WorldWideScience

Sample records for ultrasonic frequency-sweep interferometer

  1. Ultrasonic flow-through filtration of microparticles in a microfluidic channel using frequency sweep technique

    International Nuclear Information System (INIS)

    Seo, Dae Cheol; Ahn, Bong Young; Cho, Seung Hyun; Siddique, A. K. M. Ariful Haque; Kim, Cheol Gi

    2013-01-01

    Many studies have been conducted on the filtration of microparticles using the acoustic radiation force of ultrasonic standing wave. The present work concerns a flow-through particle filtration method by utilizing frequency varying ultrasound. The periodical frequency sweep of the ultrasonic standing wave translocates particles across a microchannel, where particles in fluid flow are filtrated without barriers. The present filtration technique in a microfluidic channel was proposed conceptually in the 1990s. However, its experimental realization on actual particles in a microfluidic channel has not been carried out in a notable way. Several sizes of polystyrene microspheres (10 µm to 90 µm) and silicon carbide (SiC) particles (37 µm) suspended in water were applied as a test sample. For filtration of those particles, a Y-branched microfluidic channel with one inlet and two outlets was made out of steel and acrylic as a form of modulized device. Ultrasound of a few MHz in band frequency (1.75 MHz to 3.05 MHz) was transmitted into one side of the channel wall to generate a standing wave field in fluid flow. The periodical frequency sweep operation showed successful filtration performance, whereby particles in water flowed into one outlet and purified water flowed into the other outlet of the Y branch of the channel.

  2. Microwave frequency sweep interferometer for plasma density measurements in ECR ion sources: Design and preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, Giuseppe [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); University Mediterranea of Reggio Calabria, Reggio Calabria (Italy); Mascali, David; Neri, Lorenzo; Leonardi, Ornella; Celona, Luigi; Castro, Giuseppe; Agnello, Riccardo; Caruso, Antonio; Passarello, Santi; Longhitano, Alberto; Gammino, Santo [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Sorbello, Gino [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); University of Catania, Catania, Italy and INFN-LNS, Catania (Italy); Isernia, Tommaso [University Mediterranea of Reggio Calabria, Reggio Calabria (Italy)

    2016-02-15

    The Electron Cyclotron Resonance Ion Sources (ECRISs) development is strictly related to the availability of new diagnostic tools, as the existing ones are not adequate to such compact machines and to their plasma characteristics. Microwave interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for plasma density measurement in hostile environment. Interferometry in ECRISs is a challenging task mainly due to their compact size. The typical density of ECR plasmas is in the range 10{sup 11}–10{sup 13} cm{sup −3} and it needs a probing beam wavelength of the order of few centimetres, comparable to the chamber radius. The paper describes the design of a microwave interferometer developed at the LNS-INFN laboratories based on the so-called “frequency sweep” method to filter out the multipath contribution in the detected signals. The measurement technique and the preliminary results (calibration) obtained during the experimental tests will be presented.

  3. Nonadiabatic exchange dynamics during adiabatic frequency sweeps.

    Science.gov (United States)

    Barbara, Thomas M

    2016-04-01

    A Bloch equation analysis that includes relaxation and exchange effects during an adiabatic frequency swept pulse is presented. For a large class of sweeps, relaxation can be incorporated using simple first order perturbation theory. For anisochronous exchange, new expressions are derived for exchange augmented rotating frame relaxation. For isochronous exchange between sites with distinct relaxation rate constants outside the extreme narrowing limit, simple criteria for adiabatic exchange are derived and demonstrate that frequency sweeps commonly in use may not be adiabatic with regard to exchange unless the exchange rates are much larger than the relaxation rates. Otherwise, accurate assessment of the sensitivity to exchange dynamics will require numerical integration of the rate equations. Examples of this situation are given for experimentally relevant parameters believed to hold for in-vivo tissue. These results are of significance in the study of exchange induced contrast in magnetic resonance imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Fiber-optic Michelson interferometer fixed in a tilted tube for direction-dependent ultrasonic detection

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Qiao, Xueguang; Li, JiaCheng; Shao, Zhihua; Tong, Rongxin; Rong, Qiangzhou

    2017-01-01

    A fiber-optic interferometer is proposed and demonstrated experimentally for ultrasonic detection. The sensor consists of a compact Michelson interferometer (MI), which is fixed in a tilted-tube end-face (45°). Thin gold films are used for the reflective coatings of two arms and one of the interference arms is etched serving as the sensing arm. The spectral sideband filter technique is used to interrogate the continuous and pulse ultrasonic signals (with frequency of 300 KHz). Furthermore, because of the asymmetrical structure of the sensor, it presents strong direction-dependent ultrasonic sensitivity, such that the sensor can be considered a vector detector. The experimental results show that the sensor is highly sensitive to ultrasonic signals, and thus it can be a candidate for ultrasonic imaging of seismic physical models.

  5. Simulation and theory of spontaneous TAE frequency sweeping

    International Nuclear Information System (INIS)

    Wang Ge; Berk, H.L.

    2012-01-01

    A simulation model, based on the linear tip model of Rosenbluth, Berk and Van Dam (RBV), is developed to study frequency sweeping of toroidal Alfvén eigenmodes (TAEs). The time response of the background wave in the RBV model is given by a Volterra integral equation. This model captures the properties of TAE waves both in the gap and in the continuum. The simulation shows that phase space structures form spontaneously at frequencies close to the linearly predicted frequency, due to resonant particle–wave interactions and background dissipation. The frequency sweeping signals are found to chirp towards the upper and lower continua. However, the chirping signals penetrate only the lower continuum, whereupon the frequency chirps and mode amplitude increases in synchronism to produce an explosive solution. An adiabatic theory describing the evolution of a chirping signal is developed which replicates the chirping dynamics of the simulation in the lower continuum. This theory predicts that a decaying chirping signal will terminate at the upper continuum though in the numerical simulation the hole disintegrates before the upper continuum is reached. (paper)

  6. Simulation and theory of spontaneous TAE frequency sweeping

    Science.gov (United States)

    Wang, Ge; Berk, H. L.

    2012-09-01

    A simulation model, based on the linear tip model of Rosenbluth, Berk and Van Dam (RBV), is developed to study frequency sweeping of toroidal Alfvén eigenmodes (TAEs). The time response of the background wave in the RBV model is given by a Volterra integral equation. This model captures the properties of TAE waves both in the gap and in the continuum. The simulation shows that phase space structures form spontaneously at frequencies close to the linearly predicted frequency, due to resonant particle-wave interactions and background dissipation. The frequency sweeping signals are found to chirp towards the upper and lower continua. However, the chirping signals penetrate only the lower continuum, whereupon the frequency chirps and mode amplitude increases in synchronism to produce an explosive solution. An adiabatic theory describing the evolution of a chirping signal is developed which replicates the chirping dynamics of the simulation in the lower continuum. This theory predicts that a decaying chirping signal will terminate at the upper continuum though in the numerical simulation the hole disintegrates before the upper continuum is reached.

  7. Laser-based ultrasonics by dual-probe interferometer detection and narrow-band ultrasound generation

    Science.gov (United States)

    Huang, Jin

    1993-01-01

    Despite the advantages of laser-based ultrasonic (LBU) systems, the overall sensitivity of LBU systems needs to be improved for practical applications. Progress is reported to achieve better LBU detection accuracy and sensitivity for applications with surface waves and Lamb waves. A novel dual-probe laser interferometer has been developed to measure the same signal at two points. The dual-probe interferometer is a modification of a conventional single-probe interferometer in that the reference beam is guided to a second detecting point on the specimen surface to form a differential measurement mode, which measure the difference of the displacements at the two points. This dual-probe interferometer is particularly useful for accurate measurements of the speed and attenuation of surface waves and Lamb waves. The dual-probe interferometer has been applied to obtain accurate measurements of the surface wave speed and attenuation on surfaces of increasing surface roughness. It has also been demonstrated that with an appropriate signal processing method, namely, the power cepstrum method, the dual-probe interferometer is applicable to measure the local surface wave speed even when the probe separation is so small that the two waveforms in the interferometer output signal overlap in the time domain. Narrow-band signal generation and detection improve the sensitivity of LBU systems. It is proposed to use a diffraction grating to form an array of illuminating strips which form a source of narrowband surface and Lamb waves. The line-array of thermoelastic sources generates narrow-band signals whose frequency and bandwidth can be easily controlled. The optimum line-array parameters, such as width, spacing and the number of lines in the array have been derived theoretically and verified experimentally. Narrow-band signal generation with optimum parameters has been demonstrated. The enhanced LBU system with dual-probe detection and narrowband signal generation has been

  8. Wingbeat frequency-sweep and visual stimuli for trapping male Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    Combinations of female wingbeat acoustic cues and visual cues were evaluated to determine their potential for use in male Aedes aegypti (L.) traps in peridomestic environments. A modified Centers for Disease control (CDC) light trap using a 350-500 Hz frequency-sweep broadcast from a speaker as an a...

  9. Detection of Ultrasonic Stress Waves in Structures Using 3D Shaped Optic Fiber Based on a Mach-Zehnder Interferometer.

    Science.gov (United States)

    Lan, Chengming; Zhou, Wensong; Xie, Yawen

    2018-04-16

    This work proposes a 3D shaped optic fiber sensor for ultrasonic stress waves detection based on the principle of a Mach–Zehnder interferometer. This sensor can be used to receive acoustic emission signals in the passive damage detection methods and other types of ultrasonic signals propagating in the active damage detection methods, such as guided wave-based methods. The sensitivity of an ultrasonic fiber sensor based on the Mach–Zehnder interferometer mainly depends on the length of the sensing optical fiber; therefore, the proposed sensor achieves the maximum possible sensitivity by wrapping an optical fiber on a hollow cylinder with a base. The deformation of the optical fiber is produced by the displacement field of guided waves in the hollow cylinder. The sensor was first analyzed using the finite element method, which demonstrated its basic sensing capacity, and the simulation signals have the same characteristics in the frequency domain as the excitation signal. Subsequently, the primary investigations were conducted via a series of experiments. The sensor was used to detect guided wave signals excited by a piezoelectric wafer in an aluminum plate, and subsequently it was tested on a reinforced concrete beam, which produced acoustic emission signals via impact loading and crack extension when it was loaded to failure. The signals obtained from a piezoelectric acoustic emission sensor were used for comparison, and the results indicated that the proposed 3D fiber optic sensor can detect ultrasonic signals in the specific frequency response range.

  10. Detection of Ultrasonic Stress Waves in Structures Using 3D Shaped Optic Fiber Based on a Mach–Zehnder Interferometer

    Science.gov (United States)

    Xie, Yawen

    2018-01-01

    This work proposes a 3D shaped optic fiber sensor for ultrasonic stress waves detection based on the principle of a Mach–Zehnder interferometer. This sensor can be used to receive acoustic emission signals in the passive damage detection methods and other types of ultrasonic signals propagating in the active damage detection methods, such as guided wave-based methods. The sensitivity of an ultrasonic fiber sensor based on the Mach–Zehnder interferometer mainly depends on the length of the sensing optical fiber; therefore, the proposed sensor achieves the maximum possible sensitivity by wrapping an optical fiber on a hollow cylinder with a base. The deformation of the optical fiber is produced by the displacement field of guided waves in the hollow cylinder. The sensor was first analyzed using the finite element method, which demonstrated its basic sensing capacity, and the simulation signals have the same characteristics in the frequency domain as the excitation signal. Subsequently, the primary investigations were conducted via a series of experiments. The sensor was used to detect guided wave signals excited by a piezoelectric wafer in an aluminum plate, and subsequently it was tested on a reinforced concrete beam, which produced acoustic emission signals via impact loading and crack extension when it was loaded to failure. The signals obtained from a piezoelectric acoustic emission sensor were used for comparison, and the results indicated that the proposed 3D fiber optic sensor can detect ultrasonic signals in the specific frequency response range. PMID:29659540

  11. Suppression of nonlinear frequency-sweeping of resonant interchange modes in a magnetic dipole with applied radio frequency fields

    International Nuclear Information System (INIS)

    Maslovsky, D.; Levitt, B.; Mauel, M. E.

    2003-01-01

    Interchange instabilities excited by energetic electrons trapped by a magnetic dipole nonlinearly saturate and exhibit complex, coherent spectral characteristics and frequency sweeping [H. P. Warren and M. E. Mauel, Phys. Plasmas 2, 4185 (1995)]. When monochromatic radio frequency (rf) fields are applied in the range of 100-1000 MHz, the saturation behavior of the interchange instability changes dramatically. For applied fields of sufficient intensity and pulse-length, coherent interchange fluctuations are suppressed and frequency sweeping is eliminated. When rf fields are switched off, coherent frequency sweeping reappears. Since low frequency interchange instabilities preserve the electron's first and second adiabatic invariants, these observations can be interpreted as resulting from nonlinear resonant wave-particle interactions described within a particle phase-space, (ψ,φ), comprised of the third adiabatic invariant and the azimuthal angle. Self-consistent numerical simulation is used to study (1) the nonlinear development of the instability, (2) the radial mode structure of the interchange instability, and (3) the suppression of frequency sweeping. When the applied rf heating is modeled as an 'rf collisionality', the simulation reproduces frequency sweeping suppression and suggests an explanation for the observations that is consistent with Berk and co-workers [H. L. Berk et al., Phys. Plasmas 6, 3102 (1999)

  12. Production of artificial ionospheric layers by frequency sweeping near the 2nd gyroharmonic

    Directory of Open Access Journals (Sweden)

    T. Pedersen

    2011-01-01

    Full Text Available Artificial ionospheric plasmas descending from the background F-region have been observed on multiple occasions at the High Frequency Active Auroral Research Program (HAARP facility since it reached full 3.6 MW power. Proximity of the transmitter frequency to the 2nd harmonic of the electron gyrofrequency (2fce has been noted as a requirement for their occurrence, and their disappearance after only a few minutes has been attributed to the increasing frequency mismatch at lower altitudes. We report new experiments employing frequency sweeps to match 2fce in the artificial plasmas as they descend. In addition to revealing the dependence on the 2fce resonance, this technique reliably produces descending plasmas in multiple transmitter beam positions and appears to increase their stability and lifetime. High-speed ionosonde measurements are used to monitor the altitude and density of the artificial plasmas during both the formation and decay stages.

  13. Oxide vapor distribution from a high-frequency sweep e-beam system

    Science.gov (United States)

    Chow, R.; Tassano, P. L.; Tsujimoto, N.

    1995-03-01

    Oxide vapor distributions have been determined as a function of operating parameters of a high frequency sweep e-beam source combined with a programmable sweep controller. We will show which parameters are significant, the parameters that yield the broadest oxide deposition distribution, and the procedure used to arrive at these conclusions. A design-of-experimental strategy was used with five operating parameters: evaporation rate, sweep speed, sweep pattern (pre-programmed), phase speed (azimuthal rotation of the pattern), profile (dwell time as a function of radial position). A design was chosen that would show which of the parameters and parameter pairs have a statistically significant effect on the vapor distribution. Witness flats were placed symmetrically across a 25 inches diameter platen. The stationary platen was centered 24 inches above the e-gun crucible. An oxide material was evaporated under 27 different conditions. Thickness measurements were made with a stylus profilometer. The information will enable users of the high frequency e-gun systems to optimally locate the source in a vacuum system and understand which parameters have a major effect on the vapor distribution.

  14. Frequency comb calibrated frequency-sweeping interferometry for absolute group refractive index measurement of air.

    Science.gov (United States)

    Yang, Lijun; Wu, Xuejian; Wei, Haoyun; Li, Yan

    2017-04-10

    The absolute group refractive index of air at 194061.02 GHz is measured in real time using frequency-sweeping interferometry calibrated by an optical frequency comb. The group refractive index of air is calculated from the calibration peaks of the laser frequency variation and the interference signal of the two beams passing through the inner and outer regions of a vacuum cell when the frequency of a tunable external cavity diode laser is scanned. We continuously measure the refractive index of air for 2 h, which shows that the difference between measured results and Ciddor's equation is less than 9.6×10-8, and the standard deviation of that difference is 5.9×10-8. The relative uncertainty of the measured refractive index of air is estimated to be 8.6×10-8. The data update rate is 0.2 Hz, making it applicable under conditions in which air refractive index fluctuates fast.

  15. Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation.

    Science.gov (United States)

    Hefferman, Gerald; Chen, Zhen; Wei, Tao

    2017-07-01

    This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

  16. Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation

    Science.gov (United States)

    Hefferman, Gerald; Chen, Zhen; Wei, Tao

    2017-07-01

    This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

  17. Generation of constant-amplitude radio-frequency sweeps at a tunnel junction for spin resonance STM

    International Nuclear Information System (INIS)

    Paul, William; Lutz, Christopher P.; Heinrich, Andreas J.; Baumann, Susanne

    2016-01-01

    We describe the measurement and successful compensation of the radio-frequency transfer function of a scanning tunneling microscope over a wide frequency range (15.5–35.5 GHz) and with high dynamic range (>50 dB). The precise compensation of cabling resonances and attenuations is critical for the production of constant-voltage frequency sweeps for electric-field driven electron spin resonance (ESR) experiments. We also demonstrate that a well-calibrated tunnel junction voltage is necessary to avoid spurious ESR peaks that can arise due to a non-flat transfer function.

  18. Generation of constant-amplitude radio-frequency sweeps at a tunnel junction for spin resonance STM

    Energy Technology Data Exchange (ETDEWEB)

    Paul, William; Lutz, Christopher P.; Heinrich, Andreas J. [IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120 (United States); Baumann, Susanne [IBM Research Division, Almaden Research Center, 650 Harry Road, San Jose, California 95120 (United States); Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

    2016-07-15

    We describe the measurement and successful compensation of the radio-frequency transfer function of a scanning tunneling microscope over a wide frequency range (15.5–35.5 GHz) and with high dynamic range (>50 dB). The precise compensation of cabling resonances and attenuations is critical for the production of constant-voltage frequency sweeps for electric-field driven electron spin resonance (ESR) experiments. We also demonstrate that a well-calibrated tunnel junction voltage is necessary to avoid spurious ESR peaks that can arise due to a non-flat transfer function.

  19. Frequency sweep of the field scattered by an inhomogeneous structure using method of moments and asymptotic waveform evaluation

    DEFF Research Database (Denmark)

    Troelsen, Jens; Meincke, Peter; Breinbjerg, Olav

    2000-01-01

    into account. To the knowledge of the authors the AWE technique has not previously been applied to a MoM solution based on this kind of integral equation. It is the purpose of this paper to investigate the use of the AWE technique as a tool to obtain a fast frequency sweep of the field scattered......In many radar applications it is necessary to determine the scattering from an object over a wide frequency band. The asymptotic waveform evaluation (AWE), which is a moment matching (MM) technique, constitutes a method to this end. In general, MM techniques provide a reduced-order model...

  20. Technique for long and absolute distance measurement based on laser pulse repetition frequency sweeping

    Science.gov (United States)

    Castro Alves, D.; Abreu, Manuel; Cabral, A.; Jost, Michael; Rebordão, J. M.

    2017-11-01

    In this work we present a technique to perform long and absolute distance measurements based on mode-locked diode lasers. Using a Michelson interferometer, it is possible to produce an optical cross-correlation between laser pulses of the reference arm with the pulses from the measurement arm, adjusting externally their degree of overlap either changing the pulse repetition frequency (PRF) or the position of the reference arm mirror for two (or more) fixed frequencies. The correlation of the travelling pulses for precision distance measurements relies on ultra-short pulse durations, as the uncertainty associated to the method is dependent on the laser pulse width as well as on a highly stable PRF. Mode-locked Diode lasers are a very appealing technology for its inherent characteristics, associated to compactness, size and efficiency, constituting a positive trade-off with regard to other mode-locked laser sources. Nevertheless, main current drawback is the non-availability of frequency-stable laser diodes. The laser used is a monolithic mode-locked semiconductor quantum-dot (QD) laser. The laser PRF is locked to an external stabilized RF reference. In this work we will present some of the preliminary results and discuss the importance of the requirements related to laser PRF stability in the final metrology system accuracy.

  1. Ultrasonic characterization of GRC with high percentage of fly ash substitution.

    Science.gov (United States)

    Genovés, V; Gosálbez, J; Miralles, R; Bonilla, M; Payá, J

    2015-07-01

    New applications of non-destructive techniques (NDT) with ultrasonic tests (attenuation and velocity by means of ultrasonic frequency sweeps) have been developed for the characterization of fibre-reinforced cementitious composites. According to new lines of research on glass-fibre reinforced cement (GRC) matrix modification, two similar GRC composites with high percentages of fly ash and different water/binder ratios will be studied. Conventional techniques have been used to confirm their low Ca(OH)(2) content (thermogravimetry), fibre integrity (Scanning Electron Microscopy), low porosity (Mercury Intrusion Porosimetry) and good mechanical properties (compression and four points bending test). Ultrasound frequency sweeps allowed the estimation of the attenuation and pulse velocity as functions of frequency. This ultrasonic characterization was correlated successfully with conventional techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. A low-cost, high-performance, digital signal processor-based lock-in amplifier capable of measuring multiple frequency sweeps simultaneously

    International Nuclear Information System (INIS)

    Sonnaillon, Maximiliano Osvaldo; Bonetto, Fabian Jose

    2005-01-01

    A high-performance digital lock-in amplifier implemented in a low-cost digital signal processor (DSP) board is described. This lock in is capable of measuring simultaneously multiple frequencies that change in time as frequency sweeps (chirps). The used 32-bit DSP has enough computing power to generate N=3 simultaneous reference signals and accurately measure the N=3 responses, operating as three lock ins connected in parallel to a linear system. The lock in stores the measured values in memory until they are downloaded to the a personal computer (PC). The lock in works in stand-alone mode and can be programmed and configured through the PC serial port. Downsampling and multiple filter stages were used in order to obtain a sharp roll off and a long time constant in the filters. This makes measurements possible in presence of high-noise levels. Before each measurement, the lock in performs an autocalibration that measures the frequency response of analog output and input circuitry in order to compensate for the departure from ideal operation. Improvements from previous lock-in implementations allow measuring the frequency response of a system in a short time. Furthermore, the proposed implementation can measure how the frequency response changes with time, a characteristic that is very important in our biotechnological application. The number of simultaneous components that the lock in can generate and measure can be extended, without reprogramming, by only using other DSPs of the same family that are code compatible and work at higher clock frequencies

  3. A low-cost, high-performance, digital signal processor-based lock-in amplifier capable of measuring multiple frequency sweeps simultaneously

    Energy Technology Data Exchange (ETDEWEB)

    Sonnaillon, Maximiliano Osvaldo; Bonetto, Fabian Jose [Laboratorio de Cavitacion y Biotecnologia, San Carlos de Bariloche (8400) (Argentina)

    2005-02-01

    A high-performance digital lock-in amplifier implemented in a low-cost digital signal processor (DSP) board is described. This lock in is capable of measuring simultaneously multiple frequencies that change in time as frequency sweeps (chirps). The used 32-bit DSP has enough computing power to generate N=3 simultaneous reference signals and accurately measure the N=3 responses, operating as three lock ins connected in parallel to a linear system. The lock in stores the measured values in memory until they are downloaded to the a personal computer (PC). The lock in works in stand-alone mode and can be programmed and configured through the PC serial port. Downsampling and multiple filter stages were used in order to obtain a sharp roll off and a long time constant in the filters. This makes measurements possible in presence of high-noise levels. Before each measurement, the lock in performs an autocalibration that measures the frequency response of analog output and input circuitry in order to compensate for the departure from ideal operation. Improvements from previous lock-in implementations allow measuring the frequency response of a system in a short time. Furthermore, the proposed implementation can measure how the frequency response changes with time, a characteristic that is very important in our biotechnological application. The number of simultaneous components that the lock in can generate and measure can be extended, without reprogramming, by only using other DSPs of the same family that are code compatible and work at higher clock frequencies.

  4. Modelling of Extrinsic Fiber Optic Sagnac Ultrasound Interferometer ...

    African Journals Online (AJOL)

    Ultrasonic waves are used extensively in nondestructive testing both for characterization of material properties, in this paper, we describe a fiber optic sensor suitable for detection of ultrasonic waves. This sensor is based on an extrinsic fiber optic sagnac interferometer. The proposed sensor model can act as a conventional ...

  5. Extrinsic Fabry-Perot ultrasonic detector

    Science.gov (United States)

    Kidwell, J. J.; Berthold, John W., III

    1996-10-01

    We characterized the performance of a commercial fiber optic extrinsic Fabry-Perot interferometer for use as an ultrasonic sensor, and compared the performance with a standard lead zirconate titanate (PZT) detector. The interferometer was unstabilized. The results showed that the fiber sensor was about 12 times less sensitive than the PZT detector. Ultrasonic frequency response near 100 kHz was demonstrated. We describe the design of the fiber sensor, the details of the tests performed, and potential applications.

  6. Michelson Interferometer

    Science.gov (United States)

    Rogers, Ryan

    2007-01-01

    The Michelson Interferometer is a device used in many applications, but here it was used to measure small differences in distance, in the milli-inch range, specifically for defects in the Orbiter windows. In this paper, the method of using the Michelson Interferometer for measuring small distances is explained as well as the mathematics of the system. The coherence length of several light sources was calculated in order to see just how small a defect could be measured. Since white light is a very broadband source, its coherence length is very short and thus can be used to measure small defects in glass. After finding the front and back reflections from a very thin glass slide with ease and calculating the thickness of it very accurately, it was concluded that this system could find and measure small defects on the Orbiter windows. This report also discusses a failed attempt for another use of this technology as well as describes an area of promise for further analysis. The latter of these areas has applications for finding possible defects in Orbiter windows without moving parts.

  7. Contact-free ultrasonic testing: applications to metrology and NDT

    International Nuclear Information System (INIS)

    Le Brun, A.

    1988-01-01

    In some cases classical ultrasonic testing is impossible because of adverse environment (high temperature, ionizing radiations, etc). Ultrasonic waves are created by laser impact and detected by electromagneto-acoustic transducers or laser interferometry. Association of ultrasonics generation by photoacoustic effect and reception by heterodyne interferometer is promising for the future [fr

  8. Ultrasonic Testing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeong Jun; Kuk, Jeong Han

    2002-02-15

    This book introduces ultrasonic testing, which tells of outline of ultrasonic testing, principle of ultrasonic testing, prosperities of ultrasonic waves, radiographic test and ultrasonic test, basic theory on ultrasonic testing, mode conversion, transmission and diffraction, ultrasonic flaw detection and probe, standard test piece and reference test piece, like KS(JIS) ASME and ASTM, classification and properties of ultrasonic testing, straight beam method, angle beam method, ASME SEC.V.Art.5 ASTMA 388 and KS B 0817 Korean industrial standard.

  9. Special relativity and interferometers

    Science.gov (United States)

    Han, D.; Kim, Y. S.

    1988-01-01

    A new generation of gravitational wave detectors is expected to be based on interferometers. Yurke et al. (1986) introduced a class of interferometers characterized by SU(1,1) which can in principle achieve a phase sensitivity approaching 1/N, where N is thte total number of photons entering the interferometer. It is shown here that the SU(1,1) interferometer can serve as an analog computer for Wigner's little group of the Poincare\\'| group.

  10. Stable fiber interferometer

    International Nuclear Information System (INIS)

    Izmajlov, G.N.; Nikolaev, F.A.; Ozolin, V.V.; Grigor'yants, V.V.; Chamorovskij, Yu.K.

    1989-01-01

    The problem of construction the long-base Michelson interferometer for gravitational wave detection is discussed. Possible sources of noise and instability are considered. It is shown that evacuation of fiber interferometer, the winding of its arms on the glass ceramic bases, stabilization of radiation source frequency and seismic isolation of the base allow one to reduce its instability to the level, typical of mirror interferometer with the comparable optical base. 10 refs.; 2 figs

  11. Atom Wave Interferometers

    National Research Council Canada - National Science Library

    Pritchard, David

    1999-01-01

    Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

  12. X-ray interferometers

    International Nuclear Information System (INIS)

    Franks, A.

    1980-01-01

    An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

  13. Fidelity of quantum interferometers

    International Nuclear Information System (INIS)

    Bahder, Thomas B.; Lopata, Paul A.

    2006-01-01

    For a generic interferometer, the conditional probability density distribution p(φ|m), for the phase φ given measurement outcome m will generally have multiple peaks. Therefore, the phase sensitivity of an interferometer cannot be adequately characterized by the standard deviation, such as Δφ∼1/√(N) (the standard limit), or Δφ∼1/N (the Heisenberg limit). We propose an alternative measure of phase sensitivity--the fidelity of an interferometer--defined as the Shannon mutual information between the phase shift φ and the measurement outcomes m. As an example application of interferometer fidelity, we consider a generic optical Mach-Zehnder interferometer, used as a sensor of a classical field. For the case where there exists no a priori information on the phase shift, we find the surprising result that maximally entangled state input leads to a lower fidelity than Fock state input, for the same photon number

  14. Self-calibrating interferometer

    International Nuclear Information System (INIS)

    Nussmeier, T.A.

    1982-01-01

    A self-calibrating interferometer is disclosed which forms therein a pair of Michelson interferometers with one beam length of each Michelson interferometer being controlled by a common phase shifter. The transfer function measured from the phase shifter to either of a pair of detectors is sinusoidal with a full cycle for each half wavelength of phase shifter travel. The phase difference between these two sinusoidal detector outputs represents the optical phase difference between a path of known distance and a path of unknown distance

  15. Ultrasonic characterization of single drops of liquids

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Dipen N. (Los Alamos, NM)

    1998-01-01

    Ultrasonic characterization of single drops of liquids. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities.

  16. Fizeau plasma interferometer

    International Nuclear Information System (INIS)

    Frank, A.M.

    1980-01-01

    This paper describes a technique by which the sensitivity of plasma interferometers can be increased. Stabilization and fractional fringe measurement techniques have improved to the point where additional optical sensitivity could be useful

  17. Atom Wave Interferometers

    National Research Council Canada - National Science Library

    Pritchard, David

    2000-01-01

    Long-term research objective: Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

  18. Michelson and His Interferometer

    Science.gov (United States)

    Shankland, Robert S.

    1974-01-01

    Presents a brief historical account of Michelson's invention of his interferometer with some subsequent ingenious applications of its capabilities for precise measurement discussed in details, including the experiment on detrmination of the diameters for heavenly bodies. (CC)

  19. Ultrasonic signature

    International Nuclear Information System (INIS)

    Borloo, E.; Crutzen, S.

    1974-12-01

    The unique and tamperproof identification technique developed at Ispra is based on ultrasonic Non-Destructive-Techniques. Reading fingerprints with ultrasonic requires high reproducibility of standard apparatus and transducers. The present report gives an exhaustive description of the ultrasonic technique developed for identification purposes. Different applications of the method are described

  20. Nonlinear Acoustic and Ultrasonic NDT of Aeronautical Components

    Science.gov (United States)

    Van Den Abeele, Koen; Katkowski, Tomasz; Mattei, Christophe

    2006-05-01

    In response to the demand for innovative microdamage inspection systems, with high sensitivity and undoubted accuracy, we are currently investigating the use and robustness of several acoustic and ultrasonic NDT techniques based on Nonlinear Elastic Wave Spectroscopy (NEWS) for the characterization of microdamage in aeronautical components. In this report, we illustrate the results of an amplitude dependent analysis of the resonance behaviour, both in time (signal reverberation) and in frequency (sweep) domain. The technique is applied to intact and damaged samples of Carbon Fiber Reinforced Plastics (CFRP) composites after thermal loading or mechanical fatigue. The method shows a considerable gain in sensitivity and an incontestable interpretation of the results for nonlinear signatures in comparison with the linear characteristics. For highly fatigued samples, slow dynamical effects are observed.

  1. Ultrasonic testing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin [Sungkwunkwan Univ., Seoul (Korea, Republic of); Jeong, Hyun Jo [Wonkwang Univ., Iksan (Korea, Republic of)

    2004-02-15

    For the proper performance of ultrasonic testing of steel welded joints, and anisotropic material it is necessary to have sound understanding on the underlying physics. To provide such an understanding, it is beneficial to have simulation tools for ultrasonic testing. In order to address such a need, we develop effective approaches to simulate angle beam ultrasonic testing with a personal computer. The simulation is performed using ultrasonic measurement models based on the computationally efficient multi-Gaussian beams. This reach will describe the developed ultrasonic testing models together with the experimental verification of their accuracy.

  2. Mariner 9 Michelson interferometer.

    Science.gov (United States)

    Hanel, R.; Schlachman, B.; Rodgers, D.; Breihan, E.; Bywaters, R.; Chapman, F.; Rhodes, M.; Vanous, D.

    1972-01-01

    The Michelson interferometer on Mariner 9 measures the thermal emission spectrum of Mars between 200 and 2000 per cm (between 5 and 50 microns) with a spectral resolution of 2.4 per cm in the apodized mode. A noise equivalent radiance of 0.5 x 10 to the minus 7th W/sq cm/ster/cm is deduced from data recorded in orbit around Mars. The Mariner interferometer deviates in design from the Nimbus 3 and 4 interferometers in several areas, notably, by a cesium iodide beam splitter and certain aspects of the digital information processing. Special attention has been given to the problem of external vibration. The instrument performance is demonstrated by calibration data and samples of Mars spectra.

  3. 2-mm microwave interferometer

    International Nuclear Information System (INIS)

    Futch, A.H.; Mortensen, W.K.

    1977-01-01

    A 2-mm microwave interferometer has been developed, and phase shift measurements have been made on the Baseball II experiment. The interferometer system employs a 140-GHz receiver for double down conversion of the plasma signal to a 60-MHz, IF frequency. The 140-GHz references signal is also down-converted and compared with the plasma signal to provide the desired phase change of the signal passing through the plasma. A feedback voltage from a 60-MHz discriminator to a voltage-controlled oscillator in the receiver provides frequency stability of the 60-MHz IF signals

  4. Ultrasonic physics

    CERN Document Server

    Richardson, E G

    1962-01-01

    Ultrasonic Physics, Second Edition, provides an introduction to the fundamental principles of ultrasonic physics. The book opens with a discussion of the sources of ultrasound. This is followed by separate chapters on the properties and detection of ultrasonic radiation; measurement of propagation constants, i.e., the velocity and absorption, of ultrasound; ultrasound propagation in gases, liquids, and solids; and ultrasound propagation in aerosols, suspensions, and emulsions. The final chapter covers miscellaneous physical and physico-chemical actions, including dispersion and coagulation of

  5. Semiconductor laser shearing interferometer

    International Nuclear Information System (INIS)

    Ming Hai; Li Ming; Chen Nong; Xie Jiaping

    1988-03-01

    The application of semiconductor laser on grating shearing interferometry is studied experimentally in the present paper. The method measuring the coherence of semiconductor laser beam by ion etching double frequency grating is proposed. The experimental result of lens aberration with semiconductor laser shearing interferometer is given. Talbot shearing interferometry of semiconductor laser is also described. (author). 2 refs, 9 figs

  6. Japanese large-scale interferometers

    CERN Document Server

    Kuroda, K; Miyoki, S; Ishizuka, H; Taylor, C T; Yamamoto, K; Miyakawa, O; Fujimoto, M K; Kawamura, S; Takahashi, R; Yamazaki, T; Arai, K; Tatsumi, D; Ueda, A; Fukushima, M; Sato, S; Shintomi, T; Yamamoto, A; Suzuki, T; Saitô, Y; Haruyama, T; Sato, N; Higashi, Y; Uchiyama, T; Tomaru, T; Tsubono, K; Ando, M; Takamori, A; Numata, K; Ueda, K I; Yoneda, H; Nakagawa, K; Musha, M; Mio, N; Moriwaki, S; Somiya, K; Araya, A; Kanda, N; Telada, S; Sasaki, M; Tagoshi, H; Nakamura, T; Tanaka, T; Ohara, K

    2002-01-01

    The objective of the TAMA 300 interferometer was to develop advanced technologies for kilometre scale interferometers and to observe gravitational wave events in nearby galaxies. It was designed as a power-recycled Fabry-Perot-Michelson interferometer and was intended as a step towards a final interferometer in Japan. The present successful status of TAMA is presented. TAMA forms a basis for LCGT (large-scale cryogenic gravitational wave telescope), a 3 km scale cryogenic interferometer to be built in the Kamioka mine in Japan, implementing cryogenic mirror techniques. The plan of LCGT is schematically described along with its associated R and D.

  7. Ultrasonic inspection

    International Nuclear Information System (INIS)

    Satittada, Gannaga

    1984-01-01

    Ultrasonic inspection is one of the most widely used methods for nondestructive inspection. The beam of high-frequency sound wave, ultrasonic wave, is introduced into the material. It travels through the material with some attendant loss of energy and can be reflected at interfaces. The reflected beam is detected and analyzed. Ultrasonic inspection is used to detect flaws in metal parts as well as in welded, brazed and bonded joints during research work and developing production and service. It is also used to detect and locate porosity, pipe, and flakes. In addition, it can be used for the measurement of metal thickness. Ultrasonic inspection is therefore used for quality control and material inspection in all major industries

  8. Ultrasonic mammography

    International Nuclear Information System (INIS)

    Hueneke, B.

    1982-01-01

    608 women are examined by means of ultrasonic mammography during the period of 1 year. 432 patients were examined with the compound method with the U.I. Octoson, a water tank scanner, and 176 patients with the real time method with a directly connected linear-array-scanner. The following results were obtained at the end of the examination period: In the ultrasonic and also in the X-ray mammogram tumour diameters can be determined with an error rate of +- 30%. In the diagnosing of carcinomas, a significant dependence of the exactness on the sice of the tumour is found for the combination of the five methods tested (clinical examination, X-ray mammography, ultrasonic mammography, thermography, cytology). Classifying the individual methods with regard to their exactness, X-ray mammography ranks in front of ultrasonic mammography. Mastopathic changes in the breast can be screened by means of ultrasonic mammography. The structure of the changes can be determined more exactly than with an X-ray picture which is due to the possibility of differentiating solid and cystic structures. In diagnosing fibro-adenomas and establishing diagnoses on young women with dense gland bodies, ultrasonic mammography is superior to radiology both in the ability of screening a finding of a fibro-adenoma (US=88%, X-ray=75%) and in the possibility of classifying it as ''more benign than malignant''. (orig./MG) [de

  9. Naval Prototype Optical Interferometer (NPOI)

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Used for astrometry and astronomical imaging, the Naval Prototype Optical Interferometer (NPOI) is a distributed aperture optical telescope. It is operated...

  10. Arrayed waveguide Sagnac interferometer.

    Science.gov (United States)

    Capmany, José; Muñoz, Pascual; Sales, Salvador; Pastor, Daniel; Ortega, Beatriz; Martinez, Alfonso

    2003-02-01

    We present a novel device, an arrayed waveguide Sagnac interferometer, that combines the flexibility of arrayed waveguides and the wide application range of fiber or integrated optics Sagnac loops. We form the device by closing an array of wavelength-selective light paths provided by two arrayed waveguides with a single 2 x 2 coupler in a Sagnac configuration. The equations that describe the device's operation in general conditions are derived. A preliminary experimental demonstration is provided of a fiber prototype in passive operation that shows good agreement with the expected theoretical performance. Potential applications of the device in nonlinear operation are outlined and discussed.

  11. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  12. AMI: Augmented Michelson Interferometer

    Science.gov (United States)

    Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

    2015-10-01

    Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

  13. Parametric Instability in Advanced Laser Interferometer Gravitational Wave Detectors

    International Nuclear Information System (INIS)

    Ju, L; Grass, S; Zhao, C; Degallaix, J; Blair, D G

    2006-01-01

    High frequency parametric instabilities in optical cavities are radiation pressure induced interactions between test mass mechanical modes and cavity optical modes. The parametric gain depends on the cavity power and the quality factor of the test mass internal modes (usually in ultrasonic frequency range), as well as the overlap integral for the mechanical and optical modes. In advanced laser interferometers which require high optical power and very low acoustic loss test masses, parametric instabilities could prevent interferometer operation if not suppressed. Here we review the problem of parametric instabilities in advanced detector configurations for different combinations of sapphire and fused silica test masses, and compare three methods for control or suppression of parametric instabilities-thermal tuning, surface damping and active feedback

  14. Ultrasonic neuromodulation

    Science.gov (United States)

    Naor, Omer; Krupa, Steve; Shoham, Shy

    2016-06-01

    Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

  15. Ultrasonic flowmeters

    International Nuclear Information System (INIS)

    Wittekind, W.D.

    1979-01-01

    A prototype ultrasonic flowmeter was assembled and tested. The theoretical basis of this prototype ultrasonic flowmeter is reviewed; the equipment requirements for a portable unit are discussed; the individual electronic modules contained in the prototype are described; the operating procedures and configuration are explained; and the data from preliminary calibrations are presented. The calibration data confirm that the prototype operates according to theoretical predictions and can indeed provide nonintrusive flow measurements to predicted accuracies for pipes larger than two inches, under single phase stable flow conditions

  16. Guided magnonic Michelson interferometer.

    Science.gov (United States)

    Ahmed, Muhammad H; Jeske, Jan; Greentree, Andrew D

    2017-01-30

    Magnonics is an emerging field with potential applications in classical and quantum information processing. Freely propagating magnons in two-dimensional media are subject to dispersion, which limits their effective range and utility as information carriers. We show the design of a confining magnonic waveguide created by two surface current carrying wires placed above a spin-sheet, which can be used as a primitive for reconfigurable magnonic circuitry. We theoretically demonstrate the ability of such guides to counter the transverse dispersion of the magnon in a spin-sheet, thus extending the range of the magnon. A design of a magnonic directional coupler and controllable Michelson interferometer is shown, demonstrating its utility for information processing tasks.

  17. Michelson interferometer for measuring temperature

    OpenAIRE

    Xie, Dong; Xu, Chunling; wang, Anmin

    2016-01-01

    We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displa...

  18. Ultrasonic characterization of single drops of liquids

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, D.N.

    1998-04-14

    Ultrasonic characterization of single drops of liquids is disclosed. The present invention includes the use of two closely spaced transducers, or one transducer and a closely spaced reflector plate, to form an interferometer suitable for ultrasonic characterization of droplet-size and smaller samples without the need for a container. The droplet is held between the interferometer elements, whose distance apart may be adjusted, by surface tension. The surfaces of the interferometer elements may be readily cleansed by a stream of solvent followed by purified air when it is desired to change samples. A single drop of liquid is sufficient for high-quality measurement. Examples of samples which may be investigated using the apparatus and method of the present invention include biological specimens (tear drops; blood and other body fluid samples; samples from tumors, tissues, and organs; secretions from tissues and organs; snake and bee venom, etc.) for diagnostic evaluation, samples in forensic investigations, and detection of drugs in small quantities. 5 figs.

  19. Michelson Interferometer (MINT)

    Science.gov (United States)

    Lacis, Andrew; Carlson, Barbara

    1993-01-01

    MINT is a Michelson interferometer designed to measure the thermal emission from the earth at high spectral resolution (2/cm) over a broad spectral range (250-1700/cm, 6-40 mu m) with contiguous 3-pixel wide (12 mrad, 8 km field of view) along-track sampling. MINT is particularly well suited for monitoring cloud properties (cloud cover, effective temperature, optical thickness, ice/water phase, and effective particle size) both day and night, as well as tropospheric water vapor, ozone, and temperature. The key instrument characteristics that make MINT ideally suited for decadal monitoring purposes are: high wavelength to wavelength precision across the full IR spectrum with high spectral resolution; space-proven long-term durability and calibration stability; and small size, low cost, low risk instrument incorporating the latest detector and electronics technology. MINT also incorporates simplicity in design and operation by utilizing passively cooled DTGS detectors and nadir viewing geometry (with target motion compensation). MINT measurement objectives, instrument characteristics, and key advantages are summarized in this paper.

  20. Integrated Ultrasonic-Photonic Devices

    DEFF Research Database (Denmark)

    Barretto, Elaine Cristina Saraiva

    in channel waveguides and Mach-Zehnder interferometers. Numerical models are developed based on the finite element method, and applied to several scenarios, such as optimization of the geometrical parameters of waveguides, use of slow light in photonic crystal waveguides and use of Lamb waves in membranized......This thesis deals with the modeling, design, fabrication and characterization of integrated ultrasonic-photonic devices, with particular focus on the use of standard semiconductor materials such as GaAs and silicon. The devices are based on the use of guided acoustic waves to modulate the light...... investigated. Comparisons are made with the numerical and experimental results, and they validate the obtained response of the acoustic and photonic components of the device. Finally, a new design for an optical frequency shifter is proposed, posing several advantages over existing devices in terms of size...

  1. Ultrasonic hydrometer

    Science.gov (United States)

    Swoboda, Carl A.

    1984-01-01

    The disclosed ultrasonic hydrometer determines the specific gravity (density) of the electrolyte of a wet battery, such as a lead-acid battery. The hydrometer utilizes a transducer that when excited emits an ultrasonic impulse that traverses through the electrolyte back and forth between spaced sonic surfaces. The transducer detects the returning impulse, and means measures the time "t" between the initial and returning impulses. Considering the distance "d" between the spaced sonic surfaces and the measured time "t", the sonic velocity "V" is calculated with the equation "V=2d/t". The hydrometer also utilizes a thermocouple to measure the electrolyte temperature. A hydrometer database correlates three variable parameters including sonic velocity in and temperature and specific gravity of the electrolyte, for temperature values between 0.degree. and 40.degree. C. and for specific gravity values between 1.05 and 1.30. Upon knowing two parameters (the calculated sonic velocity and the measured temperature), the third parameter (specific gravity) can be uniquely found in the database. The hydrometer utilizes a microprocessor for data storage and manipulation. The disclosed modified battery has a hollow spacer nub on the battery side wall, the sonic surfaces being on the inside of the nub and the electrolyte filling between the surfaces to the exclusion of intervening structure. An accessible pad exposed on the nub wall opposite one sonic surface allows the reliable placement thereagainst of the transducer.

  2. Michelson interferometer for measuring temperature

    Science.gov (United States)

    Xie, Dong; Xu, Chunling; Wang, An Min

    2017-09-01

    We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displaying Kerr nonlinearity. We obtain the analytical equations and numerically calculate the precision with parameters within the reach of current technology, proving that the precision of temperature can be greatly enhanced by using a nonlinear medium. Our results show that one can create an accurate thermometer by measuring the photons in the Michelson interferometer, with no need to directly measure the population of thermalized sample.

  3. Computerized lateral-shear interferometer

    Science.gov (United States)

    Hasegan, Sorin A.; Jianu, Angela; Vlad, Valentin I.

    1998-07-01

    A lateral-shear interferometer, coupled with a computer for laser wavefront analysis, is described. A CCD camera is used to transfer the fringe images through a frame-grabber into a PC. 3D phase maps are obtained by fringe pattern processing using a new algorithm for direct spatial reconstruction of the optical phase. The program describes phase maps by Zernike polynomials yielding an analytical description of the wavefront aberration. A compact lateral-shear interferometer has been built using a laser diode as light source, a CCD camera and a rechargeable battery supply, which allows measurements in-situ, if necessary.

  4. Magdalena Ridge Observatory Interferometer: Status Update

    National Research Council Canada - National Science Library

    Creech-Eakman, M. J; Bakker, E. J; Buscher, D. F; Coleman, T. A; Haniff, C. A; Jurgenson, C. A; Klinglesmith, III, D. A; Parameswariah, C. B; Romero, V. D; Shtromberg, A. V; Young, J. S

    2006-01-01

    The Magdalena Ridge Observatory Interferometer (MROI) is a ten element optical and near-infrared imaging interferometer being built in the Magdalena mountains west of Socorro, NM at an altitude of 3230 m...

  5. Liquid-helium-cooled Michelson interferometer

    Science.gov (United States)

    Augason, G. C.; Young, N.

    1972-01-01

    Interferometer serves as a rocket-flight spectrometer for examination of the far infrared emission spectra of astronomical objects. The double beam interferometer is readily adapted to make spectral scans and for use as a detector of discrete line emissions.

  6. Ultrasonic signal analysis according to laser ultrasound generation position for the detection of delamination in composites

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Kyung Min; Choi In Young; Kim, Seong Jong; Kang, Young June [Chonbuk National University, Jeonju (Korea, Republic of); Lee, Gil Dong [GP Inc., Daejeon (Korea, Republic of)

    2015-11-15

    Carbon-fiber-reinforced plastic should be inspected in the fabrication process to enhance quality by preventing defects, such as delamination and voids. Conventional ultrasonic evaluation methods cannot be applied during the fabrication process because they require contact measurement by a transducer. Thus, an optical method using a laser was employed in this study for non-contact ultrasonic evaluation. Ultrasonic signals were generated by a pulsed laser and received by using a laser interferometer. First, an ultrasonic signal was generated from the back side of a material sample with artificial internal defects in the composite. The ultrasonic signal directed through the interior of the specimen was then detected at the front side. After determining the locations of the internal defects, the defects were quantitatively evaluated from the front side of the composite by using ultrasonic signal generation and reception.

  7. Process monitoring using optical ultrasonic wave detection

    International Nuclear Information System (INIS)

    Telschow, K.L.; Walter, J.B.; Garcia, G.V.; Kunerth, D.C.

    1989-01-01

    Optical ultrasonic wave detection techniques are being developed for process monitoring. An important limitation on optical techniques is that the material surface, in materials processing applications, is usually not a specular reflector and in many cases is totally diffusely reflecting. This severely degrades the light collected by the detection optics, greatly reducing the intensity and randomly scattering the phase of the reflected light. A confocal Fabry-Perot interferometer, which is sensitive to the Doppler frequency shift resulting from the surface motion and not to the phase of the collected light, is well suited to detecting ultrasonic waves in diffusely reflecting materials. This paper describes the application of this detector to the real-time monitoring of the sintering of ceramic materials. 8 refs., 5 figs

  8. Standing waves in fiber-optic interferometers

    NARCIS (Netherlands)

    De Haan, V.; Santbergen, R.; Tijssen, M.; Zeman, M.

