Low voltage electron multiplying CCD in a CMOS process
Dunford, Alice; Stefanov, Konstantin; Holland, Andrew
2016-07-01
Low light level and high-speed image sensors as required for space applications can suffer from a decrease in the signal to noise ratio (SNR) due to the photon-starved environment and limitations of the sensor's readout noise. The SNR can be increased by the implementation of Time Delay Integration (TDI) as it allows photoelectrons from multiple exposures to be summed in the charge domain with no added noise. Electron Multiplication (EM) can further improve the SNR and lead to an increase in device performance. However, both techniques have traditionally been confined to Charge Coupled Devices (CCD) due to the efficient charge transfer required. With the increase in demand for CMOS sensors with equivalent or superior functionality and performance, this paper presents findings from the characterisation of a low voltage EMCCD in a CMOS process using advanced design features to increase the electron multiplying gain. By using the CMOS process, it is possible to increase chip integration and functionality and achieve higher readout speeds and reduced pixel size. The presented characterisation results include analysis of the photon transfer curve, the dark current, the electron multiplying gain and analysis of the parameters' dependence on temperature and operating voltage.
Evaluation of the photoelectric performance parameters measurement for electron multiplying CCD
Fang, Jie; Zhang, Wenwen; Gao, Jin; Li, Chaowei; Chen, Qian; Gu, Guohua
2016-10-01
The measurement of the electron multiplying CCD(EMCCD) photoelectric performance parameters plays an important role in the development of the chip and imaging system. Measurement uncertainty is an important index to evaluate the quality of the measurement results. A measurement platform for EMCCD photoelectric performance parameters is set up. An EMCCD camera's photoelectric performance parameters are measured based on photon transfer technique and the uncertainty of the measurement results is analyzed. Based on the method of GUM, the influences of the integrating sphere light source stability, EMCCD camera electronics system stability, installation posture, stray light in dark environment, camera's digital resolution and measurement sampling on the measurement results are analyzed. Based on the theoretical model of different photoelectric performance parameters, the uncertainty sources are discussed. The combined standard uncertainty is determined by the type A uncertainty and the type B uncertainty. The uncertainty evaluation model is established for the measurement of EMCCD photoelectric performance parameters, including convert gain, readout noise, full well, signal to noise ratio and multiplication gain. The uncertainty of the measurement results is calculated by using the established model. At last, we get the following results: relative standard uncertainty of the convert gain is 0.637% (k = 1), relative standard uncertainty of the readout noise is 0.653% (k = 1), relative standard uncertainty of the full well is 2.384% (k = 1), relative standard uncertainty of the signal to noise ratio is 2.301% (k = 1) and relative standard uncertainty of the multiplication gain is 1.259% (k = 1). The above uncertainty results show that the measurement results of this paper are accurate and reliable.
Transmission electron microscope CCD camera
Downing, Kenneth H.
1999-01-01
In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.
A study of gas electron multiplier
AN Shao-Hui; LI Cheng; ZHOU Yi; XU Zi-Zong
2004-01-01
A new kind of gas detector based on gas electron multiplier (GEM) is studied for X-ray imaging of high luminosity. A single-GEM device is designed to test the property of GEM foil .The effective gain and counting capability of a double-GEM detector are measured by an X-ray tube with Cu target. An initial X-ray imaging experiment is carried out using a triple-GEM detector and the position resolution of less than 0.1mm is achieved. The 3D distribution of electrostatic field of GEM mesh is also presented.
Gas Electron multipliers for low energy beams
Arnold, F; Ropelewski, L; Spanggaard, J; Tranquille, G
2010-01-01
Gas Electron Multipliers (GEM) find their way to more and more applications in beam instrumentation. Gas Electron Multiplication uses a very similar physical phenomenon to that of Multi Wire Proportional Chambers (MWPC) but for small profile monitors they are much more cost efficient both to produce and to maintain. This paper presents the new GEM profile monitors intended to replace the MWPCs currently used at CERN’s low energy Antiproton Decelerator (AD). It will be shown how GEMs overcome the documented problems of profile measurements with MWPCs for low energy beams, where the interaction of the beam with the detector has a large influence on the measured profile. Results will be shown of profile measurements performed at 5 MeV using four different GEM prototypes, with discussion on the possible use of GEMs at even lower energies needed at the AD in 2013.
Single electron based binary multipliers with overflow detection
ATHARVA
Multipliers with overflow detection based on serial and parallel ... current following through a tunnel junction is a series of events in which only one electron ..... Processing delay based on SED and analyzed SED for parallel prefix circuit.
The Tynode: A new vacuum electron multiplier
van der Graaf, Harry; Akhtar, Hassan; Budko, Neil; Chan, Hong Wah; Hagen, Cornelis W.; Hansson, Conny C. T.; Nützel, Gert; Pinto, Serge D.; Prodanović, Violeta; Raftari, Behrouz; Sarro, Pasqualina M.; Sinsheimer, John; Smedley, John; Tao, Shuxia; Theulings, Anne M. M. G.; Vuik, Kees
2017-03-01
By placing, in vacuum, a stack of transmission dynodes (tynodes) on top of a CMOS pixel chip, a single free electron detector could be made with outstanding performance in terms of spatial and time resolution. The essential object is the tynode: an ultra thin membrane, which emits, at the impact of an energetic electron on one side, a multiple of electrons at the other side. The electron yields of tynodes have been calculated by means of GEANT-4 Monte Carlo simulations, applying special low-energy extensions. The results are in line with another simulation based on a continuous charge-diffusion model. By means of Micro Electro Mechanical System (MEMS) technology, tynodes and test samples have been realized. The secondary electron yield of several samples has been measured in three different setups. Finally, several possibilities to improve the yield are presented.
The Gas Electron Multiplier Chamber Exhibition LEPFest 2000
2000-01-01
The Gas Electron Multiplier (GEM) is a novel device introduced in 1996.Large area detectors based on this technology are in construction for high energy physics detectors.This technology can also be used for high-rate X-ray imaging in medical diagnostics and for monitoring irradiation during cancer treatment
Gas Electron Multiplier detectors with high reliability and stability
Ovchinnikov, B M; Ovchinnikov, Yu B
2010-01-01
The Gas Electron Multiplier detectors with wire and metallic electrodes, with a gas filling in the gap between them were proposed and tested. The main advantage of these Gas Electron Multipliers compared to standard ones consists in their increased stability and reliability. The experimental results on testing of such detectors with gaps between the electrodes of 1 and 3 mm are reported. It is demonstrated, that the best gas filling for the gas electron multipliers is neon with small admixture of quenching gases (for example, (N2+H2O) at ~100ppm). This filling offers the greatest coefficient of proportional multiplication as compared with other gases, at small electric potential difference between the GEM electrodes, in absence of streamer discharges in the proportional region. The results on operation of the multi-channel gas electron multiplier with wire cathode and continuous anode filled with Ne, Ar, Ar+CH4 and Ar+1%Xe are presented also. Based on the experimental observations, the explanation of the mech...
The gas electron multiplier (GEM): Operating principles and applications
Sauli, Fabio
2016-01-01
Introduced by the author in 1997, The Gas Electron Multiplier (GEM) constitutes a powerful addition to the family of fast radiation detectors; originally developed for particle physics experiments, the device and has spawned a large number of developments and applications; a web search yields more than 400 articles on the subject. This note is an attempt to summarize the status of the design, developments and applications of the new detector.
CCD Readout Electronics for the Subaru Prime Focus Spectrograph
Hope, Stephen C; Loomis, Craig P; Fitzgerald, Roger E; Peacock, Grant O
2014-01-01
We present details of the design for the CCD readout electronics for the Subaru Telescope Prime Focus Spectrograph (PFS). The spectrograph is comprised of four identical spectrograph modules, each collecting roughly 600 spectra. The spectrograph modules provide simultaneous wavelength coverage over the entire band from 380 nm to 1260 nm through the use of three separate optical channels: blue, red, and near infrared (NIR). A camera in each channel images the multi-object spectra onto a 4k x 4k, 15 um pixel, detector format. The two visible cameras use a pair of Hamamatsu 2k x 4k CCDs with readout provided by custom electronics, while the NIR camera uses a single Teledyne HgCdTe 4k x 4k detector and ASIC Sidecar to read the device. The CCD readout system is a custom design comprised of three electrical subsystems: the Back End Electronics (BEE), the Front End Electronics (FEE), and a Pre-amplifier. The BEE is an off-the-shelf PC104 computer, with an auxiliary Xilinx FPGA module. The computer serves as the main...
Electron capture dissociation of singly and multiply phosphorylated peptides
Stensballe, A; Jensen, Ole Nørregaard; Olsen, J V
2000-01-01
Analysis of phosphotyrosine and phosphoserine containing peptides by nano-electrospray Fourier transform ion cyclotron resonance (FTICR) mass spectrometry established electron capture dissociation (ECD) as a viable method for phosphopeptide sequencing. In general, ECD spectra of synthetic...... and native phosphopeptides appeared less complex than conventional collision activated dissociation (CAD) mass spectra of these species. ECD of multiply protonated phosphopeptide ions generated mainly c- and z(.)-type peptide fragment ion series. No loss of water, phosphate groups or phosphoric acid from......(III)-affinity chromatography combined with nano-electrospray FTMS/ECD facilitated phosphopeptide analysis and amino acid sequencing from crude proteolytic peptide mixtures....
A First Mass Production of Gas Electron Multipliers
Barbeau, P S; Geissinger, J D; Miyamoto, J; Shipsey, I; Yang, R
2003-01-01
We report on the manufacture of a first batch of approximately 2,000 Gas Electron Multipliers (GEMs) using 3M's fully automated roll to roll flexible circuit production line. This process allows low-cost, reproducible fabrication of a high volume of GEMs of dimensions up to 30$\\times$30 cm$^{2}$. First tests indicate that the resulting GEMs have optimal properties as radiation detectors. Production techniques and preliminary measurements of GEM performance are described. This now demonstrated industrial capability should help further establish the prominence of micropattern gas detectors in accelerator based and non-accelerator particle physics, imaging and photodetection.
Antiproton beam profile measurements using Gas Electron Multipliers
Pinto, Serge Duarte; Spanggaard, Jens; Tranquille, Gerard
2011-01-01
The new beam profile measurement for the Antiproton Decelerator (AD) at CERN is based on a single Gas Electron Multiplier (GEM) with a 2D readout structure. This detector is very light, ~0.4% X_0, as required by the low energy of the antiprotons, 5.3 MeV. This overcomes the problems previously encountered with multi-wire proportional chambers (MWPC) for the same purpose, where beam interactions with the detector severely affect the obtained profiles. A prototype was installed and successfully tested in late 2010, with another five detectors now installed in the ASACUSA and AEgIS beam lines. We will provide a detailed description of the detector and discuss the results obtained. The success of these detectors in the AD makes GEM-based detectors likely candidates for upgrade of the beam profile monitors in all experimental areas at CERN. The various types of MWPC currently in use are aging and becoming increasingly difficult to maintain.
Aging measurements with the gas electron multiplier (GEM)
Altunbas, M C; Kappler, S; Ketzer, B; Ropelewski, Leszek; Sauli, Fabio; Simon, F
2003-01-01
Continuing previous aging measurements with detectors based on the Gas Electron Multiplier (GEM), a $31\\times 31$cm$^2$ triple-GEM detector, as used in the small area tracking of the COMPASS experiment at CERN, was investigated. With a detector identical to those installed in the experiment, long-term, high-rate exposures to $8.9$keV X-ray radiation were performed to study its aging properties. In standard operation conditions, with Ar:CO$_2$ (70:30) filling and operated at an effective gain of $8.5\\cdot 10^3$, no change in gain and energy resolution is observed after collecting a total charge of 7mC/mm$^2$, corresponding to seven years of normal operation. This observation confirms previous results demonstrating the relative insensitivity of GEM detectors to aging, even when manufactured with common materials.
Suborbital Soft X-Ray Spectroscopy with Gaseous Electron Multipliers
Rogers, Thomas D.
This thesis consists of the design, fabrication, and launch of a sounding rocket payload to observe the spectrum of the soft X-ray emission (0.1-1 keV) from the Cygnus Loop supernova remnant. This instrument, designated the Off-plane Grating Rocket for Extended Source Spectroscopy (OGRESS), was launched from White Sands Missile Range on May 2nd, 2015. The X-ray spectrograph incorporated a wire-grid focuser feeding an array of gratings in the extreme off-plane mount which dispersed the spectrum onto Gaseous Electron Multiplier (GEM) detectors. The gain characteristics of OGRESS's GEM detectors were fully characterized with respect to applied voltage and internal gas pressure, allowing operational settings to be optimized. The GEMs were optimized to operate below laboratory atmospheric pressure, allowing lower applied voltages, thus reducing the risk of both electrical arcing and tearing of the thin detector windows. The instrument recorded 388 seconds of data and found highly uniform count distributions over both detector faces, in sharp contrast to the expected thermal line spectrum. This signal is attributed to X-ray fluorescence lines generated inside the spectrograph. The radiation is produced when thermal ionospheric particles are accelerated into the interior walls of the spectrograph by the high voltages of the detector windows. A fluorescence model was found to fit the flight data better than modeled supernova spectra. Post-flight testing and analysis revealed that electrons produce distinct signal on the detectors which can also be successfully modeled as fluorescence emission.
Using a CCD for the direct detection of electrons in a low energy space plasma spectrometer
Bedington, R.; Kataria, D.; Walton, D.
2012-01-01
An E2V CCD64 back-illuminated, ion-implanted CCD (charge-coupled device) has been used as a direct electron imaging detector with CATS (Conceptual And Tiny Spectrometer), a highly miniaturised prototype plasma analyser head. This is in place of an MCP (microchannel plate) with a position sensing anode which would more conventionally be used as a detector in traditional low energy space plasma analyser instruments. The small size of CATS however makes it well matched to the size of the CCD, and the ion implants reduce the depth of the CCD backside electron potential well making it more sensitive to lower energy electrons than standard untreated silicon. Despite ionisation damage from prolonged exposure to excessively energetic electrons, the CCD has been able to detect electrons with energies above 500eV, at temperatures around room temperature. Using both a long integration 'current measuring' mode and a short integration `electron counting' mode it has been used to image the low energy electrons exiting the analyser, enhancing our understanding of the CATS electrostatic optics. The CCD has been selected as the detector for use with CATS for an instrument on a low-altitude student sounding rocket flight. Although it cannot detect the lowest energy electrons that an MCP can detect, and it is more sensitive to stray light, the low voltages required, the lack of vacuum requirements and its novelty and availability made it the most attractive candidate detector.
Investigation of the Decelerating Field of an Electron Multiplier under Negative Ion Impact
Larsen, Elfinn; Kjeldgaard, K.
1973-01-01
The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions...... by a factor of 100. The secondary electron emission coefficient for the negative halogen ions relative to I− were measured on CuBe at the kinetic energies 1.0 and 1.5 keV....
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).
Deep sub electron noise readout in CCD systems using digital filtering techniques
Cancelo, Gustavo; Moroni, Guillermo Fernandez; Treptow, Ken; Zmuda, Ted; Diehl, Tom
2011-01-01
Scientific CCDs designed in thick high resistivity silicon (Si) are excellent detectors for astronomy, high energy and nuclear physics, and instrumentation. Many applications can benefit from CCDs ultra low noise readout systems. The present work shows how sub electron noise CCD images can be achieved using digital signal processing techniques. These techniques allow readout bandwidths of up to 10 K pixels per second and keep the full CCD spatial resolution and signal dynamic range.
Modelling electron distributions within ESA's Gaia satellite CCD pixels to mitigate radiation damage
Seabroke, G M; Burt, D; Robbins, M S
2009-01-01
The Gaia satellite is a high-precision astrometry, photometry and spectroscopic ESA cornerstone mission, currently scheduled for launch in 2012. Its primary science drivers are the composition, formation and evolution of the Galaxy. Gaia will achieve its unprecedented positional accuracy requirements with detailed calibration and correction for radiation damage. At L2, protons cause displacement damage in the silicon of CCDs. The resulting traps capture and emit electrons from passing charge packets in the CCD pixel, distorting the image PSF and biasing its centroid. Microscopic models of Gaia's CCDs are being developed to simulate this effect. The key to calculating the probability of an electron being captured by a trap is the 3D electron density within each CCD pixel. However, this has not been physically modelled for the Gaia CCD pixels. In Seabroke, Holland & Cropper (2008), the first paper of this series, we motivated the need for such specialised 3D device modelling and outlined how its future resu...
Electron loss from multiply protonated lysozyme ions in high energy collisions with molecular oxygen
Hvelplund, P; Nielsen, SB; Sørensen, M
2001-01-01
We report on the electron loss from multiply protonated lysozyme ions Lys-Hn(n)+ (n = 7 - 17) and the concomitant formation of Lys-Hn(n+1)+. in high-energy collisions with molecular oxygen (laboratory kinetic energy = 50 x n keV). The cross section for electron loss increases with the charge stat...
Single-electron and single-photon sensitivity with a silicon Skipper CCD
Tiffenberg, Javier [Fermilab; Sofo-Haro, Miguel [Balseiro Inst., San Carlos de Bariloche; Drlica-Wagner, Alex [Fermilab; Essig, Rouven [YITP, Stony Brook; Guardincerri, Yann [Fermilab; Holland, Steve [LBL, Berkeley; Volansky, Tomer [Tel Aviv U.; Yu, Tien-Tien [CERN
2017-05-31
We have developed a non-destructive readout system that uses a floating-gate amplifier on a thick, fully depleted charge coupled device (CCD) to achieve ultra-low readout noise of 0.068 e- rms/pix. This is the first time that discrete sub-electron readout noise has been achieved reproducibly over millions of pixels on a stable, large-area detector. This allows the precise counting of the number of electrons in each pixel, ranging from pixels with 0 electrons to more than 1500 electrons. The resulting CCD detector is thus an ultra-sensitive calorimeter. It is also capable of counting single photons in the optical and near-infrared regime. Implementing this innovative non-destructive readout system has a negligible impact on CCD design and fabrication, and there are nearly immediate scientific applications. As a particle detector, this CCD will have unprecedented sensitivity to low-mass dark matter particles and coherent neutrino-nucleus scattering, while astronomical applications include future direct imaging and spectroscopy of exoplanets.
Salter, Mike; Clapp, Matthew; King, James; Morse, Tom; Mihalcea, Ionut; Waltham, Nick; Hayes-Thakore, Chris
2016-07-01
World Space Observatory Ultraviolet (WSO-UV) is a major Russian-led international collaboration to develop a large space-borne 1.7 m Ritchey-Chrétien telescope and instrumentation to study the universe at ultraviolet wavelengths between 115 nm and 320 nm, exceeding the current capabilities of ground-based instruments. The WSO Ultraviolet Spectrograph subsystem (WUVS) is led by the Institute of Astronomy of the Russian Academy of Sciences and consists of two high resolution spectrographs covering the Far-UV range of 115-176 nm and the Near-UV range of 174-310 nm, and a long-slit spectrograph covering the wavelength range of 115-305 nm. The custom-designed CCD sensors and cryostat assemblies are being provided by e2v technologies (UK). STFC RAL Space is providing the Camera Electronics Boxes (CEBs) which house the CCD drive electronics for each of the three WUVS channels. This paper presents the results of the detailed characterisation of the WUVS CCD drive electronics. The electronics include a novel high-performance video channel design that utilises Digital Correlated Double Sampling (DCDS) to enable low-noise readout of the CCD at a range of pixel frequencies, including a baseline requirement of less than 3 electrons rms readout noise for the combined CCD and electronics system at a readout rate of 50 kpixels/s. These results illustrate the performance of this new video architecture as part of a wider electronics sub-system that is designed for use in the space environment. In addition to the DCDS video channels, the CEB provides all the bias voltages and clocking waveforms required to operate the CCD and the system is fully programmable via a primary and redundant SpaceWire interface. The development of the CEB electronics design has undergone critical design review and the results presented were obtained using the engineering-grade electronics box. A variety of parameters and tests are included ranging from general system metrics, such as the power and mass
Schweinzer, J; Brandenburg, R; Bray, [No Value; Hoekstra, R; Aumayr, F; Janev, RK; Winter, HP
1999-01-01
New experimental and theoretical cross-section data for inelastic collision processes of Li atoms in the ground state and excited states (up to n = 4) with electrons, protons, and multiply charged ions have been reported since the database assembled by Wutte et al. [ATOMIC DATA AND NUCLEAR DATA TABL
Design and function of an electron mobility spectrometer with a thick gas electron multiplier
Orchard, Gloria M., E-mail: gloria.spirou@gmail.com [Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada, L1H 7K4 (Canada); Puddu, Silvia [CERN, 1211 Geneva 23, Switzerland and University of Bern, LHEP, Sidlerstrasse 5, 3012 Bern (Switzerland); Waker, Anthony J., E-mail: anthony.waker@uoit.ca [Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada, L1H 7K4 (Canada)
2016-04-11
The design and function of an electron mobility spectrometer (EMS) including a thick gas electron multiplier (THGEM) is presented. The THGEM was designed to easily be incorporated in an existing EMS to investigate the ability to detect tritium in air using a micropattern gas detector. The THGEM and a collection plate (anode) were installed and the appropriate circuitry was designed and connected to supply the required voltages to the THGEM-EMS. An alpha source ({sup 241}Am) was used to generate electron-ion pairs within the gas-filled sensitive volume of the EMS. The electrons were used to investigate the THGEM-EMS response as a function of applied voltage to the THGEM and anode. The relative gas-gain and system resolution of the THGEM-EMS were measured at various applied voltage settings. It was observed a potential difference across the THGEM of +420 V and potential difference across the induction region of +150 V for this EMS setup resulted in the minimum voltage requirements to operate with a stable gain and system resolution. Furthermore, as expected, the gain is strongly affected not only by the potential difference across the THGEM, but also by the applied voltage to the anode and resulting potential difference between the THGEM and anode.
Yang, S; Buck, B; Li, C; Ljubicic, T; Majka, R; Shao, M; Smirnov, N; Visser, G; Xu, Z; Zhou, Y
2014-01-01
A thick gas electron multiplier (THGEM) chamber with an effective readout area of 10$\\times$10 cm$^{2}$ and a 11.3 mm ionization gap has been tested along with two regular gas electron multiplier (GEM) chambers in a cosmic ray test system. The thick ionization gap makes the THGEM chamber a mini-drift chamber. This kind mini-drift THGEM chamber is proposed as part of a transition radiation detector (TRD) for identifying electrons at an Electron Ion Collider (EIC) experiment. Through this cosmic ray test, an efficiency larger than 94$\\%$ and a spatial resolution $\\sim$220 $\\mu$m are achieved for the THGEM chamber at -3.65 kV. Thanks to its outstanding spatial resolution and thick ionization gap, the THGEM chamber shows excellent track reconstruction capability. The gain uniformity and stability of the THGEM chamber are also presented.
A tiled CCD detector with 2x2 array and tapered fibre optics for electron microscopy
Faruqi, A R; Cattermole, D M; Stubbings, S
2002-01-01
Charge coupled devices (CCD)-based detectors have made a major impact on data collection in electron microscopy over the past few years. There have been a number of successful applications of CCDs in electron crystallography of two-dimensional protein crystal arrays but high-resolution imaging has been hampered by the relatively poor spatial resolution (and fewer independent pixels) compared to film. A partial solution to this problem, presented in this paper, are to design detectors with larger effective pixel sizes and with more pixels. A CCD detector with a much greater number of 'independent' pixels, achieved by tiling a 2x2 array of CCDs, each of which has 1242x1152 pixels is described here. The sensitive area of the detector, using fibre optics with a demagnification of 2.5 : 1, is 140x130 mm sup 2; the pixel size is 56 mu m square and there is a total of approx 2500x2300 pixels.
A toolkit for the characterization of CCD cameras for transmission electron microscopy.
Vulovic, M; Rieger, B; van Vliet, L J; Koster, A J; Ravelli, R B G
2010-01-01
Charge-coupled devices (CCD) are nowadays commonly utilized in transmission electron microscopy (TEM) for applications in life sciences. Direct access to digitized images has revolutionized the use of electron microscopy, sparking developments such as automated collection of tomographic data, focal series, random conical tilt pairs and ultralarge single-particle data sets. Nevertheless, for ultrahigh-resolution work photographic plates are often still preferred. In the ideal case, the quality of the recorded image of a vitrified biological sample would solely be determined by the counting statistics of the limited electron dose the sample can withstand before beam-induced alterations dominate. Unfortunately, the image is degraded by the non-ideal point-spread function of the detector, as a result of a scintillator coupled by fibre optics to a CCD, and the addition of several inherent noise components. Different detector manufacturers provide different types of figures of merit when advertising the quality of their detector. It is hard for most laboratories to verify whether all of the anticipated specifications are met. In this report, a set of algorithms is presented to characterize on-axis slow-scan large-area CCD-based TEM detectors. These tools have been added to a publicly available image-processing toolbox for MATLAB. Three in-house CCD cameras were carefully characterized, yielding, among others, statistics for hot and bad pixels, the modulation transfer function, the conversion factor, the effective gain and the detective quantum efficiency. These statistics will aid data-collection strategy programs and provide prior information for quantitative imaging. The relative performance of the characterized detectors is discussed and a comparison is made with similar detectors that are used in the field of X-ray crystallography.
Gas electron multiplier based on laser-perforated CVD diamond film: First tests
Franchino, S; Bolshakov, A; Ashkinazi, E; Kalkan, Y; Popovich, A; Komlenok, M; Sosnovtsev, V; Ralchenko, V
2016-01-01
Gas electron multiplier (GEM) is widely used in modern gas detectors of ionizing radiation in experiments on high-energy physics at accelerators and in other fields of science. Typically the GEM devices are based on a dielectric foil with holes and electrodes on both sides. GEMs made by radiation-hard dielectrics or wide band-gap semiconductors are desirable for some applications. The results of the first tests of the gas electron multiplier made of radiation-hard materials, such as polycrystalline CVD diamond with a thickness of 100 microns is described. Here we report on fabrication of GEM based on free-standing polycrystalline CVD diamond film and its first test.
Mirkovic, M. A.; Nedeljkovic, N. N.
2008-07-01
We analyze the angular momentum distributions of the electron transferred into the Rydberg states of multiply charged ions escaping the solid surfaces. The population probabilities are calculated within the framework of two-state-vector model; in the case of large values of the angular momentum quantum numbers l the model takes into account an importance of a wide space region around the projectile trajectory. The reionization of the previously populated states is also taken into account. The corresponding ionization rates are obtained by the appropriate etalon equation method; in the large-l case the radial electronic coordinate rho is treated as variational parameter. The theoretical predictions based on the proposed population-reionization mechanism fit the available beam-foil experimental data; the obtained large-l distributions are also used to elucidate the recent experimental data concerning the multiply charged Rydberg ions interacting with micro-capillary foil.
Method of automatic tuning pf preset coefficient of electron gain of photoelectron multiplier
Smirnov, O Yu
2002-01-01
Paper describes technique to time the preset coefficient of electron gain of photoelectron multiplier (PEM) ensuring high accuracy at minimal involvement of an operator. Subsequent to rough setting of voltage in PEM the automatic system tunes high voltage so that coefficient of electron gain of PEM corresponds to the preset one within the limits of the required accuracy (up to 2%). The technique was efficiently used to tune two thousands of PEMs for the Borexino solar neutrino detector in the Gran Sasso National Laboratory, Italy
A Sealed, UHV Compatible, Soft X-ray Detector Utilizing Gas Electron Multipliers
Schaknowski, N.A.; Smith, G.
2009-10-25
An advanced soft X-ray detector has been designed and fabricated for use in synchrotron experiments that utilize X-ray absorption spectroscopy in the study a wide range of materials properties. Fluorescence X-rays, in particular C{sub K} at 277eV, are converted in a low pressure gas medium, and charge multiplication occurs in two gas electron multipliers, fabricated in-house from glass reinforced laminate, to enable single photon counting. The detector satisfies a number of demanding characteristics often required in synchrotron environments, such as UHV compatibility compactness, long-term stability, and energy resolving capability.
Construction of a Gas Electron Multiplier (GEM) Detector for Medical Imaging
2013-01-01
A prototype Gas Electron Multiplier (GEM) detector is under construction for medical imaging purposes. A single thick GEM of size 10x10 cm^2 is assembled inside a square shaped air-tight box which is made of Perspex glass. In order to ionize gas inside the drift field two types of voltage supplier circuits were fabricated, and array of 2x4 pads of each size 4x8 mm^2 were utilized for collecting avalanche charges. Preliminary testing results show that the circuit which produces high voltage an...
Coupled-Multiplier Accelerator Produces High-Power Electron Beams for Industrial Applications
Hatridge, M.; McIntyre, P.; Roberson, S.; Sattarov, A.; Thomas, E.; Meitzler, Charles
2003-08-01
The coupled multiplier is a new approach to efficient generation of MeV d.c. power for accelerator applications. High voltage is produced by a series of modules, each of which consists of a high-power alternator, step-up transformer, and 3-phase multiplier circuit. The alternators are connected mechanically along a rotating shaft, and connected by insulating flexible couplers. This approach differs from all previous d.c. technologies in that power is delivered to the various stages of the system mechanically, rather than through capacitive or inductive electrical coupling. For this reason the capital cost depends linearly on required voltage and power, rather than quadratically as with conventional technologies. The CM technology enables multiple electron beams to be driven within a common supply and insulating housing. MeV electron beam is extremely effective in decomposing organic contaminants in water. A 1 MeV, 100 kW industrial accelerator using the CM technology has been built and is being installed for treatment of wastewater at a petrochemical plant.
Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus
2016-06-01
Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times.
High gain micro-channel plate multipliers for particle tracking or single photo-electron counting
Oba, K.; Rehak, P.; Smith, S.D.
1980-01-01
Micro-channel plate multipliers have been used to detect the passage of relativistic charged particles. Measurements of the detection efficiency and pulse height response versus micro-channel plate gain are presented for one, two and three micro-channel plate arrays. Values describing temporal response and transit time jitter are also given. In a separate measurement, the response of a single micro-channel plate to individual slow electrons (less than or equal to 1 keV) was studied. By using a special technique output bunches as small as three electrons may be seen for low average micro-channel plate gain. The results of attempts to improve the micro-channel plate response are also presented.
Construction of a Gas Electron Multiplier (GEM) Detector for Medical Imaging
Mondal, N N; Mazumdar, M R Dutta; Dubey, A K; Vioygi, Y P
2013-01-01
A prototype Gas Electron Multiplier (GEM) detector is under construction for medical imaging purposes. A single thick GEM of size 10x10 cm^2 is assembled inside a square shaped air-tight box which is made of Perspex glass. In order to ionize gas inside the drift field two types of voltage supplier circuits were fabricated, and array of 2x4 pads of each size 4x8 mm^2 were utilized for collecting avalanche charges. Preliminary testing results show that the circuit which produces high voltage and low current is better than that of low voltage and high current supplier circuit in terms of x-ray signal counting rates.
Badertscher, A; Degunda, U; Epprecht, L; Gendotti, A; Horikawa, S; Knecht, L; Lussi, D; Marchionni, A; Natterer, G; Nguyen, K; Resnati, F; Rubbia, A; Viant, T
2012-01-01
We have operated a liquid-argon large-electron-multiplier time-projection chamber (LAr LEM-TPC) with a large active area of 76 $\\times$ 40 cm$^2$ and a drift length of 60 cm. This setup represents the largest chamber ever achieved with this novel detector concept. The chamber is equipped with an immersed built-in cryogenic Greinacher multi-stage high-voltage (HV) multiplier, which, when subjected to an external AC HV of $\\sim$1 kV$_{\\mathrm{pp}}$, statically charges up to a voltage a factor of $\\sim$30 higher inside the LAr vessel, creating a uniform drift field of $\\sim$0.5 kV/cm over the full drift length. This large LAr LEM-TPC was brought into successful operation in the double-phase (liquid-vapor) operation mode and tested during a period of $\\sim$1 month, recording impressive three-dimensional images of very high-quality from cosmic particles traversing or interacting in the sensitive volume. The double phase readout and HV systems achieved stable operation in cryogenic conditions demonstrating their go...
Martin, S.; Ortega, C.; Chen, L.; Bredy, R.; Vernier, A.; Dugourd, P.; Antoine, R.; Bernard, J.; Reitsma, G.; Gonzalez Magana, Olmo; Hoekstra, Ronnie; Schlathölter, Thomas
2014-01-01
Electron-transfer processes in interaction between highly charged ions and multiply protonated proteins have been studied. Collisions between Xe8+ at 96 keV and protonated cytochrome-C at selected charge state (q from 15+ to 19+) result inmass spectra composed mainly of intact molecular ions. From t
Large Gas Electron Multiplier Trackers for Super Bigbite Spectrometer at Jefferson lab Hall A
Saenboonruang, K.; Gnanvo, K.; Liyanage, N.; Nelyubin, V.; Sacher, S.; Cisbani, E.; Musico, P.; Wojtsekhowski, B.
2013-04-01
The 12 GeV upgrade at Jefferson Lab (JLAB) makes many exciting nuclear experiments possible. These experiments also require new high performance instrumentation. The Super Bigbite Spectrometer (SBS) was proposed to perform a series of high precision nucleon form factor experiments at large momentum transfer. The SBS will be capable of operating at a very high luminosity and provide a large solid angle acceptance of 76 msr. SBS will be equipped with a double focal plane polarimeter. Thus, SBS will have three large trackers made of Gas Electron Multiplier (GEM) chambers. The first, second, and third trackers will consist of six, four, and four tracking layers respectively. When completed in 2017, the SBS GEM trackers will form one of the largest sets of GEM chambers in the world. The GEM trackers allow the SBS to operate under high background rates over 500 kHz/cm^2, while providing an excellent spatial resolution of 70 μm. The first tracker will be constructed at the Istituto Nazionale di Fisica Nucleare in Italy, while the second and third trackers will be built at the University of Virginia. In 2012, the first UVa SBS GEM chamber prototype was successfully constructed and tested. The GEM chamber construction details and test results will be presented in this talk.
Gas Electron Multipliers: Development of large area GEMs and spherical GEMs
Duarte Pinto, Serge; Brock, Ian
2011-01-01
Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDs) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I will describe the properties and the application of GEMs and GEM detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs (~m^2) for particle physics experiments and GEMs with a spherical shape for x-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry.
Investigations with Gaseous Electron Multipliers for use on the ISIS spallation neutron source
Duxbury, D.; Rhodes, N.; Schooneveld, E.; Spill, E.
2012-01-01
Several investigations have been undertaken to ascertain the suitability of gaseous electron multipliers (GEMs) for use as a neutron detector on the ISIS spallation neutron source. Our initial investigations focused purely on whether these devices could be operated at the elevated pressure of 3He and CF4 necessary for 1mm position resolution (2.6 bars of CF4). In fact we were able to operate the GEMs at suitable gains with 3.5 bars of CF4. However encouraging these results were, we found that the GEMs charged up over time, which we postulated was due to the kapton substrate. A similar problem was seen at the early stages of the development of the microstrip gas chamber (MSGC), a solution of which was to use the semiconducting glass Schott S8900 as the substrate. Therefore we focused our attention to the manufacture of a GEM structure on an S8900 substrate. Our first devices were manufactured from 1mm thick glass and exhibit gains in excess of 1 × 104 for a single GEM stage in an argon isobutane gas mixture, when illuminated with 55Fe x-rays. A small amount of charging under irradiation has been observed in a flowing gas mixture, but the GEMs quickly stabilise and track atmospheric conditions. Further measurements in a 3He:CF4 atmosphere will show how suited these devices are to the needs of ISIS.
Lopes, J A M; Conde, C A N; Morgado, R E
1999-01-01
The performance of a novel integrated photosensor for use in a xenon gas proportional scintillation detector is described. Earlier integrated photo-sensor designs were limited in charge gains due to the onset of electrical breakdown, which was ascribed to optical positive feedback from scintillation photons produced in the charge amplification stage. The present design uses a gas electron multiplier (GEM) composed of a 50 mu m thick Kapton film with copper-plated electrode surfaces on both sides and perforated with 200 mu m holes at a 300 mu m pitch. The front surface is made photosensitive with a 150-nm-thick CsI film. When an appropriate voltage is applied between the copper electrodes, the resulting electric field directs photoelectrons produced on the front surface through the holes in the GEM and onto a wire chamber where charge amplification occurs. Optical positive feedback is essentially eliminated since the charge amplification stage is optically de-coupled from the photocathode. The GEM also provide...
Feasibility Study of Gas Electron Multiplier Detector as an X-Ray Image Sensor
Shin, Sukyoung; Lee, Soonhyouk
2015-01-01
For its ease manufacturing, flexible geometry, and cheap manufacturing cost, the gas electron multiplier (GEM) detector can be used as an x-ray image sensor. For this purpose, we acquired relative detection efficiencies and suggested a method to increase the detection efficiency in order to study the possibility of GEM detector as an x-ray image sensor. The GEM detector system is composed of GEM foils, the instrument system, the gas system, and the negative power supply. The instrument system consists of the A225 charge sensitive preamp, A206 discriminator, and MCA8000D multichannel analyzer. For the gas system, Argon gas was mixed with CO2 to the ratio of 8:2, and for the negative 2,000 volts, the 3106D power supply was used. The CsI-coated GEM foil was used to increase the detection efficiency. Fe-55 was used as an x-ray source and the relative efficiency was acquired by using the ratio of GEM detector to the CdTe detector. The total count method and the energy spectrum method were used to calculate the rel...
The current status of the Gas Electron Multiplier (GEM) research at Kasetsart University, Thailand
Kumpiranon, P.; Kulasri, K.; Rittirong, A.; Saenboonruang, K.
2017-06-01
During the past decade, Gas Electron Multiplier (GEM) detectors have been greatly developed and utilized in numbers of applications including advanced nuclear and particle researches, medical imaging, astrophysics, and neutron detection for national security. Our GEM research group at the Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Thailand, realized in its excellent properties/potentials and started extensive researches on GEM detectors. To build a strong foundation on our research group, two 10 cm × 10 cm triple GEM detectors were characterized on their important properties including absolute gains and detection uniformity. Moreover, to widen applications of the GEM detector, our group had modified the GEM detector by introducing either solid or gaseous neutron converters to the detector so that the detector could effectively detect neutrons. These modifications included coating a thin film of 10B and natB to the GEM drift cathode for thermal neutron detection and flowing a gas mixture of He/CO2 (80:20 and 70:30) and C4H10/He/CO2 (7:70:23) for fast neutron detection. Results showed that the modified GEM-based neutron detector could detect both types of neutrons with different relative efficiencies and gains depending on thicknesses and types of neutron converters. This article discusses basic knowledge of the GEM detector, construction and testing procedures, results, and discussion.
Gas electron multipliers. Development of large area GEMS and spherical GEMS
Pinto, Serge Duarte
2011-08-15
Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDS) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I describe the properties and the application of GEMs and GEM. detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs ({proportional_to}m{sup 2}) for particle physics experiments and GEMs with a spherical shape for X-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry. (orig.)
Quality Control (QC2) of Gas Electron Multiplier (GEM) for GE1/1 at CMS Experiment
Sharma, Archana
2016-01-01
Gas Electron Multiplier (GEM) is a gas ionization detector that detect charged particles and will be implemented on CMS system. It is designed to improve muon trigger and tracking performance at high luminosity after the second Long Shutdown (LS2). For my project, GEM foils, a component of the Triple GEM detector have been studied. In order to pass the test, the foils need to run in the Fast Test and Long Test of QC2.
High-power free-electron maser operated in a two-mode frequency-multiplying regime
N. Yu. Peskov
2016-06-01
Full Text Available The frequency multiplication effects in high-power free-electron masers (FEM with Bragg cavities were studied to provide the advance of the oscillators into short-wavelength bands. Theoretical analysis of frequency-multiplying FEMs was carried out within the framework of the averaged coupled-wave approach. Proof-of-principle experiments were performed based on a moderately relativistic induction linac LIU-3000 (JINR. As a result, an FEM multiplier operated with a megawatt power level in the 6-mm and 4-mm wavelength bands at the second and third harmonics, respectively, was realized. The possibility of using two-mode bichromatic FEMs for powering a double-frequency accelerating structure was discussed.
Photoionisation detection of single {sup 87}Rb-atoms using channel electron multipliers
Henkel, Florian Alexander
2011-09-02
Fast and efficient detection of single atoms is a universal requirement concerning modern experiments in atom physics, quantum optics, and precision spectroscopy. In particular for future quantum information and quantum communication technologies, the efficient readout of qubit states encoded in single atoms or ions is an elementary prerequisite. The rapid development in the field of quantum optics and atom optics in the recent years has enabled to prepare individual atoms as quantum memories or arrays of single atoms as qubit registers. With such systems, the implementation of quantum computation or quantum communication protocols seems feasible. This thesis describes a novel detection scheme which enables fast and efficient state analysis of single neutral atoms. The detection scheme is based on photoionisation and consists of two parts: the hyperfine-state selective photoionisation of single atoms and the registration of the generated photoion-electron pairs via two channel electron multipliers (CEMs). In this work, both parts were investigated in two separate experiments. For the first step, a photoionisation probability of p{sub ion}=0.991 within an ionisation time of t{sub ion}=386 ns is achieved for a single {sup 87}Rb-atom in an optical dipole trap. For the second part, a compact detection system for the ionisation fragments was developed consisting of two opposing CEM detectors. Measurements show that single neutral atoms can be detected via their ionisation fragments with a detection efficiency of {eta}{sub atom}=0.991 within a detection time of t{sub det}=415.5 ns. In a future combined setup, this will allow the state-selective readout of optically trapped, single neutral {sup 87}Rb-atoms via photoionisation detection with an estimated detection efficiency {eta}=0.982 and a detection time of t{sub tot} = 802 ns. Although initially developed for single {sup 87}Rb-atoms, the concept of photoionisation detection is in principle generally applicable to any
Ortiz, J. F.; Grau, A.
1985-07-01
In the present paper an iterative method is applied to study the variation of dynode response in the multiplier phototube. Three different situation are considered that correspond to the following ways of electronic incidence on the first dynode: incidence of exactly one electron, incidence of exactly r electrons and incidence of an average r electrons. The responses are given for a number of steps between 1 and 5, and for values of the multiplication factor of 2.1, 2.5, 3 and 5. We study also the variance, the skewness and the excess of jurtosis for different multiplication factors. (Author) 11 refs.
R. Nandi
2009-01-01
Full Text Available A new dual-input differential input active integrator using a current differencing buffered amplifier (CDBA is proposed. A multiplier element is appropriately used in the circuit whose control voltage (Vc tunes the integrator time constant (τ electronically. The design of a voltage controlled quadrature oscillator (VCQO based on the proposed integrator had been satisfactorily implemented. A new type of measurement for the tuning error of the oscillator based on the Nyquist plot is presented that shows an error of only 2% at fo≈ 1 MHz with Total Harmonic Distortion (THD less than 3%.
Electron-multiplying CCDs for future soft X-ray spectrometers
Tutt, J. H.; Holland, A. D.; Murray, N. J.; Harriss, R. D.; Hall, D. J.; Soman, M.
2012-02-01
CCDs have been used in several high resolution soft X-ray spectrometers for both space and terrestrial applications such as the Reflection Grating Spectrometer on XMM-Newton and the Super Advanced X-ray Emission Spectrometer at the Paul Scherrer Institut in Switzerland. However, with their ability to use multiplication gain to amplify signal and suppress readout noise, EM-CCDs are being considered instead of CCDs for future soft X-ray spectrometers. When detecting low energy X-rays, EM-CCDs are able to increase the Signal-to-Noise ratio of the device, making the X-rays much easier to detect. If the signal is also significantly split between neighbouring pixels, the increase in the size of the signal will make complete charge collection and techniques such as centroiding easier to accomplish. However, multiplication gain from an EM-CCD does cause a degradation of the energy resolution of the device and there are questions about how the high field region in an EM-CCD will behave over time in high radiation environments. This paper analyses the possible advantages and disadvantages of using EM-CCDs for high resolution soft X-ray spectroscopy and suggests in which situations using them would not only be possible, but also beneficial to the instrument.
Roth, Roger R.
1983-01-01
A CCD camera capable of observing a moving object which has varying intensities of radiation eminating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other.
Hirvonen, Liisa M.; Jiggins, Stephen; Sergent, Nicolas; Zanda, Gianmarco; Suhling, Klaus, E-mail: klaus.suhling@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom)
2014-12-15
We have used an electron-bombarded CCD for optical photon counting imaging. The photon event pulse height distribution was found to be linearly dependent on the gain voltage. We propose on this basis that a gain voltage sweep during exposure in an electron-bombarded sensor would allow photon arrival time determination with sub-frame exposure time resolution. This effectively uses an electron-bombarded sensor as a parallel-processing photoelectronic time-to-amplitude converter, or a two-dimensional photon counting streak camera. Several applications that require timing of photon arrival, including Fluorescence Lifetime Imaging Microscopy, may benefit from such an approach. A simulation of a voltage sweep performed with experimental data collected with different acceleration voltages validates the principle of this approach. Moreover, photon event centroiding was performed and a hybrid 50% Gaussian/Centre of Gravity + 50% Hyperbolic cosine centroiding algorithm was found to yield the lowest fixed pattern noise. Finally, the camera was mounted on a fluorescence microscope to image F-actin filaments stained with the fluorescent dye Alexa 488 in fixed cells.
Aiola, S.
2016-10-21
We measured the properties of a novel combination of two Gas Electron Multipliers with a Micromegas for use as amplification devices in high-rate gaseous time projection chambers. The goal of this design is to minimize the buildup of space charge in the drift volume of such detectors in order to eliminate the standard gating grid and its resultant dead time, while preserving good tracking and particle identification performance. We measured the positive ion back-flow and energy resolution at various element gains and electric fields, using a variety of gases, and additionally studied crosstalk effects and discharge rates. At a gain of 2000, this configuration achieves an ion back-flow below 0.4% and an energy resolution better than $\\sigma/\\text{E}=12\\%$ for $^{55}$Fe X-rays.
Chernyshova, M.; Malinowski, K.; Czarski, T.; Wojeński, A.; Vezinet, D.; Poźniak, K. T.; Kasprowicz, G.; Mazon, D.; Jardin, A.; Herrmann, A.; Kowalska-Strzeciwilk, E.; Krawczyk, R.; Kolasiński, P.; Zabołotny, W.; Zienkiewicz, P.
2016-11-01
A Gaseous Electron Multiplier (GEM)-based detector is being developed for soft X-ray diagnostics on tokamaks. Its main goal is to facilitate transport studies of impurities like tungsten. Such studies are very relevant to ITER, where the excessive accumulation of impurities in the plasma core should be avoided. This contribution provides details of the preliminary tests at ASDEX Upgrade (AUG) with a focus on the most important aspects for detector operation in harsh radiation environment. It was shown that both spatially and spectrally resolved data could be collected, in a reasonable agreement with other AUG diagnostics. Contributions to the GEM signal include also hard X-rays, gammas, and neutrons. First simulations of the effect of high-energy photons have helped understanding these contributions.
Chernyshova, M., E-mail: maryna.chernyshova@ipplm.pl; Malinowski, K.; Czarski, T.; Kowalska-Strzęciwilk, E. [Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw (Poland); Wojeński, A.; Poźniak, K. T.; Kasprowicz, G.; Krawczyk, R.; Kolasiński, P.; Zabołotny, W.; Zienkiewicz, P. [Institute of Electronic Systems, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw (Poland); Vezinet, D.; Herrmann, A. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Mazon, D.; Jardin, A. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)
2016-11-15
A Gaseous Electron Multiplier (GEM)-based detector is being developed for soft X-ray diagnostics on tokamaks. Its main goal is to facilitate transport studies of impurities like tungsten. Such studies are very relevant to ITER, where the excessive accumulation of impurities in the plasma core should be avoided. This contribution provides details of the preliminary tests at ASDEX Upgrade (AUG) with a focus on the most important aspects for detector operation in harsh radiation environment. It was shown that both spatially and spectrally resolved data could be collected, in a reasonable agreement with other AUG diagnostics. Contributions to the GEM signal include also hard X-rays, gammas, and neutrons. First simulations of the effect of high-energy photons have helped understanding these contributions.
Aiola, S.; Ehlers, R. J.; Gu, S.; Harris, J. W.; Majka, R.; Mulligan, J. D.; Oliver, M.; Schambach, J.; Smirnov, N.
2016-10-01
We measured the properties of a novel combination of two Gas Electron Multipliers with a Micromegas for use as amplification devices in high-rate gaseous time projection chambers. The goal of this design is to minimize the buildup of space charge in the drift volume of such detectors in order to eliminate the standard gating grid and its resultant dead time, while preserving good tracking and particle identification performance. To characterize this micro-pattern gas detector configuration, we measured the positive ion back-flow and energy resolution at various element gains and electric fields, using a variety of gases, and additionally studied crosstalk effects and discharge rates. At a gain of 2000, this configuration achieves an ion back-flow below 0.4% and an energy resolution better than σ / E = 12 % for 55Fe X-rays.
Study of spatial resolution of coordinate detectors based on Gas Electron Multipliers
Kudryavtsev, V. N.; Maltsev, T. V.; Shekhtman, L. I.
2017-02-01
Spatial resolution of GEM-based tracking detectors is determined in the simulation and measured in the experiments. The simulation includes GEANT4 implemented transport of high energy electrons with careful accounting of atomic relaxation processes including emission of fluorescent photons and Auger electrons and custom post-processing with accounting of diffusion, gas amplification fluctuations, distribution of signals on readout electrodes, electronics noise and particular algorithm of final coordinate calculation (center of gravity). The simulation demonstrates that the minimum of spatial resolution of about 10 μm can be achieved with a gas mixture of Ar -CO2 (75-25 %) at a strips pitch from 250 μm to 300 μm. At a larger pitch the resolution quickly degrades reaching 80-100 μm at a pitch of 460-500 μm. Spatial resolution of low-material triple-GEM detectors for the DEUTERON facility at the VEPP-3 storage ring is measured at the extracted beam facility of the VEPP-4 M collider. One-coordinate resolution of the DEUTERON detector is measured with electron beam of 500 MeV, 1 GeV and 3.5 GeV energies. The determined value of spatial resolution varies in the range from approximately 35 μm to 50 μm for orthogonal tracks in the experiments.
Anvari, Akbar; Aghamiri, Seyed Mahmoud Reza; Mahdavi, Seyed Rabie; Alaei, Parham
2015-01-01
Dosimetric properties of a CCD camera-based Electronic Portal Imaging Device (EPID) for clinical dosimetric application have been evaluated. Characteristics obtained by EPID also compared with commercial 2D array of ion chambers. Portal images acquired in dosimetry mode then exported raw fluence or uncorrected images were investigated. Integration time of image acquisition mode has adjusted on 1 s per frame. As saturation of camera of the EPID, dose response does not have linear behavior. The slight nonlinearity of the camera response can be corrected by a logarithmic expression. A fourth order polynomial regression model with coefficient of determination of 0.998 predicts a response to absolute dose values at less than 50 cGy. A field size dependent response of up to 7% (0.99-1.06) relative OCTAVIUS detector measurement was found. The EPID response can be fitted by a cubic regression for field size changes, yielded coefficient of determination of 0.999. These results indicate that the EPID is well suited for accurate dosimetric purposes, the major limitation currently being due to integration time and dead-time in frame acquisition.
McMullen, Timothy; Liyanage, Nilanga; Xiong, Weizhi; Zhao, Zhiwen
2017-01-01
Our research has focused on simulating the response of a Gas Electron Multiplier (GEM) detector using computational methods. GEM detectors provide a cost effective solution for radiation detection in high rate environments. A detailed simulation of GEM detector response to radiation is essential for the successful adaption of these detectors to different applications. Using Geant4 Monte Carlo (GEMC), a wrapper around Geant4 which has been successfully used to simulate the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab, we are developing a simulation of a GEM chamber similar to the detectors currently used in our lab. We are also refining an object-oriented digitization program, which translates energy deposition information from GEMC into electronic readout which resembles the readout from our physical detectors. We have run the simulation with beta particles produced by the simulated decay of a 90Sr source, as well as with a simulated bremsstrahlung spectrum. Comparing the simulation data with real GEM data taken under similar conditions is used to refine the simulation parameters. Comparisons between results from the simulations and results from detector tests will be presented.
