WorldWideScience

Sample records for deflection detector noise

  1. Effect of deflecting ring on noise generated by outdoor set of a split-unit air conditioner

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Junwei; Ding, Guoliang [Institute of Refrigeration and Cryogenics, Shanghai JiaoTong University, Shanghai 200030 (China)

    2006-05-15

    In order to analyze the influence of the deflecting ring on the noise generated by the outdoor set of a split-unit air conditioner, the flow field in the outdoor set is simulated with the CFD software STAR-CD, the relative turbulent intensities are computed and the influence of the width and contoured duct of the deflecting ring on the noise generated by the outdoor set is analyzed. The results of computation and experiment show that there is an optimal width of the deflecting ring, corresponding to the minimum noise generated by the outdoor set. In addition, the influence of the contoured duct of the deflecting ring on the noise generated by the outdoor set is analyzed and a double contoured duct is designed. The results of computation and experiment verify that the deflecting ring with double contoured duct can improve the aerodynamic performance and reduce the noise generated by the outdoor set. (author)

  2. How noise affects quantum detector tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q., E-mail: wang@physics.leidenuniv.nl; Renema, J. J.; Exter, M. P.van; Dood, M. J. A. de [Huygens Kamerlingh-Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden (Netherlands); Gaggero, A.; Mattioli, F.; Leoni, R. [Istituto di Fotonica e Nanotecnologie (IFN), CNR, via Cineto Romano 42, 00156 Roma (Italy)

    2015-10-07

    We determine the full photon number response of a NbN superconducting nanowire single photon detector via quantum detector tomography, and the results show the separation of linear, effective absorption efficiency from the internal detection efficiencies. In addition, we demonstrate an error budget for the complete quantum characterization of the detector. We find that for short times, the dominant noise source is shot noise, while laser power fluctuations limit the accuracy for longer timescales. The combined standard uncertainty of the internal detection efficiency derived from our measurements is about 2%.

  3. A real-time, nonintrusive trace gas detector based on laser photothermal deflection

    Science.gov (United States)

    de Vries, H. S. M.; Dam, N.; van Lieshout, M. R.; Sikkens, C.; Harren, F. J. M.; Reuss, J.

    1995-09-01

    We present the layout and technical details of a trace gas monitor based on photothermal deflection. The operating principle of this instrument, i.e., the deflection of a (weak) probe laser beam by the thermal refractive index gradient induced by trace gas absorption of an intense pump laser beam, allows nonintrusive measurements with good space and time resolution. An intra-cavity CO2 laser is used as the pump beam and a red HeNe laser as the probe. The latter runs perpendicular to the pump beam to optimize spatial resolution. To increase sensitivity, the probe laser is incorporated in a multipass setup. The instrument is demonstrated by the localization of ethylene emission sites on a cherry tomato and by monitoring ammonia production due to nitrogen fixation by cyanobacteria. Both C2H4 and NH3 can be detected at the 1-3 ppb level, at a spatial resolution of 2 mm (along the pump laser)×0.6 mm (perpendicular to it), and a response time of 0.1 s (without background correction) or 15 s (including background correction). Sensitivity can be increased at the expense of spatial resolution, and vice versa. In principle, this instrument is applicable to all those gases possessing a characteristic (``fingerprint'') spectrum in the CO2 laser range. The great advantage of the photothermal deflection technique with respect to other trace gas detection schemes lies in the nonintrusive character of the measurements. There is no need to enclose the sample in a vessel or to suck large volumes of air into the detector; measurements can be performed in open air and in real time. This should prove especially useful where sticky (polar) gases, like H2O, NH3, CH3OH, etc., are to be detected quantitatively. Main applications include air quality monitoring, especially concerning dry deposition rate measurements using the eddy correlation technique, and the study of volatile metabolite emission of biological samples.

  4. Dichotomous-noise-induced chaos in a generalized Duffing-type oscillator with fractional-order deflection

    Science.gov (United States)

    Lei, Youming; Fu, Rui; Yang, Yong; Wang, Yanyan

    2016-02-01

    The chaotic behavior of a generalized Duffing-type oscillator with fractional-order deflection under dichotomous noise excitation is discussed in detail. Using the Melnikov method together with mean-square criterion, necessary conditions for the onsets of chaos are derived. It is shown that with the increase of noise transition rate, the threshold of noise amplitude for chaos firstly decreases to a minimum, and then increases. The effects of dichotomous noise on the Duffing-type oscillator are also obtained by vanishing the mean largest Lyapunov exponent of the oscillator. This is further verified by phase portraits and time histories with numerical simulations.

  5. Active noise canceling system for mechanically cooled germanium radiation detectors

    Science.gov (United States)

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  6. Electronic noise in CT detectors: Impact on image noise and artifacts.

    Science.gov (United States)

    Duan, Xinhui; Wang, Jia; Leng, Shuai; Schmidt, Bernhard; Allmendinger, Thomas; Grant, Katharine; Flohr, Thomas; McCollough, Cynthia H

    2013-10-01

    The objective of our study was to evaluate in phantoms the differences in CT image noise and artifact level between two types of commercial CT detectors: one with distributed electronics (conventional) and one with integrated electronics intended to decrease system electronic noise. Cylindric water phantoms of 20, 30, and 40 cm in diameter were scanned using two CT scanners, one equipped with integrated detector electronics and one with distributed detector electronics. All other scanning parameters were identical. Scans were acquired at four tube potentials and 10 tube currents. Semianthropomorphic phantoms were scanned to mimic the shoulder and abdominal regions. Images of two patients were also selected to show the clinical values of the integrated detector. Reduction of image noise with the integrated detector depended on phantom size, tube potential, and tube current. Scans that had low detected signal had the greatest reductions in noise, up to 40% for a 30-cm phantom scanned using 80 kV. This noise reduction translated into up to 50% in dose reduction to achieve equivalent image noise. Streak artifacts through regions of high attenuation were reduced by up to 45% on scans obtained using the integrated detector. Patient images also showed superior image quality for the integrated detector. For the same applied radiation level, the use of integrated electronics in a CT detector showed a substantially reduced level of electronic noise, resulting in reductions in image noise and artifacts, compared with detectors having distributed electronics.

  7. Characterization of non-Gaussianity in gravitational wave detector noise

    Science.gov (United States)

    Yamamoto, Takahiro; Hayama, Kazuhiro; Mano, Shuhei; Itoh, Yousuke; Kanda, Nobuyuki

    2016-04-01

    The first detection of a gravitational wave (GW) has been achieved by two detectors of the advanced LIGO. Routine detections of GW events from various GW sources are expected in the coming decades. Although the first signal was statistically significant, we expect to see numerous low signal-to-noise ratio (SNR) events with which we may be able to learn various aspects of the Universe that have yet to be unveiled. On the other hand, instrumental glitches due to nonstationarity and/or a non-Gaussian tail of detector noise distribution prevent us from confidently identifying true but low SNR GW signals out of instrumental noise. Thus, to make the best use of data from GW detectors, it is important to establish a method to safely distinguish true GW signals from false signals due to instrumental noises. For this purpose, we urgently need to understand characteristics of detector noises, since the nonstationarity and non-Gaussianity inherent in detector outputs are known to increase false detections of signals. Focusing on identifying the non-Gaussian noise components, this paper introduces a new measure for characterizing the non-Gaussian noise components using the parameter ν which characterizes the weight of tail in a Student-t distribution. A confidence interval is reported on the extent to which detector noise deviates from Gaussianity. Our method revealed stationary and transient deterioration of Gaussianity in LIGO S5 data.

  8. Switching bilateral filter with a texture/noise detector for universal noise removal.

    Science.gov (United States)

    Lin, Chih-Hsing; Tsai, Jia-Shiuan; Chiu, Ching-Te

    2010-09-01

    In this paper, we propose a switching bilateral filter (SBF) with a texture and noise detector for universal noise removal. Operation was carried out in two stages: detection followed by filtering. For detection, we propose the sorted quadrant median vector (SQMV) scheme, which includes important features such as edge or texture information. This information is utilized to allocate a reference median from SQMV, which is in turn compared with a current pixel to classify it as impulse noise, Gaussian noise, or noise-free. The SBF removes both Gaussian and impulse noise without adding another weighting function. The range filter inside the bilateral filter switches between the Gaussian and impulse modes depending upon the noise classification result. Simulation results show that our noise detector has a high noise detection rate as well as a high classification rate for salt-and-pepper, uniform impulse noise and mixed impulse noise. Unlike most other impulse noise filters, the proposed SBF achieves high peak signal-to-noise ratio and great image quality by efficiently removing both types of mixed noise, salt-and-pepper with uniform noise and salt-and-pepper with Gaussian noise. In addition, the computational complexity of SBF is significantly less than that of other mixed noise filters.

  9. Particle-impact noise detector (PIND)

    Science.gov (United States)

    Barr, R. J.; Jackson, D. E.; Leaf, W. D.; Meza, R. G.; Rader, G. E.

    1978-01-01

    Package, in page assembly, is subjected to low-frequency vibration, and noise generated by particle impacts is picked up by transducer. Test procedure calls for three transverse shocks to be applied to page to dislodge any trapped particles.

  10. General quantum constraints on detector noise in continuous linear measurements

    Science.gov (United States)

    Miao, Haixing

    2017-01-01

    In quantum sensing and metrology, an important class of measurement is the continuous linear measurement, in which the detector is coupled to the system of interest linearly and continuously in time. One key aspect involved is the quantum noise of the detector, arising from quantum fluctuations in the detector input and output. It determines how fast we acquire information about the system and also influences the system evolution in terms of measurement backaction. We therefore often categorize it as the so-called imprecision noise and quantum backaction noise. There is a general Heisenberg-like uncertainty relation that constrains the magnitude of and the correlation between these two types of quantum noise. The main result of this paper is to show that, when the detector becomes ideal, i.e., at the quantum limit with minimum uncertainty, not only does the uncertainty relation takes the equal sign as expected, but also there are two new equalities. This general result is illustrated by using the typical cavity QED setup with the system being either a qubit or a mechanical oscillator. Particularly, the dispersive readout of a qubit state, and the measurement of mechanical motional sideband asymmetry are considered.

  11. Tanlock loop noise reduction using an optimised phase detector

    Science.gov (United States)

    Al-kharji Al-Ali, Omar; Anani, Nader; Al-Qutayri, Mahmoud; Al-Araji, Saleh

    2013-06-01

    This article proposes a time-delay digital tanlock loop (TDTL), which uses a new phase detector (PD) design that is optimised for noise reduction making it amenable for applications that require wide lock range without sacrificing the level of noise immunity. The proposed system uses an improved phase detector design which uses two phase detectors; one PD is used to optimise the noise immunity whilst the other is used to control the acquisition time of the TDTL system. Using the modified phase detector it is possible to reduce the second- and higher-order harmonics by at least 50% compared with the conventional TDTL system. The proposed system was simulated and tested using MATLAB/Simulink using frequency step inputs and inputs corrupted with varying levels of harmonic distortion. A hardware prototype of the system was implemented using a field programmable gate array (FPGA). The practical and simulation results indicate considerable improvement in the noise performance of the proposed system over the conventional TDTL architecture.

  12. Radiation Response of Emerging High Gain, Low Noise Detectors

    Science.gov (United States)

    Becker, Heidi N.; Farr, William H; Zhu, David Q.

    2007-01-01

    Data illustrating the radiation response of emerging high gain, low noise detectors are presented. Ionizing dose testing of silicon internal discrete avalanche photodiodes, and 51-MeV proton testing of InGaAs/InAlAs avalanche photodiodes operated in Geiger mode are discussed.

  13. Master equation approach of classical noise in intersubband detectors

    Science.gov (United States)

    Delga, A.; Carras, M.; Trinité, V.; Guériaux, V.; Doyennette, L.; Nedelcu, A.; Schneider, H.; Berger, V.

    2012-06-01

    Electronic transport in intersubband detectors is investigated theoretically and experimentally. Within the framework of inter-Wannier-Stark levels electron scattering, consistent dark current and low-frequency noise expressions are obtained through the resolution of the two first moments of a master equation for classical particles. In particular, the formulation of noise bridges over the vision of uncorrelated Johnson and shot contributions. Theoretical predictions are compared to measurements for five quantum well detectors, either photovoltaic or photoconductive, whose detection wavelength span from 8μm to 17μm. Quantitative agreement with experiment is found for a broad range of biases and temperatures. Correlation effects are discussed and proven to either reduce or enhance the noise.

  14. Countermeasure against blinding attacks on low-noise detectors with a background-noise-cancellation scheme

    Science.gov (United States)

    Lee, Min Soo; Park, Byung Kwon; Woo, Min Ki; Park, Chang Hoon; Kim, Yong-Su; Han, Sang-Wook; Moon, Sung

    2016-12-01

    We developed a countermeasure against blinding attacks on low-noise detectors with a background-noise-cancellation scheme in quantum key distribution (QKD) systems. Background-noise cancellation includes self-differencing and balanced avalanche photon diode (APD) schemes and is considered a promising solution for low-noise APDs, which are critical components in high-performance QKD systems. However, its vulnerability to blinding attacks has been recently reported. In this work, we propose a countermeasure that prevents this potential security loophole from being used in detector blinding attacks. An experimental QKD setup is implemented and various tests are conducted to verify the feasibility and performance of the proposed method. The obtained measurement results show that the proposed scheme successfully detects occurring blinding-attack-based hacking attempts.

  15. Generation-recombination noise: the fundamental sensitivity limit for kinetic inductance detectors

    NARCIS (Netherlands)

    De Visser, P.J.; Baselmans, J.J.A.; Diener, P.; Yates, S.J.C.; Endo, A.; Klapwijk, T.M.

    2012-01-01

    We present measurements of quasiparticle generation-recombination noise in aluminium Microwave Kinetic Inductance Detectors, the fundamental noise source for these detectors. Both the quasiparticle lifetime and the number of quasiparticles can be determined from the noise spectra. The number of

  16. Generation-recombination noise: the fundamental sensitivity limit for kinetic inductance detectors

    NARCIS (Netherlands)

    De Visser, P.J.; Baselmans, J.J.A.; Diener, P.; Yates, S.J.C.; Endo, A.; Klapwijk, T.M.

    2012-01-01

    We present measurements of quasiparticle generation-recombination noise in aluminium Microwave Kinetic Inductance Detectors, the fundamental noise source for these detectors. Both the quasiparticle lifetime and the number of quasiparticles can be determined from the noise spectra. The number of quas

  17. Classification methods for noise transients in advanced gravitational-wave detectors

    OpenAIRE

    Powell, Jade; Trifiro, Daniele; Cuoco, Elena; Heng, Ik Siong; Cavaglià, Marco

    2015-01-01

    Noise of non-astrophysical origin will contaminate science data taken by the Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO) and Advanced Virgo gravitational-wave detectors. Prompt characterization of instrumental and environmental noise transients will be critical for improving the sensitivity of the advanced detectors in the upcoming science runs. During the science runs of the initial gravitational-wave detectors, noise transients were manually classified by visually e...

  18. Therapy imaging: a signal-to-noise analysis of metal plate/film detectors.

    Science.gov (United States)

    Munro, P; Rawlinson, J A; Fenster, A

    1987-01-01

    We have measured the modulation transfer functions [MTF (f)'s] and the noise power spectra [NPS (f)] of therapy x-ray detectors irradiated by 60Co, 6- and 18-MV radiotherapy beams. Using these quantities, we have calculated the noise-equivalent quanta [NEQ (f)] and the detective quantum efficiency [DQE (f)] to quantitate the limitations of therapy detectors. The detectors consisted of film or fluorescent screen-film combinations in contact with copper, lead, or tungsten metal plates. The resolution of the detectors was found to be comparable to fluorescent screen-film combinations used in diagnostic radiology, however, the signal-to-noise ratio [SNR (f)] of the detectors was limited due to film granularity. We conclude that improved images can be obtained by using alternative detector systems which have less noise or film granularity.

  19. Newtonian-noise cancellation in large-scale interferometric GW detectors using seismic tiltmeters

    Science.gov (United States)

    Harms, Jan; Venkateswara, Krishna

    2016-12-01

    The mitigation of terrestrial gravity noise, also known as Newtonian noise (NN), is one of the foremost challenges to improve low-frequency sensitivity of ground-based gravitational-wave detectors. At frequencies above 1 Hz, it is predicted that gravity noise from seismic surface Rayleigh waves is the dominant contribution to NN in surface detectors, and may still contribute significantly in future underground detectors. Noise cancellation based on a coherent estimate of NN using data from a seismometer array was proposed in the past. In this article, we propose an alternative scheme to cancel NN using a seismic tiltmeter. It is shown that even under pessimistic assumptions concerning the complexity of the seismic field, a single tiltmeter under each test mass of the detector is sufficient to achieve substantial noise cancellation. A technical tiltmeter design is presented to achieve the required sensitivity in the Newtonian-noise frequency band.

  20. Noise considerations of the Beetle amplifier used with long silicon strip detectors

    CERN Document Server

    Köstner, S

    2005-01-01

    An attempt is made to predict the thermal noise and the shot noise for silicon strip detectors connected to the Beetle preamplifier from basic electronic noise principles. The calibration pulse shapes are used to determine the frequency dependant gain function of the Beetle. The calculated noise values are compared with measurements on the prototype ladders. In addition the signal propagation in the very long ladders is studied using a spice simulation. From this the effect of the thermal noise originating from the ohmic resistors of the detector readout strips is estimated.

  1. Modeling Thermal Noise From Crystalline Coatings For Gravitational-Wave Detectors

    Science.gov (United States)

    Demos, Nicholas; Lovelace, Geoffrey; LSC Collaboration

    2017-01-01

    In 2015, Advanced LIGO made the first direct detection of gravitational waves. The sensitivity of current and future ground-based gravitational-wave detectors is limited by thermal noise in each detector's test mass substrate and coating. This noise can be modeled using the fluctuation-dissipation theorem, which relates thermal noise to an auxiliary elastic problem. I will present results from a new code that numerically models thermal noise for different crystalline mirror coatings. The thermal noise in crystalline mirror coatings could be significantly lower but is challenging to model analytically. The code uses a finite element method with adaptive mesh refinement to model the auxiliary elastic problem which is then related to thermal noise. Specifically, I will show results for a crystal coating on an amorphous substrate of varying sizes and elastic properties. This and future work will help develop the next generation of ground-based gravitational-wave detectors.

  2. RareNoise: non-equilibrium effects in detectors of gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Conti, L [INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Bonaldi, M [Istituto di Fotonica e Nanotecnologie, CNR-Fondazione Bruno Kessler, 38100 Povo, Trento (Italy); Rondoni, L, E-mail: Livia.Conti@pd.infn.i [Dip. di Matematica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2010-04-21

    The RareNoise project investigates non-equilibrium effects in gravitational wave detectors. We illustrate the physics behind the project and the planned project development, involving experimental, numerical and theoretical research.

  3. Classification methods for noise transients in advanced gravitational-wave detectors

    CERN Document Server

    Powell, Jade; Cuoco, Elena; Heng, Ik Siong; Cavaglia, Marco

    2015-01-01

    Noise of non-astrophysical origin will contaminate science data taken by the Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO) and Advanced Virgo gravitational-wave detectors. Prompt characterization of instrumental and environmental noise transients will be critical for improving the sensitivity of the advanced detectors in the upcoming science runs. During the science runs of the initial gravitational-wave detectors, noise transients were manually classified by visually examining the time-frequency scan of each event. Here, we present three new algorithms designed for the automatic classification of noise transients in advanced detectors. Two of these algorithms are based on Principal Component Analysis. They are Principal Component Analysis for Transients (PCAT), and an adaptation of LALInference Burst (LIB). The third algorithm is a combination of an event generator called Wavelet Detection Filter (WDF) and machine learning techniques for classification. We test these algorithms on simu...

  4. Measurements of Low Frequency Noise of Infrared Photo-Detectors with Transimpedance Detection System

    Directory of Open Access Journals (Sweden)

    Ciura Łukasz

    2014-08-01

    Full Text Available The paper presents the method and results of low-frequency noise measurements of modern mid-wavelength infrared photodetectors. A type-II InAs/GaSb superlattice based detector with nBn barrier architecture is compared with a high operating temperature (HOT heterojunction HgCdTe detector. All experiments were made in the range 1 Hz - 10 kHz at various temperatures by using a transimpedance detection system, which is examined in detail. The power spectral density of the nBn’s dark current noise includes Lorentzians with different time constants while the HgCdTe photodiode has more uniform 1/f - shaped spectra. For small bias, the low-frequency noise power spectra of both devices were found to scale linearly with bias voltage squared and were connected with the fluctuations of the leakage resistance. Leakage resistance noise defines the lower noise limit of a photodetector. Other dark current components give raise to the increase of low-frequency noise above this limit. For the same voltage biasing devices, the absolute noise power densities at 1 Hz in nBn are 1 to 2 orders of magnitude lower than in a MCT HgCdTe detector. In spite of this, low-frequency performance of the HgCdTe detector at ~ 230K is still better than that of InAs/GaSb superlattice nBn detector.

  5. Two-level system noise reduction for Microwave Kinetic Inductance Detectors

    CERN Document Server

    Noroozian, Omid; Zmuidzinas, Jonas; LeDuc, Henry G; Mazin, Benjamin A

    2009-01-01

    Noise performance is one of the most crucial aspects of any detector. Superconducting Microwave Kinetic Inductance Detectors (MKIDs) have an "excess" frequency noise that shows up as a small time dependent jitter of the resonance frequency characterized by the frequency noise power spectrum measured in units of Hz^2/Hz. Recent studies have shown that this noise almost certainly originates from a surface layer of two-level system (TLS) defects on the metallization or substrate. Fluctuation of these TLSs introduces noise in the resonator due to coupling of the TLS electric dipole moments to the resonator's electric field. Motivated by a semi-empirical quantitative theory of this noise mechanism, we have designed and tested new resonator geometries in which the high-field "capacitive" portion of the CPW resonator is replaced by an interdigitated capacitor (IDC) structure with 10 - 20 micron electrode spacing, as compared to the 2 micron spacing used for our more conventional CPW resonators. Measurements show tha...

  6. Correlated noise in networks of gravitational-wave detectors: subtraction and mitigation

    CERN Document Server

    Thrane, Eric; Schofield, Robert M S; Effler, Anamaria

    2014-01-01

    One of the key science goals of advanced gravitational-wave detectors is to observe a stochastic gravitational-wave background. However, recent work demonstrates that correlated magnetic fields from Schumann resonances can produce correlated strain noise over global distances, potentially limiting the sensitivity of stochastic background searches with advanced detectors. In this paper, we estimate the correlated noise budget for the worldwide Advanced LIGO network and conclude that correlated noise may affect upcoming measurements. We investigate the possibility of a Wiener filtering scheme to subtract correlated noise from Advanced LIGO searches, and estimate the required specifications. We also consider the possibility that residual correlated noise remains following subtraction, and we devise an optimal strategy for measuring astronomical parameters in the presence of correlated noise. Using this new formalism, we estimate the loss of sensitivity for a broadband, isotropic stochastic background search usin...

  7. Mirror thermal noise in laser interferometer gravitational wave detectors operating at room and cryogenic temperature

    CERN Document Server

    Franc, Janyce; Flaminio, Raffaele; Nawrodt, Ronny; Martin, Iain; Cunningham, Liam; Cumming, Alan; Rowan, Sheila; Hough, James

    2009-01-01

    Mirror thermal noise is and will remain one of the main limitations to the sensitivity of gravitational wave detectors based on laser interferometers. We report about projected mirror thermal noise due to losses in the mirror coatings and substrates. The evaluation includes all kind of thermal noises presently known. Several of the envisaged substrate and coating materials are considered. The results for mirrors operated at room temperature and at cryogenic temperature are reported.

  8. Focal-plane optimization for detector noise limited performance in cryogenic Fourier transform spectrometer /FTS/ sensors

    Science.gov (United States)

    Mcguirk, M.; Logan, L.

    1980-01-01

    A study was performed to determine the optimum focal plane configuration including optics, filters and detector-preamplifier selection. The configuration was optimized particularly with respect to minimizing the noise level, but fabrication considerations for a cryogenic environment were also taken into account. The noise terms from source, background, detector electronics and charged particle radiation were quantitatively evaluated. It appears that noise equivalent spectral radiance less than 10 to the -11th W/sq cm per sr per kayser can be achieved between 2.5 and 20 microns.

  9. Thermal imager fixed pattern noise prediction using a characterization of the infrared detector

    Science.gov (United States)

    Mariani, Paolo; Zatti, Stefano; Giunti, Claudio; Sozzi, Barbara; Guadagnoli, Emanuele; Porta, Antonio

    2014-12-01

    Cooled infrared detectors are typically characterized by well-known electro-optical parameters: responsivity, noise equivalent temperature difference, shot noise, 1/f noise, and so on. Particularly important for staring arrays is also the residual fixed pattern noise (FPN) that can be obtained after the application of the nonuniformity correction (NUC) algorithm. A direct measure of this parameter is usually hard to define because the residual FPN strongly depends, other than on the detector, on the choice of the NUC algorithm and the operative scenario. We introduce three measurable parameters: instability, nonlinearity, and a residual after a polynomial fitting of the detector response curve, and we demonstrate how they are related to the residual FPN after the application of an NUC (the relationship with three common correction algorithms is discussed). A comparison with experimental data is also presented and discussed.

  10. BayesLine: Bayesian Inference for Spectral Estimation of Gravitational Wave Detector Noise

    CERN Document Server

    Littenberg, Tyson B

    2014-01-01

    Gravitational wave data from ground-based detectors is dominated by instrument noise. Signals will be comparatively weak, and our understanding of the noise will influence detection confidence and signal characterization. Mis-modeled noise can produce large systematic biases in both model selection and parameter estimation. Here we introduce a multi-component, variable dimension, parameterized model to describe the Gaussian-noise power spectrum for data from ground-based gravitational wave interferometers. Called BayesLine, the algorithm models the noise power spectral density using cubic splines for smoothly varying broad-band noise and Lorentzians for narrow-band line features in the spectrum. We describe the algorithm and demonstrate its performance on data from the fifth and sixth LIGO science runs. Once fully integrated into LIGO/Virgo data analysis software, BayesLine will produce accurate spectral estimation and provide a means for marginalizing inferences drawn from the data over all plausible noise s...

  11. Takeoff and landing performance and noise measurements of a deflected slipstream STOL airplane with interconnected propellers and rotating cylinder flaps

    Science.gov (United States)

    Weiberg, J. A.; Giulianetti, D.; Gambucci, B.; Innis, R. C.

    1973-01-01

    A YOV-10A aircraft was modified to incorporate rotating cylinder flaps and interconnected propellers with Lycoming T-53-L11 engines. Flight tests were made to evaluate the low speed handling qualities and performance characteristics. The flight test results indicated that landings could be made with approach speeds of 55 to 65 knots (CL = 4.5) and descent angles of 6 deg to 8 deg for total flap angles of 60 deg to 75 deg. At higher flap angles, deterioration of stability and control characteristics precluded attempts at landing. The noise level on the ground under an 8 deg landing approach path was below 86 PNdB at distances beyond 1 nautical mile from touchdown. Takeoffs were made with 30 deg to 45 deg flaps at lift off speeds of 75 to 80 knots and climb angles of 4 deg to 8 deg. Noise levels were below 83 PNdB at 3.5 nautical miles from the start of ground roll.

  12. Low noise CMOS readout for CdZnTe detector arrays

    CERN Document Server

    Jakobson, C G; Lev, S B; Nemirovsky, Y

    1999-01-01

    A low noise CMOS readout for CdTe and CdZnTe X- and gamma-ray detector arrays has been designed and implemented in the CMOS 2 mu m low noise analog process provided by the multi-chip program of Metal Oxide Semiconductor Implementation Service. The readout includes CMOS low noise charge sensitive preamplifier and a multiplexed semi-Gaussian pulse shaper. Thus, each detector has a dedicated charge sensitive preamplifier that integrates its signal, while a single shaping amplifier shapes the pulses after the multiplexer. Low noise and low-power operation are achieved by optimizing the input transistor of the charge sensitive preamplifier. Two optimization criteria are used to reduce noise. The first criterion is based on capacitance matching between the input transistor and the detector. The second criterion is based on bandwidth optimization, which is obtained by tailoring the shaper parameters to the particular noise mechanisms of the MOS transistor and the CdZnTe detector. Furthermore, the multiplexing functi...

  13. Low noise CMOS readout for CdZnTe detector arrays

    Energy Technology Data Exchange (ETDEWEB)

    Jakobson, C.G.; Asa, G.; Lev, S. Bar; Nemirovsky, Y. E-mail: nemirov@ee.technion.ac.il

    1999-06-01

    A low noise CMOS readout for CdTe and CdZnTe X- and gamma-ray detector arrays has been designed and implemented in the CMOS 2 {mu}m low noise analog process provided by the multi-chip program of Metal Oxide Semiconductor Implementation Service. The readout includes CMOS low noise charge sensitive preamplifier and a multiplexed semi-Gaussian pulse shaper. Thus, each detector has a dedicated charge sensitive preamplifier that integrates its signal, while a single shaping amplifier shapes the pulses after the multiplexer. Low noise and low-power operation are achieved by optimizing the input transistor of the charge sensitive preamplifier. Two optimization criteria are used to reduce noise. The first criterion is based on capacitance matching between the input transistor and the detector. The second criterion is based on bandwidth optimization, which is obtained by tailoring the shaper parameters to the particular noise mechanisms of the MOS transistor and the CdZnTe detector. Furthermore, the multiplexing function incorporated in the shaper provides low power and reduces chip area. The system is partitioned into a chip containing the charge amplifiers and a chip containing the semi-Gaussian pulse shaper and multiplexer. This architecture minimizes coupling from multiplexer switches as well as shaper output to the input of the charge sensitive preamplifiers.

  14. Effects of detector blur and correlated noise on digital breast tomosynthesis reconstruction

    Science.gov (United States)

    Zheng, Jiabei; Fessler, Jeffrey A.; Chan, Heang-Ping

    2017-03-01

    To improve digital breast tomosynthesis (DBT) image quality, we are developing model-based iterative reconstruction methods. We developed the SQS-DBCN algorithm, which incorporated detector blur into the system model and correlation into the noise model under some simplifying assumptions. In this paper, we further improved the regularization in the SQS-DBCN method by incorporating neighbors along the diagonal directions. To further understand the role of the different components in the system model of the SQS-DBCN method, we reconstructed DBT images without modeling either the detector blur or noise correlation for comparison. Visual comparison of the reconstructed images showed that regularizing with diagonal directions reduced artifacts and the noise level. The SQS-DBCN reconstructed images had better image quality than reconstructions without models for detector blur or correlated noise, as indicated by the contrast-to-noise ratios (CNR) of MCs and textural artifacts. These results indicated that regularized DBT reconstruction with detector blur and correlated noise modeling, even with simplifying assumptions, can improve DBT image quality compared to that without system modeling.

  15. Development of noise-suppressed detector for single ion hit system

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Takuro; Hamano, Tsuyoshi; Suda, Tamotsu; Hirao, Toshio; Kamiya, Tomihiro [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    A noise-suppressed detector for single ion detection has been developed, and combined with the heavy ion microbeam apparatus. This detector consists of a pair of micro channel plates (MCP`s) and a very thin carbon foil. The detection signal is formed by the coincidence of the signals from these MCP`s, so that this detector and the coincidence measurement unit can reduce miscounting in the circuit. The detection efficiency for 15 MeV heavy ions was evaluated to be comparable to that of a silicon surface-barrier detector (SSD) and the miscounting rate was 4 orders lower than the noise rate of a single MCP. The rise time of the detection signal was also estimated. (author)

  16. Local-Oscillator Noise Coupling in Balanced Homodyne Readout for Advanced Gravitational Wave Detectors

    CERN Document Server

    Steinlechner, Sebastian; Bell, Angus S; Danilishin, Stefan L; Gläfke, Andreas; Gräf, Christian; Hennig, Jan-Simon; Houston, E Alasdair; Huttner, Sabina H; Leavey, Sean S; Pascucci, Daniela; Sorazu, Borja; Spencer, Andrew; Strain, Kenneth A; Wright, Jennifer; Hild, Stefan

    2015-01-01

    The second generation of interferometric gravitational wave detectors are quickly approaching their design sensitivity. For the first time these detectors will become limited by quantum back-action noise. Several back-action evasion techniques have been proposed to further increase the detector sensitivity. Since most proposals rely on a flexible readout of the full amplitude- and phase-quadrature space of the output light field, balanced homodyne detection is generally expected to replace the currently used DC readout. Up to now, little investigation has been undertaken into how balanced homodyne detection can be successfully transferred from its ubiquitous application in table-top quantum optics experiments to large-scale interferometers with suspended optics. Here we derive implementation requirements with respect to local oscillator noise couplings and highlight potential issues with the example of the Glasgow Sagnac Speed Meter experiment, as well as for a future upgrade to the Advanced LIGO detectors.

  17. Fisher information vs. signal-to-noise ratio for a split detector

    CERN Document Server

    Knee, George C

    2015-01-01

    We study the problem of estimating the magnitude of a Gaussian beam displacement using a two pixel or 'split' detector. We calculate the maximum likelihood estimator, and compute its asymptotic mean-squared-error via the Fisher information. Although the signal-to-noise ratio is known to be simply related to the Fisher information under idealised detection, we find the two measures of precision differ markedly for a split detector. We show that a greater signal-to-noise ratio 'before' the detector leads to a greater information penalty, unless adaptive realignment is used. We find that with an initially balanced split detector, tuning the normalised difference in counts to 0.884753... gives the highest posterior Fisher information, and that this provides an improvement by at least a factor of about 2.5 over operating in the usual linear regime. We discuss the implications for weak-value amplification, a popular probabilistic signal amplification technique.

  18. Development of Low-Noise High Value Chromium Silicide Resistors for Cryogenic Detector Applications

    Science.gov (United States)

    Jhabvala, Murzy; Babu, Sachi; Monroy, Carlos; Darren, C.; Krebs, Carolyn A. (Technical Monitor)

    2001-01-01

    Extremely high sensitivity detectors, such as silicon bolometers are required in many NASA missions for detection of photons from the x-ray to the far infrared regions. Typically, these detectors are cooled to well below the liquid helium (LHe) temperature (4.2 K) to achieve the maximum detection performance. As photoconductors, they are generally operated with a load resistor and a pre-set bias voltage, which is then coupled to the input gate of a source-follower Field Effect Transistor (FET) circuit. It is imperative that the detector system signal to noise performance be limited by the noise of the detector and not by the noise of the external components. The load resistor value is selected to optimize the detector performance. These two criteria tend to be contradictory in that these detectors require load resistors in the hundreds of megaohms, which leads to a higher Johnson noise. Additionally, the physical size of the resistor must be small for device integration as required by such missions as the NASA High Resolution Airborne Wide-Band Camera (HAWC) instrument and the Submillimeter High Angular Resolution Camera (SHARC) for the Caltech Submillimeter Observatory (CSO). We have designed, fabricated and characterized thin film resistors using a CrSi/TiW/Al metal system on optical quality quartz substrates. The resistor values range from 100 megaohms to over 650 megaohms and are Johnson noise limited at LHe temperatures. The resistor film is sputtered with a sheet resistance ranging from 300 ohms to 1600 ohms and the processing sequence developed for these devices allows for chemically fine tuning the sheet resistance in-situ. The wafer fabrication process was of sufficiently high yield (>80%) providing clusters of good resistors for integrated multiple detector channels, a very important feature in the assembly of these two instruments.

  19. Subtraction-noise projection in gravitational-wave detector networks

    CERN Document Server

    Harms, Jan; Otto, Markus; Priess, Malte

    2008-01-01

    In this paper, we present a successful implementation of a subtraction-noise projection method into a simple, simulated data analysis pipeline of a gravitational-wave search. We investigate the problem to reveal a weak stochastic background signal which is covered by a strong foreground of compact-binary coalescences. The foreground which is estimated by matched filters, has to be subtracted from the data. Even an optimal analysis of foreground signals will leave subtraction noise due to estimation errors of template parameters which may corrupt the measurement of the background signal. The subtraction noise can be removed by a noise projection. We apply our analysis pipeline to the proposed future-generation space-borne Big Bang Observer (BBO) mission which seeks for a stochastic background of primordial GWs in the frequency range $\\sim 0.1-1 $Hz covered by a foreground of black-hole and neutron-star binaries. Our analysis is based on a simulation code which provides a dynamical model of a time-delay interfe...

  20. Measurement of SQUID noise levels for SuperCDMS SNOLAB detectors - Final Paper

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Maxwell [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-27

    SuperCDMS SNOLAB is a second generation direct dark matter search. In the SuperCDMS SNOLAB experiment, detectors are able to pick up from signals from dark matter nuclear recoil interactions which occur inside the bulk of the detectors. These interactions produce both phonon and charge signals. HEMTs read out charge signals whereas TES are used to detect phonon signals which are then read out by SQUID amplifiers. SQUID amplifiers must add negligible noise to the TES intrinsic noise which has been previously measured and is approximately 50pA/√Hz down to 100Hz for ease of signal distinguishability in dark matter nuclear interactions. The intrinsic noise level of the SQUID was tested in the SLAC 300mK fridge and determined to provide adequately low levels of noise with a floor of approximately 3pA/√Hz. Furthermore, a 10x amplifier was tested for addition of extraneous noise. This noise was investigated with and without this amplifier, and it was found that it did not add a significant amount of noise to the intrinsic SQUID noise.

  1. High power and ultra-low-noise photodetector for squeezed-light enhanced gravitational wave detectors.

    Science.gov (United States)

    Grote, Hartmut; Weinert, Michael; Adhikari, Rana X; Affeldt, Christoph; Kringel, Volker; Leong, Jonathan; Lough, James; Lück, Harald; Schreiber, Emil; Strain, Kenneth A; Vahlbruch, Henning; Wittel, Holger

    2016-09-05

    Current laser-interferometric gravitational wave detectors employ a self-homodyne readout scheme where a comparatively large light power (5-50 mW) is detected per photosensitive element. For best sensitivity to gravitational waves, signal levels as low as the quantum shot noise have to be measured as accurately as possible. The electronic noise of the detection circuit can produce a relevant limit to this accuracy, in particular when squeezed states of light are used to reduce the quantum noise. We present a new electronic circuit design reducing the electronic noise of the photodetection circuit in the audio band. In the application of this circuit at the gravitational-wave detector GEO 600 the shot-noise to electronic noise ratio was permanently improved by a factor of more than 4 above 1 kHz, while the dynamic range was improved by a factor of 7. The noise equivalent photocurrent of the implemented photodetector and circuit is about 5μA/Hz above 1 kHz with a maximum detectable photocurrent of 20 mA. With the new circuit, the observed squeezing level in GEO 600 increased by 0.2 dB. The new circuit also creates headroom for higher laser power and more squeezing to be observed in the future in GEO 600 and is applicable to other optics experiments.

  2. Signal and noise analysis of a-Si:H radiation detector-amplifier system

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Gyuseong.

    1992-03-01

    Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme showed that the storage time and the readout time are limited by the resistances of the reverse-biased pixel diode and the forward biased switching diodes respectively. A prototype charge-sensitive amplifier was made using poly-Si TFTs to test the feasibility of making pixel-level amplifiers which would be required in small-signal detection. The measured overall gain-bandwidth product was {approximately}400 MHz and the noise charge {approximately}1000 electrons at a 1 {mu}sec shaping time. When the amplifier is connected to a pixel detector of capacitance 0.2 pF, it would give a charge-to-voltage gain of {approximately}0.02 mV/electron with a pulse rise time less than 100 nsec and a dynamic range of 48 dB.

  3. Thermal noise in BEC-phononic gravitational wave detectors

    CERN Document Server

    Sabín, Carlos; Bruschi, David Edward; Fuentes, Ivette

    2015-01-01

    Quasiparticles in a Bose-Einstein condensate are sensitive to space-time distortions. Gravitational waves can induce transformations on the state of phonons that can be observed through quantum state discrimination techniques. We show that this method is highly robust to thermal noise and depletion. We derive a bound on the strain sensitivity that shows that the detection of waves in the kHz regime is not significantly affected by temperature in a wide range of parameters that are well within current experimental reach.

  4. Low noise pixel detectors based on gated geiger mode avalanche photodiodes

    OpenAIRE

    Vilella Figueras, Eva; Comerma Montells, Albert; Alonso Casanovas, Oscar; Diéguez Barrientos, Àngel

    2011-01-01

    The gated operation is proposed as an effective method to reduce the noise in pixel detectors based on Geiger mode avalanche photodiodes. A prototype with the sensor and the front-end electronics monolithically integrated has been fabricated with a conventional HV-CMOS process. Experimental results demonstrate the increase of the dynamic range of the sensor by applying this technique.

  5. Evaluation of Interest Point Detectors in Presence of Noise

    Directory of Open Access Journals (Sweden)

    Adrian Ziomek

    2016-03-01

    Full Text Available Detection of repeatable keypoints is often one of the first steps leading to obtain a solution able to recognise objects on images. Such objects are characterised by content of image patches indicated by keypoints. A given image patch is worth being described and processed in further steps, if the interest point inside of it can be found despite different image transformations or distortions. Therefore, it is important to compare keypoint detection techniques using image datasets that contain transformed or noisy images. Since most of detector evaluations rely on small datasets or are focused on a specific application of compared techniques, in this paper two large datasets which cover typical transformations, as well as challenging distortions that can occur while image processing, are used. The first dataset contains 200,000 transformed images, and it has been prepared for the purpose of this study. The second dataset, TID2013, is widely used for perceptual image quality assessment; it contains 3,000 images with 24 distortions. Finally, interest point detectors are evaluated on four datasets, and repeatability score and time of detection are used as measures of their performance.

  6. A SOI-Based Low Noise and Wide Dynamic Range Event-Driven Detector for X-Ray Imaging

    CERN Document Server

    Shrestha, Sumeet; Kawahito, Shoji; Yasutomi, Keita; Kagawa, Keiichiro; Takeda, Ayaki; Tsuru, Takeshi Go; Arai, Yasuo

    2015-01-01

    A low noise and wide dynamic range event driven detector for the detection of X-Ray energy is realized using 0.2 [um] Silicon on insulator (SOI) technology. Pixel circuits are divided into two parts; signal sensing circuit and event detection circuit. Event detection circuit is activated when X-Ray energy falls into the detector. In-pixel gain selection is implemented for the detection of a small signal and wide band of energy particle. Adaptive gain and capability of correlated double sampling (CDS) technique for the kTC noise canceling of charge detector realizes the low noise and high dynamic range event driven detector.

  7. A novel SWIR detector with an ultra-high internal gain and negligible excess noise

    Science.gov (United States)

    Mohseni, H.; Memis, O. G.; Kong, S. C.; Katsnelson, A.; Wu, W.

    2007-10-01

    Short wave infrared (SWIR) imaging systems have several advantages due to the spectral content of the nightglow and better discrimination against camouflage. Achieving single photon detection sensitivity can significantly improve the image quality of these systems. However, the internal noise of the detector and readout circuits are significant barriers to achieve this goal. One can prove that the noise limitations of the readout can be alleviated, if the detector exhibits sufficiently high internal gain. Unfortunately, the existing detectors with internal gain have a very high noise as well. Here we present the recent results from our novel FOcalized Carrier aUgmented Sensor (FOCUS). It utilizes very high charge compression into a nano-injector, and subsequent carrier injection to achieve high quantum efficiency and high sensitivity at short infrared at room temperature. We obtain internal gain values exceeding several thousand at bias values of less than 1 volt. The current responsivity at 1.55 μm is more than 1500 A/W, and the noise equivalent power (NEP) is less that 0.5 x10 -15 W/Hz 1/2 at room temperature. These are significantly better than the performance of the existing room temperature devices with internal gain. Also, unlike avalanche-based photodiodes, the measured excess noise factor for our device is near unity, even at very high gain values. The stable gain of the device combined with the low operating voltage are unique advantages of this technology for high-performance SWIR imaging arrays.

  8. Deep Neural Networks for identifying noise transients in Gravitational-Wave Detectors

    Science.gov (United States)

    Kim, Hwansun; Kim, Young-Min; Oh, John J.; Oh, Sang Hoon; Son, Edwin J.; Chu, Hyoungseok

    2015-08-01

    We apply Deep Neural Networks(DNNs) to identification of transient noise artifacts (glitches) in gravitational-wave (GW) data using auxiliary channel information of GW detectors. Reducing instrumental noises in the gravitational wave data is of great importance, since the sensitivity of search for GW signals is often limited by non-gaussian and non-stationary noise from GW detectors. Various approaches have been used to identify glitches and they successfully reduced glitches from the data. However, there still remains significant excess of glitches beyond the tail of gaussian distribution.In order to reduce the excess of the glitches, we investigate the viability to utilize DNN as an alternative glitch identifier. DNN overcomes caveats of neural networks such as overtraining, local minima, etc. by imposing sparsity in connections between hidden layers and replacing activation functions with a rectifier unit. We demonstrate the performance of DNN in classification of glitchy and clean time of GW data.

  9. Noise performance of the multiwavelength sub/millimeter inductance camera (MUSIC) detectors

    Science.gov (United States)

    Siegel, S. R.

    2015-07-01

    MUSIC is a multi-band imaging camera that employs 2304 Microwave Kinetic Inductance Detectors (MKIDs) in 576 spatial pixels to cover a 14 arc-minute field of view, with each pixel simultaneously sensitive to 4 bands centered at 0.87, 1.04, 1.33, and 1.98 mm. In April 2012 the MUSIC instrument was commissioned at the Caltech Submillimeter Observatory with a subset of the full focal plane. We examine the noise present in the detector timestreams during observations taken in the first year of operation. We find that fluctuations in atmospheric emission dominate at long timescales (< 0.5 Hz), and fluctuations in the amplitude and phase of the probe signal due to readout electronics contribute significant 1/f-type noise at shorter timescales. We describe a method to remove the amplitude, phase, and atmospheric noise using the fact that they are correlated among carrier tones. After removal, the complex signal is decomposed, or projected, into dissipation and frequency components. White noise from the cryogenic HEMT amplifier dominates in the dissipation component. An excess noise is observed in the frequency component that is likely due to fluctuations in two-level system (TLS) defects in the device substrate. We compare the amplitude of the TLS noise with previous measurements.

  10. Analysis of upper and lower bounds of the frame noise in linear detector arrays

    Science.gov (United States)

    Jaggi, S.

    1991-01-01

    This paper estimates the upper and lower bounds of the frame noise of a linear detector array that uses a one-dimensional scan pattern. Using chi-square distribution, it is analytically shown why it is necessary to use the average of the variances and not the average of the standard deviations to estimate these bounds. Also, a criteria for determining whether any excessively noisy lines exist among the detectors is derived from these bounds. Using a Gaussian standard random variable generator, these bounds are demonstrated to be accurate within the specified confidence interval. A silicon detector array is then used for actual dark current measurements. The criterion developed for determination of noisy detectors is checked on the experimentally obtained data.

  11. Signal-to-Noise Measurements on Irradiated CMS Tracker Detector Modules in an Electron Testbeam

    CERN Document Server

    Bleyl, Mark; Steinbruck, G; Stoye, M; Dragicevica, M; Hrubec, Josef; Krammer, M; Frey, M; Hartmann, F; Weiler, T; Hegner, B

    2006-01-01

    The CMS experiment at the Large Hadron Collider at CERN is in the last phase of its construction. The harsh radiation environment at LHC will put strong demands in radiation hardness to the innermost parts of the detector. To assess the performance of irradiated microstrip detector modules, a testbeam was conducted at the Testbeam 22 facility of the DESY research center. The primary objective was the signal-to-noise measurement of irradiated CMS Tracker modules to ensure their functionality up to 10 years of LHC operation. The paper briefly summarises the basic setup at the facility and the hardware and software used to collect and analyse the data. Some interesting subsidiary results are shown, which confirm the expected behaviour of the detector with respect to the signal-to-noise performance over the active detector area and for different electron energies. The main focus of the paper are the results of the signal-to-noise measurements for CMS Tracker Modules which were exposed to different radiation doses...

  12. Normally Off ECG SoC With Non-Volatile MCU and Noise Tolerant Heartbeat Detector.

    Science.gov (United States)

    Izumi, Shintaro; Yamashita, Ken; Nakano, Masanao; Yoshimoto, Shusuke; Nakagawa, Tomoki; Nakai, Yozaburo; Kawaguchi, Hiroshi; Kimura, Hiromitsu; Marumoto, Kyoji; Fuchikami, Takaaki; Fujimori, Yoshikazu; Nakajima, Hiroshi; Shiga, Toshikazu; Yoshimoto, Masahiko

    2015-10-01

    This paper describes an electrocardiograph (ECG) monitoring SoC using a non-volatile MCU (NVMCU) and a noise-tolerant instantaneous heartbeat detector. The novelty of this work is the combination of the non-volatile MCU for normally off computing and a noise-tolerant-QRS (heartbeat) detector to achieve both low-power and noise tolerance. To minimize the stand-by current of MCU, a non-volatile flip-flop and a 6T-4C NVRAM are used. Proposed plate-line charge-share and bit-line non-precharge techniques also contribute to mitigate the active power overhead of 6T-4C NVRAM. The proposed accurate heartbeat detector uses coarse-fine autocorrelation and a template matching technique. Accurate heartbeat detection also contributes system-level power reduction because the active ratio of ADC and digital block can be reduced using heartbeat prediction. Measurement results show that the fully integrated ECG-SoC consumes 6.14 μ A including 1.28- μA non-volatile MCU and 0.7- μA heartbeat detector.

  13. System test and noise performance studies at the ATLAS pixel detector

    Energy Technology Data Exchange (ETDEWEB)

    Weingarten, J.

    2007-09-15

    The central component of the ATLAS Inner Tracker is the pixel detector. It consists of three barrel layers and three disk-layers in the end-caps in both forward directions. The innermost barrel layer is mounted at a distance of about 5 cm from the interaction region. With its very high granularity, truly two-dimensional hit information, and fast readout it is well suited to cope with the high densities of charged tracks, expected this close to the interaction region. The huge number of readout channels necessitates a very complex services infrastructure for powering, readout and safety. After a description of the pixel detector and its services infrastructure, key results from the system test at CERN are presented. Furthermore the noise performance of the pixel detector, crucial for high tracking and vertexing efficiencies, is studied. Measurements of the single-channel random noise are presented together with studies of common mode noise and measurements of the noise occupancy using a random trigger generator. (orig.)

  14. Intrinsic noise of a superheated droplet detector for neutron background measurements in massively shielded facilities

    Science.gov (United States)

    Fernandes, Ana C.; Morlat, Tomoko A.; Felizardo, Miguel; Kling, Andreas; Marques, José G.; Prudêncio, Maria I.; Marques, Rosa; Carvalho, Fernando P.; Roche, Ignácio Lázaro; Girard, Thomas A.

    2017-09-01

    Superheated droplet detectors are a promising technique to the measurement of low-intensity neutron fields, as detectors can be rendered insensitive to minimum ionizing radiations. We report on the intrinsic neutron-induced signal of C2ClF5 devices fabricated by our group that originate from neutron- and alpha-emitting impurities in the detector constituents. The neutron background was calculated via Monte Carlo simulations using the MCNPX-PoliMi code in order to extract the recoil distributions following neutron interaction with the atoms of the superheated liquid. Various nuclear techniques were employed to characterise the detector materials with respect to source isotopes (238U, 232Th and 147Sm) for the normalisation of the simulations and also light elements (B, Li) having high (α, n) neutron production yields. We derived a background signal of 10-3 cts/day in a 1 liter detector of 1-3 wt.% C2ClF5, corresponding to a detection limit in the order of 10-8 n cm-2s-1. Direct measurements in a massively shielded underground facility for dark matter search have confirmed this result. With the borosilicate detector containers found to be the dominant background source in current detectors, possibilities for further noise reduction by 2 orders of magnitude based on selected container materials are discussed.

  15. Ultra Low Noise Infrared Detector Amplifier for Next Generation Standoff Detector

    Science.gov (United States)

    2016-02-18

    Standard Form 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 630-771-0204 55204- EL -ST2.1 W911NF-09-C-0095 Final Report a. REPORT 14. ABSTRACT 16...6  Figure 6: Noise (left) and signal (right) flow paths in a common-source amplifier with resistive feedback ...15  Figure 12: Circuit schematic of the LNA with input and output terminated with 50 Ω impedances. The feedback in the

  16. OLA, A low-noise bipolar amplifier for the readout of Silicon Drift Detectors

    Science.gov (United States)

    Dabrowski, W.; Białas, W.; Bonazzola, G.; Bonvicini, V.; Ceretto, F.; Giubellino, P.; Idzik, M.; Prest, M.; Riccati, L.; Zampa, N.

    1995-11-01

    A very low noise, 32-channel preamplifier/shaper chip has been designed for the analogue readout of silicon detectors. The circuit has been optimised in view of the operation of Silicon Drift Detectors, which have very low capacitance and produce gaussian signals of σ up to ˜ 100 ns. The chip (OLA) has been designed and manufactured using the SHPi full-custom bipolar process by Tektronix. Each channel is composed by a preamplifier, a shaper and a symmetrical line driver, which allows to drive either a positive and a negative single ended output separately on 50 Ω impedance or a differential twisted pair. The intrinsic peaking time of the circuit is ˜ 60 ns, and the noise is below 250 electrons at zero input load capacitance. The power consumption is 2 mW/channel, mostly due to the output driver.

  17. Low-noise monolithic bipolar front-end for silicon drift detectors

    Science.gov (United States)

    Dabrowski, W.; Bialas, W.; Bonazzola, G.; Bonvicini, W.; Casati, L.; Ceretto, F.; Giubellino, P.; Prest, M.; Riccati, L.; Zampa, N.

    1999-01-01

    A very low noise, 32-channel preamplifier/shaper chip has been designed for the analogue readout of silicon detectors. The circuit has been optimized in view of the operation of silicon drift detectors, which have very low capacitance and produce gaussian signals of σ of few tens of ns. The chip (OLA) has been designed and manufactured using the SHPi full-custom bipolar process by Tektronix. Each channel is composed by a preamplifier, a shaper and a symmetrical line driver, which allows to drive either a positive and a negative single ended output separately on 50 Ω impedance or a differential twisted pair. The intrinsic peaking time of the circuit is ˜60 ns, and the noise is below 250 electrons at zero input load capacitance. The power consumption is 2 mW/channel, mostly due to the output driver.

  18. Signal-to-noise ratio of Geiger-mode avalanche photodiode single-photon counting detectors

    Science.gov (United States)

    Kolb, Kimberly

    2014-08-01

    Geiger-mode avalanche photodiodes (GM-APDs) use the avalanche mechanism of semiconductors to amplify signals in individual pixels. With proper thresholding, a pixel will be either "on" (avalanching) or "off." This discrete detection scheme eliminates read noise, which makes these devices capable of counting single photons. Using these detectors for imaging applications requires a well-developed and comprehensive expression for the expected signal-to-noise ratio (SNR). This paper derives the expected SNR of a GM-APD detector in gated operation based on gate length, number of samples, signal flux, dark count rate, photon detection efficiency, and afterpulsing probability. To verify the theoretical results, carrier-level Monte Carlo simulation results are compared to the derived equations and found to be in good agreement.

  19. Low-noise mid-IR upconversion detector for improved IR-degenerate four-wave mixing gas sensing

    DEFF Research Database (Denmark)

    Høgstedt, Lasse; Dam, Jeppe Seidelin; Sahlberg, Anna-Lena

    2014-01-01

    We compare a nonlinear upconversion detector with a conventional cryogenic InSb detector for the detection of coherent infrared light showing near-shot-noise-limited performance in the upconversion system. The InSb detector is limited by dark noise, which results in a 500 times lower signal......, the upconversion system provides image information of the signal, thus adding new func- tionality compared to standard point detectionmethods.We further show that the upconversion detectorsystem can be implemented as a simple replacement of the cryogenic detector....

  20. New Transfer Theory Relationships for Signal and Noise Analyses of X-Ray Detectors

    Science.gov (United States)

    2007-11-02

    0.3 and 4 MeV, coinciding with most of the spectrum of a 6-MV therapy beam. In this section, we describe the influence of energy deposited by Compton ...rays in radiograhic screen using CCD camera (equipment 11-5) Write paper describing generalized cross-spectral density term and comparison of...deposits energy into the detector, primarily by photo-electric and Compton interactions. Image noise is directly related to the number of interacting

  1. Sagnac interferometer for photothermal deflection spectroscopy.

    Science.gov (United States)

    Shiokawa, Naoyuki; Mizuno, Yuki; Tsuchiya, Harumasa; Tokunaga, Eiji

    2012-07-01

    Photothermal deflection spectroscopy is combined with a Sagnac interferometer to enhance the sensitivity of the absorption measurement by converting the photothermal beam deflection effect into the light intensity change by the interference effect. Because of stable light interference due to the common path, the signal intensity can be amplified without increasing the noise by extending the optical path length between a sample and a photodetector. The sensitivity is further improved by the use of focusing optics and double-pass geometry. This makes photothermal deflection spectroscopy applicable to any kind of material in the whole visible region with a xenon lamp for excitation and water or air as a deflection medium.

  2. Development of low-noise kinetic inductance detectors for far-infrared astrophysics

    Science.gov (United States)

    Barlis, Alyssa; Hailey-Dunsheath, Steven; Bradford, Charles M.; McKenney, Christopher; Le Duc, Henry G.; Aguirre, James

    2017-01-01

    The star formation mechanisms at work in the early universe remain one of the major unsolved problems of modern astrophysics. Many spectral lines at far-infrared wavelengths (10 μm working to develop a detector system for a far-infrared balloon-borne spectroscopic experiment using kinetic inductance detectors (KIDs), which have the potential to achieve high sensitivity, low noise levels, high multiplexing factor, and may enable future space missions. We describe the design, fabrication, and noise performance measurements of prototype detector devices targeting an optical noise equivalent power below 1 ×10-17 WHz - 1 / 2 with readout frequencies below 250 MHz. The devices consist of arrays of 45 lumped-element KID pixels patterned out of thin-film aluminum on silicon wafers. They are optically coupled to incident radiation with a set of feedhorns. We use an FPGA-based readout system to read out the response of all the pixels in the array simultaneously. This work was supported by a NASA Space Technology Research Fellowship.

  3. Signal and noise of Diamond Pixel Detectors at High Radiation Fluences

    CERN Document Server

    Tsung, Jieh-Wen; Hügging, Fabian; Kagan, Harris; Krüger, Hans; Wermes, Norbert

    2012-01-01

    CVD diamond is an attractive material option for LHC vertex detectors because of its strong radiation-hardness causal to its large band gap and strong lattice. In particular, pixel detectors operating close to the interaction point profit from tiny leakage currents and small pixel capacitances of diamond resulting in low noise figures when compared to silicon. On the other hand, the charge signal from traversing high energy particles is smaller in diamond than in silicon by a factor of about 2.2. Therefore, a quantitative determination of the signal-to-noise ratio (S/N) of diamond in comparison with silicon at fluences in excess of 10$^{15}$ n$_{eq}$ cm$^{-2}$, which are expected for the LHC upgrade, is important. Based on measurements of irradiated diamond sensors and the FE-I4 pixel readout chip design, we determine the signal and the noise of diamond pixel detectors irradiated with high particle fluences. To characterize the effect of the radiation damage on the materials and the signal decrease, the chang...