    2011-01-01

    A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach–Zehnder and Michelson–Morley interferometer. The response of the Mach–Zehnder interferometer is similar to the Sagnac

  9. High accuracy step gauge interferometer

    Science.gov (United States)

    Byman, V.; Jaakkola, T.; Palosuo, I.; Lassila, A.

    2018-05-01

    Step gauges are convenient transfer standards for the calibration of coordinate measuring machines. A novel interferometer for step gauge calibrations implemented at VTT MIKES is described. The four-pass interferometer follows Abbe’s principle and measures the position of the inductive probe attached to a measuring head. The measuring head of the instrument is connected to a balanced boom above the carriage by a piezo translation stage. A key part of the measuring head is an invar structure on which the inductive probe and the corner cubes of the measuring arm of the interferometer are attached. The invar structure can be elevated so that the probe is raised without breaking the laser beam. During probing, the bending of the probe and the interferometer readings are recorded and the measurement face position is extrapolated to zero force. The measurement process is fully automated and the face positions of the steps can be measured up to a length of 2 m. Ambient conditions are measured continuously and the refractive index of air is compensated for. Before measurements the step gauge is aligned with an integrated 2D coordinate measuring system. The expanded uncertainty of step gauge calibration is U=\\sqrt{{{(64 nm)}2}+{{(88× {{10}-9}L)}2}} .

  10. Surface topography measurement by frequency sweeping digital holography.

    Czech Academy of Sciences Publication Activity Database

    Lédl, Vít; Psota, Pavel; Kaván, František; Matoušek, Ondřej; Mokrý, Pavel

    2017-01-01

    Roč. 56, č. 28 (2017), s. 7808-7814 ISSN 1559-128X R&D Projects: GA MŠk(CZ) LO1206; GA ČR(CZ) GA16-11965S Institutional support: RVO:61389021 Keywords : Wavelenght Scanning Interferometry * Shape measurement * Profilomerty Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Electrical and electronic engineering Impact factor: 1.650, year: 2016 https://doi.org/10.1364/AO.56.007808

  11. Ultrasonic study on ternary liquid systems by laser-sound interaction

    International Nuclear Information System (INIS)

    Behboudnia, M.; Necati Ecevit, F.; Aydin, R.

    1994-01-01

    To investigate the ultrasound velocity in liquid mixtures an interferometer based on Raman-Nath diffraction of laser light by sound waves is described. Ultrasonic velocity measurements in water in dependence of temperature and in carboxylic acids with triethylamine in benzene of different mole fractions are presented. (author). 14 refs, 4 figs, 1 tab

  12. The TEXT upgrade vertical interferometer

    International Nuclear Information System (INIS)

    Hallock, G.A.; Gartman, M.L.; Li, W.; Chiang, K.; Shin, S.; Castles, R.L.; Chatterjee, R.; Rahman, A.S.

    1992-01-01

    A far-infrared interferometer has been installed on TEXT upgrade to obtain electron density profiles. The primary system views the plasma vertically through a set of large (60-cm radialx7.62-cm toroidal) diagnostic ports. A 1-cm channel spacing (59 channels total) and fast electronic time response is used, to provide high resolution for radial profiles and perturbation experiments. Initial operation of the vertical system was obtained late in 1991, with six operating channels

  13. Unequal-Arms Michelson Interferometers

    Science.gov (United States)

    Tinto, Massimo; Armstrong, J. W.

    2000-01-01

    Michelson interferometers allow phase measurements many orders of magnitude below the phase stability of the laser light injected into their two almost equal-length arms. If, however, the two arms are unequal, the laser fluctuations can not be removed by simply recombining the two beams. This is because the laser jitters experience different time delays in the two arms, and therefore can not cancel at the photo detector. We present here a method for achieving exact laser noise cancellation, even in an unequal-arm interferometer. The method presented in this paper requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. By linearly combining the two data sets with themselves, after they have been properly time shifted, we show that it is possible to construct a new data set that is free of laser fluctuations. An application of this technique to future planned space-based laser interferometer detector3 of gravitational radiation is discussed.

  14. Optical configurations for the Virgo interferometer

    International Nuclear Information System (INIS)

    Hello, P.

    1993-01-01

    We present, in this paper, the potential optical configurations for the VIRGO interferometer, as well as for other similar antennas (LIGO...), and the implications for its sensitivity for the detection of gravitational waves (GW's). The dual recycling arrangement may particularly relax the severe optical specifications required in a power recycling interferometer. Finally, a new idea to improve the symmetry of the interferometer is presented. (author). 11 refs., 2 figs

  15. Laser ultrasonic receivers based on photorefractive materials in non-destructive testing

    International Nuclear Information System (INIS)

    Zamiri Hosseinzadeh, S.

    2014-01-01

    The field of laser ultrasonics is one of the most interesting topics in which laser light is used for the generation and the detection of ultrasound waves in materials. This contactless method is extremely useful for materials inspection being nondestructive and contactless, especially for hazardous environments. In this method a pulsed laser with a short pulse length of e.g. nano- or even picoseconds is focused on the surface of a specimen and then ultrasonic waves, nanometer vibrations, such as surface and bulk waves are generated and propagate in all directions on to the material. For contactless detection of ultrasonic waves several interferometers such as confocal Fabry-Perot, Michelson, and long path difference interferometers have been applied. Each of them has its individual advantages and disadvantages concerning, e.g., frequency responses and sensitivity. However, most of these interferometers work best on mirror-like surfaces and exhibit reduced sensitivity on rough surfaces. Also these kinds of interferometer are sensible to external noise as air fluctuations, sample vibrations or thermal deformations, thus requiring relatively complex stabilization techniques. This hinders their applicability in industrial applications with harsh environmental conditions. As an alternative to the before mentioned techniques interferometers based on photorefractive materials (PR) have been established. A typical two wave mixing interferometer (TWMI) configuration enables broadband ultrasonic measurements on rough surfaces. These types of interferometers have a good sensitivity up to 3e-7 nm(W/Hz) 1/2 spatially for samples with a high rough surface unlike the Michelson interferometer. By using ferroelectric photorefractive crystals such as LiNbO:Fe+2, sensitivity even is enhanced to 4e-8 nm(W/Hz) 1/2 but response time in these crystals is slower. In this work, contactless interferometer set ups based on photorefractive materials such as BSO (Bismuth Silicon Oxide: Bi 12

  16. Handheld ESPI-speckle interferometer

    DEFF Research Database (Denmark)

    Skov Hansen, René

    2003-01-01

    . The interferometer presented here is a compact version of the set-up, Which is capable of measuring displacements of small objects, having either a specularly reflecting-or a diffusely scattering surface. The small optical set-up together with the use of the popular USB-communication for acquiring the images...... and controlling the phase of the reference wave constitutes a compact "handheld" instrument and eliminates the need for installing extra hardware, such as frame grabber and Digital to Analog converter, in the host computer....

  17. Ultrasonic horn design for ultrasonic machining technologies

    Directory of Open Access Journals (Sweden)

    Naď M.

    2010-07-01

    Full Text Available Many of industrial applications and production technologies are based on the application of ultrasound. In many cases, the phenomenon of ultrasound is also applied in technological processes of the machining of materials. The main element of equipments that use the effects of ultrasound for machining technology is the ultrasonic horn – so called sonotrode. The performance of ultrasonic equipment, respectively ultrasonic machining technologies depends on properly designed of sonotrode shape. The dynamical properties of different geometrical shapes of ultrasonic horns are presented in this paper. Dependence of fundamental modal properties (natural frequencies, mode shapes of various sonotrode shapes for various geometrical parameters is analyzed. Modal analyses of the models are determined by the numerical simulation using finite element method (FEM design procedures. The mutual comparisons of the comparable parameters of the various sonotrode shapes are presented.

  18. Step index fibre using laser interferometer

    Indian Academy of Sciences (India)

    2014-03-04

    Mar 4, 2014 ... We propose the following model to describe the cladded fibre placed inside a liquid wedge interferometer. For simplicity, we assume square interferometer plates of dimensions 2a,. 2b and refractive index μL. The fibre radius is rf and the core radius is rc with skin and core indices μs, μc respectively. Hence ...

  19. Heterodyne displacement interferometer, insensitive for input polarization

    NARCIS (Netherlands)

    Meskers, A.J.H.; Spronck, J.W.; Munnig Schmidt, R.H.

    2014-01-01

    Periodic nonlinearity (PNL) in displacement interferometers is a systematic error source that limits measurement accuracy. The PNL of coaxial heterodyne interferometers is highly influenced by the polarization state and orientation of the source frequencies. In this Letter, we investigate this error

  20. A Michelson interferometer for ultracold neutrons

    International Nuclear Information System (INIS)

    Steyerl, A.; Malik, S.S.; Steinhauser, K.A.; Berger, L.

    1979-01-01

    We propose a neutron Michelson Interferometer installed within a focussing 'gravity diffractometer' for ultracold neutrons. In this arrangement the expected interference pattern depends only on the well-defined vertical component of neutron wavevector. Possible applications of such an interferometer are discussed. (orig.)

  1. Algorithms for Unequal-Arm Michelson Interferometers

    Science.gov (United States)

    Giampieri, Giacomo; Hellings, Ronald W.; Tinto, Massimo; Bender, Peter L.; Faller, James E.

    1994-01-01

    A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam.

  2. In-fiber integrated Michelson interferometer.

    Science.gov (United States)

    Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

    2006-09-15

    A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

  3. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

    This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

  4. Ultrasonic testing device

    International Nuclear Information System (INIS)

    Lawrie, W.E.

    1978-01-01

    The ultrasonic transmitter made of polarized ferroelectric ceramic material (lead zirconate titanate) is arranged in a strip carrier which allows it to be introduced between the fuel elements of a fuel subassembly in a water cooled nuclear reactor. The ultrasonic transmitter is insulated relative to the carrier. The echo of the ra dal ultrasonic pulse is recorded which changes as faulty water filled fuel elements are detected. (RW) [de

  5. The LTP interferometer and phasemeter

    International Nuclear Information System (INIS)

    Heinzel, G; Wand, V; GarcIa, A; Jennrich, O; Braxmaier, C; Robertson, D; Middleton, K; Hoyland, D; Ruediger, A; Schilling, R; Johann, U; Danzmann, K

    2004-01-01

    The LISA Technology Package (LTP), to be launched by ESA in 2006/2007, is a technology demonstration mission in preparation for the LISA space-borne gravitational wave detector. A central part of the LTP is the optical metrology package (heterodyne interferometer with phasemeter) which monitors the distance between two test masses with a noise level of 10 pm Hz -1/2 between 3 mHz and 30 mHz. It has a dynamic range of >100 μm without any actuators for the pathlength. In addition to the longitudinal measurements, it provides alignment measurements with an expected noise level of -1/2 . While the basic design has been described previously by Heinzel et al (2003 Class. Quantum Grav. 20 S153-61), this paper gives new details on the laser stabilization, the phasemeter and recent prototype results

  6. Multiple spacecraft Michelson stellar interferometer

    Science.gov (United States)

    Stachnik, R. V.; Arnold, D.; Melroy, P.; Mccormack, E. F.; Gezari, D. Y.

    1984-01-01

    Results of an orbital analysis and performance assessment of SAMSI (Spacecraft Array for Michelson Spatial Interferometry) are presented. The device considered includes two one-meter telescopes in orbits which are identical except for slightly different inclinations; the telescopes achieve separations as large as 10 km and relay starlight to a central station which has a one-meter optical delay line in one interferometer arm. It is shown that a 1000-km altitude, zero mean inclination orbit affords natural scanning of the 10-km baseline with departures from optical pathlength equality which are well within the corrective capacity of the optical delay line. Electric propulsion is completely adequate to provide the required spacecraft motions, principally those needed for repointing. Resolution of 0.00001 arcsec and magnitude limits of 15 to 20 are achievable.

  7. Pneumatic probe with laser interferometer

    International Nuclear Information System (INIS)

    Wilkens, P.H.

    1978-01-01

    Improvements to upgrade the accuracy of Rotacon probes by a complete redesign of probe to include a Michelson interferometer to replace the existing long-range capacity transducer are described. This has resulted in a compact and interchangeable probe cartridge with a 3 μin. resolution and accuracy; the cartridge can be installed and replaced in the Rotacon gauge with the minimum of realignment, which should reduce our dependence on operator skill. In addition, the stylus contact force can be reduced to 750 mg for the contacting types, but an alternative feature, which we are still developing, will use a gas jet cushion in place of the stylus to provide a noncontacting version of the same basic probe cartridge. This device is very sensitive to external vibration effects because it is virtually frictionless

  8. Dispersion cancellation in a triple Laue interferometer

    International Nuclear Information System (INIS)

    Lemmel, Hartmut

    2014-01-01

    The concept of dispersion cancellation has been established in light optics to improve the resolution of interferometric measurements on dispersive media. Odd order dispersion cancellation allows to measure phase shifts without defocusing the interferometer due to wave packet displacements, while even order dispersion cancellation allows to measure time lags without losing resolution due to wave packet spreading. We report that either type of dispersion cancellation can be realized very easily in a triple Laue interferometer. Such interferometers are Mach–Zehnder interferometers based on Bragg diffraction, and are commonly used for neutrons and x-rays. Although the first x-ray interferometer was built nearly five decades ago, the feature of dispersion cancellation hasn't been recognized so far because the concept was hardly known in the neutron and x-ray community. However, it explains right away the surprising decoupling of phase shift and spatial displacement that we have discovered recently in neutron interferometry (Lemmel and Wagh 2010 Phys. Rev. A 82 033626). Furthermore, this article might inspire the light optics community to consider whether a triple Laue interferometer for laser light would be useful and feasible. We explain how dispersion cancellation works in neutron interferometry, and we describe the setup rigorously by solving the Schrödinger equation and by calculating the path integral. We point out, that the latter has to be evaluated with special care since in our setup the beam trajectory moves with respect to the crystal lattice of the interferometer. (paper)

  9. Study on talbot pattern for grating interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ju; Oh, Oh Sung; Lee, Seung Wook [Dept. of School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of); Kim, Jong Yul [Neutron Instrument Division, Korea Atomic Energy Reserch Institute, Daejeon (Korea, Republic of)

    2015-04-15

    One of properties which X-ray and Neutron can be applied nondestructive test is penetration into the object with interaction leads to decrease in intensity. X-ray interaction with the matter caused by electrons, Neutron caused by atoms. They share applications in nondestructive test area because of their similarities of interaction mechanism. Grating interferometer is the one of applications produces phase contrast image and dark field image. It is defined by Talbot interferometer and Talbot-Lau interferometer according to Talbot effect and Talbot-Lau effect respectively. Talbot interferometer works with coherence beam like X-ray, and Talbot-Lau has an effect with incoherence beam like Neutron. It is important to expect the interference in grating interferometer compared normal nondestructive system. In this paper, simulation works are conducted according to Talbot and Talbot-Lau interferometer in case of X-ray and Neutron. Variation of interference intensity with X-ray and Neutron based on wave theory is constructed and calculate elements consist the system. Additionally, Talbot and Talbot-Lau interferometer is simulated in different kinds of conditions.

  10. Mid-IR laser ultrasonic testing for fiber reinforced plastics

    Science.gov (United States)

    Kusano, Masahiro; Hatano, Hideki; Oguchi, Kanae; Yamawaki, Hisashi; Watanabe, Makoto; Enoki, Manabu

    2018-04-01

    Ultrasonic testing is the most common method to detect defects in materials and evaluate their sizes and locations. Since piezo-electric transducers are manually handled from point to point, it takes more costs for huge products such as airplanes. Laser ultrasonic testing (LUT) is a breakthrough technique. A pulsed laser generates ultrasonic waves on a material surface due to thermoelastic effect or ablation. The ultrasonic waves can be detected by another laser with an interferometer. Thus, LUT can realize instantaneous inspection without contacting a sample. A pulse laser with around 3.2 μm wavelength (in the mid-IR range) is more suitable to generate ultrasonic waves for fiber reinforced plastics (FRPs) because the light is well absorbed by the polymeric matrix. On the other hand, such a laser is not available in the market. In order to emit the mid-IR laser pulse, we came up with the application of an optical parametric oscillator and developed an efficient wavelength conversion device by pumping a compact Nd:YAG solid-state laser. Our mid-IR LUT system is most suitable for inspection of FRPs. The signal-to-noise ratio of ultrasonic waves generated by the mid-IR laser is higher than that by the Nd:YAG laser. The purpose of the present study is to evaluate the performance of the mid-IR LUT system in reflection mode. We investigated the effects of the material properties and the laser properties on the generated ultrasonic waves. In addition, C-scan images by the system were also presented.

  11. Ultrasonic flow meter

    NARCIS (Netherlands)

    Lötters, Joost Conrad; Snijders, G.J.; Volker, A.W.F.

    2014-01-01

    The invention relates to an ultrasonic flow meter comprising a flow tube for the fluid whose flow rate is to be determined. The flow meter comprises a transmitting element for emitting ultrasonic waves, which is provided on the outer jacket of the flow tube. A receiving element, which is provided on

  12. Ultrasonic decontamination robot

    International Nuclear Information System (INIS)

    Patenaude, R.S.

    1984-01-01

    An ultrasonic decontamination robot removes radioactive contamination from the internal surface of the inlet and outlet headers, divider plate, tube sheet, and lower portions of tubes of a nuclear power plant steam generator. A programmable microprocessor controller guides the movement of a robotic arm mounted in the header manway. An ultrasonic transducer having a solvent delivery subsystem through which ultrasonic action is achieved is moved by the arm over the surfaces. A solvent recovery suction tube is positioned within the header to remove solvent therefrom while avoiding interference with the main robotic arm. The solvent composition, temperature, pressure, viscosity, and purity are controlled to optimize the ultrasonic scrubbing action. The ultrasonic transducer is controlled at a power density, frequency, and on-off mode cycle such as to optimize scrubbing action within the range of transducer-to-surface distance and solvent layer thickness selected for the particular conditions encountered. Both solvent and transducer control actions are optimized by the programmable microprocessor. (author)

  13. Measurement of absolute displacement-amplitude of ultrasonic wave using piezo-electric detection method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seong Hyun; Kim, Jong Beom; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

    2017-02-15

    A nonlinear ultrasonic parameter is defined by the ratio of displacement amplitude of the fundamental frequency component to that of the second-order harmonic frequency component. In this study, the ultrasonic displacement amplitude of an SUS316 specimen was measured via a piezo-electric-based method to identify the validity of piezo-electric detection method. For comparison, the ultrasonic displacement was also determined via a laser-based Fabry-Pérot interferometer. The experimental results for both measurements were in good agreement. Additionally, the stability of the repeated test results from the piezo-electric method exceeded that of the laser-interferometric method. This result indicated that the piezo-electric detection method can be utilized to measure a nonlinear ultrasonic parameter due to its excellent stability although it involves a complicated process.

  14. Measurement of absolute displacement-amplitude of ultrasonic wave using piezo-electric detection method

    International Nuclear Information System (INIS)

    Park, Seong Hyun; Kim, Jong Beom; Jhang, Kyung Young

    2017-01-01

    A nonlinear ultrasonic parameter is defined by the ratio of displacement amplitude of the fundamental frequency component to that of the second-order harmonic frequency component. In this study, the ultrasonic displacement amplitude of an SUS316 specimen was measured via a piezo-electric-based method to identify the validity of piezo-electric detection method. For comparison, the ultrasonic displacement was also determined via a laser-based Fabry-Pérot interferometer. The experimental results for both measurements were in good agreement. Additionally, the stability of the repeated test results from the piezo-electric method exceeded that of the laser-interferometric method. This result indicated that the piezo-electric detection method can be utilized to measure a nonlinear ultrasonic parameter due to its excellent stability although it involves a complicated process

  15. Comparative Sensitivities of Gravitational Wave Detectors Based on Atom Interferometers and Light Interferometers

    Science.gov (United States)

    Baker, John G.; Thorpe, J. I.

    2012-01-01

    We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe. Whether this potential advantage outweighs the additional complexity associated with including atom interferometers will require further study.

  16. Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Monolithic Interferometer Design and Test

    Science.gov (United States)

    Harlander, John M.; Englert, Christoph R.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Zastera, Vaz; Bach, Bernhard W.; Mende, Stephen B.

    2017-10-01

    The design and laboratory tests of the interferometers for the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument which measures thermospheric wind and temperature for the NASA-sponsored Ionospheric Connection (ICON) Explorer mission are described. The monolithic interferometers use the Doppler Asymmetric Spatial Heterodyne (DASH) Spectroscopy technique for wind measurements and a multi-element photometer approach to measure thermospheric temperatures. The DASH technique and overall optical design of the MIGHTI instrument are described in an overview followed by details on the design, element fabrication, assembly, laboratory tests and thermal control of the interferometers that are the heart of MIGHTI.

  17. Double-grating interferometer with a one-to-one correspondence with a Michelson interferometer.

    Science.gov (United States)

    Xu, Yande; Sasaki, Osami; Suzuki, Takamasa

    2003-10-01

    We describe a double-grating interferometer that has a one-to-one correspondence with a Michelson interferometer. The half spatial periods of the gratings are equivalent to the wavelengths of the interferometer. The widths of the interference fringes can be changed easily. The intensity distribution of the interference pattern is independent of the wavelength of the light source used. The surface profile of an object can be measured because two interference beams can coincide precisely on the image plane of the object. The measuring range is much larger than that of a Michelson interferometer.

  18. Direct reading fast microwave interferometer for EBT

    International Nuclear Information System (INIS)

    Uckan, T.

    1984-10-01

    A simple and inexpensive 4-mm direct reading fast (rise time approx. 100 μs) microwave interferometer is described. The system is particularly useful for density measurements on the ELMO Bumpy Torus (EBT) during pulsed operation

  19. Turbulence-Free Double-slit Interferometer

    Science.gov (United States)

    Smith, Thomas A.; Shih, Yanhua

    2018-02-01

    Optical turbulence can be detrimental for optical observations. For instance, atmospheric turbulence may reduce the visibility or completely blur out the interference produced by an interferometer in open air. However, a simple two-photon interference theory based on Einstein's granularity picture of light makes a turbulence-free interferometer possible; i.e., any refraction index, length, or phase variations along the optical paths of the interferometer do not have any effect on its interference. Applying this mechanism, the reported experiment demonstrates a two-photon double-slit interference that is insensitive to atmospheric turbulence. The turbulence-free mechanism and especially the turbulence-free interferometer would be helpful in optical observations that require high sensitivity and stability such as for gravitational-wave detection.

  20. Improved double-pass michelson interferometer

    Science.gov (United States)

    Schindler, R. A.

    1978-01-01

    Interferometer design separates beams by offsetting centerlines of cat's-eye retroreflectors vertically rather than horizontally. Since beam splitter is insensitive to minimum-thickness condition in this geometry, relatively-low-cost, optically flat plate can be used.

  1. Naturally stable Sagnac-Michelson nonlinear interferometer.

    Science.gov (United States)

    Lukens, Joseph M; Peters, Nicholas A; Pooser, Raphael C

    2016-12-01

    Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing-conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9% interference visibility and find evidence for noise reduction based on phase-sensitive gain. Our configuration utilizes fewer components than previous demonstrations and requires no active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.

  2. Vertical Josephson Interferometer for Tunable Flux Qubit

    Energy Technology Data Exchange (ETDEWEB)

    Granata, C [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Vettoliere, A [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Lisitskiy, M [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Rombetto, S [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Russo, M [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Ruggiero, B [Istituto di Cibernetica ' E. Caianiello' del Consiglio Nazionale delle Ricerche, I- 80078, Pozzuoli (Italy); Corato, V [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-8 1031, Aversa (Italy) and Istituto di Cibernetica ' E. Caianiello' del CNR, I-80078, Pozzuoli (Italy); Russo, R [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-8 1031, Aversa (Italy) and Istituto di Cibernetica ' E. Caianiello' del CNR, I-80078, Pozzuoli (Italy); Silvestrini, P [Dipartimento di Ingegneria dell' Informazione, Seconda Universita di Napoli, I-8 1031, Aversa (Italy) and Istituto di Cibernetica ' E. Caianiello' del CNR, I-80078, Pozzuoli (Italy)

    2006-06-01

    We present a niobium-based Josephson device as prototype for quantum computation with flux qubits. The most interesting feature of this device is the use of a Josephson vertical interferometer to tune the flux qubit allowing the control of the off-diagonal Hamiltonian terms of the system. In the vertical interferometer, the Josephson current is precisely modulated from a maximum to zero with fine control by a small transversal magnetic field parallel to the rf superconducting loop plane.

  3. Nonlinear Michelson interferometer for improved quantum metrology

    OpenAIRE

    Luis, Alfredo; Rivas, Ángel

    2015-01-01

    We examine quantum detection via a Michelson interferometer embedded in a gas with Kerr nonlinearity. This nonlinear interferometer is illuminated by pulses of classical light. This strategy combines the robustness against practical imperfections of classical light with the improvement provided by nonlinear processes. Regarding ultimate quantum limits, we stress that, as a difference with linear schemes, the nonlinearity introduces pulse duration as a new variable into play along with the ene...

  4. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...

  5. Ultrasonic testing X gammagraphy

    International Nuclear Information System (INIS)

    Mello Campos, A.M. de

    1989-01-01

    The experience of 10 years for substituting gammagraphy tests by ultrasonic tests is related. A comparative evaluation of data obtained from both techniques applied to welded butt joints is presented. (author)

  6. Ultrasonic grinding method

    International Nuclear Information System (INIS)

    Miyahara, Shuji.

    1990-01-01

    An ultrasonic generator and a liquid supply nozzle are opposed to an object to be ground and a pump is started in this state to supply an organic solvent. Matters to be decontaminated which adheres to the surface of the object to be ground and are difficult to be removed by a mere mechanical removing method can be eliminated previously by the surface active effect of the organic solvent such as ethanol prior to the oscillation of the ultrasonic generator. Subsequently, when the ultrasonic generator is oscillated, scales in the floated state can be removed simply. Further, since the organic solvent can penetrate to provide the surface active effect even in such a narrow portion that the top end of the ultrasonic generator is difficult to the intruded at the surface of the object to be ground, the decontaminating treatment can be applied also to such a narrow portion. (T.M.)

  7. Directivity measurements in aluminum using a laser ultrasonics system

    International Nuclear Information System (INIS)

    Sakamoto, J M S; Pacheco, G M; Tittmann, B R; Baba, A

    2011-01-01

    A laser ultrasonics system was setup to measure the directivity (angular dependence pattern) of the amplitude of ultrasonic waves generated in aluminum samples. A pulsed Nd:YAG laser operating at 1064 nm optical wavelength, with typical pulse width (FWHM) of 8 ns, and energy per pulse of 450 mJ, was used to generate the ultrasound waves in the samples. The laser detection system was a Mach-Zehnder interferometer with typical noise-limited resolution of 0.25 nm (rms), frequency range from 50 kHz to 20 MHz, and measurement range from -75 nm/V to +75 nm/V. Two different optical spot sizes of the Nd:YAG laser were used to generate waves in the ablation regime: one was focused and the other was unfocused. Using the obtained data, the directivity graphics were drawn and compared with the theoretical curves, showing a good agreement. The experiments showed the directivity as a function of the optical spot size. For a point ultrasonic source (or focused optical spot), the directivity shows that the longitudinal waves present considerable amplitude in all directions. For a larger ultrasonic source (or an unfocused optical spot) the directivity shows that the longitudinal waves are generated with the higher amplitudes inside angles around ±10 0 .

  8. Fundamentals of Medical Ultrasonics

    CERN Document Server

    Postema, Michiel

    2011-01-01

    This book sets out the physical and engineering principles of acoustics and ultrasound as used for medical applications. It covers the basics of linear acoustics, wave propagation, non-linear acoustics, acoustic properties of tissue, transducer components, and ultrasonic imaging modes, as well as the most common diagnostic and therapeutic applications. It offers students and professionals in medical physics and engineering a detailed overview of the technical aspects of medical ultrasonic imaging, whilst serving as a reference for clinical and research staff.

  9. Assessing ultrasonic examination results

    International Nuclear Information System (INIS)

    Deutsch, V.; Vogt, M.

    1977-01-01

    Amongst nondestructive examination methods, the ultrasonic examination plays an important role. The reason why its scope of application is so wide is because the sound conducting capacity is the only property the material of a test specimen has to have. As the fields are so manifold, only main aspects can be described briefly. The list of references, however, is very extensive and gives plenty of information of all the problems concerning the assessment of ultrasonic examination results. (orig./RW) [de

  10. Comparison of Atom Interferometers and Light Interferometers as Space-Based Gravitational Wave Detectors

    Science.gov (United States)

    Baker, John G.

    2012-01-01

    We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.

  11. Ultrasonic viewing device

    International Nuclear Information System (INIS)

    Ito, Juro.

    1979-01-01

    Purpose: To improve the safety of reactor operation by enabling to detect the states and positions of fuel assemblies over a wide range with a set of ultrasonic viewing device comprising a rotatable ultrasonic transmitter-receiver and a reflector mounted with an adjustable angle. Constitution: A driving portion for a ultrasonic viewing device is provided to a rotary plug closing the opening of a reactor vessel and a guide pipe suspending below the coolant level is provided to the driving portion. An ultrasonic transmitter-receiver is provided at the end of the holder tube in the guide pipe. A reflector is provided at the upper position of the reactor core so as to correspond to the ultrasonic transmitter-receiver. The ultrasonic transmitter-receiver, positioned by the driving portion, performs horizontal movement for scanning the entire surface of the top of the reactor core, as well as vertical movement covering the gap between the upper mechanism on the reactor and the reactor core, whereby the confirmation for the separation of the control rod and the detection for the states of the reactor core can be conducted by the reflection waves from the reflector. (Moriyama, K.)

  12. ULTRASONIC ASSEMBLY [REVIEW

    Directory of Open Access Journals (Sweden)

    PORAV Viorica

    2015-05-01

    Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

  13. Perfect crystal interferometer and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Yuji [Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria)

    1996-08-01

    The interferometry with angstrom scale wavelength has developed steadily, and various types of interferometers have been investigated. Among them, LLL interferometers are widely used. The first neutron interferometry was achieved in 1962 by Maier-Leibnitz et al. A new type of neutron interferometers was constructed with a perfect crystal, and experimentally performed in 1974 by Rauch et al. The precise measurements with LLL neutron interferometers were performed on scattering length, gravitational effect, coherence, Fizeau effects, spin superposition, complementarity, and post-selection effects. Since the early stage of quantum physics, the double-slit experiment has served as the example of the epistemologically strange features of quantum phenomena, and its course of study is described. The time-delayed interferometry with nuclear resonant scattering of synchrotron radiation and phase transfer in time-delayed interferometry with nuclear resonant scattering were experimented, and are briefly reported. A geometric phase factor was derived for a split beam experiment as an example of cyclic evolution. The geometric phase was observed with a two-loop neutron interferometer. All the experimental results showed complete agreement with the theoretical treatment. (K.I.)

  14. Michelson interferometer based spatial phase shift shearography.

    Science.gov (United States)

    Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

    2013-06-10

    This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

  15. Advanced Gouy phase high harmonics interferometer

    Science.gov (United States)

    Mustary, M. H.; Laban, D. E.; Wood, J. B. O.; Palmer, A. J.; Holdsworth, J.; Litvinyuk, I. V.; Sang, R. T.

    2018-05-01

    We describe an extreme ultraviolet (XUV) interferometric technique that can resolve ∼100 zeptoseconds (10‑21 s) delay between high harmonic emissions from two successive sources separated spatially along the laser propagation in a single Gaussian beam focus. Several improvements on our earlier work have been implemented in the advanced interferometer. In this paper, we report on the design, characterization and optimization of the advanced Gouy phase interferometer. Temporal coherence for both atomic argon and molecular hydrogen gases has been observed for several harmonic orders. It has been shown that phase shift of XUV pulses mainly originates from the emission time delay due to the Gouy phase in the laser focus and the observed interference is independent of the generating medium. This interferometer can be a useful tool for measuring the relative phase shift between any two gas species and for studying ultrafast dynamics of their electronic and nuclear motion.

  16. Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)

    Science.gov (United States)

    Roberts, B.

    1986-01-01

    The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

  17. Quantum Spin Transport in Mesoscopic Interferometer

    Directory of Open Access Journals (Sweden)

    Zein W. A.

    2007-10-01

    Full Text Available Spin-dependent conductance of ballistic mesoscopic interferometer is investigated. The quantum interferometer is in the form of ring, in which a quantum dot is embedded in one arm. This quantum dot is connected to one lead via tunnel barrier. Both Aharonov- Casher and Aharonov-Bohm e ects are studied. Our results confirm the interplay of spin-orbit coupling and quantum interference e ects in such confined quantum systems. This investigation is valuable for spintronics application, for example, quantum information processing.

  18. Streak camera recording of interferometer fringes

    International Nuclear Information System (INIS)

    Parker, N.L.; Chau, H.H.

    1977-01-01

    The use of an electronic high-speed camera in the streaking mode to record interference fringe motion from a velocity interferometer is discussed. Advantages of this method over the photomultiplier tube-oscilloscope approach are delineated. Performance testing and data for the electronic streak camera are discussed. The velocity profile of a mylar flyer accelerated by an electrically exploded bridge, and the jump-off velocity of metal targets struck by these mylar flyers are measured in the camera tests. Advantages of the streak camera include portability, low cost, ease of operation and maintenance, simplified interferometer optics, and rapid data analysis

  19. Superconducting on-chip microwave interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, Edwin P.; Fischer, Michael; Schneider, Christian; Baust, Alexander; Eder, Peter; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Wulschner, Karl Friedrich; Xie, Edwar; Zhong, Ling; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Marx, Achim; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany)

    2015-07-01

    In the realm of all-microwave quantum computation, information is encoded in itinerant microwave photons propagating along transmission lines. In such a system unitary operations are implemented by linear elements such as beam splitters or interferometers. However, for two-qubit operations non-linear gates, e.g., c-phase gates are required. In this work, we investigate superconducting interferometers as a building block of a c-phase gate. We experimentally characterize their scattering properties and compare them to simulation results. Finally, we discuss our progress towards the realization of a c-phase gate.

  20. Multiple reflection Michelson interferometer with picometer resolution.

    Science.gov (United States)

    Pisani, Marco

    2008-12-22

    A Michelson interferometer based on an optical set-up allowing multiple reflection between two plane mirrors performs the multiplication of the optical path by a factor N, proportionally increasing the resolution of the measurement. A multiplication factor of almost two orders of magnitude has been demonstrated with a simple set-up. The technique can be applied to any interferometric measurement where the classical interferometer limits due to fringe nonlinearities and quantum noise are an issue. Applications in precision engineering, vibration analysis, nanometrology, and spectroscopy are foreseen.

  1. Two-wavelength HeNe laser interferometer

    International Nuclear Information System (INIS)

    Granneman, E.H.A.

    1981-01-01

    This paper presents an interferometer set-up in which two wavelengths are used simultaneously. This enables one to determine separately the phase shifts caused by changes in plasma density and by mechanical vibrations of the interferometer structure

  2. Ultrasonic dip seal maintenance system

    International Nuclear Information System (INIS)

    Poindexter, A.M.; Ricks, H.E.

    1978-01-01

    Disclosed is a system for removing impurities from the surfaces of liquid dip seals and for wetting the metal surfaces of liquid dip seals in nuclear components. The system comprises an ultrasonic transducer that transmits ultrasonic vibrations along an ultrasonic probe to the metal and liquid surfaces of the dip seal thereby loosening and removing those impurities

  3. Artificial Intelligence Assists Ultrasonic Inspection

    Science.gov (United States)

    Schaefer, Lloyd A.; Willenberg, James D.

    1992-01-01

    Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

  4. Ultrasonic Stir Welding

    Science.gov (United States)

    Nabors, Sammy

    2015-01-01

    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  5. Ultrasonic nondestructive materials characterization

    Science.gov (United States)

    Green, R. E., Jr.

    1986-01-01

    A brief review of ultrasonic wave propagation in solid materials is presented with consideration of the altered behavior in anisotropic and nonlinear elastic materials in comparison with isotropic and linear elastic materials. Some experimental results are described in which ultrasonic velocity and attenuation measurements give insight into materials microstructure and associated mechanical properties. Recent developments with laser beam non-contact generation and detection of ultrasound are presented. The results of several years of experimental measurements using high-power ultrasound are discussed, which provide substantial evidence of the inability of presently accepted theories to fully explain the interaction of ultrasound with solid materials. Finally, a special synchrotron X-ray topographic system is described which affords the possibility of observing direct interaction of ultrasonic waves with the microstructural features of real crystalline solid materials for the first time.

  6. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

  7. Ultrasonic tests. Pt. 2

    International Nuclear Information System (INIS)

    Goebbels, K.

    1980-01-01

    After a basic treatment of ultrasonic wave propagation, of the state-of-the-art methods and the technical background in the preceeding part, advanced ultrasonic NDT techniques are presented here. The discussion of new development includes - manipulation systems, - automation of ultrasonic testing methods, documentation and evaluation. In the middle of this part the main problem areas will be discussed: - detection of defects (e.g. in coarse grained structures and welds), - classification of defects (e.g. discrimination between crack-like and volumetric faults), - sizing of defects. Research in the field of acoustical holography, development of probes and phased arrays, electromagnetic acoustic transducers and signal enhancement are the main contributing parts to the report. (orig./RW)

  8. Guided-wave tomographic imaging of plate defects by laser-based ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Junpil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Busan (Korea, Republic of)

    2016-12-15

    Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

  9. Hidden corrosion detection in aircraft aluminum structures using laser ultrasonics and wavelet transform signal analysis.

    Science.gov (United States)

    Silva, M Z; Gouyon, R; Lepoutre, F

    2003-06-01

    Preliminary results of hidden corrosion detection in aircraft aluminum structures using a noncontact laser based ultrasonic technique are presented. A short laser pulse focused to a line spot is used as a broadband source of ultrasonic guided waves in an aluminum 2024 sample cut from an aircraft structure and prepared with artificially corroded circular areas on its back surface. The out of plane surface displacements produced by the propagating ultrasonic waves were detected with a heterodyne Mach-Zehnder interferometer. Time-frequency analysis of the signals using a continuous wavelet transform allowed the identification of the generated Lamb modes by comparison with the calculated dispersion curves. The presence of back surface corrosion was detected by noting the loss of the S(1) mode near its cutoff frequency. This method is applicable to fast scanning inspection techniques and it is particularly suited for early corrosion detection.

  10. A study on laser-based ultrasonic technique by the use of guided wave tomographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Junpil, E-mail: jpp@pusan.ac.kr; Lim, Juyoung, E-mail: jpp@pusan.ac.kr [Graduate school, School of Mechanical Engineering, Pusan National University (Korea, Republic of); Cho, Younho [School of Mechanical Engineering, Pusan National University (Korea, Republic of); Krishnaswamy, Sridhar [Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, IL (United States)

    2015-03-31

    Guided wave tests are impractical for investigating specimens with limited accessibility and coarse surfaces or geometrically complicated features. A non-contact setup with a laser ultrasonic transmitter and receiver is the classic attractive for guided wave inspection. The present work was done to develop a non-contact guided-wave tomography technique by laser ultrasonic technique in a plate-like structure. A method for Lam wave generation and detection in an aluminum plate with a pulse laser ultrasonic transmitter and a Michelson interferometer receiver has been developed. In the images obtained by laser scanning, the defect shape and area showed good agreement with the actual defect. The proposed approach can be used as a non-contact-based online inspection and monitoring technique.

  11. Guided-wave tomography imaging plate defects by laser-based ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Pil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Pusan (Korea, Republic of)

    2014-12-15

    Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

  12. Plasmonic interferometers: From physics to biosensing applications

    Science.gov (United States)

    Zeng, Xie

    Optical interferometry has a long history and wide range of applications. In recent years, plasmonic interferometer arouses great interest due to its compact size and enhanced light-matter interaction. They have demonstrated attractive applications in biomolecule sensing, optical modulation/switching, and material characterization, etc. In this work, we first propose a practical far-field method to extract the intrinsic phase dispersion, revealing important phase information during interactions among free-space light, nanostructure, and SPs. The proposed approach is confirmed by both simulation and experiment. Then we design novel plasmonic interferometer structure for sensitive optical sensing applications. To overcome two major limitations suffered by previously reported double-slit plasmonic Mach-Zehnder interferometer (PMZI), two new schemes are proposed and investigated. (1) A PMZI based on end-fire coupling improves the SP coupling efficiency and enhance the interference contrast more than 50 times. (2) In another design, a multi-layered metal-insulator-metal PMZI releases the requirement for single-slit illumination, which enables sensitive, high-throughput sensing applications based on intensity modulation. We develop a sensitive, low-cost and high-throughput biosensing platform based on intensity modulation using ring-hole plasmonic interferometers. This biosensor is then integrated with cell-phone-based microscope, which is promising to develop a portable sensor for point-of-care diagnostics, epidemic disease control and food safety monitoring.

  13. Stable mounting of beamsplitters for an interferometer

    NARCIS (Netherlands)

    Veggel, van A.A.; Nijmeijer, H.

    2008-01-01

    The Basic Angle Monitoring (BAM) system for satellite GAIA (2012–2018) will measure variation on the angle between the lines-of-sight between two telescopes with 2.5 prad uncertainty. It is a laser-interferometer system consisting of two optical benches with a number of mirrors and beamsplitters.

  14. Smart photogalvanic running-grating interferometer

    DEFF Research Database (Denmark)

    Kukhtarev, N. V.; Kukhtareva, T.; Edwards, M. E.

    2005-01-01

    Photogalvanic effect produces actuation of periodic motion of macroscopic LiNbO3 crystal. This effect was applied to the development of an all-optical moving-grating interferometer usable for optical trapping and transport of algae chlorella microorganisms diluted in water with a concentration of...

  15. LTP interferometer-noise sources and performance

    International Nuclear Information System (INIS)

    Robertson, David; Killow, Christian; Ward, Harry; Hough, Jim; Heinzel, Gerhard; Garcia, Antonio; Wand, Vinzenz; Johann, Ulrich; Braxmaier, Claus

    2005-01-01

    The LISA Technology Package (LTP) uses laser interferometry to measure the changes in relative displacement between two inertial test masses. The goals of the mission require a displacement measuring precision of 10 pm Hz -1/2 at frequencies in the 3-30 mHz band. We report on progress with a prototype LTP interferometer optical bench in which fused silica mirrors and beamsplitters are fixed to a ZERODUR (registered) substrate using hydroxide catalysis bonding to form a rigid interferometer. The couplings to displacement noise of this interferometer of two expected noise sources-laser frequency noise and ambient temperature fluctuations-have been investigated, and an additional, unexpected, noise source has been identified. The additional noise is due to small amounts of signal at the heterodyne frequency arriving at the photodiode preamplifiers with a phase that quasistatically changes with respect to the optical signal. The phase shift is caused by differential changes in the external optical paths the beams travel before they reach the rigid interferometer. Two different external path length stabilization systems have been demonstrated and these allowed the performance of the overall system to meet the LTP displacement noise requirement

  16. Background reduction in a young interferometer biosensor

    NARCIS (Netherlands)

    Mulder, H. K P; Subramaniam, V.; Kanger, J. S.

    2014-01-01

    Integrated optical Young interferometer (IOYI) biosensors are among the most sensitive label-free biosensors. Detection limits are in the range of 20 fg/mm2. The applicability of these sensors is however strongly hampered by the large background that originates from both bulk refractive index

  17. Thermoluminescence spectra measured with a Michelson interferometer

    International Nuclear Information System (INIS)

    Haschberger, P.

    1991-01-01

    A Michelson interferometer was redesigned to prove its capabilities in the measurement of short-lived, low-intensity thermoluminescence spectra. Interferograms are collected during heating up the thermoluminescent probe in a heater plate. A personal computer controls the data acquisition and processes the Fourier transform. As the results show, even a comparatively simple and limited setup leads to relevant and reproducible spectra. (author)

  18. The effect of rotations on Michelson interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Maraner, Paolo, E-mail: pmaraner@unibz.it

    2014-11-15

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations.

  19. The effect of rotations on Michelson interferometers

    International Nuclear Information System (INIS)

    Maraner, Paolo

    2014-01-01

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations

  20. Laser frequency stabilization using a transfer interferometer

    Science.gov (United States)

    Jackson, Shira; Sawaoka, Hiromitsu; Bhatt, Nishant; Potnis, Shreyas; Vutha, Amar C.

    2018-03-01

    We present a laser frequency stabilization system that uses a transfer interferometer to stabilize slave lasers to a reference laser. Our implementation uses off-the-shelf optical components along with microcontroller-based digital feedback, and offers a simple, flexible, and robust way to stabilize multiple laser frequencies to better than 1 MHz.

  1. Laser-Ultrasonic Testing and its Applications to Nuclear Reactor Internals

    Science.gov (United States)

    Ochiai, M.; Miura, T.; Yamamoto, S.

    2008-02-01

    A new nondestructive testing technique for surface-breaking microcracks in nuclear reactor components based on laser-ultrasonics is developed. Surface acoustic wave generated by Q-switched Nd:YAG laser and detected by frequency-stabilized long pulse laser coupled with confocal Fabry-Perot interferometer is used to detect and size the cracks. A frequency-domain signal processing is developed to realize accurate sizing capability. The laser-ultrasonic testing allows the detection of surface-breaking microcrack having a depth of less than 0.1 mm, and the measurement of their depth with an accuracy of 0.2 mm when the depth exceeds 0.5 mm including stress corrosion cracking. The laser-ultrasonic testing system combined with laser peening system, which is another laser-based maintenance technology to improve surface stress, for inner surface of small diameter tube is developed. The generation laser in the laser-ultrasonic testing system can be identical to the laser source of the laser peening. As an example operation of the system, the system firstly works as the laser-ultrasonic testing mode and tests the inner surface of the tube. If no cracks are detected, the system then changes its work mode to the laser peening and improves surface stress to prevent crack initiation. The first nuclear industrial application of the laser-ultrasonic testing system combined with the laser peening was completed in Japanese nuclear power plant in December 2004.

  2. Development of a multi-beam laser ultrasonic inspection system and its application on flaw sizing

    International Nuclear Information System (INIS)

    Chivavibul, Pornthep; Lin, Shan; Fukutomi, Hiroyuki; Higuchi, Sadao; Ogata, Takashi; Fukuchi, Tetsuo

    2006-01-01

    Laser ultrasonic technique is a powerful tool for non-contact, nondestructive testing of materials. It is expected to apply to where the conventional ultrasonic technique is not applicable. However, this technique suffers from low sensitivity. In order to overcome this shortcoming, a multi-beam laser ultrasonic system was developed to increase signal-to-noise ratio (SNR) and steer beam direction. The system consisted of eight pulsed Nd:YAG lasers used for ultrasonic generation, and a two-wave mixing interferometer with a long-pulsed Nd:YAG used for ultrasonic detection. Spatial and temporal control of the firing of the individual lasers permitted the generation of both phased array single pulse and narrow-band ultrasonic signals. The performance of developed system was verified using aluminum specimens with the wave generation in a slight ablation mode. A significant increase in sensitivity was obtained, with an increase in signal amplitude with no change in noise level. In the narrow band case, tone bursts were successfully generated in both surface and bulk waves. Beam steering of bulk waves was also performed, and the directivity was confirmed by visualization using a conventional transducer. The developed system was applied to flaw sizing using two techniques: shadow and short-path of diffraction (SPOD), using aluminum specimens with 2-mm, 5-mm, 8-mm slit depths. The shadow technique accurately measured the 5- and 8-mm slits, but not the 2-mm slit. The SPOD technique, carried out using a 5-MHz normal longitudinal transducer as a detector instead of TWN interferometer, accurately measured slits in all specimens with an error less than 0.5 mm. (author)

  3. A generalized, periodic nonlinearity-reduced interferometer for straightness measurements

    International Nuclear Information System (INIS)

    Wu Chienming

    2008-01-01

    Periodic nonlinearity is a systematic error limiting the accuracy of displacement measurements at the nanometer level. However, an interferometer with a displacement measurement accuracy of less than 1 nm is required in nanometrology and in fundamental scientific research. To meet this requirement, a generalized, periodic nonlinearity-reduced interferometer, based on three construction principles has been developed for straightness measurements. These three construction principles have resulted in an interferometer with a highly stable design with reduced periodic nonlinearity. Verifications by a straightness interferometer have demonstrated that the periodic nonlinearity was less than 40 pm. The results also demonstrate that the interferometer design is capable of subnanometer accuracy and is useful in nanometrology

  4. Ultrasonic weld testing.

    Science.gov (United States)

    1970-12-01

    The study was broken down into two phases. Phase I consisted of a laboratory investigation of test specimens to determine the reliability of the ultrasonic equipment and testing procedure. Phase II was a field study where the knowledge, skills and ab...

  5. Ultrasonic leak detection

    International Nuclear Information System (INIS)

    Murphy, R.V.

    1977-01-01

    A scanning ultrasonic microphone was used to detect the presence and locate the sources of hydraulic noises in piping systems in a reactor environment. The intensity changes of the noises correspond to changes of flow conditions within the system caused by throttled valves, flow rate changes, and leaks. (author)

  6. Ultrasonic Bat Deterrent Technology

    Energy Technology Data Exchange (ETDEWEB)

    Kinzie, Kevin; Rominger, Kathryn M.

