WorldWideScience

Sample records for charge coupled devices

  1. Charge coupled device image sensor study

    Science.gov (United States)

    1974-01-01

    An evaluation of a charge-coupled device (CCD) image sensors for use in spacecraft-borne imaging systems was conducted. The study resulted in design recommendations for two sensors, an approximately 500 times 500 element imaging device and a 1 times 190 element linear imaging device with a 190 times 121 buffer store. Emphasis was placed on the higher resolution, area-imaging sensor. The objectives of the proposed sensors are listed, results of the experiments are analyzed, and estimates of the device performance are presented. A summary of the major technical recommendations is included.

  2. Simulation for signal charge transfer of charge coupled devices

    Institute of Scientific and Technical Information of China (English)

    Wang Zujun; Liu Yinong; Chen Wei; Tang Benqi; Xiao Zhigang; Huang Shaoyan; Liu Minbo; Zhang Yong

    2009-01-01

    Physical device models and numerical processing methods are presented to simulate a linear buried channel charge coupled devices (CCDs). The dynamic transfer process of CCD is carried out by a three-phase clock pulse driver. By using the semiconductor device simulation software MEDICI, dynamic transfer pictures of signal charges cells, electron concentration and electrostatic potential are presented. The key parameters of CCD such as charge transfer efficiency (CTE) and dark electrons are numerically simulated. The simulation results agree with the theoretic and experimental results.

  3. Electrostatically focused intensified charge coupled devices

    Science.gov (United States)

    Walker, J. W.

    1977-01-01

    Work performed to develop intensified charge coupled devices (ICCDs) is presented. Four ICCDs, containing 100 x 160 arrays, were fabricated. Electron gains up to 3200 at 15 keV were achieved. Photocathode sensitivities ranged from 190 to 410 micro A/lumen. Dark currents varied from 11 nA/sq cm to 37 nA/sq cm. There was serious concern about the reliability of the bonding scheme for ICCDs due to occassional bond failure. Two solutions to this problem were developed. One involved a modification of the existing bonding technique, and the other was the development of a protected bond pad employing a barrier metal between the aluminum metallization and the gold bond wire. An accumulation process was characterized with respect to its most critical variable. This characterization led to the achievement of reproducible spectral response and the discovery and elimination of dark current increase associated with this process.

  4. Electrical coupling in multi-array charge coupled devices

    Science.gov (United States)

    Singh, Parul; Sakarvadiya, Vishal; Dubey, Neeraj; Kirkire, Shweta; Thapa, Nitesh; Banerjee, Arup

    2016-05-01

    Silicon based charge coupled device (CCD) performances have improved immensely over the years. Scientific community across the globe target challenging remote sensing applications with CCD as optical imaging detector. Over the years, both pixel count (from few hundreds to few tens of thousands) and line readout rate (from few kHz to few tens of kHz) have increased considerably. Pixels are readout using a large number of output ports driven up to few tens of MHz Moreover, for multi-spectral applications, same Si die contains multiple arrays sharing input stimuli. This is usually done to optimize package pin count. Si die as well as package level layout of clock and bias lines become critical for closely spaced multi-array devices. The inter-array separation may go down to few hundreds of microns when filter coating is laid on top of the die. Die level layout becomes quite critical for devices with such architecture. The inter-array (consecutive arrays) separation is optimized to reduce optical coupling / stray light in devices integrated multi-band strip filter. Layout constraints along with shared bias/clock lines are known to produce electrical cross-talk or coupling. Effect of this (within one array or between two arrays) cross-talk is more pronounced in systems having low noise floor. Video signal dependent coupling in a multi-port system becomes quite complex and leads to a relatively noisier system (post correction). The paper presents results of simulations and tests (pre and post correction) addressing this type of electrical coupling. The paper presents cause, impact and possible remedial measures to minimize such coupling in a multi-array, multi-port TDI CCD from 1.3% to below 0.06%.

  5. SEMICONDUCTOR DEVICES: Simulation for signal charge transfer of charge coupled devices

    Science.gov (United States)

    Zujun, Wang; Yinong, Liu; Wei, Chen; Benqi, Tang; Zhigang, Xiao; Shaoyan, Huang; Minbo, Liu; Yong, Zhang

    2009-12-01

    Physical device models and numerical processing methods are presented to simulate a linear buried channel charge coupled devices (CCDs). The dynamic transfer process of CCD is carried out by a three-phase clock pulse driver. By using the semiconductor device simulation software MEDICI, dynamic transfer pictures of signal charges cells, electron concentration and electrostatic potential are presented. The key parameters of CCD such as charge transfer efficiency (CTE) and dark electrons are numerically simulated. The simulation results agree with the theoretic and experimental results.

  6. Surface contamination of the charge-coupled device

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An experimental method to study the influence of surface contamination of a thinned, backside illuminated charge-coupled device(CCD) upon its quantum efficiency in soft X-ray region is suggested. A transmission grating spectrometer(TGS),in which the transmission grating is coupled to a thinned, backside illuminated charge coupled device, is used to measure the continuum X-ray emission from the end of cylindrical target irradiated by laser. In the measured spectra, only the carbon K absorption edge at wavelength of 4.4nm due to condensation of the vacuum oil on the CCD surface is clearly seen. The surface contamination is considered as an effective "carbon filter" and the filter absorption to correct the quantum efficiency of the CCD camera is taken into account. The effective thickness of the carbon filter is determined by comparing the jump height of the measured spectra at 4.4nm with those of the carbon absorption coefficient curves obtained from various carbon thickness. The accuracy of this method is tested by comparing the X-ray spectrum measured by the TGS with that obtained by a soft X-ray spectrometer.

  7. Single molecule detection using charge-coupled device array technology

    Energy Technology Data Exchange (ETDEWEB)

    Denton, M.B.

    1992-07-29

    A technique for the detection of single fluorescent chromophores in a flowing stream is under development. This capability is an integral facet of a rapid DNA sequencing scheme currently being developed by Los Alamos National Laboratory. In previous investigations, the detection sensitivity was limited by the background Raman emission from the water solvent. A detection scheme based on a novel mode of operating a Charge-Coupled Device (CCD) is being developed which should greatly enhance the discrimination between fluorescence from a single molecule and the background Raman scattering from the solvent. Register shifts between rows in the CCD are synchronized with the sample flow velocity so that fluorescence from a single molecule is collected in a single moving charge packet occupying an area approaching that of a single pixel while the background is spread evenly among a large number of pixels. Feasibility calculations indicate that single molecule detection should be achieved with an excellent signal-to-noise ratio.

  8. Imaging charge-coupled devices for deep-space surveillance

    Science.gov (United States)

    Streuber, D. W., Jr.; Bailis, E. I.

    1980-01-01

    The Ground-Based Electro-Optical Deep Space Surveillance (GEODSS) system will employ a SIT vidicon camera to detect satellites. Imaging charge-coupled devices (CCDs) are being evaluated as a means to improve GEODSS capability. This paper presents performance models and uses them to evaluate currently available CCDs and to determine the characteristics of the ideal CCD array for GEODSS. The analysis includes an approach for determining the CCD pixel size which maximizes signal-to-noise ratio; this approach can be used in many applications. The impact of response nonuniformity and a simple compensation method are also discussed. The combination of a suitable CCD array, response nonuniformity compensation, and moving target indicator (MTI) processing is expected to substantially increase the detection and search rate capability of the GEODSS system.

  9. High speed single charge coupled device Cranz-Schardin camera

    Science.gov (United States)

    Deblock, Y.; Ducloux, O.; Derbesse, L.; Merlen, A.; Pernod, P.

    2007-03-01

    This article describes an ultrahigh speed visualization system based on a miniaturization of the Cranz-Schardin principle. It uses a set of high power light emitting diodes (LEDs) (Golden Dragon) as the light source and a highly sensitive charge coupled device (CCD) camera for reception. Each LED is fired in sequence and images the refraction index variation between two relay lenses, on a partial region of a CCD image sensor. The originality of this system consists in achieving several images on a single CCD during a frame time. The number of images is 4. The time interval between successive firings determines the speed of the imaging system. This time lies from 100nsto10μs. The light pulse duration lies from 100nsto10μs. The principle and the optical and electronic parts of such a system are described. As an example, some images of acoustic waves propagating in water are presented.

  10. Edge passivated charge-coupled device image sensor

    Science.gov (United States)

    Kosonocky, Walter F. (Inventor); Elabd, Hammam (Inventor)

    1987-01-01

    A charge-coupled device (CCD) image sensor includes in a substrate of single crystalline silicon of one conductivity type an array of a plurality of spaced, parallel channel regions of the opposite conductivity type extending along one major surface of the substrate. A plurality of parallel conductive gates are over the one major surface of the substrate and extend transversely across the channel regions. The outermost channel regions of the array are positioned adjacent edges of the substrate so that a plurality of the image sensors can be mounted in edge-to-edge relation with the channel regions of the various sensors being close together. The sensor includes passivating means between each outermost channel region and the adjacent edge to prevent charge carriers generated by the edge from being injected into the outermost channel region. The passivating means includes a highly conductive drain region of a conductivity type opposite to that of the substrate within the substrate and extending along the one major surface between the outermost channel region and the edge. Also, a highly conductive region of the same conductivity type as the substrate is on the substrate and extends along the one major surface directly at the edge.

  11. Combining Charge Couple Devices and Rate Sensors for the Feedforward Control System of a Charge Coupled Device Tracking Loop.

    Science.gov (United States)

    Tang, Tao; Tian, Jing; Zhong, Daijun; Fu, Chengyu

    2016-01-01

    A rate feed forward control-based sensor fusion is proposed to improve the closed-loop performance for a charge couple device (CCD) tracking loop. The target trajectory is recovered by combining line of sight (LOS) errors from the CCD and the angular rate from a fiber-optic gyroscope (FOG). A Kalman filter based on the Singer acceleration model utilizes the reconstructive target trajectory to estimate the target velocity. Different from classical feed forward control, additive feedback loops are inevitably added to the original control loops due to the fact some closed-loop information is used. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability. The bandwidth of the Kalman filter is the major factor affecting the control stability and close-loop performance. Both simulations and experiments are provided to demonstrate the benefits of the proposed algorithm. PMID:27347970

  12. Neutron-computed tomography using charge-coupled devices

    International Nuclear Information System (INIS)

    This paper reports on a prototype position- sensitive neutron detector designed and built for two- and three-dimensional tomographic imaging of materials and complex assemblies. The detector system consists of an LiF- ZnS scintillator screen optically coupled to a cooled charge- coupled device (CCD). Practical resolution limits of the single screen system were calculated to be approximately 100 μm, determined by the neutron beam divergence and the resolution of the scintillator screen. Contrast resolution in a (200 μm)3 volume element was calculated to be 1% of the cross-section in small samples. The system included the MIT Research Reactor as a thermal neutron source (nominal flux approximately 2.4 x 108 n degrees/cm2 sec), a rotating sample holder, and the two-dimensional position-sensitive detector. Two- and three-dimensional tomograms were obtained of phantoms and several demonstration objects, including a control valve and oil well dolomite core sample. The spatial resolution in the images compared favorably to predictions, and it is expected that the final system will improve resolution by at least a factor of 10 over current technology

  13. An efficient image compressor for charge coupled devices camera.

    Science.gov (United States)

    Li, Jin; Xing, Fei; You, Zheng

    2014-01-01

    Recently, the discrete wavelet transforms- (DWT-) based compressor, such as JPEG2000 and CCSDS-IDC, is widely seen as the state of the art compression scheme for charge coupled devices (CCD) camera. However, CCD images project on the DWT basis to produce a large number of large amplitude high-frequency coefficients because these images have a large number of complex texture and contour information, which are disadvantage for the later coding. In this paper, we proposed a low-complexity posttransform coupled with compressing sensing (PT-CS) compression approach for remote sensing image. First, the DWT is applied to the remote sensing image. Then, a pair base posttransform is applied to the DWT coefficients. The pair base are DCT base and Hadamard base, which can be used on the high and low bit-rate, respectively. The best posttransform is selected by the l p -norm-based approach. The posttransform is considered as the sparse representation stage of CS. The posttransform coefficients are resampled by sensing measurement matrix. Experimental results on on-board CCD camera images show that the proposed approach significantly outperforms the CCSDS-IDC-based coder, and its performance is comparable to that of the JPEG2000 at low bit rate and it does not have the high excessive implementation complexity of JPEG2000. PMID:25114977

  14. Plasma effect in silicon charge coupled devices (CCDs)

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, J., E-mail: estrada@fnal.gov [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Molina, J., E-mail: jmolina@ing.una.py [Facultad de Ingenieria, Universidad Nacional de Asuncion, Laboratorio de Mecanica y Energia, Campus de la UNA, San Lorenzo 2160 (Paraguay); Blostein, J.J., E-mail: jeronimo@cab.cnea.gov.ar [CONICET (Argentina); Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Bariloche (Argentina); Fernandez, G., E-mail: fmoroni.guillermo@gmail.com [Universidad Nacional del Sur, Bahia Blanca (Argentina)

    2011-02-11

    Plasma effect is observed in CCDs exposed to heavy ionizing {alpha}-particles with energies in the range 0.5-5.5 MeV. The results obtained for the size of the charge clusters reconstructed on the CCD pixels agree with previous measurements in the high energy region ({>=}3.5 MeV). The measurements were extended to lower energies using {alpha}-particles produced by (n,{alpha}) reactions of neutrons in a {sup 10}B target. The effective linear charge density for the plasma column is measured as a function of energy. The results demonstrate the potential for high position resolution in the reconstruction of {alpha} particles, which opens an interesting possibility for using these detectors in neutron imaging applications.

  15. Plasma effect in Silicon Charge Couple Devices (CCDs)

    CERN Document Server

    Estrada, Juan; Blostein, J

    2011-01-01

    Plasma effect is observed in CCDs exposed to heavy ionizing alpha-particles with energies in the range 0.5 - 5.5 MeV. The results obtained for the size of the charge clusters reconstructed on the CCD pixels agrees with previous measurements in the high energy region (>3.5 MeV). The measurements were extended to lower energies using alpha-particles produced by (n,alpha) reactions of neutrons in a Boron-10 target. The effective linear charge density for the plasma column is measured as a function of energy. The results demonstrate the potential for high position resolution in the reconstruction of alpha particles, which opens an interesting possibility for using these detectors in neutron imaging applications.

  16. A Charge-Coupled Device CCD line-scan system for road luminance measurement.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1996-01-01

    The problems involved in measuring road luminance are discussed and a new measuring system described which is based on a line-scan Charge Coupled Device (CCD) configuration. It is designed for the assessment of average road surface luminance and degree of non-uniformity of road lighting. Additionall

  17. Direct X-Ray Response Of Charge-Coupled Devices And Photodiode Linear Arrays

    Science.gov (United States)

    Launspach, J.; Bourgade, J. L.; Cavailler, C.; de Mascureau, J.; Mens, A.; Sauneuf, R.

    1986-08-01

    For x-ray calibration of detectors used on laser created plasma experiments we have developed and characterized two kinds of sources : classical continuous x-ray sources operating at 1.8 keV and 5.4 keV and a pulsed source obtained by modifying a plasma Focus device. Calibration data for x-ray Charge - Coupled Devices (CCD) and photodiode linear array cameras are presented.

  18. Feedback Direct Injection Current Readout For Infrared Charge-Coupled Devices

    Science.gov (United States)

    Kubo, Kazuya; Wakayama, Hiroyuki; Kajihara, Nobuyuki; Awamoto, Kenji; Miyamoto, Yoshihiro

    1990-01-01

    We are proposing current readout for infrared charge coupled devices (IRCCDs) which can operate at higher temperatures. Feedback direct injection (FDI) consists of a simple amplifier of gain, AFDI was used in a medium-wavelength IRCCD operating at a high temperature. We made a 64-element HgCdTe linear IRCCD using FDI. The device operates at 195 K with an NETD of 0.5 K.

  19. The noise performance of electron-multiplying charge-coupled devices at X-ray energies

    OpenAIRE

    Tutt, James H.; Holland, Andrew D.; Hall, David J.; Harriss, Richard D.; Murray, Neil J.

    2012-01-01

    Electron-multiplying charge-coupled devices (EMCCDs) are used in low-light-level (L3) applications for detecting optical, ultraviolet, and near-infrared photons (10–1100 nm). The on-chip gain process is able to increase the detectability of any signal collected by the device through the multiplication of the signal before the output node. Thus, the effective readout noise can be reduced to subelectron levels, allowing the detection of single photons. However, this gain process introduces an a...

  20. A Simple Illustrative Model of a Charge-Coupled Device (CCD)

    Science.gov (United States)

    Santillo, Michael F.

    2009-10-01

    Many students (as well as the general public) use modern technology without an understanding of how these devices actually work. They are what scientists refer to in the laboratory as "black boxes." Students often wonder how physics relates to the technology used in the real world and are interested in such applications. An example of one such "black box" is the charge-coupled device (CCD), an electronic imaging sensor invented in 1970 by Bell Labs researchers Willard Boyle and George Smith. Astronomers first embraced CCD technology in the early 1980s because CCDs are very light sensitive, consume low amounts of power, and generate digital images quickly. More than three decades later, CCDs have become ubiquitous, as they are found in consumer digital cameras, scanners, photocopiers, medical imaging devices and spectroscopic detectors. This paper presents a model of a CCD "chip" that can be easily adapted as a classroom demonstration.

  1. Single molecule detection using charge-coupled device array technology. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Denton, M.B.

    1992-07-29

    A technique for the detection of single fluorescent chromophores in a flowing stream is under development. This capability is an integral facet of a rapid DNA sequencing scheme currently being developed by Los Alamos National Laboratory. In previous investigations, the detection sensitivity was limited by the background Raman emission from the water solvent. A detection scheme based on a novel mode of operating a Charge-Coupled Device (CCD) is being developed which should greatly enhance the discrimination between fluorescence from a single molecule and the background Raman scattering from the solvent. Register shifts between rows in the CCD are synchronized with the sample flow velocity so that fluorescence from a single molecule is collected in a single moving charge packet occupying an area approaching that of a single pixel while the background is spread evenly among a large number of pixels. Feasibility calculations indicate that single molecule detection should be achieved with an excellent signal-to-noise ratio.

  2. Preliminary evaluation of charge-coupled device (CCD) multispectral analysis in ophthalmology

    International Nuclear Information System (INIS)

    The work described was originally aimed at providing a new diagnostic technique for the early detection of malignant ocular tumors through their spectral signature. The instrument developed comprises a modified fundus camera, a Charge-coupled device (CCD) camera and a 16 bit microcomputer equipped with floopy disk drives and a 512 x 512 x 8-bit display device. The system allows the recording of digitized fundus or iris reflectance pictures in eight spectral bands between 500 and 1100 nm. After calibration and preprocessing of the data, a multispectral analysis is performed by means of a VAX computer. The image processing methods are described and their ability to characterize pigmented lesions or other ocular anatomical features through their spectral signature is evaluated

  3. Determining the Spectral Resolution of a Charge-Coupled Device (CCD) Raman Instrument

    DEFF Research Database (Denmark)

    Liu, Chuan; Berg, Rolf W.

    2012-01-01

    A new method based on dispersion equations is described to express the spectral resolution of an applied charge-coupled device (CCD) Czerny-Turner Raman instrument entirely by means of one equation and principal factors determined by the actual setup. The factors involved are usual quantities suc...... in many contemporary works reporting Raman spectra. A reason for this is that many Raman bands are too wide to show the effect.......A new method based on dispersion equations is described to express the spectral resolution of an applied charge-coupled device (CCD) Czerny-Turner Raman instrument entirely by means of one equation and principal factors determined by the actual setup. The factors involved are usual quantities...... such as wavenumber values for the laser and the Raman band, the diffraction grating groove density, the second focal length, the angle between the incident and the diffracted light, and the full width at half-maximum (FWHM) value of the signal on the detector. A basic formula is derived to estimate the spectral...

  4. X-ray apparatus with scintillator and charge-coupled devices (CCD) sensor for dental radiography

    International Nuclear Information System (INIS)

    The apparatus includes an X-ray source coupled with a receiver both being placed on a support which can rotate about a vertical axis. The receiver comprises a slit receiving incident X-rays which are collected by a charge-coupled device (CCD) sensor via a scintillator screen. The sensor consists of an array of X-ray detectors which generate the X-ray image line by line. The image is transferred to an output amplifier and processed so that each element of the image is digitized and stored in a memory unit. The receiver also includes a mobile part which can be moved with the speed of a radiography film. The advantage of this technology is to enable panoramic images of objects using CCD detectors which can be adapted to existing apparatus. (authors). 2 figs

  5. [A study of the necessity of cooling of charge-coupled devices in x-ray imaging systems].

    Science.gov (United States)

    Morgun, O N; Nemchenko, K E; Rogov, Iu V

    2006-01-01

    The goal of this work was to study one of the widely used X-ray imaging systems: luminescent screen-optical system-matrix of photosensitive charge-coupled device (CCD)-amplifier-analog-to-digital converter. Experimental and theoretical studies were performed to substantiate the necessity of cooling of charge-coupled devices for improvement of X-ray image characteristics. The obtained results reveal the necessity of cooling of CCD-matrix crystals in the X-ray imaging system under consideration. PMID:16610280

  6. Angular sensitivity of modeled scientific silicon charge-coupled devices to initial electron direction

    Science.gov (United States)

    Plimley, Brian; Coffer, Amy; Zhang, Yigong; Vetter, Kai

    2016-08-01

    Previously, scientific silicon charge-coupled devices (CCDs) with 10.5-μm pixel pitch and a thick (650 μm), fully depleted bulk have been used to measure gamma-ray-induced fast electrons and demonstrate electron track Compton imaging. A model of the response of this CCD was also developed and benchmarked to experiment using Monte Carlo electron tracks. We now examine the trade-off in pixel pitch and electronic noise. We extend our CCD response model to different pixel pitch and readout noise per pixel, including pixel pitch of 2.5 μm, 5 μm, 10.5 μm, 20 μm, and 40 μm, and readout noise from 0 eV/pixel to 2 keV/pixel for 10.5 μm pixel pitch. The CCD images generated by this model using simulated electron tracks are processed by our trajectory reconstruction algorithm. The performance of the reconstruction algorithm defines the expected angular sensitivity as a function of electron energy, CCD pixel pitch, and readout noise per pixel. Results show that our existing pixel pitch of 10.5 μm is near optimal for our approach, because smaller pixels add little new information but are subject to greater statistical noise. In addition, we measured the readout noise per pixel for two different device temperatures in order to estimate the effect of temperature on the reconstruction algorithm performance, although the readout is not optimized for higher temperatures. The noise in our device at 240 K increases the FWHM of angular measurement error by no more than a factor of 2, from 26° to 49° FWHM for electrons between 425 keV and 480 keV. Therefore, a CCD could be used for electron-track-based imaging in a Peltier-cooled device.

  7. One-dimensional ionizing radiation detector on the charge-coupled device basis

    International Nuclear Information System (INIS)

    Basic features of the one-dimensional ionizing radiation detector designed on the charge-coupled device (CCD) basis with surface as well as deepened channel are studied. The eta (E) dependence of the detector quantum efficiency on the density of soft X radiation energy is given. It has been found on the basis of the analysis of the eta(E) dependence that the most acceptable range of using CCD-detectors lies in the limits of radiation energy from 2 to 12 keV. In this energy region the linearity of ionizing radiation flux conversion into electrical charge is assured. The CCD-detector sensitivity constitutes 2x108 photon/(cm2xs). The upper limit of the detector dynamic range equals to 1010 photon/(cm2xs) while the whole dynamic range equals to 50. The effect of long-term irradiation on the basic features of the CCD-detectors is considered as well as restoration methods of their operating performances are proposed. The real irradiation levels, which the CCD-detectors made on the n-Si base withstand, constitute (1-3)x104 rad. It is pointed out that most prospective CCD-detectors are those with a deepened channel and Schottky gates in which control through the oxide layer is missing

  8. A simple, low-cost, versatile charge-coupled device spectrometer for plasma spectroscopy

    International Nuclear Information System (INIS)

    We have constructed a simple, low-cost charge-coupled device (CCD) spectrometer capable of both high resolution (Δλ≤0.015 nm) and large bandpass (110 nm with Δλ∼0.3 nm). These two modes of operation provide two broad areas of capability for plasma spectroscopy. The first major application is measurement of emission line broadening; the second is emission line surveys from the ultraviolet to the near infrared. Measurements have been made on a low-temperature plasma produced by a miniature electrostatic plasma source and the high-temperature plasma in the Madison Symmetric Torus reversed-field pinch. The spectrometer is a modified Jarrell endash Ash 0.5 m Ebert endash Fastie monochromator. Light is coupled into the entrance slit with a fused silica fiber optic bundle. The exposure time (2 ms minimum) is controlled by a fast electro-mechanical shutter. The exit plane detector is a compact and robust CCD detector developed for amateur astronomy by Santa Barbara Instrument Group. The CCD detector is controlled and read out by a Macintosh reg-sign computer. This spectrometer is sophisticated enough to serve well in a research laboratory, yet is simple and inexpensive enough to be affordable for instructional use. copyright 1997 American Institute of Physics

  9. Multi-dimensional neutron-computed tomography using cooled charge-coupled devices

    International Nuclear Information System (INIS)

    This paper reports on a prototype position-sensitive neutron detector designed and built for two- and three-dimensional tomographic imaging of materials and complex assemblies. The detector system consists of an Lif-ZnS scintillator screen optically coupled to a cooled charge-coupled device (CCD). Practical resolution limits of the single screen system were calculated to be approximately 100 μm, determined by the neutron beam divergence and the resolution of the scintillator screen. Contrast resolution in a (200 μm)3 volume element was calculated to be 1% of the cross-section in small samples. The system included the MIT Research Reactor as a thermal neutron source (nominal flux approximately 2.4 x 108 n degrees/cm2-sec), a rotating sample holder, and the two-dimensional position-sensitive detector. The effects of scatter were estimated and compared to data. Two- and three-dimensional tomograms were obtained of phantoms and several demonstration objects, including a control valve and an oil well dolomite core sample. The spatial resolution in the images compared favorably to predictions, and it is expected that the final system will improve resolution by at least a factor 10 over current technology

  10. Development of a novel neutron detection technique by using a boron layer coating a Charge Coupled Device

    OpenAIRE

    Blostein, Juan Jerónimo; Estrada, Juan; Tartaglione, Aureliano; Haro, Miguel Sofo; Moroni, Guillermo Fernández; Cancelo, Gustavo

    2014-01-01

    This article describes the design features and the first test measurements obtained during the installation of a novel high resolution 2D neutron detection technique. The technique proposed in this work consists of a boron layer (enriched in ${^{10}}$B) placed on a scientific Charge Coupled Device (CCD). After the nuclear reaction ${^{10}}$B(n,$\\alpha$)${^{7}}$Li, the CCD detects the emitted charge particles thus obtaining information on the neutron absorption position. The above mentioned io...

  11. Use of a charge-coupled device camera for broadband coherent anti-Stokes Raman scattering measurements.

    Science.gov (United States)

    Rakestraw, D J; Lucht, R P; Dreier, T

    1989-10-01

    The use of an unintensified charge-coupled device (CCD) camera for the acquisition of broadband CARS signals is demonstrated. The CCD camera offers significant advantages compared to intensified, linear photodiode array (PDA) detectors that are generally used for broadband CARS measurements. These advantages include higher spectral resolution and improved instrument function, larger dynamic range, and a 2-D format. PMID:20555836

  12. An image compression method for space multispectral time delay and integration charge coupled device camera

    Institute of Scientific and Technical Information of China (English)

    Li Jin; Jin Long-Xu; Zhang Ran-Feng

    2013-01-01

    Multispectral time delay and integration charge coupled device (TDICCD) image compression requires a lowcomplexity encoder because it is usually completed on board where the energy and memory are limited.The Consultative Committee for Space Data Systems (CCSDS) has proposed an image data compression (CCSDS-IDC) algorithm which is so far most widely implemented in hardware.However,it cannot reduce spectral redundancy in multispectral images.In this paper,we propose a low-complexity improved CCSDS-IDC (ICCSDS-IDC)-based distributed source coding (DSC) scheme for multispectral TDICCD image consisting of a few bands.Our scheme is based on an ICCSDS-IDC approach that uses a bit plane extractor to parse the differences in the original image and its wavelet transformed coefficient.The output of bit plane extractor will be encoded by a first order entropy coder.Low-density parity-check-based Slepian-Wolf (SW) coder is adopted to implement the DSC strategy.Experimental results on space multispectral TDICCD images show that the proposed scheme significantly outperforms the CCSDS-IDC-based coder in each band.

  13. An image compression method for space multispectral time delay and integration charge coupled device camera

    International Nuclear Information System (INIS)

    Multispectral time delay and integration charge coupled device (TDICCD) image compression requires a low-complexity encoder because it is usually completed on board where the energy and memory are limited. The Consultative Committee for Space Data Systems (CCSDS) has proposed an image data compression (CCSDS-IDC) algorithm which is so far most widely implemented in hardware. However, it cannot reduce spectral redundancy in multispectral images. In this paper, we propose a low-complexity improved CCSDS-IDC (ICCSDS-IDC)-based distributed source coding (DSC) scheme for multispectral TDICCD image consisting of a few bands. Our scheme is based on an ICCSDS-IDC approach that uses a bit plane extractor to parse the differences in the original image and its wavelet transformed coefficient. The output of bit plane extractor will be encoded by a first order entropy coder. Low-density parity-check-based Slepian—Wolf (SW) coder is adopted to implement the DSC strategy. Experimental results on space multispectral TDICCD images show that the proposed scheme significantly outperforms the CCSDS-IDC-based coder in each band

  14. Charge Coupled Devices for detection of coherent neutrino-nucleus scattering

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Moroni, Guillermo [Fermilab; Estrada, Juan [Fermilab; Paolini, Eduardo E. [Buenos Aires U.; Cancelo, Gustavo [Fermilab; Tiffenberg, Javier [Fermilab; Molina, Jorge [Asuncion Natl. U.

    2015-04-03

    In this article the feasibility of using charge coupled devices (CCD) to detect low-energy neutrinos through their coherent scattering with nuclei is analyzed. The detection of neutrinos through this standard model process has been elusive because of the small energy deposited in such interaction. Typical particle detectors have thresholds of a few keV, and most of the energy deposition expected from coherent scattering is well below this level. The CCD detectors discussed in this paper can operate at a threshold of approximately 30 eV, making them ideal for observing this signal. On a CCD array of 500 g located next to a power nuclear reactor the number of coherent scattering events expected is about 3000 events/year. Our results shows that a detection with a confidence level of 99% can be reached within 16 days of continuous operation; with the current 52 g detector prototype this time lapse extends to five months.

  15. Image Reconstruction of a Charge Coupled Device Based Optical Tomographic Instrumentation System for Particle Sizing

    Directory of Open Access Journals (Sweden)

    Mohd Hafiz Fazalul Rahiman

    2010-10-01

    Full Text Available This research investigates the use of charge coupled device (abbreviated as CCD linear image sensors in an optical tomographic instrumentation system used for sizing particles. The measurement system, consisting of four CCD linear image sensors are configured around an octagonal shaped flow pipe for a four projections system is explained. The four linear image sensors provide 2,048 pixel imaging with a pixel size of 14 micron × 14 micron, hence constituting a high-resolution system. Image reconstruction for a four-projection optical tomography system is also discussed, where a simple optical model is used to relate attenuation due to variations in optical density, [R], within the measurement section. Expressed in matrix form this represents the forward problem in tomography [S] [R] = [M]. In practice, measurements [M] are used to estimate the optical density distribution by solving the inverse problem [R] = [S]−1[M]. Direct inversion of the sensitivity matrix, [S], is not possible and two approximations are considered and compared—the transpose and the pseudo inverse sensitivity matrices.

  16. Quantifying the performance of charge-coupled devices in ambient conditions - Oral presentation

    Energy Technology Data Exchange (ETDEWEB)

    Dungee, Ryan [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-22

    Telescope surveys have given us a great deal of information about our universe, but the images they capture carry with them an inherent limitation. The question then is how do we take this information to the next level? The answer: the Dark Energy Spectroscopic Instrument (DESI). DESI is an instrument that will measure the distance to tens of millions of galaxies in our night sky. This information can be combined with already existing images to construct a three dimensional map of our universe providing a great deal of new opportunities for cosmological research. The DESI guidance system consists of 10 detectors called charge-coupled devices (CCDs). Each CCD is made of silicon atoms that emit electrons when struck with light, the electrons are counted and then used to reconstruct an image. But, CCDs suffer from an issue known as ‘dark current’ which are false counts that come from thermal motions of the silicon atoms. This is particularly problematic since they contribute to the uncertainty of a measurement without contributing to our signal. This causes a drop in the signal to noise ratio, a value that needs to be maximized in order to meet DESI’s high precision requirements. This summer was spent ensuring the DESI guidance system would meet its specifications. Data was collected using a CCD of the same type that would be used on DESI and the effectiveness of dark current removal was tested. Exposures were taken for a wide range of temperatures and exposure lengths and a number of dark current removal methods were implemented. While further testing is required, the initial results are quite promising and the DESI guidance system is on track to meet its specifications

  17. Texas Instruments /TI/ 800 x 800 charge-coupled device /CCD/ image sensor

    Science.gov (United States)

    Blouke, M. M.; Hall, J. E.; Cowens, M. W.; Janesick, J. R.

    1981-01-01

    Very-large area high-performance CCD image sensors with 800 x 800 pixel format have been successfully fabricated and operated on the basis of a three-level polysilicon gate technology. They are thinned to 8 microns over the entire 12.2 x 12.2 mm active area, and are used in the rear illumination mode. The light transfer characteristic has a gamma value of 1.000 + or - 0.002 over most of the dynamic range. Analysis of the noise behavior shows that the device SNR is shot-noise-limited over most of the dynamic range. Simple on-chip signal processing can be performed using an integration well to noiselessly collect signal charge from multiple pixels prior to reading out the charge. A UV-sensitive phosphor has been applied to the chip, yielding a device capable of imaging at wavelengths from the vacuum UV to the near IR.

  18. Analysis of electron multiplying charge coupled device and scientific CMOS readout noise models for Shack–Hartmann wavefront sensor accuracy.

    OpenAIRE

    Basden, A. G.

    2015-01-01

    In recent years, detectors with subelectron 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: electron multiplying charge coupled device (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 ...

  19. A comparison of image characteristics and convenience in panoramic radiography using charge-coupled device, storage phosphor, and film receptors

    OpenAIRE

    Farman, Allan G.; Farman, Taeko Takemori

    2001-01-01

    This study compared the image layer characteristics, dose requirements, and convenience in use of panoramic radiography using each of four different image receptors including traditional indirect exposure x-ray film, a storage phosphor system, and two solid-state sensors. The OP 100 D (Instrumentarium Imaging, Tuusula, Finland) charge-coupled device (CCD) sensor provided an instant image with a wide focal trough, making patient positioning error unlikely, but at the same time required a patie...

  20. Programmable scan/read circuitry for charge coupled device imaging detectors. [spcecraft attitude control and star trackers

    Science.gov (United States)

    Salomon, P. M.; Smilowitz, K.

    1984-01-01

    A circuit for scanning and outputting the induced charges in a solid state charge coupled device (CCD) image detector is disclosed in an image detection system for use in a spacecraft attitude control system. The image detection system includes timing control circuitry for selectively controlling the output of the CCD detector so that video outputs are provided only with respect to induced charges corresponding to predetermined sensing element lines of the CCD detector. The timing control circuit and the analog to digital converter are controlled by a programmed microprocessor which defines the video outputs to be converted and further controls the timing control circuit so that no video outputs are provided during the delay associated with analog to digital conversion.

  1. Development of a novel neutron detection technique by using a boron layer coating a Charge Coupled Device

    CERN Document Server

    Blostein, Juan Jerónimo; Tartaglione, Aureliano; Haro, Miguel Sofo; Moroni, Guillermo Fernández; Cancelo, Gustavo

    2014-01-01

    This article describes the design features and the first test measurements obtained during the installation of a novel high resolution 2D neutron detection technique. The technique proposed in this work consists of a boron layer (enriched in ${^{10}}$B) placed on a scientific Charge Coupled Device (CCD). After the nuclear reaction ${^{10}}$B(n,$\\alpha$)${^{7}}$Li, the CCD detects the emitted charge particles thus obtaining information on the neutron absorption position. The above mentioned ionizing particles, with energies in the range 0.5-5.5 MeV, produce a plasma effect in the CCD which is recorded as a circular spot. This characteristic circular shape, as well as the relationship observed between the spot diameter and the charge collected, is used for the event recognition, allowing the discrimination of undesirable gamma events. We present the first results recently obtained with this technique, which has the potential to perform neutron tomography investigations with a spatial resolution better than that...

  2. The noise performance of electron-multiplying charge-coupled devices at soft X-ray energy values

    OpenAIRE

    Tutt, James H.; Holland, Andrew D.; Murray, Neil J.; Hall, David J.; Harriss, Richard D.; Clarke, Andrew; Evagora, Anthony M.

    2012-01-01

    The use of electron-multiplying charge-coupled devices (CCDs) for high-resolution soft X-ray spectroscopy has been proposed in previous studies, and the analysis that followed experimentally identified and verified a modified Fano factor for X-ray detection using an 55Fe X-ray source. However, further experiments with soft X-rays at 1000 eV were less successful, attributed to excessive split events. More recently, through the use of deep-depletion e2v CCD220 and on-chip binning, it has been p...

  3. Fabrication, Testing and Integration Technologies of Polymer Microlens for Pt/Si Schottky-Barrier Infrared Charge Coupled Device Applications

    Institute of Scientific and Technical Information of China (English)

    KE Cai-Jun; YI Xin-Jian; LAI Jian-Jun; CHEN Si-Hai

    2005-01-01

    @@ A novel polymer refractive microlens array has been formed on the surface of 256(V)×290(H) PtSi Schottkybarrier infrared charge coupled device (IRCCD) image sensors to improve the photoresponsivity of the IRCCD.The fabrication process flows of polymer microlens array are described. An effective aperture ratio in excess of 92% of microlens array has been achieved. An experimental facility to evaluate the optical performance ofmicrolens array is introduced. The measurement results show that the microlens array indicates better than 4% non-uniformity of focal length and high optical performance. The application of the microlens array to improve the photosensitivity of infrared CCD is discussed.

  4. Degradation of saturation output of the COTS array charge-coupled devices induced by total dose radiation damage

    International Nuclear Information System (INIS)

    Experiments of total dose radiation effects on COTS array charge-coupled device (CCD) and annealing measurements are shown. Degradations of saturation output voltage at different bias conditions are analyzed, and their mechanisms induced by radiation are also demonstrated. Degradations of saturation output imaging at different total doses and the recovery after annealing are also compared. The phenomena of imaging degradation induced by total dose irradiation are analyzed. The camera imaging quality of resolution test card degraded by total dose irradiation is also analyzed. Finally, integration research from the irradiation-sensitive parameter degradation to the camera imaging degradation of the array CCD is achieved

  5. Development of a novel neutron detection technique by using a boron layer coating a Charge Coupled Device

    Energy Technology Data Exchange (ETDEWEB)

    Blostein, Juan Jerónimo; Estrada, Juan; Tartaglione, Aureliano; Sofo haro, Miguel; Fernández Moroni, Guillermo; Cancelo, Gustavo

    2015-01-19

    This article describes the design features and the first test measurements obtained during the installation of a novel high resolution 2D neutron detection technique. The technique proposed in this work consists of a boron layer (enriched in ${^{10}}$B) placed on a scientific Charge Coupled Device (CCD). After the nuclear reaction ${^{10}}$B(n,$\\alpha$)${^{7}}$Li, the CCD detects the emitted charge particles thus obtaining information on the neutron absorption position. The above mentioned ionizing particles, with energies in the range 0.5-5.5 MeV, produce a plasma effect in the CCD which is recorded as a circular spot. This characteristic circular shape, as well as the relationship observed between the spot diameter and the charge collected, is used for the event recognition, allowing the discrimination of undesirable gamma events. We present the first results recently obtained with this technique, which has the potential to perform neutron tomography investigations with a spatial resolution better than that previously achieved. Numerical simulations indicate that the spatial resolution of this technique will be about 15 $\\mu$m, and the intrinsic detection efficiency for thermal neutrons will be about 3 %. We compare the proposed technique with other neutron detection techniques and analyze its advantages and disadvantages.

  6. Position sensitive detector of soft x-radiation and alpha particles on the charge-coupled device base

    International Nuclear Information System (INIS)

    The position-sensitive detector based on a matrix of charge-coupled devices (CCD) operating on-line with the Pravets personal computer is designed. Application of the yttrium oxysulfide as a converter and give an opportunity to obtain 1300 electrons in CCD matrix per 1 photon absorbed in a phosphore for 8 keV X-ray photons. The detector ensures detection of single 5.5 MeV α particles. Spatial resolution for the detector with Y2O2S-Tb phosphore 40 mm in-diameter is about 350 μm for both X-ray photons and α particles. Detection efficiency nonuniformity over the detector area is ≤1% when the correcting matrix is used

  7. Analysis of electron multiplying charge coupled device and scientific CMOS readout noise models for Shack-Hartmann wavefront sensor accuracy

    Science.gov (United States)

    Basden, Alastair G.

    2015-07-01

    In recent years, detectors with subelectron 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: electron multiplying charge coupled device (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 we recommend that a proper treatment of the sCMOS root mean square readout noise probability distribution should be considered during instrument performance modeling and development.

  8. Measuring a charge-coupled device point spread function. Euclid visible instrument CCD273-84 PSF performance

    Science.gov (United States)

    Niemi, Sami-Matias; Cropper, Mark; Szafraniec, Magdalena; Kitching, Thomas

    2015-06-01

    In this paper we present the testing of a back-illuminated development Euclid Visible Instrument (VIS) Charge-Coupled Device (CCD) to measure the intrinsic CCD Point Spread Function (PSF) characteristics using a novel modelling technique. We model the optical spot projection system and the CCD273-84 PSF jointly. We fit a model using Bayesian posterior probability density function, sampling to all available data simultaneously. The generative model fitting is shown, using simulated data, to allow good parameter estimations even when these data are not well sampled. Using available spot data we characterise a CCD273-84 PSF as a function of wavelength and intensity. The CCD PSF kernel size was found to increase with increasing intensity and decreasing wavelength.

  9. MIDAS prototype Multispectral Interactive Digital Analysis System for large area earth resources surveys. Volume 2: Charge coupled device investigation

    Science.gov (United States)

    Kriegler, F.; Marshall, R.; Sternberg, S.

    1976-01-01

    MIDAS is a third-generation, fast, low cost, multispectral recognition system able to keep pace with the large quantity and high rates of data acquisition from large regions with present and projected sensors. MIDAS, for example, can process a complete ERTS frame in forty seconds and provide a color map of sixteen constituent categories in a few minutes. A principal objective of the MIDAS Program is to provide a system well interfaced with the human operator and thus to obtain large overall reductions in turn-around time and significant gains in throughput. The need for advanced onboard spacecraft processing of remotely sensed data is stated and approaches to this problem are described which are feasible through the use of charge coupled devices. Tentative mechanizations for the required processing operations are given in large block form. These initial designs can serve as a guide to circuit/system designers.

  10. On-line monitoring system for roller wear with axes shift compensation based on laser-linear charge coupled device

    Science.gov (United States)

    Wei, Liansuo; Guo, Yuan

    2013-04-01

    Based on the principle of laser-linear array charge-coupled device (CCD) detection technology, a high accuracy nontouch on-line system for monitoring roller wear is brought forward. The principle and composition of the laser-linear array CCD detection system and the operation process were expatiated. Aiming at the errors of the roller's axes shifting during the detection process, compensating steps were adopted from the vertical and the parallel direction to the detection surface. This effectively enhanced the accuracy of the detection system. Experiments proved that the accuracy of the system could reach the demand of the practical production process. It provides a new method for high speed, accuracy, and automatic on-line monitoring of roller wear. r shapegear array CCD detection. A simulation-software program is also compiled based on this principle. By using this program, the I/O signals's data for this system is gained and the detection curves can be drawn automatically.

  11. Measuring a Charge-Coupled Device Point Spread Function: Euclid Visible Instrument CCD273-84 PSF Performance

    CERN Document Server

    Niemi, Sami-Matias; Szafraniec, Magdalena; Kitching, Thomas

    2014-01-01

    In this paper we present the testing of a back-illuminated development Euclid Visible Instrument (VIS) Charge-Coupled Device (CCD) to measure the intrinsic CCD Point Spread Function (PSF) characteristics using a novel modelling technique. We model the optical spot projection system and the CCD273-84 PSF jointly. We fit a model using Bayesian posterior probability density function, sampling to all available data simultaneously. The generative model fitting is shown, using simulated data, to allow good parameter estimations even when data are not well sampled. Using available spot data we characterise a CCD273-84 PSF as a function of wavelength and intensity. The CCD PSF kernel size was found to increase with increasing intensity and decreasing wavelength.

  12. Teaching Charge Coupled Devices Using Models as Part of the Engineering Design Process at Maui Community College

    CERN Document Server

    Mostafanezhad, Isar; Rozic, Ciril; Harrington, David; Jacobs, Brad; Swindle, Ryan; Reader, Elisabeth

    2010-01-01

    The CCD Modeling Activity was designed to supplement the curriculum of the Electrical and Computing Engineering Technology program at the Maui Community College. The activity was designed to help learners understand how a Charge Coupled Device (CCD) works. A team of visiting graduate students was invited to teach an activity through the Teaching and Curriculum Collaborative (TeCC) as part of the Center for Adaptive Optics/Institute for Science and Engineer Educators Professional Development Program. One of the primary goals was to have students gain an understanding of the function of a CCD by constructing a model representing the CCD readout process. In this paper we discuss the design and implementation of the activity and the challenges we faced.

  13. Test of scintillating bars coupled to Silicon Photomultipliers for a charged particle tracking device

    CERN Document Server

    Cecchini, S; Esposti, L Degli; Lax, I; Mandrioli, G; Mauri, N; Pasqualini, L; Patrizii, L; Pozzato, M; Sirri, G; Tenti, M

    2016-01-01

    The results obtained in laboratory tests, using scintillator bars read by silicon photomultipliers are reported. The present approach is the first step for designing a precision tracking system to be placed inside a free magnetized volume for the charge identification of low energy crossing particles. The devised system is demonstrated able to provide a spatial resolution better than 2 mm.

  14. Four-shooter - A large format charge-coupled device camera for the Hale telescope

    Science.gov (United States)

    Gunn, James E.; Carr, Michael; Danielson, G. Edward; Lorenz, Ernest O.; Lucinio, Richard; Nenow, Victor E.; Smith, J. Devere; Westphal, James A.; Schneider, Donald P.; Zimmerman, Barbara A.

    1987-01-01

    The Hale telescope has employed an astronomical camera using four 800x800 CCDs in an optical arrangement that allows the imaging of a contiguous 1600-pixel-square region of the sky; reimaging optics are then used to yield a scale of 0.33 arcsec/pixel. Optical coatings are incorporated to yield a throughput at peak efficiency of nearly 50 percent, including telescope losses. This camera can be used in a scanning mode, in which the telescope tracking rate is offset and the charge is clocked in the chips in such a way that the charge image remains aligned with the optical image. Attention is given to the results of a survey for high-redshift quasars using this equipment, which has produced images for the most distant galaxy clusters yet discovered.

  15. Initial Measurement of Intrapixel Variations in Back-Illuminated, High-Resistivity, p-Channel, Charge Coupled Device

    Science.gov (United States)

    Puls, Jason; Oluseyi, Hakeem M.

    2008-05-01

    In 1929 Edwin Hubble discovered the universe's expansion. Seventy years later it was unexpectedly found that the rate of expansion is accelerating due to some vast cosmic energy. This cosmic energy, apparently gravitationally repulsive and spread homogeneously through the universe, has come to be known as dark energy. To better understand this universal force, scientists utilize Type Ia supernovae and weak gravitational lensing as cosmological probes. Lawrence Berkeley National Laboratory (LBNL) is developing the Supernova Acceleration Probe (SNAP), a proposed space-based telescope that will be used to identify and measure supernovae and measure weak gravitational lensing signals across fifteen square degrees of the sky. The SNAP telescope will incorporate an innovative camera that consists of back-illuminated, high-resistivity, p-channel charged coupled devices (CCDs) for visible to near-infrared light detection. Presented are results obtained from the measurement and analysis of a 10.5 μm pixel pitch, 1.4k by 1.4k format, p-channel CCD fabricated on high-resistivity silicon at LBNL. The fully depleted device is 300 μm thick and backside illuminated. We report on the first measurement of the intrapixel sensitivity and spatial variations of these CCDs. We also report measurements of electric field distortions near the edges of the CCD active area.

  16. High Voltage CMOS control interface for astronomy—Grade charged coupled devices

    Science.gov (United States)

    Martin, E.; Varner, G.; Koga, A.; Ruckman, L.; Onaka, P.; Tonry, J.; Lee, A.

    2008-08-01

    The Pan-STARRS telescope consists of an array of smaller mirrors viewed by a Giga-pixel arrays of CCDs. These focal planes employ Orthogonal Transfer CCDs (OTCCDs) to allow on-chip image stabilization. Each OTCCD has advanced logic features that are controlled externally. A CMOS Interface Device for High Voltage has been developed to provide the appropiate voltage signal levels from a readout and control system designated STARGRASP. OTCCD chip output levels range from -3.3V to 16.7V, with two different output drive strengths required depending on load capacitance (50pF and 1000pF), with 24mA of drive and a rise time on the order of 100ns. Additional testing Wilkinson ADC structures have been included in this chip to evaluate future functional additions for a next version of the chip.

  17. High Voltage CMOS Control Interface for Astronomy - Grade Charged Coupled Devices

    CERN Document Server

    Martin, Elena; Koga, Aaron; Ruckman, Larry; Onaka, Peter; Tonry, John; Lee, Aaron

    2008-01-01

    The Pan-STARRS telescope consists of an array of smaller mirrors viewed by a Gigapixel arrays of CCDs. These focal planes employ Orthogonal Transfer CCDs (OTCCDs) to allow on-chip image stabilization. Each OTCCD has advanced logic features that are controlled externally. A CMOS Interface Device for High Voltage has been developed to provide the appropiate voltage signal levels from a readout and control system designated STARGRASP. OTCCD chip output levels range from -3.3V to 16.7V, with two different output drive strenghts required depending on load capacitance (50pF and 1000pF), with 24mA of drive and a rise time on the order of 100ns. Additional testing ADC structures have been included in this chip to evaluate future functional additions for a next version of the chip.

  18. Liquid-crystal-display projector-based modulation transfer function measurements of charge-coupled-device video camera systems.

    Science.gov (United States)

    Teipen, B T; MacFarlane, D L

    2000-02-01

    We demonstrate the ability to measure the system modulation transfer function (MTF) of both color and monochrome charge-coupled-device (CCD) video camera systems with a liquid-crystal-display (LCD) projector. Test matrices programmed to the LCD projector were chosen primarily to have a flat power spectral density (PSD) when averaged along one dimension. We explored several matrices and present results for a matrix produced with a random-number generator, a matrix of sequency-ordered Walsh functions, a pseudorandom Hadamard matrix, and a pseudorandom uniformly redundant array. All results are in agreement with expected filtering. The Walsh matrix and the Hadamard matrix show excellent agreement with the matrix from the random-number generator. We show that shift-variant effects between the LCD array and the CCD array can be kept small. This projector test method offers convenient measurement of the MTF of a low-cost video system. Such characterization is useful for an increasing number of machine vision applications and metrology applications. PMID:18337921

  19. Improving the spatial resolution of soft X-ray detection using an Electron-Multiplying Charge-Coupled Device

    International Nuclear Information System (INIS)

    The Super Advanced X-ray Emission Spectrometer (SAXES) is an instrument at the Swiss Light Source designed for Resonant Inelastic X-ray Scattering with an energy resolution (E/ΔE) better than 12000 at 930 eV. Improvements to the instrument have been predicted that could allow the energy resolution to be improved by a factor of two. To achieve this, the spatial resolution of the detector (currently a Charge-Coupled Device, CCD) over which the energy spectrum is dispersed would have to be improved to better than 5 μm. X-ray photons with energies between a few hundred to a few thousand electron volts primarily interact within the field-free region of back-illuminated CCDs, where each photon forms an electron cloud that diffuses isotropically before reaching the depleted region close to the electrodes. Each photon's electron cloud is likely to be detected as an event with signal split across multiple pixels. Analysing these split events using centroiding techniques allows the photon's interaction position to be determined to a sub-pixel level. PolLux is a soft X-ray microspectroscopy endstation at the Swiss Light Source that can focus 200 eV to 1200 eV X-rays to a spot size of approximately 20 nm. Previous studies using data taken with a linear scan across the centre of a pixel in 3 μm steps predicted an improved resolution by applying centroiding techniques and using an Electron-Multiplying CCD (EM-CCD). In this study, a full 2D map of the centroiding accuracy in the pixel is presented, formed by rastering in two dimensions across the image plane in single micron steps. The improved spatial resolution from centroiding events in the EM-CCD in all areas of the pixel over the standard CCD is attributed to the improved signal to noise ratio provided by the multiplication register even at high pixel readout speeds (tens of MHz).

  20. Improving the spatial resolution of soft X-ray detection using an Electron-Multiplying Charge-Coupled Device

    Science.gov (United States)

    Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

    2013-01-01

    The Super Advanced X-ray Emission Spectrometer (SAXES) is an instrument at the Swiss Light Source designed for Resonant Inelastic X-ray Scattering with an energy resolution (E/ΔE) better than 12000 at 930 eV. Improvements to the instrument have been predicted that could allow the energy resolution to be improved by a factor of two. To achieve this, the spatial resolution of the detector (currently a Charge-Coupled Device, CCD) over which the energy spectrum is dispersed would have to be improved to better than 5 μm. X-ray photons with energies between a few hundred to a few thousand electron volts primarily interact within the field-free region of back-illuminated CCDs, where each photon forms an electron cloud that diffuses isotropically before reaching the depleted region close to the electrodes. Each photon's electron cloud is likely to be detected as an event with signal split across multiple pixels. Analysing these split events using centroiding techniques allows the photon's interaction position to be determined to a sub-pixel level. PolLux is a soft X-ray microspectroscopy endstation at the Swiss Light Source that can focus 200 eV to 1200 eV X-rays to a spot size of approximately 20 nm. Previous studies using data taken with a linear scan across the centre of a pixel in 3 μm steps predicted an improved resolution by applying centroiding techniques and using an Electron-Multiplying CCD (EM-CCD). In this study, a full 2D map of the centroiding accuracy in the pixel is presented, formed by rastering in two dimensions across the image plane in single micron steps. The improved spatial resolution from centroiding events in the EM-CCD in all areas of the pixel over the standard CCD is attributed to the improved signal to noise ratio provided by the multiplication register even at high pixel readout speeds (tens of MHz).

  1. Absolute determination of charge-coupled device quantum detection efficiency using Si K-edge x-ray absorption fine structure

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J; Steel, A B

    2012-05-06

    We report a method to determine the quantum detection efficiency and the absorbing layers on a front-illuminated charge-coupled device (CCD). The CCD under study, as part of a crystal spectrometer, measures intense continuum x-ray emission from a picosecond laser-produced plasma and spectrally resolves the Si K-edge x-ray absorption fine structure features due to the electrode gate structure of the device. The CCD response across the Si K-edge shows a large discontinuity as well as a number of oscillations that are identified individually and uniquely from Si, SiO{sub 2}, and Si{sub 3}N{sub 4} layers. From the spectral analysis of the structure and K-edge discontinuity, the active layer thickness and the different absorbing layers thickness can be determined precisely. A precise CCD detection model from 0.2-10 keV can be deduced from this highly sensitive technique.

  2. An integrated enzyme-linked immunosorbent assay system with an organic light-emitting diode and a charge-coupled device for fluorescence detection.

    Science.gov (United States)

    Nakajima, Hizuru; Okuma, Yukiko; Morioka, Kazuhiro; Miyake, Mayo; Hemmi, Akihide; Tobita, Tatsuya; Yahiro, Masayuki; Yokoyama, Daisuke; Adachi, Chihaya; Soh, Nobuaki; Nakano, Koji; Xue, Shuhua; Zeng, Hulie; Uchiyama, Katsumi; Imato, Toshihiko

    2011-10-01

    A fluorescence detection system for a microfluidic device using an organic light-emitting diode (OLED) as the excitation light source and a charge-coupled device (CCD) as the photo detector was developed. The OLED was fabricated on a glass plate by photolithography and a vacuum deposition technique. The OLED produced a green luminescence with a peak emission at 512 nm and a half bandwidth of 55 nm. The maximum external quantum efficiency of the OLED was 7.2%. The emission intensity of the OLED at 10 mA/cm(2) was 13 μW (1.7 mW/cm(2)). The fluorescence detection system consisted of the OLED device, two band-pass filters, a five microchannel poly(dimethylsiloxane) (PDMS) microfluidic device and a linear CCD. The fluorescence detection system was successfully used in a flow-based enzyme-linked immunosorbent assay on a PDMS microfluidic device for the rapid determination of immunoglobulin A (IgA), a marker for human stress. The detection limit (S/N=3) for IgA was 16.5 ng/mL, and the sensitivity was sufficient for evaluating stress. Compared with the conventional 96-well microtiter plate assay, the analysis time and the amounts of reagent and sample solutions could all be reduced.

  3. Development of two-channel prototype ITER vacuum ultraviolet spectrometer with back-illuminated charge-coupled device and microchannel plate detectors.

    Science.gov (United States)

    Seon, C R; Choi, S H; Cheon, M S; Pak, S; Lee, H G; Biel, W; Barnsley, R

    2010-10-01

    A vacuum ultraviolet (VUV) spectrometer of a five-channel spectral system is designed for ITER main plasma impurity measurement. To develop and verify the system design, a two-channel prototype system is fabricated with No. 3 (14.4-31.8 nm) and No. 4 (29.0-60.0 nm) among the five channels. The optical system consists of a collimating mirror to collect the light from source to slit, two holographic diffraction gratings with toroidal geometry, and two different electronic detectors. For the test of the prototype system, a hollow cathode lamp is used as a light source. To find the appropriate detector for ITER VUV system, two kinds of detectors of the back-illuminated charge-coupled device and the microchannel plate electron multiplier are tested, and their performance has been investigated.

  4. Charge coupled devices (CCD) photometry and long-term optical variability of gamma-ray-loud BL Lacertae object Mkn 421

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiong; Zheng Yong-Gang; Zhang Hao-Jing; Hu Shao-Ming; Xie Zhao-Hua

    2006-01-01

    Evidence for the long-term optical curve variability and colour behaviour of the BL Lac object Mkn 421 is presented.Our results show that the amplitude of the optical variations of Mkn 421 is only about ΔB=4.7 magnitude in the B-band for its photometric history from 1899 to 2002. The results of optical photometric monitoring of the Mkn 421 from April 2000 to Jan 2002 are provided. During our observation, Mkn 421 shows significant rapid variations and exhibits short time variability of 2.42 hours in the B band. A strong correlation between the B - V colour index and the magnitude in the B band is found. Our charge coupled device (CCD) photometry of Mkn 421 shows that the measured results are in good agreement with the predicted optical variability period of about 23 years.

  5. Development of two-channel prototype ITER vacuum ultraviolet spectrometer with back-illuminated charge-coupled device and microchannel plate detectors

    Energy Technology Data Exchange (ETDEWEB)

    Seon, C. R.; Choi, S. H.; Cheon, M. S.; Pak, S.; Lee, H. G. [National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Biel, W. [Institut fuer Plasmaphysik, Forschungszentrum Juelich Gmbh, D-52425 Juelich (Germany); Barnsley, R. [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France)

    2010-10-15

    A vacuum ultraviolet (VUV) spectrometer of a five-channel spectral system is designed for ITER main plasma impurity measurement. To develop and verify the system design, a two-channel prototype system is fabricated with No. 3 (14.4-31.8 nm) and No. 4 (29.0-60.0 nm) among the five channels. The optical system consists of a collimating mirror to collect the light from source to slit, two holographic diffraction gratings with toroidal geometry, and two different electronic detectors. For the test of the prototype system, a hollow cathode lamp is used as a light source. To find the appropriate detector for ITER VUV system, two kinds of detectors of the back-illuminated charge-coupled device and the microchannel plate electron multiplier are tested, and their performance has been investigated.

  6. Experimental study of heavy-ion computed tomography using a scintillation screen and an electron-multiplying charged coupled device camera for human head imaging

    Science.gov (United States)

    Muraishi, Hiroshi; Hara, Hidetake; Abe, Shinji; Yokose, Mamoru; Watanabe, Takara; Takeda, Tohoru; Koba, Yusuke; Fukuda, Shigekazu

    2016-03-01

    We have developed a heavy-ion computed tomography (IonCT) system using a scintillation screen and an electron-multiplying charged coupled device (EMCCD) camera that can measure a large object such as a human head. In this study, objective with the development of the system was to investigate the possibility of applying this system to heavy-ion treatment planning from the point of view of spatial resolution in a reconstructed image. Experiments were carried out on a rotation phantom using 12C accelerated up to 430 MeV/u by the Heavy-Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). We demonstrated that the reconstructed image of an object with a water equivalent thickness (WET) of approximately 18 cm was successfully achieved with the spatial resolution of 1 mm, which would make this IonCT system worth applying to the heavy-ion treatment planning for head and neck cancers.

  7. Proton irradiation experiment for X-ray charge-coupled devices of the monitor of all-sky X-ray image mission onboard the international space station. 1. Experimental setup and measurement of the charge transfer inefficiency

    International Nuclear Information System (INIS)

    We have investigated the radiation damage effects on a charge-coupled device (CCD) to be employed in the Japanese X-ray astronomy mission including the monitor of all-sky X-ray image (MAXI) onboard the international space station (ISS). Since low-energy protons release their energy mainly at the charge transfer channel, resulting in a decrease of the charge transfer efficiency, we focused on low-energy protons in our experiments. A 171 keV to 3.91 MeV proton beam was irradiated onto a given device. We measured the degradation of the charge transfer inefficiency (CTI) as a function of incremental fluence. A 292 keV proton beam degraded the CTI critically. Taking into account the proton energy dependence of the CTI, we confirmed that the transfer channel has the lowest radiation tolerance. We have also developed different device architectures to reduce the radiation damage in orbit. Among them, the 'notch' CCD, in which the buried channel implant concentration is increased, resulting in a potential well deeper than outside, has a three times higher radiation tolerance than that of the normal CCD. We then estimated the CTI of the CCD in the orbit of the ISS, considering the proton energy spectrum. The CTI value is estimated to be 1.1x10-5 per transfer after two years of mission life in the worst case analysis if the highest radiation tolerant device is employed. This value is well within the acceptable limit and we have confirmed the high radiation-tolerance of CCDs for the MAXI mission. (author)

  8. Detection of 1 - 100 keV x-rays from high intensity, 500 fs laser- produced plasmas using charge-coupled devices

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J.; Young, B.K.F.; Conder, A.D.; Stewart, R.E.

    1996-01-01

    We describe a compact, vacuum compatible, large format, charge- coupled device (CCD) camera for scientific imaging and detection of 1- 100 keV x rays in experiments at LLNL JANUS-1ps laser. A standard, front-illuminated, multi-pin phase device with 250 k electron full well capacity, low dark current (10 pA/cm{sup 2} at 20 C) and low read noise (5 electron rms) is cooled to -35 C to give the camera excellent 15-bit dynamic range and signal-to-noise response. Intensity and x-ray energy linear response were determined for optical and x-ray (<65 keV) photons and are in excellent agreement. Departure from linearity was less than 0.7%. Inherent linearity and energy dispersive characteristics of CCD cameras are well suited for hard x-ray photon counting. X-rays absorbed within the depletion and field-free regions can be distinguished by studying the pulse height spectrum. Results are presented for the detection of 1-100 keV Bremsstrahlung continuum, K-shell and L-shell fluorescence spectra emitted from high intensity (10{sup 18}W cm{sup -2}), 500 fs laser- produced plasmas.

