WorldWideScience

Sample records for beta spectral measurements

  1. Beta particle measurement fundamentals

    International Nuclear Information System (INIS)

    Alvarez, J.L.

    1986-01-01

    The necessary concepts for understanding beta particle behavior are stopping power, range, and scattering. Dose as a consequence of beta particle interaction with tissue can be derived and explained by these concepts. Any calculations of dose, however, assume or require detailed knowledge of the beta spectrum at the tissue depth of calculation. A rudimentary knowledge of the incident spectrum can be of use in estimating dose, interpretating dose measuring devices and designing protection. The stopping power and range based on the csda will give a conservative estimate in cases of protection design, as scattering will reduce the range. Estimates of dose may be low because scattering effects were neglected

  2. Photovoltaic spectral responsivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Emery, K.; Dunlavy, D.; Field, H.; Moriarty, T. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    This paper discusses the various elemental random and nonrandom error sources in typical spectral responsivity measurement systems. The authors focus specifically on the filter and grating monochrometer-based spectral responsivity measurement systems used by the Photovoltaic (PV) performance characterization team at NREL. A variety of subtle measurement errors can occur that arise from a finite photo-current response time, bandwidth of the monochromatic light, waveform of the monochromatic light, and spatial uniformity of the monochromatic and bias lights; the errors depend on the light source, PV technology, and measurement system. The quantum efficiency can be a function of he voltage bias, light bias level, and, for some structures, the spectral content of the bias light or location on the PV device. This paper compares the advantages and problems associated with semiconductor-detector-based calibrations and pyroelectric-detector-based calibrations. Different current-to-voltage conversion and ac photo-current detection strategies employed at NREL are compared and contrasted.

  3. Beta measurement evaluation and upgrade

    International Nuclear Information System (INIS)

    Swinth, K.L.; Rathbun, L.A.; Roberson, P.L.; Endres, G.W.R.

    1986-01-01

    This program focuses on the resolution of problems associated with the field measurement of the beta dose component at Department of Energy (DOE) facilities. The change in DOE programs, including increased efforts in improved waste management and decontamination and decommissioning (D and D) of facilities, coupled with beta measurement problems identified at Three Mile Island has increased the need to improve beta measurements. In FY 1982, work was initiated to provide a continuing effort to identify problems associated with beta dose assessment at DOE facilities. The problems identified resulted in the development of this program. The investigation includes (1) an assessment of measurement systems now in use, (2) development of improved calibration systems and procedures, (3) application of innovative beta dosimetry concepts, (4) investigation of new instruments or concepts for monitoring and spectroscopy, and (5) development of recommendations to assure an adequate beta measurement program within DOE facilities

  4. Automating spectral measurements

    Science.gov (United States)

    Goldstein, Fred T.

    2008-09-01

    This paper discusses the architecture of software utilized in spectroscopic measurements. As optical coatings become more sophisticated, there is mounting need to automate data acquisition (DAQ) from spectrophotometers. Such need is exacerbated when 100% inspection is required, ancillary devices are utilized, cost reduction is crucial, or security is vital. While instrument manufacturers normally provide point-and-click DAQ software, an application programming interface (API) may be missing. In such cases automation is impossible or expensive. An API is typically provided in libraries (*.dll, *.ocx) which may be embedded in user-developed applications. Users can thereby implement DAQ automation in several Windows languages. Another possibility, developed by FTG as an alternative to instrument manufacturers' software, is the ActiveX application (*.exe). ActiveX, a component of many Windows applications, provides means for programming and interoperability. This architecture permits a point-and-click program to act as automation client and server. Excel, for example, can control and be controlled by DAQ applications. Most importantly, ActiveX permits ancillary devices such as barcode readers and XY-stages to be easily and economically integrated into scanning procedures. Since an ActiveX application has its own user-interface, it can be independently tested. The ActiveX application then runs (visibly or invisibly) under DAQ software control. Automation capabilities are accessed via a built-in spectro-BASIC language with industry-standard (VBA-compatible) syntax. Supplementing ActiveX, spectro-BASIC also includes auxiliary serial port commands for interfacing programmable logic controllers (PLC). A typical application is automatic filter handling.

  5. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  6. Calibration with near-continuous spectral measurements

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Rasmussen, Michael; Madsen, Henrik

    2001-01-01

    In chemometrics traditional calibration in case of spectral measurements express a quantity of interest (e.g. a concentration) as a linear combination of the spectral measurements at a number of wavelengths. Often the spectral measurements are performed at a large number of wavelengths and in thi...... by an example in which the octane number of gasoline is related to near infrared spectral measurements. The performance is found to be much better that for the traditional calibration methods....

  7. Monte Carlo simulation of the spectral response of beta-particle emitters in LSC systems

    International Nuclear Information System (INIS)

    Ortiz, F.; Los Arcos, J.M.; Grau, A.; Rodriguez, L.

    1992-01-01

    This paper presents a new method to evaluate the counting efficiency and the effective spectra at the output of any dynodic stage, for any pure beta-particle emitter, measured in a liquid scintillation counting system with two photomultipliers working in sum-coincidence mode. The process is carried out by a Monte Carlo simulation procedure that gives the electron distribution, and consequently the counting efficiency, at any dynode, in response to the beta particles emitted, as a function of the figure of merit of the system and the dynodic gains. The spectral outputs for 3 H and 14 C have been computed and compared with experimental data obtained with two sets of quenched radioactive standards of these nuclides. (orig.)

  8. Precision measurements in nuclear beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Naviliat-Cuncic, Oscar, E-mail: naviliat@nscl.msu.edu [Michigan State University, National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy (United States)

    2013-03-15

    Precision measurements in nuclear beta decay provide sensitive means to determine the fundamental coupling of charged fermions to weak bosons and to test discrete symmetries in the weak interaction. The main motivation of such measurements is to find deviations from Standard Model predictions as possible indications of new physics. I focus here on two topics related to precision measurements in beta decay, namely: (i) the determination of the V{sub ud} element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix from nuclear mirror transitions and (ii) selected measurements of time reversal violating correlations in nuclear and neutron decays. These topics complement those presented in other contributions to this conference.

  9. Spectral measurements of loess TL

    International Nuclear Information System (INIS)

    Rendell, H.M.; Mann, S.J.; Townsend, P.D.

    1988-01-01

    Variations in thermoluminescence (TL) glow curves are reported for two loess samples when examined with broad band filters in the range 275-650 nm. Samples show striking differences in bleaching behaviour, when their TL emissions are observed in the u.v., blue, green and yellow spectral regions. The age estimates, given by the equivalent dose (ED) values, differ by up to a factor of two for analyses using the green and u.v. TL signals. These ED values also vary with prolonged room temperature storage between the bleaching and irradiation steps. The anomalies in the bleaching behaviour are interpreted in terms of changes in TL efficiency. The results have major implications for the regeneration method of TL dating for these fine-grained sediments and suggest that reliable dates obtained by it may be fortuitous. (author)

  10. Average beta measurement in EXTRAP T1

    International Nuclear Information System (INIS)

    Hedin, E.R.

    1988-12-01

    Beginning with the ideal MHD pressure balance equation, an expression for the average poloidal beta, Β Θ , is derived. A method for unobtrusively measuring the quantities used to evaluate Β Θ in Extrap T1 is described. The results if a series of measurements yielding Β Θ as a function of externally applied toroidal field are presented. (author)

  11. Spectral shapes and a beta-gamma directional correlation in the beta decay of 172Tm (Jpi = 2-)

    DEFF Research Database (Denmark)

    Gregers Hansen, P.; Loft Nielsen, H.; Wilsky, K.

    1966-01-01

    The isotope 172Tm populates the 0+, 2+ and 4+ states of the 172Yb ground-state rotational band directly in beta decay. The shapes and intensities of the three beta groups have been measured by means of a six-gap magnetic spectrometer operated in coincidence with a Nal(Tl) crystal. The experimenta...

  12. Card controlled beta backscatter thickness measuring instrument

    International Nuclear Information System (INIS)

    Schlesinger, J.

    1978-01-01

    An improved beta backscatter instrument for the nondestructive measurement of the thickness of thin coatings on a substrate is described. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness

  13. Behaviour of spectral entropy, spectral edge frequency 90%, and alpha and beta power parameters during low-dose propofol infusion.

    LENUS (Irish Health Repository)

    Mahon, P

    2012-02-03

    BACKGROUND: In this study we analyse the behaviour, potential clinical application and optimal cortical sampling location of the spectral parameters: (i) relative alpha and beta power; (ii) spectral edge frequency 90%; and (iii) spectral entropy as monitors of moderate propofol-induced sedation. METHODS: Multi-channel EEG recorded from 12 ASA 1 (American Society of Anesthesiologists physical status 1) patients during low-dose, target effect-site controlled propofol infusion was used for this analysis. The initial target effect-site concentration was 0.5 microg ml(-1) and increased at 4 min intervals in increments of 0.5 to 2 microg ml(-1). EEG parameters were calculated for 2 s epochs in the frequency ranges 0.5-32 and 0.5-47 Hz. All parameters were calculated in the channels: P4-O2, P3-O1, F4-C4, F3-C3, F3-F4, and Fp1-Fp2. Sedation was assessed clinically using the OAA\\/S (observer\\'s assessment of alertness\\/sedation) scale. RESULTS: Relative beta power and spectral entropy increased with increasing propofol effect-site concentration in both the 0.5-47 Hz [F(18, 90) = 3.455, P<0.05 and F(18, 90) = 3.33, P<0.05, respectively] and 0.5-32 Hz frequency range. This effect was significant in each individual channel (P<0.05). No effect was seen of increasing effect-site concentration on relative power in the alpha band. Averaged across all channels, spectral entropy did not outperform relative beta power in either the 0.5-32 Hz [Pk=0.79 vs 0.814 (P>0.05)] or 0.5-47 Hz range [Pk=0.81 vs 0.82 (P>0.05)]. The best performing indicator in any single channel was spectral entropy in the frequency range 0.5-47 Hz in the frontal channel F3-F4 (Pk=0.85). CONCLUSIONS: Relative beta power and spectral entropy when considered over the propofol effect-site range studied here increase in value, and correlate well with clinical assessment of sedation.

  14. Glue Film Thickness Measurements by Spectral Reflectance

    International Nuclear Information System (INIS)

    Marshall, B.R.

    2010-01-01

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 (micro)m, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  15. Glue Film Thickness Measurements by Spectral Reflectance

    Energy Technology Data Exchange (ETDEWEB)

    B. R. Marshall

    2010-09-20

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 μm, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  16. Spectral interferometric length measurement and tomography

    International Nuclear Information System (INIS)

    Pinkl, W.

    1998-01-01

    This work presents a new method for optical length measurement using the principles of spectral interferometry. Results of thickness measurements on glass plates, the human cornea in vivo and human finger and toe nails in vivo and in vitro are discussed. It could be demonstrated that the absorption coefficient of red and green ink can be measured depth sensitive. Another chapter describes a new technique to measure a thickness profile of a sample within the illuminating beam. It could be demonstrated that a thickness profile over a distance of a few millimeters can be measured with one single measurement. At the Institute of Medical Physics of the University of Vienna a method to measure intraocular distances by the means of interferometry has been developed during the last ten years. Basing on this method (dual beam interferometry) an optical in vivo tomography experiment could be established. A thickness map of the retina of a human eye in vivo can be easily measured. The dual beam technique uses a Michelson interferometer with a moving mirror to adjust the length of the interferometer arms. The mirror is moved by a stepper motor. This movement induces vibrations, misalignment and other disadvantages. So mechanically moved parts as reasons for possible errors should be eliminated. This work shows one possible solution - using the principle of spectral interferometry. A spectral interferometry experiment is a static experiment, no moving parts are used. A spectral interferometry experiment has been used to measure the thickness of glass plates and stacks of glass plates. Using two light sources of different wavelengths spectral absorption properties of a sample can be measured depth sensitive. This could be demonstrated with stacks of glass plates and the use of red and green ink between two plates. The obtained results are compared to the results of a computer simulation. To demonstrate the ability of spectral interferometry to measure the thickness of biologic

  17. Spectral and electronic measurements of solar radiation

    International Nuclear Information System (INIS)

    Suzuki, Mamoru; Hanyu, Mitsuhiro

    1977-01-01

    The spectral data of solar radiation are necessary if detailed discussion is intended in relation to the utilization of solar energy. Since those data have not been fully prepared so far, a measuring equipment developed in Electro-technical Laboratory to obtain those data is described. The laboratory is now continuing the measurement at the wavelength of 0.3 μm to 1.1 μm. The equipment employs the system to always calibrate with the standard light source, it can measure both the direct light of the sun only and the sun light including sky light, and it enables to obtain the value based on the secondary standard of spectral illumination intensity established by the laboratory. The solar spectral irradiance is determined with the current readings of photomultiplier in the standard light source and the sun-light measurements at a wavelength and with the spectral illumination intensity from the standard light source. In order to practice such measurement many times at various wavelengths, control of the equipment, data collection, computation, drawing and listing are performed by a microcomputer. As an example, the data on Sept. 10, 1976, are shown comparing the graphs at three different hours. It can be well observed that the transmissivity attenuates with shorter wavelength, and the transmissivity in near infra-red region changes greatly due to the absorption of radiation by water vapour. (Wakatsuki, Y.)

  18. The BETA ® nursing measure: Calibrating construct validity with ...

    African Journals Online (AJOL)

    Background: The BETA nursing measure has been introduced as a tool to routinely measure and monitor the outcomes of patients' activities of daily living in a restorative nursing care context. Objectives: To investigate the BETA's construct validity using the Rasch model with specific reference to the BETA's potential to be ...

  19. AGS vertical beta function measurements for Run 15

    Energy Technology Data Exchange (ETDEWEB)

    Harper, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ahrens, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-10-07

    One key parameter for running the AGS efficiently is by maintaining a low emittance. To measure emittance, one needs to measure the beta function throughout the cycle. This can be done by measuring the beta function at the ionization profile monitors (IPM) in the AGS. This tech note delves into the motivation, the measurement, and some strides that were made throughout Run15.

  20. Proceedings of the Department of Energy workshop on beta measurements

    International Nuclear Information System (INIS)

    Swinth, K.L.; Vallario, E.J.

    1987-09-01

    Participants discussed current practices, efforts to upgrade the quality of beta measurements, and initiatives necessary to improve the measurement and control of beta doses. This proceedings includes papers presented at the workshop, transcripts of panel and open discussions, and documentation of question and answer sessions. The information exchange resulting from this meeting is expected to provide a clearer focus on the problems of beta measurements

  1. Proceedings of the Department of Energy workshop on beta measurements

    Energy Technology Data Exchange (ETDEWEB)

    Swinth, K.L.; Vallario, E.J.

    1987-09-01

    Participants discussed current practices, efforts to upgrade the quality of beta measurements, and initiatives necessary to improve the measurement and control of beta doses. This proceedings includes papers presented at the workshop, transcripts of panel and open discussions, and documentation of question and answer sessions. The information exchange resulting from this meeting is expected to provide a clearer focus on the problems of beta measurements.

  2. Extreme ultraviolet spectral irradiance measurements since 1946

    Science.gov (United States)

    Schmidtke, G.

    2015-03-01

    In the physics of the upper atmosphere the solar extreme ultraviolet (EUV) radiation plays a dominant role controlling most of the thermospheric/ionospheric (T/I) processes. Since this part of the solar spectrum is absorbed in the thermosphere, platforms to measure the EUV fluxes became only available with the development of rockets reaching altitude levels exceeding 80 km. With the availability of V2 rockets used in space research, recording of EUV spectra started in 1946 using photographic films. The development of pointing devices to accurately orient the spectrographs toward the sun initiated intense activities in solar-terrestrial research. The application of photoelectric recording technology enabled the scientists placing EUV spectrometers aboard satellites observing qualitatively strong variability of the solar EUV irradiance on short-, medium-, and long-term scales. However, as more measurements were performed more radiometric EUV data diverged due to the inherent degradation of the EUV instruments with time. Also, continuous recording of the EUV energy input to the T/I system was not achieved. It is only at the end of the last century that there was progress made in solving the serious problem of degradation enabling to monitore solar EUV fluxes with sufficient radiometric accuracy. The data sets available allow composing the data available to the first set of EUV data covering a period of 11 years for the first time. Based on the sophisticated instrumentation verified in space, future EUV measurements of the solar spectral irradiance (SSI) are promising accuracy levels of about 5% and less. With added low-cost equipment, real-time measurements will allow providing data needed in ionospheric modeling, e.g., for correcting propagation delays of navigation signals from space to earth. Adding EUV airglow and auroral emission monitoring by airglow cameras, the impact of space weather on the terrestrial T/I system can be studied with a spectral terrestrial

  3. Beta Beams for Precision Measurements of Neutrino Oscillation Parameters

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Damjanovic, S; Payet, J; Chancé, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, V; Gramegna, F; Marchi, T; Collazuol, G; Mezzetto, M; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Burt, G; Dexter, A; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A; Vardaci, E; Di Nitto, A; Brondi, A; La Rana, G; Moro, R; De Rosa, G; Palladino, V

    2012-01-01

    Neutrino oscillations have implications for the Standard Model of particle physics. The CERN Beta Beam has outstanding capabilities to contribute to precision measurements of the parameters governing neutrino oscillations. The FP7 collaboration EUROnu (2008-2012) is a design study that will review three facilities (Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make decisions on future European neutrino oscillation facilities. ”Beta Beams” produce collimated pure electron (anti)neutrinos by accelerating beta active ions to high energies and having them decay in a storage ring. Using existing machines and infrastructure is an advantage for the cost evaluation; however, this choice is also constraining the Beta Beams. Recent work to make the Beta Beam facility a solid option will be described: production of Beta Beam isotopes, the 60 GHz pulsed ECR source development, integratio...

  4. Correlation and spectral density measurements by LDA

    International Nuclear Information System (INIS)

    Pfeifer, H.J.

    1986-01-01

    The present paper is intended to give a review on the state-of-the art in correlation and spectral density measurements by means of laser Doppler anemometry. As will be shown in detail the most important difference in performing this type of studies is the fact that laser anemometry relies on the presence of particles in the flow serving as flow velocity indicators. This means that, except in heavily seeded flows, the instantaneous velocity can only be sampled at random instants. This calls for new algorithms to calculate estimates of both correlation functions and power spectra. Various possibilities to handle the problem of random sampling have been developed in the past. They are explained from the theoretical point of view and the experimental aspects are detailed as far as they are different from conventional applications of laser anemometry

  5. Beta ray backscattering studies for thickness measurements

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M; Sharma, K K [Punjabi Univ., Patiala (India). Nuclear Science Labs.

    1979-01-01

    Back-scattering of beta rays from /sup 204/Tl (Esub(..beta..)max = 740 keV) and /sup 90/Sr-/sup 90/Y (Esub(..beta..)max =550 and 2250 keV) has been studied in an improved reflection geometry, using annular sources, from a number of elemental targets with Z values ranging from 13 to 82. Source to target and target to detector geometry factors are 0.0225 and 0.0282 respectively. Values of saturation back scattering thickness obtained in the two cases are 72 +- 10 and 190 +- 40 mg/cm/sup 2/ respectively. It is observed that the intensity of back scattered radiation varies linearly with thickness upto a value of 12 +- 2 mg/cm/sup 2/ in /sup 204/Tl and 17 +- 3 mg/cm/sup 2/ in /sup 90/Sr-/sup 90/Y.

  6. Measuring Systematic Risk Using Implicit Beta

    OpenAIRE

    Andrew F. Siegel

    1995-01-01

    A new technology is proposed for estimating the systematic (beta) risk of a firm's stock. Just as the implicit volatility of an asset is revealed by an ordinary call option, the "implicit beta" of a stock would be revealed by the price of an option to exchange shares of stock for shares of a market index. Considerable benefits would accrue to those involved with the theory and practice of finance, if and when these exchange options begin trading, due to the availability of instantaneous, up-t...

  7. Field measurement and interpretation of beta doses and dose rates

    International Nuclear Information System (INIS)

    Selby, J.M.; Swinth, K.L.; Hooker, C.D.; Kenoyer, J.L.

    1983-01-01

    A large number of portable survey instruments employing G.M., ionization chamber, and scintillation detectors used for gamma measurements are also used for monitoring in beta fields by using removable shields to separate the beta and gamma components of the radiation field. The difference does not correspond to an absorbed dose rate for the beta field due to a variety of factors. Among these factors are the dependence on beta energy, source-detector geometries, mixed fields and variable ambient conditions. Attempting to use such measurements directly can lead to errors as high as a factor of 100. Appropriate calibrations and correction factors can be used to reduce the errors in beta measurements to a tolerable level

  8. Towards a measurement of the spectral runnings

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz, Julian B.; Kovetz, Ely D.; Raccanelli, Alvise; Kamionkowski, Marc; Silk, Joseph, E-mail: julianmunoz@jhu.edu, E-mail: ekovetz1@jhu.edu, E-mail: alvise@icc.ub.edu, E-mail: mkamion1@jhu.edu, E-mail: joseph.silk@physics.ox.ac.uk [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States)

    2017-05-01

    Single-field slow-roll inflation predicts a nearly scale-free power spectrum of perturbations, as observed at the scales accessible to current cosmological experiments. This spectrum is slightly red, showing a tilt (1− n {sub s} )∼ 0.04. A direct consequence of this tilt are nonvanishing runnings α {sub s} = d n {sub s} / dlog k , and β {sub s} = dα {sub s} / dlog k , which in the minimal inflationary scenario should reach absolute values of 10{sup −3} and 10{sup −5}, respectively. In this work we calculate how well future surveys can measure these two runnings. We consider a Stage-4 (S4) CMB experiment and show that it will be able to detect significant deviations from the inflationary prediction for α {sub s} , although not for β {sub s} . Adding to the S4 CMB experiment the information from a WFIRST-like or a DESI-like survey improves the sensitivity to the runnings by ∼ 20%, and 30%, respectively. A spectroscopic survey with a billion objects, such as the SKA, will add enough information to the S4 measurements to allow a detection of α {sub s} =10{sup −3}, required to probe the single-field slow-roll inflationary paradigm. We show that only a very-futuristic interferometer targeting the dark ages will be capable of measuring the minimal inflationary prediction for β {sub s} . The results of other probes, such as a stochastic background of gravitational waves observable by LIGO, the Ly-α forest, and spectral distortions, are shown for comparison. Finally, we study the claims that large values of β {sub s} , if extrapolated to the smallest scales, can produce primordial black holes of tens of solar masses, which we show to be easily testable by the S4 CMB experiment.

  9. Status of beta measurement evaluation and upgrade program

    International Nuclear Information System (INIS)

    Swinth, K.L.

    1986-01-01

    In 1983, the US Department of Energy (DOE) initiated a program to evaluate and upgrade beta dosimetry capabilities at DOE and DOE-contractor facilities. The program has several elements which structure the development of improvements in beta measurement practices. In addition to Pacific Northwest Laboratory (PNL), universities, private corporations, and other DOE facilities are involved in the research efforts

  10. On the absolute measure of Beta activities

    International Nuclear Information System (INIS)

    Sanchez del Rio, C.; Jimenez Reynaldo, O.; Rodriguez Mayquez, E.

    1956-01-01

    A new method for absolute beta counting of solid samples is given. The mea surements is made with an inside Geiger-Muller tube of new construction. The backscattering correction when using an infinite thick mounting is discussed and results for different materials given. (Author)

  11. Source preparations for alpha and beta measurements

    Energy Technology Data Exchange (ETDEWEB)

    Holm, E. [Risoe National Lab., Roskilde (Denmark)

    2001-01-01

    Regarding alpha particle emitters subject for environmental studies, electrodeposition or co-precipitation as fluorides are the most common methods. For electro deposition stainless steel is generally used as cathode material but also other metals such as Ni, Ag, and Cu showed promising results. The use of other anode material than platinum, such as graphite should be investigated. For other purposes such as optimal resolution other more sophisticated methods are used but often resulting in poorer recovery. For beta particle emitters the type of detection system will decide the source preparation. Similar methods as for alpha particle emitters, electrodeposition or precipitation techniques can be used. Due to the continuous energy distribution of the beta pulse height distribution a high resolution is not required. Thicker sources from the precipitates or a stable isotopic carrier can be accepted but correction for absorption in the source must be done. (au)

  12. Enzyme activity measurement via spectral evolution profiling and PARAFAC

    DEFF Research Database (Denmark)

    Baum, Andreas; Meyer, Anne S.; Garcia, Javier Lopez

    2013-01-01

    The recent advances in multi-way analysis provide new solutions to traditional enzyme activity assessment. In the present study enzyme activity has been determined by monitoring spectral changes of substrates and products in real time. The method relies on measurement of distinct spectral...... fingerprints of the reaction mixture at specific time points during the course of the whole enzyme catalyzed reaction and employs multi-way analysis to detect the spectral changes. The methodology is demonstrated by spectral evolution profiling of Fourier Transform Infrared (FTIR) spectral fingerprints using...

  13. Electrophysiological measurements of spectral sensitivities: a review

    Directory of Open Access Journals (Sweden)

    R.D. DeVoe

    1997-02-01

    Full Text Available Spectral sensitivities of visual systems are specified as the reciprocals of the intensities of light (quantum fluxes needed at each wavelength to elicit the same criterion amplitude of responses. This review primarily considers the methods that have been developed for electrophysiological determinations of criterion amplitudes of slow-wave responses from single retinal cells. Traditional flash methods can require tedious dark adaptations and may yield erroneous spectral sensitivity curves which are not seen in such modifications as ramp methods. Linear response methods involve interferometry, while constant response methods involve manual or automatic adjustments of continuous illumination to keep response amplitudes constant during spectral scans. In DC or AC computerized constant response methods, feedback to determine intensities at each wavelength is derived from the response amplitudes themselves. Although all but traditional flash methods have greater or lesser abilities to provide on-line determinations of spectral sensitivities, computerized constant response methods are the most satisfactory due to flexibility, speed and maintenance of a constant adaptation level

  14. Spectral difference method applied in determination of beta-carotene, chlorophyll a and b from irradiated seeds of Calendula Officinalis

    International Nuclear Information System (INIS)

    Cucu, Delia-Irina; Dorobantu, Ioan

    2002-01-01

    Beta-carotene is part of the class of the carotenoid pigments that have a special function in the pigmentation of flowers and fruits. These pigments are essential in photosynthesis where they are retaining energy and are photoprotectors by forming the redox system. They are also precursors of vitamin A, pigments involved in the process of seeing. Beta-carotene is responsible for the growth and development of organisms, for the protection and recovery of epithelial tissue, etc. Next to chlorophyll, carotenoids are the major components of the complex pigment-protein from the thylacoide membrane, and some of them, such as beta-carotene, were for a long time considered to be protecting the membrane against destructive events caused by the over excitement of the chlorophyll. This paper presents spectral difference method for physico-chemical characterisation of three components (beta-carotene, chlorophyll a and b) from Calendula officinalis leaves and stalks, after irradiation of germinated seeds. The germinated seeds of Calendula officinalis has been irradiated at 8 different doses ( 1 k Rad, 3 k Rad, 5 k Rad, 10 k Rad, 20 k Rad, 50 k Rad, 100 k Rad, 500 krad), one set of seeds remaining unirradiated for comparison. The plants had been grown in the same conditions of light, temperature and humidity. The identification of beta-carotene was performed through thin layer chromatography. The chemical concentrations of beta-carotene, chlorophyll a and b were determined by spectral difference method. (authors)

  15. Field measurement and interpretation of beta doses and dose rates

    International Nuclear Information System (INIS)

    Selby, J.M.; Swinth, K.L.; Hooker, C.D.; Kenoyer, J.L.

    1983-01-01

    A wide variety of portable survey instruments employing GM, ionization chamber and scintillation detectors exist for the measurement of gamma exposure rates. Often these same survey instruments are used for monitoring beta fields. This is done by making measurements with and without a removable shield which is intended to shield out the non-penetrating component (beta) of the radiation field. The difference does not correspond to an absorbed dose rate for the beta field due to a variety of factors. Among these factors are the dependence on beta energy, source-detector geometries, mixed fields and variable ambient conditions. Attempting to use such measurements directly can lead to errors as high as a factor of 100. In many instances correction factors have been derived, that if properly applied, can reduce these errors substantially. However, this requires some knowledge of the beta spectra, calibration techniques and source geometry. This paper discusses some aspects of the proper use of instruments for beta measurements including the application of appropriate correction factors. Ionization type instruments are commonly used to measure beta dose rates. Through design and calibration these instruments will give an accurate reading only for uniform irradiation of the detection volume. Often in the field it is not feasible to meet these conditions. Large area uniform distributions of activity are not generally encountered and it is not possible to use large source-to-detector distances due to beta particle absorption in air. An example of correction factors required for various point sources is presented when a cutie pie ionization chamber is employed. The instrument reading is multiplied by the appropriate correction factor to obtain the dose rate at the window. When a different detector is used or for other geometries, a different set of correction factors must be used

  16. Spectral Irradiance Measurements Based on Detector

    International Nuclear Information System (INIS)

    Lima, M S; Menegotto, T; Duarte, I; Da Silva, T Ferreira; Alves, L C; Alvarenga, A D; Almeida, G B; Couceiro, I B; Teixeira, R N

    2015-01-01

    This paper presents the preliminary results of the realization of absolute spectral irradiance scale at INMETRO in the ultraviolet, visible and infrared regions using filter radiometers as secondary standards. In the construction of these instruments are used, at least, apertures, interference filters and a trap detector. In the assembly of the trap detectors it was necessary to characterize several photocells in spatial uniformity and shunt resistance. All components were calibrated and these results were analyzed to mount the filter radiometer

  17. On the absolute measure of Beta activities; Sobre la medida absoluta de actividades Beta

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez del Rio, C; Jimenez Reynaldo, O; Rodriguez Mayquez, E

    1956-07-01

    A new method for absolute beta counting of solid samples is given. The measurements is made with an inside Geiger-Muller tube of new construction. The backscattering correction when using an infinite thick mounting is discussed and results for different materials given. (Author)

  18. FSD: Frequency Space Differential measurement of CMB spectral distortions

    Science.gov (United States)

    Mukherjee, Suvodip; Silk, Joseph; Wandelt, Benjamin D.

    2018-04-01

    Although the Cosmic Microwave Background agrees with a perfect blackbody spectrum within the current experimental limits, it is expected to exhibit certain spectral distortions with known spectral properties. We propose a new method, Frequency Space Differential (FSD) to measure the spectral distortions in the CMB spectrum by using the inter-frequency differences of the brightness temperature. The difference between the observed CMB temperature at different frequencies must agree with the frequency derivative of the blackbody spectrum, in the absence of any distortion. However, in the presence of spectral distortions, the measured inter-frequency differences would also exhibit deviations from blackbody which can be modeled for known sources of spectral distortions like y & μ. Our technique uses FSD information for the CMB blackbody, y, μ or any other sources of spectral distortions to model the observed signal. Successful application of this method in future CMB missions can provide an alternative method to extract spectral distortion signals and can potentially make it feasible to measure spectral distortions without an internal blackbody calibrator.

  19. Beta Neutrino Correlation Measurement with Trapped Radioactive Ions

    International Nuclear Information System (INIS)

    Velten, Ph.; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O.; Mery, A.; Rodriguez, D.; Thomas, J.-C.

    2010-01-01

    The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of 6 He. A deviation from the standard model prediction would indicate the existence of tensor like couplings, possibly mediated by new bosons like leptoquarks. The aim of the LPCTrap experiment is to measure this coefficient with a statistical uncertainty of 0.5% using a novel transparent Paul trap. The status of the experiment is briefly presented along with the work in progress.

  20. 47 CFR 2.1515 - Spectral measurements.

    Science.gov (United States)

    2010-10-01

    ... RULES AND REGULATIONS FCC Procedure for Testing Class A, B and S Emergency Position Indicating... § 2.1515(a) is to be used in this method of measuring signal enhancement. Other methods may be used if.... Amplitude scale: 5 dB/div. Scan width: 20 Hz/div. Center frequency: 121.5 MHz Step (6) Measure and record...

  1. The continuous monitoring of the artificial beta aerosol activity by measuring the alpha and beta activity in aerosol simultaneously

    International Nuclear Information System (INIS)

    Hayakawa, Hironobu; Oonishi, Masaki; Matsuura, Hiroyuki

    1990-01-01

    We have constructed the system to monitor the artificial beta aerosol activity around the nuclear power plants continuously in real time. The smaller releases of artificial radionuclides from the nuclear power plants can be lost in the fluctuations of the natural background of the beta aerosol activity, when only the beta activity of the aerosol is measured. This method to discriminate the artificial and the natural beta activity of the aerosol is based on the fact that the ratio of the natural alpha and beta activities of the aerosol is almost constant. The detection limit of this system is below 3 Bq/m 3 . (author)

  2. Beta measurements and modeling the Tevatron

    International Nuclear Information System (INIS)

    Gelfand, N.M.

    1993-06-01

    The Tevatron collider is now able with two low-β (β*=0.25--0.5m) interaction regions denoted as B0 and D0. This lattice allows independent operation of the interaction regions which required that the previous collider lattice, used in 1988--89, had to be modified. In order to see how well the lattice conforms to the design, measurements of the β function have been carried out at 15 locations in the new Tevatron collider lattice. Agreement can be obtained between the measurements and a computer model for the Tevatron, based on the design, only if the strengths of the gradients in the quadrupoles in the low-β triplet are allowed to differ from their design values. It is also observed that the lattice is very sensitive to the precise values of the gradients in these magnets

  3. Spectral irradiance measurements using a novel spectroradiometer

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Desa, B.A.E.; DeSa, E.J.; Desai, R.G.P.

    A novel design of a spectroradiometer has been implemented and tested in the sea to measure underwater optical and physical properties. The spectroradiometer has two high resolution diffraction-based spectrographs assembled back to back in a...

  4. Spectral measurements of the cosmic microwave background

    Energy Technology Data Exchange (ETDEWEB)

    Kogut, A.J.

    1989-04-01

    Three experiments have measured the intensity of the Cosmic Microwave Background (CMB) at wavelengths 4.0, 3.0, and 0.21 cm. The measurement at 4.0 cm used a direct-gain total-power radiometer to measure the difference in power between the zenith sky and a large cryogenic reference target. Foreground signals are measured with the same instrument and subtracted from the zenith signal, leaving the CMB as the residual. The reference target consists of a large open-mouth cryostat with a microwave absorber submerged in liquid helium; thin windows block the radiative heat load and prevent condensation atmospheric gases within the cryostat. The thermodynamic temperature of the CMB at 4.0 cm is 2.59 +- 0.07 K. The measurement at 3.0 cm used a superheterodyne Dicke-switched radiometer with a similar reference target to measure the zenith sky temperature. A rotating mirror allowed one of the antenna beams to be redirected to a series of zenith angles, permitting automated atmospheric measurements without moving the radiometer. A weighted average of 5 years of data provided the thermodynamic temperature of the CMB at 3.0 cm of 2.62 +- 0.06 K. The measurement at 0.21 cm used Very Large Array observations of interstellar ortho-formaldehyde to determine the CMB intensity in molecular clouds toward the giant HII region W51A (G49.5-0.4). Solutions of the radiative transfer problem in the context of a large velocity gradient model provided estimates of the CMB temperature within the foreground clouds. Collisional excitation from neutral hydrogen molecules within the clouds limited the precision of the result. The thermodynamic temperature of the CMB at 0.21 cm is 3.2 +- 0.9 K. 72 refs., 27 figs., 38 tabs.

  5. Spectral measurements of the cosmic microwave background

    International Nuclear Information System (INIS)

    Kogut, A.J.

    1989-04-01

    Three experiments have measured the intensity of the Cosmic Microwave Background (CMB) at wavelengths 4.0, 3.0, and 0.21 cm. The measurement at 4.0 cm used a direct-gain total-power radiometer to measure the difference in power between the zenith sky and a large cryogenic reference target. Foreground signals are measured with the same instrument and subtracted from the zenith signal, leaving the CMB as the residual. The reference target consists of a large open-mouth cryostat with a microwave absorber submerged in liquid helium; thin windows block the radiative heat load and prevent condensation atmospheric gases within the cryostat. The thermodynamic temperature of the CMB at 4.0 cm is 2.59 +- 0.07 K. The measurement at 3.0 cm used a superheterodyne Dicke-switched radiometer with a similar reference target to measure the zenith sky temperature. A rotating mirror allowed one of the antenna beams to be redirected to a series of zenith angles, permitting automated atmospheric measurements without moving the radiometer. A weighted average of 5 years of data provided the thermodynamic temperature of the CMB at 3.0 cm of 2.62 +- 0.06 K. The measurement at 0.21 cm used Very Large Array observations of interstellar ortho-formaldehyde to determine the CMB intensity in molecular clouds toward the giant HII region W51A (G49.5-0.4). Solutions of the radiative transfer problem in the context of a large velocity gradient model provided estimates of the CMB temperature within the foreground clouds. Collisional excitation from neutral hydrogen molecules within the clouds limited the precision of the result. The thermodynamic temperature of the CMB at 0.21 cm is 3.2 +- 0.9 K. 72 refs., 27 figs., 38 tabs

  6. High-precision thickness measurements using beta backscatter

    International Nuclear Information System (INIS)

    Heckman, R.V.