    2017-12-14

    The project objective was to advance the development and testing of an Near commercial bat-deterrent system with a goal to increase the current GE deterrent system effectiveness to over 50% with broad species applicability. Additionally, the research supported by this program has provided insights into bat behavior and ultrasonic deterrent design that had not previously been explored. Prior research and development had demonstrated the effectiveness of a commercial-grade, air-powered, ultrasonic bat deterrent to be between 30-50% depending upon the species of bat. However, the previous research provided limited insight into the behavioral responses of bats in the presence of ultrasonic deterrent sound fields that could be utilized to improve effectiveness. A unique bat flight room was utilized to observe the behavioral characteristics of bats in the presence of ultrasonic sound fields. Behavioral testing in the bat flight facility demonstrated that ultrasonic sounds similar to those produced by the GE deterrent influenced the activities and behaviors, primarily those associated with foraging, of the species exposed. The study also indicated that continuous and pulsing ultrasonic signals had a similar effect on the bats, and confirmed that as ultrasonic sounds attenuate, their influence on the bats’ activities and behavior decreases. Ground testing at Wolf Ridge Wind, LLC and Shawnee National Forest assessed both continuous and pulsing deterrent signals emitted from the GE deterrent system and further enhanced the behavioral understanding of bats in the presence of the deterrent. With these data and observations, the existing 4-nozzle continuous, or steady, emission ultrasonic system was redesigned to a 6-nozzle system that could emit a pulsing signal covering a larger air space around a turbine. Twelve GE 1.6-100 turbines were outfitted with the deterrent system and a formal three-month field study was performed using daily carcass searches beneath the 12

  7. Dental hard tissue characterization using laser-based ultrasonics

    Science.gov (United States)

    Blodgett, David W.; Massey, Ward L.

    2003-07-01

    Dental health care and research workers require a means of imaging the structures within teeth in vivo. One critical need is the detection of tooth decay in its early stages. If decay can be detected early enough, the process can be monitored and interventional procedures, such as fluoride washes and controlled diet, can be initiated to help re-mineralize the tooth. Currently employed x-ray imaging is limited in its ability to visualize interfaces and incapable of detecting decay at a stage early enough to avoid invasive cavity preparation followed by a restoration. To this end, non-destructive and non-contact in vitro measurements on extracted human molars using laser-based ultrasonics are presented. Broadband ultrasonic waves are excited in the extracted sections by using a pulsed carbon-dioxide (CO2) laser operating in a region of high optical absorption in the dental hard tissues. Optical interferometric detection of the ultrasonic wave surface displacements in accomplished with a path-stabilized Michelson-type interferometer. Results for bulk and surface in-vitro characterization of caries are presented on extracted molars with pre-existing caries.

  8. Analysis of threshold curves for superconducting interferometers

    International Nuclear Information System (INIS)

    Peterson, R.L.; Hamilton, C.A.

    1979-01-01

    Threshold curves for multijunction superconducting interferometers have been calculated previously, showing general agreement with observed features, especially in symmetric cases. We here add some more details to the analysis, paying particular attention to the effects of asymmetries in coupling, inductance, or critical currents. Feed-loop inductance and flux quantization in the feed loop can be important. A changing lobe pattern over many periods, asymmetries within a period, shifting patterns between runs spanning a warm-up, and sudden changes in pattern because of noise in the environment are all quantitatively explainable on the basis of this model. By use of a single ''calibration curve'', the inductance for symmetric two- or three-junction interferometers can be obtained immediately

  9. Direct-reading type microwave interferometer

    International Nuclear Information System (INIS)

    Matsuura, Kiyokata; Fujita, Junji; Ogata, Atsushi; Haba, Kiichiro.

    1977-10-01

    A new microwave interferometer has been developed and applied to the electron density measurement on JIPP T-II plasma device. The interferometer generates an output voltage proportional to the number of fringe shifts and also output pulses which indicate the change of electron density for the convenience of data processing, where the resolution is a quarter of fringe shift. The principle is based on the digitization of fringe shifts utilizing the phase detection of microwave signals with two-level modulation of source frequency. With this system and 70 GHz microwave source, a change of electron density as rapid as about 2 x 10 13 cm -3 in 1 ms has been measured at the tokamak operation of JIPP T-II. (auth.)

  10. Noise sources in the LTP heterodyne interferometer

    International Nuclear Information System (INIS)

    Wand, V; Bogenstahl, J; Braxmaier, C; Danzmann, K; GarcIa, A; Guzman, F; Heinzel, G; Hough, J; Jennrich, O; Killow, C; Robertson, D; Sodnik, Z; Steier, F; Ward, H

    2006-01-01

    The LISA Technology Package uses a heterodyne Mach-Zehnder interferometer to monitor the relative motion of the test masses with picometer accuracy. This paper discusses two classes of noise sources that were identified and investigated during the prototype experiments. Most troublesome are electrically induced sidebands on the light, which give rise to nonlinearities in the interferometer output. Even worse, if the differential pathlength between two optical fibres fluctuates, a noise term of milliradian amplitude appears and completely spoils the performance. We discuss the origin and mitigation of this process. Dissimilar beam shapes of the interfering beams produce another type of noise in conjunction with beam jitter and spatially inhomogeneous photodetectors. To study and minimize this effect, we have built a real-time high-resolution phasefront imaging system that will be used for the production of the flight model

  11. Parametric instability in GEO 600 interferometer

    International Nuclear Information System (INIS)

    Gurkovsky, A.G.; Vyatchanin, S.P.

    2007-01-01

    We present analysis of undesirable effect of parametric instability in signal recycled GEO 600 interferometer. The basis for this effect is provided by excitation of additional (Stokes) optical mode, having frequency ω 1 , and mirror elastic mode, having frequency ω m , when the optical energy stored in the main FP cavity mode, having frequency ω 0 , exceeds a certain threshold and detuning Δ=ω 0 -ω 1 -ω m is small. We discuss the potential of observing parametric instability and its precursors in GEO 600 interferometer. This approach provides the best option to get familiar with this phenomenon, to develop experimental methods to depress it and to test the effectiveness of these methods in situ

  12. First Colombian Solar Radio Interferometer: current stage

    Science.gov (United States)

    Guevara Gómez, J. C.; Martínez Oliveros, J. C.; Calvo-Mozo, B.

    2017-10-01

    Solar radio astronomy is a fast developing research field in Colombia. Here, we present the scientific goals, specifications and current state of the First Colombian Solar Radio Interferometer consisting of two log-periodic antennas covering a frequency bandwidth op to 800 MHz. We describe the importance and benefits of its development to the radioastronomy in Latin America and its impact on the scientific community and general public.

  13. Progress in gravitational wave detection: Interferometers

    International Nuclear Information System (INIS)

    Kuroda, Kazuaki

    2002-01-01

    A gravitational wave (GW) is a physical entity of space-time derived from Einstein's theory of general relativity. Challenging projects to observe gravitational waves are being conducted throughout the world. A Japanese project involving a 300 m baseline laser interferometer, TAMA, achieved 1000 hr of continuous observation with the best sensitivity in the world during the summer of 2001. After achieving promising results, the realization of LCGT (Large-scale Cryogenic Gravitational wave Telescope) will become possible in the near future

  14. Fine art of computing nulling interferometer maps

    Science.gov (United States)

    Hénault, F.

    2008-07-01

    Spaceborne nulling interferometers are often characterized by means of their nulling ratio, which is defined as the deepest possible extinction of one target star supposed to harbor an extra-solar system. Herein is shown that another parameter, which is the transmitting efficiency of nearby bright fringes, is also of prime importance. More generally, "nulling maps" formed by the whole destructive and constructive fringe pattern projected on-sky, are found to be very sensitive on the design of some subsystems constituting the interferometer. In particular, we consider Spatial Filtering (SF) and Achromatic Phase Shifter (APS) devices, both required achieving planet detection and characterization. Consequences of the SF choice (pinhole or single-mode optical fiber) and APS properties (with or without induced pupil-flip) are discussed, for both monochromatic and polychromatic cases. Examples of numerical simulations are provided for single Bracewell interferometer, Angel cross and X-array configurations, demonstrating noticeable differences in the aspect of resulting nulling maps. It is concluded that both FS and APS designs exhibit variable capacities for serendipitous planet discovery.

  15. Dispersion interferometer for controlled fusion devices

    International Nuclear Information System (INIS)

    Drachev, V.P.; Krasnikov, Yu.I.; Bagryansky, P.A.

    1992-01-01

    A common feature in interferometry is the presence of two independent optical channels. Since wave phase in a medium depends on the geometrical path, polarization and radiation frequency, respectively, one can distinguish three types of interferometric schemes when the channels are geometrically separated, or separation occurs in polarizations or radiation frequencies. We have developed a measurement scheme based on a dispersion interferometer (DI) for plasma diagnostics in the experiments on controlled fusion. DI optical channels have the same geometrical path and are separated in radiation frequency. Use of a common optical path causes the main advantage of the DI technique - low sensitivity to vibrations of optical elements. The use of the DI technique for diagnostics of a laser spark in air and of arc discharges has shown its essential advantages as compared to classical interferometers. Interest in the DI technique from the viewpoint of its application in controlled fusion devices is determined also generated by the possibility of developing a compact multichannel interferometer not requiring a vibration isolation structure. (author) 14 refs., 3 figs

  16. Ultrasonic calibration assembly

    International Nuclear Information System (INIS)

    1981-01-01

    Ultrasonic transducers for in-service inspection of nuclear reactor vessels have several problems associated with them which this invention seeks to overcome. The first is that of calibration or referencing a zero start point for the vertical axis of transducer movement to locate a weld defect. The second is that of verifying the positioning (vertically or at a predetermined angle). Thirdly there is the problem of ascertaining the speed per unit distance in the operating medium of the transducer beam prior to the actual inspection. The apparatus described is a calibration assembly which includes a fixed, generally spherical body having a surface for reflecting an ultrasonic beam from one of the transducers which can be moved until the reflection from the spherical body is the highest amplitude return signal indicating radial alignment from the body. (U.K.)

  17. Pulsed ultrasonic stir welding system

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

  18. A Laser-based Ultrasonic Inspection System to Detect Micro Fatigue Cracks

    International Nuclear Information System (INIS)

    Park, Seung Kyu; Baik, Sung Hoon; Park, Moon Cheol; Lim, Chang Hwan; Cha, Hyung Ki

    2005-01-01

    Laser-based ultrasonic techniques have been established as a viable non-contact alternative to piezoelectric transducers for generating and receiving ultrasound. Laser-based ultrasonic inspection system provides a number of advantages over the conventional generation by piezoelectric transducers, especially a non-contact generation and detection of ultrasonic waves, high spatial scanning resolution, controllable narrow-band and wide-band spectrum, absolute measurements of the moving distance, use of fiber optics, and an ability to operate on curved and rough surfaces and at hard-to-access locations like a nuclear power plant. Ochiai and Miura used the laser-based ultrasound to detect micro fatigue cracks for the inspection of a material degradation in nuclear power plants. This widely applicable laser-based ultrasonic inspection system is comparatively expensive and provides low signal-to-noise ratio to measure ultrasound by using the laser interferometer. Many studies have been carried out to improve the measuring efficiency of the laser interferometer. One of the widely used laser interferometer types to measure the ultrasound is the Confocal Fabry-Perot Interferometer(CFPI). The measurement gain of the CFPI is slightly and continually varied according to the small change of the cavity length and the fluctuations of the measuring laser beam frequency with time. If we continually adjust the voltage of a PZT which is fixed to one of the interferometer mirrors, the optimum working point of the CFPI can be fixed. Though a static stabilizer can fix the gain of the CFPI where the CW laser beam is targeted at one position, it can not be used when the CW laser beam is scanned like a scanning laser source(SLS) technique. A dynamic stabilizer can be used for the scanning ultrasonic inspection system. A robust dynamic stabilizer is needed for an application to the industrial inspection fields. Kromine showed that the SLS technique is effective to detect small fatigue cracks

  19. Wave–particle duality in a Raman atom interferometer

    International Nuclear Information System (INIS)

    Jia Ai-Ai; Yang Jun; Yan Shu-Hua; Hu Qing-Qing; Luo Yu-Kun; Zhu Shi-Yao

    2015-01-01

    We theoretically investigate the wave–particle duality based on a Raman atom interferometer, via the interaction between the atom and Raman laser, which is similar to the optical Mach–Zehnder interferometer. The wave and which-way information are stored in the atomic internal states. For the φ − π − π/2 type of atom interferometer, we find that the visibility (V) and predictability (P) still satisfy the duality relation, P 2 + V 2 ≤ 1. (paper)

  20. Vibrometer based on a self-mixing effect interferometer

    International Nuclear Information System (INIS)

    Marti-Lopez, Luis; Gonzalez-Penna, R.; Martinez-Celorio, R. A.

    2009-01-01

    We outline the basic principles of the self-mixing effect and present the design and construction of an interferometer based on this phenomenon. It differs from the previously reported in the literature by the use of two photodetectors, located at different arms of the interferometer. This feature allows widening the arsenal of strategies for the digital processing of the signal. The interferometer is used as vibrometer for the characterization of professional loudspeakers. Experimental results are presented as an illustration. (Author)

  1. Gravitational Wave Detection with Single-Laser Atom Interferometers

    Science.gov (United States)

    Yu, Nan; Tinto, Massimo

    2011-01-01

    A new design for a broadband detector of gravitational radiation relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser are used for operating the two atom interferometers. The innovation here involves the fact that the atoms in the atom interferometers are not only considered as perfect test masses, but also as highly stable clocks. Atomic coherence is intrinsically stable, and can be many orders of magnitude more stable than a laser.

  2. Analysis of a four-mirror-cavity enhanced Michelson interferometer.

    Science.gov (United States)

    Thüring, André; Lück, Harald; Danzmann, Karsten

    2005-12-01

    We investigate the shot-noise-limited sensitivity of a four-mirror-cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature gives boundary conditions allowing systematic parameter studies.

  3. Special topics in infrared interferometry. [Michelson interferometer development

    Science.gov (United States)

    Hanel, R. A.

    1985-01-01

    Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

  4. A nanofabricated, monolithic, path-separated electron interferometer

    OpenAIRE

    Agarwal, Akshay; Kim, Chung-Soo; Hobbs, Richard; Dyck, Dirk van; Berggren, Karl K.

    2017-01-01

    Progress in nanofabrication technology has enabled the development of numerous electron optic elements for enhancing image contrast and manipulating electron wave functions. Here, we describe a modular, self-aligned, amplitude-division electron interferometer in a conventional transmission electron microscope. The interferometer consists of two 45-nm-thick silicon layers separated by 20??m. This interferometer is fabricated from a single-crystal silicon cantilever on a transmission electron m...

  5. High-accuracy vibration sensor based on a Fabry-Perot interferometer with active phase-tracking technology.

    Science.gov (United States)

    Xia, Wei; Li, Chuncheng; Hao, Hui; Wang, Yiping; Ni, Xiaoqi; Guo, Dongmei; Wang, Ming

    2018-02-01

    A novel position-sensitive Fabry-Perot interferometer was constructed with direct phase modulation by a built-in electro-optic modulator. Pure sinusoidal phase modulation of the light was produced, and the first harmonic of the interference signal was extracted to dynamically maintain the interferometer phase to the most sensitive point of the interferogram. Therefore, the minute vibration of the object was coded on the variation of the interference signal and could be directly retrieved by the output voltage of a photodetector. The operating principle and the signal processing method for active feedback control of the interference phase have been demonstrated in detail. The developed vibration sensor was calibrated through a high-precision piezo-electric transducer and tested by a nano-positioning stage under a vibration magnitude of 60 nm and a frequency of 300 Hz. The active phase-tracking method of the system provides high immunity against environmental disturbances. Experimental results show that the proposed interferometer can effectively reconstruct tiny vibration waveforms with subnanometer resolution, paving the way for high-accuracy vibration sensing, especially for micro-electro-mechanical systems/nano-electro-mechanical systems and ultrasonic devices.

  6. CAMEX-3 ATMOSPHERIC EMITTED RADIANCE INTERFEROMETER (AERI) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Atmospheric Emitted Radiance Interferometer (AERI) was used to make atmospheric temperature and moisture retrievals. AERI provides absolutely calibrated...

  7. Two-path plasmonic interferometer with integrated detector

    Science.gov (United States)

    Dyer, Gregory Conrad; Shaner, Eric A.; Aizin, Gregory

    2016-03-29

    An electrically tunable terahertz two-path plasmonic interferometer with an integrated detection element can down convert a terahertz field to a rectified DC signal. The integrated detector utilizes a resonant plasmonic homodyne mixing mechanism that measures the component of the plasma waves in-phase with an excitation field that functions as the local oscillator in the mixer. The plasmonic interferometer comprises two independently tuned electrical paths. The plasmonic interferometer enables a spectrometer-on-a-chip where the tuning of electrical path length plays an analogous role to that of physical path length in macroscopic Fourier transform interferometers.

  8. A double-pass interferometer for measurement of dimensional changes

    International Nuclear Information System (INIS)

    Ren, Dongmei; Lawton, K M; Miller, J A

    2008-01-01

    A double-pass interferometer was developed for measuring dimensional changes of materials in a nanoscale absolute interferometric dilatometer. This interferometer realized the double-ended measurement of a sample using a single-detection double-pass interference system. The nearly balanced design, in which the measurement beam and the reference beam have equal optical path lengths except for the path difference caused by the sample itself, makes this interferometer have high stability, which is verified by the measurement of a quasi-zero-length sample. The preliminary experiments and uncertainty analysis show that this interferometer should be able to measure dimensional changes with characteristic uncertainty at the nanometer level

  9. Application of a fiber Fabry-Perot interferometer sensor for receiving SH-EMAT signals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hyuk; Kim, Dae Hyun; Park, Ik Keun [Seoul National University of Technology, Seoul (Korea, Republic of)

    2014-04-15

    Shear horizontal (SH) waves propagate as a type of plate wave in a thin sheet. The dispersion characteristics of SH waves can be used for signal analysis. Therefore, SH-waves are useful for monitoring the structural health of a thin-sheet-structure. An electromagnetic acoustic transducer (EMAT), which is a non-contact ultrasonic transducer, can generate SH-waves easily by varying the shape and array of magnets and coils. Therefore, an EMAT can be applied to an automated ultrasonic testing system for structural health monitoring. When used as a sensor, however, the EMAT has a weakness in that electromagnetic interference (EMI) noise can occur easily in the automated system because of motors and electric devices. Alternatively, a fiber optic sensor works well in the same environment with EMI noise because it uses a light signal instead of an electric signal. In this paper, a fiber Fabry-Prot interferometer (FFPI) was proposed as a sensor to receive the SH-waves generated by an EMAT. A simple test was performed to verify the performance of the FFPI sensor. It is thus shown that the FFPI can receive SH-wave signals clearly.

  10. Interferometers as probes of Planckian quantum geometry

    Science.gov (United States)

    Hogan, Craig J.

    2012-03-01

    A theory of position of massive bodies is proposed that results in an observable quantum behavior of geometry at the Planck scale, tP. Departures from classical world lines in flat spacetime are described by Planckian noncommuting operators for position in different directions, as defined by interactions with null waves. The resulting evolution of position wave functions in two dimensions displays a new kind of directionally coherent quantum noise of transverse position. The amplitude of the effect in physical units is predicted with no parameters, by equating the number of degrees of freedom of position wave functions on a 2D space-like surface with the entropy density of a black hole event horizon of the same area. In a region of size L, the effect resembles spatially and directionally coherent random transverse shear deformations on time scale ≈L/c with typical amplitude ≈ctPL. This quantum-geometrical “holographic noise” in position is not describable as fluctuations of a quantized metric, or as any kind of fluctuation, dispersion or propagation effect in quantum fields. In a Michelson interferometer the effect appears as noise that resembles a random Planckian walk of the beam splitter for durations up to the light-crossing time. Signal spectra and correlation functions in interferometers are derived, and predicted to be comparable with the sensitivities of current and planned experiments. It is proposed that nearly colocated Michelson interferometers of laboratory scale, cross-correlated at high frequency, can test the Planckian noise prediction with current technology.

  11. Combined shearing interferometer and hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Hutchin, R. A.

    1985-01-01

    A sensitive wavefront sensor combining attributes of both a Hartmann type of wavefront sensor and an AC shearing interferometer type of wavefront sensor. An incident wavefront, the slope of which is to be detected, is focussed to first and second focal points at which first and second diffraction gratings are positioned to shear and modulate the wavefront, which then diverges therefrom. The diffraction patterns of the first and second gratings are positioned substantially orthogonal to each other to shear the wavefront in two directions to produce two dimensional wavefront slope data for the AC shearing interferometer portion of the wavefront sensor. First and second dividing optical systems are positioned in the two diverging wavefronts to divide the sheared wavefront into an array of subapertures and also to focus the wavefront in each subaperture to a focal point. A quadrant detector is provided for each subaperture to detect the position of the focal point therein, which provides a first indication, in the manner of a Hartmann wavefront sensor, of the local wavefront slope in each subaperture. The total radiation in each subaperture, as modulated by the diffraction grating, is also detected by the quadrant detector which produces a modulated output signal representative thereof, the phase of which relative to modulation by the diffraction grating provides a second indication of the local wavefront slope in each subaperture, in the manner of an AC shearing interferometer wavefront sensor. The data from both types of sensors is then combined by long term averaging thereof to provide an extremely sensitive wavefront sensor

  12. Atomic interferometers in an optical lattice

    International Nuclear Information System (INIS)

    Pelle, Bruno

    2013-01-01

    The aim of the ForCa-G project, for Casimir force and short range Gravitation, lies into the measurement of short range forces between atoms and a mirror using atomic interferometry techniques. Particularly, the Casimir-Polder force and the pursuit of short range gravitational tests in the frame of potential deviations of Newton's law are aimed. This experiment is based on the trapping of neutral atoms in a 1D vertical optical lattice, where the energy eigenvalues of the Hamiltonian describing this system is the so-called Wannier-Stark ladder of discrete energy states localized in each lattice well. This work constitutes a demonstration of principle of this project with atoms set far from the mirror. Each energy state is thus separated from the one of the adjacent well by the potential energy increment between those two wells, called the Bloch frequency ν B . Then, atomic interferometers are realized in the lattice using Raman or microwave pulses where the trapped atomic wave functions are placed, and then recombined, in a superposition of states between different energy states localized either in the same well, either in adjacent wells. This work presents the study of different kinds of atomic interferometers in this optical lattice, characterized in terms of sensibility and systematic effects on the Bloch frequency measurement. One of the studied interferometers accessed to a sensitivity on the Bloch frequency of σ δ ν B /ν B =9.0x10 -6 at 1∼s in relative, which integrates until σ δ ν B /ν B =1. 10 -7 in 2800∼s. This corresponds to a state-of-the-art measurement of the gravity acceleration g for a trapped atomic gravimeter. (author)

  13. Ultrasonic attenuation in superconducting zinc

    International Nuclear Information System (INIS)

    Auluck, S.

    1978-01-01

    The differences in the Zn ultrasonic attenuation data of different workers are analyzed. The superconducting energy gaps deduced from our analysis of the ultrasonic-attenuation data of Cleavelin and Marshall are consistent with the gaps deduced from the knowledge of the Fermi surface and the electron-phonon mass enhancement factor

  14. Lumber defect detection by ultrasonics

    Science.gov (United States)

    K. A. McDonald

    1978-01-01

    Ultrasonics, the technology of high-frequency sound, has been developed as a viable means for locating most defects In lumber for use in digital form in decision-making computers. Ultrasonics has the potential for locating surface and internal defects in lumber of all species, green or dry, and rough sawn or surfaced.

  15. X-ray speckle correlation interferometer

    International Nuclear Information System (INIS)

    Eisenhower, Rachel; Materlik, Gerhard

    2000-01-01

    Speckle Pattern Correlation Interferometry (SPCI) is a well-established technique in the visible-light regime for observing surface disturbances. Although not a direct imaging technique, SPCI gives full-field, high-resolution information about an object's motion. Since x-ray synchrotron radiation beamlines with high coherent flux have allowed the observation of x-ray speckle, x-ray SPCI could provide a means to measure strains and other quasi-static motions in disordered systems. This paper therefore examines the feasibility of an x-ray speckle correlation interferometer

  16. Virgo an interferometer for gravitational wave detection

    International Nuclear Information System (INIS)

    Passaquieti, R.

    2000-01-01

    Gravitational waves propagating from rapidly accelerating star masses can be detected by means of interfer- ometric techniques. The Virgo detector is a Michelson interferometer, with two 3 km long Fabry-Perot cavities, that is going to be built in the countryside of Pisa (Italy). Principles of interferometric gravitational wave detection, and the main noise sources in the Virgo apparatus are treated. The Virgo optical scheme and its main components are also described. Finally, an overview on the status of works at the Virgo site is presented

  17. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

    1976-01-01

    The ultrasonic examination of austenitic stainless steel weld metal has always been regarded as a difficult proposition because of the large and variable ultrasonic attenuations and back scattering obtained from apparently similar weld deposits. The work to be described shows how the existence of a fibre texture within each weld deposit (as a result of epitaxial growth through successive weld beads) produces a systematic variation in the ultrasonic attenuation coefficient and the velocity of sound, depending upon the angle between the ultrasonic beam and the fibre axis. Development work has shown that it is possible to adjust the welding parameters to ensure that the crystallographic texture within each weld is compatible with improved ultrasonic transmission. The application of the results to the inspection of a specific weld in type 316 weld metal is described

  18. A stellar interferometer on the Moon

    Science.gov (United States)

    Porro, Irene

    The work I present in this document has been divided into two main parts, the first one related to the IOTA project and the second one related to the study on the lunar interferometer, and an introduction section. Each section can be read independently from the other, however they are presented following the logical order in which the research work has been developed. As a guide for the reader here I describe the content of each chapter, which represents the original contribution (except when it is specifically declared) to the research accomplished. This section consists in the Introduction itself, with a presentation of the motivations for this research work, and in the chapter Interferometry from the Earth and from the Moon. The first part of this chapter shows the performances which are expected to be reached by ground-based interferometers (Colavita, 1992) by using adaptive optics systems (Beckers, 1993). The evaluation is made separately for the case of high resolution imaging and for high accuracy astrometric measurements. The most optimistic results expected for ground-based instruments determine the level of the performance that has to be required from a space interferometer (both an orbiting and a lunar instrument). In the second part of the chapter I specifically deal with the case of a lunar interferometer, which allows to put together the advantages o ered by a ground-based instrument (very long baseline, a stable platform) and those offered by the space environment (absence of atmospheric turbulence, long integration times, and wavelength range of observation from the ultraviolet to the far infrared). In order to evaluate the limits of the lunar interferometer, I need to consider three subjects with which I did not explicitly dealt for the study on IOTA: the maximum length of the baseline (Tango and Twiss, 1974), the maximum integration time, and the performances obtainable at the minimum temperature of operation (Ridgway, 1990). The chapter ends with

  19. Ultrasonic variables affecting inspection

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.; Whiting, A.R.; McElroy, J.T.

    1977-01-01

    There are many variables which affect the detection of the effects and reproducibility of results when utilizing ultrasonic techniques. The most important variable is the procedure, as this document specifies, to a great extent, the controls that are exercised over the other variables. The most important variable is personnel with regards to training, qualification, integrity, data recording, and data analysis. Although the data is very limited, these data indicate that, if the procedure is carefully controlled, reliability of defect detection and reproducibility of results are both approximately 90 percent for reliability of detection, this applies to relatively small defects as reliability increases substantially as defect size increases above the recording limit. (author)

  20. Adaptive DFT-Based Interferometer Fringe Tracking

    Science.gov (United States)

    Wilson, Edward; Pedretti, Ettore; Bregman, Jesse; Mah, Robert W.; Traub, Wesley A.

    2005-12-01

    An automatic interferometer fringe tracking system has been developed, implemented, and tested at the Infrared Optical Telescope Array (IOTA) Observatory at Mount Hopkins, Arizona. The system can minimize the optical path differences (OPDs) for all three baselines of the Michelson stellar interferometer at IOTA. Based on sliding window discrete Fourier-transform (DFT) calculations that were optimized for computational efficiency and robustness to atmospheric disturbances, the algorithm has also been tested extensively on offline data. Implemented in ANSI C on the 266 MHz PowerPC processor running the VxWorks real-time operating system, the algorithm runs in approximately [InlineEquation not available: see fulltext.] milliseconds per scan (including all three interferograms), using the science camera and piezo scanners to measure and correct the OPDs. The adaptive DFT-based tracking algorithm should be applicable to other systems where there is a need to detect or track a signal with an approximately constant-frequency carrier pulse. One example of such an application might be to the field of thin-film measurement by ellipsometry, using a broadband light source and a Fourier-transform spectrometer to detect the resulting fringe patterns.

  1. Adaptive DFT-Based Interferometer Fringe Tracking

    Directory of Open Access Journals (Sweden)

    Wesley A. Traub

    2005-09-01

    Full Text Available An automatic interferometer fringe tracking system has been developed, implemented, and tested at the Infrared Optical Telescope Array (IOTA Observatory at Mount Hopkins, Arizona. The system can minimize the optical path differences (OPDs for all three baselines of the Michelson stellar interferometer at IOTA. Based on sliding window discrete Fourier-transform (DFT calculations that were optimized for computational efficiency and robustness to atmospheric disturbances, the algorithm has also been tested extensively on offline data. Implemented in ANSI C on the 266 MHz PowerPC processor running the VxWorks real-time operating system, the algorithm runs in approximately 2.0 milliseconds per scan (including all three interferograms, using the science camera and piezo scanners to measure and correct the OPDs. The adaptive DFT-based tracking algorithm should be applicable to other systems where there is a need to detect or track a signal with an approximately constant-frequency carrier pulse. One example of such an application might be to the field of thin-film measurement by ellipsometry, using a broadband light source and a Fourier-transform spectrometer to detect the resulting fringe patterns.

  2. Feedback stabilized tandem Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Fukushima, Hiroyuki; Ito, Mikio; Shirasu, Hiroshi.

    1986-01-01

    A new system for measuring the isotopic ratio of uranium, in which two plane-type Fabry-Perot interferometers (tandem FP) are connected in series. The parallelism between the two FPs is achieved automatically by a feedback control mechanism based on laser interference fringe monitoring. The structure of the tandem FP, feedback control system, automatic parallelism adjustment mechanism and wavelength synchronization mechanism are described in detail. For experiments, a hollow cathode discharge tube of a pulse discharge type is employed. Measurements are made to determine the effects of pulse width on the 238 U peak height of 502.7 nm line, recorder traces of 235 U and 238 U lines, half width for 238 U component of the 502.7 nm line, SN ratio, reproducibility of the 235 U/ 238 U peak height ratio and 235 U/ 238 U intensity ratio. Considerations are made on the spectral line width, contrast, transmission factor, and stability of automatic parallelism control and wavelength synchronization. Results obtained indicates that a single-type interferometer would serve adequately for measuring the 235 U/ 238 U ratio if the automatic parallelism control developed here is used. The ultimate object of the tandem system is to make measurement of 236 U. Satisfactory results have not obtained as yet, but most likely the present system would make it possible if a light source of a higher intensity and advanced photometric techniques are developed. (Nogami, K.)

  3. A prototype imaging second harmonic interferometer

    International Nuclear Information System (INIS)

    Jobes, F.C.; Bretz, N.L.

    1997-01-01

    We have built a prototype imaging second harmonic interferometer, which is intended to test critical elements of a design for a tangential array interferometer on C-Mod 6 . The prototype uses a pulsed, 35 mJ, 10 Hz multimode, Nd:YAG laser, LiB 3 O 5 doublers, a fan beam created by a cylindrical lens, four retroreflector elements, and a CCD camera as a detector. The prototype also uses a polarization scheme in which the interference information is eventually carried by two second harmonic beams with crossed polarization. These are vector summed and differenced, and separated, by a Wollaston prism, to give two spots on the CCD. There is a pair of these spots for each retroreflector used. The phase information is directly available as the ratio of the difference to sum the intensities of the two spots. We have tested a single channel configuration of this prototype, varying the phase by changing the pressure in an air cell, and we have obtained a 5:1 light to dark ratio, and a clear sinusoidal variation of the ratio as a function of pressure change. copyright 1997 American Institute of Physics

  4. An X-ray BBB Michelson interferometer.

    Science.gov (United States)

    Sutter, John P; Ishikawa, Tetsuya; Kuetgens, Ulrich; Materlik, Gerhard; Nishino, Yoshinori; Rostomyan, Armen; Tamasaku, Kenji; Yabashi, Makina

    2004-09-01

    A new X-ray Michelson interferometer based on the BBB interferometer of Bonse and Hart and designed for X-rays of wavelength approximately 1 A was described in a previous paper. Here, a further test carried out at the SPring-8 1 km beamline BL29XUL is reported. One of the BBB's mirrors was displaced by a piezo to introduce the required path-length difference. The resulting variation of intensity with piezo voltage as measured by an avalanche photodiode could be ascribed to the phase variation resulting from the path-length change, with a small additional contribution from the change of the position of the lattice planes of the front mirror relative to the rest of the crystal. This 'Michelson fringe' interpretation is supported by the observed steady movement across the output beam of the interference fringes produced by a refractive wedge when the piezo voltage was ramped. The front-mirror displacement required for one complete fringe at the given wavelength is only 0.675 A; therefore, a quiet environment is vital for operating this device, as previous experiments have shown.

  5. Advanced ultrasonic inspections

    International Nuclear Information System (INIS)

    Ghia, S.

    1990-08-01

    Acoustic Emission (AE) continuous monitoring and periodical inspections by advanced ultrasonic have been applied to evaluate defect evolution within a PWR reduced scale (1:5) pressure vessel subjected to cyclic mechanical fatigue test. This experimental activity has been carried out in the frame of the Primary Circuit Component Life Prediction programme. In the time period covered by this report actions were performed as following: (1) Ultrasonic examination by multifrequency acoustic holography to evaluate defect evolution subsequently repair and heat treatment of the R2 vessel carried out in March 1988. For the purpose, measurements were performed both at 0 and 200 bar of internal pressure. As uniformity of the procedures adopted, for calibration and testing, made the results comparable with the previous ones no evidence for significant growing of the examined defects has been found. (2) Acoustic emission monitoring has then been carried out during fatigue test from 416000 to 565000 fatigue cycles. Analysis of a large amount of data has been performed paying particular attention to the distinction between friction phenomena and crack growth in order to obtain a correct diagnosis of flaw evolution. The signal duration distribution and the correlation of AE appearance time versus load cycle phase were considered to characterise stick-slip processes. A general intensification of AE activity has been recorded during this last period of monitoring and previous known AE sources were confirmed together with the appearance of new AE sources some of them correlable with real defects

  6. System for ultrasonic examination

    International Nuclear Information System (INIS)

    Lund, S.A.; Kristensen, W.D.

    1987-01-01

    A computerized system for the recording of flaw images by ultrasonic examination according to the pulse-echo method includes at least one ultrasonic probe which can be moved in steps over the surface of an object along a rectilinear scanning path. Digital signals containing information on the successive positions of the sound beam, on echo amplitudes, and on the lengths of sound paths to reflectors inside the object, are processed and used for the accumulated storage of circular patterns of echo amplitude data in a matrix memory associated with a sectional plane through the object. A video screen terminal controls the system and transforms the accumulated data into displays of sectional flaw images of greatly improved precision and sharpness of definition. A gradual transfer of filtered data from a number of parallel sectional planes to three further matrix memories associated with projection planes at right angles to each other permits presentation in three dimensions of equally improved projection flaw images. (author) 2 figs

  7. Michelson interferometer based interleaver design using classic IIR filter decomposition.

    Science.gov (United States)

    Cheng, Chi-Hao; Tang, Shasha

    2013-12-16

    An elegant method to design a Michelson interferometer based interleaver using a classic infinite impulse response (IIR) filter such as Butterworth, Chebyshev, and elliptic filters as a starting point are presented. The proposed design method allows engineers to design a Michelson interferometer based interleaver from specifications seamlessly. Simulation results are presented to demonstrate the validity of the proposed design method.

  8. Synthesis And Study Of Ultrasonic Properties Of Ag Cu amp Ni Nanofluids

    Directory of Open Access Journals (Sweden)

    Mannu Kaur

    2015-08-01

    Full Text Available By dispersing nanoparticles in a base fluid we get a colloidal suspension called Nanofluids. These possess important properties required in thermal engineering application physical chemical stability and high thermal conductivity. In this work we have synthesized Silver Copper and Nickel nanofluids by greener reduction method using Tannic acid. So prepared nanofluids were characterized by UV-Visible Spectroscopy and Dynamic Light Scattering Techniques. We have measured Ultrasonic Velocity of synthesized nanofluid by using Nanofluid Interferometer NF-10 as a function of concentration at different temperature also we have calculated Thermal Conductivity and Adiabatic Compressibility of the nanofluids.

  9. 102(ℎ/2π)k Large Area Atom Interferometers

    International Nuclear Information System (INIS)

    Chiow, Sheng-wey; Kovachy, Tim; Chien, Hui-Chun; Kasevich, Mark A.

    2011-01-01

    We demonstrate atom interferometers utilizing a novel beam splitter based on sequential multiphoton Bragg diffractions. With this sequential Bragg large momentum transfer (SB-LMT) beam splitter, we achieve high contrast atom interferometers with momentum splittings of up to 102 photon recoil momenta (102(ℎ/2π)k). To our knowledge, this is the highest momentum splitting achieved in any atom interferometer, advancing the state-of-the-art by an order of magnitude. We also demonstrate strong noise correlation between two simultaneous SB-LMT interferometers, which alleviates the need for ultralow noise lasers and ultrastable inertial environments in some future applications. Our method is intrinsically scalable and can be used to dramatically increase the sensitivity of atom interferometers in a wide range of applications, including inertial sensing, measuring the fine structure constant, and detecting gravitational waves.

  10. Imaging techniques for ultrasonic testing

    International Nuclear Information System (INIS)

    2013-01-01

    These seminar proceedings contain 16 lectures on the following topics: 1. From imaging to quantification - ultrasound methods in medical diagnostics; 2. SAFT, TOFD, Phased Array - classical applications and recent developments in ultrasonic imaging; 3. Innovative ultrasonic imaging methods in research and application; 4. Industrial ultrasonic testing of fibre-reinforced structures of complex geometry; 5. Visualisation of crack tips in the inspection of wheel set shafts with longitudinal boreholes as a means of avoiding unnecessary wheel set changes; 6. Areal analysis of the propagation of Lamb waves on curved, anisotropic structures; 7. High-resolution representation in immersion technique testing; 8. Variants in generating images from phased array measurement data - practical examples involving copper, carbon-fibre reinforced plastic and other materials; 9. GIUM - an unconventional method of microstructure imaging using ultrasonic stimulation and laser vibrometry scanning; 10. Innovative air-ultrasonic testing concepts for improved imaging; 11. Use of imaging methods for improving the quality of test results from nondestructive testing; 12. Modelling and visualisation of EMUS stimulation for transducer optimisation; 13. Use of SAFT in the manufacture of energy conversion machines; 14. Ultrasonic imaging tests for improved defect characterisation during weld seam inspection on longitudinally welded large-diameter pipes; 15. SAFT reconstruction for testing austenitic weld seams and dissimilar metal weld seams for transverse cracks; 16. Imaging-based optimisation method for quantitative ultrasonic testing of anisotropic inhomogeneous austenitic welded joints with determination and utilisation of their elastic properties. One contribution has been abstracted separately. [de

  11. Irradiation Testing of Ultrasonic Transducers

    International Nuclear Information System (INIS)

    Daw, J.; Rempe, J.; Palmer, J.; Tittmann, B.; Reinhardt, B.; Kohse, G.; Ramuhalli, P.; Montgomery, R.; Chien, H.T.; Villard, J.F.

    2013-06-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of numerous parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10 21 n/cm 2 (E> 0.1 MeV). This test will be an instrumented lead test; and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. By characterizing magnetostrictive and piezoelectric transducer survivability during irradiation, test results will enable the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. (authors)

  12. Standard-free Pressure Measurement by Ultrasonic Interferometry in a Multi-Anvil Device

    Science.gov (United States)

    Mueller, H. J.; Lathe, C.; Schilling, F. R.; Lauterjung, J.

    2002-12-01

    A key question to all high pressure research arises from the reliability of pressure standards. There is some indication and discussion of an uncertainty of 10-20% for higher pressures in all standards. Simultaneous and independent investigation of the dynamical (ultrasonic interferometry of elastic wave velocities) and static (XRD-measurement of the pressure-induced volume decline) compressibility on a sample reveal the possibility of a standard-free pressure calibration (see Getting, 1998) and, consequently an absolute pressure measurement. Ultrasonic interferometry is used to measure velocities of elastic compressional and shear waves in the multi-anvil high pressure device MAX80 at HASYLAB Hamburg enabling simultaneous XRD and ultrasonic experiments. Two of the six anvils were equipped with overtone polished lithium niobate transducers of 33.3 MHz natural frequency, for generation and detection of ultrasonic waves with a frequency sweep between 5 and 55 MHz. Different buffer - reflector combinations were tested to optimize the critical interference between both sample echoes. NaCl powder of 99.5 % purity (analytical grade by Merck) was used as starting material for manufacturing the samples used as pressure calibrant after Decker (1971). The medium grain size was 50 μm. The powder was pressed to a crude sample cylinder of 10 mm diameter and a length of 20 mm using a load of 6 tons resulting in an effective pressure of 0.25 to 0.3 GPa. The millimeter sized samples (diameter 2.4 mm and 1.6 mm length for 6 mm anvil truncation and diameter 3.1 mm and 1.1 mm length for 3.5 mm anvil truncation) for the high pressure experiments were shaped with a high-precision (+/- 0.5 μm) cylindrical grinding machine and polished at the front faces. From the ultrasonic wave velocity data we calculated the compressibility of NaCl. This requires in situ density data. Therefore the sample deformation during the high pressure experiments was analyzed in detail and the results were

  13. Chaos and Beyond in a Water Filled Ultrasonic Resonance System

    Science.gov (United States)

    Lazlo, Adler; Yost, W.; Cantrell, John H.

    2013-01-01

    Finite amplitude ultrasonic wave resonances in a one-dimensional liquid-filled cavity, formed by a narrow band transducer and a plane reflector, are reported. The resonances are observed to include not only the expected harmonic and subharmonic signals (1,2) but chaotic signals as well. The generation mechanism requires attaining a threshold value of the driving amplitude that the liquid-filled cavity system becomes sufficiently nonlinear in response. The nonlinear features of the system were recently investigated via the construction of an ultrasonic interferometer having optical precision. The transducers were compressional, undamped quartz and lithium niobate crystals having the frequency range 1-10 MHz, driven by a high power amplifier. Both an optical diffraction system to characterize the diffraction pattern of laser light normally incident to the cavity and a receiving transducer attached to an aligned reflector with lapped flat and parallel surfaces were used to assess the generated resonance response in the cavity. At least 5 regions of excitation are identified.

  14. Guided ultrasonic wave beam skew in silicon wafers

    Science.gov (United States)

    Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul

    2018-04-01

    In the photovoltaic industry, monocrystalline silicon wafers are employed for solar cells with high conversion efficiency. Micro-cracks induced by the cutting process in the thin wafers can lead to brittle wafer fracture. Guided ultrasonic waves would offer an efficient methodology for the in-process non-destructive testing of wafers to assess micro-crack density. The material anisotropy of the monocrystalline silicon leads to variations of the guided wave characteristics, depending on the propagation direction relative to the crystal orientation. Selective guided ultrasonic wave excitation was achieved using a contact piezoelectric transducer with custom-made wedges for the A0 and S0 Lamb wave modes and a transducer holder to achieve controlled contact pressure and orientation. The out-of-plane component of the guided wave propagation was measured using a non-contact laser interferometer. The phase slowness (velocity) of the two fundamental Lamb wave modes was measured experimentally for varying propagation directions relative to the crystal orientation and found to match theoretical predictions. Significant wave beam skew was observed experimentally, especially for the S0 mode, and investigated from 3D finite element simulations. Good agreement was found with the theoretical predictions based on nominal material properties of the silicon wafer. The important contribution of guided wave beam skewing effects for the non-destructive testing of silicon wafers was demonstrated.

  15. Pulsed ultrasonic stir welding method

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

  16. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

    This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

  17. Computer automation of ultrasonic testing. [inspection of ultrasonic welding

    Science.gov (United States)

    Yee, B. G. W.; Kerlin, E. E.; Gardner, A. H.; Dunmyer, D.; Wells, T. G.; Robinson, A. R.; Kunselman, J. S.; Walker, T. C.

    1974-01-01

    Report describes a prototype computer-automated ultrasonic system developed for the inspection of weldments. This system can be operated in three modes: manual, automatic, and computer-controlled. In the computer-controlled mode, the system will automatically acquire, process, analyze, store, and display ultrasonic inspection data in real-time. Flaw size (in cross-section), location (depth), and type (porosity-like or crack-like) can be automatically discerned and displayed. The results and pertinent parameters are recorded.

  18. Apparatus for ultrasonic nebulization

    International Nuclear Information System (INIS)

    Olson, K.W.; Haas, W.J. Jr.; Fassel, V.A.

    1978-01-01

    An improved apparatus is described for ultrasonic nebulization of liquid samples or suspensions in which the piezoelectric transducer is protected from chemical attack and erosion. The transducer is protected by being bonded to the inner surface of a glass plate which forms one end wall of a first hollow body provided with apparatus for circulating a fluid for cooling and stabilizing the transducer. The glass plate, which is one-half wavelength in thickness to provide an acoustically coupled outer nebulizing surface, seals an opening in a second hollow body which encloses an aerosol mixing chamber. The second body includes apparatus for delivering the sample solution to the nebulizing surface, a gas inlet for providing a flow of carrier gas for transporting the aerosol of the nebulized sample and an aerosol outlet

  19. High resolution ultrasonic densitometer

    International Nuclear Information System (INIS)

    Dress, W.B.

    1983-01-01

    The velocity of torsional stress pulses in an ultrasonic waveguide of non-circular cross section is affected by the temperature and density of the surrounding medium. Measurement of the transit times of acoustic echoes from the ends of a sensor section are interpreted as level, density, and temperature of the fluid environment surrounding that section. This paper examines methods of making these measurements to obtain high resolution, temperature-corrected absolute and relative density and level determinations of the fluid. Possible applications include on-line process monitoring, a hand-held density probe for battery charge state indication, and precise inventory control for such diverse fluids as uranium salt solutions in accountability storage and gasoline in service station storage tanks

  20. Ultrasonic imaging in concrete

    International Nuclear Information System (INIS)

    Ribay, G.; Paris, O.; Rambach, J.M.

    2009-01-01

    The third and final protection barrier confining nuclear reactors is usually a concrete containment structure. Monitoring the structural integrity of these barriers is critical in ensuring the safety of nuclear power plants. The Institute for Radiological Protection and Nuclear Safety (IRSN) in France in collaboration with the French Atomic commission (CEA/LIST) has developed an ultrasonic phased-array technique capable of inspecting thick concrete walls. The non-destructive method is dedicated to detect cracks and bulk defects. Given the thickness of the structure (1.2 m) undergoing inspection and the heterogeneity of the concrete, the optimal frequency lies in the 50-300 kHz range. At these frequencies, the ultrasonic beam profiles are widespread (non-directive) with poor signal-to-noise ratio. Previous studies have shown the potential of using phased-array techniques (i.e., beam focusing and beam steering) in order to improve detection resolution and sizing accuracy. In this paper we present experimental studies performed with array up to 16 transducers working at 200 kHz. Experiments are carried out on representative concrete blocks containing artificial defects. One is a reinforced mock-up representative of the first reinforcing mesh of wall containment. Experimental results show that in spite of the reinforcement, artificial defects deep as half a meter can be detected. Reconstructed images resulting from phased array acquisitions on an artificial crack embedded in a concrete block are also presented and discussed. The presented method allows detecting oriented defects in concrete with improved signal to noise ratio and sensibility. A simulation model of the interaction of ultrasound with a heterogeneous medium like concrete is briefly commented. (authors)

  1. VINCI: the VLT Interferometer commissioning instrument

    Science.gov (United States)

    Kervella, Pierre; Coudé du Foresto, Vincent; Glindemann, Andreas; Hofmann, Reiner

    2000-07-01

    The Very Large Telescope Interferometer (VLTI) is a complex system, made of a large number of separated elements. To prepare an early successful operation, it will require a period of extensive testing and verification to ensure that the many devices involved work properly together, and can produce meaningful data. This paper describes the concept chosen for the VLTI commissioning instrument, LEONARDO da VINCI, and details its functionalities. It is a fiber based two-way beam combiner, associated with an artificial star and an alignment verification unit. The technical commissioning of the VLTI is foreseen as a stepwise process: fringes will first be obtained with the commissioning instrument in an autonomous mode (no other parts of the VLTI involved); then the VLTI telescopes and optical trains will be tested in autocollimation; finally fringes will be observed on the sky.

  2. Distributed acoustic sensing with Michelson interferometer demodulation

    Science.gov (United States)

    Liu, Xiaohui; Wang, Chen; Shang, Ying; Wang, Chang; Zhao, Wenan; Peng, Gangding; Wang, Hongzhong

    2017-09-01

    The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

  3. Laser interferometer array for Big Dee

    International Nuclear Information System (INIS)

    Fairbanks, E.S.

