex beam based optical fan for high-precision optical measurements and optical switching.

    PubMed

    Zhou, Zhi-Yuan; Li, Yan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen

    2014-09-01

    The polarization and orbital angular momentum properties of light are of great importance in optical science and technology in the fields of high-precision optical measurements and high-capacity and high-speed optical communications. Here we show a method for the construction of a simple and robust scheme to rotate a light beam such as a fan, which is based on a combination of these two properties and using the thermal-dispersion and electro-optical effect of birefringent crystals. Using a computer-based digital image-processing technique, we determine the temperature and thermal-dispersion difference of the crystal with high resolution. We also use the rotation phenomenon to realize thermo-optic and electro-optic switches. The basic operating principles for measurement and switching processes are presented in detail. The methods developed here will have wide practical applicability in various fields, including remote sensing, materials science, and optical communication networks. PMID:25166083

  9. Precision tracking at high background rates with the ATLAS muon spectrometer

    E-print Network

    Hertenberger, Ralf; The ATLAS collaboration

    2012-01-01

    Since start of data taking the ATLAS muon spectrometer performs according to specification. End of this decade after the luminosity upgrade of LHC by a factor of ten the proportionally increasing background rates require the replacement of the detectors in the most forward part of the muon spectrometer to ensure high quality muon triggering and tracking at background hit rates of up to 15,kHz/cm$^2$. Square meter sized micromegas detectors together with improved thin gap trigger detectors are suggested as replacement. Micromegas detectors are intrinsically high rate capable. A single hit spatial resolution below 40,$mu$m has been shown for 250,$mu$m anode strip pitch and perpendicular incidence of high energy muons or pions. The ongoing development of large micromegas structures and their investigation under non-perpendicular incidence or in high background environments requires precise and reliable monitoring of muon tracks. A muon telescope consisting of six small micromegas works reliably and is presently ...

  10. High-precision astrometry with VVV. I. An independent reduction pipeline for VIRCAM@VISTA

    E-print Network

    Libralato, M; Bedin, L R; Anderson, J; Piotto, G; Nascimbeni, V; Platais, I; Minniti, D; Zoccali, M

    2015-01-01

    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 V\\'ia L\\'actea (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 square degree. This geometric-distortion correction is made available to the community. As a test bed, we chose a field centered 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 and to isolate each population observed in the field (cluster, Bulge and Disk) using proper motions. We used proper-motion-selected field stars to measure the motion difference between Galactic disk and...

  11. 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.

  12. High precision regions of phase sensitivity for the superposition of coherent fields

    NASA Astrophysics Data System (ADS)

    Berrada, K.

    2014-09-01

    We investigate the problem of parameter estimation for the superposition of coherent fields under perfect and lossy regimes. We show the optimal range for higher precision of phase estimation by exactly solving a model consisting of a Schrödinger-cat state (SCS) subject to zero-temperature under a decoherence effect due to a dissipative interaction with an environment. We find the phenomenon that the quantum Fisher information (QFI), namely, the precision of estimation, is slowly reduced with the environment effect and affected by the photon number effects. We find that revivals and retardation of the QFI loss may occur by adjusting the mean photon number, and increasing the photons strongly enhances the coherence and hence augments the resolution of the parameter estimation. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement between the coherent field and its environment is investigated during the dissipation. We show that partial entanglement trapping occurs during the dynamics depending on the mean photon number. These features make the SCS with a larger average number of photons a good candidate for implementation of schemes of quantum optics and information with high precision.

  13. High-Precision Marine Sr Isotope Geochronology in Deep Time: Permian Tuffs and Conodonts

    NASA Astrophysics Data System (ADS)

    Schmitz, M. D.; Davydov, V. I.; Snyder, W. S.

    2007-12-01

    Stratigraphic sections of the Southern Urals containing abundant and well-preserved fauna for precise biostratigraphic correlation and common instratified volcanic ash beds dated by U-Pb zircon geochronology offer a unique opportunity to constrain a temporally accurate Late Pennsylvanian-Early Permian seawater Sr curve. The 87Sr/86Sr compositions of conodonts (biogenic apatite) were measured by high-precision thermal ionization mass spectrometry following rigorous pretreatment protocols, and plotted within an age model calibrated by 13 high-precision U-Pb zircon ash bed ages. The resulting seawater Sr curve shows a significant reduction in data scatter by comparison to earlier curves (Denison et al., 1994; Veizer et al., 1999; Bruckschen et al., 1999; Korte et al., 2006), suggesting that our conodont pre-dissolution treatment was highly effective for retrieving the original seawater Sr signal. The relatively flat Late Moscovian through mid-Ghzelian seawater Sr curve of this study is generally consistent with that of Bruckschen et al. (1999). Beginning in the mid-Ghzelian, our data define a decreasing trend in 87Sr/86Sr through the mid-Sakmarian, consistent with the data of Korte et al. (2006). By combining our high precision 87Sr/86Sr measurements and U-Pb age calibration, the resolution of Sr isotope geochronology approaches 0.5 Ma in this interval. This highly resolved seawater 87Sr/86Sr record obtained for the Late Moscovian through mid-Sakmarian will aid in global carbonate chemostratigraphic correlation and contribute to our understanding of the timing of Late Paleozoic glacial and tectonic events. References: Bruckschen, P., Oesmann, S., Veizer, J., 1999. Isotope stratigraphy of the European Carboniferous: proxy signals for ocean chemistry, climate and tectonics. Chemical Geology 161, p. 127-163. Denison, R.E., Koepnick, R.B., Burke, W.H., Hetherington, E.A., Fletcher, A., 1994. Construction of the Mississippian, Pennsylvanian and Permian seawater 87Sr/86Sr curve. Chemical Geology 112, p.145-167. Veizer, J., Ala, D., Azmy, K., Bruckschen, P., Buhl, D., Bruhn, J., Carden, G.A.F., Diener, A., Ebneth, S., Godderis, Y., Jasper, T., Korte, C., Pawellek, F., Podlaha, O.G., Strauss, H., 1999. 87Sr/86Sr, ´13C and ?18O evolution of Phanerozoic seawater. Chemical Geology 161, p. 59-88. Korte, C., Jasper, T., Kozur, H.W., Veizer, J., 2006. 87Sr/86Sr record of Permian seawater. Palaeogeography, Pala3eoclimatology, Palaeoecology 240, p. 89-107.

  14. Fractional high-harmonic combs by attosecond-precision split-spectrum pulse control

    NASA Astrophysics Data System (ADS)

    Raith, Philipp; Ott, Christian; Anderson, Christopher P.; Kaldun, Andreas; Meyer, Kristina; Laux, Martin; Zhang, Yizhu; Pfeifer, Thomas

    2013-03-01

    Few-cycle laser fields enable pulse-shaping control of high-order harmonic generation by time delaying variable broadband spectral sections. We report the experimental generation of fractional (noninteger) high-harmonic combs by the controlled interference of two attosecond pulse trains. Additionally the energy of the high harmonics is strongly tuned with the relative time delay. We quantify the tuning to directly result from the controlled variation of the instantaneous laser frequency at the shaped driver pulse intensity maximum.

  15. 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

  16. High-precision determination of iron oxidation state in silicate glasses using XANES

    SciTech Connect

    Cottrell, Elizabeth; Kelley, Katherine A.; Lanzirotti, Antonio; Fischer, Rebecca A.; (Rhode Island); (UC); (Smithsonian)

    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.

  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 ?l) 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. Adaptive Robust Precision Motion Control of High-Speed Linear Motors with On-line Cogging Force Compensations

    E-print Network

    Yao, Bin

    Adaptive Robust Precision Motion Control of High-Speed Linear Motors with On-line Cogging Force nonlinear cogging forces. For these types of linear motor, to have a smooth motion, it is necessary Compensations Bin Yao, Chuxiong Hu and Qingfeng Wang Abstract-- This paper studies the precision motion control

  19. Allowance for the influence of geopotential in the high-precision numerical integration of artificial-earth-satellite orbits

    Microsoft Academic Search

    Iu. D. Stepin

    1982-01-01

    The paper considers the influence of discarded terms of the geopotential expansion on the error in the prediction of satellite orbit position in the case of high-precision numerical integration in rectangular coordinates. Upper summation bounds are presented, which assure the achievement of prescribed prediction precision for various orbits and time intervals.

  20. High-precision gas gain and energy transfer measurements in Ar-CO2 mixtures

    NASA Astrophysics Data System (ADS)

    ?ahin, Özkan; Kowalski, Tadeusz Z.; Veenhof, Rob

    2014-12-01

    Ar-CO2 is a Penning mixture since a fraction of the energy stored in Ar 3p5 3 d and higher excited states can be transferred to ionize CO2 molecules. In the present work, concentration and pressure dependence of Penning transfer rate and photon feedback parameter in Ar-CO2 mixtures have been investigated with recent systematic high-precision gas gain measurements which cover the range 1-50% CO2 at 400, 800, 1200, 1800 hPa and gas gain from 1 to 5×105.

  1. High-precision photometry by telescope defocussing. III. The transiting planetary system WASP2

    Microsoft Academic Search

    John Southworth; L. Mancini; S. Calchi Novati; M. Dominik; M. Glitrup; T. C. Hinse; U. G. Jorgensen; M. Mathiasen; D. Ricci; G. Maier; F. Zimmer; V. Bozza; P. Browne; I. Bruni; M. Burgdorf; M Dall'Ora; F. Finet; K. Harpsoe; M. Hundertmark; C. Liebig; S. Rahvar; G. Scarpetta; J. Skottfelt; B. Smalley; C. Snodgrass; J. Surdej

    2010-01-01

    We present high-precision photometry of three transits of the extrasolar\\u000aplanetary system WASP-2, obtained by defocussing the telescope, and achieving\\u000apoint-to-point scatters of between 0.42 and 0.73 mmag. These data are modelled\\u000ausing the JKTEBOP code, and taking into account the light from the\\u000arecently-discovered faint star close to the system. The physical properties of\\u000athe WASP-2 system are derived

  2. 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

    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.

  3. High precision pointing system based on Risley prism: analysis and simulation

    NASA Astrophysics Data System (ADS)

    Li, Jin-ying; Peng, Qi; Chen, Ke; Fu, Cheng-yu

    2015-02-01

    This paper presents the key issues for high precision pointing system using Risley prism. An iterative optimization algorithm is proposed to solve the inverse problem of Risley Prism and anti-achromatic Risley Prism. Different error sources, particularly Risley prism's rotation errors and rotation axis jitters are considered. Error propagation formula between pointing accuracy and rotation position is deduced. Finally, a beam steering simulation system including target position creating module, Risley Prism inverse solution module, Risley Prism rotation control module and beam pointing module is established. The simulation results show that it can achieve better than 1 arcsec pointing accuracy.

  4. 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.

  5. MCAO: Wavefront sensing only as a tool for high precision photometry?

    NASA Astrophysics Data System (ADS)

    Viotto, V.; Ragazzoni, R.; Bergomi, M.; Brunelli, A.; Dima, M.; Farinato, J.; Magrin, D.; Marafatto, L.; Nascimbeni, V.; Piotto, G.

    2012-07-01

    In MCAO the correction of the wavefront for an extended Field of View is obtained at the expense of a stretching of the actual instantaneous meta-pupils over the high altitude layers, just to compensate their average curvature. While this effect does average out in long term exposures and is of secondary interest in compensated imaging, it gives the input for the idea of using MCAO-like information, collectable over a certain Field of View, to assess in a time resolved mode (not necessarily in real time) the actual geometrical light throughput in a given direction. In principle this would allow, with proper time tagging, to achieve high precision photometry, as part of the scintillation could be measured on line during the observation. Simple averaging of neighbor stars to flat field starlight, for example, represents the equivalent of this concept for the ground-layer correction only. It can be seen that, once a direction is defined, it is relevant only the derivative of the wavefront around or in the proximity of that edges, but the range at which this happen is a crucial parameter. However, the strong interest in high precision measurements of exoplanetary transits or asteroseismology could make this approach not as lunatic as it could sound. view

  6. [High-precision 3D morphology measurement by digital gatling method based on structured light].

    PubMed

    Luo, Gang-Yin; Tang, Yu-Guo; Qiao, Pei-Yu; Wang, Bi-Dou; Jia, Zan-Dong; Xu, Zhong

    2012-09-01

    In order to measure the microscopic 3D morphology of the objects with high-precision, a 3D texture measurement system of digital gatling based on structured light was designed, which can calculate the 3D height information with the analytic phase method. First, the authors collected sixteen equal step phase images by the four-step equal step method, and calculated their main value by dividing them into four groups. Then, the authors found the average as the final phase main value. The pretreatment on the fringe was done by the adaptive Wiener filter and wavelet multi-threshold method to eliminate the various effects of noise, projector distortion and CCD camera distortion. Besides, gradient-oriented phase unwrapping algorithm based on multifrequency was introduced to avoid phase discontinuity point in the course phase unwrapping, and it was proven to be effective and stable. Experiments showed that the system's 3D resolution was 2.75 microm, and the high degree accuracy was better than 0.5 microm, when the system was running with the fringe parameter p0 = 22.7 mm(-1). In addition, the system has many advantages such as fast measuring, simple operation and non-contact, which can meet the need of the high precision measurement requirements for the microscopic 3D morphology. PMID:23240390

  7. 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 ?m 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.

  8. 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.

  9. 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 measuring, by analogue FOS, has been ˜ 10-4 %. Substantially accessible values are yet worse on 2-3 order. The reason of poor precise performances of measurers on the basis of analogue FOS is metrologically poor quality of a stream of optical radiation carrying out role of the carrier and receptor of the information. It is a high level of photon noise and a small blanket intensity level. First reason reflects the fact of discreteness of flow of high-energy photons, and it is consequence of second one - smallness, on absolute value, of inserted power into OF from available radiation sources (RS). Works on improvement of FO elements are carrying out. Certainly, it will be created RS allow to insert enough of power into standard OF. But simple increasing of optical flow power in measuring path of FOS will not be able to decide radically the problem of increasing of measuring prices: with raising of power in proportion of square root of its value there is raising a power of photon noises - 1000-times increase of power promises only 30-times increase of measuring precise; insertion into OF more large power (˜ 1 W for standard silicon OF) causes an appearance of non-linear effects in it, which destroying an operating principle of analogue FOS. Thus, it is needed to constatate impossibility of building, at that time, measurers of analogue FOS, concurated with traditional (electrical) measurers on measuring precise. At that all, advantages of FO, as basis of building of FO MD requires to find ways for decision of these problems. Analysis of problem of sensitivity of usual (analogue) FOS has brought us to conclusion about necessity of reviewing of principles of information signal forming in FOS and principles its next electronic processing. For radical increasing of accuracy of measurements with using FOS it is necessary to refuse analogue modulation of optical flow and to transfer to discreet its modulations, entering thus in optical flow new, non-optical, parameters, which will serve as recipients of the information. It allows to save up all advantages of FOS (carrier of in

  10. 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

  11. 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 ?m 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 ?m, 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.

  12. Modern experimental techniques for high speed flow measurements

    Microsoft Academic Search

    Dariush Modarress; M. Azzazy

    1988-01-01

    This review paper examines the applicability of experimental techniques to high speed flows. Existing flow facilities are reviewed and measurement requirements are evaluated. Experimental techniques that are reviewed include: laser Doppler velocimetry, laser induced fluorescence, and coherent Raman spectroscopy for measurement of gas velocity in high speed flow facilities. Also reviewed are application of laser holography and tomography to high

  13. Rers2014 and Mrs2014: New High-Precision Rigid Earth Rotation and Moon Rotation Series

    NASA Astrophysics Data System (ADS)

    Pashkevich, V. V.

    2015-03-01

    Numerical investigation of the Earth and Moon rotational motion dynamics is carried out at a long time intervals. In our previous studies (Pashkevich, 2013), (Pashkevich and Eroshkin, 2011) the high-precision Rigid Earth Rotation Series (designated RERS2013) and Moon Rotation Series (designated MRS2011) were constructed. RERS2013 are dynamically adequate to the JPL DE422/LE422 (Folkner, 2011) ephemeris over 2000 and 6000 years and include about 4113 periodical terms (without attempt to estimate new subdiurnal and diurnal periodical terms). MRS2011 are dynamically adequate to the JPL DE406/LE406 (Standish, 1998) ephemeris over 418, 2000 and 6000 years and include about 1520 periodical terms. In present research have been improved the Rigid Earth Rotation Series RERS2013 and Moon Rotation Series MRS2011, and as a result have been constructed the new high-precision Rigid Earth Rotation Series RERS2014 and Moon Rotation Series MRS2014 dynamically adequate to the JPL DE422/LE422 ephemeris over 2000 and 6000 years, respectively. The elaboration of RERS2013 is carried out by means recalculation of sub-diurnal and diurnal periodical terms. The residuals in Euler angles between the numerical solution and RERS2014 do not surpass 3 ìas over 2000 years. Improve the accuracy of the series MRS2011 is obtained by using the JPL DE422/LE422 ephemeris. The residuals in the perturbing terms of the physical librations between the numerical solution and MRS2014 do not surpass 8 arc seconds over 6000 years

  14. HIGH-PRECISION ASTROMETRIC MILLIMETER VERY LONG BASELINE INTERFEROMETRY USING A NEW METHOD FOR ATMOSPHERIC CALIBRATION

    SciTech Connect

    Rioja, M.; Dodson, R., E-mail: maria.rioja@icrar.org [ICRAR, UWA, Perth (Australia)

    2011-04-15

    We describe a new method which achieves high-precision very long baseline interferometry (VLBI) astrometry in observations at millimeter (mm) wavelengths. It combines fast frequency-switching observations, to correct for the dominant non-dispersive tropospheric fluctuations, with slow source-switching observations, for the remaining ionospheric dispersive terms. We call this method source-frequency phase referencing. Provided that the switching cycles match the properties of the propagation media, one can recover the source astrometry. We present an analytic description of the two-step calibration strategy, along with an error analysis to characterize its performance. Also, we provide observational demonstrations of a successful application with observations using the Very Long Baseline Array at 86 GHz of the pairs of sources 3C274 and 3C273 and 1308+326 and 1308+328 under various conditions. We conclude that this method is widely applicable to mm-VLBI observations of many target sources, and unique in providing bona fide astrometrically registered images and high-precision relative astrometric measurements in mm-VLBI using existing and newly built instruments, including space VLBI.

  15. 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

  16. 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

  17. Precision tracking at high background rates with the ATLAS muon spectrometer

    E-print Network

    Hertenberger, R; The ATLAS collaboration

    2012-01-01

    Precision tracking at high background rates with the ATLAS muon spectrometer The ATLAS muon spectrometer performs to the specs of efficiency, occupancy and spatial resolution at present LHC peak-luminosities of $4 \\times 10^{33}$ $\\frac{1}{cm^2~s}$. Ten times higher peak-luminosities are envisaged after the LHC upgrade by end of this decade. Currently used tracking detectors in the most forward part of the muon spectrometer need to be replaced to cope with the expected huge background hit rates of up to 15~kHz/cm$^2$ to ensure muon trigger and precision reconstruction capabilities. Square meter sized micromegas or 15~mm diameter drift-tube detectors together with thin gap trigger detectors are under study as replacement. When exposed at our irradiation facility at the Garching Tandem accelerator laboratory, the track reconstruction efficiency and spatial resolution of 15~mm drift-tube detectors is robust against up to 20~kHz/cm$^2$ highly ionizing background hits. No signs of ageing were observed after accumu...

  18. High precision geometric correction based on DEM data and GCP outlier detection for MODIS data

    NASA Astrophysics Data System (ADS)

    Guo, Shan; Sun, Weidong

    2005-11-01

    Terrain Height Error is one of the most important factors which influences the accuracy of direct system correction and has an obvious effect along the scanning direction. In this paper, taking Moderate-resolution Imaging Spectroradiometer (MODIS) data received from Earth Observing System (EOS) satellites as an example, and focusing on the high precision geolocation techniques of the moderate resolution optical satellite data, a high precision algorithm based on Digital Elevation Model (DEM) data and Ground Control Point (GCP) outlier detection is proposed to correct this kind of influences of Terrain Height Error. For more efficient and intelligent processing in practical applications, a group of GCPs should be used in the further geometric correction. But the correction result using GCPs is not so stabile, because it is often influenced by the data conditions. In this paper, a new idea based on local distortion similarity is proposed for the GCP outlier detection too. In this method, the distortion is described by a 2-D Gaussian distribution in the local area, and a decision rule is made to find out the abnormal GCPs according to the variance of the Gaussian distribution. Some experiment results using MODIS data show that the proposed algorithm based on DEM data and GCP outlier detection is feasible and valid. The final average location error of the new algorithm is about 0.13 pixels which is sufficient for many application requirements.

  19. 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.

  20. High-precision time-resolved cyclotron resonance measurements at microwave frequencies

    NASA Astrophysics Data System (ADS)

    Porţeanu, H. E.

    2005-03-01

    This work is a theoretical and experimental study of the time-resolved microwave spectroscopy, close to the limit ???? ˜1, especially applied for the case of cyclotron resonance. A dynamic perturbation theory of a resonator is presented. While the amplitude of a transmitted signal in a standard measuring setup can be determined quickly and accurately, the phase relation requires much longer time for the same accuracy. The use of a resonant system enhances the sensitivity for determination of amplitude and phase, but reduces the time resolution, both by a factor Q. The nonlinear regime for conductivity in cyclotron resonance conditions is compensated by the use of constant energy density in the resonator, independent of frequency. Examples for classical semiconductors are presented. Compared with terahertz time-resolved spectroscopy, this method offers precise information in a different time scale and essentially in a different experimental regime of conductivity: pulsed, E ˜1kV/cm in the first case; cw, E ˜1V/cm in ours.

  1. Development of a high-precision ADS-B based conflict alerting system for operations in the airport environment

    E-print Network

    Kunzi, Fabrice

    2014-01-01

    The introduction of Automatic Dependent Surveillance - Broadcast (ADS-B) as the future source of aircraft surveillance worldwide provides an opportunity to introduce high-precision airborne conflict alerting systems for ...

  2. High-precision test of collective versus single-particle motion of protons and neutrons in the

    E-print Network

    sources: DOE Office of Science, Office of Nuclear Physics Resources: Holifield Radioactive Beam Facility for the nuclear shell model (basic microscopic model of all nuclear theory). · These high-precision results

  3. 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.

  4. High precision mapping of kidney stones using ?-IR spectroscopy to determine urinary lithogenesis.

    PubMed

    Blanco, Francisco; Ortiz-Alías, Pilar; López-Mesas, Montserrat; Valiente, Manuel

    2015-06-01

    Evolution of urinary lithiasis is determined by the metabolism and life-style of the related patient. The appropriate classification of the stone is mandatory for the identification of the lithogenic process. In this study, cros-sections from a single stone of each of the most frequent urolithiasis types (calcium oxalate mono and dihydrate and carbonate apatite) have been selected and imaged using IR microspectroscopy. Moreover, the use of high definition sFTIR (synchrotron source) has revealed hidden information to the conventional FTIR. This work has demonstrated that minor components become key factors on the description of the stages of stone formation. Intensity map for COM (1630 cm(-1) peak). The high spatial definition achieved is key for the precise description of the kidney stone history. PMID:25091212

  5. High-precision photometry by telescope defocussing. VI. WASP-24, WASP-25 and WASP-26

    E-print Network

    Southworth, John; Burgdorf, M; Novati, S Calchi; Dominik, M; Galianni, P; Gerner, T; Giannini, E; Gu, S -H; Hundertmark, M; Jorgensen, U G; Juncher, D; Kerins, E; Mancini, L; Rabus, M; Ricci, D; Schaefer, 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; Jaimes, R Figuera; Hardis, S; Harpsoe, K; Jessen-Hansen, J; Kains, N; Kjeldsen, H; Korhonen, H; Liebig, C; Lund, M N; Lundkvist, M; Mathiasen, M; Penny, M T; Popovas, A; Proft, S; Rahvar, S; Sahu, K; Scarpetta, G; Schmidt, R W; Schoenebeck, F; Snodgrass, C; Street, R A; Surdej, J; Tsapras, Y; Vilela, C

    2014-01-01

    We present time-series photometric observations of thirteen 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 to 1.2 mmag relative to their best-fitting geometric models. We used 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.