  9. Shuttle and Transfer Orbit Thermal Analysis and Testing of the Chandra X-Ray Observatory Charge-Couple Device Imaging Spectrometer Radiator Shades

    Science.gov (United States)

    Sharp, John R.

    1999-01-01

    Thermal analyses of the Shuttle and Transfer Orbit of the Advanced X-Ray Astrophysics Facility Charge-Coupled Device (CCD) Imaging Spectrometer (ACIS), one of two science instruments on the Chandra X-Ray Observatory, revealed a low-earth orbit (LEO) overheating problem on the goldized Kapton faces of two radiator shades. The shades were coated with the goldized Kapton to provide a low hemispherical emittance to minimize direct and backloaded heating from the sun and the observatory and high specularity to optimize the coupling to space on two passive radiators which cool the focal plane to -120 C +/- 1 C during on-orbit operations. Since the observatory has a highly elliptical final orbit of 10,000 kilometers by 140,000 kilometers and the ACIS radiators and shades are oriented anti-sun, the high solar absorptance to emittance ratio of the goldized Kapton was not an issue. However, during Shuttle bay-to-earth operations, the short duration solar heating occurring near the eclipse entry and exit resulted in shade temperatures in excess of the cure temperature of the adhesive used to bond the goldized Kapton and honeycomb face-sheets. The detailed thermal analysis demonstrating the LEO overheating as well as the redesign options and thermal testing of a redesigned development unit shade are presented.

  10. CCD[charge-coupled device]-based synchrotron x-ray detector for protein crystallography: Performance projected from an experiment

    International Nuclear Information System (INIS)

    The intense x radiation from a synchrotron source could, with a suitable detector, provide a complete set of diffraction images from a protein crystal before the crystal is damaged by radiation (2 to 3 min). An area detector consisting of a 40 mm dia. x-ray fluorescing phosphor, coupled with an image intensifier and lens to a CCD image sensor, was developed to determine the effectiveness of such a detector in protein crystallography. The detector was used in an experiment with a rotating anode x-ray generator. Diffraction patterns from a lysozyme crystal obtained with this detector are compared to those obtained with film. The two images appear to be virtually identical. The flux of 104 x-ray photons/s was observed on the detector at the rotating anode generator. At the 6-GeV synchrotron being designed at Argonne, the flux on an 80 x 80 mm2 detector is expected to be >109 photons/s. The projected design of such a synchrotron detector shows that a diffraction-peak count >106 could be obtained in ∼0.5 s. With an additional ∼0.5 s readout time of a 512 x 512 pixel CCD, the data acquisition time per frame would be ∼1 s so that ninety 10 diffraction images could be obtained, with approximately 1% precision, in less than 3 min

  11. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device

    International Nuclear Information System (INIS)

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots’ energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the “3D detector method” as a promising tool for material investigations to separate bending and strain for technical materials

  12. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device

    Energy Technology Data Exchange (ETDEWEB)

    Abboud, A.; Send, S.; Pashniak, N.; Pietsch, U. [Department of Physics, University of Siegen, Siegen 57072 (Germany); Kirchlechner, C. [Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf 40237 (Germany); Montanuniversität Leoben, Leoben 8700 (Austria); Micha, J. S.; Ulrich, O. [CEA-Grenoble/DRFMC/SprAM, 17 rue des Martyrs, Grenoble Cedex 9, F-38054 (France); Strüder, L. [PNSensor GmbH, Munich 80803 (Germany); Keckes, J. [Montanuniversität Leoben, Leoben 8700 (Austria); Material Center Leoben Forschungs GmbH, Leoben 8700 (Austria)

    2014-11-15

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots’ energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the “3D detector method” as a promising tool for material investigations to separate bending and strain for technical materials.

  13. Evaluation and improvement in the accuracy of a charge-coupled-device-based pyrometer for temperature field measurements of continuous casting billets

    Science.gov (United States)

    Bai, Haicheng; Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei

    2013-06-01

    This paper presents a radiometric high-temperature field measurement model based on a charge-coupled-device (CCD). According to the model, an intelligent CCD pyrometer with a digital signal processor as the core is developed and its non-uniformity correction algorithm for reducing the differences in accuracy between individual pixel sensors is established. By means of self-adaptive adjustment for the light-integration time, the dynamic range of the CCD is extended and its accuracy in low-temperature range is improved. The non-uniformity correction algorithm effectively reduces the accuracy differences between different pixel sensors. The performance of the system is evaluated through a blackbody furnace and an integrating sphere, the results of which show that the dynamic range of 400 K is obtained and the accuracy in low temperature range is increased by 7 times compared with the traditional method based on the fixed light-integration time. In addition, the differences of accuracy between the on-axis pixel and the most peripheral pixels are decreased from 19.1 K to 2.8 K. Therefore, this CCD pyrometer ensures that the measuring results of all pixels tend to be equal-accuracy distribution across the entire measuring ranges. This pyrometric system has been successfully applied to the temperature field measurements in continuous casting billets.

  14. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device.

    Science.gov (United States)

    Abboud, A; Kirchlechner, C; Send, S; Micha, J S; Ulrich, O; Pashniak, N; Strüder, L; Keckes, J; Pietsch, U

    2014-11-01

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots' energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the "3D detector method" as a promising tool for material investigations to separate bending and strain for technical materials.

  15. Design of Low-Noise Output Amplifiers for P-channel Charge-Coupled Devices Fabricated on High-Resistivity Silicon

    Energy Technology Data Exchange (ETDEWEB)

    Haque, S; Frost, F Dion R.; Groulx, R; Holland, S E; Karcher, A; Kolbe, W F; Roe, N A; Wang, G; Yu, Y

    2011-12-22

    We describe the design and optimization of low-noise, single-stage output amplifiers for p-channel charge-coupled devices (CCDs) used for scientific applications in astronomy and other fields. The CCDs are fabricated on high-resistivity, 4000–5000 -cm, n-type silicon substrates. Single-stage amplifiers with different output structure designs and technologies have been characterized. The standard output amplifier is designed with an n{sup +} polysilicon gate that has a metal connection to the sense node. In an effort to lower the output amplifier readout noise by minimizing the capacitance seen at the sense node, buried-contact technology has been investigated. In this case, the output transistor has a p{sup +} polysilicon gate that connects directly to the p{sup +} sense node. Output structures with buried-contact areas as small as 2 μm × 2 μm are characterized. In addition, the geometry of the source-follower transistor was varied, and we report test results on the conversion gain and noise of the various amplifier structures. By use of buried-contact technology, better amplifier geometry, optimization of the amplifier biases and improvements in the test electronics design, we obtain a 45% reduction in noise, corresponding to 1.7 e{sup -} rms at 70 kpixels/sec.

  16. Breath-hold monitoring and visual feedback for radiotherapy using a charge-coupled device camera and a head-mounted display. System development and feasibility

    International Nuclear Information System (INIS)

    The aim of this study was to present the technical aspects of the breath-hold technique with respiratory monitoring and visual feedback and to evaluate the feasibility of this system in healthy volunteers. To monitor respiration, the vertical position of the fiducial marker placed on the patient's abdomen was tracked by a machine vision system with a charge-coupled device camera. A monocular head-mounted display was used to provide the patient with visual feedback about the breathing trace. Five healthy male volunteers were enrolled in this study. They held their breath at the end-inspiration and the end-expiration phases. They performed five repetitions of the same type of 15-s breath-holds with and without a head-mounted display, respectively. A standard deviation of five mean positions of the fiducial marker during a 15-s breath-hold in each breath-hold type was used as the reproducibility value of breath-hold. All five volunteers well tolerated the breath-hold maneuver. For the inspiration breath-hold, the standard deviations with and without visual feedback were 1.74 mm and 0.84 mm, respectively (P=0.20). For the expiration breath-hold, the standard deviations with and without visual feedback were 0.63 mm and 0.96 mm, respectively (P=0.025). Our newly developed system might help the patient achieve improved breath-hold reproducibility. (author)

  17. Coupling Electromagnetism to Global Charge

    CERN Document Server

    Guendelman, Eduardo

    2013-01-01

    It is shown that an alternative to the standard scalar QED is possible. In this new version there is only global gauge invariance as far as the charged scalar fields are concerned although local gauge invariance is kept for the electromagnetic field. The electromagnetic coupling has the form $j_\\mu (A^{\\mu} +\\partial^{\\mu}B)$ where $B$ is an auxiliary field and the current $j_\\mu$ is $A_{\\mu}$ independent so that no "sea gull terms" are introduced. In a model of this kind spontaneous breaking of symmetry does not lead to photon mass generation, instead the Goldstone boson becomes a massless source for the electromagnetic field. Infrared questions concerning the theory when spontaneous symmetry breaking takes place and generalizations to global vector QED are discussed. In this framework Q-Balls and other non topological solitons that owe their existence to a global U(1) symmetry can be coupled to electromagnetism and could represent multiply charged particles now in search in the LHC. Finally, we give an exam...

  18. Two-dimensional microchemical observation of mast cell biogenic amine release as monitored by a 128 × 128 array-type charge-coupled device ion image sensor.

    Science.gov (United States)

    Hattori, Toshiaki; Tamamura, Youichiro; Tokunaga, Kenta; Sakurai, Takashi; Kato, Ryo; Sawada, Kazuaki

    2014-05-01

    Available array-type, chemical-sensing image sensors generally only provide on/off responses to the sensed chemical and produce qualitative information. Therefore, there is a need for an array sensor design that can detect chemical concentration changes to produce quantitative, event-sensitive information. In this study, a 128 × 128 array-type image sensor was modified and applied to imaging of biogenic amines released from stimulated rat mast cells, providing recordable responses of the time course of their release and diffusion. The imaging tool was manufactured by an integrated circuit process, including complementary metal oxide semiconductor and charge-coupled device technology. It was fitted with an amine-sensitive membrane prepared from plasticized poly(vinyl chloride) including a hydrophobic anion, which allowed the sensor to detect amines, such as histamine and serotonin, in Tyrode's solution. As mast cells were larger in diameter than the pixel hollows, some pixels monitored amines released from single cells. The image from the array responses yielded sequential snapshots at a practical frame speed that followed amine concentration changes over time, after mast cell amine release was synchronized by chemical stimulation. This sensor was shown to be sensitive to amine release at very low stimulus concentrations and was able to detect localized spots of high amine release. The entire time course of the amine release was recorded, including maximum concentration at 4-6 s and signal disappearance at 30 s after stimulation. With further development, this sensor will increase opportunities to study a variety of biological systems, including neuronal chemical processes. PMID:24731060

  19. Reading and writing charge on graphene devices

    OpenAIRE

    Connolly, M. R.; Herbschleb, E. D.; Puddy, R.K.; Roy, M.; Anderson, D.(California Institute of Technology, Pasadena, USA); Jones, G. A. C.; Maksym, P.; Smith, C. G.

    2011-01-01

    We use a combination of charge writing and scanning gate microscopy to map and modify the local charge neutrality point of graphene field-effect devices. We give a demonstration of the technique by writing remote charge in a thin dielectric layer over the graphene-metal interface and detecting the resulting shift in local charge neutrality point. We perform electrostatic simulations to characterize the gating effect of a realistic scanning probe tip on a graphene bilayer and find a good agree...

  20. Energy storage device with large charge separation

    Energy Technology Data Exchange (ETDEWEB)

    Holme, Timothy P.; Prinz, Friedrich B.; Iancu, Andrei

    2016-04-12

    High density energy storage in semiconductor devices is provided. There are two main aspects of the present approach. The first aspect is to provide high density energy storage in semiconductor devices based on formation of a plasma in the semiconductor. The second aspect is to provide high density energy storage based on charge separation in a p-n junction.

  1. New Charged Particles from Higgs Couplings

    CERN Document Server

    Cohen, Andrew G

    2012-01-01

    The recently reported observation of a new particle with mass about 125 GeV and couplings generally resembling those of the Standard Model Higgs boson provides a potential probe of the physics of electroweak symmetry breaking. Although the current data only provides hints, we suggest a particular combination of Higgs couplings as an assay for new charged particles connected with electroweak symmetry breaking, and construct a simple model with charge 5/3 quarks as a demonstration of its use.

  2. Signal processing applications of massively parallel charge domain computing devices

    Science.gov (United States)

    Fijany, Amir (Inventor); Barhen, Jacob (Inventor); Toomarian, Nikzad (Inventor)

    1999-01-01

    The present invention is embodied in a charge coupled device (CCD)/charge injection device (CID) architecture capable of performing a Fourier transform by simultaneous matrix vector multiplication (MVM) operations in respective plural CCD/CID arrays in parallel in O(1) steps. For example, in one embodiment, a first CCD/CID array stores charge packets representing a first matrix operator based upon permutations of a Hartley transform and computes the Fourier transform of an incoming vector. A second CCD/CID array stores charge packets representing a second matrix operator based upon different permutations of a Hartley transform and computes the Fourier transform of an incoming vector. The incoming vector is applied to the inputs of the two CCD/CID arrays simultaneously, and the real and imaginary parts of the Fourier transform are produced simultaneously in the time required to perform a single MVM operation in a CCD/CID array.

  3. Proton Irradiation Experiment for the X-ray Charge-Coupled Devices of the Monitor of All-sky X-ray Image mission onboard the International Space Station I. Experimental Setup and Measurement of the Charge Transfer Inefficiency

    CERN Document Server

    Miyata, E; Kouno, H; Mihara, M; Matsuta, K; Tsunemi, H; Tanaka, K; Minamisono, T; Tomida, H; Miyaguchi, K

    2002-01-01

    We have investigated the radiation damage effects on a CCD to be employed in the Japanese X-ray astronomy mission including the Monitor of All-sky X-ray Image (MAXI) onboard the International Space Station (ISS). Since low energy protons release their energy mainly at the charge transfer channel, resulting a decrease of the charge transfer efficiency, we thus focused on the low energy protons in our experiments. A 171 keV to 3.91 MeV proton beam was irradiated to a given device. We measured the degradation of the charge transfer inefficiency (CTI) as a function of incremental fluence. A 292 keV proton beam degraded the CTI most seriously. Taking into account the proton energy dependence of the CTI, we confirmed that the transfer channel has the lowest radiation tolerance. We have also developed the different device architectures to reduce the radiation damage in orbit. Among them, the ``notch'' CCD, in which the buried channel implant concentration is increased, resulting in a deeper potential well than outsi...

  4. Measurements of Charge Transfer Efficiency in a Proton-irradiated Swept Charge Device

    CERN Document Server

    YuSa, Wang; XiaoYan, Liu; WeiWei, Cui; YuPeng, Xu; ChengKui, Li; MaoShun, Li; DaWei, Han; TianXiang, Chen; Jia, Huo; Juan, Wang; Wei, Li; Wei, Hu; Yi, Zhang; Bo, Lu; GuoHe, Yin; Yue, Zhu; ZiLiang, Zhang

    2013-01-01

    Charge Coupled Devices (CCDs) have been successfully used in several low energy X-ray astronomical satellite over the past two decades. Their high energy resolution and high spatial resolution make them an perfect tool for low energy astronomy, such as formation of galaxy clusters and environment of black holes. The Low Energy X-ray Telescope (LE) group is developing Swept Charge Device (SCD) for the Hard X-ray Modulation Telescope (HXMT) satellite. SCD is a special low energy X-ray CCD, which could be read out a thousand times faster than traditional CCDs, simultaneously keeping excellent energy resolution. A test method for measuring the charge transfer efficiency (CTE) of a prototype SCD has been set up. Studies of the charge transfer inefficiency (CTI) have been performed at a temperature range of operation, with a proton-irradiated SCD.

  5. Device for measuring charge density distribution in charged particle beams

    International Nuclear Information System (INIS)

    A device to measure charge density distribution in charged particle beams has been described. The device contains a set of hollow interinsulated current-receiving electrodes, recording system, and cooling system. The invention is aimed at the increase of admissible capacity of the beams measured at the expense of cooling efficiency increase. The aim is achieved by the fact, that in the device a dynamic evaporating-condensational cooling of electrodes is realized by means of cooling agent supply in perpendicular to their planes through the tubes introduced inside special cups. Spreading in radial direction over electrode surface the cooling agent gradually and intensively washes the side surface of the cup, after that, it enters the cooling cavity in the form of vapour-liquid mixture. In the cavity the cooling agent, supplied using dispensina and receiving collectors in which vapoUr is condensed, circulates. In the device suggested the surface of electrode cooling is decreased significantly at the expense of side surface of the cups which receives the electrode heat

  6. Compensating strong coupling with large charge

    CERN Document Server

    Alvarez-Gaume, Luis; Orlando, Domenico; Reffert, Susanne

    2016-01-01

    We study (conformal) field theories with global symmetries in the sector where the value of the global charge $Q$ is large. We find (as expected) that the low energy excitations of this sector are described by the general form of Goldstone's theorem in the non-relativistic regime. We also derive the unexpected result, first presented in [Hellerman:2015], that the effective field theory describing such sector of fixed $Q$ contains effective couplings $\\lambda_{\\text{eff}}\\sim \\lambda^b /Q^{a}$, where $\\lambda$ is the original coupling. Hence, large charge leads to weak coupling. In the last section of the paper we present an outline of how to compute anomalous dimensions in this limit.

  7. Transverse Mode Coupling Instability with Space Charge

    CERN Document Server

    Balbekov, V

    2016-01-01

    Transverse mode coupling instability of a bunch with space charge and wake field is considered in frameworks of the boxcar model. Eigenfunctions of the bunch without wake are used as the basis for solution of the equations with the wake field included. Dispersion equation for the bunch eigentunes is obtained in the form of an infinite continued fraction. It is shown that influence of space charge on the instability essentially depends on the wake sign. In particular, threshold of the negative wake increases in absolute value until the space charge tune shift is rather small, and goes to zero at higher space charge. The explanation of this behavior is developed by analysis of the bunch spectrum. A comparison of the results with published articles is represented.

  8. Transverse Mode Coupling Instability with Space Charge

    Energy Technology Data Exchange (ETDEWEB)

    Balbekov, V. [Fermilab

    2016-03-11

    Transverse mode coupling instability of a bunch with space charge and wake field is considered in frameworks of the boxcar model. Eigenfunctions of the bunch without wake are used as the basis for solution of the equations with the wake field included. Dispersion equation for the bunch eigentunes is obtained in the form of an infinite continued fraction. It is shown that influence of space charge on the instability essentially depends on the wake sign. In particular, threshold of the negative wake increases in absolute value until the space charge tune shift is rather small, and goes to zero at higher space charge. The explanation of this behavior is developed by analysis of the bunch spectrum. A comparison of the results with published articles is represented.

  9. Proton irradiation experiment for x-ray charge-coupled devices of the monitor of all-sky x-ray image mission onboard the international space station. 2. Degradation of dark current and identification of electron trap level

    International Nuclear Information System (INIS)

    We have investigated the radiation damage effects on a charge-coupled device (CCD) to be used for the Japanese X-ray mission, the monitor of all-sky X-ray image (MAXI), onboard the international space station (ISS). A temperature dependence of the dark current as a function of incremental dose is studied. We found that the protons having energy of >292 keV seriously increased the dark current of the devices. In order to improve the radiation tolerance of the devices, we have developed various device architectures to minimize the radiation damage in orbit. Among them, nitride oxide enables us to reduce the dark current significantly and therefore we adopted nitride oxide for the flight devices. We also compared the dark current of a device in operation and that out of operation during the proton irradiation. The dark current of the device in operation became twofold that out of operation, and we thus determined that devices would be turned off during the passage of the radiation belt. The temperature dependence of the dark current enables us to determine the electron trap level that generates the dark current. We fitted dark current as a function of temperature by the theoretical models and found that the dark current increase after proton irradiations is caused by, at least, two kinds of electron trap levels. The shallow trap level (Ec - Et c and Et are the energy at the bottom of the conduction band and the energy level of electron trap) might be associated with oxygen which is dominant at the operating temperature of >210 K. On the other hand, another trap level is located roughly at the center of the silicon bandgap which might be associated with divacancies or P-V traps. We finally investigated the spatial distribution of the low-energy protons in the orbit of the ISS. Their density has a peak around l - 20deg and b - 55deg independent of the altitude. The peak value is roughly two orders of magnitude higher than that at the South Atlantic Anomaly. (author)

  10. Design And Construction Of Wireless Charging System Using Inductive Coupling

    Directory of Open Access Journals (Sweden)

    Do Lam Mung

    2015-06-01

    Full Text Available Abstract Wireless charging system described by using the method of inductive coupling. In this project oscillation circuit converts DC energy to AC energytransmitter coil to transmit magnetic field by passing frequency and then induce the receiver coil. The properties of Induction coupling are wavemagnetic field-wideband rangevery shortcm efficiencyhight and operation frequencyLF-bandseveral handred kHz.The project shows as a small charging for 5V battery of phone in this method. The system bases on coupling magnetic field then designed and constructed as two parts. There are transmitter part and receiver part. The transmitter coil transmitter part transmits coupling magnetic field to receiver coil receiver part by passing frequency at about 1.67MHz. The Amperes law Biot-Savart law and Faraday law are used to calculate the inductive coupling between the transmitter coil and the receiver coil. The calculation of this law shows how many power transfer in receiver part when how many distance between the transmitter coil and the receiver coil. The system is safe for users and neighbouring electronic devices. To get more accurate wireless charging system it needs to change the design of the following keywords.

  11. Improving the spatial resolution of a soft X-ray Charge Coupled Device used for Resonant Inelastic X-ray Scattering

    Science.gov (United States)

    Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

    2011-11-01

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Advanced Resonant Scattering (ADRESS) beamline of the Swiss Light Source is a high-resolution X-ray spectrometer used as an end station for Resonant Inelastic X-ray Scattering from 400 eV to 1600 eV. Through the dispersion of photons across a CCD, the energy of scattered photons may be determined by their detected spatial position. The limiting factor of the energy resolution is currently the spatial resolution achieved with the CCD, reported at 24 μm FWHM. For this energy range the electron clouds are formed by interactions in the `field free' region of the back-illuminated CCD. These clouds diffuse in all directions whilst being attracted to the electrodes, leading to events that are made up of signals in multiple pixels. The spreading of the charge allows centroiding techniques to be used to improve the CCD spatial resolution and therefore improve the energy resolution of SAXES. The PolLux microscopy beamline at the SLS produces an X-ray beam with a diameter of 20 nm. The images produced from scanning the narrow beam across CCD pixels (13.5 × 13.5 μm2) can aid in the production of event recognition algorithms, allowing the matching of event profiles to photon interactions in a specific region of a pixel. Through the use of this information software analysis can be refined with the aim of improving the energy resolution.

  12. Fabrication and electrical characteristics of graphene-based charge-trap memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Se J. [Dongguk University, Seoul (Korea, Republic of); Kim, Sung M.; Song, Emil B.; Wang, Kang L. [University of California Los Angeles, CA (United States); Seo, David H. [Samsung Electronics Co. Ltd., Yongin (Korea, Republic of); Seo, Sun A. [Sejong University, Seoul (Korea, Republic of)

    2012-07-15

    Graphene-based non-volatile charge-trap memory devices were fabricated and characterized to investigate the implementation effect of both 2-dimensional graphene and the 3-dimensional memory structure. The single-layer-graphene (SLG) channel devices exhibit larger memory windows compared to the multi-layer-graphene (MLG) channel devices. This originates from the gate-coupling strength being larger in SLG devices than in MLG devices. Namely, the electrostatic charge screening effect becomes enhanced upon increasing the number of graphene layers; therefore, the gate tunability is reduced in MLG compared to SLG. The results suggest that SLG is more desirable for memory applications than MLG.

  13. Fully Depleted Charge-Coupled Devices

    International Nuclear Information System (INIS)

    We have developed fully depleted, back-illuminated CCDs that build upon earlier research and development efforts directed towards technology development of silicon-strip detectors used in high-energy-physics experiments. The CCDs are fabricated on the same type of high-resistivity, float-zone-refined silicon that is used for strip detectors. The use of high-resistivity substrates allows for thick depletion regions, on the order of 200-300 um, with corresponding high detection efficiency for near-infrared and soft x-ray photons. We compare the fully depleted CCD to the p-i-n diode upon which it is based, and describe the use of fully depleted CCDs in astronomical and x-ray imaging applications

  14. Charge Redistribution from Anomalous Magnetovorticity Coupling

    Science.gov (United States)

    Hattori, Koichi; Yin, Yi

    2016-10-01

    We investigate novel transport phenomena in a chiral fluid originated from an interplay between a vorticity and strong magnetic field, which induces a redistribution of vector charges in the system and an axial current along the magnetic field. The corresponding transport coefficients are obtained from an energy-shift argument for the chiral fermions in the lowest Landau level due to a spin-vorticity coupling and also from diagrammatic computations on the basis of the linear response theory. Based on consistent results from both methods, we observe that the transport coefficients are proportional to the anomaly coefficient and are independent of temperature and chemical potential. We therefore speculate that these transport phenomena are connected to quantum anomaly.

  15. Measuring Charge Carrier Diffusion in Coupled Colloidal Quantum Dot Solids

    KAUST Repository

    Zhitomirsky, David

    2013-06-25

    Colloidal quantum dots (CQDs) are attractive materials for inexpensive, room-temperature-, and solution-processed optoelectronic devices. A high carrier diffusion length is desirable for many CQD device applications. In this work we develop two new experimental methods to investigate charge carrier diffusion in coupled CQD solids under charge-neutral, i.e., undepleted, conditions. The methods take advantage of the quantum-size-effect tunability of our materials, utilizing a smaller-bandgap population of quantum dots as a reporter system. We develop analytical models of diffusion in 1D and 3D structures that allow direct extraction of diffusion length from convenient parametric plots and purely optical measurements. We measure several CQD solids fabricated using a number of distinct methods and having significantly different doping and surface ligand treatments. We find that CQD materials recently reported to achieve a certified power conversion efficiency of 7% with hybrid organic-inorganic passivation have a diffusion length of 80 ± 10 nm. The model further allows us to extract the lifetime, trap density, mobility, and diffusion coefficient independently in each material system. This work will facilitate further progress in extending the diffusion length, ultimately leading to high-quality CQD solid semiconducting materials and improved CQD optoelectronic devices, including CQD solar cells. © 2013 American Chemical Society.

  16. Charge Transport in DNA-Based Devices

    OpenAIRE

    Porath, Danny; Cuniberti, Gianaurelio; Di Felice, Rosa

    2004-01-01

    Charge migration along DNA molecules has attracted scientific interest for over half a century. Reports on possible high rates of charge transfer between donor and acceptor through the DNA, obtained in the last decade from solution chemistry experiments on large numbers of molecules, triggered a series of direct electrical transport measurements through DNA single molecules, bundles and networks. These measurements are reviewed and presented here. From these experiments we conclude that elect...

  17. Charge transport in DNA-based devices

    OpenAIRE

    Porath, Danny; Cuniberti, Gianaurelio; Felice, Rosa di

    2004-01-01

    Charge migration along DNA molecules attracted scientific interest for over half a century. Reports on possible high rates of charge transfer between donor and acceptor through the DNA, obtained in the last decade from solution chemistry experiments on large numbers of molecules, triggered a series of direct electrical transport measurements through DNA single molecules, bundles and networks. These measurements are reviewed and presented here. From these experiments we conclude that electrica...

  18. Coupled Thermoelectric Devices: Theory and Experiment

    Directory of Open Access Journals (Sweden)

    Jaziel A. Rojas

    2016-07-01

    Full Text Available In this paper, we address theoretically and experimentally the optimization problem of the heat transfer occurring in two coupled thermoelectric devices. A simple experimental set up is used. The optimization parameters are the applied electric currents. When one thermoelectric is analysed, the temperature difference Δ T between the thermoelectric boundaries shows a parabolic profile with respect to the applied electric current. This behaviour agrees qualitatively with the corresponding experimental measurement. The global entropy generation shows a monotonous increase with the electric current. In the case of two coupled thermoelectric devices, elliptic isocontours for Δ T are obtained in applying an electric current through each of the thermoelectrics. The isocontours also fit well with measurements. Optimal figure of merit is found for a specific set of values of the applied electric currents. The entropy generation-thermal figure of merit relationship is studied. It is shown that, given a value of the thermal figure of merit, the device can be operated in a state of minimum entropy production.

  19. Non-coupled charge explosion and geo-mechanical dynamics

    Institute of Scientific and Technical Information of China (English)

    Zhou Fengjun; Li Xiaojun; Zhou Li; Zheng Lei

    2012-01-01

    The non-coupled charge explosion and geo-mechanical dynamics problem in real air condition is studied in this paper. It analyzes and calculates the problem by using the real air state equations. Through researching on the non- coupled charge rock bench blasting with big clearance of air, its result indicates that the borehole wall reflection over- pressure is far higher than strength of rock, but much lower than detonation front pressure of the charge. So non-coupled charge explosion blasting engineering is very successful. Furthermore, it introduces the method of shaft forming by blas- ting once and the new tube room technology. And the non-coupled charge explosion is used successfully in the method of shaft forming by blasting once. As it drills and blasts in the top and removes the broken rock from the bottom tunnel, it increases the construction efficiency significantly. This paper has important reference on the improvement of the large- span underground engineering construction.

  20. Charge transfer devices. Citations from the NTIS data base

    Science.gov (United States)

    Reed, W. E.

    1980-04-01

    The technology, design, fabrication, and applications of charge transfer devices are presented in the cited research reports. Applications include imaging, signal processing, detectors, filters, amplifiers, and memory devices. This updated bibliography contains 107 abstracts, all of which are new entries to the previous edition.

  1. SEMICONDUCTOR DEVICES A novel modified charge pumping method for trapped charge characterization in nanometer-scale devices

    Science.gov (United States)

    Peng, Zhu; Liyang, Pan; Haiming, Gu; Fengying, Qiao; Ning, Deng; Jun, Xu

    2010-10-01

    A new modified method based on the charge pumping technique is proposed and adopted to extract the lateral profiles of oxide charges in an advanced MOSFET. A 0.12 μm SONOS device with 50 nm threshold voltage peak is designed and utilized to demonstrate the proposed method. The trapped charge distribution with a narrow peak can be precisely characterized with this method, which shows good consistency with the measured threshold voltage.

  2. Organic memory device with polyaniline nanoparticles embedded as charging elements

    Science.gov (United States)

    Kim, Yo-Han; Kim, Minkeun; Oh, Sewook; Jung, Hunsang; Kim, Yejin; Yoon, Tae-Sik; Kim, Yong-Sang; Ho Lee, Hyun

    2012-04-01

    Polyaniline nanoparticles (PANI NPs) were synthesized and fabricated as charging elements for organic memory devices. The PANI NPs charging layer was self-assembled by epoxy-amine bonds between 3-glycidylpropyl trimethoxysilane functionalized dielectrics and PANI NPs. A memory window of 5.8 V (ΔVFB) represented by capacitance-voltage hysteresis was obtained for metal-pentacene-insulator-silicon capacitor. In addition, program/erase operations controlled by gate bias (-/+90 V) were demonstrated in the PANI NPs embedded pentacene thin film transistor device with polyvinylalcohol dielectric on flexible polyimide substrate. These results can be extended to development of fully organic-based electronic device.

  3. The detection of soft X-rays with charged coupled detectors

    International Nuclear Information System (INIS)

    The characteristics of an ideal soft X-ray imaging detector are enumerated. Of recent technical developments the CCD or charge coupled device goes furthest to meeting these requirements. Several properties of CCDs are described with reference to experimental work and their application to practical instruments is reviewed

  4. Quantum superposition of charge states on capacitively coupled superconducting islands

    NARCIS (Netherlands)

    Heij, C.P.; Dixon, D.C.; Wal, C.H. van der; Hadley, P.; Mooij, J.E.

    2003-01-01

    We investigate the ground state properties of a system containing two superconducting islands coupled capacitively by a wire. The ground state is a macroscopic superposition of charge states, even though the islands cannot exchange charge carriers. The ground state of the system is probed by measuri

  5. Quantum superposition of charge states on capacitively coupled superconducting islands

    OpenAIRE

    Heij, C. P.; Dixon, D C; van der Wal, C H; Hadley, P.; Mooij, J.E.

    2003-01-01

    We investigate the ground state properties of a system containing two superconducting islands coupled capacitively by a wire. The ground state is a macroscopic superposition of charge states, even though the islands cannot exchange charge carriers. The ground state of the system is probed by measuring the switching current of a Bloch transistor containing one of the islands. Calculations based on superpositions of charge states on both islands show good agreement with the experiments. The abi...

  6. Bipolar Charge Plasma Transistor: A Novel Three Terminal Device

    OpenAIRE

    Kumar, M. Jagadesh; Nadda, Kanika

    2012-01-01

    A distinctive approach for forming a lateral Bipolar Charge Plasma Transistor (BCPT) is explored using 2-D simulations. Different metal work-function electrodes are used to induce n- and p-type charge plasma layers on undoped SOI to form the emitter, base and collector regions of a lateral NPN transistor. Electrical characteristics of the proposed device are simulated and compared with that of a conventionally doped lateral bipolar junction transistor with identical dimensions. Our simulation...

  7. Multiplexed charge-locking device for large arrays of quantum devices

    Science.gov (United States)

    Puddy, R. K.; Smith, L. W.; Al-Taie, H.; Chong, C. H.; Farrer, I.; Griffiths, J. P.; Ritchie, D. A.; Kelly, M. J.; Pepper, M.; Smith, C. G.

    2015-10-01

    We present a method of forming and controlling large arrays of gate-defined quantum devices. The method uses an on-chip, multiplexed charge-locking system and helps to overcome the restraints imposed by the number of wires available in cryostat measurement systems. The device architecture that we describe here utilises a multiplexer-type scheme to lock charge onto gate electrodes. The design allows access to and control of gates whose total number exceeds that of the available electrical contacts and enables the formation, modulation and measurement of large arrays of quantum devices. We fabricate such devices on n-type GaAs/AlGaAs substrates and investigate the stability of the charge locked on to the gates. Proof-of-concept is shown by measurement of the Coulomb blockade peaks of a single quantum dot formed by a floating gate in the device. The floating gate is seen to drift by approximately one Coulomb oscillation per hour.

  8. Multiplexed charge-locking device for large arrays of quantum devices

    Energy Technology Data Exchange (ETDEWEB)

    Puddy, R. K., E-mail: rkp27@cam.ac.uk; Smith, L. W; Chong, C. H.; Farrer, I.; Griffiths, J. P.; Ritchie, D. A.; Smith, C. G. [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Al-Taie, H.; Kelly, M. J. [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Centre for Advanced Photonics and Electronics, Electrical Engineering Division, Department of Engineering, 9 J. J. Thomson Avenue, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Pepper, M. [Department of Electronic and Electrical Engineering, University College London, WC1E 7JE (United Kingdom)

    2015-10-05

    We present a method of forming and controlling large arrays of gate-defined quantum devices. The method uses an on-chip, multiplexed charge-locking system and helps to overcome the restraints imposed by the number of wires available in cryostat measurement systems. The device architecture that we describe here utilises a multiplexer-type scheme to lock charge onto gate electrodes. The design allows access to and control of gates whose total number exceeds that of the available electrical contacts and enables the formation, modulation and measurement of large arrays of quantum devices. We fabricate such devices on n-type GaAs/AlGaAs substrates and investigate the stability of the charge locked on to the gates. Proof-of-concept is shown by measurement of the Coulomb blockade peaks of a single quantum dot formed by a floating gate in the device. The floating gate is seen to drift by approximately one Coulomb oscillation per hour.

  9. Macroscopic charge quantization in single-electron devices

    NARCIS (Netherlands)

    I.S. Burmistrov; A.M.M. Pruisken

    2010-01-01

    In a recent paper by the authors [I. S. Burmistrov and A. M. M. Pruisken, Phys. Rev. Lett. 101, 056801 (2008)] it was shown that single-electron devices (single-electron transistor or SET) display "macroscopic charge quantization" which is completely analogous to the quantum Hall effect observed on

  10. Magnetization States of All-Oxide Spin Valves Controlled by Charge-orbital Ordering of Coupled Ferromagnets

    OpenAIRE

    SHVETS, IGOR

    2013-01-01

    PUBLISHED Charge-orbital ordering is commonly present in complex transition metal oxides and offers interesting opportunities for novel electronic devices. In this work, we demonstrate for the first time that the magnetization states of the spin valve can be directly manipulated by charge-orbital ordering. We investigate the interlayer exchange coupling (IEC) between two epitaxial magnetite layers separated by a nonmagnetic epitaxial MgO dielectric. We find that the state of the charge-orb...

  11. Coupled electron-nuclear dynamics: Charge migration and charge transfer initiated near a conical intersection

    Science.gov (United States)

    Mendive-Tapia, David; Vacher, Morgane; Bearpark, Michael J.; Robb, Michael A.

    2013-07-01

    Coupled electron-nuclear dynamics, implemented using the Ehrenfest method, has been used to study charge migration with fixed nuclei, together with charge transfer when nuclei are allowed to move. Simulations were initiated at reference geometries of neutral benzene and 2-phenylethylamine (PEA), and at geometries close to potential energy surface crossings in the cations. Cationic eigenstates, and the so-called sudden approximation, involving removal of an electron from a correlated ground-state wavefunction for the neutral species, were used as initial conditions. Charge migration without coupled nuclear motion could be observed if the Ehrenfest simulation, using the sudden approximation, was started near a conical intersection where the states were both strongly coupled and quasi-degenerate. Further, the main features associated with charge migration were still recognizable when the nuclear motion was allowed to couple. In the benzene radical cation, starting from the reference neutral geometry with the sudden approximation, one could observe sub-femtosecond charge migration with a small amplitude, which results from weak interaction with higher electronic states. However, we were able to engineer large amplitude charge migration, with a period between 10 and 100 fs, corresponding to oscillation of the electronic structure between the quinoid and anti-quinoid cationic electronic configurations, by distorting the geometry along the derivative coupling vector from the D6h Jahn-Teller crossing to lower symmetry where the states are not degenerate. When the nuclear motion becomes coupled, the period changes only slightly. In PEA, in an Ehrenfest trajectory starting from the D2 eigenstate and reference geometry, a partial charge transfer occurs after about 12 fs near the first crossing between D1, D2 (N+-Phenyl, N-Phenyl+). If the Ehrenfest propagation is started near this point, using the sudden approximation without coupled nuclear motion, one observes an

  12. Organization of synchronized storage at a matrix charge-coupled photodetector in modulation spectrometer

    International Nuclear Information System (INIS)

    To increase fast response of detection and primary data processing in the systems of radioactivity detection on the basis of optical-digital spectrometer it is suggested to use photodetectors with matrix charged-coupled devices (MCCD). MCCD permit to expand the system potentialities at the expense of utilization of second spatial coordinate for conducting analogous optical and electronic processing. Possibility of organization of the modulated signal synchronous accumulation in a charge form is shown. Experimental investigation results allow one to make a conclusion on possibility of signal modulation frequency increase in a modulation spectrometer by one-two orders without any equipment modification of the computer input channel

  13. Mode-selective vibrational modulation of charge transport in organic electronic devices

    KAUST Repository

    Bakulin, Artem A.

    2015-08-06

    The soft character of organic materials leads to strong coupling between molecular, nuclear and electronic dynamics. This coupling opens the way to influence charge transport in organic electronic devices by exciting molecular vibrational motions. However, despite encouraging theoretical predictions, experimental realization of such approach has remained elusive. Here we demonstrate experimentally that photoconductivity in a model organic optoelectronic device can be modulated by the selective excitation of molecular vibrations. Using an ultrafast infrared laser source to create a coherent superposition of vibrational motions in a pentacene/C60 photoresistor, we observe that excitation of certain modes in the 1,500–1,700 cm−1 region leads to photocurrent enhancement. Excited vibrations affect predominantly trapped carriers. The effect depends on the nature of the vibration and its mode-specific character can be well described by the vibrational modulation of intermolecular electronic couplings. This presents a new tool for studying electron–phonon coupling and charge dynamics in (bio)molecular materials.

  14. Integrated FET and charge reset device for gamma spectrometers

    International Nuclear Information System (INIS)

    This paper reports on a specially designed and processed five-terminal device incorporating a low noise field effect transistor and an integrated charge restoration mechanism used with an HPGe coaxial detector to produce a high rate, high resolution gamma spectrometer. A controlled charge pulse is injected into the FET channel and then collected by the gate to discharge the feedback capacitor and reset the amplifier. The reset time is fast and the high resolution is maintained at energy rate products in excess of 1011 eV/s. The FET input capacitance is 8 pF and the noise voltage is 0.45 nV/sq. root Hz at optimum temperature, When it is used with a 22 pF HPGe n-type coaxial detector the total pulser noise is 420 eV at 12 μs amplifier peaking time

  15. Spin-coupled charge dynamics in layered manganite crystals

    CERN Document Server

    Tokura, Y; Ishikawa, T

    1998-01-01

    Anisotropic charge dynamics has been investigated for single crystals of layered manganites, La sub 2 sub - sub 2 sub x Sr sub 1 sub + sub 2 sub x Mn sub 2 O sub 7 (0.3<=X<=0.5). Remarkable variations in the magnetic structure and in the charge-transport properties are observed by changing the doping level x . A crystal with x = 0.3 behaves like a 2-dimensional ferromagnetic metal in the temperature region between approx 90 K and approx 270 K and shows an interplane tunneling magnetoresistance at lower temperatures which is sensitive to the interplane magnetic coupling between the adjacent MnO sub 2 bilayers. Optical probing of these layered manganites has also clarified the highly anisotropic and incoherent charge dynamics.

  16. Emittance coupling driven by space charge in the CSNS linac

    Institute of Scientific and Technical Information of China (English)

    YIN Xue-Jun; FU Shi-Nian; PENG Jun

    2009-01-01

    In the conventional design of RF linacs, the bunched beams are not in thermal equilibrium. The space charge forces couple the particle motions between the transverse and the longitudinal directions. Fur-thermore it will cause the equipartitioning process which leads to emittance growth and halo formation. In the design of the China Spallation Neutron Source (CSNS) linac, three cases are investigated using the Hofmann stability charts. In this paper, we present the equipartitioning beam study of the CSNS Alvarez DTL linac.

  17. Charge transport models for reliability engineering of semiconductor devices

    International Nuclear Information System (INIS)

    The simulation of semiconductor devices is important for the assessment of device lifetimes before production. In this context, this work investigates the influence of the charge carrier transport model on the accuracy of bias temperature instability and hot-carrier degradation models in MOS devices. For this purpose, a four-state defect model based on a non-radiative multi phonon (NMP) theory is implemented to study the bias temperature instability. However, the doping concentrations typically used in nano-scale devices correspond to only a small number of dopants in the channel, leading to fluctuations of the electrostatic potential. Thus, the granularity of the doping cannot be ignored in these devices. To study the bias temperature instability in the presence of fluctuations of the electrostatic potential, the advanced drift diffusion device simulator Minimos-NT is employed. In a first effort to understand the bias temperature instability in p-channel MOSFETs at elevated temperatures, data from direct-current-current-voltage measurements is successfully reproduced using a four-state defect model. Differences between the four-state defect model and the commonly employed trapping model from Shockley, Read and Hall (SRH) have been investigated showing that the SRH model is incapable of reproducing the measurement data. This is in good agreement with the literature, where it has been extensively shown that a model based on SRH theory cannot reproduce the characteristic time constants found in BTI recovery traces. Upon inspection of recorded recovery traces after bias temperature stress in n-channel MOSFETs it is found that the gate current is strongly correlated with the drain current (recovery trace). Using a random discrete dopant model and non-equilibrium greens functions it is shown that direct tunnelling cannot explain the magnitude of the gate current reduction. Instead it is found that trap-assisted tunnelling, modelled using NMP theory, is the cause of this

  18. Seismic isolation device having charging function by a transducer

    Science.gov (United States)

    Yamaguchi, Takashi; Miura, Nanako; Takahashi, Masaki

    2016-04-01

    In late years, many base isolated structures are planned as the seismic design, because they suppress vibration response significantly against large earthquake. To achieve greater safety, semi-active or active vibration control system is installed in the structures as earthquake countermeasures. Semi-active and active vibration control systems are more effective than passive vibration control system to large earthquake in terms of vibration reduction. However semi-active and active vibration control system cannot operate as required when external power supply is cut off. To solve the problem of energy consumption, we propose a self-powered active seismic isolation floor which achieve active control system using regenerated vibration energy. This device doesn't require external energy to produce control force. The purpose of this study is to propose the seismic isolation device having charging function and to optimize the control system and passive elements such as spring coefficients and damping coefficients using genetic algorithm. As a result, optimized model shows better performance in terms of vibration reduction and electric power regeneration than the previous model. At the end of this paper, the experimental specimen of the proposed isolation device is shown.

  19. Dynamical Couplings and Charge Confinement/Deconfinement from Gravity Coupled to Nonlinear Gauge Fields

    CERN Document Server

    Guendelman, Eduardo; Nissimov, Emil; Pacheva, Svetlana

    2013-01-01

    We briefly outline several main results concerning various new physically relevant features found in gravity -- both ordinary Einstein or $f(R)=R+R^2$ gravity in the first-order formalism, coupled to a special kind of nonlinear electrodynamics containing a square-root of the standard Maxwell Lagrangian and known to produce charge confinement in flat spacetime.

  20. Neutrino-Electron Scattering: Charge Radius and Effective Couplings

    International Nuclear Information System (INIS)

    In this work the neutral-current scattering cross-section for neutrinos on electrons is calculated assuming that a massive Dirac neutrino is characterized by a phenomenological parameters, a charge radius (r2) and the right-handed currents are present in the framework of a Left-Right symmetric model (LR). Using the CHARM II result for the charge radius of the muon-neutrino |(r2)| < 6.0 × 10−33 cm2, we place a bound on −7.9 × 10−33 cm2 ≤ (r2)LR ≤ 7.9 × 10−33 cm2. We discuss the relationship between the electron neutral couplings gveV and gveA and the LR model parameters

  1. Charged current top quark couplings at the LHC

    International Nuclear Information System (INIS)

    The top quark plays an important role in current particle physics, from a theoretical point of view because of its uniquely large mass, but also experimentally because of the large number of top events recorded by the LHC experiments ATLAS and CMS, which makes it possible to directly measure the properties of this particle, for example its couplings to the other particles of the standard model (SM), with previously unknown precision. In this thesis, an effective field theory approach is employed to introduce a minimal and consistent parametrization of all anomalous top couplings to the SM gauge bosons and fermions which are compatible with the SM symmetries. In addition, several aspects and consequences of the underlying effective operator relations for these couplings are discussed. The resulting set of couplings has been implemented in the parton level Monte Carlo event generator WHIZARD in order to provide a tool for the quantitative assessment of the phenomenological implications at present and future colliders such as the LHC or a planned international linear collider. The phenomenological part of this thesis is focused on the charged current couplings of the top quark, namely anomalous contributions to the trilinear tbW coupling as well as quartic four-fermion contact interactions of the form tbff', both affecting single top production as well as top decays at the LHC. The study includes various aspects of inclusive cross section measurements as well as differential distributions of single tops produced in the t channel, bq → tq', and in the s channel, u anti d→t anti b. We discuss the parton level modelling of these processes as well as detector effects, and finally present the prospected LHC reach for setting limits on these couplings with 10 resp. 100 fb-1 of data recorded at √(s)=14 TeV.

  2. Charged current top quark couplings at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Bach, Fabian

    2013-07-01

    The top quark plays an important role in current particle physics, from a theoretical point of view because of its uniquely large mass, but also experimentally because of the large number of top events recorded by the LHC experiments ATLAS and CMS, which makes it possible to directly measure the properties of this particle, for example its couplings to the other particles of the standard model (SM), with previously unknown precision. In this thesis, an effective field theory approach is employed to introduce a minimal and consistent parametrization of all anomalous top couplings to the SM gauge bosons and fermions which are compatible with the SM symmetries. In addition, several aspects and consequences of the underlying effective operator relations for these couplings are discussed. The resulting set of couplings has been implemented in the parton level Monte Carlo event generator WHIZARD in order to provide a tool for the quantitative assessment of the phenomenological implications at present and future colliders such as the LHC or a planned international linear collider. The phenomenological part of this thesis is focused on the charged current couplings of the top quark, namely anomalous contributions to the trilinear tbW coupling as well as quartic four-fermion contact interactions of the form tbff', both affecting single top production as well as top decays at the LHC. The study includes various aspects of inclusive cross section measurements as well as differential distributions of single tops produced in the t channel, bq {yields} tq', and in the s channel, u anti d{yields}t anti b. We discuss the parton level modelling of these processes as well as detector effects, and finally present the prospected LHC reach for setting limits on these couplings with 10 resp. 100 fb{sup -1} of data recorded at {radical}(s)=14 TeV.

  3. Simulating charge transport to understand the spectral response of Swept Charge Devices

    CERN Document Server

    Athiray, P S; Narendranath, S; Gow, J P D

    2015-01-01

    Swept Charge Devices (SCD) are novel X-ray detectors optimized for improved spectral performance without any demand for active cooling. The Chandrayaan-1 X-ray Spectrometer (C1XS) experiment onboard the Chandrayaan-1 spacecraft used an array of SCDs to map the global surface elemental abundances on the Moon using the X-ray fluorescence (XRF) technique. The successful demonstration of SCDs in C1XS spurred an enhanced version of the spectrometer on Chandrayaan-2 using the next-generation SCD sensors. The objective of this paper is to demonstrate validation of a physical model developed to simulate X-ray photon interaction and charge transportation in a SCD. The model helps to understand and identify the origin of individual components that collectively contribute to the energy-dependent spectral response of the SCD. Furthermore, the model provides completeness to various calibration tasks, such as generating spectral response matrices (RMFs - redistribution matrix files), estimating efficiency, optimizing event...

  4. Luminescent coupling in planar opto-electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Matthew, E-mail: mwilkins@eecs.uottawa.ca; Valdivia, Christopher E.; Gabr, Ahmed M.; Hinzer, Karin [School of Electrical Engineering and Computer Science, University of Ottawa, 25 Templeton St., Ottawa, Ontario K1N 6N5 (Canada); Masson, Denis; Fafard, Simon [Azastra Opto, Inc., Suite M50-IPF-206, 1200 Montreal Rd, Ottawa, Ontario K1A 0R6 (Canada)

    2015-10-14

    Effects of luminescent coupling are observed in monolithic 5 V, five-junction GaAs phototransducers. Power conversion efficiency was measured at 61.6% ± 3% under the continuous, monochromatic illumination for which they were designed. Modeling shows that photon recycling can account for up to 350 mV of photovoltage in these devices. Drift-diffusion based simulations including a luminescent coupling term in the continuity equation show a broadening of the internal quantum efficiency curve which agrees well with experimental measurements. Luminescent coupling is shown to expand the spectral bandwidth of the phototransducer by a factor of at least 3.5 for devices with three or more junctions, even in cases where multiple absorption/emission events are required to transfer excess carriers into the limiting junction. We present a detailed description of the novel luminescent coupling modeling technique used to predict these performance enhancements.

  5. Luminescent coupling in planar opto-electronic devices

    Science.gov (United States)

    Wilkins, Matthew; Valdivia, Christopher E.; Gabr, Ahmed M.; Masson, Denis; Fafard, Simon; Hinzer, Karin

    2015-10-01

    Effects of luminescent coupling are observed in monolithic 5 V, five-junction GaAs phototransducers. Power conversion efficiency was measured at 61.6% ± 3% under the continuous, monochromatic illumination for which they were designed. Modeling shows that photon recycling can account for up to 350 mV of photovoltage in these devices. Drift-diffusion based simulations including a luminescent coupling term in the continuity equation show a broadening of the internal quantum efficiency curve which agrees well with experimental measurements. Luminescent coupling is shown to expand the spectral bandwidth of the phototransducer by a factor of at least 3.5 for devices with three or more junctions, even in cases where multiple absorption/emission events are required to transfer excess carriers into the limiting junction. We present a detailed description of the novel luminescent coupling modeling technique used to predict these performance enhancements.

  6. Field enhanced charge carrier reconfiguration in electronic and ionic coupled dynamic polymer resistive memory

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Junhui; Thomson, Douglas J; Freund, Michael S [Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB (Canada); Pilapil, Matt; Pillai, Rajesh G; Aminur Rahman, G M, E-mail: thomson@ee.umanitoba.ca, E-mail: michael_freund@umanitoba.ca [Department of Chemistry, University of Manitoba, Winnipeg, MB (Canada)

    2010-04-02

    Dynamic resistive memory devices based on a conjugated polymer composite (PPy{sup 0}DBS{sup -}Li{sup +} (PPy: polypyrrole; DBS{sup -}: dodecylbenzenesulfonate)), with field-driven ion migration, have been demonstrated. In this work the dynamics of these systems has been investigated and it has been concluded that increasing the applied field can dramatically increase the rate at which information can be 'written' into these devices. A conductance model using space charge limited current coupled with an electric field induced ion reconfiguration has been successfully utilized to interpret the experimentally observed transient conducting behaviors. The memory devices use the rising and falling transient current states for the storage of digital states. The magnitude of these transient currents is controlled by the magnitude and width of the write/read pulse. For the 500 nm length devices used in this work an increase in 'write' potential from 2.5 to 5.5 V decreased the time required to create a transient conductance state that can be converted into the digital signal by 50 times. This work suggests that the scaling of these devices will be favorable and that 'write' times for the conjugated polymer composite memory devices will decrease rapidly as ion driving fields increase with decreasing device size.

  7. Quantification of strain and charge co-mediated magnetoelectric coupling on ultra-thin Permalloy/PMN-PT interface.

    Science.gov (United States)

    Nan, Tianxiang; Zhou, Ziyao; Liu, Ming; Yang, Xi; Gao, Yuan; Assaf, Badih A; Lin, Hwaider; Velu, Siddharth; Wang, Xinjun; Luo, Haosu; Chen, Jimmy; Akhtar, Saad; Hu, Edward; Rajiv, Rohit; Krishnan, Kavin; Sreedhar, Shalini; Heiman, Don; Howe, Brandon M; Brown, Gail J; Sun, Nian X

    2014-01-01

    Strain and charge co-mediated magnetoelectric coupling are expected in ultra-thin ferromagnetic/ferroelectric multiferroic heterostructures, which could lead to significantly enhanced magnetoelectric coupling. It is however challenging to observe the combined strain charge mediated magnetoelectric coupling, and difficult in quantitatively distinguish these two magnetoelectric coupling mechanisms. We demonstrated in this work, the quantification of the coexistence of strain and surface charge mediated magnetoelectric coupling on ultra-thin Ni0.79Fe0.21/PMN-PT interface by using a Ni0.79Fe0.21/Cu/PMN-PT heterostructure with only strain-mediated magnetoelectric coupling as a control. The NiFe/PMN-PT heterostructure exhibited a high voltage induced effective magnetic field change of 375 Oe enhanced by the surface charge at the PMN-PT interface. Without the enhancement of the charge-mediated magnetoelectric effect by inserting a Cu layer at the PMN-PT interface, the electric field modification of effective magnetic field was 202 Oe. By distinguishing the magnetoelectric coupling mechanisms, a pure surface charge modification of magnetism shows a strong correlation to polarization of PMN-PT. A non-volatile effective magnetic field change of 104 Oe was observed at zero electric field originates from the different remnant polarization state of PMN-PT. The strain and charge co-mediated magnetoelectric coupling in ultra-thin magnetic/ferroelectric heterostructures could lead to power efficient and non-volatile magnetoelectric devices with enhanced magnetoelectric coupling. PMID:24418911

  8. Tuning The Optical, Charge Injection, and Charge Transport Properties of Organic Electronic Devices

    Science.gov (United States)

    Zalar, Peter

    Since the early 1900's, synthetic insulating polymers (plastics) have slowly taken over the role that traditional materials like wood or metal have had as basic components for construction, manufactured goods, and parts. Plastics allow for high throughput, low temperature processing, and control of bulk properties through molecular modifications. In the same way, pi-conjugated organic molecules are emerging as a possible substitute for inorganic materials due to their electronic properties. The semiconductive nature of pi-conjugated materials make them an attractive candidate to replace inorganic materials, primarily due to their promise for low cost and large-scale production of basic semiconducting devices such as light-emitting diodes, solar cells, and field-effect transistors. Before organic semiconductors can be realized as a commercial product, several hurdles must be cleared. The purpose of this dissertation is to address three distinct properties that dominate the functionality of devices harnessing these materials: (1) optical properties, (2) charge injection, and (3) charge transport. First, it is shown that the electron injection barrier in the emissive layer of polymer light-emitting diodes can be significantly reduced by processing of novel conjugated oligoelectrolytes or deoxyribonucleic acid atop the emissive layer. Next, the charge transport properties of several polymers could be modified by processing them from solvents containing small amounts of additives or by using regioregular and enantiopure chemical structures. It is then demonstrated that the optical and electronic properties of Lewis basic polymer structures can be readily modified by interactions with strongly electron-withdrawing Lewis acids. Through red-shifted absorption, photoluminescence, and electroluminescence, a single pi-conjugated backbone can be polychromatic. In addition, interaction with Lewis acids can remarkably p-dope the hole transport of the parent polymer, leading to a

  9. Quasiclassical methods for spin-charge coupled dynamics in low-dimensional systems

    Energy Technology Data Exchange (ETDEWEB)

    Corini, Cosimo

    2009-06-12

    Spintronics is a new field of study whose broad aim is the manipulation of the spin degrees of freedom in solid state systems. One of its main goals is the realization of devices capable of exploiting, besides the charge, the carriers' - and possibly the nuclei's - spin. The presence of spin-orbit coupling in a system enables the spin and charge degrees of freedom to ''communicate'', a favorable situation if one is to realize such devices. More importantly, it offers the opportunity of doing so by relying solely on electric fields, whereas magnetic fields are otherwise required. Eminent examples of versatile systems with built-in and variously tunable spin-orbit interaction are two-dimensional electron - or hole - gases. The study of spin-charge coupled dynamics in such a context faces a large number of open questions, both of the fundamental and of the more practical type. To tackle the problem we rely on the quasiclassical formalism. This is an approximate quantum-field theoretical formulation with a solid microscopic foundation, perfectly suited for describing phenomena at the mesoscopic scale, and bearing a resemblance to standard Boltzmann theory which makes for physical transparency. Originally born to deal with transport in electron-phonon systems, we first generalize it to the case in which spin-orbit coupling is present, and then move on to apply it to specific situations and phenomena. Among these, to the description of the spin Hall effect and of voltage induced spin polarizations in two-dimensional electron gases under a variety of conditions - stationary or time-dependent, in the presence of magnetic and non-magnetic disorder, in the bulk or in confined geometries -, and to the problem of spin relaxation in narrow wires. (orig.)

  10. Quasiclassical methods for spin-charge coupled dynamics in low-dimensional systems

    International Nuclear Information System (INIS)

    Spintronics is a new field of study whose broad aim is the manipulation of the spin degrees of freedom in solid state systems. One of its main goals is the realization of devices capable of exploiting, besides the charge, the carriers' - and possibly the nuclei's - spin. The presence of spin-orbit coupling in a system enables the spin and charge degrees of freedom to ''communicate'', a favorable situation if one is to realize such devices. More importantly, it offers the opportunity of doing so by relying solely on electric fields, whereas magnetic fields are otherwise required. Eminent examples of versatile systems with built-in and variously tunable spin-orbit interaction are two-dimensional electron - or hole - gases. The study of spin-charge coupled dynamics in such a context faces a large number of open questions, both of the fundamental and of the more practical type. To tackle the problem we rely on the quasiclassical formalism. This is an approximate quantum-field theoretical formulation with a solid microscopic foundation, perfectly suited for describing phenomena at the mesoscopic scale, and bearing a resemblance to standard Boltzmann theory which makes for physical transparency. Originally born to deal with transport in electron-phonon systems, we first generalize it to the case in which spin-orbit coupling is present, and then move on to apply it to specific situations and phenomena. Among these, to the description of the spin Hall effect and of voltage induced spin polarizations in two-dimensional electron gases under a variety of conditions - stationary or time-dependent, in the presence of magnetic and non-magnetic disorder, in the bulk or in confined geometries -, and to the problem of spin relaxation in narrow wires. (orig.)

  11. Charge redistribution from anomalous magneto-vorticity coupling

    CERN Document Server

    Hattori, Koichi

    2016-01-01

    We investigate novel transport phenomena in a chiral fluid originated from an interplay between a vorticity and strong magnetic field, which induces a redistribution of vector charges in the system and an axial current along the magnetic field. The corresponding transport coefficients are obtained from an energy-shift argument for the chiral fermions in the lowest Landau level (LLL) due to a spin-vorticity coupling and also from diagrammatic computations on the basis of the linear response theory. Based on consistent results from the both methods, we observe that the transport coefficients are proportional to the anomaly coefficient and are independence of temperature and chemical potential. We therefore speculate that these transport phenomena are connected to quantum anomaly.

  12. Charge transport and magnetoresistance of G4-DNA molecular device modulated by counter ions and dephasing effect

    Science.gov (United States)

    Kang, Da-wei; Sun, Meng-le; Zuo, Zheng-wei; Wang, Hui-xian; Lv, Shi-jie; Li, Xin-zhong; Li, Li-ben

    2016-02-01

    The charge transport properties of the G4-DNA molecular device in the presence of counter ions and dephasing effect are investigated based on the Green function method and Landauer-Büttiker theory. The currents through the G4-DNA molecular device depend on the interference patterns at different coupling configurations. There is an effective electrostatic interaction between the counter ions and the G4-DNA molecule which introduces disorder into the on-site energies of G bases. The current through the device can be enhanced by the small disorder which avoids the strong interference of electrons at the same energy in some coupling configurations, however the diagonal disorder can suppress the overall current due to the Anderson localization of charge carriers when the disorder is large. In the presence of dephasing effect the current through the device at all coupling configurations can be enhanced as a result of the phase coherence losing of electron. As for the magnetic field response, the magnetoresistance of the device is always suppressed by the counter ions and dephasing effect.

  13. Conserved Charges of Minimal Massive Gravity Coupled to Scalar Field

    CERN Document Server

    Setare, M R

    2016-01-01

    Recently, the theory of Topologically massive gravity non-minimally coupled to a scalar field has been proposed which comes from Lorentz-Chern-Simons theory \\cite{1}. That theory is a torsion free one. We extend that theory by adding an extra term which makes torsion to be non-zero. The extended theory can be regarded as an extension of Minimal massive gravity such that it is non-minimally coupled to a scalar field. We obtain equations of motion of extended theory such that they are expressed in terms of usual torsion free spin-connection. We show that BTZ spacetime is a solution of this theory when scalar field is constant. We define quasi-local conserved charge by the concept of generalized off-shell ADT current which both are conserved for any asymptotically Killing vector field as well as a Killing vector field which is admitted by spacetime everywhere. Also we find general formula for entropy of stationary black hole solution in the context of considered theory. We apply the obtained formulas on BTZ blac...

  14. Design of Image Processing System Based on Charge Coupled Device

    Directory of Open Access Journals (Sweden)

    Xu Guosheng

    2013-01-01

    Full Text Available To speed up the image acquisition and make full use of effective information, a design method of CCD partial image scanning system is presented. The system achieves to functions of the high -speed data collection, the high -speed video data compression the real time video data Network Transmission and the real time compression picture data storage. the data processed was transferred to PC through USB2.0 real-time to reconstruct defects microscopic images. The experimental results demonstrated that defects within 50μm~1000μm were inspected effectively by the CCD scanning defects inspection instrument, that this method has a repetition error no more than 2.24 pixels, with high precision and good anti-noise ability.

