The energy resolution, absolute efficiency, time resolution, and other performance parameters of bismuth germanate detectors for high-energy gamma detection are reported. (WHK)

... Title : THE ABSOLUTE QUANTUM EFFICIENCY OF SODIUM SALICYLATE EXCITED BY EXTREME ULTRAVIOLET LIGHT. ...

Neutron transport simulations have been carried out to calculate the absolute detection efficiency of a moderated sup 235 U neutron detector which is used on the TFTR as a part of the primary fission detector diagnostic system for measuring fusion power y...

A new method for determining the absolute detection efficiencies of a microchannel plate (MCP) detector is presented. This method uses a charge transfer reaction and can be applied to determine not only the detection efficiencies for ions but also those for neutral atoms. The measurements were ...

A two-layer quasigeostrophic model is used to investigate whether dissipation can induce absolute instability in otherwise convectively unstable or stable background states. It is shown that dissipation of either temperature or lower-layer potential vorticity can cause absolute instabilities over a wide range of parameter values and over a wide range of ...

We experimentally demonstrate a detection scheme suitable for state analysis of single optically trapped atoms in less than 1 ?s with an overall detection efficiency ? exceeding 98%. The method is based on hyperfine-state-selective photoionization and subsequent registration of the correlated photoion-electron pairs by coincidence ...

This paper describes direct photon counting data on several pixels of the Rockwell SSPM detector array, about which absolute single photon detection efficiencies and time responses were reported previously by Kwiat et al. The new data shows a substantiall...

Close-geometry efficiency calibration has been performed for a 25.4 mm�25.4 mm cylindrical LaBr3(Ce) detector using calibrated point sources of 137Cs and 60Co placed on the top of the detector surface. The absolute total detection efficiency and the absolute photo-peak ...

This paper describes direct photon counting data on several pixels of the Rockwell SSPM detector array, about which absolute single photon detection efficiencies and time responses were reported previously by Kwiat et al. The new data shows a substantially larger efficiency, 85%, and suggests that damage in the ...

We developed an integrated monochromatic excitation light source integrating sphere based detection system to accurately characterize the absolute photoluminescence quantum efficiency of commonly used polymer light emitting films without using a reference sample. Our methodology is similar to the method reported by de Mello et al. ...

... Title : Absolute Length Changes by Remote Interferometry. ... Descriptors : *Interferometers, *Dilatometers, *Thermal stability, *Change detection ...

A method is described whereby the absolute radiative quantum efficiency of paramagnetic ions in liquids or solids can be determined from photoacoustic measurements. 1 figure.

A prototype gas-filled proportional counter (PC) based on micro-scale tungsten wire and carbon fiber, and nano-scale carbon nanotube (CNT) anodes was built and tested with a 90Sr source. Tungsten anodes of 500 ?m down to 4 ?m diameter were used to observe the gradual decrease in operating voltage for the proportional region with a decreasing anode diameter. The 40 nm diameter CNTs anodes ranged in ...

The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are ...

The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are ...

The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are ...

The electron beam ion trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of X-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen X-ray energies. X-rays are ...

The electron beam ion trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of X-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete mono-energetic lines at appropriately chosen X-ray energies. X rays are ...

Recent theoretical work has shown conceptual feasibility for the airborne measurement of the absolute oil fluorescence spectral conversion efficiency (AOFSCE) of crude and refined petroleum oils on the ocean surface without a priori knowledge of the film thickness. Reported herein are airborne lidar oil spill experiments conducted to determine the ...

A collective Thomson scattering (CTS) system based on CO2 laser is being developed in JT-60U to demonstrate the feasibility of ion temperature and alpha particle measurement in international thermonuclear experimental reactor (ITER). A new and effective method of measuring the spatial profile of absolute detection efficiency of an ...

The shortage of 3He has triggered the search for effective alternative neutron detection technologies for national security and safeguards applications. Any new detection technology must satisfy two basic criteria: (1) it must meet a neutron detection efficiency requirement, and (2) it must be insensitive to ...