  4. Ultra-Low-Noise Sub-mm/Far-IR Detectors for Space-Based Telescopes

    Science.gov (United States)

    Rostem, Karwan

    The sub-mm and Far-IR spectrum is rich with information from a wide range of astrophysical sources, including exoplanet atmospheres and galaxies at the peak star formation. In the 10-400 μm range, the spectral lines of important chemical species such H2O, HD, and [OI] can be used to map the formation and evolution of planetary systems. Dust emission in this spectral range is also an important tool for characterizing the morphology of debris disks and interstellar magnetic fields. At larger scales, accessing the formation and distribution of luminous Far-IR and sub-mm galaxies is essential to understanding star formation triggers, as well as the last stages of reionization at z 6. Detector technology is essential to realizing the full science potential of a next-generation Far-IR space telescope (Far-IR Surveyor). The technology gap in large-format, low-noise and ultra-low-noise Far-IR direct detectors is specifically highlighted by NASA's Cosmic Origins Program, and prioritized for development now to enable a flagship mission such as the Far-IR Surveyor that will address the key Cosmic Origins science questions of the next two decades. The detector requirements for a mid-resolution spectrometer are as follows: (1) Highly sensitive detectors with performance approaching 10^-19 - 10^-20 WHz 1/2 for background- limited operation in telescopes with cold optics. (2) Detector time constant in the sub- millisecond range. (3) Scalable architecture to a kilo pixel array with uniform detector characteristics. (4) Compatibility with space operation in the presence of particle radiation. We propose phononic crystals to meet the requirements of ultra-low-noise thermal detectors. By design, a phononic crystal exhibits phonon bandgaps where heat transport is forbidden. The size and location of the bandgaps depend on the elastic properties of the dielectric and the geometry of the phononic unit cell. A wide-bandwidth low-pass thermal filter with a cut-off frequency of 1.5 GHz and

  5. On line power spectra identification and whitening for the noise in interferometric gravitational wave detectors

    CERN Document Server

    Cuoco, E; Fabbroni, L; Losurdo, G; Mazzoni, M; Stanga, R M; Vetrano, F

    2001-01-01

    In this paper we address both to the problem of identifying the noise Power Spectral Density of interferometric detectors by parametric techniques and to the problem of the whitening procedure of the sequence of data. We will concentrate the study on a Power Spectral Density like the one of the Italian-French detector VIRGO and we show that with a reasonable finite number of parameters we succeed in modeling a spectrum like the theoretical one of VIRGO, reproducing all its features. We propose also the use of adaptive techniques to identify and to whiten on line the data of interferometric detectors. We analyze the behavior of the adaptive techniques in the field of stochastic gradient and in the Least Squares ones.

  6. Electromagnetic noise studies in a silicon strip detector, used as part of a luminosity monitor at LEP

    Science.gov (United States)

    Ødegaard, Trygve; Tafjord, Harald; Buran, Torleiv

    1995-02-01

    As part of the luminosity monitor, SAT, in the DELPHI [1] experiment at CERN's Large Electron Positron collider, a tracking detector constructed from silicon strip detector elements was installed in front of an electromagnetic calorimeter. The luminosity was measured by counting the number of Bhabha events at the interaction point of the electron and the positron beans. The tracking detector reconstructs from the interaction point and the calorimeter measures the corresponding particles' energies. The SAT Tracker [2] consists of 504 silicon strip detectors. The strips are DC-coupled to CMOS VLSI-chips, baptized Balder [3,4]. The chip performs amplification, zero-suppression, digitalisation, and multiplexing. The requirements of good space resolution and high efficiency put strong requirements on noise control. A short description of the geometry and the relevant circuit layout is given. We describe the efforts made to minimise the electromagnetic noise in the detector and present some numbers of the noise level using various techniques.

  7. Ultra-low phase noise 10 GHz oscillator to pump the parametric transducers of the Mario Schenberg gravitational wave detector

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Luiz A [Divisao de Materiais, Centro Tecnico Aeroespacial, Sao Jose dos Campos, SP 12201-970 (Brazil); Costa, Cesar A [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Aguiar, Odylio D [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, CP 515, Sao Jose dos Campos, SP 12201-970 (Brazil); Frajuca, Carlos [Centro Federal de Educacao Tecnologica de Sao Paulo, Rua Pedro Vicente 625, SP 01109-010 (Brazil); Mosso, Marbey M [CETUC, Centro de Estudos em Telecomunicacoes, PUC-RJ, Rio de Janeiro, RJ (Brazil); Podcameni, Abelardo [CETUC, Centro de Estudos em Telecomunicacoes, PUC-RJ, Rio de Janeiro, RJ (Brazil); Silva, Henrique J P P da [CETUC, Centro de Estudos em Telecomunicacoes, PUC-RJ, Rio de Janeiro, RJ (Brazil); Magalhaes, Nadja S [Instituto Tecnologica de Aeronautica, Departamento de FIsica, Praca Marechal Eduardo Gomes, 50, Sao Jose dos Campos, SP 12228-900 (Brazil)

    2004-03-07

    We developed a 10 GHz feedback oscillator with ultra-low phase noise. The oscillator was constructed to operate as the pump for the parametric transducers of the Mario Schenberg gravitational wave detector. We calculated the performance of the detector with this pump oscillator and determined how much improvement in phase noise would be necessary in order to reach the standard quantum limit in sensitivity.

  8. Mechanical radiation detection via sub-Brownian lever deflections

    Science.gov (United States)

    Hammig, Mark David

    2005-07-01

    A micromechanical lever that deflects in response to the impacts of charged particles is proposed as a means of improving upon the capabilities of existing radiation detection technology. When a particle strikes an object, momentum is transferred to the impacted body. The resulting body motion can be correlated to the energy of the incident particle. The momentum detector offers promise as a highly discriminating, high-resolution tool for ion sensing. Advances required to successfully realize a spectroscopic capability have been completed; specifically, techniques for reproducibly fabricating micromechanical structures have been optimized, and an instrument that measures miniscule deflections has been developed. Even absent substantial refinement efforts, the novel coupled-cavity optical detector can resolve lever motions on the order of 1--10 picometers. A method by which the Brownian motion of the lever can be stilled has been proven which elicits reductions sufficient to measure heavy-ion impact, the deflections from which may be several orders of magnitude below the thermal vibration amplitude. Using active forcing techniques, the Brownian vibration of the microlevers has been reduced from room temperature (288 K) to sub-Kelvin temperatures, for levers vibrating in air. The mechanical factors that limit the noise reduction magnitude are discussed and methods of surmounting those limitations are identified.

  9. Digital pulse processing and electronic noise analysis for improving energy resolutions in planar TlBr detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Tsutomu, E-mail: tada.t@cyric.tohoku.ac.j [Cyclotron and Radioisotope Center, Tohoku University, 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Hitomi, Keitaro [Cyclotron and Radioisotope Center, Tohoku University, 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Tanaka, Tomonobu [Divisions of Electronics, Graduate School of Engineering, Tohoku Institute of Technology, 35-1 Yagiyama, Kasumi-cho, Taihakuku, Sendai, Miyagi 982-8577 (Japan); Wu, Yan; Kim, Seong-Yun; Yamazaki, Hiromichi [Cyclotron and Radioisotope Center, Tohoku University, 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Ishii, Keizo [Department of Quantum Science and Energy Engineering, Graduate School of Engineering, Tohoku University, 6-6-1 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)

    2011-05-11

    Digital pulse processing and electronic noise analysis are proposed for improving energy resolution in planar thallium bromide (TlBr) detectors. An energy resolution of 5.8% FWHM at 662 keV was obtained from a 0.5 mm thick planar TlBr detector at room temperature using a digitizer with a sampling rate of 100 MS/s and 8 bit resolution. The electronic noise in the detector-preamplifier system was measured as a function of pulse shaping time in order to investigate the optimum shaping time for the detector. The depth of interaction (DOI) in TlBr detectors for incident gamma-rays was determined by taking the ratio of pulse heights for fast-shaped to slow-shaped signals. FWHM energy resolution of the detector was improved from 5.8% to 4.2% by implementing depth correction and by using the obtained optimum shaping time.

  10. Seismic gravity-gradient noise in interferometric gravitational-wave detectors

    CERN Document Server

    Hughes, S A; Hughes, Scott A.; Thorne, Kip S.

    1998-01-01

    When ambient seismic waves pass near an interferometric gravitational-wave detector, they induce density perturbations in the earth which produce fluctuating gravitational forces on the interferometer's test masses. These forces mimic a stochastic background of gravitational waves and thus constitute noise. We compute this noise using the theory of multimode Rayleigh and Love waves propagating in a layered medium that approximates the geological strata at the LIGO sites. We characterize the noise by a transfer function $T(f) motion $\\tilde W(f)$ to the spectrum of test mass motion $\\tilde x(f) = L\\tilde h(f)$ (where $L$ is the length of the interferometer's arms, and $\\tilde h(f)$ is the spectrum of gravitational-wave noise). This paper's primary foci are (i) a study of how $T(f)$ depends on the various seismic modes; (ii) an attempt to estimate which modes are excited at the LIGO sites at quiet and noisy times; and (iii) a corresponding estimate of the seismic gravity-gradient noise level. At quiet times the...

  11. Optimization of a photon rejecter to separate electronic noise in a photon-counting detector

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hyo-Min; Choi, Yu-Na; Lee, Seung-Wan; Lee, Young-Jin; Ryu, Hyun-Ju; Kim, Hee-Joung [Yonsei University, Wonju (Korea, Republic of)

    2012-12-15

    Photon-counting-based X-ray imaging technology provides the capability to count individual photons and to characterize photon energies. The cadmium telluride (CdTe)-based photon-counting detector is limited in capability, however, under a high X-ray flux. A photon rejecter composed of aluminum, for example, can reduce this limitation by modulating the incident number of photons. In addition to this function, the optimal photon rejecter can separate electronic noise, which degrades image quality. The aim of this work was to optimize a photon rejecter for high-quality image acquisition by removing electronic noise from the actual pulse signal. The images and spectra were acquired using a micro-focus X-ray source with a CdTe-based photon-counting detector. We acquired data with various types of photon-rejecter materials composed of aluminum (Al) and iodine at three different tube voltages (50, 70, and 90 kVp). A phantom composed of high-atomic-number materials was imaged to evaluate the efficiency of the photon rejecter. Photon rejecters composed of 1-mm Al, 10-mm Al, and a combination of 10-mm Al and iodine provided optimum capability at 50, 70, and 90 kVp, respectively. Each optimal combination of photon-rejecter material and voltage effectively separated electronic noise from the actual pulse signal and gave the highest contrast-to-noise ratio for materials on the image. These optimized types of photon rejecters can effectively discriminate electronic noise and improve image quality at different tube voltages.

  12. Development of a low noise integrated readout electronic for pixel detectors in CMOS technology for a Compton camera

    OpenAIRE

    Hausmann, Joachim

    2006-01-01

    Semiconductor detectors are very popular, particularly for their good energy resolution and their easy handling. Combined with a two dimensional spatial resolution such a detector is predestined to realise an active collimation in a Compton camera for medical applications. To measure the deposited energy in each channel (pixel), a self-triggering integrated electronic has been developed, which is directly bonded on top of the detector. The design of the low noise readout ele...

  13. Correlations between detectors allow violation of the Heisenberg noise-disturbance principle for position and momentum measurements.

    Science.gov (United States)

    Di Lorenzo, Antonio

    2013-03-22

    Heisenberg formulated a noise-disturbance principle stating that there is a tradeoff between noise and disturbance when a measurement of position and a measurement of momentum are performed sequentially, and another principle imposing a limitation on the product of the uncertainties in a joint measurement of position and momentum. We prove that the former, the Heisenberg sequential noise-disturbance principle, holds when the detectors are assumed to be initially uncorrelated from each other, but that it can be violated for some properly correlated initial preparations of the detectors.

  14. Novel silicon drift detector design enabling low dark noise and simple manufacturing

    Science.gov (United States)

    Aurola, A.; Marochkin, V.; Golovleva, M.; Tuuva, T.

    2015-02-01

    The Silicon Drift Detectors (SDDs) have replaced simple diodes in demanding X-ray fluorescence applications like in element analysers capable of detecting light elements. The reason for this is that with similar collection area the SDDs have a much smaller output capacitance than diodes due to a much smaller anode size. Thus the SDDs provide much better Signal to Noise Ratio (SNR) at smaller signal levels than diodes. The small capacitance in SDDs is achieved by placing concentric rings around a miniature sized anode. These rings are biased such that inside the SDD's fully depleted bulk a radial electric field component is established guiding signal charges towards the anode. Problems complicating the design of SDDs are positive oxide charge and interface dark noise. The latter is caused when leakage current generated at depleted interfaces mixes with the signal charge. It has been shown previously that by utilizing a chain of resistors connected to SDD's p+ drift rings and intermediate n+ rings both of these problems can be solved but the resistor chain arrangement requires an additional process step, which may not be standardly available. The interface generated dark noise and the requirement for a resistor chain can be removed by implementing suitable gaps in the p+ rings or with a resistive spiral as well as by implementing an additional anode for the collection of interface leakage current. Such SDDs are, however, vulnerable to accumulation of positive oxide charge complicating the manufacturing and likely reducing the effective lifetime of the detector.We present an SDD design comprising a novel ring arrangement preventing the formation of interface dark noise, being resistant to positive oxide charge, and removing the need for a resistor chain. In this work the design and operation principle of the proposed SDD is presented. The operation of the proposed SDD has been evaluated on TCAD with cylindrically symmetric 3D process and device simulations.

  15. Improved energy resolution of highly segmented HPGe detectors by noise reduction

    Energy Technology Data Exchange (ETDEWEB)

    Wiens, A.; Birkenbach, B.; Bruyneel, B.; Eberth, J.; Hess, H.; Pascovici, Gh.; Reiter, P. [Institut fuer Kernpyhsik, Koeln (Germany); Bazzacco, D.; Farnea, E.; Michelagnoli, C.; Recchia, F. [INFN, Sezione di Padova, Padova (Italy); Collaboration: for the AGATA Collaboration

    2013-04-15

    Built-in redundancies in highly segmented high-purity Ge detectors are exploited to increase the energy resolution of these semiconductor devices for detection of electromagnetic radiation in the X-ray and {gamma}-ray regime. The information of the two electronically decoupled independent measurements, the cathode and the anode electrodes, provides an improved signal-to-noise ratio through a combination of the individually measured signals performed on an event-by-event basis. The average energy resolution values of the AGATA triple cluster detector for an energy deposition of 60keV was measured to be 1.1 keV (FWHM) for the 36 segments and 1.2 keV for the core. The averaged signals of the core and the segments show an improved resolution value of 0.87 keV which is close to the expected theoretical limit. At higher {gamma}-ray energy the averaging technique allows for an enhanced energy resolution with a FWHM of 2.15keV at 1.3MeV. By means of the position sensitive operation of AGATA a new value for the Fano factor was determined and the noise contributions to the FWHM of a {gamma}-ray peak separated. (orig.)

  16. Monte Carlo analysis of megavoltage x-ray interaction-induced signal and noise in cadmium tungstate detectors for cargo container inspection

    Science.gov (United States)

    Kim, J.; Park, J.; Kim, J.; Kim, D. W.; Yun, S.; Lim, C. H.; Kim, H. K.

    2016-11-01

    For the purpose of designing an x-ray detector system for cargo container inspection, we have investigated the energy-absorption signal and noise in CdWO4 detectors for megavoltage x-ray photons. We describe the signal and noise measures, such as quantum efficiency, average energy absorption, Swank noise factor, and detective quantum efficiency (DQE), in terms of energy moments of absorbed energy distributions (AEDs) in a detector. The AED is determined by using a Monte Carlo simulation. The results show that the signal-related measures increase with detector thickness. However, the improvement of Swank noise factor with increasing thickness is weak, and this energy-absorption noise characteristic dominates the DQE performance. The energy-absorption noise mainly limits the signal-to-noise performance of CdWO4 detectors operated at megavoltage x-ray beam.

  17. Fundamental x-ray interaction limits in diagnostic imaging detectors: frequency-dependent Swank noise.

    Science.gov (United States)

    Hajdok, G; Battista, J J; Cunningham, I A

    2008-07-01

    A frequency-dependent x-ray Swank factor based on the "x-ray interaction" modulation transfer function and normalized noise power spectrum is determined from a Monte Carlo analysis. This factor was calculated in four converter materials: amorphous silicon (a-Si), amorphous selenium (a-Se), cesium iodide (CsI), and lead iodide (PbI2) for incident photon energies between 10 and 150 keV and various converter thicknesses. When scaled by the quantum efficiency, the x-ray Swank factor describes the best possible detective quantum efficiency (DQE) a detector can have. As such, this x-ray interaction DQE provides a target performance benchmark. It is expressed as a function of (Fourier-based) spatial frequency and takes into consideration signal and noise correlations introduced by reabsorption of Compton scatter and photoelectric characteristic emissions. It is shown that the x-ray Swank factor is largely insensitive to converter thickness for quantum efficiency values greater than 0.5. Thus, while most of the tabulated values correspond to thick converters with a quantum efficiency of 0.99, they are appropriate to use for many detectors in current use. A simple expression for the x-ray interaction DQE of digital detectors (including noise aliasing) is derived in terms of the quantum efficiency, x-ray Swank factor, detector element size, and fill factor. Good agreement is shown with DQE curves published by other investigators for each converter material, and the conditions required to achieve this ideal performance are discussed. For high-resolution imaging applications, the x-ray Swank factor indicates: (i) a-Si should only be used at low-energy (e.g., mammography); (ii) a-Se has the most promise for any application below 100 keV; and (iii) while quantum efficiency may be increased at energies just above the K edge in CsI and PbI2, this benefit is offset by a substantial drop in the x-ray Swank factor, particularly at high spatial frequencies.

  18. Signal and noise transfer properties of photoelectric interactions in diagnostic x-ray imaging detectors.

    Science.gov (United States)

    Hajdok, G; Yao, J; Battista, J J; Cunningham, I A

    2006-10-01

    Image quality in diagnostic x-ray imaging is ultimately limited by the statistical properties governing how, and where, x-ray energy is deposited in a detector. This in turn depends on the physics of the underlying x-ray interactions. In the diagnostic energy range (10-100 keV), most of the energy deposited in a detector is through photoelectric interactions. We present a theoretical model of the photoelectric effect that specifically addresses the statistical nature of energy absorption by photoelectrons, K and L characteristic x rays, and Auger electrons. A cascaded-systems approach is used that employs a complex structure of parallel cascades to describe signal and noise transfer through the photoelectric effect in terms of the modulation transfer function, Wiener noise power spectrum, and detective quantum efficiency (DQE). The model was evaluated by comparing results with Monte Carlo calculations for x-ray converters based on amorphous selenium (a-Se) and lead (Pb), representing both low and high-Z materials. When electron transport considerations can be neglected, excellent agreement (within 3%) is obtained for each metric over the entire diagnostic energy range in both a-Se and Pb detectors up to 30 cycles/mm, the highest frequency tested. The cascaded model overstates the DQE when the electron range cannot be ignored. This occurs at approximately two cycles/mm in a-Se at an incident photon energy of 80 keV, whereas in Pb, excellent agreement is obtained for the DQE over the entire diagnostic energy range. However, within the context of mammography (20 keV) and micro-computed tomography (40 keV), the effects of electron transport on the DQE are negligible compared to fluorescence reabsorption, which can lead to decreases of up to 30% and 20% in a-Se and Pb, respectively, at 20 keV; and 10% and 5%, respectively, at 40 keV. It is shown that when Swank noise is identified in a Fourier model, the Swank factor must be frequency dependent. This factor decreases

  19. Human Gravity-Gradient Noise in Interferometric Gravitational-Wave Detectors

    CERN Document Server

    Thorne, K S; Thorne, Kip S.; Winstein, Carolee J.

    1999-01-01

    Among all forms of routine human activity, the one which produces the strongest gravity-gradient noise in interferometric gravitational-wave detectors (e.g. LIGO) is the beginning and end of weight transfer from one foot to the other during walking. The beginning and end of weight transfer entail sharp changes (timescale tau ~ 20msec) in the horizontal jerk (first time derivative of acceleration) of a person's center of mass. These jerk pairs, occuring about twice per second, will produce gravity-gradient noise in LIGO in the frequency band 2.5 Hz <~ f <~ 1/(2 tau) ~= 25 Hz with the form sqrt{S_h(f)} sum is over all the walking people, r_i is the distance of the i'th person from the nearest interferometer test mass, and we estimate this formula to be accurate to within a factor 3. To ensure that this noise is neglible in advanced LIGO interferometers, people should be prevented from coming nearer to the test masses than r ~= 10m. A r ~= 10m exclusion zone will also reduce to an acceptable level gravity ...

  20. Experimental verification of clock noise transfer and components for space based gravitational wave detectors.

    Science.gov (United States)

    Sweeney, Dylan; Mueller, Guido

    2012-11-05

    The Laser Interferometer Space Antenna (LISA) and other space based gravitational wave detector designs require a laser communication subsystem to, among other things, transfer clock signals between spacecraft (SC) in order to cancel clock noise in post-processing. The original LISA baseline design requires frequency synthesizers to convert each SC clock into a 2 GHz signal, and electro-optic modulators (EOMs) to modulate this 2 GHz clock signal onto the laser light. Both the frequency synthesizers and the EOMs must operate with a phase fidelity of 2×10(-4)cycles/√Hz. In this paper we present measurements of the phase fidelity of frequency synthesizers and EOMs. We found that both the frequency synthesizers and the EOMs meet the requirement when tested independently and together. We also performed an electronic test of the clock noise transfer using frequency synthesizers and the University of Florida LISA Interferometry (UFLIS) phasemeter. We found that by applying a time varying fractional delay filter we could suppress the clock noise to a level below our measurement limit, which is currently determined by timing jitter and is less than an order of magnitude above the LISA requirement for phase measurements.

  1. Noise characterization of silicon strip detectors-comparison of sensors with and without integrated jfet source-follower.

    CERN Document Server

    Giacomini, Gabriele

    Noise is often the main factor limiting the performance of detector systems. In this work a detailed study of the noise contributions in different types of silicon microstrip sensors is carried on. We investigate three sensors with double-sided readout fabricated by different suppliers for the ALICE experiment at the CERN LHC, in addition to detectors including an integrated JFET Source-Follower as a first signal conditioning stage. The latter have been designed as an attempt at improving the performance when very long strips, obtained by gangling together several sensors, are required. After a description of the strip sensors and of their operation, the “static” characterization measurements performed on them (current and capacitance versus voltage and/or frequency) are illustrated and interpreted. Numerical device simulation has been employed as an aid in interpreting some of the measurement results. The commonly used models for expressing the noise of the detector-amplifier system in terms of its relev...

  2. Thermoelastic dissipation in inhomogeneous media: loss measurements and displacement noise in coated test masses for interferometric gravitational wave detectors

    CERN Document Server

    Fejer, M M; Cagnoli, G; Crooks, D R M; Gretarsson, A M; Harry, G M; Hough, J; Penn, S D; Sneddon, P H; Vyatchanin, S P

    2004-01-01

    The displacement noise in the test mass mirrors of interferometric gravitational wave detectors is proportional to their elastic dissipation at the observation frequencies. In this paper, we analyze one fundamental source of dissipation in thin coatings, thermoelastic damping associated with the dissimilar thermal and elastic properties of the film and the substrate. We obtain expressions for the thermoelastic dissipation factor necessary to interpret resonant loss measurements, and for the spectral density of displacement noise imposed on a Gaussian beam reflected from the face of a coated mass. The predicted size of these effects is large enough to affect the interpretation of loss measurements, and to influence design choices in advanced gravitational wave detectors.

  3. Low-noise detector and amplifier design for 100 ns direct detection CO{sub 2} LIDAR receiver

    Energy Technology Data Exchange (ETDEWEB)

    Cafferty, M.M.; Cooke, B.J.; Laubscher, B.E.; Olivas, N.L.; Fuller, K.

    1997-06-01

    The development and test results of a prototype detector/amplifier design for a background limited, pulsed 100 ns, 10--100 kHz repetition rate LIDAR/DIAL receiver system are presented. Design objectives include near-matched filter detection of received pulse amplitude and round trip time-of-flight, and the elimination of excess correlated detector/amplifier noise for optimal pulse averaging. A novel pole-zero cancellation amplifier, coupled with a state-of-the-art SBRC (Santa Barbara Research Center) infrared detector was implemented to meet design objectives. The pole-zero cancellation amplifier utilizes a tunable, pseudo-matched filter technique to match the width of the laser pulse to the shaping time of the filter for optimal SNR performance. Low frequency correlated noise, (l/f and drift noise) is rejected through a second order high gain feedback loop. The amplifier also employs an active detector bias stage minimizing detector drift. Experimental results will be provided that demonstrate near-background limited, 100 ns pulse detection performance given a 8.5--11.5 {micro}m (300 K B.B.) radiant background, with the total noise floor spectrally white for optimal pulse averaging efficiency.

  4. Using the Moon As A Low-Noise Seismic Detector For Strange Quark Nuggets

    Science.gov (United States)

    Banerdt, W. Bruce; Chui, Talso; Griggs, Cornelius E.; Herrin, Eugene T.; Nakamura, Yosio; Paik, Ho Jung; Penanen, Konstantin; Rosenbaum, Doris; Teplitz, Vigdor L.; Young, Joseph

    2006-01-01

    Strange quark matter made of up, down and strange quarks has been postulated by Witten [1]. Strange quark matter would be nearly charge neutral and would have density of nuclear matter (10(exp 14) gm/cu cm). Witten also suggested that nuggets of strange quark matter, or strange quark nuggets (SQNs), could have formed shortly after the Big Bang, and that they would be viable candidates for cold dark matter. As suggested by de Rujula and Glashow [2], an SQN may pass through a celestial body releasing detectable seismic energy along a straight line. The Moon, being much quieter seismically than the Earth, would be a favorable place to search for such events. We review previous searches for SQNs to illustrate the parameter space explored by using the Moon as a low-noise detector of SQNs. We also discuss possible detection schemes using a single seismometer, and using an International Lunar Seismic Network.

  5. Using the Moon As A Low-Noise Seismic Detector For Strange Quark Nuggets

    Science.gov (United States)

    Banerdt, W. Bruce; Chui, Talso; Griggs, Cornelius E.; Herrin, Eugene T.; Nakamura, Yosio; Paik, Ho Jung; Penanen, Konstantin; Rosenbaum, Doris; Teplitz, Vigdor L.; Young, Joseph

    2006-01-01

    Strange quark matter made of up, down and strange quarks has been postulated by Witten [1]. Strange quark matter would be nearly charge neutral and would have density of nuclear matter (10(exp 14) gm/cu cm). Witten also suggested that nuggets of strange quark matter, or strange quark nuggets (SQNs), could have formed shortly after the Big Bang, and that they would be viable candidates for cold dark matter. As suggested by de Rujula and Glashow [2], an SQN may pass through a celestial body releasing detectable seismic energy along a straight line. The Moon, being much quieter seismically than the Earth, would be a favorable place to search for such events. We review previous searches for SQNs to illustrate the parameter space explored by using the Moon as a low-noise detector of SQNs. We also discuss possible detection schemes using a single seismometer, and using an International Lunar Seismic Network.

  6. Noise-free high-efficiency photon-number-resolving detectors

    CERN Document Server

    Rosenberg, D; Miller, A J; Nam, S W; Rosenberg, Danna; Lita, Adriana E.; Miller, Aaron J.; Nam, Sae Woo

    2005-01-01

    High-efficiency optical detectors that can determine the number of photons in a pulse of monochromatic light have applications in a variety of physics studies, including post-selection-based entanglement protocols for linear optics quantum computing and experiments that simultaneously close the detection and communication loopholes of Bell's inequalities. Here we report on our demonstration of fiber-coupled, noise-free, photon-number-resolving transition-edge sensors with 88% efficiency at 1550 nm. The efficiency of these sensors could be made even higher at any wavelength in the visible and near-infrared spectrum without resulting in a higher dark-count rate or degraded photon-number resolution.

  7. Controlling kilometre-scale interferometric detectors for gravitational wave astronomy: Active phase noise cancellation using EOMs

    Science.gov (United States)

    Arnaud, N.; Balembois, L.; Bizouard, M. A.; Brisson, V.; Casanueva, J.; Cavalier, F.; Davier, M.; Frey, V.; Hello, P.; Huet, D.; Leroy, N.; Loriette, V.; Maksimovic, I.; Robinet, F.

    2017-02-01

    The second generation of Gravitational waves detectors are kilometric Michelson interferometers with additional recycling Fabry-Perot cavities on the arms and ​the addition of two more recycling cavities to enhance their sensitivity, with the particularity that all the mirrors are suspended. In order to control them a new technique, based on the use of auxiliary lasers, has been developed to bring the interferometer to its working point, with all the cavities on their resonance, in an adiabatic way. The implementation of this technique in Advanced Virgo is under preparation and the propagation of a stable laser through a 3-km optical fibre is one of the most problematic issues. A new technique of active phase noise cancellation based on the use of Electro Optical Modulators has been developed, and a first prototype has been successfully tested.

  8. The Design and Research of the Operation Status Detector for Marine Engine Room Power Plant Based on Noise

    Directory of Open Access Journals (Sweden)

    Li Hang

    2016-01-01

    Full Text Available Designed in this paper, based on the noise of ship engine room power plant running status of detector, is mainly used in the operation of the power plant of acoustic shell size to determine when the machine running state, this device is composed of signal disposal and alarm display adjustment part of two parts. Detector that can show the size of the voice, if exceed the set limit alarm value, the detector can sound an alarm, to remind staff equipment fails, it shall timely inspection maintenance, improve the safety of the operation of the ship.

  9. SU-E-I-77: A Noise Reduction Technique for Energy-Resolved Photon-Counting Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lam Ng, A; Ding, H; Cho, H; Molloi, S [University of California, Irvine, CA (United States)

    2014-06-01

    Purpose: Finding the optimal energy threshold setting for an energy-resolved photon-counting detector has an important impact on the maximization of contrast-to-noise-ratio (CNR). We introduce a noise reduction method to enhance CNR by reducing the noise in each energy bin without altering the average gray levels in the projection and image domains. Methods: We simulated a four bin energy-resolved photon-counting detector based on Si with a 10 mm depth of interaction. TASMIP algorithm was used to simulate a spectrum of 65 kVp with 2.7 mm Al filter. A 13 mm PMMA phantom with hydroxyapatite and iodine at different concentrations (100, 200 and 300 mg/ml for HA, and 2, 4, and 8 mg/ml for Iodine) was used. Projection-based and Image-based energy weighting methods were used to generate weighted images. A reference low noise image was used for noise reduction purposes. A Gaussian-like weighting function which computes the similarity between pixels of interest was calculated from the reference image and implemented on a pixel by pixel basis for the noisy images. Results: CNR improvement compared to different methods (Charge-Integrated, Photon-Counting and Energy-Weighting) and after noise reduction was highly task-dependent. The CNR improvement with respect to the Charge-Integrated CNR for hydroxyapatite and iodine were 1.8 and 1.5, respectively. In each of the energy bins, the noise was reduced by approximately factor of two without altering their respective average gray levels. Conclusion: The proposed noise reduction technique for energy-resolved photon-counting detectors can significantly reduce image noise. This technique can be used as a compliment to the current energy-weighting methods in CNR optimization.

  10. Development of a low noise readout ASIC for CZT detectors for gamma-ray spectroscopy applications

    Science.gov (United States)

    Luo, J.; Deng, Z.; Wang, G.; Li, H.; Liu, Y.

    2012-08-01

    A multi-channel readout ASIC for pixelated CZT detectors has been developed for gamma-ray spectroscopy applications. Each channel consists of a low noise dual-stage charge sensitive amplifier (CSA), a CR-(RC)4 semi-Gaussian shaper and a class-AB output buffer. The equivalent noise charge (ENC) of input PMOS transistor is optimized for 5 pF input capacitance and 1 μs peaking time using gm/ID design methodology. The gain can be adjusted from 100 mV/fC to 400 mV/fC and the peaking time can be adjusted from 1 μs to 4 μs. A 16-channel chip has been designed and fabricated in 0.35 μm 2P4M CMOS technology. The test results show that the chip works well and fully satisfies the design specifications. The ENC was measured to be 72 e + 26 e/pF at 1 μs peaking time and 86 e + 20 e/pF at 4 μs peaking time. The non-uniformity of the channel gain and ENC was less than ±12% and ±11% respectively for 16 channels in one chip. The chip was also tested with a pixelated CZT detector at room temperature. The measured energy resolution at 59.5 keV photopeak of 241Am and 122 keV photopeak of 57Co were 4.5% FWHM and 2.8% FWHM for the central area pixels, respectively.

  11. A low noise, low power BiCMOS preamplifier-shaper for microstrip detectors using DMILL process and irradiation measurements

    CERN Document Server

    Hu, Y; Dulinski, W

    1999-01-01

    A low noise, low power consumption BiCMOS preamplifier-shaper for microstrip detector readout in the future LHC experiments has been designed and fabricated using the radiation hard SOI BiCMOS-PJFET process of DMILL. In the present prototype, an ENC noise of 571 electrons at 0 pF with a noise slope of 37 electrons/pF has been obtained for a shaping time of 25 ns, a gain of 30 mV/MIP and a power consumption of 1 mW per channel. Measurements after irradiations by gamma photons and neutrons are also presented in this paper.

  12. An Integrated MASS/DIMM Monitor Based on a Low-Noise CCD Detector

    Science.gov (United States)

    Guesalaga, A.; Osborn, J.; Sarazin, M.; Neichel, B.; Perera, S.; Wilson, R.; Wizinowich, P.

    2015-12-01

    We propose a novel design for a turbulence profiler. Using a single detector, images of the pupil (scintillation) and stars (image motion) are formed in the detector plane. The instrument is called FASS (Full Aperture Scintillation Sensor), as it uses the full aperture of the telescope. Different processing strategies are evaluated, including spatial segmentation and Fourier analysis. The different approaches are tested via simulation and on-sky data from two telescopes and compared to profiles obtained with the Durham Stereo-SCIDAR monitor. Overall, simulations shows that the method is more accurate that the classical MASS configuration, but it is shown that the photon noise plays an important role in the accuracy of the method, imposing stringent requirements on the pixel size, which must be significantly smaller than the speckle size formed from turbulence close to the ground (Fresnel law for speckle size). Encouraging results have been obtained for on-sky data and compared to contemporaneous profiles obtained with a Stereo-Scidar technique.

  13. Displacement noise from back scattering and specular reflection of input optics in advanced gravitational wave detectors.

    Science.gov (United States)

    Canuel, B; Genin, E; Vajente, G; Marque, J

    2013-05-06

    The second generation of ground-based interferometric gravitational wave detectors are currently being built and installed. They are designed to be better in strain sensitivity by about a factor 10 with respect to the first generation. Light originating from the laser and following unintended paths, called stray light, has been a major problem during the commissioning of all of the first generation detectors. Indeed, stray light carries information about the phase of the emitting object. Therefore, in the next generation all the optics will be suspended in the vacuum in order to mitigate their associated stray light displacement noise. Despite this additional precaution, the challenging target sensitivity at low frequency which is partially limited by quantum radiation pressure combined with up-conversion effects, requires more detailed investigation. In this paper, we turn our attention to stray light originating from auxiliary optical benches. We use a dedicated formalism to compute the re-coupling of back-reflected and back-scattered light. We show, in particular, how much care should be taken in designing and setting requirements for the input bench optics.

  14. All-optical optoacoustic microscopy system based on probe beam deflection technique

    Science.gov (United States)

    Maswadi, Saher M.; Tsyboulskic, Dmitri; Roth, Caleb C.; Glickman, Randolph D.; Beier, Hope T.; Oraevsky, Alexander A.; Ibey, Bennett L.

    2016-03-01

    It is difficult to achieve sub-micron resolution in backward mode OA microscopy using conventional piezoelectric detectors, because of wavefront distortions caused by components placed in the optical path, between the sample and the objective lens, that are required to separate the acoustic wave from the optical beam. As an alternate approach, an optoacoustic microscope (OAM) was constructed using the probe beam deflection technique (PBDT) to detect laserinduced acoustic signals. The all-optical OAM detects laser-generated pressure waves using a probe beam passing through a coupling medium, such as water, filling the space between the microscope objective lens and sample. The acoustic waves generated in the sample propagate through the coupling medium, causing transient changes in the refractive index that deflect the probe beam. These deflections are measured with a high-speed, balanced photodiode position detector. The deflection amplitude is directly proportional to the magnitude of the acoustic pressure wave, and provides the data required for image reconstruction. The sensitivity of the PBDT detector expressed as noise equivalent pressure was 12 Pa, comparable to that of existing high-performance ultrasound detectors. Because of the unimpeded working distance, a high numerical aperture objective lens, i.e. NA = 1, was employed in the OAM to achieve near diffraction-limited lateral resolution of 0.5 μm at 532nm. The all-optical OAM provides several benefits over current piezoelectric detector-based systems, such as increased lateral and axial resolution, higher sensitivity, robustness, and potentially more compatibility with multimodal instruments.

  15. Phase-Locked Loop Noise Reduction via Phase Detector Implementation for Single-Phase Systems

    Energy Technology Data Exchange (ETDEWEB)

    Thacker, Timothy [Virginia Polytechnic Institute and State University (Virginia Tech); Boroyevich, Dushan [Virginia Polytechnic Institute and State University (Virginia Tech); Burgos, Rolando [ABB; Wang, Fei [ORNL

    2011-01-01

    A crucial component of grid-connected converters is the phase-locked loop (PLL) control subsystem that tracks the grid voltage's frequency and phase angle. Therefore, accurate fast-responding PLLs for control and protection purposes are required to provide these measurements. This paper proposes a novel feedback mechanism for single-phase PLL phase detectors using the estimated phase angle. Ripple noise appearing in the estimated frequency, most commonly the second harmonic under phase-lock conditions, is reduced or eliminated without the use of low-pass filters, which can cause delays to occur and limits the overall performance of the PLL response to dynamic changes in the system. The proposed method has the capability to eliminate the noise ripple entirely and, under extreme line distortion conditions, can reduce the ripple by at least half. Other modifications implemented through frequency feedback are shown to decrease the settling time of the PLL up to 50%. Mathematical analyses with the simulated and experimental results are provided to confirm the validity of the proposed methods.

  16. Classification methods for noise transients in advanced gravitational-wave detectors II: performance tests on Advanced LIGO data

    Science.gov (United States)

    Powell, Jade; Torres-Forné, Alejandro; Lynch, Ryan; Trifirò, Daniele; Cuoco, Elena; Cavaglià, Marco; Heng, Ik Siong; Font, José A.

    2017-02-01

    The data taken by the advanced LIGO and Virgo gravitational-wave detectors contains short duration noise transients that limit the significance of astrophysical detections and reduce the duty cycle of the instruments. As the advanced detectors are reaching sensitivity levels that allow for multiple detections of astrophysical gravitational-wave sources it is crucial to achieve a fast and accurate characterization of non-astrophysical transient noise shortly after it occurs in the detectors. Previously we presented three methods for the classification of transient noise sources. They are Principal Component Analysis for Transients (PCAT), Principal Component LALInference Burst (PC-LIB) and Wavelet Detection Filter with Machine Learning (WDF-ML). In this study we carry out the first performance tests of these algorithms on gravitational-wave data from the Advanced LIGO detectors. We use the data taken between the 3rd of June 2015 and the 14th of June 2015 during the 7th engineering run (ER7), and outline the improvements made to increase the performance and lower the latency of the algorithms on real data. This work provides an important test for understanding the performance of these methods on real, non stationary data in preparation for the second advanced gravitational-wave detector observation run, planned for later this year. We show that all methods can classify transients in non stationary data with a high level of accuracy and show the benefits of using multiple classifiers.

  17. Classification methods for noise transients in advanced gravitational-wave detectors II: performance tests on Advanced LIGO data

    CERN Document Server

    Powell, Jade; Lynch, Ryan; Trifirò, Daniele; Cuoco, Elena; Cavaglià, Marco; Heng, Ik Siong; Font, José A

    2016-01-01

    The data taken by the advanced LIGO and Virgo gravitational-wave detectors contains short duration noise transients that limit the significance of astrophysical detections and reduce the duty cycle of the instruments. As the advanced detectors are reaching sensitivity levels that allow for multiple detections of astrophysical gravitational-wave sources it is crucial to achieve a fast and accurate characterization of non-astrophysical transient noise shortly after it occurs in the detectors. Previously we presented three methods for the classification of transient noise sources. They are Principal Component Analysis for Transients (PCAT), Principal Component LALInference Burst (PC-LIB) and Wavelet Detection Filter with Machine Learning (WDF-ML). In this study we carry out the first performance tests of these algorithms on gravitational-wave data from the Advanced LIGO detectors. We use the data taken between the 3rd of June 2015 and the 14th of June 2015 during the 7th engineering run (ER7), and outline the im...

  18. Using the Moon as a low-noise seismic detector for strange quark nuggets

    Energy Technology Data Exchange (ETDEWEB)

    Banerdt, W. Bruce [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Chui, Talso [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)], E-mail: talso.c.chui@jpl.nasa.gov; Griggs, Cornelius E. [Physics Department, University of Maryland, College Park, MD 20742 (United States); Herrin, Eugene T. [Department of Geology, Southern Methodist University, Dallas, TX 75275 (United States); Nakamura, Yosio [Institute for Geophysics, University of Texas at Austin, Austin, TX 78759-8500 (United States); Paik, Ho Jung [Physics Department, University of Maryland, College Park, MD 20742 (United States); Penanen, Konstantin [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Rosenbaum, Doris [Physics Department, Southern Methodist University, Dallas, TX 75275 (United States); Teplitz, Vigdor L. [Physics Department, Southern Methodist University, Dallas, TX 75275 (United States); NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Young, Joseph [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2007-04-15

    Strange quark matter made of up, down and strange quarks has been postulated by Witten [E. Witten, Phys. Rev D 30 (1984) 279]. Strange quark matter would be nearly charge neutral and would have density of nuclear matter (10{sup 14} gm/cm{sup 3}). Witten also suggested that nuggets of strange quark matter, or strange quark nuggets (SQNs), could have formed shortly after the Big Bang, and that they would be viable candidates for cold dark matter. As suggested by de Rujula and Glashow [A. de Rujula and S. Glashow, Nature 312 (1984) 734], an SQN may pass through a celestial body releasing detectable seismic energy along a straight line. The Moon, being much quieter seismically than the Earth, would be a favorable place to search for such events. We review previous searches for SQNs to illustrate the parameter space explored by using the Moon as a low-noise detector of SQNs. We also discuss possible detection schemes using a single seismometer, and using an International Lunar Seismic Network.

  19. Quantum Noise Limits in White-Light-Cavity-Enhanced Gravitational Wave Detectors

    CERN Document Server

    Zhou, Minchuan; Shahriar, Selim M

    2014-01-01

    Previously, we had proposed a gravitational wave detector that incorporates the white light cavity (WLC) effect using a compound cavity for signal recycling (CC-SR). Here, we first calculate the quantum noise (QN) limited sensitivity curves for this design, and find that the broadening of sensitivity predicted by the classical analysis is also present in these curves, but is somewhat reduced. Furthermore, we find that the curves always stay above the standard quantum limit (SQL). To circumvent this limitation, we modify the dispersion to compensate the non-linear phase variation produced by the opto-mechanical (OM) resonance effects by making use of the single sideband approximation (SSA). We find that the resonance dips in the resulting QN curves entails a 14 times higher sensitivity-bandwidth product compared to the highest sensitivity result presented by Bunanno and Chen. We also present a simpler scheme (WLC-SR) where a dispersion medium is inserted in the SR cavity. Compared to the highest sensitivity re...

  20. The line-noise-reduction for low dose x-ray fluoroscopy with the flat panel detector

    Science.gov (United States)

    Nakamura, Tadashi; Ikeda, Shigeyuki; Suzuki, Katsumi; Takenouchi, Shinobu

    2006-03-01

    A scintillator type Flat Panel Detector (FPD)1 has a good noise performance especially in Fluoroscopic images because of high DQE. Almost same dose as I.I. and CCD system is accepted in clinical use. According to the clinical study, the dose in fluoroscopy will be decreased if we can reduce the line noise coming from gate line of the Thin Film Transistor (TFT). The purpose of this study is to detect and reduce this line noise from the fluoroscopic images making it possible to perform a lower dose of fluoroscopy imaging. We detected the line noise by acquiring a dark image (without exposure) and then comparing the average of the line data along to the gate line to the neighborhood lines. We have applied this method to the dark area taken by the collimator of the Lucite phantom image and detected it. The detected line will be compensated by interpolation with neighborhood lines. The FPD of our system2 has a big detecting area (40cm x 30cm) and a zoom mode is selected in fluoroscopy because the doctor is watching an edge of the guide-wire and a contrast medium. The collimated area of the detector is displayed in a monitor after the zooming process and we can take a collimated dark area for detecting the line noise. As we applied this method to the dark image (1024pixels x 1024lines) including 54 lines with noise, we can improve 10% of SD. Visible line noise of chest phantom image was reduced with this method. It will help to lower the fluoroscopy dose.

  1. Noise

    Science.gov (United States)

    Noise is all around you, from televisions and radios to lawn mowers and washing machines. Normally, you ... sensitive structures of the inner ear and cause noise-induced hearing loss. More than 30 million Americans ...

  2. Estimation of losses in a 300 m filter cavity and quantum noise reduction in the KAGRA gravitational-wave detector

    Science.gov (United States)

    Capocasa, Eleonora; Barsuglia, Matteo; Degallaix, Jérôme; Pinard, Laurent; Straniero, Nicolas; Schnabel, Roman; Somiya, Kentaro; Aso, Yoichi; Tatsumi, Daisuke; Flaminio, Raffaele

    2016-04-01

    The sensitivity of the gravitational-wave detector KAGRA, presently under construction, will be limited by quantum noise in a large fraction of its spectrum. The most promising technique to increase the detector sensitivity is the injection of squeezed states of light, where the squeezing angle is dynamically rotated by a Fabry-Pérot filter cavity. One of the main issues in the filter cavity design and realization is the optical losses due to the mirror surface imperfections. In this work we present a study of the specifications for the mirrors to be used in a 300 m filter cavity for the KAGRA detector. A prototype of the cavity will be constructed at the National Astronomical Observatory of Japan, inside the infrastructure of the former TAMA interferometer. We also discuss the potential improvement of the KAGRA sensitivity, based on a model of various realistic sources of losses and their influence on the squeezing amplitude.

  3. Performance Analysis of Global Search Algorithm Based Multiuser Detector for Multi Carrier Code Division Multiple Access System under Clipping Noise

    Directory of Open Access Journals (Sweden)

    S. Sivanesskumar

    2011-01-01

    Full Text Available Problem statement: Multi Carrier Code Division Multiple Access (MC-CDMA, a promising technology for the 4G communication systems. The major limitation of MC-CDMA system is the Multiple Access Interference (MAI which is due to near-far effect, frequency offset and nonlinear power amplification due to clipping noise. Approach: The performance of MC-CDMA under clipping noise using Global search algorithm based Multiuser detector in AWGN, Rayleigh and Rician channel is analyzed in this study. Results: The proposed method is simulated using BPSK modulation, Walsh spreading code, number of subcarriers 64 and number of users 16 and clipping noise. Conclusion: By simulation result, BER in AWGN channel outperforms other channels as SNR is increased. The performance of Rician fading channel is better than that of Rayleigh fading channel, because of the LOS path.

  4. Development of a balanced detector with biased synchronous detection and application to near shot noise limited noise cancelling of supercontinuum pulse light.

    Science.gov (United States)

    Seto, Keisuke; Tsukada, Toshiaki; Okuda, Yoshinao; Tokunaga, Eiji; Kobayashi, Takayoshi

    2014-02-01

    We report on the development of a balanced detector suited for multicolor imaging. The source pulsed light is split into probe and reference pulsed light. The reference pulse is delayed through an optical path and the probe and reference pulses are detected by a single photodetector. The signs of the detected signals of the probe and reference pulses are flipped based on a signal synchronous to the light source. Then, the signals are averaged through a low-pass filter. The output signal is proportional to the intensity difference between the probe and the reference. This balanced detector has two features: (1) both the probe and reference pulsed lights are detected by a single photodetector and (2) a voltage bias on the sign flipping compensates for the optical-intensity unbalance between the probe and reference pulsed lights. The first feature enables the probe and reference pulses to travel along a common optical path from a sample through a spectrograph to the photodetector, which minimizes the intensity unbalance between the probe and reference pulses during imaging and spectroscopy. The second feature ensures the complete balanced-detection in whole wavelength range by compensating for the optical unbalance created by deviations in the splitting ratios of the probe and reference lights at different wavelengths. Although a higher signal to noise ratio (SNR) reached to near shot noise limited SNR is attained by attaching a resonator to the photodetector for pulse repetition, the electrical bias cannot compensate for the optical balance. This unbalance is, however, corrected by adjusting the phase of the synchronous signal. We applied the present balanced detection to a stimulated Raman microscope with supercontinuum probe light and demonstrated its noise cancelling performance through capturing polystyrene beads.

  5. Non-Geiger-Mode Single-Photon Avalanche Detector with Low Excess Noise

    Science.gov (United States)

    Zhao, Kai; Lo, YuHwa; Farr, William

    2010-01-01

    This design constitutes a self-resetting (gain quenching), room-temperature operational semiconductor single-photon-sensitive detector that is sensitive to telecommunications optical wavelengths and is scalable to large areas (millimeter diameter) with high bandwidth and efficiencies. The device can detect single photons at a 1,550-nm wavelength at a gain of 1 x 10(exp 6). Unlike conventional single photon avalanche detectors (SPADs), where gain is an extremely sensitive function to the bias voltage, the multiplication gain of this device is stable at 1 x 10(exp 6) over a wide range of bias from 30.2 to 30.9 V. Here, the multiplication gain is defined as the total number of charge carriers contained in one output pulse that is triggered by the absorption of a single photon. The statistics of magnitude of output signals also shows that the device has a very narrow pulse height distribution, which demonstrates a greatly suppressed gain fluctuation. From the histograms of both pulse height and pulse charge, the equivalent gain variance (excess noise) is between 1.001 and 1.007 at a gain of 1 x 10(exp 6). With these advantages, the device holds promise to function as a PMT-like photon counter at a 1,550- nm wavelength. The epitaxial layer structure of the device allows photons to be absorbed in the InGaAs layer, generating electron/hole (e-h) pairs. Driven by an electrical field in InGaAs, electrons are collected at the anode while holes reach the multiplication region (InAlAs p-i-n structure) and trigger the avalanche process. As a result, a large number of e-h pairs are created, and the holes move toward the cathode. Holes created by the avalanche process gain large kinetic energy through the electric field, and are considered hot. These hot holes are cooled as they travel across a p -InAlAs low field region, and are eventually blocked by energy barriers formed by the InGaAsP/ InAlAs heterojunctions. The composition of the InGaAsP alloy was chosen to have an 80 me

  6. The Deflection Question

    Science.gov (United States)

    Greenberg, A. H.; Nesvold, E.; van Heerden, E.; Erasmus, N.; Marchis, F.

    2016-12-01

    On 15 February, 2013, a 15 m diameter asteroid entered the Earth's atmosphere over Russia. The resulting shockwave injured nearly 1500 people, and incurred 33 million (USD) in infrastructure damages. The Chelyabinsk meteor served as a forceful demonstration of the threat posed to Earth by the hundreds of potentially hazardous objects (PHOs) that pass near the Earth every year. Although no objects have yet been discovered on an impact course for Earth, an impact is virtually statistically guaranteed at some point in the future. While many impactor deflection technologies have been proposed, humanity has yet to demonstrate the ability to divert an impactor when one is found. Developing and testing any single proposed technology will require significant research time and funding. This leaves open an obvious question - towards which technologies should funding and research be directed, in order to maximize our preparedness for when an impactor is eventually found? To help answer this question, we have created a detailed framework for analyzing various deflection technologies and their effectiveness. Using an n-body integrator (REBOUND), we have simulated the attempted deflections of a population of Earth-impacting objects with a variety of velocity perturbations (∂Vs), and measured the effects that these perturbations had on impact probability. We then mapped the ∂Vs applied in the orbital simulations to the technologies capable of achieving those perturbations, and analyzed which set of technologies would be most effective at preventing a PHO from impacting the earth. As a final step, we used the results of these simulations to train a machine learning algorithm. This algorithm, combined with a simulated PHO population, can predict which technologies are most likely to be needed. The algorithm can also reveal which impactor observables (mass, spin, orbit, etc.) have the greatest effect on the choice of deflection technology. These results can be used as a tool to

  7. Equivalence of optical and electrical noise equivalent power of hybrid NbTiN-Al microwave kinetic inductance detectors

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, R. M. J., E-mail: r.m.j.janssen@tudelft.nl [Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands); Endo, A. [Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands); Department of Microelectronics, Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS), Delft University of Technology, Mekelweg 4, 2628 CD Delft (Netherlands); Visser, P. J. de [Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands); SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht (Netherlands); Klapwijk, T. M. [Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands); Physics Department, Moscow State Pedagogical University, Moscow 119991 (Russian Federation); Baselmans, J. J. A. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584CA Utrecht (Netherlands)

    2014-11-10

    We have measured and compared the response of hybrid NbTiN-Al Microwave Kinetic Inductance Detectors (MKIDs) to changes in bath temperature and illumination by sub-mm radiation. We show that these two stimulants have an equivalent effect on the resonance feature of hybrid MKIDs. We determine an electrical noise equivalent power (NEP) from the measured temperature responsivity, quasiparticle recombination time, superconducting transition temperature, and noise spectrum, all of which can be measured in a dark environment. For the two hybrid NbTiN-Al MKIDs studied in detail, the electrical NEP is within a factor of two of the optical NEP, which is measured directly using a blackbody source.

  8. A Comparison of Fundamental Noise in Kinetic Inductance Detectors and Transition Edge Sensors for Millimeter-wave Applications

    CERN Document Server

    Lowitz, A E; Golwala, S R; Timbie, P T

    2014-01-01

    Kinetic inductance detectors (KIDs) show promise as a competitive technology for astronomical observations over a wide range of wavelengths. We are interested in comparing the fundamental limitations to the sensitivity of KIDs with that of transition edge sensors (TESs) at millimeter wavelengths, specifically over the wavelengths required for studies of the Cosmic Microwave Background (CMB). We calculate the total fundamental noise arising from optical and thermal excitations in TESs and KIDs for a variety of bath temperatures and optical loading scenarios for applications at millimeter wavelengths. Special consideration is given to the case of ground-based observations of 100 GHz radiation with a 100 mK bath temperature, conditions consistent with the planned second module of the QUBIC telescope, a CMB instrument. Under these conditions, a titanium nitride KID with optimized critical temperature pays a few percent noise penalty compared to a typical optimized TES.

  9. Equivalence of Optical and Electrical Noise Equivalent Power of Hybrid NbTiN-Al Microwave Kinetic Inductance Detectors

    CERN Document Server

    Janssen, R M J; de Visser, P J; Klapwijk, T M; Baselmans, J J A

    2014-01-01

    We have measured and compared the response of hybrid NbTiN-Al Microwave Kinetic Inductance Detectors (MKIDs) to changes in bath temperature and illumination by sub-mm radiation. We show that these two stimulants have an equivalent effect on the resonance feature of hybrid MKIDs. We determine an electrical NEP from the measured temperature responsivity, quasiparticle recombination time, superconducting transition temperature and noise spectrum, all of which can be measured in a dark environment. For the two hybrid NbTiN-Al MKIDs studied in detail the electrical NEP is within a factor of two of the optical NEP, which is measured directly using a blackbody source.

  10. Demonstration of a passive, low-noise, millimeter-wave detector array for imaging

    Science.gov (United States)

    Wikner, David; Grossman, Erich

    2009-05-01

    The design of a millimeter-wave (MMW) camera is presented. The camera is meant to serve as a demonstration platform for a new 32-channel MMW detector array that requires no pre-amplification prior to detection. The Army Research Laboratory (ARL) and National Institute of Standards and Technology (NIST) have worked with the Defense Advanced Research Projects Agency and several contractors for four years to develop an affordable MMW detector array technology suitable for use in a large staring array. The camera described uses one particular embodiment of detector array that resulted from the program. This paper reviews the design of the MMW optics that will be used to form imagery with the linear array and the tradeoffs made in that design. Also presented are the results of laboratory tests of the detector array that were made at both ARL and NIST.

  11. Instrumentation for high accuracy noise characterisation of front-end devices in detector applications

    Energy Technology Data Exchange (ETDEWEB)

    Re, V. [Pavia Univ. (Italy). Ist. di Elettronica]|[Istituto Nazionale di Fisica Nucleare, Milan (Italy); Svelto, F. [Pavia Univ. (Italy). Ist. di Elettronica]|[Istituto Nazionale di Fisica Nucleare, Milan (Italy)

    1995-11-01

    The paper describes the instrumentation that was developed for the noise characterisation of field-effect and bipolar transistors. Very accurate measurements of the series noise spectral density in the frequency range 100mHz-100MHz and of the equivalent noise charge at processing times ranging from 10ns to 10{mu}s are made possible. A review of results on various device types shows how these data are used in view of applications to a broad range of experimental conditions in elementary particle and nuclear physics. (orig.).

  12. Very High Gain and Low Noise Near Infrared Single Photon Counting Detectors and Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Amplification Technologies Inc ("ATI") proposes to develop the enabling material and device technology for the design of ultra low noise, high gain and low...

  13. Reducing the read noise of HAWAII-2RG based detector systems with improved reference sampling and subtraction (IRS2)

    Science.gov (United States)

    Rauscher, Bernard J.; Arendt, Richard G.; Fixen, D. J.; Lander, Matthew; Lindler, Don; Loose, Markus; Moseley, S. H.; Wilson, Donna V.; Xenophontos, Christos

    2011-10-01

    In a previous paper,1 we described a method for significantly reducing the read noise of HAWAII-2RG (H2RG) and SIDECAR application specific integrated circuit (ASIC) based detector systems by making better use of reference signals. "Improved Reference Sampling & Subtraction" (IRS2; pronounced "IRS-square") is based on: (1) making better use of the H2RG's reference output, (2) sampling reference pixels more frequently in the time domain, and (3) optimal subtraction of both the reference output and reference pixels in the Fourier domain. Here we demonstrate that IRS2 works as expected using an engineering grade James Webb Space Telescope (JWST) SIDECAR ASIC and H2RG detector array. We were able to reduce the read noise per frame from 25 e- rms using traditional JWST readout to 10 e- rms per frame using IRS2. The only aspect of the system that we changed to make these impressive improvements was the SIDECAR ASIC readout software -we did not change the hardware.

  14. Signal and noise analysis of flat-panel sandwich detectors for single-shot dual-energy x-ray imaging

    Science.gov (United States)

    Kim, Dong Woon; Kim, Ho Kyung; Youn, Hanbean; Yun, Seungman; Han, Jong Chul; Kim, Junwoo; Kam, Soohwa; Tanguay, Jesse; Cunningham, Ian A.

    2015-03-01

    We have developed a novel sandwich-style single-shot (single-kV) detector by stacking two indirect-conversion flat-panel detectors for preclinical mouse imaging. In the sandwich detector structure, extra noise due to the direct x-ray absorption in photodiode arrays is inevitable. We develop a simple cascaded linear-systems model to describe signal and noise propagation in the flat-panel sandwich detector considering direct x-ray interactions. The noise-power spectrum (NPS) and detective quantum efficiency (DQE) obtained from the front and rear detectors are analyzed by using the cascaded-systems model. The NPS induced by the absorption of direct x-ray photons that are unattenuated within the photodiode layers is white in the spatial-frequency domain like the additive readout noise characteristic; hence that is harmful to the DQE at higher spatial frequencies at which the number of secondary quanta lessens. The model developed in this study will be useful for determining the optimal imaging techniques with sandwich detectors and their optimal design.