    1984-01-01

    A twelve channel interferometer array is planned for obtaining electron density profiles on Big Dee. Three of the channels are vertical; the remainder are radial or diagonal in an azimuthal plane. Each channel consists of coaxial CO/sub 2/ and HeNe laser beams. The reference beam is formed by splitting off half of the laser power at each wavelength by using acousto-optic modulators which introduce a 40 MHz frequency shift in the reference beam. In the radial channels the probe beam passes through a barium fluoride window to a plane metal mirror on the inside wall of the vacuum vessel. The reflected beam passes back out of the vacuum vessel, through the same window, to a beam splitter where the probe beam and the reference beam are again combined

  4. Quantum contextuality in neutron interferometer experiments

    International Nuclear Information System (INIS)

    Hasegawa, Yuji; Loidl, Rudolf; Baron, Matthias; Badurek, Gerald; Rauch, Helmut

    2006-01-01

    Non-local correlations between sufficiently separated subsystems have been extensively discussed. Such a non-locality can be interpreted as a consequence of the correlation between commuting observables. A more general concept, i.e., contextuality, compared to non-locality can be introduced to describe striking phenomena predicted by quantum theory. As the first example, we report a neutron interferometer experiment, where the spin and the path degrees of freedom are used to exhibit the clear violation of a Bell-like inequality. Other aspects of the quantum contextuality is presented, e.g., a flavor of Kochen-Specker-like contradiction in neutron optical experiments, in addition to the quantum state tomography of the Bell-states which are used in the experiments

  5. FIR interferometer and scattering measurements of ATF

    International Nuclear Information System (INIS)

    Ma, C.H.; Hutchinson, D.P.; Fockedey, Y.; Vander Sluis, K.L.; Bennett, C.A.

    1989-01-01

    A 15-channel far-infrared (FIR) interferometer system has been constructed to measure the electron densities on the ATF plasmas. The system consists of a pair of cw 214-μm difluoromethane (CH 2 F 2 ) lasers, optically pumped by separate CO 2 lasers. The large number of channels is achieved by the use of reflective beam expansion optics to create a beam of 2 cm /times/ 45 cm. After passing through the plasma discharge, the elongated beam produced by the cylindrical mirrors is dissected by an array of 15 off-axis paraboloid reflectors, each of which illuminates a single Schottky-diode detector. The use of the beam expanding optics system reduces the number of optical elements required for the interferometer to approximately 2-3 per channel. The FIR laser beams are transported from the laser room to the experimental area by 25 mm i.d. dielectric waveguides purged with dry nitrogen. The system can also be operated at a wavelength of 119-μm by changing the gas in FIR laser cavities to methanol for high density experiments. Details of the system are described. A study is underway to determine the optimum design of a FIR scattering system for the ATF. This scattering system will be used to investigate density fluctuations with scale lengths from 0.1 cm to the plasma radius. The laser for this scattering system may be operated at wavelengths of 447, 307, 214, 184, and 119 μm with power levels of 100 to 500 mW. A summary of the study is presented. 6 refs., 1 fig

  6. Case studies in ultrasonic testing

    International Nuclear Information System (INIS)

    Prasad, V.; Satheesh, C.; Varde, P.V.

    2015-01-01

    Ultrasonic testing is widely used Non Destructive Testing (NDT) method and forms the essential part of In-service inspection programme of nuclear reactors. Main application of ultrasonic testing is for volumetric scanning of weld joints followed by thickness gauging of pipelines and pressure vessels. Research reactor Dhruva has completed the first In Service Inspection programme in which about 325 weld joints have been volumetrically scanned, in addition to thickness gauging of 300 meters of pipe lines of various sizes and about 24 nos of pressure vessels. Ultrasonic testing is also used for level measurements, distance measurements and cleaning and decontamination of tools. Two case studies are brought out in this paper in which ultrasonic testing is used successfully for identification of butterfly valve opening status and extent of choking in pipe lines in Dhruva reactor systems

  7. Ultrasonic Technology in Duress Alarms.

    Science.gov (United States)

    Lee, Martha A.

    2000-01-01

    Provides the pros and cons of the most commonly used technologies in personal duress alarm systems in the school environment. Discussed are radio frequency devices, infrared systems, and ultrasonic technology. (GR)

  8. Ultrasonic extensometer measures bolt preload

    Science.gov (United States)

    Daniels, C. M., Jr.

    1978-01-01

    Extensometer using ultrasonic pulse reflections to measure elongations in tightened belts and studs is much more accurate than conventional torque wrenches in application of specified preload to bolts and other threaded fasteners.

  9. Fatigue crack growth monitoring in multi-layered structures using guided ultrasonic waves

    International Nuclear Information System (INIS)

    Kostson, E; Fromme, P

    2009-01-01

    This contribution investigates the application of low frequency guided ultrasonic waves for monitoring fatigue crack growth at fastener holes in the 2nd layer of multi-layered plate structures, a common problem in aerospace industry. The model multi-layered structure investigated consists of two aluminum plate-strips adhesively bonded using a structural paste adhesive. Guided ultrasonic waves were excited using multiple piezoelectric discs bonded to the surface of the multi-layered structure. The wave propagation in the tensile specimen was measured using a laser interferometer and compared to numerical simulations. Thickness and width mode shapes of the excited flexural waves were identified from Semi-Analytical Finite Element (SAFE) calculations. Experiments and 3D Finite Element (FE) simulations show a change in the scattered field around fastener holes caused by a defect in the 2nd layer. The amplitude of the guided ultrasonic wave was monitored during fatigue experiments at a single point. The measured changes in the amplitude of the ultrasonic signal due to fatigue crack growth agree well with FE simulations.

  10. Michelson-type Radio Interferometer for University Education

    Science.gov (United States)

    Koda, Jin; Barrett, J. W.; Hasegawa, T.; Hayashi, M.; Shafto, G.; Slechta, J.

    2013-01-01

    Despite the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the futue generation of astronomers. Students need hands-on experiments to fully understand the basic concepts of interferometry. Professional interferometers are often too complicated for education, and it is difficult to guarantee access for classes in a university course. We have built a simple and affordable radio interferometer for education and used it for an undergraduate and graduate laboratory project. This interferometer's design is based on the Michelson & Peace's stellar optical interferometer, but operates at a radio wavelength using a commercial broadcast satellite dish and receiver. Two side mirrors are surfaced with kitchen aluminum foil and slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, a nice daytime experiment which can be carried out even under a marginal weather (i.e., partial cloud coverage). Commercial broadcast satellites provide convenient point sources. By comparing the Sun and satellites, students can learn how an interferometer works and resolves structures in the sky.

  11. Two-Particle Four-Mode Interferometer for Atoms

    Science.gov (United States)

    Dussarrat, Pierre; Perrier, Maxime; Imanaliev, Almazbek; Lopes, Raphael; Aspect, Alain; Cheneau, Marc; Boiron, Denis; Westbrook, Christoph I.

    2017-10-01

    We present a free-space interferometer to observe two-particle interference of a pair of atoms with entangled momenta. The source of atom pairs is a Bose-Einstein condensate subject to a dynamical instability, and the interferometer is realized using Bragg diffraction on optical lattices, in the spirit of our recent Hong-Ou-Mandel experiment. We report on an observation ruling out the possibility of a purely mixed state at the input of the interferometer. We explain how our current setup can be extended to enable a test of a Bell inequality on momentum observables.

  12. A combined scanning tunnelling microscope and x-ray interferometer

    Science.gov (United States)

    Yacoot, Andrew; Kuetgens, Ulrich; Koenders, Ludger; Weimann, Thomas

    2001-10-01

    A monolithic x-ray interferometer made from silicon and a scanning tunnelling microscope have been combined and used to calibrate grating structures with periodicities of 100 nm or less. The x-ray interferometer is used as a translation stage which moves in discrete steps of 0.192 nm, the lattice spacing of the silicon (220) planes. Hence, movements are traceable to the definition of the metre and the nonlinearity associated with the optical interferometers used to measure displacement in more conventional metrological scanning probe microscopes (MSPMs) removed.

  13. Development of holographic interferometer for non-destructive testing

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Baik, Sung Hoon; Shin, Jang Soo; Cho, Jai Wan; Kim, Duk Hyeon; Hong, Suck Kyoung; Lee, Sang Kil; Kim, Heon Jun; Park, Chang Jin

    1993-02-01

    This project sets the goal at development of holographic interferometer. In this interferometer, fringe localization and imaging of object are considered. And collimated beam and wedge are used for the high-speed recording and formation of carrier fringes, respectively. With this real-time holographic interferometer, not only experiments were conducted on natural convection and flame jet, but also on high speed flow phenomena such as shock wave propagation. Visualization of high-speed flow is recorded in high-speed camera with framing rate ∼ 35000f/s. And to analyze axis symmetric phase object, analysis program was developed. (Author)

  14. Using the Talbot_Lau_interferometer_parameters Spreadsheet

    Energy Technology Data Exchange (ETDEWEB)

    Kallman, Jeffrey S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-06-04

    Talbot-Lau interferometers allow incoherent X-ray sources to be used for phase contrast imaging. A spreadsheet for exploring the parameter space of Talbot and Talbot-Lau interferometers has been assembled. This spreadsheet allows the user to examine the consequences of choosing phase grating pitch, source energy, and source location on the overall geometry of a Talbot or Talbot-Lau X-ray interferometer. For the X-ray energies required to penetrate scanned luggage the spacing between gratings is large enough that the mechanical tolerances for amplitude grating positioning are unlikely to be met.

  15. EIT Based Gas Detector Design by Using Michelson Interferometer

    International Nuclear Information System (INIS)

    Abbasian, K.; Rostami, A.; Abdollahi, M. H.

    2011-01-01

    Electromagnetically induced transparency (EIT) is one of the interesting phenomena of light-matter interaction which modifies matter properties for propagation of light. In other words, we can change the absorption and refractive index (RI) in neighborhood of the resonant frequency using EIT. In this paper, we have doped 3-level quantum dots in one of the Michelson Interferometer's mirror and used EIT to change its RI. So, a controllable phase difference between lights in two arms of interferometer is created. Long response time is the main drawback of Michelson interferometer based sensor, which is resolved by this technique.

  16. A novel polarization interferometer for measuring upper atmospheric winds

    International Nuclear Information System (INIS)

    Ting-Kui, Mu; Chun-Min, Zhang

    2010-01-01

    A static polarization interferometer for measuring upper atmospheric winds is presented, based on two Savart plates with their optical axes perpendicular to each other. The principle and characteristics of the interferometer are described. The interferometer with a wide field of view can offer a stable benchmark optical path difference over a specified spectral region of 0.55–0.63 μm because there are no quarter wave plates. Since the instrument employs a straight line common-path configuration but without moving parts and slits, it is very compact, simple, inherently robust and has high throughput. The paper is limited to a theoretical analysis. (general)

  17. Picometre displacement measurements using a differential Fabry–Perot optical interferometer and an x-ray interferometer

    International Nuclear Information System (INIS)

    Çelik, Mehmet; Hamid, Ramiz; Kuetgens, Ulrich; Yacoot, Andrew

    2012-01-01

    X-ray interferometry is emerging as an important tool for dimensional nanometrology both for sub-nanometre measurement and displacement. It has been used to verify the performance of the next generation of displacement measuring optical interferometers within the European Metrology Research Programme project NANOTRACE. Within this project a more detailed set of comparison measurements between the x-ray interferometer and a dual channel Fabry–Perot optical interferometer (DFPI) have been made to demonstrate the capabilities of both instruments for picometre displacement metrology. The results show good agreement between the two instruments, although some minor differences of less than 5 pm have been observed. (paper)

  18. Picometre displacement measurements using a differential Fabry-Perot optical interferometer and an x-ray interferometer

    Science.gov (United States)

    Çelik, Mehmet; Hamid, Ramiz; Kuetgens, Ulrich; Yacoot, Andrew

    2012-08-01

    X-ray interferometry is emerging as an important tool for dimensional nanometrology both for sub-nanometre measurement and displacement. It has been used to verify the performance of the next generation of displacement measuring optical interferometers within the European Metrology Research Programme project NANOTRACE. Within this project a more detailed set of comparison measurements between the x-ray interferometer and a dual channel Fabry-Perot optical interferometer (DFPI) have been made to demonstrate the capabilities of both instruments for picometre displacement metrology. The results show good agreement between the two instruments, although some minor differences of less than 5 pm have been observed.

  19. Detailed simulation of ultrasonic inspections

    International Nuclear Information System (INIS)

    Chaplin, K.R.; Douglas, S.R.; Dunford, D.

    1997-01-01

    Simulation of ultrasonic inspection of engineering components have been performed at the Chalk River Laboratories of AECL for over 10 years. The computer model, called EWE for Elastic Wave Equations, solves the Elastic Wave Equations using a novel finite difference scheme. It simulates the propagation of an ultrasonic wave from the transducer to a flaw, the scatter of waves from the flaw, and measurement of signals at a receive transducer. Regions of different materials, water and steel for example, can be simulated. In addition, regions with slightly different material properties from the parent material can be investigated. The two major types of output are displays of the ultrasonic waves inside the component and the corresponding A-scans. EPRI and other organizations have used ultrasonic models for: defining acceptable ultrasonic inspection procedures, designing and evaluating inspection techniques, and for quantifying inspection reliability. The EWE model has been applied to the inspection of large pipes in a nuclear plant, gas pipeline welds and steam generator tubes. Most recent work has dealt with the ultrasonic inspection of pressure tubes in CANDU reactors. Pressure tube inspections can reliably detect and size defects; however, there are improvements that can be made. For example, knowing the sharpness of a flaw-tip is crucial for fitness for service assessments. Computer modelling of the ultrasonic inspection of flaws with different root radius has suggested inspection techniques that provide flaw tip radius information. A preliminary investigation of these methods has been made in the laboratory. The basis for the model will be reviewed at the presentation. Then the results of computer simulations will be displayed on a PC using an interactive program that analyzes simulated A-scans. This software tool gives inspection staff direct access to the results of computer simulations. (author)

  20. Herriott Cell Augmentation of a Quadrature Heterodyne Interferometer

    National Research Council Canada - National Science Library

    Antonsen, Erik

    2002-01-01

    A quadrature heterodyne interferometer is augmented with a Herriott Cell multi-pass reflector to increase instrument resolution and enable a separation of the phase shift due to neutral density from room vibrations...

  1. Slow-Light-Enhanced Spectral Interferometers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We proposoe a research program aimed at developing spectral interferometers with dramatically enhanced performance. A key aspect of our approach is to place a highly...

  2. A Michelson interferometer for X-rays and thermal neutrons

    International Nuclear Information System (INIS)

    Appel, A.

    1992-01-01

    The introduced interferometer consists of an LLL interferometer and a phase-displacing Bragg groove component. A part of the radiation path between the Lane mirrors in the Bragg grooves is replaced by a radiation path, whose wave number vector has a slightly different direction compared to the Lane case by the refraction correction. If the angles of incidence in the two grooves are different, then a difference in path is produced between the beams producing interference. This is the first X-ray interferometer which works like an optical Michelson interferometer. As there are no basic limits to resolution by absorption or dispersion, for example, it opens up the possibility of carrying out Fourier spectroscopy in the A wavelength range. (orig.) [de

  3. Performance evaluation of a thermal Doppler Michelson interferometer system.

    Science.gov (United States)

    Mani, Reza; Dobbie, Steven; Scott, Alan; Shepherd, Gordon; Gault, William; Brown, Stephen

    2005-11-20

    The thermal Doppler Michelson interferometer is the primary element of a proposed limb-viewing satellite instrument called SWIFT (Stratospheric Wind Interferometer for Transport studies). SWIFT is intended to measure stratospheric wind velocities in the altitude range of 15-45 km. SWIFT also uses narrowband tandem etalon filters made of germanium to select a line out of the thermal spectrum. The instrument uses the same technique of phase-stepping interferometry employed by the Wind Imaging Interferometer onboard the Upper Atmosphere Research Satellite. A thermal emission line of ozone near 9 microm is used to detect the Doppler shift due to winds. A test bed was set up for this instrument that included the Michelson interferometer and the etalon filters. For the test bed work, we investigate the behavior of individual components and their combination and report the results.

  4. Plasma flow velocity measurements using a modulated Michelson interferometer

    International Nuclear Information System (INIS)

    Howard, J.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (orig.)

  5. Ultrasonic measurements and technologies

    CERN Document Server

    Kočiš, Štefan

    1996-01-01

    An impulse for writing this book has originated from the effort to sum­ marize and publicise the acquired results of a research team at the De­ partment of Automation of the Faculty of Electrical Engineering and In­ formatics, Slovak Technical University in Bratislava. The research team has been involved for a long time with control problems for machine production mechanisms and, in recent (approximately 15) years, its effort was aimed mostly at the control of electrical servosystems of robots. Within this scope, the members of the authors' staff solved the State Re­ search Task Ultrasonic sensing of the position of a robot hand, which was coordinated by the Institute of Technical Cybernetics of the Slovak Academy of Sciences in Bratislava. The problem was solved in a complex way, i.e. from a conceptual de­ sign of the measurement, through the measurement and evaluation sys­ tem, up to connection to the control system of a robot. Compensation of the atmospheric influence on the precision of measurement,...

  6. Ultrasonic-testing method

    International Nuclear Information System (INIS)

    Thome, Paul.

    1973-01-01

    Description is given of a device adapted to the detection, by means of ultrasonic waves, of all the flaws and defects included in workpieces when only one face of the latter is accessible. A beam is directed towards the rear-face of the workpiece (e.g. a plate) on which it is reflected. The image thus reflected is fed into a receiver. The latter is under the control of the displacement of that image; simultaneously a transducer checks the condition of the mirror at the places where the beam is reflected. Whenever a flow or defect comes between, a silent zone is formed. By recording the silent zones with respect to the positions of several emitters, it is possible to locates a flaw and to define the outline thereof. The apparatus comprises several ''emitter-receiver'' groups intersecting over the emitter used in order to check the good conditions of the mirror. The invention can be used for searching and identifying flaws and defects in buildings which have to be of top quality (e.g., cofferdams, nuclear devices, shipbuilding yards, aeronautics) [fr

  7. Ultrasonic monitoring system

    International Nuclear Information System (INIS)

    McLain, R.E.

    1975-01-01

    The ultrasonic monitoring system is used in LMFBR's, BWR's or PWR's. A remotely controlled, movable instrument carrier may be used which contains the piezo-electric transducer and is connected to the main control console by a transmission cable. An excitation pulse coming from a pulse generator is used to excite the transducer with a maximum of energy, independent of the length of the transmission line. Pulse width and pulse amplitude can be set without any direct interference into the transducer. For this purpose, a resistor whose impedance has been matched to that of the transmission line is connected to the input of the transmission line. Moreover, a capacitor for generation of the excitation pulse is coupled with the transmission line by means of a four-layer switching diode and is discharged. For termination of the excitation and the control pulses, respectively, another four-layer switching diode connected parallel to the capacitor quickly discharges the capacitor. The capacitor and the capacitance of the line constitute a voltage divider. In this way it is possible to change the length of the transmission line and, to safeguard the generation of a pulse of the desired amplitude, only vary the capacitance of the capacitor. (DG/RF) [de

  8. Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

    Science.gov (United States)

    Zhang, Xinpu; Peng, Wei; Zhang, Yang

    2015-12-01

    We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity.

  9. Noise cancellation properties of displacement noise free interferometer

    International Nuclear Information System (INIS)

    Sato, Shuichi; Kawamura, Seiji; Nishizawa, Atsushi; Chen Yanbei

    2010-01-01

    We have demonstrated the practical feasibility of a displacement- and frequency-noise-free laser interferometer (DFI) by partially implementing a recently proposed optical configuration using bi-directional Mach-Zehnder interferometers (MZIs). The noise cancellation efficiency was evaluated by comparing the displacement noise spectrum of the MZIs and the DFI, demonstrating up to 50 dB of noise cancellation. In addition, the possible extension of DFI as QND device is explored.

  10. Comment on "Rovibrational quantum interferometers and gravitational waves"

    OpenAIRE

    Khriplovich, I. B.; Lamoreaux, S. K.; Sushkov, A. O.; Sushkov, O. P.

    2009-01-01

    In a recent paper, Wicht, L\\"ammerzahl, Lorek, and Dittus [Phys. Rev. {\\bf A 78}, 013610 (2008)] come to the conclusion that a molecular rotational-vibrational quantum interferometer may possess the sensitivity necessary to detect gravitational waves. We do not agree with their results and demonstrate here that the true sensitivity of such interferometer is many orders of magnitude worse than that claimed in the mentioned paper. In the present comment we estimate the expected energy shifts an...

  11. Design of an optical spatial interferometer with transformation optics

    International Nuclear Information System (INIS)

    Naghibi, Atefeh; Shokooh-Saremi, Mehrdad

    2015-01-01

    In this paper, we apply transformation optics to design an optical spatial interferometer. The transformation equations are described and two-dimensional finite element simulations are presented to numerically confirm the functionality of the device. It is shown that a small change in the refractive index can alter the interference pattern and hence can be detected. The design of the interferometer could expand transformation optics’ applications and make way for introduction of new structures with unique electromagnetic or optical functionalities. (paper)

  12. Two-photon quantum interference in a Michelson interferometer

    International Nuclear Information System (INIS)

    Odate, Satoru; Wang Haibo; Kobayashi, Takayoshi

    2005-01-01

    We have observed two-photon quantum interference in a Michelson interferometer. For the first time, we experimentally demonstrated two-photon quantum interference patterns, which show the transition from nonsubwavelength interference fringes to the general subwavelength interference. At the same time, a photon bunching effect was also shown by a postselection. The |1, 1> state with a single photon in a mode corresponding to each arm of the interferometer was exclusively postselected by using path difference between two arms

  13. Potentiality of an orbiting interferometer for space-time experiments

    International Nuclear Information System (INIS)

    Grassi Strini, A.M.; Strini, G.; Tagliaferri, G.

    1979-01-01

    It is suggested that by putting a Michelson interferometer aboard a spacecraft orbiting around the earth, very substantial progress could be made in space-time experiments. It is estimated that in measurements of e.g. some anisotropy of the light velocity, a spacecraft-borne interferometer of quite small size (0.1 m arm-length) would reach a sensitivity greater by a factor of approximately 10 8 than the best achievements to date of ground-based devices. (author)

  14. Experimental implementation of phase locking in a nonlinear interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hailong; Jing, Jietai, E-mail: jtjing@phy.ecnu.edu.cn [State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062 (China); Marino, A. M. [Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 West Brooks Street, Norman, Oklahoma 73019 (United States)

    2015-09-21

    Based upon two cascade four-wave mixing processes in two identical hot rubidium vapor cells, a nonlinear interferometer has been experimentally realized [Jing et al., Appl. Phys. Lett. 99, 011110 (2011); Hudelist et al., Nat. Commun. 5, 3049 (2014)]. It has a higher degree of phase sensitivity than a traditional linear interferometer and has many potential applications in quantum metrology. Phase locking of the nonlinear interferometer is needed before it can find its way into applications. In this letter, we investigate the experimental implementation of phase locking of the relative phase between the three beams at different frequencies involved in such a nonlinear interferometer. We have utilized two different methods, namely, beat note locking and coherent modulation locking. We find that coherent modulation locking can achieve much better phase stability than beat note locking in our system. Our results pave the way for real applications of a nonlinear interferometer in precision measurement and quantum manipulation, for example, phase control in phase-sensitive N-wave mixing process, N-port nonlinear interferometer and quantum-enhanced real-time phase tracking.

  15. An absolute distance interferometer with two external cavity diode lasers

    International Nuclear Information System (INIS)

    Hartmann, L; Meiners-Hagen, K; Abou-Zeid, A

    2008-01-01

    An absolute interferometer for length measurements in the range of several metres has been developed. The use of two external cavity diode lasers allows the implementation of a two-step procedure which combines the length measurement with a variable synthetic wavelength and its interpolation with a fixed synthetic wavelength. This synthetic wavelength is obtained at ≈42 µm by a modulation-free stabilization of both lasers to Doppler-reduced rubidium absorption lines. A stable reference interferometer is used as length standard. Different contributions to the total measurement uncertainty are discussed. It is shown that the measurement uncertainty can considerably be reduced by correcting the influence of vibrations on the measurement result and by applying linear regression to the quadrature signals of the absolute interferometer and the reference interferometer. The comparison of the absolute interferometer with a counting interferometer for distances up to 2 m results in a linearity error of 0.4 µm in good agreement with an estimation of the measurement uncertainty

  16. Highly stable polarization independent Mach-Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Mičuda, Michal, E-mail: micuda@optics.upol.cz; Doláková, Ester; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Fiurášek, Jaromír; Ježek, Miroslav, E-mail: jezek@optics.upol.cz [Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-08-15

    We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

  17. Development of stable monolithic wide-field Michelson interferometers.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-20

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations. © 2011 Optical Society of America

  18. Ultrasonic propulsion of kidney stones.

    Science.gov (United States)

    May, Philip C; Bailey, Michael R; Harper, Jonathan D

    2016-05-01

    Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the ureteropelvic junction with relief of pain, and differentiating large stones from a collection of small fragments. Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing ureteropelvic junction stones into the kidney to alleviate acute renal colic.

  19. Contribution to the theory of atom interferometers

    International Nuclear Information System (INIS)

    Antoine, Ch.

    2004-12-01

    This work deals with the study of atom interferometers. It consists of theoretical developments and more practical parts (modeling). As regards modeling, this work explains how to obtain a general analytical expression of the fringes signal, which particularly accounts for the simultaneous action of all the inertial and gravitational fields whose representative potential is at most quadratic in position and momentum (rotations, accelerations, gradients of acceleration, gravitational waves...), as well as the dispersive structuring due to atomic beam splitters in the presence of such external fields (velocity selection, anomalous dispersion and Borrmann effect). From a theoretical point of view, this thesis develops new tools of atom optics. They deal with the propagation of matter waves in unspecified inertial and gravitational fields (extension of the ABCD formalism using first integral operators), the study of laser beam splitters in the presence of some of these fields (generalized ttt scheme, strong fields ttt modeling, generalized Borrmann effect...), as well as the highlight of symplectic invariants which are very useful for the interpretation and the simplification of the phase shift expression ('homologous paths' and 'four end points theorem'). (author)

  20. Ultrasonic stir welding process and apparatus

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2009-01-01

    An ultrasonic stir welding device provides a method and apparatus for elevating the temperature of a work piece utilizing at least one ultrasonic heater. Instead of relying on a rotating shoulder to provide heat to a workpiece an ultrasonic heater is utilized to provide ultrasonic energy to the workpiece. A rotating pin driven by a motor assembly performs the weld on the workpiece. A handheld version can be constructed as well as a fixedly mounted embodiment.

  1. The effects of ultrasonic solidification on aluminum

    OpenAIRE

    Đorđević Slavko 1

    2003-01-01

    The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

  2. The effects of ultrasonic solidification on aluminum

    Directory of Open Access Journals (Sweden)

    Đorđević Slavko 1

    2003-01-01

    Full Text Available The effect of ultrasound on characteristics of solidified aluminum was shown. An ultrasonic head and ultrasonic system for modification was designed and applied to the crystallizing aluminum melt. The ultrasonic generator allows power of 50-500 W, amplitude of oscillations 10-100 um.m and the operating frequency of 25 kHz. Ultrasonic modification was done by ultrasound introduced from above into the melt. Microstructure photographs show decreasing of the grain size more than five times.

  3. 21 CFR 872.4850 - Ultrasonic scaler.

    Science.gov (United States)

    2010-04-01

    ... DEVICES DENTAL DEVICES Surgical Devices § 872.4850 Ultrasonic scaler. (a) Identification. An ultrasonic scaler is a device intended for use during dental cleaning and periodontal (gum) therapy to remove calculus deposits from teeth by application of an ultrasonic vibrating scaler tip to the teeth. (b...

  4. Pitch-catch only ultrasonic fluid densitometer

    Science.gov (United States)

    Greenwood, M.S.; Harris, R.V.

    1999-03-23

    The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.

  5. Ultrasonic techniques for fluids characterization

    CERN Document Server

    Povey, Malcolm J W

    1997-01-01

    This book is a comprehensive and practical guide to the use of ultrasonic techniques for the characterization of fluids. Focusing on ultrasonic velocimetry, the author covers the basic topics and techniques necessaryfor successful ultrasound measurements on emulsions, dispersions, multiphase media, and viscoelastic/viscoplastic materials. Advanced techniques such as scattering, particle sizing, and automation are also presented. As a handbook for industrial and scientific use, Ultrasonic Techniques for Fluids Characterization is an indispensable guide to chemists and chemical engineers using ultrasound for research or process monitoring in the chemical, food processing, pharmaceutical, cosmetic, biotechnology,and fuels industries. Key Features * Appeals to anyone using ultrasound to study fluids * Provides the first detailed description of the ultrasound profiling technique for dispersions * Describes new techniques for measuring phase transitions and nucleation, such as water/ice and oil/fat * Presents the l...

  6. Ultrasonic inspection development at HEDL

    International Nuclear Information System (INIS)

    Day, C.K.; Mech, S.J.; Michaels, T.E.; Dixon, N.E.

    1978-01-01

    Ultrasonic testing methods and equipment are being developed to support preservice and in-service inspection of selected FFTF welds. A digital computer system is employed in the analysis of both simulated FFTF pipe sections and plate specimens containing fatigue cracks. It is anticipated that test evaluation standards containing fatigue cracks will partially eliminate questions formerly associated with weld test calibration producers by providing natural cracks which follow grain boundaries and stress patterns resembling piping situ conditions. Studies have revealed that commercial transducers may satisfy LMFBR ultrasonic pipe inspection applications: The test system evaluation included transducers and wedge coupling and fluid coupling materials which exhibited acceptable performance at temperatures to 2300C. Results are presented that demonstrate the feasibility of ultrasonic inspection of components immersed in sodium at temperatures to 2600C. (UK)

  7. Ultrasonic wave propagation in powders

    Science.gov (United States)

    Al-Lashi, R. S.; Povey, M. J. W.; Watson, N. J.

    2018-05-01

    Powder clumps (cakes) has a significant effect on the flowability and stability of powders. Powder caking is mainly caused by moisture migration due to wetting and environmental (temperature and humidity) changes. The process of moisture migration caking involves creating liquid bridges between the particles during condensation which subsequently harden to form solid bridges. Therefore, an effective and reliable technique is required to quantitatively and non-invasively monitor caking kinetics and effective stiffness. This paper describes two ultrasonic instruments (ultrasonic velocity pulse and airborne ultrasound systems) that have been used to monitor the caking phenomenon. Also, it discusses the relationship between the ultrasonic velocity and attenuation measurements and tracking caking kinetics and the effective stiffness of powders.

  8. With the VLT Interferometer towards Sharper Vision

    Science.gov (United States)

    2000-05-01

    The Nova-ESO VLTI Expertise Centre Opens in Leiden (The Netherlands) European science and technology will gain further strength when the new, front-line Nova-ESO VLTI Expertise Centre (NEVEC) opens in Leiden (The Netherlands) this week. It is a joint venture of the Netherlands Research School for Astronomy (NOVA) (itself a collaboration between the Universities of Amsterdam, Groningen, Leiden, and Utrecht) and the European Southern Observatory (ESO). It is concerned with the Very Large Telescope Interferometer (VLTI). The Inauguration of the new Centre will take place on Friday, May 26, 2000, at the Gorlaeus Laboratory (Lecture Hall no. 1), Einsteinweg 55 2333 CC Leiden; the programme is available on the web. Media representatives who would like to participate in this event and who want further details should contact the Nova Information Centre (e-mail: jacques@astro.uva.nl; Tel: +31-20-5257480 or +31-6-246 525 46). The inaugural ceremony is preceded by a scientific workshop on ground and space-based optical interferometry. NEVEC: A Technology Centre of Excellence As a joint project of NOVA and ESO, NEVEC will develop in the coming years the expertise to exploit the unique interferometric possibilities of the Very Large Telescope (VLT) - now being built on Paranal mountain in Chile. Its primary goals are the * development of instrument modeling, data reduction and calibration techniques for the VLTI; * accumulation of expertise relevant for second-generation VLTI instruments; and * education in the use of the VLTI and related matters. NEVEC will develop optical equipment, simulations and software to enable interferometry with VLT [1]. The new Center provides a strong impulse to Dutch participation in the VLTI. With direct involvement in this R&D work, the scientists at NOVA will be in the front row to do observations with this unique research facility, bound to produce top-level research and many exciting new discoveries. The ESO VLTI at Paranal ESO PR Photo 14a/00

  9. Broadband W-band Rapid Frequency Sweep Considerations for Fourier Transform EPR.

    Science.gov (United States)

    Strangeway, Robert A; Hyde, James S; Camenisch, Theodore G; Sidabras, Jason W; Mett, Richard R; Anderson, James R; Ratke, Joseph J; Subczynski, Witold K

    2017-12-01

    A multi-arm W-band (94 GHz) electron paramagnetic resonance spectrometer that incorporates a loop-gap resonator with high bandwidth is described. A goal of the instrumental development is detection of free induction decay following rapid sweep of the microwave frequency across the spectrum of a nitroxide radical at physiological temperature, which is expected to lead to a capability for Fourier transform electron paramagnetic resonance. Progress toward this goal is a theme of the paper. Because of the low Q-value of the loop-gap resonator, it was found necessary to develop a new type of automatic frequency control, which is described in an appendix. Path-length equalization, which is accomplished at the intermediate frequency of 59 GHz, is analyzed. A directional coupler is favored for separation of incident and reflected power between the bridge and the loop-gap resonator. Microwave leakage of this coupler is analyzed. An oversize waveguide with hyperbolic-cosine tapers couples the bridge to the loop-gap resonator, which results in reduced microwave power and signal loss. Benchmark sensitivity data are provided. The most extensive application of the instrument to date has been the measurement of T 1 values using pulse saturation recovery. An overview of that work is provided.

  10. Solving the Capacitive Effect in the High-Frequency sweep for Langmuir Probe in SYMPLE

    International Nuclear Information System (INIS)

    Pramila; Patel, J J; Rajpal, R; Hansalia, C J; Anitha, V P; Sathyanarayana, K

    2017-01-01

    Langmuir Probe based measurements need to be routinely carried out to measure various plasma parameters such as the electron density (n e ), the electron temperature (T e ), the floating potential (V f ), and the plasma potential (V p ). For this, the diagnostic electronics along with the biasing power supplies is installed in standard industrial racks with a 2KV isolation transformer. The Signal Conditioning Electronics (SCE) system is populated inside the 4U-chassis based system with the front-end electronics, designed using high common mode differential amplifiers which can measure small differential signal in presence of high common mode dc- bias or ac ramp voltage used for biasing the probes. DC-biasing of the probe is most common method for getting its I-V characteristic but method of biasing the probe with a sweep at high frequency encounters the problem of corruption of signal due to capacitive effect specially when the sweep period and the discharge time is very fast and die down in the order of μs or lesser. This paper presents and summarises the method of removing such effects encountered while measuring the probe current. (paper)

  11. Model for spontaneous frequency sweeping of an Alfvén wave in a toroidal plasma

    Science.gov (United States)

    Wang, Ge; Berk, H. L.

    2012-05-01

    We study the frequency chirping signals arising from spontaneously excited toroidial Alfvén eigenmode (TAE) waves that are being driven by an inverted energetic particle distribution whose free energy is tapped from the generic particle/wave resonance interaction. Initially a wave is excited inside the Alfvén gap with a frequency determined from the linear tip model of Rosenbluth, Berk and Van dam (RBV) [1]. Hole/clumps structures are formed and are observed to chirp towards lower energy states. We find that the chirping signals from clump enter the Alfvén continuum which eventually produce more rapid chirping signals. The accuracy of the adiabatic approximation for the mode evolution is tested and verified by demonstrating that a WKB-like decomposition of the time response for the field phase and amplitude agree with the data. Plots of the phase space structure correlate well with the chirping dependent shape of the separatrix structure. A novel aspect of the simulation is that it performed close to the wave frame of the phase space structure, which enables the numerical time step to remain the same during the simulation, independent of the rest frame frequency.

  12. Numerical and analytic models of spontaneous frequency sweeping for energetic particle-driven Alfven eigenmodes

    Science.gov (United States)

    Wang, Ge; Berk, H. L.

    2011-10-01

    The frequency chirping signal arising from spontaneous a toroidial Alfven eigenmode (TAE) excited by energetic particles is studied for both numerical and analytic models. The time-dependent numerical model is based on the 1D Vlasov equation. We use a sophisticated tracking method to lock onto the resonant structure to enable the chirping frequency to be nearly constant in the calculation frame. The accuracy of the adiabatic approximation is tested during the simulation which justifies the appropriateness of our analytic model. The analytic model uses the adiabatic approximation which allows us to solve the wave evolution equation in frequency space. Then, the resonant interactions between energetic particles and TAE yield predictions for the chirping rate, wave frequency and amplitudes vs. time. Here, an adiabatic invariant J is defined on the separatrix of a chirping mode to determine the region of confinement of the wave trapped distribution function. We examine the asymptotic behavior of the chirping signal for its long time evolution and find agreement in essential features with the results of the simulation. Work supported by Department of Energy contract DE-FC02-08ER54988.

  13. Solving the Capacitive Effect in the High-Frequency sweep for Langmuir Probe in SYMPLE

    Science.gov (United States)

    Pramila; Patel, J. J.; Rajpal, R.; Hansalia, C. J.; Anitha, V. P.; Sathyanarayana, K.

    2017-04-01

    Langmuir Probe based measurements need to be routinely carried out to measure various plasma parameters such as the electron density (ne), the electron temperature (Te), the floating potential (Vf), and the plasma potential (Vp). For this, the diagnostic electronics along with the biasing power supplies is installed in standard industrial racks with a 2KV isolation transformer. The Signal Conditioning Electronics (SCE) system is populated inside the 4U-chassis based system with the front-end electronics, designed using high common mode differential amplifiers which can measure small differential signal in presence of high common mode dc- bias or ac ramp voltage used for biasing the probes. DC-biasing of the probe is most common method for getting its I-V characteristic but method of biasing the probe with a sweep at high frequency encounters the problem of corruption of signal due to capacitive effect specially when the sweep period and the discharge time is very fast and die down in the order of μs or lesser. This paper presents and summarises the method of removing such effects encountered while measuring the probe current.

  14. 1 μs broadband frequency sweeping reflectometry for plasma density and fluctuation profile measurements

    Science.gov (United States)

    Clairet, F.; Bottereau, C.; Medvedeva, A.; Molina, D.; Conway, G. D.; Silva, A.; Stroth, U.; ASDEX Upgrade Team; Tore Supra Team; Eurofusion Mst1 Team

    2017-11-01

    Frequency swept reflectometry has reached the symbolic value of 1 μs sweeping time; this performance has been made possible, thanks to an improved control of the ramp voltage driving the frequency source. In parallel, the memory depth of the acquisition system has been upgraded and can provide up to 200 000 signals during a plasma discharge. Additional improvements regarding the trigger delay determination of the acquisition and the voltage ramp linearity required by this ultra-fast technique have been set. While this diagnostic is traditionally dedicated to the plasma electron density profile measurement, such a fast sweeping rate can provide the study of fast plasma events and turbulence with unprecedented time and radial resolution from the edge to the core. Experimental results obtained on ASDEX Upgrade plasmas are presented to demonstrate the performances of the diagnostic.

  15. Ion source plasma parameters measurement based on Langmuir probe with commercial frequency sweep

    International Nuclear Information System (INIS)

    Xie, Y.H.; Hu, C.D.; Liu, S.; Shong, S.H.; Jiang, C.C.; Liu, Z.M.

    2010-01-01

    Langmuir probe is one of the main diagnostic tools to measure the plasma parameters in the ion source. In this article, the commercial frequency power, which is sine wave of 50 Hz, was supplied on the Langmuir probe to measure the plasma parameters. The best feature of this probe sweep voltage is that it does not need extra design. The probe I-V characteristic curve can be got in less than 5 ms and the plasma parameters, the electron temperature and the electron density, varying with the time can be got in one plasma discharge of 400 ms.

  16. On line ultrasonic integrated backscatter

    International Nuclear Information System (INIS)

    Landini, L.; Picano, E.; Mazzarisi, A.; Santarelli, F.; Benassi, A.; De Pieri, G.

    1988-01-01

    A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

  17. Ultrasonically assisted drilling of rocks

    Science.gov (United States)

    Mikhailova, N. V.; Onawumi, P. Y.; Roy, A.; Silberschmidt, V. V.

    2018-05-01

    Conventional drilling of rocks can generate significant damage in the drilled material; a material layer is often split off a back surface of a sample during drilling, negatively affecting its strength. To improve finish quality, ultrasonically assisted drilling (UAD) was employed in two rocks - sandstone and marble. Damage areas in both materials were reduced in UAD when compared to conventional drilling. Reductions in a thrust force and a torque reduction were observed only for UAD in marble; ultrasonic assistance in sandstone drilling did not result in improvements in this regard.

  18. Very high temperature ultrasonic thermometer

    International Nuclear Information System (INIS)

    Jorzik, E.

    1983-01-01

    An ultrasonic thermometer comprises an electric pulse transducer head, a pulse transmission line, a notched sensor wire attached to and extending along the axis of said transmission line and a sheath enclosing the transmission line and the sensor wire, a portion of the interior face of the sheath being covered by a stuffing material along at least the length of the notched part of the sensor wire, such that contact between the sensor wire and the stuffing material does not substantially give rise to reflection of an ultrasonic pulse at the point of contact. (author)

  19. Measurement of a 3D Ultrasonic Wavefield Using Pulsed Laser Holographic Microscopy for Ultrasonic Nondestructive Evaluation

    Directory of Open Access Journals (Sweden)

    Xing Wang

    2018-02-01

    Full Text Available In ultrasonic array imaging, 3D ultrasonic wavefields are normally recorded by an ultrasonic piezo array transducer. Its performance is limited by the configuration and size of the array transducer. In this paper, a method based on digital holographic interferometry is proposed to record the 3D ultrasonic wavefields instead of the array transducer, and the measurement system consisting of a pulsed laser, ultrasonic excitation, and synchronization and control circuit is designed. A consecutive sequence of holograms of ultrasonic wavefields are recorded by the system. The interferograms are calculated from the recorded holograms at different time sequence. The amplitudes and phases of the transient ultrasonic wavefields are recovered from the interferograms by phase unwrapping. The consecutive sequence of transient ultrasonic wavefields are stacked together to generate 3D ultrasonic wavefields. Simulation and experiments are carried out to verify the proposed technique, and preliminary results are presented.

  20. dc readout experiment at the Caltech 40m prototype interferometer

    International Nuclear Information System (INIS)

    Ward, R L; Adhikari, R; Abbott, B; Abbott, R; Bork, R; Fricke, T; Heefner, J; Ivanov, A; Miyakawa, O; Smith, M; Taylor, R; Vass, S; Waldman, S; Weinstein, A; Barron, D; Frolov, V; McKenzie, K; Slagmolen, B

    2008-01-01

    The Laser Interferometer Gravitational Wave Observatory (LIGO) operates a 40m prototype interferometer on the Caltech campus. The primary mission of the prototype is to serve as an experimental testbed for upgrades to the LIGO interferometers and for gaining experience with advanced interferometric techniques, including detuned resonant sideband extraction (i.e. signal recycling) and dc readout (optical homodyne detection). The former technique will be employed in Advanced LIGO, and the latter in both Enhanced and Advanced LIGO. Using dc readout for gravitational wave signal extraction has several technical advantages, including reduced laser and oscillator noise couplings as well as reduced shot noise, when compared to the traditional rf readout technique (optical heterodyne detection) currently in use in large-scale ground-based interferometric gravitational wave detectors. The Caltech 40m laboratory is currently prototyping a dc readout system for a fully suspended interferometric gravitational wave detector. The system includes an optical filter cavity at the interferometer's output port, and the associated controls and optics to ensure that the filter cavity is optimally coupled to the interferometer. We present the results of measurements to characterize noise couplings in rf and dc readout using this system

  1. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

    1976-01-01

    Optical and X-ray metallography combined with ultrasonic testing by compression waves was used for inspection of stainless steel weld metal produced by three different welding techniques. X-ray diffraction showed that each weld possessed a characteristic fibre textured structure which was shown by optical microscopy to be parallel to columnar grain boundaries. Metallographic evidence suggested that the development of fibre texture is due to the mechanism of competitive growth. From observations made as a result of optical metallographic examination the orientation of the fibre axis could be predicted if the weld geometry and welding procedure were known. Ultrasonic velocity and attenuation measurements as a continuous function of grain orientation, made on cylinders machined from weld samples, showed that attenuation was strongly orientation dependent. It was concluded that the sensitivity of ultrasonic inspection to small defects is unlikely to be as high for austenitic welds as for ferritic even when transmission is improved by modifying the welding procedure to improve the ultrasonic transmission. (U.K.)

  2. Atmospheric contamination during ultrasonic scaling

    NARCIS (Netherlands)

    Timmerman, MF; Menso, L; Steinfort, J; van Winkelhoff, AJ; van der Weijden, GA

    Objective: The aim of this study was to determine the microbial atmospheric contamination during initial periodontal treatment using a piezoelectric ultrasonic scaler in combination with either high-volume evacuation (HVE) or conventional dental suction (CDS). Methods: The study included 17

  3. Automated evaluation of ultrasonic indications

    International Nuclear Information System (INIS)

    Hansch, M.K.T.; Stegemann, D.

    1994-01-01

    Future requirements of reliability and reproducibility in quality assurance demand computer evaluation of defect indications. The ultrasonic method with its large field of applications and a high potential for automation provides all preconditions for fully automated inspection. The survey proposes several desirable hardware improvements, data acquisition requirements and software configurations. (orig.) [de

  4. Ultrasonic flowmeters. Progress report II

    International Nuclear Information System (INIS)

    Wittekind, W.D.

    1980-01-01

    This progress report presents results of in-plant testing of the prototype ultrasonic flowmeter and describes modifications to the prototype as a result of these tests. The modified prototype, designated MOD-I, is described in detail including the principle of operation, equipment used and the results of both laboratory and in-plant demonstrations

  5. Calculations for Piezoelectric Ultrasonic Transducers

    DEFF Research Database (Denmark)

    Jensen, Henrik

    1986-01-01

    Analysis of piezoelectric ultrasonic transducers implies a solution of a boundary value problem, for a boay which consists of different materials, including a piezoelectric part. The problem is dynamic at frequencies, where a typical wavelength is somewhat less than the size of the body. Radiation...

  6. High-Frequency Fiber-Optic Ultrasonic Sensor Using Air Micro-Bubble for Imaging of Seismic Physical Models.

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Rong, Qiangzhou; Qiao, Xueguang; Liang, Lei; Liu, Nan; Tong, Rongxin; Liu, Xiaobo; Bian, Ce

    2016-12-14

    A micro-fiber-optic Fabry-Perot interferometer (FPI) is proposed and demonstrated experimentally for ultrasonic imaging of seismic physical models. The device consists of a micro-bubble followed by the end of a single-mode fiber (SMF). The micro-structure is formed by the discharging operation on a short segment of hollow-core fiber (HCF) that is spliced to the SMF. This micro FPI is sensitive to ultrasonic waves (UWs), especially to the high-frequency (up to 10 MHz) UW, thanks to its ultra-thin cavity wall and micro-diameter. A side-band filter technology is employed for the UW interrogation, and then the high signal-to-noise ratio (SNR) UW signal is achieved. Eventually the sensor is used for lateral imaging of the physical model by scanning UW detection and two-dimensional signal reconstruction.

  7. Using a heterodyne vibrometer in combination with pulse excitation for primary calibration of ultrasonic hydrophones in amplitude and phase

    Science.gov (United States)

    Weber, Martin; Wilkens, Volker

    2017-08-01

    A high-frequency vibrometer was used with ultrasonic pulse excitation in order to perform a primary hydrophone calibration. This approach enables the simultaneous characterization of the amplitude and phase transfer characteristic of ultrasonic hydrophones. The method allows a high frequency resolution in a considerably short time for the measurement. Furthermore, the uncertainty contributions of this approach were investigated and quantified. A membrane hydrophone was calibrated and the uncertainty budget for this measurement was determined. The calibration results are presented up to 70~\\text{MHz} . The measurement results show good agreement with the results obtained by sinusoidal burst excitation through the use of the vibrometer and by a homodyne laser interferometer, with RMS deviation of approximately 3% -4% in the frequency range from 1 to 60~\\text{MHz} . Further hydrophones were characterized up to 100~\\text{MHz} with this procedure to demonstrate the suitability for very high frequency calibration.

  8. An ultrasonic noncontact method to monitor the doneness of bakery products

    Science.gov (United States)

    Chimenti, D. E.; Faeth, L.

    2000-05-01

    The paper describes a method using ultrasonics and fluid dynamics to assess the state of "doneness" of bakery products, such as bread loaves, online and in situ. The problem in the baking industry is that bread doneness determined by time and temperature can be inaccurate, leaving some product underbaked. We describe a noncontact method using air-pulse excitation and air-coupled ultrasonic motion sensing to infer the state of doneness of the baking loaf while still in the oven and on a moving belt. The ultrasonic sensor operates at 100 kHz using a toneburst excitation and pitch-catch transducer geometry. The problem is one of detecting small (50 micron) movements in the loaf, whose position may vary up to several mm. Further, the loaf movements caused by the air-pulse excitation are rapid (20 to 50 msec). We present a signal-processing system, incorporating a boxcar integrator, that functions as a pulsed, time-domain acoustic interferometer. This instrument is capable of both the high time and spatial resolution essential for the successful operation of the instrument. We estimate a spatial resolution of 30 micron and a temporal resolution of 5 msec, using 100 kHz acoustic waves. The results of numerous in-oven measurements on one-pound bread loaves during the bake cycle will be presented to illustrate the performance of the instrument.