  6. High Precision Tune and Coupling Feedback and Beam Transfer Function Measurements 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.; Schultheiss, C.; Wilinski, M.

    2010-05-23

    Precision measurement and control of the betatron tunes and betatron coupling in the Relativistic Heavy Ion Collider (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. High-precision GPS autonomous platforms for sea ice dynamics and physical oceanography

    NASA Astrophysics Data System (ADS)

    Elosegui, P.; Wilkinson, J.; Olsson, M.; Rodwell, S.; James, A.; Hagan, B.; Hwang, B.; Forsberg, R.; Gerdes, R.; Johannessen, J.; Wadhams, P.; Nettles, M.; Padman, L.

    2012-12-01

    Project "Arctic Ocean sea ice and ocean circulation using satellite methods" (SATICE), is the first high-rate, high-precision, continuous GPS positioning experiment on sea ice in the Arctic Ocean. The SATICE systems collect continuous, dual-frequency carrier-phase GPS data while drifting on sea ice. Additional geophysical measurements also collected include ocean water pressure, ocean surface salinity, atmospheric pressure, snow-depth, air-ice-ocean temperature profiles, photographic imagery, and others, enabling sea ice drift, freeboard, weather, ice mass balance, and sea-level height determination. Relatively large volumes of data from each buoy are streamed over a satellite link to a central computer on the Internet in near real time, where they are processed to estimate the time-varying buoy positions. SATICE system obtains continuous GPS data at sub-minute intervals with a positioning precision of a few centimetres in all three dimensions. Although monitoring of sea ice motions goes back to the early days of satellite observations, these autonomous platforms bring out a level of spatio-temporal detail that has never been seen before, especially in the vertical axis. These high-resolution data allows us to address new polar science questions and challenge our present understanding of both sea ice dynamics and Arctic oceanography. We will describe the technology behind this new autonomous platform, which could also be adapted to other applications that require high resolution positioning information with sustained operations and observations in the polar marine environment, and present results pertaining to sea ice dynamics and physical oceanography.

  8. High-Precision Simulation of the Gravity Field of Rapidly-Rotating Barotropes in Hydrostatic Equilibrium

    NASA Astrophysics Data System (ADS)

    Hubbard, W. B.

    2013-12-01

    The so-called theory of figures (TOF) uses potential theory to solve for the structure of highly distorted rotating liquid planets in hydrostatic equilibrium. TOF is noteworthy both for its antiquity (Maclaurin 1742) and its mathematical complexity. Planned high-precision gravity measurements near the surfaces of Jupiter and Saturn (possibly detecting signals ~ microgal) will place unprecedented requirements on TOF, not because one expects hydrostatic equilibrium to that level, but because nonhydrostatic components in the surface gravity, at expected levels ~ 1 milligal, must be referenced to precise hydrostatic-equilibrium models. The Maclaurin spheroid is both a useful test of numerical TOF codes (Hubbard 2012, ApJ Lett 756:L15), and an approach to an efficient TOF code for arbitrary barotropes of variable density (Hubbard 2013, ApJ 768:43). For the latter, one trades off vertical resolution by replacing a continuous barotropic pressure-density relation with a stairstep relation, corresponding to N concentric Maclaurin spheroids (CMS), each of constant density. The benefit of this trade-off is that two-dimensional integrals over the mass distributions at each interface are reduced to one-dimensional integrals, quickly and accurately evaluated by Gaussian quadrature. The shapes of the spheroids comprise N level surfaces within the planet and at its surface, are gravitationally coupled to each other, and are found by self-consistent iteration, relaxing to a final configuration to within the computer's precision limits. The angular and radial variation of external gravity (using the usual geophysical expansion in multipole moments) can be found to the limit of typical floating point precision (~ 1.e-14), much better than the expected noise/signal for either the Juno or Cassini gravity experiments. The stairstep barotrope can be adjusted to fit a prescribed continuous or discontinuous interior barotrope, and can be made to approximate it to any required precision by increasing N. One can insert a higher density of CMSs toward the surface of an interior model in order to more accurately model high-order gravitational moments. The magnitude of high-order moments predicted by TOF declines geometrically with order number, and falls below the magnitude of expected non-hydrostatic terms produced by interior dynamics at ~ order 10 and above. Juno's sensitivity is enough to detect tidal gravity signals from Galilean satellites. The CMS method can be generalized to predict tidal zonal and tesseral terms consistent with an interior model fitted to measured zonal harmonics. For this purpose, two-dimensional Gaussian quadrature is necessary at each CMS interface. However, once the model is relaxed to equilibrium, one need not refit the model to the average zonal harmonics because of the smallness of the tidal terms. I will describe how the CMS method has been validated through comparisons with standard TOF models for which fully or partially analytic solutions exist, as well as through consistency checks. At this stage in software development in preparation for Jupiter orbit, we are focused on increasing the speed of the code in order to more efficiently search the parameter space of acceptable Jupiter interior models, as well as to interface it with advanced hydrogen-helium equations of state.

  9. Highly precise and developmentally programmed genome assembly in Paramecium requires ligase IV-dependent end joining.

    PubMed

    Kapusta, Aurélie; Matsuda, Atsushi; Marmignon, Antoine; Ku, Michael; Silve, Aude; Meyer, Eric; Forney, James D; Malinsky, Sophie; Bétermier, Mireille

    2011-04-01

    During the sexual cycle of the ciliate Paramecium, assembly of the somatic genome includes the precise excision of tens of thousands of short, non-coding germline sequences (Internal Eliminated Sequences or IESs), each one flanked by two TA dinucleotides. It has been reported previously that these genome rearrangements are initiated by the introduction of developmentally programmed DNA double-strand breaks (DSBs), which depend on the domesticated transposase PiggyMac. These DSBs all exhibit a characteristic geometry, with 4-base 5' overhangs centered on the conserved TA, and may readily align and undergo ligation with minimal processing. However, the molecular steps and actors involved in the final and precise assembly of somatic genes have remained unknown. We demonstrate here that Ligase IV and Xrcc4p, core components of the non-homologous end-joining pathway (NHEJ), are required both for the repair of IES excision sites and for the circularization of excised IESs. The transcription of LIG4 and XRCC4 is induced early during the sexual cycle and a Lig4p-GFP fusion protein accumulates in the developing somatic nucleus by the time IES excision takes place. RNAi-mediated silencing of either gene results in the persistence of free broken DNA ends, apparently protected against extensive resection. At the nucleotide level, controlled removal of the 5'-terminal nucleotide occurs normally in LIG4-silenced cells, while nucleotide addition to the 3' ends of the breaks is blocked, together with the final joining step, indicative of a coupling between NHEJ polymerase and ligase activities. Taken together, our data indicate that IES excision is a "cut-and-close" mechanism, which involves the introduction of initiating double-strand cleavages at both ends of each IES, followed by DSB repair via highly precise end joining. This work broadens our current view on how the cellular NHEJ pathway has cooperated with domesticated transposases for the emergence of new mechanisms involved in genome dynamics. PMID:21533177

  10. Radiography of a normal fault system by 64,000 high-precision earthquake locations: The 2009 L'Aquila

    E-print Network

    Cerveny, Vlastislav

    of a normal fault system by 64,000 high-precision earthquake locations: The 2009 L'Aquila (central Italy) caseRadiography of a normal fault system by 64,000 high-precision earthquake locations: The 2009 L'Aquila (central Italy) case study L. Valoroso,1 L. Chiaraluce,1 D. Piccinini,1 R. Di Stefano,1 D. Schaff,2 and F

  11. The value of high-frequency, high-precision methane isotopologue measurements for source and sink estimation

    NASA Astrophysics Data System (ADS)

    Rigby, M.; Manning, A. J.; Prinn, R. G.

    2012-06-01

    We present an observing system simulation experiment examining the potential benefits of new methane isotopologues measurements for global- and national-scale source and sink inversions. New measurements are expected in the coming years, using quantum cascade laser spectroscopy with sample preconcentration, that will allow observations of?13C - CH4 and ?D - CH4at approximately hourly intervals and higher precision than previously possible. Using model-generated `pseudo-data', we predict the variability that these new systems should encounter in the atmosphere, and estimate the additional uncertainty reduction that should result from their use in source and sink inversions. We find that much of the?-value variability from seasonal to daily timescales should be resolvable at the target precision of the new observations. For global source estimation, we find additional uncertainty reductions of between 3-9 Tg/year for four major source categories (microbial, biomass burning, landfill and fossil fuel), compared to mole fraction-only inversions, if the higher end of the anticipated isotopologue-measurement precisions can be achieved. On national scales, we obtain average uncertainty reductions of ˜10% of the source strength for countries close to high-frequency monitoring sites, although the degree of uncertainty reduction on such small scales varies significantly (from close to 0% to almost 50%) for different sources and countries.

  12. Closed tubes preparation of graphite for high-precision AMS radiocarbon analysis

    NASA Astrophysics Data System (ADS)

    Hajdas, I.; Michczynska, D.; Bonani, G.; Maurer, M.; Wacker, L.

    2009-04-01

    Radiocarbon dating is an established tool applied in Geochronology. Technical developments of Accelerator Mass Spectrometry AMS, which allow measurements of samples containing less than 1 mg of carbon, opened opportunities for new applications. Moreover, high resolution records of the past changes require high-resolution chronologies i.e. sampling for 14C dating. In result, the field of applications is rapidly expanding and number of radiocarbon analysis is growing rapidly. Nowadays dedicated 14C AMS machines have great capacity for analysis but in order to keep up with the demand for analysis and provide the results as fast as possible a very efficient way of sample preparation is required. Sample preparation for 14C AMS analysis consists of two steps: separation of relevant carbon from the sample material (removing contamination) and preparation of graphite for AMS analysis. The last step usually involves reaction of CO2 with H2, in the presence of metal catalyst (Fe or Co) of specific mesh size heated to 550-625°C, as originally suggested by Vogel et al. (1984). Various graphitization systems have been built in order to fulfil the requirement of sample quality needed for high-precision radiocarbon data. In the early 90ties another method has been proposed (Vogel 1992) and applied by few laboratories mainly for environmental or biomedical samples. This method uses TiH2 as a source of H2 and can be easily and flexibly applied to produce graphite. Sample of CO2 is frozen in to the tube containing pre-conditioned Zn/TiH2 and Fe catalyst. Torch sealed tubes are then placed in the stepwise heated oven at 500/550°C and left to react for several hours. The greatest problem is the lack of control of the reaction completeness and considerable fractionation. However, recently reported results (Xu et al. 2007) suggest that high precision dating using graphite produced in closed tubes might be possible. We will present results of radiocarbon dating of the set of standards and secondary IAEA standards to demonstrate to what level this method can be used for high precision radiocarbon dating. References Vogel JS. 1992. Rapid Production of Graphite without Contamination for Biomedical Ams. Radiocarbon 34: 344-350. Vogel JS, Southon JR, Nelson DE, and Brown TA. 1984. Performance of Catalytically Condensed Carbon for Use in Accelerator Mass-Spectrometry. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms 233: 289-293. Xu X, Trumbore SE, Zheng S, Southon JR, McDuffee KE, Luttgen M, and Liu JC. 2007. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: Reducing background and attaining high precision. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms Accelerator Mass Spectrometry - Proceedings of the Tenth International Conference on Accelerator Mass Spectrometry 259: 320-329.

  13. High precision corrections to the neutron beta decay rate and electron asymmetry and current determination of Vud

    Microsoft Academic Search

    J. L. García-Luna; A. García

    2006-01-01

    The goal of the present analysis is to find, in the free neutron beta decay, the expressions for the decay rate and the electron asymmetry that contain all the theoretical effects at the 10-4 level. This accuracy is better than the current experimental precision that modern experiments allow. For this aim it is necessary to study the strong interaction effects,

  14. Surface-enhanced resonance Raman scattering nanostars for high-precision cancer imaging.

    PubMed

    Harmsen, Stefan; Huang, Ruimin; Wall, Matthew A; Karabeber, Hazem; Samii, Jason M; Spaliviero, Massimiliano; White, Julie R; Monette, Sébastien; O'Connor, Rachael; Pitter, Kenneth L; Sastra, Stephen A; Saborowski, Michael; Holland, Eric C; Singer, Samuel; Olive, Kenneth P; Lowe, Scott W; Blasberg, Ronald G; Kircher, Moritz F

    2015-01-21

    The inability to visualize the true extent of cancers represents a significant challenge in many areas of oncology. The margins of most cancer types are not well demarcated because the cancer diffusely infiltrates the surrounding tissues. Furthermore, cancers may be multifocal and characterized by the presence of microscopic satellite lesions. Such microscopic foci represent a major reason for persistence of cancer, local recurrences, and metastatic spread, and are usually impossible to visualize with currently available imaging technologies. An imaging method to reveal the true extent of tumors is desired clinically and surgically. We show the precise visualization of tumor margins, microscopic tumor invasion, and multifocal locoregional tumor spread using a new generation of surface-enhanced resonance Raman scattering (SERRS) nanoparticles, which are termed SERRS nanostars. The SERRS nanostars feature a star-shaped gold core, a Raman reporter resonant in the near-infrared spectrum, and a primer-free silication method. In genetically engineered mouse models of pancreatic cancer, breast cancer, prostate cancer, and sarcoma, and in one human sarcoma xenograft model, SERRS nanostars enabled accurate detection of macroscopic malignant lesions, as well as microscopic disease, without the need for a targeting moiety. Moreover, the sensitivity (1.5 fM limit of detection) of SERRS nanostars allowed imaging of premalignant lesions of pancreatic and prostatic neoplasias. High sensitivity and broad applicability, in conjunction with their inert gold-silica composition, render SERRS nanostars a promising imaging agent for more precise cancer imaging and resection. PMID:25609167

  15. High-precision tracking of brownian boomerang colloidal particles confined in quasi two dimensions.

    PubMed

    Chakrabarty, Ayan; Wang, Feng; Fan, Chun-Zhen; Sun, Kai; Wei, Qi-Huo

    2013-11-26

    In this article, we present a high-precision image-processing algorithm for tracking the translational and rotational Brownian motion of boomerang-shaped colloidal particles confined in quasi-two-dimensional geometry. By measuring mean square displacements of an immobilized particle, we demonstrate that the positional and angular precision of our imaging and image-processing system can achieve 13 nm and 0.004 rad, respectively. By analyzing computer-simulated images, we demonstrate that the positional and angular accuracies of our image-processing algorithm can achieve 32 nm and 0.006 rad. Because of zero correlations between the displacements in neighboring time intervals, trajectories of different videos of the same particle can be merged into a very long time trajectory, allowing for long-time averaging of different physical variables. We apply this image-processing algorithm to measure the diffusion coefficients of boomerang particles of three different apex angles and discuss the angle dependence of these diffusion coefficients. PMID:24171648

  16. 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. [Max-Planck-Institute for Nuclear Physics, D-69117 Heidelberg (Germany)

    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.

  17. 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

  18. 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.

  19. 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 dd? formation rates, the rate for hyperfine transitions in d? 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 ?CF theories. The energy of the loosely bound dd? state with quantum numbers J = 1, ? = 1, which is central to the mechanism of resonant molecule formation, is extracted with precision ?11(fit) = -1.9651(7) eV. in impressive agreement with the latest theoretical results ?11(theory) = -1.9646 eV.

  20. Portable, high intensity isotopic neutron source provides increased experimental accuracy

    NASA Technical Reports Server (NTRS)

    Mohr, W. C.; Stewart, D. C.; Wahlgren, M. A.

    1968-01-01

    Small portable, high intensity isotopic neutron source combines twelve curium-americium beryllium sources. This high intensity of neutrons, with a flux which slowly decreases at a known rate, provides for increased experimental accuracy.

  1. 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.

  2. Oscillations of high energy neutrinos in matter: Precise formalism and parametric resonance

    E-print Network

    E. Kh. Akhmedov; M. Maltoni; A. Yu. Smirnov

    2005-07-08

    We present a formalism for precise description of oscillation phenomena in matter at high energies or high densities, V > \\Delta m^2/2E, where V is the matter-induced potential of neutrinos. The accuracy of the approximation is determined by the quantity \\sin^2 2\\theta_m \\Delta V/2\\pi V, where \\theta_m is the mixing angle in matter and \\Delta V is a typical change of the potential over the oscillation length (l \\sim 2\\pi/V). We derive simple and physically transparent formulas for the oscillation probabilities, which are valid for arbitrary matter density profiles. They can be applied to oscillations of high energy (E > 10 GeV) accelerator, atmospheric and cosmic neutrinos in the matter of the Earth, substantially simplifying numerical calculations and providing an insight into the physics of neutrino oscillations in matter. The effect of parametric enhancement of the oscillations of high energy neutrinos is considered. Future high statistics experiments can provide an unambiguous evidence for this effect.

  3. Crystal optics for precision x-ray spectroscopy on highly charged ions—conception and proof

    NASA Astrophysics Data System (ADS)

    Beyer, H. F.; Gassner, T.; Trassinelli, M.; Heß, R.; Spillmann, U.; Bana?, D.; Blumenhagen, K.-H.; Bosch, F.; Brandau, C.; Chen, W.; Dimopoulou, Chr; Förster, E.; Grisenti, R. E.; Gumberidze, A.; Hagmann, S.; Hillenbrand, P.-M.; Indelicato, P.; Jagodzinski, P.; Kämpfer, T.; Kozhuharov, Chr; Lestinsky, M.; Liesen, D.; Litvinov, Yu A.; Loetzsch, R.; Manil, B.; Märtin, R.; Nolden, F.; Petridis, N.; Sanjari, M. S.; Schulze, K. S.; Schwemlein, M.; Simionovici, A.; Steck, M.; Stöhlker, Th; Szabo, C. I.; Trotsenko, S.; Uschmann, I.; Weber, G.; Wehrhan, O.; Winckler, N.; Winters, D. F. A.; Winters, N.; Ziegler, E.

    2015-07-01

    The experimental investigation of quantum-electrodydamic contributions to the binding energies of inner shells of highly charged heavy ions requires an accurate spectroscopy in the region of hard x-rays suitable at a limited source strength. For this purpose the focusing compensated asymmetric Laue crystal optics has been developed and a twin-spectrometer assembly has been built and commissioned at the experimental storage ring of the GSI Helmholtzzentrum Darmstadt. We characterize the crystal optics and demonstrate the usefulness of the instrumentation for accurate spectroscopy of both stationary and fast moving x-ray sources. The experimental procedures discussed here may also be applied for other spectroscopic studies where a transition from conventional germanium x-ray detectors to crystal spectrometers seems too demanding because of low source intensity.

  4. High-resolution estimation of the water balance of high-precision lysimeters

    NASA Astrophysics Data System (ADS)

    Hannes, Matthias; Wollschläger, Ute; Vogel, Hans-Jörg; Fank, Johann; Pütz, Thomas; Durner, Wolfgang; Schrader, Frederik; Gebler, Sebastian

    2014-05-01

    Lysimeters offer the opportunity to determine precipitation, evapotranspiration and groundwater recharge with high accuracy. In comparison to other techniques, like Eddy-flux-systems or evaporation pans, lysimeters provide a direct measurement of evapotranspiration via the built-in weighing system. The measurement of precipitation can benefit of the much higher surface area compared to typical rain gauge systems. Nevertheless, lysimeters are exposed to several external influences that could falsify the calculated fluxes. Therefore, the estimation of the relevant fluxes requires an adequate data processing, while accounting for the various possible error sources. Most lysimeter studies correct noise in the data by applying a smoothing of the data using a time window of about one hour. These high averaging times can lead to a falsification of the water balance and a loss of information on the dynamics of the processes. In the present study, we present a processing scheme which is based on five filter components that refer to different possible error sources and allow a simple implementation. We further use a set of 12 crop lysimeters and 6 grass lysimeters of the TERENO SoilCan research site Bad Lauchstädt to show that a temporally highly resolved data processing of lysimeter data with a high temporal resolution and good accuracy is possible.

  5. QCD Precision Measurements and Structure Function Extraction at a High Statistics, High Energy Neutrino Scattering Experiment: NuSOnG

    SciTech Connect

    Adams, T.; /Florida State U.; Batra, P.; /Columbia U.; Bugel, Leonard G.; /Columbia U.; Camilleri, Leslie Loris; /Columbia U.; Conrad, Janet Marie; /MIT; de Gouvea, A.; /Northwestern U.; Fisher, Peter H.; /MIT; Formaggio, Joseph Angelo; /MIT; Jenkins, J.; /Northwestern U.; Karagiorgi, Georgia S.; /MIT; Kobilarcik, T.R.; /Fermilab /Texas U.

    2009-06-01

    We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDFs). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parameterized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of 'Beyond the Standard Model' physics.

  6. Glacial rebound of the British Isles?II. A high-resolution, high-precision model

    Microsoft Academic Search

    Kurt Lambeck

    1993-01-01

    SUMMARY Observations of ice movements across the British Isles and of sea-level changes around the shorelines during Late Devensian time (after about 25 000 yr BP) have been used to establish a high spatial and temporal resolution model for the rebound of Great Britain and associated sea-level change. The sea-level observations include sites within the margins of the former ice

  7. Nuclear reactions studied by quasi-elastic measurements with high precision at backward angles

    NASA Astrophysics Data System (ADS)

    Lin, C. J.; Jia, H. M.; Zhang, H. Q.; Yang, F.; Xu, X. X.; Liu, Z. H.; Zhang, S. T.

    2011-10-01

    The excitation functions of quasi-elastic scatterings at backward angles were measured with high precision to study the mechanisms of heavy-ion reactions at near- and sub-barrier energies. The surface diffuseness parameters for the 16O+144,152,154Sm, 170Er, 174Yb, 184,186W, 194,196Pt, and 208Pb systems have been extracted by the single-channel and coupled-channels calculations, respectively. No anomaly was found in these quasi-elastic processes. The barrier heights and barrier distributions were systematically investigated for these systems. Moreover, the coupled-channels effects of neutron transfers with positive Q-value and the breakup effects of weakly-bound nuclei on the fusion processes were also studied for the 32S+90,96Zr systems and the 6,7Li, 9Be+208Pb systems, respectively.

  8. High precision frequency characterization of THz quantum cascade lasers by heterodyne mixing

    NASA Astrophysics Data System (ADS)

    Lee, Mark; Wanke, Michael; Lerttamrab, Maytee; Young, Erik; Grine, Albert; Reno, John; Dengler, Robert; Siegel, Peter

    2008-03-01

    Terahertz quantum cascade lasers (QCLs) have been used together with a monolithic planar Schottky diode receiver to study the heterodyne mixing between dual internal modes of a QCL and between a single mode of a QCL and a known molecular line from a molecular gas laser. Dual mode mixing using a single QCL shows that the intrinsic linewidth of a free-running QCL is < 30 kHz. Both standard and distributed feedback grating QCLs were mixed against known molecular gas laser lines. Resulting difference frequency spectra gave a high precision measurement of a QCL's absolute frequency against known references. Unusual slow transient turn-on behavior was also observed in a pulsed standard QCL. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  9. TRB3: a 264 channel high precision TDC platform and its applications

    NASA Astrophysics Data System (ADS)

    Neiser, A.; Adamczewski-Musch, J.; Hoek, M.; Koenig, W.; Korcyl, G.; Linev, S.; Maier, L.; Michel, J.; Palka, M.; Penschuck, M.; Traxler, M.; U?ur, C.; Zink, A.

    2013-12-01

    The TRB3 features four FPGA-based TDCs with < 20 ps RMS time precision between two channels and 256+4+4 channels in total. One central FPGA provides flexible trigger functionality and GbE connectivity including powerful slow control. We present recent users' applications of this platform following the COME&KISS principle: successful test beamtimes at CERN (CBM), in Jülich and Mainz with an FPGA-based discriminator board (PaDiWa), a charge-to-width FEE board with high dynamic range, read-out of the n-XYTER ASIC and software for data unpacking and TDC calibration in ROOT. We conclude with an outlook on future developments.