  15. Relevancies of multiple-interaction events and signal-to-noise ratio for Anger-logic based PET detector designs

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Hao, E-mail: penghao@mcmaster.ca [Department of Medical Physics, McMaster University, Canada L8S 4K1 (Canada); Department of Electrical and Computer Engineering, McMaster University, Canada L8S 4K1 (Canada)

    2015-10-21

    A fundamental challenge for PET block detector designs is to deploy finer crystal elements while limiting the number of readout channels. The standard Anger-logic scheme including light sharing (an 8 by 8 crystal array coupled to a 2×2 photodetector array with an optical diffuser, multiplexing ratio: 16:1) has been widely used to address such a challenge. Our work proposes a generalized model to study the impacts of two critical parameters on spatial resolution performance of a PET block detector: multiple interaction events and signal-to-noise ratio (SNR). The study consists of the following three parts: (1) studying light output profile and multiple interactions of 511 keV photons within crystal arrays of different crystal widths (from 4 mm down to 1 mm, constant height: 20 mm); (2) applying the Anger-logic positioning algorithm to investigate positioning/decoding uncertainties (i.e., “block effect”) in terms of peak-to-valley ratio (PVR), with light sharing, multiple interactions and photodetector SNR taken into account; and (3) studying the dependency of spatial resolution on SNR in the context of modulation transfer function (MTF). The proposed model can be used to guide the development and evaluation of a standard Anger-logic based PET block detector including: (1) selecting/optimizing the configuration of crystal elements for a given photodetector SNR; and (2) predicting to what extent additional electronic multiplexing may be implemented to further reduce the number of readout channels.

  16. A low-power CMOS ASIC for X-ray Silicon Drift Detectors low-noise pulse processing

    Science.gov (United States)

    Ahangarianabhari, M.; Bertuccio, G.; Macera, D.; Malcovati, P.; Grassi, M.; Rashevsky, A.; Rashevskaya, I.; Vacchi, A.; Zampa, G.; Zampa, N.; Fuschino, F.; Evangelista, Y.; Campana, R.; Labanti, C.; Feroci, M.

    2014-03-01

    We present an Application Specific Integrated Circuit (ASIC), named VEGA-1, designed and manufactured for low-power analog pulse processing of signals from Silicon Drift Detectors (SDDs). The VEGA-1 ASIC consists of an analog and a digital/mixed-signal section to achieve all the functionalities and specifications required for high-resolution X-ray spectroscopy in the energy range from 500 eV to 60 keV with low power consumption. The VEGA-1 ASIC has been designed and manufactured in 0.35-μm CMOS mixed-signal technology in single and 32-channel version with dimensions of 200 μm × 500 μm per channel. A minimum intrinsic ENC of 12 electrons r.m.s. at 3.6 μs shaping time and room temperature is measured for the ASIC without detector. The VEGA-1 has been tested with Q10-SDD designed in Trieste and fabricated at FBK, with an active area of 10 mm2 and a thickness of 450 μm. The aforementioned detector has an anode current of about 180 pA at +22°C. A minimum Equivalent Noise Charge (ENC) of 16 electrons r.m.s. at 3.0 μs shaping time and -30°C has been demonstrated with a total measured power consumption of 482 μW.

  17. Relevancies of multiple-interaction events and signal-to-noise ratio for Anger-logic based PET detector designs

    Science.gov (United States)

    Peng, Hao

    2015-10-01

    A fundamental challenge for PET block detector designs is to deploy finer crystal elements while limiting the number of readout channels. The standard Anger-logic scheme including light sharing (an 8 by 8 crystal array coupled to a 2×2 photodetector array with an optical diffuser, multiplexing ratio: 16:1) has been widely used to address such a challenge. Our work proposes a generalized model to study the impacts of two critical parameters on spatial resolution performance of a PET block detector: multiple interaction events and signal-to-noise ratio (SNR). The study consists of the following three parts: (1) studying light output profile and multiple interactions of 511 keV photons within crystal arrays of different crystal widths (from 4 mm down to 1 mm, constant height: 20 mm); (2) applying the Anger-logic positioning algorithm to investigate positioning/decoding uncertainties (i.e., "block effect") in terms of peak-to-valley ratio (PVR), with light sharing, multiple interactions and photodetector SNR taken into account; and (3) studying the dependency of spatial resolution on SNR in the context of modulation transfer function (MTF). The proposed model can be used to guide the development and evaluation of a standard Anger-logic based PET block detector including: (1) selecting/optimizing the configuration of crystal elements for a given photodetector SNR; and (2) predicting to what extent additional electronic multiplexing may be implemented to further reduce the number of readout channels.

  18. Design of a beam position sensitive cavity as a Schottky noise detector for mass measurements in CR rate at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangcheng; Huelsmann, Peter; Nolden, Fritz; Steck, Markus [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Sanjari, Shahab [ExtreMe Matter Institute, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Litvinov, Yuri [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Piotrowski, Jeremi [AGH University of Science and Technology, Krakow (Poland)

    2014-07-01

    Mass is one of fundamental characteristics of a nucleus. It plays an important role in many areas of physics, as well as other science branches. Especially in nuclear astrophysics, the masses of unstable nuclei close to nucleon drip lines are of great interests, since they are indispensable quantities for modelling nucleosynthesis processes in stellar objects. The Facility for Antiproton and Ion Research (FAIR), by providing high-intensity high-energy secondary beams, will enable unprecedented opportunities to investigate such nuclei. In particular, the collector ring (CR) is designed to be operated in the isochronous ion-optical mode as a high precision mass spectrometer. In order to satisfy the stringent requirements on accuracy and sensitivity for the future mass measurements, a non-destructive detector that is sensitive to single ions is being developed. Owing to the position sensitivity, it will be possible to correct for errors originating from different orbit lengths. In this work, we present simulation results of several possible designs of a cavity-based detector and discuss their potential applications as Schottky-noise detectors.

  19. Quantum key distribution at telecom wavelengths with noise-free detectors

    CERN Document Server

    Rosenberg, D; Hiskett, P A; Peterson, C G; Hughes, R J; Nordholt, J E; Lita, A E; Miller, A J; Rosenberg, Danna; Nam, Sae Woo; Hiskett, Philip A.; Peterson, Charles G.; Hughes, Richard J.; Nordholt, Jane E.; Lita, Adriana E.; Miller, Aaron J.

    2005-01-01

    The length of a secure link over which a quantum key can be distributed depends on the efficiency and dark-count rate of the detectors used at the receiver. We report on the first demonstration of quantum key distribution using transition-edge sensors with high efficiency and negligible dark-count rates. Using two methods of synchronization, a bright optical pulse scheme and an electrical signal scheme, we have successfully distributed key material at 1,550 nm over 50 km of optical fiber. We discuss how use of these detectors in a quantum key distribution system can result in dramatic increases in range and performance.

  20. Ultra-low noise single-photon detector based on Si avalanche photodiode.

    Science.gov (United States)

    Kim, Yong-Su; Jeong, Youn-Chang; Sauge, Sebastien; Makarov, Vadim; Kim, Yoon-Ho

    2011-09-01

    We report operation and characterization of a lab-assembled single-photon detector based on commercial silicon avalanche photodiodes (PerkinElmer C30902SH, C30921SH). Dark count rate as low as 5 Hz was achieved by cooling the photodiodes down to -80 °C. While afterpulsing increased as the photodiode temperature was decreased, total afterpulse probability did not become significant due to detector's relatively long deadtime in a passively-quenched scheme. We measured photon detection efficiency >50% at 806 nm. © 2011 American Institute of Physics

  1. Optimizing edge detectors for robust automatic threshold selection : Coping with edge curvature and noise

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.

    1998-01-01

    The Robust Automatic Threshold Selection algorithm was introduced as a threshold selection based on a simple image statistic. The statistic is an average of the grey levels of the pixels in an image weighted by the response at each pixel of a specific edge detector. Other authors have suggested that

  2. Photon noise from chaotic and coherent millimeter-wave sources measured with horn-coupled, aluminum lumped-element kinetic inductance detectors

    CERN Document Server

    Flanigan, Daniel; Jones, Glenn; Johnson, Bradley R; Ade, Peter; Araujo, Derek; Bradford, Kristi; Cantor, Robin; Che, George; Day, Peter K; Doyle, Simon; Kjellstrand, Carl Bjorn; LeDuc, Henry G; Limon, Michele; Luu, Vy; Mauskopf, Philip; Miller, Amber; Mroczkowski, Tony; Tucker, Carole; Zmuidzinas, Jonas

    2015-01-01

    We report photon-noise limited performance of horn-coupled, aluminum lumped-element kinetic inductance detectors at millimeter wavelengths. The detectors are illuminated by a millimeter-wave source that uses an active multiplier chain to produce radiation between 140 and 160 GHz. We feed the multiplier with either amplified broadband noise or a continuous-wave tone from a microwave signal generator. We demonstrate that the detector response over a 40 dB range of source power is well-described by a simple model that considers the number of quasiparticles. The detector noise-equivalent power (NEP) is dominated by photon noise when the absorbed power is greater than approximately 1 pW, which corresponds to $\\mathrm{NEP} \\approx 2 \\times 10^{-17} \\; \\mathrm{W} \\; \\mathrm{Hz}^{-1/2}$, referenced to absorbed power. At higher source power levels we observe the relationships between noise and power expected from the photon statistics of the source signal: $\\mathrm{NEP} \\propto P$ for broadband (chaotic) illumination ...

  3. A fundamental method to determine the signal-to-noise ratio (SNR) and detective quantum efficiency (DQE) for a photon counting pixel detector

    Energy Technology Data Exchange (ETDEWEB)

    Michel, T. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany)]. E-mail: thilo.michel@physik.uni-erlangen.de; Anton, G. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Boehnel, M. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Durst, J. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Firsching, M. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Korn, A. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Kreisler, B. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Loehr, A. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Nachtrab, F. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Niederloehner, D. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Sukowski, F. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany); Takoukam Talla, P. [Physikalisches Institut, Universitaet Erlangen-Nuernberg, Erwin-Rommel-Strasse 1, 91058 Erlangen (Germany)

    2006-12-01

    We outline in this paper that the noise of a photon counting pixel detector depends on the detection efficiency and the average multiplicity of counts per interacting photon. We give a simple expression for the signal-to-noise ratio (SNR) and zero-frequency detective quantum efficiency (DQE). We describe a method to determine the DQE from measured data and to optimize the DQE as a function of energy threshold.

  4. Phase-dependent deterministic switching of magnetoelectric spin wave detector in the presence of thermal noise via compensation of demagnetization

    Science.gov (United States)

    Dutta, Sourav; Nikonov, Dmitri E.; Manipatruni, Sasikanth; Young, Ian A.; Naeemi, Azad

    2015-11-01

    The possibility of achieving phase-dependent deterministic switching of the magnetoelectric spin wave detector in the presence of thermal noise has been discussed. The proposed idea relies on the modification of the energy landscape by partially canceling the out-of-plane demagnetizing field and the resultant change in the intrinsic magnetization dynamics to drive the nanomagnet towards a preferential final magnetization state. The remarkable increase in the probability of successful switching can be accounted for by the shift in the location of the saddle point in the energy landscape and a resultant change in the nature of the relaxation dynamics of the magnetization from a highly precessional to a fairly damped one and an increased dependence on the initial magnetization values, a crucial requirement for phase-dependent spin wave detection.

  5. Time-frequency, bi-frequency detector analysis of noise technology radar

    OpenAIRE

    Heuschel, Eugene R.

    2006-01-01

    Enemy integrated air defense systems (IADS) using low probability of intercept (LPI) emitters can cause significant problems for suppression of enemy air defense (SEAD) techniques. New threat emitter configurations using low-power random noise modulation have a significant processing gain unavailable to non-cooperative intercept receivers. Consequently, the detection of these emitters can not be accomplished with conventional intercept receiver detection methods. This thesis examines the...

  6. Measurements of the modulation transfer function, normalized noise power spectrum and detective quantum efficiency for two flat panel detectors: a fluoroscopic and a cone beam computer tomography flat panel detectors.

    Science.gov (United States)

    Benítez, Ricardo Betancourt; Ning, Ruola; Conover, David; Liu, Shaohua

    2009-01-01

    The physical performance of two Flat Panel Detectors has been evaluated. The first Flat Panel Detector is for Fluoroscopic applications, Varian PaxScan 2520, and the second is for Cone Beam Computer Tomography applications, Varian PaxScan 4030CB. First, the spectrum of the X-ray source was measured. Second, the linearity of the detectors was investigated by using an ionization chamber and the average ADU values of the detectors. Third, the temporal resolution was characterized by evaluating their image lag. Fourth, their spatial resolution was characterized by the pre-sampling Modulation Transfer Function. Fifth, the Normalized Noise Power Spectrum was calculated for various exposures levels. Finally, the Detective Quantum Efficiency was obtained as a function of spatial frequency and entrance exposure. The results illustrate that the physical performance in Detective Quantum Efficiency and Normalized Noise Power Spectrum of the Cone Beam Computer Tomography detector is superior to that of the fluoroscopic detector whereas the latter detector has a higher spatial resolution as demonstrated by larger values of its Modulation Transfer Function at large spatial frequencies.

  7. Thermal noise in interferometric gravitational wave detectors due to dielectric optical coatings

    CERN Document Server

    Harry, G M; Saulson, P R; Penn, S D; Startin, W J; Kittelberger, S E; Crooks, D R M; Hough, J; Cagnoli, G; Nakagawa, N; Rowan, S; Fejer, M M; Harry, Gregory M.; Gretarsson, Andri M.; Saulson, Peter R.; Penn, Steven D.; Startin, William J.; Kittelberger, Scott; Hough, Jim; Cagnoli, Gianpietro; Nakagawa, Norio; Rowan, Sheila; Fejer, Martin M.

    2002-01-01

    We report on thermal noise from the internal friction of dielectric coatings made from alternating layers of Ta2O5 and SiO2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to optical coatings, when the material properties of the coating are different from those of the substrate and the mechanical loss angle in the coating is anisotropic. The loss angle in the coatings for strains parallel to the substrate surface was determined from ringdown experiments. We measured the mechanical quality factor of three fused silica samples with coatings deposited on them. The loss angle of the coating material for strains parallel to the coated surface was found to be (4.2 +- 0.3)*10^(-4) for coatings deposited on commercially polished slides and (1.0 +- 0.3)*10^{-4} for a coating deposited on a superpolished disk. Using these numbers, we estimate the effect of coatings on thermal noise in the initial LIGO and advanced LIGO interferometers. We also...

  8. Design and performances of a low-noise and radiation-hardened readout ASIC for CdZnTe detectors

    Science.gov (United States)

    Bo, Gan; Tingcun, Wei; Wu, Gao; Yongcai, Hu

    2016-06-01

    In this paper, we present the design and performances of a low-noise and radiation-hardened front-end readout application specific integrated circuit (ASIC) dedicated to CdZnTe detectors for a hard X-ray imager in space applications. The readout channel is comprised of a charge sensitive amplifier, a CR-RC shaping amplifier, an analog output buffer, a fast shaper, and a discriminator. An 8-channel prototype ASIC is designed and fabricated in TSMC 0.35-μm mixed-signal CMOS technology, the die size of the prototype chip is 2.2 × 2.2 mm2. The input energy range is from 5 to 350 keV. For this 8-channel prototype ASIC, the measured electrical characteristics are as follows: the overall gain of the readout channel is 210 V/pC, the linearity error is less than 2%, the crosstalk is less than 0.36%, The equivalent noise charge of a typical channel is 52.9 e- at zero farad plus 8.2 e- per picofarad, and the power consumption is less than 2.4 mW/channel. Through the measurement together with a CdZnTe detector, the energy resolution is 5.9% at the 59.5-keV line under the irradiation of the radioactive source 241Am. The radiation effect experiments show that the proposed ASIC can resist the total ionization dose (TID) irradiation of higher than 200 krad(Si). Project supported by the National Key Scientific Instrument and Equipment Development Project (No. 2011YQ040082), the National Natural Science Foundation of China (Nos. 11475136, 11575144, 61176094), and the Shaanxi Natural Science Foundation of China (No. 2015JM1016).

  9. Experiments on Deflecting & Oscillating Waterjet

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new type jet,the oscillating & deflecting jet ,is put forward and its oscillating and deflecting characteristics are investigated.The nozzle of the self-oscillating & deflecting water jet consists of an upstream nozzle,a downstream nozzle,an oscillating chamber and two switches,It is experimentally shown that the deflective angle may reach 9.53 degeree,the generated pressure fluctuation is very regular and the jet can efficiently increase the ability for bradking and cutting by eliminating the water cushion effect associated with a continuous jet.

  10. A study of coating mechanical and optical losses in view of reducing mirror thermal noise in gravitational wave detectors

    Energy Technology Data Exchange (ETDEWEB)

    Flaminio, R; Franc, J; Michel, C; Morgado, N; Pinard, L; Sassolas, B, E-mail: flaminio@lma.in2p3.f [Laboratoire des Materiaux Avances, CNRS/IN2P3, 7 Avenue Pierre de Coubertin, 69622 Villeurbanne Cedex (France)

    2010-04-21

    Mirror coatings play a crucial role in the performance of laser interferometers devoted to gravitational wave detection such as Virgo and LIGO. Mechanical losses in the coating material limit the sensitivity of the detectors due to the associated mirror thermal noise. The absorption of light in the coating induces a thermal lens in the mirror substrate which reduces the quality of the optical interference and requires sophisticated thermal compensation systems. This paper describes the work ongoing at LMA in order to reduce mechanical losses and optical absorption in the coating. The results obtained by doping Ta{sub 2}O{sub 5} layers and testing different high-index materials are described. Finally the performances of different potential coatings are compared and the results obtained with a 40 kg mirror are reported. Titania doped Ta{sub 2}O{sub 5} shows mechanical losses of 2 x 10{sup -4} and absorption below 0.5 ppm. Nb{sub 2}O{sub 5} appears to be the best competitor from the thermal noise point of view but it has an optical absorption four to five times larger.

  11. A gravitational wave detector operating beyond the quantum shot-noise limit: Squeezed light in application

    Directory of Open Access Journals (Sweden)

    Schnabel Roman

    2013-08-01

    Full Text Available This contribution reviews our recent progress on the generation of squeezed light [1], and also the recent squeezed-light enhancement of the gravitational wave detector GEO 600 [2]. GEO 600 is currently the only GW observatory operated by the LIGO Scientific Collaboration in its search for gravitational waves. With the help of squeezed states of light it now operates with its best ever sensitivity, which not only proves the qualification of squeezed light as a key technology for future gravitational wave astronomy but also the usefulness of quantum entanglement.

  12. Directed energy deflection laboratory measurements

    Science.gov (United States)

    Brashears, Travis; Lubin, Phillip; Hughes, Gary B.; Meinhold, Peter; Suen, Jonathan; Batliner, Payton; Motta, Caio; Griswold, Janelle; Kangas, Miikka; Johansson, Isbella; Alnawakhtha, Yusuf; Prater, Kenyon; Lang, Alex; Madajian, Jonathan

    2015-09-01

    We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DESTAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.

  13. Configurable Electronics with Low Noise and 14-bit Dynamic Range for Photodiode-based Photon Detectors

    CERN Document Server

    Müller, H; Yin, Z; Zhou, D; Cao, X; Li, Q; Liu, Y; Zou, F; Skaali, B; Awes, T C

    2006-01-01

    We describe the principles and measured performance characteristics of custom configurable 32-channel shaper/digitizer Front End Electronics (FEE) cards with 14-bit dynamic range for use with gain-adjustable photon detectors. The electronics has been designed for the PHOS calorimeter of ALICE with avalanche photodiode (APD) readout operated at -25 C ambient temperature and a signal shaping time of $1 {\\mu}s$. The electronics has also been adopted by the EMCal detector of ALICE with the same APD readout, but operated at an ambient temperature of +20 C and with a shaping time of 100ns. The CR-RC2 signal shapers on the FEE cards are implemented in discrete logic on a 10-layer board with two shaper sections for each input channel. The two shaper sections with gain ratio of 16:1 are digitized by 10-bit ADCs and provide an effective dynamic range of 14 bits. Gain adjustment for each individual APD is available through 32 bias voltage control registers of 10-bit range. The fixed gains and shaping times of the pole-z...

  14. Noise evaluation of silicon strip super-module with ABCN250 readout chips for the ATLAS detector upgrade at the High Luminosity LHC

    Energy Technology Data Exchange (ETDEWEB)

    Todome, K., E-mail: todome@hep.phys.titech.ac.jp [Department of Physics, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8551 (Japan); Solid State Div., Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 (Japan); Jinnouchi, O. [Department of Physics, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8551 (Japan); Solid State Div., Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 (Japan); Clark, A.; Barbier, G.; Cadoux, F.; Favre, Y.; Ferrere, D.; Gonzalez-Sevilla, S.; Iacobucci, G.; La Marra, D.; Perrin, E.; Weber, M. [DPNC, University of Geneva, CH-1211 Geneva 4 (Switzerland); Solid State Div., Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 (Japan); Ikegami, Y.; Nakamura, K.; Takubo, Y.; Unno, Y. [Institute of Particle and Nuclear Study, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Solid State Div., Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 (Japan); Takashima, R. [Department of Science Education, Kyoto University of Education, Kyoto 612-8522 (Japan); Solid State Div., Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 (Japan); Tojo, J. [Department of Physics, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Solid State Div., Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 (Japan); Kono, T. [Ochadai Academic Production, Ochanomizu University, 2-1-1, Otsuka, Bunkyo-ku, Tokyo 112-8610 (Japan); Solid State Div., Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 (Japan); and others

    2016-09-21

    Toward High Luminosity LHC (HL-LHC), the whole ATLAS inner tracker will be replaced, including the semiconductor tracker (SCT) which is the silicon micro strip detector for tracking charged particles. In development of the SCT, integration of the detector is the important issue. One of the concepts of integration is the “super-module” in which individual modules are assembled to produce the SCT ladder. A super-module prototype has been developed to demonstrate its functionality. One of the concerns in integrating the super-modules is the electrical coupling between each module, because it may increase intrinsic noise of the system. To investigate the electrical performance of the prototype, the new Data Acquisition (DAQ) system has been developed by using SEABAS. The electric performance of the super-module prototype, especially the input noise and random noise hit rate, was investigated by using SEABAS system.

  15. Electric Deflection of Rotating Molecules

    CERN Document Server

    Gershnabel, E

    2010-01-01

    We provide a theory of the deflection of polar and non-polar rotating molecules by inhomogeneous static electric field. Rainbow-like features in the angular distribution of the scattered molecules are analyzed in detail. Furthermore, we demonstrate that one may efficiently control the deflection process with the help of short and strong femtosecond laser pulses. In particular the deflection process may by turned-off by a proper excitation, and the angular dispersion of the deflected molecules can be substantially reduced. We study the problem both classically and quantum mechanically, taking into account the effects of strong deflecting field on the molecular rotations. In both treatments we arrive at the same conclusions. The suggested control scheme paves the way for many applications involving molecular focusing, guiding, and trapping by inhomogeneous fields.

  16. CMOS low-noise switched charge sensitive preamplifier for CdTe and CdZnTe X-ray detectors

    Energy Technology Data Exchange (ETDEWEB)

    Jakobson, C.G.; Nemirovsky, Y. [Technion-Israel Inst. of Tech., Haifa (Israel)

    1997-02-01

    CdTe and CdZnTe X-ray detector arrays for imaging and spectroscopy provide low capacitance current sources with low leakage currents. The optimal shaping time for low-noise operation is relatively high in CMOS analog channels that provide the readout for these detectors. The shaper is centered at lower frequencies, and thus the l/f noise from the electronics is the main noise source that limits the resolution of the channel. The optimal dimensions of the input stage MOSFET are determined by this noise. In this paper a design criterion for the optimization of the resolution and the power consumption in a l/f noise dominated readout is introduced. A readout based on CMOS switched charge sensitive preamplifier without feedback resistor has been designed and fabricated in the CMOS 2-{mu} low-noise analog process provided by MOSIS. This design provides high sensitivity and the possibility to integrate a large number of channels with low power consumption. Measurements of the performance of a first prototype chip are presented.

  17. Deflection of Resilient Materials for Reduction of Floor Impact Sound

    OpenAIRE

    Jung-Yoon Lee; Jong-Mun Kim

    2014-01-01

    Recently, many residents living in apartment buildings in Korea have been bothered by noise coming from the houses above. In order to reduce noise pollution, communities are increasingly imposing bylaws, including the limitation of floor impact sound, minimum thickness of floors, and floor soundproofing solutions. This research effort focused specifically on the deflection of resilient materials in the floor sound insulation systems of apartment houses. The experimental program involved condu...

  18. Effects of characteristic x rays on the noise power spectra and detective quantum efficiency of photoconductive x-ray detectors.

    Science.gov (United States)

    Zhao, W; Ji, W G; Rowlands, J A

    2001-10-01

    The effects of K fluorescence on the imaging performance of photoconductor-based x-ray imaging systems are investigated. A cascaded linear systems model was developed, where a parallel cascaded process was implemented to take into account the effect of K-fluorescence reabsorption on the modulation transfer function (MTF), noise power spectrum (NPS), and the spatial frequency dependent detective quantum efficiency [DQE(f)] of an imaging system. The investigation was focused on amorphous selenium (a-Se), which is the most highly developed photoconductor material for x-ray imaging. The results were compared to those obtained with Monte Carlo simulation using the same imaging condition and detector parameters, so that the validity of the cascaded linear system model could be confirmed. Our results revealed that K-fluorescence reabsorption in a-Se is responsible for a 18% drop in NPS at high spatial frequencies with an incident x-ray photon energy of E=20 keV (which is just above the K edge of 12.5 keV). When E increases to 60 keV, the effects of K-fluorescence reabsorption on NPS decrease to approximately 12% at high spatial frequencies. Because the high frequency drop is present in both MTF and NPS, the effect of K fluorescence on DQE(f) is minimal, especially for E that is much higher than the K edge. We also applied the cascaded linear system model to a newly developed compound photoconductor, lead iodide (PbI2), and found that at 60 keV there is a high frequency drop in NPS of 19%. The calculated NPS were compared to previously published measurements of PbI2 detectors.

  19. A fast, low power and low noise charge sensitive amplifier ASIC for a UV imaging single photon detector

    Science.gov (United States)

    Seljak, A.; Cumming, H. S.; Varner, G.; Vallerga, J.; Raffanti, R.; Virta, V.

    2017-04-01

    NASA has funded, through their Strategic Astrophysics Technology (SAT) program, the development of a cross strip (XS) microchannel plate (MCP) detector with the intention to increase its technology readiness level (TRL), enabling prototyping for future NASA missions. One aspect of the development is to convert the large and high powered laboratory Parallel Cross Strip (PXS) readout electronics into application specific integrated circuits (ASICs) to decrease their mass, volume, and power consumption (all limited resources in space) and to make them more robust to the environments of rocket launch and space. The redesign also foresees to increase the overall readout event rate, and decrease the noise contribution of the readout system. This work presents the design and verification of the first stage for the new readout system, the 16 channel charge sensitive amplifier ASIC, called the CSAv3. The single channel amplifier is composed of a charge sensitive amplifier (pre-amplifier), a pole zero cancellation circuit and a shaping amplifier. An additional output stage buffer allows polarity selection of the output analog signal. The operation of the amplifier is programmable via serial bus. It provides an equivalent noise charge (ENC) of around 600 e^- and a baseline gain of 10 mV/fC. The full scale pulse shaped output signal is confined within 100 ns, without long recovery tails, enabling up to 10 MHz periodic event rates without signal pile up. This ASIC was designed and fabricated in 130 nm, TSMC CMOS 1.2 V technology. In addition, we briefly discuss the construction of the readout system and plans for the future work.

  20. Influence of x-ray energy spectrum, contrasting detail and detector on the signal-to-noise ratio (SNR) and detective quantum efficiency (DQE) in projection radiography

    Energy Technology Data Exchange (ETDEWEB)

    Sandborg, Michael; Carlsson, G.A. (Linkoeping Univ. (Sweden). Dept. of Radiation Physics)

    1992-06-01

    A lower limit to patient irradiation in diagnostic radiology is set by the fundamental stochastics of the energy imparted to the image receptor (quantum noise). Image quality is investigated here and expressed in terms of the signal-to-noise ratio due to quantum noise. The Monte Carlo method is used to calculate signal-to-noise ratios (SNR{sub {Delta}S}) and detective quantum efficiencies (DQE{sub {Delta}S}) in imaging thin contrasting details of air, fat, bone and iodine within a water phantom using x-ray spectra (40-140 kV) and detectors of CsI, BaFCl and Gd{sub 2}O{sub 2}S. The atomic composition of the contrasting detail influences considerably the values of SNR{sub {Delta}S} due to the different modulations of the energy spectra of primary photons passing beside and through the contrasting detail. (author).

  1. Minimizing ultraviolet noise due to mis-matches between detector flow cell and post column mobile phase temperatures in supercritical fluid chromatography: effect of flow cell design.

    Science.gov (United States)

    Berger, Terry A

    2014-10-17

    A mis-match between the post-column mobile phase temperature and the UV detector flow cell temperature can cause significant UV noise in supercritical fluid chromatography (SFC). Deviations as little as 5 °C can increase noise as much as 5 times, making the detector unsuited for trace analysis. Two approaches were used to minimize this noise. When a flow cell was in direct thermal contact (metal on metal) with the detector optical bench, the mobile phase temperature was actively controlled to the measured flow cell temperature, by using one of the heat exchangers (HX) in the column compartment. However, with some older, but still widely used flow cell designs, this required repeated, hourly monitoring of the flow cell temperature and repeated manual adjustment of the heat exchanger temperature, due to thermal drift. Flow cell design had a strong influence on susceptibility to this thermally induced noise. Thermally insulating the flow cell from the optical bench made some cells much less susceptible to such thermally induced noise. Five different flow cells, some insulated, some un-insulated, were evaluated. Most had a truncated conical flow path, but one had a cylindrical flow path. Using either approach, the ASTM noise, with a 10mm, 13 μL conical flow cell, could be optimized to ≈0.007 mAU at 2.5 Hz, in SFC, which is very near the 0.006 mAU manufacturer's specification for HPLC. The insulated version of this flow cell required far less optimization, compared to the un-insulated version. At 150 bar, an experimental 3mm, 2 μL flow cell, with only one side insulated, yielded noise slightly too high (≈0.16-0.18 mAU) for trace analysis, at 80 Hz. However, at 200 bar, noise at 80 Hz was noise ratio (S/N) >10. Even partially un-insulated, this flow cell design was much less susceptible to thermally induced noise. Further insulating this flow cell design failed to improve performance.

  2. Toward VIP-PIX: A Low Noise Readout ASIC for Pixelated CdTe Gamma-Ray Detectors for Use in the Next Generation of PET Scanners

    OpenAIRE

    Macias-Montero, Jose-Gabriel; Sarraj, Maher; Chmeissani, Mokhtar; Puigdengoles, Carles; Lorenzo, Gianluca De; Martínez, Ricardo

    2013-01-01

    VIP-PIX will be a low noise and low power pixel readout electronics with digital output for pixelated Cadmium Telluride (CdTe) detectors. The proposed pixel will be part of a 2D pixel-array detector for various types of nuclear medicine imaging devices such as positron-emission tomography (PET) scanners, Compton gamma cameras, and positron-emission mammography (PEM) scanners. Each pixel will include a SAR ADC that provides the energy deposited with 10-bit resolution. Simultaneously, the self-...

  3. Detector of Optical Vortices as the Main Element of the System of Data Transfer: Principles of Operation, Numerical Model, and Influence of Noise and Atmospheric Turbulence

    Directory of Open Access Journals (Sweden)

    Valerii Aksenov

    2012-01-01

    Full Text Available The method is proposed of optical vortex topological charge detection along with a design of a corresponding detector. The developed technique is based on measurements of light field intensity. Mathematical model simulating performance of the detector is described in the paper, and results of numerical experiments are presented which illustrate recognition of a vortex in a turbulent medium and in the presence of amplitude and phase noise in the registered radiation. Influence of shifts of the system optical axis on precision of registration is also considered in the paper.

  4. On the (In)Efficiency of the Cross-Correlation Statistic for Gravitational Wave Stochastic Background Signals with Non-Gaussian Noise and Heterogeneous Detector Sensitivities

    CERN Document Server

    Lionel, Martellini

    2015-01-01

    Under standard assumptions including stationary and serially uncorrelated Gaussian gravitational wave stochastic background signal and noise distributions, as well as homogenous detector sensitivities, the standard cross-correlation detection statistic is known to be optimal in the sense of minimizing the probability of a false dismissal at a fixed value of the probability of a false alarm. The focus of this paper is to analyze the comparative efficiency of this statistic, versus a simple alternative statistic obtained by cross-correlating the \\textit{squared} measurements, in situations that deviate from such standard assumptions. We find that differences in detector sensitivities have a large impact on the comparative efficiency of the cross-correlation detection statistic, which is dominated by the alternative statistic when these differences reach one order of magnitude. This effect holds even when both the signal and noise distributions are Gaussian. While the presence of non-Gaussian signals has no mate...

  5. Conversion of mammographic images to appear with the noise and sharpness characteristics of a different detector and x-ray system

    Energy Technology Data Exchange (ETDEWEB)

    Mackenzie, Alistair; Dance, David R.; Workman, Adam; Yip, Mary; Wells, Kevin; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford, GU2 7XX, United Kingdom and Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Northern Ireland Regional Medical Physics Service, Forster Green Hospital, Belfast, BT8 4HD (United Kingdom); Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Centre for Vision, Speech and Signal Processing, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom); National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford, GU2 7XX, United Kingdom and Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom)

    2012-05-15

    Purpose: Undertaking observer studies to compare imaging technology using clinical radiological images is challenging due to patient variability. To achieve a significant result, a large number of patients would be required to compare cancer detection rates for different image detectors and systems. The aim of this work was to create a methodology where only one set of images is collected on one particular imaging system. These images are then converted to appear as if they had been acquired on a different detector and x-ray system. Therefore, the effect of a wide range of digital detectors on cancer detection or diagnosis can be examined without the need for multiple patient exposures. Methods: Three detectors and x-ray systems [Hologic Selenia (ASE), GE Essential (CSI), Carestream CR (CR)] were characterized in terms of signal transfer properties, noise power spectra (NPS), modulation transfer function, and grid properties. The contributions of the three noise sources (electronic, quantum, and structure noise) to the NPS were calculated by fitting a quadratic polynomial at each spatial frequency of the NPS against air kerma. A methodology was developed to degrade the images to have the characteristics of a different (target) imaging system. The simulated images were created by first linearizing the original images such that the pixel values were equivalent to the air kerma incident at the detector. The linearized image was then blurred to match the sharpness characteristics of the target detector. Noise was then added to the blurred image to correct for differences between the detectors and any required change in dose. The electronic, quantum, and structure noise were added appropriate to the air kerma selected for the simulated image and thus ensuring that the noise in the simulated image had the same magnitude and correlation as the target image. A correction was also made for differences in primary grid transmission, scatter, and veiling glare. The method was

  6. Multiplexed Force and Deflection Sensing Shell Membranes for Robotic Manipulators

    Science.gov (United States)

    Park, Yong-Lae; Black, Richard; Moslehi, Behzad; Cutkosky, Mark; Chau, Kelvin

    2012-01-01

    Force sensing is an essential requirement for dexterous robot manipulation, e.g., for extravehicular robots making vehicle repairs. Although strain gauges have been widely used, a new sensing approach is desirable for applications that require greater robustness, design flexibility including a high degree of multiplexibility, and immunity to electromagnetic noise. This invention is a force and deflection sensor a flexible shell formed with an elastomer having passageways formed by apertures in the shell, with an optical fiber having one or more Bragg gratings positioned in the passageways for the measurement of force and deflection.

  7. On the analogy between pulse-pile-up in energy-sensitive, photon-counting detectors and level-crossing of shot noise

    Science.gov (United States)

    Roessl, Ewald; Bartels, Matthias; Daerr, Heiner; Proksa, Roland

    2016-03-01

    Shot noise processes are omnipresent in physics and many of their properties have been extensively studied in the past, including the particular problem of level crossing of shot noise. Energy-sensitive, photon-counting detectors using comparators to discriminate pulse-heights are currently heavily investigated for medical applications, e.g. for x-ray computed tomography and x-ray mammography. Surprisingly, no mention of the close relation between the two topics can be found in the literature on photon-counting detectors. In this paper, we point out the close analogy between level crossing of shot noise and the problem of determining count rates of photon- counting detectors subject to pulse pile-up. The latter is very relevant for obtaining precise forward models for photon-counting detectors operated under conditions of very high x-ray flux employed in clinical x-ray computed tomography. Although several attempts have been made to provide reasonably accurate, approximative models for the registered number of counts in x-ray detectors under conditions of high flux and arbitrary x-ray spectra, see, e.g., no exact, analytic solution is given in the literature for general continuous pulse shapes. In this paper we present such a solution for arbitrary response functions, x-ray spectra and continuous pulse shapes based on a result from the theory of level crossing. We briefly outline the theory of level crossing including the famous Rice theorem and translate from the language of level crossing to the language of photon-counting detection.

  8. Model-based iterative reconstruction for flat-panel cone-beam CT with focal spot blur, detector blur, and correlated noise

    Science.gov (United States)

    Tilley, Steven, II; Siewerdsen, Jeffrey H.; Webster Stayman, J.

    2016-01-01

    While model-based reconstruction methods have been successfully applied to flat-panel cone-beam CT (FP-CBCT) systems, typical implementations ignore both spatial correlations in the projection data as well as system blurs due to the detector and focal spot in the x-ray source. In this work, we develop a forward model for flat-panel-based systems that includes blur and noise correlation associated with finite focal spot size and an indirect detector (e.g. scintillator). This forward model is used to develop a staged reconstruction framework where projection data are deconvolved and log-transformed, followed by a generalized least-squares reconstruction that utilizes a non-diagonal statistical weighting to account for the correlation that arises from the acquisition and data processing chain. We investigate the performance of this novel reconstruction approach in both simulated data and in CBCT test-bench data. In comparison to traditional filtered backprojection and model-based methods that ignore noise correlation, the proposed approach yields a superior noise-resolution tradeoff. For example, for a system with 0.34 mm FWHM scintillator blur and 0.70 FWHM focal spot blur, using the correlated noise model instead of an uncorrelated noise model increased resolution by 42% (with variance matched at 6.9  ×  10-8 mm-2). While this advantage holds across a wide range of systems with differing blur characteristics, the improvements are greatest for systems where source blur is larger than detector blur.

  9. A Low-Noise CsI Detector Array for the Precision Measurement of Parity Nonconservation in n + p --> d + gamma

    Energy Technology Data Exchange (ETDEWEB)

    M. T. Gericke; C. Blessinger; J. D. Bowman; R. D. Carlini; T. E. Chupp; K. P. Coulter; M. Dawkins; M. Dabaghyan; D. Desai; S. J. Freedman; T. R. Gentile; R. C. Gillis; G. L. Greene; J. Hartfield; F. W. Hersman; T. Ino; G. L. Jones; B. Lauss; M. Leuschner; B. Losowski; R. Mahurin; Y. Masuda; G. S. Mitchell; S. Muto; H. Nann; S. A. Page; S. I. Penttila; W. D. Ramsay; S. Santra; P.-N. Seo; E. T. Sharapov; T. B. Smith; W. M. Snow; J. Tasson; W. S. Wilburn; H. Zhu

    2004-09-26

    We have built a CsI(Tl) gamma-ray detector array for the NPDGamma experiment to search for a small parity-violating directional asymmetry in the angular distribution of 2.2 MeV gamma-rays from the capture of polarized cold neutrons by protons with a sensitivity of several ppb. The weak pion-nucleon coupling constant can be determined from this asymmetry. The small size of the asymmetry requires control of systematic errors at the ppb level, and the use of current-mode gamma-ray detection with vacuum photo diodes and low-noise solid-state preamplifiers. The detectors were tested for noise performance, sensitivity to magnetic fields, pedestal stability, and cosmic background. False asymmetries due to gain changes and electronic pickup in the detector system were measured to be consistent with zero to an accuracy of 10^–9 in a few hours. We show that the detector array operates at counting statistics and present asymmetry results for B_4C , CCl_4 , ^27Al, Cu, and In. B_4C ,^27Al, Cu, and In are used throughout the experimental apparatus.

  10. A low-noise wide-dynamic-range event-driven detector using SOI pixel technology for high-energy particle imaging

    Science.gov (United States)

    Shrestha, Sumeet; Kamehama, Hiroki; Kawahito, Shoji; Yasutomi, Keita; Kagawa, Keiichiro; Takeda, Ayaki; Tsuru, Takeshi Go; Arai, Yasuo

    2015-08-01

    This paper presents a low-noise wide-dynamic-range pixel design for a high-energy particle detector in astronomical applications. A silicon on insulator (SOI) based detector is used for the detection of wide energy range of high energy particles (mainly for X-ray). The sensor has a thin layer of SOI CMOS readout circuitry and a thick layer of high-resistivity detector vertically stacked in a single chip. Pixel circuits are divided into two parts; signal sensing circuit and event detection circuit. The event detection circuit consisting of a comparator and logic circuits which detect the incidence of high energy particle categorizes the incident photon it into two energy groups using an appropriate energy threshold and generate a two-bit code for an event and energy level. The code for energy level is then used for selection of the gain of the in-pixel amplifier for the detected signal, providing a function of high-dynamic-range signal measurement. The two-bit code for the event and energy level is scanned in the event scanning block and the signals from the hit pixels only are read out. The variable-gain in-pixel amplifier uses a continuous integrator and integration-time control for the variable gain. The proposed design allows the small signal detection and wide dynamic range due to the adaptive gain technique and capability of correlated double sampling (CDS) technique of kTC noise canceling of the charge detector.

  11. Benchmarking Asteroid-Deflection Experiment

    Science.gov (United States)

    Remington, Tane; Bruck Syal, Megan; Owen, John Michael; Miller, Paul L.

    2016-10-01

    An asteroid impacting Earth could have devastating consequences. In preparation to deflect or disrupt one before it reaches Earth, it is imperative to have modeling capabilities that adequately simulate the deflection actions. Code validation is key to ensuring full confidence in simulation results used in an asteroid-mitigation plan. We are benchmarking well-known impact experiments using Spheral, an adaptive smoothed-particle hydrodynamics code, to validate our modeling of asteroid deflection. We describe our simulation results, compare them with experimental data, and discuss what we have learned from our work. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-695540

  12. Geometric formula for prism deflection

    Indian Academy of Sciences (India)

    Apoorva G Wagh; Veer Chand Rakhecha

    2004-08-01

    While studying neutron deflections produced by a magnetic prism, we have stumbled upon a simple `geometric' formula. For a prism of refractive index close to unity, the deflection simply equals the product of the refractive power − 1 and the base-to-height ratio of the prism, regardless of the apex angle. The base and height of the prism are measured respectively along and perpendicular to the direction of beam propagation within the prism. The geometric formula greatly simplifies the optimisation of prism parameters to suit any specific experiment.

  13. Relativistic Stern-Gerlach Deflection

    CERN Document Server

    Talman, Richard

    2016-01-01

    Modern advances in polarized beam control should make it possible to accurately measure Stern-Gerlach (S-G) deflection of relativistic beams. Toward this end a relativistically covariant S-G formalism is developed that respects the opposite behavior under inversion of electric and magnetic fields. Not at all radical, or even new, this introduces a distinction between electric and magnetic fields that is not otherwise present in pure Maxwell theory. Experimental configurations (mainly using polarized electron beams passing through magnetic or electric quadrupoles) are described. Electron beam preparation and experimental methods needed to detect the extremely small deflections are discussed.

  14. Rayleigh scattering in sapphire test mass for laser interferometric gravitational-wave detectors:. II: Rayleigh scattering induced noise in a laser interferometric-wave detector

    Science.gov (United States)

    Benabid, F.; Notcutt, M.; Ju, L.; Blair, D. G.

    1999-10-01

    We present the level of noise induced by Rayleigh-scattered light from sapphire test mass, the limit of scattering loss on build-up power inside the interferometer and finally the tolerable absorption loss in order to meet the specification of the interferometer sensitivity. The results show that the Rayleigh scattering induced noise remains below h˜10 -25 Hz -1/2 and a higher tolerance on the absorption level in sapphire substrate compared with silica substrate.

  15. Toward VIP-PIX: A Low Noise Readout ASIC for Pixelated CdTe Gamma-Ray Detectors for Use in the Next Generation of PET Scanners.

    Science.gov (United States)

    Macias-Montero, Jose-Gabriel; Sarraj, Maher; Chmeissani, Mokhtar; Puigdengoles, Carles; Lorenzo, Gianluca De; Martínez, Ricardo

    2013-08-01

    VIP-PIX will be a low noise and low power pixel readout electronics with digital output for pixelated Cadmium Telluride (CdTe) detectors. The proposed pixel will be part of a 2D pixel-array detector for various types of nuclear medicine imaging devices such as positron-emission tomography (PET) scanners, Compton gamma cameras, and positron-emission mammography (PEM) scanners. Each pixel will include a SAR ADC that provides the energy deposited with 10-bit resolution. Simultaneously, the self-triggered pixel which will be connected to a global time-to-digital converter (TDC) with 1 ns resolution will provide the event's time stamp. The analog part of the readout chain and the ADC have been fabricated with TSMC 0.25 μm mixed-signal CMOS technology and characterized with an external test pulse. The power consumption of these parts is 200 μW from a 2.5 V supply. It offers 4 switchable gains from ±10 mV/fC to ±40 mV/fC and an input charge dynamic range of up to ±70 fC for the minimum gain for both polarities. Based on noise measurements, the expected equivalent noise charge (ENC) is 65 e(-) RMS at room temperature.

  16. The DEPFET Sensor-Amplifier Structure: A Method to Beat 1/f Noise and Reach Sub-Electron Noise in Pixel Detectors

    Directory of Open Access Journals (Sweden)

    Gerhard Lutz

    2016-04-01

    Full Text Available Depleted field effect transistors (DEPFET are used to achieve very low noise signal charge readout with sub-electron measurement precision. This is accomplished by repeatedly reading an identical charge, thereby suppressing not only the white serial noise but also the usually constant 1/f noise. The repetitive non-destructive readout (RNDR DEPFET is an ideal central element for an active pixel sensor (APS pixel. The theory has been derived thoroughly and results have been verified on RNDR-DEPFET prototypes. A charge measurement precision of 0.18 electrons has been achieved. The device is well-suited for spectroscopic X-ray imaging and for optical photon counting in pixel sensors, even at high photon numbers in the same cell.

  17. AIDA: Asteroid Impact & Deflection Assessment

    Science.gov (United States)

    Cheng, A. F.; Galvez, A.; Carnelli, I.; Michel, P.; Rivkin, A.; Reed, C.

    2012-12-01

    To protect the Earth from a hazardous asteroid impact, various mitigation methods have been proposed, including deflection of the asteroid by a spacecraft impact. AIDA, consisting of two mission elements, the Double Asteroid Redirection Test (DART) and the Asteroid Impact Monitoring (AIM) mission, is a demonstration of asteroid deflection. To date, there has been no such demonstration, and there is major uncertainty in the result of a spacecraft impact onto an asteroid, that is, the amount of deflection produced by a given momentum input from the impact. This uncertainty is in part due to unknown physical properties of the asteroid surface, such as porosity and strength, and in part due to poorly understood impact physics such that the momentum carried off by ejecta is highly uncertain. A first mission to demonstrate asteroid deflection would not only be a major step towards gaining the capability to mitigate an asteroid hazard, but in addition it would return unique information on an asteroid's strength, other surface properties, and internal structure. This information return would be highly relevant to future human exploration of asteroids. We report initial results of the AIDA joint mission concept study undertaken by the Johns Hopkins Applied Physics Laboratory and ESA with support from NASA centers including Goddard, Johnson and Jet Propulsion Laboratory. For AIDA, the DART spacecraft impactor study is coordinated with an ESA study of the AIM mission, which would rendezvous with the same asteroid to measure effects of the impact. Unlike the previous Don Quijote mission study performed by ESA in 2005-2007, DART envisions an impactor spacecraft to intercept the secondary member of a binary near-Earth asteroid. DART includes ground-based observations to measure the deflection independently of the rendezvous spacecraft observations from AIM, which also measures deflection and provides detailed characterization of the target asteroid. The joint mission AIDA

  18. Elevator deflections on the icing process

    Science.gov (United States)

    Britton, Randall K.

    1990-01-01

    The effect of elevator deflection of the horizontal stabilizer for certain icing parameters is investigated. Elevator deflection can severely change the lower and upper leading-edge impingement limits, and ice can accrete on the elevator itself. Also, elevator deflection had practically no effect on the maximum local collection efficiency. It is shown that for severe icing conditions (large water droplets), elevator deflections that increase the projected height of the airfoil can significantly increase the total collection efficiency of the airfoil.

  19. Application of photothermal deflection spectroscopy to electrochemical interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rudnicki, J.D.; McLarnon, F.R.; Cairns, E.J.

    1992-03-01

    This dissertation discusses the theory and practice of Photothermal Deflection Spectroscopy (PDS, which is also known as probe beam deflection spectroscopy, PBDS, probe deflection technique, and mirage effect spectroscopy) with respect to electrochemical systems. Much of the discussion is also relevant to non-electrochemical systems. PDS can measure the optical absorption spectrum of interfaces and concentration gradients in the electrolyte adjacent to the electrode. These measurements can be made on a wide variety of electrode surfaces and can be performed under dynamic conditions. The first three chapters discuss the theory of the phenomena that can be detected by PDS, and the equipment used in a PDS system. A ``secondary gradient technique`` is proposed, which places the probe beam on the back of an electrode. The results of a numerical model yield a method for determining the offset of the probe beam from the electrode surface based on the frequency response of the PDS signal. The origin and control of noise in the PDS signal are discussed. A majority of the signal noise appears to be acoustic in origin. The electrochemical oxidation of platinum is used to demonstrate that PDS has sub-monolayer sensitivity necessary to study interfacial chemistry. The results allow us to propose a two-reaction oxidation mechanism: the platinum is electrochemically oxidized to form platinum dihydroxide and dehydrated by a non-electrochemical second-order reaction. The final chapter discusses the relation of PDS to similar and competing techniques, and considers possibilities for the future of the technique.

  20. A step-wise steerable source of illumination for low-noise "Violin-Mode" shadow sensors, intended for use in interferometric gravitational wave detectors.

    Science.gov (United States)

    Lockerbie, N A; Tokmakov, K V

    2016-01-01

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ∼100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral "Violin-Mode" resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors-one intended for each of the four fibres in a suspension-comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors-these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8  × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a "reverse Galilean" telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre's shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre's shadow to be re-centred, so as to bridge once again both elements of its photodiode detector-even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in anti-phase in the two

  1. Design of a Low-Noise Readout Circuit for CZT Detector%CZT探测器低噪声读出电路设计

    Institute of Scientific and Technical Information of China (English)

    曾蕙明; 魏廷存; 高武

    2013-01-01

    采用TSMC 0.35 μm CMOS工艺,设计了CZT探测器低噪声读出电路链和一款多通道能量读出ASIC,该电路将应用于8×8 CZT像素探测器的能量读出.给出了系统框图及低噪声能量读出电路链,分析了低噪声技术策略.实验结果表明,能量分辨范围为20 keV~4 MeV,等效噪声电荷(ENC)小于150个电子,电荷转电压增益为9.2 V/pC,非线性度小于3%,多通道串扰小于10个电子,满足设计需求.%A low-noise front-end readout circuit chain and a multi-channel energy readout ASIC for CZT detector in PET imaging system were designed based on TSMC's 0.35 μm mixed-signal CMOS process.Architecture of the PET imaging system and the low-noise energy readout circuit chain were presented,and low-noise technology strategy was analyzed.Simulation results showed that the energy resolution was from 20 keV to 4 MeV,the equivalent noise charge (ENC) was less than 150 electrons (rms),the charge-to-voltage gain was 9.2 V/pC,the non-linearity was below 3%,and crosstalk of multi channels was less than 10 electrons,satisfying requirements of the design.

  2. Noise studies of n-strip on n-bulk silicon microstrip detectors using fast binary readout electronics after irradiation to 3x10 sup 1 sup 4 p cm sup - sup 2

    CERN Document Server

    Robinson, D; Bizzell, J; Buttar, C; Carter, A A; Carter, J R; Goodrick, M; Greenall, A; Hill, J C; Morgan, D; Munday, D J; Ohsugi, T; Phillips, P W; Riedler, P; Smith, N A; Terada, S; Turner, P R; Unno, Y

    1999-01-01

    N-strip on n-bulk silicon microstrip detectors were irradiated at the CERN PS to 3x10 sup 1 sup 4 p cm sup - sup 2 and their post-irradiation performance evaluated using fast binary readout electronics. Strip noise measurements demonstrate that detectors using conventional p-stop strip isolation are vulnerable to microdischarge at high bias voltages after irradiation. However, a novel isolation technique is shown to suppress microdischarge and lead to excellent post-irradiation characteristics.

  3. IR Imaging Using Arrays of SiO2 Micromechanical Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Grbovic, Dragoslav [ORNL; Lavrik, Nickolay V [ORNL; Rajic, Slobodan [ORNL; Datskos, Panos G [ORNL; Hunter, Scott Robert [ORNL

    2012-01-01

    In this letter, we describe the fabrication of an array of bimaterial detectors for infrared (IR) imaging that utilize SiO2 as a structural material. All the substrate material underneath the active area of each detector element was removed. Each detector element incorporates an optical resonant cavity layer in the IR absorbing region of the sensing element. The simplified microfabrication process requires only four photolithographic steps with no wet etching or sacrificial layers. The thermomechanical deflection sensitivity was 7.9 10-3 rad/K which corresponds to a noise equivalent temperature difference (NETD) of 2.9 mK. In the present work the array was used to capture IR images while operating at room temperature and atmospheric pressure and no need for vacuum packaging. The average measured NETD of our IR detector system was approximately 200 mK but some sensing elements exhibited an NETD of 50 mK.

  4. Field distribution analysis in deflecting structures

    Energy Technology Data Exchange (ETDEWEB)

    Paramonov, V.V. [Joint Inst. for Nuclear Research, Moscow (Russian Federation)

    2013-02-15

    Deflecting structures are used now manly for bunch rotation in emittance exchange concepts, bunch diagnostics and to increase the luminosity. The bunch rotation is a transformation of a particles distribution in the six dimensional phase space. Together with the expected transformations, deflecting structures introduce distortions due to particularities - aberrations - in the deflecting field distribution. The distributions of deflecting fields are considered with respect to non linear additions, which provide emittance deteriorations during a transformation. The deflecting field is treated as combination of hybrid waves HE{sub 1} and HM{sub 1}. The criteria for selection and formation of deflecting structures with minimized level of aberrations are formulated and applied to known structures. Results of the study are confirmed by comparison with results of numerical simulations.

  5. Linear analysis of signal and noise characteristics of a nonlinear CMOS active-pixel detector for mammography

    Science.gov (United States)

    Yun, Seungman; Kim, Ho Kyung; Han, Jong Chul; Kam, Soohwa; Youn, Hanbean; Cunningham, Ian A.

    2017-03-01

    The imaging properties of a complementary metal-oxide-semiconductor (CMOS) active-pixel photodiode array coupled to a thin gadolinium-based granular phosphor screen with a fiber-optic faceplate are investigated. It is shown that this system has a nonlinear response at low detector exposure levels (<10 mR), resulting in an over-estimation of the detective quantum efficiency (DQE) by a factor of two in some cases. Errors in performance metrics on this scale make it difficult to compare new technologies with established systems and predict performance benchmarks that can be achieved in practice and help understand performance bottlenecks. It is shown the CMOS response is described by a power-law model that can be used to linearize image data. Linearization removed an unexpected dependence of the DQE on detector exposure level.

  6. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  7. Linearity enhancement design of a 16-channel low-noise front-end readout ASIC for CdZnTe detectors

    Science.gov (United States)

    Zeng, Huiming; Wei, Tingcun; Wang, Jia

    2017-03-01

    A 16-channel front-end readout application-specific integrated circuit (ASIC) with linearity enhancement design for cadmium zinc telluride (CdZnTe) detectors is presented in this paper. The resistors in the slow shaper are realized using a high-Z circuit to obtain constant resistance value instead of using only a metal-oxide-semiconductor (MOS) transistor, thus the shaping time of the slow shaper can be kept constant for different amounts of input energies. As a result, the linearity of conversion gain is improved significantly. The ASIC was designed and fabricated in a 0.35 μm CMOS process with a die size of 2.60 mm×3.53 mm. The tested results show that a typical channel provides an equivalent noise charge (ENC) of 109.7e-+16.3e-/pF with a power consumption of 4 mW and achieves a conversion gain of 87 mV/fC with a nonlinearity of <0.4%. The linearity of conversion gain is improved by at least 86.6% as compared with the traditional approaches using the same front-end readout architecture and manufacture process. Moreover, the inconsistency among channels is <0.3%. An energy resolution of 2.975 keV (FWHM) for gamma rays of 59.5 keV was measured by connecting the ASIC to a 5 mm×5 mm ×2 mm CdZnTe detector at room temperature. The front-end readout ASIC presented in this paper achieves an outstanding linearity performance without compromising the noise, power consumption, and chip size performances.

  8. Deflection Control in Rigid Pavements

    Science.gov (United States)

    Varunkrishna, Nulu; Jayasankar, R.

    2017-07-01

    The need for modern transportation systems together with the high demand for perpetual pavements under the drastically increasing applied loads has led to a great deal of research on concrete as a pavement material worldwide. This research indeed instigated many modifications in concrete aiming for improving the concrete properties. Pavement Quality Concrete requires higher flexural strength and fewer deflections in hardened state. Fiber reinforcement and latex modification are two reliable approaches serving the required purposes. The concrete made with these two modifications is called Polymer-modified Fiber-reinforced concrete. The present study deals with the usage of polypropylene as fiber and SBR (Styrene Butadiene Rubber) Latex as polymer. M30 grade concrete was modified by replacing cement with two different percentages of fiber (0.5%, 1.0% of weight of cement) and with three different percentages of SBR latex (10%, 15% & 20% of weight of cement).

  9. Optimized frequency dependent photothermal beam deflection spectroscopy

    Science.gov (United States)

    Korte, D.; Cabrera, H.; Toro, J.; Grima, P.; Leal, C.; Villabona, A.; Franko, M.

    2016-12-01

    In the letter the optimization of the experimental setup for photothermal beam deflection spectroscopy is performed by analyzing the influence of its geometrical parameters (detector and sample position, probe beam radius and its waist position etc) on the detected signal. Furthermore, the effects of the fluid’s thermo-optical properties, for optimized geometrical configuration, on the measurement sensitivity and uncertainty determination of sample thermal properties is also studied. The examined sample is a recently developed CuFeInTe3 material. It is seen from the obtained results, that it is a complex problem to choose the proper geometrical configuration as well as sensing fluid to enhance the sensitivity of the method. A signal enhancement is observed at low modulation frequencies by placing the sample in acetonitrile (ACN), while at high modulation frequencies the sensitivity is higher for measurements made in air. For both, detection in air and acetonitrile the determination of CuFeInTe3 thermal properties is performed. The determined values of thermal diffusivity and thermal conductivity are (0.048  ±  0.002)  ×  10-4 m2 s-1 and 4.6  ±  0.2 W m-1 K-1 and (0.056  ±  0.005)  ×  10-4 m2 s-1 and 4.8  ±  0.4 W m-1 K-1 for ACN and air, respectively. It is seen, that the determined values agree well within the range of their measurement uncertainties for both cases, although the measurement uncertainty is two times lower for the measurements in ACN providing more accurate results. The analysis is performed by the use of recently developed theoretical description based on the complex geometrical optics. It is also shown, how the presented work fits into the current status of photothermal beam deflection spectroscopy.

  10. Exploring the Spatial Resolution of the Photothermal Beam Deflection Technique in the Infrared Region

    CERN Document Server

    Seidel, Wolfgang

    2004-01-01

    In photothermal beam deflection spectroscopy (PTBD) generating and detection of thermal waves occur generally in the sub-millimeter length scale. Therefore, PTBD provides spatial information about the surface of the sample and permits imaging and/or microspectrometry. Recent results of PTBD experiments are presented with a high spatial resolution which is near the diffraction limit of the infrared pump beam (CLIO-FEL). We investigated germanium substrates showing restricted O+-doped regions with an infrared absorption line at a wavelength around 11.6 microns. The spatial resolution was obtained by strongly focusing the probe beam (i.e. a HeNe laser) on a sufficiently small spot. The strong divergence makes it necessary to refocus the probe beam in front of the position detector. The influence of the focusing elements on spatial resolution and signal-to-noise ratio is discussed. In future studies we expect an enhanced spatial resolution due to an extreme focusing of the probe beam leading to a highly sensitive...