A spectroscopic radiation portal monitor (SPM) prototype consisting of four 10.16 cm x 10.16 cm x 40.64 cm (4�x4�x16�) sodium iodide (NaI) crystals has been constructed at Pacific Northwest National Laboratory (PNNL). The prototype was put through a variety of tests, including measurements of the absolute detection efficiency of ...

The absolute detection efficiency for protons and for hydrogen atoms in the energy range 5--60 keV is determined for a resistance strip magnetic electron multiplier particle-counting system. Significant history-dependent gain variations are discussed. The detector system is suitable for use in coincidence experiments requiring ...

Reported here are the results of measurements performed to determine the efficiency of 3He filled proportional counters as a function of gas pressure in the SAIC system. Motivation for these measurements was largely to validate the current model of the SAIC system. Those predictions indicated that the neutron detection efficiency ...

... by time averaging the syndrome detection from ... a Hamming (15,11) single error detecting and ... only the absolute delay, since correct absolute delays ...

Image painting is an image doctoring method to remove particular objects. In this paper, a novel passive detection method for paint-doctored JPEG images is proposed when the doctored image is saved in an uncompressed format or in the JPEG compressed format. We detect the doctored region by computing the average of sum of absolute ...

Absolutely calibrated measurements of the neutron yield are important for the evaluation of the plasma performance such as the fusion gain {ital Q} in D-D operating tokamaks. The time-resolved neutron yield is measured with {sup 235}U and {sup 238}U fission chambers and {sup 3}He proportional counters in the JT-60U tokamak. The {ital in} {ital situ} calibration was performed ...

A shielded high purity germanium detector has been used to measure the abundance of U, Th and K in aggregate, sand and cement. The measurements were performed in order to demonstrate that the materials contained less than 10 ppm U and less than 20 ppm Th and were therefore suitable for the construction of a low background shielding enclosure. A particular feature of this work is the simplicity of ...

Knowledge on absolute protein concentrations is mandatory for the simulation of biological processes in the context of systems biology. A novel approach for the absolute quantification of proteins at a global scale has been developed and its applicability demonstrated using glucose starvation of the Gram-positive model bacterium Bacillus subtilis and the ...

Mass spectroscopy has the distinct advantage of detecting atoms rather than radioactive decay products for nuclides of low specific activity. Electrothermal vaporization (ETV) is an efficient means of introducing small volumes of prepared samples into an inductively coupled mass spectrometer to achieve the lowest absolute ...

Precise calibration of monitors and dosimeters for use with high energy neutrons necessitates reliable and accurate neutron fluences being evaluated with use of a reference point. A highly efficient Proton Recoil counter Telescope (PRT) to make absolute measurements with use of a reference point was developed to evaluate neutron fluences in ...

We present Monte Carlo studies on the singly tagged D mesons, which are crucial in the absolute measurements of D meson decays, based on a full Monte Carlo simulation for the BES-III detector, with the BES-III Offline Software System. The expected detection efficiencies and mass resolutions of the tagged D mesons are well estimated.

Extensive atmospheric showers observed in coincidence by an underwater neutrino telescope and a HELYCON (HEllenic LYceum Cosmic Observatories Network) floating scintillation array, offer an efficient calibration tool for the angular offset and the absolute position of a deep sea neutrino Cherenkov telescope. We report results of our studies concerning ...

Contents: Design of a solar total energy system with auxiliary heater; Short-range and long-range in the detection of a moving dot; Multiple row-folded programmable logic array and its easy-to-alter implementation (in English); Absolute efficiency of lami...

Deuterated liquid scintillators are promising from the perspective of n/? separation and neutron energy measurement without time-of-flight. In order to turn these into precision instruments for nuclear physics, however, the absolute efficiency must be known. The efficiency is typically a function of energy and is strongly dependent on ...