Richter, S.; Alonso, A.; Aregbe, Y.; Eykens, R.; Kehoe, F.; Kühn, He; Kivel, N.; Verbruggen, A.; Wellum, R.; Taylor, P. D. P.
2009-04-01
A new series of gravimetrically prepared uranium isotope reference materials, the so-called IRMM-074 series, with the n(235U)/n(238U) isotope ratio held constant at unity and the n(233U)/n(238U) isotope ratios varying from 1.0 to 10-6 has been prepared and certified. This series is suited for calibration of secondary electron multipliers used widely in isotope mass spectrometry, in particular for techniques such as thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (ICPMS), accelerator mass spectrometry (AMS) and resonance ionization mass spectrometry (RIMS). The new IRMM-074 was prepared as a replacement for the already exhausted IRMM-072 predecessor series. Uranium materials with high isotopic enrichments of 233U, 235U and 238U were purified using identical methods involving separation on anion and cation column followed by a precipitation as peroxide. The oxides were calcined to convert them to U3O8 simultaneously, in an oven installed in a glove-box that provided a controlled low-humidity environment. The oxides of 235U and 238U were weighed and mixed with a mole ratio n(235U)/n(238U) = 1.0 and then dissolved. The 233U oxide was dissolved to form a separate solution with the same concentration and 6rom this primary solution three dilutions were made by weighing. A weighed amount of the n(235U)/n(238U) solution and weighed amounts of the 233U solutions were mixed in various proportions in order to achieve n(233U)/n(238U) isotope ratios varying from 1.0 to 10-6. The methods for the preparation, the mixing and the mixing calculations are described. The expanded uncertainties (coverage factor k = 2) of the certified isotope ratios for the IRMM-074 series are 0.015% for the n(235U)/n(238U) ratio and 0.025% for the n(233U)/n(238U) ratios, which constitutes an improvement compared to those of the predecessor IRMM-072 series. In addition, recent observations regarding the linearity response of secondary electron multipliers (SEMs
Zander, Anette
2001-01-01
Micro strip gas chambers (MSGCs) are promising candidates for large scale applications. They combine a good spatial resolution with high granularity and low cost. As a possible extension of the plain MSGC, a Gas Electron Multiplier (GEM) foil may be implemented into the detector in order to increase the safety of operation. It was planned to equip the outer part of the tracking system of the Compact Muon Solenoid (CMS) experiment at the future Large Hadron Collider (LHC) at the Centre de Recherche Nucleaire (CERN) with MSGCs. In the barrel part of the tracker, plain MSGCs were to be used. For the forward part, the MSGC+GEM technology was envisaged. This thesis describes the assembly and test of a pre-series of 18 fully functional MSGC+GEM forward detector modules to determine their radiation hardness and their readiness for mass production. Five of the modules were built at Aachen, thirteen more at the 'Institut für Experimentelle Kernphysik' in Karlsruhe. For the pre-series, two different types of GEM foils...
Gola, Mohit
2017-01-01
As the CERN LHC is heading towards a high luminosity phase a very high flux is expected in the endcaps of the CMS Detector. The presence of muons in collision events can be due to rare or new physics so it is important to maintain the high trigger efficiency of the CMS muon system. The CMS Collaboration has proposed to instrument the high-eta region (1.6 lt IetaI lt 2.2) of the muon endcaps with Gas Electron Multiplier (GEM) detectors, referred to as GE1/1 chambers, during the LS2. This technology will help in maintaining optimum trigger performance with maximum selection efficiency of muons even in a high flux environment. We describe plans for a Slice Test to installa few GE1/1 chambers covering 50 degrees in azimuthal angle within the CMS detector in 2017, with subsequent operation during the current Run 2 of the LHC. We show the performance of the GE1/1 chambers to be installed during the slice test, specifically GEM foil leakage currents, chamber gas volume integrity, high voltage circuit performanc...
Preliminary results of the Gas Electron Multiplier (GEM) as real-time beam monitor in hadron therapy
Aza, E.; Ciocca, M.; Murtas, F.; Puddu, S.; Pullia, M.; Silari, M.
2017-01-01
The use of proton and carbon ion beams in cancer therapy (also known as hadron therapy) is progressively growing worldwide due to their improved dose distributions, sparing of healthy tissues and (for carbon ions) increased radiobiological effectiveness especially for radio-resistant tumours. Strict Quality Assurance (QA) protocols need to be followed for guaranteeing the clinical beam specifications. The aim of this study was to assess the performance of a gaseous detector based on the Gas Electron Multiplier (GEM) technology for measuring the beam spot dimensions and the homogeneity of the scanned irradiation field, which are daily QA tasks commonly performed using radiochromic films. Measurements performed at the National Centre for Oncological Hadron Therapy (CNAO) in Pavia (Italy) showed that the detector is able to monitor the 2D beam image on-line with a pad granularity of 2 mm and a response proportional to the number of delivered particles. The dose homogeneity was measured with low deviation from the results obtained with radiochromic films.
Dickson, Shannon; Gausa, Michael; Robertson, Scott; Sternovsky, Zoltan
2013-04-01
We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 80 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on two sounding rockets to the mesosphere. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void behind (relative to the direction of motion) an aft-facing surface. An enclosure containing the CEM was placed forward of an aft-facing deck and a valve was opened during flight to expose the CEM to the aerodynamically evacuated region behind it. The CEM operated successfully from apogee down to ∼80 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.
Dickson, S.; Gausa, M. A.; Robertson, S. H.; Sternovsky, Z.
2012-12-01
We demonstrate that a channel electron multiplier (CEM) can be operated on a sounding rocket in the pulse-counting mode from 120 km to 75 km altitude without the cryogenic evacuation used in the past. Evacuation of the CEM is provided only by aerodynamic flow around the rocket. This demonstration is motivated by the need for additional flights of mass spectrometers to clarify the fate of metallic compounds and ions ablated from micrometeorites and their possible role in the nucleation of noctilucent clouds. The CEMs were flown as guest instruments on the two sounding rockets of the CHAMPS (CHarge And mass of Meteoritic smoke ParticleS) rocket campaign which were launched into the mesosphere in October 2011 from Andøya Rocket Range, Norway. Modeling of the aerodynamic flow around the payload with Direct Simulation Monte-Carlo (DSMC) code showed that the pressure is reduced below ambient in the void beneath an aft-facing surface. An enclosure containing the CEM was placed above an aft-facing deck and a valve was opened on the downleg to expose the CEM to the aerodynamically evacuated region below. The CEM operated successfully from apogee down to ~75 km. A Pirani gauge confirmed pressures reduced to as low as 20% of ambient with the extent of reduction dependent upon altitude and velocity. Additional DSMC simulations indicate that there are alternate payload designs with improved aerodynamic pumping for forward mounted instruments such as mass spectrometers.
Zhao, Qiaole; Schelen, Ben; Schouten, Raymond; van den Oever, Rein; Leenen, René; van Kuijk, Harry; Peters, Inge; Polderdijk, Frank; Bosiers, Jan; Raspe, Marcel; Jalink, Kees; Geert Sander de Jong, Jan; van Geest, Bert; Stoop, Karel; Young, Ian Ted
2012-12-01
We have built an all-solid-state camera that is directly modulated at the pixel level for frequency-domain fluorescence lifetime imaging microscopy (FLIM) measurements. This novel camera eliminates the need for an image intensifier through the use of an application-specific charge coupled device design in a frequency-domain FLIM system. The first stage of evaluation for the camera has been carried out. Camera characteristics such as noise distribution, dark current influence, camera gain, sampling density, sensitivity, linearity of photometric response, and optical transfer function have been studied through experiments. We are able to do lifetime measurement using our modulated, electron-multiplied fluorescence lifetime imaging microscope (MEM-FLIM) camera for various objects, e.g., fluorescein solution, fixed green fluorescent protein (GFP) cells, and GFP-actin stained live cells. A detailed comparison of a conventional microchannel plate (MCP)-based FLIM system and the MEM-FLIM system is presented. The MEM-FLIM camera shows higher resolution and a better image quality. The MEM-FLIM camera provides a new opportunity for performing frequency-domain FLIM.
Sharma, Ram Krishna
2017-01-01
The High Luminosity LHC (HL-LHC) will provide exceptional high instantaneous and integrated luminosity. The forward region $\\mid \\eta \\mid \\geq 1.5$ of the CMS detector will face extremely high particle rates in tens of $KHz/cm^{2}$ and hence it will affect the momentum resolution and longevity of the muon detectors. To overcome these issues the CMS collaboration has decided to install new large size rate capable Triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The first set of Triple GEM detectors will be installed in the GE1/1 region $(1.5 \\leq \\eta \\leq 2.2)$ of muon endcap during the LS2 of the LHC and the next one will be installed in the GE2/1 region $(1.6 \\leq \\eta \\leq 2.5)$, during the LS3. Towards this goal, full-size CMS Triple GEM prototype chambers have been fabricated and put under the test beam at the CERN SPS test beam facility. The GEM detectors were operated with two gas mixtures $Ar/CO_{2}$ (70/30) and $Ar/CO_{2}/CF_{4}$ (40/15/45). In 2014 and 2016, ...
Commercial and Cost Effective Production of Gas Electron Multiplier (GEM) Foils
Woody, Craig
2009-03-31
The nuclear and high energy physics research community is constantly searching for new and improved tracking and radiation detectors. The introduction of micropattern detectors has opened new opportunities for improving the rate capabilities, as well as the spatial and time resolution of particle detectors in these applications. GEM detectors in particular have received enormous interest for use in detectors planned for a number of new and upgraded experiments at many different research facilities. These include both the STAR and PHENIX experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, experiments at the Thomas Jefferson National Laboratory, Oak Ridge National Laboratory, and at the future electron-positron Linear Collider. At the present time, CERN is not able to supply foils in sufficient quantities to accommodate the needs of these experiments. Compounding this problem, there is a strong interest in GEM foils for numerous other applications, such as in astrophysics, medical imaging and detectors for homeland security. It would therefore be of significant benefit to the research community to develop a commercial source of GEM foils for all of these applications. Tech-Etch is in a unique position to develop this technology for commercial use. Tech-Etch has not only experience in numerous related high precision etched Kapton® products, but it also has strong ties with several research institutions (namely Brookhaven, Yale and MIT) that can help develop and evaluate the performance of the GEM foils produced at Tech-Etch. Additionally, since Tech-Etch is a small company, it also has the capability to produce a large variety of part configurations, as well as the flexibility to shift production methods, equipment, and chemistry to optimize the GEM foil manufacturing process without being constrained by existing work running on high volume continuous coil equipment.
电荷耦合器件在电子束参数测量中的损伤问题%Damage problem of CCD in the electron beam parameters measure
王远; 江孝国; 李成刚; 禹海军; 张开志
2012-01-01
针对直线感应电子加速器(LIA)实验束参数测量技术应用过程中,电荷耦合器件(CCD)在纳秒激光辐照下工作的损伤效应方面进行研究.在分析 CCD 感光成像原理及其高能粒子测量应用的基础上,通过监测这种辐射下 CCD 输出信号的变化和实验后 CCD 的成像,对 CCD 中发生的软、硬损伤进行探讨,得到 CCD 能量损伤阈值的光子的响应特性和辐射损伤评估,保证了加速器束参数测量的可靠性.%There are strong electromagnetism interruption in the process of high power electron beam parameters measure and diagnosis. The Charge Coupled Devioes(CCD) is irradiated by strong electron pulse, laser and X-ray. According to the analysis on the CCD imaging principle and the measure on high energy particles, the changes of the CCD output signals under the radiation environment are monitored as well as the CCD imaging after the experiment. The soft-damage and hard-damage of CCD are discussed. It is found that the damage occurs at the grid electrode of the device instead of at the light activated elements. The response characteristics of beam whose energy reaches the damage threshold are obtained. The evaluation on radiation damage is given, which ensures the reliability of beam parameters measure of accelerator.
Empirical Study on the Impact of Electronic Money on Money Multiplier%电子货币对货币乘数影响的实证研究
郭艳艳
2015-01-01
分析了准备金率、现金存款比率及电子货币替代率对货币乘数的影响,结果表明电子货币的使用对货币乘数具有双重的影响,一是提高存款准备金率而降低货币乘数;二是降低现金漏损率而提高货币乘数,而使货币乘数下降的作用更强. 同时,电子货币对货币乘数的影响在2006年以后发生了波动,特别是近几年收缩现象比较明显.%It studied the impact of reserve ratio ,cash-deposit ratio and electronic money usage on money multiplier .The effect of increasing is stronger for reducing the money multiplier by increasing reserve rati-o,and increasing the money multiplier by reducing cash-deposit ratio .It also showed the impact of money multiplier is not always expansion , and it has appeared fluctuation since 2006, especially it appeared shrinkage in recent years .
Kuhls, Andrew T.; Yadava, Girijesh; Patel, Vikas; Bednarek, Daniel R.; Rudin, Stephen
2007-03-01
A new high-resolution, high-sensitivity, low-noise x-ray detector based on EMCCDs has been developed. The EMCCD detector module consists of a 1kx1k, 8μm pixel EMCCD camera coupled to a CsI(Tl) scintillating phosphor via a fiber optic taper (FOT). Multiple modules can be used to provide the desired field-of-view (FOV). The detector is capable of acquisitions over 30fps. The EMCCD's variable gain of up to 2000x for the pixel signal enables high sensitivity for fluoroscopic applications. With a 3:1 FOT, the detector can operate with a 144μm effective pixel size, comparable to current flat-panel detectors. Higher resolutions of 96 and 48μm pixel size can also be achieved with various binning modes. The detector MTFs and DQEs were calculated using a linear-systems analysis. The zero frequency DQE was calculated to be 59% at 74 kVp. The DQE for the 144μm pixel size was shown to exhibit quantum-noise limited behavior down to ~0.1μR using a conservative 30x gain. At this low exposure, gains above 30x showed limited improvements in DQE suggesting such increased gains may not be necessary. For operation down to 48Âµm pixel sizes, the detector instrumentation noise equivalent exposure (INEE), defined as the exposure where the instrumentation noise equals the quantum-noise, was flat-panel detectors for applications such as fluoroscopy and angiography requiring high frame rates, resolution, dynamic range and sensitivity while maintaining essentially no lag and very low INEE. Initial images from a prototype detector are also presented.
2013-01-01
A few weeks ago, I had a vague notion of what TED was, and how it worked, but now I’m a confirmed fan. It was my privilege to host CERN’s first TEDx event last Friday, and I can honestly say that I can’t remember a time when I was exposed to so much brilliance in such a short time. TEDxCERN was designed to give a platform to science. That’s why we called it Multiplying Dimensions – a nod towards the work we do here, while pointing to the broader importance of science in society. We had talks ranging from the most subtle pondering on the nature of consciousness to an eighteen year old researcher urging us to be patient, and to learn from our mistakes. We had musical interludes that included encounters between the choirs of local schools and will.i.am, between an Israeli pianist and an Iranian percussionist, and between Grand Opera and high humour. And although I opened the event by announcing it as a day off from physics, we had a quite brill...
LIUJikun; ZHAOBaoyun
1997-01-01
Work has been done with extending the useful imaging and detection rage of CCD.This was accomplished through direct optical coupling and bonding of image intensifiers to the CCD.It has been shown that the useful range of a CCD may be extended two orders of magnitude using these techniques in coupling a microchannel plate image intensifier to the CCD array.All of these works were done with presently available CCD made by China
周蓓蓓; 陈钱; 何伟基
2011-01-01
In order to study the characteristics of the charge multiplication and charge transfer in the charge carrier multiplier (CCM) of the electron multiplying charge-coupled device (EMCCD), a distributed equivalent circuit model was proposed for the charge delivery in CCM.The potential distribution in the CCM element of uniform doping was carried out by solving the Possion equation.The maximum potential expression in the CCM element was obtained by the Kirchhoff’s voltage law (KVL), and the distributed equivalent circuit of the CCM element was shown.Combined with the potential distribution in the CCM element, the distributed equivalent circuit model of the CCM was also gained.The analysis of this model shows that if the interelectrode gap length in the CCM elements decreases, the rate of the charge multiplication increases.The charge delivery mainly depends on the self-induced field and the thermal diffusion field.Most of the stored charges transfer to the next CCM element in the beginning of the clock cycle due to the electron mobility generated by the self-induced field.%为了研究电子倍增电荷耦合器件(EMCCD)中电荷载流子倍增寄存器(CCM)内部电荷的倍增及转移特性,提出了一种适用于CCM的电荷传输机制仿真的分布式等效电路模型.利用泊松方程求解了均匀掺杂条件下CCM单元的电势分布,通过基尔霍夫电压定律(KVL)得到了该单元的最大电势表达式,从而得到了其分布式等效电路.同时,结合该单元内的电势分布求解,最终得到了分布式等效电路模型.通过对该模型的分析表明:CCM单元内电极间的间隙越小,电荷倍增率越大.CCM电荷传输主要受到自感生电场和热扩散电场作用,由于自感生电场的电荷迁移率作用,大部分电荷在时钟周期的初始阶段完成转移.
Analysis of Gilbert Multiplier Using Pspice
Mayank Kumar,
2014-05-01
Full Text Available In this paper, the implementation of gilbert multiplier has been done using pspice. In this paper the three analysis of Gilbert Multiplier have been done i.e. DC Analysis, AC Analysis and TRANSIENT analysis with the help of SPICE software. So Spice is a general purpose circuit program that simulates electronic circuits and can perform various analysis of electronic circuits. So with the help of pspice, the analysis of gilbert multiplier has been proposed in this paper.
Cortesi, M; Mittig, W; Limonge, Y Ayyad; Bazin, D; Yurkon, J; Stolz, A
2016-01-01
The operating principle and performances of the Multi-layer Thick Gaseous Electron Multiplier (M-THGEM) is presented. The M-THGEM is a novel hole-type gaseous electron multiplier produced by multi-layer printed circuit board technology; it consists of a densely perforated assembly of multiple insulating substrate sheets (e.g., FR-4), sandwiched between thin metallic-electrode layers. The electron avalanche processes occur along the successive multiplication stages within the M-THGEM holes, under the action of strong dipole fields resulting from the application of suitable potential differences between the electrodes. The present work focuses on investigation of two different geometries: a two-layer M-THGEM (either as single or double-cascade detector) and a single three-layer M-THGEM element, tested in various low-pressure He-based gas mixtures. The intrinsically robust confinement of the avalanche volume within the M-THGEM holes provides an efficient suppression of the photon-induced secondary effects, resul...
CCD research. [design, fabrication, and applications
Gassaway, J. D.
1976-01-01
The fundamental problems encountered in designing, fabricating, and applying CCD's are reviewed. Investigations are described and results and conclusions are given for the following: (1) the development of design analyses employing computer aided techniques and their application to the design of a grapped structure; (2) the role of CCD's in applications to electronic functions, in particular, signal processing; (3) extending the CCD to silicon films on sapphire (SOS); and (4) all aluminum transfer structure with low noise input-output circuits. Related work on CCD imaging devices is summarized.
Pipelined Vedic-Array Multiplier Architecture
Vaijyanath Kunchigik
2014-05-01
Full Text Available In this paper, pipelined Vedic-Array multiplier architecture is proposed. The most significant aspect of the proposed multiplier architecture method is that, the developed multiplier architecture is designed based on the Vedic and Array methods of multiplier architecture. The multiplier architecture is optimized in terms of multiplication and addition to achieve efficiency in terms of area, delay and power. This also gives chances for modular design where smaller block can be used to design the bigger one. So the design complexity gets reduced for inputs of larger number of bits and modularity gets increased. The proposed Vedic-Array multiplier is coded in Verilog, synthesized and simulated using EDA (Electronic Design Automation tool - XilinxISE12.3, Spartan 3E, Speed Grade-4. Finally the results are compared with array and booth multiplier architectures. Proposed multiplier is better in terms of delay and area as compared to booth multiplier and array multiplier respectively. The proposed multiplier architecture can be used for high-speed requirements.
An Empirical Analysis of the Impact of Electronic Money on Money Multiplier%电子货币对货币乘数影响的实证分析
都红雯; 徐斌
2016-01-01
以货币乘数理论为依据建立电子货币对货币乘数影响的分析框架,并运用2008-2014年的季度数据进行实证检验。研究结果表明,电子货币的发行会影响货币乘数,进而影响货币供应量；不同类别的电子货币对不同层次的货币乘数有不同的影响：卡基电子货币会放大货币乘数m1和m2,而网基电子货币会减小货币乘数m1、放大货币乘数m2。%Based on the theory of monetary multiplier, this article builds an analytical framework for the impact of elec-tronic money on monetary multiplier, and carries out the empirical test using the quarterly data from 2008 to 2014. The empirical studies indicate that the issue of electronic money will affect the money multiplier and money supply;different types of electronic money have different effects on different levels of monetary multiplier: card-based electronic money will enlarge the monetary multiplier m1, m2, network-based electronic money will reduce the monetary multiplier m1 while enlarge the monetary multiplier m2.
CCD digital radiography system
Wang, Yi; Kang, Xi; Li, Yuanjing; Cheng, Jianping; Hou, Yafei; Han, Haiwei
2009-07-01
Amorphous silicon flat-panel detector is the mainstream used in digital radiography (DR) system. In latest years, scintillation screen coupled with CCD DR is becoming more popular in hospital. Compared with traditional amorphous silicon DR, CCD-DR has better spatial resolution and has little radiation damage. It is inexpensive and can be operated easily. In this paper, A kind of CCD based DR system is developed. We describe the construction of the system, the system performances and experiment results.
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.
POSTHUMUS, JH; MORGENSTERN, R
1992-01-01
We have investigated multielectron capture processes in collisions of Ar9+ on Ar by measuring the resulting Auger electrons in coincidence with charge-state-analyzed target ions. In this way it was possible to reconstruct partial electron energy spectra, each corresponding to a particular number of
Janesick, James R.; Elliott, Tom
1987-01-01
New diagnostic tool used to understand performance and failures of microelectronic devices. Microscope integrated to low-noise charge-coupled-device (CCD) camera to produce new instrument for analyzing performance and failures of microelectronics devices that emit infrared light during operation. CCD camera also used to indentify very clearly parts that have failed where luminescence typically found.
电子货币对货币乘数的影响分析%Analysis on the Effection of Electronic Currency on Money Multiplier
周丹丹
2015-01-01
Electronic currency changed People’s Daily life and the mode of payment, brings the huge challenge for the conduct of monetary policy. In this article, through the method of empirical analysis, with the consumption amount in the bank card and the amount of transfer data on behalf of electronic currency, and money multiplier mod-el,found that electronic money using the money multiplier has certain effect to enlarge,increase the endogenous mon-ey supply,reduce the central bank to control money supply,increased the difficulty of the central bank's monetary pol-icy implementation. Electronic money has substitution effect to cash, cash in circulation to demand deposits, sped up the currency circulation speed at the same time,has important effects on money supply.%电子货币改变了人们的日常生活和支付方式，对货币政策的实施带来巨大的挑战。本文通过实证分析的方法，分别以银行卡中的消费金额和转账金额数据代表电子货币，建立与货币乘数的相关模型，研究发现电子货币与货币乘数之间存在着稳定的均衡关系，电子货币对货币乘数具有放大作用，增大了货币乘数的内生性。电子货币对现金有替代作用，促使流通中的现金向活期存款转化，同时加快了货币的流通速度，降低了央行对货币供给量的控制，增加了央行货币政策实施的难度。
Das, Madhulita; Pal, S
2016-01-01
We analyze atomic structures of plasma embedded aluminum (Al) atom and its ions in the weakly and strongly coupling regimes. The plasma screening effects in these atomic systems are accounted for using the Debye and ion sphere (IS) potentials for the weakly coupling and strongly coupling plasmas, respectively. Within the Debye model, special attention is given to investigate the spherical and non-spherical plasma-screening effects considering in the electron-electron interaction potential. The relativistic coupled-cluster (RCC) method has been employed to describe the relativistic and electronic correlation effects in the above atomic systems. The variation in the ionization potentials (IPs) and excitation energies (EEs) of the plasma embedded Al ions are presented. It is found that the atomic systems exhibit more stability when the exact screening effects are taken into account. It is also showed that in the presence of strongly coupled plasma environment, the highly ionized Al ions show blue and red shifts ...
Traditional and Truncation schemes for Different Multiplier
Yogesh M. Motey
2013-03-01
Full Text Available A rapid and proficient in power requirement multiplier is always vital in electronics industry like DSP, image processing and ALU in microprocessors. Multiplier is such an imperative block w ith respect to power consumption and area occupied in the system. In order to meet the demand for high speed, various parallel array multiplication algorithms have been proposed by a number of authors. The array multipliers use a large amount of hardware, consequently consuming a large amount of power. One of the methods for multiplication is based on Indian Vedic mathematics. The total Vedic mathematics is based on sixteen sutras (word formulae and manifests a merged structure of mathematics. The parallel multipliers for example radix 2 and radix 4 booth multiplier does the computations using less number of adders and less number of iterative steps that results in, they occupy less space to that of serial multiplier. Truncated multipliers offer noteworthy enhancements in area, delay, and power. Truncated multiplication provides different method for reducing the power dissipation and area of rounded parallel multipliers in DSP systems. Since in a truncated multiplier the x less significant bits of the full-width product are discarded thus partial products are removed and replaced by a suit- able compensation equations, match the accuracy with hardware cost. A pseudo-carry compensation truncation (PCT scheme, it is for the multiplexer based array multiplier, which yields less average error among existing truncation methods.After studying many research papers it’s found that some of the schemes for multiplier are suitable because their own uniqueness of multiplication. Such schemes are listed in this paper for example the different truncation schemes like constant-correction truncation (CCT, variable -correction truncation (VCT, pseudo-carry compensation truncation (PCT are most suitable for truncated multiplier.
Gruchala, Marek Michal
2016-01-01
The high luminosity LHC will require new detectors in the CMS endcap muon system to suppress the trigger rate of background events, to maintain high trigger efficiency for low transverse momentum muons, to enhance the robustness of muon detection in the high-flux environment of the endcap, and to extend the geometrical acceptance. We report on the design and recent progress towards implementing a new system of large-area, triple-foil gas electron-multiplier (GEM) detectors that will be installed in the first three of five muon detector stations in each endcap, the first station being closest to the interaction point. The first station will extend the geometric acceptance in pseudo-rapidity to eta lt 3.0 from the current limit of eta lt 2.4. The second and third stations will enhance the performance in the range 1.6 lt eta lt 2.4. We describe the design of the chambers and readout electronics and report on the performance of prototype systems in tests with cosmic ray muons, high-energy particlebeams, a...
Grebenshchikov, Sergy Yu.
2013-01-01
The global potential energy surfaces of the first six singlet electronic states of CO$_2$, 1---3$^1/!A'$ and 1---3$^1/!A"$ are constructed using high level ab initio calculations. In linear molecule, they correspond to $\\tilde{X}^1\\Sigma_g^+$, $1^1\\Delta_u$, $1^1\\Sigma_u^-$, and $1^1\\Pi_g$. The calculations accurately reproduce the known benchmarks for all states and establish missing benchmarks for future calculations. The calculated states strongly interact at avoided crossings and true int...
Grebenshchikov, Sergy Yu.
2013-06-01
The global potential energy surfaces of the first six singlet electronic states of CO2, 1—31A', and 1—31A″ are constructed using high level ab initio calculations. In linear molecule, they correspond to tilde{X}^1Σ _g^+, 11Δu, 1^1Σ _u^-, and 11Πg. The calculations accurately reproduce the known benchmarks for all states and establish missing benchmarks for future calculations. The calculated states strongly interact at avoided crossings and true intersections, both conical and glancing. Near degeneracies can be found for each pair of six states and many intersections involve more than two states. In particular, a fivefold intersection dominates the Franck-Condon zone for the ultraviolet excitation from the ground electronic state. The seam of this intersection traces out a closed loop. All states are diabatized, and a diabatic 5 × 5 potential matrix is constructed, which can be used in quantum mechanical calculations of the absorption spectrum of the five excited singlet valence states.
Grebenshchikov, Sergy Yu
2013-01-01
The global potential energy surfaces of the first six singlet electronic states of CO$_2$, 1---3$^1/!A'$ and 1---3$^1/!A"$ are constructed using high level ab initio calculations. In linear molecule, they correspond to $\\tilde{X}^1\\Sigma_g^+$, $1^1\\Delta_u$, $1^1\\Sigma_u^-$, and $1^1\\Pi_g$. The calculations accurately reproduce the known benchmarks for all states and establish missing benchmarks for future calculations. The calculated states strongly interact at avoided crossings and true intersections, both conical and glancing. Near degeneracies can be found for each pair of six states and many intersections involve more than two states. In particular, a fivefold intersection dominates the Franck-Condon zone for the ultraviolet excitation from the ground electronic state. The seam of this intersection traces out a closed loop. All states are diabatized, and a diabatic $5\\times 5$ potential matrix is constructed, which can be used in quantum mechanical calculations of the absorption spectrum of the five exci...
Advanced CCD camera developments
Condor, A. [Lawrence Livermore National Lab., CA (United States)
1994-11-15
Two charge coupled device (CCD) camera systems are introduced and discussed, describing briefly the hardware involved, and the data obtained in their various applications. The Advanced Development Group Defense Sciences Engineering Division has been actively designing, manufacturing, fielding state-of-the-art CCD camera systems for over a decade. These systems were originally developed for the nuclear test program to record data from underground nuclear tests. Today, new and interesting application for these systems have surfaced and development is continuing in the area of advanced CCD camera systems, with the new CCD camera that will allow experimenters to replace film for x-ray imaging at the JANUS, USP, and NOVA laser facilities.
Ruiz Alvarez, Jose David
2016-01-01
A new data acquisition and on-line control system is being developed for gas-electron multiplier (GEM) detectors which will be installed in the forward region (1.6 \\( < \\eta < \\) 2.2) of the CMS muon spectrometer during the 2nd long shutdown of the LHC, planned for the period 2018-2019. A prototype system employs the TOTEM VFAT2 ASIC that will eventually be replaced with the VFAT3 ASIC, under development. The front-end ASIC communicates over printed circuit lines with an intermediate on-detector board called the opto-hybrid. Data, trigger, and control information is transmitted via optical fiber between the opto-hybrid and an off-detector readout system using micro-TCA technology. On-line software, implemented in the CMS XDAQ framework, includes applications for latency and HV scans, and system management. We report on the operational status of the prototype system that has been tested using cosmic ray muons and extracted high-energy particle beams. This work is preparatory for the operation of a prot...
CMS Collaboration
2015-01-01
The CMS detector is one of two general-purpose detectors at the CERN LHC. LHC will provide exceptional high instantaneous and integrated luminosities after second long shutdown. The forward region $\\mid \\eta \\mid \\geq 1.5$ of the CMS detector will face extremely high particle rates in 10s of kHz/cm2 and hence it will affect the momentum resolution and longevity of the muon detectors. To overcome these issues, the CMS-GEM collaboration has proposed to install new large size high rate capable triple Gas Electron Multiplier (GEM) detectors in the forward region of CMS muon system. The proposal has been approved recently. The first set of Triple GEM detectors will be installed in the GE1/1 region ($1.6 < \\mid \\eta \\mid < 2.2$) of muon endcap during phase-II upgrade of the LHC. Towards this goal, full size CMS Triple GEM prototype chambers have been fabricated and put under the test beam at the CERN SPS test beam facility. The GEM detectors were operated with two gas mixtures: Ar:CO2 (70:30) and Ar:CO2:CF4 (...
马善乐; 杨兰兰; 屠彦; 陈仲珊; 张盼盼; 秦娜娜
2013-01-01
气体电子倍增器(GEM)是近年来发展起来的一种新型气体探测器.本文首先介绍了GEM的结构和模拟的原理,然后基于有限元的方法建立GEM三维模型,并计算电场分布,将所得的GEM结构模型导入GARFIELD软件,实现GEM透过率和增益的计算.并进一步改变GEM的各项参数,如结构、电场和所充气体气压、配比等研究对GEM透过率和增益的影响,分析了参数变化对GEM性能的影响,从而为GEM的参数优化提供理论指导.%The electric field distribution of the gas electron multiplied GEM) ,a newly-developed gas detector, was physically modeled and mathematically simulated in finite element method. The electron transparency and gain characteristics were simulated with the software package, GARFTELD, based on the 3-dimensioii GEM model. The impacts of the various factors involved, such as the GEM geometry, electric field distribution, pressure, and proportion of different gases, on the electron transparency and gain of the GEM were simulated. We suggest that the simulated results may be of much technological interest in optimizing the GEM design and its operating conditions. Further simulation of the multi-layered GEM and thick gas electron multiplier(THGEM)was also tentatively discussed.
刘甜; 杜军
2016-01-01
通过选取我国1990—2015年的电子货币相关样本数据，以现金漏损率和电子货币替代率作为解释变量，狭义货币乘数和广义货币乘数为被解释变量，建立计量经济模型，对电子货币与货币乘数的相关性进行计量分析和研究。从而得出以下结论：电子货币的发展对货币乘数不再是单纯的放大效应。一方面通过降低现金漏损率提高货币乘数，另一方面通过提高存款准备金率降低货币乘数，且后者的作用效果更加明显。因此，电子货币的应用使得我国货币乘数的内生性和不稳定性大大增加，货币政策的有效性遭到削弱。%By choosing the electronic currency related sample data in 1990⁃2015 and electronic money in cash leakage ratio replacement rate as variables the econometric model is established and their correlation of electronic money and monetary multiplier statistical tests. The development of electronic currency on monetary multiplier is no longer a simple amplification effect. On the one hand by reducing the cash leakage rate to raise money multiplier on the other hand by raising the deposit reserve ratio to reduce the money multiplier but make the monetary multiplier effect even stronger. The use of electronic money to enhance endogenous and instability of monetary multiplier in our country reducing the effectiveness of monetary policy.
Pierce, Paul E.
1986-01-01
A hardware processor is disclosed which in the described embodiment is a memory mapped multiplier processor that can operate in parallel with a 16 bit microcomputer. The multiplier processor decodes the address bus to receive specific instructions so that in one access it can write and automatically perform single or double precision multiplication involving a number written to it with or without addition or subtraction with a previously stored number. It can also, on a single read command automatically round and scale a previously stored number. The multiplier processor includes two concatenated 16 bit multiplier registers, two 16 bit concatenated 16 bit multipliers, and four 16 bit product registers connected to an internal 16 bit data bus. A high level address decoder determines when the multiplier processor is being addressed and first and second low level address decoders generate control signals. In addition, certain low order address lines are used to carry uncoded control signals. First and second control circuits coupled to the decoders generate further control signals and generate a plurality of clocking pulse trains in response to the decoded and address control signals.
Active Pixel Sensors: Are CCD's Dinosaurs?
Fossum, Eric R.
1993-01-01
Charge-coupled devices (CCD's) are presently the technology of choice for most imaging applications. In the 23 years since their invention in 1970, they have evolved to a sophisticated level of performance. However, as with all technologies, we can be certain that they will be supplanted someday. In this paper, the Active Pixel Sensor (APS) technology is explored as a possible successor to the CCD. An active pixel is defined as a detector array technology that has at least one active transistor within the pixel unit cell. The APS eliminates the need for nearly perfect charge transfer -- the Achilles' heel of CCDs. This perfect charge transfer makes CCD's radiation 'soft,' difficult to use under low light conditions, difficult to manufacture in large array sizes, difficult to integrate with on-chip electronics, difficult to use at low temperatures, difficult to use at high frame rates, and difficult to manufacture in non-silicon materials that extend wavelength response.
Buckley, T. N.
2008-12-01
The application of optimisation theory to vegetation processes has rarely extended beyond the context of diurnal to intra-annual gas exchange of individual leaves and crowns. One reason is that the Lagrange multipliers in the leaf-scale solutions, which are marginal products for allocatable photosynthetic resource inputs (water and nitrogen), are mysterious in origin, and their numerical values are difficult to measure -- let alone to predict or interpret in concrete physiological or ecological terms. These difficulties disappear, however, when the optimisation paradigm itself is extended to encompass carbon allocation and growth at the lifespan scale. The trajectories of leaf (and canopy) level marginal products are then implicit in the trajectory of plant and stand structure predicted by optimal carbon allocation. Furthermore, because the input and product are the same resource -- carbon -- in the whole plant optimisation, the product in one time step defines the input constraint, and hence implicitly the marginal product for carbon, in the next time step. This effectively converts the problem from a constrained optimisation of a definite integral, in which the multipliers are undetermined, to an unconstrained maximisation of a state, in which the multipliers are all implicit. This talk will explore how the marginal products for photosynthetic inputs as well as the marginal product for carbon -- i.e., the 'final multiplier,' omega -- are predicted to vary over time and in relation to environmental change during tree growth.
Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range
Soman, M.R., E-mail: m.r.soman@open.ac.uk [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Hall, D.J.; Tutt, J.H.; Murray, N.J.; Holland, A.D. [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Schmitt, T.; Raabe, J.; Schmitt, B. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)
2013-12-11
The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 µm from the current 24 µm spatial resolution (FWHM). The 400 eV–1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 µm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these
Developing a CCD camera with high spatial resolution for RIXS in the soft X-ray range
Soman, M. R.; Hall, D. J.; Tutt, J. H.; Murray, N. J.; Holland, A. D.; Schmitt, T.; Raabe, J.; Schmitt, B.
2013-12-01
The Super Advanced X-ray Emission Spectrometer (SAXES) at the Swiss Light Source contains a high resolution Charge-Coupled Device (CCD) camera used for Resonant Inelastic X-ray Scattering (RIXS). Using the current CCD-based camera system, the energy-dispersive spectrometer has an energy resolution (E/ΔE) of approximately 12,000 at 930 eV. A recent study predicted that through an upgrade to the grating and camera system, the energy resolution could be improved by a factor of 2. In order to achieve this goal in the spectral domain, the spatial resolution of the CCD must be improved to better than 5 μm from the current 24 μm spatial resolution (FWHM). The 400 eV-1600 eV energy X-rays detected by this spectrometer primarily interact within the field free region of the CCD, producing electron clouds which will diffuse isotropically until they reach the depleted region and buried channel. This diffusion of the charge leads to events which are split across several pixels. Through the analysis of the charge distribution across the pixels, various centroiding techniques can be used to pinpoint the spatial location of the X-ray interaction to the sub-pixel level, greatly improving the spatial resolution achieved. Using the PolLux soft X-ray microspectroscopy endstation at the Swiss Light Source, a beam of X-rays of energies from 200 eV to 1400 eV can be focused down to a spot size of approximately 20 nm. Scanning this spot across the 16 μm square pixels allows the sub-pixel response to be investigated. Previous work has demonstrated the potential improvement in spatial resolution achievable by centroiding events in a standard CCD. An Electron-Multiplying CCD (EM-CCD) has been used to improve the signal to effective readout noise ratio achieved resulting in a worst-case spatial resolution measurement of 4.5±0.2 μm and 3.9±0.1 μm at 530 eV and 680 eV respectively. A method is described that allows the contribution of the X-ray spot size to be deconvolved from these
Microwave Frequency Multiplier
Velazco, J. E.
2017-02-01
High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing
Nelson, Jane Bray
2012-01-01
As a new physics teacher, I was explaining how to find the weight of an object sitting on a table near the surface of the Earth. It bothered me when a student asked, "The object is not accelerating so why do you multiply the mass of the object by the acceleration due to gravity?" I answered something like, "That's true, but if the table were not…
Nelson, Jane Bray
2012-01-01
As a new physics teacher, I was explaining how to find the weight of an object sitting on a table near the surface of the Earth. It bothered me when a student asked, "The object is not accelerating so why do you multiply the mass of the object by the acceleration due to gravity?" I answered something like, "That's true, but if the table were not…
A Comparative Performance Analysis of Low Power Bypassing Array Multipliers
Nirlakalla Ravi
2013-07-01
Full Text Available Low power design of VLSI circuits has been identified as vital technology in battery powered portable electronic devices and signal processing applications such as Digital Signal Processors (DSP. Multiplier has an important role in the DSPs. Without degrading the performance of the processor, low power parallel multipliers are needed to be design. Bypassing is the widely used technique in the DSPs when the input operand of the multiplier is zero. A Row based Bypassing Multiplier with compressor at the final addition of the ripple carry adder (RCA is designed to focus on low power and high speed. The proposed bypassing multiplier with compressor shows high performance and energy efficiency than Kuo multiplier with Carry Save Adder (CSA at the final RCA.
Radiation events in astronomical CCD images
Smith, A. R.; McDonald, R. J.; Hurley, D. L.; Holland, S. E.; Groom, D. E.; Brown, W E; Gilmore, D. K.; Stover, R.J.; Wei, M.
2001-01-01
The remarkable sensitivity of depleted silicon to ionizing radiation is a nuisance to astronomers. "Cosmic rays" degrade images because of struck pixels, leading to modified observing strategies and the development of algorithms to remove the unwanted artifacts. In the new-generation CCD's with thick sensitive regions, cosmic-ray muons make recognizable straight tracks and there is enhanced sensitivity to ambient gamma radiation via Compton-scattered electrons ("worms"). Beta emitters i...
Casas, Ricard; Cardiel-Sas, Laia; Castander, Francisco J.; Jiménez, Jorge; de Vicente, Juan
2014-08-01
The focal plane of the PAU camera is composed of eighteen 2K x 4K CCDs. These devices, plus four spares, were provided by the Japanese company Hamamatsu Photonics K.K. with type no. S10892-04(X). These detectors are 200 μm thick fully depleted and back illuminated with an n-type silicon base. They have been built with a specific coating to be sensitive in the range from 300 to 1,100 nm. Their square pixel size is 15 μm. The read-out system consists of a Monsoon controller (NOAO) and the panVIEW software package. The deafualt CCD read-out speed is 133 kpixel/s. This is the value used in the calibration process. Before installing these devices in the camera focal plane, they were characterized using the facilities of the ICE (CSIC- IEEC) and IFAE in the UAB Campus in Bellaterra (Barcelona, Catalonia, Spain). The basic tests performed for all CCDs were to obtain the photon transfer curve (PTC), the charge transfer efficiency (CTE) using X-rays and the EPER method, linearity, read-out noise, dark current, persistence, cosmetics and quantum efficiency. The X-rays images were also used for the analysis of the charge diffusion for different substrate voltages (VSUB). Regarding the cosmetics, and in addition to white and dark pixels, some patterns were also found. The first one, which appears in all devices, is the presence of half circles in the external edges. The origin of this pattern can be related to the assembly process. A second one appears in the dark images, and shows bright arcs connecting corners along the vertical axis of the CCD. This feature appears in all CCDs exactly in the same position so our guess is that the pattern is due to electrical fields. Finally, and just in two devices, there is a spot with wavelength dependence whose origin could be the result of a defectous coating process.
Experiments on the use of CCD's to detect photoelectron images
Choisser, J. P.
1975-01-01
Image tube design and processing requirements for building an ICCD are discussed. Work is under way at EVC for building an ICCD using the Fairchild CCD 201 (100 x 100) array, and progress will be reported. Demountable tests have been made, exposing parts of a CCD 201 to 15 kilovolt electrons over five radiation levels from approximately 10 to 1 million rads. Other tubes built by EVC over the last few years which successfully use semiconductors to detect photoelectrons will be described briefly.
A Radix-10 Combinational Multiplier
Lang, Tomas; Nannarelli, Alberto
2006-01-01
reduces the number of partial product precomputations and uses counters to eliminate the need of the decimal equivalent of a 4:2 adder. The results of the implementation show that the combinational decimal multiplier offers a good compromise between latency and area when compared to other decimal multiply...
Children's Culture Database (CCD)
Wanting, Birgit
a Dialogue inspired database with documentation, network (individual and institutional profiles) and current news , paper presented at the research seminar: Electronic access to fiction, Copenhagen, November 11-13, 1996...
Maximilien Brice
2002-01-01
Photo 0210005_11: The CTF3 linac accelerates an electron beam up to 350 MeV. Photo 0210005_1: At the front, the yellow dipole is used for the spectrometer line. At the back, a doublet of blue quadrupole for the matching. Photo 0210005_03: The CTF3 transfer line between the electron linac and the isochronous ring. Photo 0210005_04: One arc of the EPA isochronous ring. Photo 0210005_06: The CTF3 bunching system. The first RF wave guide feeds the Pre-Buncher while the second RF wave guide feeds the Buncher. They provide a bunched electron beam at 4 MeV. The blue magnet is a solenoid around the Buncher. Photo 0210005_07: A LIL accelerating structure used for CTF3. It is 4.5 meters long and provides an energy gain of 45 MeV. One can see 3 quadrupoles around the RF structure.
Blazhevich, S. V.; Noskov, A. V.; Nemtsev, S. N.
2016-11-01
A dynamic theory of coherent x-radiation emitted by a divergent beam of relativistic electrons traversing a thin single-crystal plate is developed which takes into account multiple scattering of the electrons on the target atoms. The case is considered in which the target is quite thin, so that it is not necessary to take absorption of radiation into account, but the electron path in the target is quite long, so that it is necessary to take multiple scattering into account. Expressions are obtained which describe the spectral-angular characteristics of parametric x-radiation and diffracted transient radiation under these conditions. Conditions are described under which diffracted bremsstrahlung radiation can be neglected. The possibility of manifesting the effects of dynamic diffraction is investigated.
NULL Convention Floating Point Multiplier
Anitha Juliette Albert
2015-01-01
Full Text Available Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.
NULL convention floating point multiplier.
Albert, Anitha Juliette; Ramachandran, Seshasayanan
2015-01-01
Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.
CCD sensors in synchrotron X-ray detectors
Strauss, M. G.; Naday, I.; Sherman, I. S.; Kraimer, M. R.; Westbrook, E. M.; Zaluzec, N. J.
1988-04-01
The intense photon flux from advanced synchrotron light sources, such as the 7-GeV synchrotron being designed at Argonne, require integrating-type detectors. Charge-coupled devices (CCDs) are well suited as synchrotron X-ray detectors. When irradiated indirectly via a phosphor followed by reducing optics, diffraction patterns of 100 cm 2 can be imaged on a 2 cm 2 CCD. With a conversion efficiency of ˜ 1 CCD electron/X-ray photon, a peak saturation capacity of > 10 6 X-rays can be obtained. A programmable CCD controller operating at a clock frequency of 20 MHz has been developed. The readout rate is 5 × 10 6 pixels/s and the shift rate in the parallel registers is 10 6 lines/s. The test detector was evaluated in two experiments. In protein crystallography diffraction patterns have been obtained from a lysozyme crystal using a conventional rotating anode X-ray generator. Based on these results we expect to obtain at a synchrotron diffraction images at a rate of ˜ 1 frame/s or a complete 3-dimensional data set from a single crystal in ˜ 2 min. In electron energy-loss spectroscopy (EELS), the CCD was used in a parallel detection mode which is similar to the mode array detectors are used in dispersive EXAFS. With a beam current corresponding to 3 × 10 9 electron/s on the detector, a series of 64 spectra were recorded on the CCD in a continuous sequence without interruption due to readout. The frame-to-frame pixel signal fluctuations had σ = 0.4% from which DQE = 0.4 was obtained, where the detector conversion efficiency was 2.6 CCD electrons/X-ray photon. These multiple frame series also showed the time-resolved modulation of the electron microscope optics by stray magnetic fields.
NULL Convention Floating Point Multiplier
Anitha Juliette Albert; Seshasayanan Ramachandran
2015-01-01
Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to p...
Low Power CMOS Analog Multiplier
Shipra Sachan
2015-12-01
Full Text Available In this paper Low power low voltage CMOS analog multiplier circuit is proposed. It is based on flipped voltage follower. It consists of four voltage adders and a multiplier core. The circuit is analyzed and designed in 0.18um CMOS process model and simulation results have shown that, under single 0.9V supply voltage, and it consumes only 31.8µW quiescent power and 110MHZ bandwidth.
Grosbol, Preben
The image-processing and data-reduction functions of the IHAP and MIDAS software packages developed at ESO for CCD astronomy are briefly reviewed. IHAP and MIDAS perform the same basic operations on HP 1000 and VAX computers, respectively, and MIDAS is currently being modified to run in the UNIX operating system as well as in VAX VMS. Consideration is given to the special properties of CCD data, the removal of gross errors (due to bad pixels and cosmic-ray events), photometric correction for dark current and sensitivity variations, digital filtering and Fourier transforms, detection and classification algorithms for direct imaging, surface photometry of extended objects, function fitting, and image deconvolution.
EUV astronomical spectroscopy with CCD detectors
Stern, R. A.; Catura, R. C.; Blouke, M. M.; Winzenread, M.
1986-01-01
The applicability of CCD detectors to astronomical extreme ultraviolet (EUV) spectroscopy (100-1250 A) is discussed. The advantages of CCDs in this spectral region include internal electron yield, the potential for very high quantum efficiency (about 50-90 percent), and broad wavelength response. Visible light suppression is achieved by a combination of low grating scattering, greater than unity electron yield in the EUV, and various filter techniques. For the current generation of CCDs, detection of only a few EUV photons will rapidly overwhelm the read noise; thus, for all practical S/N ratios used in astronomical spectroscopy, read noise will be negligible compared to the poisson statistics of the detected photons. A model based on experimental data for the quantum efficiency and electron yield of CCDs in the EUV is discussed.
Optical Readout of a Two Phase Liquid Argon TPC using CCD Camera and TGEMs
Mavrokoridis, K; Carroll, J; Lazos, M; McCormick, K J; Smith, N A; Touramanis, C; Walker, J
2014-01-01
This paper presents a preliminary study into the use of CCDs to image secondary scintillation light generated by Thick Gas Electron Multipliers (TGEMs) in a two phase LAr TPC. A Sony ICX285AL CCD chip was mounted above a double TGEM in the gas phase of a 40 litre two-phase LAr TPC with the majority of the camera electronics positioned externally via a feedthrough. An Am-241 source was mounted on a rotatable motion feedthrough allowing the positioning of the alpha source either inside or outside of the field cage. Developed for and incorporated into the TPC design was a novel high voltage feedthrough featuring LAr insulation. Furthermore, a range of webcams were tested for operation in cryogenics as an internal detector monitoring tool. Of the range of webcams tested the Microsoft HD-3000 (model no:1456) webcam was found to be superior in terms of noise and lowest operating temperature. In ambient temperature and atmospheric pressure 1 ppm pure argon gas, the TGEM gain was approximately 1000 and using a 1 msec...
CCD emulator design for LSST camera
Lu, W.; O'Connor, P.; Fried, J.; Kuczewski, J.
2016-07-01
As part of the LSST project, a comprehensive CCD emulator that operates three CCDs simultaneously has been developed for testing multichannel readout electronics. Based on an Altera Cyclone V FPGA for timing and control, the emulator generates 48 channels of simulated video waveform in response to appropriate sequencing of parallel and serial clocks. Two 256Mb serial memory chips are adopted for storage of arbitrary grayscale images. The arbitrary image or fixed pattern image can be generated from the emulator in triple as three real CCDs perform, for qualifying and testing the LSST 3-stripe Science Raft Electronics Board (REB) simultaneously. Using the method of comparator threshold scanning, all 24 parallel clocks and 24 serial clocks from the REB are qualified for sequence, duration and level before the video signal is generated. In addition, 66 channels of input bias and voltages are sampled through the multi-channel ADC to verify that correct values are applied to the CCD. In addition, either a Gigabit Ethernet connector or USB bus can be used to control and read back from the emulator board. A user-friendly PC software package has been developed for controlling and communicating with the emulator.