    1978-11-01

    A two-axis, automated fixture for use with a high-intensity Pm-147 source and a photomultiplier-scintillation beta-backscatter probe for making thickness measurements has been designed and built. A custom interface was built to connect the system to a minicomputer, and software was written to position the tables, control the probe, and make the measurements. Measurements can be made in less time with much greater precision than by the method previously used

  7. Beta activity measurements in high, variable gamma backgrounds

    International Nuclear Information System (INIS)

    Stanga, D.; Sandu, E.; Craciun, L.

    1997-01-01

    In many cases beta activity measurements must be performed in high and variable gamma backgrounds. In such instances it is necessary to use well-shielded detectors but this technique is limited to laboratory equipment and frequently insufficient. In order to perform in a simple manner beta activity measurements in high and variable backgrounds a software-aided counting technique have been developed and a counting system have been constructed. This technique combines the different counting techniques with traditional method of successive measurement of the sample and background. The counting system is based on a programmable multi-scaler which is endowed with appropriate software and allow all operations to be performed via keyboard in an interactive fashion. Two large - area proportional detectors were selected in order to have the same background and the same gamma response within 5%. A program has been developed for the counting data analysis and beta activity computing. The software-aided counting technique has been implemented for beta activity measurement in high and variable backgrounds. (authors)

  8. Time-resolved spectral measurements above 80 A

    International Nuclear Information System (INIS)

    Kauffman, R.L.; Ceglio, N.; Medecki, H.

    1983-01-01

    We have made time-resolved spectral measurements above 80 A from laser-produced plasmas. These are made using a transmission grating spectrograph whose primary components are a cylindrically-curved x-ray mirror for light collection, a transmission grating for spectral dispersions, and an x-ray streak camera for temporal resolution. A description of the instrument and an example of the data are given

  9. A GUI tool for beta function measurement using MATLAB

    International Nuclear Information System (INIS)

    Chen Guangling; Tian Shunqiang; Liu Guimin; Jiang Bocheng

    2009-01-01

    The beta function measurement is used to detect the shift in the betatron tune as the strength of an individual quadrupole magnet is varied. A GUI (graphic user interface) tool for the beta function measurement is developed using the MATLAB program language in the Linux environment, which facilitates the commissioning of the Shanghai Synchrotron Radiation Facility (SSRF) storage ring. In this paper, we describe the design of the application and give some measuring results and discussions about the definition of the measurement. The program has been optimized to solve some restrictions of the AT tracking code. After the correction with LOCO (linear optics from closed orbits), the horizontal and the vertical root mean square values (rms values) can be reduced to 0.12 and 0.10. (authors)

  10. Prototype simulates remote sensing spectral measurements on fruits and vegetables

    Science.gov (United States)

    Hahn, Federico

    1998-09-01

    A prototype was designed to simulate spectral packinghouse measurements in order to simplify fruit and vegetable damage assessment. A computerized spectrometer is used together with lenses and an externally controlled illumination in order to have a remote sensing simulator. A laser is introduced between the spectrometer and the lenses in order to mark the zone where the measurement is being taken. This facilitates further correlation work and can assure that the physical and remote sensing measurements are taken in the same place. Tomato ripening and mango anthracnose spectral signatures are shown.

  11. Humidity measurement using alpha-ray and beta-ray

    International Nuclear Information System (INIS)

    Matsumoto, Shigeaki; Kobayashi, Hisanobu

    1981-01-01

    Two new hygrometers using radioisotopes were proposed, and the results of tests are described. The one is a dew-point hygrometer utilizing the backscattering phenomena of beta-ray by dew, and the other is a hygrometer by measuring the variation of ionization current by alpha ray due to humidity. The backscattering of beta-ray depends on the atomic number of scatters and the energy of beta-ray. Therefore, the backscattering from dew on a gold plate is different from that from the gold itself. The temperature dependence of the backscattering intensity was measured with a GM counter. Decrease of the intensity was seen at the dew point. A control circuit was designed to measure the dew point automatically. The error of the measurement was within 1 degree C. An alpha-ray ionization hygrometer was constructed. The dependence of ionization current on humidity was measured with an operational amplifier. The resolution of humidity measurement was within 5 percent. (Kato, T.)

  12. Hand Monitor for Simultaneous Measurements of Alpha and Beta Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, I Oe; Braun, J; Soederlund, B

    1960-11-15

    An instrument is described which measures {alpha} and {beta} contamination of the hands simultaneously. This has been achieved by using as detectors 8 flow counters paired in 4 units of two chambers, one unit for each side of the hand. The inner chamber of every unit (adjacent to the hands) delivers {alpha}-pulses, the outer chambers deliver {beta}-pulses. When two finger contacts are pushed the detectors are closing around the hands and the measurement is started. Audible and visual warnings operate when the MPL is exceeded. Similar warnings ope.rate if hands are removed before the end of the counting period. The activity levels are logarithmically indicated on four pointer instruments, which are automatically zeroed when the next measurement is started. The instrument is now commercially available.

  13. First Beta-Beating Measurement in the LHC

    CERN Document Server

    Aiba, M; Franchi, A; Giovannozzi, M; Kain, V; Morita, A; Tomás, R; Vanbavinckhove, G; Wenninger, J

    2009-01-01

    This note reports on the first LHC beta-beating and coupling measurements. Thanks to an excellent functioning of the BPM system and the related software, injection oscillations were recorded for the first 90 turns at all BPMs of Beam 2. Three different algorithms are used to measure the optics parameters from the BPM data. All algorithms show consistent measurements but feature different accuracy. The Singular Value Decomposition (SVD) approach shows a high resolution despite the limited number of turns. The vertical beta-beating is observed to be about a factor of two larger than in the horizontal plane. This asymetry is partly due to sextupoles misalignments but also suggests the possible existance of focusing errors at defocussing locations. Rather large coupling is observed since no skew quadrupole was excited at the time of the data acquisition. We also report a list of suspected malfunctioning BPMs identified through various analyses.

  14. Airborne spectral measurements of surface anisotropy during SCAR-B

    Science.gov (United States)

    Tsay, Si-Chee; King, Michael D.; Arnold, G. Thomas; Li, Jason Y.

    1998-12-01

    During the Smoke, Clouds, and Radiation-Brazil (SCAR-B) deployment, angular distributions of spectral reflectance for vegetated surfaces and smoke layers were measured using the scanning cloud absorption radiometer (CAR) mounted on the University of Washington C-131A research aircraft. The CAR contains 13 narrowband spectral channels between 0.3 and 2.3 μm with a 190° scan aperture (5° before zenith to 5° past nadir) and 1° instantaneous field of view. The bidirectional reflectance is obtained by flying a clockwise circular orbit above the surface, resulting in a ground track ˜3 km in diameter within about 2 min. Although the CAR measurements are contaminated by minor atmospheric effects, results show distinct spectral characteristics for various types of surfaces. Spectral bidirectional reflectances of three simple and well-defined surfaces are presented: cerrado (August 18, 1995) and dense forest (August 25, 1995), both measured in Brazil under nearly clear-sky conditions, and thick smoke layers over dense forest (September 6 and 11, 1995). The bidirectional reflectances of cerrado and dense forest revealed fairly symmetric patterns along the principal plane, with varying maximal strengths and widths spectrally in the backscattering direction. In the shortwave-infrared region the aerosol effect is very small due to low spectral optical depth. Also, these backscattering maxima can be seen on the bidirectional reflectance of smoke layer over dense forest. These detailed measurements of the angular distribution of spectral reflectance can be parameterized by a few independent variables and utilized to retrieve either surface characteristics or aerosol microphysical and optical properties (e.g., size distribution and single-scattering parameters), if proper physical and radiation models are used. The spectral-hemispherical albedo of these surfaces is obtained directly by integrating all angular measurements and is compared with the measured nadir reflectance

  15. Automated multifunction apparatus for spectral and polarization measurements

    International Nuclear Information System (INIS)

    Stepanov, A.N.; Kurakov, A.Ya.

    1992-01-01

    An automated spectral apparatus is described that is based on an SDL-2 spectrometer for spectral and polarization measurements with small specimens (0.15 x 0.15 mm) by the Fourier-coefficient method in the visible and ultraviolet regions over a wide range of temperatures. The absorption, dichroism, birefringence, and polarization orientation of natural waves are determined simultaneously in a single measurement cycle. Polarization-luminescence spectra can also be recorded from one region of the specimen without its adjustment. 3 refs., 3 figs

  16. Are resting state spectral power measures related to executive functions in healthy young adults?

    Science.gov (United States)

    Gordon, Shirley; Todder, Doron; Deutsch, Inbal; Garbi, Dror; Getter, Nir; Meiran, Nachshon

    2018-01-08

    Resting-state electroencephalogram (rsEEG) has been found to be associated with psychopathology, intelligence, problem solving, academic performance and is sometimes used as a supportive physiological indicator of enhancement in cognitive training interventions (e.g. neurofeedback, working memory training). In the current study, we measured rsEEG spectral power measures (relative power, between-band ratios and asymmetry) in one hundred sixty five young adults who were also tested on a battery of executive function (EF). We specifically focused on upper Alpha, Theta and Beta frequency bands given their putative role in EF. Our indices enabled finding correlations since they had decent-to-excellent internal and retest reliability and very little range restriction relative to a nation-wide representative large sample. Nonetheless, Bayesian statistical inference indicated support for the null hypothesis concerning lack of monotonic correlation between EF and rsEEG spectral power measures. Therefore, we conclude that, contrary to the quite common interpretation, these rsEEG spectral power measures do not indicate individual differences in the measured EF abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Measuring pion beta decay with high-energy pion beams

    International Nuclear Information System (INIS)

    McFarlane, W.K.; Hoffman, C.M.

    1993-01-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay π + → π 0 e + vε is predicted by the Standard Model (SM) to be R(π + → π 0 e + vε) = 0.3999±0.0005 s -1 . The best experimental number, obtained using in-flight decays, is R(π + → π 0 e + vε) = 0.394 ± 0.015 s -1 . A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required

  18. Measurement quality assurance for beta particle calibrations at NIST

    International Nuclear Information System (INIS)

    Soares, C.G.; Pruitt, J.S.

    1993-01-01

    Standardized beta-particle fields have been established in an international standard and have been adopted for use in several U.S. dosimeter and instrument testing standards. Calibration methods and measurement quality assurance procedures employed at the National Institute of Standards and Technology (NIST) for beta-particle calibrations in these reference fields are discussed. The calibration facility including the NIST-automated extrapolation ionization chamber is described, and some sample results of calibrations are shown. Methods for establishing and maintaining traceability to NIST of secondary laboratories are discussed. Currently, there are problems in finding a good method for routine testing of traceability to NIST. Some examples of past testing methods are given and solutions to this problem are proposed

  19. Measurement quality assurance for beta particle calibrations at NIST

    Energy Technology Data Exchange (ETDEWEB)

    Soares, C.G.; Pruitt, J.S. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    1993-12-31

    Standardized beta-particle fields have been established in an international standard and have been adopted for use in several U.S. dosimeter and instrument testing standards. Calibration methods and measurement quality assurance procedures employed at the National Institute of Standards and Technology (NIST) for beta-particle calibrations in these reference fields are discussed. The calibration facility including the NIST-automated extrapolation ionization chamber is described, and some sample results of calibrations are shown. Methods for establishing and maintaining traceability to NIST of secondary laboratories are discussed. Currently, there are problems in finding a good method for routine testing of traceability to NIST. Some examples of past testing methods are given and solutions to this problem are proposed.

  20. "Calibration" system for spectral measurements and its experimental results

    Science.gov (United States)

    Bruchkouskaya, Sviatlana I.; Katkovsky, Leonid V.; Belyaev, Boris I.; Malyshev, Vladislav B.

    2017-04-01

    "Calibration" system has been developed at A. N. Sevchenko Research Institute of Applied Physical Problems of the Belarusian State University. It was designed for measuring the characteristics of spectral reflectance of all types of natural surfaces (test sites) in ground conditions or on board of aircraft carriers and has the following components: - Photospectroradiometr (PhSR) of high resolution with a range of 400-900 nm, equipped with a digital time-lapse video system; - Two-channel modular spectroradiometer (TMS) with a range of 400-900 nm, designed for simultaneous measurements of reflected light brightness of the underlying surface and the incident radiation from the upper hemisphere; - Two portable spectroradiometers (PSR-700 and PSR-1300) with a spectral range 800-1500 nm; 1200-2500 nm; - Scanning solar spectropolarimeter (SSP-600) with a range of 350-950 nm for measurements of direct sunlight and scattered by the atmosphere at different angles; "Calibration" system provides spectral resolution of 5.2 nm in a range of 400-900 nm, 10 nm in a range of 800-1500 nm and 15 nm in a range of 1200-2500 nm. Measurements of the optical characteristics of solar radiation (for determining parameters of the atmosphere) and that of underlying surface are synchronous. There is also a set of special nozzles for measurements of spectral brightness coefficients, polarization characteristics and spectral albedo. Spectra and images are geotagged to the navigation data (time, GPS). For the measurements of spectral reflection dependencies within "Monitoring-SG" framework expeditions to the Kuril Islands, Kursk aerospace test site and Kamchatka Peninsula were conducted in 2015 and 2016. The spectra of different underlying surfaces have been obtained: soils, plants and water objects, sedimentary and volcanic rocks. These surveys are a valuable material for further researches and selection of test facilities for flight calibration of space imaging systems. Information obtained

  1. Spectral and Temporal Properties of the Alpha and Beta Subunits and (alpha Beta) Monomer Isolated from Nostoc SP. Using Picosecond Laser Spectroscopy.

    Science.gov (United States)

    Dagen, Aaron J.

    1985-12-01

    The fluorescence decay profiles, relative quantum yield and transmission of the (alpha), (beta) and ((alpha)(beta)) complexes from phycoerythrin isolated from the photosynthetic antenna system of Nostoc sp. and measured by single picosecond laser spectroscopic techniques is studied. The fluorescence decay profiles of all three complexes are found to be intensity independent for the intensity range investigated ((TURN)4 x 10('13) to (TURN)4 x 10('15) photons-cm('-2) per pulse). The apparent decrease in the relative quantum yield of all three complexes as intensity increases is offset by a corresponding increase in the relative transmission. This evidence, along with the intensity independent fluorescence kinetics, suggests that exciton annihilation is absent in these complexes. The decay profiles are fit to models assuming energy transfer amongst fluorescing chromophores. The intraprotein transfer rate is found to be 100 ps in the (alpha) subunit, 666 ps in the (beta) subunit. Constraining these rates to be identical in the monomer results in explaining the monomer kinetics by an increase in the nonradiative rate of the f(,(beta)) chromophore, an apparent result of aggregation effects.

  2. High temperature spectral emissivity measurement using integral blackbody method

    Science.gov (United States)

    Pan, Yijie; Dong, Wei; Lin, Hong; Yuan, Zundong; Bloembergen, Pieter

    2016-10-01

    Spectral emissivity is a critical material's thermos-physical property for heat design and radiation thermometry. A prototype instrument based upon an integral blackbody method was developed to measure material's spectral emissivity above 1000 °. The system was implemented with an optimized commercial variable-high-temperature blackbody, a high speed linear actuator, a linear pyrometer, and an in-house designed synchronization circuit. A sample was placed in a crucible at the bottom of the blackbody furnace, by which the sample and the tube formed a simulated blackbody which had an effective total emissivity greater than 0.985. During the measurement, the sample was pushed to the end opening of the tube by a graphite rod which was actuated through a pneumatic cylinder. A linear pyrometer was used to monitor the brightness temperature of the sample surface through the measurement. The corresponding opto-converted voltage signal was fed and recorded by a digital multi-meter. A physical model was proposed to numerically evaluate the temperature drop along the process. Tube was discretized as several isothermal cylindrical rings, and the temperature profile of the tube was measurement. View factors between sample and rings were calculated and updated along the whole pushing process. The actual surface temperature of the sample at the end opening was obtained. Taking advantages of the above measured voltage profile and the calculated true temperature, spectral emissivity under this temperature point was calculated.

  3. Quantitative Spectral Radiance Measurements in the HYMETS Arc Jet

    Science.gov (United States)

    Danehy, Paul M.; Hires, Drew V.; Johansen, Craig T.; Bathel, Brett F.; Jones, Stephen B.; Gragg, Jeffrey G.; Splinter, Scott C.

    2012-01-01

    Calibrated spectral radiance measurements of gaseous emission spectra have been obtained from the HYMETS (Hypersonic Materials Environmental Test System) 400 kW arc-heated wind tunnel at NASA Langley Research Center. A fiber-optic coupled spectrometer collected natural luminosity from the flow. Spectral radiance measurements are reported between 340 and 1000 nm. Both Silicon Carbide (SiC) and Phenolic Impregnated Carbon Ablator (PICA) samples were placed in the flow. Test gases studied included a mostly-N2 atmosphere (95% nitrogen, 5% argon), a simulated Earth Air atmosphere (75% nitrogen, 20% oxygen, 5% argon) and a simulated Martian atmosphere (71% carbon dioxide, 24% nitrogen, 5% argon). The bulk enthalpy of the flow was varied as was the location of the measurement. For the intermediate flow enthalpy tested (20 MJ/kg), emission from the Mars simulant gas was about 10 times higher than the Air flow and 15 times higher than the mostly-N2 atmosphere. Shock standoff distances were estimated from the spectral radiance measurements. Within-run, run-to-run and day-to-day repeatability of the emission were studied, with significant variations (15-100%) noted.

  4. $\\beta$-asymmetry measurements in nuclear $\\beta$-decay as a probe for non-standard model physics

    CERN Multimedia

    Roccia, S

    2002-01-01

    We propose to perform a series of measurements of the $\\beta$-asymmetry parameter in the decay of selected nuclei, in order to investigate the presence of possible time reversal invariant tensor contributions to the weak interaction. The measurements have the potential to improve by a factor of about four on the present limits for such non-standard model contributions in nuclear $\\beta$-decay.

  5. Coherent states and covariant semi-spectral measures

    International Nuclear Information System (INIS)

    Scutaru, H.

    1976-01-01

    The close connection between Mackey's theory of imprimitivity systems and the so called generalized coherent states introduced by Perelomov is established. Coherent states give a covariant description of the ''localization'' of a quantum system in the phase space in a similar way as the imprimitivity systems give a covariant description of the localization of a quantum system in the configuration space. The observation that for any system of coherent states one can define a covariant semi-spectral measure made possible a rigurous formulation of this idea. A generalization of the notion of coherent states is given. Covariant semi-spectral measures associated with systems of coherent states are defined and characterized. Necessary and sufficient conditions for a unitary representation of a Lie group to be i) a subrepresentation of an induced one and ii) a representation with coherent states are given (author)

  6. Precision measurements in nuclear {beta}-decay with LPCTrap

    Energy Technology Data Exchange (ETDEWEB)

    Ban, Gilles; Durand, Dominique; Flechard, Xavier; Lienard, Etienne [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Naviliat-Cuncic, Oscar [NSCL and Department of Physics and Astronomy, Michigan State University, East-Lansing, MI (United States)

    2013-09-15

    The experimental achievements and the current program with the LPCTrap device installed at the LIRAT beam line of the SPIRAL1-GANIL facility are presented. The device is dedicated to the study of the weak interaction at low energy by means of precise measurements of the {beta}-{nu} angular correlation parameter. Technical aspects as well as the main results are reviewed. The future program with new available beams is briefly discussed. (copyright 2013 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Fast Computations for Measures of Phylogenetic Beta Diversity.

    Directory of Open Access Journals (Sweden)

    Constantinos Tsirogiannis

    Full Text Available For many applications in ecology, it is important to examine the phylogenetic relations between two communities of species. More formally, let [Formula: see text] be a phylogenetic tree and let A and B be two samples of its tips, representing the examined communities. We want to compute a value that expresses the phylogenetic diversity between A and B in [Formula: see text]. There exist several measures that can do this; these are the so-called phylogenetic beta diversity (β-diversity measures. Two popular measures of this kind are the Community Distance (CD and the Common Branch Length (CBL. In most applications, it is not sufficient to compute the value of a beta diversity measure for two communities A and B; we also want to know if this value is relatively large or small compared to all possible pairs of communities in [Formula: see text] that have the same size. To decide this, the ideal approach is to compute a standardised index that involves the mean and the standard deviation of this measure among all pairs of species samples that have the same number of elements as A and B. However, no method exists for computing exactly and efficiently this index for CD and CBL. We present analytical expressions for computing the expectation and the standard deviation of CD and CBL. Based on these expressions, we describe efficient algorithms for computing the standardised indices of the two measures. Using standard algorithmic analysis, we provide guarantees on the theoretical efficiency of our algorithms. We implemented our algorithms and measured their efficiency in practice. Our implementations compute the standardised indices of CD and CBL in less than twenty seconds for a hundred pairs of samples on trees with 7 ⋅ 10(4 tips. Our implementations are available through the R package PhyloMeasures.

  8. Feasibility of in situ beta ray measurements in underwater environment.

    Science.gov (United States)

    Park, Hye Min; Park, Ki Hyun; Kang, Sung Won; Joo, Koan Sik

    2017-09-01

    We describe an attempt at the development of an in situ detector for beta ray measurements in underwater environment. The prototype of the in situ detector is based on a CaF2: Eu scintillator using crystal light guide and Si photomultiplier. Tests were conducted using various reference sources for evaluating the linearity and stability of the detector in underwater environment. The system is simple and stable for long-term monitoring, and consumes low power. We show here an effective detection distance of 7 mm and a 2.273 MeV end-point energy spectrum of 90 Sr/ 90 Y when using the system underwater. The results demonstrate the feasibility of in situ beta ray measurements in underwater environment and can be applied for designing an in situ detector for radioactivity measurement in underwater environment. The in situ detector can also have other applications such as installation on the marine monitoring platform and quantitative analysis of radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Quality assurance of the Brewer spectral UV measurements in Finland

    Directory of Open Access Journals (Sweden)

    K. Lakkala

    2008-06-01

    Full Text Available The quality assurance of the two Brewer spectrophotometers of the Finnish Meteorological Institute is discussed in this paper. The complete data processing chain from raw signal to high quality spectra is presented. The quality assurance includes daily maintenance, laboratory characterizations, calculation of long-term spectral responsivity, data processing and quality assessment. The cosine correction of the measurements is based on a new method, and is included in the data processing software. The results showed that the actual cosine correction factor of the two Finnish Brewers can vary between 1.08–1.13 and 1.08–1.12, respectively, depending on the sky radiance distribution and wavelength. The temperature characterization showed a linear temperature dependence between the instruments' internal temperature and the photon counts per cycle, and a temperature correction was used for correcting the measurements. The long-term spectral responsivity was calculated using the time series of several lamps using two slightly different methods. The long-term spectral responsivity was scaled to the irradiance scale of the Helsinki University of Technology (HUT for the whole of the measurement time-periods 1990–2006 and 1995–2006 for Sodankylä and Jokioinen, respectively. Both Brewers have participated in many international spectroradiometer comparisons, and have shown good stability. The differences between the Brewers and the portable reference spectroradiometer QASUME have been within 5% during 2002–2007.

  10. Measuring Identification and Quantification Errors in Spectral CT Material Decomposition

    Directory of Open Access Journals (Sweden)

    Aamir Younis Raja

    2018-03-01

    Full Text Available Material decomposition methods are used to identify and quantify multiple tissue components in spectral CT but there is no published method to quantify the misidentification of materials. This paper describes a new method for assessing misidentification and mis-quantification in spectral CT. We scanned a phantom containing gadolinium (1, 2, 4, 8 mg/mL, hydroxyapatite (54.3, 211.7, 808.5 mg/mL, water and vegetable oil using a MARS spectral scanner equipped with a poly-energetic X-ray source operated at 118 kVp and a CdTe Medipix3RX camera. Two imaging protocols were used; both with and without 0.375 mm external brass filter. A proprietary material decomposition method identified voxels as gadolinium, hydroxyapatite, lipid or water. Sensitivity and specificity information was used to evaluate material misidentification. Biological samples were also scanned. There were marked differences in identification and quantification between the two protocols even though spectral and linear correlation of gadolinium and hydroxyapatite in the reconstructed images was high and no qualitative segmentation differences in the material decomposed images were observed. At 8 mg/mL, gadolinium was correctly identified for both protocols, but concentration was underestimated by over half for the unfiltered protocol. At 1 mg/mL, gadolinium was misidentified in 38% of voxels for the filtered protocol and 58% of voxels for the unfiltered protocol. Hydroxyapatite was correctly identified at the two higher concentrations for both protocols, but mis-quantified for the unfiltered protocol. Gadolinium concentration as measured in the biological specimen showed a two-fold difference between protocols. In future, this methodology could be used to compare and optimize scanning protocols, image reconstruction methods, and methods for material differentiation in spectral CT.

  11. A scintillation detector for measuring inert gas beta rays

    International Nuclear Information System (INIS)

    Shi Hengchang; Yu Yunchang

    1989-10-01

    The inert gas beta ray scintillation detector, which is made of organic high polymers as the base and coated with compact fluorescence materials, is a lower energy scintillation detector. It can be used in the nuclear power plant and radioactive fields as a lower energy monitor to detect inert gas beta rays. Under the conditions of time constant 10 minutes, confidence level is 99.7% (3σ), the intensity of gamma rays 2.6 x 10 -7 C/kg ( 60 Co), and the minimum detectable concentration (MDC) of this detector for 133 Xe 1.2 Bq/L. The measuring range for 133 Xe is 11.1 ∼ 3.7 x 10 4 Bq/L. After a special measure is taken, the device is able to withstand 3 x 10 5 Pa gauge pressure. In the loss-of-cooolant-accident, it can prevent the radioactive gas of the detector from leaking. This detector is easier to be manufactured and decontaminated

  12. Detection and spectral measurements of coherent synchrotron radiation at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher

    2010-02-15

    The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 {mu}m to 110 {mu}m. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 {mu}m to 160 {mu}m were done. (orig.)

  13. Detection and spectral measurements of coherent synchrotron radiation at FLASH

    International Nuclear Information System (INIS)

    Behrens, Christopher

    2010-02-01

    The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 μm to 110 μm. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 μm to 160 μm were done. (orig.)

  14. Spectral BRDF measurements of metallic samples for laser processing applications

    International Nuclear Information System (INIS)

    Vitali, L; Fustinoni, D; Gramazio, P; Niro, A

    2015-01-01

    The spectral bidirectional reflectance distribution function (BRDF) of metals plays an important role in industrial processing involving laser-surface interaction. In particular, in laser metal machining, absorbance is strongly dependent on the radiation incidence angle as well as on finishing and contamination grade of the surface, and in turn it can considerably affect processing results. Very recently, laser radiation is also used to structure metallic surfaces, in order to produce many particular optical effects, ranging from a high level polishing to angular color shifting. Of course, full knowledge of the spectral BRDF of these structured layers makes it possible to infer reflectance or color for any irradiation and viewing angles. In this paper, we present Vis-NIR spectral BRDF measurements of laser-polished metallic, opaque, flat samples commonly employed in such applications. The resulting optical properties seem to be dependent on the atmospheric composition during the polishing process in addition to the roughness. The measurements are carried out with a Perkin Elmer Lambda 950 double-beam spectrophotometer, equipped with the Absolute Reflectance/Transmittance Analyzer (ARTA) motorized goniometer. (paper)

  15. Cortical Reorganization after Hand Immobilization: The beta qEEG Spectral Coherence Evidences

    Science.gov (United States)

    Fortuna, Marina; Teixeira, Silmar; Machado, Sérgio; Velasques, Bruna; Bittencourt, Juliana; Peressutti, Caroline; Budde, Henning; Cagy, Mauricio; Nardi, Antonio E.; Piedade, Roberto; Ribeiro, Pedro; Arias-Carrión, Oscar

    2013-01-01

    There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes. PMID:24278213

  16. Establishing a method to measure bone structure using spectral CT

    Science.gov (United States)

    Ramyar, M.; Leary, C.; Raja, A.; Butler, A. P. H.; Woodfield, T. B. F.; Anderson, N. G.

    2017-03-01

    Combining bone structure and density measurement in 3D is required to assess site-specific fracture risk. Spectral molecular imaging can measure bone structure in relation to bone density by measuring macro and microstructure of bone in 3D. This study aimed to optimize spectral CT methodology to measure bone structure in excised bone samples. MARS CT with CdTe Medipix3RX detector was used in multiple energy bins to calibrate bone structure measurements. To calibrate thickness measurement, eight different thicknesses of Aluminium (Al) sheets were scanned one in air and the other around a falcon tube and then analysed. To test if trabecular thickness measurements differed depending on scan plane, a bone sample from sheep proximal tibia was scanned in two orthogonal directions. To assess the effect of air on thickness measurement, two parts of the same human femoral head were scanned in two conditions (in the air and in PBS). The results showed that the MARS scanner (with 90μm voxel size) is able to accurately measure the Al (in air) thicknesses over 200μm but it underestimates the thicknesses below 200μm because of partial volume effect in Al-air interface. The Al thickness measured in the highest energy bin is overestimated at Al-falcon tube interface. Bone scanning in two orthogonal directions gives the same trabecular thickness and air in the bone structure reduced measurement accuracy. We have established a bone structure assessment protocol on MARS scanner. The next step is to combine this with bone densitometry to assess bone strength.

  17. Upside and downside beta portfolio construction: A different approach to risk measurement and portfolio construction

    Directory of Open Access Journals (Sweden)

    Austin Guy

    2015-11-01

    Full Text Available Traditional financial measurements of risk are limited to variance-based methodologies. The most common measurement tool is beta. The beta calculation, however, is directionally agnostic and relies on the assumption of a normal distribution. This is a poor metric by which risk is measured, and is incomplete. The ability to break down beta into Upside and Downside beta allows investors the ability to more intelligently build risk into a portfolio. Using three-year trailing betas may also allow investors the ability to benefit from mean reversion and generate excess returns on a risk-adjusted basis.

  18. Measurement of the beta spectrum of the 0/sup -/ (120 keV) state of /sup 16/N

    Energy Technology Data Exchange (ETDEWEB)

    Champagne, A; Beaudoin, G; Hamel, L A; Jeremie, H; Lessard, L

    1988-08-01

    We have measured the beta spectrum of the 0/sup -/ (120 keV, t/sub 1/2/ = 5.25 ..mu..s) state of /sup 16/N. The response function of our detector has been measured, parameterized and then fitted to known spectral shapes taken under conditions close to those in the actual experiment. Using this response function and subtracting a 56 ..mu..s half-life background due to neutron capture in the detector, the measured 0/sup -/ spectrum compares well with the allowed shape for the 0/sup -/ -> 0/sup +/ spectrum plus a small contribution from the allowed 0/sup -/ -> 1/sup -/ transition.

  19. Spectral measurements of muzzle flash with multispectral and hyperspectral sensor

    Science.gov (United States)

    Kastek, M.; Dulski, R.; Trzaskawka, P.; Piątkowski, T.; Polakowski, H.

    2011-08-01

    The paper presents some practical aspects of the measurements of muzzle flash signatures. Selected signatures of sniper shot in typical scenarios has been presented. Signatures registered during all phases of muzzle flash were analyzed. High precision laboratory measurements were made in a special ballistic laboratory and as a result several flash patterns were registered. The field measurements of a muzzle flash were also performed. During the tests several infrared cameras were used, including the measurement class devices with high accuracy and frame rates. The registrations were made in NWIR, SWIR and LWIR spectral bands simultaneously. An ultra fast visual camera was also used for visible spectra registration. Some typical infrared shot signatures were presented. Beside the cameras, the LWIR imaging spectroradiometer HyperCam was also used during the laboratory experiments and the field tests. The signatures collected by the HyperCam device were useful for the determination of spectral characteristics of the muzzle flash, whereas the analysis of thermal images registered during the tests provided the data on temperature distribution in the flash area. As a result of the measurement session the signatures of several types handguns, machine guns and sniper rifles were obtained which will be used in the development of passive infrared systems for sniper detection.

  20. Multi-spectral pyrometer for gas turbine blade temperature measurement

    Science.gov (United States)

    Gao, Shan; Wang, Lixin; Feng, Chi

    2014-09-01

    To achieve the highest possible turbine inlet temperature requires to accurately measuring the turbine blade temperature. If the temperature of blade frequent beyond the design limits, it will seriously reduce the service life. The problem for the accuracy of the temperature measurement includes the value of the target surface emissivity is unknown and the emissivity model is variability and the thermal radiation of the high temperature environment. In this paper, the multi-spectral pyrometer is designed provided mainly for range 500-1000°, and present a model corrected in terms of the error due to the reflected radiation only base on the turbine geometry and the physical properties of the material. Under different working conditions, the method can reduce the measurement error from the reflect radiation of vanes, make measurement closer to the actual temperature of the blade and calculating the corresponding model through genetic algorithm. The experiment shows that this method has higher accuracy measurements.

  1. Cerenkov radiation imaging as a method for quantitative measurements of beta particles in a microfluidic chip

    International Nuclear Information System (INIS)

    Cho, Jennifer S; Taschereau, Richard; Olma, Sebastian; Liu Kan; Chen Yichun; Shen, Clifton K-F; Van Dam, R Michael; Chatziioannou, Arion F

    2009-01-01

    It has been observed that microfluidic chips used for synthesizing 18 F-labeled compounds demonstrate visible light emission without nearby scintillators or fluorescent materials. The origin of the light was investigated and found to be consistent with the emission characteristics from Cerenkov radiation. Since 18 F decays through the emission of high-energy positrons, the energy threshold for beta particles, i.e. electrons or positrons, to generate Cerenkov radiation was calculated for water and polydimethylsiloxane (PDMS), the most commonly used polymer-based material for microfluidic chips. Beta particles emitted from 18 F have a continuous energy spectrum, with a maximum energy that exceeds this energy threshold for both water and PDMS. In addition, the spectral characteristics of the emitted light from 18 F in distilled water were also measured, yielding a broad distribution from 300 nm to 700 nm, with higher intensity at shorter wavelengths. A photograph of the 18 F solution showed a bluish-white light emitted from the solution, further suggesting Cerenkov radiation. In this study, the feasibility of using this Cerenkov light emission as a method for quantitative measurements of the radioactivity within the microfluidic chip in situ was evaluated. A detector previously developed for imaging microfluidic platforms was used. The detector consisted of a charge-coupled device (CCD) optically coupled to a lens. The system spatial resolution, minimum detectable activity and dynamic range were evaluated. In addition, the calibration of a Cerenkov signal versus activity concentration in the microfluidic chip was determined. This novel method of Cerenkov radiation measurements will provide researchers with a simple yet robust quantitative imaging tool for microfluidic applications utilizing beta particles.

  2. Measurement of the Strange Spectral Function in Hadronic $\\tau$ Decays

    CERN Document Server

    Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Ciocca, C.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harel, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kramer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A.J.; Masetti, G.; Mashimo, T.; Mattig, Peter; McKenna, J.; McPherson, R.A.; Meijers, F.; Menges, W.; Menke, S.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schorner-Sadenius, T.; Schroder, Matthias; Schumacher, M.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

    2004-01-01

    Tau Lepton decays with open strangeness in the final state are measured with the OPAL detector at LEP to determine the strange hadronic spectral function of the tau lepton. The decays tau- -> (Kpi)-nu tau, (Kpipi)-nu tau and (Kpipipi)-nu tau with final states consisting of neutral and charged kaons and pions have been studied. The invariant mass distributions of 93.4% of these final states have been experimentally determined. Monte Carlo simulations have been used for the remaining 6.6% and for the strange final states including eta mesons. The reconstructed strange final states, corrected for resolution effects and detection efficiencies, yield the strange spectral function of the tau lepton. The moments of the spectral function and the ratio of strange to non-strange moments, which are important input parameters for theoretical analyses, are determined. Furthermore, the branching fractions B(tau- -> K-pi0nu tau) = (0.471+-0.059stat+-0.023sys)% and B(tau- -> K-pi+pi-nu tau) = (0.415+-0.053stat+-0.040sys)% ha...