  10. Frequency-comb-referenced mid-infrared source for high-precision spectroscopy.

    PubMed

    Peltola, Jari; Vainio, Markku; Fordell, Thomas; Hieta, Tuomas; Merimaa, Mikko; Halonen, Lauri

    2014-12-29

    We report on a tunable continuous-wave mid-infrared optical parametric oscillator (OPO), which is locked to a fully stabilized near-infrared optical frequency comb using a frequency doubling scheme. The OPO is used for 40 GHz mode-hop-free, frequency-comb-locked scans in the wavelength region between 2.7 and 3.4 ?m. We demonstrate the applicability of the method to high-precision cavity-ring-down spectroscopy of nitrous oxide (N2O) and water (H2O) at 2.85 µm and of methane (CH4) at 3.2 ?m. PMID:25607205

  11. High precision measurements of {sup 26}Na {beta}{sup -} decay

    SciTech Connect

    Grinyer, G.F.; Svensson, C.E.; Andreoiu, C.; Finlay, P.; Hyland, B.; Phillips, A.A.; Schumaker, M.A.; Valiente-Dobon, J.J. [Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Andreyev, A.N.; Ball, G.C.; Chakrawarthy, R.S.; Hackman, G.; Macdonald, J.A.; Morton, A.C.; Osborne, C.J.; Pearson, C.J.; Sarazin, F.; Scraggs, H.C.; Smith, M.B. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada); Austin, R.A.E. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4K1 (Canada)] [and others

    2005-04-01

    High-precision measurements of the half-life and {beta}-branching ratios for the {beta}{sup -} decay of {sup 26}Na to {sup 26}Mg have been measured in {beta}-counting and {gamma}-decay experiments, respectively. A 4{pi} proportional counter and fast tape transport system were employed for the half-life measurement, whereas the {gamma} rays emitted by the daughter nucleus {sup 26}Mg were detected with the 8{pi} {gamma}-ray spectrometer, both located at TRIUMF's isotope separator and accelerator radioactive beam facility. The half-life of {sup 26}Na was determined to be T{sub 1/2}=1.07128{+-}0.00013{+-}0.00021 s, where the first error is statistical and the second systematic. The logft values derived from these experiments are compared with theoretical values from a full sd-shell model calculation.

  12. Non-contact high precision measurement of surface form tolerances and central thickness for optical elements

    NASA Astrophysics Data System (ADS)

    Lou, Ying

    2010-10-01

    The traditional contact measuring methods could not satisfy the current optical elements measuring requirements. Noncontact high precision measuring theory, principle and instrument of the surface form tolerances and central thickness for optical elements were studied in the paper. In comparison with other types of interferometers, such as Twyman-Green and Mach-Zehnder, a Fizeau interferometer has the advantages of having fewer optical components, greater accuracy, and is easier to use. Some relations among the 3/A(B/C), POWER/PV and N/?N were studied. The PV with POWER removed can be the reference number of ?N. The chromatic longitudinal aberration of a special optical probe can be used for non-contanct central thickness measurement.

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

    E-print Network

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

    2015-01-01

    We report a direct lattice QCD calculation of the strange nucleon electromagnetic form factors $G_E^s$ and $G_M^s$ in the kinematic range $0 \\leq Q^2 \\lesssim 1.2\\: {\\rm GeV}^2$. For the first time, both $G_E^s$ and $G_M^s$ are shown to be nonzero with high significance. This work uses closer-to-physical lattice parameters than previous calculations, and achieves an unprecedented 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. We compare our results to parity-violating electron-proton scattering data and to other theoretical studies.

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

    E-print Network

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

    2015-05-22

    We report a direct lattice QCD calculation of the strange nucleon electromagnetic form factors $G_E^s$ and $G_M^s$ in the kinematic range $0 \\leq Q^2 \\lesssim 1.2\\: {\\rm GeV}^2$. For the first time, both $G_E^s$ and $G_M^s$ are shown to be nonzero with high significance. This work uses closer-to-physical lattice parameters than previous calculations, and achieves an unprecedented 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. We compare our results to parity-violating electron-proton scattering data and to other theoretical studies.

  15. TITAN-EBIT — charge breeding of radioactive isotopes for high precision mass measurements

    NASA Astrophysics Data System (ADS)

    Gallant, A. T.; Brodeur, M.; Brunner, T.; Ettenauer, S.; Good, M.; Lapierre, A.; Ringle, R.; Simon, V. V.; Delheij, P.; Dilling, J.

    2010-08-01

    TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) is a multi-ion trap facility with the goal of high precision mass measurements of radio-nuclides. TITAN is coupled to the ISAC on-line facility at TRIUMF, Vancouver, Canada, and consists of a Radio-Frequency Quadrupole (RFQ) buncher and cooler, an Electron Beam Ion Trap (EBIT), a Cooler Penning Trap (CPET), presently under construction and installation planned for 2011, and the Measurement Penning Trap (MPET). To date the TITAN EBIT has been used for charge breeding of stable and radioactive isotopes. In this paper we report the successful injection and extraction of stable Na and radioactive 25Na. Preliminary emittance measurements have been completed and the emittance in the vertical direction was found to be epsilonrms = 15.7±0.5?mm-mrad at a beam energy of 1.95 keV.

  16. High precision Penning trap mass spectrometry of rare isotopes produced by projectile fragmentation

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, A. A.; Barquest, B. R.; Block, M.; Bollen, G.; Campbell, C. M.; Ferrer, R.; Lincoln, D. L.; Morrissey, D. J.; Pang, G. K.; Redshaw, M.; Ringle, R.; Schwarz, S.; Savory, J.

    2011-09-01

    The Low Energy Beam and Ion Trap (LEBIT) is the only present facility to combine high precision Penning trap mass spectrometry with fast beam projectile fragmentation. Located at the National Superconducting Cyclotron Laboratory (NSCL), LEBIT is able to measure radionuclides produced in a chemically independent process with minimal decay losses. Recent exotic mass measurements include 66As, 63-66Fe, and 32Si. 66As is a new candidate to test the Conserved Vector Current (CVC) hypothesis. The masses of the neutron-rich iron isotopes provide additional information about the mass surface and the subshell closure at N = 40. 32Si is a member of the A = 32, T = 2 quintet; its measurement permits the most stringent test of the validity of the isobaric multiplet mass equation (IMME). An overview of some recent measurements will be presented as well as advanced techniques for ion manipulation.

  17. High precision and convenient extension simulation platform for satellite attitude and orbit system

    NASA Astrophysics Data System (ADS)

    Cui, Hongzheng; Han, Chao; Chen, Pei; Luo, Qinqin

    2012-01-01

    In this paper, a high precision and convenient extension simulation platform for satellite attitude and orbit system is developed, to demonstrate the satellite attitude and orbit system for given space mission, and test the new underdeveloped algorithms for attitude/orbit dynamics, attitude determination, orbit navigation, and attitude/orbit control. The simulation platform is based on Matlab/Simulink software, using the technique of Simulink modeling, importing C/Fortran code in Matlab/Simulink, and embedded Matlab function, with beautiful reusability, inheritability and expansibility. The paper orderly presents the background behind the development of the platform, the platform design architecture and capability, the validity of the platform, the inheritability and expansibility of the platform, the platform implementation example for Chinese weather satellite (FY-3), and the future development for the platform.

  18. High precision and convenient extension simulation platform for satellite attitude and orbit system

    NASA Astrophysics Data System (ADS)

    Cui, Hongzheng; Han, Chao; Chen, Pei; Luo, Qinqin

    2011-12-01

    In this paper, a high precision and convenient extension simulation platform for satellite attitude and orbit system is developed, to demonstrate the satellite attitude and orbit system for given space mission, and test the new underdeveloped algorithms for attitude/orbit dynamics, attitude determination, orbit navigation, and attitude/orbit control. The simulation platform is based on Matlab/Simulink software, using the technique of Simulink modeling, importing C/Fortran code in Matlab/Simulink, and embedded Matlab function, with beautiful reusability, inheritability and expansibility. The paper orderly presents the background behind the development of the platform, the platform design architecture and capability, the validity of the platform, the inheritability and expansibility of the platform, the platform implementation example for Chinese weather satellite (FY-3), and the future development for the platform.

  19. Upgrade of the SPIRAL identification station for high-precision measurements of nuclear ? decay

    NASA Astrophysics Data System (ADS)

    Grinyer, G. F.; Thomas, J. C.; Blank, B.; Bouzomita, H.; Austin, R. A. E.; Ball, G. C.; Bucaille, F.; Delahaye, P.; Finlay, P.; Frémont, G.; Gibelin, J.; Giovinazzo, J.; Grinyer, J.; Kurtukian-Nieto, T.; Laffoley, A. T.; Leach, K. G.; Lefèvre, A.; Legruel, F.; Lescalié, G.; Perez-Loureiro, D.

    2014-03-01

    The low-energy identification station at SPIRAL (Système de Production d'Ions Radioactifs Accélérés en Ligne) has been upgraded for studying the ? decays of short-lived radioactive isotopes and to perform high-precision half-life and branching-ratio measurements for superallowed Fermi and isospin T=1/2 mirror ? decays. These new capabilities, combined with an existing Paul trap setup for measurements of ?-? angular-correlation coefficients, provide a powerful facility for investigating fundamental properties of the electroweak interaction through nuclear ? decays. A detailed description of the design study, construction, and first results obtained from an in-beam commissioning experiment on the ?+ decays 14 O and 17F are presented.

  20. An Efficient, Compact, and Versatile Fiber Double Scrambler for High Precision Radial Velocity Instruments

    NASA Astrophysics Data System (ADS)

    Halverson, Samuel; Roy, Arpita; Mahadevan, Suvrath; Ramsey, Lawrence; Levi, Eric; Schwab, Christian; Hearty, Fred; MacDonald, Nick

    2015-06-01

    We present the design and test results of a compact optical fiber double-scrambler for high-resolution Doppler radial velocity instruments. This device consists of a single optic: a high-index n ? 2 ball lens that exchanges the near and far fields between two fibers. When used in conjunction with octagonal fibers, this device yields very high scrambling gains (SGs) and greatly desensitizes the fiber output from any input illumination variations, thereby stabilizing the instrument profile of the spectrograph and improving the Doppler measurement precision. The system is also highly insensitive to input pupil variations, isolating the spectrograph from telescope illumination variations and seeing changes. By selecting the appropriate glass and lens diameter the highest efficiency is achieved when the fibers are practically in contact with the lens surface, greatly simplifying the alignment process when compared to classical double-scrambler systems. This prototype double-scrambler has demonstrated significant performance gains over previous systems, achieving SGs in excess of 10,000 with a throughput of ?87% using uncoated Polymicro octagonal fibers. Adding a circular fiber to the fiber train further increases the SG to >20,000, limited by laboratory measurement error. While this fiber system is designed for the Habitable-zone Planet Finder spectrograph, it is more generally applicable to other instruments in the visible and near-infrared. Given the simplicity and low cost, this fiber scrambler could also easily be multiplexed for large multi-object instruments.

  1. High Precision Differential Abundance Measurements in Globular Clusters: Chemical Inhomogeneities in NGC 6752

    E-print Network

    Yong, David; 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

    2013-01-01

    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%). 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...

  2. Correlated cryo-fluorescence and cryo-electron microscopy with high spatial precision and improved sensitivity.

    PubMed

    Schorb, Martin; Briggs, John A G

    2014-08-01

    Performing fluorescence microscopy and electron microscopy on the same sample allows fluorescent signals to be used to identify and locate features of interest for subsequent imaging by electron microscopy. To carry out such correlative microscopy on vitrified samples appropriate for structural cryo-electron microscopy it is necessary to perform fluorescence microscopy at liquid-nitrogen temperatures. Here we describe an adaptation of a cryo-light microscopy stage to permit use of high-numerical aperture objectives. This allows high-sensitivity and high-resolution fluorescence microscopy of vitrified samples. We describe and apply a correlative cryo-fluorescence and cryo-electron microscopy workflow together with a fiducial bead-based image correlation procedure. This procedure allows us to locate fluorescent bacteriophages in cryo-electron microscopy images with an accuracy on the order of 50 nm, based on their fluorescent signal. It will allow the user to precisely and unambiguously identify and locate objects and events for subsequent high-resolution structural study, based on fluorescent signals. PMID:24275379

  3. Development of the High Precision Telescope on the RISING-2 micro satellite

    NASA Astrophysics Data System (ADS)

    Kurihara, Junichi; Takahashi, Yukihiro

    We developed the High Precision Telescope (HPT) which will be installed on a micro satellite, RISING-2. The RISING-2 satellite is the succession mission of the RISING satellite, which was successfully launched on 23 January 2009. These two 50 kg class satellites have been developed in-house by the universities. The HPT uses a zero thermal expansion pore-free ceramics (ZPF) mirror for the optical system, a liquid crystal tunable filter (LCTF) for the spectrometry, and high-sensitivity charge coupled device (CCD) cameras for the imaging. The HPT is a highly-functional multi-purpose space telescope that can be widely used for near-IR observations of the Earth and planets, such as the Jupiter and Venus. One of the applications is a high-resolution observation of thunderclouds in the Earth. Detailed information on a thundercloud structure will help to issue early-warnings of floods caused by torrential rains. The thundercloud structure observations from space are useful especially in areas without a weather radar network. The HPT will give a technology demonstration of the multi-spectral telescopic imaging for global remote sensing of weather disasters, land-use, ocean development, etc.

  4. Achieving high-precision pointing on ExoplanetSat: initial feasibility analysis

    NASA Astrophysics Data System (ADS)

    Pong, Christopher M.; Lim, Sungyung; Smith, Matthew W.; Miller, David W.; Villaseñor, Jesus S.; Seager, Sara

    2010-07-01

    ExoplanetSat is a proposed three-unit CubeSat designed to detect down to Earth-sized exoplanets in an orbit out to the habitable zone of Sun-like stars via the transit method. To achieve the required photometric precision to make these measurements, the target star must remain within the same fraction of a pixel, which is equivalent to controlling the pointing of the satellite to the arcsecond level. The satellite will use a two-stage control system: coarse control will be performed by a set of reaction wheels, desaturated by magnetic torque coils, and fine control will be performed by a piezoelectric translation stage. Since no satellite of this size has previously demonstrated this high level of pointing precision, a simulation has been developed to prove the feasibility of realizing such a system. The current baseline simulation has demonstrated the ability to hold the target star to within 0.05 pixels or 1.8 arcseconds (with an 85 mm lens and 15 ?m pixels), in the presence of large reaction wheel disturbances as well as external environmental disturbances. This meets the current requirement of holding the target star to 0.14 pixels or 5.0 arcseconds. Other high-risk aspects of the design have been analyzed such as the effect of changing the guide star centroiding error, changing the CMOS sampling frequency, and reaction wheel selection on the slew performance of the satellite. While these results are promising as an initial feasibility analysis, further model improvements and hardware-in-the-loop tests are currently underway.

  5. Evaluation of the Precision of High-Performance Liquid Chromatography for Wheat Cultivar Identification

    Microsoft Academic Search

    M. G. SCANLON; H. D. SAPIRSTEIN; W. BUSHUK

    Cereal Chem. 66(2): 112-116 The reproducibility of computer-derived reversed-phase high- computed peak areas and heights, and percentage peak areas and heights. performance liquid chromatography (RP-HPLC) quantitation parameters Whereas chromatographic resolution was relatively constant over time, following prolonged use of a single commercially available column was prolonged column use significantly retarded peak retention times especially studied. Using a standardized experimental procedure,

  6. High-Precision Measurements of the Superallowed Beta+ Decays of 38Ca and 46V

    E-print Network

    Park, Hyo-In

    2012-10-19

    counter or the branching ratio is determined with a plastic scintillator and 70% high- purity germanium detector (HPGe). A detailed description of our experimental setup and procedures is given in this chapter. A. Production of isotopes 1. The Momentum... with constant pressure maintained at 2 atm. 19 MARS beamline shielding tape transport deck #1 tape transport deck #2 plastic scintillator aluminum degraders HPGe aluminized mylar tape Hydrogen Gas Target scale (meter) 0 5Coffin...

  7. High-resolution estimation of the water balance components from high-precision lysimeters

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    Lysimeters offer the opportunity to determine precipitation, evapotranspiration and groundwater-recharge with high accuracy. In contrast to other techniques, like Eddy-flux systems or evaporation pans, lysimeters provide a direct measurement of evapotranspiration from a clearly defined surface area at the scale of a soil profile via the built-in weighing system. In particular the estimation of precipitation can benefit from the much higher surface area compared to typical raingauge systems. Nevertheless, lysimeters are exposed to several external influences that could falsify the calculated fluxes. Therefore, the estimation of the relevant fluxes requires an appropriate data processing with respect to various error sources. Most lysimeter studies account for noise in the data by averaging. However, the effects of smoothing by averaging on the accuracy of the estimated water balance is rarely investigated. In this study, we present a filtering scheme, which is designed to deal with the various kinds of possible errors. We analyze the influence of averaging times and thresholds on the calculated water balance. We further investigate the ability of two adaptive filtering methods (the Adaptive Window and Adaptive Threshold filter (AWAT-filter) (Peters et al., 2014) and the consecutively described synchro-filter) in further reducing the filtering error. On the basis of the data sets of 18 simultanously running lysimeters of the TERENO SoilCan research site in Bad Lauchstädt, we show that the estimation of the water balance with high temporal resolution and good accuracy is possible.

  8. Redefining ALL classification: toward detecting high-risk ALL and implementing precision medicine.

    PubMed

    Hunger, Stephen P; Mullighan, Charles G

    2015-06-25

    Acute lymphoblastic leukemia (ALL) is the commonest childhood tumor and remains a leading cause of cancer death in the young. In the last decade, microarray and sequencing analysis of large ALL cohorts has revolutionized our understanding of the genetic basis of this disease. These studies have identified new ALL subtypes, each characterized by constellations of structural and sequence alterations that perturb key cellular pathways, including lymphoid development, cell-cycle regulation, and tumor suppression; cytokine receptor, kinase, and Ras signaling; and chromatin modifications. Several of these pathways, particularly kinase-activating lesions and epigenetic alterations, are logical targets for new precision medicine therapies. Genomic profiling has also identified important interactions between inherited genetic variants that influence the risk of leukemia development and the somatic genetic alterations that are required to establish the leukemic clone. Moreover, sequential sequencing studies at diagnosis, remission, and relapse have provided important insights into the relationship among genetic variants, clonal heterogeneity, and the risk of relapse. Ongoing studies are extending our understanding of coding and noncoding genetic alterations in B-progenitor and T-lineage ALL and using these insights to inform the development of faithful experimental models to test the efficacy of new treatment approaches. PMID:25999453

  9. High-Precision Measurement of the 19Ne Half-Life and Implications for Right-Handed Weak Currents

    E-print Network

    S. Triambak; P. Finlay; C. S. Sumithrarachchi; G. Hackman; G. C. Ball; P. E. Garrett; C. E. Svensson; D. S. Cross; A. B. Garnsworthy; R. Kshetri; J. N. Orce; M. R. Pearson; E. R. Tardiff; H. Al-Falou; R. A. E. Austin; R. Churchman; M. K. Djongolov; R. D'Entremont; C. Kierans; L. Milovanovic; S. O'Hagan; S. Reeve; S. K. L. Sjue; S. J. Williams

    2012-06-26

    We report a precise determination of the 19Ne half-life to be $T_{1/2} = 17.262 \\pm 0.007$ s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current Standard Model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.

  10. Mid-infrared frequency comb for broadband high precision and sensitivity molecular spectroscopy.

    PubMed

    Galli, I; Bartalini, S; Cancio, P; Cappelli, F; Giusfredi, G; Mazzotti, D; Akikusa, N; Yamanishi, M; De Natale, P

    2014-09-01

    We report on the experimental demonstration of the metrological and spectroscopic performances of a mid-infrared comb generated by a nonlinear downconversion process from a Ti:sapphire-based near-infrared comb. A quantum cascade laser at 4330 nm was phase-locked to a single tooth of this mid-infrared comb and its frequency-noise power spectral density was measured. The mid-infrared comb itself was also used as a multifrequency highly coherent source to perform ambient air direct comb spectroscopy with the Vernier technique, by demultiplexing it with a high-finesse Fabry-Perot cavity. PMID:25166071

  11. High-Precision Half-Life Measurement for the Superallowed {beta}{sup +} Emitter {sup 26}Al{sup m}

    SciTech Connect

    Finlay, P.; Svensson, C. E.; Green, K. L.; Leach, K. G.; Phillips, A. A.; Sumithrarachchi, C. S. [Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Ettenauer, S. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z4 (Canada); Ball, G. C.; Bandyopadhyay, D.; Djongolov, M.; Hackman, G.; Pearson, C. J.; Williams, S. J [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada); Leslie, J. R. [Department of Physics, Queen's University, Kingston, Ontario, K7L 3N6 (Canada); Andreoiu, C.; Cross, D. S. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada); Austin, R. A. E. [Astronomy and Physics Department, Saint Mary's University, Halifax, Nova Scotia, B3H 3C3 (Canada); Demand, G. [Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Department of Physics, Queen's University, Kingston, Ontario, K7L 3N6 (Canada); Garrett, P. E.; Triambak, S. [Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (Canada)

    2011-01-21

    A high-precision half-life measurement for the superallowed {beta}{sup +} emitter {sup 26}Al{sup m} was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T{sub 1/2}=6346.54{+-}0.46{sub stat{+-}}0.60{sub syst} ms, consistent with, but 2.5 times more precise than, the previous world average. The {sup 26}Al{sup m} half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed {beta} decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for {sup 26}Al{sup m}, 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi {beta}-decay studies used to test the conserved vector current hypothesis and determine the V{sub ud} element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

  12. Sensor for High Speed, High Precision Measurement of 2-D Positions

    PubMed Central

    Luna, Carlos A.; Lázaro, José L.; Mazo, Manuel; Cano, Angel

    2009-01-01

    A sensor system to measure the 2-D position of an object that intercepts a plane in space is presented in this paper. This sensor system was developed with the aim of measuring the height and lateral position of contact wires supplying power to electric locomotives. The sensor comprises two line-scans focused on the zone to be measured and positioned in such a way that their viewing planes are on the same plane. The report includes a mathematical model of the sensor system, and details the method used for calibrating the sensor system. The procedure used for high speed measurement of object position in space is also described, where measurement acquisition time was less than 0.7 ms. Finally, position measurement results verifying system performance in real time are given. PMID:22291537

  13. b-CGC versus IP-Sat and high precision combined HERA data

    E-print Network

    Amir H. Rezaeian

    2014-07-23

    The Impact-Parameter dependent Color Glass Condensate (b-CGC) and Saturation (IP-Sat) dipole models incorporate key features of small-x physics properties and match smoothly to the perturbative QCD regime at large $Q^2$ for a given $x$. Although both models include saturation effects and depend on impact-parameter, the former is based on the non-linear BK equation, while the latter is based on DGLAP evolution. After confronting the models to the recently released high precision combined HERA data, we show that in both models, the typical impact-parameter probed in the total $\\gamma^{*}p$ cross-section is about $b\\approx 2\\div 3\\,\\text{GeV}^{-1}$ and the proton saturation scale is $Q_SIP-Sat models give significantly different predictions beyond the current HERA kinematics for the structure functions at very low x and high virtualities $Q^2$, and for the exclusive diffractive vector meson and DVCS production at high $t$.