Oura, Masaki; Wagai, Tatsuya; Chainani, Ashish; Miyawaki, Jun; Sato, Hiromi; Matsunami, Masaharu; Eguchi, Ritsuko; Kiss, Takayuki; Yamaguchi, Takashi; Nakatani, Yasuhiro; Togashi, Tadashi; Katayama, Tetsuo; Ogawa, Kanade; Yabashi, Makina; Tanaka, Yoshihito; Kohmura, Yoshiki; Tamasaku, Kenji; Shin, Shik; Ishikawa, Tetsuya
2014-01-01
In order to utilize high-brilliance photon sources, such as X-ray free-electron lasers (XFELs), for advanced time-resolved photoelectron spectroscopy (TR-PES), a single-shot CCD-based data acquisition system combined with a high-resolution hemispherical electron energy analyzer has been developed. The system's design enables it to be controlled by an external trigger signal for single-shot pump-probe-type TR-PES. The basic performance of the system is demonstrated with an offline test, followed by online core-level photoelectron and Auger electron spectroscopy in 'single-shot image', 'shot-to-shot image (image-to-image storage or block storage)' and `shot-to-shot sweep' modes at soft X-ray undulator beamline BL17SU of SPring-8. In the offline test the typical repetition rate for image-to-image storage mode has been confirmed to be about 15 Hz using a conventional pulse-generator. The function for correcting the shot-to-shot intensity fluctuations of the exciting photon beam, an important requirement for the TR-PES experiments at FEL sources, has been successfully tested at BL17SU by measuring Au 4f photoelectrons with intentionally controlled photon flux. The system has also been applied to hard X-ray PES (HAXPES) in `ordinary sweep' mode as well as shot-to-shot image mode at the 27 m-long undulator beamline BL19LXU of SPring-8 and also at the SACLA XFEL facility. The XFEL-induced Ti 1s core-level spectrum of La-doped SrTiO3 is reported as a function of incident power density. The Ti 1s core-level spectrum obtained at low power density is consistent with the spectrum obtained using the synchrotron source. At high power densities the Ti 1s core-level spectra show space-charge effects which are analysed using a known mean-field model for ultrafast electron packet propagation. The results successfully confirm the capability of the present data acquisition system for carrying out the core-level HAXPES studies of condensed matter induced by the XFEL.
ccdAB system and the encoding toxin protein-CcdB%ccdAB系统及其编码的毒素蛋白CcdB
贾卉; 井申荣
2009-01-01
ccdAB系统(control of cell division or death system)是目前已知的一种毒素-抗毒素系统(toxin-antitoxin system,TA系统),存在于致病性大肠杆菌F质粒及染色体骨架上,由ccdA和ccdB两个基因组成.质粒上的ccdAB系统编码一种毒素蛋白CcdB,在缺乏抗毒素的情况下,CcdB使细胞内促旋酶中毒,从而干扰DNA的合成,杀伤宿主细胞.本文对ccdAB系统的结构和功能,以及所编码CcdB的作用机制进行了综述.
Last Multipliers on Lie Algebroids
Mircea Crasmareanu; Cristina-Elena Hreţcanu
2009-06-01
In this paper we extend the theory of last multipliers as solutions of the Liouville’s transport equation to Lie algebroids with their top exterior power as trivial line bundle (previously developed for vector fields and multivectors). We define the notion of exact section and the Liouville equation on Lie algebroids. The aim of the present work is to develop the theory of this extension from the tangent bundle algebroid to a general Lie algebroid (e.g. the set of sections with a prescribed last multiplier is still a Gerstenhaber subalgebra). We present some characterizations of this extension in terms of Witten and Marsden differentials.
High-Voltage Clock Driver for Photon-Counting CCD Characterization
Baker, Robert
2013-01-01
A document discusses the CCD97 from e2v technologies as it is being evaluated at Goddard Space Flight Center's Detector Characterization Laboratory (DCL) for possible use in ultra-low background noise space astronomy applications, such as Terrestrial Planet Finder Coronagraph (TPF-C). The CCD97 includes a photoncounting mode where the equivalent output noise is less than one electron. Use of this mode requires a clock signal at a voltage level greater than the level achievable by the existing CCD (charge-coupled-device) electronics. A high-voltage waveform generator has been developed in code 660/601 to support the CCD97 evaluation. The unit generates required clock waveforms at voltage levels from -20 to +50 V. It deals with standard and arbitrary waveforms and supports pixel rates from 50 to 500 kHz. The system is designed to interface with existing Leach CCD electronics.
The Ortega Telescope Andor CCD
Tucker, M.; Batcheldor, D.
2012-07-01
We present a preliminary instrument report for an Andor iKon-L 936 charge-couple device (CCD) being operated at Florida Tech's 0.8 m Ortega Telescope. This camera will replace the current Finger Lakes Instrumentation (FLI) Proline CCD. Details of the custom mount produced for this camera are presented, as is a quantitative and qualitative comparison of the new and old cameras. We find that the Andor camera has 50 times less noise than the FLI, has no significant dark current over 30 seconds, and has a smooth, regular flat field. The Andor camera will provide significantly better sensitivity for direct imaging programs and, once it can be satisfactorily tested on-sky, will become the standard imaging device on the Ortega Telescope.
Low cost CCD camera protection against neutron radiation damage.
Kok, J G M
2005-01-01
At a radiotherapy department cancer patients are treated with high energy electron and photon beams. These beams are produced by a linear accelerator. A closed circuit television system is used to monitor patients during treatment. Although CCD cameras are rather resistant to stray radiation, they are damaged by the low flux of neutrons which are produced by the linac as a side effect. PVC can be used to reduce damage to CCD cameras induced by neutron radiation. A box with 6 cm thick walls will extend the life of the camera at least by a factor of two. A PVC neutron shield is inexpensive. PVC is easy to obtain and the box is simple to construct. A similar box made out of PE will not reduce neutron damage to a CCD camera. Although PE is a good medium to moderate faster neutrons, thereby reducing some of the bulk defects, it will not capture thermal neutrons which induce surface damage.
Afif, H; Allali, N; Couturier, M; Van Melderen, L
2001-07-01
The ccd operon of the F plasmid encodes CcdB, a toxin targeting the essential gyrase of Escherichia coli, and CcdA, the unstable antidote that interacts with CcdB to neutralize its toxicity. Although work from our group and others has established that CcdA and CcdB are required for transcriptional repression of the operon, the underlying mechanism remains unclear. The results presented here indicate that, although CcdA is the DNA-binding element of the CcdA-CcdB complex, the stoichiometry of the two proteins determines whether or not the complex binds to the ccd operator-promoter region. Using electrophoretic mobility shift assays, we show that a (CcdA)2-(CcdB)2 complex binds DNA. The addition of extra CcdB to that protein-DNA complex completely abolishes DNA retardation. Based on these results, we propose a model in which the ratio between CcdA and CcdB regulates the repression state of the ccd operon. When the level of CcdA is superior or equal to that of CcdB, repression results. In contrast, derepression occurs when CcdB is in excess of CcdA. By ensuring an antidote-toxin ratio greater than one, this mechanism could prevent the harmful effect of CcdB in plasmid-containing bacteria.
Money Multiplier under Reserve Option Mechanism
Halit AKTURK; Gocen, Hasan; Duran, Suleyman
2015-01-01
This paper introduces a generalized money (M2) multiplier formula to the literature for a monetary system with Reserve Option Mechanism (ROM). Various features of the proposed multiplier are then explored using monthly Turkish data during the decade 2005 to 2015. We report a step increase in the magnitude and a slight upward adjustment in the long-run trend of the multiplier with the adoption of ROM. We provide evidence for substantial change in the seasonal pattern of the multiplier, cash ra...
The multipliers of multiple trigonometric Fourier series
Ydyrys, Aizhan; Sarybekova, Lyazzat; Tleukhanova, Nazerke
2016-11-01
We study the multipliers of multiple Fourier series for a regular system on anisotropic Lorentz spaces. In particular, the sufficient conditions for a sequence of complex numbers {λk}k∈Zn in order to make it a multiplier of multiple trigonometric Fourier series from Lp[0; 1]n to Lq[0; 1]n , p > q. These conditions include conditions Lizorkin theorem on multipliers.
Multiplier theorems for special Hermite expansions on
张震球; 郑维行
2000-01-01
The weak type (1,1) estimate for special Hermite expansions on Cn is proved by using the Calderon-Zygmund decomposition. Then the multiplier theorem in Lp(1 < p < ω ) is obtained. The special Hermite expansions in twisted Hardy space are also considered. As an application, the multipli-ers for a certain kind of Laguerre expansions are given in Lp space.
Interregional multipliers : looking backward, looking forward
Dietzenbacher, Erik
2002-01-01
Backward linkages are usually measured using output multipliers as based on the input matrix. Similarly, value-added and import multipliers are derived by additionally using the corresponding primary input coefficients. For measuring forward linkages, input multipliers have been frequently used. Wit
Auger neutralization rates of multiply charged ions near metal surfaces
Nedeljkovic, N.N.; Janev, R.K.; Lazur, V.Y.
1988-08-15
Transition rates for the Auger neutralization processes of multiply charged ions on metal surfaces are calculated in closed analytical form. The core potential of a multiply charged ion is represented by a pseudopotential, which accounts for the electron screening effects and allows transition to the pure Coulomb case (fully stripped ions). The relative importance of various neutralization channels in slow-ion--surface collisions is discussed for the examples of He/sup 2+/+Mo(100) and C/sup 3+/+Mo(100) collisional systems.
Parametric Model for the Response of a Photo-multiplier Tube
Aguilar, M.; Alcaraz, J.; Berdugo, J.; Casaus, J.; Delgado, C.; Diaz, C.; Lanciotti, E.; Mana, C.; Marin, J.; Martinez, G.; Molla, M.; Palomares, C.; Rodriguez, J.; Sanchez, E.; Sevilla, A.; Torrento, A.
2005-07-01
When a photon impinges upon a photon-multiplier tube, an electron is emitted with certain probability and, after several amplification stages, an electron shower is collected at the anode. However, when the first electron is emitted from one of the amplification dynodes or the photon-multiplier is operated under untoward conditions (external magnetic fields...) smaller showers are collected. In this paper, we present a bi-parametric model which describers the response of a photo-multiplier tube over a wide range of circumstances. (Author)
CCD characterization and measurements automation
Kotov, I.V., E-mail: kotov@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973 (United States); Frank, J.; Kotov, A.I. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Kubanek, P. [Institute of Physics of the Academy of Sciences, Prague, CZ 18221 (Czech Republic); Image Processing Laboratory, Universidad de Valencia (Spain); O' Connor, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Prouza, M. [Institute of Physics of the Academy of Sciences, Prague, CZ 18221 (Czech Republic); Radeka, V.; Takacs, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States)
2012-12-11
Modern mosaic cameras have grown both in size and in number of sensors. The required volume of sensor testing and characterization has grown accordingly. For camera projects as large as the LSST, test automation becomes a necessity. A CCD testing and characterization laboratory was built and is in operation for the LSST project. Characterization of LSST study contract sensors has been performed. The characterization process and its automation are discussed, and results are presented. Our system automatically acquires images, populates a database with metadata information, and runs express analysis. This approach is illustrated on {sup 55}Fe data analysis. {sup 55}Fe data are used to measure gain, charge transfer efficiency and charge diffusion. Examples of express analysis results are presented and discussed.
Ruelas, A.; Sánchez, L. J.; Herrera, G.; Nigoche-Netro, A.
2011-10-01
We present CCD observations of the galactic globular cluster M15, in the B and V filters. The cluster was reasonably covered, except in its northern region where our observations present a gap. We obtained a Hertszprung-Russell (HR) diagram for each region observed, and later we produced a combined HR diagram containing more than 3000 stars. We generate a clean Colour Magnitude Diagram (CMD) and a Super Fiducial Line (SFL). Application of several methods and isochrone fitting leads us to obtain values for the metallicity [Fe/H]_{M15} ˜ -2.16±0.10, the reddening E(B-V)_{M15} ˜ 0.11±0.03, and a distance modulus of [(m-M)_0]_{M15}˜ 15.03.
Robotic CCD microscope for enhanced crystal recognition
Segelke, Brent W.; Toppani, Dominique
2007-11-06
A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.
Status Of Sofradir IR-CCD Detectors
Tribolet, Philippe; Radisson, Patrick
1988-05-01
The topics of this paper deal with the IR-CCD detectors manufactured by SOFRADIR the new French joint venture. Description of the IRCCD technology and the advantages of this approach are given. In conclusion, some IR-CCD typical results are given.
Faster and Low Power Twin Precision Multiplier
Sreedeep, V; Kittur, Harish M
2011-01-01
In this work faster unsigned multiplication has been achieved by using a combination of High Performance Multiplication [HPM] column reduction technique and implementing a N-bit multiplier using 4 N/2-bit multipliers (recursive multiplication) and acceleration of the final addition using a hybrid adder. Low power has been achieved by using clock gating technique. Based on the proposed technique 16 and 32-bit multipliers are developed. The performance of the proposed multiplier is analyzed by evaluating the delay, area and power, with TCBNPHP 90 nm process technology on interconnect and layout using Cadence NC launch, RTL compiler and ENCOUNTER tools. The results show that the 32-bit proposed multiplier is as much as 22% faster, occupies only 3% more area and consumes 30% lesser power with respect to the recently reported twin precision multiplier.
Linear CCD attitude measurement system based on the identification of the auxiliary array CCD
Hu, Yinghui; Yuan, Feng; Li, Kai; Wang, Yan
2015-10-01
Object to the high precision flying target attitude measurement issues of a large space and large field of view, comparing existing measurement methods, the idea is proposed of using two array CCD to assist in identifying the three linear CCD with multi-cooperative target attitude measurement system, and to address the existing nonlinear system errors and calibration parameters and more problems with nine linear CCD spectroscopic test system of too complicated constraints among camera position caused by excessive. The mathematical model of binocular vision and three linear CCD test system are established, co-spot composition triangle utilize three red LED position light, three points' coordinates are given in advance by Cooperate Measuring Machine, the red LED in the composition of the three sides of a triangle adds three blue LED light points as an auxiliary, so that array CCD is easier to identify three red LED light points, and linear CCD camera is installed of a red filter to filter out the blue LED light points while reducing stray light. Using array CCD to measure the spot, identifying and calculating the spatial coordinates solutions of red LED light points, while utilizing linear CCD to measure three red LED spot for solving linear CCD test system, which can be drawn from 27 solution. Measured with array CCD coordinates auxiliary linear CCD has achieved spot identification, and has solved the difficult problems of multi-objective linear CCD identification. Unique combination of linear CCD imaging features, linear CCD special cylindrical lens system is developed using telecentric optical design, the energy center of the spot position in the depth range of convergence in the direction is perpendicular to the optical axis of the small changes ensuring highprecision image quality, and the entire test system improves spatial object attitude measurement speed and precision.
High speed multiplier design using Decomposition Logic
Ramanathan Palaniappan
2009-01-01
Full Text Available The multiplier forms the core of a Digital Signal Processor and is a major source of power dissipation. Often, the multiplier forms the limiting factor for the maximum speed of operation of a Digital Signal Processor. Due to continuing integrating intensity and the growing needs of portable devices, low-power, high-performance design is of prime importance. A new technique of implementing a multiplier circuit using Decomposition Logic is proposed here which improves speed with very little increase in power dissipation when compared to tree structured Dadda multipliers. Tanner EDA was used for simulation in the TSMC 180nm technology.
Multiplier phenomenology in random multiplicative cascade processes
Jouault, B; Greiner, M; Jouault, Bruno; Lipa, Peter; Greiner, Martin
1999-01-01
We demonstrate that the correlations observed in conditioned multiplier distributions of the energy dissipation in fully developed turbulence can be understood as an unavoidable artefact of the observation procedure. Taking the latter into account, all reported properties of both unconditioned and conditioned multiplier distributions can be reproduced by cascade models with uncorrelated random weights if their bivariate splitting function is non-energy conserving. For the alpha-model we show that the simulated multiplier distributions converge to a limiting form, which is very close to the experimentally observed one. If random translations of the observation window are accounted for, also the subtle effects found in conditioned multiplier distributions are precisely reproduced.
Multiply Phased Traveling BPS Vortex
Kimm, Kyoungtae; Cho, Y M
2016-01-01
We present the multiply phased current carrying vortex solutions in the U(1) gauge theory coupled to an $(N+1)$-component SU(N+1) scalar multiplet in the Bogomolny limit. Our vortex solutions correspond to the static vortex dressed with traveling waves along the axis of symmetry. What is notable in our vortex solutions is that the frequencies of traveling waves in each component of the scalar field can have different values. The energy of the static vortex is proportional to the topological charge of $CP^N$ model in the BPS limit, and the multiple phase of the vortex supplies additional energy contribution which is proportional to the Noether charge associated to the remaining symmetry.
A CMOS floating point multiplier
Uya, M.; Kaneko, K.; Yasui, J.
1984-10-01
This paper describes a 32-bit CMOS floating point multiplier. The chip can perform 32-bit floating point multiplication (based on the proposed IEEE Standard format) and 24-bit fixed point multiplication (two's complement format) in less than 78.7 and 71.1 ns, respectively, and the typical power dissipation is 195 mW at 10 million operations per second. High-speed multiplication techniques - a modified Booth's allgorithm, a carry save adder scheme, a high-speed CMOS full adder, and a modified carry select adder - are used to achieve the above high performance. The chip is designed for compatibility with 16-bit microcomputer systems, and is fabricated in 2 micron n-well CMOS technology; it contains about 23000 transistors of 5.75 x 5.67 sq mm in size.
Radiation events in astronomical CCD images
Smith, Alan R.; McDonald, Richard J.; Hurley, D. C.; Holland, Steven E.; Groom, Donald E.; Brown, William E.; Gilmore, David K.; Stover, Richard J.; Wei, Mingzhi
2002-04-01
The remarkable sensitivity of depleted silicon to ionizing radiation is a nuisance to astronomers. 'Cosmic rays' degrade images because of struck pixels, leading to modified observing strategies and the development of algorithms to remove the unwanted artifacts. In the new-generation CCD's with thick sensitive regions, cosmic-ray muons make recognizable straight tracks and there is enhanced sensitivity to ambient gamma radiation via Compton-scattered electrons ('worms'). Beta emitters inside the dewar, for example high-potassium glasses such as BK7 , also produce worm-like tracks. The cosmic-ray muon rate is irreducible and increases with altitude. The gamma rays are mostly by- products of 40K decay and the U and Th decay chains; these elements commonly appear as traces in concrete and other materials. The Compton recoil event rate can be reduced significantly by the choice of materials in the environment and dewar and by careful shielding. Telescope domes appear to have significantly lower rates than basement laboratories and Coude spectrograph rooms. Radiation sources inside the dewar can be eliminated by judicious choice of materials. Cosmogenic activation during high-altitude fights does not appear to be a problem. Our conclusion are supported by tests at the Lawrence Berkeley National Laboratory low-level counting facilities in Berkeley and at Oroville, California (180 m underground).
Method for eliminating artifacts in CCD imagers
Turko, B. T.; Yates, G. J.
1990-06-01
An electronic method for eliminating artifacts in a video camera employing a charge coupled device (CCD) as an image sensor is presented. The method comprises the step of initializing the camera prior to normal readout. The method includes a first dump cycle period for transferring radiation generated charge into the horizontal register. This occurs while the decaying image on the phosphor being imaged is being integrated in the photosites, and a second dump cycle period, occurring after the phosphor image has decayed, for rapidly dumping unwanted smear charge which has been generated in the vertical registers. Image charge is then transferred from the photosites and to the vertical registers and readout in conventional fashion. The inventive method allows the video camera to be used in environments having high ionizing radiation content, and to capture images of events of very short duration and occurring either within or outside the normal visual wavelength spectrum. Resultant images are free from ghost, smear, and smear phenomena caused by insufficient opacity of the registers, and are also free from random damage caused by ionization charges which exceed the charge limit capacity of the photosites.
Vacancy rearrangement processes in multiply ionized atoms
Czarnota, M [Institute of Physics, Swietokrzyska Academy, 25-406 Kielce (Poland); Pajek, M [Institute of Physics, Swietokrzyska Academy, 25-406 Kielce (Poland); Banas, D [Institute of Physics, Swietokrzyska Academy, 25-406 Kielce (Poland); Dousse, J-Cl [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Maillard, Y-P [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Mauron, O [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Raboud, P A [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Berset, M [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Hoszowska, J [European Synchrotron Radiation Facility (ESRF), F-38043 Grenoble (France); Slabkowska, K [Faculty of Chemistry, Nicholas Copernicus University, 87-100 Torun (Poland); Polasik, M [Faculty of Chemistry, Nicholas Copernicus University, 87-100 Torun (Poland); Chmielewska, D [Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Rzadkiewicz, J [Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Sujkowski, Z [Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland)
2007-03-01
We demonstrate that in order to interpret the x-ray satellite structure of Pd L{alpha}{sub 1,2}(L{sub 3}M{sub 4,5}) transitions excited by fast O ions, which was measured using a high-resolution von Hamos crystal spectrometer, the vacancy rearrangement processes, taking place prior to the x-ray emission, have to be taken into account. The measured spectra were compared with the predictions of the multi-con.guration Dirac-Fock (MCDF) calculations using the fluorescence and Coster-Kronig yields which were modiffed due to a reduced number of electrons available for relaxation processes and the effect of closing the Coster-Kronig transitions. We demonstrate that the vacancy rearrangement processes can be described in terms of the rearrangement factor, which can be calculated by solving the system of rate equations modelling the flow of vacancies in the multiply ionized atom. By using this factor, the ionization probability at the moment of collision can be extracted from the measured intensity distribution of x-ray satellites. The present results support the independent electron picture of multiple ionization and indicate the importance of use of Dirac-Hartree-Fock wave functions to calculate the ionization probabilities.
Modelling Gaia CCD pixels with Silvaco 3D engineering software
Seabroke, G M; Hopkinson, G; Burt, D; Robbins, M; Holland, A
2010-01-01
Gaia will only achieve its unprecedented measurement accuracy requirements with detailed calibration and correction for radiation damage. We present our Silvaco 3D engineering software model of the Gaia CCD pixel and two of its applications for Gaia: (1) physically interpreting supplementary buried channel (SBC) capacity measurements (pocket-pumping and first pixel response) in terms of e2v manufacturing doping alignment tolerances; and (2) deriving electron densities within a charge packet as a function of the number of constituent electrons and 3D position within the charge packet as input to microscopic models being developed to simulate radiation damage.
Multiply-negatively charged aluminium clusters and fullerenes
Walsh, Noelle
2008-07-15
Multiply negatively charged aluminium clusters and fullerenes were generated in a Penning trap using the 'electron-bath' technique. Aluminium monoanions were generated using a laser vaporisation source. After this, two-, three- and four-times negatively charged aluminium clusters were generated for the first time. This research marks the first observation of tetra-anionic metal clusters in the gas phase. Additionally, doubly-negatively charged fullerenes were generated. The smallest fullerene dianion observed contained 70 atoms. (orig.)
Performance of a multianode photo multiplier cluster equipped with lenses
Gibson, V; Wotton, S A; Albrecht, E; Eklund, L; Eisenhardt, S; Muheim, F; Playfer, S; Petrolini, A; Easo, S; Halley, A; Barber, G; Duane, A; Price, D; Websdale, D M; Calvi, M; Paganoni, M; Bibby, J; Charles, M J; Harnew, N; Libby, J; Rademacker, J; Smale, N J; Topp-Jørgensen, S; Wilkinson, G; Baker, J; French, M
2001-01-01
Studies of Multi{anode Photo Multiplier Tubes (MaPMTs), which are a possible photo{detector for the LHCb RICHes, are presented. These studies include those of a cluster of MaPMTs equipped with lenses at the SPS beam during the Summer of 1999. The read{out electronics used were capable of capturing the data at 40 MHz. Results on the effect of charged particles and magnetic fields on MaPMTs are also presented.
Design of optimized Interval Arithmetic Multiplier
Rajashekar B.Shettar
2011-07-01
Full Text Available Many DSP and Control applications that require the user to know how various numericalerrors(uncertainty affect the result. This uncertainty is eliminated by replacing non-interval values withintervals. Since most DSPs operate in real time environments, fast processors are required to implementinterval arithmetic. The goal is to develop a platform in which Interval Arithmetic operations areperformed at the same computational speed as present day signal processors. So we have proposed thedesign and implementation of Interval Arithmetic multiplier, which operates with IEEE 754 numbers. Theproposed unit consists of a floating point CSD multiplier, Interval operation selector. This architectureimplements an algorithm which is faster than conventional algorithm of Interval multiplier . The costoverhead of the proposed unit is 30% with respect to a conventional floating point multiplier. Theperformance of proposed architecture is better than that of a conventional CSD floating-point multiplier,as it can perform both interval multiplication and floating-point multiplication as well as Intervalcomparisons
Electronic cameras for low-light microscopy.
Rasnik, Ivan; French, Todd; Jacobson, Ken; Berland, Keith
2013-01-01
This chapter introduces to electronic cameras, discusses the various parameters considered for evaluating their performance, and describes some of the key features of different camera formats. The chapter also presents the basic understanding of functioning of the electronic cameras and how these properties can be exploited to optimize image quality under low-light conditions. Although there are many types of cameras available for microscopy, the most reliable type is the charge-coupled device (CCD) camera, which remains preferred for high-performance systems. If time resolution and frame rate are of no concern, slow-scan CCDs certainly offer the best available performance, both in terms of the signal-to-noise ratio and their spatial resolution. Slow-scan cameras are thus the first choice for experiments using fixed specimens such as measurements using immune fluorescence and fluorescence in situ hybridization. However, if video rate imaging is required, one need not evaluate slow-scan CCD cameras. A very basic video CCD may suffice if samples are heavily labeled or are not perturbed by high intensity illumination. When video rate imaging is required for very dim specimens, the electron multiplying CCD camera is probably the most appropriate at this technological stage. Intensified CCDs provide a unique tool for applications in which high-speed gating is required. The variable integration time video cameras are very attractive options if one needs to acquire images at video rate acquisition, as well as with longer integration times for less bright samples. This flexibility can facilitate many diverse applications with highly varied light levels.
Erdal, E; Rappaport, M; Shchemelinin, S; Vartsky, D; Breskin, A
2016-01-01
The bubble-assisted Liquid Hole-Multiplier (LHM) is a recently-introduced detection concept for noble-liquid time projection chambers. In this "local dual-phase" detection element, a gas bubble is supported underneath a perforated electrode (e.g., Thick Gas Electron Multiplier - THGEM, or Gas Electron Multiplier - GEM). Electrons drifting through the holes induce large electroluminescence signals as they pass into the bubble. In this work we report on recent results of THGEM and GEM electrodes coated with cesium iodide and immersed in liquid xenon, allowing - for the first time - the detection of primary VUV scintillation photons in addition to ionization electrons using LHMs.
Liquid Hole Multipliers: bubble-assisted electroluminescence in liquid xenon
Arazi, L; Coimbra, A E C; Rappaport, M L; Vartsky, D; Chepel, V; Breskin, A
2015-01-01
In this work we discuss the mechanism behind the large electroluminescence signals observed at relatively low electric fields in the holes of a Thick Gas Electron Multiplier (THGEM) electrode immersed in liquid xenon. We present strong evidence that the scintillation light is generated in xenon bubbles trapped below the THGEM holes. The process is shown to be remarkably stable over months of operation, providing - under specific thermodynamic conditions - energy resolution similar to that of present dual-phase liquid xenon experiments. The observed mechanism may serve as the basis for the development of Liquid Hole Multipliers (LHMs), capable of producing local charge-induced electroluminescence signals in large-volume single-phase noble-liquid detectors for dark matter and neutrino physics experiments.
Designing a Novel Ternary Multiplier Using CNTFET
Nooshin Azimi
2014-11-01
Full Text Available Today, multipliers are included as substantial keys of many systems with high efficiency such as FIR filters, microprocessors and processors of digital signals. The efficiency of the systems are mainly evaluated by their multipliers capability since multipliers are generally the slowest components of a system while occupying the most space. Multiple Valued Logic reduces the number of the required operations to implement a function and decreases the chip surface. Carbon Nanotube Field Effect Transistors (CNTFET are considered as good substitutes for Silicon Transistors (MOSFET. Combining the abilities of Carbon Nanotubes Transistors with the advantages of Multiple Valued can provide a unique design which has a higher speed and less complexity. In this paper, a new multiplier is presented by nanotechnology using a ternary logic that improves the consuming power, raises the speed and decreased the chip surface as well. The presented design is simulated using CNTFET of Stanford University and HSPICE software, and the results are compared with other instances.
IMPLEMENTATION OF VEDIC MULTIPLIER USING REVERSIBLE GATES
P. Koti Lakshmi
2015-07-01
Full Text Available With DSP applications evolving continuously, there is continuous need for improved multipliers which are faster and power efficient. Reversible logic is a new and promising field which addresses the problem of power dissipation. It has been shown to consume zero power theoretically. Vedic mathematics techniques have always proven to be fast and efficient for solving various problems. Therefore, in this paper we implement Urdhva Tiryagbhyam algorithm using reversible logic thereby addressing two important issues – speed and power consumption of implementation of multipliers. In this work, the design of 4x4 Vedic multiplier is optimized by reducing the number of logic gates, constant inputs, and garbage outputs. This multiplier can find its application in various fields like convolution, filter applications, cryptography, and communication.
Hyperbolicity of semigroups and Fourier multipliers
Latushkin, Yuri; Shvidkoy, Roman
2001-01-01
We present a characterization of hyperbolicity for strongly continuous semigroups on Banach spaces in terms of Fourier multiplier properties of the resolvent of the generator. Hyperbolicity with respect to classical solutions is also considered. Our approach unifies and simplifies the M. Kaashoek-- S. Verduyn Lunel theory and multiplier-type results previously obtained by S. Clark, M. Hieber, S. Montgomery-Smith, F. R\\"{a}biger, T. Randolph, and L. Weis.
CCD BVI c observations of Cepheids
Berdnikov, L. N.; Kniazev, A. Yu.; Sefako, R.; Kravtsov, V. V.; Zhujko, S. V.
2014-02-01
In 2008-2013, we obtained 11333 CCD BVI c frames for 57 Cepheids from the General Catalogue of Variable Stars. We performed our observations with the 76-cm telescope of the South African Astronomical Observatory (SAAO, South Africa) and the 40-cm telescope of the Cerro Armazones Astronomical Observatory of the Universidad Católica del Norte (OCA, Chile) using the SBIG ST-10XME CCD camera. The tables of observations, the plots of light curves, and the current light elements are presented. Comparison of our light curves with those constructed from photoelectric observations shows that the differences between their mean magnitudes exceed 0ṃ05 in 20% of the cases. This suggests the necessity of performing CCD observations for all Cepheids.
Vacuum compatible miniature CCD camera head
Conder, Alan D.
2000-01-01
A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.
Simulation of a gas electron multiplier using a PIC-MCC model%基于粒子-蒙特卡洛模型的气体电子倍增探测器的研究
杨兰兰; 屠彦; 张盼盼; 秦娜娜; 蔡国龙; 陈仲珊; 马善乐
2011-01-01
采用粒子一蒙特卡罗模型(Particle in Cell-Monte Carlo Collision,PIC-MCC)对气体电子倍增探测器(Gaselectron multiplier,GEM)的倍增放大过程进行了模拟,这对更好的理解和把握GEM的物理机理具有重要的意义.在电场分析的基础上,从GEM空间粒子数和粒子的空间分布随时间的变化分析GEM的倍增过程,并建立GEM增益和各边界层收集到的电子个数之间的关系.研究结果为进一步利用该模型对GEM优化结构、选择工作参数及探讨物理机理建立了基础.
Robust CCD photoelectric autocollimator for outdoor use
Min Gao; Zuoren Dong; Zhenglan Bian; Qing Ye; Zujie Fang; Ronghui Qu
2011-01-01
A robust charge-coupled device (CCD) photoelectric autocollimator for outdoor use is designed and demonstrated. The influence of outdoor conditions on the signal-to-noise ratio (SNR) and imaging quality of the measuring system is experimentally analyzed. The pulse width modulation technology is applied to the automatic feedback control of the actively regulated illuminating light source of the measuring system to maximize SNR while avoiding image saturation. A Fourier phase shift method for subpixel estimation is adopted to achieve high-accuracy measurement in the presence of noises. Experimental results indicate that the technologies proposed here largely improve the measuring stability, dynamic range, and accuracy of the CCD photoelectric autocollimator used outdoors.%@@ A robust charge-coupled device(CCD)photoelectric autocollimator for outdoor use is designed and demonstrated.The influence of outdoor conditions on the signal-to-noise ratio(SNR)and imaging quality of the measuring system is experimentally analyzed.The pulse width modulation technology is applied to the automatic feedback control of the actively regulated illuminating light source of the measuring system to maximize SNR while avoiding image saturation.A Fourier phase shift method for subpixel estimation is adopted to achieve high-accuracy measurement in the presence of noises.Experimental results indicate that the technologies proposed here largely improve the measuring stability,dynamic range,and accuracy of the CCD photoelectric autocollimator used outdoors.
HIGH-PRECISION DETERMINATION OF THE ANGULAR POSITION FOR POINT LIGHT SOURCE WITH CCD-ARRAYS
Y. G. Lebedko
2015-05-01
Full Text Available Subject of study. A method of angular position measuring for point light source in the system with CCD arrays is proposed by converting of angle – time – code in low light conditions and at high signal / noise ratio. Assessment of the method potential accuracy is given. It is determined by instrumental irremovable random errors of measurement in terms of optimal processing of incoming information with a single reading it with CCD – arrays. Method. This work introduces an optoelectronic system circuit with CCD arrays with stretched sensing elements and a point of reference for angular position measuring. In this case the arrays have images projections of both the reference point source and the target point source, which angular position is measured with high precision. From the CCD array output the signals arrive at an optimal (or apt linear filter, and then to the signal peak position detection circuit. The scheme provides minimum error due to the influence of noise. Pulse edges, corresponding to the signals maximum, make a time interval filled with high-frequency counting pulses. The number of pulses in this interval will correspond to the measured angular position of the target point source. Main results. Analysis of random errors has been carried out in terms of statistical decision theory. Analysis takes into account the spectral function of the signals defined by transfer functions of the optical system and a CCD array as an image analyzer. Research of measurement accuracy is carried out depending on the clock frequency of reading information from CCD arrays for different values of signal-to-noise ratio. It has been shown that even with a single readout with CCD array by the proposed opto-electronic circuit measuring error does not exceed 0.01 of the sensing element size. Practical significance. The results are usable in high-precision measuring opto-electronic systems of star sensors for determining the angular position of the low
Efficient Realization of BCD Multipliers Using FPGAs
Shuli Gao
2017-01-01
Full Text Available In this paper, a novel BCD multiplier approach is proposed. The main highlight of the proposed architecture is the generation of the partial products and parallel binary operations based on 2-digit columns. 1 × 1-digit multipliers used for the partial product generation are implemented directly by 4-bit binary multipliers without any code conversion. The binary results of the 1 × 1-digit multiplications are organized according to their two-digit positions to generate the 2-digit column-based partial products. A binary-decimal compressor structure is developed and used for partial product reduction. These reduced partial products are added in optimized 6-LUT BCD adders. The parallel binary operations and the improved BCD addition result in improved performance and reduced resource usage. The proposed approach was implemented on Xilinx Virtex-5 and Virtex-6 FPGAs with emphasis on the critical path delay reduction. Pipelined BCD multipliers were implemented for 4 × 4, 8 × 8, and 16 × 16-digit multipliers. Our realizations achieve an increase in speed by up to 22% and a reduction of LUT count by up to 14% over previously reported results.
Seabroke, G M; Murray, N J; Crowley, C; Hopkinson, G; Brown, A G A; Kohley, R; Holland, A
2013-01-01
The European Space Agency (ESA) Gaia satellite has 106 CCD image sensors which will suffer from increased charge transfer inefficiency (CTI) as a result of radiation damage. To aid the mitigation at low signal levels, the CCD design includes Supplementary Buried Channels (SBCs, otherwise known as `notches') within each CCD column. We present the largest published sample of Gaia CCD SBC Full Well Capacity (FWC) laboratory measurements and simulations based on 13 devices. We find that Gaia CCDs manufactured post-2004 have SBCs with FWCs in the upper half of each CCD that are systematically smaller by two orders of magnitude (<50 electrons) compared to those manufactured pre-2004 (thousands of electrons). Gaia's faint star (13 < G < 20 mag) astrometric performance predictions by Prod'homme et al. and Holl et al. use pre-2004 SBC FWCs as inputs to their simulations. However, all the CCDs already integrated onto the satellite for the 2013 launch are post-2004. SBC FWC measurements are not available for on...
Parity nonconservation in dielectronic recombination of multiply charged ions
Kozlov, M G; Currell, F J
2007-01-01
We discuss a parity nonconserving (PNC) asymmetry in the cross section of dielectronic recombination of polarized electrons on multiply charged ions with Z>40. This effect is strongly enhanced for close doubly-excited states of opposite parity in the intermediate compound ion. Such states are known for He-like ions. However, these levels have large energy and large radiative widths which hampers observation of the PNC asymmetry. We argue that accidentally degenerate states of the more complex ions may be more suitable for the corresponding experiment.
Helical channel multiplier package design for space instrumentation
Hoshiko, H. H.
1975-01-01
The package considered is intended for the channel electron multiplier (CEM) detectors which are to be used for the extreme ultraviolet telescope and helium glow detector instruments of the Apollo-Soyuz test project. In the package design selected, the cone of the CEM is supported at the front end by a silicone rubber ring which is molded in place and self-bonded to both the cone and the housing wall. The helix is supported and insulated from the housing by a fiber glass sleeve which is bonded to the inside of the housing.
Low Power Complex Multiplier based FFT Processor
V.Sarada
2015-08-01
Full Text Available High speed processing of signals has led to the requirement of very high speed conversion of signals from time domain to frequency domain. Recent years there has been increasing demand for low power designs in the field of Digital signal processing. Power consumption is the most important aspect while considering the system performance. In order to design high performance Fast Fourier Transform (FFT and realization, efficient internal structure is required. In this paper we present FFT Single Path Delay feedback (SDF pipeline architecture using radix -24 algorithm .The complex multiplier is realized by using Digit Slicing Concept multiplier less architecture. To reduce computation complexity radix 24 algorithms is used. The proposed design has been coded in Verilog HDL and synthesizes by Cadence tool. The result demonstrates that the power is reduced compared with complex multiplication used CSD (Canonic Signed Digit multiplier.
Lotka-Volterra system with Volterra multiplier.
Gürlebeck, Klaus; Ji, Xinhua
2011-01-01
With the aid of Volterra multiplier, we study ecological equations for both tree system and cycle system. We obtain a set of sufficient conditions for the ultimate boundedness to nonautonomous n-dimensional Lotka-Volterra tree systems with continuous time delay. The criteria are applicable to cooperative model, competition model, and predator-prey model. As to cycle system, we consider a three-dimensional predator-prey Lotka-Volterra system. In order to get a condition under which the system is globally asymptotic stable, we obtain a Volterra multiplier, so that in a parameter region the system is with the Volterra multiplier it is globally stable. We have also proved that in regions in which the condition is not satisfied, the system is unstable or at least it is not globally stable. Therefore, we say that the three-dimensional cycle system is with global bifurcation.
Problem of Electromagnetoviscoelasticity for Multiply Connected Plates
Kaloerov, S. A.; Samodurov, A. A.
2015-11-01
A method for solving the problem of electromagnetoviscoelasticity for multiply connected plates is proposed. The small-parameter method is used to reduce this problem to a recursive sequence of problems of electromagnetoelasticity, which are solved by using complex potentials. A procedure is developed to determine, using complex potentials, approximations of the basic characteristics (stresses, electromagnetic-field strength, electromagnetic-flux density) of the electromagnetoelastic state at any time after application of a load. A plate with an elliptic hole is considered as an example. The variation in the electromagnetoelastic state of the multiply connected plate with time is studied
Fully depleted back-illuminated p-channel CCD development
Bebek, Chris J.; Bercovitz, John H.; Groom, Donald E.; Holland, Stephen E.; Kadel, Richard W.; Karcher, Armin; Kolbe, William F.; Oluseyi, Hakeem M.; Palaio, Nicholas P.; Prasad, Val; Turko, Bojan T.; Wang, Guobin
2003-07-08
An overview of CCD development efforts at Lawrence Berkeley National Laboratory is presented. Operation of fully-depleted, back-illuminated CCD's fabricated on high resistivity silicon is described, along with results on the use of such CCD's at ground-based observatories. Radiation damage and point-spread function measurements are described, as well as discussion of CCD fabrication technologies.
VLSI Implementation of Fault Tolerance Multiplier based on Reversible Logic Gate
Ahmad, Nabihah; Hakimi Mokhtar, Ahmad; Othman, Nurmiza binti; Fhong Soon, Chin; Rahman, Ab Al Hadi Ab
2017-08-01
Multiplier is one of the essential component in the digital world such as in digital signal processing, microprocessor, quantum computing and widely used in arithmetic unit. Due to the complexity of the multiplier, tendency of errors are very high. This paper aimed to design a 2×2 bit Fault Tolerance Multiplier based on Reversible logic gate with low power consumption and high performance. This design have been implemented using 90nm Complemetary Metal Oxide Semiconductor (CMOS) technology in Synopsys Electronic Design Automation (EDA) Tools. Implementation of the multiplier architecture is by using the reversible logic gates. The fault tolerance multiplier used the combination of three reversible logic gate which are Double Feynman gate (F2G), New Fault Tolerance (NFT) gate and Islam Gate (IG) with the area of 160μm x 420.3μm (67.25 mm2). This design achieved a low power consumption of 122.85μW and propagation delay of 16.99ns. The fault tolerance multiplier proposed achieved a low power consumption and high performance which suitable for application of modern computing as it has a fault tolerance capabilities.
CCD Photometry of Asteroid (147) Protogeneia
Xi-Liang Zhang; Xiao-Bin Wang; Li-Yun Zhang
2006-01-01
We measured the light-curve of the asteroid (147) Protogeneia in November 2004, with a CCD detector attached to the 1-meter telescope at the Yunnan Observatory, China. The synodic period and maximum amplitude of (147) at this apparition are 7.852 hours and 0.25 mag, respectively. The value of a/b for (147), from a preliminary estimation, is not less than 1.26:1.
Scott, Paul
2009-01-01
These days, multiplying two numbers together is a breeze. One just enters the two numbers into one's calculator, press a button, and there is the answer! It never used to be this easy. Generations of students struggled with tables of logarithms, and thought it was a miracle when the slide rule first appeared. In this article, the author discusses…
Delay Reduction in Optimized Reversible Multiplier Circuit
Mohammad Assarian
2012-01-01
Full Text Available In this study a novel reversible multiplier is presented. Reversible logic can play a significant role in computer domain. This logic can be applied in quantum computing, optical computing processing, DNA computing, and nanotechnology. One condition for reversibility of a computable model is that the number of input equate with the output. Reversible multiplier circuits are the circuits used frequently in computer system. For this reason, optimization in one reversible multiplier circuit can reduce its volume of hardware on one hand and increases the speed in a reversible system on the other hand. One of the important parameters that optimize a reversible circuit is reduction of delays in performance of the circuit. This paper investigates the performance characteristics of the gates, the circuits and methods of optimizing the performance of reversible multiplier circuits. Results showed that reduction of the reversible circuit layers has lead to improved performance due to the reduction of the propagation delay between input and output period. All the designs are in the nanometric scales.
Pipelined C2 Mos Register High Speed Modified Booth Multiplier
N.Ravi
2011-07-01
Full Text Available This paper presents C2 Mos register Pipelined Modified Booth Multiplier (PMBM to improve the speed of the multiplier by allowing the data parallel. The pipeline registers are designed with two p-mos and two n-mos transistors in series which is C2 Mos. Wallace multiplier also used to improve the speed of the multiplier with Carry Save Addition. 16-Transitor Full adders are used for better performance of the multiplier. The PMBM is 28.51% more speed than the Modified Booth Multiplier (MBM. This is calculated with TSMC 0.18um technology using Hspice.
Design of a High Speed Multiplier (Ancient Vedic Mathematics Approach)
2013-01-01
In this paper, an area efficient multiplier architecture is presented. The architecture is based on Ancient algorithms of the Vedas, propounded in the Vedic Mathematics scripture of Sri Bharati Krishna Tirthaji Maharaja. The multiplication algorithm used here is called Nikhilam Navatascaramam Dasatah. The multiplier based on the ancient technique is compared with the modern multiplier to highlight the speed and power superiority of the Vedic Multipliers.
Noncommutative Figa-Talamanca-Herz algebras for Schur multipliers
Arhancet, Cédric
2009-01-01
We introduce a noncommutative analogue of the Fig\\'a-Talamanca-Herz algebra $A_p(G)$ on the natural predual of the operator space $\\frak{M}_{p,cb}$ of completely bounded Schur multipliers on Schatten space $S_p$. We determine the isometric Schur multipliers and prove that the space $\\frak{M}_{p}$ of bounded Schur multipliers on Schatten space $S_p$ is the closure in the weak operator topology of the span of the isometric multipliers.
Design of a High Speed Multiplier (Ancient Vedic Mathematics Approach
R. Sridevi, Anirudh Palakurthi, Akhila Sadhula, Hafsa Mahreen
2013-07-01
Full Text Available In this paper, an area efficient multiplier architecture is presented. The architecture is based on Ancient algorithms of the Vedas, propounded in the Vedic Mathematics scripture of Sri Bharati Krishna Tirthaji Maharaja. The multiplication algorithm used here is called Nikhilam Navatascaramam Dasatah. The multiplier based on the ancient technique is compared with the modern multiplier to highlight the speed and power superiority of the Vedic Multipliers.
Design of a High Performance Reversible Multiplier
Md.Belayet Ali
2011-11-01
Full Text Available Reversible logic circuits are increasingly used in power minimization having applications such as low power CMOS design, optical information processing, DNA computing, bioinformatics, quantum computing and nanotechnology. The problem of minimizing the number of garbage outputs is an important issue in reversible logic design. In this paper we propose a new 44 universal reversible logic gate. The proposed reversible gate can be used to synthesize any given Boolean functions. The proposed reversible gate also can be used as a full adder circuit. In this paper we have used Peres gate and the proposed Modified HNG (MHNG gate to construct the reversible fault tolerant multiplier circuit. We show that the proposed 44 reversible multiplier circuit has lower hardware complexity and it is much better and optimized in terms of number of reversible gates and number of garbage outputs with compared to the existing counterparts.
ALU Using Area Optimized Vedic Multiplier
Anshul Khare
2014-07-01
Full Text Available —The load on general processor is increasing. For Fast Operations it is an extreme importance in Arithmetic Unit. The performance of Arithmetic Unit depends greatly on it multipliers. So, researchers are continuous searching for new approaches and hardware to implement arithmetic operation in huge efficient way in the terms of speed and area. Vedic Mathematics is the old system of mathematics which has a different technique of calculations based on total 16 Sutras. Proposed work has discussion of the quality of Urdhva Triyakbhyam Vedic approach for multiplication which uses different way than actual process of multiplication itself. It allows parallel generation of elements of products also eliminates undesired multiplication steps with zeros and mapped to higher level of bit using Karatsuba technique with processors, the compatibility to various data types. It is been observed that lot of delay is required by the conventional adders which are needed to have the partial products so in the work it is further optimized the Vedic multiplier type Urdhva Triyakbhyam by replacing the traditional adder with Carry save Adder to have more Delay Optimization. The proposed work shows improvement of speed as compare with the traditional designs. After the proposal discussion of the Vedic multiplier in the paper, It is been used for the implementation of Arithmetic unit using proposed efficient Vedic Multiplier it is not only useful for the improve efficiency the arithmetic module of ALU but also it is useful in the area of digital signal processing. The RTL entry of proposed Arithmetic unit done in VHDL it is synthesized and simulated with Xilinx ISE EDA tool. At the last the proposed Arithmetic Unit is validated on a FPGA device Vertex-IV.
Multiply manifolded molten carbonate fuel cells
Krumpelt, M.; Roche, M.F.; Geyer, H.K.; Johnson, S.A.
1994-08-01
This study consists of research and development activities related to the concept of a molten carbonate fuel cell (MCFC) with multiple manifolds. Objective is to develop an MCFC having a higher power density and a longer life than other MCFC designs. The higher power density will result from thinner gas flow channels; the extended life will result from reduced temperature gradients. Simplification of the gas flow channels and current collectors may also significantly reduce cost for the multiply manifolded MCFC.
Multiplier-free filters for wideband SAR
Dall, Jørgen; Christensen, Erik Lintz
2001-01-01
This paper derives a set of parameters to be optimized when designing filters for digital demodulation and range prefiltering in SAR systems. Aiming at an implementation in field programmable gate arrays (FPGAs), an approach for the design of multiplier-free filters is outlined. Design results ar...... are presented in terms of filter complexity and performance. One filter has been coded in VHDL and preliminary results indicate that the filter can meet a 2 GHz input sample rate....
Ghost Images in Schmidt CCD Photometry
无
2002-01-01
The wide field of the Schmidt telescope implies a greater chance of the field containing bright objects, and the presence of a corrector lens produces a certain type of ghost images. We summarize and confirm the features of such ghost images in Schmidt CCD photometry. The ghost images could be star-like under special observational conditions. The zenith distance of the telescope, among other factors, is found to correlate with different patterns of the ghost images. Some relevant issues are discussed and possible applications of our results are suggested.
New CCD Photometry Study of RV UMa
Tasselli, D
2015-01-01
All available CCD observation of RV UMa have been analyzed to obtain an accurate mathematical description of the ligh variation. We discuss in this paper a new study of variable star RV UMa, a short period RRab star, in orther to determine through the light curve and the physical parameters, the presence of "Blazhko effect". The Star were observed for a total of 839 sessions shooting, and exhibits light curve modulation with the shortest modulation Period=0.468002 ever observed. The result detect small but definite modification in temperature and mean radius of the star itself. All results are compared with previously published literature values and discussed.
Automobile Industry Retail Price Equivalent and Indirect Cost Multipliers
This report develops a modified multiplier, referred to as an indirect cost (IC) multiplier, which specifically evaluates the components of indirect costs that are likely to be affected by vehicle modifications associated with environmental regulation. A range of IC multipliers a...
Event Pileup in AXAF's ACIS CCD Camera
McNamara, Brian R.
1998-01-01
AXAF's high resolution mirrors will focus a point source near the optical axis to a spot that is contained within a radius of about two pixels on the ACIS Charge Coupled Devices (CCD) camera. Because of the small spot size, the accuracy to which fluxes and spectral energy distributions of bright point sources can be measured will be degrad3ed by event pileup. Event pileup occurs when two or more X-ray photons arrive simultaneously in a single detection cell on a CCD readout frame. When pileup occurs, ACIS's event detection algorithm registers the photons as a single X-ray event. The pulse height channel of the event will correspond to an energy E approximately E-1 + E-2...E-n, where n is the number of photons registered per detection cell per readout frame. As a result, pileup artificially hardens the observed spectral energy distribution. I will discuss the effort at the AXAF Science Center Lo calibrate pileup in ACIS using focused, nearly monochromatic X-ray source. I will discuss techniques for modeling and correcting pileup effects in polychromatic spectra.
Recent advances in ultrasensitive CCD camera technology
Christenson, Mark; Guntupalli, Ravi K.
2002-06-01
The current trend in diagnostic assay development is toward the use of smaller and smaller biological samples. The assay will then be required to identify a trace amount of a particular protein, nucleic acid or chemical species within a complex mixture of molecules. Due to the inherently low amount of analyte in these samples, a very sensitive detection device is required to make the measurement. In addition, many assays are becoming multi-parametric in order to reduce cost and lower the turnaround time of analysis. The increase in sample numbers can be dealt with by highly parallel analysis of samples either in an array format or in adjacent micro-channels. Another factor pushing the development toward highly parallel analysis is the desire to use high throughput methods to do measurements on multiple source samples in parallel. The highly parallel analysis can be readily achieved with imaging methods in contrast to the point measurements usually employed in current instrumentation. This paper will examine the recent trends in scientific grade CCD based imaging systems that are being driven by new development in CCD sensors, intensifiers and camera designs.
Aly, Radi; Dubey, Neeraj Kumar; Yahyaa, Mosaab; Abu-Nassar, Jackline; Ibdah, Mwafaq
2014-01-01
Strigolactones are phytohormones that stimulate seed germination of parasitic plants including Phelipanche aegyptiaca. Strigolactones are derived from carotenoids via a pathway involving the carotenoid cleavage dioxygenases CCD7 and CCD8. We report here identification of PaCCD7 and PaCCD8 orthologous genes from P. aegyptiaca. Expression analysis of PaCCD7 and PaCCD8 genes showed significant variation in their transcript levels in seeds and tubercles of P. aegyptiaca at different developmental stages. These two parasitic PaCCD7 and PaCCD8 genes were silenced in P. aegyptiaca using a trans-silencing approach in Nicotiana benthamiana. The transient knock-down of PaCCD7 and PaCCD8 inhibited tubercle development and the infestation process in host plants. Our results suggest an important role of the strigolactone associated genes (PaCCD7 and PaCCD8) in the parasite life cycle.