An absolute calibration technique for a spontaneously fissioning nuclide (which involves no arbitrary parameters) allows unique determination of the detector efficiency for that nuclide, hence of the fission source strength.

Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic ...

Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic ...

... detect, classify, locate, track and monitor marine mammals in their ... estimating absolute density or abundance of marine mammal populations using ...

Development and application of multidimensional gas chromatography for ... The fire detection strategy is based on absolute detection of a fire (a fire of ...

A conditional unitary transformation (90 deg. polarization rotation) is performed at single-photon level. The transformation is realized by rotating polarization for one of the photons of a polarization-entangled biphoton state (signal photon) by means of a Pockel cell triggered by the detection of the other (idler) photon after polarization selection. As a result, the state ...

Neutron detectors are used in national security applications for detecting potential radioactive material entering the country. Due to the shortage of Helium-3 for neutron detectors, Lithium-6 glass scintillators could be a good material for a replacement detector. Lithium-6 has a large neutron capture cross section, which gives high neutron detection ...

This paper reviews recent advances in emission and detection of terahertz (THz) radiation utilizing two-dimensional plasmons in semiconductor heterostructures and their possible sensing and spectroscopic applications. The device is introduced as a light source into a Fourier-transform THz spectrometer. Water-vapor absorption lines as well as fingerprints of honey and maple ...

Contents: Absolute spectrofluorometry; Absolute quantum efficiencies; Phosphorimetry; Measurements of absolute values in biochemical fluorescence spectroscopy; Newer fluorometric methods for the analysis of biologically important compounds; Inorganic ions...

Binocular detection of brief light flashes is presented under various conditions of both absolute and relative disparity, where absolute disparity is defined in terms of the relative locus of the images on the retinas of each eye and relative disparity in terms of the difference between the absolute disparity of ...

Directed self-guidance, whereby trainees independently practice a skill-set in a structured setting, may be an effective technique for novice training. Currently, however, most evaluation methods require an expert to be present during practice. The study aim was to determine if absolute symmetry error, a clinically important measure that can be assessed by the trainee, is a ...

A method for the collection of two volatile organic mercury compounds in the atmosphere is described, using Chromosorb 101 as a collection substrate. The analytical method involves direct elution of the organic mercury compounds from the collection substrate onto a gas chromatographic column prior to detection with a microwave plasma detector. Methylmercury chloride (MMC) is ...

Absolute partial and total cross sections for electron-impact ionization of methanol, ethanol, and 1-propanol are reported for electron energies from threshold to 1000 eV. The product ions are mass analyzed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output demonstrates that all product ion species are ...

... source in water and in two aluminum and water mixtures. ... By use of experimentally determined counting efficiencies, absolute saturation activities ...

Absolute and relative detector efficiencies measured. Apparatus uses coincidence-counting techniques

An electrostatic precipitation method is described for the individual alpha-particle activities associated with radionuclidic decays that trace their origin to sites in the surface layers of solid matter. The energy resolution is sufficient to resolve all of the detected, major alpha-particle groups of the identifying member(s) of the uranium, thorium, and actinium series. The ...

We report results of the TFTR fission detector calibration performed in December 1988. A NBS-traceable, remotely controlled {sup 252}Cf neutron source was moved toroidally through the TFTR vacuum vessel. Detection efficiencies for two {sup 235}U detectors were measured for 930 locations of the neutron point source in toroidal scans at 16 different major ...

To investigate the characteristics of a reactor and a neutron generator, a small scintillation detector with an optical fiber with ThO(2) has been developed to measure fast neutrons. However, experimental facilities where (232)Th can be used are limited by regulations, and S/N ratio is low because the background counts of this detector are increase by alpha decay of (232)Th. The purpose of this ...

The /sup 252/Cf-source-driven noise analysis method determines the subcriticality of a system containing fissionable material from the ratio of cross power spectral densities between the detectors that detect particles from the fission process and between these detectors and an ionization chamber containing a spontaneously fissioning neutron source which provides neutrons to ...