  3. Ground-based spectral measurements of solar radiation, (2)

    International Nuclear Information System (INIS)

    Murai, Keizo; Kobayashi, Masaharu; Goto, Ryozo; Yamauchi, Toyotaro

    1979-01-01

    A newly designed spectro-pyranometer was used for the measurement of the global (direct + diffuse) and the diffuse sky radiation reaching the ground. By the subtraction of the diffuse component from the global radiation, we got the direct radiation component which leads to the spectral distribution of the optical thickness (extinction coefficient) of the turbid atmosphere. The measurement of the diffuse sky radiation reveals the scattering effect of aerosols and that of the global radiation allows the estimation of total attenuation caused by scattering and absorption of aerosols. The effects of the aerosols are represented by the deviation of the real atmosphere measured from the Rayleigh atmosphere. By the combination of the measured values with those obtained by theoretical calculation for the model atmosphere, we estimated the amount of absorption by the aerosols. Very strong absorption in the ultraviolet region was recognized. (author)

  4. Measurement of Spectral Functions of Ultracold Atoms in Disordered Potentials

    Science.gov (United States)

    Volchkov, Valentin V.; Pasek, Michael; Denechaud, Vincent; Mukhtar, Musawwadah; Aspect, Alain; Delande, Dominique; Josse, Vincent

    2018-02-01

    We report on the measurement of the spectral functions of noninteracting ultracold atoms in a three-dimensional disordered potential resulting from an optical speckle field. Varying the disorder strength by 2 orders of magnitude, we observe the crossover from the "quantum" perturbative regime of low disorder to the "classical" regime at higher disorder strength, and find an excellent agreement with numerical simulations. The method relies on the use of state-dependent disorder and the controlled transfer of atoms to create well-defined energy states. This opens new avenues for experimental investigations of three-dimensional Anderson localization.

  5. RESEARCH OF BETA AS ADEQUATE RISK MEASURE-IS BETA STILL ALIVE?

    Directory of Open Access Journals (Sweden)

    Ante Perković

    2011-02-01

    Full Text Available The capital asset pricing model (CAPM is one of the most important models in financial economics and it has a long history of theoretical and empirical investigations. The main underlying concept of the CAPM model is that assets with a high risk (high beta should earn a higher return than assets with a low risk (low beta and vice versa. The implication which can be drawn out of this is that all assets with a beta above zero bear some risk and therefore their expected return is above the return of the risk-free rate. In this research observation on monthly stock prices on Croatian stock market from January 1st 2005 until December 31st 2009 is used to form our sample. CROBEX index is used as proxy of the market portfolio. The results demonstrate that beta can not be trusted in making investment decisions and rejects the validity of the whole CAPM model on Croatian stock market.

  6. Scattering and absorption measurements of cervical tissues measures using low cost multi-spectral imaging

    Science.gov (United States)

    Bernat, Amir S.; Bar-Am, Kfir; Cataldo, Leigh; Bolton, Frank J.; Kahn, Bruce S.; Levitz, David

    2018-02-01

    Cervical cancer is a leading cause of death for women in low resource settings. In order to better detect cervical dysplasia, a low cost multi-spectral colposcope was developed utilizing low costs LEDs and an area scan camera. The device is capable of both traditional colposcopic imaging and multi-spectral image capture. Following initial bench testing, the device was deployed to a gynecology clinic where it was used to image patients in a colposcopy setting. Both traditional colposcopic images and spectral data from patients were uploaded to a cloud server for remote analysis. Multi-spectral imaging ( 30 second capture) took place before any clinical procedure; the standard of care was followed thereafter. If acetic acid was used in the standard of care, a post-acetowhitening colposcopic image was also captured. In analyzing the data, normal and abnormal regions were identified in the colposcopic images by an expert clinician. Spectral data were fit to a theoretical model based on diffusion theory, yielding information on scattering and absorption parameters. Data were grouped according to clinician labeling of the tissue, as well as any additional clinical test results available (Pap, HPV, biopsy). Altogether, N=20 patients were imaged in this study, with 9 of them abnormal. In comparing normal and abnormal regions of interest from patients, substantial differences were measured in blood content, while differences in oxygen saturation parameters were more subtle. These results suggest that optical measurements made using low cost spectral imaging systems can distinguish between normal and pathological tissues.

  7. Spectral measurements of gamma radiation streaming through ducts

    International Nuclear Information System (INIS)

    Meenakshisundaram, P.K.; Bhatnagar, V.M.; Raghunath, V.M.; Gopinath, D.V.

    1979-01-01

    The paper presents the spectral measurements of gamma radiation streaming through multi-legged rectangular concrete ducts for cesium-137 and cobald-60 sources. Effect of lead lining the inner surface of the duct on the streaming radiation spectrum and optimization of liner thickness for minimum streaming radiation dose have been studied. For three-legged ducts, a comparative analysis of lead lining the entire duct as against lining any one or both the corners of the duct is reported. It is seen that lead lining any one of the corners would reduce the streaming radiation dose by a factor of 5 to 12. Lining both the corners which is nearly as effective as lining the entire duct reduces the dose by a factor of 16 to 60 depending on the soruce energy and duct dimensions. (orig.)

  8. Pulse shape analyzer/timing-SCA application to beta measurement

    International Nuclear Information System (INIS)

    Selvi, S.; Celiktas, C.

    2001-01-01

    Electrical noise contribution to pulse height distributions from beta sources due to BC-400 plastic scintillator(PS), preamplifier and spectroscopy amplifier was rejected by setting the electronic set-up processing of the modified beta spectrometer consisted of pulse shape analyzer/timing single channel analyzer (PSA/SCA) and related complementary equipments. Improved noise rejection performance was evaluated in terms of elimination practically only all of the noise band of C-14 and Tl-204 spectra obtained using the two alternate beta spectrometer

  9. Innovative Mobile Smart Photonic Dimensional, Color and Spectral Measurement Engineering

    Science.gov (United States)

    Hofmann, Dr Dietrich, Prof; Dittrich (B. Eng. , Paul-Gerald; Höfner (B. Eng. , Dieter; Kraus, Daniel

    2015-02-01

    Aim of the paper is the demonstration of a paradigm shift in dimensional, color and spectral measurements in industry, biology/medicine, farming/environmental protection and security, as well as in education and training: Measurement engineering and quality assurance become mobile, modular and smart. Smartpads, smartphones and smartwatches (smartcomps) in combination with innovative hardware apps (hwapps) and conventional software apps (swapps) are fundamental enablers for the transformation from conventional stationary working places towards innovative mobile working places with in-field measurements and point-of-care (POC) diagnostics. Furthermore mobile open online courses (MOOCs) are transforming the study habits. Practical examples for the application of innovative photonic micro dimensiometers, colorimeters and spectrometers will be given. The innovative approach opens so far untapped enormous markets for measurement science, engineering, applications, education and training. These innovative working conditions will be fast accepted due to their convenience, reliability and affordability. A highly visible advantage of smartcomps is the huge number of their real distribution, their worldwide connectivity via Internet and cloud services, the standardized interfaces like USB and HDMI and the experienced capabilities of their users for practical operations, obtained with their private smartcomps.

  10. Innovative Mobile Smart Photonic Dimensional, Color and Spectral Measurement Engineering

    International Nuclear Information System (INIS)

    Hofmann, Dietrich; Dittrich, Paul-Gerald; Höfner, Dieter; Kraus, Daniel

    2015-01-01

    Aim of the paper is the demonstration of a paradigm shift in dimensional, color and spectral measurements in industry, biology/medicine, farming/environmental protection and security, as well as in education and training: Measurement engineering and quality assurance become mobile, modular and smart. Smartpads, smartphones and smartwatches (smartcomps) in combination with innovative hardware apps (hwapps) and conventional software apps (swapps) are fundamental enablers for the transformation from conventional stationary working places towards innovative mobile working places with in-field measurements and point-of-care (POC) diagnostics. Furthermore mobile open online courses (MOOCs) are transforming the study habits. Practical examples for the application of innovative photonic micro dimensiometers, colorimeters and spectrometers will be given. The innovative approach opens so far untapped enormous markets for measurement science, engineering, applications, education and training. These innovative working conditions will be fast accepted due to their convenience, reliability and affordability. A highly visible advantage of smartcomps is the huge number of their real distribution, their worldwide connectivity via Internet and cloud services, the standardized interfaces like USB and HDMI and the experienced capabilities of their users for practical operations, obtained with their private smartcomps

  11. Design study for a two-color beta measurement system

    Science.gov (United States)

    1982-01-01

    Design analysis of the beam splitter combined two color beta system is presented. Conventional and dichroic beam splitters are discussed. Design analysis of the beta system employing two beams with focusing at separate points is presented. Alterations and basic parameters of the two beam system are discussed. Alterations in the focus of the initial laser and the returning beams are also discussed. Heterodyne efficiencies for the on axis and off axis reflected radiation are included.

  12. LDA measurements and turbulence spectral analysis in an agitated vessel

    Directory of Open Access Journals (Sweden)

    Chára Zdeněk

    2013-04-01

    Full Text Available During the last years considerable improvement of the derivation of turbulence power spectrum from Laser Doppler Anemometry (LDA has been achieved. The irregularly sampled LDA data is proposed to approximate by several methods e.g. Lomb-Scargle method, which estimates amplitude and phase of spectral lines from missing data, methods based on the reconstruction of the auto-correlation function (referred to as correlation slotting technique, methods based on the reconstruction of the time series using interpolation between the uneven sampling and subsequent resampling etc. These different methods were used on the LDA data measured in an agitated vessel and the results of the power spectrum calculations were compared. The measurements were performed in the mixing vessel with flat bottom. The vessel was equipped with four baffles and agitated with a six-blade pitched blade impeller. Three values of the impeller speed (Reynolds number were tested. Long time series of the axial velocity component were measured in selected points. In each point the time series were analyzed and evaluated in a form of power spectrum.

  13. LDA measurements and turbulence spectral analysis in an agitated vessel

    Science.gov (United States)

    Kysela, Bohuš; Konfršt, Jiří; Chára, Zdeněk

    2013-04-01

    During the last years considerable improvement of the derivation of turbulence power spectrum from Laser Doppler Anemometry (LDA) has been achieved. The irregularly sampled LDA data is proposed to approximate by several methods e.g. Lomb-Scargle method, which estimates amplitude and phase of spectral lines from missing data, methods based on the reconstruction of the auto-correlation function (referred to as correlation slotting technique), methods based on the reconstruction of the time series using interpolation between the uneven sampling and subsequent resampling etc. These different methods were used on the LDA data measured in an agitated vessel and the results of the power spectrum calculations were compared. The measurements were performed in the mixing vessel with flat bottom. The vessel was equipped with four baffles and agitated with a six-blade pitched blade impeller. Three values of the impeller speed (Reynolds number) were tested. Long time series of the axial velocity component were measured in selected points. In each point the time series were analyzed and evaluated in a form of power spectrum.

  14. Investigations on critical parameters, growth, structural and spectral studies of beta-alaninium picrate (BAP) single crystals

    International Nuclear Information System (INIS)

    Shanthi, D; Selvarajan, P; Perumal, S

    2014-01-01

    Beta-alaninium picrate (BAP) salt has been synthesized and the solubility of the synthesized sample in double distilled water was determined at different temperatures. Solution stability was studied by observing the metastable zone width by employing the polythermal method. Induction period values for different supersaturation ratios at room temperature were determined based on the isothermal method. The nucleation parameters such as critical radius, critical free energy change, interfacial tension, and nucleation rate have been estimated for BAP salt on the basis of the classical nucleation theory. The lattice parameters of the grown BAP crystal were determined using the x-ray diffraction (XRD) technique. The reflection planes of the sample were confirmed by the powder XRD study and diffraction peaks were indexed. Fourier transform infrared spectroscopy and Fourier transform–Raman studies were used to confirm the presence of various functional groups in the BAP crystal. The nonlinear optical property of the grown crystal was studied using the Kurtz–Perry powder technique. UV–visible spectral studies were carried out to understand optical transparency and the type of band gap of the grown BAP crystal. (paper)

  15. A New Measurement of the Spectral Lag of Gamma-Ray Bursts and its Implications for Spectral Evolution Behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Lang; Wang, Fu-Ri; Cheng, Ye-Hao; Zhang, Xi; Yu, Bang-Yao; Xi, Bao-Jia; Wang, Xue; Feng, Huan-Xue; Zhang, Meng, E-mail: lshao@hebtu.edu.cn [Department of Space Sciences and Astronomy, Hebei Normal University, Shijiazhuang 050024 (China); Zhang, Bin-Bin [Instituto de Astrofísica de Andalucá (IAA-CSIC), P.O. Box 03004, E-18080 Granada (Spain); Wu, Xue-Feng [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Xu, Dong [Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2017-08-01

    We carry out a systematical study of the spectral lag properties of 50 single-pulsed gamma-ray bursts (GRBs) detected by the Fermi Gamma-Ray Burst Monitor. By dividing the light curves into multiple consecutive energy channels, we provide a new measurement of the spectral lag that is independent of energy channel selections. We perform a detailed statistical study of our new measurements. We find two similar power-law energy dependencies of both the pulse arrival time and pulse width. Our new results on the power-law indices would favor the relativistic geometric effects for the origin of spectral lag. However, a complete theoretical framework that can fully account for the diverse energy dependencies of both arrival time and pulse width revealed in this work is still lacking. We also study the spectral evolution behaviors of the GRB pulses. We find that a GRB pulse with negligible spectral lag would usually have a shorter pulse duration and would appear to have a “hardness-intensity tracking” behavior, and a GRB pulse with a significant spectral lag would usually have a longer pulse duration and would appear to have a “hard-to-soft” behavior.

  16. Spectral induced polarization (SIP) measurement of NAPL contaminated soils

    Science.gov (United States)

    Schwartz, N.; Huisman, J. A.; Furman, A.

    2010-12-01

    The potential applicability of spectral induce polarization (SIP) as a tool to map NAPLs (non aqueous phase liquids) contaminants at the subsurface lead researchers to investigate the electric signature of those contaminant on the spectral response. However, and despite the cumulative efforts, the effect of NAPL on the electrical properties of soil, and the mechanisms that control this effect are largely unknown. In this work a novel experiment is designed to further examine the effect of NAPL on the electrical properties of partially saturated soil. The measurement system that used is the ZEL-SIP04 impedance meter developed at the Forschungszentrum Julich, Germany. The system accurately (nominal phase precision of 0.1 mrad below 1 kHz) measures the phase and the amplitude of a material possessing a very low polarization (such as soil). The sample holder has a dimension of 60 cm long and 4.6 cm in diameter. Current and potential electrodes were made of brass, and while the current electrodes were inserted in full into the soil, the contact between the potential electrode and the soil was made through an Agarose bridge. Two types of soils were used: clean quartz sand, and a mixture of sand with clean Bentonite. Each soil (sandy or clayey) was mixed with water to get saturation degree of 30%. Following the mixture with water, NAPL was added and the composite were mixed again. Packing was done by adding and compressing small portions of the soil to the column. A triplicate of each mixture was made with a good reproducible bulk density. Both for the sandy and clayey soils, the results indicate that additions of NAPL decrease the real part of the complex resistivity. Additionally, for the sandy soil this process is time depended, and that a further decrease in resistivity develops over time. The results are analyzed considering geometrical factors: while the NAPL is electrically insulator, addition of NAPL to the soil is expected to increase the connectivity of the

  17. Measurement of gross beta radioactivity in high-level liquid waste

    International Nuclear Information System (INIS)

    Lu Feng; Lin Cansheng; Zhang Xianzi; Chen Guoan; Zhang Chonghai

    1992-01-01

    Using beta plastic scintillation counter of low level background, gross beta radioactivity of twelve samples for high-level liquid waste is determined directly. Beta efficiency curves of plastic scintillation counter for four mass thickness are calibrated in advance. Determining gross beta radioactivity, gross efficiency of the scintillation counter for various energy beta ray is calculated via weighted mean method with the ratio of radioactivity for each nuclide. The ratio of radioactivity for nuclides which have gamma disintegration is determined in terms of the radioactivity measured by gamma spectrometer. The ratio of the radioactivity for 90 Sr which has purity beta disintegration is calculated in terms of half life time approximation. The ratio of the radioactivity for 147 Pm which also has purity disintegration is calculated by means of apparent cooling-time approximation. The uncertainty of results for the present work is about +-15%

  18. The Majorana project: sup 7 sup 6 Ge 0 nu beta beta-decay neutrino mass measurement

    CERN Document Server

    Aalseth, C E

    2002-01-01

    Interest in, and the relevance of, next-generation 0 nu beta beta-decay experiments is increasing. Even with nonzero neutrino mass strongly suggested by SNO, Super Kamiokande, and similar experiments sensitive to delta m sup 2 , 0 nu beta beta-decay experiments are still the only way to establish the Dirac or Majorana nature of neutrinos by measuring effective electron neutrino mass, . Various theorists have recently argued in favor of a neutrino mass between 0.01 and 1 eV. The Majorana Project aims to probe this effective neutrino mass range, reaching a sensitivity of 0.02-0.07 eV. The experiment relies entirely on proven technology and has been devised based upon the materials, technology, and data analysis demonstrated to produce the lowest background per kilogram of fiducial germanium. The project plan includes 500 kg of germanium detector material enriched to 85% in sup 7 sup 6 Ge, specialized pulse-acquisition electronics and detector segmentation for background rejection, and underground electroformed ...

  19. Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

    Energy Technology Data Exchange (ETDEWEB)

    Asner, D.M.; Burns, K.; Campbell, L.W.; Greenfield, B.; Kos, M.S., E-mail: markskos@gmail.com; Orrell, J.L.; Schram, M.; VanDevender, B.; Wood, L.S.; Wootan, D.W.

    2015-03-11

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

  20. Testing the performance of beta diversity measures based on incidence data: the robustness to undersampling

    DEFF Research Database (Denmark)

    Bondoso Cardoso, Pedro Miguel; Borges, Paulo A. V.; Veech, Joseph A.

    2009-01-01

    computing beta diversity for selected pairs of samples. The robustness of these beta diversity accumulation curves was assessed for the purpose of finding the best measures for undersampled communities. Results The Harrison et al.ß-2 and the Williams ß-3 are particularly robust to undersampling...

  1. Production and Separation of T = 1/2 Nuclides for {beta}--{nu} angular correlation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, P.; Bajeat, O.; Saint Laurent, M. G.; Thomas, J. C.; Traykov, E. [GANIL, CEA/DSM-CNRS/IN2P3, Bd. Becquerel, BP 55027, 14076 CAEN Cedex 05 (France); Couratin, C. [GANIL, CEA/DSM-CNRS/IN2P3, Bd. Becquerel, BP 55027, 14076 CAEN Cedex 05 (France); LPC Caen, 6 bd Marechal Juin, 14050 CAEN Cedex (France); Lienard, E.; Ban, G.; Durand, D.; Flechard, X. [LPC Caen, 6 bd Marechal Juin, 14050 CAEN Cedex (France); Naviliat-Cuncic, O. [NSCL, Michigan State University, 1 Cyclotron, East Lansing, Michigan 48824-1321 (United States); Stora, T. [ISOLDE, CERN, 1211 Geneva 23 (Switzerland); Collaboration: GANISOL Group

    2011-11-30

    The SPIRAL facility at GANIL, which uses the so-called ISOL method to produce radioactive ion beams, is being upgraded to extend its production capabilities to the metallic beams of neutron deficient isotopes. We discuss here the potentialities offered by this upgrade for the measurement of the {beta}--{nu} angular correlation in the {beta}--decay of mirror nuclides.

  2. An experimental method for making spectral emittance and surface temperature measurements of opaque surfaces

    International Nuclear Information System (INIS)

    Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Daniel Maynes, R.; Baxter, Larry L.

    2011-01-01

    An experimental procedure has been developed to make spectral emittance and temperature measurements. The spectral emittance of an object is calculated using measurements of the spectral emissive power and of the surface temperature of the object obtained using a Fourier transform infrared (FTIR) spectrometer. A calibration procedure is described in detail which accounts for the temperature dependence of the detector. The methods used to extract the spectral emissive power and surface temperature from measured infrared spectra were validated using a blackbody radiator at known temperatures. The average error in the measured spectral emittance was 2.1% and the average difference between the temperature inferred from the recorded spectra and the temperature indicated on the blackbody radiator was 1.2%. The method was used to measure the spectral emittance of oxidized copper at various temperatures.

  3. DB-1900 low-background measuring device of alpha and beta

    International Nuclear Information System (INIS)

    Liu Hongquan; Gan Jinbang; Chen Qi; Zhao Yunqing

    1997-08-01

    The device is a box-type detector used to measure the emissivity of Alpha and Beta from dry samples under 2π geometry in radionuclide metrology. It is composed of a high efficiency αβ detector with electrostatic screen of zero potential [patent ZL92111938.0 (in China)] and anticoincidence detector in lead chamber, and has been reasonably combined with double anticoincidence technique to form integral equipment. The characteristics of the device are as follows: It can stably measure the emissivity of Alpha and Beta from dry samples with less surface conductivity (the surface resistance of the samples: 13 Ω) in detector. It can measure Beta emissivity from samples in which Alpha coexist with Beta, and discrimination between Alpha and Beta emissivities can be made simultaneously by two paths. It is a good quantitative means for measuring Alpha and Beta radiation in radiometry, radiation protection and environmental protection. It could be used to measure weak radiativity of Alpha and Beta samples from scientific research, minerals, building materials, plastics, medicinal materials, seas and oceans biology, et al. (7 refs., 8 tabs., 17 figs.)

  4. Spectral measurements of runway electrons in the TEXTOR tokamak

    International Nuclear Information System (INIS)

    Kudyakov, Timur

    2009-01-01

    The generation of multi-MeV runaway electrons is a well known effect related to the plasma disruptions in tokamaks. The runaway electrons can substantially reduce the lifetime of the future tokamak ITER. In this thesis physical properties of runaway electrons and their possible negative effects on ITER have been studied in the TEXTOR tokamak. A new diagnostic, a scanning probe, has been developed to provide direct measurements of the absolute number of runaway electrons coming from the plasma, its energy distribution and the related energy load in the material during low density (runaway) discharges and during disruptions. The basic elements of the probe are YSO crystals which transform the energy of runaway electrons into visible light which is guided via optical fibres to photomultipliers. In order to obtain the energy distribution of runaways, the crystals are covered with layers of stainless steel (or tungsten in two earlier test versions) of different thicknesses. The final probe design has 9 crystals and can temporally and spectrally resolve electrons with energies between 4 MeV and 30 MeV. The probe is tested and absolutely calibrated at the linear electron accelerator ELBE in Rossendorf. The measurements are in good agreement with Monte Carlo simulations using the Geant4 code. The runaway transport in the presence of the internal and externally applied magnetic perturbations has been studied. The diffusion coefficient and the value of the magnetic fluctuation for runaways were derived as a function of B t . It was found that an increase of runaway losses from the plasma with the decreasing toroidal magnetic field is accompanied with a growth of the magnetic fluctuation in the plasma. The magnetic shielding picture could be confirmed which predicts that the runaway loss occurs predominantly for low energy runaways (few MeV) and considerably less for the high energy ones. In the case of the externally applied magnetic perturbations by means of the dynamic

  5. Spectral measurements of runway electrons in the TEXTOR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Kudyakov, Timur

    2009-07-22

    The generation of multi-MeV runaway electrons is a well known effect related to the plasma disruptions in tokamaks. The runaway electrons can substantially reduce the lifetime of the future tokamak ITER. In this thesis physical properties of runaway electrons and their possible negative effects on ITER have been studied in the TEXTOR tokamak. A new diagnostic, a scanning probe, has been developed to provide direct measurements of the absolute number of runaway electrons coming from the plasma, its energy distribution and the related energy load in the material during low density (runaway) discharges and during disruptions. The basic elements of the probe are YSO crystals which transform the energy of runaway electrons into visible light which is guided via optical fibres to photomultipliers. In order to obtain the energy distribution of runaways, the crystals are covered with layers of stainless steel (or tungsten in two earlier test versions) of different thicknesses. The final probe design has 9 crystals and can temporally and spectrally resolve electrons with energies between 4 MeV and 30 MeV. The probe is tested and absolutely calibrated at the linear electron accelerator ELBE in Rossendorf. The measurements are in good agreement with Monte Carlo simulations using the Geant4 code. The runaway transport in the presence of the internal and externally applied magnetic perturbations has been studied. The diffusion coefficient and the value of the magnetic fluctuation for runaways were derived as a function of B{sub t}. It was found that an increase of runaway losses from the plasma with the decreasing toroidal magnetic field is accompanied with a growth of the magnetic fluctuation in the plasma. The magnetic shielding picture could be confirmed which predicts that the runaway loss occurs predominantly for low energy runaways (few MeV) and considerably less for the high energy ones. In the case of the externally applied magnetic perturbations by means of the dynamic

  6. First measurement of several $\\beta$-delayed neutron emitting isotopes beyond N=126

    CERN Document Server

    Caballero-Folch, R.; Agramunt, J.; Algora, A.; Ameil, F.; Arcones, A.; Ayyad, Y.; Benlliure, J.; Borzov, I.N.; Bowry, M.; Calvino, F.; Cano-Ott, D.; Cortés, G.; Davinson, T.; Dillmann, I.; Estrade, A.; Evdokimov, A.; Faestermann, T.; Farinon, F.; Galaviz, D.; García, A.R.; Geissel, H.; Gelletly, W.; Gernhäuser, R.; Gómez-Hornillos, M.B.; Guerrero, C.; Heil, M.; Hinke, C.; Knöbel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Y.; Maier, L.; Marganiec, J.; Marketin, T.; Marta, M.; Martínez, T.; Martínez-Pinedo, G.; Montes, F.; Mukha, I.; Napoli, D.R.; Nociforo, C.; Paradela, C.; Pietri, S.; Podolyák, Zs.; Prochazka, A.; Rice, S.; Riego, A.; Rubio, B.; Schaffner, H.; Scheidenberger, Ch.; Smith, K.; Sokol, E.; Steiger, K.; Sun, B.; Taín, J.L.; Takechi, M.; Testov, D.; Weick, H.; Wilson, E.; Winfield, J.S.; Wood, R.; Woods, P.; Yeremin, A.

    2016-01-01

    The $\\beta$-delayed neutron emission probabilities of neutron rich Hg and Tl nuclei have been measured together with $\\beta$-decay half-lives for 20 isotopes of Au, Hg, Tl, Pb and Bi in the mass region N$\\gtrsim$126. These are the heaviest species where neutron emission has been observed so far. These measurements provide key information to evaluate the performance of nuclear microscopic and phenomenological models in reproducing the high-energy part of the $\\beta$-decay strength distribution. In doing so, it provides important constraints to global theoretical models currently used in $r$-process nucleosynthesis.

  7. Method of measuring the disintegration rate of a beta-emitting radionuclide in a liquid sample

    International Nuclear Information System (INIS)

    Horrocks, D.L.

    1980-01-01

    A novel liquid scintillation counting method of measuring the disintegration rate of a beta-emitting radionuclide is described which involves counting the sample at at least two different quench levels. (UK)

  8. Activity measurement of phosphorus-32 in the presence of pure beta-emitting impurities

    CSIR Research Space (South Africa)

    Simpson, B

    2006-02-27

    Full Text Available Activity measurements undertaken at the CSIR's National Metrology Laboratory (NML) on a solution of the pure beta-emitting radionuclide phosphorus-32, which formed part of an international key comparison, are described. Since exploratory source...

  9. Characteristics of beta detection and dose measurement at Department of Energy facilities

    International Nuclear Information System (INIS)

    Mulvehill, J.M.; Brackenbush, L.W.

    1987-02-01

    This report considers the current state of the art of beta dosimetry practices and beta detection methods used by health physicists at US Department of Energy facilities. This information is based on a survey of DOE facilities. Beta measurements are technically difficult and innovative efforts must be expended to improve their accuracy. Perhaps the most pronounced problem is that beta dosimetry and instrumentation in use are highly energy and angular dependent. Many believe that beta exposures are adequately controlled because beta to photon ratios are assumed to be low. This assumption is not always valid as demonstrated by the accident at Three Mile Island (TMI). Significant beta doses exist where personnel are exposed to mixed fission products; for example, chemical reprocessing plants, reactor accidents, or where uranium metals are processed. This report is part of an effort to increase the DOE response to this technically difficult area of health protection. Problem areas are addressed and methods recommended to improve beta dosimetry through a cooperative effort among the various DOE contractors. 34 refs., 2 figs., 16 tabs

  10. Measurement of aerosol concentration with a beta-ray gage

    International Nuclear Information System (INIS)

    Auzac, G. d'; Dubillot, J.

    1978-01-01

    Because dusts in suspension are a dangerous polluting agent, several methods have been used to monitor their concentration. Among these, the beta-ray gage enjoys a privileged position. The authors describe such a gage and discuss the conditions to be observed for it to be capable of giving results comparable to those obtained with manual gravimetric methods. The satisfactory results obtained led to standardization of the method and a whole range of instruments based on this principle are employed in pollution supervising networks and for continuously monitoring industrial emissions [fr

  11. Factors affecting quality for beta dose rate measurements using ISO 6980 series I reference sources

    Energy Technology Data Exchange (ETDEWEB)

    Burns, R.E. Jr.; O`Brien, J.M. Jr. [Atlan-Tech, Rosewll, GA (United States)

    1993-12-31

    Atlan-Tech, Inc. has performed several calibrations of ISO 6980 Series 1 reference beta sources over the past two to three years. There were many problems encountered in attempting to compare the results of these calibrations with those from other laboratories, indicating the need for more standardization in the methodology employed for the measurement of the absorbed dose rate from ISO 6980 Series 1 reference beta sources. This document describes some of the problems encountered in attempting to intercompare results of beta dose-rate measurements. It proposes some solutions in an attempt to open a dialogue among facilities using reference beta standards for the purpose of promoting better measurement quality assurance through data intercomparison.

  12. Factors affecting quality for beta dose rate measurements using ISO 6980 series I reference sources

    International Nuclear Information System (INIS)

    Burns, R.E. Jr.; O'Brien, J.M. Jr.

    1993-01-01

    Atlan-Tech, Inc. has performed several calibrations of ISO 6980 Series 1 reference beta sources over the past two to three years. There were many problems encountered in attempting to compare the results of these calibrations with those from other laboratories, indicating the need for more standardization in the methodology employed for the measurement of the absorbed dose rate from ISO 6980 Series 1 reference beta sources. This document describes some of the problems encountered in attempting to intercompare results of beta dose-rate measurements. It proposes some solutions in an attempt to open a dialogue among facilities using reference beta standards for the purpose of promoting better measurement quality assurance through data intercomparison

  13. Technical progress report: Completion of spectral rotating shadowband radiometers and analysis of atmospheric radiation measurement spectral shortwave data

    Energy Technology Data Exchange (ETDEWEB)

    Michalsky, J.; Harrison, L. [State Univ. of New York, Albany, NY (United States)

    1996-04-01

    Our goal in the Atmospheric Radiation Measurement (ARM) Program is the improvement of radiation models used in general circulation models (GCMs), especially in the shortwave, (1) by providing improved shortwave radiometric measurements for the testing of models and (2) by developing methods for retrieving climatologically sensitive parameters that serve as input to shortwave and longwave models. At the Atmospheric Sciences Research Center (ASRC) in Albany, New York, we are acquiring downwelling direct and diffuse spectral irradiance, at six wavelengths, plus downwelling broadband longwave, and upwelling and downwelling broadband shortwave irradiances that we combine with National Weather Service surface and upper air data from the Albany airport as a test data set for ARM modelers. We have also developed algorithms to improve shortwave measurements made at the Southern Great Plains (SGP) ARM site by standard thermopile instruments and by the multifilter rotating shadowband radiometer (MFRSR) based on these Albany data sets. Much time has been spent developing techniques to retrieve column aerosol, water vapor, and ozone from the direct beam spectral measurements of the MFRSR. Additionally, we have had success in calculating shortwave surface albedo and aerosol optical depth from the ratio of direct to diffuse spectral reflectance.

  14. Production measurements on the quadrupole correctors for the new Low- Beta System for the Tevatron Collider

    International Nuclear Information System (INIS)

    Mokhtarani, A.; Brown, B.C.; Hanft, R.; Oleck, A.R.; Peterson, T.; Turkot, F.

    1991-05-01

    Each of the Low Beta Systems for the Tevatron Collider requires 12 spool pieces; eight of the spool pieces contain superconducting quadrupoles as part of the low beta insertion as well as standard correction magnets. The remaining four provide correction magnets, beam position monitors, and current feeds for the neighboring low beta main quadrupoles. Thirty-two of these new spools have been fabricated. We describe here the mechanical, cryogenic and magnetic properties of these new spools as determined in the production test and measurement activities. 8 refs., 7 figs., 1 tab

  15. An assessment of anti-neutrino mass determination via electrostatic measurements of tritium beta-decay

    International Nuclear Information System (INIS)

    Le Bas, P.A.

    1984-01-01

    Data on the mass of the anti-neutrino determined via electrostatic measurements of tritium beta-decay are assessed. Relativistic calculations concerning the finite mass of the electron anti-neutrino and the recoil of the nucleus, are given for the theoretical end-point spectrum of tritium beta-decay. The specifications are given for an electrostatic Spherical Retarding Beta-Spectrometer, and an electrostatic Cylindrical Mirror Analyser, both used in the tritium beta-decay experiment. The electrostatic measurements lead to a value of less than 50 ev (90% C.L.) for the electron anti-neutrino mass. These results are discussed in terms of the resolution of the electrostatic equipment and the Monte Carlo simulations of the data collection. (UK)

  16. Magnetic measurements on human erythrocytes: Normal, beta thalassemia major, and sickle

    Science.gov (United States)

    Sakhnini, Lama

    2003-05-01

    In this article magnetic measurements were made on human erythrocytes at different hemoglobin states (normal and reduced hemoglobin). Different blood samples: normal, beta thalassemia major, and sickle were studied. Beta thalassemia major and sickle samples were taken from patients receiving lifelong blood transfusion treatment. All samples examined exhibited diamagnetic behavior. Beta thalassemia major and sickle samples showed higher diamagnetic susceptibilities than that for the normal, which was attributed to the increase of membrane to hemoglobin volume ratio of the abnormal cells. Magnetic measurements showed that the erythrocytes in the reduced state showed less diamagnetic response in comparison with erythrocytes in the normal state. Analysis of the paramagnetic component of magnetization curves gave an effective magnetic moment of μeff=7.6 μB per reduced hemoglobin molecule. The same procedure was applied to sickle and beta thalassemia major samples and values for μeff were found to be comparable to that of the normal erythrocytes.

  17. Spectrally adjustable quasi-monochromatic radiance source based on LEDs and its application for measuring spectral responsivity of a luminance meter

    International Nuclear Information System (INIS)

    Hirvonen, Juha-Matti; Poikonen, Tuomas; Vaskuri, Anna; Kärhä, Petri; Ikonen, Erkki

    2013-01-01

    A spectrally adjustable radiance source based on light-emitting diodes (LEDs) has been constructed for spectral responsivity measurements of radiance and luminance meters. A 300 mm integrating sphere source with adjustable output port is illuminated using 30 thermally stabilized narrow-band LEDs covering the visible wavelength range of 380–780 nm. The functionality of the measurement setup is demonstrated by measuring the relative spectral responsivities of a luminance meter and a photometer head with cosine-corrected input optics. (paper)

  18. Pulse shape analyzer/timing-SCA application to beta measurement by plastic scintillator

    International Nuclear Information System (INIS)

    Celiktas, C.; Selvi, S.

    2000-01-01

    Noise contribution to pulses from BC-400 plastic scintillators, preamplifier and spectroscopy amplifier is rejected by using electronics processing of the modified beta spectrometer containing pulse shape analyzer/timing SCA and related complementary equipment. The noise rejection capability of the spectrometer which have been developed to measure pure and scattered beta spectra, which are reliable in view of evaluations of the detector and target electron scattering characteristics correctly. (author)

  19. Absolute measurement of the $\\beta\\alpha$ decay of $^{16}$N

    CERN Multimedia

    We propose to study the $\\beta$-decay of $^{16}$N at ISOLDE with the aim of determining the branching ratio for $\\beta\\alpha$ decay on an absolute scale. There are indications that the previously measured branching ratio is in error by an amount significantly larger than the quoted uncertainty. This limits the precision with which the S-factor of the astrophysically important $^{12}$C($\\alpha, \\gamma)^{16}$O reaction can be determined.