Novel CCD image processor for Z-plane architecture
Kemeny, S. E.; Eid, E.-S.; Fossum, E. R.
1989-09-01
The use of charge-coupled device (CCD) circuits in Z-plane architectures for focal-plane image processing is discussed. The low-power, compact layout nature of CCDs makes them attractive for Z-plane application. Three application areas are addressed: non-uniformity compensation using CCD MDAC circuits, neighborhood image processing functions implemented with CCD circuits, and the use of CCDs for buffering multiple image frames. Such buffering enables spatial-temporal image transformation for lossless compression.
Systolic multipliers for finite fields GF(2 exp m)
Yeh, C.-S.; Reed, I. S.; Truong, T. K.
1984-01-01
Two systolic architectures are developed for performing the product-sum computation AB + C in the finite field GF(2 exp m) of 2 exp m elements, where A, B, and C are arbitrary elements of GF(2 exp m). The first multiplier is a serial-in, serial-out one-dimensional systolic array, while the second multiplier is a parallel-in, parallel-out two-dimensional systolic array. The first multiplier requires a smaller number of basic cells than the second multiplier. The second multiplier needs less average time per computation than the first multiplier, if a number of computations are performed consecutively. To perform single computations both multipliers require the same computational time. In both cases the architectures are simple and regular and possess the properties of concurrency and modularity. As a consequence, they are well suited for use in VLSI systems.
Hall, David J., E-mail: d.j.hall@open.ac.uk [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Holland, Andrew; Soman, Matthew [e2v centre for electronic imaging, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)
2012-06-21
When considering the 'standard' gamma-camera, one might picture an array of photo-multiplier tubes or a similar array of small-area detectors. This array of imaging detectors would be attached to a corresponding array of scintillator modules (or a solid layer of scintillator) in order to give a high detection efficiency in the energy region of interest, usually 8-140 keV. Over recent years, developments of gamma-cameras capable of achieving much higher spatial resolutions have led to a new range of systems based on Charge-Coupled Devices with some form of signal multiplication between the scintillator and the CCD in order for one to distinguish the light output from the scintillator above the CCD noise. The use of an Electron-Multiplying Charge-Coupled Device (EM-CCD) incorporates the gain process within the CCD through a form of 'impact ionisation', however, the gain process introduces an 'excess noise factor' due to the probabilistic nature of impact ionisation and this additional noise consequently has an impact on the spatial and spectral resolution of the detector. Internal fluorescence in the scintillator, producing K-shell X-ray fluorescence photons that can be detected alongside the incident gamma-rays, also has a major impact on the imaging capabilities of gamma-cameras. This impact varies dramatically from the low spatial resolution to high spatial resolution camera system. Through a process of simulation and experimental testing focussed on the high spatial resolution (EM-CCD based) variant, the factors affecting the performance of gamma-camera systems are discussed and the results lead to important conclusions to be considered for the development of future systems. This paper presents a study into the influence of the EM-CCD gain process and the internal X-ray fluorescence in the scintillator on the performance of scintillator-based gamma cameras (CCD-based or otherwise), making use of Monte Carlo simulations to demonstrate
Proximity effects in cold gases of multiply charged atoms (Review)
Chikina, I.; Shikin, V.
2016-07-01
Possible proximity effects in gases of cold, multiply charged atoms are discussed. Here we deal with rarefied gases with densities nd of multiply charged (Z ≫ 1) atoms at low temperatures in the well-known Thomas-Fermi (TF) approximation, which can be used to evaluate the statistical properties of single atoms. In order to retain the advantages of the TF formalism, which is successful for symmetric problems, the external boundary conditions accounting for the finiteness of the density of atoms (donors), nd ≠ 0, are also symmetrized (using a spherical Wigner-Seitz cell) and formulated in a standard way that conserves the total charge within the cell. The model shows that at zero temperature in a rarefied gas of multiply charged atoms there is an effective long-range interaction Eproxi(nd), the sign of which depends on the properties of the outer shells of individual atoms. The long-range character of the interaction Eproxi is evaluated by comparing it with the properties of the well-known London dispersive attraction ELond(nd) interaction in gases. For the noble gases argon, krypton, and xenon Eproxi>0 and for the alkali and alkaline-earth elements Eproxi neutral complexes into charged fragments. This phenomenon appears consistently in the TF theory through the temperature dependence of the different versions of Eproxi. The anomaly in the thermal proximity effect shows up in the following way: for T ≠ 0 there is no equilibrium solution of TS statistics for single multiply charged atoms in a vacuum when the effect is present. Instability is suppressed in a Wigner-Seitz model under the assumption that there are no electron fluxes through the outer boundary R3 ∝ n-1d of a Wigner-Seitz cell. Eproxi corresponds to the definition of the correlation energy in a gas of interacting particles. This review is written so as to enable comparison of the results of the TF formalism with the standard assumptions of the correlation theory for classical plasmas. The classic
Design and Characterization of the CCD Detector Assemblies for ICON FUV
Champagne, J.; Syrstad, E. A.; Siegmund, O.; Darling, N.; Jelinsky, S. R.; Curtis, T.
2015-12-01
The Far Ultraviolet Imaging Spectrograph (FUV) on the upcoming Ionospheric Connection Explorer (ICON) mission uses dual image-intensified CCD camera systems, capable of detecting individual UV photons from both spectrometer channels (135.6 and 155 nm). Incident photons are converted to visible light using a sealed tube UV converter. The converter output is coupled to the CCD active area using a bonded fiber optic taper. The CCD (Teledyne DALSA FTT1010M) is a 1024x1024 frame transfer architecture. The camera readout electronics provide video imagery to the spacecraft over a 21 bit serialized LVDS interface, nominally at 10 frames per second and in 512x512 format (2x2 pixel binning). The CCD and primary electronics assembly reside in separate thermal zones, to minimize dark current without active cooling.Engineering and flight camera systems have been assembled, integrated, and tested under both ambient pressure and thermal vacuum environments. The CCD cameras have been fully characterized with both visible light (prior to integration with the UV converter) and UV photons (following system integration). Measured parameters include camera dark current, dark signal non-uniformity, read noise, linearity, gain, pulse height distribution, dynamic range, charge transfer efficiency, resolution, relative efficiency, quantum efficiency, and full well capacity. UV characterization of the camera systems over a range of microchannel plate (MCP) voltages during thermal vacuum testing demonstrates that camera performance will meet the critical on-orbit FUV dynamic range requirements. Flight camera integration with the FUV instrument and sensor calibration is planned for Fall 2015. Camera design and full performance data for the engineering and flight model cameras will be presented.
VLSI binary multiplier using residue number systems
Barsi, F.; Di Cola, A.
1982-01-01
The idea of performing multiplication of n-bit binary numbers using a hardware based on residue number systems is considered. This paper develops the design of a VLSI chip deriving area and time upper bounds of a n-bit multiplier. To perform multiplication using residue arithmetic, numbers are converted from binary to residue representation and, after residue multiplication, the result is reconverted to the original notation. It is shown that the proposed design requires an area a=o(n/sup 2/ log n) and an execution time t=o(log/sup 2/n). 7 references.
Programmable Clock Waveform Generation for CCD Readout
Vicente, J. de; Castilla, J.; Martinez, G.; Marin, J.
2006-07-01
Charge transfer efficiency in CCDs is closely related to the clock waveform. In this paper, an experimental framework to explore different FPGA based clock waveform generator designs is described. Two alternative design approaches for controlling the rise/fall edge times and pulse width of the CCD clock signal have been implemented: level-control and time-control. Both approaches provide similar characteristics regarding the edge linearity and noise. Nevertheless, dissimilarities have been found with respect to the area and frequency range of application. Thus, while the time-control approach consumes less area, the level control approach provides a wider range of clock frequencies since it does not suffer capacitor discharge effect. (Author) 8 refs.
Resolved CCD Photometry of Pluto and Charon
Jones, J.H.; Waddell, P.; Christian, C.A.
1988-04-01
Highly resolved CCD images of Pluto and Charon near maximum separation are measured with point spread function fitting techniques to determine independent magnitudes and an accurate separation for Pluto and Charon. A measured separation of 0.923 + or - 0.005 arcsec at a position angle of 173.3 + or - 0.3 deg on June 18, 1987 UT produced a value of 19558.0 + or - 153.0 km for the radius of Charon's orbit. An apparent B magnitude of 14.877 + or - 0.009 and (B-I) color of 1.770 + or - 0.015 are determined for Pluto, while Charon is fainter with B = 18.826 + or - 0.011 and slightly bluer with (B-I) = 1.632 + or - 0.018. 18 references.
New CCD photometry of asteroid (1028) Lydina
Yi-Bo Wang; Xiao-Bin Wang
2012-01-01
New CCD photometric observations for asteroid (1028) Lydina,carried out with the 1-m and 2.4-m telescopes at Yunnan Observatory from 2011 December 19 to 2012 February 3,are presented.Using the new light curves,the rotation period of 11.680±0.001 hours is derived with the Phase Dispersion Minimization (PDM) method.In addition,using the Amplitude-Aspect method,the elementary results of the pole orientation of asteroid (1028) Lydina are obtained:λp＝ 111°+4°-4°,βp＝ 31°+4°-5°.Meanwhile,the axial ratios of the tri-axial ellipsoid are estimated:a/b ＝ 1.77+0.10-0.08and b/c ＝ 1.17+0.07-0.09.
Evryscope Robotilter automated camera / ccd alignment system
Ratzloff, Jeff K.; Law, Nicholas M.; Fors, Octavi; Ser, Daniel d.; Corbett, Henry T.
2016-08-01
We have deployed a new class of telescope, the Evryscope, which opens a new parameter space in optical astronomy - the ability to detect short time scale events across the entire sky simultaneously. The system is a gigapixel-scale array camera with an 8000 sq. deg. field of view, 13 arcsec per pixel sampling, and the ability to detect objects brighter than g = 16 in each 2-minute exposure. The Evryscope is designed to find transiting exoplanets around exotic stars, as well as detect nearby supernovae and provide continuous records of distant relativistic explosions like gamma-ray-bursts. The Evryscope uses commercially available CCDs and optics; the machine and assembly tolerances inherent in the mass production of these parts introduce problematic variations in the lens / CCD alignment which degrades image quality. We have built an automated alignment system (Robotilters) to solve this challenge. In this paper we describe the Robotilter system, mechanical and software design, image quality improvement, and current status.
A CCD Spectrometer for One Dollar
Beaver, J.; Robert, D.
2011-09-01
We describe preliminary tests on a very low-cost system for obtaining stellar spectra for instructional use in an introductory astronomy laboratory. CCD imaging with small telescopes is now commonplace and relatively inexpensive. Giving students direct experience taking stellar spectra, however, is much more difficult, and the equipment can easily be out of reach for smaller institutions, especially if one wants to give the experience to large numbers of students. We have performed preliminary tests on an extremely low-cost (about $1.00) objective grating that can be coupled with an existing CCD camera or commercial digital single-lens reflex (DSLR) camera and a small telescope typical of introductory astronomy labs. With this equipment we believe it is possible for introductory astronomy students to take stellar spectra that are of high enough quality to distinguish between many MK spectral classes, or to determine standard B and V magnitudes. We present observational tests of this objective grating used on an 8" Schmidt-Cassegrain with a low-end, consumer DSLR camera. Some low-cost strategies for reducing the raw data are compared, with an eye toward projects ranging from individual undergraduate research projects to use by many students in a non-majors introductory astronomy lab. Toward this end we compare various trade offs between complexity of the observing and data reduction processes and the usefulness of the final results. We also describe some undergraduate astronomy education projects that this system could potentially be used for. Some of these projects could involve data-sharing collaborations between students at different institutions.
Radiation damage of the PCO Pixelfly VGA CCD camera of the BES system on KSTAR tokamak
Náfrádi, Gábor, E-mail: nafradi@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Kovácsik, Ákos, E-mail: kovacsik.akos@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Pór, Gábor, E-mail: por@reak.bme.hu [NTI, BME, EURATOM Association, H-1111 Budapest (Hungary); Lampert, Máté, E-mail: lampert.mate@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary); Un Nam, Yong, E-mail: yunam@nfri.re.kr [NFRI, 169-148 Gwahak-Ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of); Zoletnik, Sándor, E-mail: zoletnik.sandor@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary)
2015-01-11
A PCO Pixelfly VGA CCD camera which is part a of the Beam Emission Spectroscopy (BES) diagnostic system of the Korea Superconducting Tokamak Advanced Research (KSTAR) used for spatial calibrations, suffered from serious radiation damage, white pixel defects have been generated in it. The main goal of this work was to identify the origin of the radiation damage and to give solutions to avoid it. Monte Carlo N-Particle eXtended (MCNPX) model was built using Monte Carlo Modeling Interface Program (MCAM) and calculations were carried out to predict the neutron and gamma-ray fields in the camera position. Besides the MCNPX calculations pure gamma-ray irradiations of the CCD camera were carried out in the Training Reactor of BME. Before, during and after the irradiations numerous frames were taken with the camera with 5 s long exposure times. The evaluation of these frames showed that with the applied high gamma-ray dose (1.7 Gy) and dose rate levels (up to 2 Gy/h) the number of the white pixels did not increase. We have found that the origin of the white pixel generation was the neutron-induced thermal hopping of the electrons which means that in the future only neutron shielding is necessary around the CCD camera. Another solution could be to replace the CCD camera with a more radiation tolerant one for example with a suitable CMOS camera or apply both solutions simultaneously.
Radiation damage of the PCO Pixelfly VGA CCD camera of the BES system on KSTAR tokamak
Náfrádi, Gábor; Kovácsik, Ákos; Pór, Gábor; Lampert, Máté; Un Nam, Yong; Zoletnik, Sándor
2015-01-01
A PCO Pixelfly VGA CCD camera which is part a of the Beam Emission Spectroscopy (BES) diagnostic system of the Korea Superconducting Tokamak Advanced Research (KSTAR) used for spatial calibrations, suffered from serious radiation damage, white pixel defects have been generated in it. The main goal of this work was to identify the origin of the radiation damage and to give solutions to avoid it. Monte Carlo N-Particle eXtended (MCNPX) model was built using Monte Carlo Modeling Interface Program (MCAM) and calculations were carried out to predict the neutron and gamma-ray fields in the camera position. Besides the MCNPX calculations pure gamma-ray irradiations of the CCD camera were carried out in the Training Reactor of BME. Before, during and after the irradiations numerous frames were taken with the camera with 5 s long exposure times. The evaluation of these frames showed that with the applied high gamma-ray dose (1.7 Gy) and dose rate levels (up to 2 Gy/h) the number of the white pixels did not increase. We have found that the origin of the white pixel generation was the neutron-induced thermal hopping of the electrons which means that in the future only neutron shielding is necessary around the CCD camera. Another solution could be to replace the CCD camera with a more radiation tolerant one for example with a suitable CMOS camera or apply both solutions simultaneously.
Rhinoplasty for the multiply revised nose.
Foda, Hossam M T
2005-01-01
To evaluate the problems encountered on revising a multiply operated nose and the methods used in correcting such problems. The study included 50 cases presenting for revision rhinoplasty after having had 2 or more previous rhinoplasties. An external rhinoplasty approach was used in all cases. Simultaneous septal surgery was done whenever indicated. All cases were followed for a mean period of 32 months (range, 1.5-8 years). Evaluation of the surgical result depended on clinical examination, comparison of pre- and postoperative photographs, and degree of patients' satisfaction with their aesthetic and functional outcome. Functionally, 68% suffered nasal obstruction that was mainly caused by septal deviations and nasal valve problems. Aesthetically, the most common deformities of the upper two thirds of the nose included pollybeak (64%), dorsal irregularities (54%), dorsal saddle (44%), and open roof deformity (42%), whereas the deformities of lower third included depressed tip (68%), tip contour irregularities (60%), and overrotated tip (42%). Nasal grafting was necessary in all cases; usually more than 1 type of graft was used in each case. Postoperatively, 79% of the patients, with preoperative nasal obstruction, reported improved breathing; 84% were satisfied with their aesthetic result; and only 8 cases (16%) requested further revision to correct minor deformities. Revision of a multiply operated nose is a complex and technically demanding task, yet, in a good percentage of cases, aesthetic as well as functional improvement are still possible.
CCD characterization for a range of color cameras
Withagen, P.J.; Groen, F.C.A.; Schutte, K.
2005-01-01
CCD cameras are widely used for remote sensing and image processing applications. However, most cameras are produced to create nice images, not to do accurate measurements. Post processing operations such as gamma adjustment and automatic gain control are incorporated in the camera. When a (CCD) cam
Production of multiply charge-state ions in a multicusp ion source
Williams, M. D.; deVries, G. J.; Gough, R. A.; Leung, K. N.; Monroy, M.
1996-03-01
High charge state ion beams are commonly used in atomic and nuclear physics experiments. Multiply charged ions are normally produced in an ECR or in an EBIS. Multicusp generators can confine primary electrons very efficiently. Therefore, the electrical and gas efficiencies of these devices are high. Since the magnetic cusp fields are localized near the chamber wall, large volumes of uniform and high density plasmas can be obtained at low pressure, conditions favorable for the formation of multiply charged state ions. Attempts have been made at LBNL to generate multiply charged ion beams by employing a 25-cm diam by 25-cm long multicusp source. Experimental results demonstrated that charge states as high as 7+ can be obtained with argon or xenon plasmas. Multiply charged metallic ions such as tungsten and titanium have also been successfully formed in the multicusp source by evaporation and sputtering processes. In order to extend the charge state to higher values, a novel technique of injecting high energy electrons into the source plasma is proposed. If this is successful, the multicusp source will become very useful for radioactive beam accelerators, ion implantation, and nuclear physics applications.
Production of multiply charge-state ions in a multicusp ion source
Williams, M.D.; deVries, G.J.; Gough, R.A.; Leung, K.N.; Monroy, M. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
1996-03-01
High charge state ion beams are commonly used in atomic and nuclear physics experiments. Multiply charged ions are normally produced in an ECR or in an EBIS. Multicusp generators can confine primary electrons very efficiently. Therefore, the electrical and gas efficiencies of these devices are high. Since the magnetic cusp fields are localized near the chamber wall, large volumes of uniform and high density plasmas can be obtained at low pressure, conditions favorable for the formation of multiply charged state ions. Attempts have been made at LBNL to generate multiply charged ion beams by employing a 25-cm diam by 25-cm long multicusp source. Experimental results demonstrated that charge states as high as 7+ can be obtained with argon or xenon plasmas. Multiply charged metallic ions such as tungsten and titanium have also been successfully formed in the multicusp source by evaporation and sputtering processes. In order to extend the charge state to higher values, a novel technique of injecting high energy electrons into the source plasma is proposed. If this is successful, the multicusp source will become very useful for radioactive beam accelerators, ion implantation, and nuclear physics applications. {copyright} {ital 1996 American Institute of Physics.}
Performance of the low light level CCD camera for speckle imaging
Saha, S K
2002-01-01
A new generation CCD detector called low light level CCD (L3CCD) that performs like an intensified CCD without incorporating a micro channel plate (MCP) for light amplification was procured and tested. A series of short exposure images with millisecond integration time has been obtained. The L3CCD is cooled to about $-80^\\circ$ C by Peltier cooling.
Zima, W; De Ridder, J; Salmon, S; Catala, C; Kjeldsen, H; Aerts, C
2010-01-01
The PLATO satellite mission project is a next generation ESA Cosmic Vision satellite project dedicated to the detection of exo-planets and to asteroseismology of their host-stars using ultra-high precision photometry. The main goal of the PLATO mission is to provide a full statistical analysis of exo-planetary systems around stars that are bright and close enough for detailed follow-up studies. Many aspects concerning the design trade-off of a space-based instrument and its performance can best be tackled through realistic simulations of the expected observations. The complex interplay of various noise sources in the course of the observations made such simulations an indispensable part of the assessment study of the PLATO Payload Consortium. We created an end-to-end CCD simulation software-tool, dubbed PLATOSim, which simulates photometric time-series of CCD images by including realistic models of the CCD and its electronics, the telescope optics, the stellar field, the pointing uncertainty of the satellite ...
On multipliers of Fourier series in the Lorentz space
Ydyrys, Aizhan Zh.; Tleukhanova, Nazerke T.
2016-08-01
We study the multipliers of Fourier series on the Lorentz spaces, in particular, the sufficient conditions for a sequence of complex numbers {λk}k∈Z in order to make it a multiplier of trigonometric Fourier series of space Lp,r [0; 1] in the Lq,r [0; 1]. In the paper there is a new multipliers theorem which is supplement of the well-known theorems, and given a counterexample.
Implementation of MAC by using Modified Vedic Multiplier
2013-01-01
Multiplier Accumulator Unit (MAC) is a part of Digital Signal Processors. The speed of MAC depends on the speed of multiplier. So by using an efficient Vedic multiplier which excels in terms of speed, power and area, the performance of MAC can be increased. For this fast method of multiplication based on ancient Indian Vedic mathematics is proposed in this paper. Among various method of multiplication in Vedic mathematics, Urdhva Tiryagbhyam is used and the multiplication is for 32 X 32 bits....
Multiplier Accounting of Indian Mining Industry--The Concept
Hussain, A.; Karmakar, N. C.
2015-04-01
Input-output multipliers are indicators used for predicting the total impact on an economy due to the changes in its industrial demand and output. Also, input-output tables provide detailed dissection of the intermediate transactions in an economy. The aim of the paper is to put forward a basic framework of input-output economics as well as the multiplier concept. The outline of the methodology for calculating the multiplier associated with Indian mining industry is also presented.
Xue, Bo; Mao, Bingjing; Chen, Xiaomei; Ni, Guoqiang
2010-11-01
This paper renders a configurable distributed high performance computing(HPC) framework for TDI-CCD imaging simulation. It uses strategy pattern to adapt multi-algorithms. Thus, this framework help to decrease the simulation time with low expense. Imaging simulation for TDI-CCD mounted on satellite contains four processes: 1) atmosphere leads degradation, 2) optical system leads degradation, 3) electronic system of TDI-CCD leads degradation and re-sampling process, 4) data integration. Process 1) to 3) utilize diversity data-intensity algorithms such as FFT, convolution and LaGrange Interpol etc., which requires powerful CPU. Even uses Intel Xeon X5550 processor, regular series process method takes more than 30 hours for a simulation whose result image size is 1500 * 1462. With literature study, there isn't any mature distributing HPC framework in this field. Here we developed a distribute computing framework for TDI-CCD imaging simulation, which is based on WCF[1], uses Client/Server (C/S) layer and invokes the free CPU resources in LAN. The server pushes the process 1) to 3) tasks to those free computing capacity. Ultimately we rendered the HPC in low cost. In the computing experiment with 4 symmetric nodes and 1 server , this framework reduced about 74% simulation time. Adding more asymmetric nodes to the computing network, the time decreased namely. In conclusion, this framework could provide unlimited computation capacity in condition that the network and task management server are affordable. And this is the brand new HPC solution for TDI-CCD imaging simulation and similar applications.
Studying discharges in the Gas Electron Multiplies in Alice Detector
EُlGedawy, Omar
2016-01-01
Characterizing discharges is very important in the operation of the GEM detector. Once the discharges happen, a current will go through the GEM, the voltages across the GEM foils sides drop, charge amplification cannot take place anymore, resulting in a loss of signal. So the goal is to understand how the discharges evolve and propagate, in order to find requirements on the voltage settings, which allow to decrease the discharge probability.
Gaseous Electron Multiplier (GEM), foil holes deformation studies
Suhaj, Adam; CERN. Geneva. PH Department
2015-01-01
GEM detectors play an important role in the upcoming high-luminosity LHC upgrade in 2018 where they will be exposed to high doses of radiation in the muon endcap region. A series of tensile tests were performed on neutron irradiated and non-irradiated GEM foils where the shape of the holes was thoroughly examined. It was found that the GEM foil does not deform much at lower loads but the deformation gets exponentially bigger after applying more than a 60 N force. Both sets of samples behaved similarly at lower loads up to 40 N after which the holes of the irradiated samples started to deform more rapidly than the non-irradiated ones. The failure point of the non-irradiated samples occurred consistently at around 135 N while the irradiated samples experienced failure at around 85 N with two outliers failing at 120 and 135 N.
Ultrafast interatomic electronic decay in multiply excited clusters
Kuleff, Alexander I; Kopelke, Soeren; Cederbaum, Lorenz S
2010-01-01
An ultrafast mechanism belonging to the family of interatomic Coulombic decay (ICD) phenomena is proposed. When two excited species are present, an ultrafast energy transfer can take place bringing one of them to its ground state and ionizing the other one. It is shown that if large homoatomic clusters are exposed to an ultrashort and intense laser pulse whose photon energy is in resonance with an excitation transition of the cluster constituents, the large majority of ions will be produced by this ICD mechanism rather than by two-photon ionization. A related collective-ICD process that is operative in heteroatomic systems is also discussed.
Optimized Modulo Multiplier Based On R.N.S
Manjula.S.Doddamane
2013-07-01
Full Text Available To implement long and repetitive multiplications of cryptographic and signal processing algorithmwe often adopt residue number system. In this paper a new low power and low modulo multiplier foe well established {2n-1,2n,2n+1} based is proposed .Radix-8 Booth encoding technique is used in the proposed modulo 2n-1 and modulo 2n+1 multipliers. In the proposed modulo 2n-1 multiplier, the number of partial products is lowered to [n/3]+1. For modulo 2n+1 multiplication ,the aggregate bias due to the hard multiple and the modulo reduced partial product generation is composed of multiplier dependent dynamic bias and multiplier-independent static bias .In the proposed modulo 2n+1 multiplier , the number of partial products is lowered to n/3+6 .For different modulo 2n-1 and modulo 2n+1 multiplier our proposed modulo multiplier consumes less area and has minimum power dissipation over radix-4 Booth encoded and non-encoded modulo multiplier
Fission of Multiply Charged Alkali Clusters
Barnett, Robert N.; Yannouleas, Constantine; Landman, Uzi
2001-03-01
We use ab-initio molecular dynamics simulations to investigate the fission of multiply charged pure and mixed alkali clusters. Positive (+2 to +4) clusters of up to 30 atoms are considered. The clusters are initially equilibrated with a charge of +1 or +2 (depending on size) and at temperatures of 150 to 800 K. subsequently the clusters are further ionized and their evolution is followed. For doubly charged clusters binary fission occurs, while higher charged clusters fission through ternary or quaternary channels. The most common occurrence is the emission of a singly charged 3-atom cluster, which may occur repeatedly until the remaining cluster is stable. The dynamics of the fission process is discussed, and the results are compared with experiments and with the predictions of the liquid-drop and shell-corrected jellium models.
Four-gate transistor analog multiplier circuit
Mojarradi, Mohammad M. (Inventor); Blalock, Benjamin (Inventor); Cristoloveanu, Sorin (Inventor); Chen, Suheng (Inventor); Akarvardar, Kerem (Inventor)
2011-01-01
A differential output analog multiplier circuit utilizing four G.sup.4-FETs, each source connected to a current source. The four G.sup.4-FETs may be grouped into two pairs of two G.sup.4-FETs each, where one pair has its drains connected to a load, and the other par has its drains connected to another load. The differential output voltage is taken at the two loads. In one embodiment, for each G.sup.4-FET, the first and second junction gates are each connected together, where a first input voltage is applied to the front gates of each pair, and a second input voltage is applied to the first junction gates of each pair. Other embodiments are described and claimed.
无
2005-01-01
我最近看到富士公司新上市的数字相机FinePix S3 Pro的像素为：617万S像素，617万R像素，共1234万像素。请问：什么是S像素，什么是R像素？为什么富士的相机的像素标明S和R像素．而其它品牌的数字相机没有这样标明．富士相机的Super CCD SR传感器与其他品牌数字相机的CCD传感器相比，有什么特点？为什么总像素1234万像素；而有效像素却只有610万像素？另外。数字相机用的CMOS传感器与CCD传感器有什么异同?
Satish S Bhairannawar
2014-06-01
Full Text Available The Digital Image processing applications like medi cal imaging, satellite imaging, Biometric trait ima ges etc., rely on multipliers to improve the quality of image. However, existing multiplication techniques introduce errors in the output with consumption of more time, hence error free high speed multipliers has to be designed. In this paper we propose FPGA based Recursive Error Free Mitchell Log Multiplier (REFMLM for image Filters. The 2x2 error free Mitc hell log multiplier is designed with zero error by introducing error correction term is used in higher order Karastuba-Ofman Multiplier (KOM Architectures. The higher order KOM multipliers is decomposed into number of lower order multipliers using radix 2 till basic multiplier block of order 2x2 which is designed by error free Mitchell log mu ltiplier. The 8x8 REFMLM is tested for Gaussian filter to rem ove noise in fingerprint image. The Multiplier is synthesized using Spartan 3 FPGA family device XC3S 1500-5fg320. It is observed that the performance parameters such as area utilization, speed, error a nd PSNR are better in the case of proposed architec ture compared to existing architectures
Multipliers for Floating-Point Double Precision and Beyond on FPGAs
Banescu, Sebastian; De Dinechin, Florent; Pasca, Bogdan; Tudoran, Radu
2010-01-01
International audience; The implementation of high-precision floating-point applications on reconfigurable hardware requires a variety of large multipliers: Standard multipliers are the core of floating-point multipliers; Truncated multipliers, trading resources for a well-controlled accuracy degradation, are useful building blocks in situations where a full multiplier is not needed. This work studies the automated generation of such multipliers using the embedded multipliers and adders prese...
Development of the analog ASIC for multi-channel readout X-ray CCD camera
Nakajima, Hiroshi; Idehara, Toshihiro; Anabuki, Naohisa; Tsunemi, Hiroshi; Doty, John P; Ikeda, Hirokazu; Katayama, Haruyoshi; Kitamura, Hisashi; Uchihori, Yukio; 10.1016/j.nima.2010.12.174
2011-01-01
We report on the performance of an analog application-specific integrated circuit (ASIC) developed aiming for the front-end electronics of the X-ray CCDcamera system onboard the next X-ray astronomical satellite, ASTRO-H. It has four identical channels that simultaneously process the CCD signals. Distinctive capability of analog-to-digital conversion enables us to construct a CCD camera body that outputs only digital signals. As the result of the front-end electronics test, it works properly with low input noise of =<30 uV at the pixel rate below 100 kHz. The power consumption is sufficiently low of about 150 mW/chip. The input signal range of 720 mV covers the effective energy range of the typical X-ray photon counting CCD (up to 20 keV). The integrated non-linearity is 0.2% that is similar as those of the conventional CCDs in orbit. We also performed a radiation tolerance test against the total ionizing dose (TID) effect and the single event effect. The irradiation test using 60Co and proton beam showed ...
Log-converting processor element for CCD linear imaging arrays.
Chang, S H; Boyd, J T
1983-11-15
A photosensor element suitable for incorporation into charge-coupled device (CCD) imaging arrays in which the charge injected into the CCD is proportional to the logarithm of incident light intensity is presented. The photosensor element consists of a photodiode directly coupled to a two-stage MOSFET common source amplifier. This element occupies an area of 25 x 100 microm and is arranged so that it could be incorporated into a linear CCD imaging array having a period of 25 microm. A logarithmic response is measured over a 68.6-dB range of incident light intensity with a sensitivity of 55 mV/decade of light intensity.
Puesta en marcha de un microdensitómetro automático basado en CCD
Calderón, J. H.; Bustos Fierro, I. H.
We present the commisioning of a CCD-based microdensitometer intended to perform astrometric measurements of photographic plates. The work done consisted in the installation of a CCD camera, the modification of the motion system, the construction of a new illumination device, the adaptation of the electronics, and the development of software. The instrument is intended to be used for the astrometric measurement mainly of plates of the Astrographic Catalog and Carte du Ciel collections from Córdoba Observatory. In this phase of the project we counted with the collaboration of the Instituto Provincial de Enseñanza Media No 59, 25 de Mayo, Cruz Alta (Province of Córdoba). The origin and importance of such collaboration is commented.
Growth of delta-doped layers on silicon CCD/S for enhanced ultraviolet response
Hoenk, Michael E. (Inventor); Grunthaner, Paula J. (Inventor); Grunthaner, Frank J. (Inventor); Terhune, Robert W. (Inventor); Hecht, Michael H. (Inventor)
1994-01-01
The backside surface potential well of a backside-illuminated CCD is confined to within about half a nanometer of the surface by using molecular beam epitaxy (MBE) to grow a delta-doped silicon layer on the back surface. Delta-doping in an MBE process is achieved by temporarily interrupting the evaporated silicon source during MBE growth without interrupting the evaporated p+ dopant source (e.g., boron). This produces an extremely sharp dopant profile in which the dopant is confined to only a few atomic layers, creating an electric field high enough to confine the backside surface potential well to within half a nanometer of the surface. Because the probability of UV-generated electrons being trapped by such a narrow potential well is low, the internal quantum efficiency of the CCD is nearly 100% throughout the UV wavelength range. Furthermore, the quantum efficiency is quite stable.
Upgrade of ESO's FIERA CCD Controller and PULPO Subsystem
Reyes-Moreno, J.; Geimer, C.; Balestra, A.; Haddad, N.
An overview of FIERA is presented with emphasis on its recent upgrade to PCI. The PCI board hosts two DSPs, one for real time control of the camera and another for on-the-fly processing of the incoming video data. In addition, the board is able to make DMA transfers, to synchronize to other boards alike, to be synchronized by a TIM bus and to control PULPO via RS232. The design is based on the IOP480 chip from PLX, for which we have developed a device driver for both Solaris and Linux. One computer is able to host more than one board and therefore can control an array of FIERA detector electronics. PULPO is a multifunctional subsystem widely used at ESO for the housekeeping of CCD cryostat heads and for shutter control. The upgrade of PULPO is based on an embedded PC running Linux. The upgraded PULPO is able to handle 29 temperature sensors, control 8 heaters and one shutter, read out one vacuum sensor and log any combination of parameters.
Enzymatic study on AtCCD4 and AtCCD7 and their potential to form acyclic regulatory metabolites
Bruno, Mark
2016-09-29
The Arabidopsis carotenoid cleavage dioxygenase 4 (AtCCD4) is a negative regulator of the carotenoid content of seeds and has recently been suggested as a candidate for the generation of retrograde signals that are thought to derive from the cleavage of poly-cis-configured carotene desaturation intermediates. In this work, we investigated the activity of AtCCD4 in vitro and used dynamic modeling to determine its substrate preference. Our results document strict regional specificity for cleavage at the C9–C10 double bond in carotenoids and apocarotenoids, with preference for carotenoid substrates and an obstructing effect on hydroxyl functions, and demonstrate the specificity for all-trans-configured carotenes and xanthophylls. AtCCD4 cleaved substrates with at least one ionone ring and did not convert acyclic carotene desaturation intermediates, independent of their isomeric states. These results do not support a direct involvement of AtCCD4 in generating the supposed regulatory metabolites. In contrast, the strigolactone biosynthetic enzyme AtCCD7 converted 9-cis-configured acyclic carotenes, such as 9-cis-ζ-carotene, 9\\'-cis-neurosporene, and 9-cis-lycopene, yielding 9-cis-configured products and indicating that AtCCD7, rather than AtCCD4, is the candidate for forming acyclic retrograde signals.
A new proof of the Lagrange multiplier rule
J. Brinkhuis (Jan); V. Protassov (Vladimir)
2015-01-01
textabstractWe present an elementary self-contained proof for the Lagrange multiplier rule. It does not refer to any substantial preparations and it is only based on the observation that a certain limit is positive. At the end of this note, the power of the Lagrange multiplier rule is analyzed.
Dimension of the $c$-nilpotent multiplier of Lie algebras
MEHDI ARASKHAN; MOHAMMAD REZA RISMANCHIAN
2016-08-01
The purpose of this paper is to derive some inequalities for dimension of the $c$-nilpotent multiplier of finite dimensional Lie algebras and their factor Lie algebras. We further obtain an inequality between dimensions of $c$-nilpotent multiplier of Lie algebra $L$ and tensor product of a central ideal by its abelianized factor Lie algebra
OPERATOR-VALUED FOURIER MULTIPLIER THEOREMS ON TRIEBEL SPACES
Bu Shangquan; Kim Jin-Myong
2005-01-01
The authors establish operator-valued Fourier multiplier theorems on Triebel spaces on RN, where the required smoothness of the multiplier functions depends on the dimension N and the indices of the Triebel spaces. This is used to give a sufficient condition of the maximal regularity in the sense of Triebel spaces for vector-valued Cauchy problems with Dirichlet boundary conditions.
Operator-valued Fourier Multipliers on Periodic Triebel Spaces
Shang Quan BU; Jin Myong KIM
2005-01-01
We establish operator-valued Fourier multiplier theorems on periodic Triebel spaces, where the required smoothness of the multipliers depends on the indices of the Triebel spaces. This is used to give a characterization of the maximal regularity in the sense of Triebel spaces for Cauchy problems with periodic boundary conditions.
Multiplier theorems for special Hermite expansions on Cn
无
2000-01-01
The weak type (1,1) estimate for special Hermite expansions on Cn is proved by using the Calderón-Zygmund decomposition. Then the multiplier theorem in Lp(1
multipliers for a certain kind of Laguerre expansions are given in Lp space.
Design of Reversible Multipliers for Linear Filtering Applications in DSP
Rakshith Saligram
2012-12-01
Full Text Available Multipliers in DSP computations are crucial. Thus modern DSP systems need to develop low power multipliers to reduce the power dissipation. One of the efficient ways to reduce power dissipation is by the use of bypassing technique. If a bit in the multiplier and/or multiplicand is zero the whole array of rowand/or diagonal will be bypassed and hence the name bypass multipliers. This paper presents the column Bypass multiplier and 2-D bypass multiplier using reversible logic; Reversible logic is a more prominent technology, having its applications in Low Power CMOS and quantum computations. The switching activity of any component in the bypass multiplier depends only on the input bit coefficients. The semultipliers find application in linear filtering FFT computational units, particularly during zero padding where there will be umpteen numbers of zeros. A bypass multiplier reduces the number of switching activities as well as the power consumption, above which reversible logic design acts to further almost nullify the dissipations
Multipliers for the Absolute Euler Summability of Fourier Series
Prem Chandra
2001-05-01
In this paper, the author has investigated necessary and sufficient conditions for the absolute Euler summability of the Fourier series with multipliers. These conditions are weaker than those obtained earlier by some workers. It is further shown that the multipliers are best possible in certain sense.
An Efficient 16-Bit Multiplier based on Booth Algorithm
Khan, M. Zamin Ali; Saleem, Hussain; Afzal, Shiraz; Naseem, Jawed
2012-11-01
Multipliers are key components of many high performance systems such as microprocessors, digital signal processors, etc. Optimizing the speed and area of the multiplier is major design issue which is usually conflicting constraint so that improving speed results mostly in bigger areas. A VHDL designed architecture based on booth multiplication algorithm is proposed which not only optimize speed but also efficient on energy use.
L-R smash products for multiplier Hopf algebras
ZHAO Li-hui; LU Di-ming; FANG Xiao-li
2008-01-01
The theory of L-R smash product is extended to multiplier Hopf algebras and a sufficient condition for L-R smash product to be regular multiplier Hopf algebras is given. In particular the result of the paper implies Delvaux's main theorem in the case of smash products.
Design and Performance Analysis of Various Adders and Multipliers Using GDI Technique
Simran kaur; Balwinder Singh; Jain, D.K.
2015-01-01
With the active development of portable electronic devices, the need for low power dissipation, high speed and compact implementation, give rise to several research intentions. There are several design techniques used for the circuit configuration in VLSI systems but there are very few design techniques that gives the required extensibility. This paper describes the implementation of various adders and multipliers. The design approach proposed in the article is based on the GDI (G...
Development of the data acquisition system for the x-ray CCD camera (SXI) onboard ASTRO-H
Fujinaga, Takahisa; Anabuki, Naohisa; Aoyama, Shoichi; Kawano, Hidenori; Ikeda, Shoma; Iwai, Masachika; Ozaki, Masanobu; Dotani, Tadayasu; Natsukari, Chikara; Matsuta, Keiko; Shimizu, Kazuma; Nakajima, Hiroshi; Hayashida, Kiyoshi; Tsunemi, Hiroshi; Ueda, Shutaro; Komatsu, Shoji; Murayoshi, Taku; Mori, Koji; Watanabe, Tatsuo; Uchida, Hiroyuki; Ohnishi, Takao; Hiraga, Junko S.
2011-09-01
We present the development of the data acquisition system for the X-ray CCD camera (SXI: Soft X-ray Imager) onboard the ASTRO-H satellite. Two types of breadboard models (BBMs) of SXI electronics have been produced to verify the functions of each circuit board and to establish the data acquisition system from CCD to SpaceWire (SpW) I/F. Using BBM0, we verified the basic design of the CCD driver, function of the Δ∑-ADC, data acquisition of the frame image, and stability of the SpW communication. We could demonstrate the energy resolution of 164 eV (FWHM) at 5.9 keV. Using BBM1, we verified acquisition of the housekeeping information and the frame images.
Glitch Reduction in Low- Power Low- Frequency Multiplier
Bhethala Rajasekhar
2014-01-01
Full Text Available Multiplication is an essential arithmetic operation for common DSP applications, such as filtering and fast Fourier transform (FFT. To achieve high execution speed, parallel array multipliers are widely used. These multipliers tend to consume most of the power in DSP computations, and thus power-efficient multipliers are very important for the design of low-power DSP systems. A straightforward approach is to design a full adder (FA that consumes less power. Power reduction can also be achieved through structural modification. For example, rows of partial products can be ignored. In this project a 10 transistor full adder is designed for low power which is used in the implementation of different types of multipliers. All these multipliers are compared for different technologies. A power gating technique is used by placing an MTCMOS cell is used at fine grain level so as to minimize the leakage power.
COMPARATIVE DESIGN OF REGULAR STRUCTURED MODIFIED BOOTH MULTIPLIER
Ram RackshaTripathi
2016-04-01
Full Text Available Multiplication is a crucial function and plays a vital role for practically any DSP system. Several DSP algorithms require different types of multiplications, specifically modified booth multiplication algorithm. In this paper, a simple approach is proposed for generating last partial product row for reducing extra sign (negative bit bit to achieve more regular structure. As compared to the conventional multipliers these proposed modified Booth’s multipliers can achieve improved reduction in area 5.9%, power 3.2%, and delay 0.5% for 8 x 8 multipliers. We can also observe that achievable improvement for 16 x 16 multiplier in area, power, delay are 4.0%, 2.3%, 0.3% respectively. These multipliers are implemented using verilog HDL and synthesized by using synopsis design compiler with an Artisan TSMC 90nm Technology
Atmospheric correction of CBERS CCD images with MODIS data
LI; Junsheng; ZHANG; Bing; CHEN; Zhengchao; SHEN; Qian
2006-01-01
China Brazil Earth Resource Satellite (CBERS) CCD images have much potential for inland water environmental monitoring. However, their atmospheric accuracy correction can affect their quantitative applications. This paper contains an atmospheric correction algorithm for CBERS CCD images with MODIS data from the same day, the use of which improves the atmospheric correction algorithm of ocean color remote sensing developed by Gordon (1993, 1994) and makes it applicable to inland waters. The improved algorithm retrieves atmospheric parameters from MODIS data and uses them to perform the atmospheric correction of CBERS CCD images. Experimental results show that the atmospheric correction algorithm of CBERS CCD images assisted by MODIS data is reliable. Furthermore, MODIS data can be freely obtained on a daily basis, making the algorithm developed in this paper useful for environmental monitoring of inland waters.
Correlation and image compression for limited-bandwidth CCD.
Thompson, Douglas G.
2005-07-01
As radars move to Unmanned Aerial Vehicles with limited-bandwidth data downlinks, the amount of data stored and transmitted with each image becomes more significant. This document gives the results of a study to determine the effect of lossy compression in the image magnitude and phase on Coherent Change Detection (CCD). We examine 44 lossy compression types, plus lossless zlib compression, and test each compression method with over 600 CCD image pairs. We also derive theoretical predictions for the correlation for most of these compression schemes, which compare favorably with the experimental results. We recommend image transmission formats for limited-bandwidth programs having various requirements for CCD, including programs which cannot allow performance degradation and those which have stricter bandwidth requirements at the expense of CCD performance.
Micrometer and CCD measurements of double stars (Series 51
Popović G.M.
1998-01-01
Full Text Available 36 micrometric measurements of 20 double or multiple systems carried out with the Zeiss 65/1055 cm Refractor of Belgrade Observatory are communicated. Also 35 CCD measurements of 15 double or multiple systems are included.
Target Image Matching Algorithm Based on Binocular CCD Ranging
Dongming Li
2014-01-01
Full Text Available This paper proposed target image in a subpixel level matching algorithm for binocular CCD ranging, which is based on the principle of binocular CCD ranging. In the paper, firstly, we introduced the ranging principle of the binocular ranging system and deduced a binocular parallax formula. Secondly, we deduced the algorithm which was named improved cross-correlation matching algorithm and cubic surface fitting algorithm for target images matched, and it could achieve a subpixel level matching for binocular CCD ranging images. Lastly, through experiment we have analyzed and verified the actual CCD ranging images, then analyzed the errors of the experimental results and corrected the formula of calculating system errors. Experimental results showed that the actual measurement accuracy of a target within 3 km was higher than 0.52%, which meet the accuracy requirements of the high precision binocular ranging.
Collection and processing data for high quality CCD images.
Doerry, Armin Walter
2007-03-01
Coherent Change Detection (CCD) with Synthetic Aperture Radar (SAR) images is a technique whereby very subtle temporal changes can be discerned in a target scene. However, optimal performance requires carefully matching data collection geometries and adjusting the processing to compensate for imprecision in the collection geometries. Tolerances in the precision of the data collection are discussed, and anecdotal advice is presented for optimum CCD performance. Processing considerations are also discussed.
Optimizing strassen matrix multiply on GPUs
ul Hasan Khan, Ayaz
2015-06-01
© 2015 IEEE. Many core systems are basically designed for applications having large data parallelism. Strassen Matrix Multiply (MM) can be formulated as a depth first (DFS) traversal of a recursion tree where all cores work in parallel on computing each of the NxN sub-matrices that reduces storage at the detriment of large data motion to gather and aggregate the results. We propose Strassen and Winograd algorithms (S-MM and W-MM) based on three optimizations: a set of basic algebra functions to reduce overhead, invoking efficient library (CUBLAS 5.5), and parameter-tuning of parametric kernel to improve resource occupancy. On GPUs, W-MM and S-MM with one recursion level outperform CUBLAS 5.5 Library with up to twice as faster for large arrays satisfying N>=2048 and N>=3072, respectively. Compared to NVIDIA SDK library, S-MM and W-MM achieved a speedup between 20x to 80x for the above arrays. The proposed approach can be used to enhance the performance of CUBLAS and MKL libraries.
Beyond Linear Delay Multipliers in Air Transport
Seddik Belkoura
2017-01-01
Full Text Available Delays are considered one of the most important burdens of air transport, both for their social and environmental consequences and for the cost they cause for airlines and passengers. It is therefore not surprising that a large effort has been devoted to study how they propagate through the system. One of the most important indicators to assess such propagation is the delay multiplier, a ratio between outbound and inbound average delays; in spite of its widespread utilisation, its simplicity precludes capturing all details about the dynamics behind the diffusion process. Here we present a methodology that extracts a more complete relationship between the in- and outbound delays, distinguishing a linear and a nonlinear phase and thus yielding a richer description of the system’s response as a function of the delay magnitude. We validate the methodology through the study of a historical data set of flights crossing the European airspace and show how its most important airports have heterogeneous ways of reacting to extreme delays and that this reaction strongly depends on some of their global properties.
An Optimized Sparse Approximate Matrix Multiply
Bock, Nicolas
2012-01-01
We present an optimized single-precision implementation of the Sparse Approximate Matrix Multiply (\\SpAMM{}) [M. Challacombe and N. Bock, arXiv {\\bf 1011.3534} (2010)], a fast algorithm for matrix-matrix multiplication for matrices with decay that achieves an $\\mathcal{O} (n \\ln n)$ computational complexity with respect to matrix dimension $n$. We find that the max norm of the error matrix achieved with a \\SpAMM{} tolerance of below $2 \\times 10^{-8}$ is lower than that of the single-precision {\\tt SGEMM} for quantum chemical test matrices, while outperforming {\\tt SGEMM} with a cross-over already for small matrices ($n \\sim 1000$). Relative to naive implementations of \\SpAMM{} using optimized versions of {\\tt SGEMM}, such as those found in Intel's Math Kernel Library ({\\tt MKL}) or AMD's Core Math Library ({\\tt ACML}), our optimized version is found to be significantly faster. Detailed performance comparisons are made with for quantum chemical matrices of RHF/STO-2G and RHF/6-31G${}^{**}$ water clusters.
Yang, Zhao-Di; Feng, Ji-Kang; Ren, Ai-Min; Sun, Chia-Chung
2006-12-28
We have theoretically investigated a series of multiply N-confused porphyrins and their Zn or Cu complexes for the first time by using DFT(B3LYP/6-31G*) and ZINDO/SOS methods. The electronic structure, one-photon absorption (OPA), and two-photon absorption (TPA) properties have been studied in detail. The calculated results indicate that the OPA spectra of multiply N-confused porphyrins are red-shifted and the OPA intensities decrease compared to normal porphyrin. The maximum two photon absorption wavelengths lambda(max) are blue-shifted and the TPA cross sections delta(max) are increased 22.7-112.1 GM when the N atoms one by one are inverted from core to beta position to form multiply N-confused porphyrins. Especially delta(max) of N3CP get to 164.7 GM. The electron donors -C6F5s at meso-position can make the TPA cross section delta(max) increase. After forming metal complexes with Cu or Zn, the TPA properties of multiply N-confused porphyrins are further increased except for N3CP, N4CP. Our theoretical findings demonstrate that the multiply N-confused prophyrins as well as their metal complexes and derivatives are promising molecules that can be assembled series of materials with large TPA cross section, and are sure to be the subject of further investigation.
Dyadic Bivariate Wavelet Multipliers in L2(R2)
Zhong Yan LI; Xian Liang SHI
2011-01-01
The single 2 dilation wavelet multipliers in one-dimensional case and single A-dilation (where A is any expansive matrix with integer entries and |detA|＝2)wavelet multipliers in twodimensional case were completely characterized by Wutam Consortium(1998)and Li Z.,et al.(2010).But there exist no results on multivariate wavelet multipliers corresponding to integer expansive dilation.matrix with the absolute value of determinant not 2 in L2(R2).In this paper,we choose 2I2＝(0202)as the dilation matrix and consider the 2I2-dilation multivariate wavelet Ψ＝{ψ1,ψ2,ψ3}(which is called a dyadic bivariate wavelet)multipliers.Here we call a measurable function family f＝{f1,f2,f3}a dyadic bivariate wavelet multiplier if Ψ1＝{F-1(f1ψ1),F-1(f2ψ2),F-1(f3ψ3)} is a dyadic bivariate wavelet for any dyadic bivariate wavelet Ψ={ψ1,ψ2,ψ3},where(f)and,F-1 denote the Fourier transform and the inverse transform of function f respectively.We study dyadic bivariate wavelet multipliers,and give some conditions for dyadic bivariate wavelet multipliers.We also give concrete forms of linear phases of dyadic MRA bivariate wavelets.
High-resolution image digitizing through 12x3-bit RGB-filtered CCD camera
Cheng, Andrew Y. S.; Pau, Michael C. Y.
1996-09-01
A high resolution computer-controlled CCD image capturing system is developed by using a 12 bits 1024 by 1024 pixels CCD camera and motorized RGB filters to grasp an image with color depth up to 36 bits. The filters distinguish the major components of color and collect them separately while the CCD camera maintains the spatial resolution and detector filling factor. The color separation can be done optically rather than electronically. The operation is simply by placing the capturing objects like color photos, slides and even x-ray transparencies under the camera system, the necessary parameters such as integration time, mixing level and light intensity are automatically adjusted by an on-line expert system. This greatly reduces the restrictions of the capturing species. This unique approach can save considerable time for adjusting the quality of image, give much more flexibility of manipulating captured object even if it is a 3D object with minimal setup fixers. In addition, cross sectional dimension of a 3D capturing object can be analyzed by adapting a fiber optic ring light source. It is particularly useful in non-contact metrology of a 3D structure. The digitized information can be stored in an easily transferable format. Users can also perform a special LUT mapping automatically or manually. Applications of the system include medical images archiving, printing quality control, 3D machine vision, and etc.