  11. All-optical optoacoustic microscopy based on probe beam deflection technique

    Directory of Open Access Journals (Sweden)

    Saher M. Maswadi

    2016-09-01

    Full Text Available Optoacoustic (OA microscopy using an all-optical system based on the probe beam deflection technique (PBDT for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii high sensitivity and (iv ultrawide bandwidth. Because of the unimpeded optical path in PBDT, diffraction-limited lateral resolution can be readily achieved. The sensitivity of the current PBDT sensor of 22 μV/Pa and its noise equivalent pressure (NEP of 11.4 Pa are comparable with these parameters of the optical micro-ring resonator and commercial piezoelectric ultrasonic transducers. Benefits of the present prototype OA microscope were demonstrated by successfully resolving micron-size details in histological sections of cardiac muscle.

  12. Wide-Band Optical Fibre System for Investigation of MEMS and NEMS Deflection

    Directory of Open Access Journals (Sweden)

    Orłowska Karolina

    2014-08-01

    Full Text Available In this work the construction of experimental setup for MEMS/NEMS deflection measurements is presented. The system is based on intensity fibre optic detector for linear displacement sensing. Furthermore the electronic devices: current source for driving the light source and photodetector with wide-band preamplifier are presented.

  13. Optimal low noise phase-only and binary phase-only optical correlation filters for threshold detectors

    Science.gov (United States)

    Kallman, Robert R.

    1986-12-01

    Phase-only (PO) and binary phase only (BPO) versions of recently developed Synthetic Discriminant Filters, SDFs, (Kallman, 1986) are discussed which are potentially useful for threshold optical correlation detectors. A formulation of the performance or SNR of a filter against a training set is first presented which takes into account the POF or BPOF, unlike the SDF, being unable to control the actual size of the recognition spike of the output correlation plane when a valid target is centered in the filter input plane. Numerical tests of the present recipes for POFs and BPOFs have been carried out on four SDFs made from tank imagery, and the SNR for 12 POFs and 24 BPOFs were computed.

  14. A step-wise steerable source of illumination for low-noise “Violin-Mode” shadow sensors, intended for use in interferometric gravitational wave detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance), Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2016-01-15

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ∼100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral “Violin-Mode” resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8  × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a “reverse Galilean” telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre’s shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre’s shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in

  15. A step-wise steerable source of illumination for low-noise "Violin-Mode" shadow sensors, intended for use in interferometric gravitational wave detectors

    Science.gov (United States)

    Lockerbie, N. A.; Tokmakov, K. V.

    2016-01-01

    A steerable low-noise source of illumination is described for shadow-sensors having a displacement sensitivity of ˜100 pm (rms)/√Hz, at 500 Hz, over a measuring span of at least ±0.5 mm. These sensors were designed to detect lateral "Violin-Mode" resonances in the highly tensioned fused-silica suspension fibres of the test-masses/mirrors for the Advanced Laser Interferometer Gravitational Wave Observatory gravitational wave detectors. The shadow sensors—one intended for each of the four fibres in a suspension—comprised a source of Near InfraRed (NIR) radiation (emitter) and a differential shadow-displacement sensor (detector), these bracketing the fibre under test. The suspension fibres themselves were approximately 600 mm long by 0.4 mm in diameter, and when illuminated from the side, they cast narrow, vertical, shadows onto their respective detectors—these being located at an effective distance of 50 fibre diameters behind the axes of the fibres themselves. The emitter described here was designed to compensate for a significant degree of mechanical drift or creep over time in the mean position of its suspension fibre. This was achieved by employing five adjacent columns of 8 × miniature NIR LEDs (Light Emitting Diodes, λ = 890 nm), with one column being activated at a time. When used in conjunction with a "reverse Galilean" telescope, the LED sources allowed the collimated beam from the emitter to be steered azimuthally in fine angular increments (0.65°), causing the fibre's shadow to move laterally, in a step-wise manner, across the plane of its facing detector. Each step in shadow position was approximately 0.23 mm in size, and this allowed the fibre's shadow to be re-centred, so as to bridge once again both elements of its photodiode detector—even if the fibre was off-centred by as much as ±0.5 mm. Re-centring allowed Violin-Mode vibrations of the fibre to be sensed once again as differential AC photocurrents, these flowing in anti-phase in the

  16. Profiling compact toroid plasma density on CTIX with laser deflection

    Science.gov (United States)

    Brockington, Samuel Joseph Erwin

    A laser deflectometer measures line-integrated plasma density gradient using laser diodes and amplified point detectors. A laser passing through an optically thin plasma is refracted by an amount proportional to the line-integrated electron density gradient. I have designed, installed, and operated a deflection diagnostic for the Compact Toroid Injection Experiment (CTIX), a plasma rail gun which can create compact toroid (CT) plasmas of controllable density and velocity. The diagnostic design and motivation are discussed, as well as three experiments performed with deflectometry. Thus, my thesis consists of the design of the deflectometer diagnostic, a comparison of its accuracy to interferometer density measurements, and finally a survey of compact toroid density profiles in two dimensions conducted with an array of detectors.

  17. Improved CO [lidar detector

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, P.L.; Busch, G.E.; Thompson, D.C.; Remelius, D.K.; Wells, F.D.

    1999-07-18

    A high sensitivity, CO{sub 2} lidar detector, based on recent advances in ultra-low noise, readout integrated circuits (ROIC), is being developed. This detector will combine a high speed, low noise focal plane array (FPA) with a dispersive grating spectrometer. The spectrometer will filter the large background flux, thereby reducing the limiting background photon shot noise. In order to achieve the desired low noise levels, the HgCdTe FPA will be cooled to {approximately}50K. High speed, short pulse operation of the lidar system should enable the detector to operate with the order of a few noise electrons in the combined detector/ ROIC output. Current receiver design concepts will be presented, along with their expected noise performance.

  18. Magnetic field dependence of the internal quality factor and noise performance of lumped-element kinetic inductance detectors

    CERN Document Server

    Flanigan, Daniel; Abitbol, Maximilian H; Bryan, Sean; Cantor, Robin; Day, Peter K; Jones, Glenn; Mauskopf, Philip; McCarrick, Heather; Miller, Amber; Zmuidzinas, Jonas

    2016-01-01

    We present a technique for increasing the internal quality factor of kinetic inductance detectors (KIDs) by nulling ambient magnetic fields with a properly applied magnetic field. The KIDs used in this study are made from thin-film aluminum, they are mounted inside a light-tight package made from bulk aluminum, and they are operated near $150 \\, \\mathrm{mK}$. Since the thin-film aluminum has a slightly elevated critical temperature ($T_\\mathrm{c} = 1.4 \\, \\mathrm{K}$), it therefore transitions before the package ($T_\\mathrm{c} = 1.2 \\, \\mathrm{K}$), which also serves as a magnetic shield. On cooldown, ambient magnetic fields as small as approximately $30 \\, \\mathrm{\\mu T}$ can produce vortices in the thin-film aluminum as it transitions because the bulk aluminum package has not yet transitioned and therefore is not yet shielding. These vortices become trapped inside the aluminum package below $1.2 \\, \\mathrm{K}$ and ultimately produce low internal quality factors in the thin-film superconducting resonators. W...

  19. Application of photothermal deflection spectroscopy to electrochemical interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rudnicki, J.D.; McLarnon, F.R.; Cairns, E.J.

    1992-03-01

    This dissertation discusses the theory and practice of Photothermal Deflection Spectroscopy (PDS, which is also known as probe beam deflection spectroscopy, PBDS, probe deflection technique, and mirage effect spectroscopy) with respect to electrochemical systems. Much of the discussion is also relevant to non-electrochemical systems. PDS can measure the optical absorption spectrum of interfaces and concentration gradients in the electrolyte adjacent to the electrode. These measurements can be made on a wide variety of electrode surfaces and can be performed under dynamic conditions. The first three chapters discuss the theory of the phenomena that can be detected by PDS, and the equipment used in a PDS system. A secondary gradient technique'' is proposed, which places the probe beam on the back of an electrode. The results of a numerical model yield a method for determining the offset of the probe beam from the electrode surface based on the frequency response of the PDS signal. The origin and control of noise in the PDS signal are discussed. A majority of the signal noise appears to be acoustic in origin. The electrochemical oxidation of platinum is used to demonstrate that PDS has sub-monolayer sensitivity necessary to study interfacial chemistry. The results allow us to propose a two-reaction oxidation mechanism: the platinum is electrochemically oxidized to form platinum dihydroxide and dehydrated by a non-electrochemical second-order reaction. The final chapter discusses the relation of PDS to similar and competing techniques, and considers possibilities for the future of the technique.

  20. Large Deflections of Elastic Rectangular Plates

    Science.gov (United States)

    Razdolsky, A. G.

    2015-11-01

    It is known that elastic large deflections of thin plates are governed by von Karman nonlinear equations. The analytical solution of these equations in the general case is unfeasible. Samuel Levy, in 1942, showed that large deflections of the rectangular plate can be expressed as a double series of sine-shaped harmonics (deflection harmonics). However, this method gave no way of creating the computer algorithm of solving the problem. The stress function expression taken in the Levy's method must be revised to find the approach that takes into account of all possible products of deflection coefficients. The algorithm of solving the problem for the rectangular plate with an arbitrary aspect ratio under the action of the lateral distributed load is reported in this paper. The approximation of the plate deflection is taken in the form of double series proposed by Samuel Levy. However, the expression for the stress function is presented in the form that incorporates products of deflection coefficients in the explicit form in distinction to the Levy's expression. The number of harmonics in the deflection expression may be arbitrary. The algorithm provides composing the system of governing cubic equations, which includes the deflection coefficients in the explicit form. Solving the equation system is based on using the principle of minimum potential energy. A method of the gradient descent is applied to find the equilibrium state of the plate as the minimum point of the potential energy. A computer program is developed on the basis of the present algorithm. Numerical examples carried out for the plate model with 16 deflection harmonics illustrate the potentialities of the program. The results of solving the examples are presented in the graphical form for the plates with a different aspect ratio and may be used under designing thin-walled elements of airplane and ship structures.

  1. Deflection of resilient materials for reduction of floor impact sound.

    Science.gov (United States)

    Lee, Jung-Yoon; Kim, Jong-Mun

    2014-01-01

    Recently, many residents living in apartment buildings in Korea have been bothered by noise coming from the houses above. In order to reduce noise pollution, communities are increasingly imposing bylaws, including the limitation of floor impact sound, minimum thickness of floors, and floor soundproofing solutions. This research effort focused specifically on the deflection of resilient materials in the floor sound insulation systems of apartment houses. The experimental program involved conducting twenty-seven material tests and ten sound insulation floating concrete floor specimens. Two main parameters were considered in the experimental investigation: the seven types of resilient materials and the location of the loading point. The structural behavior of sound insulation floor floating was predicted using the Winkler method. The experimental and analytical results indicated that the cracking strength of the floating concrete floor significantly increased with increasing the tangent modulus of resilient material. The deflection of the floating concrete floor loaded at the side of the specimen was much greater than that of the floating concrete floor loaded at the center of the specimen. The Winkler model considering the effect of modulus of resilient materials was able to accurately predict the cracking strength of the floating concrete floor.

  2. Deflection of Resilient Materials for Reduction of Floor Impact Sound

    Directory of Open Access Journals (Sweden)

    Jung-Yoon Lee

    2014-01-01

    Full Text Available Recently, many residents living in apartment buildings in Korea have been bothered by noise coming from the houses above. In order to reduce noise pollution, communities are increasingly imposing bylaws, including the limitation of floor impact sound, minimum thickness of floors, and floor soundproofing solutions. This research effort focused specifically on the deflection of resilient materials in the floor sound insulation systems of apartment houses. The experimental program involved conducting twenty-seven material tests and ten sound insulation floating concrete floor specimens. Two main parameters were considered in the experimental investigation: the seven types of resilient materials and the location of the loading point. The structural behavior of sound insulation floor floating was predicted using the Winkler method. The experimental and analytical results indicated that the cracking strength of the floating concrete floor significantly increased with increasing the tangent modulus of resilient material. The deflection of the floating concrete floor loaded at the side of the specimen was much greater than that of the floating concrete floor loaded at the center of the specimen. The Winkler model considering the effect of modulus of resilient materials was able to accurately predict the cracking strength of the floating concrete floor.

  3. Ion Beam Shepherd for Asteroid Deflection

    CERN Document Server

    Bombardelli, C

    2011-01-01

    We present a novel concept to impart a continuous thrust to an Earth threatening asteroid from a hovering spacecraft without need for physical attachment nor gravitational interaction with the asteroid. The concept involves an ion thruster placed at a distance of a few asteroid diameters directing a stream of quasi-neutral plasma against the asteroid surface resulting into a net transferred momentum. As the transmitted force is independent of the asteroid mass and size the method allows deflecting subkilometer asteroids with a spacecraft much lighter when compared to a gravity tractor spacecraft of equal deflection capability. The finding could make low-cost asteroid deflection missions possible in the coming years.

  4. Alaska North-South Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' surface deflection of the vertical grid for Alaska is the DEFLEC96 model. The computation used about 1.1 million terrestrial and marine gravity data...

  5. Mexico East-West Deflections (DMEX97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for Mexico, and North-Central is the DMEX97 model. The computation used about one million terrestrial and marine...

  6. Alaska East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' surface deflection of the vertical grid for Alaska is the DEFLEC96 model. The computation used about 1.1 millionterrestrial and marine gravity data held...

  7. Mexico North-South Deflections (DMEX97)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for Mexico, and North-Central is the DMEX97 model. The computation used about one million terrestrial and marine...

  8. Noise Sequence Modeling and Verification in Particle Detector Readout Circuit%粒子探测器读出电路噪声序列建模及验证

    Institute of Scientific and Technical Information of China (English)

    殷树娟; 李翔宇

    2013-01-01

    In the study of particle detectors ,based on digital signal processing ,since the particle detectors for the relatively low energy of the incident particle , the noise characteristic of the circuit impact on the ultimate performance of the circuit is very large .Particle detector readout circuit noise model created in MATLAB Simulink environment ,including thermal noise ,shot noise and low‐frequency noise .Simulation of the three types of the power spectral density of the noise on the basis of the model in this article a good fit to the three noise power spectral density function curve simulation results with the theoretical analysis of the curve obtained with the relationship of the input signal frequency changes . Further , the results are consistent with the simulation results with noise sequence of the three noise power spectral density function curve obtained by the power spectrum calculating ,in order to verify the generated noise sequence model is correct .%  在基于数字信号处理的粒子探测器的研究中,由于粒子探测器入射粒子能量相对较低,电路的噪声特性对电路最终性能影响非常大。在 MATLAB 的 Simulink 环境下建立了粒子探测器读出电路的噪声模型,包括热噪声、散粒噪声和低频噪声。基于该模型仿真验证了三类噪声的功率谱密度随着输入信号频率变化关系,三种噪声的功率谱密度函数曲线仿真结果与理论分析所得到的曲线很好地拟合。另外,三种噪声的功率谱密度函数曲线仿真结果与噪声序列通过功率谱计算得到的结果是一致的,从而验证了所生成的噪声序列模型是正确的。

  9. High-performance low-noise 128-channel readout-integrated circuit for flat-panel x-ray detector systems

    Science.gov (United States)

    Beuville, Eric J.; Belding, Mark; Costello, Adrienne N.; Hansen, Randy; Petronio, Susan M.

    2004-05-01

    A silicon mixed-signal integrated circuit is needed to extract and process x-ray induced signals from a coated flat panel thin film transistor array (TFT) in order to generate a digital x-ray image. Indigo Systems Corporation has designed, fabricated, and tested such a readout integrated circuit (ROIC), the ISC9717. This off-the-shelf, high performance, low-noise, 128-channel device is fully programmable with a multistage pipelined architecture and a 9 to 14-bit programmable A/D converter per channel, making it suitable for numerous X-ray medical imaging applications. These include high-resolution radiography in single frame mode and fluoroscopy where high frame rates are required. The ISC9717 can be used with various flat panel arrays and solid-state detectors materials: Selenium (Se), Cesium Iodide (CsI), Silicon (Si), Amorphous Silicon, Gallium Arsenide (GaAs), and Cadmium Zinc Telluride (CdZnTe). The 80-micron pitch ROIC is designed to interface (wire bonding or flip-chip) along one or two sides of the x-ray panel, where ROICs are abutted vertically, each reading out charge from pixels multiplexed onto 128 horizontal read lines. The paper will present the design and test results of the ROIC, including the mechanical and electrical interface to a TFT array, system performance requirements, output multiplexing of the digital signals to an off-board processor, and characterization test results from fabricated arrays.

  10. Image Noise, CNR, and Detectability of Low-Contrast, Low-Attenuation Liver Lesions in a Phantom: Effects of Radiation Exposure, Phantom Size, Integrated Circuit Detector, and Iterative Reconstruction.

    Science.gov (United States)

    Goenka, Ajit H; Herts, Brian R; Dong, Frank; Obuchowski, Nancy A; Primak, Andrew N; Karim, Wadih; Baker, Mark E

    2016-08-01

    Purpose To assess image noise, contrast-to-noise ratio (CNR) and detectability of low-contrast, low-attenuation liver lesions in a semianthropomorphic phantom by using either a discrete circuit (DC) detector and filtered back projection (FBP) or an integrated circuit (IC) detector and iterative reconstruction (IR) with changes in radiation exposure and phantom size. Materials and Methods An anthropomorphic phantom without or with a 5-cm-thick fat-mimicking ring (widths, 30 and 40 cm) containing liver inserts with four spherical lesions was scanned with five exposure settings on each of two computed tomography scanners, one equipped with a DC detector and the other with an IC detector. Images from the DC and IC detector scanners were reconstructed with FBP and IR, respectively. Image noise and lesion CNR were measured. Four radiologists evaluated lesion presence on a five-point diagnostic confidence scale. Data analyses included receiver operating characteristic (ROC) curve analysis and noninferiority analysis. Results The combination of IC and IR significantly reduced image noise (P < .001) (with the greatest reduction in the 40-cm phantom and at lower exposures) and improved lesion CNR (P < .001). There was no significant difference in area under the ROC curve between detector-reconstruction combinations at fixed exposure for either phantom. Reader accuracy with IC-IR was noninferior at 50% (100 mAs [effective]) and 25% (300 mAs [effective]) exposure reduction for the 30- and 40-cm phantoms, respectively (adjusted P < .001 and .04 respectively). IC-IR improved readers' confidence in the presence of a lesion (P = .029) independent of phantom size or exposure level. Conclusion IC-IR improved objective image quality and lesion detection confidence but did not result in superior diagnostic accuracy when compared with DC-FBP. Moderate exposure reductions maintained comparable diagnostic accuracy for both detector-reconstruction combinations. Lesion detection in the 40

  11. High power RF system for transverse deflecting structure XFEL TDS INJ

    Science.gov (United States)

    Volobuev, E. N.; Zavadtsev, A. A.; Zavadtsev, D. A.; Smirnov, A. J.; Sobenin, N. P.; Churanov, D. V.

    2016-09-01

    The high power RF system (HPRF) is designed for RF feeding of the transverse deflecting structure of the transverse deflecting system XFEL TDS System INJ of the European X-ray Free Electron Laser. The HPRF system includes klystron, waveguide ceramic windows, directional couplers, waveguide vacuum units, spark detector and waveguide line. Operating frequency is 2997.2 MHz. Peak input power is up to 3 MW. The HPRF system has been developed, manufactured and assembled in the XFEL Injector building. The total length of the waveguide line is 55 m from the klystron at the -5 floor to the transverse deflecting structure at the -7 floor. All designed RF parameters have been obtained experimentally at low RF power level.

  12. Base deflection and microleakage of composite restorations.

    Science.gov (United States)

    Paulillo, L A; de Goes, M F; Consani, S

    1994-06-01

    The flexural deflections of human dentin, Herculite XR, Dycal, Vidrion F, zinc phosphate base, and combinations of composite-base were determined. The influence of the flexural deflections in the marginal microleakage was also determined for the composite-base combinations. The flexural deflection test for dentin showed no statistically significant differences between the two floor cavity depths studied. There were significant differences among cements when the thickness of the base was 1 mm whereas no differences occurred at 2 mm. The composite-base combinations did not present statistical differences. There were no statistically significant differences in the microleakage levels among loaded and non-loaded specimens; however, dye penetration was visually greater in loaded samples.

  13. Small angle electron diffraction and deflection

    Directory of Open Access Journals (Sweden)

    T. Koyama

    2012-03-01

    Full Text Available Electron optical system is constructed in order to obtain small angle diffraction and Lorentz deflection of electrons at the order of down to 10-6 radian in the reciprocal space. Long-distance camera length up to 3000 m is achieved in a conventional transmission electron microscope with LaB6 thermal emission type. The diffraction pattern at 5 × 10-6 radian is presented in a carbon replica grating with 500 nm lattice spacing while the magnetic deflection pattern at 2 × 10-5 radian is exhibited in Permalloy elements. A simultaneous recording of electron diffraction and Lorentz deflection is also demonstrated in 180 degree striped magnetic domains of La0.825Sr0.175MnO3.

  14. Pixel detectors

    CERN Document Server

    Passmore, M S

    2001-01-01

    positions on the detector. The loss of secondary electrons follows the profile of the detector and increases with higher energy ions. studies of the spatial resolution predict a value of 5.3 lp/mm. The image noise in photon counting systems is investigated theoretically and experimentally and is shown to be given by Poisson statistics. The rate capability of the LAD1 was measured to be 250 kHz per pixel. Theoretical and experimental studies of the difference in contrast for ideal charge integrating and photon counting imaging systems were carried out. It is shown that the contrast differs and that for the conventional definition (contrast = (background - signal)/background) the photon counting device will, in some cases, always give a better contrast than the integrating system. Simulations in MEDICI are combined with analytical calculations to investigate charge collection efficiencies (CCE) in semiconductor detectors. Different pixel sizes and biasing conditions are considered. The results show charge shari...

  15. Laboratory experiments on arc deflection and instability

    Energy Technology Data Exchange (ETDEWEB)

    Zweben, S.; Karasik, M.

    2000-03-21

    This article describes experiments on arc deflection instability carried out during the past few years at the Princeton University Plasma Physics Laboratory (PPPL). The approach has been that of plasma physicists interested in arcs, but they believe these results may be useful to engineers who are responsible for controlling arc behavior in large electric steel furnaces.

  16. Impeller deflection and modal finite element analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Nathan A.

    2013-10-01

    Deflections of an impeller due to centripetal forces are calculated using finite element analysis. The lateral, or out of plane, deflections are an important design consideration for this particular impeller because it incorporates an air bearing with critical gap tolerances. The target gap distance is approximately 10 microns at a rotational velocity of 2500 rpm. The centripetal forces acting on the impeller cause it deflect in a concave fashion, decreasing the initial gap distance as a function of radial position. This deflection is characterized for a previous and updated impeller design for comparative purposes. The impact of design options such as material selection, geometry dimensions, and operating rotational velocity are also explored, followed by a sensitivity study with these parameters bounded by specific design values. A modal analysis is also performed to calculate the impeller's natural frequencies which are desired to be avoided during operation. The finite element modeling techniques continue to be exercised by the impeller design team to address specific questions and evaluate conceptual designs, some of which are included in the Appendix.

  17. Deflection of uncooperative targets using laser ablation

    Science.gov (United States)

    Thiry, Nicolas; Vasile, Massimiliano

    2015-09-01

    Owing to their ability to move a target in space without requiring propellant, laser-based deflection methods have gained attention among the research community in the recent years. With laser ablation, the vaporized material is used to push the target itself allowing for a significant reduction in the mass requirement for a space mission. Specifically, this paper addresses two important issues which are thought to limit seriously the potential efficiency of a laser-deflection method: the impact of the tumbling motion of the target as well as the impact of the finite thickness of the material ablated in the case of a space debris. In this paper, we developed a steady-state analytical model based on energetic considerations in order to predict the efficiency range theoretically allowed by a laser deflection system in absence of the two aforementioned issues. A numerical model was then implemented to solve the transient heat equation in presence of vaporization and melting and account for the tumbling rate of the target. This model was also translated to the case where the target is a space debris by considering material properties of an aluminium 6061-T6 alloy and adapting at every time-step the size of the computational domain along with the recession speed of the interface in order to account for the finite thickness of the debris component. The comparison between the numerical results and the analytical predictions allow us to draw interesting conclusions regarding the momentum coupling achievable by a given laser deflection system both for asteroids and space debris in function of the flux, the rotation rate of the target and its material properties. In the last section of this paper, we show how a reasonably small spacecraft could deflect a 56m asteroid with a laser system requiring less than 5kW of input power.

  18. Noise suppression by noise

    OpenAIRE

    Vilar, J. M. G.; Rubí Capaceti, José Miguel

    2001-01-01

    We have analyzed the interplay between an externally added noise and the intrinsic noise of systems that relax fast towards a stationary state, and found that increasing the intensity of the external noise can reduce the total noise of the system. We have established a general criterion for the appearance of this phenomenon and discussed two examples in detail.

  19. Invited article: The fast readout low noise camera as a versatile x-ray detector for time resolved dispersive extended x-ray absorption fine structure and diffraction studies of dynamic problems in materials science, chemistry, and catalysis

    Science.gov (United States)

    Labiche, Jean-Claude; Mathon, Olivier; Pascarelli, Sakura; Newton, Mark A.; Ferre, Gemma Guilera; Curfs, Caroline; Vaughan, Gavin; Homs, Alejandro; Carreiras, David Fernandez

    2007-09-01

    Originally conceived and developed at the European Synchrotron Radiation Facility (ESRF) as an "area" detector for rapid x-ray imaging studies, the fast readout low noise (FReLoN) detector of the ESRF [J.-C. Labiche, ESRF Newsletter 25, 41 (1996)] has been demonstrated to be a highly versatile and unique detector. Charge coupled device (CCD) cameras at present available on the public market offer either a high dynamic range or a high readout speed. A compromise between signal dynamic range and readout speed is always sought. The parameters of the commercial cameras can sometimes be tuned, in order to better fulfill the needs of specific experiments, but in general these cameras have a poor duty cycle (i.e., the signal integration time is much smaller than the readout time). In order to address scientific problems such as time resolved experiments at the ESRF, a FReLoN camera has been developed by the Instrument Support Group at ESRF. This camera is a low noise CCD camera that combines high dynamic range, high readout speed, accuracy, and improved duty cycle in a single image. In this paper, we show its application in a quasi-one-dimensional sense to dynamic problems in materials science, catalysis, and chemistry that require data acquisition on a time scale of milliseconds or a few tens of milliseconds. It is demonstrated that in this mode the FReLoN can be applied equally to the investigation of rapid changes in long range order (via diffraction) and local order (via energy dispersive extended x-ray absorption fine structure) and in situations of x-ray hardness and flux beyond the capacity of other detectors.

  20. Dark matter prospects in deflected mirage mediation

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Michael; Nelson, Brent D., E-mail: holmes.mi@neu.edu, E-mail: b.nelson@neu.edu [Department of Physics, Northeastern University, Boston, MA 02115 (United States)

    2009-07-01

    The recently introduced deflected mirage mediation (DMM) model is a string-motivated paradigm in which all three of the major supersymmetry-breaking transmission mechanisms are operative. We begin a systematic exploration of the parameter space of this rich model context, paying special attention to the pattern of gaugino masses which arise. In this work we focus on the dark matter phenomenology of the DMM model as such signals are the least influenced by the model-dependent scalar masses. We find that a large portion of the parameter space in which the three mediation mechanisms have a similar effective mass scale of 1 TeV or less will be probed by future direct and indirect detection experiments. Distinguishing deflected mirage mediation from the mirage model without gauge mediation will prove difficult without collider input, though we indicate how gamma ray signals may provide an opportunity for distinguishing between the two paradigms.

  1. Surface effects on large deflection of nanowires

    Institute of Scientific and Technical Information of China (English)

    杨帆

    2015-01-01

    Surface effects play an important role in the mechanical behavior of nanosized structural elements owing to the increased ratio of surface area to volume. The surface effects on the large deflection of nanowires were considered. Both geometric nonlinearity in finite deformation and surface effects at nanoscale were taken into account to analyze the bending of nanowires subjected to a concentrated force. For simply supported beams and clamped-clamped beams, the influence of surface effects and geometric nonlinearity were discussed in detail. It is found that both surface effects and geometric nonlinearity tend to decrease the deflection of bending nanowires and thus increase the effective elastic modulus of nanowires. Surface effects yield the size dependent behavior of nanowires.

  2. Optical forces through guided light deflections

    DEFF Research Database (Denmark)

    Palima, Darwin; Bañas, Andrew Rafael; Vizsnyiczai, Gaszton;

    2013-01-01

    Optical trapping and manipulation typically relies on shaping focused light to control the optical force, usually on spherical objects. However, one can also shape the object to control the light deflection arising from the light-matter interaction and, hence, achieve desired optomechanical effects....... In this work we look into the object shaping aspect and its potential for controlled optical manipulation. Using a simple bent waveguide as example, our numerical simulations show that the guided deflection of light efficiently converts incident light momentum into optical force with one order...... show that the force on the waveguide exceeds the combined forces on spherical trapping handles. Furthermore, it shows that static illumination can exert a constant force on a moving structure, unlike the position-dependent forces from harmonic potentials in conventional trapping....

  3. Deflection analysis of rectangular spatial coverage truss

    Directory of Open Access Journals (Sweden)

    M.N. Kirsanov

    2015-02-01

    Full Text Available An elastic spatial statically determinate truss of regular type, simulating the rectangular in plan coverage was considered. In the plane of the base the truss has two axes of symmetry. Four support structures (spherical hinge, cylindrical hinge and two vertical rods are located at its corners. An analytic solution was found for forces in the rods of the truss. Using the Maxwell-Mohr’s formula, the dependence of the deflection of the center was discovered in the truss under the influence of the concentrated force. There are five parameters of the problem in this formula: three linear dimensions, and the numbers of hinges on its lateral sides. To determine the desired patterns by means of the computer mathematics system Maple the recursion task by two parameters was solved. It was shown that dependence of the deflection on the number of panels and height of the truss detects a minimum, allowing optimizing the size of the structure.

  4. Deflection of proton beams by crystal miscut surface

    CERN Document Server

    Babaev, A A; Dabagov, S B

    2014-01-01

    First computer experiment results on proton beam deflection by the crystal miscut surface are presented. The phenomenology of proton channeling and quasichanneling has been applied to describe new features of the beam deflection. The analysis predicts efficient beam deflection by the acute crystal end due to repelling miscut potential.

  5. Deflection rheoevolution of lithosphere under subduction

    Institute of Scientific and Technical Information of China (English)

    韩玉英; 王维襄

    1997-01-01

    Along the continental margin, the tectonic system consisting of trench, island arc, back arc basin and outer rise is often known as a convergent transitional belt between the oceanic lithosphere and the continental litho-sphere. The occurrence, development and activity of trench and outer rise bear closely on the underthrusting process of the oceanic lithosphere. A generalized analytical theory of deflection rheoevolution of lithosphere under subduction is established, and solutions with universal significance have been obtained.

  6. [Pliability and deflection of diagnostic catheters].

    Science.gov (United States)

    Pelyhe, Liza; Bognár, Eszter

    2014-09-28

    The cardiac catheter is an intravascular catheter, which is introduced or implanted into the heart for diagnostic or therapeutic reasons. The catheters may break or king during their introduction and/or removal. The aim of the authors was to study the pliability of two catheters with the same material but different diameters according to the Food and Drug Administration's recommendation. The bending points, diameter decrease, deflection, and their correlation and dependence on the distance from the tip, as well as the influence of the initial diameter of the catheters were determined. The bending of catheters was performed on 9 bending points (120-280 mm from the tip by 20 mm) on 16 gauges with different radius (10-2.5 mm by 0.5 mm). A linear dependency between the diameter decrease and deflection was observed, which was independent from the placement of the measurement in both catheters examined. The larger initial diameter had significant (p = 0.05) greater diameter decrease than the smaller, but the curves characteristic of the diameter decrease and deflection were similar. The applied method seems to be useful for the examination of weak points of cardiac catheters.

  7. Comparative research on the methods for measuring the mode deflection angle of cylindrical resonator gyroscope

    Science.gov (United States)

    Wang, Kai; Fan, Zhenfang; Wang, Dongya; Wang, Yanyan; Pan, Yao; Qu, Tianliang; Xu, Guangming

    2016-10-01

    The existence of mode deflection angle in the cylindrical resonator gyroscope (CRG) leads to the signal drift on the detecting nodes of the gyro vibration and significantly decreases the performance of the CRG. Measuring the mode deflection angle efficiently is the foundation of tuning for the imperfect cylindrical shell resonator. In this paper, an optical method based on the measuring gyroscopic resonator's vibration amplitude with the laser Doppler vibrometer and an electrical method based on measuring the output voltage of the electrodes on the resonator are both presented to measure the mode deflection angle. Comparative experiments were implemented to verify the methodology and the results show that both of the two methods could recognize the mode deflection angle efficiently. The precision of the optical method relies on the number and position of testing points distributed on the resonator. The electrical method with simple circuit shows high accuracy of measuring in a less time compared to the optical method and its error source arises from the influence of circuit noise as well as the inconsistent distribution of the piezoelectric electrodes.

  8. Noise Gating Solar Images

    Science.gov (United States)

    DeForest, Craig; Seaton, Daniel B.; Darnell, John A.

    2017-08-01

    I present and demonstrate a new, general purpose post-processing technique, "3D noise gating", that can reduce image noise by an order of magnitude or more without effective loss of spatial or temporal resolution in typical solar applications.Nearly all scientific images are, ultimately, limited by noise. Noise can be direct Poisson "shot noise" from photon counting effects, or introduced by other means such as detector read noise. Noise is typically represented as a random variable (perhaps with location- or image-dependent characteristics) that is sampled once per pixel or once per resolution element of an image sequence. Noise limits many aspects of image analysis, including photometry, spatiotemporal resolution, feature identification, morphology extraction, and background modeling and separation.Identifying and separating noise from image signal is difficult. The common practice of blurring in space and/or time works because most image "signal" is concentrated in the low Fourier components of an image, while noise is evenly distributed. Blurring in space and/or time attenuates the high spatial and temporal frequencies, reducing noise at the expense of also attenuating image detail. Noise-gating exploits the same property -- "coherence" -- that we use to identify features in images, to separate image features from noise.Processing image sequences through 3-D noise gating results in spectacular (more than 10x) improvements in signal-to-noise ratio, while not blurring bright, resolved features in either space or time. This improves most types of image analysis, including feature identification, time sequence extraction, absolute and relative photometry (including differential emission measure analysis), feature tracking, computer vision, correlation tracking, background modeling, cross-scale analysis, visual display/presentation, and image compression.I will introduce noise gating, describe the method, and show examples from several instruments (including SDO

  9. Characterisation of a Mechanical Deflection Sensor

    CSIR Research Space (South Africa)

    Miyambo, M

    2012-10-01

    Full Text Available ). REFERENCES Snyman, I.M. and Reinecke, J.D. 2006. Measuring the impulse from an explosive charge, Ballistics Symposium South Africa, Denel-OTB, Bredasdorp, 15?16 Aug 2006. Miyambo, M.E. and Pandelani, T. 2012. The Mechanical Deflection Sensor Test... Mechanical Defl ection Sensor M MIYAMBO AND T PANDELANI CSIR Defence, Peace, Safety and Security, PO Box 395, Pretoria, South Africa, 0001 Email: mmiyambo@csir.co.za ? www.csir.co.za INTRODUCTION The CSIR Defence, Peace, Safety and Security (DPSS...

  10. Very high-gain and low-excess noise near-infrared single-photon avalanche detector: an NIR solid state photomultiplier

    Science.gov (United States)

    Linga, Krishna; Yevtukhov, Yuriy; Liang, Bing

    2009-05-01

    A new family of photodetectors with a Discrete Amplification (DA) mechanism allows the realization of very high gain and low excess noise factor in the visible and near infrared spectral regions and offers an alternative to conventional photomultiplier tubes and Geiger mode avalanche photodetectors. These photodetectors can operate in linear detection mode with gain-bandwidth product in excess of 4X1014 and in photon counting mode with count rates up to 108 counts/sec. Potential benefits of this technology over conventional avalanche photodetectors include ultra low excess noise factor, very high gain, and lower reset time (photodetectors in the near infrared wavelength range. The measured devices have the following performance characteristics: gain > 2X105, excess noise factor Lidar, quantum cryptography, night vision and other military, defence and aerospace applications.

  11. A Bridge Deflection Monitoring System Based on CCD

    Directory of Open Access Journals (Sweden)

    Baohua Shan

    2016-01-01

    Full Text Available For long-term monitoring of the midspan deflection of Songjiazhuang cloverleaf junction on 309 national roads in Zibo city, this paper proposes Zhang’s calibration-based DIC deflection monitoring method. CCD cameras are used to track the change of targets’ position, Zhang’s calibration algorithm is introduced to acquire the intrinsic and extrinsic parameters of CCD cameras, and the DIC method is combined with Zhang’s calibration algorithm to measure bridge deflection. The comparative test between Zhang’s calibration and scale calibration is conducted in lab, and experimental results indicate that the proposed method has higher precision. According to the deflection monitoring scheme, the deflection monitoring software for Songjiazhuang cloverleaf junction is developed by MATLAB, and a 4-channel CCD deflection monitoring system for Songjiazhuang cloverleaf junction is integrated in this paper. This deflection monitoring system includes functions such as image preview, simultaneous collection, camera calibration, deflection display, and data storage. In situ deflection curves show a consistent trend; this suggests that the proposed method is reliable and is suitable for the long-term monitoring of bridge deflection.

  12. MIMO scheme performance and detection in epsilon noise

    OpenAIRE

    Stepanov, Sander

    2006-01-01

    New approach for analysis and decoding MIMO signaling is developed for usual model of nongaussion noise consists of background and impulsive noise named epsilon - noise. It is shown that non-gaussion noise performance significantly worse than gaussion ones. Stimulation results strengthen out theory. Robust in statistical sense detection rule is suggested for such kind of noise features much best robust detector performance than detector designed for Gaussian noise in impulsive environment and...

  13. Quasi first-order Hermite Gaussian beam for enhanced sensitivity in Sagnac interferometer photothermal deflection spectroscopy.

    Science.gov (United States)

    Shiokawa, Naoyuki; Tokunaga, Eiji

    2016-05-30

    The detection sensitivity of a Sagnac interferometer photothermal deflection spectroscopy was enhanced by changing the probe beam pattern from zero-order to a quasi-first-order Hermite Gaussian (QHG) beam. The nature of the higher order HG mode, where the beam pattern is preserved during propagation with an increased field gradient, is utilized to enhance the measurement sensitivity. In this spectroscopy, the lateral beam deflection due to the photothermal effect is sensitively detected as a change in the interference light intensity. The change in intensity is amplified due to the higher field gradient of the QHG(1,0) beam at the photodetector. This amplification effect was both numerically and experimentally demonstrated to obtain twofold improvement in the signal-to-noise ratio.

  14. Biased low differential input impedance current receiver/converter device and method for low noise readout from voltage-controlled detectors

    Science.gov (United States)

    Degtiarenko, Pavel V.; Popov, Vladimir E.

    2011-03-22

    A first stage electronic system for receiving charge or current from voltage-controlled sensors or detectors that includes a low input impedance current receiver/converter device (for example, a transimpedance amplifier), which is directly coupled to the sensor output, a source of bias voltage, and the device's power supply (or supplies), which use the biased voltage point as a baseline.

  15. Delta: a charge sensitive front-end amplifier with switched gain for low-noise, large dynamic range silicon detector readout

    NARCIS (Netherlands)

    Aspell, P.; Barney, D.; Bloch, P.; Jarron, P.; Lofstedt, B.; Reynaud, S.; Tabbers, P.

    2001-01-01

    The design and results of a radiation hard switched gain charge amplifier optimised for a large dynamic range and large input capacitance are described. The peaking time is 25 ns, dynamic ranges are 0.1–50 minimum ionising particles (MIPs) (high gain) and 1–400 MIPs (low gain), signal to noise (S/N)

  16. Effects of substrate voltage on noise characteristics and hole lifetime in SOI metal-oxide-semiconductor field-effect transistor photon detector.

    Science.gov (United States)

    Putranto, Dedy Septono Catur; Priambodo, Purnomo Sidi; Hartanto, Djoko; Du, Wei; Satoh, Hiroaki; Ono, Atsushi; Inokawa, Hiroshi

    2014-09-08

    Low-frequency noise and hole lifetime in silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFETs) are analyzed, considering their use in photon detection based on single-hole counting. The noise becomes minimum at around the transition point between front- and back-channel operations when the substrate voltage is varied, and increases largely on both negative and positive sides of the substrate voltage showing peculiar Lorentzian (generation-recombination) noise spectra. Hole lifetime is evaluated by the analysis of drain current histogram at different substrate voltages. It is found that the peaks in the histogram corresponding to the larger number of stored holes become higher as the substrate bias becomes larger. This can be attributed to the prolonged lifetime caused by the higher electric field inside the body of SOI MOSFET. It can be concluded that, once the inversion channel is induced for detection of the photo-generated holes, the small absolute substrate bias is favorable for short lifetime and low noise, leading to high-speed operation.

  17. A Limited Deflection Routing Algorithm Based on Burst Loss Threshold in OBS Networks

    Institute of Scientific and Technical Information of China (English)

    WANG Ru-yan; LONG Ke-ping; WU Wei; YANG Xiao-long; ZHU Wei-le

    2005-01-01

    The deflection routing protocol is an effective contention resolution in Optical Burst Switching network. However, it can worsen loss performance of non-deflected burst on the deflection route. To improve the burst loss performance, a limited deflection routing scheme based on burst loss threshold is proposed to prevent injudicious deflection routing. By using threshold check function, it restrainedly allows the deflected burst to preemptive network resource, consequently, improve the QoS performance of non-deflected burst. Simulation results show that the scheme can efficiently prevent deflected burst contending with non-deflected burst on deflection route, and effectively improve the burst loss performance of entire networks.

  18. Deflections of Nanowires with Consideration of Surface Effects

    Institute of Scientific and Technical Information of China (English)

    LI He; YANG Zhou; ZHANG Yi-Min; WEN Bang-Chun

    2010-01-01

    @@ The elementary beam model is modified to include the surface effects and used to analyze the deflections of nanowires under different boundary conditions.The results show that compared to deflections of nanowires without consideration of surface effects,the surface effects can enlarge or reduce deflections of nanowires,and nanowire buckling occurs under certaJn conditions.This study might be helpful for design of nanowire-based nanoelectromechanical systems.

  19. Noise Analysis of Array Pixellated CZT Detector%CZT像素阵列核探测器的噪声分析

    Institute of Scientific and Technical Information of China (English)

    蒋建; 肖沙里; 蔡欣; 张流强; 陈宇晓; 曹玉琳

    2011-01-01

    碲锌镉(CdZnTe)晶体是一种新型核辐射探测材料,在室温探测环境下对X射线及低能量伽玛射线具有较高的探测效率及能量分辨率.运用低噪声快速前放模块,分析晶体内部性能以及前置放大器对探测系统噪声的影响,建立了2×2碲锌镉像素阵列探测系统.实验结果表明,探测系统输出信号噪声小、脉冲无堆积,读出电路电子学噪声得到明显抑制,能谱低能拖尾减少,电荷收集不完全噪声及漏电流噪声影响得到改善,同时对整个系统以及前置放大器进行了噪声分析并提出相关的改善方式,最后得到系统测试的结果.%As a novel nuclear radiation material, CdZnTe has many advantages of high effi ciency detection and good energy resolution for detection of x-ray and low energy gamma-ray in room temperature. The inner crystal property and effects of preamplifier on the noise is analyzed using low noise preamplifier module, while a 2× 2 array pixellated detection system is built. The results show a low noise of output signal and no pulse stack. The circuit electronic noise is obvi ously restrained. Trails of low power of energy spectrum are decreased. Noise analysis and the factors which produced the noise are given; improvement for the system is also discussed, togeth er with the test result.

  20. Deflection of elastic beam with SMA wires eccentrically inserted

    Science.gov (United States)

    Jamian, S.; Nik Mohamed, N. A.; Ihsan, A. K. A. Mohd; Ismail, A. E.; Nor, M. K. Mohd; Kamarudin, K. A.; Nor, N. H. Muhd

    2017-08-01

    This research is intended to investigate the ability of shape memory alloys (SMA), through its activation, in generating loads to control beam deflection. An elastic beam is formed by sandwiching eccentrically SMA wires between two elastic plates. SMA wires are activated by electrical current from the power supply. Laser displacement meter (LDM) is used to measures deflection of sample. Results show that the deflection of the beam is dependent on the temperature change. The temperature-deflection response also shows the existence of hysteresis.

  1. Photon deflection by a Coulomb field in noncommutative QED

    Energy Technology Data Exchange (ETDEWEB)

    Pires, C A de S [Departamento de FIsica, Universidade Federal da ParaIba, Caixa Postal 5008, 58059-970, Joao Pessoa, PB (Brazil)

    2004-12-01

    In noncommutative QED photons present self-interactions in the form of triple and quartic interactions. The triple interaction implies that, even though the photon is electrically neutral, it will deflect when in the presence of an electromagnetic field. If detected, such deflection would be undoubted evidence of noncommutative space-time. In this work we derive a general expression for the deflection of a photon by any electromagnetic field. As an application we consider the case of the deflection of a photon by an external static Coulomb field. (brief report)

  2. Photon deflection by a Coulomb field in noncommutative QED

    CERN Document Server

    De Pires, C A S

    2004-01-01

    In noncommutative QED photons present self-interactions in the form of triple and quartic interactions. The triple interaction implies that, even though the photon is electrically neutral, it will deflect when in the presence of an electromagnetic field. If detected, such deflection would be an undoubted signal of noncommutative space-time. In this work we derive the general expression for the deflection of a photon by any electromagnetic field. As an application we consider the case of the deflection of a photon by an external static Coulomb field.

  3. Development of a low-noise, 4th-order readout ASIC for CdZnTe detectors in gamma spectrometer applications

    Science.gov (United States)

    Wang, Jia; Su, Lin; Wei, Xiaomin; Zheng, Ran; Hu, Yann

    2016-09-01

    This paper presents an ASIC readout circuit development, which aims to achieve low noise. In order to compensate the leakage current and improve gain, a dual-stage CSA has been utilized. A 4th-order high-linearity shaper is proposed to obtain a Semi-Gaussian wave and further decrease the noise induced by the leakage current. The ASIC has been designed and fabricated in a standard commercial 2P4M 0.35 μm CMOS process. Die area of one channel is about 1190 μm×147 μm. The input charge range is 1.8 fC. The peaking time can be adjusted from 1 μs to 3 μs. Measured ENC is about 55e- (rms) at input capacitor of 0 F. The gain is 271 mV/fC at the peaking time of 1 μs.

  4. Directed Energy Deflection Laboratory Measurements of Asteroids and Space Debris

    Science.gov (United States)

    Brashears, T.; Lubin, P. M.

    2016-12-01

    We report on laboratory studies of the effectiveness of directed energy planetary and space defense as a part of the DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR [1][5][6] and DE-STARLITE [2][5][6] are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid [1][2][3][4][5][6]. In the DE-STAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds an "asteroid" or a space debris sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 µN/Woptical, though we assume a more conservative value of 80 µN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 µN/Woptical in our deflection modeling. Our measurements discussed here yield about 60 µN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed.

  5. Directed energy deflection laboratory measurements of common space based targets

    Science.gov (United States)

    Brashears, Travis; Lubin, Philip; Hughes, Gary B.; Meinhold, Peter; Batliner, Payton; Motta, Caio; Madajian, Jonathan; Mercer, Whitaker; Knowles, Patrick

    2016-09-01

    We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR and DE-STARLITE are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid. In the DESTAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds a common space target sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 , which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed. Results vary depending on the material tested and are limited to measurements of 1 axis, so

  6. Teach Deflection Concepts with Hacksaw Blades and Rubber Bands

    Science.gov (United States)

    Roman, Harry T.

    2013-01-01

    Technology and engineering educators can use a simple hacksaw blade to help students learn about deflection, as that which occurs in a beam. Here the beam is fixed at one end and allowed to deflect in a manner that is easy to see and measure--the hacksaw blade represents a cantilever, an overhanging structure. This simple and very inexpensive…

  7. High Sensitivity deflection detection of nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Sanii, Babak; Ashby, Paul

    2009-10-28

    A critical limitation of nanoelectromechanical systems (NEMS) is the lack of a high-sensitivity position detection mechanism. We introduce a noninterferometric optical approach to determine the position of nanowires with a high sensitivity and bandwidth. Its physical origins and limitations are determined by Mie scattering analysis. This enables a dramatic miniaturization of detectable cantilevers, with attendant reductions to the fundamental minimum force noise in highly damping environments. We measure the force noise of an 81{+-}9??nm radius Ag{sub 2}Ga nanowire cantilever in water at 6{+-}3??fN/{radical}Hz.

  8. Detectors for Tomorrow's Instruments

    Science.gov (United States)

    Moseley, Harvey

    2009-01-01

    Cryogenically cooled superconducting detectors have become essential tools for a wide range of measurement applications, ranging from quantum limited heterodyne detection in the millimeter range to direct searches for dark matter with superconducting phonon detectors operating at 20 mK. Superconducting detectors have several fundamental and practical advantages which have resulted in their rapid adoption by experimenters. Their excellent performance arises in part from reductions in noise resulting from their low operating temperatures, but unique superconducting properties provide a wide range of mechanisms for detection. For example, the steep dependence of resistance with temperature on the superconductor/normal transition provides a sensitive thermometer for calorimetric and bolometric applications. Parametric changes in the properties of superconducting resonators provides a mechanism for high sensitivity detection of submillimeter photons. From a practical point of view, the use of superconducting detectors has grown rapidly because many of these devices couple well to SQUID amplifiers, which are easily integrated with the detectors. These SQUID-based amplifiers and multiplexers have matured with the detectors; they are convenient to use, and have excellent noise performance. The first generation of fully integrated large scale superconducting detection systems are now being deployed. I will discuss the prospects for a new generation of instruments designed to take full advantage of the revolution in detector technology.

  9. Feasible Dose Reduction in Routine Chest Computed Tomography Maintaining Constant Image Quality Using the Last Three Scanner Generations: From Filtered Back Projection to Sinogram-affirmed Iterative Reconstruction and Impact of the Novel Fully Integrated Detector Design Minimizing Electronic Noise

    Directory of Open Access Journals (Sweden)

    Lukas Ebner

    2014-01-01

    Full Text Available Objective:The aim of the present study was to evaluate a dose reduction in contrast-enhanced chest computed tomography (CT by comparing the three latest generations of Siemens CT scanners used in clinical practice. We analyzed the amount of radiation used with filtered back projection (FBP and an iterative reconstruction (IR algorithm to yield the same image quality. Furthermore, the influence on the radiation dose of the most recent integrated circuit detector (ICD; Stellar detector, Siemens Healthcare, Erlangen, Germany was investigated. Materials and Methods: 136 Patients were included. Scan parameters were set to a thorax routine: SOMATOM Sensation 64 (FBP, SOMATOM Definition Flash (IR, and SOMATOM Definition Edge (ICD and IR. Tube current was set constantly to the reference level of 100 mA automated tube current modulation using reference milliamperes. Care kV was used on the Flash and Edge scanner, while tube potential was individually selected between 100 and 140 kVp by the medical technologists at the SOMATOM Sensation. Quality assessment was performed on soft-tissue kernel reconstruction. Dose was represented by the dose length product. Results: Dose-length product (DLP with FBP for the average chest CT was 308 mGycm ± 99.6. In contrast, the DLP for the chest CT with IR algorithm was 196.8 mGycm ± 68.8 (P = 0.0001. Further decline in dose can be noted with IR and the ICD: DLP: 166.4 mGycm ± 54.5 (P = 0.033. The dose reduction compared to FBP was 36.1% with IR and 45.6% with IR/ICD. Signal-to-noise ratio (SNR was favorable in the aorta, bone, and soft tissue for IR/ICD in combination compared to FBP (the P values ranged from 0.003 to 0.048. Overall contrast-to-noise ratio (CNR improved with declining DLP. Conclusion: The most recent technical developments, namely IR in combination with integrated circuit detectors, can significantly lower radiation dose in chest CT examinations.

  10. A low noise all-fiber interferometer for high resolution frequency modulated atomic force microscopy imaging in liquids.

    Science.gov (United States)

    Rasool, Haider I; Wilkinson, Paul R; Stieg, Adam Z; Gimzewski, James K

    2010-02-01

    We have developed a low noise all-fiber interferometer for use as the deflection sensor in liquid environment frequency modulated atomic force microscopy (FM-AFM). A detailed description and rationale for the choice of the critical components are provided along with the design of a simple alignment assembly. The optimization of the deflection sensor toward achieving the highest possible sensitivity and lowest deflection noise density is discussed in the context of an ideal interference cavity. Based on the provided analysis we have achieved deflection noise densities of 2 fm/square root(Hz) on commercially available cantilevers in both ambient and liquid environments. The low noise interferometer works without the need for differential detection, special focusing lenses, or polarization sensitive optics, dramatically simplifying measurements. True atomic resolution imaging of muscovite mica by FM-AFM in water is demonstrated using the developed deflection sensor.

  11. Study on the causes and methods of influencing concrete deflection

    Science.gov (United States)

    Zhou, Ying; Zhou, Xiang; Tang, Jinyu

    2017-09-01

    Under the long-term effect of static load on reinforced concrete beam, the stiffness decreases and the deformation increases with time. Therefore, the calculation of deflection is more complicated. According to the domestic and foreign research results by experiment the flexural deflection of reinforced concrete, creep, age, the thickness of the protective layer, the relative slip, the combination of steel yielding factors of reinforced concrete deflection are summarized, analyzed the advantages and disadvantages of the traditional direct measurement of deflection, that by increasing the beam height, increasing the moment of inertia, ncrease prestressed reinforcement ratio, arching, reduce the load, and other measures to reduce the deflection of prestressed construction, improve the reliability of structure.

  12. Impacts of Deflection Nose on Ballistic Trajectory Control Law

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2014-01-01

    Full Text Available The deflection of projectile nose is aimed at changing the motion of the projectile in flight with the theory of motion control and changing the exterior ballistics so as to change its range and increase its accuracy. The law of external ballistics with the deflectable nose is considered as the basis of the design of a flight control system and an important part in the process of projectile development. Based on the existing rigid external ballistic model, this paper establishes an external ballistic calculation model for deflectable nose projectile and further establishes the solving programs accordingly. Different angle of attack, velocity, coefficients of lift, resistance, and moment under the deflection can be obtained in this paper based on the previous experiments and emulation researches. In the end, the author pointed out the laws on the impaction of external ballistic trajectory by the deflection of nose of the missile.

  13. Modeling and Simulating Dynamics of Missiles with Deflectable Nose Control

    Institute of Scientific and Technical Information of China (English)

    Gao Yuan; Gu Liangxian; Pan Lei

    2009-01-01

    This article investigates the dynamic characteristics of deflectable nose missiles with rotary single-channel control. After introduction of effective attack and sideslip angles as well as quasi-body coordinates based on the spin characteristics of the missile's body, an integrated rigid kinetic model of missile with deflectable nose control is set up in the quasi-body coordinates considering the interaction between the missile's nose and body by using rootless multi-rigid-body system dynamics and is linearized. Then an analysis with simulation is conducted to investigate the coupling characteristics between the channels, the influences of nose deflection on the body and the dynamic characteristics of missile's body. The results indicate that various channels of missiles with deflectable nose control are coupled cross-linked; the nose deflection tends to make the body move in the opposite direction and, finally, evidences the correctness and reasonability of the kinetic model proposed by this article.

  14. AIDA: the Asteroid Impact & Deflection Assessment mission

    Science.gov (United States)

    Vincent, Jean-Baptiste

    2016-07-01

    The Asteroid Impact & Deflection Assessment (AIDA) mission is a joint cooperation between European and US space agencies that consists of two separate and independent spacecraft that will be launched to a binary asteroid system, the near-Earth asteroid Didymos, to assess the possibility of deflecting an asteroid trajectory by using a kinetic impactor. The European Asteroid Impact Mission (AIM) is under Phase A/B1 study at ESA from March 2015 until summer 2016. AIM is set to rendez-vous with the asteroid system a few months prior to the impact by the US Double Asteroid Redirection Test (DART) spacecraft to fully characterize the smaller of the two binary components. AIM is a unique mission as it will be the first time that a spacecraft will investigate the surface, subsurface, and internal properties of a small binary near Earth asteroid. In addition it will perform various important technology demonstrations that can serve other space missions: AIM will release a set of CubeSats in deep space and a lander on the surface of the smaller asteroid and for the first time, deep-space inter-satellite linking will be demonstrated between the main spacecraft, the CubeSats, and the lander, and data will also be transmitted from interplanetary space to Earth by a laser communication system. The knowledge obtained by this mission will have great implications for our understanding of the history of the Solar System. Small asteroids are believed to result from collisions and other processes (e.g., spinup, shaking) that made them what they are now. Having direct information on their surface and internal properties will allow us to understand how these processes work and transform these small bodies as well as, for this particular case, how a binary system forms. So far, our understanding of the collisional process and the validation of numerical simulations of the impact process rely on impact experiments at laboratory scales. With DART, thanks to the characterization of the

  15. Load Deflection Characteristics of Nickel Titanium Initial Archwires

    Directory of Open Access Journals (Sweden)

    Hossein Aghili

    2016-05-01

    Full Text Available Objectives: The aim of this study was to assess and compare the characteristics of commonly used initial archwires by their load deflection graphs.Materials and Methods: This study tested three wire designs namely copper nickel titanium (CNT, nickel titanium (NiTi, and multi-strand NiTi (MSNT archwires engaged in passive self-ligating (PSL brackets, active self-ligating (ASL brackets or conventional brackets. To evaluate the mechanical characteristics of the specimens, a three-point bending test was performed. The testing machine vertically applied force on the midpoint of the wire between the central incisor and canine teeth to obtain 2 and 4mm of deflection. The force level at maximum deflection and characteristics of plateau (the average plateau load and the plateau length were recorded. Two-way ANOVA and Tukey’s test were used at P <0.05 level of significance.Results: Force level at maximum deflection and plateau length were significantly affected by the amount of deflection. The type of archwires and brackets had significant effects on force level at maximum deflection, and plateau length. However, the bracket type had no significant effect on the average plateau force.Conclusion: With any type of brackets in deflections of 2 and 4mm, MSNT wire exerted the lowest while NiTi wire exerted the highest force level at maximum deflection and plateau phase. The force level at maximum deflection and the plateau length increased with raising the amount of primary deflection; however the average plateau force did not change significantly.

  16. The DEPFET Mini-matrix Particle Detector

    Directory of Open Access Journals (Sweden)

    J. Scheirich

    2010-01-01

    Full Text Available The DEPFET is new type of active pixel particle detector. A MOSFET is integrated in each pixel, providing the first amplification stage of the readout electronics. Excellent noise parameters are obtained with this layout. The DEPFET detector will be integrated as an inner detector in the BELLE II and ILC experiment. A flexible measuring system with a wide control cycle range and minimal noise was designed for testing small detector prototypes.Noise of 60 electrons of the equivalent input charge was achieved during the first measurements on the system.

  17. High-responsivity, low-noise, room-temperature, self-mixing terahertz detector realized using floating antennas on a GaN-based field-effect transistor

    Science.gov (United States)

    Sun, J. D.; Sun, Y. F.; Wu, D. M.; Cai, Y.; Qin, H.; Zhang, B. S.