  14. THE APPLICATION OF MULTIVIEW METHODS FOR HIGH-PRECISION ASTROMETRIC SPACE VLBI AT LOW FREQUENCIES

    SciTech Connect

    Dodson, R.; Rioja, M.; Imai, H. [International Centre for Radio Astronomy Research, M468, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009 (Australia); Asaki, Y. [Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Chuou, Sagamihara, Kanagawa 252-5210 (Japan); Hong, X.-Y.; Shen, Z., E-mail: richard.dodson@icrar.org [Shanghai Astronomical Observatory, CAS, 200030 Shanghai (China)

    2013-06-15

    High-precision astrometric space very long baseline interferometry (S-VLBI) at the low end of the conventional frequency range, i.e., 20 cm, is a requirement for a number of high-priority science goals. These are headlined by obtaining trigonometric parallax distances to pulsars in pulsar-black hole pairs and OH masers anywhere in the Milky Way and the Magellanic Clouds. We propose a solution for the most difficult technical problems in S-VLBI by the MultiView approach where multiple sources, separated by several degrees on the sky, are observed simultaneously. We simulated a number of challenging S-VLBI configurations, with orbit errors up to 8 m in size and with ionospheric atmospheres consistent with poor conditions. In these simulations we performed MultiView analysis to achieve the required science goals. This approach removes the need for beam switching requiring a Control Moment Gyro, and the space and ground infrastructure required for high-quality orbit reconstruction of a space-based radio telescope. This will dramatically reduce the complexity of S-VLBI missions which implement the phase-referencing technique.

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

    PubMed

    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. PMID:21974618

  16. 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.

  17. New technology enables high precision multislit collimators for microbeam radiation therapy

    SciTech Connect

    Braeuer-Krisch, E.; Requardt, H.; Brochard, T.; Berruyer, G.; Renier, M.; Bravin, A. [European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble (France); Laissue, J. A. [Institute of Pathology, University of Bern, Murtenstrasse 31, 3010 Bern (Switzerland)

    2009-07-15

    During the past decade microbeam radiation therapy has evolved from preclinical studies to a stage in which clinical trials can be planned, using spatially fractionated, highly collimated and high intensity beams like those generated at the x-ray ID17 beamline of the European Synchrotron Radiation Facility. The production of such microbeams typically between 25 and 100 {mu}m full width at half maximum (FWHM) values and 100-400 {mu}m center-to-center (c-t-c) spacings requires a multislit collimator either with fixed or adjustable microbeam width. The mechanical regularity of such devices is the most important property required to produce an array of identical microbeams. That ensures treatment reproducibility and reliable use of Monte Carlo-based treatment planning systems. New high precision wire cutting techniques allow the fabrication of these collimators made of tungsten carbide. We present a variable slit width collimator as well as a single slit device with a fixed setting of 50 {mu}m FWHM and 400 {mu}m c-t-c, both able to cover irradiation fields of 50 mm width, deemed to meet clinical requirements. Important improvements have reduced the standard deviation of 5.5 {mu}m to less than 1 {mu}m for a nominal FWHM value of 25 {mu}m. The specifications of both devices, the methods used to measure these characteristics, and the results are presented.

  18. New technology enables high precision multislit collimators for microbeam radiation therapy

    NASA Astrophysics Data System (ADS)

    Bräuer-Krisch, E.; Requardt, H.; Brochard, T.; Berruyer, G.; Renier, M.; Laissue, J. A.; Bravin, A.

    2009-07-01

    During the past decade microbeam radiation therapy has evolved from preclinical studies to a stage in which clinical trials can be planned, using spatially fractionated, highly collimated and high intensity beams like those generated at the x-ray ID17 beamline of the European Synchrotron Radiation Facility. The production of such microbeams typically between 25 and 100 ?m full width at half maximum (FWHM) values and 100-400 ?m center-to-center (c-t-c) spacings requires a multislit collimator either with fixed or adjustable microbeam width. The mechanical regularity of such devices is the most important property required to produce an array of identical microbeams. That ensures treatment reproducibility and reliable use of Monte Carlo-based treatment planning systems. New high precision wire cutting techniques allow the fabrication of these collimators made of tungsten carbide. We present a variable slit width collimator as well as a single slit device with a fixed setting of 50 ?m FWHM and 400 ?m c-t-c, both able to cover irradiation fields of 50 mm width, deemed to meet clinical requirements. Important improvements have reduced the standard deviation of 5.5 ?m to less than 1 ?m for a nominal FWHM value of 25 ?m. The specifications of both devices, the methods used to measure these characteristics, and the results are presented.

  19. New technology enables high precision multislit collimators for microbeam radiation therapy.

    PubMed

    Bräuer-Krisch, E; Requardt, H; Brochard, T; Berruyer, G; Renier, M; Laissue, J A; Bravin, A

    2009-07-01

    During the past decade microbeam radiation therapy has evolved from preclinical studies to a stage in which clinical trials can be planned, using spatially fractionated, highly collimated and high intensity beams like those generated at the x-ray ID17 beamline of the European Synchrotron Radiation Facility. The production of such microbeams typically between 25 and 100 microm full width at half maximum (FWHM) values and 100-400 microm center-to-center (c-t-c) spacings requires a multislit collimator either with fixed or adjustable microbeam width. The mechanical regularity of such devices is the most important property required to produce an array of identical microbeams. That ensures treatment reproducibility and reliable use of Monte Carlo-based treatment planning systems. New high precision wire cutting techniques allow the fabrication of these collimators made of tungsten carbide. We present a variable slit width collimator as well as a single slit device with a fixed setting of 50 microm FWHM and 400 microm c-t-c, both able to cover irradiation fields of 50 mm width, deemed to meet clinical requirements. Important improvements have reduced the standard deviation of 5.5 microm to less than 1 microm for a nominal FWHM value of 25 microm. The specifications of both devices, the methods used to measure these characteristics, and the results are presented. PMID:19655968

  20. Modern experimental techniques for high speed flow measurements

    NASA Astrophysics Data System (ADS)

    Modarress, Dariush; Azzazy, M.

    1988-01-01

    This review paper examines the applicability of experimental techniques to high speed flows. Existing flow facilities are reviewed and measurement requirements are evaluated. Experimental techniques that are reviewed include: laser Doppler velocimetry, laser induced fluorescence, and coherent Raman spectroscopy for measurement of gas velocity in high speed flow facilities. Also reviewed are application of laser holography and tomography to high speed flows as a quantitative diagnostic technique. Finally, a review of techniques for detection of boundary layer transition is presented.

  1. Small-scale, high-precision and high-accuracy determination of Poisson's ratios in cohesive marine sediments

    NASA Astrophysics Data System (ADS)

    L'Esperance, J. Christopher; Boudreau, Bernard P.; Barry, Mark A.; Johnson, Bruce D.

    2013-02-01

    Poisson's ratio (static) appears as a parameter in models of soft-sediment geomechanical processes such as gas bubble formation and bioturbation, and in a number of practical applications, including acoustic imaging, but is rarely measured in soft near-surface (upper 20 cm) marine sediments. A new uniaxial apparatus was developed to assess Poisson's ratios of cylindrical samples of soft cohesive sediments under finite-strain, unconfined, undrained conditions. No constraining membrane around the sample is necessary in the instrument. By monitoring the fluid level in a capillary, changes in sample volume can be determined to high precision (reproducibility). Measurements on reference materials, i.e., gelatine and polyurethane, also indicate high accuracy (veracity). For natural sediments from Nova Scotia, Canada, Poisson's ratios range from 0.4951 to 0.5 with no indication of anisotropy; therefore, such sediments act as incompressible solids to short-term/small-magnitude stresses, as occur during bubble formation and infaunal movement.

  2. High Precision CTE-Measurement of SiC-100 for Cryogenic Space-Telescopes

    E-print Network

    K. Enya; N. Yamada; T. Onaka; T. Nakagawa; H. Kaneda; M. Hirabayashi; Y. Toulemont; D. Castel; Y. Kanai; N. Fujishiro

    2007-04-12

    We present the results of high precision measurements of the thermal expansion of the sintered SiC, SiC-100, intended for use in cryogenic space-telescopes, in which minimization of thermal deformation of the mirror is critical and precise information of the thermal expansion is needed for the telescope design. The temperature range of the measurements extends from room temperature down to $\\sim$ 10 K. Three samples, #1, #2, and #3 were manufactured from blocks of SiC produced in different lots. The thermal expansion of the samples was measured with a cryogenic dilatometer, consisting of a laser interferometer, a cryostat, and a mechanical cooler. The typical thermal expansion curve is presented using the 8th order polynomial of the temperature. For the three samples, the coefficients of thermal expansion (CTE), $\\bar{\\alpha}_{#1}$, $\\bar{\\alpha}_{#2}$, and $\\bar{\\alpha}_{#3}$ were derived for temperatures between 293 K and 10 K. The average and the dispersion (1 $\\sigma$ rms) of these three CTEs are 0.816 and 0.002 ($\\times 10^{-6}$/K), respectively. No significant difference was detected in the CTE of the three samples from the different lots. Neither inhomogeneity nor anisotropy of the CTE was observed. Based on the obtained CTE dispersion, we performed an finite-element-method (FEM) analysis of the thermal deformation of a 3.5 m diameter cryogenic mirror made of six SiC-100 segments. It was shown that the present CTE measurement has a sufficient accuracy well enough for the design of the 3.5 m cryogenic infrared telescope mission, the Space Infrared telescope for Cosmology and Astrophysics (SPICA).

  3. Project GeoWSN: High precision but low-cost GNSS landslide monitoring in Austria

    NASA Astrophysics Data System (ADS)

    Koch, Daniel; Brandstätter, Michael; Kühtreiber, Norbert

    2014-05-01

    At present, GNSS monitoring of landslides is an accepted and approved method to detect movements of slopes at risk in the sub-centimetre level. However, high-precision geodetic GNSS-receivers are expensive, therefore this monitoring method is not widely applied. Recently low-cost GNSS-receivers are conquering the geodetic market and are well suited for a cost effective and yet precise GNSS-monitoring. During the project GeoWSN, which was funded by the Austrian Research Promotion Agency (FFG), an applicable low-cost monitoring system was developed at Graz University of Technology. The system is based on a so-called Wireless Sensor Network (WSN) consisting of low-cost GNSS-receivers, temperature and humidity sensors and inertial measurement units. Additionally energy-harvesting technologies and power-saving algorithms provide that the system is energy- autarkic. For real-time applications, a communication link between the sensor nodes is implemented. The relative positioning method RTK (Real Time Kinematic) is applied to reach the highest possible accuracy. The GeoWSN sensor nodes enable the detection of possible movements in the real-time processed positions of the sensor nodes. To ensure a real-time evaluation and interpretation of the data, the current status of the slope can be acquired by a local warning centre. Therefore, affected people can be warned within a short latency. Several test-scenarios have shown the acceptance of the system at the warning centre of Styria, Austria. This contribution should give an overview of the main idea of a low-cost warning system and results of the project GeoWSN.

  4. The high throughput biomedicine unit at the institute for molecular medicine Finland: high throughput screening meets precision medicine.

    PubMed

    Pietiainen, Vilja; Saarela, Jani; von Schantz, Carina; Turunen, Laura; Ostling, Paivi; Wennerberg, Krister

    2014-05-01

    The High Throughput Biomedicine (HTB) unit at the Institute for Molecular Medicine Finland FIMM was established in 2010 to serve as a national and international academic screening unit providing access to state of the art instrumentation for chemical and RNAi-based high throughput screening. The initial focus of the unit was multiwell plate based chemical screening and high content microarray-based siRNA screening. However, over the first four years of operation, the unit has moved to a more flexible service platform where both chemical and siRNA screening is performed at different scales primarily in multiwell plate-based assays with a wide range of readout possibilities with a focus on ultraminiaturization to allow for affordable screening for the academic users. In addition to high throughput screening, the equipment of the unit is also used to support miniaturized, multiplexed and high throughput applications for other types of research such as genomics, sequencing and biobanking operations. Importantly, with the translational research goals at FIMM, an increasing part of the operations at the HTB unit is being focused on high throughput systems biological platforms for functional profiling of patient cells in personalized and precision medicine projects. PMID:24661208

  5. Constraining the Recent Star Formation History of the Galactic Center with High Precision Astrometry

    NASA Astrophysics Data System (ADS)

    Yelda, Sylvana

    The proximity of the Galactic center has allowed for the detailed study of the environs of a supermassive black hole (SMBH). While the region is inhabited predominantly by old, late-type giants, there exists a population of ˜200 young (6 +/- 2 Myr), massive (10--100 msun) stars within the central parsec. Their presence here is puzzling since the standard mode of star formation cannot proceed in the face of the strong tidal forces from the SMBH. Given their youth, the dynamics of these stars can be used to understand their origin and lend insight into star formation processes in the hostile environment surrounding a supermassive black hole. In this thesis, I use high resolution infrared imaging from the W. M. Keck telescopes in order to determine precise orbital parameter estimates of the young stars and understand the Galactic center's most recent epoch of star formation. First, we present a new optical distortion model for the Keck/NIRC2 narrow camera that is based upon on-sky measurements of a globular cluster. With an improved distortion model, we show that a stable astrometric reference frame for the GC can be established with Sgr A* at rest to within 0.09 mas/yr (˜3.4 km/s at a distance of 8 kpc), thereby improving the stability of the reference frame. Accurate proper motions of the central stellar cluster are presented and the stars are shown to have significant net rotation parallel to Galactic rotation. These stars can be used as astrometric standards for defining a reference frame without requiring the assumption of no net motion of the central stellar cluster, as has been done in earlier proper motion studies. Second, we use high-precision astrometry, measured in the newly constructed reference frame, and radial velocities of ˜115 young stars at projected radii between R = 0.8" -- 13.3" in order to estimate their orbital properties. This constitutes the largest sample of stars used for this type of study to date. The median proper motion uncertainty for the stars within R=6", for which we have up to a 16-year baseline of measurements, is 0.03 mas/yr (˜1.2 km/s). Acceleration uncertainties are typically 10 microarcsec/yr/yr (˜0.4 km/s/yr), which has allowed for the detection of six significant accelerations in the plane of the sky outside the central arcsecond. Such measurements provide direct calculations of the line of sight distance and therefore precise orbital parameter estimates. We detect the clockwise stellar disk reported in previous studies, but find that the fraction of young stars within the disk is much smaller than once thought. We do not find evidence for the previously-claimed counter-rotating disk. The clockwise disk has an inclination of ˜130° and an angle to the ascending node of ˜96°, with an opening angle of 15.2°. The orientation of the disk plane does not change with radius, contrary to recent claims of a highly-warped disk. We identify a bias in the orbital solutions of disk stars near the line of nodes that stems from a previously adopted line-of-sight distance prior and show that this bias leads to an apparently-warped disk. The candidate disk members have orbital eccentricities of e ˜ 0.3. This can be explained by dynamical relaxation in an initially circular disk with a moderately top-heavy mass function (Gamma ˜ 1.6), consistent with the latest estimates of the young star population's IMF. This cannot, however, account for the high inclinations of the out-of-disk population, which makes up at least half of the central parsec's young stars. Thus, if all of the young stars formed in a single disk, an additional dynamical mechanism must be invoked to explain their orbits.

  6. High Precision, Directly Determined Radii and Effective Temperatures for Giant Stars

    NASA Astrophysics Data System (ADS)

    van Belle, Gerard

    Mission Statement. The radius and temperature scale of giant stars across the Hertzsprung-Russell diagram from red giant branch stars to horizontal branch stars is understood well enough to enable an accurate prediction of temperature and size for a given star to no better than ~2.5% and ~20%, respectively, based upon photometry. The primary reason for this is the lack of empirically determined radii and temperatures across the giant branches. One of the long-running strengths of optical interferometry has been the empirical determination of fundamental stellar parameters. Through direct measurements of effective temperature and linear radius, methods such as photometric colors that indirectly predict such values can be calibrated. A substantial body of data on this topic collected for giant stars remains unpublished and stands to benefit from the advances in ancillary data sources and computational techniques of the last dozen years. Previous efforts in this regard have been limited by data sample breadth and depth. The Experiment. We will use multi-technique and multi-wavelength data available in NASA's Archives to directly measure angular sizes and bolometric fluxes for giant stars, establishing the radius-temperature scale across the giant branches. Interferometric data from NASA's Palomar Testbed Interferometer (PTI) Archive in conjunction with recent advances in calibration techniques will allow us to directly establish fundamental parameters of temperature and radius for 425 giant stars at unprecedented levels of accuracy. The majority of these objects was observed repeatedly over the 11-year run of this well- understood instrument, allowing for exquisite control of observational systematics. Optical, near-infrared and mid-infrared data from NASA Archives, including 2MASS, COBE, MSX, and WISE will constrain the bolometric fluxes; the recent reanalysis of the Hipparcos data will provide unparalleled distances to each of the 425 giant stars in the sample. We have demonstrated the potential of all aspects of this program, and through the proposed effort will unify the diverse components to study these giants. A homogenous catalog of linear radii and effective temperatures for hundreds of giants will be generated, which in turn will be used to calibrate radius and temperature scales for application to the broad population of giants. Significance. Fundamental temperature and radius scales are used throughout stellar astrophysics, including stellar structure studies, stellar modeling, galactic spectral synthesis, planet detection studies, and star formation theory. We expect to reduce the error in effective temperature calibration by 2-4x, and the error in linear radius by 2-3x or more. A high- precision improvement to these scales will, in turn, broadly advance a wide swath of studies that depend on precisely knowing the radii and temperature of stars. This proposal aims to produce the definitive linear radius and effective temperature scales for giants. A significant improvement in the determinations of the radii and effective temperatures of giant stars across the HR diagram will have far reaching consequences across the broad expanse of astrophysical research. Relevance to NASA. High-precision calibrations of temperature scales are essential to flux calibrations of past and ongoing NASA science satellite observations, such as those from Spitzer and WISE, and a significantly improved linear radius reference markedly improves Kepler discoveries in both the exoplanet and asteroseismology areas. In addition to the high scientific potential of this program, it also provides technical benefits by furthering interferometric techniques that will be critical for future high angular resolution astronomy.

  7. High precision and high yield fabrication of dense nanoparticle arrays onto DNA origami at statistically independent binding sites

    NASA Astrophysics Data System (ADS)

    Takabayashi, Sadao; Klein, William P.; Onodera, Craig; Rapp, Blake; Flores-Estrada, Juan; Lindau, Elias; Snowball, Lejmarc; Sam, Joseph T.; Padilla, Jennifer E.; Lee, Jeunghoon; Knowlton, William B.; Graugnard, Elton; Yurke, Bernard; Kuang, Wan; Hughes, William L.

    2014-10-01

    High precision, high yield, and high density self-assembly of nanoparticles into arrays is essential for nanophotonics. Spatial deviations as small as a few nanometers can alter the properties of near-field coupled optical nanostructures. Several studies have reported assemblies of few nanoparticle structures with controlled spacing using DNA nanostructures with variable yield. Here, we report multi-tether design strategies and attachment yields for homo- and hetero-nanoparticle arrays templated by DNA origami nanotubes. Nanoparticle attachment yield via DNA hybridization is comparable with streptavidin-biotin binding. Independent of the number of binding sites, >97% site-occupation was achieved with four tethers and 99.2% site-occupation is theoretically possible with five tethers. The interparticle distance was within 2 nm of all design specifications and the nanoparticle spatial deviations decreased with interparticle spacing. Modified geometric, binomial, and trinomial distributions indicate that site-bridging, steric hindrance, and electrostatic repulsion were not dominant barriers to self-assembly and both tethers and binding sites were statistically independent at high particle densities.High precision, high yield, and high density self-assembly of nanoparticles into arrays is essential for nanophotonics. Spatial deviations as small as a few nanometers can alter the properties of near-field coupled optical nanostructures. Several studies have reported assemblies of few nanoparticle structures with controlled spacing using DNA nanostructures with variable yield. Here, we report multi-tether design strategies and attachment yields for homo- and hetero-nanoparticle arrays templated by DNA origami nanotubes. Nanoparticle attachment yield via DNA hybridization is comparable with streptavidin-biotin binding. Independent of the number of binding sites, >97% site-occupation was achieved with four tethers and 99.2% site-occupation is theoretically possible with five tethers. The interparticle distance was within 2 nm of all design specifications and the nanoparticle spatial deviations decreased with interparticle spacing. Modified geometric, binomial, and trinomial distributions indicate that site-bridging, steric hindrance, and electrostatic repulsion were not dominant barriers to self-assembly and both tethers and binding sites were statistically independent at high particle densities. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03069a

  8. High-precision Timing of Five Millisecond Pulsars: Space Velocities, Binary Evolution, and Equivalence Principles

    NASA Astrophysics Data System (ADS)

    Gonzalez, M. E.; Stairs, I. H.; Ferdman, R. D.; Freire, P. C. C.; Nice, D. J.; Demorest, P. B.; Ransom, S. M.; Kramer, M.; Camilo, F.; Hobbs, G.; Manchester, R. N.; Lyne, A. G.

    2011-12-01

    We present high-precision timing of five millisecond pulsars (MSPs) carried out for more than seven years; four pulsars are in binary systems and one is isolated. We are able to measure the pulsars' proper motions and derive an estimate for their space velocities. The measured two-dimensional velocities are in the range 70-210 km s-1, consistent with those measured for other MSPs. We also use all the available proper motion information for isolated and binary MSPs to update the known velocity distribution for these populations. As found by earlier works, we find that the velocity distribution of binary and isolated MSPs are indistinguishable with the current data. Four of the pulsars in our observing program are highly recycled with low-mass white dwarf companions and we are able to derive accurate binary parameters for these systems. For three of these binary systems, we are able to place initial constraints on the pulsar masses with best-fit values in the range 1.0-1.6 M ?. The implications of the results presented here to our understanding of binary pulsar evolution are discussed. The updated parameters for the binary systems studied here, together with recently discovered similar systems, allowed us to update previous limits on the violation of the strong equivalence principle through the parameter |?| to 4.6 × 10-3 (95% confidence) and the violation of Lorentz invariance/momentum conservation through the parameter |\\hat{\\alpha }_3| to 5.5 × 10-20 (95% confidence).

  9. Frontend electronics for high-precision single photo-electron timing using FPGA-TDCs

    NASA Astrophysics Data System (ADS)

    Cardinali, M.; Dzyhgadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Ugur, C.; Zühlsdorf, M.; Dodokhov, V. Kh.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Düren, M.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Cowie, E.; Keri, T.; Montgomery, R.; Rosner, G.; Achenbach, P.; Corell, O.; Ferretti Bondy, M. I.; Hoek, M.; Lauth, W.; Rosner, C.; Sfienti, C.; Thiel, M.; Bühler, P.; Gruber, L.; Marton, J.; Suzuki, K.

    2014-12-01

    The next generation of high-luminosity experiments requires excellent particle identification detectors which calls for Imaging Cherenkov counters with fast electronics to cope with the expected hit rates. A Barrel DIRC will be used in the central region of the Target Spectrometer of the planned PANDA experiment at FAIR. A single photo-electron timing resolution of better than 100 ps is required by the Barrel DIRC to disentangle the complicated patterns created on the image plane. R&D studies have been performed to provide a design based on the TRB3 readout using FPGA-TDCs with a precision better than 20 ps RMS and custom frontend electronics with high-bandwidth pre-amplifiers and fast discriminators. The discriminators also provide time-over-threshold information thus enabling walk corrections to improve the timing resolution. Two types of frontend electronics cards optimised for reading out 64-channel PHOTONIS Planacon MCP-PMTs were tested: one based on the NINO ASIC and the other, called PADIWA, on FPGA discriminators. Promising results were obtained in a full characterisation using a fast laser setup and in a test experiment at MAMI, Mainz, with a small scale DIRC prototype.

  10. High Precision UV Measurements in CO, Towards a Laboratory Test of the Time-Invariance of ?.

    NASA Astrophysics Data System (ADS)

    de Nijs, Adrian J.; Eikema, Kjeld S. E.; Ubachs, Wim; Bethlem, Hendrick L.

    2011-06-01

    The metastable a^3? state of CO has favourable properties for testing the time-invariance of physical constants. Due to an incidental near-degeneracy between the ?=0, J=8 and the ?=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^1?^+ ? a^3? 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 ?. H.L. Bethlem and W. Ubachs, Faraday Discussions 142, 25-36 (2009)

  11. The Spring 1985 high precision baseline test of the JPL GPS-based geodetic system

    NASA Technical Reports Server (NTRS)

    Davidson, John M.; Thornton, Catherine L.; Stephens, Scott A.; Blewitt, Geoffrey; Lichten, Stephen M.; Sovers, Ojars J.; Kroger, Peter M.; Skrumeda, Lisa L.; Border, James S.; Neilan, Ruth E.