  9. Low Energy Gamma Radiation Induced Effects on Ultrasonic Velocity and Acoustic Parameters in Polyvinylidene Fluoride Solution

    Directory of Open Access Journals (Sweden)

    S. S. Kulkarni

    2016-01-01

    Full Text Available The modification of polyvinylidene fluoride (PVDF polymer properties with irradiation is of interest as it possesses unique piezo-, pyro-, and ferroelectric properties. In this paper, we report the results of acoustic parameters of irradiated PVDF mixed with dimethylacetamide (DMAC solution with low energy γ-source (Cs-137. The polymer solution covered with mica film assures only γ-ray passage and the duration was increased from 18 to 50 hours to achieve the higher dose rate. The dose rate was estimated using the strength of the radioactive source and the duration of the exposure. The ultrasonic velocity (v, density (ρ, and viscosity (η of 0.2 wt% and 0.5 wt% PVDF dissolved in pure DMAC solution, irradiated with different dose rate were measured using ultrasonic interferometer (Mittal make, Pyknometer, and Oswald’s viscometer, respectively. It is observed that the values of v, ρ, and η change with dose rate. The acoustic parameters such as adiabatic compressibility (β, intermolecular free path length (Lf, acoustic impedance (Z, relative association (RA, ultrasonic attenuation (α/f2, and relaxation time (τ are calculated using the experimental data. These results are interpreted in terms of the solute-solvent interaction in a polymer solution and scissoring chain damage.

  10. Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics

    Science.gov (United States)

    Kimble, H. J.; Levin, Yuri; Matsko, Andrey B.; Thorne, Kip S.; Vyatchanin, Sergey P.

    2002-01-01

    The LIGO-II gravitational-wave interferometers (ca. 2006-2008) are designed to have sensitivities near the standard quantum limit (SQL) in the vicinity of 100 Hz. This paper describes and analyzes possible designs for subsequent LIGO-III interferometers that can beat the SQL. These designs are identical to a conventional broad band interferometer (without signal recycling), except for new input and/or output optics. Three designs are analyzed: (i) a squeezed-input interferometer (conceived by Unruh based on earlier work of Caves) in which squeezed vacuum with frequency-dependent (FD) squeeze angle is injected into the interferometer's dark port; (ii) a variational-output interferometer (conceived in a different form by Vyatchanin, Matsko and Zubova), in which homodyne detection with FD homodyne phase is performed on the output light; and (iii) a squeezed-variational interferometer with squeezed input and FD-homodyne output. It is shown that the FD squeezed-input light can be produced by sending ordinary squeezed light through two successive Fabry-Pérot filter cavities before injection into the interferometer, and FD-homodyne detection can be achieved by sending the output light through two filter cavities before ordinary homodyne detection. With anticipated technology (power squeeze factor e-2R=0.1 for input squeezed vacuum and net fractional loss of signal power in arm cavities and output optical train ɛ*=0.01) and using an input laser power Io in units of that required to reach the SQL (the planned LIGO-II power, ISQL), the three types of interferometer could beat the amplitude SQL at 100 Hz by the following amounts μ≡(Sh)/(SSQLh) and with the following corresponding increase V=1/μ3 in the volume of the universe that can be searched for a given noncosmological source: Squeezed input-μ~=(e-2R)~=0.3 and V~=1/0.33~=30 using Io/ISQL=1. Variational-output-μ~=ɛ1/4*~=0.3 and V~=30 but only if the optics can handle a ten times larger power: Io/ISQL~=1/(ɛ*)=10

  11. Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics

    International Nuclear Information System (INIS)

    Kimble, H.J.; Levin, Yuri; Thorne, Kip S.; Matsko, Andrey B.; Vyatchanin, Sergey P.

    2002-01-01

    The LIGO-II gravitational-wave interferometers (ca. 2006-2008) are designed to have sensitivities near the standard quantum limit (SQL) in the vicinity of 100 Hz. This paper describes and analyzes possible designs for subsequent LIGO-III interferometers that can beat the SQL. These designs are identical to a conventional broad band interferometer (without signal recycling), except for new input and/or output optics. Three designs are analyzed: (i) a squeezed-input interferometer (conceived by Unruh based on earlier work of Caves) in which squeezed vacuum with frequency-dependent (FD) squeeze angle is injected into the interferometer's dark port; (ii) a variational-output interferometer (conceived in a different form by Vyatchanin, Matsko and Zubova), in which homodyne detection with FD homodyne phase is performed on the output light; and (iii) a squeezed-variational interferometer with squeezed input and FD-homodyne output. It is shown that the FD squeezed-input light can be produced by sending ordinary squeezed light through two successive Fabry-Perot filter cavities before injection into the interferometer, and FD-homodyne detection can be achieved by sending the output light through two filter cavities before ordinary homodyne detection. With anticipated technology (power squeeze factor e -2R =0.1 for input squeezed vacuum and net fractional loss of signal power in arm cavities and output optical train ε * =0.01) and using an input laser power I o in units of that required to reach the SQL (the planned LIGO-II power, I SQL ), the three types of interferometer could beat the amplitude SQL at 100 Hz by the following amounts μ≡√(S h )/√(S h SQL ) and with the following corresponding increase V=1/μ 3 in the volume of the universe that can be searched for a given noncosmological source: Squeezed input--μ≅√(e -2R )≅0.3 and V≅1/0.3 3 ≅30 using I o /I SQL =1. Variational-output--μ≅ε * 1/4 ≅0.3 and V≅30 but only if the optics can handle a ten

  12. Improved density measurement by FIR laser interferometer on EAST tokamak

    International Nuclear Information System (INIS)

    Shen, Jie; Jie, Yinxian; Liu, Haiqing; Wei, Xuechao; Wang, Zhengxing; Gao, Xiang

    2013-01-01

    Highlights: • In 2012, the water-cooling Mo wall was installed in EAST. • A schottky barrier diode detector is designed and used on EAST for the first time. • The three-channel far-infrared laser interferometer can measure the electron density. • The improved measurement and latest experiment results are reported. • The signal we get in this experiment campaign is much better than we got in 2010. -- Abstract: A three-channel far-infrared (FIR) hydrogen cyanide (HCN) laser interferometer is in operation since 2010 to measure the line averaged electron density on experimental advanced superconducting tokamak (EAST). The HCN laser signal is improved by means of a new schottky barrier diode (SBD) detector. The improved measurement and latest experiment results of the three-channel FIR laser interferometer on EAST tokamak are reported

  13. Phase-Shifting Liquid Crystal Interferometers for Microgravity Fluid Physics

    Science.gov (United States)

    Griffin, DeVon W.; Marshall, Keneth L.

    2002-01-01

    The initial focus of this project was to eliminate both of these problems in the Liquid Crystal Point-Diffraction Interferometer (LCPDI). Progress toward that goal will be described, along with the demonstration of a phase shifting Liquid Crystal Shearing Interferometer (LCSI) that was developed as part of this work. The latest LCPDI, other than a lens to focus the light from a test section onto a diffracting microsphere within the interferometer and a collimated laser for illumination, the pink region contained within the glass plates on the rod-mounted platform is the complete interferometer. The total width is approximately 1.5 inches with 0.25 inches on each side for bonding the electrical leads. It is 1 inch high and there are only four diffracting microspheres within the interferometer. As a result, it is very easy to align, achieving the first goal. The liquid crystal electro-optical response time is a function of layer thickness, with thinner devices switching faster due to a reduction in long-range viscoelastic forces between the LC molecules. The LCPDI has a liquid crystal layer thickness of 10 microns, which is controlled by plastic or glass microspheres embedded in epoxy 'pads' at the corners of the device. The diffracting spheres are composed of polystyrene/divinyl benzene polymer with an initial diameter of 15 microns. The spheres deform slightly when the interferometer is assembled to conform to the spacing produced by the microsphere-filled epoxy spacer pads. While the speed of this interferometer has not yet been tested, previous LCPDIs fabricated at the Laboratory for Laser Energetics switched at a rate of approximately 3.3 Hz, a factor of 10 slower than desired. We anticipate better performance when the speed of these interferometers is tested since they are approximately three times thinner. Phase shifting in these devices is a function of the AC voltage level applied to the liquid crystal. As the voltage increases, the dye in the liquid crystal

  14. Multiphoton- and simultaneous conjugate Ramsey-Borde atom interferometers

    International Nuclear Information System (INIS)

    Mueller, Holger; Chiow, Sheng-wey; Herrmann, Sven; Chu, Steven

    2008-01-01

    We report on our experiment to measure h/M, the ratio of the Planck constant to the mass of Cs atoms, and thereby the fine-structure constant. The target accuracy is 1 part per billion or better. We focus on two recent milestones: (i) The first realization of atom interferometers based on light-pulse beam splitters that transfer the momentum of up to 12 photon pairs, which increases the useful signal (matter wave phase shift) by a factor of 144 compared to the beam splitters used in the best present atom interferometers. Moreover, they lead to a cancellation of important systematic effects. (ii) The first realization of a simultaneous pair of conjugate Ramsey-Borde interferometers. In these, the relative sign of the inertial term is reversed so that it can be cancelled. Simultaneous operation means that this holds for a time-dependent inertial term (vibrations) too, which promises a substantial improvement in the signal to noise ratio

  15. Six-channel adaptive fibre-optic interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Romashko, R V; Bezruk, M N; Kamshilin, A A; Kulchin, Yurii N

    2012-06-30

    We have proposed and analysed a scheme for the multiplexing of orthogonal dynamic holograms in photorefractive crystals which ensures almost zero cross talk between the holographic channels upon phase demodulation. A six-channel adaptive fibre-optic interferometer was built, and the detection limit for small phase fluctuations in the channels of the interferometer was determined to be 2.1 Multiplication-Sign 10{sup -8} rad W{sup 1/2} Hz{sup -1/2}. The channel multiplexing capacity of the interferometer was estimated. The formation of 70 channels such that their optical fields completely overlap in the crystal reduces the relative detection limit in the working channel by just 10 %. We found conditions under which the maximum cross talk between the channels was within the intrinsic noise level in the channels (-47 dB).

  16. Improved density measurement by FIR laser interferometer on EAST tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Jie, E-mail: shenjie1988@ipp.ac.cn; Jie, Yinxian; Liu, Haiqing; Wei, Xuechao; Wang, Zhengxing; Gao, Xiang

    2013-11-15

    Highlights: • In 2012, the water-cooling Mo wall was installed in EAST. • A schottky barrier diode detector is designed and used on EAST for the first time. • The three-channel far-infrared laser interferometer can measure the electron density. • The improved measurement and latest experiment results are reported. • The signal we get in this experiment campaign is much better than we got in 2010. -- Abstract: A three-channel far-infrared (FIR) hydrogen cyanide (HCN) laser interferometer is in operation since 2010 to measure the line averaged electron density on experimental advanced superconducting tokamak (EAST). The HCN laser signal is improved by means of a new schottky barrier diode (SBD) detector. The improved measurement and latest experiment results of the three-channel FIR laser interferometer on EAST tokamak are reported.

  17. CO laser interferometer for REB-plasma experiments

    International Nuclear Information System (INIS)

    Burmasov, V.S.; Kruglyakov, E.P.

    1996-01-01

    The Michelson carbon oxide laser interferometer for measuring plasma density in studies on REB-plasma interaction is described. A detail description of the interferometer and CO laser is presented. For a selection of a single wavelength laser operation the CaF 2 prism is applied. A Ge:Au photoconductor at 77 deg K is applied as the detector. The CO laser radiation at λ 5.34 μm coincides with the detector maximum sensitivity (of the order of 1000 V/W). This increases the interferometer sensitivity about ten times with respect to the He-Ne laser (λ = 3.39 μm) used as the source of light. The typical interferogram and time evolution of plasma density obtained at GOL-M device are presented. (author). 3 figs., 5 refs

  18. The POLIS interferometer for ponderomotive squeezed light generation

    Energy Technology Data Exchange (ETDEWEB)

    Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)

    2016-07-11

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  19. 30-lens interferometer for high energy x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Lyubomirskiy, M., E-mail: lyubomir@esrf.fr; Snigireva, I., E-mail: irina@esrf.fr; Vaughan, G. [European Synchrotron Radiation facility (ESRF), CS 40220, 71, av des Martyrs, F-38043, Grenoble (France); Kohn, V. [National Research Centre “Kurchatov Institute”, 123182, Moscow (Russian Federation); Kuznetsov, S.; Yunkin, V. [Institute of Microelectronics Technology RAS, 142432, Chernogolovka (Russian Federation); Snigirev, A. [Baltic Federal University, 236041, Kaliningrad (Russian Federation)

    2016-07-27

    We report a hard X-ray multilens interferometer consisting of 30 parallel compound refractive lenses. Under coherent illumination each CRL creates a diffraction limited focal spot - secondary source. An overlapping of coherent beams from these sources resulting in the interference pattern which has a rich longitudinal structure in accordance with the Talbot imaging formalism. The proposed interferometer was experimentally tested at ID11 ESRF beamline for the photon energies 32 keV and 65 keV. The fundamental and fractional Talbot images were recorded with the high resolution CCD camera. An effective source size in the order of 15 µm was determined from the first Talbot image proving that the multilens interferometer can be used as a high resolution beam diagnostic tool.

  20. The Virgo gravitational wave interferometer: status and perspectives

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    The first recording of a signal from a binary neutron star system by the Advanced LIGO and Advanced Virgo interferometers, and the observation of its remnants by telescopes in all bands of the electromagnetic spectrum, marked the beginning of multimessenger astronomy with gravitational waves. This followed the detection of gravitational wave signals by the LIGO interferometers in 2015, which started the detailed study of highly curved space time. These achievements come after decades of work spent understanding how to measure the tiny space time strain (h ~ 10-21) carried by gravitational waves. In the future, detectors will able to extract much more precise information from these events, or record signals from fainter sources, providing a new view of the Universe. After a presentation of the Virgo interferometer, the main results obtained from binary black hole and neutron star detection are reviewed. The focus will then shift on the perspective offered by a further reduction of noise in ground based interf...

  1. CO laser interferometer for REB-plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Burmasov, V S; Kruglyakov, E P [Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)

    1997-12-31

    The Michelson carbon oxide laser interferometer for measuring plasma density in studies on REB-plasma interaction is described. A detail description of the interferometer and CO laser is presented. For a selection of a single wavelength laser operation the CaF{sub 2} prism is applied. A Ge:Au photoconductor at 77 deg K is applied as the detector. The CO laser radiation at {lambda} 5.34 {mu}m coincides with the detector maximum sensitivity (of the order of 1000 V/W). This increases the interferometer sensitivity about ten times with respect to the He-Ne laser ({lambda} = 3.39 {mu}m) used as the source of light. The typical interferogram and time evolution of plasma density obtained at GOL-M device are presented. (author). 3 figs., 5 refs.

  2. Optimum design of a microwave interferometer for plasma density measurement

    International Nuclear Information System (INIS)

    Lindberg, L.; Eriksson, A.

    1980-11-01

    Theoretical and practical problems arising in the application of microwave interferometry to density measurements on transient plasmas are discussed. The conditions for unambiquous measurements in a density range as wide as possible are analyzed. It is shown that the initial zero adjustment of the interferometer bridge recommended in many text books is the worst possible choice of initial condition when the aim is high initial sensitivity at low densities. The analytic expressions needed for unambiquous evaluation of any phase shift from a few degrees to several times π (counting of fringes) are derived. The practical design of the interferometer circuit and its inherent error sources due to reflexions and non-ideal component properties are discussed. The results are applied to an interferometer operating at 80 GHz used on a pulsed plasma experiment. The minimum measurable phase shift is 2deg and the range of linear densities that have been measured is = 1 . 10 16 - 3 . 10 18 m -2

  3. Parallel Wavefront Analysis for a 4D Interferometer

    Science.gov (United States)

    Rao, Shanti R.

    2011-01-01

    This software provides a programming interface for automating data collection with a PhaseCam interferometer from 4D Technology, and distributing the image-processing algorithm across a cluster of general-purpose computers. Multiple instances of 4Sight (4D Technology s proprietary software) run on a networked cluster of computers. Each connects to a single server (the controller) and waits for instructions. The controller directs the interferometer to several images, then assigns each image to a different computer for processing. When the image processing is finished, the server directs one of the computers to collate and combine the processed images, saving the resulting measurement in a file on a disk. The available software captures approximately 100 images and analyzes them immediately. This software separates the capture and analysis processes, so that analysis can be done at a different time and faster by running the algorithm in parallel across several processors. The PhaseCam family of interferometers can measure an optical system in milliseconds, but it takes many seconds to process the data so that it is usable. In characterizing an adaptive optics system, like the next generation of astronomical observatories, thousands of measurements are required, and the processing time quickly becomes excessive. A programming interface distributes data processing for a PhaseCam interferometer across a Windows computing cluster. A scriptable controller program coordinates data acquisition from the interferometer, storage on networked hard disks, and parallel processing. Idle time of the interferometer is minimized. This architecture is implemented in Python and JavaScript, and may be altered to fit a customer s needs.

  4. Polydyne displacement interferometer using frequency-modulated light

    Science.gov (United States)

    Arablu, Masoud; Smith, Stuart T.

    2018-05-01

    A radio-frequency Frequency-Modulated (FM) signal is used to diffract a He-Ne laser beam through an Acousto-Optic Modulator (AOM). Due to the modulation of the FM signal, the measured spectra of the diffracted beams comprise a series of phase-synchronized harmonics that have exact integer frequency separation. The first diffraction side-beam emerging from the AOM is selected by a slit to be used in a polydyne displacement interferometer in a Michelson interferometer topology. The displacement measurement is derived from the phase measurement of selected modulation harmonic pairs. Individual harmonic frequency amplitudes are measured using discrete Fourier transform applied to the signal from a single photodetector. Phase signals are derived from the changes in the amplitudes of different harmonic pairs (typically odd-even pairs) with the phase being extracted using a standard quadrature method. In this study, two different modulation frequencies of 5 and 10 kHz are used at different modulation depths. The measured displacements by different harmonic pairs are compared with a commercial heterodyne interferometer being used as a reference for these studies. Measurements obtained from five different harmonic pairs when the moving mirror of the interferometer is scanned over ranges up to 10 μm all show differences of less than 50 nm from the reference interferometer measurements. A drift test was also used to evaluate the differences between the polydyne interferometer and reference measurements that had different optical path lengths of approximately 25 mm and 50 mm, respectively. The drift test results indicate that about half of the differences can be attributed to temperature, pressure, and humidity variations. Other influences include Abbe and thermal expansion effects. Rough magnitude estimates using simple models for these two effects can account for remaining observed deviations.

  5. Local readout enhancement for detuned signal-recycling interferometers

    International Nuclear Information System (INIS)

    Rehbein, Henning; Mueller-Ebhardt, Helge; Schnabel, Roman; Danzmann, Karsten; Somiya, Kentaro; Chen Yanbei; Li Chao

    2007-01-01

    High power detuned signal-recycling interferometers currently planned for second-generation interferometric gravitational-wave detectors (for example Advanced LIGO) are characterized by two resonances in the detection band, an optical resonance and an optomechanical resonance which is upshifted from the suspension pendulum frequency due to the so-called optical-spring effect. The detector's sensitivity is enhanced around these two resonances. However, at frequencies below the optomechanical resonance frequency, the sensitivity of such interferometers is significantly lower than non-optical-spring configurations with comparable circulating power; such a drawback can also compromise high-frequency sensitivity, when an optimization is performed on the overall sensitivity of the interferometer to a class of sources. In this paper, we clarify the reason for such a low sensitivity, and propose a way to fix this problem. Motivated by the optical-bar scheme of Braginsky, Gorodetsky, and Khalili, we propose to add a local readout scheme which measures the motion of the arm-cavity front mirror, which at low frequencies moves together with the arm-cavity end mirror, under the influence of gravitational waves. This scheme improves the low-frequency quantum-noise-limited sensitivity of optical-spring interferometers significantly and can be considered as an incorporation of the optical-bar scheme into currently planned second-generation interferometers. On the other hand it can be regarded as an extension of the optical-bar scheme. Taking compact binary inspiral signals as an example, we illustrate how this scheme can be used to improve the sensitivity of the planned Advanced LIGO interferometer, in various scenarios, using a realistic classical-noise budget. We also discuss how this scheme can be implemented in Advanced LIGO with relative ease

  6. A Milestone for the VLT Interferometer

    Science.gov (United States)

    2000-10-01

    Less than one month after "First Light" for the fourth 8.2-m YEPUN telescope ( ESO PR 18/00 ), another special moment occurred at ESO's Paranal Observatory. This time, it was the first truly "underground" event, in the 168-metre long Interferometric Tunnel that has been dug beneath the platform at the top of the mountain. As one staff member remarked on this occasion, it was something like "the first scheduled trip of the Paranal metro"! With the successful integration of the first Delay Line on Monday, September 25th, 2000, ESO has accomplished another important step towards the VLT Interferometer (VLTI). It will be followed by the integration of the second Delay Line by the end of November and the third is scheduled for February 2001; both are now in their final development phase in Europe. "VLTI First Light" is then expected to take place soon thereafter, by means of two small special telescopes ("siderostats"). The combination of the light beams from two of the 8.2-m Unit Telescopes will happen in mid-2001. The VLTI Delay Lines The VLTI Delay Lines form essential parts of this very complicated optical system. They serve to ensure that the light beams from several telescopes arrive in phase at the common interferometric focus. Details about how they function may be found in ESO PR 04/98. In order to achieve the necessary performance, ESO has worked with two Dutch contractors, Fokker Space and TNO-TPD - Netherlands Organization for Applied Scientific Research - Institute of Applied Physics , to arrive at a totally new Delay Line concept. Another Dutch participant in the VLTI project is the Nova-ESO VLTI Expertise Centre (NEVEC) , cf. ESO PR 14/00. The installation at Paranal The last twelve months have been very busy for the integration team, with much preparatory work at the VLTI buildings for the final installation of the Delay Line systems. The assembly of the translation mechanisms for the first two Delay Lines in the tunnel started in mid-2000. This included

  7. Characterisation of a resolution enhancing image inversion interferometer.

    Science.gov (United States)

    Wicker, Kai; Sindbert, Simon; Heintzmann, Rainer

    2009-08-31

    Image inversion interferometers have the potential to significantly enhance the lateral resolution and light efficiency of scanning fluorescence microscopes. Self-interference of a point source's coherent point spread function with its inverted copy leads to a reduction in the integrated signal for off-axis sources compared to sources on the inversion axis. This can be used to enhance the resolution in a confocal laser scanning microscope. We present a simple image inversion interferometer relying solely on reflections off planar surfaces. Measurements of the detection point spread function for several types of light sources confirm the predicted performance and suggest its usability for scanning confocal fluorescence microscopy.

  8. A SIMPLE HETERODYNE TEMPORAL SPECKLE-PATTERN INTERFEROMETER

    International Nuclear Information System (INIS)

    Wong, W. O.; Gao, Z.; Lu, J.

    2010-01-01

    A common light path design of heterodyne speckle pattern interferometer based on temporal speckle pattern interferometry is proposed for non-contact, full-field and real-time continuous displacement measurement. Double frequency laser is produced by rotating a half wave plate. An experiment was carried out to measure the dynamic displacement of a cantilever plate for testing the proposed common path heterodyne speckle pattern interferometer. The accuracy of displacement measurement was checked by measuring the motion at the mid-point of the plate with a point displacement sensor.

  9. Rational choices for the wavelengths of a two color interferometer

    International Nuclear Information System (INIS)

    Jobes, F.C.

    1995-07-01

    If in a two color interferometer for plasma density measurements, the two wavelengths are chosen to have a ratio that is a rational number, and if the signals from each of the wavelengths are multiplied in frequency by the appropriate integer of the rational number and then heterodyned together, the resultant signal will have all effects of component motion nulled out. A phase measurement of this signal will have only plasma density information in it. With CO 2 lasers, it is possible to find suitable wavelength pairs which are close enough to rational numbers to produce an improvement of about 100 in density resolution, compared to standard two color interferometers

  10. Sagnac Interferometer Based Generation of Controllable Cylindrical Vector Beams

    Directory of Open Access Journals (Sweden)

    Cristian Acevedo

    2016-01-01

    Full Text Available We report on a novel experimental geometry to generate cylindrical vector beams in a very robust manner. Continuous control of beams’ properties is obtained using an optically addressable spatial light modulator incorporated into a Sagnac interferometer. Forked computer-generated holograms allow introducing different topological charges while orthogonally polarized beams within the interferometer permit encoding the spatial distribution of polarization. We also demonstrate the generation of complex waveforms obtained by combining two orthogonal beams having both radial modulations and azimuthal dislocations.

  11. Detectability of periodic gravitational waves by initial interferometers

    International Nuclear Information System (INIS)

    Owen, Benjamin J

    2006-01-01

    I review three recent theoretical developments in neutron star physics predicting that rotating neutron stars could be very strong emitters of periodic gravitational waves. These imply a small but nonzero chance that ground-based interferometers could detect their first periodic signal in the next few years rather than after advanced upgrades. They also imply that upper limits will become astrophysically interesting before advanced upgrades. I discuss the implications for near-future searches and for the astrophysical payoffs of proposed small upgrades to initial interferometers

  12. An active interferometer-stabilization scheme with linear phase control

    DEFF Research Database (Denmark)

    Andresen, Esben Ravn; Krishnamachari, v v; Potma, E O

    2006-01-01

    We report a simple and robust computer-based active interferometer stabilization scheme which does not require modulation of the interfering beams and relies on an error signal which is linearly related to the optical path difference. In this setup, a non-collinearly propagating reference laser...... beam stabilizes the interference output of the laser light propagating collinearly through the interferometer. This stabilization scheme enables adjustable phase control with 20 ms switching times in the range from 0.02π radians to 6π radians at 632.8 nm....

  13. A reconfigurable optofluidic Michelson interferometer using tunable droplet grating.

    Science.gov (United States)

    Chin, L K; Liu, A Q; Soh, Y C; Lim, C S; Lin, C L

    2010-04-21

    This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquids. The optofluidic Michelson interferometer is highly sensitive and is suitable for the measurement of biomedical and biochemical buffer solutions. The experimental results show that it has a sensitivity of 66.7 nm per refractive index unit (RIU) and a detection range of 0.086 RIU.

  14. Near-infrared spectral imaging Michelson interferometer for astronomical applications

    Science.gov (United States)

    Wells, C. W.; Potter, A. E.; Morgan, T. H.

    1980-01-01

    The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

  15. Applications of the lateral shearing interferometer in measurement of synchrotron radiation optical elements

    International Nuclear Information System (INIS)

    Liu, Wu-ming; Takacs, P.Z.; Siddons, D.P.

    1987-11-01

    The use of a single plate shearing, or Murty, interferometer for measuring the surface quality of several optical elements is reviewed and several results are given. The principle of the Murty interferometer is also explained

  16. Validation of separated source frequency delivery for a fiber-coupled heterodyne displacement interferometer

    NARCIS (Netherlands)

    Meskers, A.J.H.; Spronck, J.W.; Munnig Schmidt, R.H.

    2014-01-01

    The use of optical fibers presents several advantages with respect to free-space optical transport regarding sourcefrequency delivery to individual heterodyne interferometers. Unfortunately, fiber delivery to individual coaxial heterodyne interferometers leads to an increase of (periodic)

  17. Results from a multi aperture Fizeau interferometer ground testbed: demonstrator for a future space-based interferometer

    Science.gov (United States)

    Baccichet, Nicola; Caillat, Amandine; Rakotonimbahy, Eddy; Dohlen, Kjetil; Savini, Giorgio; Marcos, Michel

    2016-08-01

    In the framework of the European FP7-FISICA (Far Infrared Space Interferometer Critical Assessment) program, we developed a miniaturized version of the hyper-telescope to demonstrate multi-aperture interferometry on ground. This setup would be ultimately integrated into a CubeSat platform, therefore providing the first real demonstrator of a multi aperture Fizeau interferometer in space. In this paper, we describe the optical design of the ground testbed and the data processing pipeline implemented to reconstruct the object image from interferometric data. As a scientific application, we measured the Sun diameter by fitting a limb-darkening model to our data. Finally, we present the design of a CubeSat platform carrying this miniature Fizeau interferometer, which could be used to monitor the Sun diameter over a long in-orbit period.

  18. Optical diameters of stars measured with the Mt. Wilson Mark III interferometer

    International Nuclear Information System (INIS)

    Simon, R.S.; Mozurkewich, D.; Johnston, K.J.; Gaume, R.; Hutter, D.J.; Bowers, P.F.; Colavita, M.M.; Shao, M.

    1990-01-01

    Reliable stellar angular diameters can now be determined using the Mark III Optical Interferometer located on Mt. Wilson, California. The Mark III is a Michelson Interferometer capable of measuring the interferometric fringe visibility for stars using interferometer baselines varying from 3 to 31.5 meters in length. Angular diameters measured with the Mark III Optical Interferometer are presented for 12 stars at wavelengths of 450 and 800 nm. 10 refs

  19. Optical displacement measurement with GaAs/AlGaAs-based monolithically integrated Michelson interferometers

    OpenAIRE

    Hofstetter, Daniel; Zappe, H. P.; Dändliker, René

    2008-01-01

    Two monolithically integrated optical displacement sensors fabricated in the GaAs/AlGaAs material system are reported. These single-chip microsystems are configured as Michelson interferometers and comprise a distributed Bragg reflector (DBR) laser, photodetectors, phase shifters, and waveguide couplers. While the use of a single Michelson interferometer allows measurement of displacement magnitude only, a double Michelson interferometer with two interferometer signals in phase quadrature als...

  20. Ultrasonic Linear Motor with Two Independent Vibrations

    Science.gov (United States)

    Muneishi, Takeshi; Tomikawa, Yoshiro

    2004-09-01

    We propose a new structure of an ultrasonic linear motor in order to solve the problems of high-power ultrasonic linear motors that drive the XY-stage for electron beam equipment and to expand the application fields of the motor. We pay special attention to the following three points: (1) the vibration in two directions of the ultrasonic linear motor should not influence mutually each other, (2) the vibration in two directions should be divided into the stage traveling direction and the pressing direction of the ultrasonic linear motor, and (3) the rigidity of the stage traveling direction of the ultrasonic linear motor should be increased. As a result, the supporting method of ultrasonic linear motors is simplified. The efficiency of the motor is improved and temperature rise is reduced. The stage position drift is also improved.

  1. Effect of Ultrasonic Frequency on Lactic Acid Fermentation Promotion by Ultrasonic Irradiation

    Science.gov (United States)

    Shimada, Tadayuki; Ohdaira, Etsuzo; Masuzawa, Nobuyoshi

    2004-05-01

    The authors have been researching the promotion of lactic acid fermentation by ultrasonic irradiation. In the past research, it was proven that ultrasonic irradiation is effective in the process of fermentation, and the production of yoghurt and kefir was promoted. In this study, the effect of the ultrasonic frequency in this fermentation process was examined. In the frequency range of this study, it was found that the action of fermentation promotion was exponentially proportionate to the irradiated ultrasonic frequency.

  2. Broadband sensitivity enhancement of detuned dual-recycled Michelson interferometers with EPR entanglement

    Science.gov (United States)

    Brown, Daniel D.; Miao, Haixing; Collins, Chris; Mow-Lowry, Conor; Töyrä, Daniel; Freise, Andreas

    2017-09-01

    We demonstrate the applicability of the EPR entanglement squeezing scheme for enhancing the shot-noise-limited sensitivity of detuned dual-recycled Michelson interferometers. In particular, this scheme is applied to the GEO600 interferometer. The effect of losses throughout the interferometer, arm length asymmetries, and imperfect separation of the signal and idler beams is considered.

  3. High-resolution ultrasonic spectroscopy

    Directory of Open Access Journals (Sweden)

    V. Buckin

    2018-03-01

    Full Text Available High-resolution ultrasonic spectroscopy (HR-US is an analytical technique for direct and non-destructive monitoring of molecular and micro-structural transformations in liquids and semi-solid materials. It is based on precision measurements of ultrasonic velocity and attenuation in analysed samples. The application areas of HR-US in research, product development, and quality and process control include analysis of conformational transitions of polymers, ligand binding, molecular self-assembly and aggregation, crystallisation, gelation, characterisation of phase transitions and phase diagrams, and monitoring of chemical and biochemical reactions. The technique does not require optical markers or optical transparency. The HR-US measurements can be performed in small sample volumes (down to droplet size, over broad temperature range, at ambient and elevated pressures, and in various measuring regimes such as automatic temperature ramps, titrations and measurements in flow.

  4. Ultrasonic inspection of austenitic welds

    Energy Technology Data Exchange (ETDEWEB)

    Tomlinson, J R; Wagg, A R; Whittle, M J [N.D.T. Applications Centre, CEGB, Manchester (United Kingdom)

    1980-11-01

    The metallurgical structure of austenitic welds is described and contrasted with that found in ferritic welds. It is shown that this structure imparts a marked elastic anisotropy in the ultrasonic propagation parameters. Measurements of variations in the apparent attenuation of sound and deviations in the beam direction are described. The measurements are interpreted in terms of the measured velocity anisotropy. Two applications of the fundamental work are described. In the first it is shown how, by using short pulse compression wave probes, and with major modification of the welding procedure, a stainless steel fillet weld in an AGR boiler can be inspected. In the second application, alternative designs of a transition butt weld have been compared for ease of ultrasonic inspection. The effects of two different welding processes on such an inspection are described. Finally, the paper examines the prospects for future development of inspection and defect-sizing techniques for austenitic welds. (author)

  5. Proposed new ultrasonic test bed

    International Nuclear Information System (INIS)

    Maxfield, B.W.

    1978-01-01

    Within the last four or five years, a great deal of progress has been made both here and in a number of other laboratories in developing techniques that will enable considerably more information to be obtained from the ultrasonic examination of an object. Some of these recent developments relate to information contained within the diffracted beam which does not return along the incident path. An ultrasonic examination based upon an evaluation of diffracted energy must use at least two transducers, one for transmission and the other for reception. Current indications are that even more reliable test results will be achieved using a receiving transducer that can scan a significant portion of the diffracted field including that portion which is back-reflected. In general, this scan can be interpreted most accurately if it follows a path related to the surface shape. If more than one region within the object is to be interrogated, then the transmitting transducer must also be scanned, again along a path related to the surface shape. The large quantity of information obtained as the result of such an examination must be subjected to sophisticated computer analysis in order to be displayed in a meaningful and intelligible manner. Although one motivation for building such an instrument is to explore new ultrasonic test procedures that are evolving from current laboratory research, this is neither the sole motivation nor the only use for this instrument. Such a mechanical and electronic device would permit conventional ultrasonic tests to be performed on parts of complex geometry without the expensive and time-consuming special fixturing that is currently required. May possible test geometries could be explored in practice prior to the construction of a specialized test apparatus. Hence, it would be necessary to design much, if any, flexibility into the special test apparatus

  6. Ultrasonic sizing of fatigue cracks

    International Nuclear Information System (INIS)

    Burns, D.J.

    1983-12-01

    Surface and buried fatigue cracks in steel plates have been sized using immersion probes as transmitters-receivers, angled to produce shear waves in the steel. Sizes have been estimated by identifying the ultrasonic waves diffracted from the crack tip and by measuring the time taken for a signal to travel to and from the crack tip. The effects of compression normal to a fatigue crack and of crack front curvature are discussed. Another diffraction technique, developed by UKAEA, Harwell, is reviewed

  7. Ultrasonic characterization of yogurt fermentation process

    OpenAIRE

    IZBAIM , DRIS; FAIZ , BOUAZZA; MOUDDEN , ALI; MALAININE , MOHAMED; ABOUDAOUD , Idriss

    2012-01-01

    International audience; The objective of this work is to characterize the fermentation of yogurt based on an ultrasonic technique. Conventionally, the acidity of the yogurt is measured by a pH meter to determine the progress of fermentation. However, the pH meter should be cleaned and calibrated for each measurement and, therefore, this method is not practical. In this regard, ultrasonic techniques are fast, non-invasive and inexpensive. The measurement of ultrasonic parameters such as amplit...

  8. Experimental investigation of ultrasonic velocity anisotropy in ...

    Indian Academy of Sciences (India)

    Permanent link: https://www.ias.ac.in/article/fulltext/pram/077/02/0345-0355. Keywords. Magnetic fluids; ultrasonic wave; sound velocity; anisotropy. Abstract. Magnetic field-induced dispersion of ultrasonic velocity in a Mn0.7Zn0.3Fe2O4 fluid (applied magnetic field is perpendicular to the ultrasonic propagation vector) is ...

  9. Automated ultrasonic inspection using PULSDAT

    International Nuclear Information System (INIS)

    Naybour, P.J.

    1992-01-01

    PULSDAT (Portable Ultrasonic Data Acquisition Tool) is a system for recording the data from single probe automated ultrasonic inspections. It is one of a range of instruments and software developed by Nuclear Electric to carry out a wide variety of high quality ultrasonic inspections. These vary from simple semi-automated inspections through to multi-probe, highly automated ones. PULSDAT runs under the control of MIPS software, and collects data which is compatible with the GUIDE data display system. PULSDAT is therefore fully compatible with Nuclear Electric's multi-probe inspection systems and utilises all the reliability and quality assurance of the software. It is a rugged, portable system that can be used in areas of difficult access. The paper discusses the benefits of automated inspection and gives an outline of the main features of PULSDAT. Since April 1990 PULSDAT has been used in several applications within Nuclear Electric and this paper presents two examples: the first is a ferritic set-through nozzle and the second is an austenitic fillet weld. (Author)

  10. Last technology and results from the IOTA interferometer

    Science.gov (United States)

    Pedretti, Ettore; Traub, Wesley A.; Monnier, John D.; Schuller, Peter A.; Ragland, Sam; Berger, Jean–Philippe; Millan-Gabet, Rafael; Wallace, Gary; Burke, Michael; Lacasse, Marc G.; Thureau, Nathalie D.; Carleton, Nathaniel

    2008-07-01

    The infrared optical telescope array (IOTA), one of the most productive interferometers in term of science and new technologies was decommissioned in summer 2006. We discuss the testing of a low-resolution spectrograph coupled with the IOTA-3T integrated-optics beam combiner and some of the scientific results obtained from this instrument.

  11. galario: Gpu Accelerated Library for Analyzing Radio Interferometer Observations

    Science.gov (United States)

    Tazzari, Marco; Beaujean, Frederik; Testi, Leonardo

    2017-10-01

    The galario library exploits the computing power of modern graphic cards (GPUs) to accelerate the comparison of model predictions to radio interferometer observations. It speeds up the computation of the synthetic visibilities given a model image (or an axisymmetric brightness profile) and their comparison to the observations.

  12. Quasi-quadrature interferometer for plasma density radial profile measurements

    International Nuclear Information System (INIS)

    Lowenthal, D.D.; Hoffman, A.L.

    1979-01-01

    A cw Mach Zehnder multichannel interferometer has been developed to measure time-dependent fractional fringe shifts with an accuracy of one-fortieth fringe. The design is quasi-quadrature in that known phase shifts, introduced in the reference beam, are time multiplexed with the normal reference beam. This technique requires only one detector per interferometer channel as compared to two detectors for most quadrature designs. The quadrature information makes the sense of density changes unambiguous, it automatically calibrates the instrument during the plasma event, and it makes fringe shift measurements virtually independent of fringe contrast fluctuations caused by plasma refractive and/or absorptive effects. The interferometer optical design is novel in that the electro-optic crystal used to introduce the 90 0 phase shifts is located in the common 2-mm-diam HeNe entrance beam to the interferometer, by exploiting polarization techniques, rather than in the expanded 1--2-cm reference beam itself. This arrangement greatly reduces the size, cost, and high-voltage requirements for the phase modulating crystal

  13. Talbot Carpet Simulation for X-ray grating interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youngju; Oh, Ohsung; Jeong, Hanseong; Kim, Jeongho; Lee, Seung Wook [Pusan National University, Busan (Korea, Republic of); Kim, Jongyul; Moon, Myungkook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    In this study, Talbot carpet simulator has been developed to visualize the X-ray grating interference patterns in grating interferometer. We have simulated X-ray interference for a variety of simulations and demonstrated a few examples in this summary. Grating interferometer produces interference of X-ray called Talbot pattern with gratings manufactured in micro scale. Talbot pattern is self-images of phase grating which develops interference as beam splitter that is one of gratings consisted of interferometer. As the other gratings, there are source grating makes coherence and analyze grating is used to analyze interference onto detector. Talbot carpet has been studied as the beam behavior which is distinguished with common X-ray imaging systems. It is helpful to understand grating interferometer and possible to expect beams' oscillation for designing theoretically. We confirm pattern has periodicity produced by interference after pi and pi/2 phase grating and changes in the perpendicular direction to entrance face according to phase objects.

  14. Virgo: a laser interferometer to detect gravitational waves

    NARCIS (Netherlands)

    Accadia, T.; van den Brand, J.F.J.; Bulten, H.J.; Ketel, T.J.; van der Voet, H.; Mul, F.A.; Rabeling, D.S.

    2012-01-01

    This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with 3 km-long arms. In this paper, following a presentation of the physics requirements, leading to the

  15. Off-Diagonal Geometric Phase in a Neutron Interferometer Experiment

    International Nuclear Information System (INIS)

    Hasegawa, Y.; Loidl, R.; Baron, M.; Badurek, G.; Rauch, H.

    2001-01-01

    Off-diagonal geometric phases acquired by an evolution of a 1/2 -spin system have been observed by means of a polarized neutron interferometer. We have successfully measured the off-diagonal phase for noncyclic evolutions even when the diagonal geometric phase is undefined. Our data confirm theoretical predictions and the results illustrate the significance of the off-diagonal phase

  16. Quantitative Phase Determination by Using a Michelson Interferometer

    Science.gov (United States)

    Pomarico, Juan A.; Molina, Pablo F.; D'Angelo, Cristian

    2007-01-01

    The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as…

  17. Measurement of Refractive Index Using a Michelson Interferometer.

    Science.gov (United States)

    Fendley, J. J.

    1982-01-01

    Describes a novel and simple method of measuring the refractive index of transparent plates using a Michelson interferometer. Since it is necessary to use a computer program when determining the refractive index, undergraduates could be given the opportunity of writing their own programs. (Author/JN)

  18. Correlation functions formed by a femtosecond pulse interferometer

    NARCIS (Netherlands)

    Cui, M.; Bhattacharya, N.; Urbach, H.P.; Van den berg, S.A.

    2008-01-01

    We experimentally demonstrate that a stabilized femtosecond frequency comb can be applied as a tool for distance measurement. The scheme is based on optical interference between individual pulses in a Michelson type interferometer. The cross-correlation functions between individual pulses with a

  19. Plasma flow velocity measurements using a modulated Michelson interferometer

    NARCIS (Netherlands)

    Howard, J.; Meijer, F. G.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (C) 1997 Elsevier Science S.A.

  20. Realization of an optical interferometer based on holographic optics ...

    Indian Academy of Sciences (India)

    The paper describes a simple and cost effective method for the realization of an optical interferometer based on holographic optics, which use minimal bulk optical components. The optical arrangement in the proposed method involves a very simple alignment procedure and inexpensive holographic recording material is ...

  1. Recent progress in online ultrasonic process monitoring

    Science.gov (United States)

    Wen, Szu-Sheng L.; Chen, Tzu-Fang; Ramos-Franca, Demartonne; Nguyen, Ky T.; Jen, Cheng-Kuei; Ihara, Ikuo; Derdouri, A.; Garcia-Rejon, Andres

    1998-03-01

    On-line ultrasonic monitoring of polymer co-extrusion and gas-assisted injection molding are presented. During the co- extrusion of high density polyethylene and Santoprene ultrasonic sensors consisting of piezoelectric transducers and clad ultrasonic buffer rods are used to detect the interface between these two polymers and the stability of the extrusion. The same ultrasonic sensor also measures the surface temperature of the extruded polymer. The results indicate that temperature measurements using ultrasound have a faster response time than those obtained by conventional thermocouple. In gas-assisted injection molding the polymer and gas flow front positions are monitored simultaneously. This information may be used to control the plunger movement.

  2. Internal ultrasonic inspection of flexible pipe

    Energy Technology Data Exchange (ETDEWEB)

    Baltzersen, O. (IKU Petroleumsforskning A/S, Trondheim (Norway) Norwegian Inst. of Tech., Trondheim (Norway). Div. of Petroleum Engineering and Applied Geophysics); Waag, T.I. (IKU Petroleumsforskning A/S, Trondheim (Norway))

    1993-10-01

    Methods for internal ultrasonic inspection of flexible pipe have been investigated through experiments with a short sample of Coflexip pipe. Ultrasonic backscatter methods using normal and non-normal incidence have been used for qualitative high contrast ultrasonic imaging of the inner surface of the pipe. Analysis of the internal cross-section has been performed based on the use of a non-contact ultrasonic caliper, and processing procedures which enable calculation of, and compensation for, eccentricity of the tool in the pipe. The methods developed can be used to quantitatively estimate the thickness of the internal carcass, and perform high resolution topographic mapping of the inner surface. (Author)

  3. Under sodium ultrasonic imaging system for PFBR

    International Nuclear Information System (INIS)

    Patankar, V.H.; Lalwani, S.K.; Agashe, A.A.

    2014-01-01

    Under Sodium UltraSonic Scanner (USUSS) has been developed to detect the growth and protrusion of fuel sub-assemblies of PFBR, submerged in liquid sodium by using the ultrasonic imaging technique during reactor shut-down when liquid sodium is at 180 ℃. The imaging is carried out prior to every Fuel handling operation. Electronics Division, BARC has designed and developed an 8-Channel Ultrasonic Imaging System (UIS) which consists of 4 downward viewing and 4 side viewing ultrasonic transducers alongwith pulser-receiver, signal processing electronics hardware and software. An automated mechanical scanner developed by IGCAR houses sodium immersible transducers to image the fuel sub assemblies. The system has been successfully tested with dummy protruding and grown FSAs, submerged under liquid sodium. Such ultrasonic imaging systems are not available to India from international market. The USUSS developed indigenously has all the features available in similar systems developed by other countries. After every imaging campaign, the mechanical scanner containing ultrasonic transducers is stored in the Argon filled storage-pit. Before every campaign of USUSS, it is necessary to check the healthiness of the sodium immersible and contaminated ultrasonic transducers, as the under-sodium scanner is decontaminated once in five years. For this purpose, a novel Non Contact Ultrasonic Inspection System (NCUIS) has been designed and developed by Electronics Division, BARC to check the functionality of the high-temperature and contaminated transducers of USUSS, using air-coupled ultrasonic technique. (author)

  4. Stresses in ultrasonically assisted bone cutting

    International Nuclear Information System (INIS)

    Alam, K; Mitrofanov, A V; Silberschmidt, V V; Baeker, M

    2009-01-01

    Bone cutting is a frequently used procedure in the orthopaedic surgery. Modern cutting techniques, such as ultrasonic assisted drilling, enable surgeons to perform precision operations in facial and spinal surgeries. Advanced understanding of the mechanics of bone cutting assisted by ultrasonic vibration is required to minimise bone fractures and to optimise the technique performance. The paper presents results of finite element simulations on ultrasonic and conventional bone cutting analysing the effects of ultrasonic vibration on cutting forces and stress distribution. The developed model is used to study the effects of cutting and vibration parameters (e.g. amplitude and frequency) on the stress distributions in the cutting region.

  5. Detection of Fatigue Damage by Using Frequency Attenuation of a Laser Ultrasonic Longitudinal Wave

    International Nuclear Information System (INIS)

    Park, Seung-Kyu; Baik, Sung-Hoon; Jung, Hyun-Kyu; Joo, Young-Sang; Cha, Hyung-Ki; Kang, Young-June

    2006-01-01

    The measurement of fatigue damage in nuclear power plant components is very important to prevent a catastrophic accident and the subsequent severe losses. Specifically, it is preferred to detect at an early stage of the fatigue damage. If the fatigue damage that is in danger of growing into a fracture is accurately detected, an appropriate treatment could be carried out to improve the condition. Although most engineers and designers take precautions against fatigue, some breakdowns of nuclear power plant components still occur due to fatigue damage. It is considered that ultrasound testing technique is the most promising method to detect the fatigue damage in many nondestructive testing methods. Ultrasound testing method has a variety of elastic waves, such as a longitudinal wave, a shear wave, a surface wave and a lamb wave. Also we can use various analysis methods, such as a velocity variation and a signal attenuation. Laser ultrasonic testing has attracted attention as a non-contact testing technique. This system consists of a pulse laser to remotely generate ultrasound and a laser interferometer to remotely measure the surface displacement due to the generated ultrasound. This noncontact testing technique has the following advantages over the conventional piezoelectric transducers. Firstly, the inspection system can be remotely operated for a structure in hostile environments, such as in high radioactivity, high temperatures and narrow spaces. Secondly, we can obtain lots of information from the received ultrasonic waveforms because the laser ultrasonic technique does not require fluid couplant which disturbs the ultrasonic waveforms. Thirdly, laser ultrasound has a wideband spectrum and a high spatial resolution. Therefore, the laser ultrasound provides more accurate information for a testing material and has potential for the detection of fatigue damage in various metals composing a nuclear power plant

  6. Comparison of the performance of the next generation of optical interferometers

    Science.gov (United States)

    Pisani, Marco; Yacoot, Andrew; Balling, Petr; Bancone, Nicola; Birlikseven, Cengiz; Çelik, Mehmet; Flügge, Jens; Hamid, Ramiz; Köchert, Paul; Kren, Petr; Kuetgens, Ulrich; Lassila, Antti; Bartolo Picotto, Gian; Şahin, Ersoy; Seppä, Jeremias; Tedaldi, Matthew; Weichert, Christoph

    2012-08-01

    Six European National Measurement Institutes (NMIs) have joined forces within the European Metrology Research Programme funded project NANOTRACE to develop the next generation of optical interferometers having a target uncertainty of 10 pm. These are needed for NMIs to provide improved traceable dimensional metrology that can be disseminated to the wider nanotechnology community, thereby supporting the growth in nanotechnology. Several approaches were followed in order to develop the interferometers. This paper briefly describes the different interferometers developed by the various partners and presents the results of a comparison of performance of the optical interferometers using an x-ray interferometer to generate traceable reference displacements.

  7. A study of microwave interferometers for electron density measurements in REB-plasma experiments

    International Nuclear Information System (INIS)

    Saxena, A.C.; Paithankar, A.S.; Iyyengar, S.K.; Rohatgi, V.K.