  15. Performance and analysis of wireless power charging system from room temperature to HTS magnet via strong resonance coupling method

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y. D.; Lee, S. Y.; Lee, T. W.; Kim, J. S. [Suwon Science College, Suwon (Korea, Republic of); Lee, C. Y. [Korea Railroad Institute, Uiwang (Korea, Republic of)

    2016-03-15

    The technology of supplying the electric power by wireless power transfer (WPT) is expected for the next generation power feeding system since it can supply the power to portable devices without any connectors through large air gap. As such a technology based on strongly coupled electromagnetic resonators is possible to deliver the large power and recharge them seamlessly; it has been considered as a noble option to wireless power charging system in the various power applications. Recently, various HTS wires have now been manufactured for demonstrations of transmission cables, motors, MAGLEV, and other electrical power components. However, since the HTS magnets have a lower index n value intrinsically, they are required to be charged from external power system through leads or internal power system. The portable area is limited as well as the cryogen system is bulkier. Thus, we proposed a novel design of wireless power charging system for superconducting HTS magnet (WPC4SM) based on resonance coupling method. As the novel system makes possible a wireless power charging using copper resonance coupled coils, it enables to portable charging conveniently in the superconducting applications. This paper presented the conceptual design and operating characteristics of WPC4SM using different shapes' copper resonance coil. The proposed system consists of four components; RF generator of 370 kHz, copper resonance coupling coils, impedance matching (IM) subsystem and HTS magnet including rectifier system.

  16. Induction charging device for the MGU NIIYaF electrostatic accelerator

    International Nuclear Information System (INIS)

    Operation principle for induction-type charging device set on the MGU NIIYaF electrostatic accelerator is presented. Design of units is described and main parameters of induction charging device (ICD) are given. Comparison of ICD with foreign charging devices of induction-type allows to speak about certain advantages of ICD. Current transfered by ICD transport unit is higher by several times than that of pelletron. ICD transport unit is comparable with laddetron according to value of transfered current. Weight of length unit of ICD transport part is however by 2-3 times less than that of laddetron. 6 refs.; 9 figs

  17. Investigation of Interface Charges at the Heterojunction Discontinuity in HBT Devices

    DEFF Research Database (Denmark)

    Fuente, Jesús Grajal de al; Krozer, Viktor

    2002-01-01

    In this paper we investigate the impact of interface charges at heterojunctions on the performance of heterostructure bipolar transistors (HBT). Interface charges can modify the limiting process for the carrier transport in a device. Therefore. intentional interface charges introduced by delta......-doped layers are basic tools for interface engineering. An accurate modelling of heterointerfaces which includes thermionic-field emission, surface charges, and surface dipoles allows to analyse the electrical performance of some modern devices based on band gap and interface engineering. It is demonstrated...

  18. Tight-binding modeling of charge migration in DNA devices

    OpenAIRE

    Cuniberti, G.; Macia, E.; Rodriguez, A.; R.A. Römer

    2007-01-01

    Long range charge transfer experiments in DNA oligomers and the subsequently measured -- and very diverse -- transport response of DNA wires in solid state experiments exemplifies the need for a thorough theoretical understanding of charge migration in DNA-based natural and artificial materials. Here we present a review of tight-binding models for DNA conduction which have the intrinsic merit of containing more structural information than plain rate-equation models while still retaining suffi...

  19. Energy and Charge Transfer from Guest to Host in Doped Organic Electroluminescent Devices

    Institute of Scientific and Technical Information of China (English)

    李宏建; 彭景翠; 许雪梅; 瞿述; 罗小华; 赵楚军

    2002-01-01

    The luminescence properties of doped organic electroluminescent devices are explained by means off Hamiltonian model. The results show that there is a corresponding relation between the amount of transferred charge and the change of the energy originating from charge transfer, and the relation can be influenced by dopant concentration.As the amount of transferred charge increases, the total energy decreases and the luminescence intensity increases.Therefore, we deduce that the energy transfer from guest to host may be derived from the charge transfer. For a given organic electroluminescent device, the maximum value of the conductivity can be observed in a specific dopant concentration. The calculated results show that the greater the transferred charges, the higher the conductivities in doped organic electroluminescent devices. The results agree basically with experimental results.

  20. Coupled spin, elastic and charge dynamics in magnetic nanostructures

    NARCIS (Netherlands)

    Kamra, A.

    2015-01-01

    In this Thesis, I address the interaction of magnetic degrees of freedom with charge current and elastic dynamics in hybrid systems composed of magnetic and non-magnetic materials. The objective, invariably, is to control and study spin dynamics using charge and elastic degrees of freedom. In certai

  1. Gold nanoparticle charge trapping and relation to organic polymer memory devices.

    Science.gov (United States)

    Prime, D; Paul, S; Josephs-Franks, P W

    2009-10-28

    Nanoparticle-based polymer memory devices (PMDs) are a promising technology that could replace conventional silicon-based electronic memory, offering fast operating speeds, simple device structures and low costs. Here we report on the current state of nanoparticle PMDs and review some of the problems that are still present in the field. We also present new data regarding the charging of gold nanoparticles in metal-insulator-semiconductor capacitors, showing that charging is possible under the application of an electric field with a trapped charge density due to the nanoparticles of 3.3 x 10(12) cm(-2). PMID:19770145

  2. Development of Pointing Device Using DC-Coupled Electrooculogram

    Science.gov (United States)

    Uchitomi, Hirotaka; Hori, Junichi

    A purpose of this study is to support communication of developmentally disabled individuals with motor paralysis, such as Guillain-Barre Syndrome, brain-stem infarction, having difficulty in conveying their intention. In the present paper, a pointing device controlled by DC-coupled electrooculograms (EOGs) has been developed. The optic angle of the subject was estimated from the amplitude of vertical and horizontal EOGs for determining the two dimensional pointing position on the PC screen in real time. The eye blinking artifact was reduced using a median filter. The displacement of electrode position was compensated by considering the potential gradient. Moreover, the position error caused by drift phenomenon was adjusted by using head movement. The accuracy and operating speed of the proposed method were evaluated in human experiments.

  3. Charge-Transfer CMOS Image Sensors: Device and Radiation Aspects

    OpenAIRE

    Ramachandra Rao, P.

    2009-01-01

    The aim of this thesis was twofold: investigating the effect of ionizing radiation on 4-T CMOS image sensors and the possibility of realizing a CCD like sensor in standard 0.18-μm CMOS technology (for medical applications). Both the aims are complementary; borrowing and lending many aspects of radiation and device physics amongst each other.

  4. Tunable capacitive coupling between two semiconductor charge qubits

    Science.gov (United States)

    Yu, Guo-Dong; Li, Hai-Ou; Cao, Gang; Xiao, Ming; Jiang, Hong-Wen; Guo, Guo-Ping

    2016-08-01

    Strong coupling between two qubits is one of the main requirements for high fidelity two-qubit logic operations. Here we experimentally investigate the capacitive coupling between two double quantum dots. A pair of open slot confinement gates is used to enhance the coupling. We find that the coupling energy J can be conveniently tuned in a broad range. Through numerical simulations, we study the effect of J on two-qubit operations. The analysis shows that our experimentally obtained J is adequate to achieve high fidelity two-qubit entanglement and logic gates.

  5. Experimental Studies of Charge Transport in Single Crystal Diamond Devices

    OpenAIRE

    Majdi, Saman

    2012-01-01

    Diamond is a promising material for high-power, high-frequency and high- temperature electronics applications, where its outstanding physical properties can be fully exploited. It exhibits an extremely high bandgap, very high carrier mobilities, high breakdown field strength, and the highest thermal conductivity of any wide bandgap material. It is therefore an outstanding candidate for the fastest switching, the highest power density, and the most efficient electronic devices obtainable, with...

  6. Phenomenology of Enhanced Light Quark Yukawa Couplings and the $W^\\pm h$ Charge Asymmetry

    CERN Document Server

    Yu, Felix

    2016-01-01

    I propose the measurement of the $W^\\pm h$ charge asymmetry as a consistency test for the Standard Model (SM) Higgs, which is sensitive to enhanced Yukawa couplings of the first and second generation quarks. I present a collider analysis for the charge asymmetry in the same-sign lepton final state, $p p \\to W^\\pm h \\to (\\ell^\\pm \

  7. Electronic coupling calculations with transition charges, dipoles, and quadrupoles derived from electrostatic potential fitting

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Kazuhiro J., E-mail: fujimoto@ruby.kobe-u.ac.jp [Department of Computational Science, Graduate School of System Informatics, Kobe University, 1-1, Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-12-07

    A transition charge, dipole, and quadrupole from electrostatic potential (TrESP-CDQ) method for electronic coupling calculations is proposed. The TrESP method is based on the classical description of electronic Coulomb interaction between transition densities for individual molecules. In the original TrESP method, only the transition charge interactions were considered as the electronic coupling. In the present study, the TrESP method is extended to include the contributions from the transition dipoles and quadrupoles as well as the transition charges. Hence, the self-consistent transition density is employed in the ESP fitting procedure. To check the accuracy of the present approach, several test calculations are performed to a helium dimer, a methane dimer, and an ethylene dimer. As a result, the TrESP-CDQ method gives a much improved description of the electronic coupling, compared with the original TrESP method. The calculated results also show that the self-consistent treatment to the transition densities contributes significantly to the accuracy of the electronic coupling calculations. Based on the successful description of the electronic coupling, the contributions to the electronic coupling are also analyzed. This analysis clearly shows a negligible contribution of the transition charge interaction to the electronic coupling. Hence, the distribution of the transition density is found to strongly influence the magnitudes of the transition charges, dipoles, and quadrupoles. The present approach is useful for analyzing and understanding the mechanism of excitation-energy transfer.

  8. Does a coupling capacitor enhance the charge balance during neural stimulation? An empirical study

    NARCIS (Netherlands)

    Van Dongen, M.N.; Serdijn, W.A.

    2015-01-01

    Due to their DC-blocking characteristic, coupling capacitors are widely used to prevent potentially harmful charge buildup at the electrode–tissue interface. Although the capacitors can be an effective safety measure, it often seems overlooked that coupling capacitors actually introduce an offset vo

  9. $\\rho$-Nucleon Tensor Coupling and Charge-Exchange Resonances

    CERN Document Server

    De Conti, C; Krmpotic, F

    2000-01-01

    The Gamow-Teller resonances are discussed in the context of a self-consistentRPA, based on the relativistic mean field theory. We inquire on the possibilityof substituting the phenomenological Landau-Migdal force by a microscopicnucleon-nucleon interaction, generated from the rho-nucleon tensor coupling.The effect of this coupling turns out to be very small when the short rangecorrelations are not taken into account, but too large when these correlationsare simulated by the simple extraction of the contact terms from the resultingnucleon-nucleon interaction.

  10. External Cooling Coupled to Reduced Extremity Pressure Device

    Science.gov (United States)

    Kuznetz, Lawrence H.

    2011-01-01

    Although suited astronauts are currently cooled with a Liquid Cooled Ventilation Garment (LCVG), which can remove up to 85 percent of body heat, their effectiveness is limited because cooling must penetrate layers of skin, muscle, fat, bone, and tissue to reach the bloodstream, where its effect is prominent. Vasoconstriction further reduces the effectiveness by limiting arterial flow when exposed to cold (the frostbite response), resulting in a time constant on the order of 20 minutes from application to maximum effect. This delay can be crucial in severe exposure to hypo- or hyper-thermic conditions, compromising homeostasis. The purpose of this innovation is to provide a lightweight, effective means of delivering heat or cold from an external source directly to the bloodstream. The effectiveness of this ECCREP (External Cooling Coupled to Reduced Extremity Pressure) device is based on not having to penetrate layers of skin, muscle, fat, and tissue, thereby avoiding the thermal lag associated with their mass and heat capacity. This is accomplished by means of an outer boot operating at a slightly reduced pressure than the rest of the body, combined with an inner boot cooled or heated by an external source via water or chemicals. Heat transfer from the external source to the foot takes place by means of circulating water or flexible heat pipes.

  11. Strong-coupling electrostatic theory of polymer counterions close to planar charges

    Science.gov (United States)

    Dutta, Sandipan; Jho, Y. S.

    2016-01-01

    Strong-coupling phenomena, such as like-charge macroion attraction, opposite-charged macroion repulsion, charge renormalization, and charge inversion, are known to be mediated by multivalent counterions. Most theories treat the counterions as point charges and describe the system by a single coupling parameter that measures the strength of the Coulomb interactions. In many biological systems, the counterions are highly charged and have finite sizes and can be well-described by polyelectrolytes. The shapes and orientations of these polymer counterions play a major role in the thermodynamics of these systems. In this work we apply a field-theoretic description in the strong-coupling regime to the polymer counterions in the presence of a fixed charge distribution. We work out the special cases of rodlike polymer counterions confined by one, and two charged walls, respectively. The effects of the geometry of the rodlike counterions and the excluded volume of the walls on the density, pressure, and free energy of the rodlike counterions are discussed.

  12. The c-axis charge traveling wave in a coupled system of Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Hamdipour, M.

    2012-05-01

    We demonstrate a manifestation of the charge traveling wave along the c axis (TW) in current voltage characteristics of coupled Josephson junctions in high- T c superconductors. The branches related to the TW with different wavelengths are found for the stacks with different number of Josephson junctions at different values of system's parameters. Transitions between the TW branches and the outermost branch are observed. The electric charge in the superconducting layers and charge-charge correlation functions for TW and outermost branches show different behavior with bias current. We propose an experimental testing of the TW branching by microwave irradiation.

  13. Anomalous Threshold Voltage Variability of Nitride Based Charge Storage Nonvolatile Memory Devices

    Directory of Open Access Journals (Sweden)

    Meng Chuan Lee

    2013-01-01

    Full Text Available Conventional technology scaling is implemented to meet the insatiable demand of high memory density and low cost per bit of charge storage nonvolatile memory (NVM devices. In this study, effect of technology scaling to anomalous threshold voltage ( variability is investigated thoroughly on postcycled and baked nitride based charge storage NVM devices. After long annealing bake of high temperature, cell’s variability of each subsequent bake increases within stable distribution and found exacerbate by technology scaling. Apparent activation energy of this anomalous variability was derived through Arrhenius plots. Apparent activation energy (Eaa of this anomalous variability is 0.67 eV at sub-40 nm devices which is a reduction of approximately 2 times from 110 nm devices. Technology scaling clearly aggravates this anomalous variability, and this poses reliability challenges to applications that demand strict control, for example, reference cells that govern fundamental program, erase, and verify operations of NVM devices. Based on critical evidence, this anomalous variability is attributed to lateral displacement of trapped charges in nitride storage layer. Reliability implications of this study are elucidated. Moreover, potential mitigation methods are proposed to complement technology scaling to prolong the front-runner role of nitride based charge storage NVM in semiconductor flash memory market.

  14. Improved blue light-emitting polymeric device by the tuning of drift mobility and charge balance

    Science.gov (United States)

    Chin, Byung Doo; Suh, Min Chul; Lee, Seong Taek; Chung, Ho Kyoon; Lee, Chang Hee

    2004-03-01

    We have prepared blue polymer-small molecule hybrid electroluminescence devices with improved efficiency and lower driving voltage by the statistical design method. Analysis of time-of-flight measurement shows that amorphous small molecule hole-transporter blended with a blue light-emitting polymer increases the field-dependent hole mobility, with transition from nondispersive to dispersive transport induced by the charge-trapping effect. Moreover, at the electroluminescent devices with different electron injection/transport layer (LiF/Al, LiF/Ca/Al, and Alq3/LiF/Al), efficiency was further increased. We have analyzed that carrier mobility of a multilayered device can also be controlled by the change of electron injection and transport layers. We find that structural design and matching overall charge balance is an essential factor to improve both the operating voltage and efficiency of existing blue polymer devices.

  15. Radiation detector device for rejecting and excluding incomplete charge collection events

    Science.gov (United States)

    Bolotnikov, Aleksey E.; De Geronimo, Gianluigi; Vernon, Emerson; Yang, Ge; Camarda, Giuseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B.

    2016-05-10

    A radiation detector device is provided that is capable of distinguishing between full charge collection (FCC) events and incomplete charge collection (ICC) events based upon a correlation value comparison algorithm that compares correlation values calculated for individually sensed radiation detection events with a calibrated FCC event correlation function. The calibrated FCC event correlation function serves as a reference curve utilized by a correlation value comparison algorithm to determine whether a sensed radiation detection event fits the profile of the FCC event correlation function within the noise tolerances of the radiation detector device. If the radiation detection event is determined to be an ICC event, then the spectrum for the ICC event is rejected and excluded from inclusion in the radiation detector device spectral analyses. The radiation detector device also can calculate a performance factor to determine the efficacy of distinguishing between FCC and ICC events.

  16. Charge order from orbital-dependent coupling evidenced by NbSe2.

    Science.gov (United States)

    Flicker, Felix; van Wezel, Jasper

    2015-01-01

    Niobium diselenide has long served as a prototype of two-dimensional charge ordering, believed to arise from an instability of the electronic structure analogous to the one-dimensional Peierls mechanism. Despite this, various anomalous properties have recently been identified experimentally, which cannot be explained by Peierls-like weak-coupling theories. Here, we consider instead a model with strong electron-phonon coupling, taking into account both the full momentum and orbital dependence of the coupling matrix elements. We show that both are necessary for a consistent description of the full range of experimental observations. We argue that NbSe2 is typical in this sense, and that any charge-ordered material in more than one dimension will generically be shaped by the momentum and orbital dependence of its electron-phonon coupling as well as its electronic structure. The consequences will be observable in many charge-ordered materials, including cuprate superconductors. PMID:25948390

  17. Proton-Coupled Electron Transfer: Moving Together and Charging Forward

    OpenAIRE

    Hammes-Schiffer, Sharon

    2015-01-01

    Proton-coupled electron transfer (PCET) is ubiquitous throughout chemistry and biology. This Perspective discusses recent advances and current challenges in the field of PCET, with an emphasis on the role of theory and computation. The fundamental theoretical concepts are summarized, and expressions for rate constants and kinetic isotope effects are provided. Computational methods for calculating reduction potentials and pK a’s for molecular electrocatalysts, as well as insights into linear c...

  18. Longitudinal spin-charge responses and collective modes in spin-polarized quantum devices

    CERN Document Server

    Yi, K S; Bae, Y N; Quinn, J J

    1999-01-01

    The generalized longitudinal charge-spin susceptibility functions and the collective excitations of spin-polarized quantum structures are investigated within the framework of spin-dependent linear response theory. We evaluate the charge response and the longitudinal spin response to a general external disturbance. Exchange-correlation effects between electrons of spin sigma and sigma' are included by using spin-polarization dependent generalized local field factors. Both collective charge-density and spin-density excitations are examined. The present results are compared with the case of a spin-unpolarized system. In contrast to the result for an unpolarized system, the mixing of charge and spin responses results in coupled charge-spin excitations in the spin polarized system.

  19. Three-phase inductive-coupled structures for contactless PHEV charging system

    Science.gov (United States)

    Lee, Jia-You; Shen, Hung-Yu; Li, Cheng-Bin

    2016-07-01

    In this article, a new-type three-phase inductive-coupled structure is proposed for the contactless plug-in hybrid electric vehicle (PHEV) charging system regarding with SAE J-1773. Four possible three-phase core structures are presented and subsequently investigated by the finite element analysis. To study the correlation between the core geometric parameter and the coupling coefficient, the magnetic equivalent circuit model of each structure is also established. In accordance with the simulation results, the low reluctance and the sharing of flux path in the core material are achieved by the proposed inductive-coupled structure with an arc-shape and three-phase symmetrical core material. It results in a compensation of the magnetic flux between each phase and a continuous flow of the output power in the inductive-coupled structure. Higher coupling coefficient between inductive-coupled structures is achieved. A comparison of coupling coefficient, mutual inductance, and self-inductance between theoretical and measured results is also performed to verify the proposed model. A 1 kW laboratory scale prototype of the contactless PHEV charging system with the proposed arc-shape three-phase inductive-coupled structure is implemented and tested. An overall system efficiency of 88% is measured when two series lithium iron phosphate battery packs of 25.6 V/8.4 Ah are charged.

  20. Subterahertz acoustical pumping of electronic charge in a resonant tunneling device.

    Science.gov (United States)

    Young, E S K; Akimov, A V; Henini, M; Eaves, L; Kent, A J

    2012-06-01

    We demonstrate that controlled subnanosecond bursts of electronic charge can be transferred through a resonant tunneling diode by successive picosecond acoustic pulses. The effect exploits the nonlinear current-voltage characteristics of the device and its asymmetric response to the compressive and tensile components of the strain pulse. This acoustoelectronic pump opens new possibilities for the control of quantum phenomena in nanostructures. PMID:23003634

  1. Recent charge-breeding developments with EBIS/T devices (invited)

    Science.gov (United States)

    Schwarz, S.; Lapierre, A.

    2016-02-01

    Short breeding times, narrow charge state distributions, low background, high efficiency, and the flexible time structure of the ejected low-emittance ion pulses are among the most attractive features of electron beam ion source or trap (EBIS/T) based charge breeders. Significant progress has been made to further improve these properties: Several groups are working to increase current densities towards 103 or even 104 A/cm2. These current densities will become necessary to deliver high charge states of heavy nuclei in a short time and/or provide sufficient space-charge capacity to handle high-current ion beams in next-generation rare-isotope beam (RIB) facilities. Efficient capture of continuous beams, attractive because of its potential of handling highest-current ion beams, has become possible with the development of high-density electron beams of >1 A. Requests for the time structure of the charge bred ion pulse range from ultra-short pulses to quasi-continuous beams. Progress is being made on both ends of this spectrum, by either dividing the extracted charge in many pulse-lets, adjusting the extraction potential for a near-uniform long pulse, or adding dedicated devices to spread the ion bunches delivered from the EBIS/T in time. Advances in EBIS/T charge state breeding are summarized, including recent results with NSCL's ReA EBIS/T charge breeder.

  2. Recent charge-breeding developments with EBIS/T devices (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, S., E-mail: schwarz@nscl.msu.edu; Lapierre, A. [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824 (United States)

    2016-02-15

    Short breeding times, narrow charge state distributions, low background, high efficiency, and the flexible time structure of the ejected low-emittance ion pulses are among the most attractive features of electron beam ion source or trap (EBIS/T) based charge breeders. Significant progress has been made to further improve these properties: Several groups are working to increase current densities towards 10{sup 3} or even 10{sup 4} A/cm{sup 2}. These current densities will become necessary to deliver high charge states of heavy nuclei in a short time and/or provide sufficient space-charge capacity to handle high-current ion beams in next-generation rare-isotope beam (RIB) facilities. Efficient capture of continuous beams, attractive because of its potential of handling highest-current ion beams, has become possible with the development of high-density electron beams of >1 A. Requests for the time structure of the charge bred ion pulse range from ultra-short pulses to quasi-continuous beams. Progress is being made on both ends of this spectrum, by either dividing the extracted charge in many pulse-lets, adjusting the extraction potential for a near-uniform long pulse, or adding dedicated devices to spread the ion bunches delivered from the EBIS/T in time. Advances in EBIS/T charge state breeding are summarized, including recent results with NSCL’s ReA EBIS/T charge breeder.

  3. Recent charge-breeding developments with EBIS/T devices (invited)

    International Nuclear Information System (INIS)

    Short breeding times, narrow charge state distributions, low background, high efficiency, and the flexible time structure of the ejected low-emittance ion pulses are among the most attractive features of electron beam ion source or trap (EBIS/T) based charge breeders. Significant progress has been made to further improve these properties: Several groups are working to increase current densities towards 103 or even 104 A/cm2. These current densities will become necessary to deliver high charge states of heavy nuclei in a short time and/or provide sufficient space-charge capacity to handle high-current ion beams in next-generation rare-isotope beam (RIB) facilities. Efficient capture of continuous beams, attractive because of its potential of handling highest-current ion beams, has become possible with the development of high-density electron beams of >1 A. Requests for the time structure of the charge bred ion pulse range from ultra-short pulses to quasi-continuous beams. Progress is being made on both ends of this spectrum, by either dividing the extracted charge in many pulse-lets, adjusting the extraction potential for a near-uniform long pulse, or adding dedicated devices to spread the ion bunches delivered from the EBIS/T in time. Advances in EBIS/T charge state breeding are summarized, including recent results with NSCL’s ReA EBIS/T charge breeder

  4. Proton-Coupled Electron Transfer: Moving Together and Charging Forward.

    Science.gov (United States)

    Hammes-Schiffer, Sharon

    2015-07-22

    Proton-coupled electron transfer (PCET) is ubiquitous throughout chemistry and biology. This Perspective discusses recent advances and current challenges in the field of PCET, with an emphasis on the role of theory and computation. The fundamental theoretical concepts are summarized, and expressions for rate constants and kinetic isotope effects are provided. Computational methods for calculating reduction potentials and pKa's for molecular electrocatalysts, as well as insights into linear correlations and non-innocent ligands, are also described. In addition, computational methods for simulating the nonadiabatic dynamics of photoexcited PCET are discussed. Representative applications to PCET in solution, proteins, electrochemistry, and photoinduced processes are presented, highlighting the interplay between theoretical and experimental studies. The current challenges and suggested future directions are outlined for each type of application, concluding with an overall view to the future. PMID:26110700

  5. The c-axis charge traveling wave in coupled system of Josephson junctions

    OpenAIRE

    Shukrinov, Yu M.; Hamdipour, M.

    2011-01-01

    We demonstrate a manifestation of the charge traveling wave along the c-axis (TW) in current voltage characteristics of coupled Josephson junctions in high-$T_c$ superconductors. The branches related to the TW with different wavelengths are found for the stacks with different number of Josephson junctions at different values of system's parameters. Transitions between the TW branches and the outermost branch are observed. Time dependence of the electric charge in the superconducting layers an...

  6. Charged colloids, polyelectrolytes and biomolecules viewed as strongly coupled Coulomb systems

    CERN Document Server

    Löwen, H; Likos, C N; Blaak, R; Dzubiella, J; Jusufi, A; Hoffmann, N; Harreis, H M

    2003-01-01

    A brief review is given on recent studies of charged soft matter solutions, as modelled by the 'primitive' approach of strongly coupled Coulomb systems, where the solvent just enters as a dielectric background. These include charged colloids, biological macromolecules such as proteins and DNA, polyelectrolytes and polyelectrolyte stars. Also some original results are presented on colloid-polyelectrolyte complex formation near walls and on the anomalous fluid structure of polyelectrolyte stars as a function of increasing concentration.

  7. Dust-Acoustic Waves in Strongly Coupled Dusty Plasmas Containing Variable-Charge Impurities

    Institute of Scientific and Technical Information of China (English)

    XIE Bai-Song; HE Kai-Fen; M. Y. Yu

    2000-01-01

    A relatively self-consistent theory of dust-acoustic waves in the strongly coupled dusty plasmas containing variable charge impurities is given. Relevant physical processes such as dust elastic relaxation and dust charge relaxation are taken into account. It is shown that the negative dispersion of dust-acoustic waves due to the strong correlation of dusts is enhanced in the presence of dust-neutral collisions.

  8. Charged colloids, polyelectrolytes and biomolecules viewed as strongly coupled Coulomb systems

    International Nuclear Information System (INIS)

    A brief review is given on recent studies of charged soft matter solutions, as modelled by the 'primitive' approach of strongly coupled Coulomb systems, where the solvent just enters as a dielectric background. These include charged colloids, biological macromolecules such as proteins and DNA, polyelectrolytes and polyelectrolyte stars. Also some original results are presented on colloid-polyelectrolyte complex formation near walls and on the anomalous fluid structure of polyelectrolyte stars as a function of increasing concentration

  9. Low Exciton-Phonon Coupling, High Charge Carrier Mobilities, and Multiexciton Properties in Two-Dimensional Lead, Silver, Cadmium, and Copper Chalcogenide Nanostructures.

    Science.gov (United States)

    Ding, Yuchen; Singh, Vivek; Goodman, Samuel M; Nagpal, Prashant

    2014-12-18

    The development of two-dimensional (2D) nanomaterials has revealed novel physical properties, like high carrier mobilities and the tunable coupling of charge carriers with phonons, which can enable wide-ranging applications in optoelectronic and thermoelectric devices. While mechanical exfoliation of graphene and some transition metal dichalcogenides (e.g., MoS2, WSe2) has enabled their fabrication as 2D semiconductors and integration into devices, lack of similar syntheses for other 2D semiconductor materials has hindered further progress. Here, we report measurements of fundamental charge carrier interactions and optoelectronic properties of 2D nanomaterials made from two-monolayers-thick PbX, CdX, Cu2X, and Ag2X (X = S, Se) using colloidal syntheses. Extremely low coupling of charge carriers with phonons (2-6-fold lower than bulk and other low-dimensional semiconductors), high carrier mobilities (0.2-1.2 cm(2) V(-1) s(-1), without dielectric screening), observation of infrared surface plasmons in ultrathin 2D semiconductor nanostructures, strong quantum-confinement, and other multiexcitonic properties (different phonon coupling and photon-to-charge collection efficiencies for band-edge and higher-energy excitons) can pave the way for efficient solution-processed devices made from these 2D nanostructured semiconductors. PMID:26273976

  10. Isovector coupling channel and central properties of the charge density distribution in heavy spherical nuclei

    Indian Academy of Sciences (India)

    S Haddad

    2010-09-01

    The influence of the isovector coupling channel on the central depression parameter and the central value of the charge density distribution in heavy spherical nuclei was studied. The isovector coupling channel leads to about 50% increase of the central depression parameter, and weakens the dependency of both central depression parameter and central density on the asymmetry, impressively contributing to the semibubble form of the charge density distribution in heavy nuclei, and increasing the probability of larger nuclei with higher proton numbers and higher neutron-to-proton ratios stable.

  11. Proton-Coupled Electron Transfer: Moving Together and Charging Forward

    Energy Technology Data Exchange (ETDEWEB)

    Hammes-Schiffer, Sharon

    2015-06-25

    Proton-coupled electron transfer (PCET) is ubiquitous throughout chemistry and biology. This Perspective discusses recent advances and current challenges in the field of PCET, with an emphasis on the role of theory and computation. The fundamental theoretical concepts are summarized, and expressions for rate constants and kinetic isotope effects are provided. Computational methods for calculating reduction potentials and pKa’s for molecular electrocatalysts, as well as methods for simulating the nonadiabatic dynamics of photoinduced processes, are also described. Representative applications to PCET in solution, proteins, electrochemistry, and photoinduced processes are presented, highlighting the interplay between theoretical and experimental studies. The current challenges and suggested future directions are outlined for each type of application, concluding with an overall view to the future. The work described herein was supported by National Science Foundation Grant CHE-13-61293 (theory development), National Institutes of Health Grant GM056207 (soybean lipoxygenase), Center for Chemical Innovation of the National Science Foundation Solar Fuels Grant CHE-1305124 (cobalt catalysts), Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (nickel catalysts), and Air Force Office of Scientific Research Award No. FA9550-14-1-0295 (photoinduced PCET).

  12. Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices

    Science.gov (United States)

    Dyakonov, Vladimir

    2013-03-01

    The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the

  13. Plasmon Decay and Thermal Transport from Spin-Charge Coupling in Generic Luttinger Liquids

    Science.gov (United States)

    Levchenko, Alex

    2014-11-01

    We discuss the violation of spin-charge separation in generic nonlinear Luttinger liquids and investigate its effect on the relaxation and thermal transport of genuine spin-1 /2 electron liquids in ballistic quantum wires. We identify basic scattering processes compatible with the symmetry of the problem and conservation laws that lead to the decay of plasmons into the spin modes. We derive a closed set of coupled kinetic equations for the spin-charge excitations and solve the problem of thermal conductance of interacting electrons for an arbitrary relation between the quantum wire length and spin-charge thermalization length.

  14. Effect of interjunction coupling on superconducting current and charge correlations in intrinsic Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Hamdipour, M.; Kolahchi, M. R.

    2009-07-01

    Charge formations on superconducting layers and creation of the longitudinal plasma wave in the stack of intrinsic Josephson junctions change crucially the superconducting current through the stack. Investigation of the correlations of superconducting currents in neighboring Josephson junctions and the charge correlations in neighboring superconducting layers allows us to predict the additional features in the current-voltage characteristics. The charge autocorrelation functions clearly demonstrate the difference between harmonic and chaotic behavior in the breakpoint region. Use of the correlation functions gives us a powerful method for the analysis of the current-voltage characteristics of coupled Josephson junctions.

  15. Generating the Schroedinger cat state in a nanomechanical resonator coupled to a charge qubit

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jian-Qi; Feng, Mang [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan (China); Xiong, Wei [Department of Physics and State of Key Laboratory of Surface Physics, Fudan University, Shanghai (China); Zhang, Shuo [College of Science, National University of Defense Technology, Changsha (China); Li, Yong [Beijing Computational Science Research Center, Beijing (China)

    2015-01-01

    A scheme for generating the Schroedinger cat state based on geometric operations by a nanomechanical resonator coupled to a superconducting charge qubit is proposed. The charge qubit, driven by two strong classical fields, interacts with a high-frequency phonon mode of the nanomechanical resonator. During the operation, the charge qubit undergoes no real transitions, while the phonon mode of the nanomechanical resonator is displaced along different paths in the phase space, dependent on the states of the charge qubit. This generates the entangled cat state between the NAMR and charge qubit, and the NAMR cat state can be achieved after some operations applied on this entangled cat state. The robustness of the scheme is justified by considering noise from environment, and the feasibility of the scheme is discussed. (copyright 2014 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. ReO{sub x} charge injection/blocking layers in organic electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Luo Jiaxiu; Xiao Lixin; Chen Zhijian; Qu Bo; Gong Qihuang, E-mail: xiao66@pku.edu.c, E-mail: qhgong@pku.edu.c [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China)

    2010-09-29

    The charge transport of rhenium oxide (ReO{sub x}) in organic electronic devices was investigated. The hole injection/transport was blocked and the electron injection/transport was enhanced with doping of ReO{sub x} in organic electronic devices. Thus the charge balance and efficiency of organic light-emitting diodes were improved; current efficiency of 2.7 cd A{sup -1} at 20 mA cm{sup -2} for the device with ReO{sub x} was higher than 1.5 cd A{sup -1} for the device without it. In the case of organic photovoltaic cells, the open-circuit voltage (V{sub oc}), 0.58 V, was higher compared with the device without ReO{sub x} (0.44 V) due to the improvement of interface properties. The power conversion efficiency was increased to 2.27% by the combination of ReO{sub x} (increases V{sub oc}) with poly(3,4-ethylenedioxythiophene) : poly(styrene-sulfonate) (improves hole transport to increase J{sub sc}) on the modification of the anode, higher than 1.85% for the device without ReO{sub x}.

  17. InAs quantum dots as charge storing elements for applications in flash memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Sk Masiul; Biswas, Pranab [Materials Science Centre, Indian Institute of Technology, Kharagpur 721 302 (India); Banerji, P., E-mail: pallab@matsc.iitkgp.ernet.in [Materials Science Centre, Indian Institute of Technology, Kharagpur 721 302 (India); Chakraborty, S. [Applied Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Sector-I, Kolkata 700 064 (India)

    2015-08-15

    Graphical abstract: - Highlights: • Catalyst-free growth of InAs quantum dots was carried out on high-k ZrO{sub 2}. • Memory device with InAs quantum dots as charge storage nodes are fabricated. • Superior memory window, low leakage and reasonably good retention were observed. • Carrier transport phenomena are explained in both program and erase operations. - Abstract: InAs quantum dots (QDs) were grown by metal organic chemical vapor deposition technique to use them as charge storage nodes. Uniform QDs were formed with average diameter 5 nm and height 5–10 nm with a density of 2 × 10{sup 11} cm{sup −2}. The QDs were grown on high-k dielectric layer (ZrO{sub 2}), which was deposited onto ultra-thin GaP passivated p-GaAs (1 0 0) substrate. A charge storage device with the structure Metal/ZrO{sub 2}/InAs QDs/ZrO{sub 2}/(GaP)GaAs/Metal was fabricated. The devices containing InAs QDs exhibit superior memory window, low leakage current density along with reasonably good charge retention. A suitable electronic band diagram corresponding to programming and erasing operations was proposed to explain the operation.

  18. Charging of Superconducting Layers and Novel Type of Hysteresis in Coupled Josephson Junctions

    OpenAIRE

    Shukrinov, Yu M.; Gaafar, Ma. A.

    2011-01-01

    A manifestation of a novel type of hysteresis related to the parametric resonance in the system of coupled Josephson junctions is demonstrated. Opposite to McCumber and Steward hysteresis, we find that the width of this hysteresis is inversely proportional to the McCumber parameter and depends also on coupling between junctions and the boundary conditions. An investigation of time dependence of the electric charge in superconducting layers allow us to explain the origin of this hysteresis by ...

  19. Charging effect in Au nanoparticle memory device with biomolecule binding mechanism.

    Science.gov (United States)

    Jung, Sung Mok; Kim, Hyung-Jun; Kim, Bong-Jin; Yoon, Tae-Sik; Kim, Yong-Sang; Lee, Hyun Ho

    2011-07-01

    Organic memory device having gold nanoparticle (Au NPs) has been introduced in the structure of metal-pentacene-insulator-silicon (MPIS) capacitor device, where the Au NPs layer was formed by a new bonding method. Biomolecule binding mechanism between streptavidin and biotin was used as a strong binding method for the formation of monolayered Au NPs on polymeric dielectric of poly vinyl alcohol (PVA). The self-assembled Au NPs was functioned to show storages of charge in the MPIS device. The binding by streptavidin and biotin was confirmed by AFM and UV-VIS. The UV-VIS absorption of the Au NPs was varied at 515 nm and 525 nm depending on the coating of streptavidin. The AFM image showed no formation of multi-stacked layers of the streptavidin-capped Au NPs on biotin-NHS layer. Capacitance-voltage (C-V) performance of the memory device was measured to investigate the charging effect from Au NPs. In addition, charge retention by the Au NPs storage was tested to show 10,000 s in the C-V curve.

  20. Longitudinal Waves in Strongly Coupled Magnetized Dusty Plasma with Dust Charging Relaxation

    Institute of Scientific and Technical Information of China (English)

    谢柏松

    2002-01-01

    Low-frequency longitudinal dust waves in strongly coupled magnetized dusty plasmas are investigated. The dustcharging relaxation is taken into account. It is found that the frequency and damping of dust waves are modifiedsignificantly due to the existence of the magnetic field as well as the effect of dust charging.

  1. Precise Determination of Charge Dependent Pion-Nucleon-Nucleon Coupling Constants

    CERN Document Server

    Perez, R Navarro; Arriola, E Ruiz

    2016-01-01

    We undertake a covariance error analysis of the pion-nucleon-nucleon coupling constants from the Granada-2013 np and pp database comprising a total of 6713 scattering data. Assuming a unique pion-nucleon coupling constant we obtain $f^2=0.0761(3)$. The effects of charge symmetry breaking on the $^3P_0$, $^3P_1$ and $^3P_2$ partial waves are analyzed and we find $f_{p}^2 = 0.0759(4)$, $f_{0}^2 = 0.079(1)$ and $f_{c}^2 = 0.0763(6)$ with minor correlations among the coupling constants. We successfully test normality for the residuals of the fit.

  2. Mercuric iodide (HgI2) semiconductor devices as charged-particle detectors

    International Nuclear Information System (INIS)

    The properties of HgI2 semiconductor devices as charged particle detectors have been investigated. Nearly linear energy response with FWHM resolution of 5 to 15% is observed for 12H and 34He ions, E 1010 protons/cm2. However, based on measurements with two HgI2 detectors, little fast neutron damage is apparent at fluences up to 1015 neutrons/cm2. This suggests considerably greater resistance to radiation damage than is observed for Si and other solid state devices

  3. Persistent Spin and Charge Currents in Open Conducting Ring Subjected to Rashba Spin-Orbit Coupling

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xi-Sua; XIONG Shi-Jie

    2008-01-01

    We investigate persistent charge and spin currents of a one-dimensional ring with Rashba spin-orbit coupling and connected asymmetrically to two external leads spanned with angle (φ)0.Because of the asymmetry of the structure and the spin-reflection,the persistent charge and spin currents can be induced.The magnification of persistent currents can be obtained when tuning the energy of incident electron to the sharp zero and sharp resonance of transmission depending on the Aharonov-Casher (AC) phase due to the spin-orbit coupling and the angle spanned by two leads (φ)0.The general dependence of the charge and spin persistent currents on these parameters is obtained.This suggests a possible method of controlling the magnitude and direction of persistent currents by tuning the AC phase and (φ)0,without the electromagnetic flux though the ring.

  4. Charge creation and nucleation of the longitudinal plasma wave in coupled Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Hamdipour, M.

    2010-11-01

    We study the phase dynamics in coupled Josephson junctions described by a system of nonlinear differential equations. Results of detailed numerical simulations of charge creation in the superconducting layers and the longitudinal plasma wave (LPW) nucleation are presented. We demonstrate the different time stages in the development of the LPW and present the results of FFT analysis at different values of bias current. The correspondence between the breakpoint position on the outermost branch of current voltage characteristics (CVC) and the growing region in time dependence of the electric charge in the superconducting layer is established. The effects of noise in the bias current and the external microwave radiation on the charge dynamics of the coupled Josephson junctions are found. These effects introduce a way to regulate the process of LPW nucleation in the stack of IJJ.

  5. Thin silicon layer SOI power device with linearly-distance fixed charge islands

    International Nuclear Information System (INIS)

    A new high-voltage LDMOS with linearly-distanced fixed charge islands is proposed (LFI LDMOS). A lot of linearly-distanced fixed charge islands are introduced by implanting the Cs or I ion into the buried oxide layer and dynamic holes are attracted and accumulated, which is crucial to enhance the electric field of the buried oxide and the vertical breakdown voltage. The surface electric field is improved by increasing the distance between two adjacent fixed charge islands from source to drain, which lead to the higher concentration of the drift region and a lower on-resistance. The numerical results indicate that the breakdown voltage of 500 V with Ld = 45 μm is obtained in the proposed device in comparison to 209 V of conventional LDMOS, while maintaining low on-resistance. (paper)

  6. Charged cosmological dust solutions of the coupled Einstein and Maxwell equations

    CERN Document Server

    Spruck, Joel

    2010-01-01

    It is well known through the work of Majumdar, Papapetrou, Hartle, and Hawking that the coupled Einstein and Maxwell equations admit a static multiple blackhole solution representing a balanced equilibrium state of finitely many point charges. This is a result of the exact cancellation of gravitational attraction and electric repulsion under an explicit condition on the mass and charge ratio. The resulting system of particles, known as an extremely charged dust, gives rise to examples of spacetimes with naked singularities. In this paper, we consider the continuous limit of the Majumdar--Papapetrou--Hartle--Hawking solution modeling a space occupied by an extended distribution of extremely charged dust. We show that for a given smooth distribution of matter of finite ADM mass there is a continuous family of smooth solutions realizing asymptotically flat space metrics.

  7. Charged Rotating AdS Black Holes with Chern-Simons coupling

    CERN Document Server

    Mir, Mozhgan

    2016-01-01

    We obtain a perturbative solution for rotating charged black holes in 5-dimensional Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant. We start from a small undeformed Kerr-AdS solution and use the electric charge as a perturbative parameter to build up black holes with equal-magnitude angular momenta up to forth order. These black hole solutions are described by three parameters, the charge, horizon radius and horizon angular velocity. We determine the physical quantities of these black holes and study their dependence on the parameters of black holes and arbitrary Chern-Simons coefficient. In particular, for values of CS coupling constant beyond its supergravity amount, due to a rotational instability, counterrotating black holes arise. Also the rotating solutions appear to have vanishing angular momenta and do not manifest uniquely by their global charges.

  8. Strong coupling electrostatics for randomly charged surfaces: antifragility and effective interactions.

    Science.gov (United States)

    Ghodrat, Malihe; Naji, Ali; Komaie-Moghaddam, Haniyeh; Podgornik, Rudolf

    2015-05-01

    We study the effective interaction mediated by strongly coupled Coulomb fluids between dielectric surfaces carrying quenched, random monopolar charges with equal mean and variance, both when the Coulomb fluid consists only of mobile multivalent counterions and when it consists of an asymmetric ionic mixture containing multivalent and monovalent (salt) ions in equilibrium with an aqueous bulk reservoir. We analyze the consequences that follow from the interplay between surface charge disorder, dielectric and salt image effects, and the strong electrostatic coupling that results from multivalent counterions on the distribution of these ions and the effective interaction pressure they mediate between the surfaces. In a dielectrically homogeneous system, we show that the multivalent counterions are attracted towards the surfaces with a singular, disorder-induced potential that diverges logarithmically on approach to the surfaces, creating a singular but integrable counterion density profile that exhibits an algebraic divergence at the surfaces with an exponent that depends on the surface charge (disorder) variance. This effect drives the system towards a state of lower thermal 'disorder', one that can be described by a renormalized temperature, exhibiting thus a remarkable antifragility. In the presence of an interfacial dielectric discontinuity, the singular behavior of counterion density at the surfaces is removed but multivalent counterions are still accumulated much more strongly close to randomly charged surfaces as compared with uniformly charged ones. The interaction pressure acting on the surfaces displays in general a highly non-monotonic behavior as a function of the inter-surface separation with a prominent regime of attraction at small to intermediate separations. This attraction is caused directly by the combined effects from charge disorder and strong coupling electrostatics of multivalent counterions, which dominate the surface-surface repulsion due to

  9. Performance of a compact position-sensitive photon counting detector with image charge coupling to an air-side anode

    Science.gov (United States)

    Jagutzki, O.; Czasch, A.; Schössler, S.

    2013-05-01

    We discuss a novel micro-channel plate (MCP) photomultiplier with resistive screen (RS-PMT) as a detection device for space- and time-correlated single photon counting, illustrated by several applications. The photomultiplier tube resembles a standard image intensifier device. However, the rear phosphor screen is replaced by a ceramic "window" with resistive coating. The MCP output is transferred through the ceramic plate to the read-out electrode (on the air side) via capacity-coupling of the image charge. This design allows for an easy reconfiguration of the read-out electrode (e.g. pixel, charge-sharing, cross-strip, delay-line) without breaking the vacuum for optimizing the detector performance towards a certain task. It also eases the design and manufacturing process of such a multi-purpose photomultiplier tube. Temporal and spatial resolutions well below 100 ps and 100 microns, respectively, have been reported at event rates as high as 1 MHz, for up to 40 mm effective detection diameter. In this paper we will discuss several applications like wide-field fluorescence microscopy and dual γ/fast-neutron radiography for air cargo screening and conclude with an outlook on large-area detectors for thermal neutrons based on MCPs.

  10. Organic photovoltaic devices with concurrent solar energy harvesting and charge storage capability

    Science.gov (United States)

    Takshi, Arash; Tevi, Tete; Rahimi, Fatemeh

    2015-09-01

    Due to large variation of the solar energy availability in a day, energy storage is required in many applications when solar cells are used. However, application of external energy storage devices, such as batteries and supercapacitors, increases the cost of solar energy systems and requires additional charging circuitry. This combination is bulky and relatively expensive, which is not ideal for many applications. In this work, a novel idea is presented for making electrochemical devices with dual properties of solar energy harvesting and internal charge storage. The device is essentially a supercapacitor with a photoactive electrode. Energy harvesting occurs through light absorption at one of the electrodes made of a composite of a conducting polymer (i.e. PEDOT:PSS) and a Porphyrin dye. The energy storage takes place in the both photoactive and counter electrode (CE). We have studied the effect of the CE material on the device characteristics. Using Y-Carbon (a commercial available electrode), an open circuit voltage of 0.49 V was achieved in light across the cell with ~1 mF capacitance. The other two choices for CE were activated carbon and carbon nanotube based electrodes. The cyclic voltammetry and impedance spectroscopy demonstrated that the Y Carbon electrode was a better match.

  11. Mismatch of dielectric constants at the interface of nanometer metal-oxide-semiconductor devices with high- gate dielectric impacts on the inversion charge density

    Indian Academy of Sciences (India)

    Ling-Feng Mao

    2011-04-01

    The comparison of the inversion electron density between a nanometer metal-oxidesemiconductor (MOS) device with high- gate dielectric and a SiO2 MOS device with the same equivalent oxide thickness has been discussed. A fully self-consistent solution of the coupled Schrödinger–Poisson equations demonstrates that a larger dielectric-constant mismatch between the gate dielectric and silicon substrate can reduce electron density in the channel of a MOS device under inversion bias. Such a reduction in inversion electron density of the channel will increase with increase in gate voltage. A reduction in the charge density implies a reduction in the inversion electron density in the channel of a MOS device. It also implies that a larger dielectric constant of the gate dielectric might result in a reduction in the source–drain current and the gate leakage current.

  12. Integration of a waveguide self-electrooptic effect device and a vertically coupled interconnect waveguide

    Science.gov (United States)

    Vawter, G. Allen

    2008-02-26

    A self-electrooptic effect device ("SEED") is integrated with waveguide interconnects through the use of vertical directional couplers. Light initially propagating in the interconnect waveguide is vertically coupled to the active waveguide layer of the SEED and, if the SEED is in the transparent state, the light is coupled back to the interconnect waveguide.

  13. Battery Coupling Impact on the Antenna Efficiency in a Small Wearable Device

    DEFF Research Database (Denmark)

    Ruaro, Andrea; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2015-01-01

    Wearable electronics is often challenged by the extremely reduced space available to the antenna design. This study assesses the impact that the coupling to a large battery has on a small antenna for wearable devices. The coupling mechanism and its potential risks for the Electromagnetic...

  14. Electronic-vibrational coupling in single-molecule devices

    OpenAIRE

    Aji, Vivek; Moore, J. E.; Varma, C. M.

    2003-01-01

    Experiments studying vibrational effects on electronic transport through single molecules have observed several seemingly inconsistent behaviors, ranging from up to 30 harmonics of a vibrational frequency in one experiment, to an absence of higher-harmonic peaks in another. We study the different manifestations of electronic-vibrational coupling in inelastic and elastic electron transport through single molecules. For the case of inelastic transport, higher harmonics are shown to be damped by...

  15. Spectral and structural stability properties of charged particle dynamics in coupled lattices

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Hong [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Chung, Moses [Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Davidson, Ronald C.; Burby, Joshua W. [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

    2015-05-15

    It has been realized in recent years that coupled focusing lattices in accelerators and storage rings have significant advantages over conventional uncoupled focusing lattices, especially for high-intensity charged particle beams. A theoretical framework and associated tools for analyzing the spectral and structural stability properties of coupled lattices are formulated in this paper, based on the recently developed generalized Courant-Snyder theory for coupled lattices. It is shown that for periodic coupled lattices that are spectrally and structurally stable, the matrix envelope equation must admit matched solutions. Using the technique of normal form and pre-Iwasawa decomposition, a new method is developed to replace the (inefficient) shooting method for finding matched solutions for the matrix envelope equation. Stability properties of a continuously rotating quadrupole lattice are investigated. The Krein collision process for destabilization of the lattice is demonstrated.

  16. Spectral and structural stability properties of charged particle dynamics in coupled lattices

    CERN Document Server

    Qin, Hong; Davidson, Ronald C; Burby, J W

    2015-01-01

    It has been realized in recent years that coupled focusing lattices in accelerators and storage rings have significant advantages over conventional uncoupled focusing lattices, especially for high-intensity charged particle beams. A theoretical framework and associated tools for analyzing the spectral and structural stability properties of coupled lattices are formulated in this paper, based on the recently developed generalized Courant-Snyder theory for coupled lattices. It is shown that for periodic coupled lattices that are spectrally and structurally stable, the matrix envelope equation must admit matched solutions. Using the technique of normal form and pre-Iwasawa decomposition, a new method is developed to replace the (inefficient) shooting method for finding matched solutions for the matrix envelope equation. Stability properties of a continuously rotating quadrupole lattice are investigated. The Krein collision process for destabilization of the lattice is demonstrated.

  17. Electroelastic coupling between membrane surface fluctuations and membrane-embedded charges: Continuum multidielectric treatment

    International Nuclear Information System (INIS)

    The coupling of electric fields and charges with membrane-water interfacial fluctuations affects membrane electroporation, ionic conductance, and voltage gating. A modified continuum model is introduced to study charge interaction with membrane-water interfacial fluctuations in multidielectric environments. By surrounding a point charge with a low dielectric sphere, the linear Poisson–Boltzmann equation is directly solved by calculating the reaction field potential via a method that eliminates singularity contributions. This allows treatment of charges located at dielectric boundaries. Two complementary mechanisms governing charge-fluctuation interactions are considered: (1) electroelastic deformation (EED), treating the membrane as an elastic slab (smectic bilayer model), and (2) electrohydrophobic solvation (EHS), accounting for water penetration into the membrane’s hydrophobic core. EED often leads to large membrane thickness perturbations, far larger than those consistent with elastic model descriptions [M. B. Partenskii, G. V. Miloshevsky, and P. C. Jordan, Isr. J. Chem. 47, 385 (2007)]. We argue that a switch from EED to EHS can be energetically advantageous at intermediate perturbation amplitudes. Both perturbation mechanisms are simulated by introducing adjustable shapes optimized by the kinetic Monte Carlo reaction path following approach [G. V. Miloshevsky and P. C. Jordan, J. Chem. Phys. 122, 214901 (2005)]. The resulting energy profiles agree with those of recent atomistic molecular dynamics studies on translating a charged residue across a lipid bilayer [S. Dorairaj and T. W. Allen, Proc. Natl. Acad. Sci. U.S.A. 104, 4943 (2007)

  18. Electroelastic coupling between membrane surface fluctuations and membrane-embedded charges: Continuum multidielectric treatment

    Science.gov (United States)

    Miloshevsky, Gennady V.; Hassanein, Ahmed; Partenskii, Michael B.; Jordan, Peter C.

    2010-06-01

    The coupling of electric fields and charges with membrane-water interfacial fluctuations affects membrane electroporation, ionic conductance, and voltage gating. A modified continuum model is introduced to study charge interaction with membrane-water interfacial fluctuations in multidielectric environments. By surrounding a point charge with a low dielectric sphere, the linear Poisson-Boltzmann equation is directly solved by calculating the reaction field potential via a method that eliminates singularity contributions. This allows treatment of charges located at dielectric boundaries. Two complementary mechanisms governing charge-fluctuation interactions are considered: (1) electroelastic deformation (EED), treating the membrane as an elastic slab (smectic bilayer model), and (2) electrohydrophobic solvation (EHS), accounting for water penetration into the membrane's hydrophobic core. EED often leads to large membrane thickness perturbations, far larger than those consistent with elastic model descriptions [M. B. Partenskii, G. V. Miloshevsky, and P. C. Jordan, Isr. J. Chem. 47, 385 (2007)]. We argue that a switch from EED to EHS can be energetically advantageous at intermediate perturbation amplitudes. Both perturbation mechanisms are simulated by introducing adjustable shapes optimized by the kinetic Monte Carlo reaction path following approach [G. V. Miloshevsky and P. C. Jordan, J. Chem. Phys. 122, 214901 (2005)]. The resulting energy profiles agree with those of recent atomistic molecular dynamics studies on translating a charged residue across a lipid bilayer [S. Dorairaj and T. W. Allen, Proc. Natl. Acad. Sci. U.S.A. 104, 4943 (2007)].

  19. Electroelastic coupling between membrane surface fluctuations and membrane-embedded charges: Continuum multidielectric treatment

    Energy Technology Data Exchange (ETDEWEB)

    Miloshevsky, Gennady V., E-mail: gennady@purdue.edu; Hassanein, Ahmed, E-mail: hassanein@purdue.edu [School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Partenskii, Michael B., E-mail: partensky@gmail.com; Jordan, Peter C., E-mail: jordan@brandeis.edu [Department of Chemistry, MS-015, Brandeis University, P.O. Box 549110, Waltham, Massachusetts 02454-9110 (United States)

    2010-06-21

    The coupling of electric fields and charges with membrane-water interfacial fluctuations affects membrane electroporation, ionic conductance, and voltage gating. A modified continuum model is introduced to study charge interaction with membrane-water interfacial fluctuations in multidielectric environments. By surrounding a point charge with a low dielectric sphere, the linear Poisson–Boltzmann equation is directly solved by calculating the reaction field potential via a method that eliminates singularity contributions. This allows treatment of charges located at dielectric boundaries. Two complementary mechanisms governing charge-fluctuation interactions are considered: (1) electroelastic deformation (EED), treating the membrane as an elastic slab (smectic bilayer model), and (2) electrohydrophobic solvation (EHS), accounting for water penetration into the membrane’s hydrophobic core. EED often leads to large membrane thickness perturbations, far larger than those consistent with elastic model descriptions [M. B. Partenskii, G. V. Miloshevsky, and P. C. Jordan, Isr. J. Chem. 47, 385 (2007)]. We argue that a switch from EED to EHS can be energetically advantageous at intermediate perturbation amplitudes. Both perturbation mechanisms are simulated by introducing adjustable shapes optimized by the kinetic Monte Carlo reaction path following approach [G. V. Miloshevsky and P. C. Jordan, J. Chem. Phys. 122, 214901 (2005)]. The resulting energy profiles agree with those of recent atomistic molecular dynamics studies on translating a charged residue across a lipid bilayer [S. Dorairaj and T. W. Allen, Proc. Natl. Acad. Sci. U.S.A. 104, 4943 (2007)].

  20. Efficient single-mode photon-coupling device utilizing a nanofiber tip.

    Science.gov (United States)

    Chonan, Sho; Kato, Shinya; Aoki, Takao

    2014-04-24

    Single-photon sources are important elements in quantum optics and quantum information science. It is crucial that such sources be able to couple photons emitted from a single quantum emitter to a single propagating mode, preferably to the guided mode of a single-mode optical fiber, with high efficiency. Various photonic devices have been successfully demonstrated to efficiently couple photons from an emitter to a single mode of a cavity or a waveguide. However, efficient coupling of these devices to optical fibers is sometimes challenging. Here we show that up to 38% of photons from an emitter can be directly coupled to a single-mode optical fiber by utilizing the flat tip of a silica nanofiber. With the aid of a metallic mirror, the efficiency can be increased to 76%. The use of a silicon waveguide further increases the efficiency to 87%. This simple device can be applied to various quantum emitters.

  1. Securing Kiosk using Mobile Devices coupled with Visual Inspection

    CERN Document Server

    Fang, Chengfang

    2010-01-01

    A kiosk is an unsecured network terminal that a user can conveniently connect to a server over public network. There are many methods proposed to secure the kiosk, but many do not achieve high level of security, or require additional resources that are infeasible in practical scenarios. An exception is a known method seeing-is-believing which establishes a communication channel from the kiosk's display unit to a trusted mobile device's camera, and thus able to carry out server authentication via the kiosk. However, it is not clear how subsequence browsing and interactions can be carried out seamlessly and securely. In this paper, we take a human-centric approach and propose a method of subregion authentication. Essentially, under this method, a screenshot consists of a few blocks of seemingly random images but with visual cues displayed in the blocks. The user can decrypt and verify each individual block by "inspecting" it using the mobile device's camera, and can visually verify the overall blocks' arrangeme...

  2. Complementary charge islands structure for a high voltage device of partial-SOI*

    Institute of Scientific and Technical Information of China (English)

    Wu Lijuan; Hu Shengdong; Zhang Bo; Li Zhaoji

    2011-01-01

    A new partial-SOI (PSOI) high voltage device structure named CNCI PSOI (complementary n+-charge islands PSOI) is proposed. CNCI PSOI is characterized by equidistant high concentration n+-regions on the top and bottom interfaces of a dielectric buried layer of a PSOI device. When a high voltage is applied to the device, complementary holes and electron islands are formed on the two n+-regions on the top and bottom interfaces, therefore effectively enhancing the electric field of the dielectric buried layer (EI) and increasing the breakdown voltage (BV), alleviating the self-heating effect (SHE) by the silicon window under the source. An analytical model of the vertical interface electric field for the CNCI PSOI is presented and the analytical results are in good agreement with the 2D simulation results. BV and E1 of the CNCI PSOI LDMOS increase to 591 V and 512 V/μm from 216 V and 81.4 V/μm of the conventional PSOI with a lower SHE, respectively. The influence of structure parameters on the device characteristics is analyzed for the proposed device in detail.

  3. Specific Heat and Charge Density of Quasi-One-Dimensional Interchain Coupling Organic Ferromagnets

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-Long; YAO Kai-Lun

    2008-01-01

    On the basis of a generalized SSH model, an organic polymer ferromagnet theory is proposed at the finite temperature in the self-consistent mean field approximation, and the specific heat and charge density of the quasi-one-dimensional interchain coupling organic ferromagnets are presented. We find that an obvious feature is to present itself the round peak for the specific heat with the temperature. This indicates unambiguously the presence of the phase transition in the system. The transition temperature plays down with increasing of the interchain coupling t2 or decreasing of the electron repulsion u. The curves of charge density with the temperature debase monotonously. This result illustrates that the higher the temperature is, the more electrons are excited.

  4. Strong coupling critique of spin fluctuation driven charge order in underdoped cuprates

    Science.gov (United States)

    Mishra, Vivek; Norman, M. R.

    2015-08-01

    Charge order has emerged as a generic feature of doped cuprates, leading to important questions about its origin and its relation to superconductivity. Recent experiments on two classes of hole doped cuprates indicate a novel d -wave symmetry for the order. These were motivated by earlier spin fluctuation theoretical studies based on an expansion about hot spots in the Brillouin zone that indicated such an order would be competitive with d -wave superconductivity. Here, we reexamine this problem by solving strong coupling equations in the full Brillouin zone for experimentally relevant parameters. We find that bond-oriented order, as seen experimentally, is strongly suppressed. We also include coupling to B1 g phonons and do not see any qualitative change. Our results argue against an itinerant model for the charge order, implying instead that such order is likely due to Coulombic phase separation of the doped holes.

  5. Spin Polarized Photons from Axially Charged Plasma at Weak Coupling: Complete Leading Order

    CERN Document Server

    Mamo, Kiminad A

    2015-01-01

    In the presence of (approximately conserved) axial charge in the QCD plasma at finite temperature, the emitted photons are spin-aligned, which is a unique P- and CP-odd signature of axial charge in the photon emission observables. We compute this "P-odd photon emission rate" in weak coupling regime at high temperature limit to complete leading order in the QCD coupling constant: the leading log as well as the constant under the log. As in the P-even total emission rate in the literature, the computation of P-odd emission rate at leading order consists of three parts: 1) Compton and Pair Annihilation processes with hard momentum exchange, 2) soft t- and u-channel contributions with Hard Thermal Loop re-summation, 3) Landau-Pomeranchuk-Migdal (LPM) re-summation of collinear Bremstrahlung and Pair Annihilation. We present analytical and numerical evaluations of these contributions to our P-odd photon emission rate observable.

  6. Excited-state proton coupled charge transfer modulated by molecular structure and media polarization.

    Science.gov (United States)

    Demchenko, Alexander P; Tang, Kuo-Chun; Chou, Pi-Tai

    2013-02-01

    Charge and proton transfer reactions in the excited states of organic dyes can be coupled in many different ways. Despite the complementarity of charges, they can occur on different time scales and in different directions of the molecular framework. In certain cases, excited-state equilibrium can be established between the charge-transfer and proton-transfer species. The interplay of these reactions can be modulated and even reversed by variations in dye molecular structures and changes of the surrounding media. With knowledge of the mechanisms of these processes, desired rates and directions can be achieved, and thus the multiple emission spectral features can be harnessed. These features have found versatile applications in a number of cutting-edge technological areas, particularly in fluorescence sensing and imaging.