The detection efficiency of a scintillation counter can be deduced from the knowledge of the statistical distribution of the light emitted by the scintillator. When using traditional photomultiplier tubes (PMT), the resolution of the of photons' spectrum is limited by the multiplication factor of the first dynode. Even with a high-gain PMT, the resolution ...

A method for the standardization of pure BETA emitters is presented. The technique involves the inclusion of a suitable BETA -- gamma -emitting nuclide with the pure BETA emitter in the deposited source and the use of BETA , gamma -coincidence counting to determine the efficiency of detection of the betas arising from the BETA - gamma - ...

A neutron counter designed for assay of radioactive materials has been adapted for beam experiments at TUNL. The cylindrical geometry and 60% maximum efficiency make it well suited for (?,n) cross-section measurements near the neutron emission threshold. A high precision characterization of the counter has been made using neutrons from several sources. Using a combination of ...

efficiency of photon-counting detectors without reference to any externally calibrated detector standard [3 variation of the absolute response of a photon counting system can be measured at a range of wavelengthsmetrologia Absolute detector quantum-efficiency measurements using correlated photons A. L. Migdall

Food allergies are important food safety issues nowadays. To maintain the safety of people who experience allergic reactions, labeling is required in many countries and efficient and reliable detection methods are necessary. This paper reports a novel method for the rapid identification of food allergens through the use of a silicon-based optical thin-film ...

Neutron transport simulations have been carried out to calculate the absolute detection efficiency of a moderated 235U neutron detector which is used on the TFTR as part of the primary fission detector diagnostic system for measuring fusion power yields. Transport simulations provide a means by which the effects of variations in ...

Neutron transport simulations have been carried out to calculate the absolute detection efficiency of a moderated /sup 235/U neutron detector which is used on the TFTR as a part of the primary fission detector diagnostic system for measuring fusion power yields. Transport simulations provide a means by which the effects of variations ...

The effects of pH value, initial concentration of dye solution and temperature on the degradation efficiency of Acid Orange II (AO7) using gas-liquid gliding arc discharge were investigated. The influences of pH value and temperature on degradation efficiency were not apparent. Increasing initial solution concentration caused the decrease of degradation ...

Measurements and analysis of gamma-background radiation spectrum in four different places of Qatar University campus were performed at the energy range 10 keV-3 MeV using hyper pure Ge-detector. The dependence of the detector absolute photopeak efficiency on gamma-ray energies was determined and correction of the data for that was also done. The absorbed ...

The percentage of adipose (fat) tissue in the chest wall must be known to accurately measure Pu in the human lung. Correction factors of 100% or more in x-ray detection efficiency are common. Methods using simple /sup 40/K and biometric measurement techniques were investigated to determine the adipose content in the human chest wall. These methods predict ...

The design and calibration of a system for measuring absolute concentrations of O2(a1 Delta) produced in the Chemical Oxygen-Iodine Laser (COIL) are presented. The detection system features a liquid-nitrogen-cooled intrinsic germanium detector calibrated ...

Digital instrumentation for heterogeneous scintillation flow-cell radiation detection has been developed and optimized using Monte Carlo computer codes for the quantification of gross alpha and beta radionuclides in aqueous streams. A digital alpha/beta pulse shape discriminating data acquisition system utilizing CsI:Tl granules microencapsulated with 3% (ratio of coating ...

In this study Y3Al5O12: Ce powder scintillator was evaluated for use in X-ray imaging detectors. This phosphor, also known as YAG: Ce scintillator or P-46 phosphor, is a non-hygroscopic, emitting green light with very short decay time. These properties are very attractive for X-ray imaging. Y3Al5O12: Ce powder was used to prepare various test screens (33 166 mg/cm2). Absolute ...

... Capacitance Transducer for the Detection of Acoustic Emission", J ... M. Greenspan: "Surface-Wave Displacement: Absolute Measurements Using a ...