    1981-01-01

    In order to select a suitable microwave interferometer for electron density measurements in Relativistic Electron Beam (REB)-Plasma Experiments, a study has been carried out of four types of interferometers, viz. simple interferometer, standing-wave interferometer, frequency and phase modulated interferometers. Various direct reading interferometers which give a voltage proportional to the phase shift, are also discussed. Systems have been analysed in terms of time resolution, phase sensitivity, system stability, ease of measurement etc. Theoretical and experimental limitations of various systems have been indicated. Summary of the various systems is presented in a table to aid the experimentalist to select the most appropriate system for the prevailina experimental conditions. Finally, an attempt has been made to find out the interferometer system best suited for REB-Plasma Experiments. (author)

  8. Ultrasonic Abrasive Removal Of EDM Recast

    Science.gov (United States)

    Mandel, Johnny L.; Jacobson, Marlowe S.

    1990-01-01

    Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.

  9. Defect detection and sizing in ultrasonic imaging

    International Nuclear Information System (INIS)

    Moysan, J.; Benoist, P.; Chapuis, N.; Magnin, I.

    1991-01-01

    This paper introduces imaging processing developed with the SPARTACUS system in the field of ultrasonic testing. The aim of the imaging processing is to detect and to separate defects echoes from background noise. Image segmentation and particularities of ultrasonic images are the base of studied methods. 4 figs.; 6 refs [fr

  10. Reproducibility of the results in ultrasonic testing

    International Nuclear Information System (INIS)

    Chalaye, M.; Launay, J.P.; Thomas, A.

    1980-12-01

    This memorandum reports on the conclusions of the tests carried out in order to evaluate the reproducibility of ultrasonic tests made on welded joints. FRAMATOME have started a study to assess the dispersion of results afforded by the test line and to characterize its behaviour. The tests covered sensors and ultrasonic generators said to be identical to each other (same commercial batch) [fr

  11. Backward ray tracing for ultrasonic imaging

    NARCIS (Netherlands)

    Breeuwer, R.

    1990-01-01

    Focused ultrasonic beams frequently pass one or more media interfaces, strongly affecting the ultrasonic beamshape and focusing. A computer program, based on backward ray tracing was developed to compute the shape of a corrected focusing mirror. This shape is verified with another program; then the

  12. Beat-Frequency/Microsphere Medical Ultrasonic Imaging

    Science.gov (United States)

    Yost, William T.; Cantrell, John H.; Pretlow, Robert A., III

    1995-01-01

    Medical ultrasonic imaging system designed to provide quantitative data on various flows of blood in chambers, blood vessels, muscles, and tissues of heart. Sensitive enough to yield readings on flows of blood in heart even when microspheres used as ultrasonic contrast agents injected far from heart and diluted by circulation of blood elsewhere in body.

  13. Compact all-fiber interferometer system for shock acceleration measurement

    Science.gov (United States)

    Zhao, Jiang; Pi, Shaohua; Hong, Guangwei; Zhao, Dong; Jia, Bo

    2013-08-01

    Acceleration measurement plays an important role in a variety of fields in science and engineering. In particular, the accurate, continuous and non-contact recording of the shock acceleration profiles of the free target surfaces is considered as a critical technique in shock physics. Various kinds of optical interferometers have been developed to monitor the motion of the surfaces of shocked targets since the 1960s, for instance, the velocity interferometer system for any reflector, the fiber optic accelerometer, the photonic Doppler velocimetry system and the displacement interferometer. However, most of such systems rely on the coherent quasi-monochromatic illumination and discrete optic elements, which are costly in setting-up and maintenance. In 1996, L. Levin et al reported an interferometric fiber-optic Doppler velocimeter with high-dynamic range, in which fiber-coupled components were used to replace the discrete optic elements. However, the fringe visibility of the Levin's system is low because of the coupled components, which greatly limits the reliability and accuracy in the shock measurement. In this paper, a compact all-fiber interferometer system for measuring the shock acceleration is developed and tested. The advantage of the system is that not only removes the non-interfering light and enhances the fringe visibility, but also reduces polarization induced signal fading and the polarization induced phase shift. Moreover, it also does not require a source of long coherence length. The system bases entirely on single-mode fiber optics and mainly consists of a polarization beam splitter, a faraday rotator, a depolarizer and a 3×3 single-mode fiber coupler which work at 1310 nm wavelength. The optical systems of the interferometer are described and the experimental results compared with a shock acceleration calibration system with a pneumatic exciter (PneuShockTM Model 9525C by The Modal Shop) are reported. In the shock acceleration test, the

  14. The Dynamic Performance of Flexural Ultrasonic Transducers

    Directory of Open Access Journals (Sweden)

    Andrew Feeney

    2018-01-01

    Full Text Available Flexural ultrasonic transducers are principally used as proximity sensors and for industrial metrology. Their operation relies on a piezoelectric ceramic to generate a flexing of a metallic membrane, which delivers the ultrasound signal. The performance of flexural ultrasonic transducers has been largely limited to excitation through a short voltage burst signal at a designated mechanical resonance frequency. However, a steady-state amplitude response is not generated instantaneously in a flexural ultrasonic transducer from a drive excitation signal, and differences in the drive characteristics between transmitting and receiving transducers can affect the measured response. This research investigates the dynamic performance of flexural ultrasonic transducers using acoustic microphone measurements and laser Doppler vibrometry, supported by a detailed mechanical analog model, in a process which has not before been applied to the flexural ultrasonic transducer. These techniques are employed to gain insights into the physics of their vibration behaviour, vital for the optimisation of industrial ultrasound systems.

  15. Plasma Sterilizer with Ultrasonic Cavitation

    International Nuclear Information System (INIS)

    Krasnyj, V.V.; Klosovsky, A.V.; Panasko, T.A.; Shvets, O.M.; Semenova, O.T.; Taran, V.S.; Tereshin, V.I.

    2006-01-01

    A sterilizer consists of ozone generator based on a barrier glow discharge with the flat electrodes covered with dielectric with a high-voltage pulsed power supply of up to 250 W (1). The sterilization camera is equipped with ultrasonic source with the power of 100 W. The experiments on the inactivation of bacteria of the Bacillus Cereus type were carried out in the distilled water saturated by ozone. Ozone concentration in the aqueous solution was 6 mg/liter with ozone concentration at the output of ozone generator 30 mg/liter. The complete inactivation of spores took 15 min

  16. Ultrasonic imaging of projected components of PFBR

    Energy Technology Data Exchange (ETDEWEB)

    Sylvia, J.I., E-mail: sylvia@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Jeyan, M.R.; Anbucheliyan, M.; Asokane, C.; Babu, V. Rajan; Babu, B.; Rajan, K.K.; Velusamy, K.; Jayakumar, T. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

    2013-05-15

    Highlights: ► Under sodium ultrasonic scanner in PFBR is for detecting protruding objects. ► Feasibility study for detecting Absorber rods and its drive mechanisms. ► Developed in-house PC based ultrasonic imaging system. ► Different case studies were carried out on simulated ARDM's. ► Implemented the experimental results to PFBR application. -- Abstract: The 500 MWe, sodium cooled, Prototype Fast Breeder Reactor (PFBR) is under advanced stage of construction at Kalpakkam in India. Opacity of sodium restricts visual inspection of components immersed in sodium by optical means. Ultrasonic wave passes through sodium hence ultrasonic techniques using under sodium ultrasonic scanners are developed to obtain under sodium images. The main objective of such an Under Sodium Ultrasonic Scanner (USUSS) for Prototype Fast Breeder Reactor (PFBR) is to detect and ensure that no core Sub Assembly (SA) or Absorber Rod or its Drive Mechanism is protruded in the above core plenum before starting the fuel handling operation. Hence, it is necessary to detect and locate the object, if it is protruding the above core plenum. To study the feasibility of detecting the absorber rods and their drive mechanisms using direct ultrasonic imaging technique, experiments were carried out for different orientations and profiles of the projected components in a 5 m diameter water tank. The in-house developed PC based ultrasonic scanning system is used for acquisition and analysis of data. The pseudo three dimensional color images obtained are discussed and the results are applicable for PFBR. This paper gives the details of the features of the absorber rods and their drive mechanisms, their orientation in the reactor core, experimental setup, PC based ultrasonic scanning system, ultrasonic images and the discussion on the results.

  17. Fundamental study of microelectronic chip response under laser ultrasonic-interferometric inspection using C-scan method

    Science.gov (United States)

    Yang, Lei; Gong, Jie; Ume, I. Charles

    2014-02-01

    In modern surface mount packaging technologies, such as flip chips, chip scale packages, and ball grid arrays(BGA), chips are attached to the substrates/printed wiring board (PWB) using solder bump interconnections. The quality of solder bumps between the chips and the substrate/board is difficult to inspect. Laser ultrasonic-interferometric technique was proved to be a promising approach for solder bump inspection because of its noncontact and nondestructive characteristics. Different indicators extracted from received signals have been used to predict the potential defects, such as correlation coefficient, error ratio, frequency shifting, etc. However, the fundamental understanding of the chip behavior under laser ultrasonic inspection is still missing. Specifically, it is not sure whether the laser interferometer detected out-of-plane displacements were due to wave propagation or structural vibration when the chip was excited by pulsed laser. Plus, it is found that the received signals are chip dependent. Both challenges impede the interpretation of acquired signals. In this paper, a C-scan method was proposed to study the underlying phenomenon during laser ultrasonic inspection. The full chip was inspected. The response of the chip under laser excitation was visualized in a movie resulted from acquired signals. Specifically, a BGA chip was investigated to demonstrate the effectiveness of this method. By characterizing signals using discrete wavelet transform(DWT), both ultrasonic wave propagation and vibration were observed. Separation of them was successfully achieved using ideal band-pass filter and visualized in resultant movies, too. The observed ultrasonic waves were characterized and their respective speeds were measured by applying 2-D FFT. The C-scan method, combined with different digital signal processing techniques, was proved to be an very effective methodology to learn the behavior of chips under laser excitation. This general procedure can be

  18. Density Measurement of Compact Toroid with Mach-Zehnder Interferometer

    Science.gov (United States)

    Laufman-Wollitzer, Lauren; Endrizzi, Doug; Brookhart, Matt; Flanagan, Ken; Forest, Cary

    2016-10-01

    Utilizing a magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy, a dense compact toroid (CT) is created and injected at high speed into the Wisconsin Plasma Astrophysics Laboratory (WiPAL) vessel. A modified Mach-Zehnder interferometer from the Line-Tied Reconnection Experiment (LTRX) provides an absolute measurement of electron density. The interferometer is located such that the beam intersects the plasma across the diameter of the MCPG drift region before the CT enters the vessel. This placement ensures that the measurement is taken before the CT expand. Results presented will be used to further analyze characteristics of the CT. Funding provided by DoE, NSF, and WISE Summer Research.

  19. Report on the set-up of a holographic interferometer

    International Nuclear Information System (INIS)

    Koster, J.N.

    1977-10-01

    Holographic interferometry is well suited for visualizing temperature, density, pressure and concentration fields in transparent fluids. The holographic real-time interferometer allows a continuous observation of stationary and instationary flow processes. After the explanation of the measuring technique, the problems arising during the interferometer set-up as well as the necessary adjusting operations are described. For heat transfer problems new possibilities for the application of holographic interferometry are revealed. Convection in boxes, temperature fields around heated or cooled bodies, concentration and diffusion processes in two phase-flows, mixtures and solutions as well as melting and freezing processes may be investigated. On the basis of particular examples some applications are presented. (orig.) [de

  20. Quantum light in coupled interferometers for quantum gravity tests.

    Science.gov (United States)

    Ruo Berchera, I; Degiovanni, I P; Olivares, S; Genovese, M

    2013-05-24

    In recent years quantum correlations have received a lot of attention as a key ingredient in advanced quantum metrology protocols. In this Letter we show that they provide even larger advantages when considering multiple-interferometer setups. In particular, we demonstrate that the use of quantum correlated light beams in coupled interferometers leads to substantial advantages with respect to classical light, up to a noise-free scenario for the ideal lossless case. On the one hand, our results prompt the possibility of testing quantum gravity in experimental configurations affordable in current quantum optics laboratories and strongly improve the precision in "larger size experiments" such as the Fermilab holometer; on the other hand, they pave the way for future applications to high precision measurements and quantum metrology.

  1. Femto-second synchronisation with a waveguide interferometer

    Science.gov (United States)

    Dexter, A. C.; Smith, S. J.; Woolley, B. J.; Grudiev, A.

    2018-03-01

    CERN's compact linear collider CLIC requires crab cavities on opposing linacs to rotate bunches of particles into alignment at the interaction point (IP). These cavities are located approximately 25 metres either side of the IP. The luminosity target requires synchronisation of their RF phases to better than 5 fs r.m.s. This is to be achieved by powering both cavities from one high power RF source, splitting the power and delivering it along two waveguide paths that are controlled to be identical in length to within a micrometre. The waveguide will be operated as an interferometer. A high power phase shifter for adjusting path lengths has been successfully developed and operated in an interferometer. The synchronisation target has been achieved in a low power prototype system.

  2. A Fiber Interferometer for the Magnetized Shock Experiment

    International Nuclear Information System (INIS)

    Yoo, Christian

    2012-01-01

    The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory requires remote diagnostics of plasma density. Laser interferometry can be used to determine the line-integrated density of the plasma. A multi-chord heterodyne fiber optic Mach-Zehnder interferometer is being assembled and integrated into the experiment. The advantage of the fiber coupling is that many different view chords can be easily obtained by simply moving transmit and receive fiber couplers. Several such fiber sets will be implemented to provide a time history of line-averaged density for several chords at once. The multiple chord data can then be Abel inverted to provide radially resolved spatial profiles of density. We describe the design and execution of this multiple fiber interferometer.

  3. Crosstalk Cancellation for a Simultaneous Phase Shifting Interferometer

    Science.gov (United States)

    Olczak, Eugene (Inventor)

    2014-01-01

    A method of minimizing fringe print-through in a phase-shifting interferometer, includes the steps of: (a) determining multiple transfer functions of pixels in the phase-shifting interferometer; (b) computing a crosstalk term for each transfer function; and (c) displaying, to a user, a phase-difference map using the crosstalk terms computed in step (b). Determining a transfer function in step (a) includes measuring intensities of a reference beam and a test beam at the pixels, and measuring an optical path difference between the reference beam and the test beam at the pixels. Computing crosstalk terms in step (b) includes computing an N-dimensional vector, where N corresponds to the number of transfer functions, and the N-dimensional vector is obtained by minimizing a variance of a modulation function in phase shifted images.

  4. Development of measurement system for gauge block interferometer

    Science.gov (United States)

    Chomkokard, S.; Jinuntuya, N.; Wongkokua, W.

    2017-09-01

    We developed a measurement system for collecting and analyzing the fringe pattern images from a gauge block interferometer. The system was based on Raspberry Pi which is an open source system with python programming and opencv image manipulation library. The images were recorded by the Raspberry Pi camera with five-megapixel capacity. The noise of images was suppressed for the best result in analyses. The low noise images were processed to find the edge of fringe patterns using the contour technique for the phase shift analyses. We tested our system with the phase shift patterns between a gauge block and a reference plate. The phase shift patterns were measured by a Twyman-Green type of interferometer using the He-Ne laser with the temperature controlled at 20.0 °C. The results of the measurement will be presented and discussed.

  5. Beating quantum limits in interferometers with quantum locking of mirrors

    International Nuclear Information System (INIS)

    Heidmann, Antoine; Courty, Jean-Michel; Pinard, Michel; Lebars, Julien

    2004-01-01

    The sensitivity in interferometric measurements such as those made by gravitational-wave detectors is ultimately limited by the quantum noise of light. We discuss the use of feedback mechanisms to reduce the quantum effects of radiation pressure. Recent experiments have shown that it is possible to reduce the thermal motion of a mirror by cold damping. The mirror motion is measured with an optomechanical sensor based on a high-finesse cavity, and reduced by a feedback loop. We show that this technique can be extended to lock the mirror at the quantum level. In gravitational-wave interferometers with Fabry-Perot cavities in each arm, it is even possible to use a single feedback mechanism to lock one cavity mirror on the other. This quantum locking greatly improves the sensitivity of the interferometric measurement. It is furthermore insensitive to imperfections such as losses in the interferometer

  6. Sun Radio Interferometer Space Experiment (SunRISE)

    Science.gov (United States)

    Kasper, Justin C.; SunRISE Team

    2018-06-01

    The Sun Radio Interferometer Space Experiment (SunRISE) is a NASA Heliophysics Explorer Mission of Opportunity currently in Phase A. SunRISE is a constellation of spacecraft flying in a 10-km diameter formation and operating as the first imaging radio interferometer in space. The purpose of SunRISE is to reveal critical aspects of solar energetic particle (SEP) acceleration at coronal mass ejections (CMEs) and transport into space by making the first spatially resolved observations of coherent Type II and III radio bursts produced by electrons accelerated at CMEs or released from flares. SunRISE will focus on solar Decametric-Hectometric (DH, 0.1 space before major SEP events, but cannot be seen on Earth due to ionospheric absorption. This talk will describe SunRISE objectives and implementation. Presented on behalf of the entire SunRISE team.

  7. Measurement of Local Gravity via a Cold Atom Interferometer

    International Nuclear Information System (INIS)

    Zhou Lin; Xiong Zong-Yuan; Yang Wei; Tang Biao; Peng Wen-Cui; Wang Yi-Bo; Xu Peng; Wang Jin; Zhan Ming-Sheng

    2011-01-01

    We demonstrate a precision measurement of local gravity acceleration g in Wuhan by a compact cold atom interferometer. The atom interferometer is in vertical Mach—Zehnder configuration realized using a π/2 - π - π/2 Raman pulse sequence. Cold atoms were prepared in a magneto-optical trap, launched upward to form an atom fountain, and then coherently manipulated to interfere by stimulated Raman transition. Population signal vs Raman laser phase was recorded as interference fringes, and the local gravity was deduced from the interference signal. We have obtained a resolution of 7 × 10 −9 g after an integration time of 236s under the best vibrational environment conditions. The absolute g value was derived from the chirp rate with a difference of 1.5 × 10 −7 g compared to the gravity reference value. The tidal phenomenon was observed by continuously monitoring the local gravity over 123 h. (atomic and molecular physics)

  8. Optical-fiber interferometer for velocity measurements with picosecond resolution

    International Nuclear Information System (INIS)

    Weng Jidong; Tan Hua; Wang Xiang; Ma Yun; Hu Shaolou; Wang Xiaosong

    2006-01-01

    The conventional Doppler laser-interference velocimeters are made up of traditional optical elements such as lenses and mirrors and will generally restrict its applications in multipoint velocity measurements. By transfering the light from multimode optical fiber to single-mode optical fiber and using the currently available conventional telecommunications elements, the authors have constructed a velocimeter called all-fiber displacement interferometer system for any reflector. The unique interferometer system is only made up of fibers or fiber-coupled components. The viability of this technique is demonstrated by measuring the velocity of an interface moving at velocity of 2133 m/s with 50 ps time resolution. In addition, the concept of optical-fiber mode conversion would provide a way to develop various optical-fiber sensors

  9. The Michelson interferometer-how to detect invisible interference patterns

    International Nuclear Information System (INIS)

    Verovnik, Ivo; Likar, Andrej

    2004-01-01

    In a Michelson interferometer, the contrast of the interference pattern fades away due to incoherence of light when the mirrors are not in equidistant positions. We propose an experiment where the distance between the interference fringes can be determined, even when the difference in length of the interferometer arms is far beyond the coherence length of the light, i.e. when the interference pattern disappears completely for the naked eye. We used a semiconductor laser with two photodiodes as sensors, which enabled us to follow the fluctuations of the light intensity on the screen. The distance between invisible interference fringes was determined from periodic changes of the summed fluctuating signal, obtained by changing the distance between the two sensors

  10. On-chip Mach-Zehnder interferometer for OCT systems

    Science.gov (United States)

    van Leeuwen, Ton G.; Akca, Imran B.; Angelou, Nikolaos; Weiss, Nicolas; Hoekman, Marcel; Leinse, Arne; Heideman, Rene G.

    2018-04-01

    By using integrated optics, it is possible to reduce the size and cost of a bulky optical coherence tomography (OCT) system. One of the OCT components that can be implemented on-chip is the interferometer. In this work, we present the design and characterization of a Mach-Zehnder interferometer consisting of the wavelength-independent splitters and an on-chip reference arm. The Si3N4 was chosen as the material platform as it can provide low losses while keeping the device size small. The device was characterized by using a home-built swept source OCT system. A sensitivity value of 83 dB, an axial resolution of 15.2 μm (in air) and a depth range of 2.5 mm (in air) were all obtained.

  11. First 2.2 micrometer results from the iota interferometer

    Science.gov (United States)

    Dyck, H. M.; Benson, J. A.; Carlton, N. P.; Coldwell, C.; Lacasse, M. G.; Nisenson, P.; Panasyuk, A.; Papaliolios, C.; Pearlman, R. D.; Reasenberg, R. D.

    1995-01-01

    We present the first infrared fringe visibility measurements made with the Infrared Optical Telescope Array on Mt. Hopkins. Effective temperatures are derived for RX Boo, RS Cnc, and Beta Peg. RX Boo is the coolest small-amplitude variable giant star to have an effective temperature determination. We compare the size of its photosphere at infrared wavelengths with the sizes of its SiO and H20 radio emission regions. We also discuss initial performance parameters for the interferometer.

  12. NEuclid: a long-range tilt-immune homodyne interferometer

    Science.gov (United States)

    Bradshaw, M. J.; Speake, C. C.

    2017-11-01

    The new Easy to Use Compact Laser Interferometric Device (nEUCLID) is a polarisation-based homodyne interferometer with substantially unequal arms that is tolerant to target mirror tilt. The design has no active components, uses standard optical components of 25 mm diameter, has a working distance of 706 mm and a reference arm-length of 21 mm. nEUCLID optics have a footprint of 210 x 190 x 180 mm, and has a tolerance to target mirror tilt of +/- 0.5 degrees, made possible by a novel new retro-reflector design [1]. nEUCLID was built to a set of specifications laid down by Airbus Defence and Space, who required a lowmass, low-power device to measure displacement with nanometre accuracy for space applications. At the University of Birmingham we have previously built a smaller, more compact tilt-insensitive homodyne interferometer - the EUCLID [2, 3, 4] - which has a working distance of 6 mm, a working range of +/- 3 mm, and a tilt range of +/- 1° [2]. We created a new optical design to allow a much larger working distance to be achieved (as discussed in Section II) and used this in a new interferometer - the nEUCLID. Section II describes the interferometer in detail; how nEUCLID is tilt insensitive, and the optical configuration. Section III states the design specifications from Airbus Defence and Space and the components used in the final design. The output interference pattern from nEUCLID, and how it has been corrected with a meniscus lens, is also discussed. In Section IV we discuss the results demonstrating the tilt immunity range, and the sensitivity of the device. Section V describes several potential applications of nEUCLID, and Section VI draws together our conclusions.

  13. Fundamental limits of radio interferometers: calibration and source parameter estimation

    OpenAIRE

    Trott, Cathryn M.; Wayth, Randall B.; Tingay, Steven J.

    2012-01-01

    We use information theory to derive fundamental limits on the capacity to calibrate next-generation radio interferometers, and measure parameters of point sources for instrument calibration, point source subtraction, and data deconvolution. We demonstrate the implications of these fundamental limits, with particular reference to estimation of the 21cm Epoch of Reionization power spectrum with next-generation low-frequency instruments (e.g., the Murchison Widefield Array -- MWA, Precision Arra...

  14. Optical analysis and alignment applications using the infrared Smartt interferometer

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Bolen, P.D.; Liberman, I.; Seery, B.D.

    1981-01-01

    The possibility of using the infrared Smartt interferometer for optical analysis and alignment of infrared laser systems has been discussed previously. In this paper, optical analysis of the Gigawatt Test Facility at Los Alamos, as well as a deformable mirror manufactured by Rocketdyne, are discussed as examples of the technique. The possibility of optically characterizing, as well as aligning, pulsed high energy laser systems like Helios and Antares is discussed in some detail

  15. Phase correction for a Michelson interferometer with misaligned mirrors

    Science.gov (United States)

    Goorvitch, D.

    1975-01-01

    The phase correction for a Michelson interferometer with misaligned mirrors in converging light is shown to give rise to a quadratic phase shift. In general, the calculation of a spectrum from the measured interferogram needs phase correction. Phase corrections have been well worked out for the cases of a linear phase shift and a phase that is slowly varying. The standard procedures for correcting calculated spectra need to be modified, however, to remove any phase errors resulting from misaligned mirrors.

  16. Infrared spectra of lunar soils. [using a Michelson interferometer

    Science.gov (United States)

    Aronson, J. R.; Emslie, A. G.; Smith, E. M.

    1979-01-01

    Measured data obtained by Michelson interferometer spectrometer were stored in a computer file and smoothed by being passed forward and backward through a digital four-pole low pass filter. Infrared spectra of the 10 lunar samples are presented in the format of brightness temperature versus frequency. The mol % of feldspar, pyroxene, olivine, ilmenite and ferromagnetic silicate in each sample is presented in tables. The reflectance spectra of ilmenite and enstatite are shown in graphs.

  17. Fiber inline Michelson interferometer fabricated by a femtosecond laser.

    Science.gov (United States)

    Yuan, Lei; Wei, Tao; Han, Qun; Wang, Hanzheng; Huang, Jie; Jiang, Lan; Xiao, Hai

    2012-11-01

    A fiber inline Michelson interferometer was fabricated by micromachining a step structure at the tip of a single-mode optical fiber using a femtosecond laser. The step structure splits the fiber core into two reflection paths and produces an interference signal. A fringe visibility of 18 dB was achieved. Temperature sensing up to 1000°C was demonstrated using the fabricated assembly-free device.

  18. 21 CFR 882.1925 - Ultrasonic scanner calibration test block.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic scanner calibration test block. 882... Ultrasonic scanner calibration test block. (a) Identification. An ultrasonic scanner calibration test block is a block of material with known properties used to calibrate ultrasonic scanning devices (e.g., the...

  19. Ultrasonic relaxations in borate glasses

    International Nuclear Information System (INIS)

    D'Angelo, G.; Tripodo, G.; Carini, G.; Cosio, E.; Bartolotta, A.; Di Marco, G.

    2004-01-01

    The attenuation and velocity of ultrasonic waves of frequencies in the range from 10 to 70 MHz have been measured in M 2 O-B 2 O 3 borate glasses (M: Li or Ag) as a function of temperature between 15 and 350 K. The velocity of sound waves decreases with increasing temperature in all the glasses, the decrease as the temperature is increased is larger in glasses containing silver than in those with lithium. A broad relaxation peak characterises the attenuation behaviour of the lithium and silver borate glasses at temperatures below 100 K and is paralleled by a corresponding dispersive behaviour of the sound velocity. Above 100 K, the ultrasonic velocity shows a nearly linear behaviour regulated by the vibrational anharmonicity, which decreases with increasing content of modifier oxide and is smaller in lithium than in silver borates. These results suggest that the relaxation of structural defects and the anharmonicity of borate glasses are strongly affected by two parameters: the number of bridging bonds per network forming ion and the polarising power of network modifier ions which occupy sites in the existing interstices

  20. Dynamics of ultrasonic additive manufacturing.

    Science.gov (United States)

    Hehr, Adam; Dapino, Marcelo J

    2017-01-01

    Ultrasonic additive manufacturing (UAM) is a solid-state technology for joining similar and dissimilar metal foils near room temperature by scrubbing them together with ultrasonic vibrations under pressure. Structural dynamics of the welding assembly and work piece influence how energy is transferred during the process and ultimately, part quality. To understand the effect of structural dynamics during UAM, a linear time-invariant model is proposed to relate the inputs of shear force and electric current to resultant welder velocity and voltage. Measured frequency response and operating performance of the welder under no load is used to identify model parameters. Using this model and in-situ measurements, shear force and welder efficiency are estimated to be near 2000N and 80% when welding Al 6061-H18 weld foil, respectively. Shear force and welder efficiency have never been estimated before in UAM. The influence of processing conditions, i.e., welder amplitude, normal force, and weld speed, on shear force and welder efficiency are investigated. Welder velocity was found to strongly influence the shear force magnitude and efficiency while normal force and weld speed showed little to no influence. The proposed model is used to describe high frequency harmonic content in the velocity response of the welder during welding operations and coupling of the UAM build with the welder. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Deconvolution algorithms applied in ultrasonics

    International Nuclear Information System (INIS)

    Perrot, P.

    1993-12-01

    In a complete system of acquisition and processing of ultrasonic signals, it is often necessary at one stage to use some processing tools to get rid of the influence of the different elements of that system. By that means, the final quality of the signals in terms of resolution is improved. There are two main characteristics of ultrasonic signals which make this task difficult. Firstly, the signals generated by transducers are very often non-minimum phase. The classical deconvolution algorithms are unable to deal with such characteristics. Secondly, depending on the medium, the shape of the propagating pulse is evolving. The spatial invariance assumption often used in classical deconvolution algorithms is rarely valid. Many classical algorithms, parametric and non-parametric, have been investigated: the Wiener-type, the adaptive predictive techniques, the Oldenburg technique in the frequency domain, the minimum variance deconvolution. All the algorithms have been firstly tested on simulated data. One specific experimental set-up has also been analysed. Simulated and real data has been produced. This set-up demonstrated the interest in applying deconvolution, in terms of the achieved resolution. (author). 32 figs., 29 refs

  2. Ultrasonic Characterization of Aerospace Composites

    Science.gov (United States)

    Leckey, Cara; Johnston, Patrick; Haldren, Harold; Perey, Daniel

    2015-01-01

    Composite materials have seen an increased use in aerospace in recent years and it is expected that this trend will continue due to the benefits of reduced weight, increased strength, and other factors. Ongoing work at NASA involves the investigation of the large-scale use of composites for spacecraft structures (SLS components, Orion Composite Crew Module, etc). NASA is also involved in work to enable the use of composites in advanced aircraft structures through the Advanced Composites Project (ACP). In both areas (space and aeronautics) there is a need for new nondestructive evaluation and materials characterization techniques that are appropriate for characterizing composite materials. This paper will present an overview of NASA's needs for characterizing aerospace composites, including a description of planned and ongoing work under ACP for the detection of composite defects such as fiber waviness, reduced bond strength, delamination damage, and microcracking. The research approaches include investigation of angle array, guided wave, and phase sensitive ultrasonic methods. The use of ultrasonic simulation tools for optimizing and developing methods will also be discussed.

  3. Ultrasonic inspection of inpile tubes

    International Nuclear Information System (INIS)

    Boyd, D.M.; Bossi, H.

    1985-01-01

    The in-service inspection (ISI) of inpile tubes can be performed accurately and safely with a semiautomatic ultrasonic inspection system. The ultrasonic technique uses a set of multiple transducers to detect and size cracks, voids, and laminations radially and circumferentially. Welds are also inspected for defects. The system is designed to inspect stainless steel and Inconel tubes ranging from 53.8 mm (2.12 in.) to 101.6 mm (4 in.) inner diameter with wall thickness on the order of 5 mm. The inspection head contains seven transducers mounted in a surface-following device. Six angle-beam transducers generate shear waves in the tubes. Two of the six are oriented to detect circumferential cracks, and two detect axial cracks. Although each of these four transducers is used in the pulse-echo mode, they are oriented in aligned sets so pitch-catch operation is possible if desired. The remaining angle-beam transducers are angulated to detect flaws that are off axial or circumferential orientation. The seventh transducer is used for longitudinal inspection and detects and sizes laminar-type defects

  4. Calculations for piezoelectric ultrasonic transducers

    International Nuclear Information System (INIS)

    Jensen, H.

    1986-05-01

    Analysis of piezoelectric ultrasonic transducers implies a solution of a boundary value problem, for a body which consists of different materials, including a piezoelectric part. The problem is dynamic at frequencies, where a typical wavelength is somewhat less than the size of the body. Radiation losses as well as internal losses may be important. Due to the complexity of the problem, a closed form solution is the exception rather than the rule. For this reason, it is necessary to use approximate methods for the analysis. Equivalent circuits, the Rayleigh-Ritz method, Mindlin plate theory and in particular the finite element method are considered. The finite element method is utilized for analysis of axisymmetric transducers. An explicit, fully piezoelectric, triangular ring element, with linear variations in displacement and electric potential is given. The influence of a fluid half-space is also given, in the form of a complex stiffness matrix. A special stacking procedure, for analysis of the backing has been developed. This procedure gives a saving, which is similar to that of the fast fourier transform algorithm, and is also wellsuited for analysis of finite and infinite waveguides. Results obtained by the finite element method are shown and compared with measurements and exact solutions. Good agreement is obtained. It is concluded that the finite element method can be a valueable tool in analysis and design of ultrasonic transducers. (author)

  5. Analysis of a quantum nondemolition speed-meter interferometer

    International Nuclear Information System (INIS)

    Purdue, Patricia

    2002-01-01

    In the quest to develop viable designs for third-generation optical interferometric gravitational-wave detectors (e.g. LIGO-III and EURO), one strategy is to monitor the relative momentum or speed of the test-mass mirrors rather than monitoring their relative position. This paper describes and analyzes the most straightforward design for a speed meter interferometer that accomplishes this--a design (due to Braginsky, Gorodetsky, Khalili and Thorne) that is analogous to a microwave-cavity speed meter conceived by Braginsky and Khalili. A mathematical mapping between the microwave speed meter and the optical interferometric speed meter is developed and is used to show [in accord with the speed being a quantum nondemolition observable] that in principle the interferometric speed meter can beat the gravitational-wave standard quantum limit (SQL) by an arbitrarily large amount, over an arbitrarily wide range of frequencies, and can do so without the use of squeezed vacuum or any auxiliary filter cavities at the interferometer's input or output. However, in practice, to reach or beat the SQL, this specific speed meter requires exorbitantly high input light power. The physical reason for this is explored, along with other issues such as constraints on performance due to optical dissipation. This analysis forms a foundation for ongoing attempts to develop a more practical variant of an interferometric speed meter and to combine the speed meter concept with other ideas to yield a promising LIGO-III/EURO interferometer design that entails low laser power

  6. Intensity profiles behind a five-stage neutron interferometer

    International Nuclear Information System (INIS)

    Kischko, U.

    1983-01-01

    By means of the quantitative photography intensity profiles behind a five-stage ideal-crystal neutron interferometer at the thermal channel H25 of the high-flux reactor at the institute Laue-Langevin in Grenoble/France were dermined and compared with theoretical profiles. Contravily to X-rays by neutrons the hole Borrmann range is excited. This leads in the interference picture to superposition of several wave field components. It was shown that the spherical wave theory, as it was developed by W. Bauspiess, U. Bonse, and W. Graeff for the absorption-free neutron interferometer, describes well quantitatively the experimental intensity profiles. Expecially for the t-2t-t geometry the theoretically predicted focusing was confirmed. For the H-beam the intensity profile is symmetric and spatially limited; the O-beam is asymetric with intensities decreasing slowly up to the boundary. Geometrical differences within single stages lead to unique changes in the intensity profile. The pigtail pattern leading in the past to some puzzle guessing could be explained by the influence of geometrical defocusings on the phase shift. Important conclusions for the geometrical tolerances, which have to be regarded in the construction of neutron interferometers, could be obtained. (orig.) [de

  7. Phase-modulation interferometer for ICF-target characterization

    International Nuclear Information System (INIS)

    Cooper, D.E.

    1981-01-01

    Characterization requirements for high gain laser fusion targets are severe. We are required to detect defects on the surfaces of opaque and transparent shells with an amplitude resolution of +- 5 nm and a spatial resolution of 1 to 10 μm. To achieve this we have developed a laser-illuminated phase-modulation interferometer. This instrument is based on a photoelastic polarization modulation technique which allows one to convert phase information into an intensity modulation which can be easily and sensitively measured using ac signal processing techniques. This interferometer has detected path length changes as small as 1 nm and the required spatial resolution is assured by using a microscope objective to focus the probe laser beam down to a small (approx. 1 μm) spot on the surface of a microballoon. The interferometer will soon be coupled to an LSI-11 controlled 4π sphere manipulator which will allow us to automatically inspect the entire surface area of a target sphere

  8. The first educational interferometer in Mexico (FEYMANS): A novel project

    Science.gov (United States)

    Villicana Pedraza, Ilhuiyolitzin; Guesten, Rolf; Saucedo Morales, Julio Cesar; Carreto, Francisco; Valdes Estrada, Erik; Wendolyn Blanco Cardenas, Monica; Rodríguez Garza, Carolina B.; Pech Castillo, Gerardo A.; Ángel Vaquerizo, Juan

    2016-07-01

    An interferometer is composed of several radio telescopes (dishes) separated by a defined distance and used in synchrony. This kind of array produces a superior angular resolution, better than the resolution achieved by a single dish of the same combined area. In this work we propose the First Educational Youth Mexican Array North South, FEYMANS. It consists of an educational interferometer with initially four dishes. This array harvests Mexico's geography by locating each dish at the periphery of the country; creating new scientific links of provincial populations with the capital. The FEYMANS project focus in high school students and their projects on physics, chemistry and astronomy as a final project. Also, it can be used for bachelor theses. The initial and central dish-node is planed to be in Mexico City. After its construction, the efforts will focus to build subsequent nodes, on the Northwest region, Northeast, or Southeast. Region Northwest will give service to Baja California, Sonora and Chihuahua states. Region Northeast will cover Coahuila, Nuevo Leon and Tamaulipas. Finally, region Southeast will give access to Yucatan, Quintana Roo, Campeche, Tabasco and Chiapas. This project has been conceived by young professional astronomers and Mexican experts that will operate each node. Also, we have the technical support of the "Max Planck Institute fuer Radioastronomy in Bonn Germany" and the educational model of the "PARTNeR" project in Spain. This interferometer will be financed by Mexico's Federal Congress and by Mexico City's Legislative Assembly (ALDF).

  9. Silicon Integrated Dual-Mode Interferometer with Differential Outputs

    Directory of Open Access Journals (Sweden)

    Niklas Hoppe

    2017-09-01

    Full Text Available The dual-mode interferometer (DMI is an attractive alternative to Mach-Zehnder interferometers for sensor purposes, achieving sensitivities to refractive index changes close to state-of-the-art. Modern designs on silicon-on-insulator (SOI platforms offer thermally stable and compact devices with insertion losses of less than 1 dB and high extinction ratios. Compact arrays of multiple DMIs in parallel are easy to fabricate due to the simple structure of the DMI. In this work, the principle of operation of an integrated DMI with differential outputs is presented which allows the unambiguous phase shift detection with a single wavelength measurement, rather than using a wavelength sweep and evaluating the optical output power spectrum. Fluctuating optical input power or varying attenuation due to different analyte concentrations can be compensated by observing the sum of the optical powers at the differential outputs. DMIs with two differential single-mode outputs are fabricated in a 250 nm SOI platform, and corresponding measurements are shown to explain the principle of operation in detail. A comparison of DMIs with the conventional Mach-Zehnder interferometer using the same technology concludes this work.

  10. Explosive component acceptance tester using laser interferometer technology

    Science.gov (United States)

    Wickstrom, Richard D.; Tarbell, William W.

    1993-01-01

    Acceptance testing of explosive components requires a reliable and simple to use testing method that can discern less than optimal performance. For hot-wire detonators, traditional techniques use dent blocks or photographic diagnostic methods. More complicated approaches are avoided because of their inherent problems with setup and maintenance. A recently developed tester is based on using a laser interferometer to measure the velocity of flying plates accelerated by explosively actuated detonators. Unlike ordinary interferometers that monitor displacement of the test article, this device measures velocity directly and is commonly used with non-spectral surfaces. Most often referred to as the VISAR technique (Velocity Interferometer System for Any Reflecting Surface), it has become the most widely-accepted choice for accurate measurement of velocity in the range greater than 1 mm/micro-s. Traditional VISAR devices require extensive setup and adjustment and therefore are unacceptable in a production-testing environment. This paper describes a new VISAR approach which requires virtually no adjustments, yet provides data with accuracy comparable to the more complicated systems. The device, termed the Fixed-Cavity VISAR, is currently being developed to serve as a product verification tool for hot-wire detonators and slappers. An extensive data acquisition and analysis computer code was also created to automate the manipulation of raw data into final results.

  11. Mach-Zehnder atom interferometer inside an optical fiber

    Science.gov (United States)

    Xin, Mingjie; Leong, Wuiseng; Chen, Zilong; Lan, Shau-Yu

    2017-04-01

    Precision measurement with light-pulse grating atom interferometry in free space have been used in the study of fundamental physics and applications in inertial sensing. Recent development of photonic band-gap fibers allows light for traveling in hollow region while preserving its fundamental Gaussian mode. The fibers could provide a very promising platform to transfer cold atoms. Optically guided matter waves inside a hollow-core photonic band-gap fiber can mitigate diffraction limit problem and has the potential to bring research in the field of atomic sensing and precision measurement to the next level of compactness and accuracy. Here, we will show our experimental progress towards an atom interferometer in optical fibers. We designed an atom trapping scheme inside a hollow-core photonic band-gap fiber to create an optical guided matter waves system, and studied the coherence properties of Rubidium atoms in this optical guided system. We also demonstrate a Mach-Zehnder atom interferometer in the optical waveguide. This interferometer is promising for precision measurements and designs of mobile atomic sensors.

  12. Quality control of disinfection in ultrasonic baths

    Energy Technology Data Exchange (ETDEWEB)

    Schoene, H. [Technical University Dresden (Germany). Faculty of Mechanical Engineering; Jatzwauk, L. [University Hospital of the Technical University Dresden (Germany). Abt. Krankenhaushygiene

    2002-07-01

    Numerous investigations under laboratory conditions confirmed the microbicidal efficacy of ultrasonication. Morphological destruction was shown on bacteria and fungi as well as on different virus species. Ultrasonic treatment seems to increase the effect of different antibiotics and disinfectants. Reasons for this synergism are largely unknown and uninvestigated, but the active principle seems to bee the dispersing effect of ultrasonication in combination with the destruction of cell wall or cell membrane. Unfortunately no validation of test conditions exists for most of these investigations, regarding intensity and frequency of ultrasonic waves, temperature of liquid medium and measurement of cavitation which is an essential part of physical and chemical effects in ultrasonic baths. In contrast to most laboratory experiments sound density of ultrasound for treatment of medical instruments is below 1 W/cm{sup 2} because instruments will be destroyed under stronger ultrasonic conditions. The frequency is below 50 KHz. This paper describes bactericidal and fungicidal effects of low- intensity-ultrasonication and its synergistical support to chemical disinfection. (orig.)

  13. Ultrasonic tests on materials with protective coatings

    International Nuclear Information System (INIS)

    Whaley, H.L.

    1977-01-01

    Protective coatings are applied to some nuclear components such as reactor vessels to inhibit surface corrosion. Since in-service ultrasonic inspection is required for such components, a study was performed to determine whether the use of protective coatings can affect ultrasonic tests. Two 2 in. thick steel plates were uniformly machined, sandblasted, and used as bases for two types of protective coatings. The type and thickness of the coating and the presence of contamination, such as fingerprints or mild oxidation under the paint, were the independent variables associated with the coating. Tests were run to determine the effects of the protective coatings on ultrasonic tests conducted on the steel plates. Significant variations in ultrasonic test sensitivity occurred as a function of the type and thickness of protective coating, couplant (material that conducts the ultrasound from the transducer into the test part, normally water or some type of oil), transducer wear plate, and ultrasonic test frequency. Ultrasonic tests can be strongly affected by a protective coating on the component to be inspected. As compared to the test sensitivity for an uncoated reference sample, the sensitivity may be dramatically shifted up or down on the coated surface. In certain coating thickness ranges, the sensitivity can fluctuate widely with small changes in coating thickness. If a coating is chosen properly, however, components with protective coatings can be tested ultrasonically with valid results. These results are for the case of ultrasonic input on the coated surface. It is not expected that an ultrasonic test conducted from the front surface would be appreciably affected by a coating on the rear surface

  14. Computer simulation of ultrasonic waves in solids

    International Nuclear Information System (INIS)

    Thibault, G.A.; Chaplin, K.

    1992-01-01

    A computer model that simulates the propagation of ultrasonic waves has been developed at AECL Research, Chalk River Laboratories. This program is called EWE, short for Elastic Wave Equations, the mathematics governing the propagation of ultrasonic waves. This report contains a brief summary of the use of ultrasonic waves in non-destructive testing techniques, a discussion of the EWE simulation code explaining the implementation of the equations and the types of output received from the model, and an example simulation showing the abilities of the model. (author). 2 refs., 2 figs

  15. Ultrasonic characterization of vegetable oil product

    International Nuclear Information System (INIS)

    Sidek Hj Abd Aziz; Chow Sai Pew; Abdul Halim Shaari; Nor Azizah Shaari

    1992-01-01

    The ultrasonic wave velocity and attenuation of a number vegetable oil products were measured using an ultrasonic pulse echo overlap technique from room temperature up to 90 0 C. Among the liquid samples studied were refined bleach deodorized (RED) palm oil, palm olein, coconut oil, corn oil and soya bean oil. The velocity of sound in vegetable oil products varies from about 1200 to 200 ms-1 and decrease linearly as the temperature increases. The ultrasonic properties of the oil are much dependent on their viscosity, density, relaxation effect and vibrational anharmonicity

  16. On-line ultrasonic gas entrainment monitor

    International Nuclear Information System (INIS)

    Day, C.K.; Pedersen, H.N.

    1978-01-01

    Apparatus employing ultrasonic energy for detecting and measuring the quantity of gas bubbles present in liquids being transported through pipes is described. An ultrasonic transducer is positioned along the longitudinal axis of a fluid duct, oriented to transmit acoustic energy radially of the duct around the circumference of the enclosure walls. The back-reflected energy is received centrally of the duct and interpreted as a measure of gas entrainment. One embodiment employs a conical reflector to direct the transmitted acoustic energy radially of the duct and redirect the reflected energy back to the transducer for reception. A modified embodiment employs a cylindrical ultrasonic transducer for this purpose

  17. Fundamentals and applications of ultrasonic waves

    CERN Document Server

    Cheeke, J David N

    2002-01-01

    Ultrasonics. A subject with applications across all the basic sciences, engineering, medicine, and oceanography, yet even the broader topic of acoustics is now rarely offered at undergraduate levels. Ultrasonics is addressed primarily at the doctoral level, and texts appropriate for beginning graduate students or newcomers to the field are virtually nonexistent.Fundamentals and Applications of Ultrasonic Waves fills that void. Designed specifically for senior undergraduates, beginning graduate students, and those just entering the field, it begins with the fundamentals, but goes well beyond th

  18. Sensitivity of a fibre scattered-light interferometer to external phase perturbations in an optical fibre

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, A E; Potapov, V T [V.A.Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Fryazino Branch, Fryazino, Moscow region (Russian Federation); Gorshkov, B G [OOO ' Petrofaiber' , Russia, Tula region, Novomoskovsk (Russian Federation)

    2015-10-31

    Sensitivity of a fibre scattered-light interferometer to external phase perturbations is studied for the first time. An expression is derived for an average power of a useful signal at the interferometer output under external harmonic perturbations in a signal fibre of the interferometer. It is shown that the maximum sensitivity of the scattered-light interferometer depends on the dispersion of the interferogram intensity. An average signal-to-noise ratio is determined theoretically and experimentally at the output of the interferometer at different amplitudes of external perturbations. Using the measured dependences of the signal-to-noise ratio, the threshold sensitivity of the fibre scattered-light interferometer to external phase perturbations is found. The results obtained can be used to optimise characteristics of optical time-domain reflectometers and to design individual phase-sensitive fibre-optic sensors. (laser applications and other topics in quantum electronics)

  19. A laser interferometer for measuring straightness and its position based on heterodyne interferometry

    International Nuclear Information System (INIS)

    Chen Benyong; Zhang Enzheng; Yan Liping; Li Chaorong; Tang Wuhua; Feng Qibo

    2009-01-01

    Not only the magnitude but also the position of straightness errors are of concern to users. However, current laser interferometers used for measuring straightness seldom give the relative position of the straightness error. To solve this problem, a laser interferometer for measuring straightness and its position based on heterodyne interferometry is proposed. The optical configuration of the interferometer is designed and the measurement principle is analyzed theoretically. Two experiments were carried out. The first experiment verifies the validity and repeatability of the interferometer by measuring a linear stage. Also, the second one for measuring a flexure-hinge stage demonstrates that the interferometer is capable of nanometer measurement accuracy. These results show that this interferometer has advantages of simultaneously measuring straightness error and the relative position with high precision, and a compact structure.

  20. Track type ultrasonic inspection device

    International Nuclear Information System (INIS)

    Kajiyama, Shigeru; Sasaki, Tsukasa; Takahisa, Kazuo.

    1993-01-01

    The present invention concerns an improvement of a scanning device disposed near an object to be inspected such as a nuclear pressure vessel and having an ultrasonic probe, mounted thereon that travel along a running track. Specifically, one of wheel supports on both sides is attached being secured to the scanning device. The other of the supports is capable of fixing and releasing, as well as providing and releasing pressure to and from wheels upon mounting and detachment. This enables to provide a structure capable of pressing the wheels of the running device to the plane of the track and release thereof. Accordingly, it is possible to improve the running performance, reduce the size and weight and shorten the time for mounting and detachment of the running inspection device. (I.S.)

  1. Cracks assessment using ultrasonic technology

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Maria Pia; Tomasella, Marcelo [OLDELVAL S.A. Oleoductos del Valle, Rio Negro (Argentina). Pipeline Integrity Dept.