    1987-01-01

    The Spring 1985 High Precision Baseline Test (HPBT) was conducted. The HPBT was designed to meet a number of objectives. Foremost among these was the demonstration of a level of accuracy of 1 to 2:10 to the 7th power, or better, for baselines ranging in length up to several hundred kilometers. These objectives were all met with a high degree of success, with respect to the demonstration of system accuracy in particular. The results from six baselines ranging in length from 70 to 729 km were examined for repeatability and, in the case of three baselines, were compared to results from colocated VLBI systems. Repeatability was found to be 5:10 to the 8th power (RMS) for the north baseline coordinate, independent of baseline length, while for the east coordinate RMS repeatability was found to be larger than this by factors of 2 to 4. The GPS-based results were found to be in agreement with those from colocated VLBI measurements, when corrected for the physical separations of the VLBI and CPG antennas, at the level of 1 to 2:10 to the 7th power in all coordinates, independent of baseline length. The results for baseline repeatability are consistent with the current GPA error budget, but the GPS-VLBI intercomparisons disagree at a somewhat larger level than expected. It is hypothesized that these differences may result from errors in the local survey measurements used to correct for the separations of the GPS and VLBI antenna reference centers.

  12. An approach to segment lung pleura from CT data with high precision

    NASA Astrophysics Data System (ADS)

    Angelats, E.; Chaisaowong, K.; Knepper, A.; Kraus, T.; Aach, T.

    2008-03-01

    A new approach to segment pleurae from CT data with high precision is introduced. This approach is developed in the segmentation's framework of an image analysis system to automatically detect pleural thickenings. The new technique to carry out the 3D segmentation of lung pleura is based on supervised range-constrained thresholding and a Gibbs-Markov random field model. An initial segmentation is done using the 3D histogram by supervised range-constrained thresholding. 3D connected component labelling is then applied to find the thorax. In order to detect and remove trachea and bronchi therein, the 3D histogram of connected pulmonary organs is modelled as a finite mixture of Gaussian distributions. Parameters are estimated using the Expectation-Maximization algorithm, which leads to the classification of that pulmonary region. As consequence left and right lungs are separated. Finally we apply a Gibbs-Markov random field model to our initial segmentation in order to achieve a high accuracy segmentation of lung pleura. The Gibbs- Markov random field is combined with maximum a posteriori estimation to estimate optimal pleural contours. With these procedures, a new segmentation strategy is developed in order to improve the reliability and accuracy of the detection of pleural contours and to achieve a better assessment performance of pleural thickenings.

  13. High precision materials processing using a novel Q-switched CO2 laser

    NASA Astrophysics Data System (ADS)

    Gräf, Stephan; Staupendahl, Gisbert; Krämer, André; Müller, Frank A.

    2015-03-01

    Holes with diameters of about 400 ?m have been laser trepanned in Ti6Al4V and carbon fibre reinforced polymer (CFRP) thin sheets with a thickness of 0.5 mm. A commercial CO2 laser (SM1500E, FEHA LaserTec, Germany) and a novel Q-switched CO2 laser (?-storm, IAI, Netherlands) were used as radiation sources. Optical microscopy, scanning electron microscopy and replicas of the processed holes were used to investigate the influence of the CO2 laser pulse parameters (e.g. pulse energy, duration and peak power) on the processing quality. It was shown that melt formation and high temperature oxidation reactions of Ti6Al4V during thermal laser processing were reduced significantly by using short and high intense Q-switched CO2 laser pulses. During trepanning of CFRP heat affected zones resulting from the extremely different thermal properties (melting and vaporisation temperature, heat conduction) of the reinforcing carbon fibres and the polymer matrix were reduced significantly by using the Q-switched CO2 laser. The results demonstrate that Ti6Al4V and CFRP can be processed very precisely with CO2 laser radiation and air as processing gas without melt formation and thermal damage.

  14. High-precision thermal expansion measurements using small Fabry-Perot etalons

    NASA Astrophysics Data System (ADS)

    Davis, Mark J.; Hayden, Joseph S.; Farber, Daniel L.

    2007-09-01

    Coefficient of thermal expansion (CTE) measurements using small Fabry-Perot etalons were conducted on high and low thermal expansion materials differing in CTE by a factor of nearly 400. The smallest detectable change in length was ~10 -12 m. The sample consisted of a mm-sized Fabry-Perot etalon equipped with spherical mirrors; the material-under-test served as the 2.5 mm-thick spacer between the mirrors. A heterodyne optical setup was used with one laser locked to an ~780 nm hyperfine line of Rb gas and the other locked to a resonance of the sample etalon; changes in the beat frequency between the two lasers as a function of temperature directly provided a CTE value. The measurement system was tested using the high-CTE SCHOTT optical glass N-KF9 (CTE = 9.5 ppm/K at 23 °C). Measurements conducted under reproducibility conditions using five identically-prepared N-KF9 etalons demonstrate a precision of 0.1 ppm/K; absolute values (accuracy) are within 2-sigma errors with those made using mechanical dilatometers with 100-mm long sample rods. Etalon-based CTE measurements were also made on a high-CTE (~10.5 ppm/K), proprietary glass-ceramic used for high peak-pressure electrical feedthroughs and revealed statistically significant differences among parts made under what were assumed to be identical conditions. Finally, CTE measurements were made on etalons constructed from SCHOTT's ultra-low CTE Zerodur (R) glass-ceramic (CTE about -20 ppb/K at 50 °C for the material tested herein).

  15. High-precision {beta} decay half-life measurements of proton-rich nuclei for testing the CVC hypothesis

    SciTech Connect

    Kurtukian-Nieto, T. [Centre d'Etudes Nucleaires de Bordeaux-Gradignan (CENBG), Universite Bordeaux 1, CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan cedex (France); Collaboration: NEX Group of CENBG

    2011-11-30

    The experimental study of super-allowed nuclear {beta} decays serves as a sensitive probe of the conservation of the weak vector current (CVC) and allows tight limits to be set on the presence of scalar or right-handed currents. Once CVC is verified, it is possible to determine the V{sub ud} element of the CKM quark-mixing matrix. Similarly, the study of nuclear mirror {beta} decays allows to arrive at the same final quantity V{sub ud}. Whereas dedicated studies of 0{sup +}{yields}0{sup +} decays are performed for several decades now, the potential of mirror transitions was only rediscovered recently. Therefore, it can be expected that important progress is possible with high-precision studies of different mirror {beta} decays. In the present piece of work the half-life measurements performed by the CENBG group of the proton-rich nuclei {sup 42}Ti, {sup 38-39}Ca, {sup 30-31}S and {sup 29}P are summarised.

  16. High-precision gas chromatography-combustion isotope ratio mass spectrometry at low signal levels

    Microsoft Academic Search

    Keith J. Goodman; J. Thomas Brenna

    1995-01-01

    Precision and accuracy of gas chromatography-combustion isotope ratio mass spectrometry are investigated for sample levels down to about 5 pmol C in fatty acid methyl ester mixtures spanning 1000-fold in concentration. Precision and accuracy of isotope ratios diverge rapidly for conventional summation methods, and become unusable below 30 pmol material on column. At lower levels, mean isotope ratios were statistically

  17. High-Precision Isotope Analysis Of Uranium And Thorium By Tims

    SciTech Connect

    L.A. Neymark

    2006-08-31

    The U.S. Geological Survey (USGS) Yucca Mountain Project Branch laboratory in Denver, Colorado, conducts routine high-precision isotope analyses of uranium (U) and thorium (Th) using thermal ionization mass-spectrometry (TIMS). The measurements are conducted by a solid-source mass-spectrometer equipped with a Faraday multi-collector system and an energy filter in front of an active-film-type secondary electron multiplier (SEM). The abundance sensitivity of the instrument (signal at mass 237 over {sup 238}U in natural U) with the energy filter is {approx} 15 x 10{sup -9} and peak tails are reduced by a factor of {approx}100 relative to the Faraday cup measurements. Since instrument installation in April 2004, more than 500 rock and water samples have been analyzed in support of isotope-geochemical studies for the U.S. Department of Energy's Yucca Mountain Project. Isotope ratios of sub-nanogram to microgram U and Th samples are measured on graphite-coated single-filament and double-filament assemblies using zone-refined rhenium filaments. Ion beams less than 5 millivolt (mV) are measured with the SEM, which is corrected for non-linearity on the basis of measurements of National Institute of Standards and Technology (NIST) U-500 and 4321 B standards with ion beams ranging from 0.01 to 8 mV. Inter-calibration between the SEM and the Faraday multi-collector is performed for every mass cycle using a {approx}5 mV beam switched between Faraday cup and SEM ('bridging' technique), because SEM-Faraday inter-calibrations prior to the measurement failed to produce acceptable results. Either natural ({sup 235}U) or artificial ({sup 236}U, {sup 229}Th) isotopes were used for the bridging. Separate runs are conducted for minor isotopes using SEM only. These techniques result in high within-run precisions of <0.1 to 0.2 percent for {sup 234}U/{sup 238}U and 0.2 to 0.5 percent for {sup 230}Th/{sup 238}U.

  18. An Experimental Study on the Dependent on the Location for the Precision of the Network-Based RTK-GPS Positioning

    Microsoft Academic Search

    Hiromune Namie; Chunming Fan; Sumio Usui; Akio Yasuda

    2005-01-01

    The precision of a few centimeters can be easily obtained in 2drms of the horizontal positions by RTK-GPS positioning, as the range from a user GPS antenna to the satellite is determined by the phase measurement of the carrier waves. Since December 2000, it has been operated experimentally by the network-based system, known as the area correction parameter FKP (flächen-korrectur-parameter

  19. Application of high precision band structure calculations to the equation of state for beryllium oxide: SESAME equation of state number 7612

    SciTech Connect

    Boettger, J.C.; Wills, J.M.

    1992-03-01

    High precision electronic band structure calculations for BeO have revealed a large volume discontinuity structural phase transition on the 0 K isotherm at about 1 Mbar. Although, this transition has not been observed experimentally, the accuracy of the calculations is such that the existence of this transition is unambiguous. A transition of this magnitude is likely to have a substantial impact on hydrodynamic simulations involving BeO. Here we report the creation of a new SESAME equations of state for BeO which incorporates the effect of the theoretically determined phase transition. This new EOS will be added to the SESAME library as material number 7612.

  20. On the relevance of applying high-precision magnetic field models to magnetic data for studying the ionosphere

    NASA Astrophysics Data System (ADS)

    Stolle, Claudia; Michaelis, Ingo; Rauberg, Jan; Dorgerloh, Florian

    2015-04-01

    Observations of the Earth's magnetic field are an excellent tool for remote sensing ionospheric currents. For a reliable analysis of the magnetic field sources in the ionosphere, contributions from the other sources have to be estimated and removed from the data. These sources are from the Earth's core and lithosphere and from large scale currents in the magnetosphere. The latter contributions can be estimated from recent geomagnetic field modeling. A standard model is the International Geomagnetic Reference Field (IGRF) that covers the contributions from the Earth's core field. More advanced high precision magnetic field models deliver as well a description of the lithospheric and magnetospheric contributions. This work discusses the relevance of applying high precision magnetic field models against IGRF for the analysis of different ionospheric current systems, during disturbed and quiet magnetic conditions. Therefore, we will present examples and statistical analyses of magnetic residuals of ground observatory data and high-precision magnetic field observations onboard satellites.

  1. High-precision mapping of seismicity in the 2014 Bárdarbunga volcanic episode

    NASA Astrophysics Data System (ADS)

    Vogfjörd, Kristín S.; Hensch, Martin; Gudmundsson, Gunnar B.; Jónsdóttir, Kristín

    2015-04-01

    The Bárdarbunga volcano and its associated fissure swarm in Iceland's Eastern volcanic zone is a highly active system with over 20 eruptions in the last 11 centuries. The location of this active volcano and much of the fissure swarm under several hundred metres thick ice gives rise to multiple hazards, including explosive, subglacial eruptions and associated subglacial floods (jökulhlaups), as well as fissure eruptions extruding large volumes of lava. After a decade of increasing seismic activity, volcanic unrest at Bárdarbunga suddenly escalated into a minor subglacial eruption on 16 August 2014. In the following weeks seismic activity soared and surface deformation of tens of cm were observed, caused by rifting and a dyke intrusion, which propagated 48 km northward from the central volcano (Sigmundsson et al., 2014). The dyke propagation stopped just outside the glacial margin and ended in a fissure eruption at Holuhraun at the end of August. At the time of writing the eruption is ongoing, having extruded a lava volume of over 1 km3 and released high rates of SO2 into the atmosphere. Over twenty thousand microearthquakes have been recorded. Initially most were in the dyke, but after the first two weeks the activity around the caldera rim increased and over 70 shallow earthquakes with MW > 5 have been located along the caldera rim accompanied by caldera subsidence. At the onset of the unrest on 16 August, the seismicity was located in the caldera and north of the caldera rim, but already in the first few hours the activity propagated out of the caldera to the SE. Still, the activity continued for a few days in the fissure swarm to the NE of the rim. High-precision earthquake locations in the propagating dyke have revealed its very detailed, planar rifting segments, with the events distributed over a 3-4 km depth range, and mostly between 6 and 9 km. These very planar event distributions are highly unusual in volcanic areas and strongly suggest rifting of unbroken crust as the magma intruded. The lateral propagation direction of the seismicity abruptly changes direction along each new segment, sometimes by up to 90 degrees and the propagation was sporadic, advancing with varying speed and sometimes stopping for periods of time. During these times of arrest, continuous low-frequency seismic tremor was sometimes recorded for several hours. A few days following these episodes, depressions appeared on the ice surface, confirming initial assumptions that the tremor was revealing temporary magma-ice interaction on the surface below the glacier. Relative locations of microearthquakes around the caldera rim are much less constrained and their distribution is more diffuse. However, along the southern caldera rim, the events follow the linear trend of the rim and extend to a few km depth. At the northern caldera margin the distribution is more diffuse and appears to dip towards north. An overview will be given of the high-precision locations in the dyke and around the caldera rim and estimation of absolute location accuracies in horizontal and vertical direction discussed. A joint interpretation of the best fitting focal mechanisms with the rifting planes, as defined by the event distribution in the dyke, will also be presented to show the lateral variation in the stress field orientation along the dyke. The high relative, lateral location accuracy in the dyke allows detailed examination of the temporal propagation so some examples of the temporal dyke advance will also be shown. Sigmundsson and 36 others. 2014. Segmented lateral dyke growth in a rifting event at Bárðarbunga volcanic system, Iceland. Nature. doi:10.1038/nature14111.

  2. High precision and high yield fabrication of dense nanoparticle arrays onto DNA origami at statistically independent binding sites.

    PubMed

    Takabayashi, Sadao; Klein, William P; Onodera, Craig; Rapp, Blake; Flores-Estrada, Juan; Lindau, Elias; Snowball, Lejmarc; Sam, Joseph T; Padilla, Jennifer E; Lee, Jeunghoon; Knowlton, William B; Graugnard, Elton; Yurke, Bernard; Kuang, Wan; Hughes, William L

    2014-11-21

    High precision, high yield, and high density self-assembly of nanoparticles into arrays is essential for nanophotonics. Spatial deviations as small as a few nanometers can alter the properties of near-field coupled optical nanostructures. Several studies have reported assemblies of few nanoparticle structures with controlled spacing using DNA nanostructures with variable yield. Here, we report multi-tether design strategies and attachment yields for homo- and hetero-nanoparticle arrays templated by DNA origami nanotubes. Nanoparticle attachment yield via DNA hybridization is comparable with streptavidin-biotin binding. Independent of the number of binding sites, >97% site-occupation was achieved with four tethers and 99.2% site-occupation is theoretically possible with five tethers. The interparticle distance was within 2 nm of all design specifications and the nanoparticle spatial deviations decreased with interparticle spacing. Modified geometric, binomial, and trinomial distributions indicate that site-bridging, steric hindrance, and electrostatic repulsion were not dominant barriers to self-assembly and both tethers and binding sites were statistically independent at high particle densities. PMID:25311051

  3. High-precision surface measurement with an automated multiangle low coherence interferometer.

    PubMed

    Li, Yinan; Kästner, Markus; Reithmeier, Eduard

    2015-02-20

    We propose a novel measurement system based on a low coherence Michelson interferometer and six-axis hexapod platform to accurately measure structures with high aspect ratio using different tilt angles of the measured surface. In order to realize automatic measurement, the system is designed to automatically perform autofocusing, adjust the tilt angle of the test surface, make surface measurements, and merge the measurement data sets. Due to certain topography, e.g., structures with high aspect ratio, the interferometer cannot obtain enough reflected light to evaluate the height information in some areas of the test surface. For this reason, we developed a measurement system that uses measurements from different tilt angles of the test surface and stitching algorithms to realize a complete surface measurement data set. The performance of the proposed measurement system is evaluated experimentally and compared to the results of measurements using a perthometer. PMID:25968182

  4. The study of high precision assistant navigation system with micro-magnetic sensors

    NASA Astrophysics Data System (ADS)

    Huang, Xuegong; Fang, Jiancheng; Guo, Lei; Jiang, Yanwei

    2007-11-01

    Low-cost MEMS sensors often suffer from inaccuracy and are influenced greatly by temperature variation, and the orientation error is cumulate with time. The GPS can provide long term stability with high accuracy, but it has its insufficiencies, such as disturbed easy, lower data updating rate and so on, it is hard to meet the demand of real-time measuring. The micro-magnetic sensors, an independence precision tool, can offer real-time yaw attitude angle, and this can correct the orientation cumulate error, and it increase the independence in flight of the UAV. Based on analyzing the selection principles of testing sensor, comparing 3 kinds micro-magnetic sensors, the GMI magnetic sensor is best to test geomagnetic field. The Regional model of geomagnetic field is built, and a GMI-magnetic sensor navigation method is put forward. Three-axis magnetic sensor measure the geomagnetic field, and it is matching with the geomagnetic map, then the geomagnetic elements on currently position are knew, combining with the information of accelerometer, the position information can be gotten by matching algorithm.

  5. A high-precision, distributed geodetic strainmeter based on dual coaxial cable Bragg gratings

    NASA Astrophysics Data System (ADS)

    Fu, J.; Wei, T.; Wei, M.; Shen, Y.

    2014-12-01

    Observations of surface deformation are essential for understanding a wide range of geophysical problems, including earthquakes, volcanoes, landslides, and glaciers. Current geodetic technologies, such as GPS, InSAR, borehole and laser strainmeters, are costly and limited in their temporal or spatial resolution. Here we present a new type of strainmeter based on coaxial cable Bragg grating (CCBG) sensing technology that provides high-precision, distributed strain measurements at a moderate cost. The coaxial-cable-based strainmeter is designed to cover a long distance (~ km) under harsh environmental conditions such as extreme temperatures. To minimize the environmental noises, two CCBGs are introduced into the geodetic strainmeter: one is used to measure the strain applied on it, and the other acts as a reference only to detect the environmental noises. The environmental noises are removed using the inputs from the strained CCBG and the reference CCBG in a frequency mixer. The test results show that the geodetic strainmeter with dual CCBGs has micron-strain accuracy in the lab.

  6. High precision measurements of wetland sediment elevation: II. The rod surface elevation table

    USGS Publications Warehouse

    Cahoon, D.R.; Lynch, J.C.; Perez, B.C.; Segura, B.; Holland, R.D.; Stelly, C.; Stephenson, G.; Hensel, P.

    2002-01-01

    A new high-precision device for measuring sediment elevation in emergent and shallow water wetland systems is described. The rod surface-elevation table (RSET) is a balanced, lightweight mechanical leveling device that attaches to both shallow ( 1 m in order to be stable. The pipe is driven to refusal but typically to a depth shallower than the rod bench mark because of greater surface resistance of the pipe. Thus, the RSET makes it possible to partition change in sediment elevation over shallower (e.g., the root zone) and deeper depths of the sediment profile than is possible with the SET. The confidence intervals for the height of an individual pin measured by two different operators with the RSET under laboratory conditions were ?? 1.0 and ?? 1.5 mm. Under field conditions, confidence intervals for the measured height of an individual pin ranged from ?? 1.3 mm in a mangrove forest up to ?? 4.3 mm in a salt marsh.

  7. High-precision measurements of wetland sediment elevation. II The rod surface elevation table

    USGS Publications Warehouse

    Cahoon, D.R.; Lynch, J.C.; Perez, B.C.; Segura, B.; Holland, R.D.; Stelly, C.; Stephenson, G.; Hensel, P.

    2002-01-01

    A new high-precision device for measuring sediment elevation in emergent and shallow water wetland systems is described. The rod surface-elevation table (RSET) is a balanced, lightweight mechanical leveling device that attaches to both shallow ( 1 m in order to be stable. The pipe is driven to refusal but typically to a depth shallower than the rod bench mark because of greater surface resistance of the pipe. Thus, the RSET makes it possible to partition change in sediment elevation over shallower (e.g., the root zone) and deeper depths of the sediment profile than is possible with the SET. The confidence intervals for the height of an individual pin measured by two different operators with the RSET under laboratory conditions were A? 1.0 and A? 1.5 mm. Under field conditions, confidence intervals for the measured height of an individual pin ranged from A? 1.3 mm in a mangrove forest up to A? 4.3 mm in a salt marsh.

  8. Development of a micro-CMM with scanning touch probe and high-precision coplanar platform

    NASA Astrophysics Data System (ADS)

    Chu, Chih-Liang; Lu, Chin-Tu; Chen, Hung-Chi; Ke, Jhih-Sian; Chang, Chao-Ming

    2013-10-01

    This study develops a micro-CMM incorporating a scanning touch probe and a high-precision coplanar platform. The measurement performance of the proposed system was enhanced through the use of a rigid aluminum double-arch-bridge structure to support the scanning touch probe. For the working stage, a linear motor was used for long-stroke positioning and a piezoelectric actuator was then employed to fine-tune the positioning so as to achieve a requirement of highprecision. The platform has two characteristics: (i) the driving and measuring axes are designed along the same line so that Abbe error of the stage can be eliminated; (ii) the coplanar design makes the X and Y axes reach a goal of two-axis concurrent. The aforementioned two designs can reduce the error of the platform so that the micro-CMM reaches a positioning accuracy of ±0.1?m for a working volume of 80×80×40 mm3. Furthermore, the reliability of the probe mechanism of three degrees of freedom was analyzed and validated. The sensor coordinates a laser diode with Position Sensor Detectors (PSD) working with an optical path to measure placement of Z-axis and angle placement of XY-axis. By validation through an experiment, the three dimensional scanning touch probe developed by this study has a measuring range of ±1mm × ±1mm × 1mm with a unidirectional repeatability of 0.6?m.

  9. High-Precision Thermodynamic and Critical Properties from Tensor Renormalization-Group Flows

    NASA Astrophysics Data System (ADS)

    Hinczewski, Michael; Berker, A. Nihat

    2008-03-01

    The recently developed tensor renormalization-group (TRG) method [1] provides a highly precise technique for deriving thermodynamic and critical properties of lattice Hamiltonians. The TRG is a local coarse-graining transformation, with the elements of the tensor at each lattice site playing the part of the interactions that undergo the renormalization-group flows. These tensor flows are directly related [2] to the phase diagram structure of the infinite system, with each phase flowing to a distinct surface of fixed points. Fixed-point analysis and summation along the flows give the critical exponents, as well as thermodynamic functions along the entire temperature range. Thus, for the ferromagnetic triangular lattice Ising model, the free energy is calculated to better than 10-5 along the entire temperature range. Unlike previous position-space renormalization-group methods, the truncation (of the tensor index range D) in this general method converges under straightforward and systematic improvements. Our best results are easily obtained with D=24, corresponding to 4624-dimensional renormalization-group flows. [1] M. Levin and C.P. Nave, Phys. Rev. Lett. 99, 120601 (2007). [2] M. Hinczewski and A.N. Berker, arXiv:0709.2803v1 [cond-mat.stat-mech], Phys. Rev. E, in press.