    2012-01-01

    Using only optical lithography, we have fabricated a GaN/AlGaN high-electron mobility transistor with distinctive source and drain antennas electrically isolated from the electron channel. Working at room temperature, it efficiently detects terahertz radiation via self-mixing, with a responsivity (3.6 kV/W) exceptionally high for a III-V device and with a noise (40pW/√Hz ) just above the thermal limit. Performance improves at 77 K. While the device itself is micrometer-sized, our modeling indicates the asymmetric antennas induce a rather localized (<200 nm) region of strong self-mixing. Thus, a nanometer-scale active region is achieved by design and without recourse to electron-beam lithography.

  18. Coupler induced monopole component and its minimization in deflecting cavities

    Directory of Open Access Journals (Sweden)

    P. K. Ambattu

    2013-06-01

    Full Text Available Deflecting cavities are used in particle accelerators for the manipulation of charged particles by deflecting or crabbing (rotating them. For short deflectors, the effect of the power coupler on the deflecting field can become significant. The particular power coupler type can introduce multipole rf field components and coupler-specific wakefields. Coupler types that would normally be considered like standard on-cell coupler, waveguide coupler, or mode-launcher coupler could have one or two rf feeds. The major advantage of a dual-feed coupler is the absence of monopole and quadrupole rf field components in the deflecting structure. However, a dual-feed coupler is mechanically more complex than a typical single-feed coupler and needs a splitter. For most applications, deflecting structures are placed in regions where there is small space hence reducing the size of the structure is very desirable. This paper investigates the multipole field components of the deflecting mode in single-feed couplers and ways to overcome the effect of the monopole component on the beam. Significant advances in performance have been demonstrated. Additionally, a novel coupler design is introduced which has no monopole field component to the deflecting mode and is more compact than the conventional dual-feed coupler.

  19. Heavy colored SUSY partners from deflected anomaly mediation

    CERN Document Server

    Wang, Fei; Yang, Jin Min; Zhang, Yang

    2015-01-01

    We propose a deflected anomaly mediation scenario from SUSY QCD which can lead to both positive and negative deflection parameters (there is a smooth transition between these two deflection parameter regions by adjusting certain couplings). Such a scenario can naturally give a SUSY spectrum in which all the colored sparticles are heavy while the sleptons are light. As a result, the discrepancy between the Brookheaven $g_\\mu-2$ experiment and LHC data can be reconciled in this scenario. We also find that the parameter space for explaining the $g_\\mu-2$ anomaly at $1\\sigma$ level can be fully covered by the future LUX-ZEPLIN 7.2 Ton experiment.

  20. Simulations of directed energy comet deflection

    Science.gov (United States)

    Zhang, Qicheng; Lubin, Philip M.; Hughes, Gary B.

    2016-09-01

    Earth-crossing asteroids and comets pose a long-term hazard to life and property on Earth. Schemes to mitigate the impact threat have been studied extensively but tend to focus on asteroid diversion while neglecting the possibility of a comet threat. Such schemes often demand physically intercepting the target by spacecraft, a task feasible only for targets identified decades in advance in a restricted range of orbits. A threatening comet is unlikely to satisfy these criteria and so necessitates a fundamentally different approach for diversion. Comets are naturally perturbed from purely gravitational trajectories through solar heating of their surfaces which activates sublimation-driven jets. Artificial heating of a comet, such as by a high-powered laser array in Earth orbit, may supplement natural heating by the Sun to purposefully manipulate its path to avoid an impact. The effectiveness of any particular laser array for a given comet depends on the comet's heating response which varies dramatically depending on factors including nucleus size, orbit and dynamical history. These factors are incorporated into a numerical orbital model using established models of nongravitational perturbations to evaluate the effectiveness and feasibility of using high-powered laser arrays in Earth orbit or on the ground to deflect a variety of comets. Simulation results suggest that orbital arrays of 500m and 10GW operating for 10 min=d over 1 yr may be adequate for mitigating impacts by comets up to 500m in diameter. Continuously operating ground-based arrays of 100m and 10GW may be similarly effective when appropriately located.

  1. Geoid Height and Deflection of the Vertical Models

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of the National Geodetic Survey has produced a series of high-resolution gravimetric geoid models, hybrid geoid models, and associated deflection of the...

  2. Deflection measurements of LABAN canister sections in horizontal attitude

    Energy Technology Data Exchange (ETDEWEB)

    Wakeman, W.

    1985-01-08

    Deflection measurements made on the LABAN canister sections indicate that the apparent stiffness of its frames, with all the diagnostics experiments installed, is not significantly different from the stiffness of the bare frames.

  3. U.S. East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for the conterminous United States is the DEFLEC96 model. The computationused about 1.8 million terrestrial and...

  4. U.S. North-South Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for the conterminous United States is the DEFLEC96 model. The computationused about 1.8 million terrestrial and...

  5. Hawaiian Islands North-South Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for the Principal Hawaiian Islands is the DEFLEC96 model. The computation used about 61,000 terrestrial and marine...

  6. Hawaiian Islands East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for the Principal Hawaiian Islands is the DEFLEC96 model. The computation used about 61,000 terrestrial and marine...

  7. PR/VI North-South Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for Puerto Rico and the Virgin Islands is distributed as the DEFLEC96 model. The computation used about 26,000...

  8. Possible influences on bullet trajectory deflection in ballistic gelatine.

    Science.gov (United States)

    Riva, Fabiano; Kerkhoff, Wim; Bolck, Annabel; Mattijssen, Erwin J A T

    2017-02-01

    The influence of the distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots on a bullet's trajectory, when passing through ballistic gelatine, was studied. No significant difference in deflection was found when trajectories of 9mm Luger bullets, fired at a 3.5cm distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots, were compared to trajectories of bullets fired 7cm or more away from any of the aforementioned aspects. A surprisingly consistent 6.5° absolute deflection angle was found when these bullets passed through 22.5 to 23.5cm of ballistic gelatine. The projection angle, determined by the direction of the deflection, appeared to be random. The consistent absolute angle, in combination with the random projection angle, resulted in a cone-like deflection pattern.

  9. PR/VI East-West Deflections (DEFLEC96)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 2' surface deflection of the vertical grid for Puerto Rico and the Virgin Islands is distributed as the DEFLEC96 model. The computation used about 26,000...

  10. 75 FR 12981 - Eligibility for Commercial Flats Failing Deflection

    Science.gov (United States)

    2010-03-18

    ... and June 2010. Retain current deflection standards for six more months and enlist the assistance of a Lean Six-Sigma group. Response to Comments The prices proposed in our December 2009 proposal...

  11. GRAVITY detector systems

    Science.gov (United States)

    Mehrgan, Leander H.; Finger, Gert; Eisenhauer, Frank; Panduro, Johana

    2016-08-01

    GRAVITY is a second generation instrument for the VLT Interferometer, designed for high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the K-band. It will combine the AO corrected beams of the four VLT telescopes. In total, the GRAVITY instrument uses five eAPD detectors four for the infrared wavefront sensors of each telescope and one for the fringe tracker. In addition two Hawaii2RG arrays are installed, one for the acquisition camera and one for the spectrometer. The SAPHIRA eAPD array is a newly developed near-infrared detector with sub-electron noise performance at frame rates > 1Kfps. For all seven detectors the ESO common controller, NGC, is used. This paper presents an overview and comparison of GRAVITY detector systems and their final performances at the telescope

  12. Deflection and Rotation of CMEs from Active Region 11158

    Science.gov (United States)

    Kay, Christina; Gopalswamy, Nat; Xie, Hong; Yashiro, Seiji

    2017-06-01

    Between 13 and 16 February 2011, a series of coronal mass ejections (CMEs) erupted from multiple polarity inversion lines within active region 11158. For seven of these CMEs we employ the graduated cylindrical shell (GCS) flux rope model to determine the CME trajectory using both Solar Terrestrial Relations Observatory (STEREO) extreme ultraviolet (EUV) and coronagraph images. We then use the model called Forecasting a CME's Altered Trajectory (ForeCAT) for nonradial CME dynamics driven by magnetic forces to simulate the deflection and rotation of the seven CMEs. We find good agreement between ForeCAT results and reconstructed CME positions and orientations. The CME deflections range in magnitude between 10^{circ } and 30^{circ}. All CMEs are deflected to the north, but we find variations in the direction of the longitudinal deflection. The rotations range between 5^{circ} and 50^{circ} with both clockwise and counterclockwise rotations. Three of the CMEs begin with initial positions within 2^{circ} from one another. These three CMEs are all deflected primarily northward, with some minor eastward deflection, and rotate counterclockwise. Their final positions and orientations, however, differ by 20^{circ} and 30^{circ}, respectively. This variation in deflection and rotation results from differences in the CME expansion and radial propagation close to the Sun, as well as from the CME mass. Ultimately, only one of these seven CMEs yielded discernible in situ signatures near Earth, although the active region faced toward Earth throughout the eruptions. We suggest that the differences in the deflection and rotation of the CMEs can explain whether each CME impacted or missed Earth.

  13. NOISE AND SENSITIVITY IN POLYSILICON PIEZORESISTIVE CANTILEVERS*

    Institute of Scientific and Technical Information of China (English)

    于晓梅; 江兴流; J.THAYSEN; O.HANSEN; A.BOISEN

    2001-01-01

    Piezoresistive cantilevers with dimensions of 200 × 50 × 1.8μm3 have been fabricated from polycrystalline silicon using reactive ion etching (RIE) and back etching processes. Full Wheatstone bridges have been designed symmetrically on-chip, with two resistors placed on the cantilevers and two resistors on the substrate. The differential measurements of the two cantilevers can reduce the thermal shift of the signal in the system and the external noise in the laboratory.The characteristics of the fabricated cantilevers have been analysed by measuring the noise and the sensitivity. The measured noise spectra show that the 1/f noise is the dominant noise source at low frequencies. With the linear relation between 1/f noise and bias voltages, the Hooge factor (c) was calculated to be 0.0067. The 1/f noise was explained in terms of a lattice scattering model, which occurs in the depletion region of the grains. The displacement sensitivity of the cantilevers was calculated to be 1× 10-6nm-1 by measuring the resistance change and the vertical deflection of the cantilever. The gauge factor of the piezoresistive cantilever was calculated to be 19. At a 3V bias voltage and 1000 Hz measurement bandwidth, 1 nm of minimum detectable deflection has been obtained.

  14. An aerodynamic noise propagation model for wind turbines

    DEFF Research Database (Denmark)

    Zhu, Wei Jun; Sørensen, Jens Nørkær; Shen, Wen Zhong

    2005-01-01

    A model based on 2-D sound ray theory for aerodynamic noise propagation from wind turbine rotating blades is introduced. The model includes attenuation factors from geometric spreading, sound directivity of source, air absorption, ground deflection and reflection, as well as effects from temperat......A model based on 2-D sound ray theory for aerodynamic noise propagation from wind turbine rotating blades is introduced. The model includes attenuation factors from geometric spreading, sound directivity of source, air absorption, ground deflection and reflection, as well as effects from...

  15. Particlc detectors. Foundations and applications; Teilchendetektoren. Grundlagen und Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Kolanoski, Hermann; Wermes, Norbert

    2016-08-01

    The following topics are dealt with: Interaction of particles with matter, motion of charge carriers in electric and magnetic fields, signal generation by moving charges, non-electronic detectors, gas-filled detectors, semiconductor detectors, track reconstruction and momentum measurement, photodetectors, Cherenkov detectors, transition-radiation detectors, scintillation detectors, particle identification, calorimeters, detection of cosmic particles, signal processing and noise, trigger and data acquisition systems. (HSI)

  16. Deflection load characteristics of laser-welded orthodontic wires.

    Science.gov (United States)

    Watanabe, Etsuko; Stigall, Garrett; Elshahawy, Waleed; Watanabe, Ikuya

    2012-07-01

    To compare the deflection load characteristics of homogeneous and heterogeneous joints made by laser welding using various types of orthodontic wires. Four kinds of straight orthodontic rectangular wires (0.017 inch × 0.025 inch) were used: stainless-steel (SS), cobalt-chromium-nickel (Co-Cr-Ni), beta-titanium alloy (β-Ti), and nickel-titanium (Ni-Ti). Homogeneous and heterogeneous end-to-end joints (12 mm long each) were made by Nd:YAG laser welding. Two types of welding methods were used: two-point welding and four-point welding. Nonwelded wires were also used as a control. Deflection load (N) was measured by conducting the three-point bending test. The data (n  =  5) were statistically analyzed using analysis of variance/Tukey test (P welded specimens showed lower deflection loads compared to corresponding control wires and exhibited higher deflection loads compared to heterogeneously welded combinations. For homogeneous combinations, Co-Cr-Ni/Co-Cr-Ni showed a significantly (P welded groups. In heterogeneous combinations, SS/Co-Cr-Ni and β-Ti/Ni-Ti showed higher deflection loads than those of the remaining heterogeneously welded combinations (significantly higher for SS/Co-Cr-Ni). Significance (P welding method). However, no significant difference in deflection load was found between four-point and two-point welding in each homogeneous or heterogeneous combination. Heterogeneously laser-welded SS/Co-Cr-Ni and β-Ti/Ni-Ti wires provide a deflection load that is comparable to that of homogeneously welded orthodontic wires.

  17. Large deflection analysis of cantilever beam under end point and distributed load

    DEFF Research Database (Denmark)

    Kimiaeifar, Amin; Tolou, N; Barari, Amin;

    2014-01-01

    Although the deflection of beams has been studied for decades, the solutions were either linearized (i.e. small deflection) or based on elliptic integrals or functions (large deflection). The latter one includes the geometric nonlinearity but calculation of the deflection along the beam length re...

  18. Digital detectors for electron microscopy

    CERN Document Server

    Faruqi, A R

    2002-01-01

    Film has traditionally been used for recording images in transmission electron microscopes but there is an essential need for computer-interfaced electronic detectors. Cooled-CCD detectors, developed over the past few years, though not ideal, are increasingly used as the preferred detection system in a number of applications. We describe briefly the design of CCD-based detectors, along with their main properties, which have been used in electron crystallography. A newer detector design with a much bigger sensitive area, incorporating a 2x2 tiled array of CCDs with tapered fibre optics will overcome some of the limitations of existing CCD detectors. We also describe some preliminary results for 8 keV imaging, from (direct detection) silicon hybrid pixel detectors, which offer advantages over CCDs in terms of better spatial resolution, faster readout with minimal noise.

  19. Needle deflection estimation using fusion of electromagnetic trackers.

    Science.gov (United States)

    Sadjadi, H; Hashtrudi-Zaad, K; Fichtinger, G

    2012-01-01

    We present a needle deflection estimation method to compensate for needle bending during insertion into deformable tissue. We combine a kinematic needle deflection estimation model, electromagnetic (EM) trackers, and a Kalman filter (KF). We reduce the impact of error from the needle deflection estimation model by using the fusion of two EM trackers to report the approximate needle tip position in real-time. One reliable EM tracker is installed on the needle base, and estimates the needle tip position using the kinematic needle deflection model. A smaller but much less reliable EM tracker is installed on the needle tip, and estimates the needle tip position through direct noisy measurements. Using a KF, the sensory information from both EM trackers is fused to provide a reliable estimate of the needle tip position with much reduced variance in the estimation error. We then implement this method to compensate for needle deflection during simulated prostate cancer brachytherapy needle insertion. At a typical maximum insertion depth of 15 cm, needle tip mean estimation error was reduced from 2.39 mm to 0.31 mm, which demonstrates the effectiveness of our method, offering a clinically practical solution.

  20. Ultrafast optical beam deflection in a pump probe configuration

    Science.gov (United States)

    Liang, Lingliang; Tian, Jinshou; Wang, Tao; Wu, Shengli; Li, Fuli; Wang, Junfeng; Gao, Guilong

    2016-09-01

    Propagation of a signal beam in an AlGaAs/GaAs waveguide multiple-prism light deflector is theoretically investigated by solving the scalar Helmholtz equation to obtain the dependences of the temporal and spatial resolvable characteristics of the ultrafast deflector on the material dispersion of GaAs including group velocity dispersion and angular dispersion, interface reflection, and interface scattering of multiple-prism deflector. Furthermore, we experimentally confirm that, in this ultrafast beam deflection device, the deflecting angle of the signal light beam is linear with the pump fluence and the temporal resolution of the ultrafast deflection is 10 ps. Our results show that the improvement of the temporal and spatial resolvable performances is possible by properly choosing the structural parameters and enhancing the quality of the device. Project supported by the National Natural Science Foundation of China (Grant Nos. 11274377 and 61176006) and the State Major Research Equipment Project, China (Grant No. ZDY2011-2).

  1. ABRUPT DEFLECTED SUPERCRITICAL WATER FLOW IN SLOPED CHANNELS

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-kun; NI Han-gen

    2008-01-01

    The effect of the bottom slope on abrupt deflected supercritical water flow was experimentally and theoretically studied. Model tests were conducted in a flume of 1.2 m wide and 2.6 m long with sloped bottom at an angle 35.54o, its length of deflector was 0.2 m and the deflection angles were 15o and 30o. An approximate method for calculatjng the shock wave angle and depth ratio of the abrupt deflected supercritical water flow was suggested, and a correction coefficient for the hydrodynamic pressure was introduced to generalize the momentum equation in the direction perpendicular to the shock front. It must be noticed that in the sloped channel the shock wave angle and the depth ratio are no longer constant as those in the horizontal channels, but slowly change along the shock front. The calculated results are in good agreement with measured data.

  2. Linearizing Intra-Train Beam-Beam Deflection Feedback

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.R.; /SLAC

    2006-02-22

    Beam-beam deflection feedback acting within the crossing time of a single bunch train may be needed to keep linear collider beams colliding at high luminosity. In a short-pulse machine such as the Next Linear Collider (NLC) this feedback must converge quickly to be useful. The non-linear nature of beam-beam deflection vs. beam-beam offset in these machines precludes obtaining both rapid convergence and a stable steady-state lock to beam offsets with a linear feedback algorithm. We show that a simply realizable programmable non-linear amplifier in the feedback loop can linearize the feedback loop, approximately compensating the beam-beam deflection non-linearity. Performance of a prototype non-linear amplifier is shown. Improvement of convergence and stability of the beam-beam feedback loop is simulated.

  3. MUON DETECTORS: RPC

    CERN Multimedia

    P. Paolucci

    2011-01-01

    During data-taking in 2010 the RPC system behaviour was very satisfactory for both the detector and trigger performances. Most of the data analyses are now completed and many results and plots have been approved in order to be published in the muon detector paper. A very detailed analysis of the detector efficiency has been performed using 60 million muon events taken with the dedicated RPC monitor stream. The results have shown that the 96.3% of the system was working properly with an average efficiency of 95.4% at 9.35 kV in the Barrel region and 94.9% at 9.55 kV in the Endcap. Cluster size goes from 1.6 to 2.2 showing a clear and well-known correlation with the strip pitch. Average noise in the Barrel is less than 0.4 Hz/cm2 and about 98% of full system has averaged noise less then 1 Hz/cm2. A linear dependence of the noise versus the luminosity has been preliminary observed and is now under study. Detailed chamber efficiency maps have shown a few percent of chambers with a non-uniform efficiency distribu...

  4. Novel deflecting cavity design for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q.; Belomestnykh, S.; Ben-Zvi, I.

    2011-07-25

    To prevent significant loss of the luminosity due to large crossing angle in the future ERL based Electron Ion Collider at BNL (eRHIC), there is a demand for crab cavities. In this article, we will present a novel design of the deflecting/crabbing 181 MHz superconducting RF cavity that will fulfil the requirements of eRHIC. The quarter-wave resonator structure of the new cavity possesses many advantages, such as compact size, high R{sub t}/Q, the absence of the same order mode and lower order mode, and easy higher order mode damping. We will present the properties and characteristics of the new cavity in detail. As the accelerator systems grow in complexity, developing compact and efficient deflecting cavities is of great interest. Such cavities will benefit situations where the beam line space is limited. The future linac-ring type electron-ion collider requires implementation of a crab-crossing scheme for both beams at the interaction region. The ion beam has a long bunches and high rigidity. Therefore, it requires a low frequency, large kicking angle deflector. The frequency of the deflecting mode for the current collider design is 181 MHz, and the deflecting angle is {approx}5 mrad for each beam. At such low frequency, the previous designs of the crab cavities will have very large dimensions, and also will be confronted by typical problems of damping the Lower Order Mode (LOM), the Same Order Mode (SOM), and as usual, the Higher Order Modes (HOM). In this paper we describe how one can use the concept of a quarter-wave (QW) resonator for a deflecting/crabbing cavity, and use its fundamental mode to deflect the beam. The simplicity of the cavity geometry and the large separation between its fundamental mode and the first HOM make it very attractive.

  5. Cryogenic Tracking Detectors

    CERN Multimedia

    Luukka, P R; Tuominen, E M; Mikuz, M

    2002-01-01

    The recent advances in Si and diamond detector technology give hope of a simple solution to the radiation hardness problem for vertex trackers at the LHC. In particular, we have recently demonstrated that operating a heavily irradiated Si detector at liquid nitrogen (LN$_2$) temperature results in significant recovery of Charge Collection Efficiency (CCE). Among other potential benefits of operation at cryogenic temperatures are the use of large low-resistivity wafers, simple processing, higher and faster electrical signal because of higher mobility and drift velocity of carriers, and lower noise of the readout circuit. A substantial reduction in sensor cost could result The first goal of the approved extension of the RD39 program is to demonstrate that irradiation at low temperature in situ during operation does not affect the results obtained so far by cooling detectors which were irradiated at room temperature. In particular we shall concentrate on processes and materials that could significantly reduce th...

  6. Two-mode polarized traveling wave deflecting structure

    Institute of Scientific and Technical Information of China (English)

    谭建豪; 顾强; 方文程; 童德春; 赵振堂

    2015-01-01

    In this paper, we propose a two-mode polarizable deflecting structure, as a new concept for bunch measure-ment and beam control. With two modes of HEM11 and HEM12 operating in the same structure on horizontal and vertical directions, respectively, the operation status can be switched between the two polarization modes. They can be operated simultaneously with two independent input power sources. With two-mode deflecting structure, the bunch distortion caused by the geometric wake-fields in the accelerating structure can be mea-sured by one structure.

  7. Nuclear cycler: An incremental approach to the deflection of asteroids

    Science.gov (United States)

    Vasile, Massimiliano; Thiry, Nicolas

    2016-04-01

    This paper introduces a novel deflection approach based on nuclear explosions: the nuclear cycler. The idea is to combine the effectiveness of nuclear explosions with the controllability and redundancy offered by slow push methods within an incremental deflection strategy. The paper will present an extended model for single nuclear stand-off explosions in the proximity of elongated ellipsoidal asteroids, and a family of natural formation orbits that allows the spacecraft to deploy multiple bombs while being shielded by the asteroid during the detonation.

  8. Research on network failure handling technology based on deflection routing

    Institute of Scientific and Technical Information of China (English)

    Tao YU; Shanzhi CHEN; Xin LI; Zhen QIN

    2008-01-01

    A new deflection routing scheme is proposed to overcome the drawback of existing deflection routing scheme that cannot handle node failure and suffer from routing loops.A new algorithm for computing the backup shortest path tree(SPT)is proposed and a set of procedures are defined for utilizing the backup SPT in case of node or link failure.The failure can be handled swiftly and the backup routes are guaranteed to be loop-free.Experimental results show that the backup routes calculated by proposed scheme are close to the optimal routes by totally re-computing.

  9. The 1919 measurement of the deflection of light

    CERN Document Server

    Will, Clifford M

    2014-01-01

    The measurement of the deflection of starlight during a total solar eclipse on May 29, 1919 was the first verification of general relativity by an external team of scientists, brought Einstein and his theory to the attention of the general public, and left a legacy of experimental testing that continues today. The discovery of gravitational lenses turned Einstein's deflection into an important tool for astronomy and cosmology. This article reviews the history of the 1919 measurement and other eclipse measurements, describes modern measurements of the effect using radio astronomy, and of its cousin, the Shapiro time delay, and discusses gravitational lenses.

  10. An Application of Two Experimental Modal Analysis Methods for the Determination of Operational Deflection Shapes

    Science.gov (United States)

    Kromulski, J.; Hojan, E.

    1996-10-01

    Two methods are presented for the determination of operational deflection shapes (ODSs). The first method allows one to determine the ODSs by measuring mechanical vibrations at test points of the operating machine (created by the forces occurring in the actual work cycle). The second method is based on the modal model of the machine, including the forces which occur in the operation process, and yields the operational modes of vibration. The forces introduced into the model are determined by methods of pseudo-inversion of the matrix of the spectral transmissibility functions of the mechanical system and the vector of operating vibrations. The determination of the forces involved is necessary for the definition of the paths of energy transfer and the analysis of the noise emitted by the mechanical system (machine).

  11. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  12. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  13. The effect of asteroid topography on surface ablation deflection

    Science.gov (United States)

    McMahon, Jay W.; Scheeres, Daniel J.

    2017-02-01

    Ablation techniques for deflecting hazardous asteroids deposit energy into the asteroid's surface, causing an effective thrust on the asteroid as the ablating material leaves normal to the surface. Although it has long been recognized that surface topography plays an important role in determining the deflection capabilities, most studies to date have ignored this aspect of the model. This paper focuses on understanding the topography for real asteroid shapes, and how this topography can change the deflection performance of an ablation technique. The near Earth asteroids Golevka, Bennu, and Itokawa are used as the basis for this study, as all three have high-resolution shape models available. This paper shows that naive targeting of an ablation method without accounting for the surface topography can lower the deflection performance by up to 20% in the cases studied in terms of the amount of acceleration applied in the desired direction. If the ablation thrust level is assumed to be 100 N, as used elsewhere in the literature, this misapplication of thrust translates to tens of kilometers per year in decreased semimajor axis change. However, if the ablation method can freely target any visible point on the surface of the asteroid, almost all of this performance can be recovered.

  14. Deflection of Light by Gravity: A Physical Approach.

    Science.gov (United States)

    Diamond, Joshua B.

    1982-01-01

    Einstein's equivalence principle relates effects seen by an accelerating observer to those experienced by an observer in a gravitational field, providing an explanation of bending of a light beam by gravity. Because the calculations lead to results one-half the value found experimentally, obtaining the correct light deflection is discussed.…

  15. On guided versus deflected fields in controlled-source electromagnetics

    Science.gov (United States)

    Swidinsky, Andrei

    2015-06-01

    The detection of electrically resistive targets in applied geophysics is of interest to the hydrocarbon, mining and geotechnical industries. Elongated thin resistive bodies have been extensively studied in the context of offshore hydrocarbon exploration. Such targets guide electromagnetic fields in a process which superficially resembles seismic refraction. On the other hand, compact resistive bodies deflect current in a process which has more similarities to diffraction and scattering. The response of a real geological structure is a non-trivial combination of these elements-guiding along the target and deflection around its edges. In this note the electromagnetic responses of two end-member models are compared: a resistive layer, which guides the electromagnetic signal, and a resistive cylinder, which deflects the fields. Results show that the response of a finite resistive target tends to saturate at a much lower resistivity than a resistive layer, under identical survey configurations. Furthermore, while the guided electromagnetic fields generated by a buried resistive layer contain both anomalous horizontal and vertical components, the process of electromagnetic deflection from a buried resistive cylinder creates mainly anomalous vertical fields. Finally, the transmitter orientation with respect to the position of a finite body is an important survey parameter: when the distance to the target is much less than the host skin depth, a transmitter pointing towards the resistive cylinder will produce a stronger signal than a transmitter oriented azimuthally with respect to the cylinder surface. The opposite situation is observed when the distance to the target is greater than the host skin depth.

  16. Mission Design and Optimal Asteroid Deflection for Planetary Defense

    Science.gov (United States)

    Sarli, Bruno V.; Knittel, Jeremy M.; Englander, Jacob A.; Barbee, Brent W.

    2017-01-01

    Planetary defense is a topic of increasing interest for many reasons, which has been mentioned in "Vision and Voyages for Planetary Science in the Decade 2013-2022''. However, perhaps one of the most significant rationales for asteroid studies is the number of close approaches that have been documented recently. A space mission with a planetary defense objective aims to deflect the threatening body as far as possible from Earth. The design of a mission that optimally deflects an asteroid has different challenges: speed, precision, and system trade-off. This work addresses such issues and develops a fast transcription of the problem that can be implemented into an optimization tool, which allows for a broader trade study of different mission concepts with a medium fidelity. Such work is suitable for a mission?s preliminary study. It is shown, using the fictitious asteroid impact scenario 2017 PDC, that the complete tool is able to account for the orbit sensitivity to small perturbations and quickly optimize a deflection trajectory. The speed in which the tool operates allows for a trade study between the available hardware. As a result, key deflection dates and mission strategies are identified for the 2017 PDC.

  17. Mission Design and Optimal Asteroid Deflection for Planetary Defense

    Science.gov (United States)

    Sarli, Bruno V.; Knittel, Jeremy M.; Englander, Jacob A.; Barbee, Brent W.

    2017-01-01

    Planetary defense is a topic of increasing interest for many reasons, which has been mentioned in "Vision and Voyages for Planetary Science in the Decade 2013-2022". However, perhaps one of the most significant rationales for asteroid studies is the number of close approaches that have been documented recently. A space mission with a planetary defense objective aims to deflect the threatening body as far as possible from Earth. The design of a mission that optimally deflects an asteroid has different challenges: speed, precision, and system trade-off. This work addresses such issues and develops a fast transcription of the problem that can be implemented into an optimization tool, which allows for a broader trade study of different mission concepts with a medium fidelity. Such work is suitable for a mission's preliminary study. It is shown, using the fictitious asteroid impact scenario 2017 PDC, that the complete tool is able to account for the orbit sensitivity to small perturbations and quickly optimize a deflection trajectory. The speed in which the tool operates allows for a trade study between the available hardware. As a result, key deflection dates and mission strategies are identified for the 2017 PDC.

  18. Large deflection analysis of skew plates under uniformly distributed ...

    African Journals Online (AJOL)

    user

    load-deflection plane to show the effect of skew angle, aspect ratio and boundary condition. ... by edge 1, 2, 3 and 4 on the plate boundaries in Figures 1(a)-1(d). ... one-dimensional coordinate functions along normalized coordinate are shown ...

  19. An Analytical Model of Wake Deflection Due to Shear Flow

    NARCIS (Netherlands)

    Micallef, D.; Simao Ferreira, C.J.; Sant, T.; Van Bussel, G.J.W.

    2010-01-01

    The main motivation behind this work is to create a purely analytical engineering model for wind turbine wake upward deflection due to shear flow, by developing a closed form solution of the velocity field due to an oblique vortex ring. The effectiveness of the model is evaluated by comparing the re

  20. Deflection routing scheme for GMPLS-based OBS networks

    DEFF Research Database (Denmark)

    Eid, Arafat; Mahmood, Waqar; Alomar, Anwar

    2010-01-01

    is not applicable in such an integrated solution. This is due to the existence of already established Label Switched Paths (LSPs) between edge nodes in a GMPLS-based OBS network which guide the Data Burst Headers (DBHs) through the network. In this paper we propose a novel deflection routing scheme which can...

  1. Towards a mechanistic analysis of Benkelman beam deflection measurements

    NARCIS (Netherlands)

    Visser, A.F.H.M.; Priambodo Koesrindartono, D.

    2000-01-01

    This paper introduces and describes the Benkelman beam deflection test. Furthermore Benkelman beam tests are simulated using two multi-layer programs, based on an elastic and visco-elastic material model for asphalt. The results of these two programs are compared with each other. Finally, using the

  2. Cantilever deflection measurement and actuation by an nterdigitated transducer

    NARCIS (Netherlands)

    Strambini, E.; Piazza, V.; Pingue, P.; Biasiol, G.; Sorba, L.; Beltram, F.

    2010-01-01

    A scheme that allows all-electrical high-bandwidth readout of a cantilever deflection by means of an integrated interdigitated transducer is presented. The present approach takes advantage of the piezoelectricity of the chosen cantilever substrate material to generate and detect surface-acoustic-wav

  3. Electro-optical approach to pavement deflection management

    Science.gov (United States)

    Rish, Jeff W., III; Adcock, Avery D.; Tuan, Christopher Y.; Baker, Samuel L.; Welker, Hugh W., II; Johnson, Roger F.

    1995-07-01

    A prototype continuous deflection device, referred to as a rolling weight deflectometer (RWD), has been developed as a nondestructive evaluation tool for airfield pavements. The system consists of a rigid trailer equipped with specially designed optical triangulation pavement sensors, a high-speed data acquisition system, and a high-pressure tire/load platform assembly. Pavement sensors are mounted on a rigid box beam equipped with an internal sensor system that corrects, in real time, the relative pavement height position measurements for displacements induced in the beam by mechanical vibrations, changes in temperature, or nonuniform dynamic loads at points where the beam attaches to the frame. The device produces continuous deflection profiles that show pavement response to a moving loaded wheel along the path of travel. These deflection profiles, combined with multiple passes along a lane, provide a far more detailed picture of the pavement structural integrity than has ever before been possible, because existing evaluation tools only produce response information at discrete points. Preliminary results show deflections measured by the RWD are in general agreement with the expected pavement response for various loads. A discussion of the device configuration, preliminary data, and potential as a pavement management tool is presented.

  4. Observation of Beam-beam Deflections with LHC Orbit Data

    CERN Document Server

    Kozanecki, W; Wenninger, J

    2013-01-01

    The LHC luminosity is calibrated in dedicated fills with van der Meer scans (vdM) of the beams that are performed repeatedly in both planes. During vdM scans the relative separation of the two LHC beams is scanned in a range of ±6 sigma , where sigma is the single beam size, probing the beam-beam deflection over a relatively large range. Orbit data logged parasitically during those scans were analysed and the beam-beam deflections at the IP being scanned could be reconstructed from orbit fits in the LHC arcs surrounding the IP. Despite the small size of the kicks (≤ 1μrad) the coherent beam-beam deflections are clearly resolved. The beam parameters that are extracted from the fit to the beam-beam deflection data were compared to luminosity data fits and they were found to be in good agreement. The closed orbit shift due to the beam-beam kick is also clearly observed in the beam position interpolation at the collision point.

  5. Calculation of thermal noise in grating reflectors

    CERN Document Server

    Heinert, Daniel; Friedrich, Daniel; Hild, Stefan; Kley, Ernst-Bernhard; Leavey, Sean; Martin, Iain W; Nawrodt, Ronny; Tünnermann, Andreas; Vyatchanin, Sergey P; Yamamoto, Kazuhiro

    2013-01-01

    Grating reflectors have been repeatedly discussed to improve the noise performance of metrological applications due to the reduction or absence of any coating material. So far, however, no quantitative estimate on the thermal noise of these reflective structures exists. In this work we present a theoretical calculation of a grating reflector's noise. We further apply it to a proposed 3rd generation gravitational wave detector. Depending on the grating geometry, the grating material and the temperature we obtain a thermal noise decrease by up to a factor of ten compared to conventional dielectric mirrors. Thus the use of grating reflectors can substantially improve the noise performance in metrological applications.

  6. Gaseous Detectors: Charged Particle Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Hilke, H J

    2011-01-01

    Gaseous Detectors in 'Charged Particle Detectors - Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Subsection '3.1.2 Gaseous Detectors' of Section '3.1 Charged Particle Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.1.2 Gaseous Detectors 3.1.2.1 Introduction 3.1.2.2 Basic Processes 3.1.2.2.1 Gas ionization by charged particles 3.1.2.2.1.1 Primary clusters 3.1.2.2.1.2 Cluster size distribution 3.1.2.2.1.3 Total number of ion pairs 3.1.2.2.1.4 Dependence of energy deposit on particle velocity 3.1.2.2.2 Transport of...

  7. Data acquisition and detector characterization of GEO600

    CERN Document Server

    Koetter, K; Babak, S; Balasubramanian, R; Berukoff, S; Bose, S; Churches, D; Colacino, C N; Cutler, C; Danzmann, K; Davies, R; Dupuis, R; Freise, A; Grote, H; Heinzel, G; Hewitson, M; Hough, J; Lück, H B; Malec, M; Mohanty, S D; Mukherjee, S; Nagano, S; Papa, M A; Robertson, D; Sathyaprakash, B S; Schutz, B F; Sintes, A M; Strain, K A; Taylor, I J; Vecchio, A; Ward, H; Weiland, U; Willke, B; Woan, G

    2002-01-01

    The data acquisition system of the gravitational wave detector GEO600 is recording the first data now. Data from detector subsystems and environmental channels are being acquired. The data acquisition system is described and first results from the detector characterization work are being presented. We analysed environmental influences on the detector to determine noise propagation through the detector. Long-term monitoring allowed us to see long-timescale drifts in subsystems.

  8. The ZEUS microvertex detector

    CERN Document Server

    Garfagnini, A

    1999-01-01

    A new vertex detector for the ZEUS experiment at HERA will be installed during the 1999-2000 shutdown, for the high-luminosity runs of HERA. It will allow to reconstruct secondary vertex tracks, coming from the decay of long-lived particles with a lifetime of about 10 sup - sup 1 sup 2 s, and improve the global momentum resolution of the tracking system. The interaction region will be surrounded with single-sided silicon strip detectors, with capacitive charge division: three double layers in the central region (600 detectors), and 4 'wheels' in the forward region (112 silicon planes). Due to the high number of readout channels, 512 readout strips per silicon plane in the barrel region and 480 in the forward part, and the large coverage of the vertex detector (almost 1 m long), the front-end electronics has to be placed on top of the detectors and has to be radiation tolerant since doses up to 2 kGy are expected near the interaction region. The HELIX chip has been chosen as analog chip with a low-noise, charg...

  9. Noise Reduction Effect of Multiple-Sampling-Based Signal-Readout Circuits for Ultra-Low Noise CMOS Image Sensors

    OpenAIRE

    Shoji Kawahito; Min-Woong Seo

    2016-01-01

    This paper discusses the noise reduction effect of multiple-sampling-based signal readout circuits for implementing ultra-low-noise image sensors. The correlated multiple sampling (CMS) technique has recently become an important technology for high-gain column readout circuits in low-noise CMOS image sensors (CISs). This paper reveals how the column CMS circuits, together with a pixel having a high-conversion-gain charge detector and low-noise transistor, realizes deep sub-electron read noise...

  10. The next detectors for gravitational wave astronomy

    CERN Document Server

    Blair, David; Zhao, Chunnong; Wen, Linqing; Miao, Haixing; Cai, Ronggen; Gao, Jiangrui; Lin, Xuechun; Liu, Dong; Wu, Ling-An; Zhu, Zonghong; Hammond, Giles; Paik, Ho Jung; Fafone, Viviana; Rocchi, Alessio; Ma, Yiqiu; Qin, Jiayi; Page, Michael

    2016-01-01

    This paper focuses on the next detectors for gravitational wave astronomy which will be required after the current ground based detectors have completed their initial observations, and probably achieved the first direct detection of gravitational waves. The next detectors will need to have greater sensitivity, while also enabling the world array of detectors to have improved angular resolution to allow localisation of signal sources. Sect. 1 of this paper begins by reviewing proposals for the next ground based detectors, and presents an analysis of the sensitivity of an 8 km armlength detector, which is proposed as a safe and cost-effective means to attain a 4-fold improvement in sensitivity. The scientific benefits of creating a pair of such detectors in China and Australia is emphasised. Sect. 2 of this paper discusses the high performance suspension systems for test masses that will be an essential component for future detectors, while sect. 3 discusses solutions to the problem of Newtonian noise which ari...

  11. Background noise spectra of global seismic stations

    Energy Technology Data Exchange (ETDEWEB)

    Wada, M.M.; Claassen, J.P.

    1996-08-01

    Over an extended period of time station noise spectra were collected from various sources for use in estimating the detection and location performance of global networks of seismic stations. As the database of noise spectra enlarged and duplicate entries became available, an effort was mounted to more carefully select station noise spectra while discarding others. This report discusses the methodology and criteria by which the noise spectra were selected. It also identifies and illustrates the station noise spectra which survived the selection process and which currently contribute to the modeling efforts. The resulting catalog of noise statistics not only benefits those who model network performance but also those who wish to select stations on the basis of their noise level as may occur in designing networks or in selecting seismological data for analysis on the basis of station noise level. In view of the various ways by which station noise were estimated by the different contributors, it is advisable that future efforts which predict network performance have available station noise data and spectral estimation methods which are compatible with the statistics underlying seismic noise. This appropriately requires (1) averaging noise over seasonal and/or diurnal cycles, (2) averaging noise over time intervals comparable to those employed by actual detectors, and (3) using logarithmic measures of the noise.

  12. Multiantenna spectrum sensing for cognitive radio: overcoming noise uncertainty

    OpenAIRE

    López Valcarce, Roberto; Vázquez Vilar, Gonzalo; Sala Álvarez, José

    2010-01-01

    Spectrum sensing is a key ingredient of the dynamic spectrum access paradigm, but it needs powerful detectors operating at SNRs well below the decodability levels of primary signals. Noise uncertainty poses a significant challenge to the development of such schemes, requiring some degree of diversity (spatial, temporal, or in distribution) for identifiability of the noise level. Multiantenna detectors exploit spatial independence of receiver thermal noise. We review this ...

  13. A surface work function measurement technique utilizing constant deflected grazing electron trajectories: oxygen uptake on Cu(001).

    Science.gov (United States)

    Ermakov, A V; Ciftlikli, E Z; Syssoev, S E; Shuttleworth, I G; Hinch, B J

    2010-10-01

    We report on the application of a novel nondestructive in-vacuum technique for relative work function measurements, employing a grazing incidence electron deflection above a sample with a planar surface. Two deflected electron beam detectors are used as a position sensitive detector to control feedback to the sample potential as the sample work function changes. With feedback the sample potential exactly follows the surface sample-size averaged work function variation, so that the deflected beam trajectory remains stable. We also discuss methods to optimize the initial electron trajectories for this method, so as to minimize unwanted effects such as from uncontrolled external magnetic fields. As the electron beam does not impinge on the surface in this new technique electron induced desorption, ionization, dissociation, and/or decomposition is not induced at the interface. Importantly also the technique allows for free access to the surfaces enabling simultaneous deposition/evaporation and/or application of other surface characterization methods. We demonstrate its application in concurrent measurements of helium atom reflectivity and work function changes taking place during molecular oxygen exposure of a Cu(001) surface. A work function measurement sensitivity and stability is demonstrated at ∼10 mV at a sampling rate of 1 Hz and after application of an ∼7 s smoothing routine. In comparison to the helium atom reflectivity measurements, the work function measurements are more sensitive to the initial O uptake, and less so to the final coverage variations and possible surface reordering at higher O coverages.

  14. Implementation of a beam deflection system for studies of liquid interfaces on beamline I07 at Diamond.

    Science.gov (United States)

    Arnold, Thomas; Nicklin, Chris; Rawle, Jonathan; Sutter, John; Bates, Trevor; Nutter, Brian; McIntyre, Gary; Burt, Martin

    2012-05-01

    X-ray optics, based on a double-crystal deflection scheme, that enable reflectivity measurements from liquid surfaces/interfaces have been designed, built and commissioned on beamline I07 at Diamond Light Source. This system is able to deflect the beam onto a fixed sample position located at the centre of a five-circle diffractometer. Thus the incident angle can be easily varied without moving the sample, and the reflected beam is tracked either by a moving Pilatus 100K detector mounted on the diffractometer arm or by a stationary Pilatus 2M detector positioned appropriately for small-angle scattering. Thus the system can easily combine measurements of the reflectivity from liquid interfaces (Q(z) > 1 Å(-1)) with off-specular data collection, both in the form of grazing-incidence small-angle X-ray scattering (GISAXS) or wider-angle grazing-incidence X-ray diffraction (GIXD). The device allows operation over the energy range 10-28 keV.

  15. Pixel Detectors

    OpenAIRE

    Wermes, Norbert

    2005-01-01

    Pixel detectors for precise particle tracking in high energy physics have been developed to a level of maturity during the past decade. Three of the LHC detectors will use vertex detectors close to the interaction point based on the hybrid pixel technology which can be considered the state of the art in this field of instrumentation. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as the very harsh...

  16. Development of a rank detector for knock detection in cylinder pressure or loose part noise in internal combustion engines and of assessment methods for knock detectors. Entwicklung eines Rangdetektors zur Klopfdetektion im Zylinderdruck bzw. Koerperschall von Ottomotoren und von Bewertungsverfahren fuer Klopfdetektoren

    Energy Technology Data Exchange (ETDEWEB)

    Yu Xiangyang.

    1990-01-01

    The operational status of an internal combustion engine (efficiency) can be controlled by a knock detector and a corresponding sparking angle regulation up to knock limit. A knock regulating system of this kind has to be highly sensitive, robust, fast and adaptable. This is a report on the principles of a knock detector of this kind (cause, effect, combustion chamber model, frequency shift compensation, engine signal spectrum) and on the development of a nonparametric adaptive knock detector (adaptation algorithm, design concept to a rank detector). In conclusion, the results of simulations with the rank detector are presented assessed (comparative experimental results, confidence intervals). (HWJ).

  17. Quality control in digital mammography: the noise components

    Energy Technology Data Exchange (ETDEWEB)

    Leyton, Fernando [Universidade de Tarapaca, Arica (Chile). Centro de Estudios en Ciencias Radiologicas; Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Nogueira, Maria do Socorro, E-mail: mnogue@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Duran, Maria Paz [Clinica Alemana, Santiago (Chile). Dept. de Radiologia; Dantas, Marcelino, E-mail: marcelino@inb.gov.b [Industrias Nucleares do Brasil (INB), Caldas, MG (Brazil). Unidade de Tratamento de Minerios; Ubeda, Carlos, E-mail: cubeda@uta.c [Universidade de Tarapaca, Arica (Chile). Fac. de Ciencias de la Salud

    2011-07-01

    To measure the linearity of the detector and determine the noise components (quantum, electronic and structural noise) that contributed to losing image quality and to determine the signal noise ratio (SNR) and contrast noise ratio (CNR). This paper describes the results of the implementation of a protocol for quality control in digital mammography performed in two direct digital mammography equipment (Hologic, Selenia) in Santiago of Chile. Shows the results of linearity and noise analysis of the images which establishes the main cause of noise in the image of the mammogram to ensure the quality and optimize procedures. The study evaluated two digital mammography's Selenia, Hologic (DR) from Santiago, Chile. We conducted the assessment of linearity of the detector, the signal noise ratio, contrast noise ratio and was determined the contribution of different noise components (quantum, electronics and structural noise). Used different thicknesses used in clinical practice according to the protocol for quality control in digital mammography of Spanish society of medical physics and NHSBSP Equipment Report 0604 Version 3. The Selenia mammography software was used for the analysis of images and Unfors Xi detector for measuring doses. The mammography detector has a linear performance, the CNR and SNR did not comply with the Protocol for the thicknesses of 60 and 70 mm. The main contribution of the noise corresponds to the quantum noise, therefore it is necessary to adjust and optimize the mammography system. (author)

  18. Free Vibration Analysis of Rectangular Orthotropic Membranes in Large Deflection

    Directory of Open Access Journals (Sweden)

    Zheng Zhou-Lian

    2009-01-01

    Full Text Available This paper reviewed the research on the vibration of orthotropic membrane, which commonly applied in the membrane structural engineering. We applied the large deflection theory of membrane to derive the governing vibration equations of orthotropic membrane, solved it, and obtained the power series formula of nonlinear vibration frequency of rectangular membrane with four edges fixed. The paper gave the computational example and compared the two results from the large deflection theory and the small one, respectively. Results obtained from this paper provide some theoretical foundation for the measurement of pretension by frequency method; meanwhile, the results provide some theoretical foundation for the research of nonlinear vibration of membrane structures and the response solving of membrane structures under dynamic loads.

  19. Jet deflection by very weak guide fields during magnetic reconnection.

    Science.gov (United States)

    Goldman, M V; Lapenta, G; Newman, D L; Markidis, S; Che, H

    2011-09-23

    Previous 2D simulations of reconnection using a standard model of initially antiparallel magnetic fields have detected electron jets outflowing from the x point into the ion outflow exhausts. Associated with these jets are extended "outer electron diffusion regions." New PIC simulations with an ion to electron mass ratio as large as 1836 (an H(+) plasma) now show that the jets are strongly deflected and the outer electron diffusion region is broken up by a very weak out-of-plane magnetic guide field, even though the diffusion rate itself is unchanged. Jet outflow and deflection are interpreted in terms of electron dynamics and are compared to recent measurements of jets in the presence of a small guide field in Earth's magnetosheath.

  20. Estimation of the deflection of the vertical using gravity measurements

    Science.gov (United States)

    Manoussakis, Gerassimos; Korakitis, Romylos; Milas, Paraskevas

    2017-04-01

    We present a method to estimate the deflection of the vertical at a point P on the Earth's physical surface by forming a small network of three points around point P, with known geodetic coordinates (φ, λ, h) and by obtaining gravity measurements at all points. In the first step, the gravity values are used to form the Eötvös matrix of the actual gravity potential W at point P. In the second step, the gravity differences and the components of the Eötvös matrix are used to form a linear system of three algebraic equations with three unknowns, which are the first order partial derivatives of the actual potential W. The solution of the system enables us to determine the components ξ and η of the deflection of the vertical at the chosen point P. Finally, we present a numerical simulation, using several points scattered on a wide area of the Earth's surface.

  1. Deflection of Rotating Symmetric Molecules by Inhomogeneous Fields

    CERN Document Server

    Gershnabel, Erez

    2011-01-01

    We consider deflection of rotating symmetric molecules by inhomogeneous optical and static electric fields, compare results with the case of linear molecules, and find new singularities in the distribution of the scattering angle. Scattering of the prolate/oblate molecules is analyzed in detail, and it is shown that the process can be efficiently controlled by means of short and strong femtosecond laser pulses. In particular, the angular dispersion of the deflected molecules may be dramatically reduced by laser-induced molecular pre-alignment. We first study the problem by using a simple classical model, and then find similar results by means of more sophisticated methods, including the formalism of adiabatic invariants and direct numerical simulation of the Euler-Lagrange equations of motion. The suggested control scheme opens new ways for many applications involving molecular focusing, guiding, and trapping by optical and static fields.

  2. Measurement of Large Forces and Deflections in Microstructures

    CERN Document Server

    Hals, Kai Axel; Chen, Xuyuan

    2008-01-01

    Properties of typical MEMS materials have been widely investigated. Mechanical properties of MEMS structures depend not only on the bulk material properties, but also structural factors. A measurement system has been made to measure force/deflection on microstructures to examine some of the structural properties. This is a stylus setup integrated with a load cell and a linear actuator. First, the requirements for the measurement system were established. Then the system was built up and characterized. We have successfully made measurements on a typical micromechanical structure, a cantilever accelerometer design. The stylus placement accuracy, the spring constant along the proof mass, analysis of the force/deflection curve shape and destructive tests on the cantilever have been investigated in our experiment and will be presented in this paper.

  3. Strong deflection gravitational lensing by a modified Hayward black hole

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shan-Shan; Xie, Yi [Nanjing University, School of Astronomy and Space Science, Nanjing (China); Nanjing University, Ministry of Education, Key Laboratory of Modern Astronomy and Astrophysics, Nanjing (China)

    2017-05-15

    A modified Hayward black hole is a nonsingular black hole. It is proposed that it would form when the pressure generated by quantum gravity can stop matter's collapse as the matter reaches the Planck density. Strong deflection gravitational lensing occurring nearby its event horizon might provide some clues of these quantum effects in its central core. We investigate observables of the strong deflection lensing, including angular separations, brightness differences and time delays between its relativistic images, and we estimate their values for the supermassive black hole in the Galactic center. We find that it is possible to distinguish the modified Hayward black hole from a Schwarzschild one, but it demands a very high resolution, beyond current stage. (orig.)

  4. A map of UHECRs deflections through the turbulent GMF

    Energy Technology Data Exchange (ETDEWEB)

    Pshirkov, M.S. [Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsky Prospekt 13, 119992 Moscow (Russian Federation); Pushchino Radio Astronomy Observatory, 142290 Pushchino (Russian Federation); Institute for Nuclear Research of the Russian Academy of Sciences, 117312 Moscow (Russian Federation); Tinyakov, P.G. [Institute for Nuclear Research of the Russian Academy of Sciences, 117312 Moscow (Russian Federation); Université Libre de Bruxelles, Service de Physique Théorique, CP225, 1050 Brussels (Belgium); Urban, F.R. [Université Libre de Bruxelles, Service de Physique Théorique, CP225, 1050 Brussels (Belgium)

    2014-04-01

    We study the effect of the random part of the Galactic Magnetic Field (GMF) on the propagation of ultra high-energy cosmic rays. We are able to derive a clear and direct relation between the observed variance of rotation measures and the predicted cosmic ray deflections, which puts a solid upper limit of the experimentally observed displacements. Remarkably, this is obtained bypassing entirely the detailed knowledge of the magnetic properties of the turbulent plasma, and that of the electron density variance. Over most of the sky the random deflections for 40 EeV protons do not exceed 1–2°, and can be as large as 5° close to the Galactic plane.

  5. SUPERCONDUCTING RF-DIPOLE DEFLECTING AND CRABBING CAVITIES

    Energy Technology Data Exchange (ETDEWEB)

    Delayen, Jean [ODU, JLAB; De Silva, Paygalage Subashini [ODU, JLAB

    2013-09-01

    Recent interests in designing compact deflecting and crabbing structures for future accelerators and colliders have initiated the development of novel rf structures. The superconducting rf-dipole cavity is one of the first compact designs with attractive properties such as higher gradients, higher shunt impedance, the absence of lower order modes and widely separated higher order modes. Two rf-dipole designs of 400 MHz and 499 MHz have been designed, fabricated and tested as proof-of-principle designs of compact deflecting and crabbing cavities for the LHC high luminosity upgrade and Jefferson Lab 12 GeV upgrade. The first rf tests have been performed on the rf-dipole geometries at 4.2 K and 2.0 K in a vertical test assembly with excellent results. The cavities have achieved high gradients with high intrinsic quality factors, and multipacting levels were easily processed.

  6. Prediction of Double Layer Grids' Maximum Deflection Using Neural Networks

    Directory of Open Access Journals (Sweden)

    Reza K. Moghadas

    2008-01-01

    Full Text Available Efficient neural networks models are trained to predict the maximum deflection of two-way on two-way grids with variable geometrical parameters (span and height as well as cross-sectional areas of the element groups. Backpropagation (BP and Radial Basis Function (RBF neural networks are employed for the mentioned purpose. The inputs of the neural networks are the length of the spans, L, the height, h and cross-sectional areas of the all groups, A and the outputs are maximum deflections of the corresponding double layer grids, respectively. The numerical results indicate that the RBF neural network is better than BP in terms of training time and performance generality.

  7. Effect of layer length on deflection in sandwich beams

    Science.gov (United States)

    Abbu, Muthanna A.; AL-Ameri, Riyadh

    2017-09-01

    A theoretical study has been carried out on sandwich beams strengthened mechanically by two external steel plates attached to their tension and compression sides with so-called "shear connectors ". This study is based on the individual behaviour of each component of the composite sandwich section (i.e. reinforced concrete beam and upper steel plate and lower steel plate). The approach has been developed to simulate the behaviour of such beams, and is based on neglecting the separation between the three layers; i.e., the deflections are equal in each element through the same section. The differential equations reached were solved analytically. Deflection was calculated by using the approach for several beams, tested in two series, and close agreements were obtained with the experimental values. Furthermore, the interaction efficiency between the three elements in a composite sandwich beam has been considered thoroughly, from which the effect of some parameters, such as plate length upon the behaviour of such beams, were studied.

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

    Science.gov (United States)

    Jablonowski, D P; Raamot, J

    1976-06-01

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

  9. Stiffness and Angular Deflection analysis of Revolute Manipulator

    Directory of Open Access Journals (Sweden)

    Pundru Srinivasa Rao

    2014-03-01

    Full Text Available This paper proposed to determine the Cartesian stiffness matrix and angular deflection analysis of revolute manipulator. The selected manipulator has rigid fixed link, two movable links and two rotary joints with joint stiffness coefficients are taken into account. The kinematic model of revolute joint manipulator has considered as a planar kinematic chain, which is composed by rigid fixed link and two revolute joints with clearance and deformable elements. The calculation of stiffness matrix depends on Jacobian matrix and change of configuration. The rotational joints are modeled as torsion springs with the same stiffness constant. The relative angular deflections are proportional to the actuated torques taken into account. The subject of this paper has to describe a method for stiffness analysis of serial manipulator. In the present work is to derive the stiffness matrix and angular deflection equations in the Robotic manipulator under the consideration of two-link optimum geometry model for rotary joint manipulator. The stiffness values are measured by displacements of its revolute links loaded by force.

  10. Metal Detectors.

    Science.gov (United States)

    Harrington-Lueker, Donna

    1992-01-01

    Schools that count on metal detectors to stem the flow of weapons into the schools create a false sense of security. Recommendations include investing in personnel rather than hardware, cultivating the confidence of law-abiding students, and enforcing discipline. Metal detectors can be quite effective at afterschool events. (MLF)

  11. Optical Detectors

    Science.gov (United States)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  12. Noise Pollution

    Science.gov (United States)

    ... Search Clean Air Act Overview Share Facebook Twitter Google+ Pinterest Contact Us Clean Air Act Title IV - ... noises in the community (from your neighbor, boom cars, lawn equipment, etc.) and from commercial businesses (factory, ...

  13. Comparison Between Two Solutions Based on the Relationship of Load-deflection Character of a Large Deflection Rubber Circular Plate

    Institute of Scientific and Technical Information of China (English)

    段浩; 胡宗武; 杨赪石; 黎佑铭

    2003-01-01

    The rubber circular plate is considered as a kind of membrane. Based on the character that there existsno bending-moment inside a membrane, the geometric behavior of the rubber circular plate in expanding state wasdescribed with the aid of a group of mathematic method. The relationship between deflection and load was attainedby means of calculating stress and strain inside the curved-surface of rubber plate. Meantime, based on Henckymethod, the relationship between deflection and load was attained and considered as the Hencky solution. The dif-ferent results given rise by the two different resolving methods were compared. The deviation results from theHencky method was discussed, and a kind of correcting method was put forward.

  14. Deflection unit for multi-beam mask making

    Science.gov (United States)

    Letzkus, Florian; Butschke, Joerg; Irmscher, Mathias; Jurisch, Michael; Klingler, Wolfram; Platzgummer, Elmar; Klein, Christof; Loeschner, Hans; Springer, Reinhard

    2008-10-01

    Two main challenges of future mask making are the decreasing throughput of the pattern generators and the insufficient line edge roughness of the resist structures. The increasing design complexity with smaller feature sizes combined with additional pattern elements of the Optical Proximity Correction generates huge data volumes which reduce correspondingly the throughput of conventional single e-beam pattern generators. On the other hand the achievable line edge roughness when using sensitive chemically amplified resists does not fulfill the future requirements. The application of less sensitive resists may provide an improved roughness, however on account of throughput, as well. To overcome this challenge a proton multi-beam pattern generator is developed [1]. Starting with a highly parallel broad beam, an aperture-plate is used to generate thousands of separate spot beams. These beams pass through a blanking-plate unit, based on a CMOS device for de-multiplexing the writing data and equipped with electrodes placed around the apertures switching the beams "on" or "off", dependent on the desired pattern. The beam array is demagnified by a 200x reduction optics and the exposure of the entire substrate is done by a continuous moving stage. One major challenge is the fabrication of the required high aspect deflection electrodes and their connection to the CMOS device. One approach is to combine a post-processed CMOS chip with a MEMS component containing the deflection electrodes and to realize the electrical connection of both by vertical integration techniques. For the evaluation and assessment of this considered scheme and fabrication technique, a proof-of-concept deflection unit has been realized and tested. Our design is based on the generation of the deflection electrodes in a silicon membrane by etching trenches and oxide filling afterwards. In a 5mm x 5mm area 43,000 apertures with the corresponding electrodes have been structured and wired individually or in

  15. Two models for bolometer and microcalorimeter detectors with complex thermal architectures

    Energy Technology Data Exchange (ETDEWEB)

    Appel, J.W. [Department of Physics, University of Miami, P.O. Box 248046, Coral Gables, FL 33124 (United States); Galeazzi, M. [Department of Physics, University of Miami, P.O. Box 248046, Coral Gables, FL 33124 (United States)]. E-mail: galeazzi@physics.miami.edu

    2006-06-15

    We have developed two analytical models to describe the performance of cryogenic microcalorimeters and bolometers. One of the models is suitable to describe Transition Edge Sensor (TES) detectors with an integrated absorber, the other is suitable for detectors with large absorbers. Both models take into account hot-electron decoupling and absorber decoupling. The differential equations describing these models have been solved using block diagram algebra. Each model has produced closed-form solutions for the detector's responsivity, dynamic impedance, and noise equivalent power for phonon noise, Johnson noise, amplifier noise, 1/f noise, and load resistor noise.