    2005-07-01

    The goal of Oldelval Integrity Program is to prevent ruptures and leaks, developing strategies for a better handling of the integrity of our pipelines. In order to achieve it we have studied and modeled each process that involved in the integrity pipeline. Those processes are mainly based on defects reported by an internal inspection tool and supplied with field inspection and monitoring data. Years of evaluation, study and the continuous effort overturned towards a phenomenon that worries to the industry, as it is the SCC. Since 1998 up to 2004 SCC was included in the integrity program with some preventive maintenance programs. The accomplishment of the inspection based on ultrasound tools, is the culmination of years of evaluation and investigations supported by field digs and materials susceptibility. This paper describes Oldelval's results with ultrasonic crack detection tool, and how it can be reliably to detect SCC. (author)

  2. Ultrasonic Histotripsy for Tissue Therapy

    Science.gov (United States)

    Pahk, K. J.; Dhar, D. K.; Malago, M.; Saffari, N.

    2015-01-01

    Hepatocyte transplantation has been considered and investigated as a promising and alternative method to liver transplantation for treating liver-based metabolic disorder in newborns over the past two decades. Although some clinical trials have been conducted and shown clinical benefits and outcomes, it is difficult to deliver and achieve a desired level of integration and transplantation of hepatocytes in the liver parenchyma. To overcome this problem, this work introduces an alternative method to a portal-infused-hepatocyte cell transplantation. To improve the level of engraftment of transplantable hepatocytes, these are injected directly into cavities generated by ultrasonic histotripsy. Histotripsy is an extracorporeal noninvasive technique which has been recently developed using high intensity focused ultrasound (HIFU) for inducing tissue fractionation with no coagulative necrosis. The exact mechanisms for the tissue fractionation are not well understood yet; but the possible mechanisms are thought to be a combination of nonlinear wave propagation effect, explosive bubble growth and ultrasonic atomization. The main objectives of this work are to demonstrate the feasibility of this new cell therapy and evaluate and distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion. In the present work, numerical studies on the bubble dynamics (the Gilmore-Akulichev bubble model coupled with the Khokhlov-Zabolotskaya-Kuznetsov equation) and both ex- and in vivo liver experiments are conducted with histological analysis (haematoxylin and eosin stain). The numerical and the experimental results suggest that (a) the acoustic emissions emitted during the thermal ablation and the histotripsy exposure can be distinguished both numerically and experimentally and (b) the proposed cell therapy may potentially form an effective and safe clinical treatment for replacing and correcting disordered hepatocytes, although the

  3. Ultrasonic Histotripsy for Tissue Therapy

    International Nuclear Information System (INIS)

    Pahk, K J; Saffari, N; Dhar, D K; Malago, M

    2015-01-01

    Hepatocyte transplantation has been considered and investigated as a promising and alternative method to liver transplantation for treating liver-based metabolic disorder in newborns over the past two decades. Although some clinical trials have been conducted and shown clinical benefits and outcomes, it is difficult to deliver and achieve a desired level of integration and transplantation of hepatocytes in the liver parenchyma. To overcome this problem, this work introduces an alternative method to a portal-infused-hepatocyte cell transplantation. To improve the level of engraftment of transplantable hepatocytes, these are injected directly into cavities generated by ultrasonic histotripsy. Histotripsy is an extracorporeal noninvasive technique which has been recently developed using high intensity focused ultrasound (HIFU) for inducing tissue fractionation with no coagulative necrosis. The exact mechanisms for the tissue fractionation are not well understood yet; but the possible mechanisms are thought to be a combination of nonlinear wave propagation effect, explosive bubble growth and ultrasonic atomization. The main objectives of this work are to demonstrate the feasibility of this new cell therapy and evaluate and distinguish between the different types of cavitation activity for either a thermally or a mechanically induced lesion. In the present work, numerical studies on the bubble dynamics (the Gilmore-Akulichev bubble model coupled with the Khokhlov-Zabolotskaya-Kuznetsov equation) and both ex- and in vivo liver experiments are conducted with histological analysis (haematoxylin and eosin stain). The numerical and the experimental results suggest that (a) the acoustic emissions emitted during the thermal ablation and the histotripsy exposure can be distinguished both numerically and experimentally and (b) the proposed cell therapy may potentially form an effective and safe clinical treatment for replacing and correcting disordered hepatocytes, although the

  4. Sizing of small surface-breaking tight cracks by using laser-ultrasonics

    International Nuclear Information System (INIS)

    Ochiai, M.; Miura, T.; Kuroda, H.; Yamamoto, S.; Onodera, T.

    2004-01-01

    On the nondestructive testing, not only detection but also sizing of crack is desirable because the crack depth is one of the most important parameter to evaluate the impact of the crack to the material, to estimate crack growth and ultimately to predict lifetime of the component. Moreover, accurate measurement of the crack depth optimizes countermeasures and timing of repairs, and eventually reduces total cost for plant maintenance. Laser-ultrasonic is a technique that uses two laser beams; one with a short pulse for the generation of ultrasound and another one, long pulse or continuous, coupled to an optical interferometer for detection. The technique features a large detection bandwidth, which is important for small defect inspection. Another feature of laser-ultrasonics is the remote optical scanning of generation and detection points, which enables to inspect components in narrow space and/or having complex shapes. A purpose of this paper is to describe the performance of a laser-ultrasonic testing (LUT) system on stress corrosion cracking (SCC) inspection. We have developed a new technique for sizing shallow cracks, say 0.5-1.5mm, based on the laser-induced surface wave and its frequency analysis. First, sizing capability of the system will be demonstrated by using an artificial surface-breaking slot having depth of 0-2mm in a stainless steel plate. Evaluated depths show good agreement with the machined slot depths within the accuracy of about a few hundred micrometers. Then, SCCs in a stainless steel plate are examined by using the system. Depth of SCC is evaluated every 0.2mm over the crack aperture length. The evaluated depths are compared with the depths measured by the destructive testing. (author)

  5. Plasma electron density measurement with multichannel microwave interferometer on the HL-1 tokamak device

    International Nuclear Information System (INIS)

    Xu Deming; Zhang Hongyin; Liu Zetian; Ding Xuantong; Li Qirui; Wen Yangxi

    1989-11-01

    A multichannel microwave interferometer which is composed of different microwave interferometers (one 2 mm band, one 4 mm band and two 8 mm band) has been used to measure the plasma electron density on HL-1 tokamak device. The electron density approaching to 5 x 10 13 cm -3 is measured by a 2 mm band microwave interferometer. In the determinable range, the electron density profile in the cross-section on HL-1 device has been measured by this interferometer. A microcomputer data processing system is also developed

  6. Development of a suspended-mass RSE interferometer using third harmonic demodulation

    CERN Document Server

    Miyakawa, O; Heinzel, G; Kawamura, S

    2002-01-01

    The most important point of a resonant sideband extraction (RSE) experiment is the signal extraction for control of the interferometer. We proposed a new signal-sensing method for the single modulation scheme. This method uses the third harmonic demodulation (THD) with a particular asymmetry in the interferometer which makes the third-order sidebands vanish at the detecting port. We have successfully locked a suspended-mass RSE interferometer for the first time by the THD method. The transfer function of the interferometer was measured to confirm the RSE effect.

  7. Secondary wavelength stabilization of unbalanced Michelson interferometers for the generation of low-jitter pulse trains.

    Science.gov (United States)

    Shalloo, R J; Corner, L

    2016-09-01

    We present a double unbalanced Michelson interferometer producing up to four output pulses from a single input pulse. The interferometer is stabilized with the Hänsch-Couillaud method using an auxiliary low power continuous wave laser injected into the interferometer, allowing the stabilization of the temporal jitter of the output pulses to 0.02 fs. Such stabilized pulse trains would be suitable for driving multi-pulse laser wakefield accelerators, and the technique could be extended to include amplification in the arms of the interferometer.

  8. Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2012-09-15

    A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

  9. Development of a suspended-mass RSE interferometer using third harmonic demodulation

    International Nuclear Information System (INIS)

    Miyakawa, Osamu; Somiya, Kentaro; Heinzel, Gerhard; Kawamura, Seiji

    2002-01-01

    The most important point of a resonant sideband extraction (RSE) experiment is the signal extraction for control of the interferometer. We proposed a new signal-sensing method for the single modulation scheme. This method uses the third harmonic demodulation (THD) with a particular asymmetry in the interferometer which makes the third-order sidebands vanish at the detecting port. We have successfully locked a suspended-mass RSE interferometer for the first time by the THD method. The transfer function of the interferometer was measured to confirm the RSE effect

  10. Ultrasonically-assisted Thermal Stir Welding System

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2014-01-01

    A welding head assembly has a work piece disposed between its containment plates' opposing surfaces with the work piece being maintained in a plastic state thereof at least in a vicinity of the welding head assembly's stir rod as the rod is rotated about its longitudinal axis. The welding head assembly and the work piece experience relative movement there between in a direction perpendicular to the rod's longitudinal axis as the work piece is subjected to a compressive force applied by the containment plates. A first source coupled to the first containment plate applies a first ultrasonic wave thereto such that the first ultrasonic wave propagates parallel to the direction of relative movement. A second source coupled to the second containment plate applies a second ultrasonic wave thereto such that the second ultrasonic wave propagates parallel to the direction of relative movement.propagates parallel to the direction of relative movement.

  11. Ultrasonic determination of the size of defects

    International Nuclear Information System (INIS)

    Zetterwall, T.

    1989-01-01

    The paper presents results from a study of ultrasonic testing of materials. The main topic has been the determination of the size, length and deep, of cracks or defects in stainless steel plates. (K.A.E)

  12. Advanced ultrasonic technology for natural gas measurement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-11-15

    In recent years, due to rising environmental and safety concerns, increasing commodity prices, and operational inefficiencies, a paradigm shift has been taking place with respect to gas measurement. The price of natural gas depends on the location, time of the year, and type of consumer. There is wide uncertainty associated with an orifice meter. This paper presents the use of advanced ultrasonic technology for the measurement of natural gas. For many years, multi-path ultrasonic meters with intelligent sensor technology have been used for gas measurement. This paper gives the various applications of ultrasonic technology along with their advantages and a draws a comparison with orifice meters. From the study it can be concluded that extensive advances in the use of ultrasonic technology for gas measurement have widened the areas of application and that varying frequencies combined with sealed transducer designs make it possible to measure atmospheric and sour gas in custody transfer process control and flaring accurately.

  13. Ultrasonic assisted hot metal powder compaction.

    Science.gov (United States)

    Abedini, Rezvan; Abdullah, Amir; Alizadeh, Yunes

    2017-09-01

    Hot pressing of metal powders is used in production of parts with similar properties to wrought materials. During hot pressing processes, particle rearrangement, plastic deformation, creep, and diffusion are of the most effective powder densification mechanisms. Applying ultrasonic vibration is thought to result in great rates of densification and therefore higher efficiency of the process is expected. This paper deals with the effects of power ultrasonic on the densification of AA1100 aluminum powder under constant applied stress. The effects of particle size and process temperature on the densification behavior are discussed. The results show that applying ultrasonic vibration leads to an improved homogeneity and a higher relative density. Also, it is found that the effect of ultrasonic vibration is greater for finer particles. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Hand Gesture Recognition Using Ultrasonic Waves

    KAUST Repository

    AlSharif, Mohammed Hussain

    2016-01-01

    estimation of the moving hand and received signal strength (RSS). These two factors are estimated using two simple methods; channel impulse response (CIR) and cross correlation (CC) of the reflected ultrasonic signal from the gesturing hand. A customized

  15. Ultrasonic Morphological Analyzers for Breast Cancer Diagnosis

    National Research Council Canada - National Science Library

    Lizzi, Frederic

    1999-01-01

    The goal of this research is to improve ultrasonic classification of breast lesions and guide decisions regarding biopsy requirements, especially for small lesions and those in young, dense breasts...

  16. Rail inspection using noncontact laser ultrasonics

    International Nuclear Information System (INIS)

    Kim, Nak Hyeon; Sohn, Hoon; Han, Soon Woo

    2012-01-01

    In this study, a noncontact laser ultrasonic system is proposed for rail defect detection. An Nd Yag pulse laser is used for generation of ultrasonic waves, and the corresponding ultrasonic responses are measured by a laser Doppler vibrometer. For the detection of rail surface damages, the shape of the excitation laser beam is transformed into a line. On the other hand, a point source laser beam is used for the inspection of defects inside a rail head. Then, the interactions of propagating ultrasonic waves with defects are examined using actual rail specimens. Amplitude attenuation was mainly observed for a surface crack, and reflections were most noticeable from an internal damage. Finally, opportunities and challenges associated with real time rail inspection from a high speed train are discussed

  17. Nondestructive control of materials by ultrasonic tests

    International Nuclear Information System (INIS)

    Mercier, Noelle.

    1974-01-01

    A bibliographic study of nondestructive control methods of solids by ultrasonic tests, and of the ultrasonic emission of a transducer of finite dimension, is first presented. The principle of two of these methods is verified experimentally; they should permit the measurement of various physical parameters of solids, and the detection of local inhomogeneities. The first method calls upon the analysis of the ultrasonic signal (amplitude and phase), after it has crossed a constant thickness of a metallic specimen. This analysis reveals variations of attenuation and of ultrasonic propagation velocity within the specimen. A good spatial resolution is obtained by using 1mm-diameter probes. The second method leads, thanks to a test rig equipped with broad frequency band electrostatic transducers, to the knowledge of the attenuation law of the specimens as a function of frequency (present range: 5 to 15MHz); from this a classification of these specimens as regards their granulometry is deduced [fr

  18. Ultrasonic testing of materials at level 2

    International Nuclear Information System (INIS)

    1988-06-01

    Ultrasonic inspection is a nondestructive method in which high frequency sound waves are introduced into the material being inspected. Ultrasonic testing has a superior penetrating power to radiography and can detect flaws deep in the test specimen (say up to about 6 to 7 meters of steel). It is quite sensitive to small flaws and allows the precise determination of the location and size of the flaws. Basic ultrasonic test methods such as the through transmission method and the resonance method, sensors and testing techniques are described. Pulse echo type flaw detectors and their applications for inspection of welds are surveyed. Ultrasonic standards, calibration of the equipment and evaluation methods are presented. Examples of practical applications in welding, casting and forging processes are given. Figs and tabs

  19. Improvement of Ultrasonic Distance Measuring System

    Directory of Open Access Journals (Sweden)

    Jiang Yu

    2018-01-01

    Full Text Available This paper mainly introduces a kind of ultrasonic distance measuring system with AT89C51 single chip as the core component. The paper expounds the principle of ultrasonic sensor and ultrasonic ranging, hardware circuit and software program, and the results of experiment and analysis.The hardware circuit based on SCM, the software design adopts the advanced microcontroller programming language.The amplitude of the received signal and the time of ultrasonic propagation are regulated by closed loop control. [1,2]The double closed loop control technology for amplitude and time improves the measuring accuracy of the instrument. The experimental results show that greatly improves the measurement accuracy of the system.

  20. Ultrasonic Generation and Optimization for EMAT

    International Nuclear Information System (INIS)

    Jian, X.; Dixon, Steve; Edwards, Rachel S.

    2005-01-01

    A model for transient ultrasonic wave generation by EMATs in non-magnetic metals is presented. It combines analytical solutions currently available and FEM to calculate ultrasonic bulk and Rayleigh waves generated by the EMAT. Analytical solutions are used as they can be calculated quickly on a standard mathematical computer package. Calculations agree well with the experimental measurement. The model can be used to optimize EMAT design, and has explained some of the results from our previous published measurements

  1. An advanced system for automated ultrasonic testing

    International Nuclear Information System (INIS)

    Dressler, K.

    1989-01-01

    As the main component of the AUP system, an ALOK ultrasonic unit has been chosen as it allows for testing of large component areas both search for defects and description of defect geometries. All data required for fault analysis can be obtained by one measuring run. For inspection of primary circuit components in nuclear power stations, the manipulator control and the ultrasonic probe are installed behind the first sufficient shielding. (orig./HP) [de

  2. Ultrasonic flow measurements for irrigation process monitoring

    Science.gov (United States)

    Ziani, Elmostafa; Bennouna, Mustapha; Boissier, Raymond

    2004-02-01

    This paper presents the state of the art of the general principle of liquid flow measurements by ultrasonic method, and problems of flow measurements. We present an ultrasonic flowmeter designed according to smart sensors concept, for the measurement of irrigation water flowing through pipelines or open channels, using the ultrasonic transit time approach. The new flowmeter works on the principle of measuring time delay differences between sound pulses transmitted upstream and downstream in the flowing liquid. The speed of sound in the flowing medium is eliminated as a variable because the flowrate calculations are based on the reciprocals of the transmission times. The transit time difference is digitally measured by means of a suitable, microprocessor controlled logic. This type of ultrasonic flowmeter will be widely used in industry and water management, it is well studied in this work, followed by some experimental results. For pressurized channels, we use one pair of ultrasonic transducer arranged in proper positions and directions of the pipe, in this case, to determine the liquid velocity, a real time on-line analysis taking account the geometries of the hydraulic system, is applied to the obtained ultrasonic data. In the open channels, we use a single or two pairs of ultrasonic emitter-receiver according to the desired performances. Finally, the goals of this work consist in integrating the smart sensor into irrigation systems monitoring in order to evaluate potential advantages and demonstrate their performance, on the other hand, to understand and use ultrasonic approach for determining flow characteristics and improving flow measurements by reducing errors caused by disturbances of the flow profiles.

  3. Fundamentals and Applications of Ultrasonic Waves

    CERN Document Server

    Cheeke, J David N

    2012-01-01

    Designed specifically for newcomers to the field, this fully updated second edition begins with fundamentals and quickly advances beyond general wave concepts into an in-depth treatment of ultrasonic waves in isotropic media. Focusing on the physics of acoustic waves, their propagation, technology, and applications, this accessible overview of ultrasonics includes accounts of viscoelasticity and multiple scattering. It examines new technologies, including atomic force acoustic microscopy, lasers, micro-acoustics, and nanotechnology. In addition, it highlights both direct and indirect applicati

  4. Longitudinal ultrasonic waves dispersion in bars

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2001-01-01

    The exhibition intends to review some aspects of the propagation of the longitudinal ultrasonic pulses shortly in bars of traverse section uniform.Aspects they are part of the denominated geometric dispersion of the pulses.This phenomenon It can present like an additional complication in the ultrasonic essay of low frequency of thin pieces in structures and machines but takes place former ex professed in some applications of the wave guides been accustomed to in the prosecution of signs

  5. Ultrasonic Characterization of Superhard Material: Osmium Diboride

    International Nuclear Information System (INIS)

    Yadawa, P K

    2012-01-01

    Higher order elastic constants have been calculated in hexagonal structured superhard material OsB 2 at room temperature following the interaction potential model. The temperature variation of the ultrasonic velocities is evaluated along different angles with unique axis of the crystal using the second order elastic constants. The ultrasonic velocity decreases with the temperature along particular orientation with the unique axis. Temperature variation of the thermal relaxation time and Debye average velocities are also calculated along the same orientation. The temperature dependency of the ultrasonic properties is discussed in correlation with elastic, thermal and electrical properties. It has been found that the thermal conductivity is the main contributor to the behaviour of ultrasonic attenuation as a function of temperature and the responsible cause of attenuation is phonon-phonon interaction. The mechanical properties of OsB 2 at low temperature are better than at high temperature, because at low temperature it has low ultrasonic velocity and ultrasonic attenuation. Superhard material OsB 2 has many industrial applications, such as abrasives, cutting tools and hard coatings.

  6. Software for Adapting Dspz Receivers to the Uran Interferometer Network

    Science.gov (United States)

    Isaeva, E. A.; Lytvynenko, O. A.; Shepelev, V. A.

    More than 10 years ago, URAN interferometer network (Megn A.V.,1997; Konovalenko A.A., 2014) had been equipped with newly designed receivers with a pass band extended up to 250 kHz and software rejection of interferences (Rashkovskii, 2012). The broadening of bandwidth of received signal increase the sensitivity of the receivers significantly and let us to investigate the angular structure about one hundred radio sources. A software package had been developed that allows: preparing a program of observations, carrying out observations automatically, making data cross-correlation, calculating visibility functions for all pairs of antennae, and fitting models of an angular structure of the sources. Data storage formats were elaborated for each stage of recording or processing. At present, new digital radio astronomy receiver DSPZ have been developed by IRA NASU (Zakharenko, 2016). The receiver allows recording an entire bandwidth of signals of a decameter range from 8 to 32 MHz. It is used at UTR-2 and URAN radio telescopes operated in a single dish mode. Application of the receivers for interferometer observation with the URAN network provides additional advantages in accuracy and sensitivity of studies. In this report we consider the data formats and synchronization methods used in URAN equipment and DSPZ receivers, and discuss algorithms of their transformation. Newly elaborated software is described, that allows selecting a set of frequency bands of signals recorded with DSPZ and converting them to the form used by the URAN software. This approach allows us to carry out the interferometer observations in an the extended frequency range provided by DSPZ and to use as much as possible the software package developed for the URAN network for data reduction.

  7. ALISEO on MIOSat: an imaging interferometer for earth observation

    Science.gov (United States)

    Barducci, A.; Castagnoli, F.; Castellini, G.; Guzzi, D.; Marcoionni, P.; Pippi, I.

    2017-11-01

    The Italian Space Agency (ASI) decided to perform an low cost Earth observation mission based on a new mini satellite named MIOsat which will carry various technological payloads. Among them an imaging interferometer designed and now ready to be assembled and tested by our Institute. The instrument, named ALISEO (Aerospace Leap-frog Imaging Stationary interferometer for Earth Observation), operates in the common-path Sagnac configuration, and it does not utilize any moving part to scan the phase delays between the two interfering beams. The sensor acquires target images modulated by a pattern of autocorrelation functions of the energy coming from each scene pixel, and the resulting fringe pattern remains spatially fixed with respect to the instrument's field-of-view. The complete interferogram of each target location is retrieved by introducing a relative source-observer motion, which allows any image pixels to be observed under different viewing-angles and experience discrete path differences. The paper describes the main characteristics of the imaging interferometer as well as the overall optical configuration and the electronics layout. Moreover some theoretical issues concerning sampling theory in "common path" imaging interferometry are investigated. The experimental activity performed in laboratory is presented and its outcomes are analysed. Particularly, a set of measurements has been carried out using both standard (certificate) reflectance tiles and natural samples of different volcanic rocks. An algorithm for raw data pre-processing aimed at retrieving the at-sensor radiance spectrum is introduced and its performance is addressed by taking into account various issues such as dark signal subtraction, spectral instrument response compensation, effects of vignetting, and Fourier backtransform. Finally, examples of retrieved absolute reflectance of several samples are sketched at different wavelengths.

  8. Three dimensional phase imaging using a scanning optical fiber interferometer

    International Nuclear Information System (INIS)

    Walford, J.N.; Nugent, K.A.; Roberts, A.; Scholten, R.E.

    1998-01-01

    A quantitative method for measuring phase in three dimensions using a scanning optical fiber interferometer is described. By exploiting phase modulation in the reference arm, this technique is insensitive to large variations in the intensity of the field being studied, and is therefore highly suitable for measurement of phase within spatially confined optical beams. It uses only a single detector, and is not reliant on lock-in electronics. The technique is applied to the measurement of the near field of a cleaved optical fiber and shown to produce results in good agreement with theory. (authors)

  9. Multichannel spectral mode of the ALOHA up-conversion interferometer

    Science.gov (United States)

    Lehmann, L.; Darré, P.; Boulogne, H.; Delage, L.; Grossard, L.; Reynaud, F.

    2018-06-01

    In this paper, we propose a multichannel spectral configuration of the Astronomical Light Optical Hybrid Analysis (ALOHA) instrument dedicated to high-resolution imaging. A frequency conversion process is implemented in each arm of an interferometer to transfer the astronomical light to a shorter wavelength domain. Exploiting the spectral selectivity of this non-linear optical process, we propose to use a set of independent pump lasers in order to simultaneously study multiple spectral channels. This principle is experimentally demonstrated with a dual-channel configuration as a proof-of-principle.

  10. Position coincidence optical identifications using Texas interferometer radio positions

    International Nuclear Information System (INIS)

    Bozyan, E.P.

    1979-01-01

    1048 radio source positions measured with the Texas Interferometer were searched for optical identifications on glass copies of the Palomar Sky Survey E and O plates, resulting in 242 identifications and 806 blank fields. Finding charts are presented for 124 of the 125 new identifications not previously reported in the literature, and for 73 blank fields containing nearby optical objects which may be real identifications. This brings the cumulative number of Texas radio positions searched to 2015, producing 864 optical identifications and 1151 blank fields

  11. Measurement of periodically varying ECE spectra using a Michelson interferometer

    International Nuclear Information System (INIS)

    Laurent, L.; Rodriguez, L.; Talvard, M.

    1987-01-01

    In some tokamak experiments the ECE spectrum is periodically varying. If the modulation frequency is small enough (less than 10 Hz) the plasma can be considered as quasi-stationary during the typical scan time of most of the Michelson interferometers. It is possible to measure simply ECE spectra at different times of the oscillation. We present here a technique which allows to measure smaller fluctuations at larger frequencies. However the analysis requires a large number of periods of oscillation at constant frequency and a scanning mirror moving at constant velocity

  12. The Jodrell Bank radio-linked interferometer network

    International Nuclear Information System (INIS)

    Davies, J.G.; Anderson, B.; Morison, I.

    1980-01-01

    The capabilities of the Multi Telescope Radio Linked Interferometer (MTRLI) situated at Jodrell Bank, are described and some of the first maps to be made with it are presented. MTRLI produces high quality maps of radio sources with resolutions varying from approximately 1 arc s to approximately 0.02 arc s depending on the frequency of operation. The maps presented here were made at 408 MHz and are all of extragalactic sources. They illustrate the ability of MTRLI to map at low frequencies the steep spectrum emission which tends to be overlooked with existing synthesis instruments which have to work at much higher frequencies to obtain the same resolution. (U.K.)

  13. High precision neutron interferometer setup S18b

    International Nuclear Information System (INIS)

    Hasegawa, Y.; Lemmel, H.

    2011-01-01

    The present setup at S18 is a multi purpose instrument. It is used for both interferometry and a Bonse-Hart camera for USANS (Ultra Small Angle Neutron Scattering) spectroscopy with wide range tunability of wavelength. Some recent measurements demand higher stability of the instrument, which made us to propose a new setup dedicated particularly for neutron interferometer experiments requiring high phase stability. To keep both options available, we suggest building the new setup in addition to the old one. By extending the space of the present setup by 1.5 m to the upstream, both setups can be accommodated side by side. (authors)

  14. Green Bank Lunar Interferometer for Neutrino Transients: GLINT

    Energy Technology Data Exchange (ETDEWEB)

    Langston, Glen I. [NRAO, P.O. Box 2, Green Bank, WV 24944 (United States)], E-mail: glangsto@nrao.edu; Bradley, Rich [NRAO, 520 Edgemont Rd, Charlottesville, VA 22901 (United States); Hankins, Tim [New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 (United States); Mutel, Bob [University of Iowa, 706 Van Allen Hall, Iowa City, IA 52242 (United States)

    2009-06-01

    The Green Bank Lunar Interferometer for Neutrino Transients (GLINT) project is a wide band (0.3-2.6 GHz) interferometric radio array dedicated to observations of transient events. The target is detection of few bright (>2000Jy) short duration (few nano-second) pulses from the lunar regolith. The GLINT project has three goals: (1) Maximize detection of statistically significant pulses originating from the lunar surface. (2) Unambiguously differentiate neutrino pulses from other sources of interference. (3) Localize the direction of the incoming radio pulse resulting from neutrino interactions.

  15. Tracking Solar Type II Bursts with Space Based Radio Interferometers

    Science.gov (United States)

    Hegedus, Alexander M.; Kasper, Justin C.; Manchester, Ward B.

    2018-06-01

    The Earth’s Ionosphere limits radio measurements on its surface, blocking out any radiation below 10 MHz. Valuable insight into many astrophysical processes could be gained by having a radio interferometer in space to image the low frequency window for the first time. One application is observing type II bursts tracking solar energetic particle acceleration in Coronal Mass Ejections (CMEs). In this work we create a simulated data processing pipeline for several space based radio interferometer (SBRI) concepts and evaluate their performance in the task of localizing these type II bursts.Traditional radio astronomy software is hard coded to assume an Earth based array. To circumvent this, we manually calculate the antenna separations and insert them along with the simulated visibilities into a CASA MS file for analysis. To create the realest possible virtual input data, we take a 2-temperature MHD simulation of a CME event, superimpose realistic radio emission models from the CME-driven shock front, and propagate the signal through simulated SBRIs. We consider both probabilistic emission models derived from plasma parameters correlated with type II bursts, and analytical emission models using plasma emission wave interaction theory.One proposed SBRI is the pathfinder mission SunRISE, a 6 CubeSat interferometer to circle the Earth in a GEO graveyard orbit. We test simulated trajectories of SunRISE and image what the array recovers, comparing it to the virtual input. An interferometer on the lunar surface would be a stable alternative that avoids noise sources that affect orbiting arrays, namely the phase noise from positional uncertainty and atmospheric 10s-100s kHz noise. Using Digital Elevation Models from laser altimeter data, we test different sets of locations on the lunar surface to find near optimal configurations for tracking type II bursts far from the sun. Custom software is used to model the response of different array configurations over the lunar year

  16. A double well interferometer on an atom chip

    DEFF Research Database (Denmark)

    Schumm, Thorsten; Krüger, Peter; Hofferberth, S.

    2006-01-01

    Radio-Frequency coupling between magnetically trapped atomic states allows to create versatile adiabatic dressed state potentials for neutral atom manipulation. Most notably, a single magnetic trap can be split into a double well by controlling amplitude and frequency of an oscillating magnetic...... split BECs in time of flight expansion, we realize a matter wave interferometer. The observed interference pattern exhibits a stable relative phase of the two condensates, clearly indicating a coherent splitting process. Furthermore, we measure and control the deterministic phase evolution throughout...

  17. Superposition of helical beams by using a Michelson interferometer.

    Science.gov (United States)

    Gao, Chunqing; Qi, Xiaoqing; Liu, Yidong; Weber, Horst

    2010-01-04

    Orbital angular momentum (OAM) of a helical beam is of great interests in the high density optical communication due to its infinite number of eigen-states. In this paper, an experimental setup is realized to the information encoding and decoding on the OAM eigen-states. A hologram designed by the iterative method is used to generate the helical beams, and a Michelson interferometer with two Porro prisms is used for the superposition of two helical beams. The experimental results of the collinear superposition of helical beams and their OAM eigen-states detection are presented.

  18. Modulation depth of Michelson interferometer with Gaussian beam.

    Science.gov (United States)

    Välikylä, Tuomas; Kauppinen, Jyrki

    2011-12-20

    Mirror misalignment or the tilt angle of the Michelson interferometer can be estimated from the modulation depth measured with collimated monochromatic light. The intensity of the light beam is usually assumed to be uniform, but, for example, with gas lasers it generally has a Gaussian distribution, which makes the modulation depth less sensitive to the tilt angle. With this assumption, the tilt angle may be underestimated by about 50%. We have derived a mathematical model for modulation depth with a circular aperture and Gaussian beam. The model reduces the error of the tilt angle estimate to below 1%. The results of the model have been verified experimentally.

  19. Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.

    2010-01-01

    Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

  20. The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

    Science.gov (United States)

    Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

    2010-01-01

    The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

  1. Ultrasonic imaging in liquid sodium

    Energy Technology Data Exchange (ETDEWEB)

    Lubeigt, E. [CEA Cadarache, DEN/DTN/STCP/LIET, 13108 Saint-Paul-Lez-Durance Cedex (France); Laboratoire de Mecanique et d' Acoustique, CNRS UPR 7051, 13402 Marseille Cedex 20 (France); Mensah, S.; Chaix, J.F.; Rakotonarivo, S. [Laboratoire de Mecanique et d' Acoustique, CNRS UPR 7051, 13402 Marseille Cedex 20 (France); Gobillot, G. [CEA Cadarache, DEN/DTN/STCP/LIET, 13108 Saint-Paul-Lez-Durance Cedex (France)

    2015-07-01

    The fourth generation of nuclear reactor can use liquid sodium as the core coolant. When the reactor is operating, sodium temperatures can reach up to 600 deg. C. During maintenance periods, when the reactor is shut down, the coolant temperature is reduced to 200 deg. C. Because molten sodium is optically opaque, ultrasonic imaging techniques are developed for maintenance activities. Under-sodium imaging aims at i) checking the health of immersed structures. It should also allow ii) to assess component degradation or damage as cracks and shape defects as well as iii) the detection of lost objects. The under-sodium imaging system has to sustain high temperature (up to 300 deg. C) and hostility of the sodium environment. Furthermore, specific constraints such as transducers characteristics or the limited sensor mobility in the reactor vessel have to be considered. This work focuses on developing a methodology for detecting damages such as crack defects with ultrasound devices. Surface-breaking cracks or deep cracks are sought in the weld area, as welds are more subject to defects. Traditional methods enabled us to detect emerging cracks of submillimeter size with sodium-compatible high-temperature transducer. The presented approach relies on making use of prior knowledge about the environment through the implementation of differential imaging and time-reversal techniques. Indeed, this approach allows to detect a change by comparison with a reference measurement and by focusing back to any change in the environment. It is a means of analysis and understanding of the physical phenomena making it possible to design more effective inspection strategies. Difference between the measured signals reveals the acoustic field scattered by a perturbation (a crack for instance), which may occur between periodical measurements. The imaging method relies on the adequate combination of two computed ultrasonic fields, one forward and one adjoint. The adjoint field, which carries the

  2. Ultrasonic imaging in liquid sodium

    International Nuclear Information System (INIS)

    Lubeigt, E.; Mensah, S.; Chaix, J.F.; Rakotonarivo, S.; Gobillot, G.

    2015-01-01

    The fourth generation of nuclear reactor can use liquid sodium as the core coolant. When the reactor is operating, sodium temperatures can reach up to 600 deg. C. During maintenance periods, when the reactor is shut down, the coolant temperature is reduced to 200 deg. C. Because molten sodium is optically opaque, ultrasonic imaging techniques are developed for maintenance activities. Under-sodium imaging aims at i) checking the health of immersed structures. It should also allow ii) to assess component degradation or damage as cracks and shape defects as well as iii) the detection of lost objects. The under-sodium imaging system has to sustain high temperature (up to 300 deg. C) and hostility of the sodium environment. Furthermore, specific constraints such as transducers characteristics or the limited sensor mobility in the reactor vessel have to be considered. This work focuses on developing a methodology for detecting damages such as crack defects with ultrasound devices. Surface-breaking cracks or deep cracks are sought in the weld area, as welds are more subject to defects. Traditional methods enabled us to detect emerging cracks of submillimeter size with sodium-compatible high-temperature transducer. The presented approach relies on making use of prior knowledge about the environment through the implementation of differential imaging and time-reversal techniques. Indeed, this approach allows to detect a change by comparison with a reference measurement and by focusing back to any change in the environment. It is a means of analysis and understanding of the physical phenomena making it possible to design more effective inspection strategies. Difference between the measured signals reveals the acoustic field scattered by a perturbation (a crack for instance), which may occur between periodical measurements. The imaging method relies on the adequate combination of two computed ultrasonic fields, one forward and one adjoint. The adjoint field, which carries the

  3. Demonstration of a robust magnonic spin wave interferometer.

    Science.gov (United States)

    Kanazawa, Naoki; Goto, Taichi; Sekiguchi, Koji; Granovsky, Alexander B; Ross, Caroline A; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru

    2016-07-22

    Magnonics is an emerging field dealing with ultralow power consumption logic circuits, in which the flow of spin waves, rather than electric charges, transmits and processes information. Waves, including spin waves, excel at encoding information via their phase using interference. This enables a number of inputs to be processed in one device, which offers the promise of multi-input multi-output logic gates. To realize such an integrated device, it is essential to demonstrate spin wave interferometers using spatially isotropic spin waves with high operational stability. However, spin wave reflection at the waveguide edge has previously limited the stability of interfering waves, precluding the use of isotropic spin waves, i.e., forward volume waves. Here, a spin wave absorber is demonstrated comprising a yttrium iron garnet waveguide partially covered by gold. This device is shown experimentally to be a robust spin wave interferometer using the forward volume mode, with a large ON/OFF isolation value of 13.7 dB even in magnetic fields over 30 Oe.

  4. Development of an Atom Interferometer Gravity Gradiometer for Earth Sciences

    Science.gov (United States)

    Rakholia, A.; Sugarbaker, A.; Black, A.; Kasecivh, M.; Saif, B.; Luthcke, S.; Callahan, L.; Seery, B.; Feinberg, L.; Mather, J.; hide

    2017-01-01

    We report progress towards a prototype atom interferometer gravity gradiometer for Earth science studies from a satellite in low Earth orbit.The terrestrial prototype has a target sensitivity of 8 x 10(exp -2) E/Hz(sup 1/2) and consists of two atom sources running simultaneous interferometers with interrogation time T = 300 ms and 12 hk photon recoils, separated by a baseline of 2 m. By employing Raman side band cooling and magnetic lensing, we will generate atomic ensembles with N = 10(exp 6) atoms at a temperature of 3 nK. The sensitivity extrapolates to 7 x 10(exp -5) E/Hz(sup 1/2) in microgravity on board a satellite. Simulations derived from this sensitivity demonstrate a monthly time-variable gravity accuracy of 1 cm equivalent water height at 200 km resolution, yielding an improvement over GRACE by 1-2 orders of magnitude. A gravity gradiometer with this sensitivity would also benefit future planetary, lunar, and asteroidal missions.

  5. GALARIO: a GPU accelerated library for analysing radio interferometer observations

    Science.gov (United States)

    Tazzari, Marco; Beaujean, Frederik; Testi, Leonardo

    2018-06-01

    We present GALARIO, a computational library that exploits the power of modern graphical processing units (GPUs) to accelerate the analysis of observations from radio interferometers like Atacama Large Millimeter and sub-millimeter Array or the Karl G. Jansky Very Large Array. GALARIO speeds up the computation of synthetic visibilities from a generic 2D model image or a radial brightness profile (for axisymmetric sources). On a GPU, GALARIO is 150 faster than standard PYTHON and 10 times faster than serial C++ code on a CPU. Highly modular, easy to use, and to adopt in existing code, GALARIO comes as two compiled libraries, one for Nvidia GPUs and one for multicore CPUs, where both have the same functions with identical interfaces. GALARIO comes with PYTHON bindings but can also be directly used in C or C++. The versatility and the speed of GALARIO open new analysis pathways that otherwise would be prohibitively time consuming, e.g. fitting high-resolution observations of large number of objects, or entire spectral cubes of molecular gas emission. It is a general tool that can be applied to any field that uses radio interferometer observations. The source code is available online at http://github.com/mtazzari/galario under the open source GNU Lesser General Public License v3.

  6. Operational performance of the TIMED Doppler Interferometer (TIDI)

    Science.gov (United States)

    Skinner, Wilbert R.; Niciejewski, Rick J.; Killeen, Timothy L.; Solomon, Stanley C.; Gablehouse, Daniel; Wu, Qian; Ortland, David; Gell, David A.; Marshall, Alan R.; Wolfe, Edwin, Jr.; Cooper, Marie; Kafkalidis, Julie F.

    2003-11-01

    The TIMED Doppler Interferometer (TIDI) is a Fabry-Perot interferometer designed to measure winds in the mesosphere and thermosphere (60-180 km) as part of the TIMED mission. TIDI is a limb viewer and observes emissions from OI 557.7 nm and rotational lines in the O2(0-0) Atmospheric band. Wind measurement accuracies approach 3 ms-1 in the mesosphere and 15 ms-1 in the thermosphere. The TIDI instrument"s performance during the first year and a half of operation is discussed in this paper. Many subsystems are working as designed. The thermal control system is holding the instrument temperatures at their desired set-points. The CCD detector is working as expected with no changes observed in the gain, bias or read noise. The instrument suffers from a light leak that causes the background to be elevated and increases the uncertainty in the wind measurement. Nothing can be done to eliminate this problem but modeling of the background has eliminated any systematic effect. Water outgassing from the spacecraft or instrument has deposited as ice on some part of the optics and reduced the instrument"s sensitivity. This problem has been reduced by two spacecraft rolls which pointed the TIDI radiator to view more of the earth causing the optics to warm up and sublimate much of the ice.

  7. Wavelength calibration of an imaging spectrometer based on Savart interferometer

    Science.gov (United States)

    Li, Qiwei; Zhang, Chunmin; Yan, Tingyu; Quan, Naicheng; Wei, Yutong; Tong, Cuncun

    2017-09-01

    The basic principle of Fourier-transform imaging spectrometer (FTIS) based on Savart interferometer is outlined. The un-identical distribution of the optical path difference which leads to the wavelength drift of each row of the interferogram is analyzed. Two typical methods for wavelength calibration of the presented system are described. The first method unifies different spectral intervals and maximum spectral frequencies of each row by a reference monochromatic light with known wavelength, and the dispersion compensation of Savart interferometer is also involved. The second approach is based on the least square fitting which builds the functional relation between recovered wavelength, row number and calibrated wavelength by concise equations. The effectiveness of the two methods is experimentally demonstrated with monochromatic lights and mixed light source across the detecting band of the system, and the results indicate that the first method has higher precision and the mean root-mean-square error of the recovered wavelengths is significantly reduced from 19.896 nm to 1.353 nm, while the second method is more convenient to implement and also has good precision of 2.709 nm.

  8. Quantitative phase determination by using a Michelson interferometer

    International Nuclear Information System (INIS)

    Pomarico, Juan A; Molina, Pablo F; Angelo, Cristian D'

    2007-01-01

    The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as refractive index, wavelength, optical thickness, etc. Generally speaking, most of the measurements are carried out by determining phase distortions through the changes in the location and/or shape of the interference fringes. However, the extreme sensitivity of this tool, for which minimum deviations of the conditions of its branches can cause very large modifications in the fringe pattern, makes phase changes difficult to follow and measure. The purpose of this communication is to show that, under certain conditions, the sensitivity of the Michelson interferometer can be 'turned down' allowing the quantitative measurement of phase changes with relative ease. As an example we present how the angle (or, optionally, the refractive index) of a transparent standard optical wedge can be determined. Experimental results are shown and compared with the data provided by the manufacturer showing very good agreement

  9. Achieving resonance in the Advanced LIGO gravitational-wave interferometer

    International Nuclear Information System (INIS)

    Staley, A; Martynov, D; Abbott, R; Adhikari, R X; Arai, K; Brooks, A F; Ballmer, S; Barsotti, L; Evans, M; Fritschel, P; DeRosa, R T; Effler, A; Dwyer, S; Gray, C; Izumi, K; Frolov, V V; Guido, C J; Heintze, M; Gustafson, R; Hoak, D

    2014-01-01

    Interferometric gravitational-wave detectors are complex instruments comprised of a Michelson interferometer enhanced by multiple coupled cavities. Active feedback control is required to operate these instruments and keep the cavities locked on resonance. The optical response is highly nonlinear until a good operating point is reached. The linear operating range is between 0.01% and 1% of a fringe for each degree of freedom. The resonance lock has to be achieved in all five degrees of freedom simultaneously, making the acquisition difficult. Furthermore, the cavity linewidth seen by the laser is only ∼1 Hz, which is four orders of magnitude smaller than the linewidth of the free running laser. The arm length stabilization system is a new technique used for arm cavity locking in Advanced LIGO. Together with a modulation technique utilizing third harmonics to lock the central Michelson interferometer, the Advanced LIGO detector has been successfully locked and brought to an operating point where detecting gravitational-waves becomes feasible. (paper)

  10. Atmospheric Fluctuation Measurements with the Palomar Testbed Interferometer

    Science.gov (United States)

    Linfield, R. P.; Lane, B. F.; Colavita, M. M.; PTI Collaboration

    Observations of bright stars with the Palomar Testbed Interferometer, at a wavelength of 2.2 microns, have been used to measure atmospheric delay fluctuations. The delay structure function Dτ(Δ t) was calculated for 66 scans (each >= 120s in length) on seven nights in 1997 and one in 1998. For all except one scan, Dτ exhibited a clean power law shape over the time interval 50-500 msec. Over shorter time intervals, the effect of the delay line servo loop corrupts Dτ. Over longer time intervals (usually starting at > 1s), the slope of Dτ decreases, presumably due to some combination of saturation e.g. finite turbulent layer thickness) and the effect of the finite wind speed crossing time on our 110 m baseline. The mean power law slopes for the eight nights ranged from 1.16 to 1.36, substantially flatter than the value of 1.67 for three dimensional Kolmogorov turbulence. Such sub-Kolmogorov slopes will result in atmospheric seeling (θ) that improves rapidly with increasing wavelength: θ propto λ1-(2β), where β is the observed power law slope of Dτ. The atmospheric errors in astrometric measurements with an interferometer will average down more quickly than in the Kolmogorov case.

  11. Hand Gesture Recognition Using Ultrasonic Waves

    KAUST Repository

    AlSharif, Mohammed Hussain

    2016-04-01

    Gesturing is a natural way of communication between people and is used in our everyday conversations. Hand gesture recognition systems are used in many applications in a wide variety of fields, such as mobile phone applications, smart TVs, video gaming, etc. With the advances in human-computer interaction technology, gesture recognition is becoming an active research area. There are two types of devices to detect gestures; contact based devices and contactless devices. Using ultrasonic waves for determining gestures is one of the ways that is employed in contactless devices. Hand gesture recognition utilizing ultrasonic waves will be the focus of this thesis work. This thesis presents a new method for detecting and classifying a predefined set of hand gestures using a single ultrasonic transmitter and a single ultrasonic receiver. This method uses a linear frequency modulated ultrasonic signal. The ultrasonic signal is designed to meet the project requirements such as the update rate, the range of detection, etc. Also, it needs to overcome hardware limitations such as the limited output power, transmitter, and receiver bandwidth, etc. The method can be adapted to other hardware setups. Gestures are identified based on two main features; range estimation of the moving hand and received signal strength (RSS). These two factors are estimated using two simple methods; channel impulse response (CIR) and cross correlation (CC) of the reflected ultrasonic signal from the gesturing hand. A customized simple hardware setup was used to classify a set of hand gestures with high accuracy. The detection and classification were done using methods of low computational cost. This makes the proposed method to have a great potential for the implementation in many devices including laptops and mobile phones. The predefined set of gestures can be used for many control applications.

  12. Eight-chord CO2 interferometer for plasma-density measurements on ZT-40

    International Nuclear Information System (INIS)

    Jacobson, A.R.; Jolin, L.J.

    1981-01-01

    We describe a CO 2 laser interferometer which measures the path-integrated density along eight different chords simultaneously in the ZT-40 reversed-field pinch, a toroidal magnetic confinement experiment at Los Alamos. The interferometer system combines several reliable, commercially available components in a package which provides exceptional measurement resolution as well as ease of operation and maintenance

  13. All-silicon thermal independent Mach-Zehnder interferometer with multimode waveguides

    DEFF Research Database (Denmark)

    Guan, Xiaowei; Frandsen, Lars Hagedorn

    2016-01-01

    A novel all-silicon thermal independent Mach-Zehnder interferometer consisting of two multimode waveguide arms having equal lengths and widths but transmitting different modes is proposed and experimentally demonstrated. The interferometer has a temperature sensitivity smaller than 8pm/°C in a wa...

  14. Wide-area phase-contrast X-ray imaging using large X-ray interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi E-mail: momose@exp.t.u-tokyo.ac.jp; Takeda, Tohoru; Yoneyama, Akio; Koyama, Ichiro; Itai, Yuji

    2001-07-21

    Large X-ray interferometers are developed for phase-contrast X-ray imaging aiming at medical applications. A monolithic X-ray interferometer and a separate one are studied, and currently a 25 mmx20 mm view area can be generated. This paper describes the strategy of our research program and some recent developments.

  15. Wide-area phase-contrast X-ray imaging using large X-ray interferometers

    Science.gov (United States)

    Momose, Atsushi; Takeda, Tohoru; Yoneyama, Akio; Koyama, Ichiro; Itai, Yuji

    2001-07-01

    Large X-ray interferometers are developed for phase-contrast X-ray imaging aiming at medical applications. A monolithic X-ray interferometer and a separate one are studied, and currently a 25 mm×20 mm view area can be generated. This paper describes the strategy of our research program and some recent developments.

  16. A heterodyne interferometer with periodic nonlinearities smaller than ±10 pm

    International Nuclear Information System (INIS)

    Weichert, C; Köchert, P; Köning, R; Flügge, J; Andreas, B; Kuetgens, U; Yacoot, A

    2012-01-01

    The PTB developed a new optical heterodyne interferometer in the context of the European joint research project ‘Nanotrace’. A new optical concept using plane-parallel plates and spatially separated input beams to minimize the periodic nonlinearities was realized. Furthermore, the interferometer has the resolution of a double-path interferometer, compensates for possible angle variations between the mirrors and the interferometer optics and offers a minimal path difference between the reference and the measurement arm. Additionally, a new heterodyne phase evaluation based on an analogue to digital converter board with embedded field programmable gate arrays was developed, providing a high-resolving capability in the single-digit picometre range. The nonlinearities were characterized by a comparison with an x-ray interferometer, over a measurement range of 2.2 periods of the optical interferometer. Assuming an error-free x-ray interferometer, the nonlinearities are considered to be the deviation of the measured displacement from a best-fit line. For the proposed interferometer, nonlinearities smaller than ±10 pm were observed without any quadrature fringe correction. (paper)

  17. A heterodyne interferometer with periodic nonlinearities smaller than ±10 pm

    Science.gov (United States)

    Weichert, C.; Köchert, P.; Köning, R.; Flügge, J.; Andreas, B.; Kuetgens, U.; Yacoot, A.