Fix-point Multiplier Distributions in Discrete Turbulent Cascade Models
Jouault, B; Lipa, P
1998-01-01
One-point time-series measurements limit the observation of three-dimensional fully developed turbulence to one dimension. For one-dimensional models, like multiplicative branching processes, this implies that the energy flux from large to small scales is not conserved locally. This then renders the random weights used in the cascade curdling to be different from the multipliers obtained from a backward averaging procedure. The resulting multiplier distributions become solutions of a fix-point problem. With a further restoration of homogeneity, all observed correlations between multipliers in the energy dissipation field can be understood in terms of simple scale-invariant multiplicative branching processes.
Comparison of a CCD and an APS for soft X-ray diffraction
Stewart, Graeme; Bates, R.; Blue, A.; Clark, A.; Dhesi, S. S.; Maneuski, D.; Marchal, J.; Steadman, P.; Tartoni, N.; Turchetta, R.
2011-12-01
We compare a new CMOS Active Pixel Sensor (APS) to a Princeton Instruments PIXIS-XO: 2048B Charge Coupled Device (CCD) with soft X-rays tested in a synchrotron beam line at the Diamond Light Source (DLS). Despite CCDs being established in the field of scientific imaging, APS are an innovative technology that offers advantages over CCDs. These include faster readout, higher operational temperature, in-pixel electronics for advanced image processing and reduced manufacturing cost. The APS employed was the Vanilla sensor designed by the MI3 collaboration and funded by an RCUK Basic technology grant. This sensor has 520 x 520 square pixels, of size 25 μm on each side. The sensor can operate at a full frame readout of up to 20 Hz. The sensor had been back-thinned, to the epitaxial layer. This was the first time that a back-thinned APS had been demonstrated at a beam line at DLS. In the synchrotron experiment soft X-rays with an energy of approximately 708 eV were used to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of integration times with both sensors. The CCD had to be operated at a temperature of -55°C whereas the Vanilla was operated over a temperature range from 20°C to -10°C. We show that the APS detector can operate with frame rates up to two hundred times faster than the CCD, without excessive degradation of image quality. The signal to noise of the APS is shown to be the same as that of the CCD at identical integration times and the response is shown to be linear, with no charge blooming effects. The experiment has allowed a direct comparison of back thinned APS and CCDs in a real soft x-ray synchrotron experiment.
Scientific CCD characterisation at Universidad Complutense LICA Laboratory
Tulloch, S.; Gil de Paz, A.; Gallego, J.; Zamorano, J.; Tapia, Carlos
2012-07-01
A CCD test-bench has been built at the Universidad Complutensés LICA laboratory. It is initially intended for commissioning of the MEGARA1 (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) instrument but can be considered as a general purpose scientific CCD test-bench. The test-bench uses an incandescent broad-band light source in combination with a monochromator and two filter wheels to provide programmable narrow-band illumination across the visible band. Light from the monochromator can be directed to an integrating sphere for flat-field measurements or sent via a small aperture directly onto the CCD under test for high accuracy diode-mode quantum efficiency measurements. Point spread function measurements can also be performed by interposing additional optics between sphere and the CCD under test. The whole system is under LabView control via a clickable GUI. Automated measurement scans of quantum efficiency can be performed requiring only that the user replace the CCD under test with a calibrated photodiode after each measurement run. A 20cm diameter cryostat with a 10cm window and Brooks Polycold PCC closed-cycle cooler also form part of the test-bench. This cryostat is large enough to accommodate almost all scientific CCD formats has initially been used to house an E2V CCD230 in order to fully prove the test-bench functionality. This device is read-out using an Astronomical Research Camera controller connected to the UKATC's UCAM data acquisition system.
Noise limitations of multiplier phototubes in the radiation environment of space
Viehmann, W.; Eubanks, A. G.
1976-01-01
The contributions of Cerenkov emission, luminescence, secondary electron emission, and bremsstrahlung to radiation-induced data current and noise of multiplier phototubes were analyzed quantitatively. Fluorescence and Cerenkov emission in the tube window are the major contributors and can quantitatively account for dark count levels observed in orbit. Radiation-induced noise can be minimized by shielding, tube selection, and mode of operation. Optical decoupling of windows and cathode (side-window tubes) leads to further reduction of radiation-induced dark counts, as does reducing the window thickness and effective cathode area, and selection of window/cathode combinations of low fluorescence efficiency. In trapped radiation-free regions of near-earth orbits and in free space, Cerenkov emission by relativistic particles contributes predominantly to the photoelectron yield per event. Operating multiplier phototubes in the photon (pulse) counting mode will discriminate against these large pulses and substantially reduce the dark count and noise to levels determined by fluorescence.
NOVEL REVERSIBLE VARIABLE PRECISION MULTIPLIER USING REVERSIBLE LOGIC GATES
M. Saravanan; K. Suresh Manic
2014-01-01
.... In this study a reversible logic gate based design of variable precision multiplier is proposed which have the greater efficiency in power consumption and speed since the partial products received...
Design of Low Power Vedic Multiplier Based on Reversible Logic
Sagar
2017-03-01
Full Text Available Reversible logic is a new technique to reduce the power dissipation. There is no loss of information in reversible logic and produces unique output for specified inputs and vice-versa. There is no loss of bits so the power dissipation is reduced. In this paper new design for high speed, low power and area efficient 8-bit Vedic multiplier using Urdhva Tiryakbhyam Sutra (ancient methodology of Indian mathematics is introduced and implemented using Reversible logic to generate products with low power dissipation. UT Sutra generates partial product and sum in single step with less number of adders unit when compare to conventional booth and array multipliers which will reduce the delay and area utilized, Reversible logic will reduce the power dissipation. An 8-bit Vedic multiplier is realized using a 4-bit Vedic multiplier and modified ripple carry adders. The proposed logic blocks are implemented using Verilog HDL programming language, simulation using Xilinx ISE software.
A LOW-PHASE NOISE FREQUENCY MULTIPLIER CHAIN ...
Consequently, the driving crystal oscillators and the first multiplier .... the upper cut off frequency of the system and its asymptotic slope. ..... (SMHz}, the order of multipliction of the. "difference" ... upto 300GHz. To go higher in frequency it is.
Multipliers of Marcinkiewicz type for spherical harmonic expansions
陆善镇; 马柏林
1996-01-01
A sufficient condition for multipliers on the unit sphere to be bounded in is given. The condition is analogous to those of Marcinkiewicz criterions, which is an extension of A. Bonami and J. L. Clerc’s.
Gauss-Bonnet dark energy by Lagrange multipliers
Capozziello, Salvatore; Odintsov, Sergei D
2013-01-01
A string-inspired effective theory of gravity, containing Gauss-Bonnet invariant interacting with a scalar field, is considered in view of obtaining cosmological dark energy solutions. A Lagrange multiplier is inserted into the action in order to achieve the cosmological reconstruction by selecting suitable forms of couplings and potentials. Several cosmological exact solutions (including dark energy of quintessence, phantom or Little Rip type) are derived in presence and in absence of the Lagrange multiplier showing the difference in the two dynamical approaches. In the models that we consider, the Lagrange multiplier behaves as a sort of dust fluid that realizes the transitions between matter dominated and dark energy epochs. The relation between Lagrange multipliers and Noether symmetries is discussed.
Efek Multiplier Zakat Terhadap Pendapatan di Propinsi DKI Jakarta
M. Nur Rianto Al Arif
2015-10-01
Full Text Available The aim of this research is to analyze the multiplier effect of zakah revenue in DKI Jakarta, a study case at Badan Amil Zakat, Infak, and Shadaqah (BAZIS DKI Jakarta. Least square methods is used to analyze the data. The coefficient will be used to calculate the multiplier effect of zakah revenue and it will be compared with the economy without zakah revenue. The result showed 2,522 multiplier effects of zakah revenue and 3,561 multiplier effect of economic income without zakah revenue. This suggest that the management of zakah in BAZIS DKI Jakarta still can have a significant influence on the economyDOI: 10.15408/aiq.v4i1.2079
Sociophysics of sexism: normal and anomalous petrie multipliers
Eliazar, Iddo
2015-07-01
A recent mathematical model by Karen Petrie explains how sexism towards women can arise in organizations where male and female are equally sexist. Indeed, the Petrie model predicts that such sexism will emerge whenever there is a male majority, and quantifies this majority bias by the ‘Petrie multiplier’: the square of the male/female ratio. In this paper—emulating the shift from ‘normal’ to ‘anomalous’ diffusion—we generalize the Petrie model to a stochastic Poisson model that accommodates heterogeneously sexist men and woman, and that extends the ‘normal’ quadratic Petrie multiplier to ‘anomalous’ non-quadratic multipliers. The Petrie multipliers span a full spectrum of behaviors which we classify into four universal types. A variation of the stochastic Poisson model and its Petrie multipliers is further applied to the context of cyber warfare.
Visual enhancement of laparoscopic nephrectomies using the 3-CCD camera
Crane, Nicole J.; Kansal, Neil S.; Dhanani, Nadeem; Alemozaffar, Mehrdad; Kirk, Allan D.; Pinto, Peter A.; Elster, Eric A.; Huffman, Scott W.; Levin, Ira W.
2006-02-01
Many surgical techniques are currently shifting from the more conventional, open approach towards minimally invasive laparoscopic procedures. Laparoscopy results in smaller incisions, potentially leading to less postoperative pain and more rapid recoveries . One key disadvantage of laparoscopic surgery is the loss of three-dimensional assessment of organs and tissue perfusion. Advances in laparoscopic technology include high-definition monitors for improved visualization and upgraded single charge coupled device (CCD) detectors to 3-CCD cameras, to provide a larger, more sensitive color palette to increase the perception of detail. In this discussion, we further advance existing laparoscopic technology to create greater enhancement of images obtained during radical and partial nephrectomies in which the assessment of tissue perfusion is crucial but limited with current 3-CCD cameras. By separating the signals received by each CCD in the 3-CCD camera and by introducing a straight forward algorithm, rapid differentiation of renal vessels and perfusion is accomplished and could be performed real time. The newly acquired images are overlaid onto conventional images for reference and comparison. This affords the surgeon the ability to accurately detect changes in tissue oxygenation despite inherent limitations of the visible light image. Such additional capability should impact procedures in which visual assessment of organ vitality is critical.
CCD Astrophotography High-Quality Imaging from the Suburbs
Stuart, Adam
2006-01-01
This is a reference book for amateur astronomers who have become interested in CCD imaging. Those glorious astronomical images found in astronomy magazines might seem out of reach to newcomers to CCD imaging, but this is not the case. Great pictures are attainable with modest equipment. Adam Stuart’s many beautiful images, reproduced in this book, attest to the quality of – initially – a beginner’s efforts. Chilled-chip astronomical CCD-cameras and software are also wonderful tools for cutting through seemingly impenetrable light-pollution. CCD Astrophotography from the Suburbs describes one man’s successful approach to the problem of getting high-quality astronomical images under some of the most light-polluted conditions. Here is a complete and thoroughly tested program that will help every CCD-beginner to work towards digital imaging of the highest quality. It is equally useful to astronomers who have perfect observing conditions, as to those who have to observe from light-polluted city skies.
NOVEL REVERSIBLE VARIABLE PRECISION MULTIPLIER USING REVERSIBLE LOGIC GATES
M. Saravanan; K. Suresh Manic
2014-01-01
Multipliers play a vital role in digital systems especially in digital processors. There are many algorithms and designs were proposed in the earlier works, but still there is a need and a greater interest in designing a less complex, low power consuming, fastest multipliers. Reversible logic design became the promising technologies gaining greater interest due to less dissipation of heat and low power consumption. In this study a reversible logic gate based design of variable precision multi...
The Mortar Element Method with Lagrange Multipliers for Stokes Problem
Yaqin Jiang
2007-01-01
In this paper, we propose a mortar element method with Lagrange multiplier for incompressible Stokes problem, i.e., the matching constraints of velocity on mortar edges are expressed in terms of Lagrange multipliers. We also present P1 nonconforming element attached to the subdomains. By proving inf-sup condition, we derive optimal error estimates for velocity and pressure. Moreover, we obtain satisfactory approximation for normal derivatives of the velocity across the interfaces.
High Speed Area Efficient 8-point FFT using Vedic Multiplier
Avneesh Kumar Mishra
2014-12-01
Full Text Available A high speed fast fourier transform (FFT design by using three algorithm is presented in this paper. In algorithm 3, 4-bit Vedic multiplier based technique are used in FFT. In this technique used in three 4-bit ripple carry adder and four 2*2 Vedic multiplier. The main parameter of this paper is number of slice, 4-input LUTS and maximum combinational path delay were calculate.
Verilog Implementation of an Efficient Multiplier Using Vedic Mathematics
Harsh Yadav
2015-07-01
Full Text Available In this paper, the design of a 16x16 Vedic multiplier has been proposed using the 16 bit Modified Carry Select Adder and 16 bit Kogge Stone Adder. The Modified Carry Select Adder incorporates the Binary to Excess -1 Converter (BEC and is known to be the fastest adder as compared to all the conventional adders. The design is implemented using the Verilog Hardware Description Language and tested using the Modelsim simulator. The code is synthesized using the Virtex-7 family with the XC7VX330T device. The Vedic multiplier has applications in Digital Signal Processing, Microprocessors, FIR filters and communication systems. This paper presents a comparison of the results of 16x16 Vedic multiplier using Modified Carry Select Adder and 16x16 Vedic Multiplier using Kogge Stone Adder. The results show that 16x16 Vedic Multiplier using Modified Carry Select Adder is more efficient and has less time delay as compared to the 16x16 Vedic Multiplier using Kogge Stone Adder.
High speed multiplier using Nikhilam Sutra algorithm of Vedic mathematics
Pradhan, Manoranjan; Panda, Rutuparna
2014-03-01
This article presents the design of a new high-speed multiplier architecture using Nikhilam Sutra of Vedic mathematics. The proposed multiplier architecture finds out the compliment of the large operand from its nearest base to perform the multiplication. The multiplication of two large operands is reduced to the multiplication of their compliments and addition. It is more efficient when the magnitudes of both operands are more than half of their maximum values. The carry save adder in the multiplier architecture increases the speed of addition of partial products. The multiplier circuit is synthesised and simulated using Xilinx ISE 10.1 software and implemented on Spartan 2 FPGA device XC2S30-5pq208. The output parameters such as propagation delay and device utilisation are calculated from synthesis results. The performance evaluation results in terms of speed and device utilisation are compared with earlier multiplier architecture. The proposed design has speed improvements compared to multiplier architecture presented in the literature.
Thermal management for CCD peformance of one space telescope
Yang, Wengang; Wang, Yinghao; Feng, Liangjie; Wang, Chenjie; Ren, Guorui; Wang, Wei; Li, Chuang; Gao, Wei; Fan, Xuewu
2012-10-01
A space telescope containing two CCD cameras is being built for scientific observation. The CCD detectors need to operate at a temperature below -65°C in order to avoid unacceptable dark current. This cooling is achieved through detailed thermal design which minimizes the parasitic load to 2K×4K array with 13.5 micron pixels and cools this detector with a combination of thermo electric cooler(TEC). This paper will describe detailed thermal design necessary to maintain the CCD at its cold operating temperature while providing the means to reject the heat generated by the TECs. It will focus on optimized techniques developed to manage parasitic loads including material selection, surface finishes and thermal insulation. The paper will also address analytical techniques developed to characterize TEC performance. Finally, analysis results have been shown the temperature of key parts.
Noise analysis for CCD-based ultraviolet and visible spectrophotometry.
Davenport, John J; Hodgkinson, Jane; Saffell, John R; Tatam, Ralph P
2015-09-20
We present the results of a detailed analysis of the noise behavior of two CCD spectrometers in common use, an AvaSpec-3648 CCD UV spectrometer and an Ocean Optics S2000 Vis spectrometer. Light sources used include a deuterium UV/Vis lamp and UV and visible LEDs. Common noise phenomena include source fluctuation noise, photoresponse nonuniformity, dark current noise, fixed pattern noise, and read noise. These were identified and characterized by varying light source, spectrometer settings, or temperature. A number of noise-limiting techniques are proposed, demonstrating a best-case spectroscopic noise equivalent absorbance of 3.5×10(-4) AU for the AvaSpec-3648 and 5.6×10(-4) AU for the Ocean Optics S2000 over a 30 s integration period. These techniques can be used on other CCD spectrometers to optimize performance.
A quantitative striping removal algorithm for HY- 1 CCD data
孙凌; 唐军武; 张杰
2002-01-01
-- Striping is a common phenomenon in remote sensing imagery acquired by most spaceborne and airborne multispectral sensors. In contrast to the destriping of the images of optoelectronic mechanical scanners, fewer work has been done for push-broom CCD images. Based on the characteristics of HY-1 push-broom multispectral CCD camera and its prelaunch radiometric calibration results, the striping features are analyzed and a quantitative striping removal algorithm is proposed. The algorithm is to obtain the inter-detector equalization curves to reflect the differences between detectors by statistic analysis of the satellite imagery data set, and image stripes arising from the nonuniformity of the detectors of the CCD array can be removed using the estimated equalization curves. The preliminary results show that this method can effectively remove the stripes and preserve the radiometric accuracy of the raw data at the same time.
Printed circuit board for a CCD camera head
Conder, Alan D.
2002-01-01
A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close (0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.
Development of an n-channel CCD, CCD-NeXT1, for Soft X-ray Imager onboard the NeXT satellite
Takagi, Shin-ichiro [Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Hamamatsu 435-8558 (Japan); Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: s-takagi@ssd.hpk.co.jp; Tsuru, Takeshi Go [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: tsuru@cr.scphys.kyoto-u.ac.jp; Inui, Tatsuya; Matsumoto, Hironori; Koyama, Katsuji [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Ozawa, Hideki; Tohiguchi, Masakuni; Matsuura, Daisuke; Miyata, Emi; Tsunemi, Hiroshi [Department of Earth and Space Science, Graduate School of Science, Osaka University, Machikaneyama-cho, Toyonaka-shi, Osaka 560-0043 (Japan); Miyaguchi, Kazuhisa; Maeda, Kentaro; Kohno, Hirohiko [Hamamatsu Photonics K.K., 1126-1, Ichino-cho, Hamamatsu 435-8558 (Japan)
2007-11-21
NeXT (New X-ray Telescope) is the next Japanese X-ray astronomical satellite mission after the Suzaku satellite. NeXT aims to perform wide band imaging spectroscopy. Due to the successful development of a multilayer coated mirror, called a supermirror, NeXT can focus X-rays in the energy range from 0.1 up to 80 keV. To cover this wide energy range, we are in the process of developing a hybrid X-ray camera, Wideband X-ray Imager (WXI) as a focal plane detector of the supermirror. The WXI consists of X-ray CCDs (SXI) and CdTe pixelized detectors (HXI), which cover the lower and higher X-ray energy bands of 0.1-80 keV, respectively. The X-ray CCDs of the SXI are stacked above the CdTe pixelized detectors of the HXI. The X-ray CCDs of the SXI detect soft X-rays below {approx}10keV and allow hard X-rays pass into the CdTe detectors of the HXI without loss. Thus, we have been developing a 'back-supportless CCD' with a thick depletion layer, a thinned silicon wafer, and a back-supportless structure. In this paper, we report the development and performances of an evaluation model of CCD for the SXI, 'CCD-NeXT1'. We successfully fabricated two types of CCD-NeXT1, unthinned CCDs with 625-{mu}m thick wafer and 150-{mu}m thick thinned CCDs. By omitting the polishing process when making the thinned CCDs, we confirmed that the polishing process does not impact the X-ray performance. In addition, we did not find significant differences in the X-ray performance between the two types of CCDs. The energy resolution and readout noise are {approx}140eV (FWHM) at 5.9 keV and {approx}5 electrons (RMS), respectively. The estimated thickness of the depletion layer is {approx}80{mu}m. The performances almost satisfy the requirements of the baseline plan of the SXI.
A new method to evaluate imaging quality of CCD cameras
LI Wen-juan; DU Hai-hui; DAI Jing-min; CHEN Ying-hang
2005-01-01
In order to evaluate the imaging quality of CCD cameras fully and rapidly,the minimum resolvable contrast (MRC) is presented in this paper and the system of measuring MRC is constructed as well,in which two integrating spheres are proposed to illuminate two sides of the target respectively.The variable contrast can be obtained by regulating the luminance of integrating spheres. Experimental results indicate that the error of measuring luminance is within ±0.3 cd/m2,MRC rises with the increase of the spatial frequency.The experimental results show that the method proposed is an effective approach to evaluate the imaging quality of CCD cameras.
BUNDLE ADJUSTMENTS CCD CAMERA CALIBRATION BASED ON COLLINEARITY EQUATION
Liu Changying; Yu Zhijing; Che Rensheng; Ye Dong; Huang Qingcheng; Yang Dingning
2004-01-01
The solid template CCD camera calibration method of bundle adjustments based on collinearity equation is presented considering the characteristics of space large-dimension on-line measurement. In the method, a more comprehensive camera model is adopted which is based on the pinhole model extended with distortions corrections. In the process of calibration, calibration precision is improved by imaging at different locations in the whole measurement space, multi-imaging at the same location and bundle adjustments optimization. The calibration experiment proves that the calibration method is able to fulfill calibration requirement of CCD camera applied to vision measurement.
DepAstroCCD an original astrometric tool
Stojanović I.
2006-01-01
Full Text Available A complex software for preparation and treatment of astro photographic plates and double-star observations recorded with CCD cameras is developed. The preparation interface contains a catalogue base for the choice of observation objects and an interface for bringing into accordance the telescope and CCD camera performance with the assumptions of the postprocessor interface. The processing is based on the original development of image gradient removing software and classical FFT method and autocorrelation. The software has been tested on several theoretical and real images of double stars.
Technology validation of the PLATO CCD at ESA
Prod'homme, Thibaut; Verhoeve, Peter; Beaufort, Thierry; Duvet, Ludovic; Lemmel, Frederic; Smit, Hans; Blommaert, Sander; Oosterbroek, Tim; van der Luijt, Cornelis; Visser, Ivo; Heijnen, Jerko; Butler, Bart
2016-07-01
PLATO { PLAnetary Transits and Oscillations of stars { is the third medium-class mission to be selected in the European Space Agency (ESA) Science and Robotic Exploration Cosmic Vision programme. Due for launch in 2025, the payload makes use of a large format (8 cm x 8 cm) Charge-Coupled Devices (CCDs) the e2v CCD270 operated at 4 MHz. The manufacture of such large device in large quantity constitutes an unprecedented effort. To de-risk the PLATO CCD procurement and aid the mission definition process, ESA's Payload Technology Validation team is characterizing the electro-optical performance of a number of PLATO devices before and after proton irradiation.
ESA's CCD test bench for the PLATO mission
Beaufort, Thierry; Duvet, Ludovic; Bloemmaert, Sander; Lemmel, Frederic; Prod'homme, Thibaut; Verhoeve, Peter; Smit, Hans; Butler, Bart; van der Luijt, Cornelis; Heijnen, Jerko; Visser, Ivo
2016-08-01
PLATO { PLAnetary Transits and Oscillations of stars { is the third medium-class mission to be selected in the European Space Agency (ESA) Science and Robotic Exploration Cosmic Vision programme. Due for launch in 2025, the payload makes use of a large format (8 cm x 8 cm) Charge-Coupled Devices (CCDs), the e2v CCD270 operated at 4 MHz and at -70 C. To de-risk the PLATO CCD qualification programme initiated in 2014 and support the mission definition process, ESA's Payload Technology Validation section from the Future Missions Office has developed a dedicated test bench.
Mid-IR image acquisition using a standard CCD camera
Dam, Jeppe Seidelin; Sørensen, Knud Palmelund; Pedersen, Christian
2010-01-01
Direct image acquisition in the 3-5 µm range is realized using a standard CCD camera and a wavelength up-converter unit. The converter unit transfers the image information to the NIR range were state-of-the-art cameras exist.......Direct image acquisition in the 3-5 µm range is realized using a standard CCD camera and a wavelength up-converter unit. The converter unit transfers the image information to the NIR range were state-of-the-art cameras exist....
A luminescence imaging system based on a CCD camera
Duller, G.A.T.; Bøtter-Jensen, L.; Markey, B.G.
1997-01-01
to photographic systems, in order to obtain spatially resolved data. However, the former option is extremely expensive and it is difficult to obtain quantitative data from the latter. This paper describes the use of a CCD camera for imaging both thermoluminescence and optically stimulated luminescence. The system...... described here has a maximum spatial resolution of 17 mu m; though this may be varied under software control to alter the signal-to-noise ratio. The camera has been mounted on a Riso automated TL/OSL reader, and both the reader and the CCD are under computer control. In the near u.v and blue part...
Implementation of Different Low Power Multipliers Using Verilog
Koteswara Rao Ponnuru
2014-06-01
Full Text Available Low power consumption and smaller area are some of the most important criteria for the fabrication of DSP systems and high performance systems. Optimizing the speed and area of the multiplier is a major design issue. Multiplication represents a fundamental building block in all DSP tasks. The objective of a good multiplier is to provide a physically compact, good speed and low power consumption. To save significant power consumption of a VLSI design it is a good direction to reduce its dynamic power that is the major part of total power consumption. Two methods are common in current implementations: regular arrays and Wallace trees. The gate-level analyses have suggested that not only are Wallace trees faster than array schemes, they also consume much less power. However these analyses did not take wiring into account, resulting in optimistic timing and power estimates. Continuous advances of microelectronic technologies make better use of energy, encode data more effectively, reduce power consumption, etc. Particularly, many of these technologies address low-power consumption to meet the requirements of various portable applications. In these application systems, a multiplier is a fundamental arithmetic unit and widely used in circuits. I compare results for 8bit-width the working of different multipliers by comparing the power consumption by each of them. The result of my paper helps us to choose a better option between serial and parallel multiplier in fabricating different systems. Multipliers form one of the most important components of many systems. So, by analyzing the working of different multipliers helps to frame a better system with less power consumption and lesser area.
Formation and decay of the Rydberg states of multiply charged ions interacting with solid surfaces
Mirkovic, M A; Nedeljkovic, N N; Bozanic, D K, E-mail: gmirkomarko@sezampro.rs
2010-11-01
Processes of formation and decay of the Rydberg states of multiply charged ions escaping solid surfaces with intermediate velocities (v {approx} 1 a.u.) represent complex quantum events that require a detailed quantum description. We have developed a two-state vector model for the population process, with the functions {Psi}{sub 1} and {Psi}{sub 2} for definition of the state of a single active electron. The electron exchange between the solid and the moving ion is described by a mixed flux through a plane positioned between them. For the low values of the angular momentum quantum numbers l the radial electronic coordinate {rho} can be neglected, whereas for the large-l values a wide space region around the projectile trajectory was taken into account. The reionization of the previously populated states is considered as a decay of the wave function {Psi}{sub 2}. The corresponding decay rates are obtained by an appropriate etalon equation method: in the large-l case the radial electronic coordinate {rho} is treated as a variational parameter. The theoretical predictions based on that population-reionization mechanism are compared with the available beam-foil experimental data, as well as the experimental data obtained in the interaction of multiply charged ions with micro-capillary foil. Generally, the model reproduces the experimentally observed non-linear trend of the l distributions from l = 0 to l{sub max} = n - 1.
A New Technique for CCD Camera Auto-Calibration
无
2003-01-01
A novel feature-round-based coplanar drone for the CCD camera auto-calibration is designed. Based on the ellipse similarity, an ellipse recognition algorithm is proposed. The experiment indicates the calibration error is less than 0.4 pixel.
Measurements of 42 Wide CPM Pairs with a CCD
Harshaw, Richard
2015-11-01
This paper addresses the use of a Skyris 618C color CCD camera as a means of obtaining data for analysis in the measurement of wide common proper motion stars. The equipment setup is described and data collection procedure outlined. Results of the measures of 42 CPM stars are presented, showing the Skyris is a reliable device for the measurement of double stars.
Underwater implosions of large format photo-multiplier tubes
Diwan, Milind; Dolph, Jeffrey [Brookhaven National Laboratory, P.O. Box 5000, Bldg 510E, Upton, NY 11973 (United States); Ling, Jiajie, E-mail: jjling@bnl.gov [Brookhaven National Laboratory, P.O. Box 5000, Bldg 510E, Upton, NY 11973 (United States); Russo, Thomas; Sharma, Rahul; Sexton, Kenneth; Simos, Nikolaos; Stewart, James; Tanaka, Hidekazu [Brookhaven National Laboratory, P.O. Box 5000, Bldg 510E, Upton, NY 11973 (United States); Arnold, Douglas; Tabor, Philip; Turner, Stephen [Naval Underwater Warfare Center, Newport, RI 02841 (United States)
2012-04-01
Large, deep, well shielded liquid detectors have become an important technology for the detection of neutrinos over a wide dynamic range from few MeV to TeV. The critical component of this technology is the large format semi-hemispherical photo-multiplier tube with diameters in the range of 25-50 cm. The survival of an assembled array of these photo-multiplier tubes under high hydrostatic pressure is the subject of this study. These are the results from an R and D program which is intended to understand the modes of failure when a photo-multiplier tube implodes under hydrostatic pressure. Our tests include detailed measurements of the shock wave which results from the implosion of a photo-multiplier tube and a comparison of the test data to modern hydrodynamic simulation codes. Using these results we can extrapolate to other tube geometries and make recommendation on deployment of the photo-multiplier tubes in deep water detectors with a focus on risk mitigation from a tube implosion shock wave causing a chain reaction loss of multiple tubes.
Four-quadrant analogue multiplier using operational amplifier
Riewruja, Vanchai; Rerkratn, Apinai
2011-04-01
A method to realise a four-quadrant analogue multiplier using general-purpose operational amplifiers (opamps) as only the active elements is described in this article. The realisation method is based on the quarter-square technique, which utilises the inherent square-law characteristic of class AB output stage of the opamp. The multiplier can be achieved from the proposed structure with using either bipolar or complementary metal-oxide-semiconductor (CMOS) opamps. The operation principle of the proposed multiplier has been confirmed by PSPICE analogue simulation program. Simulation results reveal that the principle of proposed scheme provides an adequate performance for a four-quadrant analogue multiplier. Experimental implementations of the proposed multiplier using bipolar and CMOS opamps are performed to verify the circuit performances. Measured results of the experimental proposed schemes based on the use of bipolar and CMOS opamps with supply voltage ±2.4 V show the worst-case relative errors of 0.32% and 0.47%, and the total harmonic distortions of 0.47% and 0.98%, respectively.
Jayarajan, Jayesh; Kumar, Nishant; Verma, Amarnath; Thaker, Ramkrishna
2016-05-01
Drive electronics for generating fast, bipolar clocks, which can drive capacitive loads of the order of 5-10nF are indispensable for present day Charge Coupled Devices (CCDs). Design of these high speed bipolar clocks is challenging because of the capacitive loads that have to be driven and a strict constraint on the rise and fall times. Designing drive electronics circuits for space applications becomes even more challenging due to limited number of available discrete devices, which can survive in the harsh radiation prone space environment. This paper presents the design, simulations and test results of a set of such high speed, bipolar clock drivers. The design has been tested under a thermal cycle of -15 deg C to +55 deg C under vacuum conditions and has been designed using radiation hardened components. The test results show that the design meets the stringent rise/fall time requirements of 50+/-10ns for Multiple Vertical CCD (VCCD) clocks and 20+/-5ns for Horizontal CCD (HCCD) clocks with sufficient design margins across full temperature range, with a pixel readout rate of 6.6MHz. The full design has been realized in flexi-rigid PCB with package volume of 140x160x50 mm3.
Majkic, M. D.; Nedeljkovic, N. N.; Galijas, S. M. D.
2010-07-01
We elaborated the time-symmetric, two-state vector model to investigate the intermediate stages of the electron capture into the Rydberg states of multiply charged ions interacting with solid surface under the grazing incidence geometry. The neutralization distances for the ions XeZ+ interacting with Al-surface are calculated, for core charges Z ?[5,30]. The corresponding mean neutralization distances are in agreement with the data deduced from the measured kinetic energy gain due to the image acceleration of the ions.
Decay rates of large-l Rydberg states of multiply charged ions approaching solid surfaces
Nedeljkovic, N. N.; Mirkovic, M. A.; Bozanic, D. K.
2008-07-01
We investigate the ionization of large-l multiply charged Rydberg ions approaching solid surfaces within the framework of decay model and applying the etalon equation method. The radial coordinate rho of the active electron is treated as a variational parameter and therefore the parabolic symmetry is preserved in this procedure. The complex eigenenergies are calculated from which the energy terms and the ionization rates are derived. We find that the large-l Rydberg states decay at approximately the same ion-surface distances as the low-l states oriented toward the vacuum and considerably closer to the surface comparing to the low-l states oriented towards the surface.
OPTIMIZATION OF HYBRID FINAL ADDER FOR THE HIGH PERFORMANCE MULTIPLIER
RAMKUMAR B.
2013-04-01
Full Text Available In this work we evaluated arrival profile of the HPM based multiplier partial products reduction tree in two ways: 1.manual delay, area calculation through logical effort, 2.ASIC implementation. Based on the arrival profile, we worked with some recently proposed optimal adders and finally we proposed an optimal hybrid adder for the final addition in HPM based parallel multiplier. This work derives some mathematical expressions to find the size of different regions in the partial product arrival profile which helps to design optimal adder for each region. This work evaluates the performance of proposed hybrid adder in terms of area, power and delay using 90nm technology. This work deals with manual calculation for 8-b and ASIC simulation of different adder designs for 8-b, 16-b, 32-b and 64-b multiplier bit sizes.
Performance evaluation of high speed compressors for high speed multipliers
Nirlakalla Ravi
2011-01-01
Full Text Available This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP. This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25°C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP and Energy Delay Product (EDP of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.
Multiplier Accounting of Indian Mining Industry: The Application
Hussain, Azhar; Karmakar, Netai Chandra
2017-10-01
In the previous paper (Hussain and Karmakar in Inst Eng India Ser, 2014. doi: 10.1007/s40033-014-0058-0), the concepts of input-output transaction matrix and multiplier were explained in detail. Input-output multipliers are indicators used for predicting the total impact on an economy due to changes in its industrial demand and output which is calculated using transaction matrix. The aim of this paper is to present an application of the concepts with respect to the mining industry, showing progress in different sectors of mining with time and explaining different outcomes from the results obtained. The analysis shows that a few mineral industries saw a significant growth in their multiplier values over the years.
Dark energy from modified gravity with Lagrange multipliers
Capozziello, Salvatore [Dipartimento di Scienze Fisiche, Universita ' Federico II' di Napoli (Italy)] [INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Ed. N, via Cintia, I-80126 Napoli (Italy); Matsumoto, Jiro [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Nojiri, Shin' ichi, E-mail: nojiri@phys.nagoya-u.ac.j [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)] [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Odintsov, Sergei D. [Institucio Catalana de Recerca i Estudis Avancats (ICREA) and Institut de Ciencies de l' Espai (IEEC-CSIC), Campus UAB, Facultat de Ciencies, Torre C5-Par-2a pl, E-08193 Bellaterra, Barcelona (Spain)
2010-09-27
We study scalar-tensor theory, k-essence and modified gravity with Lagrange multiplier constraint which role is to reduce the number of degrees of freedom. Dark Energy cosmology of different types ({Lambda}CDM, unified inflation with DE, smooth non-phantom/phantom transition epoch) is reconstructed in such models. It is demonstrated that presence of Lagrange multiplier simplifies the reconstruction scenario. It is shown that mathematical equivalence between scalar theory and F(R) gravity is broken due to presence of constraint. The cosmological evolution is defined by the second F{sub 2}(R) function dictated by the constraint. The convenient F(R) gravity sector is relevant for local tests. This opens the possibility to make originally non-realistic theory to be viable by adding the corresponding constraint. A general discussion on the role of Lagrange multipliers to make higher-derivative gravity canonical is developed.
Performance Evaluation of Complex Multiplier Using Advance Algorithm
Gopichand D. Khandale
2013-06-01
Full Text Available In this paper VHDL implementation of complex number multiplier using ancient Vedic mathematics and conventional modified Booth algorithm is presented and compared. The idea for designing the multiplier unit is adopted from ancient Indian mathematics "Vedas". The Urdhva Tiryakbhyam sutra (method was selected for implementation since it is applicable to all cases of multiplication. Multiplication using Urdhva Tiryakbhyam sutra is performed by vertically and crosswise. The feature of this method is any multi-bit multiplication can be reduced down to single bit multiplication and addition. On account of these formulas, the partial products and sums are generated in one step which reduces the carry propagation from LSB to MSB. The implementation of the Vedic mathematics and their application to the complex multiplier ensure substantial reduction of propagation delay. The simulation results for 4 bit multiplication using Booth’s algorithm and using Vedic sutra are illustrated.
Multiplier Accounting of Indian Mining Industry: The Application
Hussain, Azhar; Karmakar, Netai Chandra
2016-10-01
In the previous paper (Hussain and Karmakar in Inst Eng India Ser, 2014. doi: 10.1007/s40033-014-0058-0), the concepts of input-output transaction matrix and multiplier were explained in detail. Input-output multipliers are indicators used for predicting the total impact on an economy due to changes in its industrial demand and output which is calculated using transaction matrix. The aim of this paper is to present an application of the concepts with respect to the mining industry, showing progress in different sectors of mining with time and explaining different outcomes from the results obtained. The analysis shows that a few mineral industries saw a significant growth in their multiplier values over the years.
Implementation of MAC by using Modified Vedic Multiplier
Sreelekshmi M. S.
2013-09-01
Full Text Available Multiplier Accumulator Unit (MAC is a part of Digital Signal Processors. The speed of MAC depends on the speed of multiplier. So by using an efficient Vedic multiplier which excels in terms of speed, power and area, the performance of MAC can be increased. For this fast method of multiplication based on ancient Indian Vedic mathematics is proposed in this paper. Among various method of multiplication in Vedic mathematics, Urdhva Tiryagbhyam is used and the multiplication is for 32 X 32 bits. Urdhva Tiryagbhyam is a general multiplication formula applicable to all cases of multiplication. Adder used is Carry Look Ahead adder. The proposed design shows improvement over carry save adder.
VLSI IMPLEMENTATION OF AN ANALOG MULTIPLIER FOR MODEM
SRIVIDYA .P,
2011-02-01
Full Text Available A modem (modulator-demodulator is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goalis to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Here there is a need to mix the signals of different frequencies or signals of different types, whichemphasizes the use of mixers or multipliers for different RF applications. In this paper, A CMOS analog multiplier, with less number of transistors which can operate at high frequencies with low power and high linearity is proposed. The multiplier works on the basis of parallel connected MOS operation circuit.
Isometric Multipliers of $L^p(G, X)$
U B Tewari; P K Chaurasia
2005-02-01
Let be a locally compact group with a fixed right Haar measure and a separable Banach space. Let $L^p(G, X)$ be the space of -valued measurable functions whose norm-functions are in the usual $L^p$. A left multiplier of $L^p(G, X)$ is a bounded linear operator on $L^p(G, X)$ which commutes with all left translations. We use the characterization of isometries of $L^p(G, X)$ onto itself to characterize the isometric, invertible, left multipliers of $L^p(G, X)$ for 1 ≤ < ∞, ≠ 2, under the assumption that is not the $l^p$-direct sum of two non-zero subspaces. In fact we prove that if is an isometric left multiplier of $L^p(G, X)$ onto itself then there exists $a y \\in G$ and an isometry of onto itself such that $Tf(x) = U(R_y f)(x)$. As an application, we determine the isometric left multipliers of $L^1 \\cap L^p(G, X)$ and $L^1 \\cap C_0(G, X)$ where is non-compact and is not the $l^p$-direct sum of two non-zero subspaces. If is a locally compact abelian group and is a separable Hilbert space, we define $A^p(G, H)=\\{f\\in l^1(G, H):\\hat{f}\\in L^p(, H)\\}$ where is the dual group of . We characterize the isometric, invertible, left multipliers of $A^p(G, H)$, provided is non-compact. Finally, we use the characterization of isometries of (,) for compact to determine the isometric left multipliers of (,) provided * is strictly convex.
Energy and area efficient hierarchy multiplier architecture based on Vedic mathematics and GDI logic
Mohan Shoba
2017-02-01
Full Text Available Hierarchy multiplier is attractive because of its ability to carry the multiplication operation within one clock cycle. The existing hierarchical multipliers occupy more area and also results in more delay. Therefore, in this paper, a method to reduce the computation delay of hierarchy multiplier by employing CslA and Binary to Excess 1 Converter (BEC is proposed. The use of BEC eliminates the n/4 number of adders, existing in the conventional addition scheme, where n denotes the multiplier input width. As the area of the hierarchy multiplier is determined by its base multiplier, the base multiplier is realized with the proposed Vedic multiplier, which has small area and operates with less delay than the conventional multipliers. In addition, the reduction of power consumption in the hierarchy multiplier can be ensured by implementing the designed multiplier with full swing Gate Diffusion Input (GDI logic. The performances of the proposed and the existing multipliers are evaluated by Cadence SPICE simulator using 45 nm technology model. From the simulation results, the performance parameters namely, delay and power consumption are calculated. Further, the area is measured from the corresponding layout for the same technology model. It is examined from the results that the proposed multiplier operates with 17% lesser power delay product than the recently reported hierarchy multiplier. The Monte Carlo simulation is performed to understand the robustness of the proposed hierarchy multiplier.
High performance dc-dc conversion with voltage multipliers
Harrigill, W. T.; Myers, I. T.
1974-01-01
The voltage multipliers using capacitors and diodes first developed by Cockcroft and Walton in 1932 were reexamined in terms of state of the art fast switching transistors and diodes, and high energy density capacitors. Because of component improvements, the voltage multiplier, used without a transformer, now appears superior in weight to systems now in use for dc-dc conversion. An experimental 100-watt 1000-volt dc-dc converter operating at 100 kHz was built, with a component weight of about 1 kg/kW. Calculated and measured values of output voltage and efficiency agreed within experimental error.
Optimal Final Carry Propagate Adder Design for Parallel Multipliers
B., Ramkumar
2011-01-01
Based on the ASIC layout level simulation of 7 types of adder structures each of four different sizes, i.e. a total of 28 adders, we propose expressions for the width of each of the three regions of the final Carry Propagate Adder (CPA) to be used in parallel multipliers. We also propose the types of adders to be used in each region that would lead to the optimal performance of the hybrid final adders in parallel multipliers. This work evaluates the complete performance of the analyzed designs in terms of delay, area, power through custom design and layout in 0.18 um CMOS process technology.
Comparative study of Braun’s Multiplier Using FPGA Devices
Anitha R,
2011-06-01
Full Text Available The development cost for ASIC are high, algorithms should be verified and optimized before implementation. To decrease computational delay and improve resource utilization, bypassing techniques are beapplied and braun-arhitectured multiplier is compared with its architectural modification i.e. Column-bypassing and Row-bypassing architectures and the full adder structure has been replaced by the fast adder. The architectures have been implemented on Spartan 3E, Virtex 5 and Virtex 6 LowerPower. Virtex 5 showed the best performance whereas column-bypassed multiplier has the best performance among the three architectures using Xilinx ISE and Verilog HDL.
Radial multipliers on amalgamated free products of II-factors
Möller, Sören
2014-01-01
Let ℳi be a family of II1-factors, containing a common II1-subfactor 풩, such that [ℳi : 풩] ∈ ℕ0 for all i. Furthermore, let ϕ: ℕ0 → ℂ. We show that if a Hankel matrix related to ϕ is trace-class, then there exists a unique completely bounded map Mϕ on the amalgamated free product of the ℳi...... with amalgamation over 풩, which acts as a radial multiplier. Hereby, we extend a result of Haagerup and the author for radial multipliers on reduced free products of unital C*- and von Neumann algebras....
Optimized Multiplier Using Reversible Multicontrol Input Toffoli Gates
H R Bhagyalakshmi
2013-01-01
Full Text Available Reversible logic is an important area to carry the computation into the world of quantum computing. In thispaper a 4-bit multiplier using a new reversible logic gate called BVPPG gate is presented. BVPPG gate isa 5 x 5 reversible gate which is designed to generate partial products required to perform multiplicationand also duplication of operand bits is obtained. This reduces the total cost of the circuit. Toffoli gate isthe universal and also most flexible reversible logic gate. So we have used the Toffoli gates to construct thedesigned multiplier.
Spot Pricing When Lagrange Multipliers Are Not Unique
Feng, Donghan; Xu, Zhao; Zhong, Jin
2012-01-01
Classical spot pricing theory is based on multipliers of the primal problem of an optimal market dispatch, i.e., the solution of the dual problem. However, the dual problem of market dispatch may yield multiple solutions. In these circumstances, spot pricing or any standard pricing practice based...... on multipliers cannot generate a unique clearing price. Although such situations are rare, they can cause significant uncertainties and complexities in market dispatch. In practice, this situation is solved through simple empirical methods, which may cause additional operations or biased allocation. Based...... the results of the theoretical analysis, and further demonstrate that the method performs effectively in both uniform-pricing and nodalpricing markets....
AN IMPROVED DESIGN OF A MULTIPLIER USING REVERSIBLE LOGIC GATES
H.R.BHAGYALAKSHMI
2010-08-01
Full Text Available Reversible logic gates are very much in demand for the future computing technologies as they are known to produce zero power dissipation under ideal conditions. This paper proposes an improved design of a multiplier using reversible logic gates. Multipliers are very essential for the construction of various computational units of a quantum computer. The quantum cost of a reversible logic circuit can be minimized by reducing the number of reversible logic gates. For this two 4*4 reversible logic gates called a DPG gate and a BVF gate are used.
Dielectronic recombination of multiply charged ions
Datz, S.; Dittner, P.F.; Fou, C.M.; Miller, P.D.; Pepmiller, P.L.
1986-09-01
Using a merged electron-ion merged beam apparatus in conjunction with the ORNL EN Tandem Van de Graaff, we have measured dielectronic recombination in ..delta..n = 0 transitions for a number of Li-liked (B/sup 2 +/, C/sup 3 +/, N/sup 4 +/, and O/sup 5 +/), Be-like (C/sup 2 +/, N/sup 3 +/, and O/sup 4 +/), B-like (N/sup 2 +/, O/sup 3 +/, and F/sup 4 +/), and Na-like (P/sup 4 +/, S/sup 5 +/, and Cl/sup 6 +/) ions. The results are compared with theory which includes field enhancement and extension of the more highly charged ions is discussed. 11 refs., 11 figs.
Comparing simulations and test data of a radiation damaged CCD for the Euclid mission
Skottfelt, Jesper; Hall, David; Gow, Jason; Murray, Neil; Holland, Andrew; Prod'homme, Thibaut
2016-07-01
The radiation damage effects from the harsh radiative environment outside the Earth's atmosphere can be a cause for concern for most space missions. With the science goals becoming ever more demanding, the requirements on the precision of the instruments on board these missions also increases, and it is therefore important to investigate how the radiation induced damage affects the Charge-Coupled Devices (CCDs) that most of these instruments rely on. The primary goal of the Euclid mission is to study the nature of dark matter and dark energy using weak lensing and baryonic acoustic oscillation techniques. The weak lensing technique depends on very precise shape measurements of distant galaxies obtained by a large CCD array. It is anticipated that over the 6 year nominal lifetime of mission, the CCDs will be degraded to an extent that these measurements will not be possible unless the radiation damage effects are corrected. We have therefore created a Monte Carlo model that simulates the physical processes taking place when transferring signal through a radiation damaged CCD. The software is based on Shockley-Read-Hall theory, and is made to mimic the physical properties in the CCD as close as possible. The code runs on a single electrode level and takes charge cloud size and density, three dimensional trap position, and multi-level clocking into account. A key element of the model is that it takes device specific simulations of electron density as a direct input, thereby avoiding to make any analytical assumptions about the size and density of the charge cloud. This paper illustrates how test data and simulated data can be compared in order to further our understanding of the positions and properties of the individual radiation-induced traps.
Han, Hesong; Wilson, Adam C
2013-12-01
The cytochrome c maturation system influences the expression of virulence factors in Bacillus anthracis. B. anthracis carries two copies of the ccdA gene, encoding predicted thiol-disulfide oxidoreductases that contribute to cytochrome c maturation, while the closely related organism Bacillus subtilis carries only one copy of ccdA. To investigate the roles of the two ccdA gene copies in B. anthracis, strains were constructed without each ccdA gene, and one strain was constructed without both copies simultaneously. Loss of both ccdA genes results in a reduction of cytochrome c production, an increase in virulence factor expression, and a reduction in sporulation efficiency. Complementation and expression analyses indicate that ccdA2 encodes the primary CcdA in B. anthracis, active in all three pathways. While CcdA1 retains activity in cytochrome c maturation and virulence control, it has completely lost its activity in the sporulation pathway. In support of this finding, expression of ccdA1 is strongly reduced when cells are grown under sporulation-inducing conditions. When the activities of CcdA1 and CcdA2 were analyzed in B. subtilis, neither protein retained activity in cytochrome c maturation, but CcdA2 could still function in sporulation. These observations reveal the complexities of thiol-disulfide oxidoreductase function in pathways relevant to virulence and physiology.
Manpreet Singh; Bhajan Singh; B S Sandhu
2008-01-01
An inverse response matrix converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a true photon spectrum. This also results in extraction of intensity and energy distributions of multiply scattered events originating from interactions of 279 keV photons with thick targets of bronze. The observed pulse-height distributions are a composite of singly and multiply scattered events in addition to bremmstrahlung originating from slowing down of Compton and photo-electrons in thick targets. To evaluate the contribution of multiply scattered events, the spectrum of singly scattered events contributing to inelastic Compton peak is reconstructed analytically. The optimum thickness (saturation depth), at which the number of multiply scattered events saturate, has been evaluated in different energy bin meshes chosen for scintillation detector response unfolding. Monte Carlo calculations based upon the package developed by Bauer and Pattison (Compton scattering experiments at the HMI (1981), HMI-B 364, pp. 1-106) supports the present experimental results.
Hybrid Voltage-Multipliers Based Switching Power Converters
Rosas-Caro, Julio C.; Mayo-Maldonado, Jonathan C.; Vazquez-Bautista, Rene Fabian; Valderrabano-Gonzalez, Antonio; Salas-Cabrera, Ruben; Valdez-Resendiz, Jesus Elias
2011-08-01
This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft-Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.
Multiply-Constrained Semantic Search in the Remote Associates Test
Smith, Kevin A.; Huber, David E.; Vul, Edward
2013-01-01
Many important problems require consideration of multiple constraints, such as choosing a job based on salary, location, and responsibilities. We used the Remote Associates Test to study how people solve such multiply-constrained problems by asking participants to make guesses as they came to mind. We evaluated how people generated these guesses…
Garbage-free reversible constant multipliers for arbitrary integers
Mogensen, Torben Ægidius
2013-01-01
We present a method for constructing reversible circuitry for multiplying integers by arbitrary integer constants. The method is based on Mealy machines and gives circuits whose size are (in the worst case) linear in the size of the constant. This makes the method unsuitable for large constants......, but gives quite compact circuits for small constants. The circuits use no garbage or ancillary lines....
Radial multipliers on reduced free products of operator algebras
Haagerup, Uffe; Möller, Sören
2012-01-01
Let Ai be a family of unital C*-algebras, respectively, of von Neumann algebras and \\phi: N0 \\to C. We show that if a Hankel matrix related to \\phi is trace-class, then there exists a unique completely bounded map M\\phi on the reduced free product of the Ai, which acts as a radial multiplier...