  20. Simultaneous measurement of spectral sky radiance by a non-scanning multidirectional spectroradiometer (MUDIS)

    International Nuclear Information System (INIS)

    Riechelmann, Stefan; Schrempf, Michael; Seckmeyer, Gunther

    2013-01-01

    We present a novel non-scanning multidirectional spectroradiometer (MUDIS) measuring the spectral sky radiance as a function of zenith and azimuth angle with a high spectral and temporal resolution. The instrument is based on a hyperspectral imager and measures spectral sky radiance in the wavelength range of 250–600 nm at 113 different directions simultaneously. MUDIS has been intercalibrated with a sky scanning CCD spectroradiometer (SCCD). Sky radiance measurements have been performed with both instruments under cloudless and overcast sky. The spectral actinic irradiance derived from those measurements agrees within 8% for wavelengths higher than 320 nm. The bias between synchronous MUDIS and SCCD sky radiance measurements during cloudless and overcast sky is below 5% for 320 and 500 nm with a 1σ standard deviation of less than 10%. MUDIS enables us to perform more than 220 000 spectral sky radiance measurements instead of approximately 6000 SCCD spectral sky radiance measurements per day and to measure spatial variations of spectral sky radiance simultaneously. (paper)

  1. Selection/extraction of spectral regions for autofluorescence spectra measured in the oral cavity

    NARCIS (Netherlands)

    Skurichina, M; Paclik, P; Duin, RPW; de Veld, D; Sterenborg, HJCM; Witjes, MJH; Roodenburg, JLN; Fred, A; Caelli, T; Duin, RPW; Campilho, A; DeRidder, D

    2004-01-01

    Recently a number of successful algorithms to select/extract discriminative spectral regions was introduced. These methods may be more beneficial than the standard feature selection/extraction methods for spectral classification. In this paper, on the example of autofluorescence spectra measured in

  2. Potential of optical spectral transmission measurements for joint inflammation measurements in rheumatoid arthritis patients

    Science.gov (United States)

    Meier, A. J. Louise; Rensen, Wouter H. J.; de Bokx, Pieter K.; de Nijs, Ron N. J.

    2012-08-01

    Frequent monitoring of rheumatoid arthritis (RA) patients enables timely treatment adjustments and improved outcomes. Currently this is not feasible due to a shortage of rheumatologists. An optical spectral transmission device is presented for objective assessment of joint inflammation in RA patients, while improving diagnostic accuracy and clinical workflow. A cross-sectional, nonrandomized observational study was performed with this device. In the study, 77 proximal interphalangeal (PIP) joints in 67 patients have been analyzed. Inflammation of these PIP joints was also assessed by a rheumatologist with a score varying from 1 (not inflamed) to 5 (severely inflamed). Out of 77 measurements, 27 were performed in moderate to strongly inflamed PIP joints. Comparison between the clinical assessment and an optical measurement showed a correlation coefficient r=0.63, p<0.001, 95% CI [0.47, 0.75], and a ROC curve (AUC=0.88) that shows a relative good specificity and sensitivity. Optical spectral transmission measurements in a single joint correlate with clinical assessment of joint inflammation, and therefore might be useful in monitoring joint inflammation in RA patients.

  3. Remote spectral measurements of the blood volume pulse with applications for imaging photoplethysmography

    Science.gov (United States)

    Blackford, Ethan B.; Estepp, Justin R.; McDuff, Daniel J.

    2018-02-01

    Imaging photoplethysmography uses camera image sensors to measure variations in light absorption related to the delivery of the blood volume pulse to peripheral tissues. The characteristics of the measured BVP waveform depends on the spectral absorption of various tissue components including melanin, hemoglobin, water, and yellow pigments. Signal quality and artifact rejection can be enhanced by taking into account the spectral properties of the BVP waveform and surrounding tissue. The current literature regarding the spectral relationships of remote PPG is limited. To supplement this fundamental data, we present an analysis of remotely-measured, visible and near-infrared spectroscopy to better understand the spectral signature of remotely measured BVP signals. To do so, spectra were measured from the right cheek of 25, stationary participants whose heads were stabilized by a chinrest. A collimating lens was used to collect reflected light from a region of 3 cm in diameter. The spectrometer provided 3 nm resolution measurements from 500-1000 nm. Measurements were acquired at a rate of 50 complete spectra per second for a period of five minutes. Reference physiology, including electrocardiography was simultaneously and synchronously acquired. The spectral data were analyzed to determine the relationship between light wavelength and the resulting remote-BVP signal-to-noise ratio and to identify those bands best suited for pulse rate measurement. To our knowledge this is the most comprehensive dataset of remotely-measured spectral iPPG data. In due course, we plan to release this dataset for research purposes.

  4. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  5. Improved hadronic measurements and spectral sums on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, Christian

    2008-05-15

    the order parameter for the confinement-deconfinement transition is the Polyakov loop. The order parameter for the spontaneous breaking of chiral symmetry is given by the chiral condensate, which is related to the eigenvalues of the Dirac operator. It has been shown that also the Polyakov loop can be expressed in terms of these eigenvalues, as a spectral sum. In a first step we perform a numerical study of these sums. We find that the ordinary Polyakov loop is governed by the ultraviolet modes of the Dirac operator. Therefore, in a second step we define a new order parameter for confinement, the ''dressed Polyakov loop''. This quantity has two advantages: It can be expressed as a spectral sum which has a better convergence behavior (infrared dominated) and it is closely related to the quark condensate via a Fourier transformation. Also the spectral sums for the dressed Polyakov loop are investigated numerically. (orig.)

  6. Improved hadronic measurements and spectral sums on the lattice

    International Nuclear Information System (INIS)

    Hagen, Christian

    2008-05-01

    the order parameter for the confinement-deconfinement transition is the Polyakov loop. The order parameter for the spontaneous breaking of chiral symmetry is given by the chiral condensate, which is related to the eigenvalues of the Dirac operator. It has been shown that also the Polyakov loop can be expressed in terms of these eigenvalues, as a spectral sum. In a first step we perform a numerical study of these sums. We find that the ordinary Polyakov loop is governed by the ultraviolet modes of the Dirac operator. Therefore, in a second step we define a new order parameter for confinement, the ''dressed Polyakov loop''. This quantity has two advantages: It can be expressed as a spectral sum which has a better convergence behavior (infrared dominated) and it is closely related to the quark condensate via a Fourier transformation. Also the spectral sums for the dressed Polyakov loop are investigated numerically. (orig.)

  7. Deuterium lamps as transfer standards for spectral radiance measurements

    International Nuclear Information System (INIS)

    Key, P.J.; Nettleton, D.H.

    1985-01-01

    This report describes the work carried out at NPL and PTB to improve the performance of a low pressure deuterium discharge lamp, so that it can be used as a transfer standard in the spectral range 120 to 350 nm. To this end it was necessary: - to replace the original quartz windows by magnesium fluoride single crystal plates, which were cut perpendicular to the c-axis of the crystal and which had to be free of impurities, - to construct the lamps in that way that the directional uniformity of the emitted radiation is within the demands, - to age the lamps and to preselect only those of which the irradiance was stable within ± 1% during a thirty minute period after warm-up, - to improve the commercially available electrical power supply to meet the operational needs of the lamps. Thus, the deuterium lamps drifted by about 3% over a period of 100 h at all wavelengths except at 250 nm, where the ageing increased to 4.5%. A liquid nitrogen trap has been developed which can be installed between the vacuum system and the lamp. This reduced to about 2% the decrease of the window's transmission during the first hour of operation, caused by the deposition of oil from the vacuum system

  8. Chapter 4: Measurements of total beta-activity in the fallout

    International Nuclear Information System (INIS)

    Duggleby, J.C.; Johannessen, J.C.; Kotler, L.H.; Stewart, F.M.

    1974-01-01

    In order to provide information on fresh fission products in fallout reaching Australia from nuclear tests being conducted by France in Polynesia, measurements were made of total beta activity in daily fallout deposition of 25 Australian sampling stations covering a three month period from 25 July to 23 October 1973. The methods employed to measure the radioactivity of the samples are described and the data on total beta-activity, and the calculated external gamma radiation doses from fresh fallout are presented. (R.L.)

  9. Spectral measurements in critical assemblies: MCNP specifications and calculated results

    Energy Technology Data Exchange (ETDEWEB)

    Stephanie C. Frankle; Judith F. Briesmeister

    1999-12-01

    Recently, a suite of 86 criticality benchmarks for the Monte Carlo N-Particle (MCNP) transport code was developed, and the results of testing the ENDF/B-V and ENDF/B-VI data (through Release 2) were published. In addition to the standard k{sub eff} measurements, other experimental measurements were performed on a number of these benchmark assemblies. In particular, the Cross Section Evaluation Working Group (CSEWG) specifications contain experimental data for neutron leakage and central-flux measurements, central-fission ratio measurements, and activation ratio measurements. Additionally, there exists another set of fission reaction-rate measurements performed at the National Institute of Standards and Technology (NIST) utilizing a {sup 252}Cf source. This report will describe the leakage and central-flux measurements and show a comparison of experimental data to MCNP simulations performed using the ENDF/B-V and B-VI (Release 2) data libraries. Central-fission and activation reaction-rate measurements will be described, and the comparison of experimental data to MCNP simulations using available data libraries for each reaction of interest will be presented. Finally, the NIST fission reaction-rate measurements will be described. A comparison of MCNP results published previously with the current MCNP simulations will be presented for the NIST measurements, and a comparison of the current MCNP simulations to the experimental measurements will be presented.

  10. Spectral measurements in critical assemblies: MCNP specifications and calculated results

    International Nuclear Information System (INIS)

    Frankle, Stephanie C.; Briesmeister, Judith F.

    1999-01-01

    Recently, a suite of 86 criticality benchmarks for the Monte Carlo N-Particle (MCNP) transport code was developed, and the results of testing the ENDF/B-V and ENDF/B-VI data (through Release 2) were published. In addition to the standard k eff measurements, other experimental measurements were performed on a number of these benchmark assemblies. In particular, the Cross Section Evaluation Working Group (CSEWG) specifications contain experimental data for neutron leakage and central-flux measurements, central-fission ratio measurements, and activation ratio measurements. Additionally, there exists another set of fission reaction-rate measurements performed at the National Institute of Standards and Technology (NIST) utilizing a 252 Cf source. This report will describe the leakage and central-flux measurements and show a comparison of experimental data to MCNP simulations performed using the ENDF/B-V and B-VI (Release 2) data libraries. Central-fission and activation reaction-rate measurements will be described, and the comparison of experimental data to MCNP simulations using available data libraries for each reaction of interest will be presented. Finally, the NIST fission reaction-rate measurements will be described. A comparison of MCNP results published previously with the current MCNP simulations will be presented for the NIST measurements, and a comparison of the current MCNP simulations to the experimental measurements will be presented

  11. Measurement of gross alpha and gross beta activity concentrations in human tooth

    International Nuclear Information System (INIS)

    Soeguet, Omer; Aydin, Mehmet Fatih; Kuecuekoender, Erdal; Zorer, Ozlem Selcuk; Dogru, Mahmut

    2010-01-01

    The gross alpha and gross beta activity concentrations were measured in human tooth taken from 3 to 6 age-groups to 40 and over ones. Accumulated teeth samples are investigated in two groups as under and above 18 years. The gross alpha and beta radioactivity of human tooth samples was measured by using a gas-flow proportional counter (PIC-MPC 9604-α/β counter). In tooth samples, for female age-groups, the obtained results show that the mean gross alpha and gross beta activity concentrations varied between 0.534-0.203 and 0.010-0.453 Bq g -1 and the same concentrations for male age-groups varied between 0.009-1.168 and 0.071-0.204 Bq g -1 , respectively.

  12. A digital instrument for nondestructive measurements of coating thicknesses by beta backscattering

    Science.gov (United States)

    Farcasiu, D. M.; Apostolescu, T.; Bozdog, H.; Badescu, E.; Bohm, V.; Stanescu, S. P.; Jianu, A.; Bordeanu, C.; Cracium, M. V.

    1992-02-01

    The elements of nondestructive gauging of coatings applied on various metal bases are presented. The intensity of the backscattered beta radiations is related to the thickness of the coating. With a fixed measuring geometry and radioactive sources (147Pm, 204Tl, 90Sr+90Y) the intensity of the backscattered beta particles is dependent on the following parameters: coating thickness, atomic number of the coating material and of the base, the beta particle energy and the surface finish. It can be used for the measurement of a wide range of coating thicknesses provided that the difference between the coating and the support atomic numbers is at least 20%. Fields of application include electronics, electrotechnique and so on.

  13. A digital instrument for nondestructive measurements of coating thicknesses by beta backscattering

    International Nuclear Information System (INIS)

    Farcasiu, D.M.; Apostolescu, T.; Bozdog, H.; Badescu, E.; Bohm, V.; Stanescu, S.P.; Jianu, A.; Bordeanu, C.; Craciun, M.V.

    1992-01-01

    The elements of nondestructive gauging of coatings applied on various metal bases are presented. The intensity of the backscattered beta radiations is related to the thickness of the coating. With a fixed measuring geometry and radioactive sources ( 147 Pm, 204 Tl, 90 Sr+ 90 Y) the intensity of the backscattered beta particles is dependent on the following parameters: Coating thickness, atomic number of the coating material and of the base, the beta particle energy and the surface finish. It can be used for the measurement of a wide range of coating thicknesses provided that the difference between the coating and the support atomic numbers is at least 20%. Fields of application include electronics, electrotechnique and so on. (orig.)

  14. Design and operation of dust measuring instrumentation based on the beta-radiation method

    International Nuclear Information System (INIS)

    Lilienfeld, P.

    1975-01-01

    The theory, instrument design aspects and applications of beta-radiation attenuation for the measurement of the mass concentration of airborne particulates are reviewed. Applicable methods of particle collection, beta sensing configurations, source ( 63 Ni, 14 C, 147 Pr, 85 Kr) and detector design criteria, electronic signal processing, digital control and instrument programming techniques are treated. Advantages, limitations and error sources of beta-attenuation instrumentation are analyzed. Applications to industrial dust measurements, source testing, ambient monitoring, and particle size analysis are the major areas of practical utilization of this technique, and its inherent capability for automated and unattended operation provides compatibility with process control synchronization and alarm, telemetry, and incorporation into pollution monitoring network sensing stations. (orig.) [de

  15. Stark broadening measurements of Xe III spectral lines

    International Nuclear Information System (INIS)

    Pelaez, R J; Cirisan, M; Djurovic, S; Aparicio, J A; Mar, S

    2006-01-01

    This work reports measured Stark widths of doubly ionized xenon lines. Pulsed arc was used as a plasma source. Measured electron densities and temperatures were in the ranges of (0.2 - 1.6) x 10 23 m -3 and 18 300-25 500 K, respectively. Stark halfwidths of lines from 6s-6p, 6s-4f and 5d-6p transitions have been measured and compared with available experimental and theoretical data

  16. Hand Monitor for Simultaneous Measurements of Alpha and Beta Contamination

    International Nuclear Information System (INIS)

    Andersson, I.Oe.; Braun, J.; Soederlund, B.

    1960-11-01

    An instrument is described which measures α and β contamination of the hands simultaneously. This has been achieved by using as detectors 8 flow counters paired in 4 units of two chambers, one unit for each side of the hand. The inner chamber of every unit (adjacent to the hands) delivers α-pulses, the outer chambers deliver β-pulses. When two finger contacts are pushed the detectors are closing around the hands and the measurement is started. Audible and visual warnings operate when the MPL is exceeded. Similar warnings ope.rate if hands are removed before the end of the counting period. The activity levels are logarithmically indicated on four pointer instruments, which are automatically zeroed when the next measurement is started. The instrument is now commercially available

  17. Characterizations of the Beta and the Degree Network Power Measure

    NARCIS (Netherlands)

    van den Brink, J.R.; Borm, P.; Hendrickx, R.; Owen, G.

    2008-01-01

    A symmetric network consists of a set of positions and a set of bilateral links between these positions. For every symmetric network we define a cooperative transferable utility game that measures the "power" of each coalition of positions in the network. Applying the Shapley value to this game

  18. Poster - 25: Neutron Spectral Measurements around a Scanning Proton Beam

    Energy Technology Data Exchange (ETDEWEB)

    Kildea, John; Enger, Shirin; Maglieri, Robert; Mirzakhanian, Lalageh; Dahlgren, Christina Vallhagen; Dubeau, Jacques; Witharana, Sanjeeva [Medical Physics Unit, McGill University Health Centre, Medical Physics Unit, McGill University, Medical Physics Unit, McGill University, Medical Physics Unit, McGill University, Skandion Clinic, Detec Inc., Gatineau, Quebec, Detec Inc., Gatineau, Quebec (Canada)

    2016-08-15

    We describe the measurements of neutron spectra that we undertook around a scanning proton beam at the Skandion proton therapy clinic in Uppsala, Sweden. Measurements were undertaken using an extended energy range Nested Neutron Spectrometer (NNS, Detec Inc., Gatineau, QC) operated in pulsed and current mode. Spectra were measured as a function of location in the treatment room and for various Bragg peak depths. Our preliminary unfolded data clearly show the direct, evaporation and thermal neutron peaks and we can show the effect on the neutron spectrum of a water phantom in the primary proton beam.

  19. Absolute measurement of {beta} emitters with a 4 {pi} counter; Mesure absolue des emetteurs {beta} au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Le Gallic, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-06-15

    The object of this work is to investigate the conditions under which the activity of {beta}-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 {pi} counter have been examined successively: - comparison of 4 {pi}, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 {pi} counter can be considered a very satisfactory calibration instrument. (author) [French] Le but de ce travail est de rechercher les conditions permettant d'obtenir avec le maximum de precision, la mesure de l'activite des radionuclides se desintegrant par emission et par consequent d'etudier les corrections qui s'y rapportent. Nous avons examine successivement les differents problemes se rapportant aux mesures d'activite au compteur 4 {pi}: - Comparaison des compteurs 4 {pi}, GM et proportionnel; - etude de la preparation des sources; - corrections sur la numeration des sources; - auto-absorption; - correction d'absorption. La precision obtenue dans ces mesures, variant de 1,2 a 3 pour cent, on peut donc considerer le compteur 4 {pi} comme un instrument d'etalonnage tres satisfaisant. (auteur)

  20. Absolute measurement of {beta} emitters with a 4 {pi} counter; Mesure absolue des emetteurs {beta} au compteur 4 {pi}

    Energy Technology Data Exchange (ETDEWEB)

    Le Gallic, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-06-15

    The object of this work is to investigate the conditions under which the activity of {beta}-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 {pi} counter have been examined successively: - comparison of 4 {pi}, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 {pi} counter can be considered a very satisfactory calibration instrument. (author) [French] Le but de ce travail est de rechercher les conditions permettant d'obtenir avec le maximum de precision, la mesure de l'activite des radionuclides se desintegrant par emission et par consequent d'etudier les corrections qui s'y rapportent. Nous avons examine successivement les differents problemes se rapportant aux mesures d'activite au compteur 4 {pi}: - Comparaison des compteurs 4 {pi}, GM et proportionnel; - etude de la preparation des sources; - corrections sur la numeration des sources; - auto-absorption; - correction d'absorption. La precision obtenue dans ces mesures, variant de 1,2 a 3 pour cent, on peut donc considerer le compteur 4 {pi} comme un instrument d'etalonnage tres satisfaisant. (auteur)

  1. Errors in short circuit measurements due to spectral mismatch between sunlight and solar simulators

    Science.gov (United States)

    Curtis, H. B.

    1976-01-01

    Errors in short circuit current measurement were calculated for a variety of spectral mismatch conditions. The differences in spectral irradiance between terrestrial sunlight and three types of solar simulator were studied, as well as the differences in spectral response between three types of reference solar cells and various test cells. The simulators considered were a short arc xenon lamp AMO sunlight simulator, an ordinary quartz halogen lamp, and an ELH-type quartz halogen lamp. Three types of solar cells studied were a silicon cell, a cadmium sulfide cell and a gallium arsenide cell.

  2. Spectral irradiance measurements and hazard evaluations of sunbeds and sunlamps

    International Nuclear Information System (INIS)

    Gies, H.P.; Roy, C.R.; Elliott, G.

    1985-04-01

    The proliferation of solaria, coupled with a growing awareness of the harmful effects of exposure to ultraviolet radiation (UVR) has prompted a study on solaria and the UVR sources used in them. The detrimental effects of UV-B radiation have been known for some time but recently there has been increasing concern over the effects of UV-A radiation, which had at first been thought of as relatively harmless. Previous studies of solaria have made radiometric measurements of the UVR lamp outputs, but since the biological effectiveness of UVR is wavelength dependent, particularly in the UV-B region where it varies by several orders of magnitude, there is a need for spectroradiometric measurements. Such measurements have been made at fourteen solaria in the Melbourne metropolitan area. Laboratory measurements have also been made on individual UVR fluorescent lamps and sunlamps. Results have been compared with the requirements of Australian Standard 2635 (1983), 'Installation, maintenance and operation of solaria for cosmetic purposes'

  3. Spectral emission measurements of lithium on the lithium tokamak experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gray, T. K.; Biewer, T. M.; Maingi, R. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Boyle, D. P.; Granstedt, E. M.; Kaita, R.; Majeski, R. P. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2012-10-15

    There has been a long-standing collaboration between ORNL and PPPL on edge and boundary layer physics. As part of this collaboration, ORNL has a large role in the instrumentation and interpretation of edge physics in the lithium tokamak experiment (LTX). In particular, a charge exchange recombination spectroscopy (CHERS) diagnostic is being designed and undergoing staged testing on LTX. Here we present results of passively measured lithium emission at 5166.89 A in LTX in anticipation of active spectroscopy measurements, which will be enabled by the installation of a neutral beam in 2013. Preliminary measurements are made in transient LTX plasmas with plasma current, I{sub p} < 70 kA, ohmic heating power, P{sub oh}{approx} 0.3 MW and discharge lifetimes of 10-15 ms. Measurements are made with a short focal length spectrometer and optics similar to the CHERS diagnostics on NSTX [R. E. Bell, Rev. Sci. Instrum. 68(2), 1273-1280 (1997)]. These preliminary measurements suggest that even without the neutral beam for active spectroscopy, there is sufficient passive lithium emission to allow for line-of-sight profile measurements of ion temperature, T{sub i}; toroidal velocity and v{sub t}. Results show peak T{sub i} = 70 eV and peak v{sub t} = 45 km/s were reached 10 ms into the discharge.

  4. Measurement of the 2{nu}{beta}{beta} decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state in the NEMO3 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Vala, L

    2003-09-01

    The NEMO3 detector was designed for the study of double beta decay and in particular to search for the neutrinoless double beta decay process (0{nu}{beta}{beta}). The intended sensitivity in terms of a half-life limit for the 0{nu}{beta}{beta} decay is of the order of 10{sup 25} y which corresponds to an effective neutrino mass m{sub {nu}} on the level of (0.3 - 0.1) eV. The 0{nu}{beta}{beta} process is today the most promising test of the Majorana nature of the neutrino. The detector was constructed in the Modane Underground Laboratory (LSM) in France by an international collaboration including France, Russia, the Czech Republic, the USA, the UK, Finland, and Japan. The experiment has been taking data since May 2002. The quantity of {sup 100}Mo in the detector (7 kg) allows an efficient measurement of the two-neutrino double beta decay (2{nu}{beta}{beta}) of {sup 100}Mo to the excited 0{sub 1}{sup +} state (eeN{gamma} channel). Monte-Carlo simulations of the effect and of all the relative sources of background have been produced in order to define a set of appropriate selection criteria. Both Monte-Carlo simulations and special runs with sources of {sup 208}Tl and {sup 214}Bi showed that the only significant background in the eeN{gamma} channel comes from radon that penetrated inside the wire chamber of NEMO3. The experimental data acquired from May 2002 to May 2003 have been analysed in order to determine the signal from the 2{nu}{beta}{beta} decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state and the corresponding background level. The physical result, which was obtained at the level of four standard deviations, is given in the form of an interval of half-life values at 95% confidence level: [5.84*10{sup 20}, 2.26*10{sup 21}] y for method A and [5.83*10{sup 20}, 1.71*10{sup 21}] y for method B. (author)

  5. Spectrally resolved pressure dependence measurements of air fluorescence emission with AIRFLY

    International Nuclear Information System (INIS)

    Ave, M.; Bohacova, M.; Buonomo, B.; Busca, N.; Cazon, L.; Chemerisov, S.D.; Conde, M.E.; Crowell, R.A.; Di Carlo, P.; Di Giulio, C.; Doubrava, M.; Esposito, A.; Facal, P.; Franchini, F.J.; Hoerandel, J.; Hrabovsky, M.; Iarlori, M.; Kasprzyk, T.E.; Keilhauer, B.; Klages, H.

    2008-01-01

    The knowledge of the fluorescence emission as a function of atmospheric parameters is essential for the detection of extensive air showers with the fluorescence technique. In this paper, we summarize AIRFLY published measurements of the pressure dependence of the fluorescence yield. The spectral distribution of the fluorescent light between 280 and 429 nm has been measured with high resolution. Relative intensities of 34 spectral lines have been determined. The pressure dependence of 25 lines was measured in terms of quenching reference pressures p λ ' in air. This set of AIRFLY measurements yields the most comprehensive parametrization of the pressure dependence of the fluorescent spectrum.

  6. Automatic device for measuring {beta}-emitting sources: P.A.P.A. {beta}-meters; Dispositif automatique pour la mesure de sources emettrices de rayonnement {beta}: P.A.P.A. {beta} metres

    Energy Technology Data Exchange (ETDEWEB)

    Colomer, J; Valentin, M [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

    1969-07-01

    The apparatus described is designed for measuring {beta}-emitting elements by the absorption method; it is suitable for carrying out a large number of routine analyses. A mechanical device pushes an aluminium absorption set automatically between the source and the detector; the movement is programmed for cutting on and off by a transistorized electronic unit, with printing out and punching of the results on tape; then this can be mathematically processed by a computer (tracing of absorption spectra, extrapolation and calculation of the activity). The detector is either a {beta}-probe or a proportional counter with a specially designed loop. For routine measurements, the accuracy obtained, with all corrections made, is from 5 to 8 per cent; the reproducibility is about 2 per cent. (authors) [French] L'appareillage decrit est destine aux mesures des elements emetteurs {beta} par la methode d'absorption et il permet d'effectuer, en routine, un nombre important de mesures. Un ensemble mecanique effectue le passage automatique, sous vide primaire, d'un jeu d'absorption en aluminium entre la source et le detecteur, ce passage est programme en pre-temps ou pre-coup par un ensemble electronique a transistors, avec impression et perforation sur bandes des resultats des mesures pour traitement mathematique par un ordinateur (trace du spectre d'absorption, extrapolation et calcul d'activite). Le detecteur est soit une sonde {beta}, soit un compteur proportionnel a boucle specialement realise. Sur des mesures de routine, la precision obtenue, toutes corrections effectuees, est de 5 a 8 pour cent et la reproductibilite de l'ordre de 2 pour cent. (auteur)

  7. Activity measurement of phosphorus-32 in the presence of pure beta-emitting impurities

    CSIR Research Space (South Africa)

    Simpson, BRS

    2006-01-01

    Full Text Available Authors describe the activity measurements undertaken at the CSIR’s National Metrology Laboratory on a solution of the pure beta emitting Radio nuclide phosphorus-32 that formed part of an international key comparison. Depending on the production...

  8. Determination of potassium concentration in salt water for residual beta radioactivity measurements

    International Nuclear Information System (INIS)

    Suarez-Navarro, J.A.; Pujol, Ll.

    2004-01-01

    High interferences may arise in the determination of potassium concentration in salt water. Several analytical methods were studied to determine which method provided the most accurate measurements of potassium concentration. This study is relevant for radiation protection because the exact amount of potassium in water samples must be known for determinations of residual beta activity concentration. The fitting algorithm of the calibration curve and estimation of uncertainty in potassium determinations were also studied. The reproducibility of the proposed analytical method was tested by internal and external validation. Furthermore, the residual beta activity concentration of several Spanish seawater and brackish river water samples was determined using the proposed method

  9. Measurement of Gross Alpha and Gross Beta Radioactivity of River Yobe, North Eastern Nigeria

    International Nuclear Information System (INIS)

    Abba, H. T.; Sadiq, U.; Adeyemo, D. J.

    2013-01-01

    Measurement of the gross alpha and gross beta radioactivity of River Yobe has been carried out. Fifteen samples of the river water were collected from the farming, fishing, domestic/livestock and control areas along the river and were analyzed using desktop alpha/beta (MPC 2000- DP) counting system. The count results show the average alpha activities in farming, fishing, domestic/livestock and control areas are 0.207±0.082, 0.257±0.13, 0.437±0.315 and 0.237±0.10 Bq L -1 , respectively. The average beta activities in the four areas are 0.813±0.122, 0.308±0.0145, 0.563±0.230 and 0.225±0.0096 Bq L -1 , respectively. The overall results show that the alpha and beta activities in the four areas are far below the practical screening level of radioactivity in drinking water of 0.5 Bq L -1 for alpha and 1 Bq L -1 for beta recommended by CEC-FAO and WHO and therefore may not pose any serious detrimental health side-effects to the public users of the river.

  10. Measurement of the beta-neutrino correlation in laser trapped 21Na

    Energy Technology Data Exchange (ETDEWEB)

    Scielzo, Nicholas David [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    Trapped radioactive atoms are an appealing source for precise measurements of the beta-neutrino correlation coefficient, a, since the momentum of the neutrino can be inferred from the detection of the unperturbed low-energy recoil daughter nucleus. Sodium-21 is produced on-line at the 88'' cyclotron at Lawrence Berkeley National Laboratory, and 8e5 atoms have been maintained in a magneto-optical trap. A static electric field draws daughter Neon-21 ions to a microchannel plate detector and betas are detected in coincidence with a plastic scintillator beta detector. The Neon-21 time-of-flight distribution determines the beta neutrino correlation coefficient, a. The resulting charge-state distribution is compared to a simple model based on the sudden approximation which suggests a small but important contribution from nuclear recoil-induced ionization. A larger than expected fraction of the daughters are detected in positive charge-states, but no dependence on either the beta or recoil nucleus energy was observed. We find a = 0.5243 plus or minus 0.0092, which is in 3.6 sigma disagreement with the Standard Model prediction of a = 0.559 plus or minus 0.003. Aside from a deviation from the Standard Model, a possible explanation for the discrepancy is that the branching ratio to the first excited state is in error.

  11. Measurement of the cp violation parameter sin 2 beta

    International Nuclear Information System (INIS)

    K.F. Kelley

    1999-01-01

    This thesis presents a measurement of the time-dependent asymmetry in the rate of (anti B) d 0 versus B d 0 decays to J/ψK s 0 . In the context of the Standard Model this is interpreted as a measurement of the CP violation parameter sin(2β). A total of 198±17 B d 0 /(anti B) d 0 decays were observed in p(anti p) collisions at √s=1.8 TeV by the CDF detector at the Fermilab Tevatron. The initial B flavor (whether B 0 or (anti B) 0 ) is determined by a same-side flavor tagging technique. The analysis results in sin(2β)=1.8±1.1(stat.)±0.3(syst.). This analysis demonstrates the feasibility of studying CP violation in the B 0 -(anti B) 0 system at a hadron collider. By applying the methods used in this analysis, future, higher-statistics experiments should be able to tightly constrain the parameters of the Standard Model

  12. Linear polarization measurements at H. beta. of early-type emission line stars

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, D; McLean, I S [Glasgow Univ. (UK)

    1976-02-01

    Linear polarization measurements across the H..beta.. emission lines of the stars ..gamma.. Cas, zeta Tau and 48 Per are presented. For the first two stars there is a marked reduction of the polarization at the centre of the line and for ..gamma.. Cas, this varies from night to night. During the H..beta.. observations of zeta Tau, a change of polarization over tens of minutes was indicated in a monitor channel tuned to the continuum on the blue side of H..beta... For the fainter star, 48 Per, the uncertainties of the polarimetry were increased in relation to ..gamma.. Cas and zeta Tau by a factor of about two and at this precision, no differential effects across the line were recorded. Observations of ..cap alpha.. Cyg are also given to demonstrate the reliability of the polarimeter.

  13. Measurement of low-level beta activity of samples in liquid state using plastic scintillator vials

    International Nuclear Information System (INIS)

    Wezranowski, E.; Panczyk, E.; Radwan, M.

    1977-01-01

    Plastic scintillation vials having walls from a plastic scintillator and the bottom from perspex were used. Wall thickness was 0.8 to 3 mm. The solution radioactivity was measured by a scintillation beta spectrometer. The total measurement errors were found for the following radionuclides: 14 C +-3.7%; 204 Tl +-3%; 32 P +-2.8%; 137 Cs +-2%, and 72 Ga +-5%. Detection efficiency was found to decrease rapidly with the solution layer thickness. For a solution thickness of 0.2 mm the highest detection efficiency was observed with the 4% measurement error. Linear dependence was found of detection efficiency on beta energy. For a solution layer thickness of 0.2 mm the minimum measurable activities were determined to be 30.3 pCi for 14 C and 2.12 pCi for 32 P. The use of the above vials permits quick and simple measurement without sample chemical preparation. (J.P.)

  14. Design of New Complex Detector Used for Gross Beta Measuring

    International Nuclear Information System (INIS)

    Zhang Junmin

    2010-01-01

    The level of gross β for radioactive aerosol in the containment of nuclear plants can indicate how serious the radioactive pollution is in the shell, and it can provide evidence which shows whether there is the phenomenon of leak in the boundaries of confined aquifer of the primary coolant circuit equipment.In the process of measuring, the counting of gross β is influenced by γ. In order to avoid the influence of γ, a new method was introduced and a new detector was designed using plastic scintillator as the major detecting component and BGO as the sub-component. Based on distinctive difference of light attenuation time, signal induced in them can be discriminated. γ background in plastic scintillator was subtracted according to the counting of γ in BGO. The functions of absolute detection efficiency were obtained. The simulation for Monte-Carlo method shows that the influence of γ background is decreased about one order of magnitude. (authors)

  15. The measurement of alpha, beta and gamma radiations

    International Nuclear Information System (INIS)

    Burns, P.A.

    1982-01-01

    Detection methods for nuclear radiations are based on the processes of excitation and ionization of atoms in the detection medium by the passage of a charged particle. Detectors are usually of two types, those which produce a charge pulse following ionization of the medium and those which produce a burst of light photons which are then detected by a photomultiplier tube. By processing the electronic signals produced in suitable ways either the count rate of the source, the activity, or the dose equivalent to a person may be determined. In order to make these determinations it is necessary to understand the type of nuclear transformation of the radionuclide in question, the type and energy of the radiation being emitted and the processes involved when these radiations pass through the medium of the detector. Suitable choice of detectors and extrapolation from measured data to the quantity which is to be determined can then be made

  16. MD 979: Beta-beating measurements on colliding beams

    CERN Document Server

    Goncalves Jorge, Patrik; Pieloni, Tatiana; Buffat, Xavier; Carlier, Felix Simon; Coello De Portugal - Martinez Vazquez, Jaime Maria; Fol, Elena; Langner, Andy Sven; Medina Medrano, Luis Eduardo; Olexa, Jakub; Tomas Garcia, Rogelio; Valuch, Daniel; Wegscheider, Andreas; CERN. Geneva. ATS Department

    2017-01-01

    The HL-LHC high brightness beams will give a large β-beating due to the head-on and long-range interactions since a beam-beam parameter of 0.01 per Interaction Point (IP) is expected. The β-heating induced by two head-on collision reaches 15%. A third IP, i.e. IP8, could bring the β-heating up to 24%. The aim of the Machine Development (MD) study was to test optics measurements with AC dipole and ADT on colliding beams at injection and to implement a correction of the β-heating due to to head-on collision in the two experiments IP1&5. Int his note, we summarize the first results of this test performed in the LHC.

  17. On Absolute Measurements of {beta}-Emitting Radionuclides; Mesures absolues d'emetteurs {beta}; Absolyutnye izmereniya {beta} izluchayushchikh radioizotopov; Sobre la medicion absoluta de los emisores {beta}

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, A M [Centro de Estudos de Fisica, Comisao de Estudos de Energia Nuclear, Instituto Portugues de Oncologia, Lisboa (Portugal)

    1960-06-15

    4 {pi} GM detectors are described and some of their characteristics presented. The absence of spurious pulses is shown by the measurement of the rate of arrival of intervals between pulses. Some problems related to the foil absorption and source absorption are considered using Sr{sup 90} and Y{sup 90}. Aiming at correcting the counting losses in the foil and in a certain extent also the source absorption an experimental method which uses paired sources is presented. The preparation of standards of Bi{sup 210} (RaE) is described. A note is presented on the problem of foil absorption losses in scintillation absolute counting. (author) [French] Le memoire decrit des detecteurs 4 {pi} GM et donne certaines de leurs caracteristiques. L'absence d'impulsions parasites est indiquee par la mesure de la cadence d'arrivee des impulsions. L'auteur examine plusieurs problemes que posent l'absorption par la source et l'absorption par la feuille lorsqu'on utilise du Sr{sup 90} et du Y{sup 90}. Il expose une methode experimentale dans laquelle il emploie des sources deux a deux en vue de corriger les pertes au comptage dans la feuille et aussi, dans une certaine mesure, l'absorption par la source. L'auteur decrit la preparation d'etalon de Bi{sup 210} (RaE). Il ajoute une note sur le probleme des pertes par absorption dans la feuille dans le comptage absolu par scintillations. (author) [Spanish] Se describen los detectores Geiger-Mueller 4 {pi} y algunas de sus caracteristicas. La ausencia de impulsos parasitos se comprueba midiendo el ritmo a que se suceden los intervalos entre los impulsos. Con ayuda de Sr{sup 90} y Y{sup 90}, se estudian algunos de los problemas de autoabsorcion y de la absorcion por las hojas. Con el propositio de corregir la disminucion del numero de impulsos debido a la absorcion en las hojas y, hasta cierto punto, a la autoabsorcion, el autor propone un metodo experimental que emplea fuentes pareadas. Asimismo, describe la preparacion de patrones de Ba

  18. Multi-spectral temperature measurement method for gas turbine blade

    Science.gov (United States)

    Gao, Shan; Feng, Chi; Wang, Lixin; Li, Dong

    2016-02-01

    One of the basic methods to improve both the thermal efficiency and power output of a gas turbine is to increase the firing temperature. However, gas turbine blades are easily damaged in harsh high-temperature and high-pressure environments. Therefore, ensuring that the blade temperature remains within the design limits is very important. There are unsolved problems in blade temperature measurement, relating to the emissivity of the blade surface, influences of the combustion gases, and reflections of radiant energy from the surroundings. In this study, the emissivity of blade surfaces has been measured, with errors reduced by a fitting method, influences of the combustion gases have been calculated for different operational conditions, and a reflection model has been built. An iterative computing method is proposed for calculating blade temperatures, and the experimental results show that this method has high precision.