  7. Charge creation and nucleation of longitudinal plasma wave in coupled Josephson junctions

    OpenAIRE

    Shukrinov, Yu M.; Hamdipour, M.

    2009-01-01

    We study the phase dynamics in coupled Josephson junctions describing by system of nonlinear differential equations. Results of detailed numerical simulations of charge creation in the superconducting layers and the longitudinal plasma wave (LPW) nucleation are presented. We demonstrate the different time stages in the development of the LPW and present results of FFT analysis at different values of bias current. The correspondence between the breakpoint position on the outermost branch of cu...

  8. ACCELERATORS: Emittance coupling driven by space charge in the CSNS linac

    Science.gov (United States)

    Yin, Xue-Jun; Fu, Shi-Nian; Peng, Jun

    2009-09-01

    In the conventional design of RF linacs, the bunched beams are not in thermal equilibrium. The space charge forces couple the particle motions between the transverse and the longitudinal directions. Furthermore it will cause the equipartitioning process which leads to emittance growth and halo formation. In the design of the China Spallation Neutron Source (CSNS) linac, three cases are investigated using the Hofmann stability charts. In this paper, we present the equipartitioning beam study of the CSNS Alvarez DTL linac.

  9. Charge Behaviors around Oxide Device/Pseudo-Physiological Solution Interface with Molecular Dynamic Simulations

    Science.gov (United States)

    Maekawa, Yuki; Shibuta, Yasushi; Sakata, Toshiya

    2013-12-01

    In this study, we investigated the charge behaviors of ions and water molecules at the oxide device/pseudo-physiological solution interface by use of molecular dynamics (MD) simulations because the detection principle of semiconductor-based biosensors is based on the detection of charge density changes at the oxide sensing surface in physiological environments. In particular, we designed an alpha-quartz (100) surface with some charges corresponding to pH=5.5 so that the ionic behaviors for 500 mM each of Na+ and Cl- around the interface were calculated under the surface condition with charges, considering a real system. As a result of the simulation, we defined the region of Debye length from the calculated potential distribution, in which some parameters such as diffusion coefficient and the vibration of water molecules around the interface differed from those of the bulk solution. The elucidation of the solid/liquid interfacial behaviors by the simulation technique should deepen our understanding of the detection principle of semiconductor-based biosensors and will give guidelines for the design of a bio-interface in the field of biosensing technology, because they cannot be demonstrated experimentally.

  10. A flux-coupled ac/dc magnetizing device.

    Science.gov (United States)

    Gopman, D B; Liu, H; Kent, A D

    2013-06-01

    We report on an instrument for applying ac and dc magnetic fields by capturing the flux from a rotating permanent magnet and projecting it between two adjustable pole pieces. This can be an alternative to standard electromagnets for experiments with small samples or in probe stations in which an applied magnetic field is needed locally, with advantages that include a compact form-factor, very low power requirements and dissipation as well as fast field sweep rates. This flux capture instrument (FLUXCAP) can produce fields from -400 to +400 mT, with field resolution less than 1 mT. It generates static magnetic fields as well as ramped fields, with ramping rates as high as 10 T/s. We demonstrate the use of this apparatus for studying the magnetotransport properties of spin-valve nanopillars, a nanoscale device that exhibits giant magnetoresistance. PMID:23822372

  11. FLUXCAP: A flux-coupled ac/dc magnetizing device

    CERN Document Server

    Gopman, Daniel B; Kent, Andrew D

    2012-01-01

    We report on an instrument for applying ac and dc magnetic fields by capturing the flux from a rotating permanent magnet and projecting it between two adjustable pole pieces. This can be an alternative to standard electromagnets for experiments with small samples or in probe stations in which an applied magnetic field is needed locally, with advantages that include a compact form-factor, very low power requirements and dissipation as well as fast field sweep rates. This flux capture instrument (FLUXCAP) can produce fields from -400 to +400 mT, with field resolution less than 1 mT. It generates static magnetic fields as well as ramped fields, with ramping rates as high as 10 T/s. We demonstrate the use of this apparatus for studying the magnetotransport properties of spin-valve nanopillars, a nanoscale device that exhibits giant magnetoresistance.

  12. Observation of visible forbidden lines from highly charged tungsten ions at the large helical device

    Science.gov (United States)

    Kato, D.; Goto, M.; Morita, S.; Murakami, I.; Sakaue, H. A.; Ding, X. B.; Sudo, S.; Suzuki, C.; Tamura, N.; Nakamura, N.; Watanabe, H.; Koike, F.

    2013-09-01

    Visible line emission from highly charged tungsten ions has been observed at the large helical device (LHD) using a tracer encapsulated solid pellet. One of the measured lines is assigned to a magnetic-dipole (M1) line of the ground-term fine-structure transition of W26+. The other line is unidentified but probably due to a highly charged tungsten ion. Photon emission was observed at 40 lines of sight divided along the vertical direction of a horizontally elongated poloidal cross section of the LHD plasma. The line-integrated intensity of the M1 line along each line of sight indicates a peaked profile at the plasma center where the electron temperatures are high enough so that tungsten ions are highly ionized.

  13. Enhanced out-coupling factor of microcavity organic light-emitting devices with irregular microlens array

    Science.gov (United States)

    Lim, Jongsun; Oh, Seung Seok; Youp Kim, Doo; Cho, Sang Hee; Kim, In Tae; Han, S. H.; Takezoe, Hideo; Choi, Eun Ha; Cho, Guang Sup; Seo, Yoon Ho; Oun Kang, Seung; Park, Byoungchoo

    2006-07-01

    We studied microcavity organic light-emitting devices with a microlens system. A microcavity for organic light-emitting devices (OLED) was fabricated by stacks of SiO2 and SiNx layers and a metal cathode together with the microlens array. Electroluminescence of the devices showed that color variation under the viewing angle due to the microcavity is suppressed remarkably by microlens arrays, which makes the use of devices acceptable in many applications. It was also demonstrated that the external out-coupling factor of the devise increases by a factor of ~1.8 with wide viewing angles compared to conventional OLEDs.

  14. Study and Test of Cold Storage Heat Recovery Heat Pump Coupled Solar Drying Device

    Directory of Open Access Journals (Sweden)

    Min Li

    2013-05-01

    Full Text Available In this study, we design the recovery of a heat pump combined solar drying device. Then, with this device, drying experiments of aquatic product, tilapia, were conducted, indicating that the newly designed device functions are well in temperature adjusting and controlling performance and showing that drying time is closely related to energy consumption and drying conditions. Heat recovery heat pump combined solar energy drier can improve the drying quality of aquatic products, but also can greatly reduce the drying energy consumption, which provides theoretical support to the design and processing of heat recovery heat pump of refrigeration system coupled solar drying device.

  15. Charge generation layers for solution processed tandem organic light emitting diodes with regular device architecture.

    Science.gov (United States)

    Höfle, Stefan; Bernhard, Christoph; Bruns, Michael; Kübel, Christian; Scherer, Torsten; Lemmer, Uli; Colsmann, Alexander

    2015-04-22

    Tandem organic light emitting diodes (OLEDs) utilizing fluorescent polymers in both sub-OLEDs and a regular device architecture were fabricated from solution, and their structure and performance characterized. The charge carrier generation layer comprised a zinc oxide layer, modified by a polyethylenimine interface dipole, for electron injection and either MoO3, WO3, or VOx for hole injection into the adjacent sub-OLEDs. ToF-SIMS investigations and STEM-EDX mapping verified the distinct functional layers throughout the layer stack. At a given device current density, the current efficiencies of both sub-OLEDs add up to a maximum of 25 cd/A, indicating a properly working tandem OLED.

  16. Trapping and Driving Individual Charged Micro-particles in Fluid with an Electrostatic Device

    Institute of Scientific and Technical Information of China (English)

    Jingjing Xu; Zijing Lei; Jingkun Guo; Jie Huang; Wei Wang; Uta Reibetanz; Shengyong Xu

    2016-01-01

    A variety of micro-tweezers techniques, such as optical tweezers, magnetic tweezers, and dielectrophoresis technique, have been applied intensively in precise characterization of micro/nanoparticles and bio-molecules. They have contributed remarkably in better understanding of working mechanisms of individual sub-cell organelles, proteins, and DNA. In this paper, we present a controllable electrostatic device embedded in a microchannel, which is capable of driving, trapping, and releasing charged micro-particles suspended in microfluid, demonstrating the basic concepts of electrostatic tweezers. Such a device is scalable to smaller size and offers an alternative to currently used micro-tweezers for application in sorting, selecting, manipulating, and analyzing individual micro/nanoparticles. Furthermore, the system offers the potential in being combined with dielectrophoresis and other techniques to create hybrid micro-manipulation systems.

  17. NUT-charged black holes in matter-coupled N=2, D=4 gauged supergravity

    Science.gov (United States)

    Colleoni, Marta; Klemm, Dietmar

    2012-06-01

    Using the results of Cacciatori, Klemm, Mansi, and Zorzan [J. High Energy Phys.JHEPFG1029-8479 05 (2008) 09710.1088/1126-6708/2008/05/097], where all timelike supersymmetric backgrounds of N=2, D=4 matter-coupled supergravity with Fayet-Iliopoulos gauging were classified, we construct genuine NUT-charged BPS black holes in anti-deSitter4 with nonconstant moduli. The calculations are exemplified for the SU(1,1)/U(1) model with prepotential F=-iX0X1. The resulting supersymmetric black holes have a hyperbolic horizon and carry two electric, two magnetic, and one NUT charge, which are however not all independent, but are given in terms of three free parameters. We find that turning on a NUT charge lifts the flat directions in the effective black hole potential, such that the horizon values of the scalars are completely fixed by the charges. We also oxidize the solutions to 11 dimensions, and find that they generalize the geometry found in the work of Gauntlett, Kim, Pakis, and Waldram [Phys. Rev. DPRVDAQ0556-2821 65, 026003 (2001)10.1103/PhysRevD.65.026003] corresponding to membranes wrapping holomorphic curves in a Calabi-Yau fivefold. Finally, a class of NUT-charged Nernst branes is constructed as well, but these have curvature singularities at the horizon.

  18. Electrical models of excitation-contraction coupling and charge movement in skeletal muscle.

    Science.gov (United States)

    Mathias, R T; Levis, R A; Eisenberg, R S

    1980-07-01

    The consequences of ionic current flow from the T system to the sarcoplasmic reticulum (SR) of skeletal muscle are examined. The Appendix analyzes a simple model in which the conductance gx, linking T system and SR, is in series with a parallel resistor and capacitor having fixed values. The conductance gx is supposed to increase rapidly with depolarization and to decrease slowly with repolarization. Nonlinear transient currents computed from this model have some of the properties of gating currents produced by intramembrane charge movement. In particular, the integral of the transient current upon depolarization approximates that upon repolarization. Thus, equality of nonlinear charge movement can occur without intramembrane charge movement. A more complicated model is used in the text to fit the structure of skeletal muscle and other properties of its charge movement. Rectification is introduced into gx and the membrane conductance of the terminal cisternae to give asymmetry in the time-course of the transient currents and saturation in the curve relating charge movement to depolarization, respectively. The more complex model fits experimental data quite well if the longitudinal tubules of the sarcoplasmic reticulum are isolated from the terminal cisternae by a substantial resistance and if calcium release from the terminal cisternae is, for the most part, electrically silent. Specific experimental tests of the model are proposed, and the implications for excitation-contraction coupling are discussed.

  19. Ultrasonic testing device for pipes with an acoustic coupling liquid

    International Nuclear Information System (INIS)

    System for the ultrasonic testing of tubes comprising: a probe consisting of an ultrasonic transducer integral with a mirror receiving the ultrasonic wave emitted by the transducer and centred according to the axis of the probe, a mechanism to move the probe inside the tube under inspection, facilities for detecting ultrasonic echoes returned by the tube. It also features facilities for introducing an acoustic coupling liquid in the capacity included between the tube, the transducer and the mirror when the probe enters the tube being tested as well as for drawing off this liquid when the probe is withdrawn from the tube. These facilities mainly include a soft bag tank filled with the liquid and located at the lower part of the probe and communicating with the capacity to be filled with the liquid. This bag becomes flat when entering the tube after the probe and thus pushes part of the liquid it contains towards this capacity. This liquid assembles again by gravity in the bag when it leaves the tube being tested and returns to its usual shape

  20. Identification procedures for the charge-controlled nonlinear noise model of microwave electron devices

    Science.gov (United States)

    Filicori, Fabio; Traverso, Pier Andrea; Florian, Corrado; Borgarino, Mattia

    2004-05-01

    The basic features of the recently proposed Charge-Controlled Non-linear Noise (CCNN) model for the prediction of low-to-high-frequency noise up-conversion in electron devices under large-signal RF operation are synthetically presented. It is shown that the different noise generation phenomena within the device can be described by four equivalent noise sources, which are connected at the ports of a "noiseless" device model and are non-linearly controlled by the time-varying instantaneous values of the intrinsic device voltages. For the empirical identification of the voltage-controlled equivalent noise sources, different possible characterization procedures, based not only on conventional low-frequency noise data, but also on different types of noise measurements carried out under large-signal RF operating conditions are discussed. As an example of application, the measurement-based identification of the CCNN model for a GaInP heterojunction bipolar microwave transistor is presented. Preliminary validation results show that the proposed model can describe with adequate accuracy not only the low-frequency noise of the HBT, but also its phase-noise performance in a prototype VCO implemented by using the same monolithic GaAs technology.

  1. Study on the photosensitive properties of the charge-coupled matrix as the element for measuring instruments of nuclear-physical experiment

    International Nuclear Information System (INIS)

    The main characteristics (sensitivity linearity, dynamical range and time of keeping the analogue signal) of the photomatrix assembled on charge-coupled devices (CCD) are investigated. The matrix comprising 144x232 elements have been used as a photosensitive element. The flowsheet of the bench for investigating CCD characteristics is presented. It is stated on the base of the results obtained that the dynamical range of the matrix on the CCD equals 100. Time of keeping analogue signal makes up dozens of milliseconds. Application matrix CCD with optical data input permits to decrease instrument expenditures by 100. The results obtained are the basis for development of measuring technique of nuclear-physical experiment on charge-coupled instruments

  2. Tuning Charge and Correlation Effects for a Single Molecule on a Graphene Device

    Science.gov (United States)

    Tsai, Hsin-Zon; Wickenburg, Sebastian; Lu, Jiong; Lischner, Johannes; Omrani, Arash A.; Riss, Alexander; Karrasch, Christoph; Jung, Han Sae; Khajeh, Ramin; Wong, Dillon; Watanabe, Kenji; Taniguchi, Takashi; Zettl, Alex; Louie, Steven G.; Crommie, Michael F.

    Controlling electronic devices down to the single molecule level is a grand challenge of nanotechnology. Single-molecules have been integrated into devices capable of tuning electronic response, but a drawback for these systems is that their microscopic structure remains unknown due to inability to image molecules in the junction region. Here we present a combined STM and nc-AFM study demonstrating gate-tunable control of the charge state of individual F4TCNQ molecules at the surface of a graphene field effect transistor. This is different from previous studies in that the Fermi level of the substrate was continuously tuned across the molecular orbital energy level. Using STS we have determined the resulting energy level evolution of the LUMO, its associated vibronic modes, and the graphene Dirac point (ED). We show that the energy difference between ED and the LUMO increases as EF is moved away from ED due to electron-electron interactions that renormalize the molecular quasiparticle energy. This is attributed to gate-tunable image-charge screening in graphene and corroborated by ab initio calculations.

  3. Controlling charge carrier injection in organic electroluminescent devices via ITO substrate modification

    CERN Document Server

    Day, S

    2001-01-01

    and the ITO substrate was found to shift the work function of the electrode, and so modify the barrier to hole injection. Scanning Kelvin probe measurements show that the ITO work function is increased by 0.25 eV with a film of TNAP, while a C sub 6 sub 0 film is found to reduce the work function by a comparable amount. The former has been attributed to a charge-transfer effect resulting in Fermi level alignment between the ITO and the TNAP layer, however the latter is believed to result from both charge transfer and a covalent interaction between C sub 6 sub 0 and ITO. The performance of devices incorporating these modified ITO electrode are rationalised in terms of the work function modification, film thicknesses and the hole transport properties of the two films. Competition between the induced work function change and the increasingly significant tunnelling barrier with thickness means that device performance is not as good as that provided by the SAMs. Direct processing of the ITO substrate has also been...

  4. Scaling dependence of memory windows and different carrier charging behaviors in Si nanocrystal nonvolatile memory devices

    Science.gov (United States)

    Yu, Jie; Chen, Kun-ji; Ma, Zhong-yuan; Zhang, Xin-xin; Jiang, Xiao-fan; Wu, Yang-qing; Huang, Xin-fan; Oda, Shunri

    2016-09-01

    Based on the charge storage mode, it is important to investigate the scaling dependence of memory performance in silicon nanocrystal (Si-NC) nonvolatile memory (NVM) devices for its scaling down limit. In this work, we made eight kinds of test key cells with different gate widths and lengths by 0.13-μm node complementary metal oxide semiconductor (CMOS) technology. It is found that the memory windows of eight kinds of test key cells are almost the same of about 1.64 V @ ± 7 V/1 ms, which are independent of the gate area, but mainly determined by the average size (12 nm) and areal density (1.8 × 1011/cm2) of Si-NCs. The program/erase (P/E) speed characteristics are almost independent of gate widths and lengths. However, the erase speed is faster than the program speed of test key cells, which is due to the different charging behaviors between electrons and holes during the operation processes. Furthermore, the data retention characteristic is also independent of the gate area. Our findings are useful for further scaling down of Si-NC NVM devices to improve the performance and on-chip integration. Project supported by the State Key Development Program for Basic Research of China (Grant No. 2010CB934402) and the National Natural Science Foundation of China (Grant Nos. 11374153, 61571221, and 61071008).

  5. Gutzwiller charge phase diagram of cuprates, including electron-phonon coupling effects

    Science.gov (United States)

    Markiewicz, R. S.; Seibold, G.; Lorenzana, J.; Bansil, A.

    2015-02-01

    Besides significant electronic correlations, high-temperature superconductors also show a strong coupling of electrons to a number of lattice modes. Combined with the experimental detection of electronic inhomogeneities and ordering phenomena in many high-Tc compounds, these features raise the question as to what extent phonons are involved in the associated instabilities. Here we address this problem based on the Hubbard model including a coupling to phonons in order to capture several salient features of the phase diagram of hole-doped cuprates. Charge degrees of freedom, which are suppressed by the large Hubbard U near half-filling, are found to become active at a fairly low doping level. We find that possible charge order is mainly driven by Fermi surface nesting, with competition between a near-(π ,π ) order at low doping and antinodal nesting at higher doping, very similar to the momentum structure of magnetic fluctuations. The resulting nesting vectors are generally consistent with photoemission and tunneling observations, evidence for charge density wave order in YBa2Cu3O7-δ including Kohn anomalies, and suggestions of competition between one- and two-q-vector nesting.

  6. Comparison of different coupling schemes between counterions and charged nanoparticles in multiparticle collision dynamics

    Science.gov (United States)

    Dahirel, Vincent; Zhao, Xudong; Jardat, Marie

    2016-08-01

    We applied the multiparticle collision dynamics (MPC) simulation technique to highly asymmetric electrolytes in solution, i.e., charged nanoparticles and their counterions in a solvent. These systems belong to a domain of solute size which ranges between the electrolyte and the colloidal domains, where most analytical theories are expected to fail, and efficient simulation techniques are still missing. MPC is a mesoscopic simulation method which mimics hydrodynamics properties of a fluid, includes thermal fluctuations, and can be coupled to a molecular dynamics of solutes. We took advantage of the size asymmetry between nanoparticles and counterions to treat the coupling between solutes and the solvent bath within the MPC method. Counterions were coupled to the solvent bath during the collision step and nanoparticles either through a direct interaction force or with stochastic rotation rules which mimic stick boundary conditions. Moreover, we adapted the simulation procedure to address the issue of the strong electrostatic interactions between solutes of opposite charges. We show that the short-ranged repulsion between counterions and nanoparticles can be modeled by stochastic reflection rules. This simulation scheme is very efficient from a computational point of view. We have also computed the transport coefficients for various densities. The diffusion of counterions was found in one case to increase slightly with the volume fraction of nanoparticles. The deviation of the electric conductivity from the ideal behavior (solutes at infinite dilution without any direct interactions) is found to be strong.

  7. Electric Dipole Moments of Charged Leptons from Their Majorana-type Yukawa Couplings

    CERN Document Server

    Liao, Yi

    2008-01-01

    The electric dipole moments (EDMs) of charged leptons are significantly suppressed in standard model. It has been found previously that they are even more severely suppressed in seesaw type models by powers of tiny neutrino masses as far as a leptonic CP source is concerned. We investigate whether a Majorana-type Yukawa coupling between charged leptons and a doubly charged scalar can contribute significantly to their EDMs. An observable EDM would then help unravel the Majorana nature of neutrinos by a lepton number conserving quantity. We find that the EDMs are indeed parametrically large, of the form d_\\alpha\\propto em_\\alpha(m^2_\\beta-m^2_\\gamma)/m^4 up to logarithms, where m_\\alpha and m are respectively the masses of charged leptons and the scalar. And they satisfy a sum rule to good precision, d_e/m_e+d_\\mu/m_\\mu+d_\\tau/m_\\tau=0. With the most stringent constraints from lepton flavor violating transitions taken into account, their values are still much larger than the mentioned previous results. Unfortun...

  8. Coupling between bulk- and surface chemistry in suspensions of charged colloids

    Science.gov (United States)

    Heinen, M.; Palberg, T.; Löwen, H.

    2014-03-01

    The ionic composition and pair correlations in fluid phases of realistically salt-free charged colloidal sphere suspensions are calculated in the primitive model. We obtain the number densities of all ionic species in suspension, including low-molecular weight microions, and colloidal macroions with acidic surface groups, from a self-consistent solution of a coupled physicochemical set of nonlinear algebraic equations and non-mean-field liquid integral equations. Here, we study suspensions of colloidal spheres with sulfonate or silanol surface groups, suspended in demineralized water that is saturated with carbon dioxide under standard atmosphere. The only input required for our theoretical scheme are the acidic dissociation constants pKa, and effective sphere diameters of all involved ions. Our method allows for an ab initio calculation of colloidal bare and effective charges, at high numerical efficiency.

  9. The effect of protons on the performance of swept-charge devices

    Energy Technology Data Exchange (ETDEWEB)

    Smith, David R. [Imaging for Space and Terrestrial Applications Group, School of Engineering and Design, Brunel University, Uxbridge Middlesex UB8 3PH (United Kingdom)], E-mail: david.smith@brunel.ac.uk; Gow, Jason [Imaging for Space and Terrestrial Applications Group, School of Engineering and Design, Brunel University, Uxbridge Middlesex UB8 3PH (United Kingdom)

    2009-06-01

    The e2v technologies CCD54, or swept-charge device (SCD) has been extensively radiation tested for use in the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument, to be launched as a part of the Indian Space Research Organisation (ISRO) Chandrayaan-1 payload in 2008. The principle use of the SCD is in X-ray fluorescence (XRF) applications, the device providing a relatively large collecting area of 1.1 cm{sup 2}, and achieving near Fano-limited spectroscopy at -15 deg. C, a temperature that is easily obtained using a thermoelectric cooler (TEC). This paper describes the structure and operation of the SCD and details the methodology and results obtained from two proton irradiation studies carried out in 2006 and 2008, respectively to quantify the effects of proton irradiation on the operational characteristics of the device. The analysis concentrates on the degradation of the measured FWHM of various elemental lines and quantifies the effects of proton fluence on the observed X-ray fluorescence spectra from mineralogical target samples.

  10. A “wire” signal smoothing device for laser ablation inductively coupled plasma mass spectrometry analysis

    International Nuclear Information System (INIS)

    A novel signal smoothing device for laser ablation inductively coupled plasma mass spectrometry was developed. The “wire” signal smoothing device consists of a copper cylinder filled with steel wire, with an internal volume of approx. 94 cm3. The effectiveness of the “wire” signal smoothing device was evaluated with respect to both signal stability and decay time. With the developed “wire” smoothing device, no oscillation of the signal intensity was observed, even at a repetition rate of 1 Hz. This finding indicates that this device is well suited for routine optimization of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The signal stability was improved by a factor of 11 compared to the absence of a signal smoothing device at a repetition rate of 1 Hz. Another significant advantage of the “wire” smoothing device is that the signal decay time is similar to that without the signal smoothing device. These properties cause the “wire” smoothing device to be well suited for low repetition rate laser ablation analysis, which provides smaller elemental fractionation and better spatial resolution. The proposed “wire” signal smoothing device has been successfully used for high depth resolution zircon dating. - Highlights: ► The wire stabilizer is able to provide smooth signals at a repetition rate of 1 Hz. ► The signal decay time is similar to that in the absence of a signal stabilizer. ► The wire stabilizer has been successfully used for zircon dating.

  11. Microscopic studies of the fate of charges in organic semiconductors: Scanning Kelvin probe measurements of charge trapping, transport, and electric fields in p- and n-type devices

    Science.gov (United States)

    Smieska, Louisa Marion

    Organic semiconductors could have wide-ranging applications in lightweight, efficient electronic circuits. However, several fundamental questions regarding organic electronic device behavior have not yet been fully addressed, including the nature of chemical charge traps, and robust models for injection and transport. Many studies focus on engineering devices through bulk transport measurements, but it is not always possible to infer the microscopic behavior leading to the observed measurements. In this thesis, we present scanning-probe microscope studies of organic semiconductor devices in an effort to connect local properties with local device behavior. First, we study the chemistry of charge trapping in pentacene transistors. Working devices are doped with known pentacene impurities and the extent of charge trap formation is mapped across the transistor channel. Trap-clearing spectroscopy is employed to measure an excitation of the pentacene charge trap species, enabling identification of the degradationrelated chemical trap in pentacene. Second, we examine transport and trapping in peryelene diimide (PDI) transistors. Local mobilities are extracted from surface potential profiles across a transistor channel, and charge injection kinetics are found to be highly sensitive to electrode cleanliness. Trap-clearing spectra generally resemble PDI absorption spectra, but one derivative yields evidence indicating variation in trap-clearing mechanisms for different surface chemistries. Trap formation rates are measured and found to be independent of surface chemistry, contradicting a proposed silanol trapping mechanism. Finally, we develop a variation of scanning Kelvin probe microscopy that enables measurement of electric fields through a position modulation. This method avoids taking a numeric derivative of potential, which can introduce high-frequency noise into the electric field signal. Preliminary data is presented, and the theoretical basis for electric field

  12. Chemical-Vapor-Deposited Graphene as Charge Storage Layer in Flash Memory Device

    Directory of Open Access Journals (Sweden)

    W. J. Liu

    2016-01-01

    Full Text Available We demonstrated a flash memory device with chemical-vapor-deposited graphene as a charge trapping layer. It was found that the average RMS roughness of block oxide on graphene storage layer can be significantly reduced from 5.9 nm to 0.5 nm by inserting a seed metal layer, which was verified by AFM measurements. The memory window is 5.6 V for a dual sweep of ±12 V at room temperature. Moreover, a reduced hysteresis at the low temperature was observed, indicative of water molecules or −OH groups between graphene and dielectric playing an important role in memory windows.

  13. The effect of protons on the performance of second generation Swept Charge Devices

    Energy Technology Data Exchange (ETDEWEB)

    Gow, Jason P.D., E-mail: j.p.d.gow@open.ac.uk [e2v Centre for Electronic Imaging, Planetary and Space Sciences Research Institute, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Holland, Andrew D. [e2v Centre for Electronic Imaging, Planetary and Space Sciences Research Institute, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Pool, Peter J. [e2v Technologies PLC, 106 Waterhouse Lance, Chelmsford, Essex CM1 2QU (United Kingdom); Smith, David R. [Centre for Sensors and Instrumentation, School of Engineering and Design, Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom)

    2012-07-11

    The e2v technologies Swept Charge Device (SCD) was developed as a large area detector for X-ray Fluorescence (XRF) analysis, achieving near Fano-limited spectroscopy at -15 Degree-Sign C. The SCD was flown in the XRF instruments onboard the European Space Agency's SMART-1 and the Indian Space Research Organisation's Chandrayaan-1 lunar missions. The second generation SCD, proposed for use in the soft X-ray Spectrometer on the Chandrayaan-2 lunar orbiter and the soft X-ray imager on China's HXMT mission, was developed, in part, using the findings of the radiation damage studies performed for the Chandrayaan-1 X-ray Spectrometer. This paper discusses the factor of two improvements in radiation tolerance achieved in the second generation SCD, the different SCD sizes produced and their advantages for future XRF instruments, for example through reduced shielding mass or higher operating temperatures.

  14. Charge and spin transport in PEDOT:PSS nanoscale lateral devices.

    Science.gov (United States)

    de Oliveira, Thales V A G; Gobbi, Marco; Porro, José M; Hueso, Luis E; Bittner, Alexander M

    2013-11-29

    The electrical transport of the highly conductive poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) is investigated with Ohmic and spin-polarized tunnel contacts at nanoscale lateral dimensions. Temperature-dependent charge transport measurements reveal that electrical conductivity scales non-linearly as a function of electrode spacing, which is attributed to the localization of carriers induced by the disorder introduced by the PSS polyelectrolyte. In addition, we demonstrate the integration of this conducting polymer in nanoscale lateral spin-valve devices by increasing the pH of the PEDOT:PSS solution. We present charge and magnetotransport measurement results of NiFe/AlOx/PEDOT:PSS/AlOx/NiFe lateral structures for various thicknesses of the alumina tunnel barriers. We discuss the absence of magnetoresistance of our spin valves within the framework of Valet-Fert theory, and estimate an upper limit for the spin lifetime of carriers in PEDOT:PSS to τsf ≤ 50 ns. PMID:24177495

  15. Ohmic contact and space-charge-limited current in molybdenum oxide modified devices

    Science.gov (United States)

    Lü, Zhaoyue; Deng, Zhenbo; Zheng, Jianjie; Zou, Ye; Chen, Zheng; Xu, Denghui; Wang, Yongsheng

    2009-10-01

    The effect of indium-tin oxide (ITO) surface treatment on hole injection of devices with molybdenum oxide (MoO 3) as a buffer layer on ITO was studied. The Ohmic contact is formed at the metal/organic interface due to high work function of MoO 3. Hence, the current is due to space charge limited when ITO is positively biased. The hole mobility of N, N‧-bis-(1-napthyl)-N, N‧-diphenyl-1, 1‧biphenyl-4, 4‧-diamine (NPB) at various thicknesses (100-400 nm) has been estimated by using space-charge-limited current measurements. The hole mobility of NPB, 1.09×10 -5 cm 2/V s at 100 nm is smaller than the value of 1.52×10 -4 cm 2/V s at 400 nm at 0.8 MV/cm, which is caused by the interfacial trap states restricted by the surface interaction. The mobility is hardly changed with NPB thickness for the effect of interfacial trap states on mobility which can be negligible when the thickness is more than 300 nm.

  16. Rational design of charge transport molecules for blue organic light emitting devices

    Science.gov (United States)

    Padmaperuma, Asanga; Cosimbescu, Lelia; Koech, Phillip; Polikarpov, Evgueni; Swensen, James; Gaspar, Daniel

    2012-02-01

    The efficiency and stability of blue OLEDs continue to be the primary roadblock to developing organic solid-state white lighting as well as power efficient displays. It is generally accepted that such high quantum efficiency can be achieved with the use of organometallic phosphor doped OLEDs. The transport layers can be designed to increase the carrier density as a way to reduce the drive voltage. We have developed a comprehensive library of charge transporting molecules using combination of theoretical modeling and experimental evidence. Our work focuses on using chemical structure design and computational methods to develop host, transport, emitter, and blocking materials for high efficiency blue OLEDs, along with device architectures to take advantage of these new materials. Through chemical modification of materials we are able to influence both the charge balance and emission efficiency of OLEDs, and understand the influence of the location of photon emission in OLEDs as a function of minor chemical modifications of host and electron transport materials. Design rules, structure-property relationships and results from state of the art OLEDs will be presented.

  17. Coupling Electric Vehicles and Power Grid through Charging-In-Motion and Connected Vehicle Technology

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jan-Mou [ORNL; Jones, Perry T [ORNL; Onar, Omer C [ORNL; Starke, Michael R [ORNL

    2014-01-01

    A traffic-assignment-based framework is proposed to model the coupling of transportation network and power grid for analyzing impacts of energy demand from electric vehicles on the operation of power distribution. Although the reverse can be investigated with the proposed framework as well, electricity flowing from a power grid to electric vehicles is the focus of this paper. Major variables in transportation network (including link flows) and power grid (including electricity transmitted) are introduced for the coupling. Roles of charging-in-motion technology and connected vehicle technology have been identified in the framework of supernetwork. A linkage (i.e. individual energy demand) between the two networks is defined to construct the supernetwork. To determine equilibrium of the supernetwork can also answer how many drivers are going to use the charging-in-motion services, in which locations, and at what time frame. An optimal operation plan of power distribution will be decided along the determination simultaneously by which we have a picture about what level of power demand from the grid is expected in locations during an analyzed period. Caveat of the framework and possible applications have also been discussed.

  18. Nonadiabatic couplings and charge transfer study in H + CS+ collision using time-dependent quantum dynamics

    Science.gov (United States)

    Kaur, Rajwant; Dhilip Kumar, T. J.

    2015-11-01

    Experiments have reported the high stability of HCS+ ion and inhibit to decompose over the range of collision energies. In this study, the various energy transfer channels of atomic H collision with CS+ molecular ion has been performed by ab initio computations at the multireference configuration interaction/aug-cc-pVQZ level of theory. The ground and several low-lying excited electronic state potential energy surfaces in three different molecular orientations, namely, two collinear configurations with, (1) H approaching the S atom (γ = 0°), (2) H approaching the C atom (γ = 180°) and one perpendicular configuration, (3) H approaching the centre of mass of CS (γ = 90°) with the diatom fixed at the equilibrium bond length, have been obtained. Nonadiabatic effects with Landau-Zener coupling leading to avoided crossings are observed between the ground- and the first-excited states in γ = 90° orientation, and also between the first- and second-excited states in γ = 180° orientation. Quantum dynamics have been performed to study the charge transfer using time-dependent wave packet method on the diabatic potential energy surfaces. The probability of charge transfer is found to be highest with 42% in γ = 180°. The high charge transfer probability result in the formation of H+ + CS channel which ascertains the high stability of HCS+ ion.

  19. Diffusion model for charge transfer from a photosynthetic reaction center to an electrode in a photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Takshi, Arash [Department of Microbiology and Immunology, University of British Columbia (UBC), Vancouver, BC V6T 1Z3 (Canada); Department of Electrical and Computer Engineering and Advanced Materials and Process Engineering Lab, University of British Columbia (UBC), Vancouver, BC V6T 1Z1 (Canada)], E-mail: arasht@ece.ubc.ca; Madden, John D. [Department of Electrical and Computer Engineering and Advanced Materials and Process Engineering Lab, University of British Columbia (UBC), Vancouver, BC V6T 1Z1 (Canada); Beatty, J. Thomas [Department of Microbiology and Immunology, University of British Columbia (UBC), Vancouver, BC V6T 1Z3 (Canada)

    2009-05-30

    In spite of a high quantum efficiency in the bacterial photosynthetic reaction center (RC) the overall efficiency in a RC-based photovoltaic device is very poor partly because of an inefficient collection of charges by electrodes. To explain charge transport between the RC and an electrode a diffusion model is proposed. The numerical solution of the diffusion process describes the measured photocurrent well. An approximation of the initial condition is also made to obtain analytical expressions for the photocurrent. The model suggests that the slow transient response of the photocurrent is due to the diffusion in a biological photovoltaic device.

  20. Diffusion model for charge transfer from a photosynthetic reaction center to an electrode in a photovoltaic device

    International Nuclear Information System (INIS)

    In spite of a high quantum efficiency in the bacterial photosynthetic reaction center (RC) the overall efficiency in a RC-based photovoltaic device is very poor partly because of an inefficient collection of charges by electrodes. To explain charge transport between the RC and an electrode a diffusion model is proposed. The numerical solution of the diffusion process describes the measured photocurrent well. An approximation of the initial condition is also made to obtain analytical expressions for the photocurrent. The model suggests that the slow transient response of the photocurrent is due to the diffusion in a biological photovoltaic device.

  1. The charge-exchange induced coupling between plasma-gas counterflows in the heliosheath

    Directory of Open Access Journals (Sweden)

    H. J. Fahr

    Full Text Available Many hydrodynamic models have been presented which give similar views of the interaction of the solar wind plasma bubble with the counterstreaming partially ionized interstellar medium. In the more recent of these models it is taken into account that the solar and interstellar hydrodynamic flows of neutral atoms and protons are coupled by mass-, momentum-, and energy-exchange terms due to charge exchange processes. We shall reinvestigate the theoretical basis of this coupling here by use of a simplified description of the heliospheric interface and describe the main physics of the H-atom penetration through the more or less standing well-known plasma wall ahead of the heliopause. Thereby we can show that the type of charge exchange coupling terms used in up-to-now hydrodynamic treatments unavoidably leads to an O-type critical point at the sonic point of the H-atom flow, thus not allowing for a continuation of the integration of the hydrodynamic set of differential equations. The remedy for this problem is given by a more accurate formulation of the momentum exchange term for quasi-and sub-sonic H-atom flows. With a refined momentum exchange term derived from basic kinetic Boltzmann principles, we instead arrive at a characteristic equation with an X-type critical point, allowing for a continuous solution from supersonic to subsonic flow conditions. This necessitates that the often treated problem of the propagation of inter-stellar H-atoms through the heliosheath has to be solved using these newly derived, differently effective plasma – gas friction forces. Substantially different results are to be expected from this context for the filtration efficiency of the heliospheric interface.

    Key words. Interplanetary physics (heliopause and solar wind termination; interstellar gas – Ionosphere (plasma temperature and density

  2. Charge transport in organic multi-layer devices under electric and optical fields

    Science.gov (United States)

    Park, June Hyoung

    2007-12-01

    Charge transport in small organic molecules and conjugated conducting polymers under electric or optical fields is studied by using field effect transistors and photo-voltaic cells with multiple thin layers. With these devices, current under electric field, photo-current under optical field, and luminescence of optical materials are measured to characterize organic and polymeric materials. For electric transport studies, poly(3,4-ethylenedioxythiophene) doped by polystyrenesulfonic acid is used, which is conductive with conductivity of approximately 25 S/cm. Despite their high conductance, field effect transistors based on the films are successfully built and characterized by monitoring modulations of drain current by gate voltage and IV characteristic curves. Due to very thin insulating layers of poly(vinylphenol), the transistors are relative fast under small gate voltage variation although heavy ions are involved in charge transport. In IV characteristic curves, saturation effects can be observed. Analysis using conventional field effect transistor model indicates high mobility of charge carriers, 10 cm2/V·sec, which is not consistent with the mobility of the conducting polymer. It is proposed that the effect of a small density of ions injected via polymer dielectric upon application of gate voltage and the ion compensation of key hopping sites accounts for the operation of the field effect transistors. For the studies of transport under optical field, photovoltaic cells with 3 different dendrons, which are efficient to harvest photo-excited electrons, are used. These dendrons consist of two electron-donors (tetraphenylporphyrin) and one electron-accepter (naphthalenediimide). Steady-state fluorescence measurements show that inter-molecular interaction is dominant in solid dendron film, although intra-molecular interaction is still present. Intra-molecular interaction is suggested by different fluorescence lifetimes between solutions of donor and dendrons. This

  3. The self-force on a non-minimally coupled static scalar charge outside a Schwarzschild black hole

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Demian H J; Tsokaros, Antonios A; Wiseman, Alan G [Department of Physics, University of Wisconsin-Milwaukee, PO Box 413, Milwaukee, WI 53201 (United States)

    2007-03-07

    The finite part of the self-force on a static, non-minimally coupled scalar test charge outside a Schwarzschild black hole is zero. This result is determined from the work required to slowly raise or lower the charge through an infinitesimal distance. Unlike similar force calculations for minimally-coupled scalar charges or electric charges, we find that we must account for a flux of field energy that passes through the horizon and changes the mass and area of the black hole when the charge is displaced. This occurs even for an arbitrarily slow displacement of the non-minimally coupled scalar charge. For a positive coupling constant, the area of the hole increases when the charge is lowered and decreases when the charge is raised. The fact that the self-force vanishes for a static, non-minimally coupled scalar charge in Schwarzschild spacetime agrees with a simple prediction of the Quinn-Wald axioms. However, Zel'nikov and Frolov computed a non-vanishing self-force for a non-minimally coupled charge. Our method of calculation closely parallels the derivation of Zel'nikov and Frolov, and we show that their omission of this unusual flux is responsible for their (incorrect) result. When the flux is accounted for, the self-force vanishes. This correction eliminates a potential counter example to the Quinn-Wald axioms. The fact that the area of the black hole changes when the charge is displaced brings up two interesting questions that did not arise in similar calculations for static electric charges and minimally coupled scalar charges. (1) How can we reconcile a decrease in the area of the black hole horizon with the area theorem which concludes that {delta}Area{sub horizon} {>=} 0? The key hypothesis of the area theorem is that the stress-energy tensor must satisfy a null-energy condition T{sup {alpha}}{sup {beta}}l{sub {alpha}}l{sub {beta}} {>=} 0 for any null vector l{sub {alpha}}. We explicitly show that the stress-energy associated with a non

  4. Non-reciprocal few-photon devices based on chiral waveguide-emitter couplings

    CERN Document Server

    Gonzalez-Ballestero, C; Vidal, F J Garcia; Gonzalez-Tudela, A

    2016-01-01

    We demonstrate the possibility of designing efficient, non reciprocal few-photon devices by exploiting the chiral coupling between two waveguide modes and a single quantum emitter. We show how this system can induce non-reciprocal photon transport at the single-photon level and act as an optical diode. Afterwards, we also show how the same system shows a transistor-like behaviour for a two-photon input. The efficiency in both cases is shown to be large for feasible experimental implementations. Our results illustrate the potential of chiral waveguide-emitter couplings for applications in quantum circuitry.

  5. Variable-charge method applied to study coupled grain boundary migration in the presence of oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, A. [Paul Scherrer Institute, Villigen, PSI-Villigen CH-5232 (Switzerland); Politano, O. [Institut Carnot de Bourgogne, UMR 5209 CNRS-Universite de Bourgogne, 9 Avenue Alain Savary, 21078 Dijon Cedex (France); Derlet, P.M. [Paul Scherrer Institute, Villigen, PSI-Villigen CH-5232 (Switzerland); Van Swygenhoven, H. [Paul Scherrer Institute, Villigen, PSI-Villigen CH-5232 (Switzerland)], E-mail: helena.vs@psi.ch

    2009-04-15

    One of the important differences between simulation and experiments in grain boundary (GB)-dominated metallic structures is the lack of impurities such as oxygen in computational samples. A modified variable-charge method [Elsener A, Politano O, Derlet PM, Van Swygenhoven H. Modell Simul Mater Sci Eng 2008;16:025006] based on the Streitz and Mintmire approach [Streitz FH, Mintmire JW. Phys Rev B 1994;50:11996] is used to study coupled GB motion in an Al bicrystal with a [1 1 2] symmetrical tilt GB in the presence of substitutional O, and compared with the stick-slip process identified by Cahn and Mishin [Cahn JW, Mishin Y, Suzuki A. Acta Mater 2006;54:4953]. It is found that the critical shear stress for migration of the GB increases linearly with the number of O atoms. These observations are then rationalized in terms of the internal stress signature of the O atoms in the vicinity of the boundary.

  6. Precision determination of the $\\pi N$ scattering lengths and the charged $\\pi NN$ coupling constant

    CERN Document Server

    Ericson, Torleif Eric Oskar; Thomas, A W

    2000-01-01

    We critically evaluate the isovector GMO sumrule for the charged $\\pi N N$ coupling constant using recent precision data from $\\pi ^-$p and $\\pi^-$d atoms and with careful attention to systematic errors. From the $\\pi ^-$d scattering length we deduce the pion-proton scattering lengths ${1/2}(a_{\\pi ^-p}+a_{\\pi ^-n})=(-20\\pm 6$(statistic)$ \\pm 10$ (systematic))~$\\cdot 10^{-4}m_{\\pi_c}^{-1}$ and ${1/2}(a_{\\pi ^-p}-a_{\\pi ^-n})=(903 \\pm 14)\\cdot 10^{-4}m_{\\pi_c}^{-1}$. From this a direct evaluation gives $g^2_c(GMO) =14.20\\pm 0.07$(statistic)$\\pm 0.13$(systematic) or $f^2_c= 0.0786\\pm 0.0008$.

  7. Entropy Squeezing in Coupled Field-Superconducting Charge Qubit with Intrinsic Decoherence

    Institute of Scientific and Technical Information of China (English)

    YAN Xue-Qun; SHAO Bin; ZOU Jian

    2007-01-01

    We investigate the entropy squeezing in the system of a superconducting charge qubit coupled to a single mode field. We find an exact solution of the Milburn equation for the system and discuss the influence of intrinsic decoherence on entropy squeezing. As a comparison, we also consider the variance squeezing. Our results show that in the absence of the intrinsic decoherence both entropy and variance squeezings have the same periodic properties of time,and occur at the same range of time. However, when the intrinsic decoherence is considered, we find that as the time going on the entropy squeezing disappears fast than the variance squeezing, there exists a range of time where entropy squeezing can occur but variance squeezing cannot.

  8. Penrose process in a charged axion-dilaton coupled black hole

    Energy Technology Data Exchange (ETDEWEB)

    Ganguly, Chandrima [University of Cambridge, Department of Applied Mathematics and Theoretical Physics, Cambridge (United Kingdom); SenGupta, Soumitra [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)

    2016-04-15

    Using the Newman-Janis method to construct the axion-dilaton coupled charged rotating black holes, we show that the energy extraction from such black holes via the Penrose process takes place from the axion/Kalb-Ramond field energy responsible for rendering the angular momentum to the black hole. Determining the explicit form for the Kalb-Ramond field strength, which is argued to be equivalent to spacetime torsion, we demonstrate that at the end of the energy extraction process, the spacetime becomes torsion free with a spherically symmetric non-rotating black hole remnant. In this context, applications to physical phenomena, such as the emission of neutral particles in astrophysical jets, are also discussed. It is seen that the infalling matter gains energy from the rotation of the black hole, or equivalently from the axion field, and that it is ejected as a highly collimated astrophysical jet. (orig.)

  9. Charge-flux qubit coupled to a tank circuit in strong low-frequency electromagnetic field

    International Nuclear Information System (INIS)

    A superconducting charge-phase qubit and a coupled high-quality tank circuit in low-frequency electric field have been studied. A fine structure of the multiphoton resonance lines and quantum interference effects associated with excitation of the quasi-two-level system due to the Landau-Zener-Schtukelberg tunneling have been observed. The results obtained us-ing various parameters of the measuring circuit for multiphoton resonance excitations and low-frequency oscillations of average population of quantum levels were compared. The mechanism responsible for the fine structure of resonance lines is considered. The method of measuring the impedance introduced in the tank circuit by oscillations of supercurrent in the qubit and the principal sources of the decoherence are dis-cussed

  10. Two-dimensional fluid modelling of charged particle transport in radio-frequency capacitively coupled discharges

    International Nuclear Information System (INIS)

    This paper reviews the formulation and updates some numerical procedures usually adopted in two-dimensional, time-dependent fluid models to study the transport of charged particles in radio-frequency capacitively coupled discharges. The description of charged particle transport is made by solving the continuity and momentum transfer equations for electrons and ions, coupled with Poisson's equation and the electron mean energy transport equations. Inertia terms are considered in the ion momentum transfer equations, by generalizing the earlier definition of effective electric field. The electron mean energy equations are written using specific energy transport parameters, deduced from integration over the electron energy distribution function (EEDF). The model adopts the local mean energy approximation, i.e. it computes the electron transport parameters as a function of the electron mean energy, using either a homogeneous, two-term Boltzmann equation solver or a Maxwellian EEDF. More appropriate boundary conditions for the electron and ion fluxes are used successfully. The model is solved for a GEC Cell reactor type (with 6.4 cm radius and 3.2 cm interelectrode distance) operating at frequency 13.56 MHz, pressures between 10 mTorr and 10 Torr and applied voltages from 100 to 500 V, in electropositive (helium) and electronegative (silane-hydrogen) gases or gas mixtures. The ion kinetics in silane and hydrogen is updated with respect to previous works, by further considering SiH2+, H+ and H3+ ions. In general, simulation results for some typical electrical parameters are closer to experimental measurements available than calculations reported in previous works

  11. Tunable coupling in circuit quantum electrodynamics using a superconducting charge qubit with a V-shaped energy level diagram.

    Science.gov (United States)

    Srinivasan, S J; Hoffman, A J; Gambetta, J M; Houck, A A

    2011-02-25

    We introduce a new type of superconducting charge qubit that has a V-shaped energy spectrum and uses quantum interference to provide independently tunable qubit energy and coherent coupling to a superconducting cavity. Dynamic access to the strong coupling regime is demonstrated by tuning the coupling strength from less than 200 kHz to greater than 40 MHz. This tunable coupling can be used to protect the qubit from cavity-induced relaxation and avoid unwanted qubit-qubit interactions in a multiqubit system.

  12. The all particle method: Coupled neutron, photon, electron, charged particle Monte Carlo calculations

    International Nuclear Information System (INIS)

    At the present time a Monte Carlo transport computer code is being designed and implemented at Lawrence Livermore National Laboratory to include the transport of: neutrons, photons, electrons and light charged particles as well as the coupling between all species of particles, e.g., photon induced electron emission. Since this code is being designed to handle all particles this approach is called the ''All Particle Method''. The code is designed as a test bed code to include as many different methods as possible (e.g., electron single or multiple scattering) and will be data driven to minimize the number of methods and models ''hard wired'' into the code. This approach will allow changes in the Livermore nuclear and atomic data bases, used to described the interaction and production of particles, to be used to directly control the execution of the program. In addition this approach will allow the code to be used at various levels of complexity to balance computer running time against the accuracy requirements of specific applications. This paper describes the current design philosophy and status of the code. Since the treatment of neutrons and photons used by the All Particle Method code is more or less conventional, emphasis in this paper is placed on the treatment of electron, and to a lesser degree charged particle, transport. An example is presented in order to illustrate an application in which the ability to accurately transport electrons is important. 21 refs., 1 fig

  13. Charging of superconducting layers and resonance-related hysteresis in the current-voltage characteristics of coupled Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Gaafar, M. A.

    2011-09-01

    A manifestation of a resonance-type hysteresis related to the parametric resonance in the system of coupled Josephson junctions is demonstrated. In contrast with the McCumber and Steward hysteresis, we find that the width of this hysteresis is inversely proportional to the McCumber parameter and it also depends on the coupling between junctions and the boundary conditions. Investigation of the time dependence of the electric charge in superconducting layers allows us to explain the origin of this hysteresis by different charge dynamics for increasing and decreasing bias current processes. The effect of the wavelength of the longitudinal plasma wave created at the resonance on the charging of superconducting layers is demonstrated. We find a strong effect of the dissipation in the system on the amplitude of the charge oscillations at the resonance.

  14. Effects of traps and polarization charges on device performance of AlGaN/GaN high electron mobility transistors

    Science.gov (United States)

    Hussein, A. SH.; Ghazai, Alaa J.; Salman, Emad A.; Hassan, Z.

    2013-11-01

    This paper presents the simulated electrical characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) by using ISE TCAD software. The effects of interface traps, bulk traps and polarization charges are investigated. It was observed that the role and dynamic of traps affect the device performance which requires a precondition to calculate the DC characteristics that are in agreement with the experimental data. On the other hand, polarization charges lead to quantum confinement of the electrons in the channel and form two-dimensional electron gas. The electron quantization leads to increasing the drain current and shift in the threshold voltage. The device performance can be improved by optimizing the fixed interface charge and thus reducing the bulk traps to enhance the DC characteristics.

  15. Artificial Synaptic Devices Based on Natural Chicken Albumen Coupled Electric-Double-Layer Transistors

    Science.gov (United States)

    Wu, Guodong; Feng, Ping; Wan, Xiang; Zhu, Liqiang; Shi, Yi; Wan, Qing

    2016-03-01

    Recent progress in using biomaterials to fabricate functional electronics has got growing attention for the new generation of environmentally friendly and biocompatible electronic devices. As a kind of biological material with rich source, proteins are essential natural component of all organisms. At the same time, artificial synaptic devices are of great significance for neuromorphic systems because they can emulate the signal process and memory behaviors of biological synapses. In this report, natural chicken albumen with high proton conductivity was used as the coupling electrolyte film for organic/inorganic hybrid synaptic devices fabrication. Some important synaptic functions including paired-pulse facilitation, dynamic filtering, short-term to long-term memory transition and spatial summation and shunting inhibition were successfully mimicked. Our results are very interesting for biological friendly artificial neuron networks and neuromorphic systems.

  16. Distributed and coupled 2D electro-thermal model of power semiconductor devices

    Science.gov (United States)

    Belkacem, Ghania; Lefebvre, Stéphane; Joubert, Pierre-Yves; Bouarroudj-Berkani, Mounira; Labrousse, Denis; Rostaing, Gilles

    2014-05-01

    The development of power electronics in the field of transportations (automotive, aeronautics) requires the use of power semiconductor devices providing protection and diagnostic functions. In the case of series protections power semiconductor devices which provide protection may operate in shortcircuit and act as a current limiting device. This mode of operations is very constraining due to the large dissipation of power. In these particular conditions of operation, electro-thermal models of power semiconductor devices are of key importance in order to optimize their thermal design and increase their reliability. The development of such an electro-thermal model for power MOSFET transistors based on the coupling between two computation softwares (Matlab and Cast3M) is described in this paper. The 2D electro-thermal model is able to predict (i) the temperature distribution on chip surface well as in the volume under short-circuit operations, (ii) the effect of the temperature on the distribution of the current flowing within the die and (iii) the effects of the ageing of the metallization layer on the current density and the temperature. In this paper, the electrical and thermal models are described as well as the implemented coupling scheme.

  17. Tunneling in Systems of Coupled Dopant-Atoms in Silicon Nano-devices

    Science.gov (United States)

    Moraru, Daniel; Samanta, Arup; Tyszka, Krzysztof; Anh, Le The; Muruganathan, Manoharan; Mizuno, Takeshi; Jablonski, Ryszard; Mizuta, Hiroshi; Tabe, Michiharu

    2015-09-01

    Following the rapid development of the electronics industry and technology, it is expected that future electronic devices will operate based on functional units at the level of electrically active molecules or even atoms. One pathway to observe and characterize such fundamental operation is to focus on identifying isolated or coupled dopants in nanoscale silicon transistors, the building blocks of present electronics. Here, we review some of the recent progress in the research along this direction, with a focus on devices fabricated with simple and CMOS-compatible-processing technology. We present results from a scanning probe method (Kelvin probe force microscopy) which show direct observation of dopant-induced potential modulations. We also discuss tunneling transport behavior based on the analysis of low-temperature I- V characteristics for devices representative for different regimes of doping concentration, i.e., different inter-dopant coupling strengths. This overview outlines the present status of the field, opening also directions toward practical implementation of dopant-atom devices.

  18. Cavity Photons as a Probe for Charge Relaxation Resistance and Photon Emission in a Quantum Dot Coupled to Normal and Superconducting Continua

    Science.gov (United States)

    Bruhat, L. E.; Viennot, J. J.; Dartiailh, M. C.; Desjardins, M. M.; Kontos, T.; Cottet, A.

    2016-04-01

    Microwave cavities have been widely used to investigate the behavior of closed few-level systems. Here, we show that they also represent a powerful probe for the dynamics of charge transfer between a discrete electronic level and fermionic continua. We have combined experiment and theory for a carbon nanotube quantum dot coupled to normal metal and superconducting contacts. In equilibrium conditions, where our device behaves as an effective quantum dot-normal metal junction, we approach a universal photon dissipation regime governed by a quantum charge relaxation effect. We observe how photon dissipation is modified when the dot admittance turns from capacitive to inductive. When the fermionic reservoirs are voltage biased, the dot can even cause photon emission due to inelastic tunneling to/from a Bardeen-Cooper-Schrieffer peak in the density of states of the superconducting contact. We can model these numerous effects quantitatively in terms of the charge susceptibility of the quantum dot circuit. This validates an approach that could be used to study a wide class of mesoscopic QED devices.

  19. Extreme Contrast Ratio Imaging of Sirius with a Charge Injection Device

    CERN Document Server

    Batcheldor, D; Bahr, C; Jenne, J; Ninkov, Z; Bhaskaran, S; Chapman, T

    2015-01-01

    The next fundamental steps forward in understanding our place in the universe could be a result of advances in extreme contrast ratio (ECR) imaging and point spread function (PSF) suppression. For example, blinded by quasar light we have yet to fully understand the processes of galaxy formation and evolution, and there is an ongoing race to obtain a direct image of an exoearth lost in the glare of its host star. To fully explore the features of these systems we must perform observations in which contrast ratios of at least one billion can be regularly achieved with sub 0.1" inner working angles. Here we present the details of a latest generation 32-bit charge injection device (CID) that could conceivably achieve contrast ratios on the order of one billion. We also demonstrate some of its ECR imaging abilities for astronomical imaging. At a separation of two arc minutes, we report a direct contrast ratio of Delta(m_v)=18.3, log(CR)=7.3, or 1 part in 20 million, from observations of the Sirius field. The atmosp...

  20. Off-diagonal Yukawa couplings in the s-channel charged Higgs production at LHC

    Directory of Open Access Journals (Sweden)

    Majid Hashemi

    2015-02-01

    Full Text Available The search for the heavy charged Higgs (mH±>mtop has been mainly based on the off-shell top pair production process. However, resonance production in s-channel single top events is an important channel to search for this particle. In a previous work, it was shown that this process, i.e., qq′→H+→tb¯+h.c., can lead to comparable results to what is already obtained from LHC searches. What was obtained was, however, based on diagonal Yukawa couplings between incoming quarks assuming cs¯ as the main incoming pair due to the CKM matrix element being close to unity. The aim of this paper is to show that off-diagonal couplings, like cb¯, may lead to substantial contributions to the cross section, even if the corresponding CKM matrix element is two orders of magnitude smaller. For this reason, the cross section is calculated for each initial state including all diagonal and off-diagonal terms, and all is finally added together to get the total cross section which is observed to be ∼2.7 times larger than what is obtained from cs¯ initial state. Results are eventually reflected into 95% C.L. exclusion and 5σ discovery contours at different integrated luminosities of LHC. A reasonable coverage of the parameter space is obtained by the 95% C.L. exclusion contour.

  1. Zeta potential and electroosmotic mobility in microfluidic devices fabricated from hydrophobic polymers: 1. The origins of charge.

    Science.gov (United States)

    Tandon, Vishal; Bhagavatula, Sharath K; Nelson, Wyatt C; Kirby, Brian J

    2008-03-01

    This paper combines new experimental data for electrokinetic characterization of hydrophobic polymers with a detailed discussion of the putative origins of charge at water-hydrophobe interfaces. Complexities in determining the origin of charge are discussed in the context of design and modeling challenges for electrokinetic actuation in hydrophobic microfluidic devices with aqueous working fluids. Measurements of interfacial charge are complicated by slip and interfacial water structuring phenomena (see Part 2, this issue). Despite these complexities, it is shown that (i) several hydrophobic materials, such as Teflon and Zeonor, have predictable electrokinetic properties and (ii) electrokinetic data for hydrophobic microfluidic systems is most consistent with the postulate that hydroxyl ion adsorption is the origin of charge.

  2. Analytic Couple Modeling Introducing Device Design Factor, Fin Factor, Thermal Diffusivity Factor, and Inductance Factor

    Science.gov (United States)

    Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

    2014-01-01

    A set of convenient thermoelectric device solutions have been derived in order to capture a number of factors which are previously only resolved with numerical techniques. The concise conversion efficiency equations derived from governing equations provide intuitive and straight-forward design guidelines. These guidelines allow for better device design without requiring detailed numerical modeling. The analytical modeling accounts for factors such as i) variable temperature boundary conditions, ii) lateral heat transfer, iii) temperature variable material properties, and iv) transient operation. New dimensionless parameters, similar to the figure of merit, are introduced including the device design factor, fin factor, thermal diffusivity factor, and inductance factor. These new device factors allow for the straight-forward description of phenomenon generally only captured with numerical work otherwise. As an example a device design factor of 0.38, which accounts for thermal resistance of the hot and cold shoes, can be used to calculate a conversion efficiency of 2.28 while the ideal conversion efficiency based on figure of merit alone would be 6.15. Likewise an ideal couple with efficiency of 6.15 will be reduced to 5.33 when lateral heat is accounted for with a fin factor of 1.0.

  3. Characterization of Charge-Carrier Transport in Semicrystalline Polymers: Electronic Couplings, Site Energies, and Charge-Carrier Dynamics in Poly(bithiophene- alt -thienothiophene) [PBTTT

    KAUST Repository

    Poelking, Carl

    2013-01-31

    We establish a link between the microscopic ordering and the charge-transport parameters for a highly crystalline polymeric organic semiconductor, poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT). We find that the nematic and dynamic order parameters of the conjugated backbones, as well as their separation, evolve linearly with temperature, while the side-chain dynamic order parameter and backbone paracrystallinity change abruptly upon the (also experimentally observed) melting of the side chains around 400 K. The distribution of site energies follows the behavior of the backbone paracrystallinity and can be treated as static on the time scale of a single-charge transfer reaction. On the contrary, the electronic couplings between adjacent backbones are insensitive to side-chain melting and vary on a much faster time scale. The hole mobility, calculated after time-averaging of the electronic couplings, reproduces well the value measured in a short-channel thin-film transistor. The results underline that to secure efficient charge transport in lamellar arrangements of conjugated polymers: (i) the electronic couplings should present high average values and fast dynamics, and (ii) the energetic disorder (paracrystallinity) should be small. © 2013 American Chemical Society.

  4. Simulations and measurements of coupling impedance for modern particle accelerator devices

    CERN Document Server

    AUTHOR|(CDS)2158523; Biancacci, Nicolò; Mostacci, Andrea

    In this document it has been treated the study of the coupling impedance in modern devices, already installed or not, in different particle accelerators. In the specific case: • For a device in-phase of project, several simulations for impedance calculation have been done. • For a component already realized and used, measurements of coupling impedance value have been done. Simulations are used to determine the impact of the interconnect between to magnets, designed for the future particle accelerator FCC, on the overall impedance of the machine which is about 100 km long. In particular has been done a check between theory, simulations and measurements of components already built, allowing a better and deeper study of the component we have analysed. Controls that probably will be helpful to have a clear guideline in future works. The measurements instead concern in an existing component that was already used in LHC, the longest particle accelerator ever realised on the planet, 27 km long. The coupling impe...

  5. Optically enhanced charge transfer between C60 and single-wall carbon nanotubes in hybrid electronic devices

    Science.gov (United States)

    Allen, Christopher S.; Liu, Guoquan; Chen, Yabin; Robertson, Alex W.; He, Kuang; Porfyrakis, Kyriakos; Zhang, Jin; Briggs, G. Andrew D.; Warner, Jamie H.