    2012-09-01

    The PTB developed a new optical heterodyne interferometer in the context of the European joint research project ‘Nanotrace’. A new optical concept using plane-parallel plates and spatially separated input beams to minimize the periodic nonlinearities was realized. Furthermore, the interferometer has the resolution of a double-path interferometer, compensates for possible angle variations between the mirrors and the interferometer optics and offers a minimal path difference between the reference and the measurement arm. Additionally, a new heterodyne phase evaluation based on an analogue to digital converter board with embedded field programmable gate arrays was developed, providing a high-resolving capability in the single-digit picometre range. The nonlinearities were characterized by a comparison with an x-ray interferometer, over a measurement range of 2.2 periods of the optical interferometer. Assuming an error-free x-ray interferometer, the nonlinearities are considered to be the deviation of the measured displacement from a best-fit line. For the proposed interferometer, nonlinearities smaller than ±10 pm were observed without any quadrature fringe correction.

  18. Power-recycled michelson interferometer with a 50/50 grating beam splitter

    International Nuclear Information System (INIS)

    Friedrich, D; Burmeister, O; Britzger, M; Bunkowski, A; Danzmann, K; Schnabel, R; Clausnitzer, T; Fahr, S; Kley, E-B; Tuennermann, A

    2008-01-01

    We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about F PR ∼ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed

  19. Power-recycled michelson interferometer with a 50/50 grating beam splitter

    OpenAIRE

    Friedrich, Daniel; Burmeister, O.; Britzger, M.; Bunkowski, A.; Clausnitzer, T.; Fahr, S.; Kley, E.B.; Tünnermann, A.; Danzmann, Karsten; Schnabel, Roman

    2008-01-01

    We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about FPR ≈ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed.

  20. A Fabry-Perot interferometer system for high-speed velocity measurement

    NARCIS (Netherlands)

    Cheng, L.K.; Bruinsma, A.J.A.; Prinse, W.C.; Smorenburg, C.

    1997-01-01

    The Fabry-Perot Velocity Interferometer System (F-PVIS) is designed and built for measuring the Doppler shift of light by recording positional changes in the interferometric pattern behind the Fabry-Perot interferometer. The velocity of a surface can be deduced from the Doppler shift which is caused

  1. Reducing the first-order Doppler shift in a Sagnac interferometer

    NARCIS (Netherlands)

    Hannemann, S.; Salumbides, E.J.; Ubachs, W.M.G.

    2007-01-01

    We demonstrate a technique to reduce first-order Doppler shifts in crossed atomic/molecular and laser beam setups by aligning two counterpropagating laser beams as part of a Sagnac interferometer. Interference fringes on the exit port of the interferometer reveal minute deviations from perfect

  2. Mirrors used in the LIGO interferometers for first detection of gravitational waves.

    Science.gov (United States)

    Pinard, L; Michel, C; Sassolas, B; Balzarini, L; Degallaix, J; Dolique, V; Flaminio, R; Forest, D; Granata, M; Lagrange, B; Straniero, N; Teillon, J; Cagnoli, G

    2017-02-01

    For the first time, direct detection of gravitational waves occurred in the Laser Interferometer Gravitational-wave Observatory (LIGO) interferometers. These advanced detectors require large fused silica mirrors with optical and mechanical properties and have never been reached until now. This paper details the main achievements of these ion beam sputtering coatings.

  3. Germanium on silicon mid-infrared waveguides and Mach-Zehnder interferometers

    NARCIS (Netherlands)

    Malik, A.; Muneeb, M.; Shimura, Y.; Campenhout, van J.; Loo, van de R.; Roelkens, G.C.

    2013-01-01

    In this paper we describe Ge-on-Si waveguides and Mach-Zehnder interferometers operating in the 5.2 - 5.4 µm wavelength range. 3dB/cm waveguide losses and Mach-Zehnder interferometers with 20dB extinction ratio are presented.

  4. Digital holographic amplification of interferograms in the Michelson interferometer using the phase-only LCOS modulator

    Science.gov (United States)

    Balbekin, Nikolay; Petrov, Nikolay; Pul'kin, Sergey; Shoev, Vladislav; Sevryugin, Alexander; Tursunov, Ibrohim; Venediktov, Dmitrii; Venediktov, Vladimir

    2017-10-01

    The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific "hooks", whose curvature provides the information about the atomic oscillator force. The holographic amplification "smoothes" the hooks and thus makes their analysis much simpler.

  5. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature

    NARCIS (Netherlands)

    Schmuck, S.; Fessey, J.; Gerbaud, T.; Alper, B.; Beurskens, M. N. A.; de la Luna, E.; Sirinelli, A.; Zerbini, M.

    2012-01-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron

  6. Design of a Michelson Interferometer for Quantitative Refraction Index Profile Measurements

    NARCIS (Netherlands)

    Nijholt, J.L.M.

    1998-01-01

    This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much

  7. Refractometric sensor based on all-fiber coaxial Michelson and Mach-Zehnder interferometers for ethanol detection in fuel

    International Nuclear Information System (INIS)

    Mosquera, L; Osorio, Jonas H; Hayashi, Juliano G; Cordeiro, Cristiano M B

    2011-01-01

    A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zehnder interferometer and its application to measure ethanol concentration in gasoline.

  8. Ultrasonic monitoring of pitting corrosion

    Science.gov (United States)

    Jarvis, A. J. C.; Cegla, F. B.; Bazaz, H.; Lozev, M.

    2013-01-01

    Exposure to corrosive substances in high temperature environments can cause damage accumulation in structural steels, particularly in the chemical and petrochemical industries. The interaction mechanisms are complex and varied; however initial damage propagation often manifests itself in the form of localized areas of increased material loss. Recent development of an ultrasonic wall thickness monitoring sensor capable of withstanding temperatures in excess of 500°C has allowed permanent monitoring within such hostile environments, providing information on how the shape of a pulse which has reflected from a corroding surface can change over time. Reconstructing localized corrosion depth and position may be possible by tracking such changes in reflected pulse shape, providing extra information on the state of the backwall and whether process conditions should be altered to increase plant life. This paper aims to experimentally investigate the effect certain localized features have on reflected pulse shape by `growing' artificial defects into the backwall while wall thickness is monitored using the sensor. The size and complexity of the three dimensional scattering problem lead to the development of a semi-analytical simulation based on the distributed point source method (DPSM) which is capable of simulating pulse reflection from complex surfaces measuring approximately 17×10λ Comparison to experimental results show that amplitude changes are predicted to within approximately 1dB and that pulse shape changes are accurately modelled. All experiments were carried out at room temperature, measurements at high temperature will be studied in the future.

  9. Optimization of Ultrasonic Fabric Cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Hand, T.E.

    1998-05-13

    The fundamental purpose of this project was to research and develop a process that would reduce the cost and improve the environmental efficiency of the present dry-cleaning industry. This second phase of research (see report KCP-94-1006 for information gathered during the first phase) was intended to allow the optimal integration of all factors of ultrasonic fabric cleaning. For this phase, Garment Care performed an extensive literature search and gathered data from other researchers worldwide. The Garment Care-AlliedSignal team developed the requirements for a prototype cleaning tank for studies and acquired that tank and the additional equipment required to use it properly. Garment Care and AlliedSignal acquired the transducers and generators from Surftran Martin-Walter in Sterling Heights, Michigan. Amway's Kelly Haley developed the test protocol, supplied hundreds of test swatches, gathered the data on the swatches before and after the tests, assisted with the cleaning tests, and prepared the final analysis of the results. AlliedSignal personnel, in conjunction with Amway and Garment Care staff, performed all the tests. Additional planning is under way for future testing by outside research facilities. The final results indicated repeatable performance and good results for single layered fabric swatches. Swatches that were cleaned as a ''sandwich,'' that is, three or more layers.

  10. Instrument development for atmospheric radiation measurement (ARM): Status of the Atmospheric Emitted Radiance Interferometer - extended Resolution (AERI-X), the Solar Radiance Transmission Interferometer (SORTI), and the Absolute Solar Transmission Inferometer (ASTI)

    Energy Technology Data Exchange (ETDEWEB)

    Murcray, F.; Stephen, T.; Kosters, J. [Univ. of Denver, CO (United States)

    1996-04-01

    This paper describes three instruments currently under developemnt for the Atmospheric Radiation Measurement (ARM) Program at the University of Denver: the AERI-X (Atmospheric Emitted Radiance Interferometer-Extended Resolution) and the SORTI (Solar R adiance Transmission Interferometer), and ASTI (Absolute Solar transmission Interferometer).

  11. Very small beam-size measurement by a reflective synchrotron radiation interferometer

    Directory of Open Access Journals (Sweden)

    T. Naito

    2006-12-01

    Full Text Available A synchrotron radiation (SR interferometer with Herschelian reflective optics has been developed for the measurement of beams of several μm in size. In a conventional refractive SR interferometer, the dispersion effect of the objective lens limits the instrument to a smaller range of beam-size measurements. To avoid this problem, we designed a Herschelian arrangement of reflective optics for the interferometer. The effectiveness of the reflective SR interferometer was confirmed at the KEK Accelerator Test Facility (ATF damping ring. The measured vertical beam size obtained using the reflective SR interferometer was 4.7   μm and the estimated vertical emittance was 0.97×10^{-11}   m.

  12. Quantum noise in laser-interferometer gravitational-wave detectors with a heterodyne readout scheme

    International Nuclear Information System (INIS)

    Buonanno, Alessandra; Chen Yanbei; Mavalvala, Nergis

    2003-01-01

    We analyze and discuss the quantum noise in signal-recycled laser interferometer gravitational-wave detectors, such as Advanced LIGO, using a heterodyne readout scheme and taking into account the optomechanical dynamics. Contrary to homodyne detection, a heterodyne readout scheme can simultaneously measure more than one quadrature of the output field, providing an additional way of optimizing the interferometer sensitivity, but at the price of additional noise. Our analysis provides the framework needed to evaluate whether a homodyne or heterodyne readout scheme is more optimal for second generation interferometers from an astrophysical point of view. As a more theoretical outcome of our analysis, we show that as a consequence of the Heisenberg uncertainty principle the heterodyne scheme cannot convert conventional interferometers into (broadband) quantum non-demolition interferometers

  13. A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber

    International Nuclear Information System (INIS)

    Frazão, O; Silva, S F; Viegas, J; Baptista, J M; Santos, J L; Roy, P

    2010-01-01

    A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber is demonstrated. The hybrid interferometer presents three waves. Two parallel Fabry–Perot cavities with low finesse are formed between the splice region and the end of a dual-core microstructured fiber. A Michelson configuration is obtained by the two small cores of the microstructured fiber. The spectral response of the hybrid interferometer presents two pattern fringes with different frequencies due to the respective optical path interferometers. The hybrid interferometer was characterized in strain and temperature presenting different sensitivity coefficients for each topology. Due to these characteristics, this novel sensing head is able to measure strain and temperature, simultaneously

  14. Dual-recycled cavity-enhanced Michelson interferometer for gravitational-wave detection.

    Science.gov (United States)

    Müller, Guido; Delker, Tom; Tanner, David B; Reitze, David

    2003-03-01

    The baseline design for an Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO) is a dual-recycled Michelson interferometer with cavities in each of the Michelson interferometer arms. We describe one possible length-sensing and control scheme for such a dual-recycled, cavity-enhanced Michelson interferometer. We discuss the principles of this scheme and derive the first-order sensing signals. We also present a successful experimental verification of our length-sensing system using a prototype tabletop interferometer. Our results demonstrate the robustness of the scheme against deviations from the idealized design. We also identify potential weaknesses and discuss possible improvements. These results as well as other benchtop experiments that we present form the basis for a sensing and control scheme for Advanced LIGO.

  15. The digital ultrasonic test unit for automatic equipment

    International Nuclear Information System (INIS)

    Hiraoka, T.; Matsuyama, H.

    1976-01-01

    The operations and features of the ultrasonic test unit used and the digital data processing techniques employed are described. This unit is used for a few hundred multi-channel automatic ultrasonic test equipment

  16. Ultrasonic-assisted manufacturing processes: Variational model and numerical simulations

    KAUST Repository

    Siddiq, Amir; El Sayed, Tamer

    2012-01-01

    We present a computational study of ultrasonic assisted manufacturing processes including sheet metal forming, upsetting, and wire drawing. A fully variational porous plasticity model is modified to include ultrasonic softening effects

  17. P-Scan provides accuracy and repeatability in ultrasonics

    International Nuclear Information System (INIS)

    Keys, R.L.

    1987-01-01

    The P-Scan (Projection image scanning technique) is an automated ultrasonic inspection technique, developed to overcome the problems with accuracy and repeatability experienced with manual ultrasonic systems. The equipment and its applications are described. (author)

  18. Method and apparatus to characterize ultrasonically reflective contrast agents

    Science.gov (United States)

    Pretlow, Robert A., III (Inventor)

    1993-01-01

    A method and apparatus for characterizing the time and frequency response of an ultrasonically reflective contrast agent is disclosed. An ultrasonically reflective contrast agent is injected, under constant pressure, into a fluid flowing through a pump flow circuit. The fluid and the ultrasonically reflective contrast agent are uniformly mixed in a mixing chamber, and the uniform mixture is passed through a contrast agent chamber. The contrast agent chamber is acoustically and axially interposed between an ultrasonic transducer chamber and an acoustic isolation chamber. A pulse of ultrasonic energy is transmitted into the contrast agent chamber from the ultrasonic transducer chamber. An echo waveform is received from the ultrasonically reflective contrast agent, and it is analyzed to determine the time and frequency response of the ultrasonically reflective contrast agent.

  19. Automated electronic intruder simulator for evaluation of ultrasonic intrusion detectors

    International Nuclear Information System (INIS)

    1979-01-01

    An automated electronic intruder simulator for testing ultrasonic intrusion detectors is described. This simulator is primarily intended for use in environmental chambers to determine the effects of temperature and humidity on the operation of ultrasonic intrusion detectors

  20. Development and Application of an Ultrasonic Gas Flowmeter

    International Nuclear Information System (INIS)

    Hwang, Won Ho; Jeong, Hee Don; Park, Sang Gug; Jhang, Kyung Young

    2002-01-01

    This paper describes the development and the field application of the ultrasonic gas flowmeter for accurate measurement of the volumetric flow rate of gases in a harsh environmental conditions in iron and steel making company. This ultrasonic flowmeter is especially suited for measuring LDG, COG, BFG gases produced in iron and steel making process. This is a transit time type ultrasonic flowmeter. We have developed the transmitting and receiving algorithm of ultrasonic wave and the ultrasonic signal processing algorithm to develope a transit time type ultrasonic flowmeter. We have evaluated the performance of ultrasonic flowmeter by the calibration system with Venturi type standard flowmeter. We has confirmed its reliability by extensive field tests for a year in POSCO, iron and steel making company. Now we have developed the commercial model of ultrasonic flowmeter and applied to the POSCO gas line

  1. Study on electrical impedance matching for broadband ultrasonic transducer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon Woo [University of Science and Technology, Daejeon (Korea, Republic of); Kim, Ki Bok [Korea Research Institute of Standards and Science, Center for Safety Measurement, Daejeon (Korea, Republic of); Baek, Kwang Sae [Elache Co., Busan (Korea, Republic of)

    2017-02-15

    Ultrasonic transducers with high resolution and resonant frequency are required to detect small defects (less than hundreds of μm) by ultrasonic testing. The resonance frequency and resolution of an ultrasonic transducer are closely related to the thickness of piezo-electric materials, backing materials, and the electric impedance matching technique. Among these factors, electrical impedance matching plays an important role because it can reduce the loss and reflection of ultrasonic energy differences in electrical impedance between an ultrasonic transducer and an ultrasonic defects detecting system. An LC matching circuit is the most frequently used electric matching method. It is necessary for the electrical impedance of an ultrasonic transducer to correspond to approximately 50 Ω to compensate the difference in electrical impedance between both connections. In this study, a 15 MHz immersion ultrasonic transducer was fabricated and an LC electrical impedance circuit was applied to that for having broad-band frequency characteristic.

  2. Ultrasonic extraction of flavonoids and phenolics from loquat ...

    African Journals Online (AJOL)

    Administrator

    2011-06-08

    Jun 8, 2011 ... ultrasonic pharmaceutical managing machine (Sinobest electronic. Co. Ltd., Jining, Shangdong ... During the ultrasonic treatment, the temperature ..... essential oil extraction by a hydrodistillation process using a 2(4) complete ...

  3. Electrocautery causes more ischemic peritoneal tissue damage than ultrasonic dissection.

    NARCIS (Netherlands)

    Broek, R.P.G ten; Wilbers, J.; Goor, H. van

    2011-01-01

    BACKGROUND: Minimizing peritoneal tissue injury during abdominal surgery has the benefit of reducing postoperative inflammatory response, pain, and adhesion formation. Ultrasonic dissection seems to reduce tissue damage. This study aimed to compare electrocautery and ultrasonic dissection in terms

  4. Studies on Section XI ultrasonic repeatability

    International Nuclear Information System (INIS)

    Jamison, T.D.; McDearman, W.R.

    1981-05-01

    A block representative of a nuclear component has been welded containing intentional defects. Acoustic emission data taken during the welding correlate well with ultrasonic data. Repetitive ultrasonic examinations have been performed by skilled operators using a procedure based on that desribed in ASME Section XI. These examinations were performed by different examination teams using different ultrasonic equipment in such a manner that the effects on the repeatability of the ultrasonic test method caused by the operator and by the use of different equipment could be estimated. It was tentatively concluded that when considering a large number of inspections: (1) there is no significant difference in indication sizing between operators, and (2) there is a significant difference in amplitude and defect sizing when instruments having different, Code acceptable operating characteristics are used. It was determined that the Section XI sizing parameters follow a bivariate normal distribution. Data derived from ultrasonically and physically sizing indications in nuclear components during farication show that the Section XI technique tends to overestimate the size of the reflectors

  5. Further Investigations on Simultaneous Ultrasonic Coal Flotation

    Directory of Open Access Journals (Sweden)

    Safak Gokhan Ozkan

    2017-09-01

    Full Text Available This study investigates the flotation performance of a representative hard coal slime sample (d80 particle size of minus 0.2 mm obtained from the Prosper-Haniel coal preparation plant located in Bottrop, Germany. Flotation was carried out with a newly designed flotation cell refurbished from an old ultrasonic cleaning bath (2.5 L volume equipped with a single frequency (35 kHz and two different power levels (80–160 W and a sub-aeration-type flotation machine operating at a stable impeller speed (1200 rpm and air rate (2.5 L/min. The reagent combination for conventional and simultaneous ultrasonic coal flotation tests was Ekofol-440 at variable dosages (40–300 g/t with controlling water temperature (20–25 °C at natural pH (6.5–7.0. The batch coal flotation results were analyzed by comparing the combustible recovery (% and separation efficiency (% values, taking mass yield and ash concentrations of the froths and tailings into account. It was found that simultaneous ultrasonic coal flotation increased yield and recovery values of the floated products with lower ash values than the conventional flotation despite using similar reagent dosages. Furthermore, particle size distribution of the ultrasonically treated and untreated coals was measured. Finely distributed coal particles seemed to be agglomerated during the ultrasonic treatment, while ash-forming slimes were removed by hydrodynamic cavitation.

  6. Standard practice for leaks using ultrasonics

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 Practice A, Pressurization—This practice covers procedures for calibration of ultrasonic instruments, location, and estimated measurements of gas leakage to atmosphere by the airborne ultrasonic technique. 1.2 In general practice this should be limited to leaks detected by two classifications of instruments, Class I and Class II. Class I instruments should have a minimum detectable leak rate of 6.7 × 10−7 mol/s (1.5 × 10−2 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Class II instruments should have a minimal detectable leak rate of 6.7 × 10−6 mol/s (1.5 × 10−1 std. cm3/s at 0°C) or more for the pressure method of gas leakage to atmosphere. Refer to Guide E432 for additional information. 1.3 Practice B, Ultrasonic Transmitter—For object under test not capable of being pressurized but capable of having ultrasonic tone placed/injected into the test area to act as an ultrasonic leak trace source. 1.3.1 This practice is limited to leaks producing leakage o...

  7. Ultrasonic imaging in LMFBRs using digital techniques

    International Nuclear Information System (INIS)

    Fothergill, J.R.; McKnight, J.A.; Barrett, L.M.

    Ultrasonic technology for providing images of components immersed in the opaque sodium of LMFBRs is being developed at RNL. For many years the application has been restricted by the unavailability of convenient ultrasonic sources and receivers capable of withstanding the reactor environment. Until recently, for example, important ultrasonic instrument design, such as for future sweep arms, had to be based on waveguided ultrasonics. RNL have developed an economic immersible transducer that can be deployed during reactor shut-down, when many demands for ultrasonic imaging are made. The transducer design is not suited at present to the sophisticated techniques of phased arrays; consequently image formation must depend on the physical scanning of a target using one or more transducers in pulse-echo mode. The difficulties of access into a fast reactor impose further restrictions. Some applications may involve easy scanning sequences, thus the sweep arm requires only a rotation to provide a map of the reactor core area. For a more detailed examination of the same area, however, special engineering solutions are needed to provide a more satisfactory scanning sequence. A compromise solution involving the rotating shield movement is being used for a PFR experiment to examine a limited area of the core. (author)

  8. Uncertainty estimation of ultrasonic thickness measurement

    International Nuclear Information System (INIS)

    Yassir Yassen, Abdul Razak Daud; Mohammad Pauzi Ismail; Abdul Aziz Jemain

    2009-01-01

    The most important factor that should be taken into consideration when selecting ultrasonic thickness measurement technique is its reliability. Only when the uncertainty of a measurement results is known, it may be judged if the result is adequate for intended purpose. The objective of this study is to model the ultrasonic thickness measurement function, to identify the most contributing input uncertainty components, and to estimate the uncertainty of the ultrasonic thickness measurement results. We assumed that there are five error sources significantly contribute to the final error, these sources are calibration velocity, transit time, zero offset, measurement repeatability and resolution, by applying the propagation of uncertainty law to the model function, a combined uncertainty of the ultrasonic thickness measurement was obtained. In this study the modeling function of ultrasonic thickness measurement was derived. By using this model the estimation of the uncertainty of the final output result was found to be reliable. It was also found that the most contributing input uncertainty components are calibration velocity, transit time linearity and zero offset. (author)

  9. Ultrasonic scanner for stainless steel weld inspections. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Kupperman, D. S.; Reimann, K. J.

    1978-09-01

    The large grain size and anisotropic nature of stainless steel weld metal make conventional ultrasonic testing very difficult. A technique is evaluated for minimizing the coherent ultrasonic noise in stainless steel weld metal. The method involves digitizing conventional ''A-scan'' traces and averaging them with a minicomputer. Results are presented for an ultrasonic scanner which interrogates a small volume of the weld metal while averaging the coherent ultrasonic noise.

  10. Training methods in non-destructive examination with ultrasonic testing

    International Nuclear Information System (INIS)

    Walte, F.

    1986-01-01

    German concept for inspection of LWR, leak before break, basic safety; General inspection methods; Ultrasonic inspection - basic principle, generation of ultrasound, bulk and surface waves, piezo electric and electromagnetic transducers, energy balance, scattering and adsorption, divergence; Ultra techniques in compliance with KTA-rules - pulse-echo, tandem, throughtransmission; Valuation of ultrasonic indications; Pre- and in-service inspection; Practical part - ultrasonic equipment, ultrasonic piezo electric transducers, wall thickness measurement, crack depth measurement with potential drop technique. (orig.)

  11. Ultrasonic Cleaning of Nuclear Steam Generator by Micro Bubble

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo Tae [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of); Kim, Sang Tae; Yoon, Sang Jung [Sae-An Engineering Co., Seoul (Korea, Republic of)

    2012-05-15

    In this paper, we present ultrasonic cleaning technology for a nuclear steam generator using micro bubble. We could extend the boundary of ultrasonic cleaning by using micro bubbles in water. Ultrasonic energy measured was increased about 5 times after the generation of micro bubbles in water. Furthermore, ultrasound energy was measured to be strong enough to create cavitation even though the ultrasound sensor was about 2 meters away from the ultrasonic transducer

  12. Handheld White Light Interferometer for Measuring Defect Depth in Windows

    Science.gov (United States)

    Youngquist, Robert; Simmons, Stephen; Cox, Robert

    2010-01-01

    Accurate quantification of defects (scratches and impacts) is vital to the certification of flight hardware and other critical components. The amount of damage to a particular component contributes to the performance, reliability, and safety of a system, which ultimately affects the success or failure of a mission or test. The launch-commit criteria on a Space Shuttle Orbiter window are governed by the depth of the defects that are identified by a visual inspection. This measurement of a defect is not easy to obtain given the environment, size of the defect, and location of the window(s). The determination of depth has typically been performed by taking a mold impression and measuring the impression with an optical profiling instrument. Another method of obtaining an estimate of the depth is by using a refocus microscope. To use a refocus microscope, the surface of the glass and bottom of the defect are, in turn, brought into focus by the operator. The amount of movement between the two points corresponds to the depth of the defect. The refocus microscope requires a skilled operator and has been proven to be unreliable when used on Orbiter windows. White light interferometry was chosen as a candidate to replace the refocus microscope. The White Light Interferometer (WLI) was developed to replace the refocus microscope as the instrument used for measuring the depth of defects in Orbiter windows. The WLI consists of a broadband illumination source, interferometer, detector, motion control, displacement sensor, mechanical housing, and support electronics. The illumination source for the WLI is typically a visible light emitting diode (LED) or a near-infrared superluminescent diode (SLD) with power levels of less than a milliwatt. The interferometer is a Michelson configuration consisting of a 1-in. (2.5-cm) cube beam splitter, a 0.5-in. (1.3-cm) optical window as a movable leg (used to closely match the return intensity of the fixed leg from the window), and a

  13. Experiences in using ultrasonic holography with numerical and optical reconstruction

    International Nuclear Information System (INIS)

    Schmitz, V.; Wosnitza, M.

    1978-01-01

    At present, ultrasonic holography can resolve and image faults of 1 mm and more and with distances of one ultrasonic wavelength. The main field of application is for thick-walled structural components. Depending on the expected orientation, test probe arrangements as in standard ultrasonic testing are chosen. (orig./RW) [de

  14. Numerical shaping of the ultrasonic wavelet

    International Nuclear Information System (INIS)

    Bonis, M.

    1991-01-01

    Improving the performance and the quality of ultrasonic testing requires the numerical control of the shape of the driving signal applied to the piezoelectric transducer. This allows precise shaping of the ultrasonic field wavelet and corrections for the physical defects of the transducer, which are mainly due to the damper or the lens. It also does away with the need for an accurate electric matching. It then becomes feasible to characterize, a priori, the ultrasonic wavelet by means of temporal and/or spectral specifications and to use, subsequently, an adaptative algorithm to calculate the corresponding driving wavelet. Moreover, the versatility resulting from the numerical control of this wavelet allows it to be changed in real time during a test

  15. Method of noncontacting ultrasonic process monitoring

    Science.gov (United States)

    Garcia, Gabriel V.; Walter, John B.; Telschow, Kenneth L.

    1992-01-01

    A method of monitoring a material during processing comprising the steps of (a) shining a detection light on the surface of a material; (b) generating ultrasonic waves at the surface of the material to cause a change in frequency of the detection light; (c) detecting a change in the frequency of the detection light at the surface of the material; (d) detecting said ultrasonic waves at the surface point of detection of the material; (e) measuring a change in the time elapsed from generating the ultrasonic waves at the surface of the material and return to the surface point of detection of the material, to determine the transit time; and (f) comparing the transit time to predetermined values to determine properties such as, density and the elastic quality of the material.

  16. Determine bond strength by ultrasonic measurement

    International Nuclear Information System (INIS)

    Brown, C.M.

    1978-01-01

    Application of ultrasonic methods for the evaluation and measurement of bond strength has been the object of numerous investigations in the last fifteen years. Some investigators have reported good success (in limited application) while others have experienced dismal failure. One problem common to all investigations was the difficulty in extracting and isolating the many components which comprise the ultrasonic signal reflected from a bonded interface. Part of this problem was due to manually extracting individual parameters from large volumes of raw data. However, with the vast technology now available in the field of signal analysis and computerized data processing, it is feasible to isolate and analyze individual parameters within the ultrasonic signal for great volumes of raw data

  17. Ultrasonic filtration of industrial chemical solutions

    Science.gov (United States)

    Cosma, T.

    1974-01-01

    The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

  18. Ultrasonic grinding of optical materials

    Science.gov (United States)

    Cahill, Michael; Bechtold, Michael; Fess, Edward; Stephan, Thomas; Bechtold, Rob

    2017-10-01

    Hard ceramic optical materials such as sapphire, ALON, Spinel, PCA, or Silicon Carbide can present a significant challenge in manufacturing precision optical components due to their tough mechanical properties. These are also the same mechanical properties that make them desirable materials when used in harsh environments. Slow processing speeds, premature tool wear, and poor surface quality are common results of the tough mechanical properties of these materials. Often, as a preparatory stage for polishing, the finish of the ground surface greatly influences the polishing process and the resulting finished product. To overcome these challenges, OptiPro Systems has developed an ultrasonic assisted grinding technology, OptiSonic, which has been designed for the precision optics and ceramics industry. OptiSonic utilizes a custom tool holder designed to produce oscillations, in microns of amplitude, in line with the rotating spindle. A software package, IntelliSonic, is integral to the function of this platform. IntelliSonic can automatically characterize tooling during setup to identify and select the ideal resonant peak which to operate at. Then, while grinding, IntelliSonic continuously adjusts the output frequency for optimal grinding efficiency while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more precise surface. Utilizing a variety of instruments, tests have proven to show a reduction in force between tool and part by up to 50%, while increasing the surface quality and reducing tool wear. This paper will present the challenges associated with these materials and solutions created to overcome them.

  19. Ultrasonic sludge pretreatment under pressure.

    Science.gov (United States)

    Le, Ngoc Tuan; Julcour-Lebigue, Carine; Delmas, Henri

    2013-09-01

    The objective of this work was to optimize the ultrasound (US) pretreatment of sludge. Three types of sewage sludge were examined: mixed, secondary and secondary after partial methanisation ("digested" sludge). Thereby, several main process parameters were varied separately or simultaneously: stirrer speed, total solid content of sludge (TS), thermal operating conditions (adiabatic vs. isothermal), ultrasonic power input (PUS), specific energy input (ES), and for the first time external pressure. This parametric study was mainly performed for the mixed sludge. Five different TS concentrations of sludge (12-36 g/L) were tested for different values of ES (7000-75,000 kJ/kgTS) and 28 g/L was found as the optimum value according to the solubilized chemical oxygen demand in the liquid phase (SCOD). PUS of 75-150 W was investigated under controlled temperature and the "high power input - short duration" procedure was the most effective at a given ES. The temperature increase in adiabatic US application significantly improved SCOD compared to isothermal conditions. With PUS of 150 W, the effect of external pressure was investigated in the range of 1-16 bar under isothermal and adiabatic conditions for two types of sludge: an optimum pressure of about 2 bar was found regardless of temperature conditions and ES values. Under isothermal conditions, the resulting improvement of sludge disintegration efficacy as compared to atmospheric pressure was by 22-67% and 26-37% for mixed and secondary sludge, respectively. Besides, mean particle diameter (D[4,3]) of the three sludge types decreased respectively from 408, 117, and 110 μm to about 94-97, 37-42, and 36-40 μm regardless of sonication conditions, and the size reduction process was much faster than COD extraction. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Advances in ultrasonic fuel cleaning

    International Nuclear Information System (INIS)

    Blok, J.; Frattini, P.; Moser, T.

    2002-01-01

    The economics of electric generation is requiring PWR plant operators to consider higher fuel duty and longer cycles. As a result, sub-cooled nucleate boiling is now an accepted occurrence in the upper spans of aggressively driven PWR cores. Thermodynamic and hydraulic factors determine that the boiling surfaces of the fuel favor deposition of corrosion products. Thus, the deposits on high-duty fuel tend to be axially distributed in an inhomogeneous manner. Axial offset anomaly (AOA) is the result of axially non-homogeneous distribution of boron compounds in these axially variable fuel deposits. Besides their axial asymmetry, fuel deposits in boiling cores tend to be qualitatively different from deposits on non-boiling fuel. Thus, deposits on moderate-duty PWR fuel are generally iron rich, predominating in nickel ferrites. Deposits on cores with high boiling duty, on the other hand, tend to be rich in nickel, with sizeable fractions of NiO or elemental nickel. Other unexpected compounds such as m-ZrO 2 and Ni-Fe oxy-borates have been found in significant quantity in deposits on boiling cores. This paper describes the ultrasonic fuel cleaning technology developed by EPRI. Data will be presented to confirm that the method is effective for removing fuel deposits from both high-duty and normal-duty fuel. The report will describe full-core fuel cleaning using the EPRI technology for Callaway Cycle 12 reload fuel. The favorable impact of fuel cleaning on Cycle 12 AOA performance will also be presented. (authors)

  1. Development of coaxial ultrasonic probe for fatty liver diagnostic system using ultrasonic velocity change

    Science.gov (United States)

    Hori, Makoto; Yokota, Daiki; Aotani, Yuhei; Kumagai, Yuta; Wada, Kenji; Matsunaka, Toshiyuki; Morikawa, Hiroyasu; Horinaka, Hiromichi

    2017-07-01

    A diagnostic system for fatty liver at an early stage is needed because fatty liver is linked to metabolic syndrome. We have already proposed a fatty liver diagnosis method based on the temperature coefficient of ultrasonic velocity. In this study, we fabricated a coaxial ultrasonic probe by integrating two kinds of transducers for warming and signal detection. The diagnosis system equipped with the coaxial probe was applied to tissue-mimicking phantoms including the fat area. The fat content rates corresponding to the set rates of the phantoms were estimated by the ultrasonic velocity-change method.

  2. Ultrasonic unit for line-by-line ultrasonic scanning of bodies

    International Nuclear Information System (INIS)

    Soldner, R.

    1978-01-01

    The ultrasonic unit for medical diagnostics operates by the sectorial scanning principle, which avoids direct coupling of the transducer head to the surface of the body. For this purpose, several transmitter/receiver units (approx. 100) are arranged on a partial ring of a circular arc and the ultrasonic beams, which can be triggered sequentially in time, are directed at a common intersection behind the ultrasonic window of the unit, i.e., outside the unit. A mechanical system is employed to set and adjust the partial ring carrying the transmitter/receiver units. (DG) [de

  3. Self-noise in interferometers - radio and infrared

    International Nuclear Information System (INIS)

    Kulkarni, S.R.

    1989-01-01

    A complete theory of noise in a synthesis image is proposed for a source of arbitrary strength. In the limit of faint sources, the standard estimates of noise in a synthesis image are recovered, while in the limit of strong sources, the noise in the synthesis image is found to be dominated by either self noise or by the noise generated by the source signal itself. It is found that the best VLBI maps (with noise approaching the thermal noise) may in fact be limited by self noise, and that there is a negligible bias in the standard definitions of the bispectrum phasor and the closure phase. The results suggest that at the low signal levels which are characteristic of infrared interferometers, it is best to fit the model to all the closure phases and fringe amplitudes. 13 refs

  4. Nanonewton force measurement using a modified Michelson interferometer

    International Nuclear Information System (INIS)

    Tahviliyan, Masoud; Charsooghi, Mohammad A; Akhlaghi, Ehsan A; Taghi Tavassoly, Mohammad

    2017-01-01

    In this paper, we introduce a new method to measure forces in the nanonewton range. The method is based on modification of a Michelson interferometer in which the rigid mirrors are replaced with two thin rod-like mirrors. One of the rod-like mirrors is fixed at both ends and the other has one free end. As the mirror with free end deflects in response to an applied force the spatial interference pattern is changed. Analysis of the interference fringes provides a readout of the rod deflection and thereby the applied force. The device is calibrated by applying known forces to the mirror with a free end and measuring the resulting displacement. Two different methods, mechanical and electrostatic, are used for calibration. The precision of the measurements and the propagation of the calibration uncertainty are investigated. The results show that this optical method is a good candidate for detecting small forces in the nanonewton range. (paper)

  5. Statistical measures of Planck scale signal correlations in interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Craig J. [Univ. of Chicago, Chicago, IL (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Kwon, Ohkyung [Univ. of Chicago, Chicago, IL (United States)

    2015-06-22

    A model-independent statistical framework is presented to interpret data from systems where the mean time derivative of positional cross correlation between world lines, a measure of spreading in a quantum geometrical wave function, is measured with a precision smaller than the Planck time. The framework provides a general way to constrain possible departures from perfect independence of classical world lines, associated with Planck scale bounds on positional information. A parametrized candidate set of possible correlation functions is shown to be consistent with the known causal structure of the classical geometry measured by an apparatus, and the holographic scaling of information suggested by gravity. Frequency-domain power spectra are derived that can be compared with interferometer data. As a result, simple projections of sensitivity for specific experimental set-ups suggests that measurements will directly yield constraints on a universal time derivative of the correlation function, and thereby confirm or rule out a class of Planck scale departures from classical geometry.

  6. Levitated optomechanics with a fiber Fabry-Perot interferometer

    Science.gov (United States)

    Pontin, A.; Mourounas, L. S.; Geraci, A. A.; Barker, P. F.

    2018-02-01

    In recent years, quantum phenomena have been experimentally demonstrated on variety of optomechanical systems ranging from micro-oscillators to photonic crystals. Since single photon couplings are quite small, most experimental approaches rely on the realization of high finesse Fabry-Perot cavities in order to enhance the effective coupling. Here we show that by exploiting a, long path, low finesse fiber Fabry-Perot interferometer ground state cooling can be achieved. We model a 100 m long cavity with a finesse of 10 and analyze the impact of additional noise sources arising from the fiber. As a mechanical oscillator we consider a levitated microdisk but the same approach could be applied to other optomechanical systems.

  7. Interferometer for electron density measurement in exploding wire plasma

    International Nuclear Information System (INIS)

    Batra, Jigyasa; Jaiswar, Ashutosh; Kaushik, T.C.

    2016-12-01

    Mach-Zehnder Interferometer (MZI) has been developed for measuring electron density profile in pulsed plasmas. MZI is to be used for characterizing exploding wire plasmas for correlating electron density dynamics with x-rays emission. Experiments have been carried out for probing electron density in pulsed plasmas produced in our laboratory like in spark gap and exploding wire plasmas. These are microsecond phenomenon. Changes in electron density have been registered in interferograms with the help of a streak camera for specific time window. Temporal electron density profiles have been calculated by analyzing temporal fringe shifts in interferograms. This report deals with details of MZI developed in our laboratory along with its theory. Basic introductory details have also been provided for exploding wire plasmas to be probed. Some demonstrative results of electron density measurements in pulsed plasmas of spark gap and single exploding wires have been described. (author)

  8. All-optical negabinary adders using Mach-Zehnder interferometer

    Science.gov (United States)

    Cherri, A. K.

    2011-02-01

    In contrast to optoelectronics, all-optical adders are proposed where all-optical signals are used to represent the input numbers and the control signals. In addition, the all-optical adders use the negabinary modified signed-digit number representation (an extension of the negabinary number system) to represent the input digits. Further, the ultra-speed of the designed circuits is achieved due to the use of ultra-fast all-optical switching property of the semiconductor optical amplifier and Mach-Zehnder interferometer (SOA-MZI). Furthermore, two-bit per digit binary encoding scheme is employed to represent the trinary values of the negabinary modified signed-digits.

  9. Miniature interferometer for refractive index measurement in microfluidic chip

    Science.gov (United States)

    Chen, Minghui; Geiser, Martial; Truffer, Frederic; Song, Chengli

    2012-12-01

    The design and development of the miniaturized interferometer for measurement of the refractive index or concentration of sub-microliter volume aqueous solution in microfludic chip is presented. It is manifested by a successful measurement of the refractive index of sugar-water solution, by utilizing a laser diode for light source and the small robust instrumentation for practical implementation. Theoretically, the measurement principle and the feasibility of the system are analyzed. Experimental device is constructed with a diode laser, lens, two optical plate and a complementary metal oxide semiconductor (CMOS). Through measuring the positional changes of the interference fringes, the refractive index change are retrieved. A refractive index change of 10-4 is inferred from the measured image data. The entire system is approximately the size of half and a deck of cards and can operate on battery power for long time.

  10. LIGO: the Laser Interferometer Gravitational-Wave Observatory

    International Nuclear Information System (INIS)

    Abbott, B P; Abbott, R; Adhikari, R; Anderson, S B; Araya, M; Armandula, H; Aso, Y; Ballmer, S; Ajith, P; Allen, B; Aulbert, C; Allen, G; Amin, R S; Anderson, W G; Armor, P; Arain, M A; Aston, S; Aufmuth, P; Babak, S; Baker, P

    2009-01-01

    The goal of the Laser Interferometric Gravitational-Wave Observatory (LIGO) is to detect and study gravitational waves (GWs) of astrophysical origin. Direct detection of GWs holds the promise of testing general relativity in the strong-field regime, of providing a new probe of exotic objects such as black holes and neutron stars and of uncovering unanticipated new astrophysics. LIGO, a joint Caltech-MIT project supported by the National Science Foundation, operates three multi-kilometer interferometers at two widely separated sites in the United States. These detectors are the result of decades of worldwide technology development, design, construction and commissioning. They are now operating at their design sensitivity, and are sensitive to gravitational wave strains smaller than one part in 10 21 . With this unprecedented sensitivity, the data are being analyzed to detect or place limits on GWs from a variety of potential astrophysical sources.

  11. Detection prospects for the Cosmic Neutrino Background using laser interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Domcke, Valerie [AstroParticule et Cosmologie (APC)/Paris Centre for Cosmological Physics, Université Paris Diderot, Rue Alice Domon et Leonie Duquet, Paris (France); Spinrath, Martin, E-mail: valerie.domcke@apc.univ-paris7.fr, E-mail: martin.spinrath@cts.nthu.edu.tw [Physics Division, National Center for Theoretical Sciences, National Tsing-Hua University, Hsinchu, 30013, Taiwan (China)

    2017-06-01

    The cosmic neutrino background is a key prediction of Big Bang cosmology which has not been observed yet. The movement of the earth through this neutrino bath creates a force on a pendulum, as if it were exposed to a cosmic wind. We revise here estimates for the resulting pendulum acceleration and compare it to the theoretical sensitivity of an experimental setup where the pendulum position is measured using current laser interferometer technology as employed in gravitational wave detectors. We discuss how a significant improvement of this setup can be envisaged in a micro gravity environment. The proposed setup could also function as a dark matter detector in the sub-MeV range, which currently eludes direct detection constraints.

  12. High data-rate atom interferometers through high recapture efficiency

    Science.gov (United States)

    Biedermann, Grant; Rakholia, Akash Vrijal; McGuinness, Hayden

    2015-01-27

    An inertial sensing system includes a magneto-optical trap (MOT) that traps atoms within a specified trapping region. The system also includes a cooling laser that cools the trapped atoms so that the atoms remain within the specified region for a specified amount of time. The system further includes a light-pulse atom interferometer (LPAI) that performs an interferometric interrogation of the atoms to determine phase changes in the atoms. The system includes a controller that controls the timing of MOT and cooling laser operations, and controls the timing of interferometric operations to substantially recapture the atoms in the specified trapping region. The system includes a processor that determines the amount inertial movement of the inertial sensing system based on the determined phase changes in the atoms. Also, a method of inertial sensing using this inertial sensing system includes recapture of atoms within the MOT following interferometric interrogation by the LPAI.

  13. WAMDII: The Wide Angle Michelson Doppler Imaging Interferometer

    Science.gov (United States)

    1992-01-01

    As part of an effort to learn more about the upper atmosphere and how it is linked to the weather experienced each day, NASA and NRCC are jointly sponsoring the Wide Angle Michelson Doppler Imaging Interferometer (WAMDII) Mission. WAMDII will measure atmospheric temperature and wind speed in the upper atmosphere. In addition to providing data on the upper atmosphere, the wind speed and temperature readings WAMDII takes will also be highly useful in developing and updating computer simulated models of the upper atmosphere. These models are used in the design and testing of equipment and software for Shuttles, satellites, and reentry vehicles. In making its wind speed and temperature measurements, WAMDII examines the Earth's airglow, a faint photochemical luminescence caused by the influx of solar ultraviolet energy into the upper atmosphere. During periods of high solar flare activity, the amount of this UV energy entering the upper atmosphere increases, and this increase may effect airglow emissions.

  14. Investigation of michelson interferometer for volatile organic compound sensor

    International Nuclear Information System (INIS)

    Marzuarman; Rivai, Muhammad; Sardjono, Tri Arief; Purwanto, Djoko

    2017-01-01

    The sensor device is required to monitor harmful gases in the environments and industries. Many volatile organic compounds adsorbed on the sensor material will result in changes of the optical properties including the refractive index and the film thickness. This study designed and realized a vapor detection device using the principle of Michelson Interferometer. The laser light beamed with a wavelength of 620 nm was divided by using a beam splitter. Interference occurredwhen the two separated lights were recombined. The phase difference between the two beams determined whether the interference would destruct or construct each other to produce the curved fringes. The vapor samples used in these experiments were ethanol and benzene. The results showed that the ethanol concentration of 1611-32210 ppm produced a fringe shift of 197 pixels, while the concentration of benzene of 964-19290 ppm produced a fringe shift of 273 pixels. (paper)

  15. Transverse coherence measurement using a folded Michelson interferometer.

    Science.gov (United States)

    Dean, Jesse; Bercx, Martin; Nantel, Marc; Marjoribanks, Robin

    2007-06-01

    The transverse coherence of a 1 ps pulsed laser beam was measured using a technique involving a modified Michelson interferometer and separate reference images. Using this technique, the transverse coherence of a selected plane in the laser beam was determined, in this case at the exit of a channel in a metal foil self-drilled by the laser. Images of each arm were used as references. Through this technique, it is possible to use the interference patterns produced with uneven intensity distributions and for pulsed lasers on a single-shot basis. The results of these measurements were then shown to be in agreement with those obtained using a Young's double-slit setup.

  16. Wide angle Michelson Doppler imaging interferometer. [measuring atmospheric emissions

    Science.gov (United States)

    Shepherd, G. G.

    1980-01-01

    The optical system, stepping control, phase and modulation depth, array detector, and directions sensor are described for a specialized type of Michelson interferometer which works at sufficiently high resolution to measure the line widths and Doppler shifts of naturally occurring atmospheric emissions. With its imaging capability, the instrument can potentially supply this data independently for each element of the 100 x 100 detector array. The experiment seeks: (1) to obtain vertical profiles of atmospheric winds and temperatures as functions of latitude by observing near the limb; (2) to acquire exploratory wind and temperature data on smaller scale structures in airglow irregularities and in auroral forms; and (3) to collaborate with other Spacelab experiments, such as barium cloud releases, in providing wind and temperature data.

  17. Dissipative optomechanics in a Michelson-Sagnac interferometer.

    Science.gov (United States)

    Xuereb, André; Schnabel, Roman; Hammerer, Klemens

    2011-11-18

    Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson-Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-the-art parameters, ground-state cooling and low-power quantum-limited position transduction are both possible. The possibility of a strong, tunable dissipative coupling opens up a new route towards observation of such fundamental optomechanical effects as nonlinear dynamics. Beyond optomechanics, the suggested method can be readily transferred to other setups involving nonlinear media, atomic ensembles, or single atoms.

  18. The tempo-spatially modulated polarization atmosphere Michelson interferometer.

    Science.gov (United States)

    Zhang, ChunMin; Zhu, HuaChun; Zhao, Baochang

    2011-05-09

    A space-based tempo-spatially modulated polarization atmosphere Michelson interferometer (TSMPAMI) is described. It uses the relative movement between the TSMPAMI and the measured target to change optical path difference. The acquisition method of interferogram is presented. The atmospheric temperatures and horizontal winds can be derived from the optical observations. The measurement errors of the winds and temperatures are discussed through simulations. In the presence of small-scale structures of the atmospheric fields, the errors are found to be significantly influenced by the mismatch of the scenes observed by the adjacent CCD sub-areas aligned along the orbiter's track during successive measurements due to the orbital velocity and the exposure time. For most realistic conditions of the orbit and atmosphere, however, the instrument is proven suitable for measuring the atmospheric parameters. © 2011 Optical Society of America

  19. Horizontal-view interferometer on TEXT-Upgrade

    International Nuclear Information System (INIS)

    Jiang, Y.; Brower, D.L.

    1994-01-01

    The first experimental results from the horizontal-view, multichannel, heterodyne FIR interferometer system on TEXT-Upgrade are reported. The system employs parabolic beam-expansion optics and a 15 cm array with minimum channel spacing of 1.5 cm. Profiles of the plasma electron density will be presented. In addition, small-amplitude density perturbations resulting from sawteeth and tearing modes are examined. Due to the double-pass of the laser beam through the plasma and the large distance of the detector array [2.5 m] from the plasma, refractive effects must be addressed for densities greater than 2 x 10 13 cm -3 . A ray tracing code is developed to correct the measured profiles

  20. Camera-based micro interferometer for distance sensing

    Science.gov (United States)

    Will, Matthias; Schädel, Martin; Ortlepp, Thomas

    2017-12-01

    Interference of light provides a high precision, non-contact and fast method for measurement method for distances. Therefore this technology dominates in high precision systems. However, in the field of compact sensors capacitive, resistive or inductive methods dominates. The reason is, that the interferometric system has to be precise adjusted and needs a high mechanical stability. As a result, we have usual high-priced complex systems not suitable in the field of compact sensors. To overcome these we developed a new concept for a very small interferometric sensing setup. We combine a miniaturized laser unit, a low cost pixel detector and machine vision routines to realize a demonstrator for a Michelson type micro interferometer. We demonstrate a low cost sensor smaller 1cm3 including all electronics and demonstrate distance sensing up to 30 cm and resolution in nm range.