  16. Two Models for Bolometer and Microcalorimeter Detectors with Complex Thermal Architectures

    CERN Document Server

    Appel, J W

    2005-01-01

    We have developed two analytical models to describe the performance of cryogenic microcalorimeters and bolometers. One of the models is suitable to describe Transition Edge Sensor (TES) detectors with an integrated absorber, the other is suitable for detectors with large absorbers. Both models take into account hot-electron decoupling and absorber decoupling. The differential equations describing these models have been solved using block diagram algebra. Each model has produced closed form solutions for the detector's responsivity, dynamic impedance, and noise equivalent power for phonon noise, Johnson noise, amplifier noise, 1/f noise, and load resistor noise.

  17. Quantum limited heterodyne detection of spin noise

    Science.gov (United States)

    Cronenberger, S.; Scalbert, D.

    2016-09-01

    Spin noise spectroscopy is a powerful technique for studying spin relaxation in semiconductors. In this article, we propose an extension of this technique based on optical heterodyne detection of spin noise, which provides several key advantages compared to conventional spin noise spectroscopy: detection of high frequency spin noise not limited by detector bandwidth or sampling rates of digitizers, quantum limited sensitivity even in case of very weak probe power, and possible amplification of the spin noise signal. Heterodyne detection of spin noise is demonstrated on insulating n-doped GaAs. From measurements of spin noise spectra up to 0.4 Tesla, we determined the distribution of g-factors, Δg/g = 0.49%.

  18. On aerodynamic noise generation from vortex shedding in rotating blades

    Science.gov (United States)

    Martin, B. T.; Bies, D. A.

    1992-06-01

    The interaction of the shed wakes of plates in a cascade with each following plate is investigated in a water tunnel and shown to provide an explanation for an observed very powerful aerodynamic noise source. In particular, the noise generation of an idling circular saw may be explained as due to the interaction of the wake shed by an upstream tooth with the leading edge of the following downstream tooth. When a vortex travelling downstream in the gullet between teeth encounters the leading edge of the downstream tooth it is deflected out of the gullet into the main stream. The associated impulses which the teeth encounter give rise to the radiated noise.

  19. Radiation experience with the CDF silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Husemann, Ulrich; /Rochester U.

    2005-11-01

    The silicon detectors of the CDF experiment at the Tevatron collider are operated in a harsh radiation environment. The lifetime of the silicon detectors is limited by radiation damage, and beam-related incidents are an additional risk. This article describes the impact of beam-related incidents on detector operation and the effects of radiation damage on electronics noise and the silicon sensors. From measurements of the depletion voltage as a function of the integrated luminosity, estimates of the silicon detector lifetime are derived.

  20. Wide-band detection of the third moment of shot noise by a hysteretic Josephson junction

    OpenAIRE

    Timofeev, A. V.; Meschke, M.; Peltonen, J. T.; Heikkila, T. T.; Pekola, J.P.

    2006-01-01

    We use a hysteretic Josephson junction as an on-chip detector of the third moment of shot noise of a tunnel junction. The detectable bandwidth is determined by the plasma frequency of the detector, which is about 50 GHz in the present experiment. The third moment of shot noise results in a measurable change of the switching rate when reversing polarity of the current through the noise source. We analyze the observed asymmetry assuming adiabatic response of the detector.

  1. DUMAND detector

    CERN Multimedia

    This object is one of the 256 other detectors of the DUMAND (Deep Underwater Muon And Neutrino Detection) experiment. The goal of the experiment was the construction of the first deep ocean high energy neutrino detector, to be placed at 4800 m depth in the Pacific Ocean off Keahole Point on the Big Island of Hawaii. A few years ago, a European conference with Cosmic experiments was organized at CERN as they were projects like DUMAND in Hawaii. Along with the conference, a temporary exhibition was organised as well. It was a collaboration of institutions from Germany, Japan, Switzerland and the U.S.A. CERN had borrowed equipment and objects from different institutes around the world, including this detector of the DUMAND experiment. Most of the equipment were sent back to the institutes, however this detector sphere was offered to a CERN member of the personnel.

  2. Modelling coloured residual noise in gravitational-wave signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Roever, Christian [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut) and Leibniz Universitaet Hannover, Hannover (Germany); Meyer, Renate [Department of Statistics, University of Auckland, Auckland (New Zealand); Christensen, Nelson, E-mail: christian.roever@aei.mpg.de [Physics and Astronomy, Carleton College, Northfield, MN (United States)

    2011-01-07

    We introduce a signal processing model for signals in non-white noise, where the exact noise spectrum is a priori unknown. The model is based on a Student's t distribution and constitutes a natural generalization of the widely used normal (Gaussian) model. This way, it allows for uncertainty in the noise spectrum, or more generally is also able to accommodate outliers (heavy-tailed noise) in the data. Examples are given pertaining to data from gravitational-wave detectors.

  3. Deflection by kinetic impact: Sensitivity to asteroid properties

    Science.gov (United States)

    Bruck Syal, Megan; Michael Owen, J.; Miller, Paul L.

    2016-05-01

    Impacting an asteroid with a spacecraft traveling at high speed delivers an impulsive change in velocity to the body. In certain circumstances, this strategy could be used to deflect a hazardous asteroid, moving its orbital path off of an Earth-impacting course. However, the efficacy of momentum delivery to asteroids by hypervelocity impact is sensitive to both the impact conditions (particularly velocity) and specific characteristics of the target asteroid. Here we numerically model asteroid response to kinetic impactors under a wide range of initial conditions, using an Adaptive Smoothed Particle Hydrodynamics code. Impact velocities spanning 1-30 km/s were investigated, yielding, for a particular set of assumptions about the modeled target material, a power-law dependence consistent with a velocity-scaling exponent of μ = 0.44. Target characteristics including equation of state, strength model, porosity, rotational state, and shape were varied, and corresponding changes in asteroid response were documented. The kinetic-impact momentum-multiplication factor, β, decreases with increasing asteroid cohesion and increasing porosity. Although increased porosity lowers β, larger porosities result in greater deflection velocities, as a consequence of reduced target masses for asteroids of fixed size. Porosity also lowers disruption risk for kinetic impacts near the threshold of disruption. Including fast (P = 2.5 h) and very fast (P = 100 s) rotation did not significantly alter β but did affect the risk of disruption by the impact event. Asteroid shape is found to influence the efficiency of momentum delivery, as local slope conditions can change the orientation of the crater ejecta momentum vector. These results emphasize the need for asteroid characterization studies to bracket the range of target conditions expected at near-Earth asteroids while also highlighting some of the principal uncertainties associated with the kinetic-impact deflection strategy.

  4. The 2017 Eclipse: Centenary of the Einstein Light Deflection Experiment

    Science.gov (United States)

    Kennefick, Daniel

    2017-01-01

    August 21st, 2017 will see a total eclipse of the Sun visible in many parts of the United States. Coincidentally this date marks the centenary of the first observational attempt to test Einstein's General Theory of Relativity by measuring gravitational deflection of light by the Sun. This was attempted by the Kodaikanal Observatory in India during the conjunction of Regulus with the Sun in daylight on August 21st, 1917. The observation was attempted at the urging of the amateur German-British astronomer A. F. Lindemann, with his son, F. A. Lindemann, a well-known physicist, who later played a significant role as Churchill's science advisor during World War II. A century later Regulus will once again be in conjunction with the Sun, but by a remarkable coincidence, this will occur during a solar eclipse! Efforts will be made to measure the star deflection during the eclipse and the experiment is contrasted with the famous expeditions of 1919 which were the first to actually measure the light deflection, since the 1917 effort did not meet with success. Although in recent decades there have been efforts made to suggest that the 1919 eclipse team, led by Arthur Stanley Eddington and Sir Frank Watson Dyson, over-interpreted their results in favor of Einstein this talk will argue that such claims are wrong-headed. A close study of their data analysis reveals that they had good grounds for the decisions they made and this conclusion is reinforced by comparison with a modern re-analysis of the plates by the Greenwich Observatory conducted in 1977.

  5. Spin Rate and Deflection Ratio of a Ping Pong Ball

    Directory of Open Access Journals (Sweden)

    Byung Joon Ahn

    2013-01-01

    Full Text Available To investigate the effects of a spherical object’s spin rate on the curvature of its flight, Ping Pong balls, of varying spin rates, were hit horizontally and recorded from above with a high-speed camera. It was shown that there was a proportional relationship between the ball’s spin rate and deflection ratio. Additionally, using the results of the analyzed data, a coefficient of skin friction of the Ping Pong ball was found to be approximately 0.2 under the specific conditions of this investigation.

  6. Online Estimation of wind turbine blade deflection with UWB signals

    DEFF Research Database (Denmark)

    Jensen, Tobias Lindstrøm; Jakobsen, Morten Lomholt; Østergaard, Jan;

    2015-01-01

    In this paper we use ultra-wideband (UWB) signals for the localization of blade tips on wind turbines. Our approach is to acquire two separate distances to each tip via time-delay estimation, and each tip is then localized by triangulation. We derive an approximate maximum a posteriori (MAP) delay...... estimator exploiting i) contextual prior information and ii) a direct-path approximation. The resulting deflection estimation algorithm is computationally feasible for online usage. Simulation studies are conducted to assess the overall triangulation uncertainty and it is observed that negative correlation...

  7. Direct measurement of Vorticella contraction force by micropipette deflection.

    Science.gov (United States)

    France, Danielle; Tejada, Jonathan; Matsudaira, Paul

    2017-02-01

    The ciliated protozoan Vorticella convallaria is noted for its exceptionally fast adenosine triphosphate-independent cellular contraction, but direct measurements of contractile force have proven difficult given the length scale, speed, and forces involved. We used high-speed video microscopy to image live Vorticella stalled in midcontraction by deflection of an attached micropipette. Stall forces correlate with both distance contracted and the resting stalk length. Estimated isometric forces range from 95 to 177 nanonewtons (nN), or 1.12 nN·μm(-1) of the stalk. Maximum velocity and work are also proportional to distance contracted. These parameters constrain proposed biochemical/physical models of the contractile mechanism.

  8. Angular Dispersion and Deflection Function for Heavy Ion Elastic Scattering

    Institute of Scientific and Technical Information of China (English)

    BAI Zhen; MAO Rui-Shi; YUAN Xiao-Hua; Xu Zhi-Guo; ZHANG Hong-Bin; XU Hua-Gen; QI Hui-Rong; WANG Yue; JIA Fei; WU Li-Jie; DING Xian-Li; WANG Qi; GAO Qi; GAO Hui; LI Song-Lin; LI Jun-Qing; ZHANG Ya-Peng; XIAO Guo-Qing; JIN Gen-Ming; REN Zhong-Zhou; ZHOU Shan-Gui; XU Wang; HAN Jian-Long; Fan Gong-Tao; ZHANG Shuang-Quan; PANG Dan-Yang; SERGEY Yu-Kun; XIAO Zhi-Gang; XU Hu-Shan; SUN Zhi-Yu; HU Zheng-Guo; ZHANG Xue-Ying; WANG Hong-Wei

    2007-01-01

    The differential cross sections for elastic scattering products of17 F on 208 Pb have been measured.The angular dispersion plots of In(dσ/dθ)versus θ2 are obtained from the angular distribution of the elastic scattering differential cross sections.Systematical analysis on the angular dispersion for the available experimental data indicates that there is an angular dispersion turning angle at forward angular range within the grazing angle.This turning angle can be clarified as nuclear rainbow in classical deflection function.The exotic behaviour of the nuclear rainbow angle offers a new probe to investigate the halo and skin phenomena.

  9. The Deflection of Charged Particles in an Electric Dodecapole Field

    Energy Technology Data Exchange (ETDEWEB)

    Seely, D. G.; Chalut, K.; Thompson, J. S.; Kvale, T. J.

    1997-10-10

    The properties of an ion-optical device consisting of twelve long parallel rods placed equidistantly on a circle are briefly reviewed. The use of this device in its dodecapole configuration to deflect ions in a plane perpendicular to the axis of the dodecapole is discussed. Results of trajectory computations made with the SIMION ion-optics computer program demonstrate that the device works remarkably well in separating the constituents of a multiply-charged ion beam. The use of this device to merge an ion beam with an optical beam is proposed.

  10. Wind Turbine Blade Deflection Sensing System Based on UWB Technology

    DEFF Research Database (Denmark)

    Franek, Ondrej; Zhang, Shuai; Jensen, Tobias Lindstrøm

    2016-01-01

    by triangulation. An experimental setup with corner reflector antenna mounted at the tip and horn antennas at the root of a 37.3 m long blade is described. Analyzing the data from the experiment, special attention is given to the propagation aspects of the UWB links, with focus on the multipath effects caused...... by the blade. It is demonstrated that despite the adverse effects of the multipath propagation the ranging accuracy of the system amounts to 1.5 cm, leading to maximum error of deflection 4.5 %....

  11. Observation of Femtosecond Bunch Length Using a Transverse Deflecting Structure

    Energy Technology Data Exchange (ETDEWEB)

    Huning, M.; Bolzmann, A.; Schlarb, H.; /DESY; Frisch, J.; McCormick, D.; Ross, M.; Smith, T.; /SLAC; Rossbach, J.; /Hamburg U.

    2005-12-14

    The design of the VUV-FEL at DESY demands bunch lengths in the order of 50 fs and below. For the diagnostic of such very short bunches a transverse deflecting RF structure (LOLA) has been installed which streaks the beam according to the longitudinal distribution. Tests in the VUV-FEL yielded a rich substructure of the bunches. The most pronounced peak in the has a rms length of approximately 50 fs during FEL operation and below 20 fs FWHM at maximum compression. Depending on the transverse focusing a resolution well below 50 fs was achieved.

  12. PAU camera: detectors characterization

    Science.gov (United States)

    Casas, Ricard; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Jiménez, Jorge; Maiorino, Marino; Pío, Cristóbal; Sevilla, Ignacio; de Vicente, Juan

    2012-07-01

    The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

  13. MUON DETECTORS: DT

    CERN Document Server

    Marco Dallavalle

    2012-01-01

      Although the year 2012 is the third year without access to the chambers and the Front-End electronics, the fraction of good channels is still very high at 99.1% thanks also to the constant care provided by the on-site operation team. The downtime caused to CMS as a consequence of DT failures is to-date <2%. The intervention on the LV power supplies, which required a large number of CAEN modules (137 A3050, 13 A3100, and 3 MAO) to be removed from the detector, reworked and tested during this Year-End Technical Stop, can now, after a few months of stable operation of the LV, be declared to have solved once-and-for-all the persistent problem with the overheating LV Anderson connectors. Another piece of very good news is that measurements of the noise from single-hit rate outside the drift-time box as a function of the LHC luminosity show that the noise rate and distribution are consistent with expectations of the simulations in the Muon TDR, which have guided the detector design and constru...

  14. Detector Developments for the LHC CMS TOB Silicon Detector Modules and ATLAS TileCal Read-Out Driver

    CERN Document Server

    Poveda, J; Ferrer, A

    2005-01-01

    This Research Report is divided in two different parts corresponding to two different periods of time working in different collaborations. First, a general approach to the framework where this work is set is presented at the Introduction: the CERN laboratory near Geneva, the LHC accelerator and its two general purpose experiments CMS and ATLAS. The first part of this report consists in the study of the performance of the silicon strip detectors specifically designed for the Tracker Outer Barrel (TOB) of the CMS Tracker detector. Results of the performance of CMS TOB silicon detector modules mounted on the first assembled double-sided rod at CERN are presented. These results are given in terms of noise, noise occupancies, signal to noise ratios and signal efficiencies. The detector signal efficiencies and noise occupancies are also shown as a function of threshold for a particular clustering algorithm. Signal efficiencies versus noise occupancy plots as a function of the threshold level, which could also be us...

  15. Searching for stochastic gravitational waves using data from the two co-located LIGO Hanford detectors

    CERN Document Server

    Aasi, J; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Accadia, T; Acernese, F; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ajith, P; Allen, B; Allocca, A; Ceron, E Amado; Amariutei, D; Anderson, R A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J; Ast, S; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Austin, L; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barker, D; Barnum, S H; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Behnke, B; Bejger, M; Beker, M G; Bell, A S; Bell, C; Belopolski, I; Bergmann, G; Berliner, J M; Bersanetti, D; Bertolini, A; Bessis, D; Betzwieser, J; Beyersdorf, P T; Bhadbhade, T; Bilenko, I A; Billingsley, G; Birch, J; Biscans, S; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Blom, M; Bock, O; Bodiya, T P; Boer, M; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, S; Bosi, L; Bowers, J; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brannen, C A; Brau, J E; Breyer, J; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Britzger, M; Brooks, A F; Brown, D A; Brown, D D; Brückner, F; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Bustillo, J Calderó; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castiglia, A; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Colombini, M; Constanci., M; Conte, A; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corsi, A; Costa, C A; Coughlin, M W; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Craig, K; Creighton, J D E; Creighton, T D; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dahl, K; Canton, T Da; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; Debreczeni, G; Degallaix, J; Deleeuw, E; Deléglise, S; Pozzo, W De; Denker, T; Dent, T; Dereli, H; Dergachev, V; DeRosa, R T; Rosa, R D; DeSalvo, R; Dhurandhar, S; Díaz, M; Dietz, A; Fiore, L D; Lieto, A D; Palma, I D; Virgilio, A D; Dmitry, K; Donovan, F; Dooley, K L; Doravari, S; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dumas, J -C; Dwyer, S; Eberle, T; Edwards, M; Effler, A; Ehrens, P; Eichholz, J; Eikenberry, S S; Endrőczi, G; Essick, R; Etzel, T; Evans, K; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fang, Q; Farr, B; Farr, W; Favata, M; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R; Flaminio, R; Foley, E; Foley, S; Forsi, E; Fotopoulos, N; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fujimoto, M -K; Fulda, P; Fyffe, M; Gair, J; Gammaitoni, L; Garcia, J; Garufi, F; Gehrels, N; Gemme, G; Genin, E; Gennai, A; Gergely, L; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gil-Casanova, S; Gill, C; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Griffo, C; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gushwa, K E; Gustafson, E K; Gustafson, R; Hall, B; Hall, E; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hartman, M T; Haughian, K; Hayama, K; Heefner, J; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Hong, T; Hooper, S; Horrom, T; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Hua, Z; Huang, V; Huerta, E A; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Iafrate, J; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; James, E; Jang, H; Jang, Y J; Jaranowski, P; Jiménez-Forteza, F; Johnson, W W; Jones, D I; Jones, D; Jones, R; Jonker, R J G; Ju, L; K, Hari; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Kasprzack, M; Kasturi, R; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufman, K; Kawabe, K; Kawamura, S; Kawazoe, F; Kéfélian, F; Keitel, D; Kelley, D B; Kells, W; Keppel, D G; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B K; Kim, C; Kim, K; Kim, N; Kim, W; Kim, Y -M; King, E; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Koehlenbeck, S; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D; Kremin, A; Kringel, V; Krishnan, B; Królak, A; Kucharczyk, C; Kudla, S; Kuehn, G; Kumar, A; Kumar, D Nand; Kumar, P; Kumar, R; Kurdyumov, R; Kwee, P; Landry, M; Lantz, B; Larson, S; Lasky, P D; Lawrie, C; Lazzarini, A; Leaci, P; Lebigot, E O; Lee, C -H; Lee, H K; Lee, H M; Lee, J J; Lee, J; Leonardi, M; Leong, J R; Roux, A L; Leroy, N; Letendre, N; Levine, B; Lewis, J B; Lhuillier, V; Li, T G F; Lin, A C; Littenberg, T B; Litvine, V; Liu, F; Liu, H; Liu, Y; Liu, Z; Lloyd, D; Lockerbie, N A; Lockett, V; Lodhia, D; Loew, K; Logue, J; Lombardi, A L; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J; Luan, J; Lubinski, M J; Lück, H; Lundgren, A P; Macarthur, J; Macdonald, E; Machenschalk, B; MacInnis, M; Macleod, D M; Magana-Sandoval, F; Mageswaran, M; Mailand, K; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Manca, G M; Mandel, I; Mandic, V; Mangano, V; Mantovani, M; Marchesoni, F; Marion, F; Márka, S; Márka, Z; Markosyan, A; Maros, E; Marque, J; Martelli, F; Martellini, L; Martin, I W; Martin, R M; Martini, G; Martynov, D; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Matichard, F; Matone, L; Matzner, R A; Mavalvala, N; May, G; Mazumder, N; Mazzolo, G; McCarthy, R; McClelland, D E; McGuire, S C; McIntyre, G; McIver, J; Meacher, D; Meadors, G D; Mehmet, M; Meidam, J; Meier, T; Melatos, A; Mendell, G; Mercer, R A; Meshkov, S; Messenger, C; Meyer, M S; Miao, H; Michel, C; Mikhailov, E; Milano, L; Miller, J; Minenkov, Y; Mingarelli, C M F; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moe, B; Mohan, M; Mohapatra, S R P; Mokler, F; Moraru, D; Moreno, G; Morgado, N; Mori, T; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Mukherjee, S; Mullavey, A; Munch, J; Murphy, D; Murray, P G; Mytidis, A; Nagy, M F; Nardecchia, I; Nash, T; Naticchioni, L; Nayak, R; Necula, V; Neri, I; Neri, M; Newton, G; Nguyen, T; Nishida, E; Nishizawa, A; Nitz, A; Nocera, F; Nolting, D; Normandin, M E; Nuttall, L K; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oppermann, P; O'Reilly, B; Larcher, W Orteg; O'Shaughnessy, R; Osthelder, C; Ottaway, D J; Ottens, R S; Ou, J; Overmier, H; Owen, B J; Padilla, C; Pai, A; Palomba, C; Pan, Y; Pankow, C; Paoletti, F; Paoletti, R; Papa, M A; Paris, H; Pasqualetti, A; Passaquieti, R; Passuello, D; Pedraza, M; Peiris, P; Penn, S; Perreca, A; Phelps, M; Pichot, M; Pickenpack, M; Piergiovanni, F; Pierro, V; Pinard, L; Pindor, B; Pinto, I M; Pitkin, M; Poeld, J; Poggiani, R; Poole, V; Postiglione, F; Poux, C; Predoi, V; Prestegard, T; Price, L R; Prijatelj, M; Privitera, S; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Quetschke, V; Quintero, E; Quitzow-James, R; Raab, F J; Rabeling, D S; Rácz, I; Radkins, H; Raffai, P; Raja, S; Rajalakshmi, G; Rakhmanov, M; Ramet, C; Rapagnani, P; Raymond, V; Re, V; Reed, C M; Reed, T; Regimbau, T; Reid, S; Reitze, D H; Ricci, F; Riesen, R; Riles, K; Robertson, N A; Robinet, F; Rocchi, A; Roddy, S; Rodriguez, C; Rodruck, M; Roever, C; Rolland, L; Rollins, J G; Romano, J D; Romano, R; Romanov, G; Romie, J H; Rosińska, D; Rowan, S; Rüdiger, A; Ruggi, P; Ryan, K; Salemi, F; Sammut, L; Sandberg, V; Sanders, J; Sannibale, V; Santiago-Prieto, I; Saracco, E; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Savage, R; Schilling, R; Schnabel, R; Schofield, R M S; Schreiber, E; Schuette, D; Schulz, B; Schutz, B F; Schwinberg, P; Scott, J; Scott, S M; Seifert, F; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Shaddock, D; Shah, S; Shahriar, M S; Shaltev, M; Shapiro, B; Shawhan, P; Shoemaker, D H; Sidery, T L; Siellez, K; Siemens, X; Sigg, D; Simakov, D; Singer, A; Singer, L; Sintes, A M; Skelton, G R; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M R; Smith, R J E; Smith-Lefebvre, N D; Soden, K; Son, E J; Sorazu, B; Souradeep, T; Sperandio, L; Staley, A; Steinert, E; Steinlechner, J; Steinlechner, S; Steplewski, S; Stevens, D; Stochino, A; Stone, R; Strain, K A; Straniero, N; Strigin, S; Stroeer, A S; Sturani, R; Stuver, A L; Summerscales, T Z; Susmithan, S; Sutton, P J; Swinkels, B; Szeifert, G; Tacca, M; Talukder, D; Tang, L; Tanner, D B; Tarabrin, S P; Taylor, R; Braack, A P M te; Thirugnanasambandam, M P; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, V; Tokmakov, K V; Tomlinson, C; Toncelli, A; Tonelli, M; Torre, O; Torres, C V; Torrie, C I; Travasso, F; Traylor, G; Tse, M; Ugolini, D; Unnikrishnan, C S; Vahlbruch, H; Vajente, G; Vallisneri, M; Brand, J F J va de; Broeck, C Va De; Putten, S va de; Sluys, M V va de; Heijningen, J va; Veggel, A A va; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, P J; Veitch, J; Venkateswara, K; Verkindt, D; Verma, S; Vetrano, F; Viceré, A; Vincent-Finley, R; Vinet, J -Y; Vitale, S; Vlcek, B; Vo, T; Vocca, H; Vorvick, C; Vousden, W D; Vrinceanu, D; Vyachanin, S P; Wade, A; Wade, L; Wade, M; Waldman, S J; Walker, M; Wallace, L; Wan, Y; Wang, J; Wang, M; Wang, X; Wanner, A; Ward, R L; Was, M; Weaver, B; Wei, L -W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; West, M; Westphal, T; Wette, K; Whelan, J T; White, D J; Whiting, B F; Wibowo, S; Wiesner, K; Wilkinson, C; Williams, L; Williams, R; Williams, T; Willis, J L; Willke, B; Wimmer, M; Winkelmann, L; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Yablon, J; Yakushin, I; Yamamoto, H; Yancey, C C; Yang, H; Yeaton-Massey, D; Yoshida, S; Yum, H; Yvert, M; Zadrożny, A; Zanolin, M; Zendri, J -P; Zhang, F; Zhang, L; Zhao, C; Zhu, H; Zhu, X J; Zotov, N; Zucker, M E; Zweizig, J

    2014-01-01

    Searches for a stochastic gravitational-wave background (SGWB) using terrestrial detectors typically involve cross-correlating data from pairs of detectors. The sensitivity of such cross-correlation analyses depends, among other things, on the separation between the two detectors: the smaller the separation, the better the sensitivity. Hence, a co-located detector pair is more sensitive to a gravitational-wave background than a non-co-located detector pair. However, co-located detectors are also expected to suffer from correlated noise from instrumental and environmental effects that could contaminate the measurement of the background. Hence, methods to identify and mitigate the effects of correlated noise are necessary to achieve the potential increase in sensitivity of co-located detectors. Here we report on the first SGWB analysis using the two LIGO Hanford detectors and address the complications arising from correlated environmental noise. We apply correlated noise identification and mitigation techniques...

  16. Versatile Wideband Balanced Detector for Quantum Optical Homodyne Tomography

    CERN Document Server

    Kumar, Ranjeet; MacRae, Andrew; Cairns, E; Huntington, E H; Lvovsky, A I

    2011-01-01

    We present a comprehensive theory and an easy to follow method for the design and construction of a wideband homodyne detector for time-domain quantum measurements. We show how one can evaluate the performance of a detector in a specific time-domain experiment based on electronic spectral characteristic of that detector. We then present and characterize a high-performance detector constructed using inexpensive, commercially available components such as low-noise high-speed operational amplifiers and high-bandwidth photodiodes. Our detector shows linear behavior up to a level of over 13 dB clearance between shot noise and electronic noise, in the range from DC to 100 MHz. The detector can be used for measuring quantum optical field quadratures both in the continuous-wave and pulsed regimes with pulse repetition rates up to about 250 MHz.

  17. THE HELIOCENTRIC DISTANCE WHERE THE DEFLECTIONS AND ROTATIONS OF SOLAR CORONAL MASS EJECTIONS OCCUR

    Energy Technology Data Exchange (ETDEWEB)

    Kay, C.; Opher, M., E-mail: ckay@bu.edu [Astronomy Department, Boston University, Boston, MA 02215 (United States)

    2015-10-01

    Understanding the trajectory of a coronal mass ejection (CME), including any deflection from a radial path, and the orientation of its magnetic field is essential for space weather predictions. Kay et al. developed a model, Forecasting a CME’s Altered Trajectory (ForeCAT), of CME deflections and rotation due to magnetic forces, not including the effects of reconnection. ForeCAT is able to reproduce the deflection of observed CMEs. The deflecting CMEs tend to show a rapid increase of their angular momentum close to the Sun, followed by little to no increase at farther distances. Here we quantify the distance at which the CME deflection is “determined,” which we define as the distance after which the background solar wind has negligible influence on the total deflection. We consider a wide range in CME masses and radial speeds and determine that the deflection and rotation of these CMEs can be well-described by assuming they propagate with constant angular momentum beyond 10 R{sub ⊙}. The assumption of constant angular momentum beyond 10 R{sub ⊙} yields underestimates of the total deflection at 1 AU of only 1%–5% and underestimates of the rotation of 10%. Since the deflection from magnetic forces is determined by 10 R{sub ⊙}, non-magnetic forces must be responsible for any observed interplanetary deflections or rotations where the CME has increasing angular momentum.

  18. Results on diamond timing detector for the TOTEM experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bossini, E., E-mail: edoardo.bossini@pi.infn.it [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Rome (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pisa (Italy)

    2016-07-11

    We describe the results and status of our R&D on diamond timing detectors for the TOTEM experiment at CERN. Tests with commercial devices have been done and here reported; the unsatisfactory results push us to design a new detector. We present test beams results and the front-end electronics, critical point of the design. Efficiency studies and timing performance dependence from detector capacitance will be also reported. - Highlights: • Diamond particles detector for precise Time Of Flight measurements. • Integrated very low-noise electronics. • Minimum Ionizing Particle detector. • Diamond detector development and characterization.

  19. UHECR correlations taking account of composition and Galactic magnetic deflections

    CERN Document Server

    Roberts, J

    2013-01-01

    We predict the arrival direction distribution of cosmic rays including their deflection in the Galactic magnetic field, for several combinations of source and composition hypotheses: the sources are hard X-ray AGNs or uniformly sample the matter distribution of galaxies, and the composition at the source is pure proton or is the Galactic cosmic ray composition measured by CREAM. We use the regular component of the Jansson-Farrar 2012 model for the GMF and allow for rigidities as low as 2 EeV. We report the correlations of published UHECRs, rescaling event energies so as to reconcile the spectra of the different experiments and taking the overall energy uncertainty into account; different composition hypotheses are considered. This work demonstrates the feasibility of calculating GMF deflections to low enough rigidities to allow for heavy composition in correlation studies, and that non-trivial arrival direction structure should be expected even for mixed or heavy composition, as long as UHECRs come from the l...

  20. Large deflection of flexible tapered functionally graded beam

    Institute of Scientific and Technical Information of China (English)

    A.R.Davoodinik; G.H.Rahimi

    2011-01-01

    In this paper the semi-analytical analyses of the flexible cantilever tapered functionally graded beam under combined inclined end loading and intermediate loading are studied.In order to derive the fully non-linear equations governing the non-linear deformation,a curvilinear coordinate system is introduced.A general non-linear second order differential equation that governs the shape of a deflected beam is derived based on the geometric nonlinearities,infinitesimal local displacements and local rotation concepts with remarkable physical properties of functionally graded materials.The solutions obtained from semi-analytical methods are numerically compared with the existing elliptic integral solution for the case of a flexible uniform cantilever functionally graded beam.The effects of taper ratio,inclined end load angle and material property gradient on large deflection of the beam are evaluated.The Adomian decomposition method will be useful toward the design of tapered functionally graded compliant mechanisms driven by smart actuators.

  1. Design and Field Test of a Galvanometer Deflected Streak Camera

    Energy Technology Data Exchange (ETDEWEB)

    Lai, C C; Goosman, D R; Wade, J T; Avara, R

    2002-11-08

    We have developed a compact fieldable optically-deflected streak camera first reported in the 20th HSPP Congress. Using a triggerable galvanometer that scans the optical signal, the imaging and streaking function is an all-optical process without incurring any photon-electron-photon conversion or photoelectronic deflection. As such, the achievable imaging quality is limited mainly only by optical design, rather than by multiple conversions of signal carrier and high voltage electron-optics effect. All core elements of the camera are packaged into a 12 inch x 24 inch footprint box, a size similar to that of a conventional electronic streak camera. At LLNL's Site-300 Test Site, we have conducted a Fabry-Perot interferometer measurement of fast object velocity using this all-optical camera side-by-side with an intensified electronic streak camera. These two cameras are configured as two independent instruments for recording synchronously each branch of the 50/50 splits from one incoming signal. Given the same signal characteristics, the test result has undisputedly demonstrated superior imaging performance for the all-optical streak camera. It produces higher signal sensitivity, wider linear dynamic range, better spatial contrast, finer temporal resolution, and larger data capacity as compared with that of the electronic counterpart. The camera had also demonstrated its structural robustness and functional consistence to be well compatible with field environment. This paper presents the camera design and the test results in both pictorial records and post-process graphic summaries.

  2. System for deflection measurements of floating dry docks

    Science.gov (United States)

    Gorbachev, Alexey A.; Pantyushin, Anton V.; Serikova, Mariya G.; Korotaev, Valery V.; Timofeev, Aleksandr N.

    2015-05-01

    In this paper we introduce a system for deflection measurement of floating dry docks. The system contains two measurement channels observing opposite directions of the dock. It also includes set of reference marks, an industrial computer and a display. Each channel contains CMOS camera with long focal-length lens. Reference marks are implemented as IR LED arrays with 940 nm working wavelength for better performance within bad weather conditions (e.g. fog, rain, high humidity etc.). In the paper we demonstrate results of an analysis of different optical schemes for coupling the oppositely directed channels of the measurement unit and show that the scheme with two image sensors with separated lenses is an optimal option, because it allows usage of nonequidistant location of reference marks and demonstrates the least value of parasitic shift caused by rotations of the measuring unit. The developed system was tested both on specially-designed setup and in real infrastructure of a floating dry dock. The conducted tests proved that a measuring error of the system is smaller than +/- 1.5 mm within the measurement range of +/- 150 mm when deflection of 100 m dock is measured. Obtained results showed that the system demonstrates an ability to work in a harsh environment including poor weather conditions.

  3. Algorithm for image registration and clutter and jitter noise reduction

    Energy Technology Data Exchange (ETDEWEB)

    Brower, K.L.

    1997-02-01

    This paper presents an analytical, computational method whereby two-dimensional images of an optical source represented in terms of a set of detector array signals can be registered with respect to a reference set of detector array signals. The detector image is recovered from the detector array signals and represented over a local region by a fourth order, two-dimensional taylor series. This local detector image can then be registered by a general linear transformation with respect to a reference detector image. The detector signal in the reference frame is reconstructed by integrating this detector image over the respective reference pixel. For cases in which the general linear transformation is uncertain by up to plus-or-minus two pixels, the general linear transformation can be determined by least squares fitting the detector image to the reference detector image. This registration process reduces clutter and jitter noise to a level comparable to the electronic noise level of the detector system. Test results with and without electronic noise using an analytical test function are presented.

  4. Phase-Noise and Amplitude-Noise Measurement of Low-Power Signals

    Science.gov (United States)

    Rubiola, Enrico; Salik, Ertan; Yu, Nan; Maleki, Lute

    2004-01-01

    Measuring the phase fluctuation between a pair of low-power microwave signals, the signals must be amplified before detection. In such cases the phase noise of the amplifier pair is the main cause of 1/f background noise of the instrument. this article proposes a scheme that makes amplification possible while rejecting the close in 1/f (flicker) noise of the two amplifiers. Noise rejection, which relies upon the understanding of the amplifier noise mechanism does not require averaging. Therefore, our scheme can also be the detector of a closed loop noise reduction system. the first prototype, compared to a traditional saturated mixer system under the same condition, show a 24 dB noise reduction of the 1/f region.

  5. Calorimeter detectors

    CERN Document Server

    de Barbaro, P; The ATLAS collaboration

    2013-01-01

    Although the instantaneous and integrated luminosity in HL-LHC will be far higher than the LHC detectors were originally designed for, the Barrel calorimeters of the four experiments are expected to continue to perform well  throughout the Phase II program. The conditions for the End-Cap calorimeters are far more challenging and whilst some detectors will require relatively modest changes, others require far more substantial upgrades. We present the results of longevity and performance studies for the calorimeter systems of the four main LHC experiments and outline the upgrade options under consideration. We include a discussion of the R&D required to make the final technology choices for the upgraded detectors.

  6. Determination of the Critical Value of Deflection for Embedded Cylindrical Structures

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-qi; CHEN Bin; WANG Hai-yan

    2005-01-01

    An embedded cylinder is a large-diameter cylinder embedded in a soil foundation. The state of failure of such an embedded cylindrical structure shows large deflection instead of slide and overturn of the traditional gravity type of structure placed on a rubble base or foundation base. The critical value of deflection of the embedded cylindrical structure, which is the maximum allowable deflection for stability calculation of the cylinder, is a vital control value. Through investigation on deflection and soil pressures on an embedded cylinder by model experiments, the variations of the angle of rotation θ of a cylinder with effective anti-overturning ratio η and moment MH of thrust are discussed. On the basis of experimental study, the critical value of deflection of the cylindrical structure is proposed in the paper. Meanwhile, the formulas for calculating deflection of cylinders are derived.

  7. Steady-state sinusoidal thermal characterization at chip level by internal infrared-laser deflection

    Energy Technology Data Exchange (ETDEWEB)

    Perpina, Xavier; Jorda, Xavier; Vellvehi, Miquel [Centre Nacional de Microelectronica (IMB-CNM-CSIC), Campus UAB, 08193 Bellaterra, Barcelona (Spain); Altet, Josep [Departament d' Enginyeria Electronica, Universitat Politecnica de Catalunya, Barcelona 08034 (Spain); Mestres, NarcIs [Institut de Ciencia dels Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Barcelona (Spain)

    2008-08-07

    A new approach is reported for thermally characterizing microelectronic devices and integrated circuits under a steady-state sinusoidal regime by internal infrared-laser deflection (IIR-LD). It consists of extracting the amplitude and phase Bode plots of the temperature profile inside the chip (depth-resolved measurements in the frequency domain). As a consequence, not only are the IIR-LD performances significantly improved (accuracy, robustness to noise, control of boundary conditions and heat flux confinement) but also the direct temperature measurement is feasible when thin regions are inspected and thermal parameters can be easily extracted (thermal diffusivity). In order to show the efficiency of this technique, a thermal test chip (TTC) is used. The TTC is thermally excited by imposing a cosine-like voltage waveform. As a result, a vertical temperature profile inside the die is obtained depending on the heating frequency. Repeating this procedure at several frequencies, the frequency response of the chip internal temperature profile is derived. By comparing the experimental results with the model predictions, good agreement is achieved. This technique allows evaluation of the thermal behaviour at the chip level; also it could be useful for failure analysis.

  8. Deflection routing in slotted self-routing networks with arbitrary topology

    OpenAIRE

    2002-01-01

    A deflection routing algorithm that can be applied to a novel self-routing address scheme for networks with arbitrary topology is proposed. The proposed deflection routing algorithm can be implemented all-optically using bitwise optical logic gates. Besides the primary output link selection, alternate output link choices by a packet at each node in case of deflection are also encoded in the address header. Priority classes can also be defined in the proposed address scheme. The performance of...

  9. Cascaded-systems analysis of sandwich x-ray detectors

    Science.gov (United States)

    Kim, D. W.; Kim, J.; Yun, S.; Youn, H.; Kim, H. K.

    2016-12-01

    Active sandwich-like multilayer detectors have been developed, and their potential for motion-artifact-free dual-energy x-ray imaging at a single exposure has been demonstrated in the material decomposition context. Since the sandwich detector uses the x-ray beam transmittance through the front layer, direct x-ray interaction within photodiodes in the front layer is unavoidable, and which can increase noise in the front detector images. Similar direct x-ray interaction can also occur in the rear detector layer. To obtain a better contrast performance, an additional filter layer can be placed between the two detector layers. However, this filter layer can increase adversely noise in images obtained from the rear detector layer by reducing the number of x-ray photons reaching it. A theoretical model, which can describe the signal-to-noise performance of the sandwich detector as functions of various design parameters, has been developed by using a linear cascaded-systems theory. From the cascaded-systems analysis, the direct x-ray interaction increases noise at the high spatial frequencies where the number of secondary quanta lessens. The intermediate filter layer enhances the contribution of additive electronic noise in the overall noise performance of the rear detector layer. The detailed cascaded-systems analysis on the x-ray sandwich detectors are reported in comparisons with the measured noise-power spectra and detective quantum efficiencies. The developed model will be useful for a better design and practical use of a sandwich detector for single-shot dual-energy imaging.

  10. Global Trends of CME Deflections Based on CME and Solar Parameters

    CERN Document Server

    Kay, C; Evans, R M

    2014-01-01

    Accurate space weather forecasting requires knowledge of the trajectory of coronal mass ejections (CMEs), including any deflections close to the Sun or through interplanetary space. Kay et al. 2013 introduced ForeCAT, a model of CME deflection resulting from the background solar magnetic field. For a magnetic field solution corresponding to Carrington Rotation (CR) 2029 (declining phase, April-May 2005), the majority of the CMEs deflected to the Heliospheric Current Sheet (HCS), the minimum in magnetic pressure on global scales. Most of the deflection occurred below 4 Rs. Here we extend ForeCAT to include a three dimensional description of the deflecting CME. We attempt to answer the following questions: a) Do all CMEs deflect to the magnetic minimum? and b) Does most deflection occur within the first few solar radii (~4 Rs)? Results for solar minimum and declining phase CMEs show that not every CME deflects to the magnetic minimum and that typically about half of the deflection occurs below 10 Rs. Slow, narr...

  11. Mission Analysis For the Ion Beam Deflection of Fictitious Asteroid 2015PDC

    CERN Document Server

    Bombardelli, Claudio; Cano, Juan Luis

    2015-01-01

    A realistic mission scenario for the deflection of fictitious asteroid 2015PDC is investigated that makes use of the ion beam shepherd concept as primary deflection technique. The article deals with the design of a low thrust rendezvous trajectory to the asteroid, the estimation of the propagated covariance ellipsoid and the outcome of a slow-push deflection starting from three worst case scenarios (impacts in New Delhi, Dhaka and Teheran). Displacing the impact point towards very low populated areas, as opposed to full deflection, is found to be the simplest and most effective mitigation approach. Mission design, technical and political aspects are discussed.

  12. UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction

    DEFF Research Database (Denmark)

    Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej

    2015-01-01

    A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1–5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists...... is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics...

  13. BRIEF REPORT: Photon deflection by a Coulomb field in noncommutative QED

    Science.gov (United States)

    Pires, C. A. de S.

    2004-12-01

    In noncommutative QED photons present self-interactions in the form of triple and quartic interactions. The triple interaction implies that, even though the photon is electrically neutral, it will deflect when in the presence of an electromagnetic field. If detected, such deflection would be undoubted evidence of noncommutative space-time. In this work we derive a general expression for the deflection of a photon by any electromagnetic field. As an application we consider the case of the deflection of a photon by an external static Coulomb field.

  14. Quantum Effects on the Deflection of Light and the Gauss-Bonnet Theorem

    CERN Document Server

    Jusufi, Kimet

    2016-01-01

    In this letter we apply the Gauss--Bonnet theorem to calculate the deflection angle by a quantum corrected Schwarzschild black hole in the weak limit approximation. In particular, we calculate the light deflection by two types of quantum corrected black holes: the renormalization group improved Schwarzschild solution and the quantum corrected Schwarzschild solution in Bohmian quantum mechanics. We start from the corresponding optical metrics to use then the Gauss--Bonnet theorem and calculate the Gaussian curvature in both cases. Finally, we calculate the leading terms of the deflection angle and show that quantum corrections modifies the deflection angle in both solutions.

  15. Orthogonally interdigitated shielded serpentine travelling wave cathode ray tube deflection structure

    Science.gov (United States)

    Hagen, Edward C.; Hudson, Charles L.

    1995-01-01

    A new deflection structure (12) which deflects a beam of charged particles, uch as an electron beam (15), includes a serpentine set (20) for transmitting a deflection field, and a shielding frame (25) for housing the serpentine set (20). The serpentine set (20) includes a vertical serpentine deflection element (22) and a horizontal serpentine deflection element (24). These deflection elements (22, 24) are identical, and are interdigitatedly and orthogonally disposed relative to each other, for forming a central transmission passage (75), through which the electron beam (15) passes, and is deflected by the deflection field, so as to minimize drift space signal distortion. The shielding frame (25) includes a plurality of ground blocks (26, 28, 30, 32), and forms an internal serpentine trough (77) within these ground blocks, for housing the serpentine set (20). The deflection structure (12) further includes a plurality of feedthrough connectors (35, 37, 35I, 37I), which are inserted through the shielding frame (25), and which are electrically connected to the serpentine set (20).

  16. Quantum Noise Locking

    CERN Document Server

    McKenzie, K; Goda, K; Lam, P K; Grosse, N; Gray, M B; Mavalvala, N; McClelland, D E; Kenzie, Kirk Mc; Mikhailov, Eugeniy; Goda, Keisuke; Lam, Ping Koy; Grosse, Nicolai; Gray, Malcolm B.; Mavalvala, Nergis; Clelland, David E. Mc

    2005-01-01

    Quantum optical states which have no coherent amplitude, such as squeezed vacuum states, can not rely on standard readout techniques to generate error signals for control of the quadrature phase. Here we investigate the use of asymmetry in the quadrature variances to obtain a phase-sensitive readout and to lock the phase of a squeezed vacuum state, a technique which we call noise locking (NL). We carry out a theoretical derivation of the NL error signal and the associated stability of the squeezed and anti-squeezed lock points. Experimental data for the NL technique both in the presence and absence of coherent fields are shown, including a comparison with coherent locking techniques. Finally, we use NL to enable a stable readout of the squeezed vacuum state on a homodyne detector.

  17. Quantum noise locking

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, Kirk [Center for Gravitational Physics, Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Mikhailov, Eugeniy E [LIGO Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Goda, Keisuke [LIGO Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Lam, Ping Koy [Quantum Optics Group, Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Grosse, Nicolai [Quantum Optics Group, Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Gray, Malcolm B [Center for Gravitational Physics, Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia); Mavalvala, Nergis [LIGO Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); McClelland, David E [Center for Gravitational Physics, Department of Physics, Faculty of Science, Australian National University, ACT 0200 (Australia)

    2005-10-01

    Quantum optical states which have no coherent amplitude, such as squeezed vacuum states, cannot rely on standard readout techniques to generate error signals for control of the quadrature phase. Here we investigate the use of asymmetry in the quadrature variances to obtain a phase-sensitive readout and to lock the phase of a squeezed vacuum state, a technique which we call noise locking (NL). We carry out a theoretical derivation of the NL error signal and the associated stability of the squeezed and anti-squeezed lock points. Experimental data for the NL technique both in the presence and absence of coherent fields are shown, including a comparison with coherent locking techniques. Finally, we use NL to enable a stable readout of the squeezed vacuum state on a homodyne detector.

  18. Noise performance of frequency modulation Kelvin force microscopy.

    Science.gov (United States)

    Diesinger, Heinrich; Deresmes, Dominique; Mélin, Thierry

    2014-01-02

    Noise performance of a phase-locked loop (PLL) based frequency modulation Kelvin force microscope (FM-KFM) is assessed. Noise propagation is modeled step by step throughout the setup using both exact closed loop noise gains and an approximation known as "noise gain" from operational amplifier (OpAmp) design that offers the advantage of decoupling the noise performance study from considerations of stability and ideal loop response. The bandwidth can be chosen depending on how much noise is acceptable and it is shown that stability is not an issue up to a limit that will be discussed. With thermal and detector noise as the only sources, both approaches yield PLL frequency noise expressions equal to the theoretical value for self-oscillating circuits and in agreement with measurement, demonstrating that the PLL components neither modify nor contribute noise. Kelvin output noise is then investigated by modeling the surrounding bias feedback loop. A design rule is proposed that allows choosing the AC modulation frequency for optimized sharing of the PLL bandwidth between Kelvin and topography loops. A crossover criterion determines as a function of bandwidth, temperature and probe parameters whether thermal or detector noise is the dominating noise source. Probe merit factors for both cases are then established, suggesting how to tackle noise performance by probe design. Typical merit factors of common probe types are compared. This comprehensive study is an encouraging step toward a more integral performance assessment and a remedy against focusing on single aspects and optimizing around randomly chosen key values.

  19. XMASS detector

    CERN Document Server

    Abe, K; Hiraide, K; Hirano, S; Kishimoto, Y; Kobayashi, K; Moriyama, S; Nakagawa, K; Nakahata, M; Nishiie, H; Ogawa, H; Oka, N; Sekiya, H; Shinozaki, A; Suzuki, Y; Takeda, A; Takachio, O; Ueshima, K; Umemoto, D; Yamashita, M; Yang, B S; Tasaka, S; Liu, J; Martens, K; Hosokawa, K; Miuchi, K; Murata, A; Onishi, Y; Otsuka, Y; Takeuchi, Y; Kim, Y H; Lee, K B; Lee, M K; Lee, J S; Fukuda, Y; Itow, Y; Nishitani, Y; Masuda, K; Takiya, H; Uchida, H; Kim, N Y; Kim, Y D; Kusaba, F; Motoki, D; Nishijima, K; Fujii, K; Murayama, I; Nakamura, S

    2013-01-01

    The XMASS project aims to detect dark matter, pp and $^{7}$Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  20. XMASS detector

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hieda, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Hiraide, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hirano, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kishimoto, Y.; Kobayashi, K.; Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nakagawa, K. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Ogawa, H. [Kamioka Observatory, Institute for Cosmic Ray Research, The University of Tokyo, Higashi-Mozumi, Kamioka, Hida, Gifu 506-1205 (Japan); Kavli Institute for the Physics and Mathematics of the Universe, the University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); and others

    2013-07-11

    The XMASS project aims to detect dark matter, pp and {sup 7}Be solar neutrinos, and neutrinoless double beta decay using ultra pure liquid xenon. The first phase of the XMASS experiment searches for dark matter. In this paper, we describe the XMASS detector in detail, including its configuration, data acquisition equipment and calibration system.

  1. Radiation Hardening of Silicon Detectors

    CERN Multimedia

    Leroy, C; Glaser, M

    2002-01-01

    %RD48 %title\\\\ \\\\Silicon detectors will be widely used in experiments at the CERN Large Hadron Collider where high radiation levels will cause significant bulk damage. In addition to increased leakage current and charge collection losses worsening the signal to noise, the induced radiation damage changes the effective doping concentration and represents the limiting factor to long term operation of silicon detectors. The objectives are to develop radiation hard silicon detectors that can operate beyond the limits of the present devices and that ensure guaranteed operation for the whole lifetime of the LHC experimental programme. Radiation induced defect modelling and experimental results show that the silicon radiation hardness depends on the atomic impurities present in the initial monocrystalline material.\\\\ \\\\ Float zone (FZ) silicon materials with addition of oxygen, carbon, nitrogen, germanium and tin were produced as well as epitaxial silicon materials with epilayers up to 200 $\\mu$m thickness. Their im...

  2. Periodic Relativity: Deflection of Light, Acceleration, Rotation Curves

    Directory of Open Access Journals (Sweden)

    Zaveri V. H.

    2015-01-01

    Full Text Available Vectorial analysis relating to derivation of deflection of light is presented. Curvilinear acceleration is distinguished from the Newtonian polar conic acceleration. The dif- ference between the two is due to the curvature term. Lorentz invariant expression for acceleration is derived. A physical theory of rotation curves of galaxies based on second solution to Einstein’s field equation is presented. Theory is applied to Milky Way, M31, NGC3198 and Solar system. Modified Kepler’s third law yields correct orbital periods of stars in a galaxy. Deviation factor in the line element of t he theory happens to be the ratio of the Newtonian gravitational acceleration to th e measured acceleration of the star in the galaxy. Therefore this deviation factor can replace the MOND function.

  3. Self-contained instrument for measuring subterranean tunnel wall deflection

    Science.gov (United States)

    Rasmussen, Donald Edgar; Hof, Jr., Peter John

    1978-01-01

    The deflection of a subterranean tunnel is measured with a rod-like, self-contained instrument that is adapted to be inserted into a radially extending bore of the tunnel adjacent an end of the tunnel where the tunnel is being dug. One end of the instrument is anchored at the end of the bore remote from the tunnel wall, while the other end of the intrument is anchored adjacent the end of the wall in proximity to the tunnel wall. The two ends of the instrument are linearly displaceable relative to each other; the displacement is measured by a transducer means mounted on the instrument. Included in the instrument is a data storage means including a paper tape recorder periodically responsive to a parallel binary signal indicative of the measured displacement.

  4. Asteroid Deflection Using a Spacecraft in Restricted Keplerian Motion

    CERN Document Server

    Ketema, Yohannes

    2016-01-01

    A method for asteroid deflection that makes use of a spacecraft moving back and forth on a segment of an appropriate Keplerian orbit about the asteroid is described and evaluated. It is shown that, on average, the spacecraft describing such a trajectory can exert a significantly larger force on the asteroid than e.g. a stationary gravity tractor, thereby reducing the time needed to effect a desired velocity change for the asteroid. Furthermore, the current method does not require canted thrusters on the spacecraft (unlike a stationary gravity tractor), markedly reducing the amount of fuel needed to create a given change in the asteroid velocity. In addition, the method allows for the simultaneous use of several spacecraft, further strengthening the overall tugging effect on the asteroid, and distributing the thrust requirement among the spacecraft.

  5. Fabrication and Testing of Deflecting Cavities for APS

    Energy Technology Data Exchange (ETDEWEB)

    Mammosser, John; Wang, Haipeng; Rimmer, Robert; Jim, Henry; Katherine, Wilson; Dhakal, Pashupati; Ali, Nassiri; Jim, Kerby; Jeremiah, Holzbauer; Genfa, Wu; Joel, Fuerst; Yawei, Yang; Zenghai, Li

    2013-09-01

    Jefferson Lab (Newport News, Virginia) in collaboration with Argonne National Laboratory (Argonne, IL) has fabricated and tested four first article, 2.8 GHz, deflecting SRF cavities, for Argonne's Short-Pulse X-ray (SPX) project. These cavities are unique in many ways including the fabrication techniques in which the cavity cell and waveguides were fabricated. These cavity subcomponents were milled from bulk large grain niobium ingot material directly from 3D CAD files. No forming of sub components was used with the exception of the beam-pipes. The challenging cavity and helium vessel design and fabrication results from the stringent RF performance requirements required by the project and operation in the APS ring. Production challenges and fabrication techniques as well as testing results will be discussed in this paper.

  6. Study of surface charges in ballistic deflection transistors

    Science.gov (United States)

    Millithaler, J.-F.; Iñiguez-de-la-Torre, I.; Mateos, J.; GonzáIez, T.; Margala, M.

    2015-12-01

    This paper presents a comprehensive study of the behavior of surface charges in ballistic deflection transistors, at room temperature, where the in-plane geometry associating two drains with two gates in push-pull modes allows the control of electron path. Monte Carlo simulations were performed and compared with experimental data by using different models for accounting for surface charge effects. The simple model which assumes a constant and uniform value of the surface charge provides good results at equilibrium, but it is not able to correctly reproduce the BDT’s complex behavior when biased. We have confirmed that for a correct description of the device operation it is necessary to use a model allowing the surface charge to adapt itself locally to the carrier concentration in its surroundings.

  7. Plumb line deflection varied with time obtained by repeated gravimetry

    Institute of Scientific and Technical Information of China (English)

    李辉; 付广裕; 李正心

    2001-01-01

    In this paper, the plumb line deflection varied with time (PLV) are calculated with the Vening-Meinesz formula for Xiaguan and Beijing point based on the 28 and 39 campaigns of gravimetry at the local gravity networks in the Western Yunnan Earthquake Prediction Experiment Area and the North China, respectively. Based on the results, we conclude that: ① the maximum of PLV is under 0.12 and amplitudes of interannual variation are under 0.022.②PLV can be determined with the reliability of 0.012 by the modeling based on the precession of repeated gravimetry. This implies that repeated gravimetry could be used to determine the PLV. ③There exist some common and different characteristics for the different places and different components. It may provide a new approach for the study on the local or global geodynamic by using repeated gravimetry.

  8. Crossed, Small-Deflection Energy Analyzer for Wind/Temperature Spectrometer

    Science.gov (United States)

    Herrero, Federico A.; Finne, Theodore T.

    2010-01-01

    Determination of neutral winds and ion drifts in low-Earth-orbit missions requires measurements of the angular and energy distributions of the flux of neutrals and ions entering the satellite from the ram direction. The magnitude and direction of the neutral-wind (or ion-drift) determine the location of the maximum in the angular distribution of the flux. Knowledge of the angle of maximum flux with respect to satellite coordinates (pointing) is essential to determine the wind (or ion-drift) vector. The crossed Small-Deflection Energy Analyzer (SDEA) spectrometer (see Figure 1) occupies minimal volume and consumes minimal power. Designed for upper atmosphere/ionosphere investigations at Earth altitudes above 100 km, the spectrometer operates by detecting the angular and energy distributions of neutral atoms/molecules and ions in two mutually perpendicular planes. In this configuration, the two detection planes actually cross at the spectrometer center. It is possible to merge two SDEAs so they share a common optical axis and alternate measurements between two perpendicular planes, and reduce the number of ion sources from two to one. This minimizes the volume and footprint significantly and reduces the ion source power by a factor of two. The area of the entrance aperture affects the number of ions detected/second and also determines the energy resolution. Thermionic emitters require heater power of about 100 mW to produce 1 mA of electron beam current. Typically, electron energy is about 100 eV and requires a 100-V supply for electron acceleration to supply an additional 100 mW of power. Thus, ion source power is at most 200 mW. If two ion sources were to be used, the ion source power would be, at most, 400 mW. Detector power, deflection voltage power, and microcontroller and other functions require less than 150 mW. A WTS (wind/ temperature spectrometer) with two separate optical axes would consume about 650 mW, while the crossed SDEA described here consumes about

  9. Theory of using magnetic deflections to combine charged particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Steckbeck, Mackenzie K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Several radiation effects projects in the Ion Beam Lab (IBL) have recently required two disparate charged particle beams to simultaneously strike a single sample through a single port of the target chamber. Because these beams have vastly different mass–energy products (MEP), the low-MEP beam requires a large angle of deflection toward the sample by a bending electromagnet. A second electromagnet located further upstream provides a means to compensate for the small angle deflection experienced by the high-MEP beam during its path through the bending magnet. This paper derives the equations used to select the magnetic fields required by these two magnets to achieve uniting both beams at the target sample. A simple result was obtained when the separation of the two magnets was equivalent to the distance from the bending magnet to the sample, and the equation is given by: Bs= 1/2(rc/rs) Bc, where Bs and Bc are the magnetic fields in the steering and bending magnet and rc/rs is the ratio of the radii of the bending magnet to that of the steering magnet. This result is not dependent upon the parameters of the high MEP beam, i.e. energy, mass, charge state. Therefore, once the field of the bending magnet is set for the low-MEP beam, and the field in the steering magnet is set as indicted in the equation, the trajectory path of any high-MEP beam will be directed into the sample.