... Since this is a noise that exists in all detectors at a finite temperature, it sets the absolute limit of detectivity that no detector of whatever type or ...

... the square root of the mean number of centers in resonance. To be precise, defining the ... absorption profile scaling in absolute magnitude as ,/N,. ...

... sky was measured in absolute units. Infrared radiation from the Milky Way was detected. Twilight flashes of radiation from ...

... Abstract : IN-PLANT EXPERIENCE WITH IGA SUGGESTS AN ABSOLUTE EDDY CURRENT COIL MODE IS THE KEY IN ACHIEVING RELIABLE ...

An algorithm to automatically detect brain tumors in MR images is presented. The key concern is speed in order to process efficiently large brain image databases and provide quick outcomes in clinical setting. The method is based on study of asymmetry of the brain. Tumors cause asymmetry of the brain, so we detect brain tumors in 3D MR ...

This thesis determines the role of efficiency in market share's positive relationship with profitability for U.S. manufacturing firms. Two types of efficiency measures are employed in this study. The first is an absolute measure of efficiency using a simp...

We have conducted calibrations of a microfission chamber, which was installed between the vacuum vessel and the toroidal field coils, by both a Cf-252 neutron source and real deuterium plasmas in JT-60U. The detector employs both pulse counting and Campbell (mean square voltage) modes in the electronics to cover a wide dynamic range of the neutron source strength. The pulse counting and Campbell ...

We have conducted calibrations of a microfission chamber, which was installed between the vacuum vessel and the toroidal field coils, by both a Cf-252 neutron source and real deuterium plasmas in JT-60U. The detector employs both pulse counting and Campbell (mean square voltage) modes in the electronics to cover a wide dynamic range of the neutron source strength. The pulse counting and Campbell ...

A low-level counting system used in absolute measuements of the Cr/sup 12/(p,pn)C/sup 11/ cross section is described. In this system small activities of C/sup 11/ produced in polystyrene-based plastic scintillators by irradiation with high-energy protons are detected with high efficiency by 4 pi scintillation counting. ...

A precise detector alignment and absolute pointing is crucial for point-source searches. The ANTARES neutrino telescope utilises an array of hydrophones, tiltmeters and compasses for the relative positioning of the optical sensors. The absolute calibration is accomplished by long-baseline low-frequency triangulation of the acoustic reference devices in the ...

Detect 3-20 MEarth planets around stars at a distmice of 8-30 pc. 3. Determine absolute masses of Doppler-detected planets and search for additional planets ...

Calibration methods currently employed for the analysis of radioactive samples by ?-ray spectrometry apply reference sources and the accuracy of the final results is always limited by the unavoidable differences between the composition and the counting geometry of the samples and standards. Under suitable circumstances, described in this paper, the determination of elemental concentrations can be ...

A description is given of a scintillator consisting of ZnS(Ag) mixed with uranium and thorium compounds. The absolute counting efficiency for fast neutron fission is 3.2 plus or minus 0.6x 10/sup -3/%. and 5.4 plus or minus 1.0x 10/sup -3/% for U and Th compound mixtures. The efficiency is within the experimental error ...

A new device has been constructed that measures the positron emitting radio-tracer concentration in arterial blood by extracting blood with a peristaltic pump, then measuring the activity concentration by detecting coincident pairs of 511 keV photons with a pair of heavy inorganic scintillators attached to photomultiplier tubes. The sensitivity of this device is experimentally ...

This patent describes a method for controlling an operation control amount for an internal combustion engine having a supercharger, an intake passage and an exhaust passage, comprising: detecting an engine speed; detecting an absolute pressure in the intake passage of the engine; detecting an exhaust gas pressure ...

Neutron detection efficiencies of seven detectors from the Yale neutron ball were measured as a function of threshold using a calibrated 3.77 ? Ci ^252Cf source. Relative efficiencies for each threshold (from 100 keV to 800 keV) were measured with the source located 14 cm from the detector, with absolute ...