  10. Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts

    NASA Astrophysics Data System (ADS)

    Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

    2005-02-01

    The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

  11. High-precision prompt-?-ray spectral data from the reaction Pu241(nth, f)

    NASA Astrophysics Data System (ADS)

    Oberstedt, S.; Billnert, R.; Belgya, T.; Bry?, T.; Geerts, W.; Guerrero, C.; Hambsch, F.-J.; Kis, Z.; Moens, A.; Oberstedt, A.; Sibbens, G.; Szentmiklosi, L.; Vanleeuw, D.; Vidali, M.

    2014-08-01

    In this paper we present results from the first high-precision prompt-?-ray spectral measurements from the reaction Pu241(nth, f). Apart from one recent experiment, no data are reported in the literature for this fissioning system, which motivated a new dedicated experiment. We have measured prompt-fission ? rays with three cerium-doped LaBr3 (two 5.08cm×5.08 cm and one 7.62cm×7.62 cm) and one CeBr3 (5.08cm×5.08 cm) scintillation detectors, which all exhibit excellent timing and good energy resolution. The average ?-ray multiplicity was determined to be ?¯?=(8.21±0.09) per fission, the average energy to be ??=(0.78±0.01) MeV, and the total energy to be E? ,tot=(6.41±0.06) MeV as the weighted average from all detectors. Since the results from all detectors are in excellent agreement, and the total released ? energy is modestly higher than the one in the present evaluated nuclear data files, we suspect that the underestimation of the prompt-? heating in nuclear reactors is due to fast-neutron-induced fission on U238 or rather from fission induced by ? rays from neutron capture in the construction material.

  12. A high-precision ultrasonic system for vertical movement counts in rats.

    PubMed

    Lin, M T; Chen, Y B; Li, Y C; Young, M S

    1994-10-01

    A microcomputer-aided ultrasonic system was used to measure vertical displacement of rats in response to drug injection. The system utilizes an inexpensive PC/AT microcomputer for data collection and can distinguish between number of vertical movements of small (i.e., greater than 5 mm, but less than 15 mm), and large (i.e., greater than 15 mm) displacements. In addition, rest time denotes the time elapsed for the vertical motion of less than 5-mm displacements. As little as 0.32 mg/kg of d-amphetamine increased the average amount of both small and large activity (i.e., number of movements), but decreased the average amount of rest time in rats. On the contrary, as little as 2.5 mg/kg of chlorpromazine decreased the average amount of both small and large activity, but increased the rest time in rats. When the animal activity was measured with an infrared light system, the activity responses to drugs were not detectable. Thus, it appears that the ultrasonic method provides a high-precision system for measuring animal behaviors. PMID:7800748

  13. High-precision branching-ratio measurement for the superallowed ?+ emitter 74Rb

    NASA Astrophysics Data System (ADS)

    Dunlop, R.; Ball, G. C.; Leslie, J. R.; Svensson, C. E.; Towner, I. S.; Andreoiu, C.; Chagnon-Lessard, S.; Chester, A.; Cross, D. S.; Finlay, P.; Garnsworthy, A. B.; Garrett, P. E.; Glister, J.; Hackman, G.; Hadinia, B.; Leach, K. G.; Rand, E. T.; Starosta, K.; Tardiff, E. R.; Triambak, S.; Williams, S. J.; Wong, J.; Yates, S. W.; Zganjar, E. F.

    2013-10-01

    A high-precision branching-ratio measurement for the superallowed ?+ decay of 74Rb was performed at the TRIUMF Isotope Separator and Accelerator (ISAC) radioactive ion-beam facility. The scintillating electron-positron tagging array (SCEPTAR), composed of 10 thin plastic scintillators, was used to detect the emitted ? particles; the 8? spectrometer, an array of 20 Compton-suppressed HPGe detectors, was used for detecting ? rays that were emitted following Gamow-Teller and nonanalog Fermi ?+ decays of 74Rb; and the Pentagonal Array of Conversion Electron Spectrometers (PACES), an array of 5 Si(Li) detectors, was employed for measuring ?-delayed conversion electrons. Twenty-three excited states were identified in 74Kr following 8.241(4)×108 detected 74Rb ? decays. A total of 58 ?-ray and electron transitions were placed in the decay scheme, allowing the superallowed branching ratio to be determined as B0=99.545(31)%. Combined with previous half-life and Q-value measurements, the superallowed branching ratio measured in this work leads to a superallowed ft value of 3082.8(65) s. Comparisons between this superallowed ft value and the world-average-corrected Ft¯ value, as well as the nonanalog Fermi branching ratios determined in this work, provide guidance for theoretical models of the isospin-symmetry-breaking corrections in this mass region.

  14. Baseline suppression problems for high precision measurements using optical beam profile monitors

    SciTech Connect

    Thieberger, P.; Gassner, D.; Glenn, J.; Minty, M.; Zimmer, C.

    2011-03-28

    The use of fluorescent screens (e.g. YAG screens) and Optical Transition Radiation (OTR) screens for beam profile monitors provides a simple and widely used way to obtain detailed two dimensional intensity maps. What makes this possible is the availability of relatively inexpensive CCD cameras. For high precision measurements many possible error contributions need to be considered that have to do with properties of the fluorescent screens and of the CCDs. Saturation effects, reflections within and outside the screen, non-linearities, radiation damage, etc are often mentioned. Here we concentrate on an error source less commonly described, namely erroneous baseline subtraction, which is particularly important when fitting projected images. We show computer simulations as well as measurement results having remarkable sensitivity of the fitted profile widths to even partial suppression of the profile baseline data, which often arises from large pixel-to-pixel variations at low intensity levels. Such inadvertent baseline data suppression is very easy to miss as it is usually not obvious when inspecting projected profiles. In this report we illustrate this effect and discuss possible algorithms to automate the detection of this problem as well as some possible corrective measures.

  15. High precision {sup 89}Y({alpha},{alpha}){sup 89}Y scattering at low energies

    SciTech Connect

    Kiss, G. G.; Fueloep, Zs.; Gyuerky, Gy.; Elekes, Z.; Somorjai, E. [Institute of Nuclear Research (ATOMKI), H-4001 Debrecen (Hungary); Mohr, P. [Diakonie-Klinikum, D-74523 Schwaebisch Hall (Germany); Galaviz, D. [Instituto de Estructura de la Materia, CSIC, E-28006 Madrid (Spain); Kretschmer, A.; Sonnabend, K. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); Zilges, A. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937 Koeln (Germany); Avrigeanu, M. [Horia Hulubei National Institute for Physics and Nuclear Engineering, RO-76900 Bucharest (Romania)

    2009-10-15

    Elastic scattering cross sections of the {sup 89}Y({alpha},{alpha}){sup 89}Y reaction have been measured at energies E{sub c.m.}=15.51 and 18.63 MeV. The high-precision data for the semimagic N=50 nucleus {sup 89}Y are used to derive a local potential and to evaluate the predictions of global and regional {alpha}-nucleus potentials. The variation of the elastic {alpha}-scattering cross sections along the N=50 isotonic chain is investigated by a study of the ratios of angular distributions for {sup 89}Y({alpha},{alpha}){sup 89}Y and {sup 92}Mo({alpha},{alpha}){sup 92}Mo at E{sub c.m.}{approx_equal}15.51 and 18.63 MeV. This ratio is a very sensitive probe at energies close to the Coulomb barrier, where scattering data alone is usually not enough to characterize the different potentials. Furthermore, {alpha}-cluster states in {sup 93}Nb={sup 89}Y x {alpha} are investigated.

  16. High precision predictions for near-Earth asteroids: the strange case of (3908) Nyx

    NASA Astrophysics Data System (ADS)

    Farnocchia, D.; Chesley, S. R.; Tholen, D. J.; Micheli, M.

    2014-08-01

    In November 2004 radar delay measurements of near-Earth asteroid (3908) Nyx obtained at the Arecibo radio telescope turned out to be away from the orbital prediction. We prove that this discrepancy was caused by a poor astrometric treatment and an incomplete dynamical model, which did not account for nongravitational perturbations. To improve the astrometric treatment, we remove known star catalog biases, apply suitable weights to the observations, and use an aggressive outlier rejection scheme. The main issue related to the dynamical model is having not accounted for the Yarkovsky effect. Including the Yarkovsky perturbation in the model makes the orbital prediction and the radar measurements statistically consistent by both reducing the offset and increasing the prediction uncertainty to a more realistic level. This analysis shows the sensitivity of high precision predictions to the astrometric treatment and the Yarkovsky effect. By using the full observational dataset we obtain a detection of the Yarkovsky effect acting on Nyx corresponding to an orbital drift m/year. In turn, we derive constraints on thermal inertia and bulk density. In particular, we find that the bulk density of Nyx is around 1 g/cm, possibly less. To make sure that our results are not corrupted by an asteroid impact or a close approach with a perturbing asteroid not included in our dynamical model, we show that the astrometry provides no convincing evidence of an impulsive variation of Nyx's velocity while crossing the main belt region.

  17. Design principle of high-precision flexure mechanisms based on parasitic-motion compensation

    NASA Astrophysics Data System (ADS)

    Li, Shouzhong; Yu, Jingjun

    2014-07-01

    In design of flexure mechanism, diminishing the parasitic-motion is a key point to improve the accuracy. However, most of existing topics concentrate on improving the accuracy of linear-motion flexure mechanisms via compensating the parasitic error, but few research the multi-dimensional flexure mechanisms. A general design principle and method for high-precision flexure mechanisms based on the parasitic-motion compensation is presented, and the proposed method can compensate the parasitic rotation in company with translation, or the parasitic translation in company with rotation, or both. The crucial step for the method is that the parasitic motion of a flexure mechanism is formulated and evaluated in terms of its compliance. The overall compliance matrix of a general flexure mechanism is formulated by using screw theory firstly, then the criteria for the parasitic motions is introduced by analyzing the characteristics of the resultant compliance matrix as well as with aid of the concept of instantaneous rotation center. Subsequently, a compliance-based compensation approach for reducing parasitic-motion is addressed as the most important part. The design principles and procedure are further discussed to help with improving the accuracy of flexure mechanisms, and case studies are provided to illustrate this method. Finally, an analytical verification is provided to demonstrate that the symmetry design philosophy widely used in flexure design can effectively improve accuracy in terms of the proposed method. The proposed compensation method can be well used to diminish the parasitic-motion of multi-dimensional flexure mechanisms.

  18. Troll oil pipeline: High precision seabed preparation down to 540 m water depth

    SciTech Connect

    Schuit, P. [A/S Jebsens ACZ, Gorinchem (Netherlands); Baldascino, G.; Canu, M. [Snamprogetti Spa, Fano (Italy); Oeverby, S.H. [Statoil, Stavanger (Norway)

    1996-12-01

    Oil and Gas Developments are finding their way to increasingly deep waters and complicated seabed topography, for which until recently the feasibility was doubted. Statoil`s Troll Oil pipeline Development Project is a typical example of such a project which is characterized by strong undulating seabed geometries, poor bearing capacities of the subsoil and water depths up to 540 m. By means of gravel supports and stabilization berms, removing soft soils at water depths up to 350 m and installation of concrete lateral supports, the seabed has been prepared to enable the Troll Oil pipeline to be laid without being overstressed and avoiding geotechnical instabilities of the subsoil. These seabed preparatory works were executed by means of the three Fallpipe Vessels operated by A/S Jebsens ACZ. The paper addresses the most recent developments in the execution of high precision seabed preparatory works, called Pre-lay Intervention Works, which are performed prior to laying of the pipeline. Special attention will be given to the required accuracy during construction/execution and possible improvements for future seabed preparatory works.

  19. High Precision Three-body Variational Method for Critical Nuclear Charge

    NASA Astrophysics Data System (ADS)

    Busuttil, Michael A.

    For an atom there exists a critical nuclear charge Zc that is just sufficient to bind the nucleus and its electrons into a stable configuration. A study of the critical charge for two-electron atoms is presented with the purpose of improving accuracy for Zc. To this end, high precision techniques involving the variational method with multiple basis sets in Hylleraas coordinates are employed. The method is particularly well adapted to the case where one electron is strongly bound and the other is at the limit of becoming unbound. The results are analysed in terms of fractional powers of (Z -- Zc) related to the analytic structure of the energy E( Z) and a 1/Z expansion for the energy. This results in a Zc of 0.91102808(5). Future work prompted by this study includes development of direct techniques to determine Zc utilizing the low-Z stability of the method; developing the framework and mathematical justification for a novel bootstrap analysis method used in curve-fitting; and investigating the inclusion of finite nuclear mass, relativistic effects, and other higher order corrections in the determination of Zc.

  20. High-precision calculation of loosely bound states of LiPs+ and NaPs+

    NASA Astrophysics Data System (ADS)

    Yamashita, Takuma; Kino, Yasushi

    2015-06-01

    A positronic alkali atom would be the first step to investigate behavior of a positronium(Ps) in an external field from atoms/molecules because the system can be regarded as a simple three-body system using model potentials reflecting electron orbitals of the ion core. In order to precisely determine binding energies and structures of positronic alkali atoms (LiPs+ and NaPs+), we improve the model potential so as to reproduce highly excited atomic energy levels of alkali atoms (Li and Na). The polarization potential included by the model potential is expanded in terms of Gaussian functions to finely determine a short range part of the potential which has been assumed to be a simple form. We find better reproducibility not only of atomic levels of the alkali atoms but also of the dipole polarizability of the core ion than previous works. We construct a model potential between a positron and an ion core based on the model potential between the valence electron and ion core. Binding energies associated with a dissociation of the alkali ion core and positronium, and interparticle distances are recalculated. Our results show slightly deeper bound than other previous studies.

  1. Identification of Error Sources in High Precision Weight Measurements of Gyroscopes

    E-print Network

    L?rincz, I

    2015-01-01

    A number of weight anomalies have been reported in the past with respect to gyroscopes. Much attention was gained from a paper in Physical Review Letters, when Japanese scientists announced that a gyroscope loses weight up to $0.005\\%$ when spinning only in the clockwise rotation with the gyroscope's axis in the vertical direction. Immediately afterwards, a number of other teams tried to replicate the effect, obtaining a null result. It was suggested that the reported effect by the Japanese was probably due to a vibration artifact, however, no final conclusion on the real cause has been obtained. We decided to build a dedicated high precision setup to test weight anomalies of spinning gyroscopes in various configurations. A number of error sources like precession and vibration and the nature of their influence on the measurements have been clearly identified, which led to the conclusive explanation of the conflicting reports. We found no anomaly within $\\Delta m/m<2.6 \\times 10^{-6}$ valid for both horizon...

  2. Precision Muon Physics

    E-print Network

    Gorringe, T P

    2015-01-01

    The muon is playing a unique role in sub-atomic physics. Studies of muon decay both determine the overall strength and establish the chiral structure of weak interactions, as well as setting extraordinary limits on charged-lepton-flavor-violating processes. Measurements of the muon's anomalous magnetic moment offer singular sensitivity to the completeness of the standard model and the predictions of many speculative theories. Spectroscopy of muonium and muonic atoms gives unmatched determinations of fundamental quantities including the magnetic moment ratio $\\mu_\\mu / \\mu_p$, lepton mass ratio $m_{\\mu} / m_e$, and proton charge radius $r_p$. Also, muon capture experiments are exploring elusive features of weak interactions involving nucleons and nuclei. We will review the experimental landscape of contemporary high-precision and high-sensitivity experiments with muons. One focus is the novel methods and ingenious techniques that achieve such precision and sensitivity in recent, present, and planned experiment...

  3. HIGH-PRECISION PREDICTIONS FOR THE ACOUSTIC SCALE IN THE NONLINEAR REGIME

    SciTech Connect

    Seo, Hee-Jong; Eckel, Jonathan; Eisenstein, Daniel J.; Mehta, Kushal; Metchnik, Marc; Padmanabhan, Nikhil; Pinto, Phillip; Takahashi, Ryuichi; White, Martin; Xu, Xiaoying

    2010-09-10

    We measure shifts of the acoustic scale due to nonlinear growth and redshift distortions to a high precision using a very large volume of high-force-resolution simulations. We compare results from various sets of simulations that differ in their force, volume, and mass resolution. We find a consistency within 1.5-sigma for shift values from different simulations and derive shift alpha(z) -1 = (0.300\\pm 0.015)% [D(z)/D(0)]^{2} using our fiducial set. We find a strong correlation with a non-unity slope between shifts in real space and in redshift space and a weak correlation between the initial redshift and low redshift. Density-field reconstruction not only removes the mean shifts and reduces errors on the mean, but also tightens the correlations: after reconstruction, we recover a slope of near unity for the correlation between the real and redshift space and restore a strong correlation between the low and the initial redshifts. We derive propagators and mode-coupling terms from our N-body simulations and compared with Zeldovich approximation and the shifts measured from the chi^2 fitting, respectively. We interpret the propagator and the mode-coupling term of a nonlinear density field in the context of an average and a dispersion of its complex Fourier coefficients relative to those of the linear density field; from these two terms, we derive a signal-to-noise ratio of the acoustic peak measurement. We attempt to improve our reconstruction method by implementing 2LPT and iterative operations: we obtain little improvement. The Fisher matrix estimates of uncertainty in the acoustic scale is tested using 5000 (Gpc/h)^3 of cosmological PM simulations from Takahashi et al. (2009). (abridged)

  4. 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.

  5. High-precision, cost-effective cutting system for producing thin sections of oral tissues containing dental implants

    Microsoft Academic Search

    A. Piattelli; A. Scarano; M. Quaranta

    1997-01-01

    A new high-precision, cost-effective cutting system, able to produce thin (20–30 ?m) sections of oral tissues, containing dental implants, is presented. With this system the authors have been able to obtain, in a reproducible and consistent way, thin slides containing biomaterials and biological tissues. Very high cellular detail was possible, even at high magnifications (× 1200). Histochemical reactions (e.g. acid

  6. Precision control of high temperature furnaces using an auxiliary power supply and charged particle current flow

    DOEpatents

    Pollock, G.G.

    1997-01-28

    Two power supplies are combined 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. 5 figs.

  7. Precision control of high temperature furnaces using an auxiliary power supply and charged practice current flow

    DOEpatents

    Pollock, George G. (San Ramon, CA)

    1997-01-01

    Two power supplies are combined 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.

  8. Precision determination of copper in samples of high-Tc superconductors by potentiostatic coulometry

    SciTech Connect

    Markova, I.V. [V.I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Moscow (Russian Federation)

    1994-04-10

    An important task in the creation of high-Tc superconductors of required composition is the sufficiently accurate determination of the main components of high-Tc superconductors. One of the most widely encountered elements appearing in high-Tc superconductors is copper, whose precision determination is possible by coulometry. The coulometric determination of copper is generally accomplished by reducing Cu(II) or Cu(I) to the metal on electrodes prepared from various materials (Pt, C). There have been reports to the determination of macroscopic quantities of copper with the aid of coulometric titrations. The relative standard deviation (s{sub r}) in these procedures for determining copper exceeds 0.01. A procedure for the simultaneous determination of copper and indium in CuInS{sub 2} by controlled-potential coulometry on a large mercury electrode in NaCl solutions was proposed (s{sub r} did not exceed 0.05, and the range of determinable amounts of copper extended from 0.3 to 3 mg). The determination of copper by potentiostatic coulometry on an automated computer-controlled system using a gold indicator electrode was described by Subochev et al.. They proposed the use of 1 M HCl and the reversible reaction (1) CuCl {r_equilibrium} Cu{sup 2+} + Cl{sup {minus}} + e. for the coulometric determination of macroscopic and microgram quantities of copper. This case offers an optimal situation for coulometry, under which both forms of the redox system [the reactant and product forms, which are Cu(I) and Cu(II) in the present case], remain in the solution. This makes it possible to repeat determinations many times in single aliquot portion of the solution and thus to improve the metrological characteristics of the determinations. Here, the authors investigated the possibility of using reaction (1) and a Pt screen with a large surface as the working electrode to determine copper in high-Tc superconducting materials which also contain barium, yttrium, and thallium.

  9. Experimental study of radiated emission from high speed power plane

    Microsoft Academic Search

    Wei-Shan Soh; Kye-Yak See; R. Weng-Yew Chang

    2008-01-01

    Power plane has been used commonly for high-speed PCB design to delivery stable power for the circuits as well as to provide low impedance paths for the power delivery currents. Using an experimental approach, the impacts of placement of decoupling capacitors and plane separation on radiated emission from high-speed board are carefully investigated and studied.

  10. Experimental Investigation of Using High Temperature Ground Source Heat

    Microsoft Academic Search

    Liu Yi; Li Bing-xi; Xu Xin-hai; Wang Ke-hang; Fu Zhong-bin; Zhou Yi

    2009-01-01

    High temperature ground source heat pump systems can be used to replace traditional oil or gas burning furnaces to heat output crude oil in oil transit, and can achieve better the effects of saving energy and reducing emissions. An experimental system of replaced the water jacket heater by the high temperature ground source heat pump system in a transit station

  11. High precision measurement of Gamma(Z ? bb¯)/Gamma(Z ? hadrons) with the DELPHI detector at LEP collider

    NASA Astrophysics Data System (ADS)

    Martinez Vidal, Fernando

    Among the measurements available at the Z pole center-of-mass energy, the ratio of the Z partial width into bb¯ quark pairs and its total hadronic partial width, R0b=GZ ?bbG Z?hadrons, has currently an exciting particular interest. Most electroweak and QCD radiative corrections cancel in the ratio, leaving R0b sensitive essentially to corrections to the Z ? bb¯ vertex, like the large CKM coupling to the top quark. Due to the high quality of the agreement between the Standard Model and most of precise observations, together with the recent top quark discovery and its direct mass measurement, the parameters of the Standard Model become better constrained. A precise measurement of R0b at 0.5% level tests thus not only the Standard Model but also the presence of novel radiative vertex corrections. In this way, R0b is currently one of the most interesting windows in the search for physics beyond the Standard Model. Experimentally, R0b can be obtained with only very small corrections from the ratio of cross-sections Rb, = sigma(e + e-- ? bb¯ )/sigma(e+ e -- ? hadrons). These small corrections are due to the photon propagation contribution. This thesis reports on the measurement of Rb, performed with the DELPHI detector at CERN's LEP collider, using the full LEP 1 statistics, recorded between the 1991 and 1995 years. About 60% of these data were taken with a high precision double sided silicon microvertex detector, and all the rest with a single sided silicon detector providing high resolution only in the plane transverse to the colliding beams. A total of about 4.2M hadronic Z decays were recorded and analyzed, together with about twice the data sample statistics of simulated hadronic events. In addition, dedicated Z ? bb¯ samples were used, corresponding to an equivalent amount of also twice the data sample size. The precise measurement of Rb, relies on high purity/efficiency hemisphere b tagging techniques. Due to the particular multihadronic topology of Z events at L EP 1 energies, multivariate methods provide efficient tools for performing a global flavour tagging by hemispheres, especially b identification. To optimize the event information and the high tracking resolution of the DELPHI detector, the following features are included in the algorithms: • three-dimensional and independent primary vertex reconstruction for each hemisphere of the event, reducing hemisphere-hemisphere tagging efficiency correlations; • three-dimensional secondary vertexing and invariant mass reconstruction; • three-dimensional impact parameters and related quantities; • event shape properties, like transverse and total momenta of decay products, rapidity of tracks and sphericity. For the precise determination of Rb, events are divided into hemispheres by the plane perpendicular to the thrust axis. Each hemisphere is then classified between six mutually exclusive tagging categories or tags ordered by decreasing b purity: b-tight, b-standard, b-loose, charm, uds and no-tag. There are 20 different observables (combinations of two hemisphere tags) and 17 independent unknowns: Rb, Rc and 15 uds, c and b tagging efficiencies. The direct fit of this double tag matrix is degenerated and additional constraints are needed. Two kinds of solutions were investigated. In the first one, the b efficiencies are estimated from the fraction of hemispheres tagged in one category while the opposite hemisphere is tagged as b as a function of a purity cut. The shape of the uds and c backgrounds is taken from the Monte Carlo simulation of the experiment, but the parameters themselves are measured directly from data. R c is taken from electroweak theory. This solution was proven to be systematically powerful but statistically limited due to the large number of free parameters in the fit. In the second approach, the uds and c backgrounds of the b-tight tag are estimated from simulation and introduced in the fit, taking as before Rc from electroweak theory. This approach resolves all problems of the first one. The quoted result was GZ?bb GZ?ha

  12. An Algorithm of Tool-Path Optimization for High-Speed Machining Deep-Cavity Precision Forging Die

    Microsoft Academic Search

    Q. P. Sun; Q. L. Chen; Q. F. Wang; W. H. Liao

    2009-01-01

    Aiming at the difficulty of maintaining the contour precision of forging die with deep pocket, an optimization algorithm of tool-path generation for high speed machining (abbr. HSM) forging die with deep cavity is proposed in this paper. In terms of measuring errors of pocketing die, a mathematical model correlation to the length of a tool-path, the available length of a

  13. Using Automated, High-Precision Repicking to Improve Delineation of Microseismic Structures at the Soultz Geothermal Reservoir

    E-print Network

    1 Using Automated, High-Precision Repicking to Improve Delineation of Microseismic Structures at the Soultz Geothermal Reservoir C.A. Rowe*1 , R.C. Aster1 , W.S. Phillips2 , R.H.Jones3 , B.Borchers4 and M in resolution of microseismic struc- tures using only a small fraction of the time and manpower which would

  14. Advances in hydride phase growth: Automatic high precision calorimeter-volumetric devices, for thermodynamic and kinetics analyses

    Microsoft Academic Search

    P. Dantzer; P. Millet

    2000-01-01

    A new automatic apparatus has been specifically developed for investigating phase transformations in hydrogen absorbing intermetallic compounds, providing accurate characterizations of the thermodynamic properties as well as of the dynamic aspects of the hydride phase growth over a wide range of pressures 0-4 MPa and temperatures 250-800 K. It consists essentially of a heat flow calorimeter coupled with high precision

  15. NORAD-ATOMIC-DATA NORAD-Atomic-Data contains ab initio high-precision fundamental data for radiative atomic

    E-print Network

    Nahar, Sultana Nurun

    requires several codes. In contrast to atomic structure codes, the R-matrix codes do not identify to results from atomic structure calculations, the R-matrix computations can consider and yield much largerNORAD-ATOMIC-DATA NORAD-Atomic-Data contains ab initio high-precision fundamental data

  16. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: Reducing background and attaining high precision

    Microsoft Academic Search

    Xiaomei Xu; Susan E. Trumbore; Shuhui Zheng; John R. Southon; Kelsey E. McDuffee; Madelyn Luttgen; Julia C. Liu

    2007-01-01

    The sealed tube zinc reduction method for converting CO2 to graphite for AMS 14C measurements was originally developed for rapid production of graphite in biomedical tracer experiments. The method was usually thought to have low precision and a high background. We have modified the zinc reduction method originally outlined in Vogel [J.S. Vogel, Radiocarbon 34 (3) (1992) 344] by carefully

  17. Monitoring local crustal movements using high precision GPS network and EDM baseline

    NASA Astrophysics Data System (ADS)

    Ahola, J.; Ollikainen, M.