    2013-12-01

    In this article we probe the nature of electronic interactions between the components of hybrid C60-carbon nanotube structures. Utilizing an aromatic mediator we selectively attach C60 molecules to carbon nanotube field-effect transistor devices. Structural characterization via atomic force and transmission electron microscopy confirm the selectivity of this attachment. Charge transfer from the carbon nanotube to the C60 molecules is evidenced by a blue shift of the Raman G+ peak position and increased threshold voltage of the transistor transfer characteristics. We estimate this charge transfer to increase the device density of holes per unit length by up to 0.85 nm-1 and demonstrate further optically enhanced charge transfer which increases the hole density by an additional 0.16 nm-1.In this article we probe the nature of electronic interactions between the components of hybrid C60-carbon nanotube structures. Utilizing an aromatic mediator we selectively attach C60 molecules to carbon nanotube field-effect transistor devices. Structural characterization via atomic force and transmission electron microscopy confirm the selectivity of this attachment. Charge transfer from the carbon nanotube to the C60 molecules is evidenced by a blue shift of the Raman G+ peak position and increased threshold voltage of the transistor transfer characteristics. We estimate this charge transfer to increase the device density of holes per unit length by up to 0.85 nm-1 and demonstrate further optically enhanced charge transfer which increases the hole density by an additional 0.16 nm-1. Electronic supplementary information (ESI) available: AFM line scans of the substrate before and after functionalization; scheme for measuring amorphous carbon coverage from TEM images; diameter comparisons of ac-TEM image and simulation of C60 molecule; Raman spectra D peak comparison; optical response of transfer properties of pristine devices; comparison between swept and pulsed Vg measurements

  6. Extreme Contrast Ratio Imaging of Sirius with a Charge Injection Device

    Science.gov (United States)

    Batcheldor, D.; Foadi, R.; Bahr, C.; Jenne, J.; Ninkov, Z.; Bhaskaran, S.; Chapman, T.

    2016-02-01

    The next fundamental steps forward in understanding our place in the universe could be a result of advances in extreme contrast ratio (ECR) imaging and point-spread function (PSF) suppression. For example, blinded by quasar light we have yet to fully understand the processes of galaxy and star formation and evolution, and there is an ongoing race to obtain a direct image of an exo-Earth lost in the glare of its host star. To fully explore the features of these systems, we must perform observations in which contrast ratios (CRs) of at least one billion can be regularly achieved with sub 0.″1 inner working angles. Here, we present the details of a latest-generation 32-bit charge injection device (CID) that could conceivably achieve CRs on the order of one billion. We also demonstrate some of its ECR imaging abilities for astronomical imaging. At a separation of two arcminutes, we report a direct CR of {{Δ }}{m}v=18.3,{log}({CR})=7.3, or 1 part in 20 million, from observations of the Sirius field. The atmospheric conditions present during the collection of this data prevented less modest results, and we expect to be able to achieve higher CRs, with improved inner working angles, simply by operating a CID at a world-class observing site. However, CIDs do not directly provide any PSF suppression. Therefore, combining CID imaging with a simple PSF suppression technique like angular differential imaging could provide a cheap and easy alternative to the complex ECR techniques currently being employed.

  7. Searching for the dual of the Maxwell-Chern-Simons model minimally coupled to dynamical U(1) charged matter

    International Nuclear Information System (INIS)

    The possibility of dual equivalence between the self-dual and the Maxwell-Chern-Simons (MCS) models when the latter is coupled to dynamical, U(1) fermionic charged matter is examined. The proper coupling in the self-dual model is then disclosed using the iterative gauge embedding approach. We found that the self-dual potential needs to couple directly to the Chern kernel of the source in order to establish this equivalence besides the need for a self-interaction term to render the matter sector unchanged

  8. Magnetic field controlled charge density wave coupling in underdoped YBa2Cu3O6+x

    DEFF Research Database (Denmark)

    Chang, J.; Blackburn, E.; Ivashko, O.;

    2016-01-01

    The application of magnetic fields to layered cuprates suppresses their high-temperature superconducting behaviour and reveals competing ground states. In widely studied underdoped YBa2Cu3O6+x (YBCO), the microscopic nature of field-induced electronic and structural changes at low temperatures...... at B∼15 T. The CDW signal along the a-direction is also enhanced by field, but does not develop an additional pattern of correlations. Magnetic field modifies the coupling between the CuO2 bilayers in the YBCO structure, and causes the sudden appearance of the 3D CDW order. The mirror symmetry...... remains unclear. Here we report an X-ray study of the high-field charge density wave (CDW) in YBCO. For hole dopings ∼ 0.123, we find that a field (B∼10 T) induces additional CDW correlations along the CuO chain (b-direction) only, leading to a three-dimensional (3D) ordered state along this direction...

  9. Electronic coupling effects and charge transfer between organic molecules and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Forker, Roman

    2010-07-01

    We employ a variant of optical absorption spectroscopy, namely in situ differential reflectance spectroscopy (DRS), for an analysis of the structure-properties relations of thin epitaxial organic films. Clear correlations between the spectra and the differently intense coupling to the respective substrates are found. While rather broad and almost structureless spectra are obtained for a quaterrylene (QT) monolayer on Au(111), the spectral shape resembles that of isolated molecules when QT is grown on graphite. We even achieve an efficient electronic decoupling from the subjacent Au(111) by inserting an atomically thin organic spacer layer consisting of hexa-peri-hexabenzocoronene (HBC) with a noticeably dissimilar electronic behavior. These observations are further consolidated by a systematic variation of the metal substrate (Au, Ag, and Al), ranging from inert to rather reactive. For this purpose, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) is chosen to ensure comparability of the molecular film structures on the different metals, and also because its electronic alignment on various metal surfaces has previously been studied with great intensity. We present evidence for ionized PTCDA at several interfaces and propose the charge transfer to be related to the electronic level alignment governed by interface dipole formation on the respective metals. (orig.)

  10. Magnetic field controlled charge density wave coupling in underdoped YBa2Cu3O6+x

    Science.gov (United States)

    Chang, J.; Blackburn, E.; Ivashko, O.; Holmes, A. T.; Christensen, N. B.; Hücker, M.; Liang, Ruixing; Bonn, D. A.; Hardy, W. N.; Rütt, U.; Zimmermann, M. V.; Forgan, E. M.; Hayden, S. M.

    2016-05-01

    The application of magnetic fields to layered cuprates suppresses their high-temperature superconducting behaviour and reveals competing ground states. In widely studied underdoped YBa2Cu3O6+x (YBCO), the microscopic nature of field-induced electronic and structural changes at low temperatures remains unclear. Here we report an X-ray study of the high-field charge density wave (CDW) in YBCO. For hole dopings ~0.123, we find that a field (B~10 T) induces additional CDW correlations along the CuO chain (b-direction) only, leading to a three-dimensional (3D) ordered state along this direction at B~15 T. The CDW signal along the a-direction is also enhanced by field, but does not develop an additional pattern of correlations. Magnetic field modifies the coupling between the CuO2 bilayers in the YBCO structure, and causes the sudden appearance of the 3D CDW order. The mirror symmetry of individual bilayers is broken by the CDW at low and high fields, allowing Fermi surface reconstruction, as recently suggested.

  11. Direct coupling between charge current and spin polarization by extrinsic mechanisms in graphene

    Science.gov (United States)

    Huang, Chunli; Chong, Y. D.; Cazalilla, Miguel A.

    2016-08-01

    Spintronics—the all-electrical control of the electron spin for quantum or classical information storage and processing—is one of the most promising applications of the two-dimensional material graphene. Although pristine graphene has negligible spin-orbit coupling (SOC), both theory and experiment suggest that SOC in graphene can be enhanced by extrinsic means, such as functionalization by adatom impurities. We present a theory of transport in graphene that accounts for the spin-coherent dynamics of the carriers, including hitherto-neglected spin precession processes taking place during resonant scattering in the dilute impurity limit. We uncover an "anisotropic spin precession" (ASP) scattering process in graphene, which contributes a large current-induced spin polarization and modifies the standard spin Hall effect. ASP scattering arises from two dimensionality and extrinsic SOC, and apart from graphene, it can be present in other 2D materials or in the surface states of 3D materials with a fluctuating SOC. Our theory also yields a comprehensive description of the spin relaxation mechanisms present in adatom-decorated graphene, including Elliot-Yafet and D'yakonov-Perel relaxation rates, the latter of which can become an amplification process in a certain parameter regime of the SOC disorder potential. Our work provides theoretical foundations for designing future graphene-based integrated spintronic devices.

  12. An Optimal Design of Multiple Antenna Positions on Mobile Devices Based on Mutual Coupling Analysis

    Directory of Open Access Journals (Sweden)

    Peerapong Uthansakul

    2011-01-01

    Full Text Available The topic of practical implementation of multiple antenna systems for mobile communications has recently gained a lot of attention. Due to the area constraint on a mobile device, the problem of how to design such a system in order to achieve the best benefit is still a huge challenge. In this paper, genetic algorithm (GA is used to find the optimal antenna positions on a mobile device. Two cases of 3×3 and 4×4 MIMO systems are undertaken. The effect of mutual coupling based on Z-parameter is the main factor to determine the MIMO capacity concerning the objective function of GA search. The results confirm the success of the proposed method to design MIMO antenna positions on a mobile device. Moreover, this paper introduces the method to design the antenna positions for the condition of nondeterministic channel. The concern of channel variation has been included in the process of finding optimal MIMO antenna positions. The results suggest that the averaging position from all GA solutions according to all channel conditions provides the most acceptable benefit.

  13. Charge generation layers for all-solution processed organic tandem light emitting diodes with regular device architecture

    Science.gov (United States)

    Höfle, Stefan; Bernhard, Christoph; Bruns, Michael; Kübel, Christian; Scherer, Torsten; Colsmann, Alexander

    2015-10-01

    We present multi-photon OLEDs where enhanced light emission was achieved by stacking two OLEDs utilizing a regular device architecture (top cathode) and an intermediate charge carrier generation layer (CGL) for monolithic device interconnection. With respect to future printing processes for organic optoelectronic devices, all functional layers were deposited from solution. The CGL comprises a low-work function zinc oxide layer that was applied from solution under ambient conditions and at moderate processing temperatures and a high-work function interlayer that was realized from various solution processable precursor-based metal oxides, like molybdenum-, vanadium- and tungsten-oxide. Since every injected electron-hole pair generates two photons, the luminance and the current efficiency of the tandem OLED at a given device current are doubled while the power efficiency remains constant. At a given luminance, the lower operating current in the tandem device reduces electrical stress and improves the device life-time. ToF-SIMS, TEM/FIB and EDX analyses provided evidence of a distinct layer sequence without intermixing upon solution deposition.

  14. Modeling Improvements for Air Source Heat Pumps using Different Expansion Devices at Varied Charge Levels Part II

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL

    2011-01-01

    This paper describes steady-state performance simulations performed on a 3-ton R-22 split heat pump in heating mode. In total, 150 steady-state points were simulated, which covers refrigerant charge levels from 70 % to 130% relative to the nominal value, the outdoor temperatures at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C), indoor air flow rates from 60% to 150% of the rated air flow rate, and two types of expansion devices (fixed orifice and thermostatic expansion valve). A charge tuning method, which is to calibrate the charge inventory model based on measurements at two operation conditions, was applied and shown to improve the system simulation accuracy significantly in an extensive range of charge levels. In addition, we discuss the effects of suction line accumulator in modeling a heat pump system using either a fixed orifice or thermal expansion valve. Last, we identify the issue of refrigerant mass flow mal-distribution at low charge levels and propose an improved modeling approach.

  15. Measurements of Ion Selective Containment on the RF Charge Breeder Device BRIC

    CERN Document Server

    Variale, Vincenzo; Batazova, Marina; Boggia, Antonio; Clauser, Tarcisio; Kuznetsov, Gennady I; Rainò, Antonio; Shiyankov, Sergey; Skarbo, Boris A; Valentino, Vincenzo; Verrone, Grazia

    2005-01-01

    The "charge state breeder" BRIC (BReeding Ion Charge) is based on an EBIS source and it is designed to accept Radioactive Ion Beam (RIB) with charge +1, in a slow injection mode, to increase their charge state up to +n. BRIC has been developed at the INFN section of Bari (Italy) during these last 3 years with very limited funds. Now, it has been assembled at the LNL (Italy) where are in progress the first tests as stand alone source. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion drift chamber, of a Radio Frequency (RF) Quadrupole aiming to filtering the unwanted elements and then making a more efficient containment of the wanted ions. In this contribution, the measurements of the selective effect on the ion charge state containement of the RF quadrupole field, applied on the ion chamber, will be reported and discussed. The ion charge state analisys of the ions trapped in BRIC seem confirm, as foreseen by simulation results carried out previously, that the s...

  16. A new pathway of Saturnian ring-ionosphere coupling via charged nanograins

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chin-Min; Ip, Wing-Huen, E-mail: wingip@astro.ncu.edu.tw [Institute of Space Science, National Central University, Jhongli City, Taoyuan County 32001, Taiwan (China)

    2014-05-01

    From a re-examination of the trajectories of small charged grains in the vicinity of the Saturnian rings, it is shown that the orbital motion of positively charged grains with a charge-to-mass ratio on the order of 10{sup –6} e amu{sup –1} could allow the injection of water material into the equatorial atmosphere. Thus, a mechanism of ionospheric depletion in the equatorial region is provided, as indicated by the Cassini radio occultation measurements.

  17. Target-charge dependence of the breakup coupling effects in the elastic scattering of {sup 8}B

    Energy Technology Data Exchange (ETDEWEB)

    Kucuk, Y. [University of Padova, Department of Physics and Astronomy ' ' G. Galilei' ' (Italy); Akdeniz University, Department of Physics, Antalya (Turkey); INFN, Padova (Italy); Aciksoz, E. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Akdeniz University, Department of Physics, Antalya (Turkey)

    2016-04-15

    We perform continuum discretized coupled-channels calculations for the elastic scattering of {sup 8}B on different targets to trace where the Coulomb-nuclear breakup coupling effects start to be dominant in the interaction of the proton halo nuclei. We observe a qualitative difference in angular distributions when the charge of the target increases as seen in the case of neutron halos, but the Coulomb-nuclear interference peak begins to disappear clearly at a relatively smaller value of Z{sub T} for the proton halos. (orig.)

  18. Measurement of charged current triple gauge boson couplings using W pairs at LEP

    CERN Document Server

    Abbiendi, G; Åkesson, P F; Alexander, G; Allison, J; Amaral, P; Anagnostou, G; Anderson, K J; Arcelli, S; Asai, S; Axen, D A; Azuelos, Georges; Bailey, I; Barberio, E; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brigliadori, L; Brown, R M; Büsser, K; Burckhart, H J; Campana, S; Carnegie, R K; Caron, B; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Csilling, Akos; Cuffiani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Feld, L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Fürtjes, A; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harder, K; Harel, A; Harin-Dirac, M; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Hensel, C; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J; Karapetian, G V; Karlen, Dean A; Kawagoe, K; Kawamoto, T; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klein, K; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kormos, L L; Kramer, T; Krieger, P; Von Krogh, J; Krüger, K; Kühl, T; Kupper, M; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Layter, J G; Leins, A; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, A W; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A; Mader, W; Marcellini, S; Martin, A J; Masetti, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McMahon, T J; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Moed, S; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Okpara, A N; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Patrick, G N; Pilcher, J E; Pinfold, J L; Plane, D E; Poli, B; Polok, J; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rosati, S; Roscoe, K; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Stephens, K; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Taylor, R J; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2004-01-01

    Triple gauge boson couplings are measured from W-pair and single photon events recorded by the OPAL detector at LEP at center-of-mass energies between 183 - 209 GeV with a total integrated luminosity of 680 inverse picobarns. Only CP-conserving couplings are considered and SU(2)xU(1) relations between the WWZ and the WWgamma couolings are used, resulting in four independent couplings. Each coupling is determined in a separate fit, assuming the other couplings to take their Standard Model values. Fits are also done allowing some of the couplings to vary simultaneously. The results are compared with the Standard Model predictions.

  19. Coupling between pore formation and phase separation in charged lipid membranes

    Science.gov (United States)

    Himeno, Hiroki; Ito, Hiroaki; Higuchi, Yuji; Hamada, Tsutomu; Shimokawa, Naofumi; Takagi, Masahiro

    2015-12-01

    We investigated the effect of charge on the membrane morphology of giant unilamellar vesicles (GUVs) composed of various mixtures containing charged lipids. We observed the membrane morphologies by fluorescent and confocal laser microscopy in lipid mixtures consisting of a neutral unsaturated lipid [dioleoylphosphatidylcholine (DOPC)], a neutral saturated lipid [dipalmitoylphosphatidylcholine (DPPC)], a charged unsaturated lipid [dioleoylphosphatidylglycerol (DOP G(-)) ], a charged saturated lipid [dipalmitoylphosphatidylglycerol (DPP G(-)) ], and cholesterol (Chol). In binary mixtures of neutral DOPC-DPPC and charged DOPC -DPP G(-) , spherical vesicles were formed. On the other hand, pore formation was often observed with GUVs consisting of DOP G(-) and DPPC. In a DPPC-DPPG(-) -Chol ternary mixture, pore-formed vesicles were also frequently observed. The percentage of pore-formed vesicles increased with the DPP G(-) concentration. Moreover, when the head group charges of charged lipids were screened by the addition of salt, pore-formed vesicles were suppressed in both the binary and ternary charged lipid mixtures. We discuss the mechanisms of pore formation in charged lipid mixtures and the relationship between phase separation and the membrane morphology. Finally, we reproduce the results seen in experimental systems by using coarse-grained molecular dynamics simulations.

  20. Single Charge Current in a Normal Mesoscopic Region Attached to Superconductor Leads via a Coupled Poisson Nonequilibrium Green Function Formalism

    Directory of Open Access Journals (Sweden)

    David Verrilli

    2014-01-01

    Full Text Available We study the I-V characteristic of mesoscopic systems or quantum dot (QD attached to a pair of superconducting leads. Interaction effects in the QD are considered through the charging energy of the QD; that is, the treatment of current transport under a voltage bias is performed within a coupled Poisson nonequilibrium Green function (PNEGF formalism. We derive the expression for the current in full generality but consider only the regime where transport occurs only via a single particle current. We show for this case and for various charging energies values U0 and associated capacitances of the QD the effect on the I-V characteristic. Also the influence of the coupling constants on the I-V characteristic is investigated. Our approach puts forward a novel interpretation of experiments in the strong Coulomb regime.

  1. Phonon-electron coupling and tunneling effect on charge transport in organic semi-conductor crystals of Cn-BTBT.

    Science.gov (United States)

    Zhou, Yecheng; Deng, Wei-Qiao; Zhang, Hao-Li

    2016-09-14

    Cn-[1]benzothieno[3,2-b][1]-benzothiophene (BTBT) crystals show very high hole mobilities in experiments. These high mobilities are beyond existing theory prediction. Here, we employed different quantum chemistry methods to investigate charge transfer in Cn-BTBT crystals and tried to find out the reasons for the underestimation in the theory. It was found that the hopping rate estimated by the Fermi Golden Rule is higher than that of the Marcus theory due to the high temperature approximation and failure at the classic limit. More importantly, molecular dynamics simulations revealed that the phonon induced fluctuation of electronic transfer integral is much larger than the average of the electronic transfer integral itself. Mobilities become higher if simulations implement the phonon-electron coupling. This conclusion indicates that the phonon-electron coupling promotes charge transfer in organic semi-conductors at room temperature. PMID:27634252

  2. Single-event phenomena on recent semiconductor devices. Charge-type multiple-bit upsets in high integrated memories

    Energy Technology Data Exchange (ETDEWEB)

    Makihara, Akiko; Shindou, Hiroyuki; Nemoto, Norio; Kuboyama, Satoshi; Matsuda, Sumio [National Space Development Agency, Tokyo (Japan); Ohshima, Takeshi; Hirao, Toshio; Itoh, Hisayoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-02-01

    High integrated memories are used in solid state data recorder (SSDR) of the satellite for accumulating observation data. Single event upset phenomena which turn over an accumulated data in the memory cells are caused by heavy ion incidence. Studies on single-bit upset and multiple-bit upset phenomena in the high integrated memory cells are in progress recently. 16 Mbit DRAM (Dynamic Random Access Memories) and 64 Mbit DRAM are irradiated by heavy ion species, such as iodine, bromine and nickel, in comparison with the irradiation damage in the cosmic environment. Data written on the memory devices are read out after the irradiation. The memory cells in three kinds of states, all of charged state, all of discharged state, and an alternative state of charge and discharge, are irradiated for sorting out error modes caused by heavy ion incidence. The soft error in a single memory cells is known as a turn over from charged state to discharged state. Electrons in electron-hole pair generated by heavy ion incidence are captured in a diffusion region between capacitor electrodes of semiconductor. The charged states in the capacitor electrodes before the irradiation are neutralized and changed to the discharged states. According to high integration of the memories, many of the cells are affected by a single ion incidence. The multiple-bit upsets, however, are generated in the memory cells of discharged state before the irradiation, also. The charge-type multiple-bit upsets is considered as that error data are written on the DRAM during refresh cycle of a sense-up circuit and a pre-charge circuit which control the DRAM. (M. Suetake)

  3. Nonlinear Dynamics of an Ambient Noise Driven Array of Coupled Graphene Nanostructured Devices for Energy Harvesting

    Directory of Open Access Journals (Sweden)

    El Aroudi A.

    2014-01-01

    Full Text Available Nonlinearities have been shown to play an important role in increasing the extracted energy of energy harvesting devices at the macro and micro scales. Vibration-based energy harvesting on the nano scale has also received attention. In this paper, we characterize the nonlinear dynamical behavior of an array of three coupled strained nanostructured graphene for its potential use in energy harvesting applications. The array is formed by three compressed vibrating membrane graphene sheet subject to external vibrational noise excitation. We present the continuous time dynamical model of the system in the form of a double-well three degree of freedom system. Random vibrations are considered as the main ambient energy source for the system and its performances in terms of the probability density function, RMS or amplitude value of the position, FFT spectra and state plane trajectories are presented in the steady state non-equilibrium regime when the noise level is considered as a control parameter.

  4. Enhancement of effective electromechanical coupling factor by mass loading in layered surface acoustic wave device structures

    Science.gov (United States)

    Tang, Gongbin; Han, Tao; Teshigahara, Akihiko; Iwaki, Takao; Hashimoto, Ken-ya

    2016-07-01

    This paper describes a drastic enhancement of the effective coupling factor K\\text{e}2 by mass loading in layered surface acoustic wave (SAW) device structures such as the ScAlN film/Si substrate structure. This phenomenon occurs when the piezoelectric layer exhibits a high acoustic wave velocity. The mass loading decreases the SAW velocity and causes SAW energy confinement close to the top surface where an interdigital transducer is placed. It is shown that this phenomenon is obvious even when an amorphous SiO2 film is deposited on the top surface for temperature compensation. This K\\text{e}2 enhancement was also found in various combinations of electrode, piezoelectric layer, and/or substrate materials. The existence of this phenomenon was verified experimentally using the ScAlN film/Si substrate structure.

  5. SIMULATION STUDY OF LONGITUDINAL FORCES IN THE COUPLING DEVICE OF HEAVY FREIGHT TRAINS

    Directory of Open Access Journals (Sweden)

    Józef Stokłosa

    2014-03-01

    Full Text Available On the LHS line (Broad-gauge Metallurgical Line, far out West of the railway line with a gauge of 1520 mm, heavy goods trains for a gross weight 5500 tons and a length of 850 m are operated. The article presents the results of a simulation study of the forces that occur in the automatic coupling device of SA-3 type of Russian production train consisting of 60 coal wagons of Russian construction of gross mass 91 tons each. The train moves on the 1520 mm gauge tracks curve S type (the radius of curvature of curves 300 m. Simulation studies were conducted using the Train Module of program to dynamic study multi-elements systems of Universal Mechanism UM 6.0.

  6. Generation and characterization of a perfect vortex beam with a large topological charge through a digital micromirror device.

    Science.gov (United States)

    Chen, Yue; Fang, Zhao-Xiang; Ren, Yu-Xuan; Gong, Lei; Lu, Rong-De

    2015-09-20

    Optical vortices are associated with a spatial phase singularity. Such a beam with a vortex is valuable in optical microscopy, hyper-entanglement, and optical levitation. In these applications, vortex beams with a perfect circle shape and a large topological charge are highly desirable. But the generation of perfect vortices with high topological charges is challenging. We present a novel method to create perfect vortex beams with large topological charges using a digital micromirror device (DMD) through binary amplitude modulation and a narrow Gaussian approximation. The DMD with binary holograms encoding both the spatial amplitude and the phase could generate fast switchable, reconfigurable optical vortex beams with significantly high quality and fidelity. With either the binary Lee hologram or the superpixel binary encoding technique, we were able to generate the corresponding hologram with high fidelity and create a perfect vortex with topological charge as large as 90. The physical properties of the perfect vortex beam produced were characterized through measurements of propagation dynamics and the focusing fields. The measurements show good consistency with the theoretical simulation. The perfect vortex beam produced satisfies high-demand utilization in optical manipulation and control, momentum transfer, quantum computing, and biophotonics. PMID:26406501

  7. A comprehensive study of charge trapping in organic field-effect devices with promising semiconductors and different contact metals by displacement current measurements

    International Nuclear Information System (INIS)

    A systematic and comprehensive study on the charge-carrier injection and trapping behavior was performed using displacement current measurements in long-channel capacitors based on four promising small-molecule organic semiconductors (pentacene, DNTT, C10-DNTT and DPh-DNTT). In thin-film transistors, these semiconductors showed charge-carrier mobilities ranging from 1.0 to 7.8 cm2 V−1 s−1. The number of charges injected into and extracted from the semiconductor and the density of charges trapped in the device during each measurement were calculated from the displacement current characteristics and it was found that the density of trapped charges is very similar in all devices and of the order 1012 cm−2, despite the fact that the four semiconductors show significantly different charge-carrier mobilities. The choice of the contact metal (Au, Ag, Cu, Pd) was also found to have no significant effect on the trapping behavior. (paper)

  8. Sensor-actuator coupled device for active tracheal tube using solid polymer electrolyte membrane

    Science.gov (United States)

    Ihara, Tadashi; Nakamura, Taro; Mukai, Toshiharu; Asaka, Kinji

    2007-04-01

    A sensor-actuator coupled device was developed using solid polymer electrolyte membrane (SPM) as an active tracheal tube for ventilator. Active tracheal tube is a novel type of tube for ventilator that removes patient's phlegm automatically upon sensing the narrowing of trachea by phlegm. This type of active tube is extremely useful in clinical settings as currently the sole measure to remove phlegm from patient's tube is to do it manually by a nurse every few hours. As SPM works both as a sensor and an actuator, an effective compact device was developed. SPM based sensor-actuator coupled device was fabricated with modified gold plating method. Prepared SPM was fixed as an array on a plastic pipe of diameter 22 mm and was connected to a ventilator circuit and driven by a ventilator with a volume control ventilation (VCV) mode. SPM was connected both to a sensing unit and an actuation unit. Generated voltage developed by the membrane with the setting of the maximum pressure from 5 cmH IIO to 20 cmH IIO was in order of several hundred μV. SPM sensor demonstrated a biphasic response to the ventilator flow. The sensor data showed nearly linearly proportional voltage development to the intra-tracheal pressure. The sensed signal was filtered and digitized with an A/D converting unit on a PC board. A real time operating program was used to detect the sensed signal that indicates the narrowing of trachea. The program then activated a driving signal to control the actuation of the membrane. The signal was sent to a D/A converting unit. The output of the D/A unit was sent to an amplifier and the galvanostat unit which drives the membrane with constant current regardless of the change in the load. It was demonstrated that the sensor-actuator unit detects the narrowing of trachea within several hundreds milli-seconds and responds by actuating the same membrane with the driving voltage of 3-4 V and driving current of several hundred milli-ampere for each membrane. SPM array

  9. Correlation of charge extraction properties and short circuit current in various organic binary and ternary blend photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Singh, T.B.; Chen, Xiwen; Ehlig, Tino; Kemppinen, Peter; Chen, Ming; Watkins, Scott E.; Winzenberg, Kevin N. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Materials Science and Engineering, Clayton South, Victoria (Australia); Wong, Wallace W.H.; Jones, David J. [University of Melbourne, School of Chemistry, Bio21 Institute, Parkville, Victoria (Australia); Holdcroft, Steven [Simon Fraser University, Dept. of Chemistry, Burnaby, British Columbia (Canada); Holmes, Andrew B. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Materials Science and Engineering, Clayton South, Victoria (Australia); University of Melbourne, School of Chemistry, Bio21 Institute, Parkville, Victoria (Australia)

    2012-09-15

    Charge extraction properties of various binary and ternary blends of organic photovoltaic devices covering both polymers and small molecules are studied. Due to their bipolar nature, both slow and fast carrier mobilities are identified from the extraction current transient. The equilibrium carrier concentration is also estimated for each of the blend films. The product of the slow carrier mobility and equilibrium concentration spreading two orders of magnitude can be used to estimate the short circuit current density. A good agreement between the estimated and measured short circuit current density is obtained with the accuracy reliant on the estimation of the slowest carrier mobility. This simplistic approach will be very useful to predict the short circuit current density for devices based on new materials. (orig.)

  10. Charge-based particle separation in microfluidic devices using combined hydrodynamic and electrokinetic effects

    NARCIS (Netherlands)

    Jellema, L. C.; Mey, T.; Koster, S.; Verpoorte, E.

    2009-01-01

    A new microfluidic approach for charge-based particle separation using combined hydrodynamic and electrokinetic effects is presented. A recirculating flow pattern is employed, generated through application of bi-directional flow in a narrow glass microchannel incorporating diverging or converging se

  11. Transistor memory devices with large memory windows, using multi-stacking of densely packed, hydrophobic charge trapping metal nanoparticle array

    International Nuclear Information System (INIS)

    Organic field-effect transistor (OFET) memories have rapidly evolved from low-cost and flexible electronics with relatively low-memory capacities to memory devices that require high-capacity memory such as smart memory cards or solid-state hard drives. Here, we report the high-capacity OFET memories based on the multilayer stacking of densely packed hydrophobic metal NP layers in place of the traditional transistor memory systems based on a single charge trapping layer. We demonstrated that the memory performances of devices could be significantly enhanced by controlling the adsorption isotherm behavior, multilayer stacking structure and hydrophobicity of the metal NPs. For this study, tetraoctylammonium (TOA)-stabilized Au nanoparticles (TOA-AuNPs) were consecutively layer-by-layer (LbL) assembled with an amine-functionalized poly(amidoamine) dendrimer (PAD). The formed (PAD/TOA-AuNP)n films were used as a multilayer stacked charge trapping layer at the interface between the tunneling dielectric layer and the SiO2 gate dielectric layer. For a single AuNP layer (i.e. PAD/TOA-AuNP)1) with a number density of 1.82 × 1012 cm−2, the memory window of the OFET memory device was measured to be approximately 97 V. The multilayer stacked OFET memory devices prepared with four AuNP layers exhibited excellent programmable memory properties (i.e. a large memory window (ΔVth) exceeding 145 V, a fast switching speed (1 μs), a high program/erase (P/E) current ratio (greater than 106) and good electrical reliability) during writing and erasing over a relatively short time scale under an operation voltage of 100 V applied at the gate. (paper)

  12. Real space Eliashberg approach to charge order of electrons coupled to dynamic antiferromagnetic fluctuations

    OpenAIRE

    Bauer, Johannes; Sachdev, Subir(Department of Physics, Harvard University, Cambridge, MA, 02138, USA)

    2015-01-01

    We study charge ordered solutions for fermions on a square lattice interacting with dynamic antiferromagnetic fluctuations. Our approach is based on real space Eliashberg equations which are solved self-consistently. We first show that the antiferromagnetic fluctuations can induce arc features in the spectral functions, as spectral weight is suppressed at the hot spots; however, no real pseudogap is generated. At low temperature spontaneous charge order with a $d$-form factor can be stabilize...

  13. Test of charge injection device, phase 1. [prospective star tracker application

    Science.gov (United States)

    Gradinger, A.; Sayles, M. B.; Peters, D.; Buckley, P.

    1981-01-01

    A computer-controlled automatic facility containing two interactive microprocessors, peripherals, and an optical bench was used to obtain device characteristics for use in evaluating CID's as the sensor element in a prospective star tracker application. Each of the ST-256 chips tested contains a 256 x 256 pixel element array with 65536 picture elements. Two ST-256 devices were tested at 20 C under light levels of 10%, 0.1%, and 0.01% saturation, and in darkness. The saturation level was established at 0.95 microwatts sq cm as measured by the radiometeric sensor. Two test runs under each condition were performed for each chip. Two complete sets of data for each of the devices were thus obtained. A separate data field was used to store the results of each test condition. Repetitive runs of a test condition were stored sequentially in the same file. Examination of the data using print-outs is shown in examples.

  14. Peculiarities of charge transport in a semiconductor gas discharge electronic devices

    International Nuclear Information System (INIS)

    The memory effect in planar semiconductor gas discharge system at different pressures (15-760) and interelectrode distance (60-445 μm) were experimentally studied. The study was performed on the bases of current-voltage characteristic (CVC) measurements with the time lag of several hours of afterglow periods. The influence of the active space-charge remaining from previous discharge on the breakdown voltage has been analyzed using the CVC method for different conductivity of semiconductor GaAs photocathode. On the other hand, the CVC data for subsequent dates present a correlation of memory effect and hysteresis behaviour. The explanation of such relation is based on the influence of long-lived active charges on the electronic transport mechanism of semiconductor material

  15. Charge Transport and Electrical Properties of Spin Crossover Materials: Towards Nanoelectronic and Spintronic Devices

    OpenAIRE

    Constantin LEFTER; Davesne, Vincent; Salmon, Lionel; Molnar, Gabor; Demont, Philippe; Rotaru, Aurelian; Bousseksou, Azzedine

    2016-01-01

    International audience In this paper, we present a comprehensive review of research on electrical and charge transport properties of spin crossover complexes. This includes both the effect of spin-state switching on the dielectric permittivity and electrical conductivity of the material and vice versa the influence of an applied electrical field (or current) on the spin-state of the system. The survey covers different size scales from bulk materials and thin films to nanoparticles and sing...

  16. Device and Method for Continuously Equalizing the Charge State of Lithium Ion Battery Cells

    Science.gov (United States)

    Schwartz, Paul D. (Inventor); Martin, Mark N. (Inventor); Roufberg, Lewis M. (Inventor)

    2015-01-01

    A method of equalizing charge states of individual cells in a battery includes measuring a previous cell voltage for each cell, measuring a previous shunt current for each cell, calculating, based on the previous cell voltage and the previous shunt current, an adjusted cell voltage for each cell, determining a lowest adjusted cell voltage from among the calculated adjusted cell voltages, and calculating a new shunt current for each cell.

  17. Electrochemical studies of excited charge carriers with thin platinum film electronic devices in sulfuric and hydrochloric solution

    Energy Technology Data Exchange (ETDEWEB)

    Buerstel, Damian; Scheele, Michael; Barmscheid, Andreas; Stella, Kevin; Diesing, Detlef [Fakultaet fuer Chemie, Universitaet Duisburg-Essen, D-45117 Essen (Germany)

    2011-07-01

    Excited charge carriers induced by chemical processes like the adsorption or desorption of atomic hydrogen at metal surfaces have already been investigated under UHV conditions. These carriers can be detected by systems with an internal electric barrier, like MIM-(metal-insulator-metal), MIS- (metal-insulator-semiconductor) or MS- (metal-semiconductor) sensors. The internal barrier inside the sensors separates ground state carriers from excited carriers. It is an open question, whether electrochemical reactions on metal surfaces also evoke hot charge carriers. We study the electrochemical deposition of hydrogen (via H{sub upd}) on platinum and the oxidation of platinum in sulfuric and hydrochloric solution. As sensors Pt-TaOx-Ta, Pt-SiOx-Si and Pt-Si-sensors were used with 10-30 nm thick Pt films. By electrochemical cyclovoltametry and simultaneous recording of the current at the tantalum or silicon back electrode it is possible to detect voids (down to a fraction of 10{sup -3}) in the thin platinum film. 30 nm thick platinum films were found to cover the underlying layer completely. In this case the devices can be used to monitor deviations from the electronic equilibrium since excited carriers cause a device current through the internal barrier. Deviations from the electronic ground state were found in the case of the H{sub upd} formation.

  18. In vivo demonstration of ultrasound power delivery to charge implanted medical devices via acute and survival porcine studies.

    Science.gov (United States)

    Radziemski, Leon; Makin, Inder Raj S

    2016-01-01

    Animal studies are an important step in proving the utility and safety of an ultrasound based implanted battery recharging system. To this end an Ultrasound Electrical Recharging System (USER™) was developed and tested. Experiments in vitro demonstrated power deliveries at the battery of up to 600 mW through 10-15 mm of tissue, 50 mW of power available at tissue depths of up to 50 mm, and the feasibility of using transducers bonded to titanium as used in medical implants. Acute in vivo studies in a porcine model were used to test reliability of power delivery, temperature excursions, and cooling techniques. The culminating five-week survival study involved repeated battery charging, a total of 10.5h of ultrasound exposure of the intervening living tissue, with an average RF input to electrical charging efficiency of 20%. This study was potentially the first long term cumulative living-tissue exposure using transcutaneous ultrasound power transmission to an implanted receiver in situ. Histology of the exposed tissue showed changes attributable primarily due to surgical implantation of the prototype device, and no damage due to the ultrasound exposure. The in vivo results are indicative of the potential safe delivery of ultrasound energy for a defined set of source conditions for charging batteries within implants.

  19. Development of nanomanipulator using a high-speed atomic force microscope coupled with a haptic device

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, F., E-mail: tmfiwat@ipc.shizuoka.ac.jp [Faculty of Engineering, Shizuoka University, Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, Johoku, Naka-ku, Hamamatsu 432-8011 (Japan); Ohashi, Y.; Ishisaki, I. [Faculty of Engineering, Shizuoka University, Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Picco, L.M. [H Will Physics Laboratory and IRC in Nanotechnology, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Ushiki, T. [Graduate School of Medical and Dental Sciences, Niigata University, Asahimachidori, Niigata, 951-8122 (Japan)

    2013-10-15

    The atomic force microscope (AFM) has been widely used for surface fabrication and manipulation. However, nanomanipulation using a conventional AFM is inefficient because of the sequential nature of the scan-manipulation scan cycle, which makes it difficult for the operator to observe the region of interest and perform the manipulation simultaneously. In this paper, a nanomanipulation technique using a high-speed atomic force microscope (HS-AFM) is described. During manipulation using the AFM probe, the operation is periodically interrupted for a fraction of a second for high-speed imaging that allows the topographical image of the manipulated surface to be periodically updated. With the use of high-speed imaging, the interrupting time for imaging can be greatly reduced, and as a result, the operator almost does not notice the blink time of the interruption for imaging during the manipulation. This creates a more intuitive interface with greater feedback and finesse to the operator. Nanofabrication under real-time monitoring was performed to demonstrate the utility of this arrangement for real-time nanomanipulation of sample surfaces under ambient conditions. Furthermore, the HS-AFM is coupled with a haptic device for the human interface, enabling the operator to move the HS-AFM probe to any position on the surface while feeling the response from the surface during the manipulation. - Highlights: • A nanomanipulater based on a high-speed atomic force microscope was developped. • High-speed imaging provides a valuable feedback during the manipulation operation. • Operator can feel the response from the surface via a haptic device during manipulation. • Nanofabrications under real-time monitoring were successfully performed.

  20. Spin-charge-family theory is explaining appearance of families of quarks and leptons, of Higgs and Yukawa couplings

    CERN Document Server

    Borstnik, Norma Susana Mankoc

    2013-01-01

    The so far observed three families of quarks and leptons, the vector gauge fields of the fermions charges and the scalar Higgs responsible for masses of fermions and weak bosons, all these confirming the standard model, make most of physicists to declare that the Higgs was the last missing particle to be confirmed. But can this at all be true? Is it not self evident that there must be additional scalar fields which manifest effectively the appearance of the Yukawa couplings and that the Yukawa couplings can only be understood if we understand the origin of families? The spin-charge-family theory is offering a possible explanation for the origin of families and also for several scalar fields, which are responsible for masses of fermions and weak vector boson fields. The theory is offering the explanation also for other assumptions of the standard model. The theory predicts at the observable regime two decoupled groups of four families. The fourth family, coupled to the measured three, will be observed at the L...

  1. Remarkable charge-trapping efficiency of the memory device with (TiO2)0.8(Al2O3)0.1 composite charge-storage dielectric

    Science.gov (United States)

    Jiang, K.; Ou, X.; Lan, X. X.; Cao, Z. Y.; Liu, X. J.; Lu, W.; Gong, C. J.; Xu, B.; Li, A. D.; Xia, Y. D.; Yin, J.; Liu, Z. G.

    2014-06-01

    A memory device p-Si/SiO2/(TiO2)0.8(Al2O3)0.1(TAO-81)/Al2O3/Pt was fabricated, in which a composite of two high-k dielectrics with a thickness of 1 nm was employed as the charge-trapping layer to enhance the charge-trapping efficiency of the memory device. At an applied gate voltage of ±9 V, TAO-81 memory device shows a memory window of 8.83 V in its C-V curve. It also shows a fast response to a short voltage pulse of 10-5 s. The charge-trapping capability, the endurance, and retention characteristics of TAO-81 memory device can be improved by introducing double TAO-81 charge-trapping layers intercalated by an Al2O3 layer. The charge-trapping mechanism in the memory device is mainly ascribed to the generation of the electron-occupied defect level in the band gap of Al2O3 induced by the inter-diffusion between TiO2 and Al2O3.

  2. Probing charged Higgs boson couplings at a future circular hadron collider

    Science.gov (United States)

    Ćakır, I. T.; Kuday, S.; Saygın, H.; Şenol, A.; ćakır, O.

    2016-07-01

    Many of the new physics models predict a light Higgs boson similar to the Higgs boson of the Standard Model (SM) and also extra scalar bosons. Beyond the search channels for a SM Higgs boson, the future collider experiments will explore additional channels that are specific to extended Higgs sectors. We study the charged Higgs boson production within the framework of two Higgs doublet models (THDM) in the proton-proton collisions at a future circular hadron collider (FCC-hh). With an integrated luminosity of Lint=500 fb-1 at very high energy frontier (√{s }=100 TeV ), we obtain a significant coverage of the parameter space and distinguish the charged Higgs-top-bottom interaction within the THDM or other new physics models with charged Higgs boson mass up to 1.5 TeV.

  3. Probing Charged Higgs Boson Couplings at the FCC-hh Collider

    CERN Document Server

    Cakir, I T; Saygin, H; Senol, A; Cakir, O

    2015-01-01

    Many of the new physics models predicts a light Higgs boson similar to the Higgs boson of the Standard Model (SM) and also extra scalar bosons. Beyond the search channels for a SM Higgs boson, the future collider experiments will explore additional channels that are specific to extended Higgs sectors. We study the charged Higgs boson production within the framework of two Higgs doublet models (THDM) in the proton-proton collisions at the FCC-hh collider. With an integrated luminosity of 500 fb$^{-1}$ at very high energy frontier, we obtain a significant coverage of the parameter space and distinguish the charged Higgs-top-bottom interaction within the THDM or other new physics models with charged Higgs boson mass up to 1 TeV.

  4. Conserved charges for black holes in Einstein-Gauss-Bonnet gravity coupled to nonlinear electrodynamics in AdS space

    CERN Document Server

    Miskovic, Olivera

    2010-01-01

    Motivated by possible applications within the framework of anti-de Sitter gravity/Conformal Field Theory (AdS/CFT) correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by a nonlinear electrodynamics (NED) are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary NED Lagrangian, in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Fall-off conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass...

  5. Precision matched solution of the coupled beam envelope equations for a periodic quadrupole lattice with space charge

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Edward P.

    2002-02-01

    The coupled Kapchinskij-Vladimirskij (K-V) envelope equations for a charged particle beam transported by a periodic system of quadrupoles with self-consistent space charge force have previously been solved by various approximate methods, with accuracy ranging from 1% to 10%. A new method of solution is introduced here, which is based on a double expansion of the beam envelope functions in powers of the focal strength and either the beam's emittance or its dimensionless perveance. This method results in accuracy better than 0.1% for typical lattice and beam parameters when carried through one consistent level of approximation higher than employed in previous work. Several useful quantities, such as the values of the undepressed tune and the beam's perveance in the limit of vanishing emittance, are represented by very rapidly converging power series in the focal strength, with accuracy of .01% or better.

  6. Linear, third- and fifth-order nonlinear spectroscopy of a charge transfer system coupled to an underdamped vibration

    CERN Document Server

    Dijkstra, Arend G

    2015-01-01

    We study hole, electron and exciton transport in a charge transfer system in the presence of underdamped vibrational motion. We analyze the signature of these processes in the linear and third-, and fifth-order nonlinear electronic spectra. Calculations are performed with a numerically exact hierarchical equations of motion method for an underdamped Brownian oscillator spectral density. We find that combining electron, hole and exciton transfer can lead to non-trivial spectra with more structure than with excitonic coupling alone. Traces taken during the waiting time of a two-dimensional spectrum are dominated by vibrational motion and do not reflect the electron, hole, and exciton dynamics directly. We find that the fifth-order nonlinear response is particularly sensitive to the charge transfer process. While third-order 2D spectroscopy detects the correlation between two coherences, fifth-order 2D spectroscopy (2D population spectroscopy) is here designed to detect correlations between the excited states du...

  7. Coupled quantum-classical method for long range charge transfer: relevance of the nuclear motion to the quantum electron dynamics

    International Nuclear Information System (INIS)

    Charge and excitonic-energy transfer phenomena are fundamental for energy conversion in solar cells as well as artificial photosynthesis. Currently, much interest is being paid to light-harvesting and energy transduction processes in supramolecular structures, where nuclear dynamics has a major influence on electronic quantum dynamics. For this reason, the simulation of long range electron transfer in supramolecular structures, under environmental conditions described within an atomistic framework, has been a difficult problem to study. This work describes a coupled quantum mechanics/molecular mechanics method that aims at describing long range charge transfer processes in supramolecular systems, taking into account the atomistic details of large molecular structures, the underlying nuclear motion, and environmental effects. The method is applied to investigate the relevance of electron–nuclei interaction on the mechanisms for photo-induced electron–hole pair separation in dye-sensitized interfaces as well as electronic dynamics in molecular structures. (paper)

  8. Coupled quantum-classical method for long range charge transfer: relevance of the nuclear motion to the quantum electron dynamics.

    Science.gov (United States)

    da Silva, Robson; Hoff, Diego A; Rego, Luis G C

    2015-04-10

    Charge and excitonic-energy transfer phenomena are fundamental for energy conversion in solar cells as well as artificial photosynthesis. Currently, much interest is being paid to light-harvesting and energy transduction processes in supramolecular structures, where nuclear dynamics has a major influence on electronic quantum dynamics. For this reason, the simulation of long range electron transfer in supramolecular structures, under environmental conditions described within an atomistic framework, has been a difficult problem to study. This work describes a coupled quantum mechanics/molecular mechanics method that aims at describing long range charge transfer processes in supramolecular systems, taking into account the atomistic details of large molecular structures, the underlying nuclear motion, and environmental effects. The method is applied to investigate the relevance of electron-nuclei interaction on the mechanisms for photo-induced electron-hole pair separation in dye-sensitized interfaces as well as electronic dynamics in molecular structures. PMID:25767107

  9. Electron Flood Charge Compensation Device for Ion Trap Secondary Ion Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Appelhans, Anthony David; Ward, Michael Blair; Olson, John Eric

    2002-11-01

    During secondary ion mass spectrometry (SIMS) analyses of organophosphorous compounds adsorbed onto soils, the measured anion signals were lower than expected and it was hypothesized that the low signals could be due to sample charging. An electron flood gun was designed, constructed and used to investigate sample charging of these and other sample types. The flood gun was integrated into one end cap of an ion trap secondary ion mass spectrometer and the design maintained the geometry of the self-stabilizing extraction optics used in this instrument. The SIMION ion optics program was used to design the flood gun, and experimental results agreed with the predicted performance. Results showed the low anion signals from the soils were not due to sample charging. Other insulating and conducting samples were tested using both a ReO4- and a Cs+ primary ion beam. The proximity of the sample and electron source to the ion trap aperture resulted in generation of background ions in the ion trap via electron impact (EI) ionization during the period the electron gun was flooding the sample region. When using the electron gun with the ReO4- primary beam, the required electron current was low enough that the EI background was negligible; however, the high electron flood current required with the Cs+ beam produced background EI ions that degraded the quality of the mass spectra. The consequences of the EI produced cations will have to be evaluated on a sample-by-sample basis when using electron flood. It was shown that the electron flood gun could be intentionally operated to produce EI spectra in this instrument. This offers the opportunity to measure, nearly simultaneously, species evaporating from a sample, via EI, and species bound to the surface, via SIMS.

  10. Numerical simulations of nanodiamond nitrogen-vacancy centers coupled with tapered optical fibers as hybrid quantum nanophotonic devices.

    Science.gov (United States)

    Almokhtar, Mohamed; Fujiwara, Masazumi; Takashima, Hideaki; Takeuchi, Shigeki

    2014-08-25

    Tapered optical fibers are promising one-dimensional nanophotonic waveguides that can provide efficient coupling between their fundamental mode and quantum nanoemitters placed inside them. Here, we present numerical studies on the coupling of single nitrogen-vacancy (NV) centers (single point dipoles) in nanodiamonds with tapered fibers. Our results lead to two important conclusions: (1) A maximum coupling efficiency of 53.4% can be realized for the two fiber ends when the NV bare dipole is located at the center of the tapered fiber. (2) NV centers even in 100-nm-sized nanodiamonds where bulk-like optical properties were reported show a coupling efficiency of 22% at the taper surface, with the coupling efficiency monotonically decreasing as the nanodiamond size increases. These results will be helpful in guiding the development of hybrid quantum devices for applications in quantum information science. PMID:25321215

  11. Charge and spin transport in nanoscopic structures with spin-orbit coupling

    Energy Technology Data Exchange (ETDEWEB)

    Reynoso, A. [Instituto Balseiro and Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina); Gonzalo Usaj [Instituto Balseiro and Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina); Balseiro, C.A. [Instituto Balseiro and Centro Atomico Bariloche, Comision Nacional de Energia Atomica, 8400 San Carlos de Bariloche (Argentina)]. E-mail: balseiro@cab.cnea.gov.ar

    2006-10-01

    During the last years there has been much interest, and theoretical discussion, about the possibility to use spin-orbit coupling to control the carriers spins in two-dimensional semiconducting heterostructures. Spin polarization at the sample edges may occur as the response of systems with strong SO-coupling to an external transport current, an effect known as spin Hall effect. Here, we show that in a 2DEG with Rashba SO-coupling, spin polarization near the sample edge can develop kinematically for low electron densities. We also discuss the effect in quantum wires where lateral confinement plays an important role.

  12. Design of Static Wireless Charging System for Electric Vehicles with Focus on Magnetic Coupling and Emissions

    DEFF Research Database (Denmark)

    Batra, Tushar

    Static wireless charging using resonant inductive principle offers environmental friendly, comfortable and automatic charging solution for electric vehicles. This technology as of now is nascent with few products on the market and leading companies and universities actively engaged in research...... as an equivalent power source and transmission system including the load similar to other electric system like grids. Secondly, design parameters of output power, circuit efficiency and voltage or current stress across resonant components can be expressed as simple functions of the five blocks. Inductors...

  13. Charge Transport Modulation and Optical Absorption Switching in Organic Electronic Devices

    OpenAIRE

    Andersson, Peter

    2007-01-01

    Organic electronics has evolved into a well-established research field thanks to major progresses in material sciences during recent decades. More attention was paid to this research field when “the discovery and development of conductive polymers” was awarded the Nobel Prize in Chemistry in 2000. Electronic devices that rely on tailor-made material functionalities, the ability of solution processing and low-cost manufacturing on flexible substrates by traditional printing techniques are amon...

  14. Charge-exchange Coupling between Pickup Ions across the Heliopause and its Effect on Energetic Neutral Hydrogen Flux

    Science.gov (United States)

    Zirnstein, E. J.; Heerikhuisen, J.; Zank, G. P.; Pogorelov, N. V.; McComas, D. J.; Desai, M. I.

    2014-03-01

    Pickup ions (PUIs) appear to play an integral role in the multi-component nature of the plasma in the interaction between the solar wind (SW) and local interstellar medium (LISM). Three-dimensional (3D) MHD simulations with a kinetic treatment for neutrals and PUIs are currently still not viable. In light of recent energetic neutral atom (ENA) observations by the Interstellar Boundary EXplorer, the purpose of this paper is to illustrate the complex coupling between PUIs across the heliopause (HP) as facilitated by ENAs using estimates of PUI properties extracted from a 3D MHD simulation of the SW-LISM interaction with kinetic neutrals. First, we improve upon the multi-component treatment of the inner heliosheath (IHS) plasma from Zank et al. by including the extinction of PUIs through charge-exchange. We find a significant amount of energy is transferred away from hot, termination shock-processed PUIs into a colder, "freshly injected" PUI population. Second, we extend the multi-component approach to estimate ENA flux from the outer heliosheath (OHS), formed from charge-exchange between interstellar hydrogen atoms and energetic PUIs. These PUIs are formed from ENAs in the IHS that crossed the HP and experienced charge-exchange. Our estimates, based on plasma-neutral simulations of the SW-LISM interaction and a post-processing analysis of ENAs and PUIs, suggest the majority of flux visible at 1 AU from the front of the heliosphere, between ~0.02 and 10 keV, originates from OHS PUIs, indicating strong coupling between the IHS and OHS plasmas through charge-exchange.

  15. Communication: CDFT-CI couplings can be unreliable when there is fractional charge transfer.

    Science.gov (United States)

    Mavros, Michael G; Van Voorhis, Troy

    2015-12-21

    Constrained density functional theory with configuration interaction (CDFT-CI) is a useful, low-cost tool for the computational prediction of electronic couplings between pseudo-diabatic constrained electronic states. Such couplings are of paramount importance in electron transfer theory and transition state theory, among other areas of chemistry. Unfortunately, CDFT-CI occasionally fails significantly, predicting a coupling that does not decay exponentially with distance and/or overestimating the expected coupling by an order of magnitude or more. In this communication, we show that the eigenvalues of the difference density matrix between the two constrained states can be used as an a priori metric to determine when CDFT-CI are likely to be reliable: when the eigenvalues are near 0 or ±1, transfer of a whole electron is occurring, and CDFT-CI can be trusted. We demonstrate the utility of this metric with several illustrative examples. PMID:26696039

  16. Communication: CDFT-CI couplings can be unreliable when there is fractional charge transfer

    International Nuclear Information System (INIS)

    Constrained density functional theory with configuration interaction (CDFT-CI) is a useful, low-cost tool for the computational prediction of electronic couplings between pseudo-diabatic constrained electronic states. Such couplings are of paramount importance in electron transfer theory and transition state theory, among other areas of chemistry. Unfortunately, CDFT-CI occasionally fails significantly, predicting a coupling that does not decay exponentially with distance and/or overestimating the expected coupling by an order of magnitude or more. In this communication, we show that the eigenvalues of the difference density matrix between the two constrained states can be used as an a priori metric to determine when CDFT-CI are likely to be reliable: when the eigenvalues are near 0 or ±1, transfer of a whole electron is occurring, and CDFT-CI can be trusted. We demonstrate the utility of this metric with several illustrative examples

  17. Thin-Film Ferro Electric-Coupled Microstripline Phase Shifters With Reduced Device Hysteresis

    Science.gov (United States)

    Miranda, Felix A.; Romanofsky, Robert; Mueller, Carl H.; VanKeuls, Frederick

    2010-01-01

    This work deals with the performance of coupled microstripline phase shifters (CMPS) fabricated using BaxSr 1 -xTiO 3 (BST) ferroelectric thin films. The CMPS were fabricated using commercially available pulsed laser deposition BST films with Ba:Sr ratios of 30:70 and 20:80. Microwave characterization of these CMPS was performed at upper Kuband frequencies, particularly at frequencies near 16 and 18 GHz. X-ray diffraction studies indicate that the 30:70 films exhibit almost a 1:1 ratio between the in-plane and out-of-plane lattice parameters, suggesting that their cubics create strain -free films suitable for producing CMPS devices with reduced hysteresis in the paraelectric state. The quality of performance of the CMPS was studied based on their relative phase shift and insertion loss within the DC bias range of 0 to 400 V (i.e., E-field ranges within 0 to 53 V/micron). The performance of the CMPS was tested as a function of temperature to investigate their operation in the paraelectric, as well as in the ferroelectric, state (i.e., above and below the Curie temperature, respectively). The novel behavior discussed here is based on the experimental observation of the CMPS. This behavior, observed for the aforementioned cation ratio, highlights the relevance of good crystalline structure for high-quality CMPS.

  18. Electron-phonon coupling in crystalline organic semiconductors: Microscopic evidence for nonpolaronic charge carriers

    OpenAIRE

    Vukmirovic N.; Bruder C.; Stojanovic V.M.

    2012-01-01

    We consider electron(hole)-phonon coupling in crystalline organic semiconductors, using naphthalene for our case study. Employing a first-principles approach, we compute the changes in the self-consistent Kohn-Sham potential corresponding to different phonon modes and go on to obtain the carrier-phonon coupling matrix elements (vertex functions). We then evaluate perturbatively the quasiparticle spectral residues for electrons at the bottom of the lowest-unoccupied- (LUMO) and holes at the to...

  19. A new spectrometer using multiple gratings with a two-dimensional charge-coupled diode array detector

    International Nuclear Information System (INIS)

    A new spectrometer with no moving parts uses a two-dimensional Si-based charge-coupled diode (CCD) array detector and an integrated grating consisting of three subgratings. The effective spectral range imaged on the detector is magnified threefold. The digitized spectral image in the 200-1000 nm wavelength range can be measured quickly. The nonlinear relationship between CCD pixel position and wavelength is corrected with multiple polynomial functions in the calibration procedure, which fits the data using a mathematical pattern-analysis method. The instrument can be applied for rapid spectroscopic data analyses in many types of photoelectronic experiments and routine testing

  20. NUMERICAL SIMULATION FOR DYNAMIC INITIAL SHOCK PARAMETERS OF COUPLING CHARGE ON BOREHOLE WALL UNDER THE ACTION OF HIGH EXPLOSIVES

    Institute of Scientific and Technical Information of China (English)

    倪芝芳; 李玉民

    1996-01-01

    According to detonation theory and hydrodynamic principle, a physical model has been set up in this paper. Based on the model a methodology for calculating dynamic initial shock parameters such as shock pressure p,,, shock wave velosity Dm etc. of coupling charge on borehole wall has ben developed. The shock parameters have been calculated when high explosives works on granite, limestone and marble respectively. The magnitude of every parameter on borehole wall has been obtained from ignited dot to the end of borehole along axial direction. Some important conclusions are also gained.

  1. Mass-charge-heat coupled transfers in a single cell of a proton exchange membrane fuel cell; Transferts couples masse-charge-chaleur dans une cellule de pile a combustible a membrane polymere

    Energy Technology Data Exchange (ETDEWEB)

    Ramousse, J.

    2005-11-15

    Understanding and modelling of coupled mass, charges and heat transfers phenomena are fundamental to analyze the electrical behaviour of the system. The aim of the present model is to describe electrical performances of a PEFMC according to the fluidic and thermal operating conditions. The water content of the membrane and the water distribution in the single cell are estimated according to the coupled simulations of mass transport in the thickness of the single cell and in the feeding channels of the bipolar plates. A microscopic model of a Gas Diffusion Electrode is built up to describe charges transfer phenomena occurring at the electrodes. Completed by a study of heat transfer in the Membrane Electrode Assembly, conditions and preferential sites of water vapor condensation can be highlighted. A set of measurements of the effective thermal conductivity of carbon felts used in fuel cells as porous backing layers have also been performed. Although the value of this parameter is essential for the study of heat transfer, it is still under investigation because of the strong thermal anisotropy of the medium. (author)

  2. Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

    International Nuclear Information System (INIS)

    Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

  3. Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Changyi [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Wu, Yiyong; Lv, Gang [National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin (China); Rubanov, Sergey [Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010 (Australia); Jamieson, David N., E-mail: d.jamieson@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2015-04-01

    Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

  4. Conformally coupled scalar black holes admit a flat horizon due to axionic charge

    CERN Document Server

    Bardoux, Yannis; Charmousis, Christos

    2012-01-01

    Static, charged black holes in the presence of a negative cosmological constant and with a planar horizon are found in four dimensions. The solutions have scalar secondary hair. We claim that these constitute the planar version of the Martinez-Troncoso-Zanelli black holes, only known up to now for a curved event horizon in four dimensions. Their planar version is rendered possible due to the presence of two, equal and homogeneously distributed, axionic charges dressing the flat horizon. The solutions are presented in the conformal and minimal frame and their basic properties and thermodynamics analysed. Entertaining recent applications to holographic superconductors, we expose two branches of solutions: the undressed axionic Reissner-Nordstrom-AdS black hole, and the novel black hole carrying secondary hair. We show that there is a critical temperature at which the (bald) axionic Reissner-Nordstrom-AdS black hole undergoes a second order phase transition to the hairy black hole spontaneously acquiring scalar ...

  5. Study of charge-phase diagrams for coupled system of Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hamdipour, M; Shukrinov, Y U M, E-mail: hamdipur@theor.jinr.r

    2010-11-01

    Dynamics of stacked intrinsic Josephson junctions (IJJ) in the high-Tc superconductors is theoretically investigated. We calculate the current-voltage characteristics (CVC) of IJJ and study the breakpoint region on the outermost branch of the CVC for the stacks with 9 IJJ. A method for investigation of the fine structure in CVC of IJJ based on the recording the 'phase-charge' diagrams is suggested. It is demonstrated that this method reflects the main features of the breakpoint region.

  6. Study of charge-phase diagrams for coupled system of Josephson junctions

    Science.gov (United States)

    Hamdipour, M.; Shukrinov, Y. U. M.

    2010-11-01

    Dynamics of stacked intrinsic Josephson junctions (IJJ) in the high-Tc superconductors is theoretically investigated. We calculate the current-voltage characteristics (CVC) of IJJ and study the breakpoint region on the outermost branch of the CVC for the stacks with 9 IJJ. A method for investigation of the fine structure in CVC of IJJ based on the recording the "phase-charge" diagrams is suggested. It is demonstrated that this method reflects the main features of the breakpoint region.

  7. Study of charge-phase diagrams for coupled system of Josephson junctions

    OpenAIRE

    Hamdipour, M.; Shukrinov, Yu M.

    2010-01-01

    Dynamics of stacked intrinsic Josephson junctions (IJJ) in the high-Tc superconductors is theoretically investigated. We calculate the current-voltage characteristics (CVC) of IJJ and study the breakpoint region on the outermost branch of the CVC for the stacks with 9 IJJ. A method for investigation of the fine structure in CVC of IJJ based on the recording the "phase-charge" diagrams is suggested. It is demonstrated that this method reflects the main features of the breakpoint region.

  8. A Generalized Boltzmann Fokker-Planck Method for Coupled Charged Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    Prinja, Anil K

    2012-01-09

    The goal of this project was to develop and investigate the performance of reduced-physics formulations of high energy charged particle (electrons, protons and heavier ions) transport that are computationally more efficient than not only analog Monte Carlo methods but also the established condensed history Monte Carlo technique. Charged particles interact with matter by Coulomb collisions with target nuclei and electrons, by bremsstrahlung radiation loss and by nuclear reactions such as spallation and fission. Of these, inelastic electronic collisions and elastic nuclear collisions are the dominant cause of energy-loss straggling and angular deflection or range straggling of a primary particle. These collisions are characterized by extremely short mean free paths (sub-microns) and highly peaked, near-singular differential cross sections about forward directions and zero energy loss, with the situation for protons and heavier ions more extreme than for electrons. For this reason, analog or truephysics single-event Monte Carlo simulation, while possible in principle, is computationally prohibitive for routine calculation of charged particle interaction phenomena.