  10. A practical exposure-equivalent metric for instrumentation noise in x-ray imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Yadava, G K; Kuhls-Gilcrist, A T; Rudin, S; Patel, V K; Hoffmann, K R; Bednarek, D R [Toshiba Stroke Research Center, State University of New York at Buffalo, Buffalo, NY 14214 (United States)

    2008-09-21

    The performance of high-sensitivity x-ray imagers may be limited by additive instrumentation noise rather than by quantum noise when operated at the low exposure rates used in fluoroscopic procedures. The equipment-invasive instrumentation noise measures (in terms of electrons) are generally difficult to make and are potentially not as helpful in clinical practice as would be a direct radiological representation of such noise that may be determined in the field. In this work, we define a clinically relevant representation for instrumentation noise in terms of noise-equivalent detector entrance exposure, termed the instrumentation noise-equivalent exposure (INEE), which can be determined through experimental measurements of noise-variance or signal-to-noise ratio (SNR). The INEE was measured for various detectors, thus demonstrating its usefulness in terms of providing information about the effective operating range of the various detectors. A simulation study is presented to demonstrate the robustness of this metric against post-processing, and its dependence on inherent detector blur. These studies suggest that the INEE may be a practical gauge to determine and compare the range of quantum-limited performance for clinical x-ray detectors of different design, with the implication that detector performance at exposures below the INEE will be instrumentation-noise limited rather than quantum-noise limited.

  11. Low noise road surfaces

    OpenAIRE

    Bolčina, Matjaž

    2014-01-01

    Noise is everywhere. Noise is a sound that makes people stressful and irritate. It often couses sleep disorders and also health problems like different cardiovascular disorders, hearing loss…In most cases traffic noise is the most disturbing. There are different ways to prevent people from traffic noise like building noise barriers and insulation of facades. However noise barriers and insulation of facades do not prevent noise formation, but are lowering existing noise. Another disadvantage i...

  12. Semiconductor Detectors; Detectores de Semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Cortina, E.

    2007-07-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  13. Searching for Stochastic Gravitational Waves Using Data from the Two Co-Located LIGO Hanford Detectors

    Science.gov (United States)

    Aasi, J.; Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Accadia, T.; Acernese, F.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Affeldt, C.; Agathos, M.; Aggarwal, N; Aguiar, O. D.; Ajith, P.; Allen, B.; Allocca, A.; Amador Ceron, E.; Amariutei, D.; Anderson, R. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Camp, Jordan B; Gehrels, N.; Kanner, J. B.

    2014-01-01

    Searches for a stochastic gravitational-wave background (SGWB) using terrestrial detectors typically involve cross-correlating data from pairs of detectors. The sensitivity of such cross-correlation analyses depends, among other things, on the separation between the two detectors: the smaller the separation, the better the sensitivity. Hence, a co-located detector pair is more sensitive to a gravitational-wave background than a nonco- located detector pair. However, co-located detectors are also expected to suffer from correlated noise from instrumental and environmental effects that could contaminate the measurement of the background. Hence, methods to identify and mitigate the effects of correlated noise are necessary to achieve the potential increase in sensitivity of co-located detectors. Here we report on the first SGWB analysis using the two LIGO Hanford detectors and address the complications arising from correlated environmental noise. We apply correlated noise identification and mitigation techniques to data taken by the two LIGO Hanford detectors, H1 and H2, during LIGO's fifth science run. At low frequencies, 40-460Hz, we are unable to sufficiently mitigate the correlated noise to a level where we may confidently measure or bound the stochastic gravitational-wave signal. However, at high frequencies, 460 - 1000Hz, these techniques are sufficient to set a 95% confidence level (C.L.) upper limit on the gravitational-wave energy density of Omega(f) advanced detectors, where correlated noise (e.g., from global magnetic fields) may affect even widely separated detectors.

  14. Electronic noise modeling in statistical iterative reconstruction.

    Science.gov (United States)

    Xu, Jingyan; Tsui, Benjamin M W

    2009-06-01

    We consider electronic noise modeling in tomographic image reconstruction when the measured signal is the sum of a Gaussian distributed electronic noise component and another random variable whose log-likelihood function satisfies a certain linearity condition. Examples of such likelihood functions include the Poisson distribution and an exponential dispersion (ED) model that can approximate the signal statistics in integration mode X-ray detectors. We formulate the image reconstruction problem as a maximum-likelihood estimation problem. Using an expectation-maximization approach, we demonstrate that a reconstruction algorithm can be obtained following a simple substitution rule from the one previously derived without electronic noise considerations. To illustrate the applicability of the substitution rule, we present examples of a fully iterative reconstruction algorithm and a sinogram smoothing algorithm both in transmission CT reconstruction when the measured signal contains additive electronic noise. Our simulation studies show the potential usefulness of accurate electronic noise modeling in low-dose CT applications.

  15. A design on low noise imaging circuit for SWIR sensor

    Science.gov (United States)

    Fan, Ben; Han, Zhixue; Ma, Fei; Dong, Shuli

    2016-11-01

    SWIR (Short Wave Infrared) imaging is an important imaging technology in space remote sensing. According to the characteristics of SWIR detector, the whole scheme of low noise imaging circuit is presented in this paper. For certain key circuit which noise is sensitive in the design, such as bias generation circuit, analysis of noise sources and calculation of theoretical noise value of actual circuit which is usually ignored in previous researches are proposed in order to estimate the level of circuit noise and optimize the circuit to reduce noise. The structure of analog filter amplifier circuit is also analyzed by introducing noise-factor analytic approach, based on the analysis result some design principles of the circuit are proposed. The noise suppression methods in the design are separately analyzed in both time suppression and space suppression; some specific methods for these two kinds of measures are listed in this paper. The final experiment results indicate that the low noise imaging circuit design based on above methods is reasonable and effective, the circuit has a higher SNR and can work normally at room temperature, and the whole design meets the original requirement of low noise. This low noise circuit for SWIR detector and its methods to analyze and calculate noise value are valuable examples for future similar designs.

  16. Arc Deflection Length Affected by Transverse Rotating Magnetic Field with Lateral Gas

    Science.gov (United States)

    Shiino, Toru; Ishii, Yoko; Yamamoto, Shinji; Iwao, Toru; High Current Energy Laboratory (HiCEL) Team

    2016-10-01

    Gas metal arc welding using shielding gas is often used in the welding industry. However, the arc deflection affected by lateral gas is problem because of inappropriate heat transfer. Shielding gas is used in order to prevent the instability affected by the arc deflection. However, the shielding gas causes turbulence, then blowhole of weld defect occurs because the arc affected by the instability is contaminated by the air. Thus, the magnetic field is applied to the arc in order to stabilize the arc using low amount of shielding gas. The method of applying the transverse rotating magnetic field (RMF) to the arc is one of the methods to prevent the arc instability. The RMF drives the arc because of electromagnetic force. The driven arc is considered to be prevented to arc deflection of lateral gas because the arc is restrained by the magnetic field because of the driven arc. In addition, it is assume the RMF prevented to the arc deflection of lateral gas from the multiple directions. In this paper, the arc deflection length affected by the RMF with lateral gas was elucidated in order to know the effect of the RMF for arc stabilization. Specifically, the arc deflection length affected by the magnetic frequency and the magnetic flux density is measured by high speed video camera. As a result, the arc deflection length decreases with increasing magnetic frequency, and the arc deflection length increases with increasing the magnetic flux density.

  17. Evaluation of disparate laser beam deflection technologies by means of number and rate of resolvable spots.

    Science.gov (United States)

    Bechtold, Peter; Hohenstein, Ralph; Schmidt, Michael

    2013-08-15

    We introduce a method to objectively evaluate systems of differing beam deflection technologies that commonly are described by disparate technical specifications. Using our new approach based on resolvable spots we will compare commercially available random-access beam deflection technologies, namely galvanometer scanners, piezo scanners, MEMS scanners, acousto-optic deflectors, and electro-optic deflectors.

  18. Short-term and long-term deflection of reinforced hollow core ...

    African Journals Online (AJOL)

    Short-term and long-term deflection of reinforced hollow core concrete slab systems. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... For the prediction of the long-term deflection, a measured ratio of long-term ...

  19. A nonlinear mathematical model for large deflection of incompressible saturated poroelastic beams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nonlinear governing equations are established for large deflection of incompressible fluid saturated poroelastic beams under constraint that diffusion of the pore fluid is only in the axial direction of the deformed beams. Then, the nonlinear bending of a saturated poroelastic cantilever beam with fixed end impermeable and free end permeable, subjected to a suddenly applied constant concentrated transverse load at its free end, is examined with the Galerkin truncation method. The curves of deflections and bending moments of the beam skeleton and the equivalent couples of the pore fluid pressure are shown in figures. The results of the large deflection and the small deflection theories of the cantilever poroelastic beam are compared, and the differences between them are revealed. It is shown that the results of the large deflection theory are less than those of the corresponding small deflection theory, and the times needed to approach its stationary states for the large deflection theory are much less than those of the small deflection theory.

  20. Spectral response of multi-element silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ludewigt, B.A.; Rossington, C.S.; Chapman, K. [Univ. of California, Berkeley, CA (United States)

    1997-04-01

    Multi-element silicon strip detectors, in conjunction with integrated circuit pulse-processing electronics, offer an attractive alternative to conventional lithium-drifted silicon Si(Li) and high purity germanium detectors (HPGe) for high count rate, low noise synchrotron x-ray fluorescence applications. One of the major differences between the segmented Si detectors and the commercially available single-element Si(Li) or HPGe detectors is that hundreds of elements can be fabricated on a single Si substrate using standard silicon processing technologies. The segmentation of the detector substrate into many small elements results in very low noise performance at or near, room temperature, and the count rate of the detector is increased many-fold due to the multiplication in the total number of detectors. Traditionally, a single channel of detector with electronics can handle {approximately}100 kHz count rates while maintaining good energy resolution; the segmented detectors can operate at greater than MHz count rates merely due to the multiplication in the number of channels. One of the most critical aspects in the development of the segmented detectors is characterizing the charge sharing and charge loss that occur between the individual detector strips, and determining how these affect the spectral response of the detectors.

  1. A small-gap electrostatic micro-actuator for large deflections.

    Science.gov (United States)

    Conrad, Holger; Schenk, Harald; Kaiser, Bert; Langa, Sergiu; Gaudet, Matthieu; Schimmanz, Klaus; Stolz, Michael; Lenz, Miriam

    2015-12-11

    Common quasi-static electrostatic micro actuators have significant limitations in deflection due to electrode separation and unstable drive regions. State-of-the-art electrostatic actuators achieve maximum deflections of approximately one third of the electrode separation. Large electrode separation and high driving voltages are normally required to achieve large actuator movements. Here we report on an electrostatic actuator class, fabricated in a CMOS-compatible process, which allows high deflections with small electrode separation. The concept presented makes the huge electrostatic forces within nanometre small electrode separation accessible for large deflections. Electrostatic actuations that are larger than the electrode separation were measured. An analytical theory is compared with measurement and simulation results and enables closer understanding of these actuators. The scaling behaviour discussed indicates significant future improvement on actuator deflection. The presented driving concept enables the investigation and development of novel micro systems with a high potential for improved device and system performance.

  2. Design Optimization of Deflection Caused After Release of Multilayer Structural Membrane of Symmetric Toggle Switch

    Directory of Open Access Journals (Sweden)

    K. Maninder

    2011-01-01

    Full Text Available This paper presents the optimization in deflection caused by the inbuilt stress generated in mechanical or movable membrane of Symmetric Toggle RF MEMS Switch (STS. The movable membrane of STS was initially fabricated with two different materials, i.e. Chrome and Gold. The simulated deflection at 70 °C was 11.9 µm, and experimental deflection was 11-12 µm. We present a study of inbuilt deflection reduction in multimetal movable layers without change in actuation voltage of the switch. The design study was initially carried out on cantilevers and then on structural membrane of STS. STS with proposed multilayer of Cr-Au-Au-Ti-Au has a simulated deflection of 0.56 µm at 70 °C.

  3. Four-dimensional visualization of a small-scale flame based on deflection tomography

    Science.gov (United States)

    Zhang, Bin; Liu, Zhigang; Zhao, Minmin

    2016-11-01

    Optical computed tomography is an important technique in the visualization and diagnosis of various flow fields. A small-scale diffusion flame was visualized using deflection tomography. A projection sampling system was proposed for deflection tomography to obtain deflectograms with a pair of gratings. Wave-front retrieval was employed for processing the deflectograms to obtain the deflection angles of the rays. This two-dimensional data extraction method expanded the application of deflection tomography and was suitable for the projection extraction of small-scale combustion. Deflection angle revision reconstruction algorithm was used to reconstruct the temperature distributions in 10 cross sections for each deflectogram in different instants. The flow structure was reconstructed using a visualization toolkit equipped with the marching cube and ray casting algorithms. The performed experiments demonstrated the three-dimensional dynamic visualization of temperature distributions and the flame structures of small-scale diffusion combustion.

  4. Experimental and Theoretical Deflections of Hybrid Composite Sandwich Panel under Four-point Bending Load

    Directory of Open Access Journals (Sweden)

    Jauhar Fajrin

    2017-03-01

    Full Text Available This paper presents a comparison of theoretical and experimental deflection of a hybrid sandwich panel under four-point bending load. The paper initially presents few basic equations developed under three-point load, followed by development of model under four-point bending load and a comparative analysis between theoretical and experimental results. It was found that the proposed model for predicting the deflection of hybrid sandwich panels provided fair agreement with the experimental values. Most of the sandwich panels showed theoretical deflection values higher than the experimental values, which is desirable in the design. It was also noticed that the introduction of intermediate layer does not contribute much to reduce the deflection of sandwich panel as the main contributor for the total deflection was the shear deformation of the core that mostly determined by the geometric of the samples and the thickness of the core.

  5. Improvements of the undulator spectral performance by compensating the backing beam deflection

    CERN Document Server

    Wang, C; Chang, L H; Chang, C H; Fan, T C; Bach, H; Blomqvist, I

    2002-01-01

    This study thoroughly examines how the backing beam deflection affects the undulator spectral performance. Reduction of the undulator spectral intensity owing to backing beam deflection is analytically evaluated based on plane-wave approximation. The results reveal that the amplitude and the slope of the backing beam deflection affect the undulator spectral performance. Provided is a novel figure-of-merit, rms of the regressed accumulated gap deviation, to determine the backing beam deflection budget. An example of a 3.9 m undulator supporting carriage mounted with 50-mm period length undulator magnet (U5) under a maximum magnetic loading of 5 metric tons at a minimum operating gap of 14 mm, is provided. Its mechanical features are first examined via 3D commercial finite element code ANSYS that concludes the backing beam deflection is influenced heavily by the rigidity of the undulator support frames. Examining the corresponding spectral performance shows that significantly diminishing the undulator spectral ...

  6. Numerical Simulation Study on the Surface Deflection of Cylindrical Shallow Shell

    Institute of Scientific and Technical Information of China (English)

    XING Zhongwen; BAO Jun; LIU Zhongyuan; YANG Yuying; SUN Zhenzhong

    2006-01-01

    The increasing applications of new materials such as high strength low alloy (HSAL) steels and aluminum alloy sheets have lead to greater focus on the surface deflections of auto body panels in the automobile industry in recent years. The finite element models of cylindrical shallow shell that can represent auto body panels are established. Numerical simulations of forming and unloading of cylindrical shallow shell are carried out. And a measurement and evaluation method of the surface deflection is introduced. The simulations of surface deflections with various blank holding forces (BHF) show great agreement with the experimental results. The influence laws of sheet thickness and material properties such as yield strength σs, strain-hardening exponent n, anisotropy parameter r and strength coefficient k on the surface deflection are achieved by simulations, which give a basic reference for controlling surface deflections.

  7. Commissioning of Silicon detectors for the COMPASS experiment at CERN

    CERN Document Server

    Wagner, R M

    2001-01-01

    This document describes the silicon microstrip detectors used in the COMPASS experiment. The main features of silicon microstrip detectors, mechanisms of radiation damages and the principles of the Lazarus effect are reviewed. The specific realization of silicon microstrip detectors in the COMPASS experiment is described. Production and tests done in the lab are discussed. Here, emphasis is placed on the noise performance of the detectors. The analysis of readout and performance tests in a test beam at CERN is done. Commissioning, debugging and first tests of the detectors and of the readout system on the COMPASS beam line in the 2001 beam time are presented.

  8. Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

    Science.gov (United States)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adamo, M.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackburn, L.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chatterji, S.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.; DeRosa, R. T.; De Rosa, R.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gatto, A.; Gaur, G.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.

    2016-07-01

    On 14 September 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

  9. Noise characteristics analysis of short wave infrared InGaAs focal plane arrays

    Science.gov (United States)

    Yu, Chunlei; Li, Xue; Yang, Bo; Huang, Songlei; Shao, Xiumei; Zhang, Yaguang; Gong, Haimei

    2017-09-01

    The increasing application of InGaAs short wave infrared (SWIR) focal plane arrays (FPAs) in low light level imaging requires ultra-low noise FPAs. This paper presents the theoretical analysis of FPA noise, and point out that both dark current and detector capacitance strongly affect the FPA noise. The impact of dark current and detector capacitance on FPA noise is compared in different situations. In order to obtain low noise performance FPAs, the demand for reducing detector capacitance is higher especially when pixel pitch is smaller, integration time is shorter, and integration capacitance is larger. Several InGaAs FPAs were measured and analyzed, the experiments' results could be well fitted to the calculated results. The study found that the major contributor of FPA noise is coupled noise with shorter integration time. The influence of detector capacitance on FPA noise is more significant than that of dark current. To investigate the effect of detector performance on FPA noise, two kinds of photodiodes with different concentration of the absorption layer were fabricated. The detectors' performance and noise characteristics were measured and analyzed, the results are consistent with that of theoretical analysis.

  10. Noise studies during the first Virgo science run and after

    Energy Technology Data Exchange (ETDEWEB)

    Acernese, F; Avino, S; Barone, F [INFN, Sezione di Napoli (Italy); Alshourbagy, M; Barsotti, L; Bigotta, S; Birindelli, S [INFN, Sezione di Pisa (Italy); Amico, P; Bosi, L [INFN, Sezione di Perugia (Italy); Antonucci, F; Astone, P [INFN, Sezione di Roma (Italy); Aoudia, S; Bondu, F [Lab. Artemis, Univ. NSA, Obs. Cote d' Azur, CNRS, BP 4229 06304 Nice, Cedex 4 (France); Arun, K G; Barsuglia, M; Bizouard, M A [LAL, Univ. Paris-Sud, IN2P3/CNRS, Orsay (France); Baggio, L [Laboratoire d' Annecy-le-Vieux de Physique des Particules (LAPP), IN2P3/CNRS, Universite de Savoie, Annecy-le-Vieux (France); Ballardin, G [European Gravitational Observatory (EGO), Cascina (Italy); Bauer, Th S [National Institute for Subatomic Physics, NL-1009 DB Amsterdam (Netherlands); Boccara, C [ESPCI, Paris (France)], E-mail: irene.fiori@ego-gw.it (and others)

    2008-09-21

    The first Virgo long science run (VSR1) lasted 136 days, from 18th May 2007. During the run several noise sources were identified and reduced; this significantly improved the detector sensitivity between the start and the end of the run. We describe three noise studies, showing how data monitoring programs and simple analysis tools permitted the first detection of the noise and provided useful information regarding its origin.

  11. Noise radar target detection in the presence of alpha-stable noise

    Science.gov (United States)

    Gajo, Zbigniew; Malanowski, Mateusz

    2008-01-01

    The paper presents a concept of the simple robustification of correlation detector in the continuous wave noise radar. It was assumed that the received signal was distorted with additive -stable noise. The simulation results show that using nonlinear transformation of the received signal prior to correlation it is possible to improve the radar sensitivity in the non-Gaussian impulsive environment by several dB.

  12. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli.

    Substantial progress has been made on the RPC system resulting in a high standard of operation. Impressive improvements have been made in the online software and DCS PVSS protocols that ensure robustness of the configuration phase and reliability of the detector monitoring tasks. In parallel, an important upgrade of CCU ring connectivity was pursued to avoid noise pick-up and consequent  data transmission errors during operation with magnetic field. While the barrel part is already well synchronized thanks to the long cosmics runs, some refinements are still required on the forward part. The "beam splashes" have been useful to cross check  the existing delay constants, but further efforts will be made as soon as a substantial sample of beam-halo events is available. Progress has been made on early detector performance studies. The RPC DQM tool is being extensively used and minor bugs have been found. More plots have been added and more people have been tr...

  13. Soil Electromagnetic Properties and Metal Detector Performance: Theory and Measurement

    Science.gov (United States)

    2008-11-17

    detection. Despite ongoing evolution and refinement of metal detector technology, however, the practical performance of both continuous wave (FDEM) and...noise ratio and increase the false-detection rate. At certain locations, the soil effect is so severe as to render a given metal detector practically inoperable.

  14. The CLEO-III Ring Imaging Cherenkov Detector

    CERN Document Server

    Mountain, R J; Artuso, M; Ayad, R; Azfar, F; Coan, T E; Efimov, A; Fadeev, V; Kopp, S E; Kubota, Y; Lipeles, E; Majumder, G; Schuh, S; Skwarnicki, T; Smith, A; Staeck, J; Stone, S; Viehhauser, G; Volobuev, I P

    1999-01-01

    The CLEO-III Detector upgrade for charged particle identification is discussed. The RICH design uses solid LiF crystal radiators coupled with multi-wire chamber photon detectors, using TEA as the photosensor, and low-noise Viking readout electronics. Results from our beam test at Fermilab are presented.

  15. Comet deflection by directed energy: a finite element analysis

    Science.gov (United States)

    Madajian, Jonathan; Griswold, Janelle; Gandra, Anush; Hughes, Gary B.; Zhang, Qicheng; Rupert, Nic; Lubin, Philip

    2016-09-01

    Comets and Asteroids are viable threats to our planet; if these space rocks are smaller than 25 meters, they burn up in the atmosphere, but if they are wider than 25 meters they can cause damage to the impact area. Anything more than one to two kilometers can have worldwide effects, furthermore a mile-wide asteroid travelling at 30,000 miles per hour has the energy equal to a megaton bomb and is very likely to wipe out most of the life on Earth. Residents near Chelyabinsk, Russia experienced the detrimental effects of a collision with a Near-Earth Asteroid (NEA) on 15 February 2013 as a 20 m object penetrated the atmosphere above that city. The effective yield from this object was approximately 1/2 Megaton TNT equivalent (Mt), or that of a large strategic warhead. The 1908 Tunguska event, also over Russia, is estimated to have had a yield of approximately 15 Mt and had the potential to kill millions of people had it come down over a large city1. In the face of such danger a planetary defense system is necessary and this paper proposes a design for such a system. DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) is a phased array laser system that can be used to oblate, deflect and de-spin asteroids and comets.

  16. String formulation of space charge forces in a deflecting bunch

    Science.gov (United States)

    Talman, Richard

    2004-10-01

    The force between two moving point charges, because of its inverse square law singularity, cannot be applied directly in the numerical simulation of bunch dynamics; radiative effects make this especially true for short bunches being deflected by magnets. This paper describes a formalism circumventing this restriction in which the basic ingredient is the total force on a point charge comoving with a longitudinally aligned, uniformly charged string. Bunch evolution can then be treated using direct particle-to-particle, intrabeam scattering, with no need for an intermediate, particle-in-cell, step. Electric and magnetic fields do not appear individually in the theory. Since the basic formulas are both exact (in paraxial approximation) and fully relativistic, they are applicable to beams of all particle types and all energies. But the theory is expected to be especially useful for calculating the emittance growth of the ultrashort electron bunches of current interest for energy recovery linacs and free-electron lasers. The theory subsumes coherent synchrotron radiation and centrifugal space charge force. Renormalized, on-axis, longitudinal field components are in excellent agreement with values from Saldin et al. [DESY Report No. DESY-TESLA-FEL-96-14, 1995; Nucl. Instrum. Methods Phys. Res., Sect. ANIMAER0168-9002 417, 158 (1998).10.1016/S0168-9002(98)00623-8

  17. String formulation of space charge forces in a deflecting bunch

    Directory of Open Access Journals (Sweden)

    Richard Talman

    2004-10-01

    Full Text Available The force between two moving point charges, because of its inverse square law singularity, cannot be applied directly in the numerical simulation of bunch dynamics; radiative effects make this especially true for short bunches being deflected by magnets. This paper describes a formalism circumventing this restriction in which the basic ingredient is the total force on a point charge comoving with a longitudinally aligned, uniformly charged string. Bunch evolution can then be treated using direct particle-to-particle, intrabeam scattering, with no need for an intermediate, particle-in-cell, step. Electric and magnetic fields do not appear individually in the theory. Since the basic formulas are both exact (in paraxial approximation and fully relativistic, they are applicable to beams of all particle types and all energies. But the theory is expected to be especially useful for calculating the emittance growth of the ultrashort electron bunches of current interest for energy recovery linacs and free-electron lasers. The theory subsumes coherent synchrotron radiation and centrifugal space charge force. Renormalized, on-axis, longitudinal field components are in excellent agreement with values from Saldin et al. [DESY Report No. DESY-TESLA-FEL-96-14, 1995; Nucl. Instrum. Methods Phys. Res., Sect. A 417, 158 (1998.NIMAER0168-900210.1016/S0168-9002(9800623-8

  18. A simple damage detection indicator using operational deflection shapes

    Science.gov (United States)

    Sampaio, R. P. C.; Maia, N. M. M.; Almeida, R. A. B.; Urgueira, A. P. V.

    2016-05-01

    Catastrophic structural failure of aircrafts, bridges, buildings and other structures in modern societies has always been of primary concern because of the loss of human lifes and of negative economic impact. The aging of the structures, the growing dependency on their role in our networks of transportation, energy and comunications, the smaller construction tolerances, the bigger power demanded and the media and society awardness to catastrophic events are sufficient motivations for the growing field of structural health monitoring, which aims at assessing the actual condition of a structure and to identify incipient damage. Damage identification can be considered as a two step process, the detection and the diagnosis. The former, and fundamental step, is the confirmation of an efective damage existence. When the response is affirmative, the latter step begins with the diagnosis, and then the questions are: where?, how much?, what type?, when will it fail? In this paper the authors propose a simple method to detect and relatively quantify structural damage by using measured vibrations data, specifically the operational deflections shapes. Numerical simulations and experimental tests are presented to validate the proposed method.

  19. Moth tails divert bat attack: evolution of acoustic deflection.

    Science.gov (United States)

    Barber, Jesse R; Leavell, Brian C; Keener, Adam L; Breinholt, Jesse W; Chadwell, Brad A; McClure, Christopher J W; Hill, Geena M; Kawahara, Akito Y

    2015-03-03

    Adaptations to divert the attacks of visually guided predators have evolved repeatedly in animals. Using high-speed infrared videography, we show that luna moths (Actias luna) generate an acoustic diversion with spinning hindwing tails to deflect echolocating bat attacks away from their body and toward these nonessential appendages. We pit luna moths against big brown bats (Eptesicus fuscus) and demonstrate a survival advantage of ∼ 47% for moths with tails versus those that had their tails removed. The benefit of hindwing tails is equivalent to the advantage conferred to moths by bat-detecting ears. Moth tails lured bat attacks to these wing regions during 55% of interactions between bats and intact luna moths. We analyzed flight kinematics of moths with and without hindwing tails and suggest that tails have a minimal role in flight performance. Using a robust phylogeny, we find that long spatulate tails have independently evolved four times in saturniid moths, further supporting the selective advantage of this anti-bat strategy. Diversionary tactics are perhaps more common than appreciated in predator-prey interactions. Our finding suggests that focusing on the sensory ecologies of key predators will reveal such countermeasures in prey.

  20. GPS deflection monitoring of the West Gate Bridge

    Science.gov (United States)

    Raziq, Noor; Collier, Philip

    2007-05-01

    The achievable precision and relatively high sampling rates of currently available GPS receivers are well suited for monitoring the movements of long-span engineering structures where the amplitude of movements is often more than a few centimetres and the frequency of vibrations is low (below 10 Hz). However, engineering structures often offer non-ideal environments for GPS data collection due to high multipath interference and obstructions causing cycle slips in the GPS observations. Also, for many engineering structures such as bridge decks, vertical movements are more pronounced and more structurally critical than horizontal movements. Accuracy of GPS determined positions in the vertical direction is typically two to three times poorer than in the horizontal component. This paper describes the results of a GPS deflection monitoring trial on the West Gate Bridge in Melbourne, Australia. The results are compared to the estimated frequencies and movements from the design of the bridge and previous accelerometer campaigns. The frequency information derived from the GPS results is also compared to frequency data extracted from an accelerometer installed close to a GPS receiver. GPS results agree closely to the historical results and recent accelerometer trials for key modal frequencies. This indicates the suitability of GPS receivers to monitor engineering structures that exhibit smaller movements due to their stiffness and in environments not ideally suited to using GPS.

  1. Three-dimensional parabolic equation modeling of mesoscale eddy deflection.

    Science.gov (United States)

    Heaney, Kevin D; Campbell, Richard L

    2016-02-01

    The impact of mesoscale oceanography, including ocean fronts and eddies, on global scale low-frequency acoustics is examined using a fully three-dimensional parabolic equation model. The narrowband acoustic signal, for frequencies from 2 to 16 Hz, is simulated from a seismic event on the Kerguellen Plateau in the South Indian Ocean to an array of receivers south of Ascension Island in the South Atlantic, a distance of 9100 km. The path was chosen for its relevance to seismic detections from the HA10 Ascension Island station of the International Monitoring System, for its lack of bathymetric interaction, and for the dynamic oceanography encountered as the sound passes the Cape of Good Hope. The acoustic field was propagated through two years (1992 and 1993) of the eddy-permitting ocean state estimation ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II) system. The range of deflection of the back-azimuth was 1.8° with a root-mean-square of 0.34°. The refraction due to mesoscale oceanography could therefore have significant impacts upon localization of distant low-frequency sources, such as seismic or nuclear test events.

  2. Comparison of flat-panel detector and image-intensifier detector for cone-beam CT.

    Science.gov (United States)

    Baba, Rika; Konno, Yasutaka; Ueda, Ken; Ikeda, Shigeyuki

    2002-01-01

    We evaluated a flat-panel detector (FPD) (scintillator screen and a-Si photo-sensor array) for use in a cone-beam computed tomography (CT) detector and compared it with an image-intensifier detector (IID). The FPD cone-beam CT system has a higher spatial resolution than the IID system. At equal pixel sizes, the standard deviation of noise intensity of the FPD system is equal to that of the IID system. However, the circuit noise of the FPD must be reduced, especially at low doses. Our evaluations show that the FPD system has a strong potential for use as a cone-beam CT detector because of high-spatial resolution.

  3. Comparing deflection measurements of a magnetically steerable catheter using optical imaging and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lillaney, Prasheel, E-mail: Prasheel.Lillaney@ucsf.edu; Caton, Curtis; Martin, Alastair J.; Losey, Aaron D.; Evans, Leland; Saeed, Maythem; Cooke, Daniel L.; Wilson, Mark W.; Hetts, Steven W. [Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California 94143 (United States)

    2014-02-15

    Purpose: Magnetic resonance imaging (MRI) is an emerging modality for interventional radiology, giving clinicians another tool for minimally invasive image-guided interventional procedures. Difficulties associated with endovascular catheter navigation using MRI guidance led to the development of a magnetically steerable catheter. The focus of this study was to mechanically characterize deflections of two different prototypes of the magnetically steerable catheterin vitro to better understand their efficacy. Methods: A mathematical model for deflection of the magnetically steerable catheter is formulated based on the principle that at equilibrium the mechanical and magnetic torques are equal to each other. Furthermore, two different image based methods for empirically measuring the catheter deflection angle are presented. The first, referred to as the absolute tip method, measures the angle of the line that is tangential to the catheter tip. The second, referred to the base to tip method, is an approximation that is used when it is not possible to measure the angle of the tangent line. Optical images of the catheter deflection are analyzed using the absolute tip method to quantitatively validate the predicted deflections from the mathematical model. Optical images of the catheter deflection are also analyzed using the base to tip method to quantitatively determine the differences between the absolute tip and base to tip methods. Finally, the optical images are compared to MR images using the base to tip method to determine the accuracy of measuring the catheter deflection using MR. Results: The optical catheter deflection angles measured for both catheter prototypes using the absolute tip method fit very well to the mathematical model (R{sup 2} = 0.91 and 0.86 for each prototype, respectively). It was found that the angles measured using the base to tip method were consistently smaller than those measured using the absolute tip method. The deflection angles measured

  4. Cascaded systems analysis of photon counting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Zbijewski, W.; Gang, G.; Stayman, J. W. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Taguchi, K.; Carrino, J. A. [Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Lundqvist, M.; Fredenberg, E. [Philips Healthcare, Solna 171 41 (Sweden); Siewerdsen, J. H., E-mail: jeff.siewerdsen@jhu.edu [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States)

    2014-10-15

    Purpose: Photon counting detectors (PCDs) are an emerging technology with applications in spectral and low-dose radiographic and tomographic imaging. This paper develops an analytical model of PCD imaging performance, including the system gain, modulation transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). Methods: A cascaded systems analysis model describing the propagation of quanta through the imaging chain was developed. The model was validated in comparison to the physical performance of a silicon-strip PCD implemented on an experimental imaging bench. The signal response, MTF, and NPS were measured and compared to theory as a function of exposure conditions (70 kVp, 1–7 mA), detector threshold, and readout mode (i.e., the option for coincidence detection). The model sheds new light on the dependence of spatial resolution, charge sharing, and additive noise effects on threshold selection and was used to investigate the factors governing PCD performance, including the fundamental advantages and limitations of PCDs in comparison to energy-integrating detectors (EIDs) in the linear regime for which pulse pileup can be ignored. Results: The detector exhibited highly linear mean signal response across the system operating range and agreed well with theoretical prediction, as did the system MTF and NPS. The DQE analyzed as a function of kilovolt (peak), exposure, detector threshold, and readout mode revealed important considerations for system optimization. The model also demonstrated the important implications of false counts from both additive electronic noise and charge sharing and highlighted the system design and operational parameters that most affect detector performance in the presence of such factors: for example, increasing the detector threshold from 0 to 100 (arbitrary units of pulse height threshold roughly equivalent to 0.5 and 6 keV energy threshold, respectively), increased the f{sub 50} (spatial

  5. Wideband Detection of the Third Moment of Shot Noise by a Hysteretic Josephson Junction

    OpenAIRE

    Timofeev, A. V.; Meschke, M.; Peltonen, J. T.; Heikkilä, T. T.; Pekola, Jukka P.

    2007-01-01

    We use a hysteretic Josephson junction as an C of the third moment of shot noise of a tunnel junction. The detectable bandwidth is determined by the plasma frequency of the detector, which is about 50 GHz in the present experiment. The third moment of shot noise results in a measurable change of the switching rate when reversing polarity of the current through the noise source. We analyze the observed asymmetry assuming adiabatic response of the detector. Peer reviewed

  6. The Heliocentric Distance Where the Deflections and Rotations of Solar Coronal Mass Ejections Occur

    CERN Document Server

    Kay, C

    2015-01-01

    Understanding the trajectory of a coronal mass ejection (CME), including any deflection from a radial path, and the orientation of its magnetic field is essential for space weather predictions. Kay et al. (2015b) developed a model, Forecasting a CME's Altered Trajectory (ForeCAT), of CME deflections and rotation due to magnetic forces, not including the effects of reconnection. ForeCAT is able to reproduce the deflection of observed CMEs (Kay et al. 2015a). The deflecting CMEs tend to show a rapid increase of their angular momentum close to the Sun, followed by little to no increase at farther distances. Here we quantify the distance at which the CME deflection is "determined," which we define as the distance after which the background solar wind has negligible influence on the total deflection. We consider a wide range in CME masses and radial speeds and determine that the deflection and rotation of these CMEs can be well-described by assuming they propagate with constant angular momentum beyond 10 Rs. The a...

  7. Deflection determination of concrete structures considering nonlinearity based on long-gauge strain sensors

    Science.gov (United States)

    Hong, Wan; Lv, Kui; Li, Bing; Jiang, Yuchen; Hu, Xiamin; Qu, Qizhong

    2017-10-01

    Deflection determination of concrete structures using distributed long-gauge strain sensors is investigated in this paper. Firstly, the relationship between deflection and distributed long-gauge strain of concrete beams is presented, and the method is independent of external load and takes account of structural nonlinearity. The deflection distribution along the span of a beam-like structure can be predicted from strain response for the whole process of loading (elastic stage, concrete cracking stage and steel yielding stage). Secondly, experiment of a reinforced concrete beam has been conducted to verify the accuracy of the method. Experimental results show that the relative error between the estimated and actual deflection can be controlled within about 5% while the error can reach up to about 70% if structural nonlinearity is not considered. Finally, the influence of error of material parameters and sensor gauge length on deflection estimation has been analyzed. The error of concrete compression strength has a limited influence on deflection prediction while the contribution of tensile concrete should be considered before concrete cracking. The error of area of tensile bars will affect the deflection accuracy after concrete cracking.

  8. Influence of deflection hole angle on effusion cooling in a real combustion chamber condition

    Directory of Open Access Journals (Sweden)

    Liu Xiao

    2015-01-01

    Full Text Available Fluid-solid coupling simulation is conducted to investigate the performance of effusion cooling in the real combustion chamber condition of strong rotation and primary holes. The wall temperature and film cooling effectiveness of different deflection angle is analyzed. From the results, it is concluded that the performance of effusion is better than conventional film cooling. The wall temperature and gradient is lower, the cooling efficiency is higher and the coolant is reduced by 20%, but pressure loss is slightly increased. The cooling effectiveness decreases behind primary holes because of local combustion. Comparison with the effect of deflection angle, the cooling performance of 60 deg deflection angle is best. The coolant is better attached to the wall downstream when the deflection angle is same as the rotating mainstream. In addition, the effect of deflection angle is not so significant on the coolant flow rate, but a large negative impact on the pressure loss. Although the cooling effectiveness of 60 deg deflection angle is highest, the total pressure recovery coefficient is lower. The maximum temperature drops about 70K and the outlet temperature distribution trends more consistent. So various factors should be taken into consideration when designing of deflection angle.

  9. Implementation of Input Block of Minimally Buffered Deflection NoC Router

    Directory of Open Access Journals (Sweden)

    Priti M. Shahane

    2016-08-01

    Full Text Available The traditional system on chip designs employ the shared bus architecture for data transfer in highly integrated Multiprocessor system on chips(MPSoC.Network on chip (NoCis a new paradigm for on chip communication for Multiprocessor systems on chips(MPSoCs. NoCs replace the traditional shared buses system with routing switches. Heart of the NoC is the router and it consists of an input buffer, arbiter, crossbar and an output port. The NoC router uses a buffer to store the incoming packets. These buffers improve the performance but they consume more power and area. Bufferless deflection routing is the solution for improvement in energy efficiency. In this method deflections of the packets take place to overcome the contention problem. But at high network load, deflection routing degrades the performance because of unnecessary hopping of data packets. The MinBD (minimally buffered deflection router is a new router design that uses a small buffer for bufferless deflection routing. In this paper the input block of MinBD router is implemented on FPGA which shows that a small buffer will help to reduce the network deflection rate. It also improves the performance and energy efficiency while buffering only deflected data packets.

  10. New results from the CERN-SPS beam deflection experiments with bent crystals

    Science.gov (United States)

    Baurichter, A.; Kirsebom, K.; Medenwaldt, R.; Møller, S. P.; Worm, T.; Uggerhøj, E.; Mikkelsen, U.; Graftström, P.; Gatignon, L.; Elsener, K.; Doble, N.; Biino, C.; Freund, A.; Vilakazi, Z.; Hage-Ali, M.; Siffert, P.; Clément, M.

    1996-10-01

    Results from five distinct bending experiments performed recently in the H8 beam at CERN are presented. Firstly, deflection of a positive pion beam at 200 GeV/c is compared to the "standard" 450-GeV/c proton beam for a bending angle of 3.1 mrad along the (111) plane in a 50 mm silicon crystal. Second, deflection of negative pions at 200 GeV/c is investigated for the same crystal, for incidence along the (111) plane as well as the axis. Small deflection effects are seen, but no negative particles are bent through the full bending angle of the crystal. Third, the first results from beam deflection at high energy using a germanium crystal are shown. Slightly higher deflection efficiencies than for silicon are seen for large bending angles, but significantly smaller than expected for such a crystal with higher atomic number. Fourth, deflection efficiencies using a strongly irradiated silicon crystal have been measured for the first time, and a small reduction in efficiency is seen in the irradiated region. Finally, deflection of positive particles using axial alignment of a bent silicon crystal has been investigated at 450 GeV/c. Qualitatively similar behaviour as in previous experiments at 12 GeV/c is seen; the beam splits into several beams corresponding to the different planes, and even weak planes are observed.

  11. Low-noise pulse conditioner

    Science.gov (United States)

    Bird, D.A.

    1981-06-16

    A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits. This circuit may be used for conditioning the sensor signal from the Fidler coil in a gas centrifuge for separation of isotopic gaseous mixtures.

  12. Real-Time Deflection Monitoring for Milling of a Thin-Walled Workpiece by Using PVDF Thin-Film Sensors with a Cantilevered Beam as a Case Study

    National Research Council Canada - National Science Library

    Luo, Ming; Liu, Dongsheng; Luo, Huan

    2016-01-01

    .... To understand the workpiece deflection behavior in a machining process, a new real-time nonintrusive method for deflection monitoring is presented, and a detailed analysis of workpiece deflection...

  13. High resolution imaging detectors and applications

    CERN Document Server

    Saha, Swapan K

    2015-01-01

    Interferometric observations need snapshots of very high time resolution of the order of (i) frame integration of about 100 Hz or (ii) photon-recording rates of several megahertz (MHz). Detectors play a key role in astronomical observations, and since the explanation of the photoelectric effect by Albert Einstein, the technology has evolved rather fast. The present-day technology has made it possible to develop large-format complementary metal oxide–semiconductor (CMOS) and charge-coupled device (CCD) array mosaics, orthogonal transfer CCDs, electron-multiplication CCDs, electron-avalanche photodiode arrays, and quantum-well infrared (IR) photon detectors. The requirements to develop artifact-free photon shot noise-limited images are higher sensitivity and quantum efficiency, reduced noise that includes dark current, read-out and amplifier noise, smaller point-spread functions, and higher spectral bandwidth. This book aims to address such systems, technologies and design, evaluation and calibration, control...

  14. Technology for the next gravitational wave detectors

    CERN Document Server

    Mitrofanov, Valery P; Pan, Huang-Wei; Kuo, Ling-Chi; Cole, Garrett; Degallaix, Jerome; Willke, Benno

    2016-01-01

    This paper reviews some of the key enabling technologies for advanced and future laser interferometer gravitational wave detectors, which must combine test masses with the lowest possible optical and acoustic losses, with high stability lasers and various techniques for suppressing noise. Sect. 1 of this paper presents a review of the acoustic properties of test masses. Sect. 2 reviews the technology of the amorphous dielectric coatings which are currently universally used for the mirrors in advanced laser interferometers, but for which lower acoustic loss would be very advantageous. In sect. 3 a new generation of crystalline optical coatings that offer a substantial reduction in thermal noise is reviewed. The optical properties of test masses are reviewed in sect. 4, with special focus on the properties of silicon, an important candidate material for future detectors. Sect. 5 of this paper presents the very low noise, high stability laser technology that underpins all advanced and next generation laser inter...

  15. FFTS readout for large arrays of Microwave Kinetic Inductance Detectors

    CERN Document Server

    Yates, S J C; Baselmans, J J A; Klein, B; Güsten, R

    2009-01-01

    Microwave Kinetic Inductance Detectors (MKIDs) have great potential for large very sensitive detector arrays for use in, for example, sub-mm imaging. Being intrinsically readout in the frequency domain, they are particularly suited for frequency domain multiplexing allowing $\\sim$1000s of devices to be readout with one pair of coaxial cables. However, this moves the complexity of the detector from the cryogenics to the warm electronics. We present here the concept and experimental demonstration of the use of Fast Fourier Transform Spectrometer (FFTS) readout, showing no deterioration of the noise performance compared to low noise analog mixing while allowing high multiplexing ratios.

  16. Inhibitory noise

    Directory of Open Access Journals (Sweden)

    Alain Destexhe

    2010-03-01

    Full Text Available Cortical neurons in vivo may operate in high-conductance states, in which the major part of the neuron's input conductance is due to synaptic activity, sometimes several-fold larger than the resting conductance. We examine here the contribution of inhibition in such high-conductance states. At the level of the absolute conductance values, several studies have shown that cortical neurons in vivo are characterized by strong inhibitory conductances. However, conductances are balanced and spiking activity is mostly determined by fluctuations, but not much is known about excitatory and inhibitory contributions to these fluctuations. Models and dynamic-clamp experiments show that, during high-conductance states, spikes are mainly determined by fluctuations of inhibition, or by inhibitory noise. This stands in contrast to low-conductance states, in which excitatory conductances determine spiking activity. To determine these contributions from experimental data, maximum likelihood methods can be designed and applied to intracellular recordings in vivo. Such methods indicate that action potentials are indeed mostly correlated with inhibitory fluctuations in awake animals. These results argue for a determinant role for inhibitory fluctuations in evoking spikes, and do not support feed-forward modes of processing, for which opposite patterns are predicted.

  17. Toward the detection of gravitational waves under non-Gaussian noises II. Independent Component Analysis

    CERN Document Server

    Morisaki, Soichiro; Eda, Kazunari; Itoh, Yousuke

    2016-01-01

    We introduce a new analysis method to deal with stationary non-Gaussian noises in gravitational wave detectors in terms of the independent component analysis. First, we consider the simplest case where the detector outputs are linear combinations of the inputs, consisting of signals and various noises, and show that this method may be helpful to increase the signal-to-noise ratio. Next, we take into account the time delay between the inputs and the outputs. Finally, we extend our method to nonlinearly correlated noises and show that our method can identify the coupling coefficients and remove non-Gaussian noises.

  18. Light deflection with torsion effects caused by a spinning cosmic string

    Energy Technology Data Exchange (ETDEWEB)

    Jusufi, Kimet [State University of Tetovo, Physics Department, Tetovo (Macedonia, The Former Yugoslav Republic of)

    2016-06-15

    Using a new geometrical method introduced by Werner, we find the deflection angle in the weak limit approximation by a spinning cosmic string in the context of the Einstein-Cartan (EC) theory of gravity. We begin by adopting the String-Randers optical metric, then we apply the Gauss-Bonnet theorem to the optical geometry and derive the leading terms of the deflection angle in the equatorial plane. Calculation shows that light deflection is affected by the intrinsic spin of the cosmic string and torsion. (orig.)

  19. Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

    Science.gov (United States)

    Rathod, K. D.; Singh, P. K.; Natarajan, Vasant

    2014-09-01

    We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{171}$Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.

  20. Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

    Indian Academy of Sciences (India)

    K D Rathod; P K Singh; Vasant Natarajan

    2014-09-01

    We demonstrate the generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman slower. They are then subjected to a pair of molasses beams inclined at 45° with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate the selective deflection of the bosonic isotope 174Yb and the fermionic isotope 171Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.

  1. Analysis of rolls deflection of Sendzimir mill by 3D FEM

    Institute of Scientific and Technical Information of China (English)

    YU Hai-liang; LIU Xiang-hua; LEE Gyoo Taek

    2007-01-01

    The deflection of rolls of Sendzimir mill with double AS-U-Roll was simulated by finite element method(FEM). The influences of rolling pressure, strip width and rolls-assignment on rolls deflection were analyzed. The results show that the work roll deflection increases with the increase of rolling pressure and the reduction of work roll radius, but the rigid displacement of work roll slightly changes; the work roll end might appear negative displacement for the narrow strip width and high rolling pressure that might cause the contact of work rolls. The research results are significant for guiding production and theoretical analysis of the rolls system of Sendzimir mill.

  2. Self-Deflection of Dark Screening Spatial Solitons Based on Higher-Order Space Charge Field

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guang-Yong; LIU Jin-Song; LIU Shi-Xiong; WANG Cheng; ZHANG Hui-Lan

    2007-01-01

    The effects of higher-order space charge field on the self-deflection of dark screening spatial solitons in biased photorefractive crystals are numerically investigated under steady-state conditions. The expression for an induced space-charge electric field including higher-order space-charge field terms is obtained. Numerical results indicate that dark solitons possess a self-deflection process during propagation, and the solitons always bend in the direction of the c axis of the crystal The self-deflection of dark solitons can experience considerable increase especially in the regime of high bias field strengths.

  3. Mode-locked Lasers Applied to Deflecting a Near Earth Object on Collision Course with Earth

    CERN Document Server

    Fork, Richard; Burgess, Luke; Bergstue, Grant

    2013-01-01

    We consider synchronized trains of sub-picosecond pulses generated by mode-locked lasers applied to deflection of near Earth objects (NEO) on collision course with Earth. Our method is designed to avoid a predicted collision of the NEO with Earth by at least the diameter of Earth. We estimate deflecting a 10,000 MT NEO, such as the asteroid which struck Earth near Chelyabinsk, Russia to be feasible within several months using average power in the ten kilowatt range. We see this deflection method as scalable to larger NEO to a degree not possible using continuous laser systems.

  4. Photonic-based laser driven electron beam deflection and focusing structures

    Directory of Open Access Journals (Sweden)

    T. Plettner

    2009-10-01

    Full Text Available We propose a dielectric photonic structure for ultrafast deflection and focusing of relativistic charged particle beams. The structure is designed to transform a free-space laser beam into a deflection force that acts on the free particles with the same optical phase over a distance of travel that is much greater than the laser wavelength. The proposed structure has a two-dimensional geometry and is compatible with existing nanofabrication methods. Deflection fields of GV/m magnitude and subfemtosecond switching speeds are expected to be possible from these dielectric structures. With these elements a submeter scale extreme ultraviolet synchrotron source seems feasible.

  5. Light deflection with torsion effects caused by a spinning cosmic string

    Science.gov (United States)

    Jusufi, Kimet

    2016-06-01

    Using a new geometrical method introduced by Werner, we find the deflection angle in the weak limit approximation by a spinning cosmic string in the context of the Einstein-Cartan (EC) theory of gravity. We begin by adopting the String-Randers optical metric, then we apply the Gauss-Bonnet theorem to the optical geometry and derive the leading terms of the deflection angle in the equatorial plane. Calculation shows that light deflection is affected by the intrinsic spin of the cosmic string and torsion.

  6. Multipole Field Effects for the Superconducting Parallel-Bar Deflecting/Crabbing Cavities

    Energy Technology Data Exchange (ETDEWEB)

    De Silva, Payagalage Subashini Uddika [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States) and Old Dominion University, Norfolk, VA (United States); Delayen, Jean Roger [Old Dominion University, Norfolk, VA (United States)

    2012-09-01

    The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

  7. Light Deflection with Torsion Effects Caused by a Spinning Cosmic String

    CERN Document Server

    Jusufi, Kimet

    2016-01-01

    Using a new geometrical method introduced by Werner, we find the deflection angle in the weak limit approximation by a spinning cosmic string in the context of the Einstein-Cartan (EC) theory of gravity. We begin by adopting the String-Randers optical metric, then we apply the Gauss-Bonnet theorem to the optical geometry and derive the leading terms of the deflection angle in the equatorial plane. Calculations shows that light deflection is affected by the intrinsic spin of the cosmic string and torsion.

  8. Use of radiation detectors in remote monitoring for containment and surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Dupree, S.A.; Ross, M. [Sandia National Labs., Albuquerque, NM (United States); Bonino, A. [Nuclear Regulatory Authority of Argentina, Buenos Aires (Argentina); Lucero, R.; Hasimoto, Yu [PNC Oarai Engineering Center, Ibaraki (Japan)

    1998-07-01

    Radiation detectors have been included in several remote monitoring field trial systems to date. The present study considers detectors at Embalse, Argentina, and Oarai, Japan. At Embalse four gamma detectors have been operating in the instrumentation tubes of spent fuel storage silos for up to three years. Except for minor fluctuations, three of the detectors have operated normally. One of the detectors appears never to have operated correctly. At Oarai two gamma detectors have been monitoring a spent-fuel transfer hatch for over 18 months. These detectors have operated normally throughout the period, although one shows occasional noise spikes.

  9. Upgraded VIRGO detector(s) and stochastic gravitational waves backgrounds

    CERN Document Server

    Babusci, D

    1999-01-01

    The sensitivity achievable by a pair of VIRGO detectors to stochastic and isotropic gravitational wave backgrounds of cosmological origin is discussed in view of the development of a second VIRGO interferometer. We describe a semi-analytical technique allowing to compute the signal-to-noise ratio for (monotonic or non-monotonic) logarithmic energy spectra of relic gravitons of arbitrary slope. We apply our results to the case of two correlated and coaligned VIRGO detectors and we compute their achievable sensitivities. The maximization of the overlap reduction function is discussed. We focus our attention on a class of models whose expected sensitivity is more promising, namely the case of string cosmological gravitons. We perform our calculations both for the case of minimal string cosmological scenario and in the case of a non-minimal scenario where a long dilaton dominated phase is present prior to the onset of the ordinary radiation dominated phase. In this framework, we study possible improvements of the...

  10. Occupational noise management

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-06-15

    Occupational noise is a frequently encountered on-the-job health hazard. This guide presented the responsibilities and regulatory requirements related to business activities where noise above 80 decibels is present. The guide provided a definition of noise and discussed noise hazards, types of noise, and on-the-job noise exposure. A risk assessment to noise in the work environment was also discussed. A guide to a hearing conservation program was also included. The main purpose of a hearing conservation program is the prevention of noise induced hearing loss for employees exposed to occupational noise. The components of such a program were outlined, with particular reference to noise monitoring; noise exposure control; worker education and training; hearing (audiometric) testing; and annual program review and record keeping. It was concluded that in terms of record keeping, it can be very helpful to file noise exposure assessments, particularly personal exposure measurements, with hearing test records to facilitate for future reference. refs., appendices.

  11. Noise and Hearing Protection

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Noise and Hearing Protection Noise and Hearing Protection Patient ... it is. How can I tell if a noise is dangerous? People differ in their sensitivity to ...

  12. GEO600 Online Detector Characterization System

    CERN Document Server

    Balasubramanian, R; Churches, D; Cokelaer, T

    2005-01-01

    A world-wide network of interferometric gravitational wave detectors is currently operational. The detectors in the network are still in their commissioning phase and are expected to achieve their design sensitivity over the next year or so. Each detector is a complex instrument involving many subsystems and each subsystem is a source of noise at the output of the detector. Therefore, in addition to recording the main gravitational wave data channel at the output of the interferometer, the state of each detector subsystem is monitored and recorded. This subsidiary data is both large in volume as well as complex in nature. We require an online monitoring and analysis tool which can process all the data channels for various noise artefacts and summarize the results of the analysis in a manner that can be accessed and interpreted conveniently. In this paper we describe the GEO600 Online Detector Characterization System (GODCS), which is the tool that is being used to monitor the output of the GEO600 gravitationa...

  13. Comparison of the polynomial model against explicit measurements of noise components for different mammography systems

    Science.gov (United States)

    Monnin, P.; Bosmans, H.; Verdun, F. R.; Marshall, N. W.

    2014-10-01

    Given the adverse impact of image noise on the perception of important clinical details in digital mammography, routine quality control measurements should include an evaluation of noise. The European Guidelines, for example, employ a second-order polynomial fit of pixel variance as a function of detector air kerma (DAK) to decompose noise into quantum, electronic and fixed pattern (FP) components and assess the DAK range where quantum noise dominates. This work examines the robustness of the polynomial method against an explicit noise decomposition method. The two methods were applied to variance and noise power spectrum (NPS) data from six digital mammography units. Twenty homogeneously exposed images were acquired with PMMA blocks for target DAKs ranging from 6.25 to 1600 µGy. Both methods were explored for the effects of data weighting and squared fit coefficients during the curve fitting, the influence of the additional filter material (2 mm Al versus 40 mm PMMA) and noise de-trending. Finally, spatial stationarity of noise was assessed. Data weighting improved noise model fitting over large DAK ranges, especially at low detector exposures. The polynomial and explicit decompositions generally agreed for quantum and electronic noise but FP noise fraction was consistently underestimated by the polynomial method. Noise decomposition as a function of position in the image showed limited noise stationarity, especially for FP noise; thus the position of the region of interest (ROI) used for noise decomposition may influence fractional noise composition. The ROI area and position used in the Guidelines offer an acceptable estimation of noise components. While there are limitations to the polynomial model, when used with care and with appropriate data weighting, the method offers a simple and robust means of examining the detector noise components as a function of detector exposure.

  14. Radiation detector

    Energy Technology Data Exchange (ETDEWEB)

    Taleyarkhan, Rusi P.

    2017-06-27

    Alpha particle detecting devices are disclosed that have a chamber that can hold a fluid in a tensioned metastable state. The chamber is tuned with a suitable fluid and tension such that alpha emitting materials such as radon and one or more of its decay products can be detected. The devices can be portable and can be placed in areas, such as rooms in dwellings or laboratories and used to measure radon in these areas, in situ and in real time. The disclosed detectors can detect radon at and below 4 pCi/L in air; also, at and below 4,000 pCi/L or 300 pCi/L in water.

  15. Leakage Currents and Capacitances of Thick CZT Detectors

    CERN Document Server

    Garson, Alfred; Jung, Ira V; Dowkontt, Paul; Bose, Richard; Simburger, Garry; Krawczynski, Henric

    2009-01-01

    The quality of Cadmium Zinc Telluride (CZT) detectors is steadily improving. For state of the art detectors, readout noise is thus becoming an increasingly important factor for the overall energy resolution. In this contribution, we present measurements and calculations of the dark currents and capacitances of 0.5 cm-thick CZT detectors contacted with a monolithic cathode and 8x8 anode pixels on a surface of 2 cm x 2 cm. Using the NCI ASIC from Brookhaven National Laboratory as an example, we estimate the readout noise caused by the dark currents and capacitances. Furthermore, we discuss possible additional readout noise caused by pixel-pixel and pixel-cathode noise coupling.

  16. Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

    Science.gov (United States)

    Abramowicz, H.; Abusleme, A.; Afanaciev, K.; Aguilar, J.; Alvarez, E.; Avila, D.; Benhammou, Y.; Bortko, L.; Borysov, O.; Bergholz, M.; Bozovic-Jelisavcic, I.; Castro, E.; Chelkov, G.; Coca, C.; Daniluk, W.; Dumitru, L.; Elsener, K.; Fadeyev, V.; Firlej, M.; Firu, E.; Fiutowski, T.; Ghenescu, V.; Gostkin, M.; Henschel, H.; Idzik, M.; Ishikawa, A.; Kananov, S.; Kollowa, S.; Kotov, S.; Kotula, J.; Kozhevnikov, D.; Kruchonok, V.; Krupa, B.; Kulis, Sz.; Lange, W.; Lesiak, T.; Levy, A.; Levy, I.; Lohmann, W.; Lukic, S.; Milke, C.; Moron, J.; Moszczynski, A.; Neagu, A. T.; Novgorodova, O.; Oliwa, K.; Orlandea, M.; Pandurovic, M.; Pawlik, B.; Preda, T.; Przyborowski, D.; Rosenblat, O.; Sailer, A.; Sato, Y.; Schumm, B.; Schuwalow, S.; Smiljanic, I.; Smolyanskiy, P.; Swientek, K.; Teodorescu, E.; Terlecki, P.; Wierba, W.; Wojton, T.; Yamaguchi, S.; Yamamoto, H.; Zawiejski, L.; Zgura, I. S.; Zhemchugov, A.