    2003-04-01

    Finnish Geodetic Institute (FGI) established in a co-operation with Posiva Ltd. high precision GPS networks at Olkiluoto, Kivetty and Romuvaara in 1994-1995. The goal of the work is to study local crustal deformations at the areas, which were selected as candidates for a disposal of spent nuclear fuel used in Finland. The studies are now concentrated at Olkiluoto, because the Government and the Parliament have ratified the positive policy decision that makes it possible to establish the final disposal at Olkiluoto. The GPS network at Olkiluoto includes ten reinforced concrete pillars located in different geological blocks. The FGI has observed the network semiannually since 1995. The GPS observations were made in 24 h sessions with Ashtech Z-12 GPS receivers equipped with Ashtech Dorne Margolin Choke Ring antennas. The computations were made with Bernese GPS software using the L1 and L2 frequencies and the ionosphere models. According to the 14 measurements campaigns the largest baselines change rates are about 0.5 mm ± 0.1-0.2 mm per year. We have noticed that some GPS sessions yield baseline lengths, which are systematically longer than the mean of all campaigns. The systematic error is most probably due to the ionosphere modeling. In order to solve this scaling problem we established a 511 m baseline for electronic distance measurements (EDM) between two pillars in the spring 2002. We will measure the distance between these stations with Mekometer 5000 during the GPS measurement campaigns. Two Mekometer measurements were performed in 2002. The differences between the GPS and the EDM measurements are few tenth of millimeter. More measurement campaigns are needed to determine possible crustal movements at the Olkiluoto investigation area. GPS observations and electronic distance measurements will be continued semiannually.

  18. A new device for high precision in situ sediment temperature profile measurements at the seafloor

    NASA Astrophysics Data System (ADS)

    Feseker, T.; Wetzel, G.; Heesemann, B.

    2012-04-01

    In situ sediment temperature profile measurements at the seafloor provide valuable information on fluid seepage, hydrate stability, and ambient temperature of samples. In addition, it can be convenient to approximate other parameters such as concentrations of porewater constituents from temperature or temperature gradient using transfer functions if their distribution is controlled by the same processes and direct quantification involves time-consuming sampling and laboratory analyses. We present a new instrument that can be used to obtain precisely positioned sediment temperature profile measurements from the seafloor during ROV dives. Consisting of a 0.4 m-long sensor rod equipped with eight temperature sensors and a standard data logger, the new T-Stick can be operated by an ROV in a fully autonomous mode. The temperature range of the instrument is -5 °C to 35 °C and it can withstand pressures of up to 600 bar. Compared to previously used instruments, the smaller diameter of the new T-Stick reduces the thermal inertia of the lance and results in shorter equilibration times. Virtual measurements generated by a numerical model showed that the T-Stick provides highly accurate temperature profile measurements with a root mean square error of 0.0027 K for a wide range of thermal sediment properties. Modeled temperature gradients are representative of both normal deep sea settings and cold seep environments with elevated temperature gradients of up to three orders of magnitude above normal background values, which are the primary target areas for T-Stick measurements. Deviations from the true in situ temperature profiles are caused by disturbance of the temperature field by the probe itself and may lead to underestimation of gradients and curvature in the profiles. A first field test of the T-Stick was conducted at the Håkon Mosby mud volcano at 1250 m water depth on the Barents Sea slope, where the new instrument provided useful information about the origin and extent of freshly erupted mud.

  19. High-precision genetic mapping of behavioral traits in the diversity outbred mouse population

    PubMed Central

    Logan, R W; Robledo, R F; Recla, J M; Philip, V M; Bubier, J A; Jay, J J; Harwood, C; Wilcox, T; Gatti, D M; Bult, C J; Churchill, G A; Chesler, E J

    2013-01-01

    Historically our ability to identify genetic variants underlying complex behavioral traits in mice has been limited by low mapping resolution of conventional mouse crosses. The newly developed Diversity Outbred (DO) population promises to deliver improved resolution that will circumvent costly fine-mapping studies. The DO is derived from the same founder strains as the Collaborative Cross (CC), including three wild-derived strains. Thus the DO provides more allelic diversity and greater potential for discovery compared to crosses involving standard mouse strains. We have characterized 283 male and female DO mice using open-field, light–dark box, tail-suspension and visual-cliff avoidance tests to generate 38 behavioral measures. We identified several quantitative trait loci (QTL) for these traits with support intervals ranging from 1 to 3 Mb in size. These intervals contain relatively few genes (ranging from 5 to 96). For a majority of QTL, using the founder allelic effects together with whole genome sequence data, we could further narrow the positional candidates. Several QTL replicate previously published loci. Novel loci were also identified for anxiety- and activity-related traits. Half of the QTLs are associated with wild-derived alleles, confirming the value to behavioral genetics of added genetic diversity in the DO. In the presence of wild-alleles we sometimes observe behaviors that are qualitatively different from the expected response. Our results demonstrate that high-precision mapping of behavioral traits can be achieved with moderate numbers of DO animals, representing a significant advance in our ability to leverage the mouse as a tool for behavioral genetics PMID:23433259

  20. High-precision genetic mapping of behavioral traits in the diversity outbred mouse population.

    PubMed

    Logan, R W; Robledo, R F; Recla, J M; Philip, V M; Bubier, J A; Jay, J J; Harwood, C; Wilcox, T; Gatti, D M; Bult, C J; Churchill, G A; Chesler, E J

    2013-06-01

    Historically our ability to identify genetic variants underlying complex behavioral traits in mice has been limited by low mapping resolution of conventional mouse crosses. The newly developed Diversity Outbred (DO) population promises to deliver improved resolution that will circumvent costly fine-mapping studies. The DO is derived from the same founder strains as the Collaborative Cross (CC), including three wild-derived strains. Thus the DO provides more allelic diversity and greater potential for discovery compared to crosses involving standard mouse strains. We have characterized 283 male and female DO mice using open-field, light-dark box, tail-suspension and visual-cliff avoidance tests to generate 38 behavioral measures. We identified several quantitative trait loci (QTL) for these traits with support intervals ranging from 1 to 3?Mb in size. These intervals contain relatively few genes (ranging from 5 to 96). For a majority of QTL, using the founder allelic effects together with whole genome sequence data, we could further narrow the positional candidates. Several QTL replicate previously published loci. Novel loci were also identified for anxiety- and activity-related traits. Half of the QTLs are associated with wild-derived alleles, confirming the value to behavioral genetics of added genetic diversity in the DO. In the presence of wild-alleles we sometimes observe behaviors that are qualitatively different from the expected response. Our results demonstrate that high-precision mapping of behavioral traits can be achieved with moderate numbers of DO animals, representing a significant advance in our ability to leverage the mouse as a tool for behavioral genetics. PMID:23433259

  1. Glue test results for high-precision large cryogenic lens holder

    NASA Astrophysics Data System (ADS)

    Reutlinger, A.; Mottaghibonab, A.; Gal, C.; Boesz, A.; Grupp, F.; Geis, N.; Bode, A.; Katterloher, R.; Bender, R.

    2012-09-01

    The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision large lens holders (Ø170 mm) at cryogenic temperatures (150 K). The lenses of the optical system are glued into separate lens holders, the so called adaption rings. For the selection and verification of a suitable adhesive extensive glue selection tests are performed and results presented in this paper. With potential glue candidates, handling, single lap shear, connection tension and shear tests are carried out at room temperature (RT) and 150 K (OPS). For the NISP optical system DP490 is selected as the most suitable adhesive. The test results have shown that an even distribution of the glue in the glue gap is of crucial importance for the functioning and performance of the bonded lens system. The different coefficients of thermal expansion (CTE) between lens and lens holder produce large local mechanical stress and might cause lens breakage or failure of bonding. The design of the injection channel and the gluing procedure are developed to meet the lens performance requirements. An example is shown that after thermal cycling the remaining 0.5 mm - 1 mm thick adhesive in the injection channel results in large local mechanical stresses, and hence, damage of the lens. For a successful performance of the glue interface not only an optimum glue gap of 80 - 150 ?m is important, also micro-cracks of the glass at the gluing area have to be avoided. The performed glue tests with DP490 for 3 different lens/ring material combinations show sufficient mechanical tension and shear strength for bonding of the lens system. Titanium/LF5G15 and Invar/Fused Silica combinations have reached the strength of 30 MPa at RT and 50 GPa at 150 K. These results are presented on behalf of the EUCLID consortium.

  2. Research on the Problem of High-Precision Deployment for Large-Aperture Space-Based Science Instruments

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Peterson, Lee D.; Hachkowski, M. Roman; Hinkle, Jason D.; Hardaway, Lisa R.

    1998-01-01

    The present paper summarizes results from an ongoing research program conducted jointly by the University of Colorado and NASA Langley Research Center since 1994. This program has resulted in general guidelines for the design of high-precision deployment mechanisms, and tests of prototype deployable structures incorporating these mechanisms have shown microdynamically stable behavior (i.e., dimensional stability to parts per million). These advancements have resulted from the identification of numerous heretofore unknown microdynamic and micromechanical response phenomena, and the development of new test techniques and instrumentation systems to interrogate these phenomena. In addition, recent tests have begun to interrogate nanomechanical response of materials and joints and have been used to develop an understanding of nonlinear nanodynamic behavior in microdynamically stable structures. The ultimate goal of these efforts is to enable nano-precision active control of micro-precision deployable structures (i.e., active control to a resolution of parts per billion).

  3. Experimental astrophysics with high power lasers and Z pinches

    SciTech Connect

    Remington, Bruce A.; Drake, R. Paul; Ryutov, Dmitri D. [Lawrence Livermore National Laboratory, Livermore, California 94450 (United States); University of Michigan, Ann Arbor, Michigan 48109 (United States); Lawrence Livermore National Laboratory, Livermore, California 94450 (United States)

    2006-07-15

    With the advent of high-energy-density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, millimeter-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors, equations of state relevant to planetary interiors, strong shock-driven nonlinear hydrodynamics and radiative dynamics relevant to supernova explosions and subsequent evolution, protostellar jets and high Mach number flows, radiatively driven molecular clouds and nonlinear photoevaporation front dynamics, and photoionized plasmas relevant to accretion disks around compact objects such as black holes and neutron stars.

  4. Experimental astrophysics with high power lasers and Z pinches

    SciTech Connect

    Remington, B A; Drake, R P; Ryutov, D D

    2004-12-10

    With the advent of high energy density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, mm-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors; equations of state relevant to planetary interiors; strong shock driven nonlinear hydrodynamics and radiative dynamics, relevant to supernova explosions and subsequent evolution; protostellar jets and high Mach-number flows; radiatively driven molecular clouds and nonlinear photoevaporation front dynamics; and photoionized plasmas relevant to accretion disks around compact objects, such as black holes and neutron stars.

  5. Fabrication and Metrology of High-Precision Foil Mirror Mounting Elements

    NASA Technical Reports Server (NTRS)

    Schattenburg, Mark L.

    2002-01-01

    During the period of this Cooperative Agreement, MIT (Massachusetts Institute of Technology) developed advanced methods for applying silicon microstructures for the precision assembly of foil x-ray optics in support of the Constellation-X Spectroscopy X-ray Telescope (SXT) development effort at Goddard Space Flight Center (GSFC). MIT developed improved methods for fabricating and characterizing the precision silicon micro-combs. MIT also developed and characterized assembly tools and several types of metrology tools in order to characterize and reduce the errors associated with precision assembly of foil optics. Results of this effort were published and presented to the scientific community and the GSFC SXT team. A bibliography of papers and presentations is offered.

  6. High-precision dosimetry for radiotherapy using the optically stimulated luminescence technique and thin Al2O3:C dosimeters

    Microsoft Academic Search

    E. G. Yukihara; E. M. Yoshimura; T. D. Lindstrom; S. Ahmad; K. K. Taylor; G. Mardirossian

    2005-01-01

    The potential of using the optically stimulated luminescence (OSL) technique with aluminium oxide (Al2O3:C) dosimeters for a precise and accurate estimation of absorbed doses delivered by high-energy photon beams was investigated. This study demonstrates the high reproducibility of the OSL measurements and presents a preliminary determination of the depth-dose curve in water for a 6 MV photon beam from a

  7. Investigation on a Novel Dual-Grating Macro-Micro Driven High Speed Precision Positioning System for NEMS

    Microsoft Academic Search

    L. N. Sun; D. G. Jie; Y. J. Liu; Z. C. Chen; H. G. Cai

    2006-01-01

    Microelectromechanical system (MEMS) is naturally continuing its downsizing into nanoelectromechanical system (NEMS), but at the same time it is indispensable in the package equipment used for nano-devices packaging in NEMS manufacture. A novel dual-grating macro-micro driven high speed precision XY-stage positioning system is presented in this paper. Combining macro with micro actuator, a system of large workspace and high speed

  8. A FPGA-based 7-order 1-bit sigma-delta modulator for high-precision signal generation

    Microsoft Academic Search

    Song Hongzhi; Wu Jie; Ma Yichao; Kong Yang; Zhang Jie

    2009-01-01

    This paper presents a design of a FPGA-based 7-order 1-bit sigma-delta modulator with zero points residing in noise band. The modulator, incorporating with a 24-bit sine wave source, a 1-bit DAC and a subsequent reconstruction filter, generates a signal to test a high-precision sigma-delta ADC. The test signal, which contains both sine wave and high frequency noise, is sampled by

  9. High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator.

    PubMed

    Chang, Cui-Zu; Zhao, Weiwei; Kim, Duk Y; Zhang, Haijun; Assaf, Badih A; Heiman, Don; Zhang, Shou-Cheng; Liu, Chaoxing; Chan, Moses H W; Moodera, Jagadeesh S

    2015-05-01

    The discovery of the quantum Hall (QH) effect led to the realization of a topological electronic state with dissipationless currents circulating in one direction along the edge of a two-dimensional electron layer under a strong magnetic field. The quantum anomalous Hall (QAH) effect shares a similar physical phenomenon to that of the QH effect, whereas its physical origin relies on the intrinsic spin-orbit coupling and ferromagnetism. Here, we report the experimental observation of the QAH state in V-doped (Bi,Sb)2Te3 films with the zero-field longitudinal resistance down to 0.00013 ± 0.00007h/e(2) (~3.35 ± 1.76??), Hall conductance reaching 0.9998 ± 0.0006e(2)/h and the Hall angle becoming as high as 89.993° ± 0.004° at T = 25 mK. A further advantage of this system comes from the fact that it is a hard ferromagnet with a large coercive field (Hc > 1.0 T) and a relative high Curie temperature. This realization of a robust QAH state in hard ferromagnetic topological insulators (FMTIs) is a major step towards dissipationless electronic applications in the absence of external fields. PMID:25730394

  10. Inexpensive high-precision capacitance measurements and their applications in undergraduate laboratories

    NASA Astrophysics Data System (ADS)

    Clayhold, Jeffrey; Priest, Joseph

    2008-12-01

    An inexpensive system for precision capacitance measurement is presented. The system is appropriate for undergraduate laboratories is based on a newly available capacitance-to-digital integrated circuit that can measure picofarad capacitances to six significant figures. The circuitry software for controlling the integrated circuit with a personal computer via an I2C interface bus are described. Examples of experiments that make use of the circuitry are discussed, including a novel hydrostatic magnetometer that uses precision capacitance measurement to determine the magnetization of a small sample.

  11. Selenium and tellurium systematics of the Earth’s mantle from high precision analyses of ultra-depleted orogenic peridotites

    NASA Astrophysics Data System (ADS)

    König, Stephan; Luguet, Ambre; Lorand, Jean-Pierre; Wombacher, Frank; Lissner, Moritz

    2012-06-01

    Selenium and tellurium, like the highly siderophile elements, may constitute key tracers for planetary processes such as formation of the Earth’s core and the Late Veneer composition, provided that their geochemical behavior and abundances in the primitive upper mantle (PUM) are well constrained. Within this scope, we have developed a high precision analytical method for the simultaneous determination of selenium and tellurium concentrations from a single sample aliquot and for various rock matrices, including ultra-depleted peridotites. The technique employs isotope dilution, thiol cotton fiber (TCF) separation and hydride generation ICP-MS. A selection of international mafic and ultramafic rock reference materials BIR-1, BE-N, TDB-1, UB-N, FON B 93 and BHVO-2 with a range of 30-350 ppb Se and 0.7-12 ppb Te show external reproducibilities that generally range from 3% to 8% for Se and 0.4% to 11% for Te (two relative standard deviations (r.s.d.)). We have applied this method to a suite of refractory mantle peridotites (Al2O3 <1.5 wt.%) from Lherz, previously shown to be strongly and uniformly depleted in Se, Te and incompatible elements by high degree of partial melting (20 ± 5%). While some fertile lherzolites display broadly chondritic values (Se/Te = 9), the ultra-depleted harzburgites show highly fractionated Se/Te (up to 31), which correlate with the Te concentrations. The fractionation trend is displayed by the depleted peridotites and also observed within multiple analyses of a single Lherz harzburgitic sample (64-3) and altogether results from the very heterogeneous distribution of Te trace phases present in the aliquot analyzed. Our results are in agreement with experimental studies that predict a more incompatible behavior of Te compared to Se during incongruent partial melting of mantle sulfides. In addition to re-fertilized lherzolites, depleted harzburgites therefore provide new insights into the geochemical behavior of Se and Te in the Earth’s mantle.

  12. Experimental determination of sound and high-speed flow interaction

    NASA Technical Reports Server (NTRS)

    Lumsdaine, E.; Silcox, R.

    1977-01-01

    An experimental facility for measuring the attenuation of sound at various frequencies and modes in a finite duct with high-speed flow (with or without an axial pressure gradient) is described. The facility consists of an anechoic chamber transonic compressor with inlets of different area variations (or axial gradients); sound of selected frequencies and modes is produced with eight circumferential acoustic drivers. The experimental results indicate that high Mach number inlets can increase noise propagation. In addition, an inlet with a constant axial gradient is found to have a better acoustic and aerodynamic performance than inlets of the same area ratio with steep gradients near the throat or exit.

  13. ALTAIR: Calibrated Balloon-Borne Light Sources for High-Precision Photometry

    NASA Astrophysics Data System (ADS)

    Albert, J.; Brown, Y.; Fagin, M.; Stubbs, C.; Thanjavur, K.; Vanderlinde, K.; Dobbs, M.; Cramer, C.; Deustua, S.

    2013-09-01

    Deeper understanding of the accelerating expansion of the universe, and the mysterious dark energy that causes it, will require unprecedented photometric precision, as photometry is presently the limiting uncertainty on our knowledge of dark energy and the universe's resulting acceleration. Laboratory and solar photometry and radiometry regularly achieve precisions on the order of parts in ten thousand, but photometric calibration for non-solar astronomy presently remains stuck at the percent or greater level. We discuss ALTAIR, the project to erase this discrepancy, and the steps to achieving dramatically-improved laboratory-level photometric precision for Pan-STARRS, LSST, and other major astronomical surveys both this decade and next. In particular, we show initial results from the first flights of our NIST-calibrated balloon-borne light source, as well as ground-based and near-field calibration of the source. Our technique is additionally applicable to microwave astronomy. Observation of gravitational waves in the polarized cosmic microwave background will similarly require unprecedented polarimetric and radiometric precision, and we briefly discuss our current development of a calibrated microwave source above the atmosphere as well.

  14. AN X-BAND CAVITY FOR A HIGH PRECISION BEAM POSITION MONITOR

    Microsoft Academic Search

    Ronald Johnson; Zenghai Li; Takashi Naito; Jeffrey Rifkin; Stephen Smith; Vernon Smith

    2003-01-01

    The next generation of accelerators will require increasingly precise control of beam position. For example designs for the next linear collider require beam-position monitors (BPMs) with 300 nm resolution. The accelerator designs also place difficult requirements on accuracy and stability. To meet these requirements a cavity BPM operating at 11.424 GHz was designed. The BPM consists of two cavities: an

  15. High precision thermal stress study on flip chips by synchrotron polychromatic x-ray microdiffraction

    Microsoft Academic Search

    Kai Chen; Nobumichi Tamura; Wei Tang; Martin Kunz; Yi-Chia Chou; King-Ning Tu; Yi-Shao Lai

    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

  16. High precision relative locations of earthquakes at Mount St. Helens, Washington

    Microsoft Academic Search

    Marie-José Frémont; Stephen D. Malone

    1987-01-01

    Several earthquake sequences have occurred at Mount St. Helens as clusters of shallow events with nearly identical waveforms (multiplets). We present a technique that allows the relative relocation of events within a multiplet to at least an order of magnitude higher precision than is typically possible with traditional techniques. A multiplet is studied in pairs of events called doublets. Each

  17. High precision balance from salt and water and the slow swelling of ping-pong balls

    Microsoft Academic Search

    Imre M J ´; G ´ abor Szab; Tam ´ as

    Density gradient columns are the most accurate type of equipment for determining unknown densities. Commercial equipment is designed for chemical engineering practice, where the typical sample size hardly exceeds a few grams. The accuracy of measurements crucially depends on the precision of height determination. Here we demonstrate that stratified salt water in much larger containers (used for experiments in geophysical

  18. Evaluation of the precision agricultural landscape modeling system (PALMS) in the semiarid Texas southern high plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate models to simulate the soil water balance in semiarid cropping systems are needed to evaluate management practices for soil and water conservation in both irrigated and dryland production systems. The objective of this study was to evaluate the application of the Precision Agricultural Land...