  9. Charge-injection-device performance in the high-energy-neutron environment of laser-fusion experiments.

    Science.gov (United States)

    Marshall, F J; DeHaas, T; Glebov, V Yu

    2010-10-01

    Charge-injection devices (CIDs) are being used to image x rays in laser-fusion experiments on the University of Rochester's OMEGA Laser System. The CID cameras are routinely used up to the maximum neutron yields generated (∼10(14) DT). The detectors are deployed in x-ray pinhole cameras and Kirkpatrick-Baez microscopes. The neutron fluences ranged from ∼10(7) to ∼10(9) neutrons/cm(2) and useful x-ray images were obtained even at the highest fluences. It is intended to use CID cameras at the National Ignition Facility (NIF) as a supporting means of recording x-ray images. The results of this work predict that x-ray images should be obtainable on the NIF at yields up to ∼10(15), depending on distance and shielding.

  10. Charge-injection-device performance in the high-energy-neutron environment of laser-fusion experiments

    International Nuclear Information System (INIS)

    Charge-injection devices (CIDs) are being used to image x rays in laser-fusion experiments on the University of Rochester's OMEGA Laser System. The CID cameras are routinely used up to the maximum neutron yields generated (∼1014 DT). The detectors are deployed in x-ray pinhole cameras and Kirkpatrick-Baez microscopes. The neutron fluences ranged from ∼107 to ∼109 neutrons/cm2 and useful x-ray images were obtained even at the highest fluences. It is intended to use CID cameras at the National Ignition Facility (NIF) as a supporting means of recording x-ray images. The results of this work predict that x-ray images should be obtainable on the NIF at yields up to ∼1015, depending on distance and shielding.

  11. Microelectronic image sensors: A report from the Charge Transfer Device (CTD) team at FOA 3

    Science.gov (United States)

    Engstroem, O.; Persson, S. T.; Pettersson, H.; Ryden, K. H.

    1985-05-01

    Three concepts of microelectronic image sensors where the photo effects are based on the properties of interfaces between silicon and metal silicides or insulators were investigated. An infrared sensitive image sensor for the 3 to 5 micron wavelength range was prepared. The photosensitive elements, patterned as a 4 x 4 matrix, consist of palladium silicide Schottky-diodes. Addressing of the different picture elements is made from shift registers placed on the same silicon chip. A concept for the storage of optical information was created. The basic principle relies on the possibilities to store electrons in deep lying energy levels in an insulator layer grown on silicon. A metal-insulator-semiconductor device, where the possibility of interaction between two images at the insulator-semiconductor interface is utilized for image recognition, was derived.

  12. Restoring interlayer Josephson coupling in La1.885Ba0.115CuO4 by charge transfer melting of stripe order

    Science.gov (United States)

    Khanna, V.; Mankowsky, R.; Petrich, M.; Bromberger, H.; Cavill, S. A.; Möhr-Vorobeva, E.; Nicoletti, D.; Laplace, Y.; Gu, G. D.; Hill, J. P.; Först, M.; Cavalleri, A.; Dhesi, S. S.

    2016-06-01

    We show that disruption of charge-density-wave (stripe) order by charge transfer excitation, enhances the superconducting phase rigidity in La1.885Ba0.115CuO4 . Time-resolved resonant soft x-ray diffraction demonstrates that charge order melting is prompt following near-infrared photoexcitation whereas the crystal structure remains intact for moderate fluences. THz time-domain spectroscopy reveals that, for the first 2 ps following photoexcitation, a new Josephson plasma resonance edge, at higher frequency with respect to the equilibrium edge, is induced indicating enhanced superconducting interlayer coupling. The fluence dependence of the charge-order melting and the enhanced superconducting interlayer coupling are correlated with a saturation limit of ˜0.5 mJ /cm2 . Using a combination of x-ray and optical spectroscopies we establish a hierarchy of timescales between enhanced superconductivity, melting of charge order, and rearrangement of the crystal structure.

  13. A Microscopic Capacitor Model of Voltage Coupling in Membrane Proteins: Gating Charge Fluctuations in Ci-VSD.

    Science.gov (United States)

    Kim, Ilsoo; Warshel, Arieh

    2016-01-28

    The voltage sensitivity of membrane proteins is reflected in the response of the voltage sensing domains (VSDs) to the changes in membrane potential. This response is implicated in the displacement of positively charged residues, associated with the conformational changes of VSDs. The displaced charges generate nonlinear (i.e., voltage-dependent) capacitance current called the gating current (and its corresponding gating charge), which is a key experimental quantity that characterizes voltage activation in VSMP. However, the relevant theoretical/computational approaches, aimed to correlate the structural information on VSMP to electrophysiological measurements, have been rather limited, posing a broad challenge in computer simulations of VSMP. Concomitant with the development of our coarse-graining (CG) model of voltage coupling, we apply our theoretical framework for the treatments of voltage effects in membrane proteins to modeling the VSMP activation, taking the VSDs (Ci-VSD) derived from the Ciona intestinalis voltage sensitive phosphatase (Ci-VSP) as a model system. Our CG model reproduces the observed gating charge of Ci-VSD activation in several different perspectives. In particular, a new closed-form expression of the gating charge is evaluated in both nonequilibrium and equilibrium ways, while considering the fluctuation-dissipation relation that connects a nonequilibrium measurement of the gating charge to an equilibrium measurement of charge fluctuations (i.e., the voltage-independent linear component of membrane capacitance). In turn, the expression uncovers a novel link that connects an equilibrium measurement of the voltage-independent linear capacitance to a nonequilibrium measurement of the voltage-dependent nonlinear capacitance (whose integral over voltage is equal to the gating charge). In addition, our CG model yields capacitor-like voltage dependent free energy parabolas, resulting in the free energy difference and the free energy barrier for

  14. A Microscopic Capacitor Model of Voltage Coupling in Membrane Proteins: Gating Charge Fluctuations in Ci-VSD.

    Science.gov (United States)

    Kim, Ilsoo; Warshel, Arieh

    2016-01-28

    The voltage sensitivity of membrane proteins is reflected in the response of the voltage sensing domains (VSDs) to the changes in membrane potential. This response is implicated in the displacement of positively charged residues, associated with the conformational changes of VSDs. The displaced charges generate nonlinear (i.e., voltage-dependent) capacitance current called the gating current (and its corresponding gating charge), which is a key experimental quantity that characterizes voltage activation in VSMP. However, the relevant theoretical/computational approaches, aimed to correlate the structural information on VSMP to electrophysiological measurements, have been rather limited, posing a broad challenge in computer simulations of VSMP. Concomitant with the development of our coarse-graining (CG) model of voltage coupling, we apply our theoretical framework for the treatments of voltage effects in membrane proteins to modeling the VSMP activation, taking the VSDs (Ci-VSD) derived from the Ciona intestinalis voltage sensitive phosphatase (Ci-VSP) as a model system. Our CG model reproduces the observed gating charge of Ci-VSD activation in several different perspectives. In particular, a new closed-form expression of the gating charge is evaluated in both nonequilibrium and equilibrium ways, while considering the fluctuation-dissipation relation that connects a nonequilibrium measurement of the gating charge to an equilibrium measurement of charge fluctuations (i.e., the voltage-independent linear component of membrane capacitance). In turn, the expression uncovers a novel link that connects an equilibrium measurement of the voltage-independent linear capacitance to a nonequilibrium measurement of the voltage-dependent nonlinear capacitance (whose integral over voltage is equal to the gating charge). In addition, our CG model yields capacitor-like voltage dependent free energy parabolas, resulting in the free energy difference and the free energy barrier for

  15. Superradiance of a charged scalar field coupled to the Einstein-Maxwell equations

    CERN Document Server

    Baake, Olaf

    2016-01-01

    We consider the Einstein-Maxwell-Klein-Gordon equations for a spherically symmetric scalar field scattering off a Reissner-Nordstr\\"om black hole in asymptotically flat spacetime. The equations are solved numerically using a hyperboloidal evolution scheme. For suitable frequencies of the initial data, superradiance is observed, leading to a substantial decrease of mass and charge of the black hole. We also derive a Bondi mass loss formula using the Kodama vector field and investigate the late-time decay of the scalar field.

  16. Scan direction induced charging dynamics and the application for detection of gate to S/D shorts in logic devices

    Science.gov (United States)

    Lei, Ming; Tian, Qing; Wu, Kevin; Zhao, Yan

    2016-03-01

    Gate to source/drain (S/D) short is the most common and detrimental failure mechanism for advanced process technology development in Metal-Oxide-Semiconductor-Field-Effect-Transistor (MOSFET) device manufacturing. Especially for sub-1Xnm nodes, MOSFET device is more vulnerable to gate-S/D shorts due to the aggressive scaling. The detection of this kind of electrical short defect is always challenging for in-line electron beam inspection (EBI), especially new shorting mechanisms on atomic scale due to new material/process flow implementation. The second challenge comes from the characterization of the shorts including identification of the exact shorting location. In this paper, we demonstrate unique scan direction induced charging dynamics (SDCD) phenomenon which stems from the transistor level response from EBI scan at post metal contact chemical-mechanical planarization (CMP) layers. We found that SDCD effect is exceptionally useful for gate-S/D short induced voltage contrast (VC) defect detection, especially for identification of shorting locations. The unique SDCD effect signatures of gate-S/D shorts can be used as fingerprint for ground true shorting defect detection. Correlation with other characterization methods on the same defective location from EBI scan shows consistent results from various shorting mechanism. A practical work flow to implement the application of SDCD effect for in-line EBI monitor of critical gate-S/D short defects is also proposed, together with examples of successful application use cases which mostly focus on static random-access memory (SRAM) array regions. Although the capability of gate-S/D short detection as well as expected device response is limited to passing transistors and pull-down transistors due to the design restriction from standard 6-cell SRAM structure, SDCD effect is proven to be very effective for gate-S/D short induced VC defect detection as well as yield learning for advanced technology development.

  17. Electronic Coupling Effects and Charge Transfer between Organic Molecules and Metal Surfaces

    OpenAIRE

    Forker, Roman

    2010-01-01

    We employ a variant of optical absorption spectroscopy, namely in situ differential reflectance spectroscopy (DRS), for an analysis of the structure-properties relations of thin epitaxial organic films. Clear correlations between the spectra and the differently intense coupling to the respective substrates are found. While rather broad and almost structureless spectra are obtained for a quaterrylene (QT) monolayer on Au(111), the spectral shape resembles that of isolated molecules when QT is ...

  18. Variable Charge State Impurities in Coupled Kinetic Plasma-Kinetic Neutral Transport Simulations

    Science.gov (United States)

    Stotler, D. P.; Hager, R.; Kim, K.; Koskela, T.; Park, G.

    2015-11-01

    A previous version of the XGC0 neoclassical particle transport code with two fully stripped impurity species was used to study kinetic neoclassical transport in the DIII-D H-mode pedestal. To properly simulate impurities in the scrape-off layer and divertor and to account for radiative cooling, however, the impurity charge state distributions must evolve as the particles are transported into regions of different electron temperatures and densities. To do this, the charge state of each particle in XGC0 is included as a parameter in the list that represents the particle's location in phase space. Impurity ionizations and recombinations are handled with a dedicated collision routine. The associated radiative cooling is accumulated during the process and applied to the electron population later in the time step. The density profiles of the neutral impurities are simulated with the DEGAS 2 neutral transport code and then used as a background for electron impact ionization in XGC0 via a test particle Monte Carlo method analogous to that used for deuterium. This work supported by US DOE contracts DE-AC02-09CH11466.

  19. Coupling of electric charge and magnetic field via electronic phase separation in (La,Pr,Ca)MnO3/Pb(Mg1/3Nb2/3)O3-PbTiO3 multiferroic heterostructures

    Science.gov (United States)

    Zheng, Ming; Wang, Wei

    2016-04-01

    The electric-field-tunable non-volatile resistivity and ferromagnetism switching in the (La0.5Pr0.5)0.67Ca0.33MnO3 films grown on (111)-oriented 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 ferroelectric single-crystal substrates have been investigated. By combining the 180° ferroelectric domain switching and in situ X-ray diffraction and resistivity measurements, we identify that this voltage control of order parameters stems from the domain switching-induced accumulation/depletion of charge carriers at the interface rather than induced lattice strain effect. In particular, the polarization-induced charge effect (i.e., ferroelectric field effect) is strongly dependent on the magnetic field. This, together with the charge-modulated magnetoresistance and magnetization, reveals the strong correlation between the electric charge and the magnetic field. Further, we found that this coupling is essentially driven by the electronic phase separation, the relative strength of which could be determined by recording charge-tunability of resistivity [ (Δρ/ρ)c h arg e ] under various magnetic fields. These findings present a potential strategy for elucidating essential physics of perovskite manganites and delivering prototype electronic devices for non-volatile information storage.

  20. Analysis of the magnetic coupling in binuclear systems. III. The role of the ligand to metal charge transfer excitations revisited

    Science.gov (United States)

    Calzado, Carmen J.; Angeli, Celestino; Taratiel, David; Caballol, Rosa; Malrieu, Jean-Paul

    2009-07-01

    In magnetic coordination compounds and solids the magnetic orbitals are essentially located on metallic centers but present some delocalization tails on adjacent ligands. Mean field variational calculations optimize this mixing and validate a single band modelization of the intersite magnetic exchange. In this approach, due to the Brillouin's theorem, the ligand to metal charge transfer (LMCT) excitations play a minor role. On the other hand the extensive configuration interaction calculations show that the determinants obtained by a single excitation on the top of the LMCT configurations bring an important antiferromagnetic contribution to the magnetic coupling. Perturbative and truncated variational calculations show that contrary to the interpretation given in a previous article [C. J. Calzado et al., J. Chem. Phys. 116, 2728 (2002)] the contribution of these determinants to the magnetic coupling constant is not a second-order one. An analytic development enables one to establish that they contribute at higher order as a correlation induced increase in the LMCT components of the wave function, i.e., of the mixing between the ligand and the magnetic orbitals. This larger delocalization of the magnetic orbitals results in an increase in both the ferro- and antiferromagnetic contributions to the coupling constant.

  1. Charge trapping and luminance mechanisms of organic light-emitting devices with a 5,6,11,12-tetraphenylnaphthacene emission layer.

    Science.gov (United States)

    Park, Su Hyeong; Lee, Dae Uk; Kim, Tae Whan

    2011-08-01

    The electrical and the optical properties of the organic light-emitting devices fabricated utilizing a 5,6,11,12-tetraphenylnaphthacene (rubrene) emission layer (EML) were investigated to clarify their charge trapping and luminance mechanisms. The increase in the thickness of the rubrene EML extended the width of the recombination zone, resulting in the enhancement of the efficiency and in the variation of the shoulder peak intensity of the electroluminescence spectra. The charge trapping and luminance mechanisms were affected by the total thickness of the rubrene layer, regardless of the existence of the barrier layers. The charge trapping and luminance mechanisms are described on the basis of the experimental results. PMID:22103164

  2. Study and Test of Cold Storage Heat Recovery Heat Pump Coupled Solar Drying Device

    OpenAIRE

    Min Li; Xiao-Qiang Jiang; Bao-Chuan Wu

    2013-01-01

    In this study, we design the recovery of a heat pump combined solar drying device. Then, with this device, drying experiments of aquatic product, tilapia, were conducted, indicating that the newly designed device functions are well in temperature adjusting and controlling performance and showing that drying time is closely related to energy consumption and drying conditions. Heat recovery heat pump combined solar energy drier can improve the drying quality of aquatic products, but also can gr...

  3. Atmospheric Lithosphere-Ionosphere Charge Exchange (ALICE) for coupling between earthquake regions, clouds and the ionosphere

    Science.gov (United States)

    Harrison, Giles; Aplin, Karen; Rycroft, Michael

    2014-05-01

    Atmospheric Lithosphere-Ionosphere Charge Exchange (ALICE) has been proposed as a mechanism to link seismic activity and ionospheric changes detected overhead, which has been observed in data obtained by the DEMETER spacecraft. The ALICE mechanism can explain changes in the natural extremely low frequency (ELF) radio noise observed by DEMETER nocturnally before major earthquakes. ALICE operates through the vertical fair weather current density of global atmospheric electricity, through the modification of surface layer ionisation rates and the associated current flow to the ionosphere. These ideas are extended here to include possible effects on layer clouds through which the current density passes. Specifically, we estimate possible layer cloud changes for changes in surface layer ionisation known in some earthquakes.

  4. Late-time decay of coupled electromagnetic and gravitational perturbations outside extremal charged black hole

    CERN Document Server

    Sela, Orr

    2016-01-01

    In this paper we employ the results of a previous paper on the late-time decay of scalar-field perturbations of an extreme Reissner-Nordstrom black hole, in order to find the late-time decay of coupled electromagnetic and gravitational perturbations of this black hole. We explicitly write the late-time tails of Moncrief's gauge invariant variables and of the perturbations of the metric tensor and the electromagnetic field tensor in the Regge-Wheeler gauge. We discuss some of the consequences of the results and relations to previous works.

  5. On chip complex signal processing devices using coupled phononic crystal slab resonators and waveguides

    Directory of Open Access Journals (Sweden)

    Saeed Mohammadi

    2011-12-01

    Full Text Available In this paper, we report the evidence for the possibility of achieving complex signal processing functionalities such as multiplexing/demultiplexing at high frequencies using phononic crystal (PnC slabs. It is shown that such functionalities can be obtained by appropriate cross-coupling of PnC resonators and waveguides. PnC waveguides and waveguide-based resonators are realized and cross-coupled through two different methods of mechanical coupling (i.e., direct coupling and side coupling. Waveguide-based PnC resonators are employed because of their high-Q, compactness, large spurious-free spectral ranges, and the possibility of better control over coupling to PnC waveguides. It is shown that by modifying the defects in the formation of the resonators, the frequency of the resonance can be tuned.

  6. The coupling of surface charge and boundary slip at the solid-liquid interface and their combined effect on fluid drag: A review.

    Science.gov (United States)

    Jing, Dalei; Bhushan, Bharat

    2015-09-15

    Fluid drag of micro/nano fluidic systems has inspired wide scientific interest. Surface charge and boundary slip at the solid-liquid interface are believed to affect fluid drag. This review summarizes the recent studies on the coupling of surface charge and slip, and their combined effect on fluid drag at micro/nano scale. The effect of pH on surface charge of borosilicate glass and silica surfaces in deionized (DI) water and saline solution is discussed using a method based on colloidal probe atomic force microscopy (AFM). The boundary slip of various oil-solid interfaces are discussed for samples with different degrees of oleophobicity prepared by nanoparticle-binder system. By changing the pH of solution or applying an electric field, effect of surface charge on slip of a smooth hydrophobic octadecyltrichlorosilane (OTS) in DI water and saline solution is studied. A theoretical model incorporating the coupling relationship between surface charge and slip is used to discuss the combined effect of surface charge-induced electric double layer (EDL) and slip on fluid drag of pressure-driven flow in a one-dimensional parallel-plates microchannel. A theoretical method is used to reduce the fluid drag. The studies show that the increasing magnitude of surface charge density leads to a decrease in slip length. The surface charge results in a larger fluid drag, and the coupling of surface charge and slip can further increase the fluid drag. Surface charge-induced EDLs with asymmetric zeta potentials can effectively reduce the fluid drag. PMID:26021432

  7. Relativistic mean field theory with density dependent coupling constants for nuclear matter and finite nuclei with large charge asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Typel, S.; Wolter, H.H. [Sektion Physik, Univ. Muenchen, Garching (Germany)

    1998-06-01

    Nuclear matter and ground state properties for (proton and neutron) semi-closed shell nuclei are described in relativistic mean field theory with coupling constants which depend on the vector density. The parametrization of the density dependence for {sigma}-, {omega}- and {rho}-mesons is obtained by fitting to properties of nuclear matter and some finite nuclei. The equation of state for symmetric and asymmetric nuclear matter is discussed. Finite nuclei are described in Hartree approximation, including a charge and an improved center-of-mass correction. Pairing is considered in the BCS approximation. Special attention is directed to the predictions for properties at the neutron and proton driplines, e.g. for separation energies, spin-orbit splittings and density distributions. (orig.)

  8. Precision determination of the πN scattering lengths and the charged πNN coupling constant

    Science.gov (United States)

    Ericson, T. E. O.; Loiseau, B.; Thomas, A. W.

    2000-01-01

    We critically evaluate the isovector GMO sumrule for the charged πNN coupling constant using recent precision data from π-p and π-d atoms and with careful attention to systematic errors. From the π-d scattering length we deduce the pion-proton scattering lengths 1/2(aπ-p + aπ-n) = (-20 +/- 6(statistic)+/-10 (systematic) .10-4m-1πc and 1/2(aπ-p - aπ-n) = (903 +/- 14) . 10-4m-1πc. From this a direct evaluation gives g2c(GMO)/4π = 14.20 +/- 0.07 (statistic)+/-0.13(systematic) or f2c/4π = 0.0786 +/- 0.0008.

  9. Precision determination of the πN scattering lengths and the charged πNN coupling constant

    International Nuclear Information System (INIS)

    We critically evaluate the isovector GMO sumrule for the charged πNN coupling constant using recent precision data from π-p and π-d atoms and with careful attention to systematic errors. From the π-d scattering length we deduce the pion-proton scattering lengths ((1)/(2))(aπ-p + aπ-n) = (-20 ± 6(statistic)±10 (systematic) ·10-4m-1πc and ((1)/(2))(aπ-p - aπ-n) = (903 ± 14) · 10-4m-1πc. From this a direct evaluation gives g2c(GMO)/4π = 14.20 ± 0.07 (statistic)±0.13(systematic) or f2c/4π = 0.0786 ± 0.0008

  10. A microscopic approach based on particle-vibration coupling: application to charge-exchange transitions and multiplets in odd nuclei

    Directory of Open Access Journals (Sweden)

    Colò Gianluca

    2016-01-01

    Full Text Available In this contribution, we shall describe a formalism that goes beyond the simple time-dependent mean field and is based on particle-vibration coupling (PVC. Such a formalism has been developed with the idea of being self-consistent. It makes use of Skyrme effective forces, and has been used for several applications. We will focus on charge-exchange transitions, namely we will show that our model describes well both the Gamow-Teller giant resonance width, and the low-lying transitions associated with β-decay. In this latter case, including PVC produces a significant improvement of the half-lives obtained at mean-field level, and leads to a good agreement with experimental data. We will end by discussing particle-phonon multiplets in odd nuclei.

  11. Conserved charges for black holes in Einstein-Gauss-Bonnet gravity coupled to nonlinear electrodynamics in AdS space

    Science.gov (United States)

    Mišković, Olivera; Olea, Rodrigo

    2011-01-01

    Motivated by possible applications within the framework of anti-de Sitter gravity/conformal field theory correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by nonlinear electrodynamics are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary nonlinear electrodynamic Lagrangian in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Falloff conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass and vacuum energy as conserved quantities associated to an asymptotic timelike Killing vector are computed using a background-independent regularization of the gravitational action based on the addition of counterterms which are a given polynomial in the intrinsic and extrinsic curvatures.

  12. Spin-orbit-coupling induced torque in ballistic domain walls: Equivalence of charge-pumping and nonequilibrium magnetization formalisms

    Science.gov (United States)

    Yuan, Zhe; Kelly, Paul J.

    2016-06-01

    To study the effect of spin-orbit coupling (SOC) on spin-transfer torque in magnetic materials, we have implemented two theoretical formalisms that can accommodate SOC. Using the "charge-pumping" formalism, we find two contributions to the out-of-plane spin-transfer torque parameter β in ballistic Ni domain walls (DWs). For short DWs, the nonadiabatic reflection of conduction electrons caused by the rapid spatial variation of the exchange potential results in an out-of-plane torque that increases rapidly with decreasing DW length. For long DWs, the Fermi level conduction channel anisotropy that gives rise to an intrinsic DW resistance in the presence of SOC leads to a linear dependence of β on the DW length. To understand this counterintuitive divergence of β in the long DW limit, we use the "nonequilibrium magnetization" formalism to examine the spatially resolved spin-transfer torque. The SOC-induced out-of-plane torque in ballistic DWs is found to be quantitatively consistent with the values obtained using the charge-pumping calculations, indicating the equivalence of the two theoretical methods.

  13. Linear and third- and fifth-order nonlinear spectroscopies of a charge transfer system coupled to an underdamped vibration

    Energy Technology Data Exchange (ETDEWEB)

    Dijkstra, Arend G., E-mail: arend.dijkstra@mpsd.mpg.de, E-mail: tanimura@kuchem.kyoto-u.ac.jp [Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany); Tanimura, Yoshitaka, E-mail: arend.dijkstra@mpsd.mpg.de, E-mail: tanimura@kuchem.kyoto-u.ac.jp [Department of Chemistry, Kyoto University, Kyoto (Japan)

    2015-06-07

    We study hole, electron, and exciton transports in a charge transfer system in the presence of underdamped vibrational motion. We analyze the signature of these processes in the linear and third-, and fifth-order nonlinear electronic spectra. Calculations are performed with a numerically exact hierarchical equations of motion method for an underdamped Brownian oscillator spectral density. We find that combining electron, hole, and exciton transfers can lead to non-trivial spectra with more structure than with excitonic coupling alone. Traces taken during the waiting time of a two-dimensional (2D) spectrum are dominated by vibrational motion and do not reflect the electron, hole, and exciton dynamics directly. We find that the fifth-order nonlinear response is particularly sensitive to the charge transfer process. While third-order 2D spectroscopy detects the correlation between two coherences, fifth-order 2D spectroscopy (2D population spectroscopy) is here designed to detect correlations between the excited states during two different time periods.

  14. Linear and third- and fifth-order nonlinear spectroscopies of a charge transfer system coupled to an underdamped vibration.

    Science.gov (United States)

    Dijkstra, Arend G; Tanimura, Yoshitaka

    2015-06-01

    We study hole, electron, and exciton transports in a charge transfer system in the presence of underdamped vibrational motion. We analyze the signature of these processes in the linear and third-, and fifth-order nonlinear electronic spectra. Calculations are performed with a numerically exact hierarchical equations of motion method for an underdamped Brownian oscillator spectral density. We find that combining electron, hole, and exciton transfers can lead to non-trivial spectra with more structure than with excitonic coupling alone. Traces taken during the waiting time of a two-dimensional (2D) spectrum are dominated by vibrational motion and do not reflect the electron, hole, and exciton dynamics directly. We find that the fifth-order nonlinear response is particularly sensitive to the charge transfer process. While third-order 2D spectroscopy detects the correlation between two coherences, fifth-order 2D spectroscopy (2D population spectroscopy) is here designed to detect correlations between the excited states during two different time periods.

  15. Linear and third- and fifth-order nonlinear spectroscopies of a charge transfer system coupled to an underdamped vibration

    International Nuclear Information System (INIS)

    We study hole, electron, and exciton transports in a charge transfer system in the presence of underdamped vibrational motion. We analyze the signature of these processes in the linear and third-, and fifth-order nonlinear electronic spectra. Calculations are performed with a numerically exact hierarchical equations of motion method for an underdamped Brownian oscillator spectral density. We find that combining electron, hole, and exciton transfers can lead to non-trivial spectra with more structure than with excitonic coupling alone. Traces taken during the waiting time of a two-dimensional (2D) spectrum are dominated by vibrational motion and do not reflect the electron, hole, and exciton dynamics directly. We find that the fifth-order nonlinear response is particularly sensitive to the charge transfer process. While third-order 2D spectroscopy detects the correlation between two coherences, fifth-order 2D spectroscopy (2D population spectroscopy) is here designed to detect correlations between the excited states during two different time periods

  16. Design and characteristic investigations of superconducting wireless power transfer for electric vehicle charging system via resonance coupling method

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y. D. [Suwon Science College, Suwon (Korea, Republic of); Yim, Seung Woo [Dept. of Korea Electric Power Corporation Research Institute, Daejeon (Korea, Republic of)

    2014-09-15

    As wireless power transfer (WPT) technology using strongly coupled electromagnetic resonators is a recently explored technique to realize the large power delivery and storage without any cable or wire, this technique is required for diffusion of electric vehicles (EVs) since it makes possible a convenient charging system. Typically, since the normal conducting coils are used as a transmitting coil in the CPT system, there is limited to deliver the large power promptly in the contactless EV charging system. From this reason, we proposed the combination CPT technology with HTS transmitting antenna, it is called as, superconducting contactless power transfer for EV (SUWPT4EV) system. As the HTS coil has an enough current density, it can deliver a mass amount of electric energy in spite of a small scale antenna. The SUCPT4EV system has been expected as a noble option to improve the transfer efficiency of large electric power. Such a system consists of two resonator coils; HTS transmitting antenna (Tx) coil and normal conducting receiver (Rx) coil. Especially, the impedance matching for each resonator is a sensitive and plays an important role to improve transfer efficiency as well as delivery distance. In this study, we examined the improvement of transmission efficiency and properties for HTS and copper antennas, respectively, within 45 cm distance. Thus, we obtained improved transfer efficiency with HTS antenna over 15% compared with copper antenna. In addition, we achieved effective impedance matching conditions between HTS antenna and copper receiver at radio frequency (RF) power of 370 kHz.

  17. A NEW STRUCTURE AND ITS ANALYTICAL BREAKDOWN MODEL OF HIGH VOLTAGE SOI DEVICE WITH STEP UNMOVABLE SURFACE CHARGES OF BURIED OXIDE LAYER

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new SOI (Silicon On Insulator) high voltage device with Step Unmovable Surface Charges(SUSC) of buried oxide layer and its analytical breakdown model are proposed in the paper. The unmovable charges are implemented into the upper surface of buried oxide layer to increase the vertical electric field and uniform the lateral one. The 2-D Poisson's equation is solved to demonstrate the modulation effect of the immobile interface charges and analyze the electric field and breakdown voltage with the various geometric parameters and step numbers. A new RESURF (REduce SURface Field) condition of the SOI device considering the interface charges and buried oxide is derived to maximize breakdown voltage. The analytical results are in good agreement with the numerical analysis obtained by the 2-D semiconductor devices simulator MEDICI. As a result, an 1200V breakdown voltage is firstly obtained in 3μm-thick top Si layer, 2μm-thick buried oxide layer and 70μm-length drift region using a linear doping profile of unmovable buried oxide charges.

  18. Thermodynamics of charged rotating dilaton black branes coupled to logarithmic nonlinear electrodynamics

    CERN Document Server

    Sheykhi, A; Zangeneh, M Kord

    2016-01-01

    We construct a new class of charged rotating black brane solutions in the presence of logarithmic nonlinear electrodynamics with complete set of the rotation parameters in arbitrary dimensions. The topology of the horizon of these rotating black branes are flat, while, due to the presence of the dilaton field the asymptotic behaviour of them are neither flat nor (anti)-de Sitter [(A)dS]. We investigate the physical properties of the solutions. The mass and angular momentum of the spacetime are obtained by using the counterterm method inspired by AdS/CFT correspondence. We derive temperature, electric potential and entropy associated with the horizon and check the validity of the first law of thermodynamics on the black brane horizon. We study thermal stability of the solutions in both canonical and grand canonical ensemble and disclose the effects of the rotation parameter, nonlinearity of electrodynamics and dilaton field on the thermal stability conditions. We find the solutions are thermally stable for $\\a...

  19. Correlation between charge transfer and exchange coupling in carbon-based magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Anh Tuan, E-mail: tuanna@hus.edu.vn [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Science and Technology Department, Vietnam National University, Hanoi, 144 Xuan Thuy, Cau Giay, Hanoi (Viet Nam); Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa, 923-1292 Japan (Japan); Nguyen, Van Thanh; Nguyen, Huy Sinh [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Pham, Thi Tuan Anh [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Faculty of Science, College of Hai Duong, Nguyen Thi Due, Hai Duong (Viet Nam); Do, Viet Thang [Faculty of Physics, VNU University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Faculty of Science, Haiphong University, 171 Phan Dang Luu, Kien An, Hai Phong (Viet Nam); Dam, Hieu Chi [Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi, Ishikawa, 923-1292 Japan (Japan)

    2015-10-15

    Several forms of carbon-based magnetic materials, i.e. single radicals, radical dimers, and alternating stacks of radicals and diamagnetic molecules, have been investigated using density-functional theory with dispersion correction and full geometry optimization. Our calculated results demonstrate that the C{sub 31}H{sub 15} (R{sub 4}) radical has a spin of ½. However, in its [R{sub 4}]{sub 2} dimer structure, the net spin becomes zero due to antiferromagnetic spin-exchange between radicals. To avoid antiferromagnetic spin-exchange of identical face-to-face radicals, eight alternating stacks, R{sub 4}/D{sub 2m}/R{sub 4} (with m = 3-10), were designed. Our calculated results show that charge transfer (Δn) between R{sub 4} radicals and the diamagnetic molecule D{sub 2m} occurs with a mechanism of spin exchange (J) in stacks. The more electrons that transfer from R{sub 4} to D{sub 2m}, the stronger the ferromagnetic spin-exchange in stacks. In addition, our calculated results show that Δn can be tailored by adjusting the electron affinity (E{sub a}) of D{sub 2m}. The correlation between Δn, E{sub a}, m, and J is discussed. These results give some hints for the design of new ferromagnetic carbon-based materials.

  20. Correlation between charge transfer and exchange coupling in carbon-based magnetic materials

    Directory of Open Access Journals (Sweden)

    Anh Tuan Nguyen

    2015-10-01

    Full Text Available Several forms of carbon-based magnetic materials, i.e. single radicals, radical dimers, and alternating stacks of radicals and diamagnetic molecules, have been investigated using density-functional theory with dispersion correction and full geometry optimization. Our calculated results demonstrate that the C31H15 (R4 radical has a spin of ½. However, in its [R4]2 dimer structure, the net spin becomes zero due to antiferromagnetic spin-exchange between radicals. To avoid antiferromagnetic spin-exchange of identical face-to-face radicals, eight alternating stacks, R4/D2m/R4 (with m = 3-10, were designed. Our calculated results show that charge transfer (Δn between R4 radicals and the diamagnetic molecule D2m occurs with a mechanism of spin exchange (J in stacks. The more electrons that transfer from R4 to D2m, the stronger the ferromagnetic spin-exchange in stacks. In addition, our calculated results show that Δn can be tailored by adjusting the electron affinity (Ea of D2m. The correlation between Δn, Ea, m, and J is discussed. These results give some hints for the design of new ferromagnetic carbon-based materials.

  1. Evidence of phonon mediated coupling between charge transfer and ligand field excitons in Sr$_2$CuO$_2$Cl$_2$

    OpenAIRE

    Lövenich, R.; Schumacher, A. B.; Dodge, J. S.; Chemla, D. S.; Miller, L.L.

    2001-01-01

    We present a comparative experimental and theoretical investigation of the two--dimensional charge-transfer gap in the strongly correlated material Sr$_2$CuO$_2$Cl$_2$. We observe an Urbach behaviour in the absorption profile over a surprisingly wide range of energies and temperatures. We present a model that accounts for phonon scattering to infinite order and which allows us to explain the data accurately by assuming coupling of the charge transfer gap exciton to lower energy electronic exc...

  2. A naive matrix-model approach to two-dimensional quantum gravity coupled to matter of arbitrary central charge

    CERN Document Server

    Brézin, E

    1992-01-01

    In the usual matrix-model approach to random discretized two-dimensional manifolds, one introduces n Ising spins on each cell, i.e. a discrete version of 2D quantum gravity coupled to matter with a central charge n/2. The matrix-model consists then of an integral over $2^{n}$ matrices, which we are unable to solve for $n>1$. However for a fixed genus we can expand in the cosmological constant g for arbitrary values of n, and a simple minded analysis of the series yields for n=0,1 and 2 the expected results for the exponent $\\gamma_{string}$ with an amazing precision given the small number of terms that we considered. We then proceed to larger values of n. Simple tests of universality are successfully applied; for instance we obtain the same exponents for n=3 or for one Ising model coupled to a one dimensional target space. The calculations are easily extended to states Potts models, through an integration over $q^{n}$ matrices. We see no sign of the tachyonic instability of the theory, but we have only consid...

  3. Multi-Stimuli-Responsive Charge-Transfer Hydrogel for Room-Temperature Organic Ferroelectric Thin-Film Devices.

    Science.gov (United States)

    Pandeeswar, Makam; Senanayak, Satyaprasad P; Narayan, K S; Govindaraju, T

    2016-07-01

    The possibility of designing programmable thin-film supramolecular structures with spontaneous polarization widens the utility of facile supramolecular chemistry. Although a range of low molecular mass molecular single crystals has been shown to exhibit ferroelectric polarization, demonstration of stimuli-responsive, thin-film, solution-processable supramolecular ferroelectric materials is rare. We introduce aromatic π-electron donor-acceptor molecular systems responsive to multiple stimuli that undergo supramolecular chiral mixed-stack charge-transfer (CT) coassembly through the tweezer-inclusion-sandwich process supported by hydrogen-bonding interactions. The structural synergy originating from hydrogen-bonding and chiral CT interactions resulted in the development of spontaneous unidirectional macroscopic polarization in the crystalline nanofibrous hydrogel network, under ambient conditions. Moreover, the tunability of these interactions with optical, mechanical, thermal, and electrical stimuli allowed the design of multistate thin-film memory devices. Our design strategy of the supramolecular motif is expected to help the development of new molecular engineering strategies for designing potentially useful smart multicomponent organic electronics. PMID:27305598

  4. Nanotribology-based novel characterization techniques for the dielectric charging failure mechanism in electrostatically actuated NEMS/MEMS devices using force-distance curve measurements.

    Science.gov (United States)

    Zaghloul, Usama; Bhushan, Bharat; Papaioannou, George; Coccetti, Fabio; Pons, Patrick; Plana, Robert

    2012-01-01

    The work presents a comprehensive package of novel nanoscale characterization techniques to study dielectric charging in electrostatic nano- and microelectromechanical systems (NEMS and MEMS). The proposed assessment methodologies are based on the force-distance curve (FDC) measurements performed using an atomic force microscope (AFM) to measure, for the first time, the induced surface potential and adhesive force over charged dielectric films. They were employed to study plasma enhanced chemical vapor deposition (PECVD) silicon nitride films for application in electrostatic capacitive RF MEMS switches. Three different techniques were introduced including the application of FDC measurements to study charging in bare SiN(x) films, metal-insulator-metal (MIM) capacitors, and MEMS switches. The results from the three methods were correlated and compared with the published data from other characterization techniques, mainly charge/discharge current transient (C/DCT) and Kelvin probe force microscopy (KPFM). The unique advantages of the proposed FDC-based characterization techniques are twofold. First, they can measure the multiphysics coupling between the dielectric charging phenomenon and tribological issues at the interface between the switch bridge and the dielectric surface. Second, the FDC-based techniques can measure larger levels of induced surface potential over charged dielectric films which results from the high electric field normally used to actuate MEMS switches. Based on the proposed FDC techniques, the influence of several parameters on dielectric charging/discharging processes was investigated: the dielectric film thickness, deposition conditions, substrate, and electrical stress conditions. PMID:21962432

  5. GaAs metal-oxide-semiconductor based non-volatile flash memory devices with InAs quantum dots as charge storage nodes

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Sk Masiul, E-mail: masiulelt@gmail.com; Chowdhury, Sisir; Sarkar, Krishnendu; Nagabhushan, B.; Banerji, P. [Materials Science Centre, Indian Institute of Technology, Kharagpur 721 302 (India); Chakraborty, S. [Applied Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Sector-I, Kolkata 700 064 (India); Mukherjee, Rabibrata [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

    2015-06-24

    Ultra-thin InP passivated GaAs metal-oxide-semiconductor based non-volatile flash memory devices were fabricated using InAs quantum dots (QDs) as charge storing elements by metal organic chemical vapor deposition technique to study the efficacy of the QDs as charge storage elements. The grown QDs were embedded between two high-k dielectric such as HfO{sub 2} and ZrO{sub 2}, which were used for tunneling and control oxide layers, respectively. The size and density of the QDs were found to be 5 nm and 1.8×10{sup 11} cm{sup −2}, respectively. The device with a structure Metal/ZrO{sub 2}/InAs QDs/HfO{sub 2}/GaAs/Metal shows maximum memory window equivalent to 6.87 V. The device also exhibits low leakage current density of the order of 10{sup −6} A/cm{sup 2} and reasonably good charge retention characteristics. The low value of leakage current in the fabricated memory device is attributed to the Coulomb blockade effect influenced by quantum confinement as well as reduction of interface trap states by ultra-thin InP passivation on GaAs prior to HfO{sub 2} deposition.

  6. Preparation of Entanglement and Schrodinger Cat States of Superconducting Quantum Interference Devices Qubits via Coupling to a Microwave Cavity

    Institute of Scientific and Technical Information of China (English)

    LI Sheng-Chang; YANG Wen-Xing; DUAN Wen-Shan

    2008-01-01

    An alternative scheme is proposed for the generation of n-qubit W states of superconducting quantum interference devices (SQUID) in cavity QED. In this scheme, Raman coupling of two lower flux states of SQUID system is achieved via a microwave pulse and the cavity mode. Conditioned on no photon leakage from the cavity, the n-qubit W state can be generated whether the effective coupling parameters of the SQUID to cavity mode and classical microwave fields are the same or different. Our strictly numerical simulations of the time evolution of the system including decay show that the success probability of our scheme is almost unity and the interaction time is on the order of 10-9 s. The scheme can also be used to generate the Schrfdinger cat states of multi-SQUID.

  7. Introduction of several positioning devices for accessory heads coupling%介绍几种附件头联结盘定位装置

    Institute of Scientific and Technical Information of China (English)

    王伟; 韩铁柱

    2012-01-01

    Several kinds of positioning devices for accessory heads coupling are briefly introduced in this paper. By means of the positioning device, accurate positioning of coupling can be carried out, thereupon auto changing of accessory heads is performed.%简要介绍了几种附件头联结盘的定位装置,通过定位装置可将联结盘准确定位,从而实现附件头的自动更换.

  8. 49 CFR 393.70 - Coupling devices and towing methods, except for driveaway-towaway operations.

    Science.gov (United States)

    2010-10-01

    ... that tows it. (b) Fifth wheel assemblies—(1) Mounting—(i) Lower half. The lower half of a fifth wheel... equipped with a tow-bar and a means of attaching the tow-bar to the towing and towed vehicles. The tow-bar... strength and rigidity of the frame to prevent its undue distortion. (d) Safety devices in case of...

  9. Coupling element antenna with slot tuning for handheld devices at LTE frequencies

    DEFF Research Database (Denmark)

    Barrio, Samantha Caporal Del; Pelosi, Mauro; Franek, Ondrej;

    2012-01-01

    Tunable antennas are a promising way to overcome bandwidth limitations for the new communication standards. Since it is the chassis that resonates in the low frequencies, its tuning is pertinent and allows for more compact size designs. This paper proposes a coupling element based antenna...

  10. Reliability study of opto-coupled semiconductor devices and Light Emitting Diodes (LED)

    Science.gov (United States)

    Maurer, R. C.; Weissflug, V. A.; Sisul, E. V.

    1977-01-01

    Opto-coupler and light emitting diode (LED) failure mechanisms and associated activation energies were determind from the results of environmental and accelerated lift tests of over 2,400 devices. The evaluation program included LED phototransistor opto-couplers from three sources, LED photoamplifier opto-couplers from a single source, and discrete infrared emitting LEDs from two sources. Environmental tests to evaluate device mechanical integrity included power cycling (10,000 cycles), temperature cycling (500 cycles) and a sequence of monitored shock, monitored vibration and constant acceleration. Multiple temperature operating life tests were conducted at ambient temperatures between 25 C and 200 C. Opto-couplers were operated in both the 'on' and 'off' states during life testing.

  11. Nanocellulose-based Translucent Diffuser for Optoelectronic Device Applications with Dramatic Improvement of Light Coupling.

    Science.gov (United States)

    Wu, Wei; Tassi, Nancy G; Zhu, Hongli; Fang, Zhiqiang; Hu, Liangbing

    2015-12-01

    Nanocellulose is a biogenerated and biorenewable organic material. Using a process based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)/NaClO/NaBr system, a highly translucent and light-diffusive film consisting of many layers of nanocellulose fibers and wood pulp microfibers was made. The film demonstrates a combination of large optical transmittance of ∼90% and tunable diffuse transmission of up to ∼78% across the visible and near-infrared spectra. The detailed characterizations of the film indicate the combination of high optical transmittance and haze is due to the film's large packing density and microstructured surface. The superior optical properties make the film a translucent light diffuser and applicable for improving the efficiencies of optoelectronic devices such as thin-film silicon solar cells and organic light-emitting devices. PMID:26572592

  12. Thermodynamics of Charged Kalb Ramond AdS black hole in presence of Gauss-Bonnet coupling

    CERN Document Server

    Choudhury, Sayantan

    2013-01-01

    We study the role of the Gauss-Bonnet corrections to the gravity action on the charged AdS black hole in presence of rank 3 antisymmetric Kalb Ramond tensor field strength. Analyzing the branch singularity and the killing horizon, we explicitly derive various thermodynamic parameters and study their behaviour in presence of five dimensional Gauss-Bonnet coupling in AdS space-time. The possibility of a second order phase transition is explored in the light of AdS/CMT correspondence and various critical exponents associated with the discontinuities of the various thermodynamic parameters are determined. We further comment on the universality of the well known Rushbrooke Josephson scaling law and derive a relation between the degree of homogeneity appearing in various free energies and the critical exponents by homogeneous hypothesis test. By making use of the constraints appearing from Hawking temperature and Gauss-Bonnet extended gravity version of Kubo formula we introduce a bound on the five dimensional Gaus...

  13. Ferroic ordering and charge-spin-lattice order coupling in Gd doped Fe3O4 nanoparticles

    Science.gov (United States)

    Laha, Suvra; Abdelhamid, Ehab; Palihawadana Arachchige, Maheshika; Dixit, Ambesh; Lawes, Gavin; Naik, Vaman; Naik, Ratna

    Rare earth doped spinels have been extensively studied for their potential applications in magneto-optical recording and as MRI contrast agents. In the present study, we have investigated the effect of gadolinium doping (1-5 at.%) on the magnetic and dielectric properties of Fe3O4nanoparticles synthesized by the chemical co-precipitation method. The structure and morphology of the as-synthesized gadolinium doped Fe3O4(Gd-Fe3O4) nanoparticles were characterized by XRD, SEM and TEM, and the magnetic properties were measured by a Quantum Design physical property measurement system. We find that the penetration of excess Gd3+ ions into Fe3O4 spinel matrix significantly influences the average crystallite size and saturation magnetization in Gd-Fe3O4. The average crystallite size, estimated from XRD using Scherrer equation, increases with increasing Gd doping percentage and the saturation magnetization drops monotonically with excess Gd3+ ions. Interestingly, Gd- Fe3O4develops enhanced ferroelectric ordering at low temperatures. The details of the temperature dependent dielectric, ferroelectric and magnetocapacitance measurements to understand the onset of charge-spin-lattice coupling in Gd-Fe3O4 system will be presented.

  14. Low Damage, High Anisotropy Inductively Coupled Plasma for Gallium Nitride based Devices

    KAUST Repository

    Ibrahim, Youssef H.

    2013-05-27

    Group III-nitride semiconductors possess unique properties, which make them versatile materials for suiting many applications. Structuring vertical and exceptionally smooth GaN profiles is crucial for efficient optical device operation. The processing requirements for laser devices and ridge waveguides are stringent as compared to LEDs and other electronic devices. Due to the strong bonding and chemically inert nature of GaN, dry etching becomes a critical fabrication step. The surface morphology and facet etch angle are analyzed using SEM and AFM measurements. The influence of different mask materials is also studied including Ni as well as a SiO2 and resist bilayer. The high selectivity Ni Mask is found to produce high sidewall angles ~79°. Processing parameters are optimized for both the mask material and GaN in order to achieve a highly anisotropic, smooth profile, without resorting to additional surface treatment steps. An optimizing a SF6/O2 plasma etch process resulted in smooth SiO2 mask sidewalls. The etch rate and GaN surface roughness dependence on the RF power was also examined. Under a low 2mTorr pressure, the RF and ICP power were optimized to 150W and 300W respectively, such that a smooth GaN morphology and sidewalls was achieved with reduced ion damage. The The AFM measurements of the etched GaN surface indicate a low RMS roughness ranging from 4.75 nm to 7.66 nm.

  15. Application of a particle separation device to reduce inductively coupled plasma-enhanced elemental fractionation in laser ablation-inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    The particle size distribution of laser ablation aerosols are a function of the wavelength, the energy density and the pulse duration of the laser, as well as the sample matrix and the gas environment. Further the size of the particles affects the vaporization and ionization efficiency in the inductively coupled plasma (ICP). Some matrices produce large particles, which are not completely vaporized and ionized in the ICP. The previous work has shown that analytical results such as matrix-independent calibration, accuracy and precision can be significantly influenced by the particle sizes of the particles. To minimize the particle size related incomplete conversion of the sample to ions in the ICP a particle separation device was developed, which allows effective particle separation using centrifugal forces in a thin coiled tube. In this device, the particle cut-off size is varied by changing the number of turns in the coil, as well as by changing the gas flow and the tube diameter. The interaction of the laser with the different samples leads to varying particle size distributions. When carrying out quantitative analysis with non-matrix matched calibration reference materials, it was shown that different particle cut-off sizes were required depending on the ICP conditions and the instrument used for analysis. Various sample materials were investigated in this study to demonstrate the applicability of the device. For silicate matrices, the capability of the ICP to produce ions was significantly reduced for particles larger than 0.5 μm, and was dependent on the element monitored. To reduce memory effects caused by the separated particles, a washout procedure was developed, which additionally allowed the analysis of the trapped particles. These results clearly demonstrate the very important particle size dependent ICP-MS signal response and the potential of the described particle size based separator for the reduction of ICP induced elemental fractionation

  16. Efficient charge transfer and field-induced tunneling transport in hybrid composite device of organic semiconductor and cadmium telluride quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Varade, Vaibhav, E-mail: vaibhav.tvarade@gmail.com; Jagtap, Amardeep M.; Koteswara Rao, K. S. R.; Ramesh, K. P.; Menon, R. [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Anjaneyulu, P. [Department of Physics, Gitam University, Hyderabad 502329 (India)

    2015-06-07

    Temperature and photo-dependent current–voltage characteristics are investigated in thin film devices of a hybrid-composite comprising of organic semiconductor poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and cadmium telluride quantum dots (CdTe QDs). A detailed study of the charge injection mechanism in ITO/PEDOT:PSS-CdTe QDs/Al device exhibits a transition from direct tunneling to Fowler–Nordheim tunneling with increasing electric field due to formation of high barrier at the QD interface. In addition, the hybrid-composite exhibits a huge photoluminescence quenching compared to aboriginal CdTe QDs and high increment in photoconductivity (∼ 400%), which is attributed to the charge transfer phenomena. The effective barrier height (Φ{sub B} ≈ 0.68 eV) is estimated from the transition voltage and the possible origin of its variation with temperature and photo-illumination is discussed.

  17. Efficient charge transfer and field-induced tunneling transport in hybrid composite device of organic semiconductor and cadmium telluride quantum dots

    International Nuclear Information System (INIS)

    Temperature and photo-dependent current–voltage characteristics are investigated in thin film devices of a hybrid-composite comprising of organic semiconductor poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and cadmium telluride quantum dots (CdTe QDs). A detailed study of the charge injection mechanism in ITO/PEDOT:PSS-CdTe QDs/Al device exhibits a transition from direct tunneling to Fowler–Nordheim tunneling with increasing electric field due to formation of high barrier at the QD interface. In addition, the hybrid-composite exhibits a huge photoluminescence quenching compared to aboriginal CdTe QDs and high increment in photoconductivity (∼ 400%), which is attributed to the charge transfer phenomena. The effective barrier height (ΦB ≈ 0.68 eV) is estimated from the transition voltage and the possible origin of its variation with temperature and photo-illumination is discussed

  18. Study of Interface Charge Densities for ZrO2 and HfO2 Based Metal-Oxide-Semiconductor Devices

    Directory of Open Access Journals (Sweden)

    N. P. Maity

    2014-01-01

    Full Text Available A thickness-dependent interfacial distribution of oxide charges for thin metal oxide semiconductor (MOS structures using high-k materials ZrO2 and HfO2 has been methodically investigated. The interface charge densities are analyzed using capacitance-voltage (C-V method and also conductance (G-V method. It indicates that, by reducing the effective oxide thickness (EOT, the interface charge densities (Dit increases linearly. For the same EOT, Dit has been found for the materials to be of the order of 1012 cm−2 eV−1 and it is originated to be in good agreement with published fabrication results at p-type doping level of 1×1017 cm−3. Numerical calculations and solutions are performed by MATLAB and device simulation is done by ATLAS.

  19. Re-evaluation of interferences of doubly charged ions of heavy rare earth elements on Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    We re-evaluate the interference of doubly charged heavy rare earth elements during Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). A series of mixed solutions of standard reference material SRM 987, rare earth elements, and Sr separated from rock reference materials are measured to assess the influence of isobaric interferences on the MC-ICP-MS analysis of Sr isotopes. After sample dissolution, conventional cation-exchange chromatography is employed for Sr purification of rock reference materials prior to MC-ICP-MS measurement. It has been demonstrated that if the natural abundances of Er and Yb are used to correct for doubly charged ion interferences on Sr, an overcorrection results. In contrast, the use of measured doubly charged ion ratios results in an accurate and precise correction of isobaric interference. This finding is confirmed by analytical results for several certified reference materials from mafic (basaltic) to felsic (granitic) silicate rocks. It is noteworthy that, because Er is more prone to doubly charged ion formation, it dominates over Yb doubly charged ions as an interference source. - Highlights: • We re-investigated interference of doubly charged HREE ion on Sr isotope. • Natural abundance of Er and Yb to correct the interference leads to an overcorrection. • Er is more prone to doubly charged ion formation than Yb

  20. Geometrical modification transfer between specific meshes of each coupled physical codes. Application to the Jules Horowitz research reactor experimental devices

    International Nuclear Information System (INIS)

    The CEA develops and uses scientific software, called physical codes, in various physical disciplines to optimize installation and experimentation costs. During a study, several physical phenomena interact, so a code coupling and some data exchanges between different physical codes are required. Each physical code computes on a particular geometry, usually represented by a mesh composed of thousands to millions of elements. This PhD Thesis focuses on the geometrical modification transfer between specific meshes of each coupled physical code. First, it presents a physical code coupling method where deformations are computed by one of these codes. Next, it discusses the establishment of a model, common to different physical codes, grouping all the shared data. Finally, it covers the deformation transfers between meshes of the same geometry or adjacent geometries. Geometrical modifications are discrete data because they are based on a mesh. In order to permit every code to access deformations and to transfer them, a continuous representation is computed. Two functions are developed, one with a global support, and the other with a local support. Both functions combine a simplification method and a radial basis function network. A whole use case is dedicated to the Jules Horowitz reactor. The effect of differential dilatations on experimental device cooling is studied. (author)

  1. CP-odd contributions to the $ZZ^\\ast\\gamma$, $ZZ\\gamma^\\ast$, and $ZZZ^\\ast$ vertices induced by nondiagonal charged scalar boson couplings

    CERN Document Server

    Moyotl, A; Tavares-Velasco, G

    2015-01-01

    In models with extended scalar sectors with several Higgs multiplets, such as Higgs triplet models, the $Z$ gauge boson can have nondiagonal couplings to charged Higgs bosons. In a model-independent way, we study the potential contributions arising from such theories to the CP-violating trilinear neutral gauge boson couplings $ZZ^*\\gamma$, $ZZ\\gamma^*$, and $ZZZ^*$, which are parametrized by four form factors: $h^Z_{1,2}$, $f_4^\\gamma$, and $f_4^Z$, respectively. Such form factors can only be induced if there are at least two nondegenerate charged Higgs scalars and an imaginary phase in the coupling constants. For the masses of the charged scalar bosons we consider values above 300 GeV and find that the form factors can reach the following orders of magnitude: $|h_1^Z|\\sim 10^{-5}-10^{-4}$, $|h_2^Z|\\sim 10^{-7}-10^{-6}$, $|f_4^\\gamma|\\sim 10^{-5}-10^{-3}$ and $|f_4^Z|\\sim 10^{-6}-10^{-5}$, though there could be an additional suppression factor arising from the coupling constants. We also find that the form fa...

  2. Study of the Pion-Nucleon Coupling Constant Charge Dependence on the Basis of the Low-Energy Data on Nucleon-Nucleon Interaction

    CERN Document Server

    Babenko, V A

    2016-01-01

    We study relationship between the physical quantities that characterize pion-nucleon and nucleon-nucleon interaction on the basis of the fact that nuclear forces in the nucleon-nucleon system at low energies are mainly determined by the one-pion exchange mechanism. By making use of the recommended proton-proton low-energy scattering parameters, we obtain the following value for the charged pion-nucleon coupling constant g$_{\\pi ^{\\pm }}^{2}/4\\pi =14.55(13)$. Calculated value of this quantity is in excellent agreement with the experimental result g$_{\\pi ^{\\pm }}^{2}/4\\pi =14.52(26)$ of the Uppsala Neutron Research Group. At the same time, the obtained value of the charged pion-nucleon coupling constant differs markedly from the value of the neutral pion-nucleon coupling constant g$_{\\pi ^{0}}^{2}/4\\pi =13.55(13)$. Thus, our results show considerable charge splitting of the pion-nucleon coupling constant.

  3. Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

    International Nuclear Information System (INIS)

    Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO3/Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ∼3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron’s mobility ∼2 × 10−3 cm2V−1s−1, and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10−5 cm2V−1s−1, and electron mobility of 8.7 × 10−4 cm2V−1s−1

  4. Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

    Science.gov (United States)

    Srivastava, Shashi B.; Sonar, Prashant; Singh, Samarendra P.

    2015-07-01

    Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO3/Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ˜3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron's mobility ˜2 × 10-3 cm2V-1s-1, and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10-5 cm2V-1s-1, and electron mobility of 8.7 × 10-4 cm2V-1s-1.

  5. Charge transport studies in donor-acceptor block copolymer PDPP-TNT and PC71BM based inverted organic photovoltaic devices processed in room conditions

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Shashi B.; Singh, Samarendra P., E-mail: samarendra.singh@snu.edu.in [Department of Physics, Shiv Nadar University, Gautam Buddha Nagar, Uttar Pradesh, India-201307 (India); Sonar, Prashant [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Australia-4001 (Australia)

    2015-07-15

    Diketopyrrolopyrole-naphthalene polymer (PDPP-TNT), a donor-acceptor co-polymer, has shown versatile behavior demonstrating high performances in organic field-effect transistors (OFETs) and organic photovoltaic (OPV) devices. In this paper we report investigation of charge carrier dynamics in PDPP-TNT, and [6,6]-phenyl C{sub 71} butyric acid methyl ester (PC71BM) bulk-heterojunction based inverted OPV devices using current density-voltage (J-V) characteristics, space charge limited current (SCLC) measurements, capacitance-voltage (C-V) characteristics, and impedance spectroscopy (IS). OPV devices in inverted architecture, ITO/ZnO/PDPP-TNT:PC71BM/MoO{sub 3}/Ag, are processed and characterized at room conditions. The power conversion efficiency (PCE) of these devices are measured ∼3.8%, with reasonably good fill-factor 54.6%. The analysis of impedance spectra exhibits electron’s mobility ∼2 × 10{sup −3} cm{sup 2}V{sup −1}s{sup −1}, and lifetime in the range of 0.03-0.23 ms. SCLC measurements give hole mobility of 1.12 × 10{sup −5} cm{sup 2}V{sup −1}s{sup −1}, and electron mobility of 8.7 × 10{sup −4} cm{sup 2}V{sup −1}s{sup −1}.

  6. Three-dimensional antenna coupling to core plasma in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.D.; Jaeger, E.F.; Stallings, D.C.; Galambos, J.D.; Batchelor, D.B.; Wang, C.Y.

    1995-09-01

    A complete understanding of the RF physics from the launcher to the plasma core is required to fully analyze RF experiments and to evaluate the performance of RF antenna designs in ITER. This understanding requires a consistent model for the RF power launching system, propagation and absorption through the edge region, and the response of the core plasma to the RF power. As a first step toward such a model, the three-dimensional (3D) antenna modeling code, RANT3D, has been coupled with the reduced order full wave code, PICES. Preliminary results from this model are presented in this paper for parameters similar to those found in the DIII-D experiment.

  7. Study of ICRF wave propagation and plasma coupling efficiency in a linear magnetic mirror device

    International Nuclear Information System (INIS)

    Ion Cyclotron Range of Frequency (ICRF) wave propagation in an inhomogeneous axial magnetic field in a cylindrical plasma-vacuum system has historically been inadequately modelled. Previous works either sacrifice the cylindrical geometry in favor of a simpler slab geometry, concentrate on the resonance region, use a single mode to represent the entire field structure, or examine only radial propagation. This thesis performs both analytical and computational studies to model the ICRF wave-plasma coupling and propagation problem. Experimental analysis is also conducted to compare experimental results with theoretical predictions. Both theoretical as well as experimental analysis are undertaken as part of the thesis. The theoretical studies simulate the propagation of ICRF waves in an axially inhomogeneous magnetic field and in cylindrical geometry. Two theoretical analysis are undertaken - an analytical study and a computational study. The analytical study treats the inhomogeneous magnetic field by transforming the (r,z) coordinate into another coordinate system (ρ,ξ) that allows the solution of the fields with much simpler boundaries. The plasma fields are then Fourier transformed into two coupled convolution-integral equations which are then differenced and solved for both the perpendicular mode number α as well as the complete EM fields. The computational study involves a multiple eigenmode computational analysis of the fields that exist within the plasma-vacuum system. The inhomogeneous axial field is treated by dividing the geometry into a series of transverse axial slices and using a constant dielectric tensor in each individual slice. The slices are then connected by longitudinal boundary conditions

  8. Study of ICRF wave propagation and plasma coupling efficiency in a linear magnetic mirror device

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.Y.

    1991-07-01

    Ion Cyclotron Range of Frequency (ICRF) wave propagation in an inhomogeneous axial magnetic field in a cylindrical plasma-vacuum system has historically been inadequately modelled. Previous works either sacrifice the cylindrical geometry in favor of a simpler slab geometry, concentrate on the resonance region, use a single mode to represent the entire field structure, or examine only radial propagation. This thesis performs both analytical and computational studies to model the ICRF wave-plasma coupling and propagation problem. Experimental analysis is also conducted to compare experimental results with theoretical predictions. Both theoretical as well as experimental analysis are undertaken as part of the thesis. The theoretical studies simulate the propagation of ICRF waves in an axially inhomogeneous magnetic field and in cylindrical geometry. Two theoretical analysis are undertaken - an analytical study and a computational study. The analytical study treats the inhomogeneous magnetic field by transforming the (r,z) coordinate into another coordinate system ({rho},{xi}) that allows the solution of the fields with much simpler boundaries. The plasma fields are then Fourier transformed into two coupled convolution-integral equations which are then differenced and solved for both the perpendicular mode number {alpha} as well as the complete EM fields. The computational study involves a multiple eigenmode computational analysis of the fields that exist within the plasma-vacuum system. The inhomogeneous axial field is treated by dividing the geometry into a series of transverse axial slices and using a constant dielectric tensor in each individual slice. The slices are then connected by longitudinal boundary conditions.