    2015-05-01

    Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e- collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

  17. Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector

    CERN Document Server

    Abramowicz, H.; Afanaciev, K.; Aguilar, J.; Alvarez, E.; Avila, D.; Benhammou, Y.; Bortko, L.; Borysov, O.; Bergholz, M.; Bozovic-Jelisavcic, I.; Castro, E.; Chelkov, G.; Coca, C.; Daniluk, W.; Dumitru, L.; Elsener, K.; Fadeyev, V.; Firlej, M.; Firu, E.; Fiutowski, T.; Ghenescu, V.; Gostkin, M.; Henschel, H.; Idzik, M.; Ishikawa, A.; Kananov, S.; Kollowa, S.; Kotov, S.; Kotula, J.; Kozhevnikov, D.; Kruchonok, V.; Krupa, B.; Kulis, Sz.; Lange, W.; Lesiak, T.; Levy, A.; Levy, I.; Lohmann, W.; Lukic, S.; Milke, C.; Moron, J.; Moszczynski, A.; Neagu, A.T.; Novgorodova, O.; Oliwa, K.; Orlandea, M.; Pandurovic, M.; Pawlik, B.; Preda, T.; Przyborowski, D.; Rosenblat, O.; Sailer, A.; Sato, Y.; Schumm, B.; Schuwalow, S.; Smiljanic, I.; Smolyanskiy, P.; Swientek, K.; Teodorescu, E.; Terlecki, P.; Wierba, W.; Wojton, T.; Yamaguchi, S.; Yamamoto, H.; Zawiejski, L.; Zgura, I.S.; Zhemchugov, A.

    2015-01-01

    Detector-plane prototypes of the very forward calorimetry of a future detector at an $e^+e^-$ collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio for different feedback schemes and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

  18. Thermal-noise-limited underground interferometer CLIO

    CERN Document Server

    Agatsuma, Kazuhiro; Fujimoto, Masa-Katsu; Kawamura, Seiji; Kuroda, Kazuaki; Miyakawa, Osamu; Miyoki, Shinji; Ohashi, Masatake; Suzuki, Toshikazu; Takahashi, Ryutaro; Tatsumi, Daisuke; Telada, Souichi; Uchiyama, Takashi; Yamamoto, Kazuhiro

    2009-01-01

    We report on the current status of CLIO (Cryogenic Laser Interferometer Observatory), which is a prototype interferometer for LCGT (Large scale Cryogenic Gravitational-wave Telescope). LCGT is a Japanese next-generation interferometric gravitational wave detector featuring the use of cryogenic mirrors and a quiet underground site. The main purpose of CLIO is to demonstrate a reduction of the mirror thermal noise by cooling the sapphire mirrors. CLIO is located in an underground site of the Kamioka mine, 1000 m deep from the mountain top, to verify its advantages. After a few years of commissioning work, we have achieved a thermal-noise-limited sensitivity at room temperature. One of the main results of noise hunting was the elimination of thermal noise caused by a conductive coil-holder coupled with a pendulum through magnets.

  19. Unveiling linearly and nonlinearly correlated signals between gravitational wave detectors and environmental monitors

    Science.gov (United States)

    Yuzurihara, Hirotaka; Hayama, Kazuhiro; Mano, Shuhei; Verkindt, Didier; Kanda, Nobuyuki

    2016-08-01

    Noise hunting is a critical requirement for realizing design sensitivity of a detector, and consequently, noise origins and its features have been revealed partially. Among the noise sources to be hunted, sources of nonlinearly correlated noise, such up-conversion noise, are hard to find and can limit the sensitivity of gravitational wave searches with advanced detectors. We propose using a correlation analysis method called maximal information coefficient (MIC) to find both nonlinear and linear correlations. We apply MIC to the scattered light noise correlated between the seismic activity and the strain signal, which limited the sensitivity of the Virgo detector during the first science run. The results show that MIC can find nonlinearly correlated noise more efficiently than the Pearson correlation method. When the data is linearly correlated, the efficiency of the Pearson method and MIC is comparable. On the other hand, when the data is known to be nonlinearly correlated, MIC finds the correlation while the Pearson method fails completely.

  20. Noise and frequency response of silicon photodiode operational amplifier combination.

    Science.gov (United States)

    Hamstra, R H; Wendland, P

    1972-07-01

    The noise in dark and illuminated Schottky barrier and diffused PIN non-guard-ring photodiodes has been measured between 0.1 Hz and 10 kHz and compared to theory with an excellent fit. It is shown that diodes used photovoltaically are free of 1/f noise in the dark. It is also demonstrated that there is an optimum bias (ca. 100 mV) for minimum noise equivalent power. When only a resistive load is used with a detector, it often determines the frequency response and noise of the detector circuit. We develop and demonstrate equations for the major improvements in both noise and frequency response that can be obtained using a current mode (inverting) operational amplifier.

  1. Single photon detector design features

    Science.gov (United States)

    Zaitsev, Sergey V.; Kurochkin, Vladimir L.; Kurochkin, Yury V.

    2016-12-01

    In the report are discussed the laboratory test results of SPAD detectors with InGaAs / InP avalanche photodiodes, operating in Geiger mode. Device operating in synchronous mode with the dead timer setting for proper working conditions of photodiodes. The report materials will showing the functional block diagram of the detector, real operating signals in the receiver path and clock circuits and main results of measurements. The input signal of the synchronous detector is the clock, which determines the time positions of expected photons arrival. Increasing the clock speed 1-300 MHz or getting more time positions of the time grid, we provide increased capacity for time position code of signals, when QKD information transmitted over the nets. At the same time, the maximum attainable speed of photon reception is limited by diode dead time. Diode quantum noise are minimized by inclusion of a special time interval - dead time 0.1-10 usec, after each received and registered a photon. The lowest attainable value of the dead time is determined as a compromise between transients in electrical circuits, passive avalanche «quenching» circuit and thermal transients cooling crystal diode, after each avalanche pass though photodiode. Achievable time and speed parameters are discussed with specific examples of detectors.

  2. The next detectors for gravitational wave astronomy

    Science.gov (United States)

    Blair, David; Ju, Li; Zhao, ChunNong; Wen, LinQing; Miao, HaiXing; Cai, RongGen; Gao, JiangRui; Lin, XueChun; Liu, Dong; Wu, Ling-An; Zhu, ZongHong; Hammond, Giles; Paik, Ho Jung; Fafone, Viviana; Rocchi, Alessio; Blair, Carl; Ma, YiQiu; Qin, JiaYi; Page, Michael

    2015-12-01

    This paper focuses on the next detectors for gravitational wave astronomy which will be required after the current ground based detectors have completed their initial observations, and probably achieved the first direct detection of gravitational waves. The next detectors will need to have greater sensitivity, while also enabling the world array of detectors to have improved angular resolution to allow localisation of signal sources. Sect. 1 of this paper begins by reviewing proposals for the next ground based detectors, and presents an analysis of the sensitivity of an 8 km armlength detector, which is proposed as a safe and cost-effective means to attain a 4-fold improvement in sensitivity. The scientific benefits of creating a pair of such detectors in China and Australia is emphasised. Sect. 2 of this paper discusses the high performance suspension systems for test masses that will be an essential component for future detectors, while sect. 3 discusses solutions to the problem of Newtonian noise which arise from fluctuations in gravity gradient forces acting on test masses. Such gravitational perturbations cannot be shielded, and set limits to low frequency sensitivity unless measured and suppressed. Sects. 4 and 5 address critical operational technologies that will be ongoing issues in future detectors. Sect. 4 addresses the design of thermal compensation systems needed in all high optical power interferometers operating at room temperature. Parametric instability control is addressed in sect. 5. Only recently proven to occur in Advanced LIGO, parametric instability phenomenon brings both risks and opportunities for future detectors. The path to future enhancements of detectors will come from quantum measurement technologies. Sect. 6 focuses on the use of optomechanical devices for obtaining enhanced sensitivity, while sect. 7 reviews a range of quantum measurement options.

  3. The importance of being elastic: deflection of a badminton racket during a stroke.

    Science.gov (United States)

    Kwan, Maxine; Rasmussen, John

    2010-03-01

    The deflection profiles of a badminton racket during strokes performed by elite and world-class badminton players were recorded by strain gauges and subsequently analysed to determine the role of shaft stiffness in racket performance. Deflection behaviour was consistent in all strokes across all players, suggesting a controlled use of racket elasticity. In addition, all impacts occurred within 100 ms of each other, a duration in which deflection velocity provides an increase in racket velocity, indicating that the players were able to use racket elasticity to their advantage. Since deflection behaviour is a product of the racket-player interaction, further work is required to determine the effects of different racket properties and player techniques on the elastic response of rackets during strokes.

  4. Deflection of light ray due to a charged body using Material Medium Approach

    CERN Document Server

    Roy, Saswati

    2015-01-01

    The gravitational deflection of light ray is an important prediction of General Theory of Relativity. In this paper we develop analytical expression of the deflection of light ray without any weak field approximation due to a charged gravitational body represented by Reissner_Nordstr\\"om (RN) and Janis-Newman-Winicour (JNW) space time geometry, using material medium approach. It is concluded that although both the geometries represent the charged, non-rotating, spherically symmetric gravitating body, but the effect of charge on the gravitational deflection is just opposite to each other. The gravitational deflection decreases with charge in the RN geometry and increases with charge in the JNW geometry. The calculations obtained here are compared with other methods done by different authors. The formalism is applied to an arbitrary selected pulsar PSRB1937+21 as a gravitating body, as a test case.

  5. Analysis of Deflection Problems of Large-span Continuous Rigid Frame Bridge and Prevention Measures

    Directory of Open Access Journals (Sweden)

    Chen Dong

    2015-01-01

    Full Text Available The large-span continuous rigid frame bridge is a kind of common structural form in long-span bridges of our country, but one of the main diseases of these bridges is the excessive deflection in the mid-span, which seriously affects the safety of the structure. This paper makes a comprehensive analysis for the causes of the excessive deflection, and lists the commonly-used control measures in engineering. Simultaneously, new improvement measures and the comparative analysis of before-and-after improvements are put forward on this basis. However, these measures can be used to inhibit deflection in a certain extent, but cannot avoid the occurrence of deflection completely.

  6. Evaluation of Accuracy and Precision of Several Highway Speed Deflection Devices

    OpenAIRE

    Rada, Gonzalo R; Visintine, Beth A.; Rocha,Sergio; Velarde, Jorge; Gallardo, Paola; Nazarian, Soheil; Siddharthan, Rajaratnam V.; Nasimifar, Seyyed

    2014-01-01

    Structural Session 2: Evaluation of Deflection Devices Moderated by Doug Chalman This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  7. Ge photocapacitive MIS infrared detectors

    Science.gov (United States)

    Binari, S. C.; Miller, W. E.; Tsuo, Y. H.; Miller, W. E.

    1979-01-01

    An undoped Ge photocapacitive detector is reported which has peak normalized detectivities at wavelengh 1.4 microns and chopping frequencies 13-1000 Hz of 9 x 10 to the 12th, 4 x 10 to the 9th cm Hz to the 1/2th/W operating respectively at temperatures 77, 195, and 295 K. The observed temperature, spectral, and frequency response of the signal and noise are explained in terms of the measured space charge and interface state properties of the device.

  8. CLIC Detector Power Requirements

    CERN Document Server

    Gaddi, A

    2013-01-01

    An estimate for the CLIC detector power requirements is outlined starting from the available data on power consumptions of the four LHC experiments and considering the differences between a typical LHC Detector (CMS) and the CLIC baseline detector concept. In particular the impact of the power pulsing scheme for the CLIC Detector electronics on the overall detector consumption is considered. The document will be updated with the requirements of the sub-detector electronics once they are more defined.

  9. Pixel Vertex Detectors

    OpenAIRE

    Wermes, Norbert

    2006-01-01

    Pixel vertex detectors are THE instrument of choice for the tracking of charged particles close to the interaction point at the LHC. Hybrid pixel detectors, in which sensor and read-out IC are separate entities, constitute the present state of the art in detector technology. Three of the LHC detectors use vertex detectors based on this technology. A development period of almost 10 years has resulted in pixel detector modules which can stand the extreme rate and timing requirements as well as ...

  10. Design and Development of Superconducting Parallel-Bar Deflecting/Crabbing Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Payagalage Subashini Uddi De Silva, Jean Delayen

    2012-07-01

    The superconducting parallel-bar cavity is a deflecting/crabbing cavity with attractive properties that is being considered for a number of applications. We present the designs of a 499 MHz deflecting cavity developed for the Jefferson Lab 12 GeV Upgrade and a 400 MHz crabbing cavity for the LHC High Luminosity Upgrade. Prototypes of these two cavities are now under development and fabrication.

  11. Encoding whisker deflection velocity within the rodent barrel cortex using phase-delayed inhibition.

    Science.gov (United States)

    Liu, Runjing; Patel, Mainak; Joshi, Badal

    2014-12-01

    The primary sensory feature represented within the rodent barrel cortex is the velocity with which a whisker has been deflected. Whisker deflection velocity is encoded within the thalamus via population synchrony (higher deflection velocities entail greater synchrony among the corresponding thalamic population). Thalamic (TC) cells project to regular spiking (RS) cells within the barrel cortex, as well as to inhibitory cortical fast-spiking (FS) neurons, which in turn project to RS cells. Thus, TC spikes result in EPSPs followed, with a small time lag, by IPSPs within an RS cell, and hence the RS cell decodes TC population synchrony by employing a phase-delayed inhibition synchrony detection scheme. As whisker deflection velocity is increased, the probability that an RS cell spikes rises, while jitter in the timing of RS cell spikes remains constant. Furthermore, repeated whisker deflections with fixed velocity lead to system adaptation--TC →RS, TC →FS, and FS →RS synapses all weaken substantially, leading to a smaller probability of spiking of the RS cell and increased jitter in the timing of RS cell spikes. Interestingly, RS cell activity is better able to distinguish among different whisker deflection velocities after adaptation. In this work, we construct a biophysical model of a basic 'building block' of barrel cortex - the feedforward circuit consisting of TC cells, FS cells, and a single RS cell - and we examine the ability of the purely feedforward circuit to explain the experimental data on RS cell spiking probability, jitter, adaptation, and deflection velocity discrimination. Moreover, we study the contribution of the phase-delayed inhibition network structure to the ability of an RS cell to decode whisker deflection velocity encoded via TC population synchrony.

  12. Strong deflection lensing by charged black holes in scalar-tensor gravity

    Energy Technology Data Exchange (ETDEWEB)

    Eiroa, Ernesto F.; Sendra, Carlos M. [Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Universidad de Buenos Aires, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2014-11-15

    We examine a class of charged black holes in scalar-tensor gravity as gravitational lenses. We find the deflection angle in the strong deflection limit, from which we obtain the positions and the magnifications of the relativistic images. We compare our results with those corresponding to the Reissner-Norstroem spacetime and we analyze the observational aspects in the case of the Galactic supermassive black hole. (orig.)

  13. Influence of tool deflection on micro channel pattern of 6:4 brass with rectangular tool

    Institute of Scientific and Technical Information of China (English)

    Tae-Jin JE; Kang-Won LEE; Sang-Cheon PARK; Jae-Gu KIM; Doo-Sun CHOI; Kyoung-Taik PARK; Kyung-Hyun WHANG

    2009-01-01

    Machining experiment of micro channel structure with 6:4 brass was carried out by shaping process using a single crystal diamond tool. FEM simulation using solid cantilever beam model was analyzed. In result of experiment, tool deflection is observed as machining characteristics through result of experiments such as surface roughness, cutting force and burr formations. And the influence of tool deflection is experimentally proved.

  14. X-ray imaging detectors for synchrotron and XFEL sources

    Directory of Open Access Journals (Sweden)

    Takaki Hatsui

    2015-05-01

    Full Text Available Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL experiments provide high-frame-rate integrating detectors with both high sensitivity and high peak signal. Similar performance improvements are sought in monolithic detectors. The monolithic approach also offers a lower noise floor, which is required for the detection of soft X-ray photons. The link between technology development and detector performance is described briefly in the context of potential future capabilities for X-ray imaging detectors.

  15. X-ray imaging detectors for synchrotron and XFEL sources.

    Science.gov (United States)

    Hatsui, Takaki; Graafsma, Heinz

    2015-05-01

    Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL) experiments provide high-frame-rate integrating detectors with both high sensitivity and high peak signal. Similar performance improvements are sought in monolithic detectors. The monolithic approach also offers a lower noise floor, which is required for the detection of soft X-ray photons. The link between technology development and detector performance is described briefly in the context of potential future capabilities for X-ray imaging detectors.

  16. SPADs for Vertex Tracker detectors in Future Colliders

    CERN Document Server

    Vilella, E; Vila, A; Dieguez, A

    2015-01-01

    Physics aims at the future linear colliders impose such stringent requirements on detector systems that exceed those met by any previous technology. Amongst other novel technologies, SPADs (Single Photon Avalanche Diodes) detectors are being developed to track high energy particles at ILC (International Linear Collider) and CLIC (Compact LInear Collider). These sensors offer outstanding qualities, such as an extraordinary high sensitivity, ultra-fast response time and virtually infinite gain, in addition to compatibility with standard CMOS technologies. As a result, SPAD detectors enable the direct conversion of a single particle event onto a CMOS digital signal in the sub-nanosecond time scale, which leads to the possibility of single BX (bunch crossing) resolution at some particle colliders. However, SPAD detectors suffer from two main problems, namely the noise pulses generated by the sensor and the low fill-factor. The noise pulses worsen the detector occupancy, while the low fill-factor reduces the detec...

  17. Prediction of Extrusion Pressure And Product Deflection Of Using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    D.T. GUNDU

    2013-01-01

    Full Text Available - In this paper artificial neural network was used as a modeling tool for simulation and prediction of extrusion pressure and product deflection of extrudes of lead alloys. An extensive experimental program was undertaken to extrude a lead (Pb alloy on ELE Compact-1500 compression machine. The neural model of extrusion pressure and product deflection was developed based on groups of experiments carried out as samples, Eight (8 die bearing parameters (die bearing length, radius of curvature, slip angle, die angle, die ratio ram displacement, pocket depth and die diameter were used as inputs into the network architecture of 8 [4-3]2 2 in predicting the extrusion pressure and product deflection. After series of network architectures were trained using different training algorithms such as Levenberg-Marquardt, Bayesian Regulation, Resilient Backpropagation using MATLAB 7.9.0 (R20096, the LM8 [4-3]2 2 was selected as the most appropriate model. Prediction of the neural model exhibited reasonable correlation with the experimental extrusion pressure and product deflection. The predicted extrusion pressure and product deflection gave reasonable errors and higher correlation coefficients indicating that the model is robust for predicting extrusion pressure and product deflection.

  18. Large deflection and rotation of Timoshenko beams with frictional end supports under three-point bending

    Science.gov (United States)

    Li, Dao-Kui; Li, Xian-Fang

    2016-08-01

    Three-point bending of a beam is studied based on the Timoshenko beam theory. Large deflection and large rotation of a beam resting on simple supports with friction are calculated for a concentrated force acting at the midspan. Using the Lagrangian kinematic relations, a system of non-linear differential equations are obtained for a prismatic shear-deformable Timoshenko beam. Exact solutions for the deflection, horizontal displacement, and rotation of cross-section are derived analytically. Two deflections of small and large scale exist under three-point bending. The solutions corresponding to linearized model coincide with the well-known solutions to the classical Timoshenko beams. Numerical calculations are carried out to show the effect of the important parameters such as shear rigidity of the beam and the coefficient of friction at the contact position between the beam and supports on the deflection. The load-deflection curves are graphically presented. A comparison of large deflections and large rotations with their classical counterparts and with experimental data is made. The obtained results are useful in safety design of linear and non-linear beams subject to three-point bending.

  19. Using ForeCAT Deflections and Rotations to Constrain the Early Evolution of CMEs

    CERN Document Server

    Kay, C; Colaninno, R C; Vourlidas, A

    2016-01-01

    To accurately predict the space weather effects of coronal mass ejection (CME) impacts at Earth one must know if and when a CME will impact Earth, and the CME parameters upon impact. Kay et al. (2015b) presents Forecasting a CME's Altered Trajectory (ForeCAT), a model for CME deflections based on the magnetic forces from the background solar magnetic field. Knowing the deflection and rotation of a CME enables prediction of Earth impacts, and the CME orientation upon impact. We first reconstruct the positions of the 2008 April 10 and the 2012 July 12 CMEs from the observations. The first of these CMEs exhibits significant deflection and rotation (34 degrees deflection and 58 degrees rotation), while the second shows almost no deflection or rotation (<3 degrees each). Using ForeCAT, we explore a range of initial parameters, such as the CME location and size, and find parameters that can successfully reproduce the behavior for each CME. Additionally, since the deflection depends strongly on the behavior of a ...

  20. Finite element analysis modeling of pulse-laser excited photothermal deflection (mirage effect) from aerosols.

    Science.gov (United States)

    Dada, Oluwatosin O; Bialkowski, Stephen E

    2008-12-01

    A finite element analysis method for numerical modeling of the photothermal deflection spectroscopy of aerosols is presented. The models simulate pulse-laser excited photothermal deflection from aerosols collected on a plane surface substrate in air medium. The influence of the aerosol and substrate properties on the transient photothermal deflection signal is examined. We have previously obtained experimental results for photothermal deflection spectrometry of aerosols deposited onto a plate from an impactor system (O. O. Dada and S. E. Bialkowski, Appl. Spectrosc. 62, 1336 (2008)). This paper supports the validity of the experimental results presented in that paper and helps in answering some of the questions raised. The modeling results presented here demonstrate that the (peak) normalized transient temperature change profile and (peak) normalized transient photothermal deflection profile are a good approximation and invariant with number of particles, inter-particle distance, and particulate shape, which suggests that the photothermal deflection signal amplitude may be calibrated linearly with total mass of aerosols and the method could be applied to analysis of complex aerosols.

  1. A novel deflection shape function for rectangular capacitive micromachined ultrasonic transducer diaphragms

    Directory of Open Access Journals (Sweden)

    Zhou Zheng

    2015-09-01

    Full Text Available A highly accurate analytical deflection shape function that describes the deflection profiles of capacitive micromachined ultrasonic transducers (CMUTs with rectangular membranes under electrostatic pressure has been formulated. The rectangular diaphragms have a thickness range of 0.6–1.5 μm and a side length range of 100–1000 μm. The new deflection shape function generates deflection profiles that are in excellent agreement with finite element analysis (FEA results for a wide range of geometry dimensions and loading conditions. The deflection shape function is used to analyze membrane deformations and to calculate the capacitances between the deformed membranes and the fixed back plates. In 50 groups of random tests, compared with FEA results, the calculated capacitance values have a maximum deviation of 1.486% for rectangular membranes. The new analytical deflection function can provide designers with a simple way of gaining insight into the effects of designed parameters for CMUTs and other MEMS-based capacitive type sensors.

  2. Evaluation of cuspal deflection in premolar teeth restored with low shrinkable resin composite (in vitro study).

    Science.gov (United States)

    Labib, Labib Mohamed; Nabih, Sameh Mahmoud; Baroudi, Kusai

    2015-01-01

    This study evaluated cuspal deflection in premolar teeth restored with low shrinkable resin composite. A total of 40 human premolars were used for cuspal deflection evaluation in this study. Each group was divided into four equal groups according to the type of resin composite and the adhesive used as follows: group A: Using low shrinkable resin composite (silorane) with its adhesive system; group B: Using low shrinkable composite (silorane) with G-bond; group C: Using Filtek Z350 composite with G-bond; and group D: Using Filtek Z350 composite with AdheSE. Cusp deflection was detected using Universal measuring microscope and laser horizontal metroscope. This study was done to investigate the effect of polymerization shrinkage stresses of two resin composite materials (Filtek Z350 and Filtek P90) on cuspal deflection of mesio-occluso-distal restoration. For this study, the extracted non-carious maxillary second premolars were selected. Forty teeth that showed no more than 5% variation in their dimensions were used. A significant increase in cuspal deflection of cavities restored with the methacrylate-based (Filtek Z350) compared with the silorane (P90) resin-based composites was obtained. The change in the organic matrix or materials formulation of the resin composite using silorane has a positive effect on controlling the cusp deflection.

  3. Investigation of UWB Wind Turbine Blade Deflection Sensing with a Tip Antenna inside a Blade

    DEFF Research Database (Denmark)

    Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej;

    2016-01-01

    An UWB blade deflection sensing system with a tip antenna inside a blade is investigated in this paper. The lower UWB band of 3.1-5.3 GHz is utilized. This system composes of two UWB radio links between one antenna inside the blade tip and two antennas outside the blade root. Blade deflections ar......, and the sensing system can realize the deflection tracking with a maximum deviation of 0.21 m and root mean squared error of 0.11 m.......An UWB blade deflection sensing system with a tip antenna inside a blade is investigated in this paper. The lower UWB band of 3.1-5.3 GHz is utilized. This system composes of two UWB radio links between one antenna inside the blade tip and two antennas outside the blade root. Blade deflections......-blade time-domain measurements are proposed to verify the simulations and realize the blade deflection sensing with an in-blade tip antenna. With the optimized in-blade tip antenna polarization and two root antenna locations, an accuracy of 2 cm is achieved for the tip-root antenna distance estimation...

  4. UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction.

    Science.gov (United States)

    Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej; Eggers, Patrick C F; Olesen, Kim; Byskov, Claus; Pedersen, Gert Frølund

    2015-08-12

    A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1-5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists of two UWB antennas at the blade root and one UWB antenna at the blade tip. The detailed topology and challenges of this deflection sensing system are addressed. Due to the complexity of the problem, this paper will first realize the on-blade UWB radio link in the simplest case, where the tip antenna is situated outside (and on the surface of) a blade tip. To investigate this case, full-blade time-domain measurements are designed and conducted under different deflections. The detailed measurement setups and results are provided. If the root and tip antenna locations are properly selected, the first pulse is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics on this application are listed finally.

  5. Experimental Estimating Deflection of a Simple Beam Bridge Model Using Grating Eddy Current Sensors

    Directory of Open Access Journals (Sweden)

    Hui Zhao

    2012-07-01

    Full Text Available A novel three-point method using a grating eddy current absolute position sensor (GECS for bridge deflection estimation is proposed in this paper. Real spatial positions of the measuring points along the span axis are directly used as relative reference points of each other rather than using any other auxiliary static reference points for measuring devices in a conventional method. Every three adjacent measuring points are defined as a measuring unit and a straight connecting bar with a GECS fixed on the center section of it links the two endpoints. In each measuring unit, the displacement of the mid-measuring point relative to the connecting bar measured by the GECS is defined as the relative deflection. Absolute deflections of each measuring point can be calculated from the relative deflections of all the measuring units directly without any correcting approaches. Principles of the three-point method and displacement measurement of the GECS are introduced in detail. Both static and dynamic experiments have been carried out on a simple beam bridge model, which demonstrate that the three-point deflection estimation method using the GECS is effective and offers a reliable way for bridge deflection estimation, especially for long-term monitoring.

  6. Record Deflection Efficiencies Measured for High Energy Protons in a Bent Germanium Crystal

    Science.gov (United States)

    Elsener, K.; Biino, C.; Clement, M.; Doble, N.; Gatignon, L.; Grafstrom, P.; Mikkelsen, U.; Kirsebom, K.; Møller, S. P.; Uggerhøj, E.; Worm, T.; Freund, A.

    1997-05-01

    New experimental results on the deflection of 450 GeV/c and 200 GeV/c protons in a bent Ge crystal are presented. At 450 GeV/c, the 50 mm long crystal gave record deflection efficiencies up to 60% for small angles (1 mrad), while at angles as large as 12 mrad, the efficiency is about 25 times larger than for a silicon crystal of the same size. Measurements up to 20 mrad deflection angle have been performed at 200 GeV/c as well as 450 GeV/c - the lower bending dechanneling leads to a rather slow decrease in efficiency at lower momenta, and 15% of the 200 GeV/c beam hitting the crystal are still deflected at the largest angles measured. These experimental results are in good agreement with a model for channeling deflection developed by Ellison and give confidence in extrapolations to higher energies (e.g. to LHC), other crystal materials or different deflection angles.

  7. Noise robust automatic speech recognition with adaptive quantile based noise estimation and speech band emphasizing filter bank

    DEFF Research Database (Denmark)

    Bonde, Casper Stork; Graversen, Carina; Gregersen, Andreas Gregers;

    2005-01-01

    An important topic in Automatic Speech Recognition (ASR) is to reduce the effect of noise, in particular when mismatch exists between the training and application conditions. Many noise robutness schemes within the feature processing domain use as a prerequisite a noise estimate prior...... to the appearance of the speech signal which require noise robust voice activity detection and assumptions of stationary noise. However, both of these requirements are often not met and it is therefore of particular interest to investigate methods like the Quantile Based Noise Estimation (QBNE) mehtod which...... estimates the noise during speech and non-speech sections without the use of a voice activity detector. While the standard QBNE-method uses a fixed pre-defined quantile accross all frequency bands, this paper suggests adaptive QBNE (AQBNE) which adapts the quantile individually to each frequency band...

  8. Impact of measurement precision and noise on superresolution image reconstruction.

    Science.gov (United States)

    Wood, Sally L; Lee, Shu-Ting; Yang, Gao; Christensen, Marc P; Rajan, Dinesh

    2008-04-01

    The performance of uniform and nonuniform detector arrays for application to the PANOPTES (processing arrays of Nyquist-limited observations to produce a thin electro-optic sensor) flat camera design is analyzed for measurement noise environments including quantization noise and Gaussian and Poisson processes. Image data acquired from a commercial camera with 8 bit and 14 bit output options are analyzed, and estimated noise levels are computed. Noise variances estimated from the measurement values are used in the optimal linear estimators for superresolution image reconstruction.

  9. Noise Investigations for the Tracker Turicensis of the LHCb Experiment

    CERN Document Server

    Hangartner, V

    The LHCb Tracker Turicensis is a silicon micro strip detector with low signal- to-noise ratio. On strip recorded data is buffered in a pipeline, numbered for synchronisation purposes and serialised for transmission within the data acquisition system. These processes affect both pedestals and noise. In this thesis, a method to calculate the noise taking into account the pipeline column number and its encoding is described. Furthermore, the effect on pedestals related to the pipeline column number and monitoring of low noise channels will be described

  10. MUON DETECTOR

    CERN Multimedia

    F. Gasparini

    DT As announced in the previous Bulletin MU DT completed the installation of the vertical chambers of barrel wheels 0, +1 and +2. 242 DT and RPC stations are now installed in the negative barrel wheels. The missing 8 (4 in YB-1 and 4 in YB-2) chambers can be installed only after the lowering of the two wheels into the UX cavern, which is planned for the last quarter of the year. Cabling on the surface of the negative wheels was finished in May after some difficulties with RPC cables. The next step was to begin the final commissioning of the wheels with the final trigger and readout electronics. Priority was giv¬en to YB0 in order to check everything before the chambers were covered by cables and services of the inner detectors. Commissioning is not easy since it requires both activity on the central and positive wheels underground, as well as on the negative wheels still on the surface. The DT community is requested to commission the negative wheels on surface to cope with a possible lack of time a...

  11. Airframe Noise from a Hybrid Wing Body Aircraft Configuration

    Science.gov (United States)

    Hutcheson, Florence V.; Spalt, Taylor B.; Brooks, Thomas F.; Plassman, Gerald E.

    2016-01-01

    A high fidelity aeroacoustic test was conducted in the NASA Langley 14- by 22-Foot Subsonic Tunnel to establish a detailed database of component noise for a 5.8% scale HWB aircraft configuration. The model has a modular design, which includes a drooped and a stowed wing leading edge, deflectable elevons, twin verticals, and a landing gear system with geometrically scaled wheel-wells. The model is mounted inverted in the test section and noise measurements are acquired at different streamwise stations from an overhead microphone phased array and from overhead and sideline microphones. Noise source distribution maps and component noise spectra are presented for airframe configurations representing two different approach flight conditions. Array measurements performed along the aircraft flyover line show the main landing gear to be the dominant contributor to the total airframe noise, followed by the nose gear, the inboard side-edges of the LE droop, the wing tip/LE droop outboard side-edges, and the side-edges of deployed elevons. Velocity dependence and flyover directivity are presented for the main noise components. Decorrelation effects from turbulence scattering on spectral levels measured with the microphone phased array are discussed. Finally, noise directivity maps obtained from the overhead and sideline microphone measurements for the landing gear system are provided for a broad range of observer locations.

  12. Can Noise Kill People?

    Institute of Scientific and Technical Information of China (English)

    刘玲娣

    2007-01-01

    Someone is singing next door,but you feel unhappy because her singing is just making a noise.We know that too much noise makes people feel terrible. Scientists are still trying to find out more about noise,but already it is known that a noise of over 85 decibels can make some people tired and anxious.

  13. AN AMELIORATED DETECTION STATISTICS FOR ADAPTIVE MASK MEDIAN FILTRATION OF HEAVILY NOISED DIGITAL IMAGES

    Directory of Open Access Journals (Sweden)

    Geeta Hanji

    2016-11-01

    Full Text Available Noise reduction is an important area of research in image processing applications. The performance of the digital image noise filtering method primarily depends upon the accuracy of noise detection scheme. This paper presents an effective detector based, adaptive mask, median filtration of heavily noised digital images affected with fixed value (or salt and pepper impulse noise. The proposed filter presents a novel approach; an ameliorated Rank Ordered Absolute Deviation (ROAD statistics to judge whether the input pixel is noised or noise free. If a pixel is detected as corrupted, it is subjected to adaptive mask median filtration; otherwise, it is kept unchanged. Extensive experimental results and comparative performance evaluations demonstrate that the proposed filter outperforms the existing decision type, median based filters with powerful noise detectors in terms of objective performance measures and visual retrieviation accuracy.

  14. Thermal experiment of silicon PIN detector

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-Fei; ZOU Ji-Qing; SHI Wei-Hong; ZOU Hong; HU Ran-Sheng; TIAN Da-Yu

    2008-01-01

    The experiment of this paper is the thermal test of the leakage current of silicon PIN detector.Raising temperature may cause the detector to increase leakage current,decrease depletion and increase noise.Three samples are used in the experiment.One (called △E) is the sample of 100 tan in thickness.The other two (called E1 and E2) are stacks of five detectors of 1000 μm in thickness.All of them are 12 mm in diameter.The experiment has been done for 21 hours and with power on continuously.The samples have undergone more than 60 ℃ for about one hour.They are not degenerated when back to the room temperature.The depletion rate is temperature and bias voltage related.With the circuit of the experiment and temperature at 35 ℃,△E is still depleted while E1 and E2 are 94.9% and 99.7% depleted respectively.The noises of the samples can be derived from the values at room temperature and the thermal dependence of the leakage currents.With the addition of the noise of the pre-amplifier,the noises of E1,E2 and AE at 24 ℃ are 16.4,16.3,and 10.5 keV (FWHM) respectively while at 35 ℃ are about 33.6,33.1,and 20.6 keV (FWHM) respectively.

  15. Data Quality Studies of Enhanced Interferometric Gravitational Wave Detectors

    CERN Document Server

    McIver, Jessica

    2012-01-01

    Data quality assessment plays an essential role in the quest to detect gravitational wave signals in data from the LIGO and Virgo interferometric gravitational wave detectors. Interferometer data contains a high rate of noise transients from the environment, the detector hardware, and the detector control systems. These transients severely limit the statistical significance of gravitational wave candidates of short duration and/or poorly modeled waveforms. This paper describes the data quality studies that have been performed in recent LIGO and Virgo observing runs to mitigate the impact of transient detector artifacts on the gravitational wave searches.

  16. An orientable time of flight detector for cosmic rays

    CERN Document Server

    Iori, M

    2007-01-01

    Cosmic ray studies, in particular UHECR, can be in general supported by a directional, easy deployable, simple and robust detector. The design of this detector is based on the time of flight between two parallel tiles of scintillator, to distinguish particle passing through in opposite directions; by fine time resolution and pretty adjustable acceptance it is possible to select upward(left)/downward(right) cosmic rays. It has been developed for an array of detectors to measure upward $\\tau$ from Earth-Skimming neutrino events with energy above $10^8 GeV$. The properties and performances of the detector are discussed. Test results from a high noise environment are presented.

  17. Active Noise Control for Dishwasher noise

    Science.gov (United States)

    Lee, Nokhaeng; Park, Youngjin

    2016-09-01

    The dishwasher is a useful home appliance and continually used for automatically washing dishes. It's commonly placed in the kitchen with built-in style for practicality and better use of space. In this environment, people are easily exposed to dishwasher noise, so it is an important issue for the consumers, especially for the people living in open and narrow space. Recently, the sound power levels of the noise are about 40 - 50 dBA. It could be achieved by removal of noise sources and passive means of insulating acoustical path. For more reduction, such a quiet mode with the lower speed of cycle has been introduced, but this deteriorates the washing capacity. Under this background, we propose active noise control for dishwasher noise. It is observed that the noise is propagating mainly from the lower part of the front side. Control speakers are placed in the part for the collocation. Observation part of estimating sound field distribution and control part of generating the anti-noise are designed for active noise control. Simulation result shows proposed active noise control scheme could have a potential application for dishwasher noise reduction.

  18. Mechanics of underwater noise

    CERN Document Server

    Ross, Donald

    1976-01-01

    Mechanics of Underwater Noise elucidates the basic mechanisms by which noise is generated, transmitted by structures and radiated into the sea. Organized into 10 chapters, this book begins with a description of noise, decibels and levels, significance of spectra, and passive sonar equation. Subsequent chapters discuss sound waves in liquids; acoustic radiation fundamentals; wind-generated ocean ambient noise; vibration isolation and structural damping; and radiation by plate flexural vibrations. Other chapters address cavitation, propeller cavitation noise, radiation by fluctuating-force (dipo

  19. Note: Broadband low-noise photodetector for Pound-Drever-Hall laser stabilization.

    Science.gov (United States)

    Potnis, Shreyas; Vutha, Amar C

    2016-07-01

    The Pound-Drever-Hall laser stabilization technique requires a fast, low-noise photodetector. We present a simple photodetector design that uses a transformer as an intermediary between a photodiode and cascaded low-noise radio-frequency amplifiers. Our implementation using a silicon photodiode yields a detector with 50 MHz bandwidth, gain >10(5) V/A, and input current noise <4 pA/Hz, allowing us to obtain shot-noise-limited performance with low optical power.

  20. Practical quantum random number generator based on measuring the shot noise of vacuum states

    Science.gov (United States)

    Shen, Yong; Tian, Liang; Zou, Hongxin

    2010-06-01

    The shot noise of vacuum states is a kind of quantum noise and is totally random. In this paper a nondeterministic random number generation scheme based on measuring the shot noise of vacuum states is presented and experimentally demonstrated. We use a homodyne detector to measure the shot noise of vacuum states. Considering that the frequency bandwidth of our detector is limited, we derive the optimal sampling rate so that sampling points have the least correlation with each other. We also choose a method to extract random numbers from sampling values, and prove that the influence of classical noise can be avoided with this method so that the detector does not have to be shot-noise limited. The random numbers generated with this scheme have passed ent and diehard tests.

  1. Mechanically Cooled Large-Volume Germanium Detector Systems for Nuclear Explosion Monitoring

    Science.gov (United States)

    2008-09-01

    cm3, ~ 3 kg, ~ 140 %, or larger). Maintenance-free Stirling -cycle mechanical coolers are being used. These coolers have operating lifetimes...photograph of the complete RASA 1 detector system is shown in Figure 1. The detector is cooled to temperatures below 50 K when the cooler is...cryostat- cooler combination can ultimately serve as a viable detector unit for RASA detector systems . During the pursuit of the microphonic noise

  2. Noise performance of frequency modulation Kelvin force microscopy

    Directory of Open Access Journals (Sweden)

    Heinrich Diesinger

    2014-01-01

    Full Text Available Noise performance of a phase-locked loop (PLL based frequency modulation Kelvin force microscope (FM-KFM is assessed. Noise propagation is modeled step by step throughout the setup using both exact closed loop noise gains and an approximation known as “noise gain” from operational amplifier (OpAmp design that offers the advantage of decoupling the noise performance study from considerations of stability and ideal loop response. The bandwidth can be chosen depending on how much noise is acceptable and it is shown that stability is not an issue up to a limit that will be discussed. With thermal and detector noise as the only sources, both approaches yield PLL frequency noise expressions equal to the theoretical value for self-oscillating circuits and in agreement with measurement, demonstrating that the PLL components neither modify nor contribute noise. Kelvin output noise is then investigated by modeling the surrounding bias feedback loop. A design rule is proposed that allows choosing the AC modulation frequency for optimized sharing of the PLL bandwidth between Kelvin and topography loops. A crossover criterion determines as a function of bandwidth, temperature and probe parameters whether thermal or detector noise is the dominating noise source. Probe merit factors for both cases are then established, suggesting how to tackle noise performance by probe design. Typical merit factors of common probe types are compared. This comprehensive study is an encouraging step toward a more integral performance assessment and a remedy against focusing on single aspects and optimizing around randomly chosen key values.

  3. Analysis of EMCCD and sCMOS readout noise models for Shack-Hartmann wavefront sensor accuracy

    CERN Document Server

    Basden, Alastair

    2015-01-01

    In recent years, detectors with sub-electron readout noise have been used very effectively in astronomical adaptive optics systems. Here, we compare readout noise models for the two key faint flux level detector technologies that are commonly used: EMCCD and scientific CMOS (sCMOS) detectors. We find that in almost all situations, EMCCD technology is advantageous, and that the commonly used simplified model for EMCCD readout is appropriate. We also find that the commonly used simple models for sCMOS readout noise are optimistic, and recommend that a proper treatment of the sCMOS rms readout noise probability distribution should be considered during instrument performance modelling and development.

  4. Overview on low-flux detectors

    Energy Technology Data Exchange (ETDEWEB)

    Seggern, Jan Eike von

    2013-10-15

    Laboratory based searches for weakly-interacting slim particles (WISPs) of the light-shining-through-a-wall type (LSW) use visible or near-infrared (NIR) laser light. Low-noise and highly efficient detectors are necessary to improve over previous experiments. These requirements overlap with the requirements for single-photon detectors (SPDs) for quantum information (QI) experiments. In this contribution, the sensitivity of several QI SPDs is compared to photo-multiplier tubes (PMTs) and imaging charge-coupled devices (CCDs). It is found that only transition edge sensors (TESs) are viable alternatives to CCDs if the signal can be focussed to a few {mu}m.

  5. Overview on Low-flux Detectors

    CERN Document Server

    von Seggern, Jan Eike

    2013-01-01

    Laboratory based searches for weakly-interacting slim particles (WISPs) of the light-shining-through-a-wall type (LSW) use visible or near-infrared (NIR) laser light. Low-noise and highly efficient detectors are necessary to improve over previous experiments. These requirements overlap with the requirements for single-photon detectors (SPDs) for quantum information (QI) experiments. In this contribution, the sensitivity of several QI SPDs is compared to photo-multiplier tubes (PMTs) and imaging charge-coupled devices (CCDs). It is found that only transition edge sensors (TESs) are viable alternatives to CCDs if the signal can be focussed to a few micro meters.

  6. Simple integrated single-atom detector.

    Science.gov (United States)

    Wilzbach, Marco; Heine, Dennis; Groth, Sönke; Liu, Xiyuan; Raub, Thomas; Hessmo, Björn; Schmiedmayer, Jörg

    2009-02-01

    We present a reliable and robust integrated fluorescence detector capable of detecting single atoms. The detector consists of a tapered lensed single-mode fiber for precise delivery of excitation light and a multimode fiber to collect the fluorescence. Both are mounted in lithographically defined SU-8 holding structures on an atom chip. 87Rb atoms propagating freely in a magnetic guide are detected with an efficiency of up to 66%, and a signal-to-noise ratio in excess of 100 is obtained for short integration times.

  7. Commissioning of the recoil silicon detector for the HERMES experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pickert, N.C.

    2008-02-15

    The reconstruction of the missing mass is limited by the position and momentum resolution of the HERMES spectrometer. In order to reach a higher accuracy in the measurements the backscattered nucleon must also be detected. A detector suited for this must give the possibility, to determine the momentum of the particles over a very large range: from minimally ionizing particles up to protons, which are stopped in the detector. The detector must also be able to discriminate hadrons and mesons as well as cover the complete spatial region around the target. In the winter 2005-2006 such a recoil detector was installed in the HERMES experiment. The detector sonsists of three partial detectors, a silicon counter within the scattering chamber, a sintillating-fiber detector and a photon detector. Before the installation of the detector the silicon modules were tested in a bench test and checked together with the other particle detectors in a test experiment. A large part of this dissertation is dedicated to the planning and performance of these tests as well to the evaluation of them. It could be show, that the modules worked accordly to their specifications, however because of unexpectedly high noise a signal correction became necessary. Different models for the correction were developed and tested in the framework of these thesis. In spite of the high noise cosmic muons could be detected and their energy deposition measured with a signal-to-noise ratio of 2:1. In the winter break 2005-2006 the recoil detector was installed into the HERMES experiment. First diagnosis and analysis software was developed. The silicon detector measured successfully energy depositions of minimally ionizing particles up to protons stopped in the sensor. Minimally ionizing particles could be detected with a signal-to-noise ratio of 5:1. By means of track information of the scintillating-fiber detector protons could be discriminated from pions and other mesons by the silicon detector. The HERMES

  8. Study of the background noise generated by the accelerator PEP-2 with a CsI(Na) scanning ring. Study of mass difference between B neutral mesons by using BABAR detector and DI-leptons events; Etude du bruit de fond engendre par l'accelerateur PEP-2 avec un anneau de cristaux de CsI(Na). Etude des oscillations des mesons B neutres avec le detecteur BaBar en utilisant les evenements DI-Leptons

    Energy Technology Data Exchange (ETDEWEB)

    Domenico, G. de

    2000-06-14

    The first part of this report is dedicated to the CP-violation in the sector of B quarks and to its experimental proof through 2 major equipment: the B meson factory PEP-2 and the detector BABAR. The second part deals with the background noise generated by PEP-2. The third part presents the study of the oscillations of neutral B mesons with the detector BABAR. The study of the background noise shows important differences between the experimental data and the simulation. These differences are thought to be due on one hand to the lack of accuracy of pressure models that set the normalisation of the simulated background noise, and on the other hand to the absence of simulation of particles that undergo Coulomb diffusion and do more than a lap before bumping into the void tube. The second hypothesis is backed by the evaluation of the collimation effect of the beam that appears to be more important in experimental data than in the simulation. Among the main results given by the BABAR collaboration, the measurement of the oscillation frequency of the neutral B meson is very important. This measurement is based on semi-leptonic decays of B mesons in order to tag the favour of neutral B mesons at the very moment of their decay. The data analysis was performed over 2.3 10{sup 6} decays of B meson pairs and we obtained: {delta}m{sub d} = (0.495 {+-} 0.026 {+-} 0.023) {Dirac_h}ps{sup -1}. The accuracy on the value of {delta}m{sub d} could be improved by using tagging methods based on the semi-exclusive then exclusive reconstruction of neutral B mesons. (A.C.)

  9. MUON DETECTORS: DT

    CERN Multimedia

    R.Carlin

    2010-01-01

    DT operation during 2010 LHC collisions, both in proton-proton and heavy ions, has been outstanding. The DT downtime has been below 0.1% throughout the whole year, mainly caused by the manual Resync commands that took around a minute for being processed. An automatic resynchronisation procedure has been enabled by August 27 and since then the downtime has been negligible (though constantly monitored). The need for these Resync commands is related to sporadic noise events that occasionally fill the RO buffers or unlock the readout links. Their rate is low, in the order of a few per week. Besides that, only one pp collisions run (1 hour 30 minutes run) has been marked as bad for DT, because of an incident with a temperature sensor that triggered a false alarm and powered off one wheel. Nevertheless, quite a large number of interventions (>30) have been made in the cavern during the year, in order to keep such a large fraction of the detector operational. Most of those are due to the overheating of the ...

  10. MUON DETECTORS: RPC

    CERN Multimedia

    G. Iaselli

    The RPC group has invested a large effort in the study of trigger spikes observed during CRAFT data taking. The chambers are susceptible to noise generated by the flickering of fluorescent and projector lamps in the cavern (with magnetic field on). Soon after the end of CRAFT, it was possible to reproduce the phenomena using a waveform generator and to study possible modifications to be implemented in the grounding schema. Hardware actions have been already taken in order to reduce the detector sensitivity: star washers on the chamber front panels and additional shielding have been added where possible. During the shutdown maintenance activity many different problems were tackled on the barrel part. A few faulty high voltage connector/cable problems were fixed; now only two RPC chambers are left with single-gap mode operation. One chamber in YB+2 was replaced due to gas leakage. All the front-end electronic boards were replaced in 3 chambers (stations MB2 and MB3 in YB-2), that had been damaged after the coo...

  11. Comparison measurements of DQE for two flat panel detectors: fluoroscopic detector vs. cone beam CT detector

    Science.gov (United States)

    Betancourt Benítez, Ricardo; Ning, Ruola; Conover, David

    2006-03-01

    The physical performance of two flat panel detectors (FPD) has been evaluated using a standard x-ray beam quality set by IEC, namely RQA5. The FPDs evaluated in this study are based on an amorphous silicon photodiode array that is coupled to a thallium-doped Cesium Iodide scintillator and to a thin film transistor (TFT) array. One detector is the PaxScan 2520 that is designed for fluoro imaging, and has a small dynamic range and a large image lag. The other detector is the PaxScan 4030CB that is designed for cone beam CT, and has a large dynamic range (>16-bit), a reduced image lag and many imaging modes. Varian Medical Systems manufactured both detectors. The linearity of the FPDs was investigated by using an ionization chamber and aluminum filtration in order to obtain the beam quality. Since the FPDs are used in fluoroscopic mode, image lag of the FPD was measured in order to investigate its effect on this study, especially its effect on DQE. The spatial resolution of the FPDs was determined by obtaining the pre-sampling modulation transfer function for each detector. A sharp edge was used in accordance to IEC 62220-1. Next, the Normalized Noise Power Spectrum (NNPS) was calculated for various exposures levels at RQA5 radiation quality. Finally, the DQE of each FPD was obtained with a modified version of the international standard set by IEC 62220-1. The results show that the physical performance in DQE and MTF of the PaxScan 4030CB is superior to that of PaxScan2520.

  12. Complete model of a spherical gravitational wave detector with capacitive transducers. Calibration and sensitivity optimization

    CERN Document Server

    Gottardi, L

    2006-01-01

    We report the results of a detailed numerical analysis of a real resonant spherical gravitational wave antenna operating with six resonant two-mode capacitive transducers read out by superconducting quantum interference devices (SQUID) amplifiers. We derive a set of equations to describe the electro-mechanical dynamics of the detector. The model takes into account the effect of all the noise sources present in each transducer chain: the thermal noise associated with the mechanical resonators, the thermal noise from the superconducting impedance matching transformer, the back-action noise and the additive current noise of the SQUID amplifier. Asymmetries in the detector signal-to-noise ratio and bandwidth, coming from considering the transducers not as point-like objects but as sensor with physically defined geometry and dimension, are also investigated. We calculate the sensitivity for an ultracryogenic, 30 ton, 2 meter in diameter, spherical detector with optimal and non-optimal impedance matching of the ele...

  13. Measurement of Thermal Noise in Multilayer Coatings with Optimized Layer Thickness

    CERN Document Server

    Villar, Akira E; DeSalvo, Riccardo; Libbrecht, Kenneth G; Michel, Christophe; Morgado, Nazario; Pinard, Laurent; Pinto, Innocenzo M; Pierro, Vincenzo; Galdi, Vincenzo; Principe, Maria; Taurasi, Ilaria

    2010-01-01

    A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise for a prescribed reflectivity. Coatings with the layer thicknesses optimized to minimize thermal noise could be useful in future generation interferometric gravitational wave detectors where coating thermal noise is expected to limit the sensitivity of the instrument. We present the results of direct measurements of the thermal noise of a standard quarter-wavelength coating and a low noise optimized coating. The measurements indicate a reduction in thermal noise in line with modeling predictions.

  14. A Two-Sensor Noise Reduction System: Applications for Hands-Free Car Kit

    Directory of Open Access Journals (Sweden)

    Régine Le Bouquin-Jeannès

    2003-10-01

    Full Text Available This paper presents a two-microphone speech enhancer designed to remove noise in hands-free car kits. The algorithm, based on the magnitude squared coherence, uses speech correlation and noise decorrelation to separate speech from noise. The remaining correlated noise is reduced using cross-spectral subtraction. Particular attention is focused on the estimation of the different spectral densities (noise and noisy signals power spectral densities which are critical for the quality of the algorithm. We also propose a continuous noise estimation, avoiding the need of vocal activity detector. Results on recorded signals are provided, showing the superiority of the two-sensor approach to single microphone techniques.

  15. Extended clustering analyses to constrain the deflection angular scale and source density of the ultra-high-energy cosmic rays

    CERN Document Server

    Decerprit, Guillaume; Parizot, Etienne

    2011-01-01

    The search of a clustering signal in the arrival directions of ultra-high-energy cosmic rays (UHECRs) is a standard method to assess the level of anisotropy of the data sets under investigation. Here, we first show how to quantify the sensitivity of a UHECR detector to the detection of anisotropy, and then propose a new method that pushes forward the study of the two-point auto-correlation function, enabling one to put astrophysically meaningful constraints on both the effective UHECR source density and the angular deflections that these charged particles suffer while they propagate through the galactic and intergalactic magnetic fields. We apply the method to simulated data sets obtained under various astrophysical conditions, and show how the input model parameters can be estimated through our analysis, introducing the notion of "clustering similarity" (between data sets), to which we give a precise statistical meaning. We also study how the constraining power of the method is influenced by the size of the ...

  16. Compensations of beamlet deflections for 1 MeV accelerator of ITER NBI

    Science.gov (United States)

    Kashiwagi, Mieko; Taniguchi, Masaki; Umeda, Naotaka; Dairaku, Masayuki; Tobari, Hiroyuki; Yamanaka, Haruhiko; Watanabe, Kazuhiro; Inoue, Takashi; de Esch, H. P. L.; Grisham, Larry R.; Boilson, Deirdre; Hemsworth, Ronald S.; Tanaka, Masanobu

    2013-02-01

    Compensation methods of beamlet deflections have been studied in a three dimensional (3D) beam analysis using OPERA-3d code for 1 MeV accelerator of the ITER neutral beam injector (NBI). The beamlet deflection is caused by i) magnetic field generated by permanent magnets embedded in the extraction grid (EXG) for electron suppression and ii) space charge repulsion between the beamlets and beam groups. Moreover, the beamlet deflection is caused due to electric field distortion formed by a grid support structure. In order to compensate the beamlet deflections due to i) and ii), an aperture offset of 0.6 mm was applied in the electron suppression grid (ESG) and a metal bar with 3 mm in thickness, so-called a kerb, was attached around the aperture area at the back side of the ESG, respectively. Detailed configuration of the compensation methods was also considered so as to suppress the beam spread due to the electric field distortion and to lower electric field concentrations at the edge of the kerb. For the beamlets near the grid support structure, the beamlet deflection due to the space charge repulsion could be negated due to the electric field distortion formed by the grid support structure.

  17. Feasibility study on a strain based deflection monitoring system for wind turbine blades

    Science.gov (United States)

    Lee, Kyunghyun; Aihara, Aya; Puntsagdash, Ganbayar; Kawaguchi, Takayuki; Sakamoto, Hiraku; Okuma, Masaaki

    2017-01-01

    The bending stiffness of the wind turbine blades has decreased due to the trend of wind turbine upsizing. Consequently, the risk of blades breakage by hitting the tower has increased. In order to prevent such incidents, this study proposes a deflection monitoring system that can be installed to already operating wind turbine's blades. The monitoring system is composed of an estimation algorithm to detect blade deflection and a wireless sensor network as a hardware equipment. As for the estimation method for blade deflection, a strain-based estimation algorithm and an objective function for optimal sensor arrangement are proposed. Strain-based estimation algorithm is using a linear correlation between strain and deflections, which can be expressed in a form of a transformation matrix. The objective function includes the terms of strain sensitivity and condition number of the transformation matrix between strain and deflection. In order to calculate the objective function, a simplified experimental model of the blade is constructed by interpolating the mode shape of a blade from modal testing. The interpolation method is effective considering a practical use to operating wind turbines' blades since it is not necessary to establish a finite element model of a blade. On the other hand, a sensor network with wireless connection with an open source hardware is developed. It is installed to a 300 W scale wind turbine and vibration of the blade on operation is investigated.

  18. Fusion of electromagnetic trackers to improve needle deflection estimation: simulation study.

    Science.gov (United States)

    Sadjadi, Hossein; Hashtrudi-Zaad, Keyvan; Fichtinger, Gabor

    2013-10-01

    We present a needle deflection estimation method to anticipate needle bending during insertion into deformable tissue. Using limited additional sensory information, our approach reduces the estimation error caused by uncertainties inherent in the conventional needle deflection estimation methods. We use Kalman filters to combine a kinematic needle deflection model with the position measurements of the base and the tip of the needle taken by electromagnetic (EM) trackers. One EM tracker is installed on the needle base and estimates the needle tip position indirectly using the kinematic needle deflection model. Another EM tracker is installed on the needle tip and estimates the needle tip position through direct, but noisy measurements. Kalman filters are then employed to fuse these two estimates in real time and provide a reliable estimate of the needle tip position, with reduced variance in the estimation error. We implemented this method to compensate for needle deflection during simulated needle insertions and performed sensitivity analysis for various conditions. At an insertion depth of 150 mm, we observed needle tip estimation error reductions in the range of 28% (from 1.8 to 1.3 mm) to 74% (from 4.8 to 1.2 mm), which demonstrates the effectiveness of our method, offering a clinically practical solution.

  19. An improved equivalent circuit model of a four rod deflecting cavity

    Science.gov (United States)

    Apsimon, R.; Burt, G.

    2017-03-01

    In this paper we present an improved equivalent circuit model for a four rod deflecting cavity which calculates the frequencies of the first four modes of the cavity as well as the RT/Q for the deflecting mode. Equivalent circuit models of RF cavities give intuition and understanding about how the cavity operates and what changes can be made to modify the frequency, without the need for RF simulations, which can be time-consuming. We parameterise a generic four rod deflecting cavity into a geometry consisting of simple shapes. Equations are derived for the line impedance of the rods and the capacitance between the rods and these are used to calculate the resonant frequency of the deflecting dipole mode as well as the lower order mode and the model is bench-marked against two test cases; the CEBAF separator and the HL-LHC 4-rod LHC crab cavity. CST and the equivalent circuit model agree within 4% for both cavities with the LOM frequency and within 1% for the deflecting frequency. RT/Q differs between the model and CST by 37% for the CEBAF separator and 25% for the HL-LHC 4-rod crab cavity; however this is sufficient for understanding how to optimise the cavity design. The model has then been utilised to suggest a method of separating the modal frequencies in the HL-LHC crab cavity and to suggest design methodologies to optimise the cavity geometries.

  20. Laser heating of a cavity versus a plane surface for metal targets utilizing photothermal deflection measurements

    Science.gov (United States)

    Jeong, S. H.; Greif, R.; Russo, R. E.

    1996-08-01

    The effects of a cylindrical cavity in a metal surface on the energy coupling of a laser beam with the solid were investigated by using a photothermal deflection technique. The photothermal deflection of a probe beam over the cavity was measured while the bottom of the cavity was heated with a Nd-YAG laser with a wavelength of 1064 nm. Cavities in three different materials and with two different aspect ratios were used for the experiment. Temperature distributions in the solid and the surrounding air were computed numerically and used to calculate photothermal deflections for cavity heating and for plane surface heating. Reflection of the heating laser beam inside the cavity increased the photothermal deflection amplitude significantly with larger increases for materials with larger thermal diffusivity. The computed photothermal deflections agreed more closely with the experimental results when reflection of the heating laser beam inside the cavity was included in the numerical model. The overall energy coupling between a heating laser and a solid is enhanced by a cavity.