  19. Wireless technology and satellite internet access for high-speed whole farm connectivity in precision agriculture

    Microsoft Academic Search

    J. M. McKinion; S. B. Turner; J. L. Willers; J. J. Read; J. N. Jenkins; John McDade

    2004-01-01

    An analysis of the multispectral image-based precision agriculture technology as used in the US cotton belt was undertaken to identify bottlenecks which limit the delivery and use of this technology. One area in particular was identified: the movement of data and information necessary to implement variable rate applications. Solutions to reduce or eliminate this problem were explored. A new technology

  20. A high precision reactor neutrino detector for the Double Chooz experiment

    Microsoft Academic Search

    Fumihiko Suekane

    2010-01-01

    Double Chooz is a reactor neutrino experiment which investigates the last neutrino mixing angle; ?13. It is necessary to measure reactor neutrino disappearance with precision 1% or better to detect a finite value of ?13. This requirement is the most strict compared to other reactor neutrino experiments performed so far. The Double Chooz experiment makes use of a number of

  1. High-precision optical measurements of 13 isotope ratios in organic compounds at

    E-print Network

    Zare, Richard N.

    -precision isotope ratios are special-purpose isotope-ratio mass spectrometers (IRMS) (2, 3) that are fairly costly accuracy for methane, ethane, and propane is within 3 of the values determined using isotope ratio mass; however, it should be noted that the isotopes of hydrogen, nitrogen, oxygen, and sulfur have also been

  2. Evaluation of the Precision Agricultural Landscape Modeling System (PALMS) in the Semiarid Texas Southern High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate models to simulate the soil water balance in semiarid cropping systems are needed to evaluate management practices for soil and water conservation in both irrigated and dryland production systems. The objective of this study was to evaluate the application of the Precision Agricultural Land...

  3. High precision fluidic alignment of carbon nanotubes using magnetic attraction on a metal catalyst

    Microsoft Academic Search

    Joon S. Shim; Yeo-Heung Yun; Michael J. Rust; V. Shanov; M. J. Schulz; C. H. Ahn

    2008-01-01

    Precise self-assembly of carbon nanotubes (CNTs) by magnetic attraction on a catalyst and alignment by fluidic shear forces is reported in this work. The solution containing dispersed nanotubes was flowed in a microchannel and external magnetic field was applied by a permanent magnet for attracting a metal catalyst located at the end of the CNT. The assembly procedure and electrical

  4. APPLICATION OF SMALL SATELLITES FOR HIGH PRECISION MEASURING EFFECTS OF RADIO WAVE PROPAGATION

    Microsoft Academic Search

    K. Igarashi; N. A. Armand; A. G. Pavelyev; Ch. Reigber; J. Wickert; K. Hocke; G. Beyerle; S. S. Matyugov; O. I. Yakovlev

    The radio holography methodology may be applied in the scientific programs for future small satellite that will use radio signals emitted by radio navigation, radio communication satellites for precise measuring effects of radio waves propagation at low elevation angles and for global monitoring of radio communication channels passed through the atmosphere and ionosphere. Another task consists in monitoring of the

  5. High performance controller design of HDD based on precise modeling using differential iteration method

    Microsoft Academic Search

    Motohiro KAWAFUKU; Kazuhiro OTSU; Hiromu HIRAI; Masahito KOBAYASHI

    2003-01-01

    In the positioning system of a hard disc drive (HDD), many resonance modes exist, and they are very close each other. Therefore, it is difficult to obtain a precise model when the curve fitting method was used and it is difficult to suppress both the effect of these resonances and that of any disturbances. In this paper, a differential iteration

  6. High precision calcium isotope analysis using 42Ca-48Ca double-spike TIMS technique

    NASA Astrophysics Data System (ADS)

    Feng, L.; Zhou, L.; Gao, S.; Tong, S. Y.; Zhou, M. L.

    2014-12-01

    Double spike techniques are widely used for determining calcium isotopic compositions of natural samples. The most important factor controlling precision of the double spike technique is the choice of appropriate spike isotope pair, the composition of double spikes and the ratio of spike to sample?CSp/CN?. We propose an optimal 42Ca-48Ca double spike protocol which yields the best internal precision for calcium isotopic composition determinations among all kinds of spike pairs and various spike compositions and ratios of spike to sample, as predicted by linear error propagation method. It is suggested to use spike composition of 42Ca/(42Ca+48Ca) = 0.44 mol/mol and CSp/(CN+ CSp)= 0.12mol/mol because it takes both advantages of the largest mass dispersion between 42Ca and 48Ca (14%) and lowest spike cost. Spiked samples were purified by pass through homemade micro-column filled with Ca special resin. K, Ti and other interference elements were completely separated, while 100% calcium was recovered with negligible blank. Data collection includes integration time, idle time, focus and peakcenter frequency, which were all carefully designed for the highest internal precision and lowest analysis time. All beams were automatically measured in a sequence by Triton TIMS so as to eliminate difference of analytical conditions between samples and standards, and also to increase the analytical throughputs. The typical internal precision of 100 duty cycles for one beam is 0.012?0.015 ‰ (2?SEM), which agrees well with the predicted internal precision of 0.0124 ‰ (2?SEM). Our methods improve internal precisions by a factor of 2?10 compared to previous methods of determination of calcium isotopic compositions by double spike TIMS. We analyzed NIST SRM 915a, NIST SRM 915b and Pacific Seawater as well as interspersed geological samples during two months. The obtained average ?44/40Ca (all relative to NIST SRM 915a) is 0.02 ± 0.02 ‰ (n=28), 0.72±0.04 ‰ (n=10) and 1.93±0.03 ‰ (n=21) for NIST SRM 915a, NIST SRM 915b and Pacific Seawater, respectively. The long-term reproducibility is 0.10‰ (2 ?SD), which is comparable to the best external precision of 0.04 ‰ (2 ?SD) of previous methods, but our sample throughputs are doubled with significant reduction in amount of spike used for single samples.

  7. 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

    Nowadays one of the most burning questions for the science is the rate and the reasons of the recent climate change. Greenhouse gases (GHG), mainly CO2 and CH4 in the atmosphere could affect the climate of our planet. However, the relation between the amount of atmospheric GHG and the climate is complex, full with interactions and feedbacks partly poorly known even by now. The only way to understand the processes, to trace the changes, to develop and validate mathematical models for forecasts is the extensive, high precision, continuous monitoring of the atmosphere. Fossil fuel CO2 emissions are a major component of the European carbon budget. Separation of the fossil fuel signal from the natural biogenic one in the atmosphere is, therefore, a crucial task for quantifying exchange flux of the continental biosphere through atmospheric observations and inverse modelling. An independent method to estimate trace gas emissions is the top-down approach, using atmospheric CO2 concentration measurements combined with simultaneous radiocarbon (14C) observations. As adding fossil fuel CO2 to the atmosphere, therefore, leads not only to an increase in the CO2 content of the atmosphere but also to a decrease in the 14C/12C ratio in atmospheric CO2. The ATOMKI has more than two decade long experience in atmospheric 14CO2 monitoring. As a part of an ongoing research project being carried out in Hungary to investigate the amount and temporal and spatial variations of fossil fuel CO2 in the near surface atmosphere we developed a mobile and high-precision atmospheric CO2 monitoring station. We describe the layout and the operation of the measuring system which is designed for the continuous, unattended monitoring of CO2 mixing ratio in the near surface atmosphere based on an Ultramat 6F (Siemens) infrared gas analyser. In the station one atmospheric 14CO2 sampling unit is also installed which is developed and widely used since more than one decade by ATOMKI. Mixing ratio of CO2 is measured at 2 m above the ground by the monitoring station. Air is pumped through a 9.5-mm-diameter plastic tube (PFA, Swagelok) to a CO2 analyser located in a container box. Container box (Containex) is 1.5 m wide, 1.2 m deep and 2.2 m high, designed as a mobile measuring room which is field deployable, only electric power is required. A 15 micron pore size stainless steel Tee-Type (Swagelok) particle filter is located at the inlet of the sampler tube. Diaphragm pump (KNF) is used to draw air continuously through the sampling tube from monitoring level at flow rate of ~ 2 L/min. After leaving the pump, the air at 5 psig overpressure enters a glass trap for liquid water that is cooled in a regular household refrigerator, to dry the air to a dew point of 3°-4°C. Liquid water is forced out through an orifice at the bottom of the trap. The air sample inlet tube and the standard gases (Linde Hungary) are connected to miniature solenoid valves (S Series, ASCO Numatics) in a manifold which are normally closed and controlled by the CO2 analyser, which selects which gas is sampled. The air leaving the manifold through its common outlet is further dried to a dew point of about -25°C by passage through a 360-cm-long Nafion drier (Permapure), so that the water vapour interference and dilution effect are <0.1 ppm equivalent CO2. The Nafion drier is purged in a counter flow (300 cm3/min) arrangement using waste sample air that has been further dried by passage through anhydrous CaSO4 (Drierite). Analysis is carried out using an infrared gas analyser Ultramat 6F which is a specialised model for field applications by Siemens. A constant sample flow rate of 300 cm3/min is maintained by a mass flow controller (Aalborg). The reference cell of the CO2 analyzer is continuously flushed with a compressed reference gas of 350 ppm CO2 in synthetic air (Messer Hungarogáz). The basic calibration cycle is 2 hours, consisting of a zero-point calibration and a span calibration. Each calibration is consisting of 2 min flushing and 20 sec signal integration. The usual change of the r

  8. Single-anchor support and supercritical CO2 drying enable high-precision microfabrication of three-dimensional structures.

    PubMed

    Maruo, Shoji; Hasegawa, Takuya; Yoshimura, Naoki

    2009-11-01

    In high-precision two-photon microfabrication of three-dimensional (3-D) polymeric microstructures, supercritical CO(2) drying was employed to reduce surface tension, which tends to cause the collapse of micro/nano structures. Use of supercritical drying allowed high-aspect ratio microstructures, such as micropillars and cantilevers, to be fabricated. We also propose a single-anchor supporting method to eliminate non-uniform shrinkage of polymeric structures otherwise caused by attachment to the substrate. Use of this method permitted frame models such as lattices to be produced without harmful distortion. The combination of supercritical CO(2) drying and the single-anchor supporting method offers reliable high-precision microfabrication of sophisticated, fragile 3-D micro/nano structures. PMID:19997332

  9. High-precision quadruple isotope dilution method for simultaneous determination of nitrite and nitrate in seawater by GCMS after derivatization with triethyloxonium tetrafluoroborate.

    PubMed

    Pagliano, Enea; Meija, Juris; Mester, Zoltán

    2014-05-01

    Quadruple isotope dilution mass spectrometry (ID(4)MS) has been applied for simultaneous determination of nitrite and nitrate in seawater. ID(4)MS allows high-precision measurements and entails the use of isotopic internal standards ((18)O-nitrite and (15)N-nitrate). We include a tutorial on ID(4)MS outlining optimal experimental design which generates results with low uncertainties and obviates the need for direct (separate) evaluation of the procedural blank. Nitrite and nitrate detection was achieved using a headspace GCMS procedure based on single-step aqueous derivatization with triethyloxonium tetrafluoroborate at room temperature. In this paper the sample preparation was revised and fundamental aspects of this chemistry are presented. The proposed method has detection limits in the low parts-per-billion for both analytes, is reliable, precise, and has been validated using a seawater certified reference material (MOOS-2). Simplicity of the experimental design, low detection limits, and the use of quadruple isotope dilution makes the present method superior to the state-of-the-art for determination of nitrite and nitrate, and an ideal candidate for reference measurements of these analytes in seawater. PMID:24759746

  10. High-precision mapping of seismicity in the last decades at Bárdarbunga volcano, Iceland

    NASA Astrophysics Data System (ADS)

    Vogfjörd, Kristín S.; Hensch, Martin; Hjörleifsdóttir, Vala; Jónsdóttir, Kristín

    2015-04-01

    Bárdarbunga volcano is one of Iceland's most active and hazardous volcanoes. Its location inside the Vatnajökull ice cap and completely covered by the glacier, gives rise to multitude of hazards and also makes it difficult to monitor with modern Earth- and space based monitoring networks. Therefore, much of its unrest and activity has not been well recorded in the past. Seismic monitoring, however has been gradually improving over the last decade, with a significant improvement in sensitivity in the last two years through the FUTUREVOLC supersite project. The largest earthquakes (M>5), presumably associated with unrest episodes have been detected nationally and teleseismically since the 1970s, with under 20 such events recorded between then and the beginning of 2014. The mechanisms of these events have all been represented by a CLVD source. Before 2014, the last M>5 event occurred at the end of September 1996. This event was accompanied by significantly increased microseismicity, which was recorded on the national seismic network, SIL as well as on the temporary nation-wide Passcal network, HOTSPOT. This microseismicity was located with high-precision, relative methods and showed propagation of the seismicity from the NE corner of the caldera and along the rim to the SE corner. A few days later, well located microseismicity started on a NNE-SSW lineament south of the caldera, which later becamoe the location of the Gjálp eruption. Because of the sparse network at the time, propagation of the seismicity from Bárdarbunga to the Gjálp fissure could not be unequivocally determined. In 2006 seismic activity in all the volcanoes in western Vatnajökull started to increase and this increase was greatest in Bárdarbunga and the fissure swarm extending NE from the caldera towards Kistufell. This heightened regional unrest culminated in the Grímsvötn eruption in May 2011, after which the seismicity at all volcanoes suddenly dropped. In 2012 the activity started rising again, so that in early 2014 the activity in Bárdarbunga was reaching the seismicity level of 2011. Relative location of this seismicity shows that the earthquakes are confined NE of the caldera rim and extending N and NE towards Kistufell. Furthermore, a deep vertical channel starts to appear SE of the volcano. Activity in this channel was maintained until 2014, with a number of deep earthquakes located there in May 2014, but in August 2014 it stopped. On 16 August 2014 an intense seismic swarm started at Bárdarbunga, inside the caldera and NW of it towards Kistufell. On the first day the activity propagated out of the caldera to the SW to the location of the vertical channel. There, the seismicity took a sharp turn and started propagating NE. This activity continued over the following two weeks, finally extending outside the northern margin of the glacier and ending in an eruption at Holuhraun; first a small, short-lived one on 29 September and then a second sustained eruption two days later. This eruption, which is still on-going at the time of writing, has produced a volume of over 1 km3 of lava and released large amounts of SO2 and CO2 gases. High-precision locations of the propagating seismicity delineates multiple linear segments, which have been modelled as lateral dyke propagation from the caldera to the eruption site (Sigmundsson et al, 2014). At the same time as the dyke was propagating, activity at the caldera started again, producing over 70 events of M>5, which can be modelled by negative CLVD mechanisms, and hundreds of microearthquakes around the caldera rim. The distribution of seismicity along the southern caldera rim is fairly linear and near vertical, while the event distribution along the Northern rim appears to dip towards north. In light of the recent dyke propagation to Holuhraun, the Gjálp event will be reexamined to search for deterministic signs of lateral propagation from Bárdarbunga towards the Gjálp fissure. Sigmundsson etal., 2014. Segmented lateral dyke growth in a rifting event at Bárðarbunga volcanic system,

  11. Experimental evidence for lattice effects in high temperature superconductors

    SciTech Connect

    Billinge, S.J.L.; Kwei, G.H.; Thompson, J.D.

    1994-01-18

    We present an overview of the experimental evidence for a role of the lattice in the mechanism of high temperature superconductivity. It appears unlikely that a solely conventional electron-phonon interaction produces the pairing. However, there is ample evidence of strong electron and spin to lattice coupling and observations of a response of the lattice to the electronic state. We draw attention to the importance of the local structure in discussions of lattice effects in high-{Tc} superconductivity.

  12. The experimental evaluation and application of high temperature solid lubricants

    Microsoft Academic Search

    Dellacorte

    1989-01-01

    A research program meant to develop an understanding of high temperature solid lubrication and experimental techniques through the development of a composite lubricant coating system was described. The knowledge gained through this research was then applied to a specific engineering challenge, the tribology of a sliding seal for hypersonic flight vehicles. The solid lubricant coating is a chromium carbide based

  13. EXPERIMENTAL ANALYSIS OF COMMUNICATIONS INTERFACES FOR HIGH-PERFORMANCE CLUSTERS

    E-print Network

    George, Alan D.

    EXPERIMENTAL ANALYSIS OF COMMUNICATIONS INTERFACES FOR HIGH-PERFORMANCE CLUSTERS Alan George throughput and two-way latency using several different software-based communications protocol interfaces-throughput communications. Secondly, new software protocol interfaces must be developed, and their use accepted and adopted

  14. EXPERIMENTAL ANALYSIS OF COMMUNICATIONS INTERFACES FOR HIGH-PERFORMANCE CLUSTERS

    Microsoft Academic Search

    Alan George; Robert Todd; William Phipps

    This paper provides experimental data and analysis to quantify both the peak and sustained performance characteristics of four of the most promising new networking technologies for interconnecting machines in a high-performance cluster of workstations. These technologies include Scalable Coherent Interface (SCI), Myrinet, Fibre Channel System (FCS), and Asynchronous Transfer Mode (ATM). Cluster networking performance experiments are conducted and measurements presented

  15. Some experiences with experimental high level fusion systems

    Microsoft Academic Search

    J. Biermann

    2007-01-01

    A very short overview is given on experience gained in the area of high level information fusion (JDL level 2 and 3) since 1988. The main characteristics of the referenced projects and experimental systems for the support of intelligence officers in land battle missions will be outlined. The different approaches to analyse and model military intelligence processing and the development

  16. A high precision EPMA data of olivine: comparison with LA ICP-MS

    NASA Astrophysics Data System (ADS)

    Batanova, V. G.; Sobolev, A. V.; Kuzmin, D.

    2013-12-01

    Composition of olivine provides critical information on the composition and origin of primary mantle derived melts and their sources. Especially informative are minor and trace elements Ni, Mn, Ca, Al, Cr, Co, Ti, Zn, P, Na [1, 2], which being in the concentration range over 10 ppm are assessable by EPMA. The analytical protocol built up on new JEOL JXA 8230 EPMA in ISTerre, UJF, Grenoble, France. Facility has tungsten source gun, is equipped by five WDS and one SDD EDS and placed in the environment with controlled temperature (22+/-0.3 degrees C) and humidity (50+/-3%). The analytical conditions are the following: acceleration voltage 25kV, 900 nA beam current, WDS recording for trace elements (Ni, Mn, Ca, Al, Cr, Co, Ti, Zn, P, Na) and EDS recording for Si, Mg, Fe, total counting time 12 minutes, ZAF correction. Instrumental drift during analytical sessions is monitored by repeated measurements of olivine standards. For trace elements this protocol yields detection limits from 3 to 10 ppm and average precision of individual analysis of 10 ppm (2 standard errors). For Fo of olivine precision is 300 ppm (2 standard errors). Comparison of EPMA and LA ICP-MS data for the large range of olivine compositions suggests that accuracy of EPMA is similar to precision noted above. For elements with concentration over 100 ppm the obtained EPMA precision and accuracy are better than these of LA ICP-MS. For the concentration of elements between 50-100 ppm both methods show similar precision and accuracy; and for concentration between 10-50 ppm LA ICP-MS yields better precision and accuracy. Spatial resolution of EPMA, however, is significantly better: 3-5 micrometres compared to 30-50 for LA ICP-MS. This makes our new EPMA protocol of great advantage for measurement of zoned or small olivine grains. [1] Sobolev et al., 2007. Science 316 (5823), p.412-417. [2] De Hoog et al., 2010. Chemical Geology 270, p. 196-2015

  17. Importance of the Mechanism of Resonance Enhancement of Neutrino Oscillations in Matter for the Precise Testing of the Electroweak Interaction Model. Present Experimental Status of This Resonance Mechanism

    E-print Network

    Kh. M. Beshtoev

    2007-03-23

    The mechanism of resonance enhancement of neutrino oscillations in matter and some critical remarks to this mechanism are considered. Using of this resonance mechanism is very important to examine the model of electroweak interactions since the processes induced by this mechanism grow multiply. In contrast to the electromagnetic and strong interactions in weak interactions, $P$-parity is violated therefore a problem of mass generations in the weak interactions is considered (the interaction must be left-right symmetric for mass generations). It is concluded that a possibility of mass generation in the framework of the weak interactions is not proved. The present experimental status of this resonance mechanism is considered and it is done conclusion that this effect has no clear experimental confirmation. For this purpose it is necessary to fulfil precision experiments with solar neutrinos and the neutrinos passed through the Earth matter.

  18. Study on control structure analysis and optimization of high-precision measurement platform for optical aspheric surface

    NASA Astrophysics Data System (ADS)

    Ke, Xiaolong; Guo, Yinbiao; Wang, Zhengzhong; Liu, Jianchun

    2009-05-01

    Taking high generality and efficiency into account, this paper presents a measurement and control means based on high-precision measurement platform including high-precision linear motors, contact and non-contact measurement sensor of 0.1um resolution and a new developed measuring software. This platform aims to achieve high-precision measurement for all kinds of optical aspheric workpieces for detection accuracy of 2um/200*200mm. In this paper, a measurement platform which consists of granite gantry framework, 3 axes linear motors, circle grating rotary encoder, grating linear scales, 4 axes motion control card, linear motion ball guide, contacting and non-contacting measurement sensor and so on, is designed and implemented. Through finite element stress analysis, it can find that the framework well fulfills the accuracy demand. And the performance comparison between linear motors and piezoelectric ceramics motors is then discussed. Further, it also compares the coordinated motion of "circle grating rotary encoder+2 axes linear motors" with the coordinated motion of "3 axes linear motors" to find out the difference in measurement accuracy by experiment data. Here, a better scheme for kinematic locus planning is proposed for making sure all axes have better dynamic characteristics. Aiming at various characteristics of optical workpieces, the different measurement paths are also provided. Finally, the experiments for this purpose are done to validate the measurement platform accuracy.

  19. AN X-BAND CAVITY FOR A HIGH PRECISION BEAM POSITION MONITOR

    SciTech Connect

    Johnson, R

    2003-12-08

    The next generation of accelerators will require increasingly precise control of beam position. For example designs for the next linear collider require beam-position monitors (BPMs) with 300 nm resolution. The accelerator designs also place difficult requirements on accuracy and stability. To meet these requirements a cavity BPM operating at 11.424 GHz was designed. The BPM consists of two cavities: an xy-cavity tuned to the dipole mode and a phase cavity tuned to the monopole mode. The xy-cavity uses a novel-coupling scheme that (in principal) has zero coupling to the monopole mode. This report will present the mechanical design, simulations, and test results of a prototype BPM. In addition BPM designs with even higher precision will be discussed.

  20. High precision measurement of the masses of the D0 and KS mesons

    NASA Astrophysics Data System (ADS)

    Tomaradze, A.; Dobbs, S.; Xiao, T.; Seth, Kamal K.; Bonvicini, G.

    2014-02-01

    Using 580 pb-1 of e+e- annihilation data taken with the CLEO-c detector at ?(3770), the decay D0(D¯0)?K±???+?- has been studied to make the highest precision measurement of D0 mass, M(D0)=1864.845±0.025±0.022±0.053 MeV, where the first error is statistical, the second error is systematic, and the third error is due to uncertainty in kaon masses. As an intermediate step of the present investigation, the mass of the KS meson has been measured to be M(KS)=497.607±0.007±0.015 MeV. Both M(D0) and M(KS) are the most precise single measurements of the masses of these mesons.