  9. Expressions for Form Factors for Inelastic Scattering and Charge Exchange in Plane-Wave, Distorted-Wave, and Coupled-Channels Reaction Formalisms

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, F S

    2006-09-25

    This document is intended to facilitate calculation of inelastic scattering and charge-exchange cross sections in a variety of reaction models, including the plane-wave and distorted-wave approximations and the full coupled-channels treatments. Expressions are given for the coupling potentials between the relevant channels in both coordinate and momentum space. In particular, it is expected that the plane-wave calculations should be useful as a check on the correctness of coupled-channels calculations. The Fourier transform methods used to calculate the plane-wave approximation cross sections are also intended to be used to generate the transition potentials for coupled-channels codes, using a folding model with local effective interactions. Specific expressions are given for calculating transition densities for the folding model in the random phase approximation (RPA).

  10. Unconventional Geometric Phase-Shift Gates Based on Superconducting Quantum Interference Devices Coupled to a Single-Mode Cavity

    Institute of Scientific and Technical Information of China (English)

    SONG Ke-Hui; ZHOU Zheng-Wei; GUO Guang-Can

    2006-01-01

    We present a scheme to realize geometric phase-shift gate for two superconducting quantum interference device (SQUID) qubits coupled to a single-mode microwave field. The geometric phase-shift gate operation is performed transitions during the gate operation. Thus, the docoherence due to energy spontaneous emission based on the levels of SQUIDs are suppressed. The gate is insensitive to the cavity decay throughout the operation since the cavity mode is displaced along a circle in the phase space, acquiring a phase conditional upon the two lower flux states of the SQUID qubits, and the cavity mode is still in the original vacuum state. Based on the SQUID qubits interacting with the cavity mode, our proposed approach may open promising prospects for quantum logic in SQUID-system.

  11. Valence Band Dependent Charge Transport in Bulk Molecular Electronic Devices Incorporating Highly Conjugated Multi-[(Porphinato)Metal] Oligomers.

    Science.gov (United States)

    Bruce, Robert C; Wang, Ruobing; Rawson, Jeff; Therien, Michael J; You, Wei

    2016-02-24

    Molecular electronics offers the potential to control device functions through the fundamental electronic properties of individual molecules, but realization of such possibilities is typically frustrated when such specialized molecules are integrated into a larger area device. Here we utilize highly conjugated (porphinato)metal-based oligomers (PM(n) structures) as molecular wire components of nanotransfer printed (nTP) molecular junctions; electrical characterization of these "bulk" nTP devices highlights device resistances that depend on PM(n) wire length. Device resistance measurements, determined as a function of PM(n) molecular length, were utilized to evaluate the magnitude of a phenomenological β corresponding to the resistance decay parameter across the barrier; these data show that the magnitude of this β value is modulated via porphyrin macrocycle central metal atom substitution [β(PZn(n); 0.065 Å(-1)) < β(PCu(n); 0.132 Å(-1)) < β(PNi(n); 0.176 Å(-1))]. Cyclic voltammetric data, and ultraviolet photoelectron spectroscopic studies carried out at gold surfaces, demonstrate that these nTP device resistances track with the valence band energy levels of the PM(n) wire, which were modulated via porphyrin macrocycle central metal atom substitution. This study demonstrates the ability to fabricate "bulk" and scalable electronic devices in which function derives from the electronic properties of discrete single molecules, and underscores how a critical device function--wire resistance--may be straightforwardly engineered by PM(n) molecular composition. PMID:26829704

  12. The method of canonical transformations applied to the motion of a charge coupled to the electromagnetic field in the non-relativistic approximation

    International Nuclear Information System (INIS)

    A method of canonical transformations extended to dissipative Hamiltonian systems in a previous article is here applied to the behaviour of an extended charge coupled to the em field which is deductible from a Lagrangian function explicitly dependent on time. The generating function of a transformation which decouples the variables of the system is given, for an elastic applied force, and hence the constants in motion are found by a general method. Some limit cases are examined. (auth)

  13. Effect of Molecular Coupling on Ultrafast Electron-Transfer and Charge-Recombination Dynamics in a Wide-Gap ZnS Nanoaggregate Sensitized by Triphenyl Methane Dyes.

    Science.gov (United States)

    Debnath, Tushar; Maity, Partha; Dana, Jayanta; Ghosh, Hirendra N

    2016-03-01

    Wide-band-gap ZnS nanocrystals (NCs) were synthesized, and after sensitizing the NCs with series of triphenyl methane (TPM) dyes, ultrafast charge-transfer dynamics was demonstrated. HRTEM images of ZnS NCs show the formation of aggregate crystals with a flower-like structure. Exciton absorption and lumimescence, due to quantum confinement of the ZnS NCs, appear at approximately 310 and 340 nm, respectively. Interestingly, all the TPM dyes (pyrogallol red, bromopyrogallol red, and aurin tricarboxylic acid) form charge-transfer complexes with the ZnS NCs, with the appearance of a red-shifted band. Electron injection from the photoexcited TPM dyes into the conduction band of the ZnS NCs is shown to be a thermodynamically viable process, as confirmed by steady-state and time-resolved emission studies. To unravel charge-transfer (both electron injection and charge recombination) dynamics and the effect of molecular coupling, femtosecond transient absorption studies were carried out in TPM-sensitized ZnS NCs. The electron-injection dynamics is pulse-width-limited in all the ZnS/TPM dye systems, however, the back electron transfer differs, depending on the molecular coupling of the sensitizers (TPM dyes). The detailed mechanisms for the above-mentioned processes are discussed. PMID:26548569

  14. Performance of the NIST goniocolorimeter with a broad-band source and multichannel charged coupled device based spectrometer

    Science.gov (United States)

    Podobedov, V. B.; Miller, C. C.; Nadal, M. E.

    2012-09-01

    The authors describe the NIST high-efficiency instrument for measurements of bidirectional reflectance distribution function of colored materials, including gonioapparent materials such as metallic and pearlescent coatings. The five-axis goniospectrometer measures the spectral reflectance of samples over a wide range of illumination and viewing angles. The implementation of a broad-band source and a multichannel CCD spectrometer corrected for stray light significantly increased the efficiency of the goniometer. In the extended range of 380 nm to 1050 nm, a reduction of measurement time from a few hours to a few minutes was obtained. Shorter measurement time reduces the load on the precise mechanical assembly ensuring high angular accuracy over time. We describe the application of matrix-based correction of stray light and the extension of effective dynamic range of measured fluxes to the values of 106 to 107 needed for the absolute characterization of samples. The measurement uncertainty was determined to be 0.7% (k = 2), which is comparable with similar instruments operating in a single channel configuration. Several examples of reflectance data obtained with the improved instrument indicate a 0.3% agreement compared to data collected with the single channel configuration.

  15. Long-path measurement of atmospheric NO2 with an obstruction flashlight and a charge-coupled-device spectrometer.

    Science.gov (United States)

    Yoshii, Yotsumi; Kuze, Hiroaki; Takeuchi, Nobuo

    2003-07-20

    A novel method of differential optical absorption spectroscopy (DOAS) is proposed and demonstrated to monitor the concentration of atmospheric pollutant gas. In contrast to conventional DOAS measurements with continuous light sources, the present method relies on white flashlights such as aviation obstruction lights that are generally installed on tall constructions. A simple detection system is devised by means of a telescope and a compact CCD spectrometer. A path length of 5.5 km allows us to measure atmospheric NO2 concentration with a detection limit of approximately 1 part per billion. We also discuss the possibility of deriving the aerosol optical thickness through the horizontal atmosphere from this pulsed DOAS measurement. PMID:12921286

  16. Methodology toward 3D micro X-ray fluorescence imaging using an energy dispersive charge-coupled device detector.

    Science.gov (United States)

    Garrevoet, Jan; Vekemans, Bart; Tack, Pieter; De Samber, Björn; Schmitz, Sylvia; Brenker, Frank E; Falkenberg, Gerald; Vincze, Laszlo

    2014-12-01

    A new three-dimensional (3D) micro X-ray fluorescence (μXRF) methodology based on a novel 2D energy dispersive CCD detector has been developed and evaluated at the P06 beamline of the Petra-III storage ring (DESY) in Hamburg, Germany. This method is based on the illumination of the investigated sample cross-section by a horizontally focused beam (vertical sheet beam) while fluorescent X-rays are detected perpendicularly to the sheet beam by a 2D energy dispersive (ED) CCD detector allowing the collection of 2D cross-sectional elemental images of a certain depth within the sample, limited only by signal self-absorption effects. 3D elemental information is obtained by a linear scan of the sample in the horizontal direction across the vertically oriented sheet beam and combining the detected cross-sectional images into a 3D elemental distribution data set. Results of the 3D μXRF analysis of mineral inclusions in natural deep Earth diamonds are presented to illustrate this new methodology. PMID:25346101

  17. Charge and spin transport in single and packed ruthenium-terpyridine molecular devices: Insight from first-principles calculations.

    Science.gov (United States)

    Morari, C; Buimaga-Iarinca, L; Rungger, I; Sanvito, S; Melinte, S; Rignanese, G-M

    2016-01-01

    Using first-principles calculations, we study the electronic and transport properties of rutheniumterpyridine molecules sandwiched between two Au(111) electrodes. We analyse both single and packed molecular devices, more amenable to scaling and realistic integration approaches. The devices display all together robust negative differential resistance features at low bias voltages. Remarkably, the electrical control of the spin transport in the studied systems implies a subtle distribution of the magnetisation density within the biased devices and highlights the key role of the Au(111) electrical contacts. PMID:27550064

  18. Charge and spin transport in single and packed ruthenium-terpyridine molecular devices: Insight from first-principles calculations

    Science.gov (United States)

    Morari, C.; Buimaga-Iarinca, L.; Rungger, I.; Sanvito, S.; Melinte, S.; Rignanese, G.-M.

    2016-01-01

    Using first-principles calculations, we study the electronic and transport properties of rutheniumterpyridine molecules sandwiched between two Au(111) electrodes. We analyse both single and packed molecular devices, more amenable to scaling and realistic integration approaches. The devices display all together robust negative differential resistance features at low bias voltages. Remarkably, the electrical control of the spin transport in the studied systems implies a subtle distribution of the magnetisation density within the biased devices and highlights the key role of the Au(111) electrical contacts. PMID:27550064

  19. Charge-flow structures as polymeric early-warning fire alarm devices. M.S. Thesis; [metal oxide semiconductors

    Science.gov (United States)

    Sechen, C. M.; Senturia, S. D.

    1977-01-01

    The charge-flow transistor (CFT) and its applications for fire detection and gas sensing were investigated. The utility of various thin film polymers as possible sensing materials was determined. One polymer, PAPA, showed promise as a relative humidity sensor; two others, PFI and PSB, were found to be particularly suitable for fire detection. The behavior of the charge-flow capacitor, which is basically a parallel-plate capacitor with a polymer-filled gap in the metallic tip electrode, was successfully modeled as an RC transmission line. Prototype charge-flow transistors were fabricated and tested. The effective threshold voltage of this metal oxide semiconductor was found to be dependent on whether surface or bulk conduction in the thin film was dominant. Fire tests with a PFI-coated CFT indicate good sensitivity to smouldering fires.

  20. 1D versus 3D quantum confinement in 1-5 nm ZnO nanoparticle agglomerations for application in charge-trapping memory devices.

    Science.gov (United States)

    El-Atab, Nazek; Nayfeh, Ammar

    2016-07-01

    ZnO nanoparticles (NPs) have attracted considerable interest from industry and researchers due to their excellent properties with applications in optoelectronic devices, sunscreens, photocatalysts, sensors, biomedical sciences, etc. However, the agglomeration of NPs is considered to be a limiting factor since it can affect the desirable physical and electronic properties of the NPs. In this work, 1-5 nm ZnO NPs deposited by spin- and dip-coating techniques are studied. The electronic and physical properties of the resulting agglomerations of NPs are studied using UV-vis-NIR spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM), and their application in metal-oxide-semiconductor (MOS) memory devices is analyzed. The results show that both dip- and spin-coating techniques lead to agglomerations of the NPs mostly in the horizontal direction. However, the width of the ZnO clusters is larger with dip-coating which leads to 1D quantum confinement, while the smaller ZnO clusters obtained by spin-coating enable 3D quantum confinement in ZnO. The ZnO NPs are used as the charge-trapping layer of a MOS-memory structure and the analysis of the high-frequency C-V measurements allow further understanding of the electronic properties of the ZnO agglomerations. A large memory window is achieved in both devices which confirms that ZnO NPs provide large charge-trapping density. In addition, ZnO confined in 3D allows for a larger memory window at lower operating voltages due to the Poole-Frenkel charge-emission mechanism. PMID:27232717

  1. 1D versus 3D quantum confinement in 1–5 nm ZnO nanoparticle agglomerations for application in charge-trapping memory devices

    Science.gov (United States)

    El-Atab, Nazek; Nayfeh, Ammar

    2016-07-01

    ZnO nanoparticles (NPs) have attracted considerable interest from industry and researchers due to their excellent properties with applications in optoelectronic devices, sunscreens, photocatalysts, sensors, biomedical sciences, etc. However, the agglomeration of NPs is considered to be a limiting factor since it can affect the desirable physical and electronic properties of the NPs. In this work, 1–5 nm ZnO NPs deposited by spin- and dip-coating techniques are studied. The electronic and physical properties of the resulting agglomerations of NPs are studied using UV–vis–NIR spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM), and their application in metal-oxide-semiconductor (MOS) memory devices is analyzed. The results show that both dip- and spin-coating techniques lead to agglomerations of the NPs mostly in the horizontal direction. However, the width of the ZnO clusters is larger with dip-coating which leads to 1D quantum confinement, while the smaller ZnO clusters obtained by spin-coating enable 3D quantum confinement in ZnO. The ZnO NPs are used as the charge-trapping layer of a MOS-memory structure and the analysis of the high-frequency C–V measurements allow further understanding of the electronic properties of the ZnO agglomerations. A large memory window is achieved in both devices which confirms that ZnO NPs provide large charge-trapping density. In addition, ZnO confined in 3D allows for a larger memory window at lower operating voltages due to the Poole–Frenkel charge-emission mechanism.

  2. DC Charging Device Based on Distributed PV and Wind Energy Complementary Power Source%基于分布式风光互补电源直流充电装置设计

    Institute of Scientific and Technical Information of China (English)

    刘春亮; 朴在林; 孙凤强

    2012-01-01

    The distributed wind-light complementary system was used as the charging power supply to research the electric vehicle battery quick charging problem. The design adopted three-stage charging mode, the charging early use of small current charge and pulse charging the combination of fast charging method, and in the later charge period using a trickle charging method to DC charging device for electric vehicle battery fast charging, to contact the Union Pay card as the medium charge. Through the MATLAB simulation results showed that the design of three-phase charging method of DC charging device for electric vehicle battery fast charging, and can automatically charge.%采用分布式风光互补发电系统作为充电电源,研究电动汽车蓄电池的快速充电问题.设计采用三阶段充电模式,即充电前期采用小电流预充电和脉冲充电相结合的快速充电方法,而在充电后期采用涓流补足充电法的直流充电装置对电动汽车蓄电池快速充电,以接触式银联卡作为介质收费.通过MATLAB仿真结果表明,设计的三阶段充电法的直流充电装置能对电动汽车蓄电池快速充电,并能自动收费.

  3. Role of Contact and Contact Mo dification on Photo-resp onse in a Charge Transfer Complex Single Nanowire Device

    Institute of Scientific and Technical Information of China (English)

    Rabaya Basori∗; A. K. Raychaudhuri

    2014-01-01

    We investigated the feasibility of obtaining large photoresponse in metal-semiconductor-metal (MSM) type single nanowire device where one contact can be blocking type. We showed that suitable modifi-cation of the blocking contact by deposition of a capping metal using focused electron beam (FEB) can lead to considerable enhancement of the photoresponse. The work was done in a single Cu:TCNQ nanowire device fabricated by direct growth of nanowires (NW) from pre-patterned Cu electrode which makes the contact ohmic with the other contact made from Au. Analysis of the data shows that the large photoresponse of the devices arises predominantly due to reduction of the barriers at the Au/NW blocking contact on illumination. This is caused by the diffusion of the photo generated carriers from the nanowires to the contact region. When the barrier height is further reduced by treating the contact with FEB deposited Pt, this results in a large enhancement in the device photoresponse.

  4. Constraints on the R-parity and Lepton Flavor Violating Couplings from $B^{0}$ Decays to Two Charged Leptons

    CERN Document Server

    Jang, J H; Lee Jae Sik; Jang, Ji-Ho; Kim, Jae Kwan; Lee, Jae Sik

    1997-01-01

    We derive the constraints on some products of R-parity and lepton flavor violating constants from the decays of neutral $B$ meson into two charged leptons. We find that some of these constraints are new and stronger than the previous results.

  5. Energy loss and charge state distribution of calcium ions in dense moderately coupled carbon plasma; Energieverlust und Ladungsverteilung von Calciumionen in dichtem, schwach gekoppeltem Kohlenstoffplasma

    Energy Technology Data Exchange (ETDEWEB)

    Ortner, Alex

    2015-07-15

    In this thesis the interaction of swift calcium ions (Energy: 3.5 MeV/u) with a dense and moderately coupled carbon plasma (Coupling parameter: Γ=0.1-0.5) is investigated. The plasma state is generated by heating a thin carbon foil volumetrically by thermal X-ray radiation. The thermal X-ray radiation itself is generated by the conversion of a high energy laser beam in a hohlraum cavity. Compared to earlier ion stopping experiments the electron density and the plasma coupling parameter could be increased by an order of magnitude. This work provides the first time experimental energy loss and charge state distribution data in this moderately coupled interaction regime. The thesis consists of a theoretical part where the ion beam plasma interaction is studied for a broad range of plasma parameters and an experimental part where the ion beam interaction with the hohlraum plasma target is measured. All the described experiments were carried out at the GSI Helmholtzzentrum fuer Schwerionenforschung in Darmstadt. This facility offers the unique possibility to combine a heavy ion beam from an accelerator with a high energy laser beam in one interaction chamber. An intense laser pulse (150 J of laser energy in 1 ns at λ{sub L}=527 nm) is focused inside a 600 μm diameter spherical cavity and generates a hot gold plasma that emits X-rays. The absorbed and reemitted radiation establishes a spatially uniform temperature distribution in the cavity and serves as an intense, isotropic X-ray source with a quasi-thermal spectral distribution. These thermal X-rays with a radiation temperature of T{sub r}=98±6 eV then propagate into a secondary cylindrical hohlraum (diameter: 1000 μm, length: 950 μm) where they volumetrically heat two thin carbon foils to the plasma state. The radiation temperature in the secondary hohlraum is T{sub r}=33±5 eV. This indirect laser heating scheme has the advantage that the whole sample volume is instantaneously heated and that the plasma is

  6. Research on Magnetically Coupled Resonant Wireless Charging System%磁耦合谐振式无线充电系统研究

    Institute of Scientific and Technical Information of China (English)

    徐杰; 沈锦飞

    2014-01-01

    Wireless charging technology is a new power transmission technology.This paper designs a magnetically coupled resonant battery charger,achieves wireless charging battery.Using two coupled resonant circuit to capture the re-duced electromagnetic field with the reduced distance,when the transmission circuit and the receiving circuit are in the reso-nant state,the energy exchange between the resonators can achieve high efficiency.Using a transformer mutual model anal-ysis magnetically coupled resonant wireless power transmission.Designed power 4 kW,magnetically coupled resonant fre-quency of 75 kHz experimental circuit,the experimental results indicate that the transmission distance of 0.3 m,the effi-ciency approaches 90%.%无线充电技术是一种新型的电能传输技术。文中设计了一种磁耦合谐振式蓄电池充电器,能够实现蓄电池无线充电。利用两个发生谐振耦合的电路来捕捉随距离缩减的电磁场,当发射回路和接受回路处于谐振状态时,谐振体之间能量交换可以达到很高的效率。利用变压器互感模型对磁耦合谐振无线电能传送进行了分析,设计了功率为4 kW的磁耦合谐振频率75 kHz的试验电路,实验结果表明,当传输距离为0.3 m时,效率接近90%。

  7. Constraints on anomalous charged current couplings, tau neutrino mass and fourth generation mixing from tau leptonic branching fractions

    International Nuclear Information System (INIS)

    We use recent experimental measurements of tau branching fractions to determine the weak charged current magnetic and electric dipole moments of the tau and the Michel parameter η with unprecedented precision. These results are then used to constrain the tau compositeness scale and the allowed parameter space for Higgs doublet models. We also present new constraints on the mass of the tau neutrino and its mixing with a fourth generation neutrino

  8. Characterization of CdTe Sensors with Schottky Contacts Coupled to Charge-Integrating Pixel Array Detectors for X-Ray Science

    CERN Document Server

    Becker, Julian; Shanks, Katherine S; Philipp, Hugh T; Weiss, Joel T; Purohit, Prafull; Chamberlain, Darol; Ruff, Jacob P C; Gruner, Sol M

    2016-01-01

    Pixel Array Detectors (PADs) consist of an x-ray sensor layer bonded pixel-by-pixel to an underlying readout chip. This approach allows both the sensor and the custom pixel electronics to be tailored independently to best match the x-ray imaging requirements. Here we present characterizations of CdTe sensors hybridized with two different charge-integrating readout chips, the Keck PAD and the Mixed-Mode PAD (MM-PAD), both developed previously in our laboratory. The charge-integrating architecture of each of these PADs extends the instantaneous counting rate by many orders of magnitude beyond that obtainable with photon counting architectures. The Keck PAD chip consists of rapid, 8-frame, in-pixel storage elements with framing periods $<$150 ns. The second detector, the MM-PAD, has an extended dynamic range by utilizing an in-pixel overflow counter coupled with charge removal circuitry activated at each overflow. This allows the recording of signals from the single-photon level to tens of millions of x-rays/...

  9. Interfacial Charge Transfer in Dye-Sensitized Solar Cells Using SCN-Free Terpyridine-Coordinated Ru Complex Dye and Co Complex Redox Couples.

    Science.gov (United States)

    Kono, Takahiro; Masaki, Naruhiko; Nishikawa, Masahiro; Tamura, Rei; Matsuzaki, Hiroyuki; Kimura, Mutsumi; Mori, Shogo

    2016-07-01

    The efficiency of dye-sensitized solar cells (DSSCs) using Ru complex dyes and Co complex redox couples has been increased with a strategy to prevent charge recombination via the addition of bulky or lengthy peripheral units to the dyes. However, despite the efforts, most of the DSSCs are still suffering from nonunity quantum efficiency and fast recombination. We examine the effect of SCN ligand, which has been used for many Ru complex dyes and could attract positively charged Co complexes. We find that replacing the ligands with 2,6-bis(2'-(4'-trifluoromethyl)pyrazolyl)pyridine increases the quantum efficiency and electron lifetime. With the combination of the replacement of SCN ligands and the addition of bulky moiety, ∼80% external quantum efficiency is achieved. These suggest that not only the addition of a blocking effect but also the reduction of electrostatic and dispersion forces between dyes and Co complexes are essential to control the charge separation and recombination processes. PMID:27328462

  10. Oxide Charge Engineering of Atomic Layer Deposited AlOxNy/Al2O3 Gate Dielectrics: A Path to Enhancement Mode GaN Devices.

    Science.gov (United States)

    Negara, M A; Kitano, M; Long, R D; McIntyre, P C

    2016-08-17

    Nitrogen incorporation to produce negative fixed charge in Al2O3 gate insulator layers is investigated as a path to achieve enhancement mode GaN device operation. A uniform distribution of nitrogen across the resulting AlOxNy films is obtained using N2 plasma enhanced atomic layer deposition (ALD). The flat band voltage (Vfb) increases to a significantly more positive value with increasing nitrogen concentration. Insertion of a 2 nm thick Al2O3 interlayer greatly decreases the trap density of the insulator/GaN interface, and reduces the voltage hysteresis and frequency dispersion of gate capacitance compared to single-layer AlOxNy gate insulators in GaN MOSCAPs.

  11. Oxide Charge Engineering of Atomic Layer Deposited AlOxNy/Al2O3 Gate Dielectrics: A Path to Enhancement Mode GaN Devices.

    Science.gov (United States)

    Negara, M A; Kitano, M; Long, R D; McIntyre, P C

    2016-08-17

    Nitrogen incorporation to produce negative fixed charge in Al2O3 gate insulator layers is investigated as a path to achieve enhancement mode GaN device operation. A uniform distribution of nitrogen across the resulting AlOxNy films is obtained using N2 plasma enhanced atomic layer deposition (ALD). The flat band voltage (Vfb) increases to a significantly more positive value with increasing nitrogen concentration. Insertion of a 2 nm thick Al2O3 interlayer greatly decreases the trap density of the insulator/GaN interface, and reduces the voltage hysteresis and frequency dispersion of gate capacitance compared to single-layer AlOxNy gate insulators in GaN MOSCAPs. PMID:27459343

  12. Assessment of Electromagnetic Interference with Active Cardiovascular Implantable Electronic Devices (CIEDs Caused by the Qi A13 Design Wireless Charging Board

    Directory of Open Access Journals (Sweden)

    Tobias Seckler

    2015-05-01

    Full Text Available Electromagnetic interference is a concern for people wearing cardiovascular implantable electronic devices (CIEDs. The aim of this study was to assess the electromagnetic compatibility between CIEDs and the magnetic field of a common wireless charging technology. To do so the voltage induced in CIEDs by Qi A13 design magnetic fields were measured and compared with the performance limits set by ISO 14117. In order to carry this out a measuring circuit was developed which can be connected with unipolar or bipolar pacemaker leads. The measuring system was positioned at the four most common implantation sites in a torso phantom filled with physiological saline solution. The phantom was exposed by using Helmholtz coils from 5 µT to 27 µT with 111 kHz sine‑bursts or by using a Qi A13 design wireless charging board (Qi‑A13‑Board in two operating modes “power transfer” and “pinging”. With the Helmholtz coils the lowest magnetic flux density at which the performance limit was exceeded is 11 µT. With the Qi‑A13‑Board in power transfer mode 10.8% and in pinging mode 45.7% (2.2% at 10 cm distance of the performance limit were reached at maximum. In neither of the scrutinized cases, did the voltage induced by the Qi‑A13‑Board exceed the performance limits.

  13. A new numerical description of the interaction of an ion beam with a magnetized plasma in an ECR-based charge breeding device

    Science.gov (United States)

    Galatà, A.; Mascali, D.; Neri, L.; Celona, L.

    2016-08-01

    The ion beam-plasma interaction is a relevant topic in several fields of plasma physics, from fusion devices to modern ion sources. This paper discusses the numerical modelling of the whole beam-plus-plasma-target system in case of 1+  ions entering an ECR-based charge breeder (ECR-CB). The model is able to reproduce the ion capture and the creation of the first charge states in the selected physics case, i.e. the interaction of a 85Rb1+ ions with the plasma of the 14.5 GHz PHOENIX ECR-CB installed at the Laboratoire de Physique Subatomique et de Cosmologie (LPSC) of Grenoble. The results show that a very narrow window of physical parameters for both the beam (energy and energy spread especially) and plasma (ion temperature, density, density structural distribution, self-generated ambipolar fields) exists which is able to reproduce very well the experimental results, providing an exhaustive picture of the involved phenomena. Possible non-linear interactions and the role played by the eventual onset of instabilities are also discussed.

  14. Measuring the state of charge of the electrolyte solution in a vanadium redox flow battery using a four-pole cell device

    Science.gov (United States)

    Ngamsai, Kittima; Arpornwichanop, Amornchai

    2015-12-01

    The decrease in the efficiency and capacity of a vanadium redox flow battery (VRB) caused by an electrolyte imbalance is an important impediment to its long-term operation. Knowing the state of charge (SOC) of an electrolyte solution can quantify the level of the electrolyte imbalance in the VRB. In this study, a four-pole cell device is devised and employed to predict the SOC. The proposed method directly measures the ionic resistance of the electrolyte solution and is sufficiently precise to be applied in real-time mode. Experimental studies on the effects of the operating current on the four-pole cell and the concentrations of vanadium and sulfuric acid in the electrolyte solution are carried out. The results show that the four-pole cell method can be utilized to measure the electrolyte SOC. The concentrations of vanadium and sulfuric acid in the electrolyte solution affect the ionic resistance of the solution. Regarding the capacity and efficiency of the VRB system, the results indicate that the electrical charge is determined from the concentration of vanadium and that the cell voltage depends on the concentration of sulfuric acid in the electrolyte solution. The decreased vanadium concentration and increased sulfuric acid concentration improves the cell voltage efficiency.

  15. Effect of NO annealing on charge traps in oxide insulator and transition layer for 4H-SiC metal-oxide-semiconductor devices

    Science.gov (United States)

    Jia, Yifan; Lv, Hongliang; Niu, Yingxi; Li, Ling; Song, Qingwen; Tang, Xiaoyan; Li, Chengzhan; Zhao, Yanli; Xiao, Li; Wang, Liangyong; Tang, Guangming; Zhang, Yimen; Zhang, Yuming

    2016-09-01

    The effect of nitric oxide (NO) annealing on charge traps in the oxide insulator and transition layer in n-type 4H-SiC metal-oxide-semiconductor (MOS) devices has been investigated using the time-dependent bias stress (TDBS), capacitance-voltage (C-V), and secondary ion mass spectroscopy (SIMS). It is revealed that two main categories of charge traps, near interface oxide traps (Nniot) and oxide traps (Not), have different responses to the TDBS and C-V characteristics in NO-annealed and Ar-annealed samples. The Nniot are mainly responsible for the hysteresis occurring in the bidirectional C-V characteristics, which are very close to the semiconductor interface and can readily exchange charges with the inner semiconductor. However, Not is mainly responsible for the TDBS induced C-V shifts. Electrons tunneling into the Not are hardly released quickly when suffering TDBS, resulting in the problem of the threshold voltage stability. Compared with the Ar-annealed sample, Nniot can be significantly suppressed by the NO annealing, but there is little improvement of Not. SIMS results demonstrate that the Nniot are distributed within the transition layer, which correlated with the existence of the excess silicon. During the NO annealing process, the excess Si atoms incorporate into nitrogen in the transition layer, allowing better relaxation of the interface strain and effectively reducing the width of the transition layer and the density of Nniot. Project supported by the National Natural Science Foundation of China (Grant Nos. 61404098 and 61274079), the Doctoral Fund of Ministry of Education of China (Grant No. 20130203120017), the National Key Basic Research Program of China (Grant No. 2015CB759600), the National Grid Science & Technology Project, China (Grant No. SGRI-WD-71-14-018), and the Key Specific Project in the National Science & Technology Program, China (Grant Nos. 2013ZX02305002-002 and 2015CB759600).

  16. Strong electron-lattice coupling as the mechanism behind charge densiy wave transformations in transition-metal-dichalkogenides

    OpenAIRE

    Gor'kov, Lev P.

    2011-01-01

    We consider single band of conduction electrons interacting with displacements of the transitional ions.In the classical regime strong coupling transforms the harmonic elastic energy for an ion to the one of the well with two deep minima,so that the system is described in terms of Ising spins. Inter-site interactions via the exchange by electrons order spins at lower temperatures. Extention to the quantum regime is discussed. Below the CDW-transition the energy spectrum of electrons remains m...

  17. Electroweak-Higgs unification in the two Higgs doublet model: masses and couplings of the neutral and charged Higgs bosons

    Energy Technology Data Exchange (ETDEWEB)

    Diaz C, J.L. [Facultad de Ciencias Fisico-Matematicas, BUAP, A.P. 1364, 72000 Puebla (Mexico); Rosado, A. [Instituto de Fisica, BUAP, A.P. J-48, 72570 Puebla (Mexico)

    2007-07-01

    We obtain the mass spectrum and the Higgs self-couplings of the two Higgs doublet model (THDM) in an alternative unification scenario where the parameters of the Higgs potential {lambda} (i = 1, 2, 3, 4, 5) are determined by imposing their unification on the electroweak gauge couplings. An attractive feature of this scenario is the possibility of determining the Higgs boson masses by evolving the {lambda}{sub i} from the electroweak-Higgs unification scale M{sub GH} down to the electroweak scale. The unification condition for the gauge (g{sub 1}, g{sub 2}) and Higgs couplings is written as g{sub 1} g{sub 2} = f ({lambda}{sub i}), where g{sub 1} = k{sub Y}{sup 1/2}g{sub Y}, and k{sub Y} is the normalization constant. Two variants for the unification condition are discussed: Scenario l is defined through the linear relation: g{sub 1} = g{sub 2} = k{sub H} (i){lambda}{sub i} (M{sub GH}), while Scenario ll assumes a quadratic relation g{sub 1}{sup 2} = g{sub 2}{sup 2} k{sub H} (i) {lambda}{sub i}(M{sub GH}) In Scenario l, by setting ad hoc - k{sub H}(5) = 1/2k{sub H}(4) 3/2k{sub H}(3) = k{sub H}(2) = k{sub H}(I) = 1, taking tan {beta} = 1 and using the standard normalization (k{sub Y} = 5/3), we obtain the following spectrum for the Higgs boson masses: m{sub h}{sup 0} = 109.1 GeV, m{sub H}{sup 0} = 123.2 GeV, m{sub A}{sup 0} = 115.5 GeV, and m{sub H}{sup +-} = 80.3 GeV, with similar results for other normalizations such as k{sub Y} = 3/2 and k{sub Y} = 7/4. (Author)

  18. Energy loss and charge state distribution of calcium ions in dense moderately coupled carbon plasma; Energieverlust und Ladungsverteilung von Calciumionen in dichtem, schwach gekoppeltem Kohlenstoffplasma

    Energy Technology Data Exchange (ETDEWEB)

    Ortner, Alex

    2015-07-15

    In this thesis the interaction of swift calcium ions (Energy: 3.5 MeV/u) with a dense and moderately coupled carbon plasma (Coupling parameter: Γ=0.1-0.5) is investigated. The plasma state is generated by heating a thin carbon foil volumetrically by thermal X-ray radiation. The thermal X-ray radiation itself is generated by the conversion of a high energy laser beam in a hohlraum cavity. Compared to earlier ion stopping experiments the electron density and the plasma coupling parameter could be increased by an order of magnitude. This work provides the first time experimental energy loss and charge state distribution data in this moderately coupled interaction regime. The thesis consists of a theoretical part where the ion beam plasma interaction is studied for a broad range of plasma parameters and an experimental part where the ion beam interaction with the hohlraum plasma target is measured. All the described experiments were carried out at the GSI Helmholtzzentrum fuer Schwerionenforschung in Darmstadt. This facility offers the unique possibility to combine a heavy ion beam from an accelerator with a high energy laser beam in one interaction chamber. An intense laser pulse (150 J of laser energy in 1 ns at λ{sub L}=527 nm) is focused inside a 600 μm diameter spherical cavity and generates a hot gold plasma that emits X-rays. The absorbed and reemitted radiation establishes a spatially uniform temperature distribution in the cavity and serves as an intense, isotropic X-ray source with a quasi-thermal spectral distribution. These thermal X-rays with a radiation temperature of T{sub r}=98±6 eV then propagate into a secondary cylindrical hohlraum (diameter: 1000 μm, length: 950 μm) where they volumetrically heat two thin carbon foils to the plasma state. The radiation temperature in the secondary hohlraum is T{sub r}=33±5 eV. This indirect laser heating scheme has the advantage that the whole sample volume is instantaneously heated and that the plasma is

  19. Static and collapsing spherically symmetric charged thin shells in Lovelock gravity coupled to Maxwell electromagnetism: Hamiltonian treatment and physical implications

    CERN Document Server

    Dias, G A S; Lemos, J P S; Dias, Goncalo A. S.; Gao, Sijie; Lemos, Jos\\'e P. S.

    2006-01-01

    Using a Hamiltonian treatment, charged thin shells in spherically symmetric spacetimes in d dimensional Lovelock-Maxwell theory are studied. The coefficients of the theory are chosen to obtain a sensible theory, with a negative cosmological constant appearing naturally. After writing the action and the Lagrangian for a spacetime comprised of an interior and an exterior regions, with a thin shell as a boundary in between, one finds the Hamiltonian using an ADM description. For spherically symmetric spacetimes, one reduces the relevant constraints. The dynamic and constraint equations are obtained. The vacuum solutions yield a division of the theory into two branches, d-2k-1>0 (which includes general relativity, Born-Infeld type theories) and d-2k-1=0 (which includes Chern-Simons type theories), where k gives the highest power of the curvature in the Lagrangian. An additional parameter, chi, gives the character of the vacuum solutions. For chi=1 the solutions have a black hole character. For chi=-1 the solution...

  20. Design of a 4D Emittance Measurement Device for High Charge State ECR Ion Sources%高电荷态ECR离子源引出束流4D发射度测量仪设计

    Institute of Scientific and Technical Information of China (English)

    赵阳阳; 赵红卫; 孙良亭; 杨尧; 王云; 曹云

    2013-01-01

    For the purpose of on-line beam quality diagnostics and transverse emittance coupling investigation of the ion beams delivered by an Electron Cyclotron Resonance (ECR) ion source, a real-time 4D Pepper Pot type emittance scanner is under development at IMP(Institute of Moden Physics, Chinese Academy of Sciences). The high charge state ECR ion source at IMP could produce CW or pulsed heavy ion beam intensities in the range of 1 eµA∼1 emA with the kinetic energy of 10∼35 keV/q, which needs the design of the Pepper Pot scanner to be optimized accordingly. The Pepper Pot scanner has many features, such as very short response time and wide dynamic working range that the device could be applied. Since intense heavy ion beam bombardment is expected for this device, the structure and the material selection for the device is specially considered during the design, and a feasible solution to analyze the pictures acquired after the data acquisition is also made.%为了进一步探究高电荷态电子回旋共振(ECR)离子源引出束流品质和横向相空间耦合情况,根据中国科学院近代物理研究所高电荷态离子源引出束流发射度测量需求,针对束流流强为1 eµA∼1 emA,能量范围为10∼35 keV/q的直流或脉冲高电荷态重离子束,设计了一台实时四维Pepper-pot发射度测量仪。该Pepper-pot型发射度测量仪具有响应时间快和工作范围宽等特点。针对强流重离子束诊断的特点,在结构与材料选择上做了设计与优化,并对获得图像的处理方法提出了具体的解决办法。

  1. Remarkable charge-trapping performance based in Zr0.5Hf0.5O2 with nanocrystal Ba0.6Sr0.4TiO3 blocking layer for nonvolatile memory device

    Science.gov (United States)

    Yan, X. B.; Jia, X. L.; Yang, T.; Zhao, J. H.; Li, Y. C.; Zhou, Z. Y.; Zhang, Y. Y.

    2016-10-01

    Two kinds of charge trapping memory device with Au/Zr0.5Hf0.5O2(ZHO)/SiO2/p-Si and Au/Ba0.6Sr0.4TiO3(BST)/Zr0.5Hf0.5O2/SiO2/p-Si structure were fabricated and investigated. The double BST/ZHO films exhibit a larger memory window of 7.36 V under ±14 V sweeping voltages in its C-V curve and the device has good charge retention properties with only small charge loss of ∼ 5% after more than 104 s. The good characteristics are attributed to the inter-diffusion between BST and ZHO where more deep defect sites were created after RTA treatment, which provides high potential barriers for the trapped charges to tunnel back to the silicon substrate. Furthermore, the nanocrystal in the BST layer increases the tunneling barrier of tunneling current into the gate and effectively restrains the leakage of storage charge from blocking layer, which improves the charge retention characteristic.

  2. An Imagination of Developing Mobile Reading Devices Charging Service in Library%图书馆开展移动阅读设备充电服务的设想

    Institute of Scientific and Technical Information of China (English)

    王阳

    2015-01-01

    At present, the widespread use of mobile reading devices makes readers’ reading way be changed completely. However, the congenital deficient of mobile reading devices in cruising ability brings about certain difficulties for the readers’ reading. This paper expounds the necessity of developing the charging service for mobile reading devices in library, analyzes the feasibility of developing the charging service for mobile reading devices in library, and puts forward some matters needing attention in developing the charging service for mobile reading devices in library.%当前,移动阅读设备的普遍使用使读者阅读方式发生了彻底的变化。但移动阅读设备电力续航能力的先天不足给读者阅读带来了一定的困难。阐述了图书馆开展移动阅读设备充电服务的必要性,分析了图书馆开展移动阅读设备充电服务的可行性,提出了图书馆开展移动阅读设备充电服务的注意事项。

  3. Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Praphairaksit, N.

    2000-09-12

    An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at {approximately}70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W with an outer gas flow rate of {approximately}4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added to the base of the skimmer. Electrons supplied from this source downstream of the skimmer with suitable amount and energy can neutralize the positive ions in the beam extracted from the plasma and diminish the space charge repulsion between them. As a result, the overall ion transmission efficiency and consequent analyte ion sensitivities are significantly improved while other important analytical aspects, such as metal oxide ion ratio, doubly charged ion ratio and background ions remain relatively unchanged with the operation of this electron source. This technique not only improves the ion transmission efficiency but also minimizes the matrix effects drastically. The matrix-induced suppression

  4. Luminance Mechanisms of White Organic Light-Emitting Devices Fabricated Utilizing a Charge Generation Layer with a Light-Emitting Function.

    Science.gov (United States)

    Kim, K H; Jeon, Y P; Choo, D C; Kim, T W

    2015-07-01

    The luminance mechanisms of the white organic light-emitting devices (WOLEDs) with a charge generation layer (CGL) consisting of a tungsten oxide layer and a 5,6,11,12-tetraphenyltetracene (rubrene) doped N,N',-bis-(1-naphthyl)-N,N'-diphenyl1-1'-biphenyl-4,4'-diamine (NPB) layer were investigated. Current densities and luminances of the WOLEDs increased with increasing a rubrene doping concentration because the formation of excitons in the rubrene-doped NPB layer increased due to the more exciton trapping in rubrene molecules and the delay of the electron injection due to the insertion of the litium qunolate layer. The yellow light emitted from the rubrene-doped NPB layer in the CGL combined with the blue light from the main emitting layer of the WOLEDs, resulting in the emission of the white light. The ratio between the yellow and the blue color peak intensities of the electroluminescence spectra for the WOLEDs was controlled by the rubrene doping concentration. The Commission Internationale de l'Eclairage coordinates of the fabricated WOLED were (0.31, 0.42) at 740.7 cd/m2, indicative of white emission color. PMID:26373110

  5. The effects of cage design on airborne allergens and endotoxin in animal rooms: high-volume measurements with an ion-charging device.

    Science.gov (United States)

    Platts-Mills, James; Custis, Natalie; Kenney, Alice; Tsay, Amy; Chapman, Martin; Feldman, Sanford; Platts-Mills, Thomas

    2005-03-01

    Respiratory symptoms related to both endotoxins and animal allergens continue to be an important cause of occupational disease for animal technicians and scientists working with rodents. Better sampling methods for airborne allergens and endotoxin are needed to help standardize compliance with federal occupational health regulations. Using an ion-charging device, we sampled 20 mouse rooms and four rat rooms at the University of Virginia, along with 43 domestic living rooms in houses in the Charlottesville area with at least one cat or dog. The use of filter tops on cages corresponds to a 50-fold reduction in mean levels of both airborne allergens (P < 0.001) and endotoxin (P < 0.001). The use of vented cages with filtered exhaust ports was associated with additional reductions. However, the mean airborne endotoxin level in all rooms using filter tops without a filtered exhaust port on the cages was significantly lower (P = 0.003) than the level in domestic living rooms. Our results for maximum airborne allergens or endotoxin are comparable with previous reports. However, the sensitivity of the technique allows an accurate assessment of low-level exposure, which makes it possible to evaluate the effect of cage designs. In addition, this approach allows direct comparison with results for airborne allergen and endotoxin in domestic homes. The results could allow a more consistent approach to the application of occupational health guidelines. PMID:15773770

  6. Modeling Charge Collection in Detector Arrays

    Science.gov (United States)

    Hardage, Donna (Technical Monitor); Pickel, J. C.

    2003-01-01

    A detector array charge collection model has been developed for use as an engineering tool to aid in the design of optical sensor missions for operation in the space radiation environment. This model is an enhancement of the prototype array charge collection model that was developed for the Next Generation Space Telescope (NGST) program. The primary enhancements were accounting for drift-assisted diffusion by Monte Carlo modeling techniques and implementing the modeling approaches in a windows-based code. The modeling is concerned with integrated charge collection within discrete pixels in the focal plane array (FPA), with high fidelity spatial resolution. It is applicable to all detector geometries including monolithc charge coupled devices (CCDs), Active Pixel Sensors (APS) and hybrid FPA geometries based on a detector array bump-bonded to a readout integrated circuit (ROIC).

  7. Ablation of intervertebral discs in dogs using a MicroJet-assisted dye-enhanced injection device coupled with the diode laser

    Science.gov (United States)

    Bartels, Kenneth E.; Henry, George A.; Dickey, D. Thomas; Stair, Ernest L.; Powell, Ronald; Schafer, Steven A.; Nordquist, Robert E.; Frederickson, Christopher J.; Hayes, Donald J.; Wallace, David B.

    1998-07-01

    Use of holmium laser energy for vaporization/coagulation of the nucleus pulposus in canine intervertebral discs has been previously reported and is currently being applied clinically in veterinary medicine. The procedure was originally developed in the canine model and intended for potential human use. Since the pulsed (15 Hz) holmium laser energy exerts photomechanical and photothermal effects, the potential for extrusion of additional disc material to the detriment of the patient is possible using the procedure developed for the dog. To reduce this potential complication, use of diode laser (805 nm - CW mode) energy, coupled with indocyanine green (ICG) as a selective laser energy absorber, was formulated as a possible alternative. Delivery of the ICG and diode laser energy was through a MicroJet device that could dispense dye interactively between individual laser 'shots.' Results have shown that it is possible to selectively ablate nucleus pulposus in the canine model using the device described. Acute observations (gross and histopathologic) illustrate that accurate placement of the spinal needle before introduction of the MicroJet device is critically dependent on the expertise of the interventional radiologist. In addition, the success of the overall technique depends on consistent delivery of both ICG and diode laser energy. Minimizing tissue carbonization on the tip of the MicroJet device is also of crucial importance for effective application of the technique in clinical veterinary medicine.

  8. Light coupling between vertical III-As nanowires and planar Si photonic waveguides for the monolithic integration of active optoelectronic devices on a Si platform.

    Science.gov (United States)

    Giuntoni, Ivano; Geelhaar, Lutz; Bruns, Jürgen; Riechert, Henning

    2016-08-01

    We present a new concept for the optical interfacing between vertical III-As nanowires and planar Si waveguides. The nanowires are arranged in a two-dimensional array which forms a grating structure on top of the waveguide. This grating enables light coupling in both directions between the components made from the two different material classes. Numerical simulations show that this concept permits a light extraction efficiency from the waveguide larger than 45% and a light insertion efficiency larger than 35%. This new approach would allow the monolithic integration of nanowire-based active optoelectronics devices, like photodetectors and light sources, on the Si photonics platform. PMID:27505805

  9. Localized charge carriers in graphene nanodevices

    Energy Technology Data Exchange (ETDEWEB)

    Bischoff, D., E-mail: dominikb@phys.ethz.ch; Varlet, A.; Simonet, P.; Eich, M.; Overweg, H. C.; Ihn, T.; Ensslin, K. [Solid State Physics Laboratory, ETH Zurich, 8093 Zurich (Switzerland)

    2015-09-15

    Graphene—two-dimensional carbon—is a material with unique mechanical, optical, chemical, and electronic properties. Its use in a wide range of applications was therefore suggested. From an electronic point of view, nanostructured graphene is of great interest due to the potential opening of a band gap, applications in quantum devices, and investigations of physical phenomena. Narrow graphene stripes called “nanoribbons” show clearly different electronical transport properties than micron-sized graphene devices. The conductivity is generally reduced and around the charge neutrality point, the conductance is nearly completely suppressed. While various mechanisms can lead to this observed suppression of conductance, disordered edges resulting in localized charge carriers are likely the main cause in a large number of experiments. Localized charge carriers manifest themselves in transport experiments by the appearance of Coulomb blockade diamonds. This review focuses on the mechanisms responsible for this charge localization, on interpreting the transport details, and on discussing the consequences for physics and applications. Effects such as multiple coupled sites of localized charge, cotunneling processes, and excited states are discussed. Also, different geometries of quantum devices are compared. Finally, an outlook is provided, where open questions are addressed.

  10. Comparative study on contribution of charge-transfer collision to excitations of iron ion between argon radio-frequency inductively-coupled plasma and nitrogen microwave induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Kozue; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2015-06-01

    This paper describes an ionization/excitation phenomenon of singly-ionized iron occurring in an Okamoto-cavity microwave induced plasma (MIP) as well as an argon radio-frequency inductively-coupled plasma (ICP), by comparing the Boltzmann distribution among iron ionic lines (Fe II) having a wide range of the excitation energy from 4.76 to 9.01 eV. It indicated in both the plasmas that plots of Fe II lines having lower excitation energies (4.76 to 5.88 eV) were fitted on each linear relationship, implying that their excitations were caused by a dominant thermal process such as collision with energetic electron. However, Fe II lines having higher excitation energies (more than 7.55 eV) had a different behavior from each other. In the ICP, Boltzmann plots of Fe II lines assigned to the higher excited levels also followed the normal Boltzmann relationship among the low-lying excited levels, even including a deviation from it in particular excited levels having an excitation energy of ca. 7.8 eV. This deviation can be attributed to a charge-transfer collision with argon ion, which results in the overpopulation of these excited levels, but the contribution is small. On the other hand, the distribution of the high-lying excited levels was non-thermal in the Okamoto-cavity MIP, which did not follow the normal Boltzmann relationship among the low-lying excited levels. A probable reason for the non-thermal characteristics in the MIP is that a charge-transfer collision with nitrogen molecule ion having many vibrational/rotational levels could work for populating the 3d{sup 6}4p (3d{sup 5}4s4p) excited levels of iron ion broadly over an energy range of 7.6–9.0 eV, while collisional excitation by energetic electron would occur insufficiently to excite these high-energy levels. - Highlights: • This paper describes the excitation mechanism of iron ion in Okamoto-cavity MIP in comparison with conventional ICP. • Boltzmann distribution is studied among iron ionic lines of

  11. Comparative study on contribution of charge-transfer collision to excitations of iron ion between argon radio-frequency inductively-coupled plasma and nitrogen microwave induced plasma

    International Nuclear Information System (INIS)

    This paper describes an ionization/excitation phenomenon of singly-ionized iron occurring in an Okamoto-cavity microwave induced plasma (MIP) as well as an argon radio-frequency inductively-coupled plasma (ICP), by comparing the Boltzmann distribution among iron ionic lines (Fe II) having a wide range of the excitation energy from 4.76 to 9.01 eV. It indicated in both the plasmas that plots of Fe II lines having lower excitation energies (4.76 to 5.88 eV) were fitted on each linear relationship, implying that their excitations were caused by a dominant thermal process such as collision with energetic electron. However, Fe II lines having higher excitation energies (more than 7.55 eV) had a different behavior from each other. In the ICP, Boltzmann plots of Fe II lines assigned to the higher excited levels also followed the normal Boltzmann relationship among the low-lying excited levels, even including a deviation from it in particular excited levels having an excitation energy of ca. 7.8 eV. This deviation can be attributed to a charge-transfer collision with argon ion, which results in the overpopulation of these excited levels, but the contribution is small. On the other hand, the distribution of the high-lying excited levels was non-thermal in the Okamoto-cavity MIP, which did not follow the normal Boltzmann relationship among the low-lying excited levels. A probable reason for the non-thermal characteristics in the MIP is that a charge-transfer collision with nitrogen molecule ion having many vibrational/rotational levels could work for populating the 3d64p (3d54s4p) excited levels of iron ion broadly over an energy range of 7.6–9.0 eV, while collisional excitation by energetic electron would occur insufficiently to excite these high-energy levels. - Highlights: • This paper describes the excitation mechanism of iron ion in Okamoto-cavity MIP in comparison with conventional ICP. • Boltzmann distribution is studied among iron ionic lines of various

  12. High-rate production of functional nanostructured films and devices by coupling flame spray pyrolysis with supersonic expansion

    International Nuclear Information System (INIS)

    The fabrication of functional thin films and devices by direct deposition of nanoparticles from the gas phase is a promising approach enabling, for instance, the integration of complex analytical and sensing capabilities on microfabricated platforms. Aerosol-based techniques ensure large-scale nanoparticle production and they are potentially suited for this goal. However, they are not adequate in terms of fine control over the lateral resolution of the coatings, mild processing conditions (avoiding high temperature and aggressive chemicals), low contamination and compatibility with microfabrication processes. Here we report the high-rate and efficient production of functional nanostructured films by nanoparticle assembling obtained by the combination of flame spray pyrolysis and supersonic expansion. Our approach merges the advantages of flame spray pyrolysis for bulk nanopowders such as process stability and wide material library availability with those of supersonic cluster beam deposition in terms of lateral resolution and of direct integration of nanomaterials on devices. We efficiently produced nanostructured films and devices (such as gas sensors) using metal oxide, pure noble metal and oxide-supported noble metal nanoparticles. (paper)

  13. Elastic Vibrations in the Photosynthetic Bacterial Reaction Center Coupled to the Primary Charge Separation: Implications from Molecular Dynamics Simulations and Stochastic Langevin Approach.

    Science.gov (United States)

    Milanovsky, Georgy E; Shuvalov, Vladimir A; Semenov, Alexey Yu; Cherepanov, Dmitry A

    2015-10-29

    Primary electron transfer reactions in the bacterial reaction center are difficult for theoretical explication: the reaction kinetics, almost unalterable over a wide range of temperature and free energy changes, revealed oscillatory features observed initially by Shuvalov and coauthors (1997, 2002). Here the reaction mechanism was studied by molecular dynamics and analyzed within a phenomenological Langevin approach. The spectral function of polarization around the bacteriochlorophyll special pair PLPM and the dielectric response upon the formation of PL(+)PM(-) dipole within the special pair were calculated. The system response was approximated by Langevin oscillators; the respective frequencies, friction, and energy coupling coefficients were determined. The protein dynamics around PL and PM were distinctly asymmetric. The polarization around PL included slow modes with the frequency 30-80 cm(-1) and the total amplitude of 130 mV. Two main low-frequency modes of protein response around PM had frequencies of 95 and 155 cm(-1) and the total amplitude of 30 mV. In addition, a slowly damping mode with the frequency of 118 cm(-1) and the damping time >1.1 ps was coupled to the formation of PL(+)PM(-) dipole. It was attributed to elastic vibrations of α-helices in the vicinity of PLPM. The proposed trapping of P excitation energy in the form of the elastic vibrations can rationalize the observed properties of the primary electron transfer reactions, namely, the unusual temperature and ΔG dependences, the oscillating phenomena in kinetics, and the asymmetry of the charge separation reactions. PMID:26148224

  14. Deep InP Gratings for Opto-Electronic Devices Etched by Cl2/CH4/Ar Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; TIAN Jian-Bai; XIONG Bing; SUN Chang-Zheng; HAO Zhi-Biao; LUO Yi

    2006-01-01

    @@ Deep InP gratings are etched by Cl2/CH4/Ar inductively coupled plasma (ICP) at room temperature. A comparison is made between SiNx mask patterns formed by wet and dry etching. SF6 reactive ion etching is adopted for smooth and vertical sidewall. The etching conditions of Cl2/CH4/Ar ICP are optimized for high anisotropy,and a 1.7-μm-deep InP grating with an aspect ratio of 10:1 is demonstrated. The technique is then used for the fabrication of 1.55-μm laterally coupled distributed feedback AlGaInAs-InP laser.

  15. The influence of interlayer exchange coupling in giant-magnetoresistive devices on spin diode effect in wide frequency range

    International Nuclear Information System (INIS)

    Spin diode effect in a giant magnetoresistive strip is measured in a broad frequency range, including resonance and off-resonance frequencies. The off-resonance dc signal is relatively strong and also significantly dependent on the exchange coupling between magnetic films through the spacer layer. The measured dc signal is described theoretically by taking into account magnetic dynamics induced by Oersted field created by an ac current flowing through the system

  16. Development and validation of a hydrophilic interaction chromatography method coupled with a charged aerosol detector for quantitative analysis of nonchromophoric α-hydroxyamines, organic impurities of metoprolol.

    Science.gov (United States)

    Xu, Qun; Tan, Shane; Petrova, Katya

    2016-01-25

    The European Pharmacopeia (EP) metoprolol impurities M and N are polar, nonchromophoric α-hydroxyamines, which are poorly retained in a conventional reversed-phase chromatographic system and are invisible for UV detection. Impurities M and N are currently analyzed by TLC methods in the EP as specified impurities and in the United States Pharmacopeia-National Formulary (USP-NF) as unspecified impurities. In order to modernize the USP monographs of metoprolol drug substances and related drug products, a hydrophilic interaction chromatography (HILIC) method coupled with a charged aerosol detector (CAD) was explored for the analysis of the two impurities. A comprehensive column screening that covers a variety of HILIC stationary phases (underivatized silica, amide, diol, amino, zwitterionic, polysuccinimide, cyclodextrin, and mixed-mode) and optimization of HPLC conditions led to the identification of a Halo Penta HILIC column (4.6 × 150 mm, 5 μm) and a mobile phase comprising 85% acetonitrile and 15% ammonium formate buffer (100 mM, pH 3.2). Efficient separations of metoprolol, succinic acid, and EP metoprolol impurities M and N were achieved within a short time frame (drug substance (metoprolol succinate) and drug products (metoprolol tartrate injection and metoprolol succinate extended release tablets). PMID:26580821

  17. Multiferroic materials for spin-based logic devices

    OpenAIRE

    de Sousa, Rogerio; Moore, Joel E.

    2008-01-01

    Logical devices based on spin waves offer the potential to avoid dissipation mechanisms that limit devices based on either the charge or spin of mobile electrons. Multiferroic magnetoelectrics, which are materials that combine ferroelectric and magnetic order, allow direct switching of magnetic order and thence of spin-wave properties using an applied electric field. The intrinsic coupling between polarization and magnetic moments, generated by strong electronic correlations in these multifer...

  18. Space-charge-mediated anomalous ferroelectric switching in P(VDF-TrEE) polymer films

    KAUST Repository

    Hu, Weijin

    2014-11-12

    We report on the switching dynamics of P(VDF-TrEE) copolymer devices and the realization of additional substable ferroelectric states via modulation of the coupling between polarizations and space charges. The space-charge-limited current is revealed to be the dominant leakage mechanism in such organic ferroelectric devices, and electrostatic interactions due to space charges lead to the emergence of anomalous ferroelectric loops. The reliable control of ferroelectric switching in P(VDF-TrEE) copolymers opens doors toward engineering advanced organic memories with tailored switching characteristics.

  19. Plasmon-Coupled CdSe/ZnS and CdTe/CdS/ZnS Coreshells for Hybrid Light Emitting Devices.

    Science.gov (United States)

    Rice, Quinton; Hayes, Anderson; Jung, Sungsoo; Wang, Andrew; Cho, Hyoyoung; Kim, Wan-Joong; Abdel-Fattah, Mahmoud; Tabibi, Bagher; Seo, Jaetae

    2016-02-01

    Plasmon-coupled CdSe/ZnS and CdTe/CdS/ZnS coreshells are investigated for their optoelectronic applications because of their high color purity, wide optical tunability, large PL enhancement, and compact and easy integration into electronic devices. The quantum confinement of carriers within quantum dots (QDs) with sizes near the exciton Bohr radius (CdSe ~ 5.8 nm, CdTe ~ 7 nm) exhibits the features of discrete energy states and blue-shift from the bulk bandgap (CdSe ~718 nm, CdTe ~ 863 nm) in the optical spectrum. While the fluorescence from the QDs is attributable to the exciton carrier recombination, large PL enhancement and fast emission time is achieved through plasmon-exciton coupling via the Coulomb interaction. Large PL enhancement of QDs in the vicinity of plasmonic particles was observed and attributed to the reduction of the non-radiative decay rate and large local field enhancement. The large PL enhancement and wide optical tunability along with high color purity from plasmon-coupled QDs enables the realization of hybrid LEDs. PMID:27433706

  20. Nonlocal thermoelectric effects and nonlocal Onsager relations in a three-terminal proximity-coupled superconductor-ferromagnet device

    Energy Technology Data Exchange (ETDEWEB)

    Machon, Peter; Belzig, Wolfgang [Department of Physics, University of Konstanz, D-78457 Konstanz (Germany); Eschrig, Matthias [SEPnet and Hubbard Theory Consortium, Department of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX (United Kingdom)

    2013-07-01

    We study thermal and charge transport in a three-terminal setup consisting of a superconducting and two ferromagnetic contacts. We predict that the simultaneous presence of spin-filtering and of spin-dependent scattering phase shifts at each of the two interfaces will lead to very large nonlocal thermoelectric effects both in clean and in disordered systems. The symmetries of thermal and electric transport coefficients are related to fundamental thermodynamic principles by the Onsager reciprocity. Our results show that a nonlocal version of the Onsager relations for thermoelectric currents holds in a three terminal quantum coherent ferromagnet-superconductor heterostructure including spin-dependent crossed Andreev reflection and coherent electron transfer processes.

  1. Charge-transport simulations in organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    May, Falk

    2012-07-06

    a polarization-induced stabilization of a molecule in its charged and neutral states can lead to large shifts, broadening, and traps in the distribution of charge energies. These results are especially important for multi-component systems (the emission layer of an OLED or the donor-acceptor interface of an organic solar cell), if the change in polarizability upon charging (or excitation in case of energy transport) is different for the components. Thus, the polarizability change upon charging or excitation should be added to the set of molecular parameters essential for understanding charge and energy transport in organic semiconductors. We also studied charge transport in self-assembled systems, where intermolecular packing motives induced by side chains can increase electronic couplings between molecules. This leads to larger charge mobility, which is essential for devices such as organic field effect transistors. However, it is not sufficient to match the average local molecular order induced by the side chains with maxima of the electronic couplings. It is also important to make the corresponding distributions, e.g. of the pitch angle between consecutive molecules, as narrow as possible compared to the window determined by the closest minima of the electronic couplings. The immediate implication for compound design is that the side chains should assist the self-assembling process not only via ''soft'' entropic interactions, but also via stronger specific interactions, such as hydrogen bonding.

  2. Coupling between the charge carriers and lattice distortions via modulation of the orbital angular momentum m sub l =0 of the 3d holes by polarized XAS spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pompa, M.; Turtu, S.; Campanella, F.; Pettiti, I.; Udron, D. (INFM, Dipt. di Fisica, Rome-1 Univ. (Italy)); Bianconi, A. (INFM, Dipt. di Fisica, Rome-1 Univ. (Italy) Univ. of L' Aquila (Italy)); Flank, A.M.; Lagarde, P. (LURE, 91 - Orsay (France)); Li, C. (Inst. of Physics, Academia Sinica, Beijing (China))

    1991-12-01

    The change of the orbital angular momentum m{sub l} of the Cu 3d holes going from the insulating to the metallic phase has been studied in several families of high Tc superconductors. The symmetry of the 3d{sup 9}L states in the metallic phase has been studied by quantitative analysis of the variation of polarized Cu L{sub 3} X-ray absorption spectra. At a doping level n{sub h} {approx equal} 15% we have found 10% of Zhang-Rice singlets 3d{sub x}2{sub -y}2 L(b{sub 1}) and 5% of 3d{sub 3z}2{sub -r}2L(a{sub 1}) states. Therefore the percentage of the 3d{sub 3z}2{sub -r}2L states on the total number of the 3d{sup 9}L states is about 30% i.e. much larger than the probability of single hole states 3d{sub 3z}2{sub -r}2 in the insulating phase. The EXAFS and XANES studies of the Cu site structure and dynamics in Bi{sub 2}Sr{sub 2}Ca{sub 1-x}Y{sub x}Cu{sub 2}O{sub {proportional to}} {sub 8} system point toward the coupling of the charge carriers with distortions of the Cu sites driven by the m{sub l}=0 character of the Cu 3d holes that can be called a 3d{sub z}2{sub -r}2 polaron. (orig.).