  19. White light spectral interferometer for measuring dispersion in the visible-near infrared

    Science.gov (United States)

    Arosa, Yago; Rodríguez Fernández, Carlos Damian; Algnamat, Bilal S.; López-Lago, Elena; de la Fuente, Raul

    2017-08-01

    We have designed a spectrally resolved interferometer to measure the refractive index of transparent samples over a wide spectral band from 400 to 1550 nm. The measuring device consists of a Michelson interferometer whose output is analyzed by means of three fiber spectrometers. The first one is a homemade prism spectrometer, which obtains the interferogram produced by the sample over 400 to 1050 nm; the second one is a homemade transmission grating spectrometer thought to measure the interferogram in the near infrared spectral band from 950 to 1550 nm; the last one is a commercial Czerny-Turner spectrometer used to make high precision measurements of the displacement between the Michelson mirrors also using white light interferometry. The whole system is illuminated by a white light source with an emission spectrum similar to black body. We have tested the instrument with solid and liquids samples achieving accuracy to the fourth decimal on the refractive index after fitting it to a Cauchy formula

  20. Spectral distribution measurements of neutrons in paraffin borax mixtures

    International Nuclear Information System (INIS)

    El-Khatib, A.M.; Gaber, M.; Abou El-Khier, M.A.

    1987-01-01

    Neutron fluxes from a compact D-T neutron source has been measured in paraffin-borax mixtures by using activation foil detectors with successive threshold energies. The absorbed doses, backscattering coefficients and build-up factors were determined as well. The contribution of thermal and intermediate neutron dose is much lower, compared to that of fast neutrons. Among the used mediums, paraffin loaded with 4% borax concentration was found to be the best absorbing medium against neutrons at near depths within the blocks, while at a depth around 12 cm the neutron absorption (or scattering) is independent on the type of the used medium. (author)

  1. Spectral reflectance measurement methodologies for TUZ Golu field campaign

    CSIR Research Space (South Africa)

    Boucher, Y

    2011-07-01

    Full Text Available panel. However, it's possible to take this into account in the uncertainty budget. 2.2. Instrumentation and sampling area All of the teams except INPE used a Fieldspec ASD spectroradiometer. In this case, the user has to choose the aperture... of the objective and the ASD configuration (the number of elementary spectra averaged to get one measurement, here typically 10, and the number of dark current acquisitions, here typically 25). The spectroradiometer must also be optimized from time to time...

  2. Measurement of spectral sea ice albedo at Qaanaaq fjord in northwest Greenland

    Science.gov (United States)

    Tanikawa, T.

    2017-12-01

    The spectral albedos of sea ice were measured at Qaanaaq fjord in northwest Greenland. Spectral measurements were conducted for sea ice covered with snow and sea ice without snow where snow was artificially removed around measurement point. Thickness of the sea ice was approximately 1.3 m with 5 cm of snow over the sea ice. The measurements show that the spectral albedos of the sea ice with snow were lower than those of natural pure snow especially in the visible regions though the spectral shapes were similar to each other. This is because the spectral albedos in the visible region have information of not only the snow but also the sea ice under the snow. The spectral albedos of the sea ice without the snow were approximately 0.4 - 0.5 in the visible region, 0.05-0.25 in the near-infrared region and almost constant of approximately 0.05 in the region of 1500 - 2500 nm. In the visible region, it would be due to multiple scattering by an air bubble within the sea ice. In contrast, in the near-infrared and shortwave infrared wavelengths, surface reflection at the sea ice surface would be dominant. Since a light absorption by the ice in these regions is relatively strong comparing to the visible region, the light could not be penetrated deeply within the sea ice, resulting that surface reflection based on Fresnel reflection would be dominant. In this presentation we also show the results of comparison between the radiative transfer calculation and spectral measurement data.

  3. Algorithmic Foundation of Spectral Rarefaction for Measuring Satellite Imagery Heterogeneity at Multiple Spatial Scales

    Science.gov (United States)

    Rocchini, Duccio

    2009-01-01

    Measuring heterogeneity in satellite imagery is an important task to deal with. Most measures of spectral diversity have been based on Shannon Information theory. However, this approach does not inherently address different scales, ranging from local (hereafter referred to alpha diversity) to global scales (gamma diversity). The aim of this paper is to propose a method for measuring spectral heterogeneity at multiple scales based on rarefaction curves. An algorithmic solution of rarefaction applied to image pixel values (Digital Numbers, DNs) is provided and discussed. PMID:22389600

  4. LABORATORY MEASUREMENTS OF WHITE DWARF PHOTOSPHERIC SPECTRAL LINES: Hβ

    International Nuclear Information System (INIS)

    Falcon, Ross E.; Gomez, T. A.; Montgomery, M. H.; Winget, D. E.; Rochau, G. A.; Bailey, J. E.; Nagayama, T.

    2015-01-01

    We spectroscopically measure multiple hydrogen Balmer line profiles from laboratory plasmas to investigate the theoretical line profiles used in white dwarf (WD) atmosphere models. X-ray radiation produced at the Z Pulsed Power Facility at Sandia National Laboratories initiates plasma formation in a hydrogen-filled gas cell, replicating WD photospheric conditions. Here we present time-resolved measurements of Hβ and fit this line using different theoretical line profiles to diagnose electron density, n e , and n = 2 level population, n 2 . Aided by synthetic tests, we characterize the validity of our diagnostic method for this experimental platform. During a single experiment, we infer a continuous range of electron densities increasing from n e ∼ 4 to ∼30 × 10 16 cm −3 throughout a 120-ns evolution of our plasma. Also, we observe n 2 to be initially elevated with respect to local thermodynamic equilibrium (LTE); it then equilibrates within ∼55 ns to become consistent with LTE. This supports our electron-temperature determination of T e ∼ 1.3 eV (∼15,000 K) after this time. At n e ≳ 10 17 cm −3 , we find that computer-simulation-based line-profile calculations provide better fits (lower reduced χ 2 ) than the line profiles currently used in the WD astronomy community. The inferred conditions, however, are in good quantitative agreement. This work establishes an experimental foundation for the future investigation of relative shapes and strengths between different hydrogen Balmer lines

  5. Spreadsheet design and validation for characteristic limits determination in gross alpha and beta measurement

    International Nuclear Information System (INIS)

    Prado, Rodrigo G.P. do; Dalmazio, Ilza

    2013-01-01

    The identification and detection of ionizing radiation are essential requisites of radiation protection. Gross alpha and beta measurements are widely applied as a screening method in radiological characterization, environmental monitoring and industrial applications. As in any other analytical technique, test performance depends on the quality of instrumental measurements and reliability of calculations. Characteristic limits refer to three specific statistics, namely, decision threshold, detection limit and confidence interval, which are fundamental to ensuring the quality of determinations. This work describes a way to calculate characteristic limits for measurements of gross alpha and beta activity applying spreadsheets. The approach used for determination of decision threshold, detection limit and limits of the confidence interval, the mathematical expressions of measurands and uncertainty followed standards guidelines. A succinct overview of this approach and examples are presented and spreadsheets were validated using specific software. Furthermore, these spreadsheets could be used as tool to instruct beginner users of methods for ionizing radiation measurements. (author)

  6. Measurement of Gross Alpha and Beta Emission Rates from Ceramic Tiles

    International Nuclear Information System (INIS)

    Wudthicharoonpun, Piyasak; Chankow, Nares

    2007-08-01

    Full text: Ceramic tiles normally used to cover floors and walls contain naturally occurring radioactive elements i.e. potassium-40, uranium, thorium and their daughters from raw materials. Thus, radioactivity was dependent upon source of raw materials and the amount used. The objective of this research was to measure gross alpha and beta emission rates to be used as a database for safety assessment and for selection of rooms to measure radioactive radon-222 gas

  7. Measurement of the energy dependent beta asymmetry in the decay of 8Li

    International Nuclear Information System (INIS)

    Bigelow, R.A.; Quin, P.A.; Freedman, S.J.; Napolitano, J.

    1985-01-01

    Progress is reported on a new measurement of the beta decay asymmetry in 8 Li. Polarized 8 Li is produced via the reaction 7 Li(d,p) 8 Li using vector polarized deuterons from a crossed beam polarized source. Plastic scintillation electron counters are used to measure asymmetry, tensor polarization correlation and to monitor beam current. Results are graphed and systematic error sources are discussed. 4 refs

  8. Information Retrieval from SAGE II and MFRSR Multi-Spectral Extinction Measurements

    Science.gov (United States)

    Lacis, Andrew A.; Hansen, James E. (Technical Monitor)

    2001-01-01

    Direct beam spectral extinction measurements of solar radiation contain important information on atmospheric composition in a form that is essentially free from multiple scattering contributions that otherwise tend to complicate the data analysis and information retrieval. Such direct beam extinction measurements are available from the solar occultation satellite-based measurements made by the Stratospheric and Aerosol Gas Experiment (SAGE II) instrument and by ground-based Multi-Filter Shadowband Radiometers (MFRSRs). The SAGE II data provide cross-sectional slices of the atmosphere twice per orbit at seven wavelengths between 385 and 1020 nm with approximately 1 km vertical resolution, while the MFRSR data provide atmospheric column measurements at six wavelengths between 415 and 940 nm but at one minute time intervals. We apply the same retrieval technique of simultaneous least-squares fit to the observed spectral extinctions to retrieve aerosol optical depth, effective radius and variance, and ozone, nitrogen dioxide, and water vapor amounts from the SAGE II and MFRSR measurements. The retrieval technique utilizes a physical model approach based on laboratory measurements of ozone and nitrogen dioxide extinction, line-by-line and numerical k-distribution calculations for water vapor absorption, and Mie scattering constraints on aerosol spectral extinction properties. The SAGE II measurements have the advantage of being self-calibrating in that deep space provides an effective zero point for the relative spectral extinctions. The MFRSR measurements require periodic clear-day Langley regression calibration events to maintain accurate knowledge of instrument calibration.

  9. Spectral measurements of fluctuating ω/sub pe/ radiation from Alcator C tokamak

    International Nuclear Information System (INIS)

    Gandy, R.F.; Yates, D.

    1984-01-01

    High resolution spectral measurements have been made of the fluctuating electron plasma frequency (ω/sub pe/) radiation from Alcator C. Three techniques have been used in making the measurements. Features as narrow as 350 kHz have been observed (Δf/f approx. = 6 x 10 -6 ), impling that a highly coherent process is responsible for the emission

  10. Measurement of the two neutrino double beta decay half-life of Zr-96 with the NEMO-3 detector

    Energy Technology Data Exchange (ETDEWEB)

    Argyriades, J. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Arnold, R. [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Baker, J. [INL, Idaho National Laboratory, 83415 Idaho Falls (United States); Barabash, A.S. [ITEP, Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Basharina-Freshville, A. [University College London, WC1E 6BT London (United Kingdom); Bongrand, M. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France); Broudin-Bay, G. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Brudanin, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Caffrey, A.J. [INL, Idaho National Laboratory, 83415 Idaho Falls (United States); Chapon, A. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Chauveau, E. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Daraktchieva, Z. [University College London, WC1E 6BT London (United Kingdom); Durand, D. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Egorov, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Fatemi-Ghomi, N. [University of Manchester, M13 9PL Manchester (United Kingdom); Flack, R. [University College London, WC1E 6BT London (United Kingdom); Guillon, B. [LPC, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Hubert, Ph. [Universite Bordeaux, CENBG, UMR 5797, F-33175 Gradignan (France); CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR5797, F-33175 Gradignan (France); Jullian, S. [LAL, Universite Paris-Sud 11, CNRS/IN2P3, F-91405 Orsay (France)

    2010-12-08

    Using 9.4 g of {sup 96}Zr isotope and 1221 days of data from the NEMO-3 detector corresponding to 0.031 kg y, the obtained 2{nu}{beta}{beta} decay half-life measurement is T{sub 1/2}{sup 2{nu}=}[2.35{+-}0.14(stat){+-}0.16(syst)]x10{sup 19} yr. Different characteristics of the final state electrons have been studied, such as the energy sum, individual electron energy, and angular distribution. The 2{nu} nuclear matrix element is extracted using the measured 2{nu}{beta}{beta} half-life and is M{sup 2{nu}=}0.049{+-}0.002. Constraints on 0{nu}{beta}{beta} decay have also been set.

  11. A proportional chamber to measure the screening potential in sup 3 H beta decay

    CERN Document Server

    Paterson, D J; Batkin, I S

    1999-01-01

    A gas proportional chamber has been assembled to make precise observations of the low-energy region of the sup 3 H beta spectrum. Backgrounds have been measured and understood, and are maintained at approx 2% of the data rate. Wall effects have been simulated for this chamber and are predicted at <0.5% of events. Systematic effects which may introduce errors into the observed spectrum have been carefully measured at a level below approx 10 sup - sup 4 per ADC channel. This apparatus will be used to make precise measurements of the effects of screening of the nuclear charge by orbital electrons on the beta spectrum of sup 3 H, and to attempt to observe the effect of a hypothesized admixture of heavy neutrinos in the sup 3 H spectrum.

  12. Spectral emissivity measurements of liquid refractory metals by spectrometers combined with an electrostatic levitator

    International Nuclear Information System (INIS)

    Ishikawa, Takehiko; Okada, Junpei T; Paradis, Paul-François; Ito, Yusuke; Masaki, Tadahiko; Watanabe, Yuki

    2012-01-01

    A spectral emissivity measurement system combined with an electrostatic levitator was developed for high-temperature melts. The radiation intensity from a high-temperature sample was measured with a multichannel photospectrometer (MCPD) over the 700–1000 nm spectral range, while a Fourier transform infrared spectrometer (FTIR) measured the radiation over the 1.1–6 µm interval. These spectrometers were calibrated with a blackbody radiation furnace, and the spectral hemispherical emissivity was calculated. The system's capability was evaluated with molten zirconium samples. The spectral hemispherical emissivity of molten zirconium showed a negative wavelength dependence and an almost constant variation over the 1850–2210 K temperature range. The total hemispherical emissivity of zirconium calculated by integrating the spectral hemispherical emissivity was found to be around 0.32, which showed good agreement with the literature values. The constant pressure heat capacity of molten zirconium at melting temperature was calculated to be 40.9 J mol −1 K −1 . (paper)

  13. GOSAT and OCO-2 Inter-comparison on Measured Spectral Radiance and Retrieved Carbon Dioxide

    Science.gov (United States)

    Kataoka, F.; Kuze, A.; Shiomi, K.; Suto, H.; Crisp, D.; Bruegge, C. J.; Schwandner, F. M.

    2016-12-01

    TANSO-FTS onboard GOSAT and grating spectrometer on OCO-2 use different measurement techniques to measure carbon dioxide (CO2) and molecular oxygen (O2). Both instruments observe sunlight reflected from the Earth's surface in almost the same spectral range. As a first step in cross calibrating these two instruments, we compared spectral radiance observations within the three short wave infrared (SWIR) spectral bands centered on the O2 A-band (O2A), the weak CO2 band near 1.6 microns (Weak-CO2) and 2.06 micons (Strong-CO2) bands at temporally coincident and spatially collocated points. In this work, we reconciled the different size of the footprints and evaluated at various types of surface targets such as ocean, desert and forest. For radiometric inter-comparisons, we consider long term instrument sensitivity degradation in orbit and differences in viewing geometry and associated differences in surface bidirectional reflectance distribution function (BRDF). Measured spectral radiances agree very well within 5% for all bands. This presentation will summarize these comparisons of GOSAT and OCO-2 spectral radiance observations and associated estimates of carbon dioxide and related parameters retrieved with the same algorithm at matchup points. We will also discuss instrument related uncertainties from various target observations.

  14. An experimental applications of impedance measurements by spectral analysis to electrochemistry and corrosion

    International Nuclear Information System (INIS)

    Castro, E.B.; Vilche, J.R.; Milocco, R.H.

    1984-01-01

    An impedance measurement system based on the spectral analysis of excitation and response signals was implemented using a pseudo-random binary sequence in the generation of the electrical perturbation signal. The spectral density functions were estimated through finite Fourier transforms of the original time history records by fast computation of Fourier series. Experimental results obtained using the FFT algorithm in the developed impedance measurement system which covers a wide frequency range, 10 KHz >= f >= 1 mHz, are given both for dummy cells representing conventional electric circuits in electrochemistry and corrosion systems and for the Fe/acidic chloride solution interfaces under different polarization conditions. (C.L.B.) [pt

  15. Group velocity measurement using spectral interference in near-field scanning optical microscopy

    International Nuclear Information System (INIS)

    Mills, John D.; Chaipiboonwong, Tipsuda; Brocklesby, William S.; Charlton, Martin D. B.; Netti, Caterina; Zoorob, Majd E.; Baumberg, Jeremy J.

    2006-01-01

    Near-field scanning optical microscopy provides a tool for studying the behavior of optical fields inside waveguides. In this experiment the authors measure directly the variation of group velocity between different modes of a planar slab waveguide as the modes propagate along the guide. The measurement is made using the spectral interference between pulses propagating inside the waveguide with different group velocities, collected using a near-field scanning optical microscope at different points down the guide and spectrally resolved. The results are compared to models of group velocities in simple guides

  16. Utilize the spectral line pair of the same ionized state ion to measure the ion temperature of tokamak plasma

    International Nuclear Information System (INIS)

    Lin Xiaodong

    2000-01-01

    Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in Tokamak. The advantage of this method is to higher spectral resolution and wider spectral range select

  17. Estimation of potassium concentration in coconut water by beta radioactivity measurement

    International Nuclear Information System (INIS)

    Reddy, P.J.; Narayani, K.; Bhade, S.P.D.; Anilkumar, S.; Kolekar, R.V.; Singh, Rajvir; Pradeepkumar, K.S.

    2014-01-01

    Potassium is widely distributed in soil, in all vegetable, fruits and animal tissues. Approximately half the radioactivity found in humans comes from 40 K. Potassium is an essential element in our diet since it is required for proper nerve and muscle function, as well as for maintaining the fluid balance of cells and heart rhythm. Potassium can enter the body mainly consuming fruits, vegetables and food. Tender coconut water is consumed widely as natural refreshing drink which is rich in potassium. The simple way to determine 40 K activity is by gamma ray spectrometry. However, the low abundance of this gamma photon makes the technique less sensitive compared to gross beta measurement. Many analytical methods are reported for potassium estimation which is time consuming and destructive in nature. A unique way to estimate 40 K by beta activity is by Cerenkov Counting technique using Liquid Scintillation Analyzer. Also much lower detection limit is achieved, allowing for greater precision. In this work, we have compared two methods to arrive at the potassium concentration in tender and matured coconut water by measuring 40 K. One is non-scintillator method based on measurement of the Cerenkov radiation generated from the high-energy β of 40 K. The second method is based on beta activity measurement using low background Gas flow counter

  18. Pursuing atmospheric water vapor retrieval through NDSA measurements between two LEO satellites: evaluation of estimation errors in spectral sensitivity measurements

    Science.gov (United States)

    Facheris, L.; Cuccoli, F.; Argenti, F.

    2008-10-01

    NDSA (Normalized Differential Spectral Absorption) is a novel differential measurement method to estimate the total content of water vapor (IWV, Integrated Water Vapor) along a tropospheric propagation path between two Low Earth Orbit (LEO) satellites. A transmitter onboard the first LEO satellite and a receiver onboard the second one are required. The NDSA approach is based on the simultaneous estimate of the total attenuations at two relatively close frequencies in the Ku/K bands and of a "spectral sensitivity parameter" that can be directly converted into IWV. The spectral sensitivity has the potential to emphasize the water vapor contribution, to cancel out all spectrally flat unwanted contributions and to limit the impairments due to tropospheric scintillation. Based on a previous Monte Carlo simulation approach, through which we analyzed the measurement accuracy of the spectral sensitivity parameter at three different and complementary frequencies, in this work we examine such accuracy for a particularly critical atmospheric status as simulated through the pressure, temperature and water vapor profiles measured by a high resolution radiosonde. We confirm the validity of an approximate expression of the accuracy and discuss the problems that may arise when tropospheric water vapor concentration is lower than expected.

  19. PET measures of pre- and post-synaptic cardiac beta adrenergic function

    Energy Technology Data Exchange (ETDEWEB)

    Link, Jeanne M.; Stratton, John R.; Levy, Wayne; Poole, Jeanne E.; Shoner, Steven C.; Stuetzle, Werner; Caldwell, James H. E-mail: jcald@u.washington.edu

    2003-11-01

    Positron Emission Tomography was used to measure global and regional cardiac {beta}-adrenergic function in 19 normal subjects and 9 congestive heart failure patients. [{sup 11}C]-meta-hydroxyephedrine was used to image norepinephrine transporter function as an indicator of pre-synaptic function and [{sup 11}C]-CGP12177 was used to measure cell surface {beta}-receptor density as an indicator of post-synaptic function. Pre-synaptic, but not post-synaptic, function was significantly different between normals and CHF patients. Pre-synaptic function was well matched to post-synaptic function in the normal hearts but significantly different and poorly matched in the CHF patients studied. This imaging technique can help us understand regional sympathetic function in cardiac disease.

  20. Measured Polarized Spectral Responsivity of JPSS J1 VIIRS Using the NIST T-SIRCUS

    Science.gov (United States)

    McIntire, Jeff; Young, James B.; Moyer, David; Waluschka, Eugene; Xiong, Xiaoxiong

    2015-01-01

    Recent pre-launch measurements performed on the Joint Polar Satellite System (JPSS) J1 Visible Infrared Imaging Radiometer Suite (VIIRS) using the National Institute of Standards and Technology (NIST) Traveling Spectral Irradiance and Radiance Responsivity Calibrations Using Uniform Sources (T-SIRCUS) monochromatic source have provided wavelength dependent polarization sensitivity for select spectral bands and viewing conditions. Measurements were made at a number of input linear polarization states (twelve in total) and initially at thirteen wavelengths across the bandpass (later expanded to seventeen for some cases). Using the source radiance information collected by an external monitor, a spectral responsivity function was constructed for each input linear polarization state. Additionally, an unpolarized spectral responsivity function was derived from these polarized measurements. An investigation of how the centroid, bandwidth, and detector responsivity vary with polarization state was weighted by two model input spectra to simulate both ground measurements as well as expected on-orbit conditions. These measurements will enhance our understanding of VIIRS polarization sensitivity, improve the design for future flight models, and provide valuable data to enhance product quality in the post-launch phase.

  1. Bi-photon spectral correlation measurements from a silicon nanowire in the quantum and classical regimes

    Science.gov (United States)

    Jizan, Iman; Helt, L. G.; Xiong, Chunle; Collins, Matthew J.; Choi, Duk-Yong; Joon Chae, Chang; Liscidini, Marco; Steel, M. J.; Eggleton, Benjamin J.; Clark, Alex S.

    2015-01-01

    The growing requirement for photon pairs with specific spectral correlations in quantum optics experiments has created a demand for fast, high resolution and accurate source characterisation. A promising tool for such characterisation uses classical stimulated processes, in which an additional seed laser stimulates photon generation yielding much higher count rates, as recently demonstrated for a χ(2) integrated source in A. Eckstein et al. Laser Photon. Rev. 8, L76 (2014). In this work we extend these results to χ(3) integrated sources, directly measuring for the first time the relation between spectral correlation measurements via stimulated and spontaneous four wave mixing in an integrated optical waveguide, a silicon nanowire. We directly confirm the speed-up due to higher count rates and demonstrate that this allows additional resolution to be gained when compared to traditional coincidence measurements without any increase in measurement time. As the pump pulse duration can influence the degree of spectral correlation, all of our measurements are taken for two different pump pulse widths. This allows us to confirm that the classical stimulated process correctly captures the degree of spectral correlation regardless of pump pulse duration, and cements its place as an essential characterisation method for the development of future quantum integrated devices. PMID:26218609

  2. New Beta-delayed Neutron Measurements in the Light-mass Fission Group

    Energy Technology Data Exchange (ETDEWEB)

    Agramunt, J. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); García, A.R. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Algora, A. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Äystö, J. [University of Jyväskylä, FI-40014 Jyväskyä (Finland); Caballero-Folch, R.; Calviño, F. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); Cano-Ott, D. [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Cortés, G. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); Domingo-Pardo, C. [Instituto de Física Corpuscular, CSIC-Univ. Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Eronen, T. [University of Jyväskylä, FI-40014 Jyväskyä (Finland); Gelletly, W. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Gómez-Hornillos, M.B. [Secció d' Enginyeria Nuclear, Universitat Politécnica de Catalunya, E-08028 Barcelona (Spain); and others

    2014-06-15

    A new accurate determination of beta-delayed neutron emission probabilities from nuclei in the low mass region of the light fission group has been performed. The measurements were carried out using the BELEN 4π neutron counter at the IGISOL-JYFL mass separator in combination with a Penning trap. The new results significantly improve the uncertainties of neutron emission probabilities for {sup 91}Br, {sup 86}As, {sup 85}As, and {sup 85}Ge nuclei.

  3. A standardized method for in vivo mouse pancreas imaging and semiquantitative beta cell mass measurement by dual isotope SPECT

    NARCIS (Netherlands)

    Mathijs, I.; Xavier, C.; Peleman, C.; Caveliers, V.; Brom, M.; Gotthardt, M.; Herrera, P.L.; Lahoutte, T.; Bouwens, L.

    2015-01-01

    PURPOSE: In order to evaluate future beta cell tracers in vivo, we aimed to develop a standardized in vivo method allowing semiquantitative measurement of a prospective beta cell tracer within the pancreas. PROCEDURES: 2-[(123)I]Iodo-L-phenylalanine ([(123)I]IPA) and

  4. High beta radiation exposure of medical staff measures for optimisation of radiation protection

    International Nuclear Information System (INIS)

    Barth, I.; Rimpler, A.

    2006-01-01

    Full text of publication follows: New therapies applying beta radionuclides have been introduced in medicine in recent years, especially in nuclear medicine, e. g. radio-synoviorthesis, radioimmunotherapy and palliative pain therapy. The preparation of radiopharmaceuticals, their dispensary as well as injection require the handling of vials and syringes with high activities of beta emitters at small distances to the skin. Thus the medical staff may be exposed to a high level of beta radiation. Hence the local skin dose, Hp(0,07), was measured at these workplaces with thin-layer thermoluminescent dosemeters TLD (LiF:Mg,P,Cu) fixed to the tip of the fingers at both hands of the personnel. In addition, official beta/photon ring dosemeters were worn at the first knuckle of the index finger. Very high local skin doses were measured at the tip of index finger and thumb. The findings indicate that the exposure of the staff can exceed the annual dose limit for skin of 500 mSv when working at a low protection standard. By the use of appropriate shieldings and tools (e.g. tweezers or forceps) the exposure was reduced of more than one order of magnitude. The German dosimetry services provide official beta/photon ring dosemeters for routine monitoring of the extremity exposure of occupationally exposed persons. But even monitoring with these official dosemeters does not provide suitable results to control compliance with the dose limit in the majority of cases because they can mostly not be worn at the spot of highest beta exposure (finger tip). Therefore, a study was performed to identify the difference of readings of official ring dosemeters and the maximum local skin dose at the finger tips. At workplaces of radio-synoviorthesis a correction factor of 3 was determined provided that the staff worked at high radiation protection standard and the ring dosemeters were worn at the first knuckle of the index finger. The correction factor increases significantly when the radiation

  5. Absolute measurement of {beta} activities and application to the determination of neutronic densities; Mesure absolue d'activites {beta} et application a la determination des densites neutronique

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1951-01-15

    M. Berthelot, to my entrance to the ''Commissariat a l 'Energie Atomique'', proposed me to study the absolute measurement of neutron densities. Very quickly the problem of the absolute activity of {beta} sources became the central object of this work. In a first part, we will develop the methods of absolute determination for {beta} activities. The use of a 4{pi} counter permits to get the absolute activity of all beta radioactive source, susceptible to be put as thin leaf and of period superior than some minutes. The method is independent of the spectra of the measured radioelement. we will describe in the second part some applications which use neutron densities measurement, neutron sources intensities and ratio of cross sections of capture of thermal neutrons. (M.B.) [French] M. Berthelot, a mon entree au ''Commissariat a l 'Energie Atomique'', m'a propose d'etudier la mesure absolue des densites neutroniques. Tres rapidement le probleme de l'activite absolue des sources beta est devenu l'objet central de ce travail. Dans une premiere partie, on abordera les methodes de determination absolue des activites beta. L'utilisation d'un compteur 4{pi} permet d 'obtenir l'activite absolue de toute source radioactive beta, susceptible d'etre mise sous forme de feuille mince et de periode superieure a quelques minutes. La methode est independante du spectre du radioelement mesure. On decrira dans la seconde partie quelques applications a des mesures de densites neutroniques, d'intensites de sources de neutrons et de rapport de sections efficaces de capture de neutrons thermiques. (M.B.)

  6. Absolute measurement of {beta} activities and application to the determination of neutronic densities; Mesure absolue d'activites {beta} et application a la determination des densites neutronique

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R. [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1951-01-15

    M. Berthelot, to my entrance to the ''Commissariat a l 'Energie Atomique'', proposed me to study the absolute measurement of neutron densities. Very quickly the problem of the absolute activity of {beta} sources became the central object of this work. In a first part, we will develop the methods of absolute determination for {beta} activities. The use of a 4{pi} counter permits to get the absolute activity of all beta radioactive source, susceptible to be put as thin leaf and of period superior than some minutes. The method is independent of the spectra of the measured radioelement. we will describe in the second part some applications which use neutron densities measurement, neutron sources intensities and ratio of cross sections of capture of thermal neutrons. (M.B.) [French] M. Berthelot, a mon entree au ''Commissariat a l 'Energie Atomique'', m'a propose d'etudier la mesure absolue des densites neutroniques. Tres rapidement le probleme de l'activite absolue des sources beta est devenu l'objet central de ce travail. Dans une premiere partie, on abordera les methodes de determination absolue des activites beta. L'utilisation d'un compteur 4{pi} permet d 'obtenir l'activite absolue de toute source radioactive beta, susceptible d'etre mise sous forme de feuille mince et de periode superieure a quelques minutes. La methode est independante du spectre du radioelement mesure. On decrira dans la seconde partie quelques applications a des mesures de densites neutroniques, d'intensites de sources de neutrons et de rapport de sections efficaces de capture de neutrons thermiques. (M.B.)

  7. The measurement and interpretation of Ne VII spectral line intensity ratios

    International Nuclear Information System (INIS)

    Lang, J.

    1983-03-01

    Results are presented for the measurement, using the branching ratios calibration method, of the spectral intensities of Ne VII lines emitted from a theta-pinch plasma whose electron temperature and density have been found by laser scattering and alternate techniques. (author)

  8. WINDOWS: a program for the analysis of spectral data foil activation measurements

    International Nuclear Information System (INIS)

    Stallmann, F.W.; Eastham, J.F.; Kam, F.B.K.

    1978-12-01

    The computer program WINDOWS together with its subroutines is described for the analysis of neutron spectral data foil activation measurements. In particular, the unfolding of the neutron differential spectrum, estimated windows and detector contributions, upper and lower bounds for an integral response, and group fluxes obtained from neutron transport calculations. 116 references

  9. Comparison of measured and satellite-derived spectral diffuse attenuation coefficients for the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Talaulikar, M.; Desa, E.; Matondkar, S.G.P.; Mascarenhas, A.

    The results of study comparing the spectral diffuse attenuation coefficients Kd(Lambda) measured in the Arabian Sea with those derived from the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) using three algorithms, of which two are empirical...

  10. WINDOWS: a program for the analysis of spectral data foil activation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Stallmann, F.W.; Eastham, J.F.; Kam, F.B.K.

    1978-12-01

    The computer program WINDOWS together with its subroutines is described for the analysis of neutron spectral data foil activation measurements. In particular, the unfolding of the neutron differential spectrum, estimated windows and detector contributions, upper and lower bounds for an integral response, and group fluxes obtained from neutron transport calculations. 116 references. (JFP)

  11. Artifact Interpretation of Spectral Response Measurements on Two-Terminal Multijunction Solar Cells

    NARCIS (Netherlands)

    Si, F.T.; Isabella, O.; Zeman, M.

    2016-01-01

    Multijunction solar cells promise higher power-conversion efficiency than the single-junction. With respect to two-terminal devices, an accurate measurement of the spectral response requires a delicate adjustment of the light- and voltage-biasing; otherwise it can result in artifacts in the data and

  12. Thomson scattering measurements on the high beta pinch Extrap-T1

    International Nuclear Information System (INIS)

    Karlsson, P.

    1989-11-01

    Electron temperature and density measurement on a high beta discharge in the Extrap-T1 device have been performed with Thomson scattering. It was found that the signal levels were low and the plasma background radiation high. The spread of the measured temperatures and densities was large. A computer code was developed to investigate whether this spread in measured temperatures was due to shot to shot variations or to photon statistics. The code showed that the scattered data could be explained by photon statistics

  13. Power spectral density measurements with 252Cf for a light water moderated research reactor

    International Nuclear Information System (INIS)

    King, W.T.; Mihalczo, J.T.

    1979-01-01

    A method of determining the reactivity of far subcritical systems from neutron noise power spectral density measurements with 252 Cf has previously been tested in fast reactor critical assemblies: a mockup of the Fast Flux Test Facility reactor and a uranium metal sphere. Calculations indicated that this measurement was feasible for a pressurized water reactor (PWR). In order to evaluate the ability to perform these measurements with moderated reactors which have long prompt neutron lifetimes, measurements were performed with a small plate-type research reactor whose neutron lifetime (57 microseconds) was about a factor of three longer than that of a PWR and approx. 50% longer than that of a boiling water reactor. The results of the first measurements of power spectral densities with 252 Cf for a water moderated reactor are presented

  14. Luminosity and beta function measurement at the electron-positron collider ring LEP

    CERN Document Server

    Castro, P

    1996-01-01

    The optimization of luminosity needs a fast signal which is provided with the measurement of the rate of small angle Bhabba scattered e+ and e-. It is shown that, despite the excess of background particles received at the detectors, luminosity measurements are possible by using appropriate techniques. The results presented include examples of luminosity optimization with the adjustment of the vertical beam separation at interaction points. The correlation between changes in measured beam sizes and changes in luminosity is shown. In the second part, a new method to obtain precise optics measurements is presented. The procedure to measure the phase advance using 1000-turn orbit measurements of a horizontally or vertically excited beam is described. Beta, alpha and phase advance functions can be obtained exclusively from the phase advances at beam position monitors. This method has been used to measure optics imperfections at LEP. Results of these experiments are compared with simulation results using MAD Measur...

  15. The Measurement of Spectral Characteristics and Composition of Radiation in Atlas with MEDIPIX2-USB Devices

    Science.gov (United States)

    Campbell, M.; Doležal, Z.; Greiffenberg, D.; Heijne, E.; Holy, T.; Idárraga, J.; Jakůbek, J.; Král, V.; Králík, M.; Lebel, C.; Leroy, C.; Llopart, X.; Lord, G.; Maneuski, D.; Ouellette, O.; Sochor, V.; Pospíšil, S.; Suk, M.; Tlustos, L.; Vykydal, Z.; Wilhelm, I.

    2008-06-01

    A network of devices to perform real-time measurements of the spectral characteristics and composition of radiation in the ATLAS detector and cavern during its operation is being built. This system of detectors will be a stand alone system fully capable of delivering real-time images of fluxes and spectral composition of different particle species including slow and fast neutrons. The devices are based on MEDIPIX2 pixel silicon detectors that will be operated via active USB cables and USB-Ethernet extenders through an Ethernet network by a PC located in the USA15 ATLAS control room. The installation of 14 devices inside ATLAS (detector and cavern) is in progress.