Design and Implementation of Analog Multiplier with Improved Linearity
Nandini A.S
2012-11-01
Full Text Available Analog multipliers are used for frequency conversion and are critical components in modern radio frequency (RF systems. RF systems must process analog signals with a wide dynamic range at high frequencies. A mixer converts RF power at one frequency into power at another frequency to make signalprocessing easier and also inexpensive. A fundamental reason for frequency conversion is to allow amplification of the received signal at a frequency other than the RF, or the audio, frequency. This paper deals with two such multipliers using MOSFETs which can be used in communication systems. They were designed and implemented using 0.5 micron CMOS process. The two multipliers were characterized for power consumption, linearity, noise and harmonic distortion. The initial circuit simulated is a basic Gilbert cell whose gain is fairly high but shows more power consumption and high total harmonic distortion. Our paper aims in reducing both power consumption and total harmonic distortion. The second multiplier is a new architecture that consumes 43.07 percent less power and shows 22.69 percent less total harmonic distortion when compared to the basic Gilbert cell. The common centroid layouts of both the circuits have also been developed.
Multiplier methods for optimization problems with Lipschitzian derivatives
Izmailov, A. F.; Kurennoy, A. S.
2012-12-01
Optimization problems for which the objective function and the constraints have locally Lipschitzian derivatives but are not assumed to be twice differentiable are examined. For such problems, analyses of the local convergence and the convergence rate of the multiplier (or the augmented Lagrangian) method and the linearly constraint Lagrangian method are given.
A Method for Deriving Transverse Masses Using Lagrange Multipliers
Gross, Eilam; Vitells, Ofer
2008-01-01
We use Lagrange multipliers to extend the traditional definition of Transverse Mass used in experimental high energy physics. We demonstrate the method by implementing it to derive a new Transverse Mass that can be used as a discriminator to distinguish between top decays via a charged W or a charged Higgs Boson.
New method for high performance multiply-accumulator design
Bing-jie XIA; Peng LIU; Qing-dong YAO
2009-01-01
This study presents a new method of 4-pipelined high-performance split multiply-accumulator (MAC) architecture,which is capable of supporting multiple precisions developed for media processors. To speed up the design further, a novel partial product compression circuit based on interleaved adders and a modified hybrid partial product reduction tree (PPRT) scheme are proposed. The MAC can perform 1-way 32-bit, 4-way 16-bit signed/unsigned multiply or multiply-accumulate operations and 2-way parallel multiply add (PMADD) operations at a high frequency of 1.25 GHz under worst-case conditions and 1.67 GHz under typical-case conditions, respectively. Compared with the MAC in 32-bit microprocessor without interlocked piped stages (MIPS), the proposed design shows a great advantage in speed. Moreover, an improvement of up to 32% in throughput is achieved.The MAC design has been fabricated with Taiwan Semiconductor Manufacturing Company (TSMC) 90-nm CMOS standard cell technology and has passed a functional test.
New approach to streaming semigroups with multiplying boundary conditions
Mohamed Boulanouar
2008-11-01
Full Text Available This paper concerns the generation of a C_0-semigroup by the streaming operator with general multiplying boundary conditions. A first approach, presented in [2], is based on the Hille-Yosida's Theorem. Here, we present a second approach based on the construction of the generated semigroup, without using the Hille-Yosida's Theorem.
Problems with Accurate Atomic Lfetime Measurements of Multiply Charged Ions
Trabert, E
2009-02-19
A number of recent atomic lifetime measurements on multiply charged ions have reported uncertainties lower than 1%. Such a level of accuracy challenges theory, which is a good thing. However, a few lessons learned from earlier precision lifetime measurements on atoms and singly charged ions suggest to remain cautious about the systematic errors of experimental techniques.
Design and Implementation of Analog Multiplier with Improved Linearity
Nandini A.S
2012-10-01
Full Text Available Analog multipliers are used for frequency conversion and are critical components in modern radio frequency (RF systems. RF systems must process analog signals with a wide dynamic range at high frequencies. A mixer converts RF power at one frequency into power at another frequency to make signal processing easier and also inexpensive. A fundamental reason for frequency conversion is to allow amplification of the received signal at a frequency other than the RF, or the audio, frequency. This paper deals with two such multipliers using MOSFETs which can be used in communication systems. They were designed and implemented using 0.5 micron CMOS process. The two multipliers were characterized for power consumption, linearity, noise and harmonic distortion. The initial circuit simulated is a basic Gilbert cell whose gain is fairly high but shows more power consumption and high total harmonic distortion. Our paper aims in reducing both power consumption and total harmonic distortion. The second multiplier is a new architecture that consumes 43.07 percent less power and shows 22.69 percent less total harmonic distortion when compared to the basic Gilbert cell. The common centroid layouts of both the circuits have also been developed.
Treatment of multiply controlled destructive behavior with food reinforcement.
Adelinis, J D; Piazza, C C; Goh, H L
2001-01-01
We evaluated the extent to which the positive reinforcement of communication would reduce multiply controlled destructive behavior in the absence of relevant extinction components. When edible reinforcement for appropriate communication and nonfood reinforcers for problem behavior were available simultaneously, responding was allocated almost exclusively toward the behavior that produced edible reinforcement.
Quantum noise frequency correlations of multiply scattered light
Lodahl, Peter
2006-01-01
Frequency correlations in multiply scattered light that are present in quantum fluctuations are investigated. The speckle correlations for quantum and classical noise are compared and are found to depend markedly differently on optical frequency, which was confirmed in a recent experiment....... Furthermore, novel mesoscopic correlations are predicted that depend on the photon statistics of the incoming light....
Analysis of Random Jitter in a Clock Multiplying DLL Architecture
Beek, van de R.C.H; Klumperink, E.A.M.; Vaucher, C.S.; Nauta, B.
2001-01-01
In this paper, a thorough analysis of the jitter behavior of a Delay Locked Loop (DLL) based clock multiplying architecture is presented. The noise sources that are included in the analysis are the noise of the delay elements, the reference jitter and the noise of the Phase Frequency Detector and Ch
Radial multipliers on reduced free products of operator algebras
Haagerup, Uffe; Möller, Sören
2012-01-01
Let Ai be a family of unital C*-algebras, respectively, of von Neumann algebras and \\phi: N0 \\to C. We show that if a Hankel matrix related to \\phi is trace-class, then there exists a unique completely bounded map M\\phi on the reduced free product of the Ai, which acts as a radial multiplier...
Lagrangian multiplier and massive Yang-Mills fields
Li, Z.P.
1982-09-01
If we give appropriate constraint to the gauge invariant Lagrangian, the variation principle of the action convert to the variational problems with subsidiary condition. The effective Lagrangian which contains Lagrangian multiplier may have the mass term of the mesons. In that case we obtain naturally the massive Yang-Mills fields which was discussed by Nakanishi.
A cascaded three-phase symmetrical multistage voltage multiplier
Iqbal, Shahid [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Singh, G K [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Besar, R [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia); Muhammad, G [Faculty of Information Science and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia)
2006-10-15
A cascaded three-phase symmetrical multistage Cockcroft-Walton voltage multiplier (CW-VM) is proposed in this report. It consists of three single-phase symmetrical voltage multipliers, which are connected in series at their smoothing columns like string of batteries and are driven by three-phase ac power source. The smoothing column of each voltage multiplier is charged twice every cycle independently by respective oscillating columns and discharged in series through load. The charging discharging process completes six times a cycle and therefore the output voltage ripple's frequency is of sixth order of the drive signal frequency. Thus the proposed approach eliminates the first five harmonic components of load generated voltage ripples and sixth harmonic is the major ripple component. The proposed cascaded three-phase symmetrical voltage multiplier has less than half the voltage ripple, and three times larger output voltage and output power than the conventional single-phase symmetrical CW-VM. Experimental and simulation results of the laboratory prototype are given to show the feasibility of proposed cascaded three-phase symmetrical CW-VM.
CCD Photometry of bright stars using objective wire mesh
Kamiński, Krzysztof; Zgórz, Marika [Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University, Słoneczna 36, 60-286 Poznań (Poland); Schwarzenberg-Czerny, Aleksander, E-mail: chrisk@amu.edu.pl [Copernicus Astronomical Centre, ul. Bartycka 18, PL 00-716 Warsaw (Poland)
2014-06-01
Obtaining accurate photometry of bright stars from the ground remains problematic due to the danger of overexposing the target and/or the lack of suitable nearby comparison stars. The century-old method of using objective wire mesh to produce multiple stellar images seems promising for the precise CCD photometry of such stars. Furthermore, our tests on β Cep and its comparison star, differing by 5 mag, are very encouraging. Using a CCD camera and a 20 cm telescope with the objective covered by a plastic wire mesh, in poor weather conditions, we obtained differential photometry with a precision of 4.5 mmag per two minute exposure. Our technique is flexible and may be tuned to cover a range as big as 6-8 mag. We discuss the possibility of installing a wire mesh directly in the filter wheel.
Stroboscope Based Synchronization of Full Frame CCD Sensors
Liang Shen
2017-04-01
Full Text Available The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.
Research of optical rainfall sensor based on CCD linear array
YANG; Bifeng; LIU; Yuyan; LU; Ying; WU; Shangqian
2015-01-01
Rainfall monitoring is one of the most important meteorological observation elements for the disaster weather. The maintenance of current tipping bucket rain gauge and weighing type rain gauge is a critical issue. The optical rainfall sensor based on CCD linear array is mainly studied in this paper. Because of the maintenance-free time and good adaptability,it can be widely used in the automatic rainfall monitoring in severe environment and have a good perspective in using.
Pedersen, Mads Møller; Smedegaard, Jesper; Jensen, Peter Koch
2005-01-01
ophthalmology, colour CCD camera, colour film, digital imaging, resolution, micrographs, histopathology, light microscopy......ophthalmology, colour CCD camera, colour film, digital imaging, resolution, micrographs, histopathology, light microscopy...
A Bridge Deflection Monitoring System Based on CCD
Baohua Shan
2016-01-01
Full Text Available For long-term monitoring of the midspan deflection of Songjiazhuang cloverleaf junction on 309 national roads in Zibo city, this paper proposes Zhang’s calibration-based DIC deflection monitoring method. CCD cameras are used to track the change of targets’ position, Zhang’s calibration algorithm is introduced to acquire the intrinsic and extrinsic parameters of CCD cameras, and the DIC method is combined with Zhang’s calibration algorithm to measure bridge deflection. The comparative test between Zhang’s calibration and scale calibration is conducted in lab, and experimental results indicate that the proposed method has higher precision. According to the deflection monitoring scheme, the deflection monitoring software for Songjiazhuang cloverleaf junction is developed by MATLAB, and a 4-channel CCD deflection monitoring system for Songjiazhuang cloverleaf junction is integrated in this paper. This deflection monitoring system includes functions such as image preview, simultaneous collection, camera calibration, deflection display, and data storage. In situ deflection curves show a consistent trend; this suggests that the proposed method is reliable and is suitable for the long-term monitoring of bridge deflection.
High definition 3D imaging lidar system using CCD
Jo, Sungeun; Kong, Hong Jin; Bang, Hyochoong
2016-10-01
In this study we propose and demonstrate a novel technique for measuring distance with high definition three-dimensional imaging. To meet the stringent requirements of various missions, spatial resolution and range precision are important properties for flash LIDAR systems. The proposed LIDAR system employs a polarization modulator and a CCD. When a laser pulse is emitted from the laser, it triggers the polarization modulator. The laser pulse is scattered by the target and is reflected back to the LIDAR system while the polarization modulator is rotating. Its polarization state is a function of time. The laser-return pulse passes through the polarization modulator in a certain polarization state, and the polarization state is calculated using the intensities of the laser pulses measured by the CCD. Because the function of the time and the polarization state is already known, the polarization state can be converted to time-of-flight. By adopting a polarization modulator and a CCD and only measuring the energy of a laser pulse to obtain range, a high resolution three-dimensional image can be acquired by the proposed three-dimensional imaging LIDAR system. Since this system only measures the energy of the laser pulse, a high bandwidth detector and a high resolution TDC are not required for high range precision. The proposed method is expected to be an alternative method for many three-dimensional imaging LIDAR system applications that require high resolution.
Development of X-ray CCD camera based X-ray micro-CT system.
Sarkar, Partha S; Ray, N K; Pal, Manoj K; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y; Sinha, A; Gadkari, S C
2017-02-01
Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.
Flat-Field Calibration of CCD Detector for Long TraceProfilers
Kirschman, Jonathan L.; Domning, Edward E.; Franck, Keith D.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R.; Morrison,Gregory Y.; Smith, Brian V.; Warwick, Tony; Yashchuk, Valeriy V.
2007-07-31
The next generation of synchrotrons and free electron lasersrequires x-ray optical systems with extremely high-performance,generally, of diffraction limited quality. Fabrication and use of suchoptics requires highly accurate metrology. In the present paper, wediscuss a way to improve the performance of the Long Trace Profiler(LTP), a slope measuring instrument widely used at synchrotron facilitiesto characterize x-ray optics at high-spatial-wavelengths fromapproximately 2 mm to 1 m. One of the major sources of LTP systematicerror is the detector. For optimal functionality, the detector has topossess the smallest possible pixel size/spacing, a fast method ofshuttering, and minimal non-uniformity of pixel-to-pixel photoresponse.While the first two requirements are determined by choice of detector,the non-uniformity of photoresponse of typical detectors such as CCDcameras is around 2-3 percent. We describe a flat-field calibration setupspecially developed for calibration of CCD camera photo-response and darkcurrent with an accuracy of better than 0.5 percent. Such accuracy isadequate for use of a camera as a detector for an LTP with performance of~;0.1 microradian (rms). We also present the design details of thecalibration system and results of calibration of a DALSA CCD camera usedfor upgrading our LTP-II instrument at the ALS Optical MetrologyLaboratory.
Development of X-ray CCD camera based X-ray micro-CT system
Sarkar, Partha S.; Ray, N. K.; Pal, Manoj K.; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y.; Sinha, A.; Gadkari, S. C.
2017-02-01
Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.
Improving the resolution in phase-shifting Gabor holography by CCD shift
Granero, L.; Micó, V.; Zalevsky, Z.; García, J.; Javidi, B.
2015-05-01
Holography dates back to the year when Dennis Gabor reported on a method to avoid spherical aberration and to improve image quality in electron microscopy. Gabor's two-step holographic method was pioneer but suffered from three major drawbacks: the reconstructed image is affected by coherent noise, the twin image problem of holography that also affects the final image quality, and a restricted sample range (weak diffraction assumption) for preserving the holographic behavior of the method. Nowadays, most of those drawbacks have been overcome and new capabilities have been added due to the replacement of the classical recording media (photographic plate) by digital sensors (CCD and CMOS cameras). But in the Gabor' regime, holography is restricted to weak diffraction assumptions because otherwise, diffraction prevents an accurate recovery of the object's complex wavefront. In this contribution, we present an experimental approach to overcome such limitation and improve final image resolution. We use the phase-shifting Gabor configuration while the CCD camera is shifted to different off-axis positions in order to capture a bigger portion of the diffracted wavefront. Thus, once the whole image set is recorded and digitally processed for each camera's position, we merge the resulting band-pass images into one image by assembling a synthetic aperture. Finally, a superresolved image is recovered by Fourier transformation of the information contained in the generated synthetic aperture. Experimental results are provided using a USAF resolution test target and validating our concepts for a gain in resolution of close to 2.
Test technology on CCD anti-sunlight jamming based on complex circumstance
Shi, Sheng-bing; Chen, Zhen-xing; Han, Fu-li
2016-09-01
Visible-light reconnaissance device based on CCD is applied to all kinds of weapons, CCD cannot work because of saturation when it faces intense light. Sun is intense light source in nature and assignably influences CCD performance. In this paper, aim is appraising CCD anti-sunlight ability, object reflection characteristic test system is designed, based on typical background reflection characteristic including grant, sand and so on, complex circumstance is formulated and test project is optimized with orthogonal design method, problem that is without test technology on CCD anti-sunlight jamming is solved.
14位10MHz CCD/CIS信号处理器%14-bit, 10MHz CCD/CIS signal processors
彭京湘
2000-01-01
@@ Burr-Brown公司的VSP3100是一款工作在+5V单电源的完整CCD/CIS图像处理器.这种完整的图像处理器包含处理CCD(电荷耦合器件)信号的3个相关双取样器(CDS)和可编程增益放大器(PGA)(见图1).3个通道输入(RINP--红色通道模拟输入,GINP--绿色通道模拟输入,BINP--兰色通道模拟输入)也为接触图像传感器(CIS)提供输入.
Optical and dark characterization of the PLATO CCD at ESA
Verhoeve, Peter; Prod'homme, Thibaut; Oosterbroek, Tim; Duvet, Ludovic; Beaufort, Thierry; Blommaert, Sander; Butler, Bart; Heijnen, Jerko; Lemmel, Frederic; van der Luijt, Cornelis; Smit, Hans; Visser, Ivo
2016-07-01
PLATO - PLAnetary Transits and Oscillations of stars - is the third medium-class mission (M3) to be selected in the European Space Agency (ESA) Science and Robotic Exploration Cosmic Vision programme. It is due for launch in 2025 with the main objective to find and study terrestrial planets in the habitable zone around solar-like stars. The payload consists of >20 cameras; with each camera comprising 4 Charge-Coupled Devices (CCDs), a large number of flight model devices procured by ESA shall ultimately be integrated on the spacecraft. The CCD270 - specially designed and manufactured by e2v for the PLATO mission - is a large format (8 cm x 8 cm) back-illuminated device operating at 4 MHz pixel rate and coming in two variants: full frame and frame transfer. In order to de-risk the PLATO CCD procurement and aid the mission definition process, ESA's Payload Technology Validation section is currently validating the PLATO CCD270. This validation consists in demonstrating that the device achieves its specified electrooptical performance in the relevant environment: operated at 4 MHz, at cold and before and after proton irradiation. As part of this validation, CCD270 devices have been characterized in the dark as well as optically with respect to performance parameters directly relevant for the photometric application of the CCDs. Dark tests comprise the measurement of gain sensitivity to bias voltages, charge injection tests, and measurement of hot and variable pixels after irradiation. In addition, the results of measurements of Quantum Efficiency for a range of angles of incidence, intra- pixel response (non-)uniformity, and response to spot illumination, before and after proton irradiation. In particular, the effect of radiation induced degradation of the charge transfer efficiency on the measured charge in a star-like spot has been studied as a function of signal level and of position on the pixel grid, Also, the effect of various levels of background light on the
GEM-based TPC with CCD imaging for directional dark matter detection
Phan, N. S.; Lauer, R. J.; Lee, E. R.; Loomba, D.; Matthews, J. A. J.; Miller, E. H.
2016-11-01
The most mature directional dark matter experiments at present all utilize low-pressure gas Time Projection Chamber (TPC) technologies. We discuss some of the challenges for this technology, for which balancing the goal of achieving the best sensitivity with that of cost effective scale-up requires optimization over a large parameter space. Critical for this are the precision measurements of the fundamental properties of both electron and nuclear recoil tracks down to the lowest detectable energies. Such measurements are necessary to provide a benchmark for background discrimination and directional sensitivity that could be used for future optimization studies for directional dark matter experiments. In this paper we describe a small, high resolution, high signal-to-noise GEM-based TPC with a 2D CCD readout designed for this goal. The performance of the detector was characterized using alpha particles, X-rays, gamma-rays, and neutrons, enabling detailed measurements of electron and nuclear recoil tracks. Stable effective gas gains of greater than 1 × 105 were obtained in 100 Torr of pure CF4 by a cascade of three standard CERN GEMs each with a 140 μm pitch. The high signal-to-noise and sub-millimeter spatial resolution of the GEM amplification and CCD readout, together with low diffusion, allow for excellent background discrimination between electron and nuclear recoils down below ∼10 keVee (∼23 keVr fluorine recoil). Even lower thresholds, necessary for the detection of low mass WIMPs for example, might be achieved by lowering the pressure and utilizing full 3D track reconstruction. These and other paths for improvements are discussed, as are possible fundamental limitations imposed by the physics of energy loss.
Yan Bing; Zhang Yu-Juan
2013-01-01
The potential energy curves for neutrals and multiply charged ions of carbon monosulfide are computed with highly correlated multi-reference configuration interaction wavefunctions.The correlations of inner-shell electrons with the scalar relativistic effects are included in the present computations.The spectroscopic constants,dissociation energies,ionization energies for ground and low-lying excited states together with corresponding electronic configurations of ions are obtained,and a good agreement between the present work and existing experiments is found.No theoretical evidence is found for the adiabatically stable CSq+ (q ＞ 2) ions according to the present ab initio calculations.The calculated values for lst-6th ionization energies are 11.25,32.66,64.82,106.25,159.75,and 224.64 eV,respectively.The kinetic energy release data of fragments are provided by the present work for further experimental comparisons.
A New Design for Array Multiplier with Trade off in Power and Area
Ravi, Nirlakalla; Prasad, T Jayachandra; Rao, T Subba
2011-01-01
In this paper a low power and low area array multiplier with carry save adder is proposed. The proposed adder eliminates the final addition stage of the multiplier than the conventional parallel array multiplier. The conventional and proposed multiplier both are synthesized with 16-T full adder. Among Transmission Gate, Transmission Function Adder, 14-T, 16-T full adder shows energy efficiency. In the proposed 4x4 multiplier to add carry bits with out using Ripple Carry Adder (RCA) in the final stage, the carries given to the input of the next left column input. Due to this the proposed multiplier shows 56 less transistor count, then cause trade off in power and area. The proposed multiplier has shown 13.91% less power, 34.09% more speed and 59.91% less energy consumption for TSMC 0.18nm technology at a supply voltage 2.0V than the conventional multiplier.
Buts, Lieven; De Jonge, Natalie; Loris, Remy, E-mail: reloris@vub.ac.be; Wyns, Lode; Dao-Thi, Minh-Hoa [Department of Molecular and Cellular Interactions, Vlaams Interinuversitair Instituut voor Biotechnologie and Laboratorium voor Ultrastructuur, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel (Belgium)
2005-10-01
The CcdA C-terminal domain was crystallized in complex with CcdB in two crystal forms that diffract to beyond 2.0 Å resolution. CcdA and CcdB are the antidote and toxin of the ccd addiction module of Escherichia coli plasmid F. The CcdA C-terminal domain (CcdA{sub C36}; 36 amino acids) was crystallized in complex with CcdB (dimer of 2 × 101 amino acids) in three different crystal forms, two of which diffract to high resolution. Form II belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 37.6, b = 60.5, c = 83.8 Å and diffracts to 1.8 Å resolution. Form III belongs to space group P2{sub 1}, with unit-cell parameters a = 41.0, b = 37.9, c = 69.6 Å, β = 96.9°, and diffracts to 1.9 Å resolution.
Dynamic effects of fiscal policy and fiscal multipliers in Croatia
Milan Deskar-Škrbić
2013-06-01
Full Text Available The aim of this paper is to analyze the effects of discretionary measures of fiscal policy on the economic activity and to estimate the size of fiscal multipliers in Croatia. Econometric framework is based on the structural VAR model (SVAR, with Blanchard-Perotti identification method that uses information on institutional characteristics of fiscal system. The analysis is conducted on quarterly data for total expenditures and indirect taxes of central, central consolidated and general consolidated government and aggregate demand for the period from 2004-2012. The results show that our initial assumptions about the difference in the size of the multiplier of government expenditures and indirect tax revenues between three levels of government consolidation have been confirmed.
Dark energy from modified gravity with Lagrange multipliers
Capozziello, Salvatore; Nojiri, Shin'ichi; Odintsov, Sergei D
2010-01-01
We study scalar-tensor theory, k-essence and modified gravity with Lagrange multiplier constraint which role is to reduce the number of degrees of freedom. Dark Energy cosmology of different types ($\\Lambda$CDM, unified inflation with DE, smooth non-phantom/phantom transition epoch) is reconstructed in such models. It is shown that mathematical equivalence between scalar theory and $F(R)$ gravity is broken due to presence of constraint. The cosmological dynamics of $F(R)$ gravity is modified by the second $F_2(R)$ function dictated by the constraint. Dark Energy cosmology is defined by this function while standard $F_1(R)$ function is relevant for local tests (modification of newton regime). A general discussion on the role of Lagrange multipliers to make higher-derivative gravity canonical is developed.
BroCam: a versatile PC-based CCD camera system
Klougart, Jens
1995-03-01
At the Copenhagen University, we have developed a compact CCD camera system for single and mosaic CCDs. The camera control and data acquisition is performed by a 486 type PC via a frame buffer located in one ISA-bus slot, communicating to the camera electronics on two optical fibers. The PC can run as well special purpose DOS programs, as in a more general mode under LINUX, a UNIX similar operating system. In the latter mode, standard software packages, such as SAOimage and Gnuplot, are utilized extensively thereby reducing the amount of camera specific software. At the same time the observer feels at ease with the system in an IRAF-like environment. Finally, the LINUX version enables the camera to be remotely controlled.
Ground-Based Sub-Millimagnitude CCD Photometry of Bright Stars using Snapshot Observations
Mann, Andrew W; Aldering, Greg
2011-01-01
We demonstrate ground-based sub-millimagnitude (10^7 electrons) to be acquired in a single integration; (iii) pointing the telescope so that all stellar images fall on the same detector pixels; and (iv) using a region of the CCD detector that is free of non-linear or aberrant pixels. We describe semi-automated observations with the Supernova Integrated Field Spectrograph (SNIFS) on the University of Hawaii 2.2m telescope on Mauna Kea, with which we achieved photometric precision as good as 5.2x10^-4 (0.56 mmag) with a 5 minute cadence over a two hour interval. In one experiment, we monitored 8 stars, each separated by several degrees, and achieved sub-mmag precision with a cadence (per star) of ~17 min. Our snapshot technique is suitable for automated searches for planetary transits among multiple, bright-stars.
Anomalous visualization of sub-2 THz photons on standard silicon CCD and COMS sensors
Shalaby, Mostafa; Hauri, Christoph P
2015-01-01
We experimentally show that indirect light-induced electron transitions could lead to THz detection on standard CCD and CMOS sensors, introducing this well-established technological concept to the THz range. Unlike its optical counterpart, we found that the THz sensitivity is nonlinear. We imaged 1-13 THz radiation with photon energy less than 2% of the well-established band gap energy threshold. The unprecedented small pitch and large number of pixels uniquely allowed us to visualize the complex propagation of THz radiation, as it focuses down to the physical diffraction limit. Broadband pulses were detectable at a single shot. This opens a whole new field of real time THz imaging at the frame rate of the sensor.
Reverse engineering of the homogeneous-entity product profiles based on CCD
Gan, Yong; Zhong, Jingru; Sun, Ning; Sun, Aoran
2011-08-01
This measurement system uses delaminated measurement principle, measures the three perpendicular direction values of the entities. When the measured entity is immerged in the liquid layer by layer, every layer's image are collected by CCD and digitally processed. It introduces the basic measuring principle and the working process of the measure method. According to Archimedes law, the related buoyancy and volume that soaked in different layer's depth are measured by electron balance and the mathematics models are established. Through calculating every layer's weight and centre of gravity by computer based on the method of Artificial Intelligence, we can reckon 3D coordinate values of every minute entity cell in different layers and its 3D contour picture is constructed. The experimental results show that for all the homogeneous entity insoluble in water, it can measure them. The measurement velocity is fast and non-destructive test, it can measure the entity with internal hole.
Multipliers of $A_p((0, ∞))$ with Order Convolution
Savita Bhatnagar
2005-08-01
The aim of this paper is to study the multipliers from $A_r(I)$ to $A_p(I), r≠ p$, where =(0, ∞) is the locally compact topological semigroup with multiplication max and usual topology and $A_r(I)=\\{f\\in L_1(I):\\hat{f}\\in L_r(\\hat{I})\\}$ with norm $|||f|||_r=||f||_1+||hat{f}||_r$.
Radial multipliers on reduced free products of operator algebras
Haagerup, Uffe; Møller, Søren
2012-01-01
Let AiAi be a family of unital C¿C¿-algebras, respectively, of von Neumann algebras and ¿:N0¿C¿:N0¿C. We show that if a Hankel matrix related to ¿ is trace-class, then there exists a unique completely bounded map M¿M¿ on the reduced free product of the AiAi, which acts as a radial multiplier...
Lagrange Multipliers and Third Order Scalar-Tensor Field Theories
Horndeski, Gregory W.
2016-01-01
In a space of 4-dimensions, I will examine constrained variational problems in which the Lagrangian, and constraint scalar density, are concomitants of a (pseudo-Riemannian) metric tensor and its first two derivatives. The Lagrange multiplier for these constrained extremal problems will be a scalar field. For suitable choices of the Lagrangian, and constraint, we can obtain Euler-Lagrange equations which are second order in the scalar field and third order in the metric tensor. The effect of ...
High performance pipelined multiplier with fast carry-save adder
Wu, Angus
1990-01-01
A high-performance pipelined multiplier is described. Its high performance results from the fast carry-save adder basic cell which has a simple structure and is suitable for the Gate Forest semi-custom environment. The carry-save adder computes the sum and carry within two gate delay. Results show that the proposed adder can operate at 200 MHz for a 2-micron CMOS process; better performance is expected in a Gate Forest realization.
Multiplier ideal sheaves in complex and algebraic geometry
Yum-Tong; Siu
2005-01-01
The application of the method of multiplier ideal sheaves to effective problems in algebraic geometry is briefly discussed. Then its application to the deformational invariance of plurigenera for general compact algebraic manifolds is presented and discussed.Finally its application to the conjecture of the finite generation of the canonical ring is explored, and the use of complex algebraic geometry in complex Neumann estimates is discussed.
Three states of fiscal multipliers in a small open economy
Simon Naitram; Justin Carter; Shane Lowe
2015-01-01
This research reviews the effects of fiscal expenditures on economic output in a non-linear fashion for the Barbados economy. Using the Markov-Switching methodology, fiscal expenditure multipliers are estimated for each stage of the business cycle. The data indicates that a three-regime model is the best fit â€“ capturing recession, normal growth and boom periods. Our findings suggest that increasing capital expenditure is positively correlated with economic growth at all stages of the busine...
The role of the Jacobi last multiplier and isochronous systems
Partha Guha; Anindya Ghose Choudhury
2011-11-01
We employ Jacobi’s last multiplier (JLM) to study planar differential systems. In particular, we examine its role in the transformation of the temporal variable for a system of ODEs originally analysed by Calogero–Leyvraz in course of their identiﬁcation of isochronous systems. We also show that JLM simpliﬁes to a great extent the proofs of isochronicity for the Liénard-type equations.
Is Flat fielding Safe for Precision CCD Astronomy?
Baumer, Michael; Davis, Christopher P.; Roodman, Aaron
2017-08-01
The ambitious goals of precision cosmology with wide-field optical surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST) demand precision CCD astronomy as their foundation. This in turn requires an understanding of previously uncharacterized sources of systematic error in CCD sensors, many of which manifest themselves as static effective variations in pixel area. Such variation renders a critical assumption behind the traditional procedure of flat fielding—that a sensor’s pixels comprise a uniform grid—invalid. In this work, we present a method to infer a curl-free model of a sensor’s underlying pixel grid from flat-field images, incorporating the superposition of all electrostatic sensor effects—both known and unknown—present in flat-field data. We use these pixel grid models to estimate the overall impact of sensor systematics on photometry, astrometry, and PSF shape measurements in a representative sensor from the Dark Energy Camera (DECam) and a prototype LSST sensor. Applying the method to DECam data recovers known significant sensor effects for which corrections are currently being developed within DES. For an LSST prototype CCD with pixel-response non-uniformity (PRNU) of 0.4%, we find the impact of “improper” flat fielding on these observables is negligible in nominal .7″ seeing conditions. These errors scale linearly with the PRNU, so for future LSST production sensors, which may have larger PRNU, our method provides a way to assess whether pixel-level calibration beyond flat fielding will be required.
Almost everywhere convergence of sequences of multiplier operators on local fields
郑世骏; 郑维行
1997-01-01
Let Kn be the n -dimensional vector space over a local field K . Two maximal multiplier theorems on Lp(Kn) are proved for certain multiplier operator sequences associated with regularization and dilation respectively Consequently the a. e. convergence of such multiplier operator sequences is obtained This sharpens Taibleson’s main result and applies to several important singular integral operators on Kn.
On Nilpotent Multipliers of Some Verbal Products of Groups
Hokmabadi, Azam
2010-01-01
The paper is devoted to finding a homomorphic image for the $c$-nilpotent multiplier of the verbal product of a family of groups with respect to a variety ${\\mathcal V}$ when ${\\mathcal V} \\subseteq {\\mathcal N}_{c}$ or ${\\mathcal N}_{c}\\subseteq {\\mathcal V}$. Also a structure of the $c$-nilpotent multiplier of a special case of the verbal product, the nilpotent product, of cyclic groups is given. In fact, we present an explicit formula for the $c$-nilpotent multiplier of the $n$th nilpotent product of the group $G= {\\bf {Z}}\\stackrel{n}{*}...\\stackrel{n}{*}{\\bf {Z}}\\stackrel{n}{*} {\\bf {Z}}_{r_1}\\stackrel{n}{*}...\\stackrel{n}{*}{\\bf{Z}}_{r_t}$, where $r_{i+1}$ divides $r_i$ for all $i$, $1 \\leq i \\leq t-1$, and $(p,r_1)=1$ for any prime $p$ less than or equal to $n+c$, for all positive integers $n$, $c$.
Inferring polyploid phylogenies from multiply-labeled gene trees
Petri Anna
2009-08-01
Full Text Available Abstract Background Gene trees that arise in the context of reconstructing the evolutionary history of polyploid species are often multiply-labeled, that is, the same leaf label can occur several times in a single tree. This property considerably complicates the task of forming a consensus of a collection of such trees compared to usual phylogenetic trees. Results We present a method for computing a consensus tree of multiply-labeled trees. As with the well-known greedy consensus tree approach for phylogenetic trees, our method first breaks the given collection of gene trees into a set of clusters. It then aims to insert these clusters one at a time into a tree, starting with the clusters that are supported by most of the gene trees. As the problem to decide whether a cluster can be inserted into a multiply-labeled tree is computationally hard, we have developed a heuristic method for solving this problem. Conclusion We illustrate the applicability of our method using two collections of trees for plants of the genus Silene, that involve several allopolyploids at different levels.
CCD polarization imaging sensor with aluminum nanowire optical filters.
Gruev, Viktor; Perkins, Rob; York, Timothy
2010-08-30
We report an imaging sensor capable of recording the optical properties of partially polarized light by monolithically integrating aluminum nanowire optical filters with a CCD imaging array. The imaging sensor, composed of 1000 by 1000 imaging elements with 7.4 μm pixel pitch, is covered with an array of pixel-pitch matched nanowire optical filters with four different orientations offset by 45°. The polarization imaging sensor has a signal-to-noise ratio of 45 dB and captures intensity, angle and degree of linear polarization in the visible spectrum at 40 frames per second with 300 mW of power consumption.
CCD Photometry of Dwarf Nova AL Com in Superoutburst
Pych, W.; Olech, A.
1995-01-01
We report a CCD optical photometry of a dwarf nova AL Com in superoutburst. Before superhumps occurred the light curve was highly variable with dominant periods about 41 minutes and 81.5 minutes for different nights. The period of observed superhumps is 82.5 minutes and seems to be stable. The first harmonic of the basic period is also present. We detected a weak signal corresponding to period 78.1 minutes. One of the periods 78.1 or 81.5 is suspected to be a possible signature of orbital mot...
CCD-photometry of comets at large heliocentric distances
Mueller, Beatrice E. A.
1992-01-01
CCD imaging and time series photometry are used to determine the state of activity, nuclear properties and eventually the rotational motion of cometary nuclei. Cometary activity at large heliocentric distances and mantle evolution are not yet fully understood. Results of observations carried out at the 2.1 telescope on Kitt Peak April 10-12 and May 15-16, 1991 are discussed. Color values and color-color diagrams are presented for several comets and asteroids. Estimations of nuclear radii and shapes are given.
CCD time-resolved photometry of faint cataclysmic variables. III
Howell, Steve B.; Szkody, Paula; Kreidl, Tobias J.; Mason, Keith O.; Puchnarewicz, E. M.
1990-01-01
CCD time-resolved photometry in V, B, and near-IR for 17 faint cataclysmic variables (CVs) is presented and analyzed. The data are obtained at Kitt Peak National Observatory, the Perkins reflector, Lowell Observatory, and the Observatorio del Roque de los Muchachos from April-June 1989. The degree of variability and periodicities for the CVs are examined. It is observed that the variability of most of the stars is consistent with CV class behavior. Orbital periods for five CVs are determined, and three potential eclipsing systems are detected.
ASPIC and CABAC: two ASICs to readout and pilot CCD
Antilogus, P.; Bailly, P.; Barrillon, P.; Dhellot, M.; El berni, A.; Jeglot, J.; Juramy-Gilles, C.; Lebbolo, H.; Martin, D.; Moniez, M.; Vallerand, P.
2017-03-01
For several years, a group of engineers and physicists from LAL and LPNHE have been working on the design of two front end ASICs dedicated to Charge Couple Devices (CCD). ASPIC (Analogue Signal Processing Integrated Circuit), designed in AMS CMOS 0.35 μm 5V technology, is meant to readout and process the analog signals of CCDs. CABAC (Clocks And Biases ASIC for CCDs), designed in AMS CMOS 0.35 μm 50V technology, produces the clocks and biases needed by the CCDs to work at their full potential. This paper presents the performances of the final versions of these two ASICs.
A 3-channel CCD photometer at the Xinglong Observatory
Yong-Na Mao; Xiao-Meng Lu; Jian-Feng Wang; Xiao-Jun Jiang
2013-01-01
We describe the design and construction of a new rapid 3-channel CCD photometer,dedicated to simultaneous multicolor photometric observations of rapidly variable objects.This photometer is equipped on the 1-meter telescope at the Xinglong Observatory.It allows simultaneous imaging within fields of view of 18.8' × 18.8',18.2' × 17.6' and 9.2' × 9.2' in the Sloan Digital Sky Survey's g',r' and i' bands,respectively.The results of its calibration and performance are reported.
Energy dependent charge spread function in a dedicated synchrotron beam pnCCD detector
Yousef, Hazem
2011-05-20
A scan on the pixel edges is the method which is used to resolve the electron cloud size in the pixel array of the pnCCD detector. The EDR synchrotron radiation in BESSY is the source of the X-ray photons which are used in the scans. The radius of the electron cloud as a function of the impinging photon energy is analyzed. The angle of incidence of the X-ray beam is employed in the measurements. The measurements are validated by the numerical simulation models. The inclined X-ray track leads to distribute the electron clouds in a certain number of pixels according to the incident angle of the X-ray beam. The pixels detect different electron clouds according to their generation position in the detector bulk. A collimated X-ray beam of 12.14 keV is used in the measurements with 30 and 40 entrance angles. It is shown that the two factors that leads to expand the electron clouds namely the diffusion and the mutual electrostatic repulsion can be separated from the measured electron clouds. It is noticed as well that the influence of the mutual electrostatic repulsion dominates the cloud expansion over the diffusion process in the collection time of the detector. The perpendicular X-ray track leads to determine the average radius of the electron cloud per photon energy. The results show that the size of the electron clouds (RMS) in the energy range of [5.0-21.6] keV is smaller than the pixel size. (orig.)
Measurement of spatial object's exterior attitude based on linear CCD
无
2008-01-01
It is difficult to realize real-time measurement of exterior attitude by the traditional systems based on the area image sensor which have conflict between speed and accuracy.The subsystem for three-dimensional (3D) coordinate rcconstruction of point target (S3DCRPT) which is composed of three one-dimensional (1D) cameras based on linear charge-coupled device (CCD) can determine the distant light spots' spatial position. The attitude angle of the measured object is determined by the spatial solution while the coordinate reconstruction is separately carried on by the S3DCRPT with some point cooperation targets (PCTs) on the measured object. A new optical system is designed to solve the interference problem with one-to-one relationship between the PCTs and the S3DCRPT optical subsystems,which improves the measurement accuracy and saves space. The mathematical model of the attitude measurement is established,and partial and global calibrations are realized for the multi-camera attitude measurement system.The test results show the feasibility of the exterior attitude measurement based on linear CCD.
CCD-Based Astrometric Measurement of Photographic Plates
I. H. Bustos Fierro
2003-01-01
Full Text Available Se ha desarrollado la metodología para la medición astromètrica de placas fotográficas haciendo uso de una cámara CCD. Para la medición de una placa de 2º x 2º se tomó un mosaico de 8 x 8 imágenes con 50% de superposición en ambas coordenadas. La segmentación y el centrado de las imágenes estelares se llevó a cabo con SExtractor, y por medio de software propio se identificaron las exposiciones triples. Se encontró una notable distorsión radial producida por el sistema óptico que fue corregida. La reducción a coordenadas celestes se efectuó mediante la técnica de ajuste en bloque, usándose el catálogo Tycho-2 como referencia. Las diferencias con Tycho-2 sugieren que el error de las posiciones obtenidas con CCD a partir de la placa CdC está entre 0:0020 y 0:0025. También se discute la completitud de los catálogos obtenidos.
The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)
Zacharias, Norbert; Girard, Terry; Henden, Arne; Bartlett, Jennifer; Monet, Dave; Zacharias, Marion
2012-01-01
The fourth United States Naval Observatory (USNO) CCD Astrograph Catalog, UCAC4 was released in August 2012 (double-sided DVD and CDS data center Vizier catalog I/322). It is the final release in this series and contains over 113 million objects; over 105 million of them with proper motions. UCAC4 is an updated version of UCAC3 with about the same number of stars also covering all-sky. Bugs were fixed, Schmidt plate survey data were avoided, and precise 5-band photometry were added. Astrograph observations have been supplemented for bright stars by FK6, Hipparcos and Tycho-2 data to compile a UCAC4 star catalog complete to about magnitude R = 16. Epoch 1998 to 2004 positions are obtained from observations with the 20 cm aperture USNO Astrograph's red lens, equipped with a 4k by 4k CCD. Mean positions and proper motions are derived by combining these observations with over 140 ground- and space-based catalogs, including Hipparcos/Tycho and the AC2000.2, as well as unpublished measures of over 5000 plates from ...
The second US Naval Observatory CCD Astrograph Catalog (UCAC2)
Zacharias, N; Zacharias, M I; Wycoff, G L; Hall, D M; Monet, D G; Rafferty, T J
2004-01-01
The second USNO CCD Astrograph Catalog, UCAC2 was released in July 2003. Positions and proper motions for 48,330,571 sources (mostly stars) are available on 3 CDs, supplemented with 2MASS photometry for 99.5% of the sources. The catalog covers the sky area from -90 to +40 degrees declination, going up to +52 in some areas; this completely supersedes the UCAC1 released in 2001. Current epoch positions are obtained from observations with the USNO 8-inch Twin Astrograph equipped with a 4k CCD camera. The precision of the positions are 15 to 70 mas, depending on magnitude, with estimated systematic errors of 10 mas or below. Proper motions are derived by utilizing over 140 ground-and space-based catalogs, including Hipparcos/Tycho, the AC2000.2, as well as yet unpublished re-measures of the AGK2 plates and scans from the NPM and SPM plates. Proper motion errors are about 1 to 3 mas/yr for stars to 12th magnitude, and about 4 to 7 mas/yr for fainter stars to 16th magnitude. The observational data, astrometric redu...
CCD Photometric Study and Period Investigation of AH Tauri
Xiang, Fu-Yuan; Xiao, Ting-Yu; Yu, Yun-Xia
2015-07-01
In this paper, we present new CCD photometric observations of AH Tauri in the R band observed in 2006 at the Yunnan Observatory. Two new times of light minima were derived from these observations. We modeled the light curves using the 2003 version of the Wilson-Devinney program. The results show that the variations of the light curves can be expained by a cool spot on the primary star. The fill-out factor is about 6.6%, indicating that AH Tauri is a shallow-contact system. The mass ratio was determined to be about 0.505. In addition, the orbital period variations of AH Tauri were investigated based on all of the photoelectric and CCD light minimum times, including our two new data. It was found that the orbital period exhibits a possible periodic variation with a period of {P}{mod}=54.62\\(+/- 0.20) years and a secular period decrease of {dP}/{dt}=-(1.823+/- 0.215)× {10}-7 {days} {{yr}}-1. Since AH Tauri is an overcontact solar-like system, we discuss three mechanisms of the mass transfer, the light-time effect of the third body, and magnetic activity responsible for the orbital period changes.
High frame rate CCD camera with fast optical shutter
Yates, G.J.; McDonald, T.E. Jr. [Los Alamos National Lab., NM (United States); Turko, B.T. [Lawrence Berkeley National Lab., CA (United States)
1998-09-01
A high frame rate CCD camera coupled with a fast optical shutter has been designed for high repetition rate imaging applications. The design uses state-of-the-art microchannel plate image intensifier (MCPII) technology fostered/developed by Los Alamos National Laboratory to support nuclear, military, and medical research requiring high-speed imagery. Key design features include asynchronous resetting of the camera to acquire random transient images, patented real-time analog signal processing with 10-bit digitization at 40--75 MHz pixel rates, synchronized shutter exposures as short as 200pS, sustained continuous readout of 512 x 512 pixels per frame at 1--5Hz rates via parallel multiport (16-port CCD) data transfer. Salient characterization/performance test data for the prototype camera are presented, temporally and spatially resolved images obtained from range-gated LADAR field testing are included, an alternative system configuration using several cameras sequenced to deliver discrete numbers of consecutive frames at effective burst rates up to 5GHz (accomplished by time-phasing of consecutive MCPII shutter gates without overlap) is discussed. Potential applications including dynamic radiography and optical correlation will be presented.
CCD Camera Lens Interface for Real-Time Theodolite Alignment
Wake, Shane; Scott, V. Stanley, III
2012-01-01
Theodolites are a common instrument in the testing, alignment, and building of various systems ranging from a single optical component to an entire instrument. They provide a precise way to measure horizontal and vertical angles. They can be used to align multiple objects in a desired way at specific angles. They can also be used to reference a specific location or orientation of an object that has moved. Some systems may require a small margin of error in position of components. A theodolite can assist with accurately measuring and/or minimizing that error. The technology is an adapter for a CCD camera with lens to attach to a Leica Wild T3000 Theodolite eyepiece that enables viewing on a connected monitor, and thus can be utilized with multiple theodolites simultaneously. This technology removes a substantial part of human error by relying on the CCD camera and monitors. It also allows image recording of the alignment, and therefore provides a quantitative means to measure such error.
A Design of Modified 64 bit Wallace Multiplier using 45 nm Technology
S.Sunilkumar
2013-04-01
Full Text Available Multipliers plays a vital role in the field of digital processing of information especially signal and image. The key benefit of 64 bit multiplier is high precision computation but it has to be faster aswell. In this paper, we have designed a modified 64 bit Wallace multiplier. The designed multiplier reduces the number of half adders which are mainly used in the reduction phase of multiplier and alsothey do not contribute in the reduction of partial products. For the entire multiplication process we have used only 38 half adders. The multiplier is designed using Verilog-HDL and implemented using TSMC45nm technology. It is found that the designed multiplier has reduced number of half adder in each stage and it consumes 15.22 mW at 166 MHz.
Proton irradiation test to scintillator-directory-coupled CCD onboard FFAST
Nagino, Ryo; Nakajima, Hiroshi; Sadamoto, Masaaki; Sasaki, Masayuki; Tsunemi, Hiroshi; Hayashida, Kiyoshi; Anabuki, Naohisa; Kitamura, Hisashi; Uchihori, Yukio
2013-09-01
FFAST is a large area sky survey mission at hard X-ray region by using a spacecraft formation flying. It consists of two small satellites, a telescope satellite, carrying a multilayer super mirror, and a detector satellite, carrying scintillator-deposited CCDs (SD-CCDs). SD-CCD is the imaging device which realized sensitivity to 80 keV by pasting up a scintillator on CCD directly. Soft X-ray events are directly detected in the CCD. On the other hand, Hard X-ray events are converted to optical photons by the scintillator and then the CCD detects the photons. We have obtained the spectrum with 109Cd and successfully detected the events originated from the CsI. For a space use of a CCD, we have to understand aged deterioration of CCD in high radiative environments. In addition, in the case of SD-CCD, we must investigate the influence of radio-activation of a scintillator. We performed experiments of proton irradiation to the SD-CCD as space environmental tests of cosmic rays. The SD-CCD is irradiated with the protons with the energy of 100 MeV and neglected for about 150 hours. As a result, the derived CTI profile of SD-CCD is similarly to ones of XIS/Suzaku and NeXT4 CCD/ASTRO-H. In contrast, CTIs derived from the data within 4 hours after irradiation is 10 times or more larger than the ones after 150 hours. This may be due to influence of an annealing. We also report a performance study of SD-CCD, including the detection of scintillation events, before proton irradiation.
Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions
Hetzheim, Henrik
2009-01-14
The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)
The gain in Thick GEM multipliers and its time-evolution
Alexeev, M; Bradamante, F; Bressan, A; Buechele, M; Chiosso, M; Ciliberti, P; Dalla Torre, S; Dasgupta, S; Denisov, O; Duic, V; Finger, M; Finger Jr, M; Fischer, H; Gobbo, B; Gregori, M; Herrmann, F; Koenigsmann, K; Levorato, S; Maggiora, A; Makke, N; Martin, A; Menon, G; Novakova, K; Novy, J; Panzieri, D; Pereira, F A; Santos, C A; Sbrizzai, G; Schiavon, P; Schopferer, S; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Takekawa, S; Tessarotto, F; Veloso, J F C A
2016-01-01
In the context of a project to upgrade the gas photon detectors of COMPASS RICH-1, we have performed an R&D programme aimed to develop photon detectors based on multi-layer arrangements of thick GEM electron multipliers coupled to a CsI photoconverter. For this purpose, thick GEMs have been characterised in detail including the gain performance, its dependance on the geometrical parameters and its time-evolution, a feature exhibited by the gas detectors with open insulator surfaces. The variation due to this evolution drammatically depends on the parameters themselves. In the present article we summarise the outcomes of the studies dedicated to the thick GEM gain and its evolution versus time. We also include a qualitative model which accounts for the peculiar details of the observed thick GEM gain time-evolution.
Evaluation of Photo Multiplier Tube candidates for the Cherenkov Telescope Array
Mirzoyan, R. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Müller, D., E-mail: dmueller@mpp.mpg.de [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Hanabata, Y. [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hose, J.; Menzel, U. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Nakajima, D.; Takahashi, M. [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Teshima, M. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Toyama, T. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Yamamoto, T. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada-ku, Kobe, Hyogo 658-0072 (Japan)
2016-07-11
Photo Multiplier Tubes (PMTs) are the most wide spread detectors for fast, faint light signals. Six years ago, an improvement program for the PMT candidates for the Cherenkov Telescope Array (CTA) project was started with the companies Hamamatsu Photonics K.K. and Electron Tubes Enterprises Ltd. (ETE). For maximizing the performance of the CTA imaging cameras we need PMTs with outstanding good quantum efficiency, high photoelectron collection efficiency, short pulse width, very low afterpulse probability and transit time spread. We will report on the measurements of PMT R-12992-100 from Hamamatsu as their final product and the PMT D573KFLSA as one of the latest test versions from ETE as candidate PMTs for the CTA project.
A 14-bit 40-MHz analog front end for CCD application
Jingyu, Wang; Zhangming, Zhu; Shubin, Liu
2016-06-01
A 14-bit, 40-MHz analog front end (AFE) for CCD scanners is analyzed and designed. The proposed system incorporates a digitally controlled wideband variable gain amplifier (VGA) with nearly 42 dB gain range, a correlated double sampler (CDS) with programmable gain functionality, a 14-bit analog-to-digital converter and a programmable timing core. To achieve the maximum dynamic range, the VGA proposed here can linearly amplify the input signal in a gain range from -1.08 to 41.06 dB in 6.02 dB step with a constant bandwidth. A novel CDS takes image information out of noise, and further amplifies the signal accurately in a gain range from 0 to 18 dB in 0.035 dB step. A 14-bit ADC is adopted to quantify the analog signal with optimization in power and linearity. An internal timing core can provide flexible timing for CCD arrays, CDS and ADC. The proposed AFE was fabricated in SMIC 0.18 μm CMOS process. The whole circuit occupied an active area of 2.8 × 4.8 mm2 and consumed 360 mW. When the frequency of input signal is 6.069 MHz, and the sampling frequency is 40 MHz, the signal to noise and distortion (SNDR) is 70.3 dB, the effective number of bits is 11.39 bit. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033), the National High-Tech Program of China (No. 2013AA014103), and the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory (No. ZHD201302).