  3. Research and development on power coupling device of hybrid electric tractor%混合动力拖拉机动力耦合装置的研制

    Institute of Scientific and Technical Information of China (English)

    邓晓亭; 朱思洪; 钱忠祥; 张莹

    2012-01-01

    近年来,农用车辆特别是拖拉机对环境和资源造成的压力逐年增大,开展节能环保拖拉机特别是混合动力拖拉机的研发已成为迫在眉睫的重要课题,而动力耦合装置是混合动力拖拉机的核心.该文根据拖拉机工作特性和传动特性要求,对混合动力拖拉机动力耦合装置传动比、特征参数和齿数匹配等进行了设计.根据传动载荷需求和制造工艺要求进行了结构设计和强度校核,研制了适用于并联式混合动力拖拉机的动力耦合装置.在自行搭建的混合动力拖拉机试验台上对该耦合装置进行了测试.试验结果表明,该装置能够满足拖拉机工作状态下的工作特性要求,输出端转速对动力源的转速变化很敏感,实时变化性能优,而输出端转矩对动力源转速变化不敏感.该耦合装置的研制为混合动力拖拉机的研发提供了基础.%In recent years, effects of agricultural vehicles, especially tractors on the environment and resources are increasing year by year, so carrying out the research and development of energy-conservation and environmental protection tractors, especially hybrid electric tractors has become the imminent important subject. And the power coupling is the core of hybrid electric drive system. According to the requirements of working properties and transmission characteristics of tractors, the transmission ratio, characteristic parameters and matching number of gear teeth of power coupling device for hybrid electric tractor were designed. Based on the requirement of transmission load and manufacturing technology, the structure design and strength check were processed. Then a new power coupling for parallel hybrid electric tractor was developed, which was also tested on self-developed hybrid electric tractor test-bed. The results showed that the power coupling device can meet the needs of working characteristic under working condition. In addition, the output speeds were

  4. Color-stable and efficient tandem white organic light-emitting devices using a LiF n-doping layer and a MoOx p-doping layer as charge generating unit

    International Nuclear Information System (INIS)

    We have demonstrated color-stable and efficient tandem organic light-emitting devices (OLEDs) using 4,7-diphenyl-1,10-phenanthroline (Bphen):LiF/4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)triphenylamine (m-MTDATA):molybdenum oxide (MoOx) as charge generating unit (CGU), which has the advantages of air stability and ease of fabrication; the working mechanism of Bphen:LiF/m-MTDATA:MoOx is also discussed through analysis of the electrical and spectral emission properties of tandem devices with different CGUs. The performance of tandem white OLED, comprising blue and yellow phosphorescent EL units, can be improved by optimizing the thickness of Bphen:LiF layer. The device comprised of 30 nm Bphen:LiF layer has a maximum current efficiency of 38.7 cd/A and it can still maintain 24.6 cd/A at the luminance of 10,370 cd/m2. Moreover, the Commission Internationale de L'Eclairage (CIE) coordinates of the device are rather stable and the variation is only (± 0.003, ± 0.007) over a wide range of luminance (100–13,000 cd/m2). - Highlights: • LiF n-doping layer and MoOx p-doping layer were used as charge generating units. • The device performance was improved by optimizing the thickness of n-doping layer. • High luminance and efficiency were both achieved at a very low current density. • The device showed rather stable spectra over a wide range of luminance

  5. Color-stable and efficient tandem white organic light-emitting devices using a LiF n-doping layer and a MoO{sub x} p-doping layer as charge generating unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu; Wu, Qingyang; Zhang, Zhensong; Yue, Shouzhen; Guo, Runda; Wang, Peng; Wu, Mingzhu; Gou, Changhua; Zhao, Yi, E-mail: yizhao@jlu.edu.cn; Liu, Shiyong

    2013-10-31

    We have demonstrated color-stable and efficient tandem organic light-emitting devices (OLEDs) using 4,7-diphenyl-1,10-phenanthroline (Bphen):LiF/4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)triphenylamine (m-MTDATA):molybdenum oxide (MoO{sub x}) as charge generating unit (CGU), which has the advantages of air stability and ease of fabrication; the working mechanism of Bphen:LiF/m-MTDATA:MoO{sub x} is also discussed through analysis of the electrical and spectral emission properties of tandem devices with different CGUs. The performance of tandem white OLED, comprising blue and yellow phosphorescent EL units, can be improved by optimizing the thickness of Bphen:LiF layer. The device comprised of 30 nm Bphen:LiF layer has a maximum current efficiency of 38.7 cd/A and it can still maintain 24.6 cd/A at the luminance of 10,370 cd/m{sup 2}. Moreover, the Commission Internationale de L'Eclairage (CIE) coordinates of the device are rather stable and the variation is only (± 0.003, ± 0.007) over a wide range of luminance (100–13,000 cd/m{sup 2}). - Highlights: • LiF n-doping layer and MoO{sub x} p-doping layer were used as charge generating units. • The device performance was improved by optimizing the thickness of n-doping layer. • High luminance and efficiency were both achieved at a very low current density. • The device showed rather stable spectra over a wide range of luminance.

  6. On-site analysis of volatile nitrosamines in food model systems by solid-phase microextraction coupled to a direct extraction device.

    Science.gov (United States)

    Ventanas, S; Ruiz, J

    2006-12-15

    Analysis of nitrosamine (NA) standards in a model system was carried out by extraction using SPME coupled to a direct extraction device (DED) and subsequent GC/MS in selected ion monitoring mode. Gelatine (20%, w/v) systems of a NA standard (10mugL(-1)) were prepared, in order to mimic food protein matrix systems such as meat and meat products, fish and so on. Different SPME fibre coatings were tested Both divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) and carboxen/polydimethylsiloxane (CAR/PDMS) fibres coupled to DED satisfactorily extracted all nine NA included in the studied standard (EPA 8270 nitrosamines mix, Sigma-Aldrich) from the gelatine system at 25 degrees C without any sample manipulation. Values of reproducibility, linearity and limit of detection for each type of fibre are reported. SPME-DED appears as a rapid, non-destructive technique for preliminary screening of the presence of toxic substances such as NA in solid foods.

  7. Separating device

    NARCIS (Netherlands)

    De Jong, T.P.R.

    2001-01-01

    A sorting device (1) suitable for sorting wire from a waste stream, comprising a body (2) that moves when in use, and provided with spikes or similar projections. The body is embodied as a rotatable roll (2), which oscillates axially during its rotation. The roll is coupled to an oscillation engine

  8. The effect of the thickness of tunneling layer on the memory properties of (Cu2O)0.5(Al2O3)0.5 high-k composite charge-trapping memory devices

    Science.gov (United States)

    Liu, Jinqiu; Lu, Jianxin; Yin, Jiang; Xu, Bo; Xia, Yidong; Liu, Zhiguo

    2016-06-01

    The charge-trapping memory devices namely Pt/Al2O3/(Al2O3)0.5(Cu2O)0.5/SiO2/p-Si with 2, 3 and 4 nm SiO2 tunneling layers were fabricated by using RF magnetron sputtering and atomic layer deposition techniques. At an applied voltage of ±11 V, the memory windows in the C-V curves of the memory devices with 2, 3 and 4 nm SiO2 tunneling layers were about 4.18, 9.91 and 11.33 V, respectively. The anomaly in memory properties among the three memory devices was ascribed to the different back tunneling probabilities of trapped electrons in the charge-trapping dielectric (Al2O3)0.5(Cu2O)0.5 due to the different thicknesses of SiO2 tunneling layer.

  9. Determination of Noncovalent Binding Using a Continuous Stirred Tank Reactor as a Flow Injection Device Coupled to Electrospray Ionization Mass Spectrometry

    Science.gov (United States)

    Santos, Inês C.; Waybright, Veronica B.; Fan, Hui; Ramirez, Sabra; Mesquita, Raquel B. R.; Rangel, António O. S. S.; Fryčák, Petr; Schug, Kevin A.

    2015-07-01

    Described is a new method based on the concept of controlled band dispersion, achieved by hyphenating flow injection analysis with ESI-MS for noncovalent binding determinations. A continuous stirred tank reactor (CSTR) was used as a FIA device for exponential dilution of an equimolar host-guest solution over time. The data obtained was treated for the noncovalent binding determination using an equimolar binding model. Dissociation constants between vancomycin and Ac-Lys(Ac)-Ala-Ala-OH peptide stereoisomers were determined using both the positive and negative ionization modes. The results obtained for Ac- L-Lys(Ac)- D-Ala- D-Ala (a model for a Gram-positive bacterial cell wall) binding were in reasonable agreement with literature values made by other mass spectrometry binding determination techniques. Also, the developed method allowed the determination of dissociation constants for vancomycin with Ac- L-Lys(Ac)- D-Ala- L-Ala, Ac- L-Lys(Ac)- L-Ala- D-Ala, and Ac- L-Lys(Ac)- L-Ala- L-Ala. Although some differences in measured binding affinities were noted using different ionization modes, the results of each determination were generally consistent. Differences are likely attributable to the influence of a pseudo-physiological ammonium acetate buffer solution on the formation of positively- and negatively-charged ionic complexes.

  10. A comparative theoretical study of exciton-dissociation and charge-recombination processes in oligothiophene/fullerene and oligothiophene/perylenediimide complexes for organic solar cells

    KAUST Repository

    Yi, Yuanping

    2011-01-01

    The exciton-dissociation and charge-recombination processes in donor-acceptor complexes found in α-sexithienyl/C60 and α-sexithienyl/perylenetetracarboxydiimide (PDI) solar cells are investigated by means of quantum-chemical methods. The electronic couplings and exciton-dissociation and charge-recombination rates have been evaluated for various configurations of the complexes. The results suggest that the decay of the lowest charge-transfer state to the ground state in the PDI-based devices: (i) is faster than that in the fullerene-based devices and (ii) in most cases, can compete with the dissociation of the charge-transfer state into mobile charge carriers. This faster charge-recombination process is consistent with the lower performance observed experimentally for the devices using PDI derivatives as the acceptor. © 2011 The Royal Society of Chemistry.

  11. 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.

  12. Adsorption of highly charged Gaussian polyelectrolytes onto oppositely charged surfaces

    Science.gov (United States)

    Dutta, Sandipan; Jho, Y. S.

    2016-03-01

    In many biological processes highly charged biopolymers are adsorbed onto oppositely charged surfaces of macroions and membranes. They form strongly correlated structures close to the surface which cannot be explained by the conventional Poisson-Boltzmann theory. In this work strong coupling theory is used to study the adsorption of highly charged Gaussian polyelectrolytes. Two cases of adsorptions are considered, when the Gaussian polyelectrolytes are confined (a) by one charged wall, and (b) between two charged walls. The effects of salt and the geometry of the polymers on their adsorption-depletion transitions in the strong coupling regime are discussed.

  13. Research on the charge weight and the sound source level of underwater separation of pyrotechnic separation device%火工分离装置水下分离噪声与装药量研究

    Institute of Scientific and Technical Information of China (English)

    陈霞; 田荣艳

    2012-01-01

    通过对火工分离装置水下分离噪声产生机理的分析和研究,在满足分离裕度的情况下,研究一种专用火工分离装置,探寻装药量与分离噪声声源级的关系,进行水下噪声对比测试,其研究结果对水中兵器水下分离降嗓设计提供依据.%Based on the analysis and study for the noise generation mechanism of pyrotechnically actuated separation devices which separate underwater, when meet the case of separated margin, study a special pyrotechnical separation device to explore the relationship between the charge weight and the sound source level,and develop the tests for underwater noise. The results provide the basis for noising-reducing of underwater weapons.

  14. Vegetable greenhouse temperature detection device with solar charging function%带有太阳能充电功能的蔬菜大棚温度检测装置研究

    Institute of Scientific and Technical Information of China (English)

    朱家麟; 郑祖岭; 冯泉水; 徐颖秦

    2014-01-01

    基于C51单片机和PT100温度检测技术,设计了一种带有太阳能充电功能的大棚温度自动检测装置。该装置由太阳能电池板、A/D转换器、蓄电池、单片机、温度检测电路等模块组成。通过PT100热电阻桥式测温电路,对大棚温度进行实时监测;利用单片机控制技术实现太阳能电池板和蓄电池之间的充放电管理;利用八位点阵终端显示实时温度值。通过实验验证装置性能稳定,运行良好。%the design of the automatic detection device with a solar charging function of greenhouse temperature bases on C51 MCU and PT100 temperature detection technology.The device comprises by a solar panel,battery,A/D converter,microcontrol er,temperature detection circuit module.Through the PT100 thermal resistance bridge measurement circuit,the automatic detection device monitor greenhouse temperature in real time;using single-chip microcomputer control technology to realize the management of charging and discharging between the solar panels and batteries;the eight dot matrix display real-time temperature.The device runs stably and wel in the experiment.

  15. Application of a backside-illuminated charge-coupled-device camera for single-pulse coherent anti-Stokes Raman spectroscopy N(2) thermometry.

    Science.gov (United States)

    Plath, I; Meier, W; Stricker, W

    1992-01-01

    The application of an unintensified backside-illuminated CCD for the acquisition of broadband single-pulse coherent anti-Stokes Raman spectroscopy (CARS) spectra is demonstrated. This CCD shows a quantum efficiency 5 times higher than a front-illuminated CCD and offers significant advantages compared with intensified linear photodiode array detectors generally used for single-pulse CARS thermometry. It overcomes the main drawbacks of the intensified linear photodiode array detector in single-pulse CARS N(2) spectroscopy: nonlinearity, limited dynamic range, and image persistence. A method for extending the dynamic range is demonstrated in a highly turbulent flame. PMID:19784236

  16. Application of a backside-illuminated charge-coupled-device camera for single-pulse coherent anti-Stokes Raman spectroscopy N2 thermometry

    Science.gov (United States)

    Plath, I.; Meier, W.; Stricker, W.

    1992-01-01

    The application of an unintensified backside-illuminated CCD for the acquisition of broadband single-pulse coherent anti-Stokes Raman spectroscopy (CARS) spectra is demonstrated. This CCD shows a quantum efficiency 5 times higher than a front-illuminated CCD and offers significant advantages compared with intensified linear photodiode array detectors generally used for single-pulse CARS thermometry. It overcomes the main drawbacks of the intensified linear photodiode array detector in single-pulse CARS N2 spectroscopy: nonlinearity, limited dynamic range, and image persistence. A method for extending the dynamic range is demonstrated in a highly turbulent flame.

  17. Investigation of noise and contrast sensitivity of an electron multiplying charge-coupled device (EMCCD) based cone beam micro-CT system

    Science.gov (United States)

    Bysani Krishnakumar, Sumukh; Podgorsak, Alexander R.; Setlur Nagesh, S. V.; Jain, Amit; Rudin, Stephen; Bednarek, Daniel R.; Ionita, Ciprian N.

    2016-03-01

    A small animal micro-CT system was built using an EMCCD detectors having complex pre-digitization amplification technology, high-resolution, high-sensitivity and low-noise. Noise in CBCT reconstructed images when using predigitization amplification behaves differently than commonly used detectors and warrants a detailed investigation. In this study, noise power and contrast sensitivity were estimated for the newly built system. Noise analysis was performed by scanning a water phantom. Tube voltage was lowered to minimum delivered by the tube (20 kVp and 0.5 mA) and detector gain was varied. Contrast sensitivity was analyzed by using a phantom containing different iodine contrast solutions (20% to 70%) filled in six different tubes. First, we scanned the phantom using various x-ray exposures at 40 kVp while changing the gain to maintain the background air value of the projection images constant. Next, the exposure was varied while the detector gain was maintained constant. Radial NPS plots show that noise power level increases as gain increases. Contrast sensitivity was analyzed by calculating ratio of signal-to-noise ratios (SNR) for increased gain with those of low constant gain at each exposure. The SNR value at low constant gain was always lower than SNR of high detector gain at all x-ray settings and iodine contrast. The largest increase of SNR approached 1.3 for low contrast feature for an iodine concentration of 20%. Despite an increase in noise level as gain increases, the SNR improvement shows that signal level also increases because of the unique on-chip gain of the detector.

  18. Improving the spatial resolution of a soft X-ray Charge Coupled Device used for Resonant Inelastic X-ray Scattering

    OpenAIRE

    Soman, M. R.; Hall, D. J. (David John); Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.

    2011-01-01

    The Super Advanced X-ray Emission Spectrometer (SAXES) at the Advanced Resonant Scattering (ADRESS) beamline of the Swiss Light Source is a high-resolution X-ray spectrometer used as an end station for Resonant Inelastic X-ray Scattering from 400 eV to 1600 eV. Through the dispersion of photons across a CCD, the energy of scattered photons may be determined by their detected spatial position. The limiting factor of the energy resolution is currently the spatial resolution achieved with the CC...

  19. A synthesis of star calibration techniques for ground-based narrowband electron-multiplying charge-coupled device imagers used in auroral photometry

    Science.gov (United States)

    Grubbs, Guy; Michell, Robert; Samara, Marilia; Hampton, Don; Jahn, Jorg-Micha

    2016-06-01

    A technique is presented for the periodic and systematic calibration of ground-based optical imagers. It is important to have a common system of units (Rayleighs or photon flux) for cross comparison as well as self-comparison over time. With the advancement in technology, the sensitivity of these imagers has improved so that stars can be used for more precise calibration. Background subtraction, flat fielding, star mapping, and other common techniques are combined in deriving a calibration technique appropriate for a variety of ground-based imager installations. Spectral (4278, 5577, and 8446 Å) ground-based imager data with multiple fields of view (19, 47, and 180°) are processed and calibrated using the techniques developed. The calibration techniques applied result in intensity measurements in agreement between different imagers using identical spectral filtering, and the intensity at each wavelength observed is within the expected range of auroral measurements. The application of these star calibration techniques, which convert raw imager counts into units of photon flux, makes it possible to do quantitative photometry. The computed photon fluxes, in units of Rayleighs, can be used for the absolute photometry between instruments or as input parameters for auroral electron transport models.

  20. Precise Determination of Brillouin Scattering Spectrum Using a Virtually Imaged Phase Array (VIPA) Spectrometer and Charge-Coupled Device (CCD) Camera.

    Science.gov (United States)

    Meng, Zhaokai; Yakovlev, Vladislav V

    2016-08-01

    Brillouin spectroscopy is an emerging tool for microscopic optical imaging as it allows noninvasive assessment of viscoelastic properties of materials. The use of atomic-molecular absorption cells as ultra-narrow notch filters allows acquisition of Brillouin spectra from turbid samples despite their strong elastic scattering. However, such systems alter the shapes of the Brillouin lines, making the precise determination of the Brillouin shift difficult. In this report, we propose a simple method for analyzing the Brillouin spectrum using a customized least-square fitting algorithm. The absorption spectrum induced by the atomic-molecular cell was taken into consideration. The capability of the method is confirmed by processing experimental spectroscopic data from the pure water at different temperatures. The accuracy of the measurements of ±1 MHz spectral line shift is experimentally demonstrated. PMID:27296309

  1. Study of coupled heat and mass transfer during absorption of hydrogen in MmNi4·6Al0·4 based hydrogen storage device

    Indian Academy of Sciences (India)

    P Muthukumar; Manvendra M Umekar

    2009-04-01

    A two-dimensional numerical analysis of coupled heat and mass transfer processes in a cylindrical metal hydride reactor containing MmNi4·6Al0·4 is presented. To understand the hydrogen absorption mechanism the governing equations for energy, momentum and mass conservation and reaction kinetic equations are solved simultaneously using the finite volume method (FVM). Performance studies on MmNi4·6Al0·4 based hydrogen storage device are carried out by varying the hydrogen supply pressure, absorption (cooling fluid) temperature, overall heat transfer coefficient and hydride bed thickness. Effect of convection terms in the energy equation on hydrogen storage performance is found to be negligible. The results obtained from the computer simulation showed good agreement with the available experimental data. At the supply conditions of 30 bar and 298 K, MmNi4·6Al0·4 stores about 1·28 wt%, which is very close to the experimental value of 1·3 wt%. Overall high heat transfer coefficients are found to reduce the absorption time significantly.

  2. Charge carrier transport and lifetimes in n-type and p-type phosphorene as 2D device active materials: an ab initio study.

    Science.gov (United States)

    Tea, E; Hin, C

    2016-08-10

    In this work, we provide a detailed analysis of phosphorene's performance as an n-type and p-type active material. This study is based on first principles calculations of the phosphorene electronic structure, and the resulting electron and hole scattering rates and lifetimes. Emphasis is put on extreme regimes commonly found in semiconductor devices, i.e. high electric fields and heavy doping, where impact ionization and Auger recombination can occur. We found that electron-initiated impact ionization is weaker than the hole-initiated process, when compared to carrier-phonon interaction rates, suggesting resilience to impact ionization initiated breakdown. Moreover, calculated minority electron lifetimes are limited by radiative recombination only, not by Auger processes, suggesting that phosphorene could achieve good quantum efficiencies in optoelectronic devices. The provided scattering rates and lifetimes are critical input data for the modeling and understanding of phosphorene-based device physics. PMID:27479904

  3. Inductive Charging Technology and Its Application to the Portable and Sealing Devices%感应式充电技术在便携式密封设备中的应用

    Institute of Scientific and Technical Information of China (English)

    曾海涛

    2011-01-01

    This poaper describes a induction charging systems design Hits application to poctable and sealing equipmerit,and on this program.based on the proposed single-ended flyback DC-DC converter to acchleve energy transfer, and applied to the positioning of a small portable sealed identifltion CarCl;ending the life Of auch identification cards. Experimental results show that the program can achieve the non-contact charged of portble and Sealing devices,and the security is good,simple operation, the device costs less.%该文主要介绍了便携式密封设备感应式充电系统的设计方案,并在此方案的基础上,提出了使用单端支激式DC-DC变换器实现电能传输,并应用到某小型便携式密封定位模块中,延长了该模块的使用寿命。实验结果证明,该方案能够实现便携式密封设备的非接触式充电,且安全性好,操作简单,设备成本增加较小。

  4. Electrostatic Power Generation from Negatively Charged, Simulated Lunar Regolith

    Science.gov (United States)

    Choi, Sang H.; King, Glen C.; Kim, Hyun-Jung; Park, Yeonjoon

    2010-01-01

    Research was conducted to develop an electrostatic power generator for future lunar missions that facilitate the utilization of lunar resources. The lunar surface is known to be negatively charged from the constant bombardment of electrons and protons from the solar wind. The resulting negative electrostatic charge on the dust particles, in the lunar vacuum, causes them to repel each other minimizing the potential. The result is a layer of suspended dust about one meter above the lunar surface. This phenomenon was observed by both Clementine and Surveyor spacecrafts. During the Apollo 17 lunar landing, the charged dust was a major hindrance, as it was attracted to the astronauts' spacesuits, equipment, and the lunar buggies. The dust accumulated on the spacesuits caused reduced visibility for the astronauts, and was unavoidably transported inside the spacecraft where it caused breathing irritation [1]. In the lunar vacuum, the maximum charge on the particles can be extremely high. An article in the journal "Nature", titled "Moon too static for astronauts?" (Feb 2, 2007) estimates that the lunar surface is charged with up to several thousand volts [2]. The electrostatic power generator was devised to alleviate the hazardous effects of negatively charged lunar soil by neutralizing the charged particles through capacitive coupling and thereby simultaneously harnessing power through electric charging [3]. The amount of power generated or collected is dependent on the areal coverage of the device and hovering speed over the lunar soil surface. A thin-film array of capacitors can be continuously charged and sequentially discharged using a time-differentiated trigger discharge process to produce a pulse train of discharge for DC mode output. By controlling the pulse interval, the DC mode power can be modulated for powering devices and equipment. In conjunction with a power storage system, the electrostatic power generator can be a power source for a lunar rover or other

  5. 电池梯次利用储能装置在电动汽车充换电站中的应用%Application of Battery Cascade Utilization Device in EV Battery Charging and Swapping Station

    Institute of Scientific and Technical Information of China (English)

    王泽众; 李家辉

    2012-01-01

    针对电动汽车充换电站中动力电池的梯次利用问题,设计了电池梯次利用储能站,将充换电站中即将报废的电池用于储能放电,以降低电动汽车动力电池的使用成本.介绍了电池梯次利用储能站结构、电能控制系统以及储能控制策略,可以实现电动汽车充换电站动力电池的梯次利用、对电网负荷进行峰谷调节并作为充换电站的应急和后备电源.%Aiming at the application of battery cascade utilization in EV ( electric vehicle) battery charging and swapping station, this paper design battery cascade utilization storage station. In order to decreasing the battery cost, it utilizes the reject battery of battery charging and swapping station to storage and discharge electric energy. This paper introduces the battery cascade utilization device construction, control system and electric storage control strategy. It can implement the battery cascade utilization, regulate power grid peak and valley and be emergency power of the battery charging and swapping station.

  6. Inverse problem for the scattering theory of charged particles when there is a linear relationship between the energy, the square of the orbital angular momentum, and the Coulomb coupling constant

    Energy Technology Data Exchange (ETDEWEB)

    Popushoi, M.N.

    1987-06-01

    A generalized algebraic variant is proposed for solving the inverse problem of the potential scattering of charged particles for the case when the initial scattering data are taken in the presence of a linear relationship between the energy E, the square of the orbital angular momentum l, and the Coulomb coupling constant a. Expressions are obtained for constructing a central E-, l-, and a-independent potential corresponding to a Jost function characterized by rationality with respect to the parameters E, l, and a.

  7. Ultrasonic coupling to optically generated charge carriers in CdS: Physical phenomena and applications. Ph.D. Thesis - Washington Univ., Saint Louis, Mo.

    Science.gov (United States)

    Heyman, J. S.

    1975-01-01

    Phonon-charge carrier interactions are studied as well as ultrasonic resonators. Sensitivity enhancement factors predicted by one dimensional resonator theory are verified and several sensitive ultrasonic experimental techniques are developed. Measurements are reported of an anomalous sign reversal of the acoustoelectric voltage in a CdS resonator. Applications of CdS as an ultrasonic power detector are described.

  8. Neuromimetic Circuits with Synaptic Devices based on Strongly Correlated Electron Systems

    OpenAIRE

    Ha, Sieu D.; Shi, Jian; Meroz, Yasmine; Mahadevan, L.; Ramanathan, Shriram

    2014-01-01

    Strongly correlated electron systems such as the rare-earth nickelates (RNiO3, R = rare-earth element) can exhibit synapse-like continuous long term potentiation and depression when gated with ionic liquids; exploiting the extreme sensitivity of coupled charge, spin, orbital, and lattice degrees of freedom to stoichiometry. We present experimental real-time, device-level classical conditioning and unlearning using nickelate-based synaptic devices in an electronic circuit compatible with both ...

  9. Charge transport through exciton shelves in cadmium chalcogenide quantum dot-DNA nano-bioelectronic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, Samuel M.; Singh, Vivek [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Noh, Hyunwoo [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Materials Science and Engineering Program and Department of Nanoengineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, California 92093 (United States); Cha, Jennifer N. [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Materials Science and Engineering Program and Department of Nanoengineering, University of California, 9500 Gilman Drive, La Jolla, San Diego, California 92093 (United States); Materials Science and Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Nagpal, Prashant, E-mail: pnagpal@colorado.edu [Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Materials Science and Engineering, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, Colorado 80303 (United States); Renewable and Sustainable Energy Institute, University of Colorado Boulder, 2445 Kittredge Loop, Boulder, Colorado 80309 (United States)

    2015-02-23

    Quantum dot (QD), or semiconductor nanocrystal, thin films are being explored for making solution-processable devices due to their size- and shape-tunable bandgap and discrete higher energy electronic states. While DNA has been extensively used for the self-assembly of nanocrystals, it has not been investigated for the simultaneous conduction of multiple energy charges or excitons via exciton shelves (ES) formed in QD-DNA nano-bioelectronic thin films. Here, we present studies on charge conduction through exciton shelves, which are formed via chemically coupled QDs and DNA, between electronic states of the QDs and the HOMO-LUMO levels in the complementary DNA nucleobases. While several challenges need to be addressed in optimizing the formation of devices using QD-DNA thin films, a higher charge collection efficiency for hot-carriers and our detailed investigations of charge transport mechanism in these thin films highlight their potential for applications in nano-bioelectronic devices and biological transducers.

  10. Charge transport through exciton shelves in cadmium chalcogenide quantum dot-DNA nano-bioelectronic thin films

    Science.gov (United States)

    Goodman, Samuel M.; Noh, Hyunwoo; Singh, Vivek; Cha, Jennifer N.; Nagpal, Prashant

    2015-02-01

    Quantum dot (QD), or semiconductor nanocrystal, thin films are being explored for making solution-processable devices due to their size- and shape-tunable bandgap and discrete higher energy electronic states. While DNA has been extensively used for the self-assembly of nanocrystals, it has not been investigated for the simultaneous conduction of multiple energy charges or excitons via exciton shelves (ES) formed in QD-DNA nano-bioelectronic thin films. Here, we present studies on charge conduction through exciton shelves, which are formed via chemically coupled QDs and DNA, between electronic states of the QDs and the HOMO-LUMO levels in the complementary DNA nucleobases. While several challenges need to be addressed in optimizing the formation of devices using QD-DNA thin films, a higher charge collection efficiency for hot-carriers and our detailed investigations of charge transport mechanism in these thin films highlight their potential for applications in nano-bioelectronic devices and biological transducers.

  11. Performance enhancement in p-channel charge-trapping flash memory devices with Si/Ge super-lattice channel and band-to-band tunneling induced hot-electron injection

    International Nuclear Information System (INIS)

    P-channel charge-trapping flash memory devices with Si, SiGe, and Si/Ge super-lattice channel are investigated in this work. A Si/Ge super-lattice structure with extremely low roughness and good crystal structure is obtained by precisely controlling the epitaxy thickness of Ge layer. Both programming and erasing (P/E) speeds are significantly improved by employing this Si/Ge super-lattice channel. Moreover, satisfactory retention and excellent endurance characteristics up to 106 P/E cycles with 3.8 V memory window show that the degradation on reliability properties is negligible when super-lattice channel is introduced. - Highlights: ► A super-lattice structure is proposed to introduce more Ge content into channel. ► Super-lattice structure possesses low roughness and good crystal structure. ► P-channel flash devices with Si, SiGe, and super-lattice channel are investigated. ► Programming/erasing speeds are significantly improved. ► Reliability properties can be kept for device with super-lattice channel

  12. Electrostatic shielding of a charged conducting sphere by a fine-mesh grounded screen. [for Plasma Subsystem device aboard Galileo spacecraft

    Science.gov (United States)

    Edmonds, L.

    1985-01-01

    A simple model of an electrostatic-shielding arrangement that will reduce the electric field from the Near Infrared Mapper Spectrometer aboard the Galileo spacecraft is presented. The system considered consists of a charged conducting sphere held at a fixed absolute potential via a power source. This system is screened by a larger, concentric sphere made of fine mesh which is grounded. A derivation based on elementary principles of electrostatics is used to show that the shielding effectiveness of the screen can be expressed in terms of the separation between the two spheres and another quantity B that is an intrinsic property of the screen. For a given screen, B can be determined by measuring the capacitance per unit area and separation between a flat piece of the screen and a parallel metal plate.

  13. Solution of Coal Charging Devices Control System%焦炉装煤车控制系统解决方案

    Institute of Scientific and Technical Information of China (English)

    代建华; 郭玉梅

    2011-01-01

    The production process of coke ovens batteries is analyzed. The automatic monitor of measurement process of coal charging car is implemented using hopper scale. Through wireless communication, the management of production record is implemented, which meet the requirement of producing high quality metallurgical coke.%分析焦炉炼焦生产工艺,采用料斗秤实现整个装煤车计量过程的全自动监控,通过无线通信实现生产数据的记录统计管理,满足了焦炉生产高质量冶金焦的需要。

  14. Game Analysis on Coupling Effects of Private Car License Plate Auction and Congestion Charge%私车牌照拍卖与拥挤收费的政策联动效果研究

    Institute of Scientific and Technical Information of China (English)

    冯苏苇

    2012-01-01

    As the unique city to conduct private car license plate auction in China, Shanghai gains rich experiences and great demonstration effects in regulation practice. After this policy has run for decades, the auction price climbs extremely high and more people tend to use non-local plates, which results in a decline policy performance. This paper first points out the reason for efficiency loss lies in the wide gap between relative travel rights and relative owning cost relating to local and non-local licenses. Second, with game analysis, it analyzes the coupling effects of congestion charge as a comprehensive and supplementary policy to plate auction. The result indicates that if the congestion charge objects focus on those using non-local licenses, people with high time value usually commute earlier to avoid the charge, while those with low time value remain on the road. Finally, sequential game analysis shows that under such policy coupling background of plate auction and congestion charging, the choices of local licenses will finally increase and new congestion will appear. A feasible measure should be setting up different charge rates to local and non-local licenses.%作为中国唯一实施私车牌照拍卖的城市,上海的先行实践和示范效应十分巨大.政策实施二十余年来,随着本地牌照拍卖价格不断走高,选择外地牌照的人数逐渐增加,政策绩效面临衰减的局面.本文以博弈论为工具,分析了牌照拍卖政策绩效流失的根源,研究了拥挤收费作为综合配套政策的可能效果,研究发现,如果对外地牌照拥车者征收拥挤费,高时间价值者会提前出行以规避收费,而低时间价值者留在道路上.进一步,在序贯博弈下,更多的人会选择本地牌照,道路拥挤仍旧不可避免.因此,一个可行的拥挤收费方案是,通过设置不同费率对不同牌照实施差别化收费,以弥补当前政策下相对通行权不对等问题.

  15. Measuring Charge Transport in an Amorphous Semiconductor Using Charge Sensing

    OpenAIRE

    Maclean, K; Mentzel, T. S.; Kastner, M. A.

    2009-01-01

    We measure charge transport in hydrogenated amorphous silicon (a-Si:H) using a nanometer scale silicon MOSFET as a charge sensor. This charge detection technique makes possible the measurement of extremely large resistances. At high temperatures, where the a-Si:H resistance is not too large, the charge detection measurement agrees with a direct measurement of current. The device geometry allows us to probe both the field effect and dispersive transport in the a-Si:H using charge sensing and t...

  16. Experiment and analysis for cold charging process of new energy storage device%一种新型储能装置充冷过程的实验及分析

    Institute of Scientific and Technical Information of China (English)

    迟蓬涛; 谢永奇; 余建祖; 杨宪宁

    2011-01-01

    The heat transfer enhancement ches. In order to test the cold charging effect, effect of the metal foam has been verified by dozens of researa new type of high-efficiency energy storage devices was made up by composite phase change material(PCM), which was consisted of copper foam (the heat transfer enhancement) and water. Via experimental study, the heat preservation effect of the devices in the refrigeration equipments was simulated. The model was set up and calculated through quasi-stable state method, and the results meet the test results very well. The cold charging process of the new type energy storage devices was approved to be faster and more adequate compared to the traditional energy storage devices. The entire heat transfer velocity and energy storage efficiency are obviously improved, which promises a good prospect in the refrigerated transportation.%近年来,泡沫金属作为填充材料在强化传热方面的功效已被越来越多的研究证实.采用泡沫铜和水构成新型复合相变材料,制成一种高效储能装置,通过模拟实验研究,测试了这种储能装置在冷藏装备上的保温效果.进而采用准稳态法建立了复合相变材料的数学模型并进行了数值仿真计算,计算结果与实验测试结果相符.实验和数值仿真结果都表明,相对传统储能装置,新型储能装置充冷迅速而充分,整体的传热速率和储能效率得到了显著提高,在冷藏运输中有非常好的应用前景.

  17. Electronic Coupling Calculations for Bridge-Mediated Charge Transfer Using Constrained Density Functional Theory (CDFT) and Effective Hamiltonian Approaches at the Density Functional Theory (DFT) and Fragment-Orbital Density Functional Tight Binding (FODFTB) Level

    Energy Technology Data Exchange (ETDEWEB)

    Gillet, Natacha; Berstis, Laura; Wu, Xiaojing; Gajdos, Fruzsina; Heck, Alexander; de la Lande, Aurelien; Blumberger, Jochen; Elstner, Marcus

    2016-10-11

    In this article, four methods to calculate charge transfer integrals in the context of bridge-mediated electron transfer are tested. These methods are based on density functional theory (DFT). We consider two perturbative Green's function effective Hamiltonian methods (first, at the DFT level of theory, using localized molecular orbitals; second, applying a tight-binding DFT approach, using fragment orbitals) and two constrained DFT implementations with either plane-wave or local basis sets. To assess the performance of the methods for through-bond (TB)-dominated or through-space (TS)-dominated transfer, different sets of molecules are considered. For through-bond electron transfer (ET), several molecules that were originally synthesized by Paddon-Row and co-workers for the deduction of electronic coupling values from photoemission and electron transmission spectroscopies, are analyzed. The tested methodologies prove to be successful in reproducing experimental data, the exponential distance decay constant and the superbridge effects arising from interference among ET pathways. For through-space ET, dedicated p-stacked systems with heterocyclopentadiene molecules were created and analyzed on the basis of electronic coupling dependence on donor-acceptor distance, structure of the bridge, and ET barrier height. The inexpensive fragment-orbital density functional tight binding (FODFTB) method gives similar results to constrained density functional theory (CDFT) and both reproduce the expected exponential decay of the coupling with donor-acceptor distances and the number of bridging units. These four approaches appear to give reliable results for both TB and TS ET and present a good alternative to expensive ab initio methodologies for large systems involving long-range charge transfers.

  18. Autoignition characterization of primary reference fuels and n-heptane/n-butanol mixtures in a constant volume combustion device and homogeneous charge compression ignition engine

    KAUST Repository

    Baumgardner, Marc E.

    2013-12-19

    In this study, the autoignition behavior of primary reference fuels (PRF) and blends of n-heptane/n-butanol were examined in a Waukesha Fuel Ignition Tester (FIT) and a Homogeneous Charge Compression Engine (HCCI). Fourteen different blends of iso-octane, n-heptane, and n-butanol were tested in the FIT - 28 test runs with 25 ignition measurements for each test run, totaling 350 individual tests in all. These experimental results supported previous findings that fuel blends with high alcohol content can exhibit very different ignition delay periods than similarly blended reference fuels. The experiments further showed that n-butanol blends behaved unlike PRF blends when comparing the autoignition behavior as a function of the percentage of low reactivity component. The HCCI and FIT experimental results favorably compared against single and multizone models with detailed chemical kinetic mechanisms - both an existing mechanism as well as one developed during this study were used. The experimental and modeling results suggest that that the FIT instrument is a valuable tool for analysis of high pressure, low temperature chemistry, and autoignition for future fuels in advanced combustion engines. Additionally, in both the FIT and engine experiments the fraction of low temperature heat release (fLTHR) was found to correlate very well with the crank angle of maximum heat release and shows promise as a useful metric for fuel reactivity in advanced combustion applications. © 2013 American Chemical Society.

  19. Large Spin Entangled Current from a Passive Device

    OpenAIRE

    Kolli, A.; Benjamin, S. C.; Coello, J. G.; Bose, S; Lovett, B. W.

    2008-01-01

    We show that a large entangled current can be produced from a very simple passive device: a cluster of three resonant quantum dots, tunnel coupled to one input lead and two output leads. The device can function in a `clean' mode, when almost all emitted electrons are paired in Bell states, or a `dirty' mode with a far higher emission rate but a significant portion of non-entangled electrons. Subsequent charge detection can enhance performance by identifying the pairs that are most likely to b...

  20. Coupled optical absorption, charge carrier separation, and surface electrochemistry in surface disordered/hydrogenated TiO2 for enhanced PEC water splitting reaction.

    Science.gov (United States)

    Behara, Dilip Kumar; Ummireddi, Ashok Kumar; Aragonda, Vidyasagar; Gupta, Prashant Kumar; Pala, Raj Ganesh S; Sivakumar, Sri

    2016-03-28

    The central governing factors that influence the efficiency of photoelectrochemical (PEC) water splitting reaction are photon absorption, effective charge-carrier separation, and surface electrochemistry. Attempts to improve one of the three factors may debilitate other factors and we explore such issues in hydrogenated TiO2, wherein a significant increase in optical absorption has not resulted in a significant increase in PEC performance, which we attribute to the enhanced recombination rate due to the formation of amorphization/disorderness in the bulk during the hydrogenation process. To this end, we report a methodology to increase the charge-carrier separation with enhanced optical absorption of hydrogenated TiO2. Current methodology involves hydrogenation of non-metal (N and S) doped TiO2 which comprises (1) lowering of the band gap through shifting of the valence band via less electronegative non-metal N, S-doping, (2) lowering of the conduction band level and the band gap via formation of the Ti(3+) state and oxygen vacancies by hydrogenation, and (3) material processing to obtain a disordered surface structure which favors higher electrocatalytic (EC) activity. This design strategy yields enhanced PEC activity (%ABPE = 0.38) for the N-S co-doped TiO2 sample hydrogenated at 800 °C for 24 h over possible combinations of N-S co-doped TiO2 samples hydrogenated at 500 °C/24 h, 650 °C/24 h and 800 °C/72 h. This suggests that hydrogenation at lower temperatures does not result in much increase in optical absorption and prolonged hydrogenation results in an increase in optical absorption but a decrease in charge carrier separation by forming disorderness/oxygen vacancies in the bulk. Furthermore, the difference in double layer capacitance (C(dl)) calculated from electrochemical impedance spectroscopy (EIS) measurements of these samples reflects the change in the electrochemical surface area (ECSA) and facilitates assessing the key role of surface

  1. Adsorption of highly charged Gaussian polyelectrolytes to oppositely charged surfaces

    OpenAIRE

    Dutta, Sandipan; Jho, Y. S.

    2015-01-01

    In many biological processes highly charged biomolecules are adsorbed into oppositely charged surfaces of macroions and membranes. They form strongly correlated structures close to the surface which can not be explained by the conventional Poisson-Boltzmann theory. Many of the flexible biomolecules can be described by Gaussian polymers. In this work strong coupling theory is used to study the adsorption of highly charged Gaussian polyelectrolytes. Two cases of adsorptions are considered, when...

  2. Coupling of narrow and wide band-gap semiconductors on uniform films active in bacterial disinfection under low intensity visible light: Implications of the interfacial charge transfer (IFCT)

    Energy Technology Data Exchange (ETDEWEB)

    Rtimi, S., E-mail: sami.rtimi@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-GPAO, Station 6, CH-1015 Lausanne (Switzerland); UR Catalyse/Matériaux pour l‘Environnement et les Procédés (URCMEP), Faculté des Sciences de Gabès, Université de Gabès, 6072 Gabès (Tunisia); Sanjines, R. [Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-IPMC-LNNME, Bat PH, Station 3, CH1015 Lausanne (Switzerland); Pulgarin, C., E-mail: cesar.pulgarin@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-GPAO, Station 6, CH-1015 Lausanne (Switzerland); Houas, A. [UR Catalyse/Matériaux pour l‘Environnement et les Procédés (URCMEP), Faculté des Sciences de Gabès, Université de Gabès, 6072 Gabès (Tunisia); Lavanchy, J.-C. [Université de Lausanne, IMG, Centre d’Analyse Minérale, Bat Anthropole, CH-1015 Lausanne (Switzerland); Kiwi, J. [Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LPI, Bat Chimie, Station 6, CH1015 Lausanne (Switzerland)

    2013-09-15

    Highlights: • Design, preparation, testing and characterization of uniform sputtered films. • Interfacial charge transfer from the Ag{sub 2}O (cb) to the lower laying Ta{sub 2}O{sub 5} (cb). • The optical absorption of TaON and TaON/Ag was proportional to E. coli inactivation. • Self-cleaning of the TaON/Ag polyester enables repetitive E. coli inactivation. -- Abstract: This study reports the design, preparation, testing and surface characterization of uniform films deposited by sputtering Ag and Ta on non-heat resistant polyester to evaluate the Escherichia coli inactivation by TaON, TaN/Ag, Ag and TaON/Ag polyester. Co-sputtering for 120 s Ta and Ag in the presence of N{sub 2} and O{sub 2} led to the faster E. coli inactivation by a TaON/Ag sample within ∼40 min under visible light irradiation. The deconvolution of TaON/Ag peaks obtained by X-ray photoelectron spectroscopy (XPS) allowed the assignment of the Ta{sub 2}O{sub 5} and Ag-species. The shifts observed for the XPS peaks have been assigned to AgO to Ag{sub 2}O and Ag{sup 0}, and are a function of the applied sputtering times. The mechanism of interfacial charge transfer (IFCT) from the Ag{sub 2}O conduction band (cb) to the lower laying Ta{sub 2}O{sub 5} (cb) is discussed suggesting a reaction mechanism. The optical absorption of the TaON and TaON/Ag samples found by diffuse reflectance spectroscopy (DRS) correlated well with the kinetics of E. coli inactivation. The TaON/Ag sample microstructure was characterized by contact angle (CA) and by atomic force microscopy (AFM). Self-cleaning of the TaON/Ag polyester after each disinfection cycle enabled repetitive E. coli inactivation.

  3. ELECTROCHEMICAL BEHAVIOR AND KINETICS OF THE INTERVALENCE CHARGE TRANSFER FOR THE SM(III)/SM(II) REDOX COUPLE IN LiF-CaF2 MELT

    OpenAIRE

    Stulov Yuriy Vyacheslavovich; Korenko Michal; Kubikova Blanca; Kuznetsov Sergey Aleksandrovich

    2015-01-01

    This article is focused on the electrochemical investigation (cyclic voltammetry) of the redox couple Sm(III)/Sm(II) in an eutectic LiF–CaF2 melt containing SmF3. The first step of reduction for Sm(III) ions, involving one electron exchange in soluble/soluble Sm(III)/Sm(II) system, was found on a tungsten electrode. The study of the Sm(II)/Sm(0) electrode reaction was not feasible, since it’s the redox potential is in the same range of the solvent decomposition. The first step was fo...

  4. Long Range Coupling between Metallic Nanocavities

    CERN Document Server

    Salomon, Adi; Fedoruk, Michael; Feldmann, Jochen; Kolkowski, Radoslaw; Zyss, Joseph

    2014-01-01

    When two or more metallic nanoparticles are in close proximity, their plasmonic modes may interact through the near field, leading to additional resonances of the coupled system or to shifts of their resonant frequencies. This process is analogous to atom-hybridization, as had been proposed by Gersten and Nitzan and modeled by Nordlander et al. The coupling between plasmonic modes can be in-phase (symmetric) or out-of-phase (anti-symmetric), reflecting correspondingly, the "bonding" and "anti-bonding" nature of such configurations. Since the incoming light redistributes the charge distribution around the metallic nanoparticles, its polarization features play a major role in the nonlinear optical probing of the energy-level landscape upon hybridization. Thus, controlling the nature of coupling between metallic nanostructures is of a great importance as it enables tuning their spectral responses leading to novel devices which may surpass the diffraction limit.

  5. PLASMA DEVICE

    Science.gov (United States)

    Baker, W.R.

    1961-08-22

    A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)

  6. Charge-coupled substituted garnets (Y3-xCa0.5xM0.5x)Fe5O12 (M = Ce, Th): structure and stability as crystalline nuclear waste forms.

    Science.gov (United States)

    Guo, Xiaofeng; Kukkadapu, Ravi K; Lanzirotti, Antonio; Newville, Matthew; Engelhard, Mark H; Sutton, Stephen R; Navrotsky, Alexandra

    2015-04-20

    The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce) and thorium (Th), incorporated by a charge-coupled substitution with calcium (Ca) for yttrium (Y) in YIG, namely, 2Y(3+) = Ca(2+) + M(4+), where M(4+) = Ce(4+) or Th(4+). Single-phase garnets Y3-xCa0.5xM0.5xFe5O12 (x = 0.1-0.7) were synthesized by the citrate-nitrate combustion method. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. X-ray diffraction and (57)Fe-Mössbauer spectroscopy indicated that M(4+) and Ca(2+) cations are restricted to the c site, and the local environments of both the tetrahedral and the octahedral Fe(3+) are systematically affected by the extent of substitution. The charge-coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature. PMID:25853274

  7. Charge-coupled Substituted Garnets (Y3-xCa0.5xM0.5x)Fe5O12 (M = Ce, Th): Structure and Stability as Crystalline Nuclear Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xiaofeng; Kukkadapu, Ravi K.; Lanzirotti, Anthony; Newville, Mathew; Engelhard, Mark H.; Sutton , Steven R.; Navrotsky, Alexandra

    2015-04-20

    The garnet structure has been proposed as a potential crystalline nuclear waste form for accommodation of actinide elements, especially uranium (U). In this study, yttrium iron garnet (YIG) as a model garnet host was studied for the incorporation of U analogs, cerium (Ce), and thorium (Th), incorporated by a charge-coupled substitution with calci-um (Ca) for yttrium (Y) in YIG, namely 2Y3+ = Ca2+ + M4+, where M4+ = Ce4+ or Th4+. Single phase garnets Y3-xCa0.5xM0.5xFe5O12, synthesized by the citrate-nitrate combustion method, were obtained up to x = 0.7. Ce was confirmed to be tetravalent by X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. X-ray diffraction and 57Fe-Mössbauer spectroscopy indicated that the samples are single phase, M4+ and Ca2+ cations are restricted to the c-site, the nature of M4+ has only a minor effect on the structure, and the local environments of both the tetrahedral and octahedral Fe3+ are systematically affected by the extent of substitution, especially on the tetrahedral sublattice. The charge coupled substitution has advantages in incorporating Ce/Th and in stabilizing the substituted phases, compared to a single substitution strategy. Enthalpies of formation of garnets were obtained by high temperature oxide melt solution calorimetry, and the enthalpies of substitution of Ce and Th were determined. The thermodynamic analysis demonstrates that the substituted garnets are entropically rather than energetically stabilized. This suggests that such garnets may form and persist in repositories at high temperature but might decompose near room temperature. These structural and thermodynamic findings shed light on possible incorporation of U in this garnet system.

  8. R (D(*)) and B r (B →τ ντ) in a flipped 2HDM with anomalously enhanced charged Higgs coupling to τ

    Science.gov (United States)

    Dhargyal, Lobsang

    2016-06-01

    BABAR, Belle, and recently LHCb have reported an excess in the measurements of R (D*) , R (D ) , and B r (B →τ ντ) than expected from the standard model (SM), a possible signature of lepton flavor universality violating New Physics (NP). In this work we analyze the phenomenological implications for these decay modes in a flipped two-Higg-doublet model with anomalously enhanced Yukawa coupling of H± to τ lepton. When experimental and theoretical errors are added in quadrature, we conclude that this phenomenological extension of the SM can give results in agreement within 1 σ deviation for the combination of R (D(*)) and B r (B →τ ντ) compared to about 4 σ deviation from the SM from the latest combined (BABAR, Belle, and LHCb) experimental data for these observables.

  9. Multicomponent Molecular Puzzles for Photofunction Design: Emission Color Variation in Lewis Acid-Base Pair Crystals Coupled with Guest-to-Host Charge Transfer Excitation.

    Science.gov (United States)

    Ono, Toshikazu; Sugimoto, Manabu; Hisaeda, Yoshio

    2015-08-01

    Simple yet ubiquitous multimolecular assembly systems with color-tunable emissions are realized by cooperative electron donor-acceptor interactions, such as the boron-nitrogen (B-N) dative bond as a Lewis acid-base pair and charge transfer (CT) interactions. These are ternary-component systems consisting of a naphthalenediimide derivative (NDI), tris(pentafluorophenyl)borane (TPFB), and aromatic molecules (guest) with an NDI:TPFB:guest ratio of 1:2:2. The crystal shows guest-dependent color-tunable emissions such as deep blue to orange when a guest molecule of benzene is replaced with other π-conjugated systems. A good correlation between the emission wavelength and ionization potential of the guest and electronic structure calculations indicated that the emission is due to the CT transition from the guest to the NDI. The present study suggests that a rational solution of multcomponent molecular puzzles would be useful for obtaining novel photofunctional solid-state systems. PMID:26211567

  10. Resolution enhancement using simultaneous couple illumination

    Science.gov (United States)

    Hussain, Anwar; Martínez Fuentes, José Luis

    2016-10-01

    A super-resolution technique based on structured illumination created by a liquid crystal on silicon spatial light modulator (LCOS-SLM) is presented. Single and simultaneous pairs of tilted beams are generated to illuminate a target object. Resolution enhancement of an optical 4f system is demonstrated by using numerical simulations. The resulting intensity images are recorded at a charged couple device (CCD) and stored in the computer memory for further processing. One dimension enhancement can be performed with only 15 images. Two dimensional complete improvement requires 153 different images. The resolution of the optical system is extended three times compared to the band limited system.

  11. Direct solar energy conversion and storage through coupling between photoelectrochemical and ferroelectric effects

    Directory of Open Access Journals (Sweden)

    Chi-Wei Lo

    2011-12-01

    Full Text Available Harvesting and storing solar energy has become more and more important. Current solid-state photovoltaic cells and conventional photoelectrochemical cells are not capable of directly storing the converted energy, which has to be facilitated by connecting to external storing devices. We demonstrate a device architecture that can convert and store solar energy in the electrical form within an intrinsically single structure. Mobile charge is internally stored, based on the coupling between photoelectrochemical and ferroelectric effects. The tested device architecture can be photo-charged under 1000 W/m2 of white light to an open-circuit voltage of 0.47V with a capacity of 37.62 mC/cm2. After removal of the light source, the mobile charge stored lasts more than 8 hours, and the open-circuit output voltage lasts more than 24 hours.

  12. Charge transfer and transport in DNA

    OpenAIRE

    Jortner, Joshua; Bixon, Mordechai; Langenbacher, Thomas; Michel-Beyerle, Maria E.

    1998-01-01

    We explore charge migration in DNA, advancing two distinct mechanisms of charge separation in a donor (d)–bridge ({Bj})–acceptor (a) system, where {Bj} = B1,B2, … , BN are the N-specific adjacent bases of B-DNA: (i) two-center unistep superexchange induced charge transfer, d*{Bj}a → d∓{Bj}a±, and (ii) multistep charge transport involves charge injection from d* (or d+) to {Bj}, charge hopping within {Bj}, and charge trapping by a. For off-resonance coupling, mechanism i prevails with the char...

  13. Proton irradiation effects in silicon devices

    Energy Technology Data Exchange (ETDEWEB)

    Simoen, E.; Vanhellemont, J.; Alaerts, A. [IMEC, Leuven (Belgium)] [and others

    1997-03-01

    Proton irradiation effects in silicon devices are studied for components fabricated in various substrates in order to reveal possible hardening effects. The degradation of p-n junction diodes increases in first order proportionally with the fluence, when submitted to 10 MeV proton irradiations in the range 5x10{sup 9} cm{sup -2} to 5x10{sup 11} cm{sup -2}. The damage coefficients for both p- and n-type Czochralski, Float-Zone and epitaxial wafers are reported. Charge-Coupled Devices fabricated in a 1.2 {mu}m CCD-CMOS technology are shown to be quite resistant to 59 MeV H{sup +} irradiations, irrespective of the substrate type. (author)

  14. History and latest development of ferro electric-semiconductor coupled photovoltaic devices%铁电半导体耦合光伏器件的历史与最新进展∗

    Institute of Scientific and Technical Information of China (English)

    杨彪; 刘向鑫; 李辉

    2015-01-01

    本文介绍了新型铁电-半导体耦合光伏器件的发展历史和现状,阐述了所观察到的非经典行为,即开路电压在直流偏置电场控制下的迟滞的现象。将之与含有光诱导偶极子场的有机光伏器件和量子点电池、压电光电子器件、铁电光伏器件、钙钛矿电池等进行比较,发现偶极子极化电场在多种光伏器件中均存在,甚至可能起到主导作用。因此,提出了偶极子场半导体器件的概念,期望从更广义的范围涵盖结场型器件和非结场型偶极子器件,为促进光伏发电领域更多的创新提供思路。%This paper introduces the history and current research status of the novel ferroelectric-semiconductor coupled photovoltaic devices, in which a ferroelectric field of polarized dipoles from nanoparticles separates the photogenerated carriers. Fabrication of such devices by combining a CdS nanodipole and a CdTe absorber via a feasible method is described, which involves a phase segregation process of CdS from a CdS–CdTe pseudobinary system. An irregular behavior is observed on this type of devices, i.e. the hysteresis of open circuit voltage due to external bias of direct-current (DC) electric field. Other macroscopic and microscopic evidences of the dipole field photovoltaic effect are also described. Meanwhile, similar photovoltaic mechanism observed in other types of solar cells are also discussed, such as organic photovoltaic devices and quantum dot devices with photo-induced dipole polarization field, piezo-phototronic devices, ferroelectric photovoltaic devices, as well as perovskite solar cells. It is apparent that the polarization field of dipoles not only exists in the various types of photovoltaic devices, but also may dominate the behavior of devices. Therefore, we propose that a new concept of dipole field semiconductor devices could be properly used to explain the photovoltaic behavior of both junctional and un

  15. 铁电半导体耦合光伏器件的历史与最新进展∗%History and latest development of ferro electric-semiconductor coupled photovoltaic devices

    Institute of Scientific and Technical Information of China (English)

    杨彪; 刘向鑫; 李辉

    2015-01-01

    This paper introduces the history and current research status of the novel ferroelectric-semiconductor coupled photovoltaic devices, in which a ferroelectric field of polarized dipoles from nanoparticles separates the photogenerated carriers. Fabrication of such devices by combining a CdS nanodipole and a CdTe absorber via a feasible method is described, which involves a phase segregation process of CdS from a CdS–CdTe pseudobinary system. An irregular behavior is observed on this type of devices, i.e. the hysteresis of open circuit voltage due to external bias of direct-current (DC) electric field. Other macroscopic and microscopic evidences of the dipole field photovoltaic effect are also described. Meanwhile, similar photovoltaic mechanism observed in other types of solar cells are also discussed, such as organic photovoltaic devices and quantum dot devices with photo-induced dipole polarization field, piezo-phototronic devices, ferroelectric photovoltaic devices, as well as perovskite solar cells. It is apparent that the polarization field of dipoles not only exists in the various types of photovoltaic devices, but also may dominate the behavior of devices. Therefore, we propose that a new concept of dipole field semiconductor devices could be properly used to explain the photovoltaic behavior of both junctional and un-junctional devices. The junctional devices could function with either pn junction or Schottky junction, while the un-junctional devices include all the devices mentioned above. We expect that various innovation should be inspired by this concept in photovoltaic community.%本文介绍了新型铁电-半导体耦合光伏器件的发展历史和现状,阐述了所观察到的非经典行为,即开路电压在直流偏置电场控制下的迟滞的现象。将之与含有光诱导偶极子场的有机光伏器件和量子点电池、压电光电子器件、铁电光伏器件、钙钛矿电池等进行比较,发现偶极子极化电场在

  16. 电势降落对DNA分子器件电荷输运的影响%Effect of Voltage Drop at Interface on Charge Transport Property of DNA Molecular Device

    Institute of Scientific and Technical Information of China (English)

    康大伟; 孙孟乐; 尤景汉; 姬江涛

    2012-01-01

    基于晶格格林函数和Landauer-Büttiker公式,研究了脱氧核糖核酸分子器件在不同电势降落下的电荷输运性质.界面处的电势降落可以导致负微分电导现象的出现,而且随着电势降落在脱氧核糖核酸分子上的比例的提高,这个效应更加明显.电势降落导致的分子轨道的局域化是产生负微分电导现象的关键因素.%The charge transport properties of deoxyribonucleic acid( DNA) molecular device at different voltage drop were studied based on the lattice Green function and Landauer-Btittiker formula. The voltage drop on the DNA molecule results in the negative differential conductance which becomes more prominent when the voltage drop increases. The localization of molecular orbital is the key point of the negative differential conductance.

  17. The electronic couplings in electron transfer and excitation energy transfer.

    Science.gov (United States)

    Hsu, Chao-Ping

    2009-04-21

    The transport of charge via electrons and the transport of excitation energy via excitons are two processes of fundamental importance in diverse areas of research. Characterization of electron transfer (ET) and excitation energy transfer (EET) rates are essential for a full understanding of, for instance, biological systems (such as respiration and photosynthesis) and opto-electronic devices (which interconvert electric and light energy). In this Account, we examine one of the parameters, the electronic coupling factor, for which reliable values are critical in determining transfer rates. Although ET and EET are different processes, many strategies for calculating the couplings share common themes. We emphasize the similarities in basic assumptions between the computational methods for the ET and EET couplings, examine the differences, and summarize the properties, advantages, and limits of the different computational methods. The electronic coupling factor is an off-diagonal Hamiltonian matrix element between the initial and final diabatic states in the transport processes. ET coupling is essentially the interaction of the two molecular orbitals (MOs) where the electron occupancy is changed. Singlet excitation energy transfer (SEET), however, contains a Frster dipole-dipole coupling as its most important constituent. Triplet excitation energy transfer (TEET) involves an exchange of two electrons of different spin and energy; thus, it is like an overlap interaction of two pairs of MOs. Strategies for calculating ET and EET couplings can be classified as (1) energy-gap-based approaches, (2) direct calculation of the off-diagonal matrix elements, or (3) use of an additional operator to describe the extent of charge or excitation localization and to calculate the coupling value. Some of the difficulties in calculating the couplings were recently resolved. Methods were developed to remove the nondynamical correlation problem from the highly precise coupled cluster

  18. Measurements of Charge Transfer Inefficiency in a CCD with High-Speed Column Parallel Readout

    CERN Document Server

    Sopczak, Andre; Damerell, Chris; Greenshaw, Tim; Koziel, Michal; Stefanov, Konstantin; Tikkanen, Tuomo; Woolliscroft, Tim; Worm, Steve

    2008-01-01

    Charge Coupled Devices (CCDs) have been successfully used in several high energy physics experiments over the past two decades. Their high spatial resolution and thin sensitive layers make them an excellent tool for studying short-lived particles. The Linear Collider Flavour Identification (LCFI) collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex detector of a future Linear Collider. The CPCCDs can be read out many times faster than standard CCDs, significantly increasing their operating speed. A test stand for measuring the charge transfer inefficiency (CTI) of a prototype CPCCD has been set up. Studies of the CTI have been performed at a range of readout frequencies and operating temperatures.

  19. Charge gradient microscopy

    Science.gov (United States)

    Hong, Seungbum; Tong, Sheng; Park, Woon Ik; Hiranaga, Yoshiomi; Cho, Yasuo; Roelofs, Andreas

    2014-01-01

    Here we present a simple and fast method to reliably image polarization charges using charge gradient microscopy (CGM). We collected the current from the grounded CGM probe while scanning a periodically poled lithium niobate single crystal and single-crystal LiTaO3 thin film on the Cr electrode. We observed current signals at the domains and domain walls originating from the displacement current and the relocation or removal of surface charges, which enabled us to visualize the ferroelectric domains at a scan frequency above 78 Hz over 10 μm. We envision that CGM can be used in high-speed ferroelectric domain imaging and piezoelectric energy-harvesting devices. PMID:24760831

  20. High Voltage Charge Pump

    KAUST Repository

    Emira, Ahmed A.

    2014-10-09

    Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.