The research is divided into combustion diagnostics and analytical gas phase atomic and molecular spectrometry. New and improved techniques to spatially and temporally measure flame gas temperatures and species have been and are being developed. These techniques are all based upon fluorescence detection. By measuring the ratio of two fluorescence transitions (in a probe, such ...

The monitoring of anesthetic depth is an absolutely necessary procedure in the process of surgical operation. To judge and control the depth of anesthesia has become a clinical issue which should be resolved urgently. EEG collected wiil be processed by sort entrop in this paper. Signal response of the surface of the cerebral cortex is determined for different stages of ...

The design, calibration, and performance of a low energy neutral atom spectrometer are described. Time-of-flight analysis is used to measure the energy spectrum of charge-exchange deuterium atoms emitted from the PLT tokamak plasma in the energy range from 20 to 1000 eV. The neutral outflux is gated on a 1 ..mu..sec time scale by a slotted rotating chopper disc, supported against gravity in vacuum ...

We describe an instrument developed to monitor the biological fraction of ambient aerosol. This device simultaneously sizes individual particles in an air stream, and measures their total fluorescence following excitation at 266 nm. Recent results of single blind outdoor tests carried out in Alberta, Canada are described. In these, aerosols were generated containing four different types of ...

Electrostatic precipitation within a 20.4-l container onto a solid-state charged-particle detector is employed to simultaneously collect and detect radon-decay daughter ions. Essentially complete isolation of the 6003-keV {alpha} particles associated with {sup 218}{sub 84}Po decay, for which the half-life is 3.05 min, allows radon concentrations in clean, dry air of 4 pCi/l to ...

Electrostatic precipitation within a 20.4-l container onto a solid-state charged-particle detector is employed to simultaneously collect and detect radon-decay daughter ions. Essentially complete isolation of the 6003-keV ? particles associated with 21884Po decay, for which the half-life is 3.05 min, allows radon concentrations in clean, dry air of 4 pCi/l to be determined in ...

A neutron detector has been constructed and calibrated for the accurate measurement of total neutron-production cross sections. The detector consists of a polyethylene sphere of 24'' diameter in which 8-/sup 10/BF/sub 3/ counters have been installed radially. The relative efficiency of this detector has been determined for average neutron energies, from 30 ...

Polarization properties of light can be exploited to develop more selective spectroscopic methods of chemical analysis. Modulation of polarization coupled with lock-in detection provides a powerful detection scheme with improved detectabilities. This dissertation demonstrates the importance of optical design in systems utilizing ...

We report the first use of synchrotron radiation, continuously tunable from 8 to 15 eV, for flame-sampling photoionization mass spectrometry (PIMS). Synchrotron radiation offers important advantages over the use of pulsed vacuum ultraviolet lasers for PIMS; these include superior signal-to-noise, soft ionization, and access to photon energies outside the limited tuning ranges of current VUV laser ...

We examined the reliability of prompt {gamma}-ray intensities by measuring ratios of thermal neutron capture cross sections on 23Na, 27Al, 51V, 55Mn, 64Ni, 65Cu, 141Pr, 186W, and 197Au at the Kyoto University Research Reactor Institute. The cross sections were obtained by two methods: the first is detecting prompt {gamma}-rays (which we call the prompt-{gamma} method), and the ...

We examined the reliability of prompt ?-ray intensities by measuring ratios of thermal neutron capture cross sections on 23Na, 27Al, 51V, 55Mn, 64Ni, 65Cu, 141Pr, 186W, and 197Au at the Kyoto University Research Reactor Institute. The cross sections were obtained by two methods: the first is detecting prompt ?-rays (which we call the prompt-? method), and the other is ...

We demonstrate direct measurements of the absolute molecular two-photon absorption (TPA) cross-sections using a fluorescence technique. A theoretical model of the detected fluorescence signal generated by a femtosecond laser pulse was developed. It is shown that the onset of excited-state saturation depends on the TPA cross-section and the local intensity ...