Determination of Ultimate Torque for Multiply Connected Cross Section Rod
V. L. Danilov
2015-01-01
Full Text Available The aim of this work is to determine load-carrying capability of the multiply cross-section rod. This calculation is based on the model of the ideal plasticity of the material, so that the desired ultimate torque is a torque at which the entire cross section goes into a plastic state.The article discusses the cylindrical multiply cross-section rod. To satisfy the equilibrium equation and the condition of plasticity simultaneously, two stress function Ф and φ are introduced. By mathematical transformations it has been proved that Ф is constant along the path, and a formula to find its values on the contours has been obtained. The paper also presents the rationale of the line of stress discontinuity and obtained relationships, which allow us to derive the equations break lines for simple interaction of neighboring circuits, such as two lines, straight lines and circles, circles and a different sign of the curvature.After substitution into the boundary condition at the end of the stress function Ф and mathematical transformations a formula is obtained to determine the ultimate torque for the multiply cross-section rod.Using the doubly connected cross-section and three-connected cross-section rods as an example the application of the formula of ultimate torque is studied.For doubly connected cross-section rod, the paper offers a formula of the torque versus the radius of the rod, the aperture radius and the distance between their centers. It also clearly demonstrates the torque dependence both on the ratio of the radii and on the displacement of hole. It is shown that the value of the torque is more influenced by the displacement of hole, rather than by the ratio of the radii.For the three-connected cross-section rod the paper shows the integration feature that consists in selection of a coordinate system. As an example, the ultimate torque is found by two methods: analytical one and 3D modeling. The method of 3D modeling is based on the Nadai
Making a graph crossing-critical by multiplying its edges
Beaudou, Laurent; Salazar, Gelasio
2011-01-01
A graph is crossing-critical if the removal of any of its edges decreases its crossing number. This work is motivated by the following question: to what extent is crossing- criticality a property that is inherent to the structure of a graph, and to what extent can it be induced on a noncritical graph by multiplying (all or some of) its edges? It is shown that if a nonplanar graph G is obtained by adding an edge to a cubic polyhedral graph, and G is sufficiently connected, then G can be made crossing-critical by a suitable multiplication of edges.
Verilog Implementation of an Efficient Multiplier Using Vedic Mathematics
2015-01-01
In this paper, the design of a 16x16 Vedic multiplier has been proposed using the 16 bit Modified Carry Select Adder and 16 bit Kogge Stone Adder. The Modified Carry Select Adder incorporates the Binary to Excess -1 Converter (BEC) and is known to be the fastest adder as compared to all the conventional adders. The design is implemented using the Verilog Hardware Description Language and tested using the Modelsim simulator. The code is synthesized using the Virtex-7 family with th...
Robust formation control of marine surface craft using Lagrange multipliers
Ihle, Ivar-Andre F.; Jouffroy, Jerome; Fossen, Thor I.
2006-01-01
framework we develop robust control laws for marine surface vessels to counteract unknown, slowly varying, environmental disturbances and measurement noise. Robustness with respect to time-delays in the communication channels are addressed by linearizing the system. Simulations of tugboats subject......This paper presents a formation modelling scheme based on a set of inter-body constraint functions and Lagrangian multipliers. Formation control for a °eet of marine craft is achieved by stabilizing the auxiliary constraints such that the desired formation con¯guration appears. In the proposed...
Second cohomology of Lie rings and the Schur multiplier
Max Horn
2014-06-01
Full Text Available We exhibit an explicit construction for the second cohomology group$H^2(L, A$ for a Lie ring $L$ and a trivial $L$-module $A$.We show how the elements of $H^2(L, A$ correspond one-to-one to theequivalence classes of central extensions of $L$ by $A$, where $A$now is considered as an abelian Lie ring. For a finite Liering $L$ we also show that $H^2(L, C^* cong M(L$, where $M(L$ denotes theSchur multiplier of $L$. These results match precisely the analoguesituation in group theory.
The Administration's Crisis Multiplied by the Crisis of the Administrated
Alina Livia NICU
2014-11-01
Full Text Available The starting point of this work is the idea that the concept of “crisis” should be approached with no fear. It is necessary to understand it as the signal which attracts attention upon the fact that some changes are appropriate and that some rationally thought actions ought to be taken in order to soften the social phenomena occurring within a crisis period. We may say that in the core of the crisis lies impregnated the basic substance of progress and that the moment when a crisis is declared is as well the moment of a new start. It is necessary to anticipate the crisis, in order to prepare the adequate means able to soften up the shocks created by its incipit and to bring forward the progress through its action itself. One of the most necessary and useful instruments able to smooth down the crisis' effects is the early education provided to the citizens concerning the frame of the behavior to be adopted in case of crisis. The officials and the public servants are the social actors who constitute the interface between the citizen who is going to suffer the crisis and this latter's exerted pressure. The personnel from the public administration has to assume the hardest role in reducing the most possible the crisis' effects. Some possibilities are analysed that could reduce the effects of the economical, social and political crises, among which the most important is the quality of juridical norms. The Romanian legislation concerning the public charge is studied, in respect to its capacity to motivate the public servant to perform at his up most level, during crisis periods but not only then. The idea is emphasized that panic and uncontrolled social movements in case of a crisis might lead to the multiplying of the negative effects. The personnel from the public administration comes to a direct confrontation with the pressure of the negative effect of the crisis, as it is received by the public administration - understood as a structure
Modified approximate 8-point multiplier less DCT like transform
Siddharth Pande
2015-05-01
Full Text Available Discrete Cosine Transform (DCT is widely usedtransformation for compression in image and video standardslike H.264 or MPEGv4, JPEG etc. Currently the new standarddeveloped Codec is Highly Efficient Video Coding (HEVC orH.265. With the help of the transformation matrix the computational cost can be dynamically reduce. This paper proposesa novel approach of multiplier-less modified approximate DCT like transformalgorithm and also comparison with exact DCT algorithm and theapproximate DCT like transform. This proposed algorithm willhave lower computational complexity. Furthermore, the proposedalgorithm will be modular in approach, and suitable for pipelinedVLSI implementation.
Interaction of singly and multiply charged ions with a lithium-fluoride surface
Wirtz, L
2001-01-01
Charge transfer between slow ions and an ionic crystal surface still poses a considerable challenge to theory due to the intrinsic many-body character of the system. For the neutralization of multiply charged ions in front of metal surfaces, the Classical Over the Barrier (COB) model is a widely used tool. We present an extension of this model to ionic crystal surfaces where the localization of valence electrons at the anion sites and the lack of cylindrical symmetry of the ion-surface system impede a simple analytical estimate of electron transfer rates. We use a classical trajectory Monte Carlo approach to calculate electron transfer rates for different charge states of the projectile ion. With these rates we perform a Monte Carlo simulation of the neutralization of slow Ne10+ ions in vertical incidence on an LiF surface. Capture of one or several electrons may lead to a local positive charge up of the surface. The projectile dynamics depends on the balance between the repulsion due to this charge and the a...
Wang, Lai-Sheng, E-mail: Lai-Sheng-Wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States)
2015-07-28
Electrospray ionization (ESI) has become an essential tool in chemical physics and physical chemistry for the production of novel molecular ions from solution samples for a variety of spectroscopic experiments. ESI was used to produce free multiply-charged anions (MCAs) for photoelectron spectroscopy (PES) in the late 1990 s, allowing many interesting properties of this class of exotic species to be investigated. Free MCAs are characterized by strong intramolecular Coulomb repulsions, which create a repulsive Coulomb barrier (RCB) for electron emission. The RCB endows many fascinating properties to MCAs, giving rise to meta-stable anions with negative electron binding energies. Recent development in the PES of MCAs includes photoelectron imaging to examine the influence of the RCB on the electron emission dynamics, pump-probe experiments to examine electron tunneling through the RCB, and isomer-specific experiments by coupling PES with ion mobility for biological MCAs. The development of a cryogenically cooled Paul trap has led to much better resolved PE spectra for MCAs by creating vibrationally cold anions from the room temperature ESI source. Recent advances in coupling the cryogenic Paul trap with PE imaging have allowed high-resolution PE spectra to be obtained for singly charged anions produced by ESI. In particular, the observation of dipole-bound excited states has made it possible to conduct vibrational autodetachment spectroscopy and resonant PES, which yield much richer vibrational spectroscopic information for dipolar free radicals than traditional PES.
Optimal CCD readout by digital correlated double sampling
Alessandri, Cristobal; Guzman, Dani; Passalacqua, Ignacio; Alvarez-Fontecilla, Enrique; Guarini, Marcelo
2015-01-01
Digital correlated double sampling (DCDS), a readout technique for charge-coupled devices (CCD), is gaining popularity in astronomical applications. By using an oversampling ADC and a digital filter, a DCDS system can achieve a better performance than traditional analogue readout techniques at the expense of a more complex system analysis. Several attempts to analyse and optimize a DCDS system have been reported, but most of the work presented in the literature has been experimental. Some approximate analytical tools have been presented for independent parameters of the system, but the overall performance and trade-offs have not been yet modelled. Furthermore, there is disagreement among experimental results that cannot be explained by the analytical tools available. In this work, a theoretical analysis of a generic DCDS readout system is presented, including key aspects such as the signal conditioning stage, the ADC resolution, the sampling frequency and the digital filter implementation. By using a time-dom...
CCD camera automatic calibration technology and ellipse recognition algorithm
Changku Sun; Xiaodong Zhang; Yunxia Qu
2005-01-01
A novel two-dimensional (2D) pattern used in camera calibration is presented. With one feature circle located at the center, an array of circles is photo-etched on this pattern. An ellipse recognition algorithm is proposed to implement the acquisition of interest calibration points without human intervention. According to the circle arrangement of the pattern, the relation between three-dimensional (3D) and 2D coordinates of these points can be established automatically and accurately. These calibration points are computed for intrinsic parameters calibration of charge-coupled device (CCD) camera with Tsai method. A series of experiments have shown that the algorithm is robust and reliable with the calibration error less than 0.4 pixel. This new calibration pattern and ellipse recognition algorithm can be widely used in computer vision.
Operation of the CCD/Transit Instrument (CTI)
Mcgraw, J. T.; Cawson, M. G. M.; Keane, M. J.
1986-01-01
The fully automated imaging survey telescope at Kitt Peak known as the CCD/Transit Instrument (CTI) has no moving parts, and employs two CCDs aligned east-west in the focal plane that are operated in the time delay and integrate mode, at the apparent sidereal rate, in order to produce a strip image of the sky. This image is 8.25-arcmin wide in declination and 8 hr in duration, to yield about 15 sq deg of sky from each night's survey; this, over the course of a year, represents more than 40 sq deg in a continuous strip. The CTI is addressing such astronomical tasks as the determination of the supernova production rate by counting, galactic structure investigations, and the definition of a complete sample of quasars. Attention is given to the CTI's bimetallic, thermally self-compensating structure and three-mirror wide-field optical system.
CCD $UBV(RI)_{C}$ Photometry of Twenty Open Clusters
Oralhan, Inci Akkaya; Schuster, William J; Michel, Raúl; Chavarría, Carlos
2014-01-01
Fundamental astrophysical parameters have been derived for 20 open clusters (O\\!Cs) using CCD~$U\\!BV\\!(RI)_C$ photometric data observed with the 84~cm telescope at the San Pedro M\\'artir National Astronomical Observatory, M\\'exico. The interstellar reddenings, metallicities, distances, and ages have been compared to the literature values. Significant differences are usually due to the usage of diverse empirical calibrations and differing assumptions, such as concerning cluster metallicity, as well as distinct isochrones which correspond to differing element-abundance ratios, internal stellar physics, and photometric systems. Different interstellar reddenings, as well as varying reduction and cluster-membership techniques, are also responsible for these kinds of systematic differences and errors. The morphological ages, which are derived from the morphological indices ($\\delta V$ and $\\delta 1$) in the CM diagrams, are in good agreement with the isochrone ages of 12 O\\!Cs, those with good red clump (RC) and re...
Electromagnetic Compatibility Assessment of CCD Detector Acquisition Chains not Synchronized
Nicoletto, M.; Boschetti, D.; Ciancetta, E.; Maiorano, E.; Stagnaro, L.
2016-05-01
Euclid is a space observatory managed by the European Space Agency; it is the second medium class mission (see Figure 1) in the frame of Cosmic Vision 2015-2025 program.In the frame of this project, the electromagnetic interference between two different and not synchronized Charge Coupled Device (CCD) (see Figure 2) acquisition chains has been evaluated. The key parameter used for this assessment is the electromagnetic noise induced on each other. Taking into account the specificity of the issue, radiation coupling at relative low frequency and in near field conditions, classical approach based on simulations and testing on qualification model cannot be directly applied. Based on that, it has been decided to investigate the issue by test in an incremental way.
CCD based beam loss monitor for ion accelerators
Belousov, A.; Mustafin, E.; Ensinger, W.
2014-04-01
Beam loss monitoring is an important aspect of proper accelerator functioning. There is a variety of existing solutions, but each has its own disadvantages, e.g. unsuitable dynamic range or time resolution, high cost, or short lifetime. Therefore, new options are looked for. This paper shows a method of application of a charge-coupled device (CCD) video camera as a beam loss monitor (BLM) for ion beam accelerators. The system was tested with a 500 MeV/u N+7 ion beam interacting with an aluminum target. The algorithms of camera signal processing with LabView based code and beam loss measurement are explained. Limits of applicability of this monitor system are discussed.
Digital detectors for electron microscopy
Faruqi, A R
2002-01-01
Film has traditionally been used for recording images in transmission electron microscopes but there is an essential need for computer-interfaced electronic detectors. Cooled-CCD detectors, developed over the past few years, though not ideal, are increasingly used as the preferred detection system in a number of applications. We describe briefly the design of CCD-based detectors, along with their main properties, which have been used in electron crystallography. A newer detector design with a much bigger sensitive area, incorporating a 2x2 tiled array of CCDs with tapered fibre optics will overcome some of the limitations of existing CCD detectors. We also describe some preliminary results for 8 keV imaging, from (direct detection) silicon hybrid pixel detectors, which offer advantages over CCDs in terms of better spatial resolution, faster readout with minimal noise.
Efficient Reversible Montgomery Multiplier and Its Application to Hardware Cryptography
Noor M. Nayeem
2009-01-01
Full Text Available Problem Statement: Arithmetic Logic Unit (ALU of a crypto-processor and microchips leak information through power consumption. Although the cryptographic protocols are secured against mathematical attacks, the attackers can break the encryption by measuring the energy consumption. Approach: To thwart attacks, this study proposed the use of reversible logic for designing the ALU of a crypto-processor. Ideally, reversible circuits do not dissipate any energy. If reversible circuits are used, then the attacker would not be able to analyze the power consumption. In order to design the reversible ALU of a crypto-processor, reversible Carry Save Adder (CSA using Modified TSG (MTSG gates and architecture of Montgomery multiplier were proposed. For reversible implementation of Montgomery multiplier, efficient reversible multiplexers and sequential circuits such as reversible registers and shift registers were presented. Results: This study showed that modified designs perform better than the existing ones in terms of number of gates, number of garbage outputs and quantum cost. Lower bounds of the proposed designs were established by providing relevant theorems and lemmas. Conclusion: The application of reversible circuit is suitable to the field of hardware cryptography.
Multiplying optical tweezers force using a micro-lever.
Lin, Chih-Lang; Lee, Yi-Hsiung; Lin, Chin-Te; Liu, Yi-Jui; Hwang, Jiann-Lih; Chung, Tien-Tung; Baldeck, Patrice L
2011-10-10
This study presents a photo-driven micro-lever fabricated to multiply optical forces using the two-photon polymerization 3D-microfabrication technique. The micro-lever is a second class lever comprising an optical trapping sphere, a beam, and a pivot. A micro-spring is placed between the short and long arms to characterize the induced force. This design enables precise manipulation of the micro-lever by optical tweezers at the micron scale. Under optical dragging, the sphere placed on the lever beam moves, resulting in torque that induces related force on the spring. The optical force applied at the sphere is approximately 100 to 300 pN, with a laser power of 100 to 300 mW. In this study, the optical tweezers drives the micro-lever successfully. The relationship between the optical force and the spring constant can be determined by using the principle of leverage. The arm ratio design developed in this study multiplies the applied optical force by 9. The experimental results are in good agreement with the simulation of spring property.
MULTIPLIERS AND TENSOR PRODUCTS OF WEIGHTED LP-SPACES
无
2001-01-01
Let G be a locally compact uninmodular group with Haar measure rmdx and ω be the Beurling's weight function on G (Reiter, [10]). In this paper the authors define a space APωq,q (G) and prove that Aωp,q (G) is a translation invariant Banach space. Furthermore the authors discuss inclusion properties and show that if G is a locally compact abelian group then Aωp,q (G) admits an approximate identity bounded in L1ω. (G). It is also proved that the space Lpωp (G) L1ω lPω(G) is isometrically isomorphic to the space Apω.q (G) and the space of multipliers from Lωp (G) to Lqωq-1 (G) is isometrically isomorphic to the dual of the space Aωp,q (G) iff G satisfies a property Ppq. At the end of this work it is showed that if G is a locally compact abelian group then the space of all multipliers from L1ω (G) to Aωp,q (G) is the space Aωp,q (G).
Diamond Heat-Spreader for Submillimeter-Wave Frequency Multipliers
Lin, Robert H.; Schlecht, Erich T.; Chattopadhyay, Goutam; Gill, John J.; Mehdi, Imran; Siegel, Peter H.; Ward, John S.; Lee, Choonsup; Thomas, Bertrand C.; Maestrini, Alain
2010-01-01
The planar GaAs Shottky diode frequency multiplier is a critical technology for the local oscillator (LO) for submillimeter- wave heterodyne receivers due to low mass, tenability, long lifetime, and room-temperature operation. The use of a W-band (75-100 GHz) power amplifier followed by a frequency multiplier is the most common for submillimeter-wave sources. Its greatest challenge is to provide enough input power to the LO for instruments onboard future planetary missions. Recently, JPL produced 800 mW at 92.5 GHz by combining four MMICs in parallel in a balanced configuration. As more power at W-band is available to the multipliers, their power-handling capability be comes more important. High operating temperatures can lead to degradation of conversion efficiency or catastrophic failure. The goal of this innovation is to reduce the thermal resistance by attaching diamond film as a heat-spreader on the backside of multipliers to improve their power-handling capability. Polycrystalline diamond is deposited by hot-filament chemical vapor deposition (CVD). This diamond film acts as a heat-spreader to both the existing 250- and 300-GHz triplers, and has a high thermal conductivity (1,000-1,200 W/mK). It is approximately 2.5 times greater than copper (401 W/mK) and 20 times greater than GaAs (46 W/mK). It is an electrical insulator (resistivity approx. equals 10(exp 15) Ohms-cm), and has a low relative dielectric constant of 5.7. Diamond heat-spreaders reduce by at least 200 C at 250 mW of input power, compared to the tripler without diamond, according to thermal simulation. This superior thermal management provides a 100-percent increase in power-handling capability. For example, with this innovation, 40-mW output power has been achieved from a 250-GHz tripler at 350-mW input power, while the previous triplers, without diamond, suffered catastrophic failures. This breakthrough provides a stepping-stone for frequency multipliers-based LO up to 3 THz. The future work
On the low-temperature performances of THGEM and THGEM/G-APD multipliers in gaseous and two-phase Xe
Bondar, A; Grebenuk, A; Shemyakina, E; Sokolov, A; Akimov, D; Alexandrov, I; Breskin, A
2011-01-01
The performances of THGEM multipliers in two-phase Xe avalanche mode are presented for the first time. Additional results on THGEM operation in gaseous Xe at cryogenic temperatures are provided. Stable operation of a double-THGEM multiplier was demonstrated in two-phase Xe with gains reaching 600. These are compared to existing data, summarized here for two-phase Ar, Kr and Xe avalanche detectors incorporating GEM and THGEM multipliers. The optical readout of THGEMs with Geiger-mode Avalanche Photodiodes (G-APDs) has been investigated in gaseous Xe at cryogenic temperature; avalanche scintillations were recorded in the Near Infrared (NIR) at wavelengths of up to 950 nm. At avalanche charge gain of 350, the double-THGEM/G-APD multiplier yielded 0.07 photoelectrons per initial ionization electron, corresponding to an avalanche scintillation yield of 0.7 NIR photons per avalanche electron over 4pi. The results are compared with those of two-phase Ar avalanche detectors. The advantages, limitations and possible a...
Bondar, A; Buzulutskov, A; Grebenuk, A; Shemyakina, E; Sokolov, A [Budker Institute of Nuclear Physics, Lavrentiev avenue 11, 630090 Novosibirsk (Russian Federation); Akimov, D; Alexandrov, I [Institute for Theoretical and Experimental Physics, Bolshaya Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Breskin, A, E-mail: A.F.Buzulutskov@inp.nsk.su [Weizmann Institute of Science, 76100 Rehovot (Israel)
2011-07-15
The performances of THGEM multipliers in two-phase Xe avalanche mode are presented for the first time. Additional results on THGEM operation in gaseous Xe at cryogenic temperatures are provided. Stable operation of a double-THGEM multiplier was demonstrated in two-phase Xe with gains reaching 600. These are compared to existing data, summarized here for two-phase Ar, Kr and Xe avalanche detectors incorporating GEM and THGEM multipliers. The optical readout of THGEMs with Geiger-mode Avalanche Photodiodes (G-APDs) has been investigated in gaseous Xe at cryogenic temperature; avalanche scintillations were recorded in the Near Infrared (NIR) at wavelengths of up to 950 nm. At avalanche charge gain of 350, the double-THGEM/G-APD multiplier yielded 0.07 photoelectrons per initial ionization electron, corresponding to an avalanche scintillation yield of 0.7 NIR photons per avalanche electron over 4{pi}. The results are compared with those of two-phase Ar avalanche detectors. The advantages, limitations and possible applications are discussed.
Substrate promiscuity of RdCCD1, a carotenoid cleavage oxygenase from Rosa damascena.
Huang, Fong-Chin; Horváth, Györgyi; Molnár, Péter; Turcsi, Erika; Deli, József; Schrader, Jens; Sandmann, Gerhard; Schmidt, Holger; Schwab, Wilfried
2009-03-01
Several of the key flavor compounds in rose essential oil are C(13)-norisoprenoids, such as beta-damascenone, beta-damascone, and beta-ionone which are derived from carotenoid degradation. To search for genes putatively responsible for the cleavage of carotenoids, cloning of carotenoid cleavage (di-)oxygenase (CCD) genes from Rosa damascena was carried out by a degenerate primer approach and yielded a full-length cDNA (RdCCD1). The RdCCD1 gene was expressed in Escherichia coli and recombinant protein was assayed for its cleavage activity with a multitude of carotenoid substrates. The RdCCD1 protein was able to cleave a variety of carotenoids at the 9-10 and 9'-10' positions to produce a C(14) dialdehyde and two C(13) products, which vary depending on the carotenoid substrates. RdCCD1 could also cleave lycopene at the 5-6 and 5'-6' positions to produce 6-methyl-5-hepten-2-one. Expression of RdCCD1 was studied by real-time PCR in different tissues of rose. The RdCCD1 transcript was present predominantly in rose flower, where high levels of volatile C(13)-norisoprenoids are produced. Thus, the accumulation of C(13)-norisoprenoids in rose flower is correlated to the expression of RdCCD1.
Study of Distortions in Statistics of Counts in CCD Observations using the Fano Factor
Afanasieva, I V
2016-01-01
Factors distorting the statistics of photocounts when acquiring objects with low fluxes were considered here. Measurements of the Fano factor for existing CCD systems were conducted. The study allows one to conclude on the quality of the CCD video signal processing channel. The optimal strategy for faint object observations was suggested.
VizieR Online Data Catalog: CCD photometry of CY Aqr 2012-2015 (Wiedemair+, 2016)
Wiedemair, C.; Sterken, C.; Eenmae, T.; Tuvikene, T.; Niederkofler, D.; Franzinelli, P.; Durnwalder, J.; Nardi, R.; Franzinelli, T.; Morawetz, I.; Nugroho, S. K.; Damini Hofer, J.; Seeber, J.
2016-10-01
All photometric data reported in this paper were obtained through CCD imaging obtained over more than 50 partial nights comprising a total of more than 20000 useful CCD frames. Table 1 gives the journal of observations. Heliocentric Julian Date, differential magnitudes ys,bs,vs,us in the standard system, and instrumental differential magnitudes yi,bi,vi,ui. (4 data files).
GEM-based TPC with CCD Imaging for Directional Dark Matter Detection
Phan, N S; Lee, E R; Loomba, D; Matthews, J A J; Miller, E H
2015-01-01
Directional dark matter detection will require scale-ups to large volumes if low-pressure gas Time Projection Chambers (TPCs) are the only viable technology. We discuss some of the challenges for this technology, where balancing the goal of achieving the best sensitivity with that of cost effective scale-up requires an optimization over a large parameter space. Critical for this are the precision measurements of the fundamental properties of both electron and nuclear recoil tracks down to the lowest energies. Such measurements would provide a benchmark for background discrimination and directional sensitivity that could be used for future optimization studies for directional dark matter experiments. In this paper we describe a small, high resolution, high signal-to-noise GEM-based TPC with a 2D CCD readout designed for this goal. The performance of the detector was characterized using X-rays, gamma-rays, and neutrons, enabling detailed measurements of electron and nuclear recoil tracks. Stable effective gas g...
Design of operation parameters of a high speed TDI CCD line scan camera
无
2006-01-01
This paper analyzes the operation parameters of the time delay and integration (TDI) line scan CCD camera, such as resolution, line rate, clock frequency, etc. and their mathematical relationship is deduced. By analyzing and calculating these parameters, the working clocks of the TDI CCD line scan camera are designed,which guarantees the synchronization of the line scan rate and the camera movement speed. The IL - E2 TDI CCD of DALSA Co. is used as the sensor of the camera in the paper. The working clock generator used for the TDI CCD sensor is realized by using the programmable logic device (PLD). The experimental results show that the working clock generator circuit satisfies the requirement of high speed TDI CCD line scan camera.
I. V. Bandurkin
2005-01-01
Full Text Available A method of organizing electron-wave interaction at the multiplied frequency of the signal wave is proposed. This type of electron-wave interaction provides multiplied-frequency electron bunching, which leads to formation of an intense harmonic of the electron current at a selected multiplied frequency of the signal wave. This effect is attractive for the use in klystron-type cyclotron masers with frequency multiplication as a way to increase the output frequency and improve the selectivity.
Nedeljkovic, N. N.; Galijas, S. M. D.; Obradovic, M. B.
2008-07-01
The two-state vector model is used to investigate the intermediate stages of the electron capture into the Rydberg states of multiply charged ArVIII ion, escaping solid surface. Two cases of the ionic velocities are considered: the low velocities (v approx 0 a.u.) and the intermediate velocities (v approx1 a.u.). Within the framework of the two-state vector description of the neutralization dynamics the two wave functions are used to determine the state of a single active electron. The intermediate stages of the process are characterized by the two-amplitude, the neutralization probability and rate. These quantities are obtained in two different analytical forms in the two considered cases of the projectile velocities. The key difference of the intermediate velocity case in respect to the low-velocity case, is the non- resonant character of the electron transitions. The obtained rates in the low velocity case are well localized. The neutralization rates in the intermediate velocity case are oscillatory in character. At larger ion-surface distances R the neutralization is stabilized; the behavior of the rates becomes similar to that obtained for the low ionic velocities.
Low Power Floating Point Computation Sharing Multiplier for Signal Processing Applications
Sivanantham S
2013-04-01
Full Text Available Design of low power, higher performance digital signal processing elements are the major requirements in ultra deep sub-micron technology. This paper presents an IEEE-754 standard compatible single precision Floating-point Computation SHaring Multiplier (FCSHM scheme suitable for low-power and high-speed signal processing applications. The floating-point multiplier used at thefilter taps effectively uses the computation re-use concept. Experimental results on a 10-tap programmable FIR filter show that the proposed multiplier scheme can provide a power reduction of 39.7% and significant improvements in the performance compared to conventional floating-point carry save array multiplier implementations.
Fpga Implementation of 8-Bit Vedic Multiplier by Using Complex Numbers
Gundlapalle Nandakishore,
2014-06-01
Full Text Available The paper describes the implementation of 8-bit vedic multiplier using complex numbers previous technique describes that 8-bit vedic multiplier using barrel shifter by FPGA implementation comparing the both technique in this paper propagation delay is reduced so that processing of speed will be high 8-bit vedic multiplier using barrel shifter propagation delay nearly 22nsec but present technique 8-bit vedic multiplier using complex numbers where propagation delay is 19nsec. The design is implemented and verified by FPGA and ISE simulator. The core was implemented on the Spartan 3E starts board the preferred language is used in verilog.
T-fuzzy multiply positive implicative BCC-ideals of BCC-algebras
Jianming Zhan; Zhisong Tan
2003-01-01
The concept of fuzzy multiply positive BCC-ideals of BCC-algebras is introduced, and then some related results are obtained. Moreover, we introduce the concept of T-fuzzy multiply positive implicative BCC-ideals of BCC-algebras and investigate T-product of T-fuzzy multiply positive implicative BCC-ideals of BCC-algebras, examining its properties. Using a t-norm T, the direct product and T-product of T-fuzzy multiply positive implicative BCC-ideals of BCC-algebras are discussed and their...
Improved 64-bit Radix-16 Booth Multiplier Based on Partial Product Array Height Reduction
Antelo, Elisardo; Montuschi, Paolo; Nannarelli, Alberto
2016-01-01
In this paper, we describe an optimization for binary radix-16 (modified) Booth recoded multipliers to reduce the maximum height of the partial product columns to ï£®n/4ï£¹ for [Formula: see text] unsigned operands. This is in contrast to the conventional maximum height of ï£®(n+1)/4ï£¹. Therefor...... to be included in the partial product array without increasing the delay. The method can be extended to Booth recoded radix-8 multipliers, signed multipliers, combined signed/unsigned multipliers, and other values of n....
Module homomorphisms and multipliers on locally compact quantum groups
Ramezanpour, M
2009-01-01
For a Banach algebra $A$ with a bounded approximate identity, we investigate the $A$-module homomorphisms of certain introverted subspaces of $A^*$, and show that all $A$-module homomorphisms of $A^*$ are normal if and only if $A$ is an ideal of $A^{**}$. We obtain some characterizations of compactness and discreteness for a locally compact quantum group $\\G$. Furthermore, in the co-amenable case we prove that the multiplier algebra of $\\LL$ can be identified with $\\MG.$ As a consequence, we prove that $\\G$ is compact if and only if $\\LUC={\\rm WAP}(\\G)$ and $\\MG\\cong\\mathcal{Z}({\\rm LUC}(\\G)^*)$; which partially answer a problem raised by Volker Runde.
Lagrange multiplier for perishable inventory model considering warehouse capacity planning
Amran, Tiena Gustina; Fatima, Zenny
2017-06-01
This paper presented Lagrange Muktiplier approach for solving perishable raw material inventory planning considering warehouse capacity. A food company faced an issue of managing perishable raw materials and marinades which have limited shelf life. Another constraint to be considered was the capacity of the warehouse. Therefore, an inventory model considering shelf life and raw material warehouse capacity are needed in order to minimize the company's inventory cost. The inventory model implemented in this study was the adapted economic order quantity (EOQ) model which is optimized using Lagrange multiplier. The model and solution approach were applied to solve a case industry in a food manufacturer. The result showed that the total inventory cost decreased 2.42% after applying the proposed approach.
Domingues M. O.
2013-12-01
Full Text Available We present a new adaptive multiresoltion method for the numerical simulation of ideal magnetohydrodynamics. The governing equations, i.e., the compressible Euler equations coupled with the Maxwell equations are discretized using a finite volume scheme on a two-dimensional Cartesian mesh. Adaptivity in space is obtained via Harten’s cell average multiresolution analysis, which allows the reliable introduction of a locally refined mesh while controlling the error. The explicit time discretization uses a compact Runge–Kutta method for local time stepping and an embedded Runge-Kutta scheme for automatic time step control. An extended generalized Lagrangian multiplier approach with the mixed hyperbolic-parabolic correction type is used to control the incompressibility of the magnetic field. Applications to a two-dimensional problem illustrate the properties of the method. Memory savings and numerical divergences of magnetic field are reported and the accuracy of the adaptive computations is assessed by comparing with the available exact solution.
Electromagnetic Radiation in Multiply Connected Robertson-Walker Cosmologies
Tomaschitz, R
1993-01-01
Maxwell's equations on a topologically nontrivial cosmological background are studied. The cosmology is locally determined by a Robertson-Walker line element, but the spacelike slices are open hyperbolic manifolds, whose topology and geometry may vary in time. In this context the spectral resolution of Maxwell's equations in terms of horospherical elementary waves generated at infinity of hyperbolic space is given. The wave fronts are orthogonal to bundles of unstable geodesic rays, and the eikonal of geometric optics appears just as the phase of the horospherical waves. This fact is used to attach to the unstable geodesic rays a quantum mechanical momentum. In doing so the quantized energy-momentum tensor of the radiation field is constructed in a geometrically and dynamically transparent way, without appealing to the intricacies of the second quantization. In particular Planck's radiation formula, and the bearing of the multiply connected topology on the fluctuations in the temperature of the background rad...
Scaled AAN for Fixed-Point Multiplier-Free IDCT
P. P. Zhu
2009-01-01
Full Text Available An efficient algorithm derived from AAN algorithm (proposed by Arai, Agui, and Nakajima in 1988 for computing the Inverse Discrete Cosine Transform (IDCT is presented. We replace the multiplications in conventional AAN algorithm with additions and shifts to realize the fixed-point and multiplier-free computation of IDCT and adopt coefficient and compensation matrices to improve the precision of the algorithm. Our 1D IDCT can be implemented by 46 additions and 20 shifts. Due to the absence of the multiplications, this modified algorithm takes less time than the conventional AAN algorithm. The algorithm has low drift in decoding due to the higher computational precision, which fully complies with IEEE 1180 and ISO/IEC 23002-1 specifications. The implementation of the novel fast algorithm for 32-bit hardware is discussed, and the implementations for 24-bit and 16-bit hardware are also introduced, which are more suitable for mobile communication devices.
Lagrange Multipliers and Third Order Scalar-Tensor Field Theories
Horndeski, Gregory W
2016-01-01
In a space of 4-dimensions, I will examine constrained variational problems in which the Lagrangian, and constraint scalar density, are concomitants of a (pseudo-Riemannian) metric tensor and its first two derivatives. The Lagrange multiplier for these constrained extremal problems will be a scalar field. For suitable choices of the Lagrangian, and constraint, we can obtain Euler-Lagrange equations which are second order in the scalar field and third order in the metric tensor. The effect of disformal transformations on the constraint Lagrangians, and their generalizations, is examined. This will yield other second order scalar-tensor Lagrangians which yield field equations which are at most of third order. No attempt is made to construct all possible third order scalar-tensor Euler-Lagrange equations in a 4-space, although nine classes of such field equations are presented. Two of these classes admit subclasses which yield conformally invariant field equations. A few remarks on scalar-tensor-connection theor...
L’ESPACE MULTIPLIE CHEZ SARTRE : HUIS-CLOS
Corina-Amelia GEORGESCU
2013-05-01
Full Text Available Du point de vue historique, le XXe siècle est le siècle le plus bouleversé de l’histoire connue de l’humanité, se caractérisant par plusieurs événements majeurs. C’est dans ce contexte que Jean-Paul Sartre se fraie un chemin dans la vie littéraire française en y apportant un souffle nouveau. Notre travail se propose d’analyser la pièce Huis clos dans le but de démontrer que lorque l’on parle de l’espace de l’emprisonnement, on doit prendre en considération qu’il ne s’agit pas d’un seul type d’espace et que celui-ci se multiplie justement pour rendre l’impossibilité d’y échapper.
Vortex generated fluid flows in multiply connected domains
Zemlyanova, Anna; Handley, Demond
2016-01-01
A fluid flow in a multiply connected domain generated by an arbitrary number of point vortices is considered. A stream function for this flow is constructed as a limit of a certain functional sequence using the method of images. The convergence of this sequence is discussed, and the speed of convergence is determined explicitly. The presented formulas allow for the easy computation of the values of the stream function with arbitrary precision in the case of well-separated cylinders. The considered problem is important for applications such as eddy flows in the oceans. Moreover, since finding the stream function of the flow is essentially identical to finding the modified Green's function for Laplace's equation, the presented method can be applied to a more general class of applied problems which involve solving the Dirichlet problem for Laplace's equation.
Fixed Width Booth Multiplier Based on PEB Circuit [
V.Vidya Devi
2012-04-01
Full Text Available In this brief, a probabilistic estimation bias (PEB circuit for a fixed-width two’s complement Boothmultiplier is proposed. The proposed PEB circuit is derived from theoretical computation, instead ofexhaustive simulations and heuristic compensation strategies that tend to introduce curve-fitting errors andexponential-grown simulation time. Consequently, the proposed PEB circuit provides a smaller area and alower truncation error compared with existing works. Implemented in an 8 × 8 2-D discrete cosinetransform (DCT core, the DCT core using the proposed PEB Booth multiplier improves the peak signalto-noise ratio by 17 dB with only a 2% area penalty compared with the direct-truncated method.
Simultaneous least squares fitter based on the Langrange multiplier method
Guan, Yinghui; Zheng, Yangheng; Zhu, Yong-Sheng
2013-01-01
We developed a least squares fitter used for extracting expected physics parameters from the correlated experimental data in high energy physics. This fitter considers the correlations among the observables and handles the nonlinearity using linearization during the $\\chi^2$ minimization. This method can naturally be extended to the analysis with external inputs. By incorporating with Langrange multipliers, the fitter includes constraints among the measured observables and the parameters of interest. We applied this fitter to the study of the $D^{0}-\\bar{D}^{0}$ mixing parameters as the test-bed based on MC simulation. The test results show that the fitter gives unbiased estimators with correct uncertainties and the approach is credible.
A Lagrange multiplier based divide and conquer finite element algorithm
Farhat, C.
1991-01-01
A novel domain decomposition method based on a hybrid variational principle is presented. Prior to any computation, a given finite element mesh is torn into a set of totally disconnected submeshes. First, an incomplete solution is computed in each subdomain. Next, the compatibility of the displacement field at the interface nodes is enforced via discrete, polynomial and/or piecewise polynomial Lagrange multipliers. In the static case, each floating subdomain induces a local singularity that is resolved very efficiently. The interface problem associated with this domain decomposition method is, in general, indefinite and of variable size. A dedicated conjugate projected gradient algorithm is developed for solving the latter problem when it is not feasible to explicitly assemble the interface operator. When implemented on local memory multiprocessors, the proposed methodology requires less interprocessor communication than the classical method of substructuring. It is also suitable for parallel/vector computers with shared memory and compares favorably with factorization based parallel direct methods.
Multiplying steady-state culture in multi-reactor system.
Erm, Sten; Adamberg, Kaarel; Vilu, Raivo
2014-11-01
Cultivation of microorganisms in batch experiments is fast and economical but the conditions therein change constantly, rendering quantitative data interpretation difficult. By using chemostat with controlled environmental conditions the physiological state of microorganisms is fixed; however, the unavoidable stabilization phase makes continuous methods resource consuming. Material can be spared by using micro scale devices, which however have limited analysis and process control capabilities. Described herein are a method and a system combining the high throughput of batch with the controlled environment of continuous cultivations. Microorganisms were prepared in one bioreactor followed by culture distribution into a network of bioreactors and continuation of independent steady state experiments therein. Accelerostat cultivation with statistical analysis of growth parameters demonstrated non-compromised physiological state following distribution, thus the method effectively multiplied steady state culture of microorganisms. The theoretical efficiency of the system was evaluated in inhibitory compound analysis using repeated chemostat to chemostat transfers.
Audiovisual narratives : creative processes of SIdade and MultipliSIdade
2011-01-01
Resumo: Nesta dissertação faço uma reflexão sobre os processos criativos de dois audiovisuais narrativos de minha autoria, SIdade* e MultipliSIdade**. Como linha de pensamento, adoto a questão da relação entre o fragmento e o todo, em relação à poética e às técnicas de construção das obras. A poética do trabalho refere-se ao desenvolvimento de um olhar perceptivo sobre o ambiente urbano contemporâneo, tanto em relação aos fragmentos significantes que remetem a uma identidade do todo urbano, q...
Multiply-warped product metrics and reduction of Einstein equations
Gholami, F; Haji-Badali, A
2016-01-01
It is shown that for every multidimensional metric in the multiply warped product form $\\bar{M} = K\\times_{f_1} M_1\\times_{f_2}M_2$ with warp functions $f_1$, $f_2$, associated to the submanifolds $M_1$, $M_2$ of dimensions $n_1$, $n_2$ respectively, one can find the corresponding Einstein equations $\\bar{G}_{AB}=-\\bar{\\Lambda}\\bar{g}_{AB}$, with cosmological constant $\\bar{\\Lambda}$, which are reducible to the Einstein equations $G_{\\alpha\\beta} = -\\Lambda_1 g_{\\alpha\\beta}$ and $G_{ij} =-\\Lambda_2 h_{ij}$ on the submanifolds $M_1$, $M_2$, with cosmological constants ${\\Lambda_1}$ and ${\\Lambda_2}$, respectively, where $\\bar{\\Lambda}$, ${\\Lambda_1}$ and ${\\Lambda_2}$ are functions of ${f_1}$, ${f_2}$ and $n_1$, $n_2$.
On Lagrange Multipliers in Work with Quality and Reliability Assurance
Vidal, Rene Victor Valqui; Becker, P.
1986-01-01
In optimizing some property of a system, reliability say, a designer usually has to accept certain constraints regarding cost, completion time, volume, weight, etc. The solution of optimization problems with boundary constraints can be helped substantially by the use of Lagrange multipliers techn...... in the areas of sales promotion and teaching. These maps illuminate the logic structure of solution sequences. One such map is shown, illustrating the application of LMT in one of the examples....... techniques (LMT). With representative examples of increasing complexity, the wide applicability of LMT is illustrated. Two particular features are put in focus. First, an easy to follow yet powerful new graphical approach is presented, Second, the concept of Fuller-Polya maps is shown to be helpful...
Scaled AAN for Fixed-Point Multiplier-Free IDCT
Zhu, P. P.; Liu, J. G.; Dai, S. K.; Wang, G. Y.
2009-12-01
An efficient algorithm derived from AAN algorithm (proposed by Arai, Agui, and Nakajima in 1988) for computing the Inverse Discrete Cosine Transform (IDCT) is presented. We replace the multiplications in conventional AAN algorithm with additions and shifts to realize the fixed-point and multiplier-free computation of IDCT and adopt coefficient and compensation matrices to improve the precision of the algorithm. Our 1D IDCT can be implemented by 46 additions and 20 shifts. Due to the absence of the multiplications, this modified algorithm takes less time than the conventional AAN algorithm. The algorithm has low drift in decoding due to the higher computational precision, which fully complies with IEEE 1180 and ISO/IEC 23002-1 specifications. The implementation of the novel fast algorithm for 32-bit hardware is discussed, and the implementations for 24-bit and 16-bit hardware are also introduced, which are more suitable for mobile communication devices.
Multipliers of Weighted Semigroups and Associated Beurling Banach Algebras
S J Bhatt; P A Dabhi; H V Dedania
2011-11-01
Given a weighted discrete abelian semigroup $(S,)$, the semigroup $M_(S)$ of -bounded multipliers as well as the Rees quotient $M_(S)/S$ together with their respective weights $\\overline{}$ and $\\overline{}_q$ induced by are studied; for a large class of weights , the quotient $\\ell^1(M_(S),\\overline{})/\\ell^1(S,)$ is realized as a Beurling algebra on the quotient semigroup $M_(S)/S$; the Gel’fand spaces of these algebras are determined; and Banach algebra properties like semisimplicity, uniqueness of uniform norm and regularity of associated Beurling algebras on these semigroups are investigated. The involutive analogues of these are also considered. The results are exhibited in the context of several examples.
Planar varactor frequency multiplier devices with blocking barrier
Lieneweg, Udo (Inventor); Frerking, Margaret A. (Inventor); Maserjian, Joseph (Inventor)
1994-01-01
The invention relates to planar varactor frequency multiplier devices with a heterojunction blocking barrier for near millimeter wave radiation of moderate power from a fundamental input wave. The space charge limitation of the submillimeter frequency multiplier devices of the BIN(sup +) type is overcome by a diode structure comprising an n(sup +) doped layer of semiconductor material functioning as a low resistance back contact, a layer of semiconductor material with n-type doping functioning as a drift region grown on the back contact layer, a delta doping sheet forming a positive charge at the interface of the drift region layer with a barrier layer, and a surface metal contact. The layers thus formed on an n(sup +) doped layer may be divided into two isolated back-to-back BNN(sup +) diodes by separately depositing two surface metal contacts. By repeating the sequence of the drift region layer and the barrier layer with the delta doping sheet at the interfaces between the drift and barrier layers, a plurality of stacked diodes is formed. The novelty of the invention resides in providing n-type semiconductor material for the drift region in a GaAs/AlGaAs structure, and in stacking a plurality of such BNN(sup +) diodes stacked for greater output power with and connected back-to-back with the n(sup +) GaAs layer as an internal back contact and separate metal contact over an AlGaAs barrier layer on top of each stack.
Coulomb fission in multiply charged molecular clusters: Experiment and theory
Harris, Christopher; Baptiste, Joshua; Lindgren, Eric B.; Besley, Elena; Stace, Anthony J.
2017-04-01
A series of three multiply charged molecular clusters, (C6H6)nz+ (benzene), (CH3CNnz) + (acetonitrile), and (C4H8O)nz+ (tetrahydrofuran), where the charge z is either 3 or 4, have been studied for the purpose of identifying the patterns of behaviour close to the charge instability limit. Experiments show that on a time scale of ˜10-4 s, ions close to the limit undergo Coulomb fission where the observed pathways exhibit considerable asymmetry in the sizes of the charged fragments and are all associated with kinetic (ejection) energies of between 1.4 and 2.2 eV. Accurate kinetic energies have been determined through a computer simulation of peak profiles recorded in the experiments and the results modelled using a theory formulated to describe how charged particles of dielectric materials interact with one another [E. Bichoutskaia et al., J. Chem. Phys. 133, 024105 (2010)]. The calculated electrostatic interaction energy between separating fragments gives an accurate account for the measured kinetic energies and also supports the conclusion that +4 ions fragment into +3 and +1 products as opposed to the alternative of two +2 fragments. This close match between the theory and experiment reinforces the assumption that a significant fraction of excess charge resides on the surfaces of the fragment ions. It is proposed that the high degree of asymmetry seen in the fragmentation patterns of the multiply charged clusters is due, in part, to limits imposed by the time window during which observations are made.
CCD imaging technology and the war on crime
McNeill, Glenn E.
1992-08-01
Linear array based CCD technology has been successfully used in the development of an Automatic Currency Reader/Comparator (ACR/C) system. The ACR/C system is designed to provide a method for tracking US currency in the organized crime and drug trafficking environments where large amounts of cash are involved in illegal transactions and money laundering activities. United States currency notes can be uniquely identified by the combination of the denomination serial number and series year. The ACR/C system processes notes at five notes per second using a custom transport a stationary linear array and optical character recognition (OCR) techniques to make such identifications. In this way large sums of money can be " marked" (using the system to read and store their identifiers) and then circulated within various crime networks. The system can later be used to read and compare confiscated notes to the known sets of identifiers from the " marked" set to document a trail of criminal activities. With the ACR/C law enforcement agencies can efficiently identify currency without actually marking it. This provides an undetectable means for making each note individually traceable and facilitates record keeping for providing evidence in a court of law. In addition when multiple systems are used in conjunction with a central data base the system can be used to track currency geographically. 1.
The Spectrum of Quantum Dots Film for UV CCD
Lin Jiang
2013-01-01
Full Text Available A new kind of UV-responsive film with quantum dots (QDs fabricated by a spin-coating method is proposed in this paper. In a previous study, the monolayer QDs film is deposited onto fused silica slides by the spin-coating way, which has some luminous problem. The introduction of composite QDs coating which adds PEDOT:PSS and poly-TPD films to the monolayer QDs film is found to have excellent performance. The reason can be that PEDOT:PSS and poly-TPD weaken the scattering and enhance the emitting of quantum dot fluorescence. The intensity of photoluminescence (PL for composite QDs coating is dozens of times stronger than that for monolayer QDs film. Experiment results show that this composite coating has excellent fluorescent properties and emits a blue purple glow together a wide excitation spectrum field from 190 nm to 300 nm. The spectrum of the composite coating matches accurately with the detected zone of CCD, which achieves an outstanding UV-responsive coating for conventional silicon-based image sensors.
CCD UBV(RI)C photometry of twenty open clusters
Oralhan, İnci Akkaya; Karataş, Yüksel; Schuster, William J.; Michel, Raúl; Chavarría, Carlos
2015-01-01
Fundamental astrophysical parameters have been derived for 20 open clusters (OCs) using CCD UBV(RI)C photometric data observed with the 84 cm telescope at the San Pedro Mártir National Astronomical Observatory, México. The interstellar reddenings, metallicities, distances, and ages have been compared to the literature values. Significant differences are usually due to the usage of diverse empirical calibrations and differing assumptions, such as concerning cluster metallicity, as well as distinct isochrones which correspond to differing element-abundance ratios, internal stellar physics, and photometric systems. Different interstellar reddenings, as well as varying reduction and cluster-membership techniques, are also responsible for these kinds of systematic differences and errors. The morphological ages, which are derived from the morphological indices (δV and δ1) in the CM diagrams, are in good agreement with the isochrone ages of 12 OCs, those with good red clump (RC) and red giant (RG) star candidates. No metal abundance gradient is detected for the range 6.82⩽RGC⩽15.37 kpc, nor any correlation between the cluster ages and metal abundances for these 20 OCs. Young, metal-poor OCs, observed here in the third Galactic quadrant, may be associated with stellar over-densities, such as that in Canis Major (Martin et al.) and the Monoceros Ring (Newberg et al.), or signatures of past accretion events, as discussed by Yong et al. and Carraro et al.
Wide Field CCD photometry around nine open clusters
Sharma, S; Ogura, K; Mito, H; Tarusawa, K; Sagar, R
2006-01-01
In this paper we study the evolution of core and corona of nine open clusters using the projected radial density profiles derived from homogeneous CCD photometric data obtained through the 105-cm Kiso Schmidt telescope. The age and galactocentric distance of the target clusters varies from 16 Myr to 2000 Myr and 9 kpcto 10.8 kpc respectively. Barring Be 62, which is young open cluster, other clusters show a uniform reddening across the cluster region. The reddening in Be 62varies from $E(B-V)_{min}$= 0.70 mag to $E(B-V)_{max}$= 1.00 mag. The corona of six of the clusters in the present sample is found to be elongated, however on the basis of the present sample it is not possible to establish any correlation between the age and shape of the core. The elongated core in the case of young cluster Be 62 may reflect the initial conditions in the parental molecular cloud. The other results of the present study are (i) Core radius `$r_c$' and corona size $`r_{cn}$'/cluster radius $`r_{cl}$' are linearly correlated. (...
Asteroid detection using a single multi-wavelength CCD scan
Melton, Jonathan
2016-09-01
Asteroid detection is a topic of great interest due to the possibility of diverting possibly dangerous asteroids or mining potentially lucrative ones. Currently, asteroid detection is generally performed by taking multiple images of the same patch of sky separated by 10-15 minutes, then subtracting the images to find movement. However, this is time consuming because of the need to revisit the same area multiple times per night. This paper describes an algorithm that can detect asteroids using a single CCD camera scan, thus cutting down on the time and cost of an asteroid survey. The algorithm is based on the fact that some telescopes scan the sky at multiple wavelengths with a small time separation between the wavelength components. As a result, an object moving with sufficient speed will appear in different places in different wavelength components of the same image. Using image processing techniques we detect the centroids of points of light in the first component and compare these positions to the centroids in the other components using a nearest neighbor algorithm. The algorithm was used on a test set of 49 images obtained from the Sloan telescope in New Mexico and found 100% of known asteroids with only 3 false positives. This algorithm has the advantage of decreasing the amount of time required to perform an asteroid scan, thus allowing more sky to be scanned in the same amount of time or freeing a telescope for other pursuits.