  16. The Measurement of Spectral Characteristics and Composition of Radiation in ATLAS with MEDIPIX2-USB Devices

    CERN Document Server

    Campbell, M.; Greiffenberg, D.; Heijne, E.; Holy, T.; Idárraga, J.; Jakubek, J.; Král, V.; Králík, M.; Lebel, C.; Leroy, C.; Llopart, X.; Lord, G.; Maneuski, D.; Ouellette, O.; Sochor, V.; Prospísil, S.; Suk, M; Tlustos, L.; Vykydal, Z.; Wilhelm, I.

    2008-01-01

    A network of devices to perform real-time measurements of the spectral characteristics and composition of radiation in the ATLAS detector and cavern during its operation is being built. This system of detectors will be a stand alone system fully capable of delivering real-time images of fluxes and spectral composition of different particle species including slow and fast neutrons. The devices are based on MEDIPIX2 pixel silicon detectors that will be operated via active USB cables and USB-Ethernet extenders through an Ethernet network by a PC located in the USA15 ATLAS control room. The installation of 14 devices inside ATLAS (detector and cavern) is in progress.

  17. Interpretation of UV radiometric measurements of spectrally non-uniform sources

    International Nuclear Information System (INIS)

    Murphy, P.J.; Gardner, D.G.

    1988-01-01

    Narrow bandpass UV radiometers are used in a variety of high-temperature measurement applications. Significant systematic errors, in the form of an apparent wavelength shift in the system response curve, may be introduced when interpreting data obtained from spectrally nonuniform sources. Theoretical calculations, using transmission curves from commercially available narrow bandpass filters, show that the apparent shift in the system spectral response is a function of temperature for a blackbody source. A brief comparison between the theoretical analysis and experimentaal data is presented

  18. Evaluation of discrimination measures to characterize spectrally similar leaves of African Savannah trees

    CSIR Research Space (South Africa)

    Dudeni, N

    2009-08-01

    Full Text Available tree species. SDA builds a step-by-step model which evaluates the contribution of each spectral band with respect to the discriminatory power of the model. The discriminatory power of the model is measured by the Wilk’s lambda. A spectral band... therefore enters the model if it, according to the Wilk’s lambda criterion, contributes more to the discrimination of the tree species, while it is removed if it contributes least to the discriminatory power of the model. A discriminant model can generally...

  19. Influence of crosstalk phenomenon on the measurement of gross alpha and gross beta radioactivity in drinking water

    International Nuclear Information System (INIS)

    Gerilemandahu; Haribala; Xu Xiao; Shen Na; Sai Wenga; Bai Guilin; Wang Chengguo

    2014-01-01

    Objective: To study the influence of crosstalk phenomenon on the measurement of gross radioactivity in drinking water. Methods: The gross activity in different standard materials with different thickness and area was measured using national standard method. Results: There was no obvious change in crosstalk factor with the increase of "2"4"1Am powder amount in the measurement, whereas the larger amount of uranium used might lead to larger crosstalk factor. The different measurement channels resulted in different crosstalk factors. The influence of beta radioactivity on alpha radioactivity measurement was significant. On the contrary, the alpha-to-beta crosstalk factor was negligible. The area of sample plate imposed no significant influence on crosstalk factor. Conclusions: The gross beta activity can be corrected to decrease the influence of alpha radioactivity using powder standard samples, when simultaneous alpha and beta counting mode is applied in measurement grass radioactivity in drinking water. (authors)

  20. Performance evaluation of spectral deconvolution analysis tool (SDAT) software used for nuclear explosion radionuclide measurements

    International Nuclear Information System (INIS)

    Foltz Biegalski, K.M.; Biegalski, S.R.; Haas, D.A.

    2008-01-01

    The Spectral Deconvolution Analysis Tool (SDAT) software was developed to improve counting statistics and detection limits for nuclear explosion radionuclide measurements. SDAT utilizes spectral deconvolution spectroscopy techniques and can analyze both β-γ coincidence spectra for radioxenon isotopes and high-resolution HPGe spectra from aerosol monitors. Spectral deconvolution spectroscopy is an analysis method that utilizes the entire signal deposited in a gamma-ray detector rather than the small portion of the signal that is present in one gamma-ray peak. This method shows promise to improve detection limits over classical gamma-ray spectroscopy analytical techniques; however, this hypothesis has not been tested. To address this issue, we performed three tests to compare the detection ability and variance of SDAT results to those of commercial off- the-shelf (COTS) software which utilizes a standard peak search algorithm. (author)

  1. Microscopic beta and gamma data for decay-heat needs

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1983-01-01

    Microscopic beta and gamma data for decay-heat needs are defined as absolute-intensity spectral distributions of beta and gamma rays following radioactive decay of radionuclides created by, or following, the fission process. Four well-known evaluated data files, namely the US ENDF/B-V, the UK UKFPDD-2, the French BDN (for fission products), and the Japanese JNDC Nuclear Data Library, are reviewed. Comments regarding the analyses of experimental data (particularly gamma-ray data) are given; the need for complete beta-ray spectral measurements is emphasized. Suggestions on goals for near-term future experimental measurements are presented. 34 references

  2. Measurement system study using beta radiation for determining different paper superficial density

    International Nuclear Information System (INIS)

    Vieira, Thais Molina; Madi Filho, Tufic

    2000-01-01

    Radioisotopes are used now in some areas of the industry. For quality control purposes, they are used in non-destructive analysis (NDA) which is applied to the materials examination verifying if they are adequate to the patterns demanded by technical rules or the market. Gamma, beta or neutron radiation sources may be used to do NDA, depending on material to be analyzed and the industrial process. In this work, the study of measurement system applied to quality control area was conceived and, in the evaluation of the material in test, a radioactive beta source was used. A system was designed and mounted, using a plastic scintillator detector developed in the laboratories of the Centro de Tecnologia das Radiacoes from IPEN-CNEN/SP. Two beta sources were used in the operational test: 90 Sr/ 90 Y and 204 Tl. Measures were obtained using several paper samples with different superficial density in g/m 2 . With the results, an equation correlating the relative activity with the superficial density in g/m 2 was established. (author)

  3. Spectral composition of a measuring signal during measurements of vibration rates of a moving body

    Science.gov (United States)

    Daynauskas, I. A. I.; Slepov, N. N.

    1973-01-01

    Cybernetics diagnostics of machines and mechanisms using the spectral approach is discussed. The problem of establishing the accuracy of determination of the spectral composition is investigated. In systems with rectilinear or rotary movement, the vibrations appear in the form of movement rate vibrations, which are equivalent to frequency modulation of the signal, in proportion to the mean movement rate of the body. The case of a harmonic signal which reproduces and analyzes the characteristics of the frequency modulated signal is discussed. Mathematical models are developed to show the relationships of the parameters.

  4. Ionospheric propagation effects on spectral widths measured by SuperDARN HF radars

    Directory of Open Access Journals (Sweden)

    X. Vallières

    2004-06-01

    Full Text Available SuperDARN HF radars provide a global survey of the large-scale convection transversely to the Earth's magnetic field in the high-latitude ionosphere. In addition to the mean plasma velocity, this network also provides measurements of spectral widths which are related to the level of turbulence of the sounded plasma. There is an increasing interest in using spectral widths in geophysical studies, since they are used to monitor the footprints of several magnetospheric regions. In the present paper, we show the effect of radio wave propagation through a typical turbulent ionosphere on spectral widths measured by SuperDARN radars. This effect has already been evidenced experimentally in a previous paper. Here, we model the effects of meso-scale structures on a radar wave front and study their impact on a typical measurement. Numerical simulations reproduce the effect evidenced experimentally and show the role of meso-scale structures (1-10km in the systematic bias that affects spectral width values. As in experimental data, this effect is shown to be increasing with decreasing radar frequency.

  5. Ionospheric propagation effects on spectral widths measured by SuperDARN HF radars

    Directory of Open Access Journals (Sweden)

    X. Vallières

    2004-06-01

    Full Text Available SuperDARN HF radars provide a global survey of the large-scale convection transversely to the Earth's magnetic field in the high-latitude ionosphere. In addition to the mean plasma velocity, this network also provides measurements of spectral widths which are related to the level of turbulence of the sounded plasma. There is an increasing interest in using spectral widths in geophysical studies, since they are used to monitor the footprints of several magnetospheric regions. In the present paper, we show the effect of radio wave propagation through a typical turbulent ionosphere on spectral widths measured by SuperDARN radars. This effect has already been evidenced experimentally in a previous paper. Here, we model the effects of meso-scale structures on a radar wave front and study their impact on a typical measurement. Numerical simulations reproduce the effect evidenced experimentally and show the role of meso-scale structures (1-10km in the systematic bias that affects spectral width values. As in experimental data, this effect is shown to be increasing with decreasing radar frequency.

  6. A spectral measurement method for determining white OLED average junction temperatures

    Science.gov (United States)

    Zhu, Yiting; Narendran, Nadarajah

    2016-09-01

    The objective of this study was to investigate an indirect method of measuring the average junction temperature of a white organic light-emitting diode (OLED) based on temperature sensitivity differences in the radiant power emitted by individual emitter materials (i.e., "blue," "green," and "red"). The measured spectral power distributions (SPDs) of the white OLED as a function of temperature showed amplitude decrease as a function of temperature in the different spectral bands, red, green, and blue. Analyzed data showed a good linear correlation between the integrated radiance for each spectral band and the OLED panel temperature, measured at a reference point on the back surface of the panel. The integrated radiance ratio of the spectral band green compared to red, (G/R), correlates linearly with panel temperature. Assuming that the panel reference point temperature is proportional to the average junction temperature of the OLED panel, the G/R ratio can be used for estimating the average junction temperature of an OLED panel.

  7. Moeller scattering and the measurement of beta-ray longitudinal polarization

    International Nuclear Information System (INIS)

    Kliwer, J.

    1989-01-01

    Two problems that are inherent in the measurement of longitudinal polarization of beta rays via Moeller scattering (Bhabha scattering for positrons) are the low signal-to-noise ratio due to the electron-nucleon-scattered background and the small fraction of electrons that are polarized in the target. The present article shows how to optimize the signal-to-noise ratio by the collection of Moeller-scattered events using a thick-lens beta-ray spectrometer where the entrance baffle is set very narow to accommodate the relativistically contracted cone of Moeller events; this in turn minimizes the electron-nucleon-scattered background and maximizes the signal-to-noise ratio. In the case of positrons, recent studies of electron channeling in crystals suggest a target that will reduce Bhabha scattering from the large fraction of unpolarized inner-shell electrons and predominantly pick off the polarized fraction of target electrons. (orig.)

  8. Beta Decay in the Field of an Electromagnetic Wave and Experiments on Measuring the Neutrino Mass

    International Nuclear Information System (INIS)

    Dorofeev, O.F.; Lobanov, A.E.

    2005-01-01

    Investigations of the effect of an electromagnetic wave field on the beta-decay process are used to analyze the tritium-decay experimental data on the neutrino mass. It is shown that the electromagnetic wave can distort the beta spectrum, shifting the end point to the higher energy region. This phenomenon is purely classical and it is associated with the electron acceleration in the radiation field. Since strong magnetic fields exist in setups for precise measurement of the neutrino mass, the indicated field can appear owing to the synchrotron radiation mechanism. The phenomenon under consideration can explain the experimentally observed anomalies in the spectrum of the decay electrons; in particular, the effect of the 'negative square of the neutrino mass'

  9. Measurement of high-beta tokamak pressure profiles with multipoint Thomson scattering

    International Nuclear Information System (INIS)

    Levinton, F.M.

    1983-01-01

    A multipoint Thomson-scattering system has been developed to obtain pressure profiles along the major radius of Torus II, a high-beta tokamak. The profiles obtained during the 20 to 25 μs lifetime of the discharge indicates that the plasma has a peak temperature of 80 eV and density of 1.0 x 10 15 cm - 3 . The profiles remain fairly constant during this time until the equilibrium is lost, after which the temperature and density decays to 10 eV and 10 14 cm - 3 very quickly (approx. 1 μs). Experimental results show Torus II has a high-beta ( approx. 10%) equilibrium, with a strong shift of the peak of the pressure profile towards the outside. Numerical results from a 2-D free boundary MHD equilibrium code have obtained equilibria which closely approximate the experimentally measured profiles

  10. Spectral Collection of Polyethylene Pellets at nearly Cryogenic Temperature to Improve Selectivity of Raman Measurement

    International Nuclear Information System (INIS)

    Kim, Saetbyeol; Lee, Sanguk; Hwang, Jinyoung; Chung, Hoeil

    2010-01-01

    Raman spectroscopy has been extensively used for analysis of diverse polymer samples. Normally, Raman spectral collection of samples is routinely performed at room temperature for convenience. However, the feasibility of improving spectral selectivity and the resulting quantitative accuracy, when samples are measured at nearly cryogenic temperature, has not been investigated. For this purpose, we attempted to measure the density of polyethylene (PE) pellets at cryogenic temperatures and the resulting accuracies were compared with that from room temperature measurement. Initially, each of 25 PE sample was allowed to cool down to cryogenic temperature and the corresponding Raman spectra were continuously collected while the temperature of sample increased. When the temperature of sample was at cryogenic temperature, the resulting band widths were narrower compared to those at room temperature, thereby improving the accuracy of density measurement. In overall, the proposed Raman scheme is simple and efficient; therefore, it could be further applied for analysis of other polymers.

  11. Measurement of multilayer mirror reflectivity and stimulated emission in the XUV spectral region

    International Nuclear Information System (INIS)

    Keane, C.; Nam, C.H.; Meixler, L.; Milchberg, H.; Skinner, C.H.; Suckewer, S.; Voorhees, D.; Barbee, T.

    1986-03-01

    We present measurements of multilayer mirror reflectivity and stimulated emission in the XUV spectral region. A molybdenum-silicon multilayer mirror with 12% measured reflectivity at 182 A was found to produce a 120% enhancement of the C VI 182 A line (3 → 2 transition) in a strongly recombining plasma. No such enhancement of the CV 186.7 A line was seen, demonstrating amplification of stimulated emission at 182 A

  12. Methods for measuring the spectral reflectivity of advanced materials at high temperature

    International Nuclear Information System (INIS)

    Salikhov, T.P.; Kan, V.V.

    1993-01-01

    For investigation in the domain of advanced materials as well as for new technologies there is an urgent need for knowledge of the spectral reflectivity of the materials specially at high temperatures. However the methods available are mostly intended for measuring the model materials with specular or diffuse reflection surface. This is not quite correct since advanced materials have mixed specular diffuse reflection surfaces. New methods for reflectivity measurements of materials in the visible, near and middle infrared range at high temperature, regardless of surface texture, have been developed. The advantages of the methods proposed are as flows: (a) the facility of performing the reflectivity measurements for materials with mixed specular diffuse reflectance; (b) wide spectral range 0,38-8 micro m; (c) wide temperature range 300-3000 K; (d) high accuracy and rapid measurements. The methods are based on the following principals (i) Diffuse irradiation of the sample surface and the use of Helkholtz reciprocity principle to determine the directional hemispherical reflectivity ii) Pulse polychromatic probing of the sample by additional light source. The first principle excludes the influence of the angular reflection distribution of sample surface on data obtained. The second principle gives the possibility of simultaneous measurements of the reflectivity. The second principle gives the possibility of simultaneous measurements of the reflectivity in wide spectral range. On the basis of these principles for high temperature reflectometers have been developed and discussed here. (author)

  13. Uncertainty evaluation of thickness and warp of a silicon wafer measured by a spectrally resolved interferometer

    Science.gov (United States)

    Praba Drijarkara, Agustinus; Gergiso Gebrie, Tadesse; Lee, Jae Yong; Kang, Chu-Shik

    2018-06-01

    Evaluation of uncertainty of thickness and gravity-compensated warp of a silicon wafer measured by a spectrally resolved interferometer is presented. The evaluation is performed in a rigorous manner, by analysing the propagation of uncertainty from the input quantities through all the steps of measurement functions, in accordance with the ISO Guide to the Expression of Uncertainty in Measurement. In the evaluation, correlation between input quantities as well as uncertainty attributed to thermal effect, which were not included in earlier publications, are taken into account. The temperature dependence of the group refractive index of silicon was found to be nonlinear and varies widely within a wafer and also between different wafers. The uncertainty evaluation described here can be applied to other spectral interferometry applications based on similar principles.

  14. Measurement of beta emitting radionuclides in dose calibrators routinely used in nuclear medicine departments

    International Nuclear Information System (INIS)

    Tastan, S.; Soylu, A.; Kucuk, O.; Ibis, E.

    2004-01-01

    Full text: Radionuclides for diagnostics purposes like Tc-99m, Tl-201, Ga-67 and In-111 are measured by using ionization type of dose calibrators. Therapeutic radionuclides, which emit both beta and gamma rays are detected by the same type of dose calibrators. Other therapeutic products like Y-90, P-32 and Sr-89 are pure beta emitters and they are gaining wider utility because various new therapy radiopharmaceuticals are being developed. The type of container material, like glass or plastic, may seriously affect radioactivity measurement due to attenuation, Since it is crucial to give the exact amount of radioactivity to the patient for therapy purposes, dedicated dose calibrators are specially manufactured for the measurement of these radionuclides. But these measuring systems are not widely available in nuclear medicine centers where therapy is applied to the patient. It is a known fact that dose calibrators routinely used in nuclear medicine departments can be calibrated for vials and syringes using standard sources of the same radioisotope. The method of calibration of Y-90 measurement for two ionization chamber dose calibrators available in the institute will be summarized in this presentation

  15. Measurement of beta emitting radionuclides in dose calibrators routinely used in nuclear medicine departments

    International Nuclear Information System (INIS)

    Tastan, S.; Soylu, A.; Kucuk, O.; Ibis, E.

    2004-01-01

    Radionuclides for diagnostics purposes like Tc-99m, Tl-201, Ga-67 and In-111 are measured by using ionization type of dose calibrators. Therapeutic radionuclides, which emit both beta and gamma rays are detected by the same type of dose calibrators. Other therapeutic products like Y-90, P-32 and Sr-89 are pure beta emitters and they are gaining wider utility because various new therapy radiopharmaceuticals are being developed. The type of container material, like glass or plastic, may seriously affect radioactivity measurement due to attenuation, Since it is crucial to give the exact amount of radioactivity to the patient for therapy purposes, dedicated dose calibrators are specially manufactured for the measurement of these radionuclides. But these measuring systems are not widely available in nuclear medicine centers where therapy is applied to the patient. It is a known fact that dose calibrators routinely used in nuclear medicine departments can be calibrated for vials and syringes using standard sources of the same radioisotope. The method of calibration of Y-90 measurement for two ionization chamber dose calibrators available in the institute will be summarized in this presentation. (author)

  16. Measurement of the lepton τ spectral functions and applications to quantum chromodynamic

    International Nuclear Information System (INIS)

    Hoecker, A.

    1997-01-01

    This thesis presents measurements of the τ vector (V) and axial-vector (A) hadronic spectral functions and phenomenological studies in the framework of quantum chromodynamics (QCD). Using the hypothesis of conserved vector currents (CVC), the dominant two- and four-pion vector spectral functions are compared to the corresponding cross sections from e + e - annihilation. A combined fit of the pion form factor from τ decays and e + e - data is performed using different parametrizations. The mass and the width of the ρ ± (770) and the ρ 0 (770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M ρ ± (770) - M ρ 0 (770) =(0.0±1.0) MeV/c 2 and Γ ρ ± (770) - Γ ρ 0 (770) =(0.1 ± 1.9) MeV/c 2 . Several QCD chiral sum rules involving the difference (V - A) of the spectral functions are compared to their measurements. The Borel-transformed Das-Mathur-Okubo sum rule is used to measure the pion polarizability to be α E =(2.68±0.91) x 10 -4 fm 3 . The τ vector and axial-vector hadronic widths and certain spectral moments are exploited to measure α s and non-perturbative contributions at the τ mass scale. The best, and experimentally and theoretically most robust, determination of α s (M τ ) is obtained from the inclusive (V + A) fit that yields α s (M τ )= 0.348±0.017 giving α s (M Z )=0.1211 ± 0.0021 after the evolution to the mass of the Z boson. The approach of the Operator Product Expansion (OPE) is tested experimentally by means of an evolution of the τ hadronic width to masses smaller that the τ mass. Using the difference (V - A) of the spectral functions allows one to directly measure the dominant non-perturbative OPE dimension to be D=6.9±0.5. The vector spectral functions are used to improve the precision of the experimental determination of the hadronic contribution to the anomalous magnetic moment of the muon a μ =(g - 2)/2 and to the running of the QED

  17. Measurement of reactor parameters of the 'Nora' reactor by noise analysis method - power spectral density

    International Nuclear Information System (INIS)

    Jovanovic, S.; Stormark, E.

    1966-01-01

    Measurements of reactor parameters the Nora reactor by Power Spectral Density (PSD) method are described. In case of critical reactor this method was applied for direct measurement of β/l ratio, β is the effective yield of delayed neutrons and l is the neutron lifetime. In case of subcritical reactor values of α+β-ρ/l were measured, ρ is the negative reactivity. Out coming PSD was measured by a filter or by ISAC. PSD was registered by ISAC as well as the auto-correlation function [sr

  18. Agricultural Soil Spectral Response and Properties Assessment: Effects of Measurement Protocol and Data Mining Technique

    Directory of Open Access Journals (Sweden)

    Asa Gholizadeh

    2017-10-01

    Full Text Available Soil spectroscopy has shown to be a fast, cost-effective, environmentally friendly, non-destructive, reproducible and repeatable analytical technique. Soil components, as well as types of instruments, protocols, sampling methods, sample preparation, spectral acquisition techniques and analytical algorithms have a combined influence on the final performance. Therefore, it is important to characterize these differences and to introduce an effective approach in order to minimize the technical factors that alter reflectance spectra and consequent prediction. To quantify this alteration, a joint project between Czech University of Life Sciences Prague (CULS and Tel-Aviv University (TAU was conducted to estimate Cox, pH-H2O, pH-KCl and selected forms of Fe and Mn. Two different soil spectral measurement protocols and two data mining techniques were used to examine seventy-eight soil samples from five agricultural areas in different parts of the Czech Republic. Spectral measurements at both laboratories were made using different ASD spectroradiometers. The CULS protocol was based on employing a contact probe (CP spectral measurement scheme, while the TAU protocol was carried out using a CP measurement method, accompanied with the internal soil standard (ISS procedure. Two spectral datasets, acquired from different protocols, were both analyzed using partial least square regression (PLSR technique as well as the PARACUDA II®, a new data mining engine for optimizing PLSR models. The results showed that spectra based on the CULS setup (non-ISS demonstrated significantly higher albedo intensity and reflectance values relative to the TAU setup with ISS. However, the majority of statistics using the TAU protocol was not noticeably better than the CULS spectra. The paper also highlighted that under both measurement protocols, the PARACUDA II® engine proved to be a powerful tool for providing better results than PLSR. Such initiative is not only a way to

  19. Measurement of high-temperature spectral emissivity using integral blackbody approach

    Science.gov (United States)

    Pan, Yijie; Dong, Wei; Lin, Hong; Yuan, Zundong; Bloembergen, Pieter

    2016-11-01

    Spectral emissivity is one of the most critical thermophysical properties of a material for heat design and analysis. Especially in the traditional radiation thermometry, normal spectral emissivity is very important. We developed a prototype instrument based upon an integral blackbody method to measure material's spectral emissivity at elevated temperatures. An optimized commercial variable-high-temperature blackbody, a high speed linear actuator, a linear pyrometer, and an in-house designed synchronization circuit was used to implemented the system. A sample was placed in a crucible at the bottom of the blackbody furnace, by which the sample and the tube formed a simulated reference blackbody which had an effective total emissivity greater than 0.985. During the measurement, a pneumatic cylinder pushed a graphite rode and then the sample crucible to the cold opening within hundreds of microseconds. The linear pyrometer was used to monitor the brightness temperature of the sample surface, and the corresponding opto-converted voltage was fed and recorded by a digital multimeter. To evaluate the temperature drop of the sample along the pushing process, a physical model was proposed. The tube was discretized into several isothermal cylindrical rings, and the temperature of each ring was measurement. View factors between sample and rings were utilized. Then, the actual surface temperature of the sample at the end opening was obtained. Taking advantages of the above measured voltage signal and the calculated actual temperature, normal spectral emissivity under the that temperature point was obtained. Graphite sample at 1300°C was measured to prove the validity of the method.

  20. Measurement of the spectral functions of vector current hadronic $\\tau$ decays

    CERN Document Server

    Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Pietrzyk, B; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Miquel, R; Mir, L M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Alemany, R; Becker, U; Bazarko, A O; Bright-Thomas, P G; Cattaneo, M; Cerutti, F; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Mato, P; Minten, Adolf G; Moneta, L; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rizzo, G; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Thomson, F; Turnbull, R M; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Coyle, P; Diaconu, C A; Etienne, F; Konstantinidis, N P; Leroy, O; Motsch, F; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Berlich, R; Blum, Walter; Büscher, V; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Schune, M H; Simion, S; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y S; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Yamartino, J M; Zobernig, G

    1997-01-01

    A measurement of the spectral functions of non-strange tau vector current final states is presented, using 124,358 tau pairs recorded by the ALEPH detector at LEP during the years 1991 to 1994. The spectral functions of the dominant two- and four-pion tau decay channels are compared to published results of e+e- annihilation experiments via isospin rotation. A combined fit of the pion form factor from tau decays and e+e- data is performed using different parametrizations. The mass and the width of the charged and the neutral rho(770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M(rho^+/-(770)) - M(rho^0(770)) = (0.0 +/- 1.0) MeV/c^2 and Gamma(rho^+/-(770)) - Gamma(rho^0(770)) = (0.1 +/- 1.9) MeV/c^2.

  1. 4{pi} proportional counter for absolute measurement of {beta}-emitters; Compteur 4{pi} proportionnel destine a la mesure absolue d'emetteurs {beta}

    Energy Technology Data Exchange (ETDEWEB)

    Perolat, J P; Laine, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The 4{pi} counter is commonly used to measure the activity of {beta} sources, the one we describe does not advance a new conception but the issue of several years of investigations. The apparatus presents good performances about the qualities commonly required in that kind of counter: detection efficiency, plateau and dead time. Moreover technical characteristics give a great flexibility in use, particularly a possibility of adaptation in a {beta},{gamma} coincidence unit. (authors) [French] Le compteur 4{pi} proportionnel est couramment, utilise pour mesurer l'activite de sources {beta}, celui que nous decrivons ne represente pas une conception nouvelle, mais plutot l'aboutissement de plusieurs annees d'etudes. Cette installation presente des performances satisfaisantes en ce qui concerne les qualites habituellement requises dans ce type de compteur: l'efficacite de detection, le palier et le temps mort. En outre, certaines caracteristiques techniques qui lui sont propres lui conferent une grande souplesse d'utilisation, en particulier la possibilite d'adaptation a un ensemble de mesures par coincidences 4{pi} {beta} {gamma}. (auteurs)

  2. Beam Optics Studies in the Large Hadron Collider Observations on an Anomalous Octupolar Resonance Line in the LHC -- and -- Accuracy & Feasibility of the $\\beta^*$ Measurement for LHC and HL-LHC Using K-Modulation

    CERN Document Server

    Carlier, F S

    While linear LHC dynamics are mostly understood and under control, non-linear beam dynamics will play an increasingly important role in the challenging regimes of future LHC operation. In 2012, turn-by-turn measurements of large betatron excitations of LHC Beam 2 at injection energy were carried out. These measurements revealed an unexpectedly large spectral line in the horizontal motion with frequency $-Q_x-2Q_y$. Detailed analyses and simulations are presented to understand the nature of this spectral line. -- ABSTRACT II -- The future regimes of operation of the LHC will require improved control of $\\beta^*$ measurements to succesfully level the luminosities in the interaction points. The method of K-modulation has been widely used in other machines such as, LEP, HERA, Tevatron and ALBA to measure lattice beta functions. In the LHC, K-modulation of the last quadrupoles of the IP is the method to measure $\\beta^*$ in the IP. This paper highlights the challenge of high precision tune measurements (up to $10...

  3. Selection of the ''best'' model for converting beta backscatter count readings into thickness measurements

    International Nuclear Information System (INIS)

    Smiriga, N.G.

    1976-01-01

    This report compares two models for converting beta backscatter count readings into thickness measurements. The necessary formulas to be used in an unweighted and weighted regression analysis are listed. The question of whether one should perform a regression analysis using the five available standard thicknesses or whether one should, in addition to these standard thicknesses, use zero as a standard thickness is decided. A weighted regression analysis is compared with an unweighted one for each model. The ''best'' model is selected, and the conclusions of the analysis are presented

  4. Coulomb field strength measurement by electro-optic spectral decoding system at the CALIFES beam line

    CERN Document Server

    Pan, R; Lefevre, T; Gillepsie, WA; CERN. Geneva. ATS Department

    2016-01-01

    Electro-optic (EO) techniques are increasingly used for longitudinal bunch profile measurements. A bunch profile monitor, based on electro-optic spectral decoding(EOSD), has been developed and demonstrated on the CALIFES beam line at CERN. The EO response is analysed using a frequency domain description, and two methods for extraction of absolute Coulomb field strengths from the electron bunch are demonstrated. Measurements at field strengths up to 1.3 MV/m agree with the expectation based on independent charge measurements.

  5. Stark shift measurements of Xe II and Xe III spectral lines

    International Nuclear Information System (INIS)

    Cirisan, M; Pelaez, R J; Djurovic, S; Aparicio, J A; Mar, S

    2007-01-01

    Stark shift measurements of singly and doubly ionized Xe spectral lines are presented in this paper. Shifts of 110 Xe II lines and 42 Xe III lines are reported, including a significant number of new results. A low-pressure-pulsed arc with 95% of He and 5% of Xe was used as a plasma source. All measurements were performed under the following plasma conditions: electron density (0.2-1.4) x 10 23 m -3 and electron temperature 18 000-23 000 K. The measured Stark shifts are compared with other experimental and theoretical data

  6. New experimental device for high-temperature normal spectral emissivity measurements of coatings

    International Nuclear Information System (INIS)

    Honnerová, Petra; Martan, Jiří; Kučera, Martin; Honner, Milan; Hameury, Jacques

    2014-01-01

    A new experimental device for normal spectral emissivity measurements of coatings in the infrared spectral range from 1.38 μm to 26 μm and in the temperature range from 550 K to 1250 K is presented. A Fourier transform infrared spectrometer (FTIR) is used for the detection of sample and blackbody spectral radiation. Sample heating is achieved by a fiber laser with a scanning head. Surface temperature is measured by two methods. The first method uses an infrared camera and a reference coating with known effective emissivity, the second method is based on the combination of Christiansen wavelength with contact and noncontact surface temperature measurement. Application of the method is shown on the example of a high-temperature high-emissivity coating. Experimental results obtained with this apparatus are compared with the results performed by a direct method of Laboratoire National d’Essais (LNE) in France. The differences in the spectra are analyzed. (paper)

  7. Improving the spectral measurement accuracy based on temperature distribution and spectra-temperature relationship

    Science.gov (United States)

    Li, Zhe; Feng, Jinchao; Liu, Pengyu; Sun, Zhonghua; Li, Gang; Jia, Kebin

    2018-05-01

    Temperature is usually considered as a fluctuation in near-infrared spectral measurement. Chemometric methods were extensively studied to correct the effect of temperature variations. However, temperature can be considered as a constructive parameter that provides detailed chemical information when systematically changed during the measurement. Our group has researched the relationship between temperature-induced spectral variation (TSVC) and normalized squared temperature. In this study, we focused on the influence of temperature distribution in calibration set. Multi-temperature calibration set selection (MTCS) method was proposed to improve the prediction accuracy by considering the temperature distribution of calibration samples. Furthermore, double-temperature calibration set selection (DTCS) method was proposed based on MTCS method and the relationship between TSVC and normalized squared temperature. We compare the prediction performance of PLS models based on random sampling method and proposed methods. The results from experimental studies showed that the prediction performance was improved by using proposed methods. Therefore, MTCS method and DTCS method will be the alternative methods to improve prediction accuracy in near-infrared spectral measurement.

  8. Search for new physics in a precise 20F beta spectrum shape measurement

    Science.gov (United States)

    George, Elizabeth; Voytas, Paul; Chuna, Thomas; Naviliat-Cuncic, Oscar; Gade, Alexandra; Hughes, Max; Huyan, Xueying; Liddick, Sean; Minamisono, Kei; Paulauskas, Stanley; Weisshaar, Dirk; Ban, Gilles; Flechard, Xavier; Lienard, Etienne

    2015-10-01

    We are carrying out a measurement of the shape of the energy spectrum of β particles from 20F decay. We aim to achieve a relative precision below 3%, representing an order of magnitude improvement compared to previous experiments. This level of precision will enable a test of the so-called strong form of the conserved vector current (CVC) hypothesis, and should also enable us to place competitive limits on the contributions of exotic tensor couplings in beta decay. In order to control systematic effects, we are using a technique that takes advantage of high energy radioactive beams at the NSCL to implant the decaying nuclei in a scintillation detector deep enough that the emitted beta particles cannot escape. The β-particle energy is measured with the implantation detector after switching off the beam implantation. Ancillary detectors are used to tag the 1.633-MeV γ-rays following the β decay for coincidence measurements in order to reduce backgrounds. We will give an overview and report on the status of the experiment.

  9. Measurement of Radon-Induced Backgrounds in the NEXT Double Beta Decay Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Novella, P.; et al.

    2018-04-02

    The measurement of the internal 222Rn activity in the NEXT-White detector during the so-called Run-II period with 136Xe-depleted xenon is discussed in detail, together with its implications for double beta decay searches in NEXT. The activity is measured through the alpha production rate induced in the fiducial volume by 222Rn and its alpha-emitting progeny. The specific activity is measured to be $(37.5\\pm 2.3~\\mathrm{(stat.)}\\pm 5.9~\\mathrm{(syst.)})$~mBq/m$^3$. Radon-induced electrons have also been characterized from the decay of the 214Bi daughter ions plating out on the cathode of the time projection chamber. From our studies, we conclude that radon-induced backgrounds are sufficiently low to enable a successful NEXT-100 physics program, as the projected rate contribution should not exceed 0.2~counts/yr in the neutrinoless double beta decay sample.

  10. Optical decoherence times and spectral diffusion in an Er-doped optical fiber measured by two-pulse echoes, stimulated photon echoes, and spectral hole burning

    International Nuclear Information System (INIS)

    Macfarlane, R.M.; Sun, Y.; Sellin, P.B.; Cone, R.L.

    2007-01-01

    Two-pulse and stimulated photon echoes and spectral hole burning were measured on the transition from the lowest component of the 4 I 15/2 manifold to the lowest component of 4 I 13/2 of Er 3+ in a silicate optical fiber at 1.6 K. The two-pulse echo decays gave decoherence times as long as 230 ns for magnetic fields above 2 T. A large field dependent contribution to the homogeneous line width of >2 MHz was found and interpreted in terms of coupling to magnetic tunneling modes (TLS) in the glass. The stimulated echoes measured at 2 T showed spectral diffusion of 0.8 MHz/decade of time between 0.4 and 500 μs. Spectral diffusion in this high field region is attributed to coupling to elastic TLS modes which have a distribution of flip rates in glasses. Time-resolved spectral hole burning at very low field showed stronger spectral diffusion of 5.7 MHz/decade of time, attributed to coupling to magnetic spin-elastic TLS modes

  11. Spectral Ly{alpha}, Ly{beta}, and H{alpha} line shapes for the H atom in the presence of a magnetic field in a plasma; Profils des raies spectrales Ly{alpha}, Ly{beta}, et H{alpha} de l'atome H en presence d'un champ magnetique dans un plasma

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, H; Herman, L [Laboratoire de Recherches Physiques, Faculte des sciences, 9 Quai Saint Bernard, 75 - Paris (France); Drawin, H W [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1967-02-15

    This report contains numerical data of the line shapes of Ly{alpha}, Ly{beta}, and H{alpha} for the following parameters: 1. 10{sup 2} {<=} H [gauss] {<=} 1.2. 10{sup 5} 1. 10{sup 15}{<=} N [cm{sup -3}] {<=} 1. 10{sup 18} cm{sup -3} 1. 10{sup 4} {<=} T [deg. K] {<=} 4. 10{sup 4} where H = magnetic field strength, K = density of plasma ions, T = electron temperature. (authors) [French] Dans ce rapport, on donne les valeurs numeriques des contours des raies spectrales Ly{alpha}, Ly{beta}, et H{alpha} pour les valeurs suivantes des parametres H, N et T 1. 10{sup 2} {<=} H [gauss] {<=} 1.2. 10{sup 5} 1. 10{sup 15}{<=} N [cm{sup -3}] {<=} 1. 10{sup 18} cm{sup -3} 1. 10{sup 4} {<=} T [deg. K] {<=} 4. 10{sup 4} ou H intensite du champ magnetique, N = densite des ions, T = temperature electronique. (auteurs)

  12. Spectral-Domain Measurement of Strain Sensitivity of a Two-Mode Birefringent Side-Hole Fiber

    Directory of Open Access Journals (Sweden)

    Waclaw Urbanczyk

    2012-09-01

    Full Text Available The strain sensitivity of a two-mode birefringent side-hole fiber is measured in the spectral domain. In a simple experimental setup comprising a broadband source, a polarizer, a two-mode birefringent side-hole fiber under varied elongations, an analyzer and a compact spectrometer, the spectral interferograms are resolved. These are characterized by the equalization wavelength at which spectral interference fringes have the highest visibility (the largest period due to the zero group optical path difference between the fundamental, the LP01 mode and the higher-order, the LP11 mode. The spectral interferograms with the equalization wavelength are processed to retrieve the phase as a function of the wavelength. From the retrieved phase functions corresponding to different elongations of a two-mode birefringent side-hole fiber under test, the spectral strain sensitivity is obtained. Using this approach, the intermodal spectral strain sensitivity was measured for both x and y polarizations. Moreover, the spectral polarimetric sensitivity to strain was measured for the fundamental mode when a birefringent delay line was used in tandem with the fiber. Its spectral dependence was also compared with that obtained from a shift of the spectral interferograms not including the equalization wavelength, and good agreement was confirmed.

  13. Measurement of the beta-gamma directional correlation of the transition 46Sc→46Ti

    International Nuclear Information System (INIS)

    Krexner, G.

    1978-01-01

    Measuring the forward - backward asymmetry of the direction of gamma quanta with respect to the direction of a preceding beta particle emission is one of the methods which have been developed over the past twenty years to investigate parity admixtures in nuclear states. Both theoretical calculations and experiments using this method yield very small values for the considered effect. Moreover the accuracy is limited for statistical reasons. Hence there exists a fundamental interest in proving the experimental arrangement to be free of systematic errors. The subject of this work is an experiment checking a six - detector apparatus which has been used to investigate the beta - gamma directional correlation in the decay 203 Hg→ 203 Tl. For the control measurement the transition 46 Sc→ 46 Ti was chosen. The asymmetry coefficient should yield zero and thus furnish evidence of the absence of systematic errors. The necessary 46 Sc source had to meet very restricting requirements. The feasibility of various methods for producing radioactive samples was reviewed; finally a specially designed high vacuum evaporation plant was constructed. The concept of this device and the preparation of the source are dealt with in detail. A preliminary result of the control experiment is given. However, at present a definite interpretation of the obtained values is not possible. (author)

  14. Measurement of the $\\beta$-asymmetry parameter in $^{35}$Ar decay with a laser polarized beam

    CERN Multimedia

    With this proposal we request beam time for the first two phases of a project that aims at measuring the $\\beta$-asymmetry parameter of the mirror $\\beta$-decay branch in $^{35}$Ar using an optically polarized Ar atom beam. The final goal of the experiment is to measure this parameter to a precision of 0.5%. This will allow the most precise determination of the V$_{ud}$ quark mixing matrix element from all the mirror transitions with an absolute uncertainty of 0.0007. The proposal will be presented in phases and we ask here 11 shifts (7 on-line + 4 off-line) for phase 1 and 15 shifts (6 on-line and 9 off-line) for phase 2. Phase 1 aims at establishing the optimal laser polarization scheme as well as the best implantation host for maintaining the polarization. Phase 2 aims at enhancing the beam polarization by removing the unpolarized part of the beam using re-ionization.

  15. An On-Line Water Monitor for Low Level {beta}-Radioactivity Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Quirk, E J.M.

    1968-05-15

    A detection system is described for the continuous monitoring of {beta}-radioactivity in the secondary cooling water at the Studsvik R2 reactor. Radiation emanating from a water surface is measured by a large area gas proportional detector. To protect the detector from splash caused by bursting bubbles a protective film and heater assembly is interposed between the detector and the water surface. A special feature is the programmed 'exercise' sequence for the magnetic valves which eliminates a tendency for them to stick after prolonged periods of idleness. The extent to which contamination affects the background counting rate has been studied. It is shown that for the duration of the tests described the monitor remains free from the effects of contamination so long as the scaler live time is suitably chosen. Minimum measurable specific activities obtainable in practice extend from 4 x 10{sup -6} to 3.86 x 10{sup -8} Ci/m{sup 3} depending on the {beta} end-point energy in the range 167 keV - 2.26 MeV.

  16. Spectral interferometry including the effect of transparent thin films to measure distances and displacements

    International Nuclear Information System (INIS)

    Hlubina, P.

    2004-01-01

    A spectral-domain interferometric technique is applied for measuring mirror distances and displacements in a dispersive Michelson interferometer when the effect of transparent thin films coated onto the interferometer beam splitter and compensator is known. We employ a low-resolution spectrometer in two experiments with different amounts of dispersion in a Michelson interferometer that includes fused-silica optical sample. Knowing the thickness of the optical sample and the nonlinear phase function of the thin films, the positions of the interferometer mirror are determined precisely by a least-squares fitting of the theoretical spectral interferograms to the recorded ones. We compare the results of the processing that include and do not include the effect of transparent thin films (Author)

  17. A climate index derived from satellite measured spectral infrared radiation. Ph.D. Thesis

    Science.gov (United States)

    Abel, M. D.; Fox, S. K.

    1982-01-01

    The vertical infrared radiative emitting structure (VIRES) climate index, based on radiative transfer theory and derived from the spectral radiances typically used to retrieve temperature profiles, is introduced. It is assumed that clouds and climate are closely related and a change in one will result in a change in the other. The index is a function of the cloud, temperature, and moisture distributions. It is more accurately retrieved from satellite data than is cloudiness per se. The VIRES index is based upon the shape and relative magnitude of the broadband weighting function of the infrared radiative transfer equation. The broadband weighting curves are retrieved from simulated satellite infrared sounder data (spectral radiances). The retrieval procedure is described and the error error sensitivities of the method investigated. Index measuring options and possible applications of the VIRES index are proposed.

  18. Classification of Astaxanthin Colouration of Salmonid Fish using Spectral Imaging and Tricolour Measurement

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg; Dissing, Bjørn Skovlund; Nielsen, Michael Engelbrecht

    capturing, tricolour CIELAB measurement, and manual SalmoFan inspection. Furthermore it was tested whether the best predictions come from measurements of the steak or the fillet of the fish. Methods used for classication were linear discriminant analysis (LDA), quadratic discriminant analysis (QDA......The goal of this study was to investigate if it is possible to differentiate between rainbow trout (Oncorhynchus mykiss) having been fed with natural or synthetic astaxanthin. Three different techniques were used for visual inspection of the surface colour of the fish meat: multi-spectral image...

  19. Classification of Hyperspectral or Trichromatic Measurements of Ocean Color Data into Spectral Classes

    Directory of Open Access Journals (Sweden)

    Dilip K. Prasad

    2016-03-01

    Full Text Available We propose a method for classifying radiometric oceanic color data measured by hyperspectral satellite sensors into known spectral classes, irrespective of the downwelling irradiance of the particular day, i.e., the illumination conditions. The focus is not on retrieving the inherent optical properties but to classify the pixels according to the known spectral classes of the reflectances from the ocean. The method compensates for the unknown downwelling irradiance by white balancing the radiometric data at the ocean pixels using the radiometric data of bright pixels (typically from clouds. The white-balanced data is compared with the entries in a pre-calibrated lookup table in which each entry represents the spectral properties of one class. The proposed approach is tested on two datasets of in situ measurements and 26 different daylight illumination spectra for medium resolution imaging spectrometer (MERIS, moderate-resolution imaging spectroradiometer (MODIS, sea-viewing wide field-of-view sensor (SeaWiFS, coastal zone color scanner (CZCS, ocean and land colour instrument (OLCI, and visible infrared imaging radiometer suite (VIIRS sensors. Results are also shown for CIMEL’s SeaPRISM sun photometer sensor used on-board field trips. Accuracy of more than 92% is observed on the validation dataset and more than 86% is observed on the other dataset for all satellite sensors. The potential of applying the algorithms to non-satellite and non-multi-spectral sensors mountable on airborne systems is demonstrated by showing classification results for two consumer cameras. Classification on actual MERIS data is also shown. Additional results comparing the spectra of remote sensing reflectance with level 2 MERIS data and chlorophyll concentration estimates of the data are included.

  20. Measurement of spectral phase noise in a cryogenically cooled Ti:Sa amplifier (Conference Presentation)

    Science.gov (United States)

    Nagymihaly, Roland S.; Jójárt, Péter; Börzsönyi, Ádám.; Osvay, Károly

    2017-05-01

    In most of cases the drift of the carrier envelope phase (CEP) of a chirped pulse amplifier (CPA) system is determined only [1], being the relevant parameter at laser-matter interactions. The need of coherent combination of multiple amplifier channels to further increase the peak power of pulses requires interferometric precision [2]. For this purpose, the stability of the group delay of the pulses may become equally important. Further development of amplifier systems requires the investigation of phase noise contributions of individual subsystems, like amplifier stages. Spectrally resolved interferometry (SRI), which is a completely linear optical method, makes the measurement of spectral phase noise possible of basically any part of a laser system [3]. By utilizing this method, the CEP stability of water-cooled Ti:Sa based amplifiers was investigated just recently, where the effects of seed and pump energy, repetition rate, and the cooling crystal mounts were thoroughly measured [4]. We present a systematic investigation on the noise of the spectral phase, including CEP, of laser pulses amplified in a cryogenically-cooled Ti:Sa amplifier of a CPA chain. The double-pass amplifier was built in the sample arm of a compact Michelson interferometer. The Ti:Sa crystal was cooled below 30 °K. The inherent phase noise was measured for different operation modes, as at various repetition rates, and pump depletion. Noise contributions of the vacuum pumps and the cryogenic refrigerator were found to be 43 and 47 mrad, respectively. We have also identified CEP noise having thermal as well as mechanical origin. Both showed a monotonically decreasing tendency towards higher repetition rates. We found that the widths of the noise distributions are getting broader towards lower repetition rates. Spectral phase noise with and without amplification was measured, and we found no significant difference in the phase noise distributions. The mechanical vibration was also measured in

  1. Airborne Spectral Measurements of Surface-Atmosphere Anisotropy for Arctic Sea Ice and Tundra

    Science.gov (United States)

    Arnold, G. Thomas; Tsay, Si-Chee; King, Michael D.; Li, Jason Y.; Soulen, Peter F.

    1999-01-01

    Angular distributions of spectral reflectance for four common arctic surfaces: snow-covered sea ice, melt-season sea ice, snow-covered tundra, and tundra shortly after snowmelt were measured using an aircraft based, high angular resolution (1-degree) multispectral radiometer. Results indicate bidirectional reflectance is higher for snow-covered sea ice than melt-season sea ice at all wavelengths between 0.47 and 2.3 pm, with the difference increasing with wavelength. Bidirectional reflectance of snow-covered tundra is higher than for snow-free tundra for measurements less than 1.64 pm, with the difference decreasing with wavelength. Bidirectional reflectance patterns of all measured surfaces show maximum reflectance in the forward scattering direction of the principal plane, with identifiable specular reflection for the melt-season sea ice and snow-free tundra cases. The snow-free tundra had the most significant backscatter, and the melt-season sea ice the least. For sea ice, bidirectional reflectance changes due to snowmelt were more significant than differences among the different types of melt-season sea ice. Also the spectral-hemispherical (plane) albedo of each measured arctic surface was computed. Comparing measured nadir reflectance to albedo for sea ice and snow-covered tundra shows albedo underestimated 5-40%, with the largest bias at wavelengths beyond 1 pm. For snow-free tundra, nadir reflectance underestimates plane albedo by about 30-50%.

  2. Measuring instrument for the determination of dust concentrations. [air filter with. beta. radiometric gage

    Energy Technology Data Exchange (ETDEWEB)

    Dresia, H; Spohr, F

    1975-05-22

    The measuring instrument enables a continuous determination of the dust concentration or total dust content in gases on the basis of the radiometric mass determination of dusts. The partial current method is employed, with the gas fetched through a filter cell with a topped intake by a suction pump. A filter band to take up the dust deposit is continuously driven through the filter cell. The filter point and the measuring point with a ..beta..-radionuclide and a detector are both inside the filter cell. The filter cell is sealed all around, at the entrance and exit of the filter band. The band itself acts as a seal. The filter band also has borders strengthened with, e.g., plastic strips which engage the drive. The widths of the slits are adjustable in height.

  3. Method for measuring the disintegration rate of a beta-emitting radionuclide in a liquid sample

    International Nuclear Information System (INIS)

    1977-01-01

    A method of measuring the distintegration rate of a beta-emitting radionuclide in a liquid sample by counting at least two differently quenched versions of the sample. In each counting operation the sample is counted in the presence of and in the absence of a standard radioactive source. A pulse height (PH) corresponding to a unique point on the pulse height spectrum generated in the presence of the standard is determined. A zero threshold sample count rate (CPM) is derived by counting the sample once in a counting window having a zero threshold lower limit. Normalized values of the measured pulse heights (PH) are developed and correlated with the corresponding counts (CPM) to determine the pulse count for a normalized pulse height value of zero and hence the sample disintegration rate

  4. Method of measuring the disinteration rate of beta-emitting radionuclide in a liquid sample

    International Nuclear Information System (INIS)

    Horrocks, D.L.

    1977-01-01

    A method of measuring the disintegration rate of a beta-emitting radionuclide in a liquid sample by counting at least two differently quenched versions of the sample is described. In each counting operation the sample is counted in the presence of and in the absence of a standard radioactive source. A pulse height (PH) corresponding to a unique point on the pulse height spectrum generated in the presence of the standard is determined. A zero threshold sample count rate (CPM) is derived by counting the sample once in a counting window having a zero threshold lower limit. Normalized values of the measured pulse heights (PH) are developed and correlated with the corresponding pulse counts (CPM) to determine the pulse count for a normalized pulse height value of zero and hence the sample disintegration rate

  5. Spectral Interpolation and Unfolding to Measure Multi-labelled Samples by Liquid Scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    1991-07-01

    A new procedure to determine the activity of each mixture is described. The information contained in pulse height spectra is used. The dilatation, in the steps are essential to obtain a good experimental fitting. The procedure can be applied to mixtures by {beta}''-, {beta}''-, {gamma}, {beta}''+, {beta}''+- {gamma}, EC, Ec-{gamma} and isomeric transitions. (Author) 10 refs.

  6. Radioactivity determination of sealed pure beta-sources by surface dose measurements and Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chang Heon [Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Seongmoon [Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of); Choi, Kanghyuk; Son, Kwang-Jae; Lee, Jun Sig [Hanaro Applications Research, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Ye, Sung-Joon, E-mail: sye@snu.ac.kr [Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul (Korea, Republic of); Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of); Center for Convergence Research on Robotics, Advance Institutes of Convergence Technology, Seoul National University, Suwon (Korea, Republic of)

    2016-04-21

    This study aims to determine the activity of a sealed pure beta-source by measuring the surface dose rate using an extrapolation chamber. A conversion factor (cGy s{sup −1} Bq{sup −1}), which was defined as the ratio of surface dose rate to activity, can be calculated by Monte Carlo simulations of the extrapolation chamber measurement. To validate this hypothesis the certified activities of two standard pure beta-sources of Sr/Y-90 and Si/P-32 were compared with those determined by this method. In addition, a sealed test source of Sr/Y-90 was manufactured by the HANARO reactor group of KAERI (Korea Atomic Energy Research Institute) and used to further validate this method. The measured surface dose rates of the Sr/Y-90 and Si/P-32 standard sources were 4.615×10{sup −5} cGy s{sup −1} and 2.259×10{sup −5} cGy s{sup −1}, respectively. The calculated conversion factors of the two sources were 1.213×10{sup −8} cGy s{sup −1} Bq{sup −1} and 1.071×10{sup −8} cGy s{sup −1} Bq{sup −1}, respectively. Therefore, the activity of the standard Sr/Y-90 source was determined to be 3.995 kBq, which was 2.0% less than the certified value (4.077 kBq). For Si/P-32 the determined activity was 2.102 kBq, which was 6.6% larger than the certified activity (1.971 kBq). The activity of the Sr/Y-90 test source was determined to be 4.166 kBq, while the apparent activity reported by KAERI was 5.803 kBq. This large difference might be due to evaporation and diffusion of the source liquid during preparation and uncertainty in the amount of weighed aliquot of source liquid. The overall uncertainty involved in this method was determined to be 7.3%. We demonstrated that the activity of a sealed pure beta-source could be conveniently determined by complementary combination of measuring the surface dose rate and Monte Carlo simulations.

  7. Spectral BRDF-based determination of proper measurement geometries to characterize color shift of special effect coatings.

    Science.gov (United States)

    Ferrero, Alejandro; Rabal, Ana; Campos, Joaquín; Martínez-Verdú, Francisco; Chorro, Elísabet; Perales, Esther; Pons, Alicia; Hernanz, María Luisa

    2013-02-01

    A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description of the spectral bidirectional reflectance distribution function (BRDF). The analysis of experimental spectral BRDF was carried out by means of principal component analysis. From this analysis, a set of nine measurement geometries was proposed to characterize special effect coatings. It was shown that, for two different special effect coatings, these geometries provide a good prediction of their complete color shift.

  8. Human beta-glucuronidase. Measurement of its activity in gallbladder bile devoid of intrinsic interference.

    Science.gov (United States)

    Ho, Y C; Ho, K J

    1988-04-01

    Our purpose is to develop a standard method for preparing the bile for beta-glucuronidase determination by removal of bile acids and conjugated bilirubin which interfere with its activity. The bile acids and conjugated bilirubin in their purified solutions and in the diluted gallbladder biles could be extracted completely with cholestyramine in powder form or tetrahexylammonium chloride (THAC) in chloroform or ethyl acetate. The enzyme was, however, partially precipitated with cholestyramine and denatured by chloroform but not by ethyl acetate. A standard procedure, therefore, includes extraction of the diluted gallbladder bile with THAC in ethyl acetate, followed by determination of the maximal velocity (Vmax) of the enzyme by a kinetic method employing phenolphthalein glucuronide as the substrate. The average Vmax of beta-glucuronidase in the 20 normal gallbladder biles was 165 +/- 86 nmol/min/ml (mean +/- SD), a 23.5-fold increase over the activity before extraction. The measured activity represented the true activity of the enzyme in the bile for recovery of activity of the enzyme added to the bile was practically complete.

  9. Measurement of the form factor ratio g1/f1 in LAMBDA beta decay

    International Nuclear Information System (INIS)

    Innes, W.R.

    1974-01-01

    The beta decay of 306 polarized lambdas was observed. The lambdas, which had a mean polarization of 70 percent, were produced by a 1.06 GeV/c π minus beam incident on a CH 2 target. The lambda decay particle trajectories were measured with a solenoidal magnetic spectrometer utilizing spark chambers with magnetostrictive readout. The beta decays were differentiated from other decay modes with an isobutane threshold Cherenkov counter. Using only information which depended upon the polarization, g 1 /f 1 was found to be 0.44- 0 . 13 +0 . 20 . Using only information independent of the polarization, g 1 /f 1 was found to be 0.62- 0 . 13 +0 . 17 . Combining all information yielded a value for g 1 /f 1 of 0.56- 0 . 11 +0 . 13 . Although these results taken by themselves are consistent with the Cabbibo theory prediction of 0.69, when combined with previous experiments there is a possibly significant discrepancy in the polarization dependent results. (U.S.)

  10. Rapid measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides.

    Science.gov (United States)

    Barnwal, Ravi Pratap; Rout, Ashok K; Chary, Kandala V R; Atreya, Hanudatta S

    2007-12-01

    We present two NMR experiments, (3,2)D HNHA and (3,2)D HNHB, for rapid and accurate measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides based on the principle of G-matrix Fourier transform NMR spectroscopy and quantitative J-correlation. These experiments, which facilitate fast acquisition of three-dimensional data with high spectral/digital resolution and chemical shift dispersion, will provide renewed opportunities to utilize them for sequence specific resonance assignments, estimation/characterization of secondary structure with/without prior knowledge of resonance assignments, stereospecific assignment of prochiral groups and 3D structure determination, refinement and validation. Taken together, these experiments have a wide range of applications from structural genomics projects to studying structure and folding in polypeptides.

  11. Evaluation of the spectral distribution of X-ray beams from measurements on the scattered radiation

    International Nuclear Information System (INIS)

    Casnati, E.; Baraldi, C.

    1980-01-01

    Most of the phenomena activated by photons with energies below 100 keV show an apparent or real dependence on the quantum energy. Therefore, knowledge of the beam energy characteristics is of primary importance for interpretation of the irradiation results. The greatest difficulty arises from the high flux density of the beams usually employed which does not allow direct measurements of the beam. A method was developed which permits evaluation of the spectral distribution of the X-ray beam from a spectrometric measurement of the radiation scattered by a thin foil of a suitable metal. This makes possible a new and more rational approach to the measurement of X-rays in the energy range where the interaction parameters show a large photon energy dependence. The corrections required by the presence of some collateral effects, among which the most important is the coexistence of the coherent and incoherent scattering, must be evaluated. The knowledge of the spectral distribution is of immediate usefulness for studies of radiation damage in biological and other materials, for the calibration of radiation measuring instruments and for the improvement of the radiological instrumentation response which contributes to reducing the patient's dose. (H.K.)

  12. Using absolute x-ray spectral measurements to infer stagnation conditions in ICF implosions

    Science.gov (United States)

    Patel, Pravesh; Benedetti, L. R.; Cerjan, C.; Clark, D. S.; Hurricane, O. A.; Izumi, N.; Jarrott, L. C.; Khan, S.; Kritcher, A. L.; Ma, T.; Macphee, A. G.; Landen, O.; Spears, B. K.; Springer, P. T.

    2016-10-01

    Measurements of the continuum x-ray spectrum emitted from the hot-spot of an ICF implosion can be used to infer a number thermodynamic properties at stagnation including temperature, pressure, and hot-spot mix. In deuterium-tritium (DT) layered implosion experiments on the National Ignition Facility (NIF) we field a number of x-ray diagnostics that provide spatial, temporal, and spectrally-resolved measurements of the radiated x-ray emission. We report on analysis of these measurements using a 1-D hot-spot model to infer thermodynamic properties at stagnation. We compare these to similar properties that can be derived from DT fusion neutron measurements. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  13. Measurement of chromatic dispersion of microstructured polymer fibers by white-light spectral interferometry

    DEFF Research Database (Denmark)

    Hlubina, Petr; Ciprian, Dalibor; Frosz, Michael Henoch

    2009-01-01

    We present a white-light spectral interferometric method for measuring the chromatic dispersion of microstructured fibers made of polymethyl methacrylate (PMMA). The method uses an unbalanced Mach-Zehnder interferometer with the fiber of known length placed in one of the interferometer arms...... of the method by measuring the wavelength dependence of the differential group refractive index of a pure silica fiber. We apply a five-term power series fit to the measured data and confirm by its differentiation that the chromatic dispersion of pure silica glass agrees well with theory. Second, we measure...... the chromatic dispersion for the fundamental mode supported by two different PMMA microstructured fibers, the multimode fiber and the large-mode area one....

  14. Contactless Spectral-dependent Charge Carrier Lifetime Measurements in Silicon Photovoltaic Materials

    Science.gov (United States)

    Roller, John; Hamadani, Behrang; Dagenais, Mario

    Charge carrier lifetime measurements in bulk or unfinished photovoltaic (PV) materials allow for a more accurate estimate of power conversion efficiency in completed solar cells. In this work, carrier lifetimes in PV-grade silicon wafers are obtained by way of quasi-steady state photoconductance measurements. These measurements use a contactless RF system coupled with varying narrow spectrum input LEDs, ranging in wavelength from 460 nm to 1030 nm. Spectral dependent lifetime measurements allow for determination of bulk and surface properties of the material, including the intrinsic bulk lifetime and the surface recombination velocity. The effective lifetimes are fit to an analytical physics-based model to determine the desired parameters. Passivated and non-passivated samples are both studied and are shown to have good agreement with the theoretical model.

  15. Electronic, Spectral, and Electrochemical Properties of (TPPBr(x)())Zn Where TPPBr(x)() Is the Dianion of beta-Brominated-Pyrrole Tetraphenylporphyrin and x Varies from 0 to 8.

    Science.gov (United States)

    D'Souza, Francis; Zandler, Melvin E.; Tagliatesta, Pietro; Ou, Zhongping; Shao, Jianguo; Van Caemelbecke, Eric; Kadish, Karl M.

    1998-09-07

    The electronic, spectral, and electrochemical characterization of (meso-tetraphenylporphyrinato)zinc(II) complexes bearing between 0 and 8 bromo substituents at the beta-pyrrole positions is reported. The investigated compounds are represented as (TPPBr(x)())Zn where TPPBr(x)() is the dianion of brominated 5,10,15,20-tetraphenylporphyrin and x varies between 0 and 8. Each porphyrin undergoes four well-defined one-electron transfer reactions to yield porphyrin pi-cation radicals and dications upon oxidation and porphyrin pi-anion radicals and dianions upon reduction. Half-wave potentials for the first reduction of (TPPBr(x)())Zn can be described by a single linear free energy relationship, and plots of E(1/2) versus the number of Br groups on the complex show a linear correlation with a positive slope of 63 mV per Br group. This is not the case for the other three electron transfer processes of the compounds where plots of E(1/2) versus the number of Br groups show distinctly different linear correlations for derivatives with 0-4 Br groups and those with 4-8 Br groups. The effect of increasing number of Br groups on the spectral and electrochemical properties of the neutral complexes was examined over the whole series of compounds, and these experimental results are compared to results of theoretical calculations by semiempirical molecular orbital AM1 methods using configurational interactions (CI) over the four Gouterman frontier pi-orbitals. The dihedral angle containing the four porphyrin macrocycle ring nitrogens is proposed as a measure of porphyrin ring nonplanarity, and this value increases with increasing number of Br substituents on (TPPBr(x)())Zn. Results of the AM1-CI = 4 calculations indicate that the spectrally determined HOMO-LUMO gap, i.e., the energy corresponding to the low-energy absorption band, varies in a nonlinear fashion with increasing number of Br substituents on the macrocycle and this is due to both the electronic effect of the

  16. Diagnostics of PF-1000 facility operation and plasma concentration on the basis of spectral measurements

    International Nuclear Information System (INIS)

    Skladnik-Sadowska, E.; Malinowski, K.; Sadowski, M.J.; Scholz, M.; Tsarenko, A.V.

    2005-01-01

    The paper concerns the monitoring of the operation of high-current pulse discharges and the determination of the plasma concentration within the dense magnetized plasma column by means of optical spectroscopy methods. In experiments performed within the large PF-1000 facility, which is operated at IPPLM in Warsaw, particular attention was paid to possibility of the determination of correctness of the operational mode. In order to measure the visible radiation (VR), as emitted from the collapsing current sheath and the dense pinch region, the use was made of the MECHELLE R 900-optical-spectrometer, which was equipped with a CCD measuring head. The spectral measurements were performed at an angle of about 650 to the symmetry axis of the PF electrode system, through an optical window and a special collimator coupled with the quartz optical-cable. The observed VR emission originated from a part of the inner- and outer-electrode surfaces, the collapsing current-sheath layer and a portion of the dense plasma pinch-region (located a distance of 40-50 mm from the electrode ends). Considerable differences were found in the optical spectra recorded for so-called good shots and for cases of some failures. In the case of a breakdown (damage) of the main insulator there were observed different Al-lines, which originated from the eroded insulator material. At so-called bad vacuum conditions there were recorded various C-lines, and at an uncontrolled air-leakage into the experimental chamber there appeared numerous N-lines. The appearance of these characteristic spectral lines made possible to determine whether the operation of the PF-1000 facility was correct or incorrect. The paper reports also on estimates of plasma concentration values, which have been performed on the basis of a quantitative analysis of the Stark broadening of the selected spectral lines. (author)

  17. (-)[125I]-iodopindolol, a new highly selective radioiodinated beta-adrenergic receptor antagonist: measurement of beta-receptors on intact rat astrocytoma cells

    International Nuclear Information System (INIS)

    Barovsky, K.; Brooker, G.

    1980-01-01

    (-)-Pindolol, one of the most potent beta-adrenergic receptor antagonists, was radioiodinated using chloramine-T oxidation of carrier-free Na 125I and separated from unreacted pindolol to yield 2200 Ci/mmole (-)-[125I]-iodopindolol ((-)-[125I]-IPin). Mass and ultraviolet spectra confirmed that the iodination occurred on the indole ring, presumably at the 3 position. The binding of radiolabeled (-)-[125I]-IPin to beta-adrenergic receptors has been studied using intact C6 rat astrocytoma cells (2B subclone) grown in monolayer cultures. Binding of (-)[125IPin was saturable with time and concentration. Using 13 pM (-)-[125I]IPin, binding equilibrium was reached in 90 min at 21-22 degrees C. The reverse rate constant was 0.026 min-1 at 21 0 C. Specific binding (expressed as 1 microM(-)-propranolol displaceable counts) of (-)-[125I]-IPin was 95% of total binding. Scatchard analysis of (-)-[125I]-I]Pin binding revealed approximately 4300 receptors/cell and a dissociation constant of 30 pM. This was in excellent agreement with the kinetically determined dissociation constant of 35 pM. Displacement by propranolol and isoproterenol showed that (-)-[125I]-IPin binding sites were pharmacologically and stereospecifically selective. These results indicate that (-)-[125I]-IPin, a pure (-)-stereoisomer, high specific activity radioligand, selectively binds to beta-adrenergic receptors in whole cells with a high percentage of specific binding and should therefore be useful in the study and measurement of cellular beta-adrenergic receptors

  18. Method and apparatus for simultaneously measuring a plurality of spectral wavelengths present in electromagnetic radiation

    Science.gov (United States)

    Buican, Tudor N.; Martin, John C.

    1990-01-01

    An apparatus and method simultaneously measures a plurality of spectral wavelengths present in electromagnetic radiation. A modulatable birefringent optical element is employed to divide a polarized light beam into two components, thereby producing a phase difference in two resulting light beams such that the two beams can be made to interfere with one another when recombined, the interference pattern providing the wavelength information required for the analysis of the incident light. The interferometer thus created performs in a similar manner to a Michelson interferometer, but with no moving parts, and with a resolution dependent on the degree of phase shift introduced by the modulator.

  19. Universal bounds on spectral measures of one-dimensional Schrödinger operators

    CERN Document Server

    Remling, C

    2002-01-01

    Consider a Schrödinger operator $H=-d^2/dx^2+V(x)$ on $L_2(0,\\infty)$ and suppose that an initial piece of the potential $V(x)$, $0spectral measure of intervals with a certain minimum length. This length scale is set by the eigenvalues of the problems on $[0,N]$. So in a sense (and perhaps somewhat surprisingly) the behavior of $V(x)$ becomes less important if $x$ grows. The results of this paper are developments of classical work of Chebyshev and Markov on orthogonal polynomials.

  20. Geometric optimisation of an accurate cosine correcting optic fibre coupler for solar spectral measurement

    Science.gov (United States)

    Cahuantzi, Roberto; Buckley, Alastair

    2017-09-01

    Making accurate and reliable measurements of solar irradiance is important for understanding performance in the photovoltaic energy sector. In this paper, we present design details and performance of a number of fibre optic couplers for use in irradiance measurement systems employing remote light sensors applicable for either spectrally resolved or broadband measurement. The angular and spectral characteristics of different coupler designs are characterised and compared with existing state-of-the-art commercial technology. The new coupler designs are fabricated from polytetrafluorethylene (PTFE) rods and operate through forward scattering of incident sunlight on the front surfaces of the structure into an optic fibre located in a cavity to the rear of the structure. The PTFE couplers exhibit up to 4.8% variation in scattered transmission intensity between 425 nm and 700 nm and show minimal specular reflection, making the designs accurate and reliable over the visible region. Through careful geometric optimization near perfect cosine dependence on the angular response of the coupler can be achieved. The PTFE designs represent a significant improvement over the state of the art with less than 0.01% error compared with ideal cosine response for angles of incidence up to 50°.

  1. Geometric optimisation of an accurate cosine correcting optic fibre coupler for solar spectral measurement.

    Science.gov (United States)

    Cahuantzi, Roberto; Buckley, Alastair

    2017-09-01

    Making accurate and reliable measurements of solar irradiance is important for understanding performance in the photovoltaic energy sector. In this paper, we present design details and performance of a number of fibre optic couplers for use in irradiance measurement systems employing remote light sensors applicable for either spectrally resolved or broadband measurement. The angular and spectral characteristics of different coupler designs are characterised and compared with existing state-of-the-art commercial technology. The new coupler designs are fabricated from polytetrafluorethylene (PTFE) rods and operate through forward scattering of incident sunlight on the front surfaces of the structure into an optic fibre located in a cavity to the rear of the structure. The PTFE couplers exhibit up to 4.8% variation in scattered transmission intensity between 425 nm and 700 nm and show minimal specular reflection, making the designs accurate and reliable over the visible region. Through careful geometric optimization near perfect cosine dependence on the angular response of the coupler can be achieved. The PTFE designs represent a significant improvement over the state of the art with less than 0.01% error compared with ideal cosine response for angles of incidence up to 50°.

  2. Measurements of beta-decay half-lives of short-lived nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, T.; Tsurita, Y.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.; Kasugai, Y.; Ikeda, Y.

    1997-03-01

    The {beta}-decay half-lives of short-lived nuclei produced by 14 MeV neutron bombardments were measured with Ge detectors, a High-rate spectroscopy amplifier (EG and G ORTEC model 973) and a Spectrum multi-scaler (Laboratory equipment corporation SMS-48) in the multi-scaling mode. The adequate corrections for pile-up and dead-time losses were made by applying source and pulser methods. The half-lives of {sup 53}V, {sup 53g}Fe, {sup 89m}Y and {sup 162}Tb were determined with uncertainties of 0.13-0.65%. It has been shown that previous values shorter than 10 min were systematically longer than the present ones. (author)

  3. The process of Ni-63 production and measurement of beta radiation of irradiated Ni-63

    International Nuclear Information System (INIS)

    Kim, Jin Joo; Uhma, Young Rang; Kim, Jong Bum; Choi, Sang Mu; Son, Kwang Jae; Hong, Jin Tae; Park, Jong Han

    2016-01-01

    It has the following characteristics: long service lifetime, high energy density, easy small-scale fabrication, and minimum maintenance. For this reasons, betavoltaic batteries are widely used in many low-power applications such as medical applications and power sources for micro electro-mechanical system (MEMS) because they can operate effectively at extreme environments. Proper selection of radioisotope is a critical factor in the design of a betavoltaic battery. The important factors affecting the performance of a betavoltaic battery are specific activity, half-life, and toxicity. In this study, a target for irradiation was produced using 99% Ni-62 metal power concentrate. Ni-62 target of 1 g was irradiated in MARIA reactor operated in Poland for 470 hours, and estimated production of Ni- 63 was calculated. Irradiated Ni-63 pellets were dissolved in HCl solution, and its beta radiation was measured by Liquid Scintillation Counter (LSC).

  4. Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements

    International Nuclear Information System (INIS)

    Álvarez, V; Cárcel, S; Cervera, A; Díaz, J; Ferrario, P; Bandac, I; Bettini, A; Castel, J; Cebrián, S; Dafni, T; Borges, F I G M; Conde, C A N; Dias, T H V T; Fernandes, L M P; Freitas, E D C; Egorov, M; Gehman, V M; Esteve, R; Evtoukhovitch, P; Ferreira, A L

    2013-01-01

    The ''Neutrino Experiment with a Xenon Time-Projection Chamber'' (NEXT) is intended to investigate the neutrinoless double beta decay of 136 Xe, which requires a severe suppression of potential backgrounds. An extensive screening and material selection process is underway for NEXT since the control of the radiopurity levels of the materials to be used in the experimental set-up is a must for rare event searches. First measurements based on Glow Discharge Mass Spectrometry and gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterr and apos;aneo de Canfranc (Spain) are described here. Activity results for natural radioactive chains and other common radionuclides are summarized, being the values obtained for some materials like copper and stainless steel very competitive. The implications of these results for the NEXT experiment are also discussed.

  5. Helium burning: a further measurement of the beta-delayed alpha-particle emission of 16 Na

    International Nuclear Information System (INIS)

    Gai, Moshe

    1997-01-01

    The 12 C (α,γ) 16 O is a key (but still unknown) reaction in helium burning. Several attempts to constrain the p-wave S-factor at Helium burning temperatures (200 M K) using the beta-delayed alpha-particle emission of 16 N have been made. However, some discrepancy exists between the spectra measured at Settle and that of TRIUMF. We have improved our previous study of the beta-delayed alpha-particle emission of 16 N by improving our statistical sample (by more than a factor of 5), improving the energy resolution of the experiment (by 20%), and in understanding our line shape, deduced from measured quantities. Our newly measured spectrum of the beta-delayed alpha-particle emission of 16 N is consistent with the Seattle ('95) data, as well as an earlier experiment performed at Mains ('71) and is not consistent with the TRIUMF ('94) data. (author)

  6. Beta dosimetry using partial body dosimeters II. Results of intercomparison measurements of 1998/1999 - PTB report

    International Nuclear Information System (INIS)

    Ambrosi, P.; Helmstaedter, K.