Three-dimensional imaging using TDI CCD sensors
Fenster, Aaron; Holdsworth, David W.; Drangova, Maria
1991-07-01
Atherosclerosis is an arterial disorder characterized by the development of arterial plaques which reduce the distensibility of the artery and obstruct blood flow. Little is known about the mechanisms which initiate the plaques and cause them to grow; however, it is generally agreed that hemodynamic factors are associated with the development of atherosclerosis. To study this disease it is essential to know not only the geometry of the arterial lumen but also the shape of the intimal surface in order to assess the importance of hemodynamic effects. The authors constructed a table-top volume CT scanner with high resolution in all 3 dimensions, which can be used to analyze human arterial specimens in vitro. This system uses an x-ray image intensifier optically coupled to a TDI CCD sensor to obtain low-noise, low-scatter projection digital radiographs from many angles. A slot beam of radiation is scanned across the sample to reduce the detection of scattered radiation without causing excess x-ray tube heating. Objects to be imaged are placed on a computer-controlled stage and projections are obtained as the specimen is rotated through 180 degree(s). CT reconstructions of the resulting data produces volume images with 0.12 X 0.12 X 0.15 mm(superscript 3) volume resolution.
CCD photometry of distant open clusters; 2, NGC 6791
Kaluzny, J; Kaluzny, Janusz; Rucinski, Slavek
1995-01-01
Three new photometric CCD-based datasets are presented for NGC~6791. They consist of deep UBV photometry (to V_{lim} =24, B_{lim}=24, U_{lim} = 23) of the central parts of the cluster and of selected fields around it, and of relatively shallower UBVI photometry for the whole cluster (23' \\times 23'). The data have been used to discuss the reddening, metallicity and age ofNGC~6791, a cluster which is particularly important because of (1)~its most-advanced age among open clusters, (2)~metallicity higher than solar and (3)~particularly large number of member stars. We discovered two new very blue stars increasing the total of sdB objects in the cluster to ten. They are located in a very narrow range magnitudes V=17.7 \\pm 0.5; their blue colors strongly constrain our determination of the reddening of the cluster to E(B-V)=0.17 \\pm 0.01. We detected no other blue stars except a population of faint objects with V \\approx 22 in the center of the cluster. We have used the new theoretical isochrones in a differential ...
Perfecting the Photometric Calibration of the ACS CCD Cameras
Bohlin, Ralph C
2016-01-01
Newly acquired data and improved data reduction algorithms mandate a fresh look at the absolute flux calibration of the CCD cameras on the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The goals are to achieve a 1\\% accuracy and to make this calibration more accessible to the HST guest investigator. Absolute fluxes from the CALSPEC\\footnote{http://www.stsci.edu/hst/observatory/crds/calspec.html} database for three primary hot 30,000--60,000K WDs define the sensitivity calibrations for the WFC and HRC filters. The external uncertainty for the absolute flux is $\\sim$1\\%, while the internal consistency of the sensitivities in the broadband ACS filters is $\\sim$0.3\\% among the three primary WD flux standards. For stars as cool as K type, the agreement with the CALSPEC standards is within 1\\% at the WFC1-1K subarray position, which achieves the 1\\% precision goal for the first time. After making a small adjustment to the filter bandpass for F814W, the 1\\% precision goal is achieved over the full ...
Superresolved phase-shifting Gabor holography by CCD shift
Micó, V.; Granero, L.; Zalevsky, Z.; García, J.
2009-12-01
Holography in the Gabor regime is restricted to weak diffraction assumptions. Otherwise, diffraction prevents an accurate recovery of the object's complex wavefront. We have recently proposed a modified Gabor-like setup to extend Gabor's concept to any sample provided that it be non-diffusive. However, the resolution of the final image becomes limited as a consequence of the additional elements considered in the proposed setup. In this paper we present an experimental approach to overcome such a limitation in which the former configuration is used while the CCD camera is shifted to different off-axis positions in order to generate a synthetic aperture. Thus, once the whole image set is recorded and digitally processed for each camera position, we merge the resulting band-pass images into one image by assembling a synthetic aperture. Finally, a superresolved image is recovered by Fourier transformation of the information contained in the generated synthetic aperture. Experimental results validate our concepts for a gain in resolution of close to 2.
Ahrazem, Oussama; Rubio-Moraga, Angela; Berman, Judit; Capell, Teresa; Christou, Paul; Zhu, Changfu; Gómez-Gómez, Lourdes
2016-01-01
The apocarotenoid crocetin and its glycosylated derivatives, crocins, confer the red colour to saffron. Crocetin biosynthesis in saffron is catalysed by the carotenoid cleavage dioxygenase CCD2 (AIG94929). No homologues have been identified in other plant species due to the very limited presence of crocetin and its derivatives in the plant kingdom. Spring Crocus species with yellow flowers accumulate crocins in the stigma and tepals. Four carotenoid CCDs, namely CaCCD1, CaCCD2 and CaCCD4a/b and CaCCD4c were first cloned and characterized. CaCCD2 was localized in plastids, and a longer CCD2 version, CsCCD2L, was also localized in this compartment. The activity of CaCCD2 was assessed in Escherichia coli and in a stable rice gene function characterization system, demonstrating the production of crocetin in both systems. The expression of all isolated CCDs was evaluated in stigma and tepals at three key developmental stages in relation with apocarotenoid accumulation. CaCCD2 expression parallels crocin accumulation, but C14 apocarotenoids most likely are associated to the CaCCD1 activity in Crocus ancyrensis flowers. The specific CCD2 localization and its membrane interaction will contribute to the development of a better understanding of the mechanism of crocetin biosynthesis and regulation in the chromoplast.
Fibromyalgia in patients with chronic CCD and CMD - A retrospective study of 555 patients.
Losert-Bruggner, Brigitte; Hülse, Manfred; Hülse, Roland
2017-06-05
Craniomandibular dysfunction (CMD) and craniocervical dysfunction (CCD) are clearly defined musculoskeletal pain syndromes. Relationships with fibromyalgia syndrome (FMS) have not yet been investigated. The aim of the present study is to establish possible relationships between FMS and CMD/ CCD. In a retrospective study, 555 patients with CCD and CMD were investigated with respect to the diagnostic criteria of FMS. In addition to otolaryngologic and dental examination, an instrumental functional analysis for the diagnosis of CMD/CCD was performed. Three hundred fifty-one (63%) of the 555 patients evaluated met the diagnostic criteria for FMS. Seventy-two percent of the patients had a widespread pain index of at least 7 and a severity scale score of at least 5. Twenty-nine percent had a widespread pain index of 3-6 and a severity scale score of at least 9. Using myocentric bite splint therapy and therapy with oral orthesis in combination with neuromuscular relaxation measures, a good to very good improvement of physical symptoms was seen in 84% of CMD-FMS patients, and an improvement of the symptoms in the jaw was achieved in 77% of cases. The substantial proportion of CMD and CCD patients who meet the criteria for FMS emphasizes the complexity of the two diseases. It must be assumed that FMS is a crucial factor for the formation of CMD and CCD. Conversely, CMD/ CCD could also be responsible for diverse clinical pictures of the FMS. FMS patients with synchronous CCD/CMD benefit from an interdisciplinary CMD/CCD treatment.
Tarazkar, M.; Romanov, D. A.; Levis, R. J.
2016-07-01
Dynamic second-order hyperpolarizabilities of atomic noble gases and their multiply ionized ions are computed using ab initio multiconfigurational self-consistent field cubic response theory. For each species, the calculations are performed at wavelengths ranging from the static regime to those about 100 nm above the first multiphoton resonance. The second-order hyperpolarizability coefficients progressively decrease as the electrons are removed from the system, in qualitative agreement with phenomenological calculations. In higher ionization states, the resulting nonlinear refractive index becomes less dispersive as a function of wavelength. At each ionization stage, the sign of the optical response depends on the number of electrons in the system and, if multiple state symmetries are possible, on the spin of the particular quantum state. Thus, for N e3 + and N e4 + , the hyperpolarizability coefficients in the low-spin states (P2u, and S1g, respectively) are positive, while in the high-spin states (S4u, and P3g) they are negative. However, for doubly, triply, and quadruply charged Ar and Kr these coefficients do not undergo a sign change.
Line Emission and X-ray Line Polarization of Multiply Ionized Mo Ions
Petkov, E. E.; Safronova, A. S.; Kantsyrev, V. L.; Shlyaptseva, V. V.; Stafford, A.; Safronova, U. I.; Shrestha, I. K.; Schultz, K. A.; Childers, R.; Cooper, M. C.; Beiersdorfer, P.; Hell, N.; Brown, G. V.
2016-10-01
We present a comprehensive experimental and theoretical study of the line emission from multiply ionized Mo ions produced by two different sets of experiments: at LLNL EBIT and the pulsed power generator Zebra at UNR. Mo line emission and polarization measurements were accomplished at EBIT for the first time. In particular, benchmarking experiments at the LLNL EBIT with Mo ions produced at electron beam energies from 2.75 keV up to 15 keV allowed us to break down these very complicated spectra into spectra with only few ionization stages and to select processes that influence them as well as to measure line polarization. The EBIT data were recorded using the EBIT Calorimeter Spectrometer and a crystal spectrometer with a Ge crystal. X-ray Mo spectra and pinhole images were collected from Z-pinch plasmas produced from various wire loads. Non-LTE modeling, high-precision relativistic atomic and polarization data were used to analyze L-shell Mo spectra. The influence of different plasma processes including electron beams on Mo line radiation is summarized. This work was supported by NNSA under DOE Grant DE-NA0002954. Experiments at the NTF/UNR were funded in part by DE-NA0002075. Work at LLNL was performed under the auspices of the U.S. DOE under contract DE-AC52-07NA27344.
Kwong, Victor H. S.
2003-01-01
The laser ablation/ion storage facility at the UNLV Physics Department has been dedicated to the study of atomic and molecular processes in low temperature plasmas. Our program focuses on the charge transfer (electron capture) of multiply charged ions and neutrals important in astrophysics. The electron transfer reactions with atoms and molecules is crucial to the ionization condition of neutral rich photoionized plasmas. With the successful deployment of the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Chandra X-ray Observatory by NASA high resolution VUV and X-ray emission spectra fiom various astrophysical objects have been collected. These spectra will be analyzed to determine the source of the emission and the chemical and physical environment of the source. The proper interpretation of these spectra will require complete knowledge of all the atomic processes in these plasmas. In a neutral rich environment, charge transfer can be the dominant process. The rate coefficients need to be known accurately. We have also extended our charge transfer measurements to KeV region with a pulsed ion beam. The inclusion of this facility into our current program provides flexibility in extending the measurement to higher energies (KeV) if needed. This flexibility enables us to address issues of immediate interest to the astrophysical community as new observations are made by high resolution space based observatories.
Data Acquisition and Control System for High-Performance Large-Area CCD Systems
Afanasieva, I V
2015-01-01
Astronomical CCD systems based on second-generation DINACON controllers were developed at the SAO RAS Advanced Design Laboratory more than seven years ago and since then have been in constant operation at the 6-meter and Zeiss-1000 telescopes. Such systems use monolithic large-area CCDs. We describe the software developed for the control of a family of large-area CCD systems equipped with a DINACON-II controller. The software suite serves for acquisition, primary reduction, visualization, and storage of video data, and also for the control, setup, and diagnostics of the CCD system.
Searching for bulk motions in the ICM of massive, merging clusters with Chandra CCD data
Liu, Ang; Tozzi, Paolo; Zhu, Zong-Hong
2016-01-01
We search for bulk motions in the Intra Cluster Medium (ICM) of massive clusters showing evidence of an ongoing or a recent major merger, with spatially resolved spectroscopy in {\\sl Chandra} CCD data. We identify a sample of 6 merging clusters with >150 ks {\\sl Chandra} exposure in the redshift range 0.1 1000$ km/s in the ICM of massive merging clusters at 0.1 < z < 0.3. Despite the CCD spectral resolution is not sufficient for a detailed analysis of the ICM dynamics, {\\sl Chandra} CCD data constitute a key diagnostic tool complementary to X-ray bolometers onboard future X-ray missions.
The long-run relationship between the Japanese credit and money multipliers
Mototsugu Fukushige
2013-01-01
The standard argument is that while money creation and credit creation have different channels, they provide the same theoretical size of multipliers. However, there is usually some difference in practice. Consequently, in this paper we investigate the long-run relationship between the credit and money multipliers in Japan.
A Floating Point Multiplier based FPGA Synthesis for Neural Networks Enhancement
F. BENREKIA,
2010-05-01
Full Text Available FPGA (Field Programmable Gate Array implementation of Artificial Neural Networks (ANNs calls for multipliers of various word lengths. In this paper, a new approach for designing a FloatingPoint Multiplier(FPM is developed and tested using VHDL. With VHDL (Very High Description Language analyzer and logic synthesis software, hardware prototypes could be implemented in FPGA.
THE REALIZATION OF MULTIPLIER HILBERT BIMODULE ON BIDUAL SPACE AND TIETZE EXTENSION THEOREM
无
2000-01-01
The multiplier bimodule of Hilbert bimodule is introduced in a way similar to [1],and its realization on a quotient of bidual space and Tietze extension theorem are obtained similar to that in C*-algebra case. As a result,the multiplier bimodule here is also a Hilbert bimodule.
Singular Lagrangian, Hamiltonization and Jacobi last multiplier for certain biological systems
Guha, Partha; Ghose Choudhury, Anindya
2013-07-01
We study the construction of singular Lagrangians using Jacobi's last multiplier (JLM). We also demonstrate the significance of the last multiplier in Hamiltonian theory by explicitly constructing the Hamiltonian of the Host-Parasite model and a Lotka-Volterra mutualistic system, both of which are well known first-order systems of differential equations arising in biology.
Implementation gap between the theory and practice of biodiversity offset multipliers
Bull, Joseph William; Lloyd, Samuel; Strange, Niels
2016-01-01
when considering, for example, ecological uncertainties. We propose even larger multipliers required to satisfy previously ignored considerations – including prospect theory, taboo trades, and power relationships. Conversely, our data analyses show that multipliers are smaller in practice, regularly...... used. Further research is necessary to determine reasons...
Jacobi Last Multiplier Method for Equations of Motion of Constrained Mechanical Systems
CHEN Xiang-Wei; MEI Feng-Xiang
2011-01-01
@@ The Jacobi last multiplier method for holonomic and nonholonomic mechanical systems is studied and some examples are given to attempt applications of the method.%The Jacobi last multiplier method for holonomic and nonholonomic mechanical systems is studied and some examples are given to attempt applications of the method.
Jackson-type and Bernstein-type inequalities for multipliers on Herz-type Hardy spaces
XIE LinSen; LAN JiaCheng; LAN SenHua; YAN DunYan
2009-01-01
We establish Jackson-type and Bernstein-type inequalities for multipliers on Herz-type Hardy spaces.These inequalities can be applied to some important operators in Fourier analysis,such as the Bochner-Riesz multiplier over the critical index,the generalized Bochner-Riesz mean and the generalized Able-Poisson operator.
Jackson-type and Bernstein-type inequalities for multipliers on Herz-type Hardy spaces
无
2009-01-01
We establish Jackson-type and Bernstein-type inequalities for multipliers on Herz-type Hardy spaces. These inequalities can be applied to some important operators in Fourier analysis, such as the Bochner-Riesz multiplier over the critical index, the generalized Bochner-Riesz mean and the generalized Able-Poisson operator.
WERKMAN, HA; JANSEN, C; KLEIN, JP; TENDUIS, HJ
1991-01-01
In a retrospective study involving 866 multiply-injured patients we demonstrated urinary tract injuries in 72 patients (8.3 per cent), 17 (2 per cent) of which were serious. Haematuria was a frequent finding in multiply-injured patients. In patients with serious lesions of the urinary tract, more th
Comparison of CCD, CMOS and Hybrid Pixel x-ray detectors: detection principle and data quality
Allé, P.; Wenger, E.; Dahaoui, S.; Schaniel, D.; Lecomte, C.
2016-06-01
We compare, from a crystallographic point of view, the data quality obtained using laboratory x-ray diffractometers equipped with a Molybdenum micro-source using different detector types: CCD, CMOS and XPAD hybrid pixel. First we give an overview of the working principle of these different detector types with a focus on their principal differences and their impact on the data quality. Then, using the example of an organic crystal, a comparison between the detector systems concerning the raw data statistics, the refinement agreement factors, the deformation electron density maps, and the residual density after multipolar refinement is presented. It is found that the data quality obtained with the XPAD detector is the best, even though the detection efficiency at the Mo energy (17.5 keV) is only 37% due to the Si-sensor layer thickness of 300 μm. Finally, we discuss the latest x-ray detector developments with an emphasis on the sensor material, where replacing Si by another material such as GaAs would yield detection efficiencies close to 100%, up to energies of 40 keV for hybrid pixel detectors.
OP09O-OP404-9 Wide Field Camera 3 CCD Quantum Efficiency Hysteresis
Collins, Nick
2009-01-01
The HST/Wide Field Camera (WFC) 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. At the nominal operating temperature of -83C, the QEH feature contrast was typically 0.1-0.2% or less. The behavior was replicated using flight spare detectors. A visible light flat-field (540nm) with a several times full-well signal level can pin the detectors at both optical (600nm) and near-UV (230nm) wavelengths, suppressing the QEH behavior. We are characterizing the timescale for the detectors to become unpinned and developing a protocol for flashing the WFC3 CCDs with the instrument's internal calibration system in flight. The HST/Wide Field Camera 3 UV/visible channel CCD detectors have exhibited an unanticipated quantum efficiency hysteresis (QEH) behavior. The first observed manifestation of QEH was the presence in a small percentage of flat-field images of a bowtie-shaped contrast that spanned the width of each chip. At the nominal operating temperature of -83C, the contrast observed for this feature was typically 0.1-0.2% or less, though at warmer temperatures contrasts up to 5% (at -50C) have been observed. The bowtie morphology was replicated using flight spare detectors in tests at the GSFC Detector Characterization Laboratory by power cycling the detector while cold. Continued investigation revealed that a clearly-related global QE suppression at the approximately 5% level can be produced by cooling the detector in the dark; subsequent flat-field exposures at a constant illumination show asymptotically increasing response. This QE "pinning" can be achieved with a single high signal flat-field or a series of lower signal flats; a visible light (500-580nm) flat-field with a signal level of several hundred thousand electrons per pixel is sufficient for QE pinning at both optical (600nm) and near-UV (230nm) wavelengths. We are characterizing the timescale for the detectors to become unpinned and developing a
Ieda Del'Arco Sanches
2008-02-01
Full Text Available O presente trabalho teve o objetivo de avaliar as imagens CCD/CBERS-2 quanto à possibilidade de discriminarem variedades de citros. A área de estudo localiza-se em Itirapina (SP e, para este estudo, foram utilizadas imagens CCD de três datas (30/05/2004, 16/08/2004 e 11/09/2004. Um modelo que integra os elementos componentes da cena citrícola sensoriada é proposto com o objetivo de explicar a variabilidade das respostas das parcelas de citros em imagens orbitais do tipo CCD/CBERS-2. Foram feitas classificações pelos algoritmos Isoseg e Maxver e, de acordo com o índice kappa, concluiu-se que é possível obterem-se exatidões qualificadas como muito boas, sendo que as melhores classificações foram conseguidas com imagens da estação seca.This paper was aimed at evaluating the possibility of discriminating citrus varieties in CCD imageries from CBERS-2 satellite ("China-Brazil Earth Resouces Satellite". The study area is located in Itirapina, São Paulo State. For this study, three CCD images from 2004 were acquired (May 30, August 16, and September 11. In order to acquire a better understanding and for explaining the variability of the spectral behavior of the citrus areas in orbital images (like as the CCD/CBERS-2 images a model that integrates the elements of the citrus scene is proposed and discussed. The images were classified by Isoseg and MaxVer classifiers. According to kappa index, it was possible to obtain classifications qualified as 'very good'. The best results were obtained with the images from the dry season.
On-Chip Power-Combining for High-Power Schottky Diode Based Frequency Multipliers
Siles Perez, Jose Vicente (Inventor); Chattopadhyay, Goutam (Inventor); Lee, Choonsup (Inventor); Schlecht, Erich T. (Inventor); Jung-Kubiak, Cecile D. (Inventor); Mehdi, Imran (Inventor)
2015-01-01
A novel MMIC on-chip power-combined frequency multiplier device and a method of fabricating the same, comprising two or more multiplying structures integrated on a single chip, wherein each of the integrated multiplying structures are electrically identical and each of the multiplying structures include one input antenna (E-probe) for receiving an input signal in the millimeter-wave, submillimeter-wave or terahertz frequency range inputted on the chip, a stripline based input matching network electrically connecting the input antennas to two or more Schottky diodes in a balanced configuration, two or more Schottky diodes that are used as nonlinear semiconductor devices to generate harmonics out of the input signal and produce the multiplied output signal, stripline based output matching networks for transmitting the output signal from the Schottky diodes to an output antenna, and an output antenna (E-probe) for transmitting the output signal off the chip into the output waveguide transmission line.
A Lossy Method for Compressing Raw CCD Images
Alan M. Watson
2002-01-01
Full Text Available Se presenta un método para comprimir las imágenes en bruto de dispositivos como los CCD. El método es muy sencillo: cuantizaciòn con pérdida y luego compresión sin pérdida con herramientas de uso general como gzip o bzip2. Se convierten los archivos comprimidos a archivos de FITS descomprimiéndolos con gunzip o bunzip2, lo cual es una ventaja importante en la distribución de datos comprimidos. El grado de cuantizaciòn se elige para eliminar los bits de bajo orden, los cuales sobre-muestrean el ruido, no proporcionan información, y son difíciles o imposibles de comprimir. El método es con pérdida, pero proporciona ciertas garantías sobre la diferencia absoluta máxima, la diferencia RMS y la diferencia promedio entre la imagen comprimida y la imagen original; tales garantías implican que el método es adecuado para comprimir imágenes en bruto. El método produce imágenes comprimidas de 1/5 del tamaño de las imágenes originales cuando se cuantizan imágenes en las que ningún valor cambia más de 1/2 de la desviación estándar del fondo. Esta es una mejora importante con respecto a las razones de compresión producidas por métodos sin pérdida, y aparentemente las imágenes comprimidas con bzip2 no exceden el límite teórico por más de unas decenas de por ciento.
Side 2: MSM positioning of STIS CCD Modes
Sahu, Kailash
2000-07-01
The MSM positions for different STIS modes are slightly different when the STIS is run through side 2 than when it is run from side 1. These MSM positions for various STIS prime CCD modes shall be confirmed by taking images with the IM Pt/Cr/Ne calibration lamp. For first order long-slit modes, the exposures shall be made through 52x0.1arcsec slit. For the echelle modes, the exposures shall be made through echelle slits of the nominal height, to avoid order confusion. One exposure shall be taken for each prime mode except for the medium dispersion{M}, long slit modes. For the medium dispersion, long-slit modes, additional exposures shall be taken at the long and short wavelength settings of the nominal scan range. Exposures shall be sufficiently long to bring out enough line features to confirm wavelength identifications, with sufficient signal to noise to reveal the shadows of the fiducials in the long slit images to confirm spatial pointing. This activity will test all primary modes and test the extremes of the MSM scanning cylinders by observing the extreme settings of the modes. RESULTS: All images will be downlinked and analyzed. The results are confirmation of the standard MSM encoder values for each mode. If the wavelength shifts are less than the budgeted value, the changes will be handled through updating the siaf files. If excess shifts are seen, new MSM positions will be derived and uplinked to the onboard MSM pointing table. Any modes for which revised MSM positions are uplinked will have to be re-observed for confirmation that the correct offsets were applied.
PSF and MTF Measurement Methods for Thick CCD Sensor Characterization
Takacs, P.Z.; Kotov, I.; Frank, J.; O' Connor, P.; Radeka, V.; Lawrence, D.M.
2010-06-30
Knowledge of the point spread function (PSF) of the sensors to be used in the Large Synoptic Survey Telescope (LSST) camera is essential for optimal extraction of subtle galaxy shape distortions caused by gravitational weak lensing. We have developed a number of techniques for measuring the PSF of candidate CCD sensors to be used in the LSST camera, each with its own strengths and weaknesses. The two main optical PSF measurement techniques that we use are the direct Virtual Knife Edge (VKE) scan as developed by Karcher, et al. and the indirect interference fringe method after Andersen and Sorensen that measures the modulation transfer function (MTF) directly. The PSF is derived from the MTF by Fourier transform. Other non-optical PSF measurement techniques that we employ include {sup 55}Fe x-ray cluster image size measurements and statistical distribution analysis, and cosmic ray muon track size measurements, but are not addressed here. The VKE technique utilizes a diffraction-limited spot produced by a Point-Projection Microscope (PPM) that is scanned across the sensor with sub-pixel resolution. This technique closely simulates the actual operating condition of the sensor in the telescope with the source spot size having an f/number close to the actual telescope design value. The interference fringe method uses a simple equal-optical-path Michelson-type interferometer with a single-mode fiber source that produces interference fringes with 100% contrast over a wide spatial frequency range sufficient to measure the MTF of the sensor directly. The merits of each measurement technique and results from the various measurement techniques on prototype LSST sensors are presented and compared.
2015-01-01
In order to determine the size measurement accuracy of the high temperature forging＇s multicolor CCD image by using computerprograms, this paper obtained the high temperature forging＇s CCD image by multicolor CCD camera and its fact size by thevernier caliper on the forging field, and then measured the size of the high temperature forging from its CCD image, compared thesize from the CCD image and the size from the vernier caliper, the result shows that the measurement accuracy satisfied theindustrial production.
The interaction of DNA gyrase with the bacterial toxin CcdB
Kampranis, S C; Howells, A J; Maxwell, A
1999-01-01
CcdB is a bacterial toxin that targets DNA gyrase. Analysis of the interaction of CcdB with gyrase reveals two distinct complexes. An initial complex (alpha) is formed by direct interaction between GyrA and CcdB; this complex can be detected by affinity column and gel-shift analysis, and has...... of this initial complex with ATP in the presence of GyrB and DNA slowly converts it to a second complex (beta), which has a lower rate of ATP hydrolysis and is unable to catalyse supercoiling. The efficiency of formation of this inactive complex is dependent on the concentrations of ATP and CcdB. We suggest...
PERFORMANCE EVALUATION OF SEVERAL FUSION APPROACHES FOR CCD/SAR IMAGES
无
2003-01-01
Several image fusion approaches for CCD/SAR images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAR images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAR image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAR image fusion approaches are effective.
MISR Level 1A CCD Science data, all cameras V002
National Aeronautics and Space Administration — This is the Reformatted Annotated Level 1A product for the CCD science data. The data numbers (DN) have been commuted from 12-bit numbers to 16-bit byte aligned...
Partial spectral multipliers and partial Riesz transforms for degenerate operators
ter Elst, A F M
2012-01-01
We consider degenerate differential operators $A = \\displaystyle{\\sum_{k,j=1}^d \\partial_k (a_{kj} \\partial_j)}$ on $L^2(\\mathbb{R}^d)$ with real symmetric bounded measurable coefficients. Given a function $\\chi \\in C_b^\\infty(\\mathbb{R}^d)$ (respectively, $\\Omega$ a bounded Lipschitz domain) and suppose that $(a_{kj}) \\ge \\mu > 0$ a.e.\\ on $ \\supp \\chi$ (resp., a.e.\\ on $\\Omega$). We prove a spectral multiplier type result: if $F\\colon [0, \\infty) \\to \\mathbb{C}$ is such that $\\sup_{t > 0} \\| \\varphi(.) F(t .) \\|_{C^s} d/2$ then $M_\\chi F(I+A) M_\\chi$ is weak type $(1,1)$ (resp.\\ $P_\\Omega F(I+A) P_\\Omega$ is weak type $(1,1)$). We also prove boundedness on $L^p$ for all $p \\in (1,2]$ of the partial Riesz transforms $M_\\chi \
Derylo, G.; Estrada, J.; Flaugher, B.; Hamilton, J.; Kubik, D.; Kuk, K.; Scarpine, V.
2008-07-01
We describe the results obtained cleaning the surface of DECam CCD detectors with a new electrostatic dissipative formulation of First ContactTM polymer from Photonic Cleaning Technologies. We demonstrate that cleaning with this new product is possible without ESD damage to the sensors and without degradation of the antireflective coating used to optimize the optical performance of the detector. We show that First ContactTM is more effective for cleaning a CCD than the commonly used acetone swab.
Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology.
vanEngelsdorp, Dennis; Traynor, Kirsten S; Andree, Michael; Lichtenberg, Elinor M; Chen, Yanping; Saegerman, Claude; Cox-Foster, Diana L
2017-01-01
Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors
Design of dual Beam multi-wavelength UV-visible absorbance detectors based on CCD
SHEN Shuang; TANG Zhen-an; LI Tong
2006-01-01
@@ Because the general multi-wavelength UV-Visible absorbance detector cannot avoid the noise and drift resulting from the intensity fluctuation of the light source,a dual beam multi-wavelength UV-Visible detector based on CCD was designed.The ray of light source is divided into a signal ray and a reference ray by the beam splitter after it passes through the chopper.The signal ray shines into the sample cell.The signal ray passing through the sample cell falls onto a concave mirror which focuses it onto a slot that is imaged on one portion of CCD by a concave grating.The reference ray is imaged on the other portion of CCD by the concave grating after the slot.The signal spectrum,the reference spectrum and the dark current of CCD can be measured on the same CCD under the cooperation of the optical system and accessorial circuits.The real-time compensation for the signal spectrum by using the reference spectrum and the dark current of CCD can effectively depress the noise and drift of the detector.The short-term noise is 10-5AU and the drift is 10-4AU/h.
Design of a very high frame rate camera based on an asynchronous CCD driving method
LI Bin-Kang; YANG Shao-Hua; GUO Ming-An; WANG gui-Lu; XIA Jing-Wao; LUO Tong-Ding
2011-01-01
A very high frame rate camera is designed based on an innovative CCD driving method. The CCD driving method is mainly implemented on frame transfer CCDs. Asynchronous drive timing sequences are applied in the image and storage section of the CCDs. Several rows of the charge in the image section are binned onto the same row in the storage section, and there are the same number of images to be stored in the storage section before they are read out. Based on the new driving method, the frame transfer CCDs can work at a very high frame rate in acquiring burst images though the reading speed remains at a lower level. A very high frame rate camera is designed in this paper. The innovative CCD driving method is mainly of concern. An e2v's CCD60 is adopted in the camera system, whose full size resolution is 128×128, and the up most frame rate is 1000 Hz in the conventional CCD driving method. By using the presented method, the CCD60 based imager is capable of operating at up to 40000 frames per second (fps) at a recognizable resolution of 128×32. Comparing cameras using traditional binning and region of interest technologies, the frame rate is normally less than 5000 fps while the resolution is only 32 × 32 lett.
Downing, Kenneth H; Mooney, Paul E
2008-04-01
Electron microscopists are increasingly turning to intermediate voltage electron microscopes (IVEMs) operating at 300-400 kV for a wide range of studies. They are also increasingly taking advantage of slow-scan charge coupled device (CCD) cameras, which have become widely used on electron microscopes. Under some conditions, CCDs provide an improvement in data quality over photographic film, as well as the many advantages of direct digital readout. However, CCD performance is seriously degraded on IVEMs compared to the more conventional 100 kV microscopes. In order to increase the efficiency and quality of data recording on IVEMs, we have developed a CCD camera system in which the electrons are decelerated to below 100 kV before impacting the camera, resulting in greatly improved performance in both signal quality and resolution compared to other CCDs used in electron microscopy. These improvements will allow high-quality image and diffraction data to be collected directly with the CCD, enabling improvements in data collection for applications including high-resolution electron crystallography, single particle reconstruction of protein structures, tomographic studies of cell ultrastructure, and remote microscope operation. This approach will enable us to use even larger format CCD chips that are being developed with smaller pixels.
The CCD/Transit Instrument (CTI) data-analysis system
Cawson, M. G. M.; Mcgraw, J. T.; Keane, M. J.
1995-01-01
The automated software system for archiving, analyzing, and interrogating data from the CCD/Transit Instrument (CTI) is described. The CTI collects up to 450 Mbytes of image-data each clear night in the form of a narrow strip of sky observed in two colors. The large data-volumes and the scientific aims of the project make it imperative that the data are analyzed within the 24-hour period following the observations. To this end a fully automatic and self evaluating software system has been developed. The data are collected from the telescope in real-time and then transported to Tucson for analysis. Verification is performed by visual inspection of random subsets of the data and obvious cosmic rays are detected and removed before permanent archival is made to the optical disc. The analysis phase is performed by a pair of linked algorithms, one operating on the absolute pixel-values and the other on the spatial derivative of the data. In this way both isolated and merged images are reliably detected in a single pass. In order to isolate the latter algorithm from the effects of noise spikes a 3x3 Hanning filter is applied to the raw data before the analysis is run. The algorithms reduce the input pixel-data to a database of measured parameters for each image which has been found. A contrast filter is applied in order to assign a detection-probability to each image and then x-y calibration and intensity calibration are performed using known reference stars in the strip. These are added to as necessary by secondary standards boot-strapped from the CTI data itself. The final stages involve merging the new data into the CTI Master-list and History-list and the automatic comparison of each new detection with a set of pre-defined templates in parameter-space to find interesting objects such as supernovae, quasars and variable stars. Each stage of the processing from verification to interesting image selection is performed under a data-logging system which both controls the
Design and Performance Analysis of Reversible Logic Four Quadrant Multiplier Using CSLA and CLAA
Mr. P. Dileep Kumar Reddy
2014-03-01
Full Text Available Multiplication is a fundamental operation in most signal processing algorithms. Multipliers have large area, long latency and consume considerable power. Therefore low-power multiplier design has been an important part in low- power VLSI system design. There has been extensive work on low-power multipliers at technology, physical, circuit and logic levels. A system’s performance is generally determined by the performance of the multiplier because the multiplier is generally the slowest element in the system. Furthermore, it is generally the most area consuming. Hence, optimizing the speed and area of the multiplier is a major design issue. However, area and speed are usually conflicting constraints so that improving speed results mostly in larger areas. As a result, a whole spectrum of multipliers with different area- speed constraints has been designed with reversible logic gates. The reversible logic has the promising applications in emerging computing paradigm such as quantum computing, quantum dot cellular automata, optical computing, etc. In reversible logic gates there is a unique one-to-one mapping between the inputs and outputs.
Dyadic Bivariate Fourier Multipliers for Multi-Wavelets in L2(R2)
Zhongyan Li∗; Xiaodi Xu
2015-01-01
The single 2 dilation orthogonal wavelet multipliers in one dimensional case and single A-dilation (where A is any expansive matrix with integer entries and|detA|=2) wavelet multipliers in high dimensional case were completely characterized by the Wutam Consortium (1998) and Z. Y. Li, et al. (2010). But there exist no more results on orthogonal multivariate wavelet matrix multipliers corresponding integer expansive dilation matrix with the absolute value of determinant not 2 in L2(R2). In this paper, we choose as the dilation matrix and consider the 2I2-dilation orthogonal multivariate wavelet Y={y1,y2,y3}, (which is called a dyadic bivariate wavelet) multipliers. We call the 3×3 matrix-valued function A(s)=[ fi,j(s)]3×3, where fi,j are measurable functions, a dyadic bivariate matrix Fourier wavelet multiplier if the inverse Fourier transform of A(s)(cy1(s),cy2(s),cy3(s))⊤ = ( b g1(s), b g2(s), b g3(s))⊤ is a dyadic bivariate wavelet whenever (y1,y2,y3) is any dyadic bivariate wavelet. We give some conditions for dyadic matrix bivariate wavelet multipliers. The results extended that of Z. Y. Li and X. L. Shi (2011). As an application, we construct some useful dyadic bivariate wavelets by using dyadic Fourier matrix wavelet multipliers and use them to image denoising.
Proper Motions and CCD-photometry of Stars in the Region of the Open Cluster NGC 1513
Frolov, V N; Ananjevskaja, J K; Poljakov, E V; Bronnikova, N M; Gorshanov, D L
2002-01-01
The results of astrometric and photometric investigations of the poorly studied open cluster NGC 1513 are presented. The proper motions of 353 stars with the root-mean-square error of 1.9 mas/yr were obtained by means of the automated measuring complex "Fantasy" scanning of 8 astrometric plates covering the time interval of 101 years. A total of 141 astrometric cluster members have been identified. BV CCD-photometry was made for the stars in a square size 17 arcmin x 17 arcmin centered on cluster. 33 stars with the high reliability were considered to be cluster members by two criteria. The estimation of NGC 1513 age is 2.54 E+08 years. Tables 2 and 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/.
Chavarria, A E; Pena, J; Privitera, P; Robinson, A E; Scholz, B; Sengul, C; Zhou, J; Estrada, J; Izraelevitch, F; Tiffenberg, J; Neto, J R T de Mello; Machado, D Torres
2016-01-01
We report a measurement of the ionization efficiency of silicon nuclei recoiling with sub-keV kinetic energy in the bulk silicon of a charge-coupled device (CCD). Nuclear recoils were produced by low-energy neutrons ($<$24 keV) from a $^{124}$Sb-$^{9}$Be photoneutron source, and their ionization signal was measured down to 60 eV electron-equivalent. This energy range, previously unexplored, is relevant for the detection of low-mass dark matter particles. The measured efficiency was found to deviate from the extrapolation to low energies of Lindhard model. This measurement also demonstrates the sensitivity to nuclear recoils of CCDs employed by DAMIC, a dark matter direct detection experiment located in the SNOLAB underground laboratory.
Camila Aparecida Cotrim
2010-01-01
Full Text Available Toxin-antitoxin (TA systems contribute to plasmid stability by a mechanism called post-segregational killing. The ccd was the first TA system to be discovered with CcdB being the toxin and CcdA the antitoxin. CcdA, an 8.3 kDa protein, interacts with CcdB (11.7 kDa, preventing the cytotoxic activity of CcdB on the DNA gyrase. As an approach to understanding this interaction, CcdA41, a polypeptide derived from CcdA, was synthesized by solid-phase methodology and its interaction with CcdB was analyzed by steady state fluorescence. CcdA41 formed a stable complex with CcdBET2, a peptide based on CcdB, the more recently described bacterial topoisomerase inhibitor.
Configurable multiplier modules for an adaptive computing system
O. A. Pfänder
2006-01-01
Full Text Available The importance of reconfigurable hardware is increasing steadily. For example, the primary approach of using adaptive systems based on programmable gate arrays and configurable routing resources has gone mainstream and high-performance programmable logic devices are rivaling traditional application-specific hardwired integrated circuits. Also, the idea of moving from the 2-D domain into a 3-D design which stacks several active layers above each other is gaining momentum in research and industry, to cope with the demand for smaller devices with a higher scale of integration. However, optimized arithmetic blocks in course-grain reconfigurable arrays as well as field-programmable architectures still play an important role. In countless digital systems and signal processing applications, the multiplication is one of the critical challenges, where in many cases a trade-off between area usage and data throughput has to be made. But the a priori choice of word-length and number representation can also be replaced by a dynamic choice at run-time, in order to improve flexibility, area efficiency and the level of parallelism in computation. In this contribution, we look at an adaptive computing system called 3-D-SoftChip to point out what parameters are crucial to implement flexible multiplier blocks into optimized elements for accelerated processing. The 3-D-SoftChip architecture uses a novel approach to 3-dimensional integration based on flip-chip bonding with indium bumps. The modular construction, the introduction of interfaces to realize the exchange of intermediate data, and the reconfigurable sign handling approach will be explained, as well as a beneficial way to handle and distribute the numerous required control signals.
High-resolution application of YAG:Ce and LuAG:Ce imaging detectors with a CCD X-ray camera
Touš, Jan; Horváth, Martin; Pína, Ladislav; Blažek, Karel; Sopko, Bruno
2008-06-01
A high-resolution CCD X-ray camera based on YAG:Ce or LuAG:Ce thin scintillators is presented. High-resolution in low-energy X-ray radiation is proved with several objects. The spatial resolution achieved in the images is about 1 μm. The high-resolution imaging system is a combination of a high-sensitivity digital CCD camera and an optical system with a thin scintillator-imaging screen. The screen can consist of YAG:Ce or LuAG:Ce inorganic scintillator [J.A. Mares, Radiat. Meas. 38 (2004) 353]. These materials have the advantages of mechanical and chemical stability and non-hygroscopicity. The high-resolution imaging system can be used with different types of radiation (X-ray, electrons, UV, and VUV [M. Nikl, Meas. Sci. Technol. 17 (2006) R37]). The objects used for the imaging tests are grids and small animals with features of several microns in size. The resolution capabilities were tested using different types of CCD cameras and scintillation imaging screens.
Design and Performance Analysis of Various Adders and Multipliers Using GDI Technique
Simran kaur
2015-10-01
Full Text Available With the active development of portable electronic devices, the need for low power dissipation, high speed and compact implementation, give rise to several research intentions. There are several design techniques used for the circuit configuration in VLSI systems but there are very few design techniques that gives the required extensibility. This paper describes the implementation of various adders and multipliers. The design approach proposed in the article is based on the GDI (Gate Diffusion Input technique. The paper also includes a comparative analysis of this low power method over CMOS design style with respect to power consumption, area complexity and delay. In this paper, a new GDI based cell designs are projected and are found to be efficient in terms of power consumption and area in comparison with existing CMOS based cell functionality. Power and delay has been calculated using Cadence Virtuoso tool at 45nm CMOS technology. The results obtained show better power and delay performance of the proposed designs at 1.3V supply voltage.
Computation of Floquet Multipliers Using an Iterative Method for Variational Equations
Nureki, Yu; Murashige, Sunao
This paper proposes a new method to numerically obtain Floquet multipliers which characterize stability of periodic orbits of ordinary differential equations. For sufficiently smooth periodic orbits, we can compute Floquet multipliers using some standard numerical methods with enough accuracy. However, it has been reported that these methods may produce incorrect results under some conditions. In this work, we propose a new iterative method to compute Floquet multipliers using eigenvectors of matrix solutions of the variational equations. Numerical examples show effectiveness of the proposed method.
Improved Faddeev-Jackiw quantization of the electromagnetic field and Lagrange multiplier fields
YANG Jin-Long; HUANG Yong-Chang
2008-01-01
We use the improved Faddeev-Jackiw quantization method to quantize the electromagnetic field and its Lagrange multiplier fields.The method's comparison with the usual Faddeev-Jackiw method and the Dirac method is given.We show that this method is equivalent to the Dirac method and also retains all the merits of the usual Faddeev-Jackiw method.Moreover,it is simpler than the usual one if one needs to obtain new secondary constraints.Therefore,the improved Faddeev-Jackiw method is essential.Meanwhile,we find the new meaning of the Lagrange multipliers and explain the Faddeev-Jackiw generalized brackets concerning the Lagrange multipliers.
Sebastião Renato Valverde
2003-06-01
contributing for the generation of these indicators, when one extra monetary unit is spent by the final consumers demanding for products of this particular sector. The results showed that forestry is one of the Brazilian economic sectors presenting the greatest multiplying effects for the social-economic indicators. It surpassed other sectors such as the automobilistic electric and electronic, machinery and equipment and chemicals and petroleum industries.
范凯荣; 覃石磊; 黄进波; 晁耐霞
2014-01-01
大肠杆菌毒素-抗毒素系统ccd(control of cell division or death system)编码的毒素蛋白CcdB使细胞内DNA促旋酶失活,杀伤宿主细胞,而抗毒素蛋白CcdA可以中和毒素CcdB使宿主存活.利用这个原理,CcdB可作为细菌转化时的筛选标记,在构建各种高效低背景载体上发挥重要作用.我们简要综述毒素蛋白CcdB的毒性原理及其在质粒载体构建中的广泛应用.
Hirvonen, Liisa Maija; Barber, Matthew; Suhling, Klaus
2016-01-01
Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, w...
Design of Pipeline Multiplier Based on Modified Booth's Algorithm and Wallace Tree
Yao, Aihong; Li, Ling; Sun, Mengzhe
A design of 32*32 bit pipelined multiplier is presented in this paper. The proposed multiplier is based on the modified booth algorithm and Wallace tree structure. In order to improve the throughput rate of the multiplier, pipeline architecture is introduced to the Wallace tree. Carry Select Adder is deployed to reduce the propagation delay of carry signal for the final level 64-bit adder. The multiplier is fully implemented with Verilog HDL and synthesized successfully with Quartus II. The experiment result shows that the resource consumption and power consumption is reduced to 2560LE and 120mW, the operating frequency is improved from 136.21MHz to 165.07MHz.
Chen, Shaobo; Chen, Pingxiuqi; Shao, Qiliang; Basha Shaik, Nazeem; Xie, Jiafeng
2017-05-01
The elliptic curve cryptography (ECC) provides much stronger security per bits compared to the traditional cryptosystem, and hence it is an ideal role in secure communication in smart grid. On the other side, secure implementation of finite field multiplication over GF(2 m ) is considered as the bottle neck of ECC. In this paper, we present a novel obfuscation strategy for secure implementation of systolic field multiplier for ECC in smart grid. First, for the first time, we propose a novel obfuscation technique to derive a novel obfuscated systolic finite field multiplier for ECC implementation. Then, we employ the DNA cryptography coding strategy to obfuscate the field multiplier further. Finally, we obtain the area-time-power complexity of the proposed field multiplier to confirm the efficiency of the proposed design. The proposed design is highly obfuscated with low overhead, suitable for secure cryptosystem in smart grid.
VHDL IMPLEMENTATION AND COMPARISON OF COMPLEX MUL-TIPLIER USING BOOTH’S AND VEDIC ALGORITHM
Rajashri K. Bhongade
2015-11-01
Full Text Available For designing of complex number multiplier basic idea is adopted from designing of multiplier. An ancient Indian mathematics "Vedas" is used for designing the multiplier unit. There are 16 sutra in Vedas, from that the Urdhva Tiryakb-hyam sutra (method was selected for implementation complex multiplication and basically Urdhva Tiryakbhyam sutra appli-cable to all cases of multiplication. Any multi-bit multiplication can be reduced down to single bit multiplication and addition by using Urdhva Tiryakbhyam sutra is performed by vertically and crosswise. The partial products and sums are generated in single step which reduces the carry propagation from LSB to MSB by using these formulas. In this paper simulation result for 4bit complex no. multiplication using Booth‟s algorithm and using Vedic sutra are illustrated. The implementation of the Vedic mathematics and their application to the complex multiplier was checked parameter like propagation delay.
Karatsuba-Ofman Multiplier with Integrated Modular Reduction for GF(2m
CUEVAS-FARFAN, E.
2013-05-01
Full Text Available In this paper a novel GF(2m multiplier based on Karatsuba-Ofman Algorithm is presented. A binary field multiplication in polynomial basis is typically viewed as a two steps process, a polynomial multiplication followed by a modular reduction step. This research proposes a modification to the original Karatsuba-Ofman Algorithm in order to integrate the modular reduction inside the polynomial multiplication step. Modular reduction is achieved by using parallel linear feedback registers. The new algorithm is described in detail and results from a hardware implementation on FPGA technology are discussed. The hardware architecture is described in VHDL and synthesized for a Virtex-6 device. Although the proposed field multiplier can be implemented for arbitrary finite fields, the targeted finite fields are recommended for Elliptic Curve Cryptography. Comparing other KOA multipliers, our proposed multiplier uses 36% less area resources and improves the maximum delay in 10%.
Design of High speed Low Power Reversible Vedic multiplier and Reversible Divider
Srikanth G Department of Electronics & Communication Engineerig, Indur Institute of Engineering & Technology, Siddipet, Medak, JNTUH University, Telangana, India.
2014-09-01
Full Text Available This paper bring out a 32X32 bit reversible Vedic multiplier using "Urdhva Tiryakabhayam" sutra meaning vertical and crosswise, is designed using reversible logic gates, which is the first of its kind. Also in this paper we propose a new reversible unsigned division circuit. This circuit is designed using reversible components like reversible parallel adder, reversible left-shift register, reversible multiplexer, reversible n-bit register with parallel load line. The reversible vedic multiplier and reversible divider modules have been written in Verilog HDL and then synthesized and simulated using Xilinx ISE 9.2i. This reversible vedic multiplier results shows less delay and less power consumption by comparing with array multiplier.
Potential energy curves for neutral and multiply charged carbon monoxide
Pradeep Kumar; N Sathyamurthy
2010-01-01
Potential energy curves of various electronic states of CO+ (0 ≤ ≤ 6) are generated at MRCI/CASSCF level using cc-pvQZ basis set and the results are compared with available experimental and theoretical data.
Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage
Pfeifer, Peter [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Gillespie, Andrew [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Stalla, David [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics; Dohnke, Elmar [Univ. of Missouri, Columbia, MO (United States). Dept. of Physics
2017-02-20
The purpose of the project “Multiply Surface-Functionalized Nanoporous Carbon for Vehicular Hydrogen Storage” is the development of materials that store hydrogen (H_{2}) by adsorption in quantities and at conditions that outperform current compressed-gas H_{2} storage systems for electric power generation from hydrogen fuel cells (HFCs). Prominent areas of interest for HFCs are light-duty vehicles (“hydrogen cars”) and replacement of batteries with HFC systems in a wide spectrum of applications, ranging from forklifts to unmanned areal vehicles to portable power sources. State-of-the-art compressed H_{2} tanks operate at pressures between 350 and 700 bar at ambient temperature and store 3-4 percent of H_{2} by weight (wt%) and less than 25 grams of H_{2} per liter (g/L) of tank volume. Thus, the purpose of the project is to engineer adsorbents that achieve storage capacities better than compressed H_{2} at pressures less than 350 bar. Adsorption holds H_{2} molecules as a high-density film on the surface of a solid at low pressure, by virtue of attractive surface-gas interactions. At a given pressure, the density of the adsorbed film is the higher the stronger the binding of the molecules to the surface is (high binding energies). Thus, critical for high storage capacities are high surface areas, high binding energies, and low void fractions (high void fractions, such as in interstitial space between adsorbent particles, “waste” storage volume by holding hydrogen as non-adsorbed gas). Coexistence of high surface area and low void fraction makes the ideal adsorbent a nanoporous monolith, with pores wide enough to hold high-density hydrogen films, narrow enough to minimize storage as non-adsorbed gas, and thin walls between pores to minimize the volume occupied by solid instead of hydrogen. A monolith can be machined to fit into a rectangular tank (low pressure, conformable tank), cylindrical tank
Harding, Leon K; Hoenk, Michael; Peddada, Pavani; Nemati, Bijan; Cherng, Michael; Michaels, Darren; Neat, Leo S; Loc, Anthony; Bush, Nathan; Hall, David; Murray, Neil; Gow, Jason; Burgon, Ross; Holland, Andrew; Reinheimer, Alice; Jorden, Paul R; Jordand, Douglas
2016-01-01
The Wide Field InfraRed Survey Telescope-Astrophysics Focused Telescope Asset (WFIRST-AFTA) mission is a 2.4-m class space telescope that will be used across a swath of astrophysical research domains. JPL will provide a high-contrast imaging coronagraph instrument - one of two major astronomical instruments. In order to achieve the low noise performance required to detect planets under extremely low flux conditions, the electron multiplying charge-coupled device (EMCCD) has been baselined for both of the coronagraph's sensors - the imaging camera and integral field spectrograph. JPL has established an EMCCD test laboratory in order to advance EMCCD maturity to technology readiness level-6. This plan incorporates full sensor characterization, including read noise, dark current, and clock-induced charge. In addition, by considering the unique challenges of the WFIRST space environment, degradation to the sensor's charge transfer efficiency will be assessed, as a result of damage from high-energy particles such ...
Low Power Floating Point Computation Sharing Multiplier for Signal Processing Applications
Sivanantham S; Jagannadha Naidu K; Balamurugan S; Bhuvana Phaneendra D
2013-01-01
Design of low power, higher performance digital signal processing elements are the major requirements in ultra deep sub-micron technology. This paper presents an IEEE-754 standard compatible single precision Floating-point Computation SHaring Multiplier (FCSHM) scheme suitable for low-power and high-speed signal processing applications. The floating-point multiplier used at thefilter taps effectively uses the computation re-use concept. Experimental results on a 10-tap programmable FIR filter...