    2000-12-01

    In 1998 the PTB organised a second series of intercomparison measurements for selected beta dosimeters worn on the extremities. In April 1999 these intercomparison measurements and the results obtained were discussed in a one day meeting. The contributions given and the results obtained and the conclusions drawn after extensive discussions are presented in this PTB report. (orig.) [de

  7. Beta spectrometry

    International Nuclear Information System (INIS)

    Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P.

    1977-01-01

    For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author)

  8. High Spectral Resolution Lidar Based on a Potassium Faraday Dispersive Filter for Daytime Temperature Measurement

    Directory of Open Access Journals (Sweden)

    Abo Makoto

    2016-01-01

    Full Text Available In this paper, a new high-spectral-resolution lidar technique is proposed for measuring the profiles of atmospheric temperature in daytime. Based on the theory of high resolution Rayleigh scattering, the feasibility and advantages of using potassium (K Faraday dispersive optical filters as blocking filters for measuring atmospheric temperature are demonstrated with a numerical simulation. It was found that temperature profiles could be measured within 1K error for the height of 9 km with a 500 m range resolution in 60 min by using laser pulses with 1mJ/pulse and 1 kHz, and a 50 cm diameter telescope. Furthermore, we are developing compact pulsed laser system for temperature lidar transmitter.

  9. Spectral analysis of atmospheric composition: application to surface ozone model–measurement comparisons

    Directory of Open Access Journals (Sweden)

    D. R. Bowdalo

    2016-07-01

    Full Text Available Models of atmospheric composition play an essential role in our scientific understanding of atmospheric processes and in providing policy strategies to deal with societally relevant problems such as climate change, air quality, and ecosystem degradation. The fidelity of these models needs to be assessed against observations to ensure that errors in model formulations are found and that model limitations are understood. A range of approaches are necessary for these comparisons. Here, we apply a spectral analysis methodology for this comparison. We use the Lomb–Scargle periodogram, a method similar to a Fourier transform, but better suited to deal with the gapped data sets typical of observational data. We apply this methodology to long-term hourly ozone observations and the equivalent model (GEOS-Chem output. We show that the spectrally transformed observational data show a distinct power spectrum with regimes indicative of meteorological processes (weather, macroweather and specific peaks observed at the daily and annual timescales together with corresponding harmonic peaks at one-half, one-third, etc., of these frequencies. Model output shows corresponding features. A comparison between the amplitude and phase of these peaks introduces a new comparison methodology between model and measurements. We focus on the amplitude and phase of diurnal and seasonal cycles and present observational/model comparisons and discuss model performance. We find large biases notably for the seasonal cycle in the mid-latitude Northern Hemisphere where the amplitudes are generally overestimated by up to 16 ppbv, and phases are too late on the order of 1–5 months. This spectral methodology can be applied to a range of model–measurement applications and is highly suitable for Multimodel Intercomparison Projects (MIPs.

  10. Semi-automated digital measurement as the method of choice for beta cell mass analysis.

    Directory of Open Access Journals (Sweden)

    Violette Coppens

    Full Text Available Pancreas injury by partial duct ligation (PDL activates beta cell differentiation and proliferation in adult mouse pancreas but remains controversial regarding the anticipated increase in beta cell volume. Several reports unable to show beta cell volume augmentation in PDL pancreas used automated digital image analysis software. We hypothesized that fully automatic beta cell morphometry without manual micrograph artifact remediation introduces bias and therefore might be responsible for reported discrepancies and controversy. However, our present results prove that standard digital image processing with automatic thresholding is sufficiently robust albeit less sensitive and less adequate to demonstrate a significant increase in beta cell volume in PDL versus Sham-operated pancreas. We therefore conclude that other confounding factors such as quality of surgery, selection of samples based on relative abundance of the transcription factor Neurogenin 3 (Ngn3 and tissue processing give rise to inter-laboratory inconsistencies in beta cell volume quantification in PDL pancreas.

  11. Potential of remote sensing of cirrus optical thickness by airborne spectral radiance measurements at different sideward viewing angles

    OpenAIRE

    Wolf, Kevin; Ehrlich, André; Hüneke, Tilman; Pfeilsticker, Klaus; Werner, Frank; Wirth, Martin; Wendisch, Manfred

    2017-01-01

    Spectral radiance measurements collected in nadir and sideward viewing directions by two airborne passive solar remote sensing instruments, the Spectral Modular Airborne Radiation measurement sysTem (SMART) and the Differential Optical Absorption Spectrometer (mini-DOAS), are used to compare the remote sensing results of cirrus optical thickness τ. The comparison is based on a sensitivity study using radiative transfer simulations (RTS) and on data obtained during three airb...

  12. Measurement of the most exotic beta-delayed neutron emitters at N=50 and N=126

    Science.gov (United States)

    Dillmann, Iris

    2017-09-01

    Beta-delayed neutron (βn)-emission will be the dominant decay mechanism of neutron-rich nuclei and plays an important role in the stellar nucleosynthesis of heavy elements in the ``r process''. It leads to a detour of the material β-decaying back to stability and the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. Thus the neutron branching ratio of very neutron-rich isotopes is a crucial parameter in astrophysical simulations. In addition, β-decay half-lives can be deduced from the time-dependent detection of βn's. I will talk about two recent experimental campaigns. The neutron detector BELEN was used at GSI Darmstadt to measure half-lives and neutron-branching ratios of the heaviest presently accessible βn-emitters at N=126. For isotopes between 204Au and 220Bi nine half-lives and eight neutron-branching ratios were measured for the first time and provide an important input for benchmarking theoretical models in this mass region. Its successor is the BRIKEN detector (``Beta-delayed neutron measurements at RIKEN for nuclear structure, astrophysics, and applications''), the most efficient neutron detector used so far for nuclear structure studies. In conjunction with two clover detectors and the ``Advanced Implantation Detector Array'' (AIDA) the setup has been used a few months ago to measure the most neutron-rich isotopes around 78Ni, 132Sn, and the Rare Earth Region. Some preliminary results are shown from the campaign covering the 78Ni region where the neutron-branching ratio of 78Ni and 28 more isotopes were measured for the first time, as well as the half-lives of 20 isotopes. The BRIKEN campaign aims to (re-)measure almost all βn-emitters between 76Co and 167Eu, many of them for the first time. An extension of the campaign to lighter masses is planned. This work has been supported by the NSERC and NRC in Canada, the US DOE, the Spanish

  13. Toward validation of the cepstral spectral index of dysphonia (CSID) as an objective treatment outcomes measure.

    Science.gov (United States)

    Peterson, Elizabeth A; Roy, Nelson; Awan, Shaheen N; Merrill, Ray M; Banks, Russell; Tanner, Kristine

    2013-07-01

    To examine the validity of the Cepstral Spectral Index of Dysphonia (CSID) as an objective treatment outcomes measure of dysphonia severity. Pre- and posttreatment samples of sustained vowel and connected speech productions were elicited from 112 patients across six diagnostic categories: unilateral vocal fold paralysis, adductor spasmodic dysphonia, primary muscle tension dysphonia, benign vocal fold lesions, presbylaryngis, and mutational falsetto. Listener ratings of severity in connected speech were compared with a three-factor CSID model consisting of the cepstral peak prominence (CPP), the low-to-high spectral energy ratio, and its standard deviation. Two additional variables, the CPP standard deviation and gender, were included in the five-factor CSID model to estimate severity of vowels. CSID-estimated severity for sustained vowels and connected speech was strongly associated with listener ratings pretreatment, posttreatment, and change observed pre- to posttreatment. Spectrum effects were examined, and severity of dysphonia did not influence the relationship between listener perceived severity and CSID-estimated severity. The results confirm a robust relationship between listener perceived and CSID-derived dysphonia severity estimates in sustained vowels and connected speech across diverse diagnoses and severity levels and support the clinical utility of the CSID as an objective treatment outcomes measure. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  14. The complex ion structure of warm dense carbon measured by spectrally resolved x-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, D.; Barbrel, B.; Falcone, R. W. [Department of Physics, University of California, Berkeley, California 94720 (United States); Vorberger, J. [Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden (Germany); Helfrich, J.; Frydrych, S.; Ortner, A.; Otten, A.; Roth, F.; Schaumann, G.; Schumacher, D.; Siegenthaler, K.; Wagner, F.; Roth, M. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstraße 9, 64289 Darmstadt (Germany); Gericke, D. O.; Wünsch, K. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Bachmann, B.; Döppner, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bagnoud, V.; Blažević, A. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt (Germany); and others

    2015-05-15

    We present measurements of the complex ion structure of warm dense carbon close to the melting line at pressures around 100 GPa. High-pressure samples were created by laser-driven shock compression of graphite and probed by intense laser-generated x-ray sources with photon energies of 4.75 keV and 4.95 keV. High-efficiency crystal spectrometers allow for spectrally resolving the scattered radiation. Comparing the ratio of elastically and inelastically scattered radiation, we find evidence for a complex bonded liquid that is predicted by ab-initio quantum simulations showing the influence of chemical bonds under these conditions. Using graphite samples of different initial densities we demonstrate the capability of spectrally resolved x-ray scattering to monitor the carbon solid-liquid transition at relatively constant pressure of 150 GPa. Showing first single-pulse scattering spectra from cold graphite of unprecedented quality recorded at the Linac Coherent Light Source, we demonstrate the outstanding possibilities for future high-precision measurements at 4th Generation Light Sources.

  15. Exploiting High Resolution Multi-Seasonal Textural Measures and Spectral Information for Reedbed Mapping

    Directory of Open Access Journals (Sweden)

    Alex Okiemute Onojeghuo

    2016-02-01

    Full Text Available Reedbeds across the UK are amongst the most important habitats for rare and endangered birds, wildlife and organisms. However, over the past century, this valued wetland habitat has experienced a drastic reduction in quality and spatial coverage due to pressures from human related activities. To this end, conservation organisations across the UK have been charged with the task of conserving and expanding this threatened habitat. With this backdrop, the study aimed to develop a methodology for accurate reedbed mapping through the combined use of multi-seasonal texture measures and spectral information contained in high resolution QuickBird satellite imagery. The key objectives were to determine the most effective single-date (autumn or summer and multi-seasonal QuickBird imagery suitable for reedbed mapping over the study area; to evaluate the effectiveness of combining multi-seasonal texture measures and spectral information for reedbed mapping using a variety of combinations; and to evaluate the most suitable classification technique for reedbed mapping from three selected classification techniques, namely maximum likelihood classifier, spectral angular mapper and artificial neural network. Using two selected grey-level co-occurrence textural measures (entropy and angular second moment, a series of experiments were conducted using varied combinations of single-date and multi-seasonal QuickBird imagery. Overall, the results indicate the multi-seasonal pansharpened multispectral bands (eight layers combined with all eight grey level co-occurrence matrix texture measures (entropy and angular second moment computed using windows 3 × 3 and 7 × 7 produced the optimal reedbed (76.5% and overall classification (78.1% accuracies using the maximum likelihood classifier technique. Using the optimal 16 layer multi-seasonal pansharpened multispectral and texture combined image dataset, a total reedbed area of 9.8 hectares was successfully mapped over the

  16. Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Keating, Kristina [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Slater, Lee [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Ntarlagiannis, Dimitris [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Williams, Kenneth H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division

    2015-02-24

    This documents contains the final report for the project "Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods" (DE-SC0007049) Executive Summary: Our research aimed to develop borehole measurement techniques capable of monitoring subsurface processes, such as changes in pore geometry and iron/sulfur geochemistry, associated with remediation of heavy metals and radionuclides. Previous work has demonstrated that geophysical method spectral induced polarization (SIP) can be used to assess subsurface contaminant remediation; however, SIP signals can be generated from multiple sources limiting their interpretation value. Integrating multiple geophysical methods, such as nuclear magnetic resonance (NMR) and magnetic susceptibility (MS), with SIP, could reduce the ambiguity of interpretation that might result from a single method. Our research efforts entails combining measurements from these methods, each sensitive to different mineral forms and/or mineral-fluid interfaces, providing better constraints on changes in subsurface biogeochemical processes and pore geometries significantly improving our understanding of processes impacting contaminant remediation. The Rifle Integrated Field Research Challenge (IFRC) site was used as a test location for our measurements. The Rifle IFRC site is located at a former uranium ore-processing facility in Rifle, Colorado. Leachate from spent mill tailings has resulted in residual uranium contamination of both groundwater and sediments within the local aquifer. Studies at the site include an ongoing acetate amendment strategy, native microbial populations are stimulated by introduction of carbon intended to alter redox conditions and immobilize uranium. To test the geophysical methods in the field, NMR and MS logging measurements were collected before, during, and after acetate amendment. Next, laboratory NMR, MS, and SIP measurements

  17. The stability of H/V spectral ratios from noise measurements in Armutlu Peninsula (Turkey)

    Energy Technology Data Exchange (ETDEWEB)

    Livaoğlu, Hamdullah, E-mail: hamdullah.livaoglu@kocaeli.edu.tr; Irmak, T. Serkan; Caka, Deniz; Yavuz, Evrim; Tunç, B.; Baris, S. [Faculty of Engineering, Department of Geophysics, Kocaeli University, 41380, Kocaeli (Turkey); Lühr, B. G.; Woith, H. [GFZ, German Research Centre for Geoscience, Postsdam (Germany)

    2016-04-18

    The horizontal to vertical spectral ratio (H/V) method has been successfully using in order to estimate the fundamental resonance frequency of the sedimentary cover, its thickness and amplification factor since at least 3 decades. There are numerous studies have been carried out on the stability of the H/V spectral ratios. Almost all studies showed that fundamental frequency is stable even measurements are repeated at different times. From this point of view, the results will show us an approach whether the stations are suitable for accurate estimate of earthquake studies and engineering purposes or not. Also we want to see if any effects of the amplification factor changing on the seismograms for Armutlu Seismic Network (ARNET) even though seismic stations are established far away from cultural noise and located on hard rock sites. It has been selected one hour recorded data of all stations during the most stationary times. The amplification and resonant frequency variations of H/V ratio were calculated to investigate temporal stability in time. There is a total harmony in fundamental frequencies values and H/V spectral ratio values in time-lagged periods. Some stations shows secondary minor peaks in high frequency band due to a shallow formation effect or cultural noises around. In the east side of the area ILYS station shows amplitude peak in lower fundamental frequency band from expected. This could compose a high amplification in lower frequencies and so that yield less reliable results in local earthquakes studies. By the experimental results from ambient noise analysis, it could be worked up for relocation of one station.

  18. Comparative Analysis of Mass Spectral Similarity Measures on Peak Alignment for Comprehensive Two-Dimensional Gas Chromatography Mass Spectrometry

    Science.gov (United States)

    2013-01-01

    Peak alignment is a critical procedure in mass spectrometry-based biomarker discovery in metabolomics. One of peak alignment approaches to comprehensive two-dimensional gas chromatography mass spectrometry (GC×GC-MS) data is peak matching-based alignment. A key to the peak matching-based alignment is the calculation of mass spectral similarity scores. Various mass spectral similarity measures have been developed mainly for compound identification, but the effect of these spectral similarity measures on the performance of peak matching-based alignment still remains unknown. Therefore, we selected five mass spectral similarity measures, cosine correlation, Pearson's correlation, Spearman's correlation, partial correlation, and part correlation, and examined their effects on peak alignment using two sets of experimental GC×GC-MS data. The results show that the spectral similarity measure does not affect the alignment accuracy significantly in analysis of data from less complex samples, while the partial correlation performs much better than other spectral similarity measures when analyzing experimental data acquired from complex biological samples. PMID:24151524

  19. A Fiberoptic Scalar Irradiance Microsensor - Application for Spectral Light Measurements in Sediments

    DEFF Research Database (Denmark)

    LASSEN, C.; PLOUG, H.; JØRGENSEN, BB

    1992-01-01

    in sediments was measured at 100-mu-m spatial resolution. Light was available for photosynthesis near the sediment surface at a higher intensity and a different spectral composition than could be expected from the illumination. By the combination of oxygen microelectrodes and the present fibre......The manufacturing of a new spherical fibreoptic microsensor is described. The microsensor measures scalar irradiance, i.e. the spherically integrated light at a point in space. The light collector of the probe was a 70-mu-m diffusing sphere cast on the tip of a 125-mu-m wide optical fibre tapered......-optic microsensor it is now possible to study the depth distribution of microbenthic photosynthesis in relation to the available photosynthetically active radiation at less-than-or-equal-to 100-mu-m resolution....

  20. Terahertz spectral signatures :measurement and detection LDRD project 86361 final report.

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael Clement; Brener, Igal; Lee, Mark

    2005-11-01

    LDRD Project 86361 provided support to upgrade the chemical and material spectral signature measurement and detection capabilities of Sandia National Laboratories using the terahertz (THz) portion of the electromagnetic spectrum, which includes frequencies between 0.1 to 10 THz. Under this project, a THz time-domain spectrometer was completed. This instrument measures sample absorption spectra coherently, obtaining both magnitude and phase of the absorption signal, and has shown an operating signal-to-noise ratio of 10{sub 4}. Additionally, various gas cells and a reflectometer were added to an existing high-resolution THz Fourier transform spectrometer, which greatly extend the functionality of this spectrometer. Finally, preliminary efforts to design an integrated THz transceiver based on a quantum cascade laser were begun.

  1. Quantitative measurement of phase variation amplitude of ultrasonic diffraction grating based on diffraction spectral analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Meiyan, E-mail: yphantomohive@gmail.com; Zeng, Yingzhi; Huang, Zuohua, E-mail: zuohuah@163.com [Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou, Guangdong 510006 (China)

    2014-09-15

    A new method based on diffraction spectral analysis is proposed for the quantitative measurement of the phase variation amplitude of an ultrasonic diffraction grating. For a traveling wave, the phase variation amplitude of the grating depends on the intensity of the zeroth- and first-order diffraction waves. By contrast, for a standing wave, this amplitude depends on the intensity of the zeroth-, first-, and second-order diffraction waves. The proposed method is verified experimentally. The measured phase variation amplitude ranges from 0 to 2π, with a relative error of approximately 5%. A nearly linear relation exists between the phase variation amplitude and driving voltage. Our proposed method can also be applied to ordinary sinusoidal phase grating.

  2. Measurement of transition probabilities in Kr II UV and visible spectral lines

    International Nuclear Information System (INIS)

    Mar, S; Val, J A del; RodrIguez, F; Pelaez, R J; Gonzalez, V R; Gonzalo, A B; Castro, A de; Aparicio, J A

    2006-01-01

    This work reports an extensive collection of 120 atomic transition probabilities of Kr II lines in the spectral region 350-720 nm, all of them measured in an emission experiment. For many of them, these are the first data up to the authors' knowledge. Relative intensity measurements have been obtained on a pulsed discharge lamp and the absolute A ki -values have been calculated by considering the available data from the literature as reference for the plasma temperature diagnosis. Excitation temperature (14 000-28 000 K) has been determined by using the Boltzmann-plot method. The plasma electron density (0.2-0.8 x 10 23 m -3 ) has been determined by two-wavelength interferometry. This work extends a previous one already published by our laboratory [1, 2]. Comparisons have also been made with previous literature values

  3. A brute-force spectral approach for wave estimation using measured vessel motions

    DEFF Research Database (Denmark)

    Nielsen, Ulrik D.; Brodtkorb, Astrid H.; Sørensen, Asgeir J.

    2018-01-01

    , and the procedure is simple in its mathematical formulation. The actual formulation is extending another recent work by including vessel advance speed and short-crested seas. Due to its simplicity, the procedure is computationally efficient, providing wave spectrum estimates in the order of a few seconds......The article introduces a spectral procedure for sea state estimation based on measurements of motion responses of a ship in a short-crested seaway. The procedure relies fundamentally on the wave buoy analogy, but the wave spectrum estimate is obtained in a direct - brute-force - approach......, and the estimation procedure will therefore be appealing to applications related to realtime, onboard control and decision support systems for safe and efficient marine operations. The procedure's performance is evaluated by use of numerical simulation of motion measurements, and it is shown that accurate wave...

  4. Accurate measurements of solar spectral irradiance between 4000-10000 cm-1

    Science.gov (United States)

    Elsey, J.; Coleman, M. D.; Gardiner, T.; Shine, K. P.

    2017-12-01

    The near-infrared solar spectral irradiance (SSI) is an important input into simulations of weather and climate; the distribution of energy throughout this region of the spectrum influences atmospheric heating rates and the global hydrological cycle through absorption and scattering by water vapour. Current measurements by a mixture of ground-based and space-based instruments show differences of around 10% in the 4000-7000 cm-1 region, with no resolution to this controversy in sight. This work presents observations of SSI taken using a ground-based Fourier Transform spectrometer between 4000-10000 cm-1 at a field site in Camborne, UK, with particular focus on a rigorously defined uncertainty budget. While there is good agreement between this work and the commonly-used ATLAS3 spectrum between 7000-10000 cm-1, the SSI is systematically lower by 10% than ATLAS3 between 4000-7000 cm-1, with no overlap within the k = 2 measurement uncertainties.

  5. Neutron activation system for spectral measurements of pulsed ion diode neutron production

    International Nuclear Information System (INIS)

    Hanson, D.L.; Kruse, L.W.

    1980-02-01

    A neutron energy spectrometer has been developed to study intense ion beam-target interactions in the harsh radiation environment of a relativistic electron beam source. The main component is a neutron threshold activation system employing two multiplexed high efficiency Ge(Li) detectors, an annihilation gamma coincidence system, and a pneumatic sample transport. Additional constraints on the neutron spectrum are provided by total neutron yield and time-of-flight measurements. A practical lower limit on the total neutron yield into 4π required for a spectral measurement with this system is approx. 10 10 n where the neutron yield is predominantly below 4 MeV and approx. 10 8 n when a significant fraction of the yield is above 4 MeV. Applications of this system to pulsed ion diode neutron production experiments on Hermes II are described

  6. Front-end electronics for accurate energy measurement of double beta decays

    International Nuclear Information System (INIS)

    Gil, A.; Díaz, J.; Gómez-Cadenas, J.J.; Herrero, V.; Rodriguez, J.; Serra, L.; Toledo, J.; Esteve, R.; Monzó, J.M.; Monrabal, F.; Yahlali, N.

    2012-01-01

    NEXT, a double beta decay experiment that will operate in Canfranc Underground Laboratory (Spain), aims at measuring the neutrinoless double-β decay of the 136Xe isotope using a TPC filled with enriched Xenon gas at high pressure operated in electroluminescence mode. One technological challenge of the experiment is to achieve resolution better than 1% in the energy measurement using a plane of UV sensitive photomultipliers readout with appropriate custom-made front-end electronics. The front-end is designed to be sensitive to the single photo-electron to detect the weak primary scintillation light produced in the chamber, and also to be able to cope with the electroluminescence signal (several hundred times higher and with a duration of microseconds). For efficient primary scintillation detection and precise energy measurement of the electroluminescent signals the front-end electronics features low noise and adequate amplification. The signal shaping provided allows the digitization of the signals at a frequency as low as 40 MHz.

  7. Precision measurement of the half-life and the $\\beta$-decay Q value of the superallowed 0$^{+}\\rightarrow$ 0$^{+}\\beta$-decay of $^{38}$Ca

    CERN Multimedia

    2002-01-01

    We propose to study the $\\beta$-decay of $^{38}$Ca. In a first instance, we intend to perform a high-precision study of the half-life of this nucleus as well as a measurement of its $\\beta$-decay Q-value with ISOLTRAP. At a later stage, we propose to study its decay branches to determine the super-allowed branching ratio with high precision. These measurements are essential to improve our understanding of the theoretical corrections (in particular the $\\delta$c correction factor) needed to calculate the universal Ft value from the ft value determined for individual nuclei. For this nucleus, the correction factor is predicted to increase significantly as compared to the nine well-studied nuclei between $^{10}$C and $^{54}$Co and the model calculations used to determine the corrections, in particular the shell-model calculations, are well under control in this mass region. Therefore, the T$_{Z}$= -1 nuclei between A=18 and A=38 are ideal test cases for the correction factors which limit today the precision on t...

  8. Measurements and estimation of the columnar optical depth of tropospheric aerosols in the UV spectral region

    Directory of Open Access Journals (Sweden)

    V. E. Cachorro

    2002-04-01

    Full Text Available We report values of the columnar tropospheric aerosol optical depth at UV wavelengths based on experimental measurements of the direct spectral irradiances carried out by a commercial spectroradiometer (Li1800 of Licor company covering the range from 300–1100 nm at two stations with different climate characteristics in Spain. The first station is located in a rural site in north central Spain with continental climate. The data extend from March to the end of October of 1995. The other station is a coastal site in the Gulf of Cádiz (southwest Spain of maritime climate type. This study is mainly focused on the capability of estimating aerosol optical depth values in the UV region based on the extracted information in the visible and near infrared ranges. A first method has been used based on the Ångström turbidity parameters. However, since this method requires detailed spectral information, a second method has also been used, based on the correlation between wavelengths. A correlation has been established between the experimental aerosol optical depth values at 350 nm and 500 nm wavelengths. Although the type of aerosol seems to be the key factor that determines the quality of these estimations, the evaluation of the associated error is necessary to know the behaviour of these estimations in each area of study.Key words. Atmospheric composition and structure (aerosols and particles; transmission and scattering of radiation; troposphere – composition and chemistry

  9. Measurements and estimation of the columnar optical depth of tropospheric aerosols in the UV spectral region

    Directory of Open Access Journals (Sweden)

    V. E. Cachorro

    Full Text Available We report values of the columnar tropospheric aerosol optical depth at UV wavelengths based on experimental measurements of the direct spectral irradiances carried out by a commercial spectroradiometer (Li1800 of Licor company covering the range from 300–1100 nm at two stations with different climate characteristics in Spain. The first station is located in a rural site in north central Spain with continental climate. The data extend from March to the end of October of 1995. The other station is a coastal site in the Gulf of Cádiz (southwest Spain of maritime climate type. This study is mainly focused on the capability of estimating aerosol optical depth values in the UV region based on the extracted information in the visible and near infrared ranges. A first method has been used based on the Ångström turbidity parameters. However, since this method requires detailed spectral information, a second method has also been used, based on the correlation between wavelengths. A correlation has been established between the experimental aerosol optical depth values at 350 nm and 500 nm wavelengths. Although the type of aerosol seems to be the key factor that determines the quality of these estimations, the evaluation of the associated error is necessary to know the behaviour of these estimations in each area of study.

    Key words. Atmospheric composition and structure (aerosols and particles; transmission and scattering of radiation; troposphere – composition and chemistry

  10. First application of the spectral difference method for lifetime measurements of doppler attenuated line shapes

    Energy Technology Data Exchange (ETDEWEB)

    Duckwitz, Hannah [Institut fuer Kernphysik, Koeln Univ. (Germany); Petkov, Pavel [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria)

    2016-07-01

    In this new approach to lifetime measurements via Doppler attenuated line shapes, the spectra of a feeding f and a deexciting transition d of the level of interest are used to determine the lifetime without any lineshape analysis of the feeding transition (direct or indirect). Similarly to the DDC method, the decay function λ{sub d}n{sub d}(t) of the deexciting transition is determined. The feeding of the level is included via the spectral difference of the two successive decays. Consequently, the determined lifetime is the real lifetime. After transforming both transitions into the same energy region, their spectral difference D(v{sub θ}) = S{sub d}(v{sub θ})-S{sub f}(v{sub θ}) = ∫{sub 0}{sup ∞}(∂P{sub θ}(t,v{sub θ}))/(∂t)n{sub d}(t) dt, is solved for n{sub d}(t). Dividing n{sub d}(t) by the decay function λ{sub d}n{sub d}(t) should yield a constant τ value for the level lifetime as a function of the time t. After the development and test of the procedure in 2015, it is now applied for the first time. Two level lifetimes are determined in {sup 86}Sr for the 2{sup +}{sub 2} and the 2{sup +}{sub 3} levels.

  11. Effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Mohana Kuppuswamy Parthasarathy

    2015-01-01

    Full Text Available Aim: The aim of the present study was to study the effect of ocular magnification on macular measurements made using spectral domain optical coherence tomography (OCT. Materials and Methods: One hundred and fifty-one subjects were included from the normative study of foveal morphology carried out at our hospital. Subjects underwent comprehensive eye examination and macular scanning using Cirrus high-definition OCT and axial length (AXL measurement. Macular cube 512 × 128 scan protocol was used for scanning the macula. Automated measurements of the fovea namely foveal diameter, foveal slope (lateral measurements and foveal depth (axial measurement were taken. A correction factor for ocular magnification was done using the formula t = p × q × s, where "t0" is the corrected measurement, "p" is the magnification of OCT, "q0" is the ocular magnification, and "s" is the measurement on OCT without correction. The difference between corrected and uncorrected measurements was evaluated for statistical significance. Results: Mean AXL was 22.95 ± 0.78 mm. Refractive error ranged from −3D to +4D. Mean difference between measured and corrected foveal diameter, slope and depth was 166.05 ± 95.37 ΅m (P < 0.001, 0.81° ± 0.53° (P < 0.001 and 0.05 ± 0.49 ΅m (P = 0.178 respectively. AXL lesser than the OCT calibrated value of 24.46 mm showed an increased foveal diameter (r = 0.961, P < 0.001 and a reduced foveal slope (r = −0.863, P < 0.001 than the corrected value. Conclusion: Lateral measurements made on OCT varied with AXL s other than the OCT calibrated value of 24.46 mm. Therefore, to estimate the actual dimensions of a retinal lesion using OCT, especially lateral dimensions, we recommend correction for the ocular magnification factor.

  12. A new mini-extrapolation chamber for beta source uniformity measurements

    International Nuclear Information System (INIS)

    Oliveira, M.L.; Caldas, L.V.E.

    2006-01-01

    According to recent international recommendations, beta particle sources should be specified in terms of absorbed dose rates to water at the reference point. However, because of the clinical use of these sources, additional information should be supplied in the calibration reports. This additional information include the source uniformity. A new small volume extrapolation chamber was designed and constructed at the Calibration Laboratory at Instituto de Pesquisas Energeticas e Nucleares, IPEN, Brazil, for the calibration of 90 Sr+ 90 Y ophthalmic plaques. This chamber can be used as a primary standard for the calibration of this type of source. Recent additional studies showed the feasibility of the utilization of this chamber to perform source uniformity measurements. Because of the small effective electrode area, it is possible to perform independent measurements by varying the chamber position by small steps. The aim of the present work was to study the uniformity of a 90 Sr+ 90 Y plane ophthalmic plaque utilizing the mini extrapolation chamber developed at IPEN. The uniformity measurements were performed by varying the chamber position by steps of 2 mm in the source central axis (x-and y-directions) and by varying the chamber position off-axis by 3 mm steps. The results obtained showed that this small volume chamber can be used for this purpose with a great advantage: it is a direct method, being unnecessary a previously calibration of the measurement device in relation to a reference instrument, and it provides real -time results, reducing the time necessary for the study and the determination of the uncertainties related to the measurements. (authors)

  13. Leaf Phenology of Amazonian Canopy Trees as Revealed by Spectral and Physiochemical Measurements

    Science.gov (United States)

    Chavana-Bryant, C.; Gerard, F. F.; Malhi, Y.; Enquist, B. J.; Asner, G. P.

    2013-12-01

    The phenological dynamics of terrestrial ecosystems reflect the response of the Earth's biosphere to inter- and intra-annual dynamics of climatic and hydrological regimes. Some Dynamic Global Vegetation Models (GDVMs) have predicted that by 2050 the Amazon rainforest will begin to dieback (Cox et al. 2000, Nature) or that the ecosystem will become unsustainable (Salazar et al. 2007, GRL). One major component in DGVMs is the simulation of vegetation phenology, however, modelers are challenged with the estimation of tropical phenology which is highly complex. Current modeled phenology is based on observations of temperate vegetation and accurate representation of tropical phenology is long overdue. Remote sensing (RS) data are a key tool in monitoring vegetation dynamics at regional and global scales. Of the many RS techniques available, time-series analysis of vegetation indices (VIs) has become the most common approach in monitoring vegetation phenology (Samanta et al. 2010, GRL; Bradley et al. 2011, GCB). Our research focuses on investigating the influence that age related variation in the spectral reflectance and physiochemical properties of leaves may have on VIs of tropical canopies. In order to do this, we collected a unique leaf and canopy phenological dataset at two different Amazonian sites: Inselberg, French Guyana (FG) and Tambopata, Peru (PE). Hyperspectral reflectance measurements were collected from 4,102 individual leaves sampled to represent different leaf ages and vertical canopy positions (top, mid and low canopy) from 20 different canopy tree species (8 in FG and 12 in PE). These leaf spectra were complemented with 1) leaf physical measurements: fresh and dry weight, area and thickness, LMA and LWC and 2) leaf chemical measurements: %N, %C, %P, C:N and d13C. Canopy level observations included top-of-canopy reflectance measurements obtained using a multispectral 16-band radiometer, leaf demography (tot. number and age distribution) and branch

  14. Agreement of Two Different Spectral Domain Optical Coherence Tomography Instruments for Retinal Nerve Fiber Layer Measurements

    Directory of Open Access Journals (Sweden)

    Hooshang Faghihi

    2014-01-01

    Full Text Available Purpose: To determine the agreement between Spectralis and Cirrus spectral domain optical coherence tomography (SD-OCT measurements of peripapillary retinal nerve fiber layer (RNFL thickness. Methods: Suspected or confirmed cases of glaucoma who met the inclusion criteria underwent peripapillary RNFL thickness measurement using both the Spectralis and Cirrus on the same day within a few minutes. Results: Measurements were performed on 103 eyes of 103 patients with mean age of 50.4±17.7 years. Mean RNFL thickness was 89.22±15.87 versus 84.54±13.68 μm using Spectralis and Cirrus, respectively. The difference between measurements and the average of paired measurements with the two devices showed a significant linear relationship. Bland-Altman plots demonstrated that Spectralis thickness values were systematically larger than that of Cirrus. Conclusion: Spectralis OCT generates higher peripapillary RNFL thickness readings as compared to Cirrus OCT; this should be kept in mind when values obtained with different instruments are compared during follow-up.

  15. 2D Spatial Frequency Considerations in Comparing 1D Power Spectral Density Measurements

    International Nuclear Information System (INIS)

    Takacs, P.Z.; Barber, S.; Church, E.L.; Kaznatcheev, K.; McKinney, W.R.; Yashchuk, V.Y.

    2010-01-01

    The frequency footprint of ID and 2D profiling instruments needs to be carefully considered in comparing ID surface roughness spectrum measurements made by different instruments. Contributions from orthogonal direction frequency components can not be neglected. The use of optical profiling instruments is ubiquitous in the measurement of the roughness of optical surfaces. Their ease-of-use and non-contact measurement method found widespread use in the optics industry for measuring the quality of delicate optical surfaces. Computerized digital data acquisition with these instruments allowed for quick and easy calculation of surface roughness statistics, such as root-mean-square (RMS) roughness. The computing power of the desktop computer allowed for the rapid conversion of spatial domain data into the frequency domain, enabling the application of sophisticated signal processing techniques to be applied to the analysis of surface roughness, the most powerful of which is the power spectral density (PSP) function. Application of the PSD function to surface statistics introduced the concept of 'bandwidth-limited' roughness, where the value of the RMS roughness depends critically upon the spatial frequency response of the instrument. Different instruments with different spatial frequency response characteristics give different answers when measuring the same surface.

  16. 'aspect' - a new spectrometer for the measurement of the angular correlation coefficient a in neutron beta decay

    CERN Document Server

    Zimmer, O; Grinten, M G D; Heil, W; Glück, F

    2000-01-01

    The combination of the coefficient a of the antineutrino/electron angular correlation with the beta asymmetry of the neutron provides a sensitive test for scalar and tensor contributions to the electroweak Lagrangian, as well as for right-handed currents. A method is given for measuring a with high sensitivity from the proton recoil spectrum. The method is based on a magnetic spectrometer with electrostatic retardation potentials such as used for searches of the neutrino mass in tritium beta decay. The spectrometer can also be used for similar studies using radioactive nuclei.

  17. Spectral measurements at different spatial scales in potato: relating leaf, plant and canopy nitrogen status

    Science.gov (United States)

    Jongschaap, Raymond E. E.; Booij, Remmie

    2004-09-01

    Chlorophyll contents in vegetation depend on soil nitrogen availability and on crop nitrogen uptake, which are important management factors in arable farming. Crop nitrogen uptake is important, as nitrogen is needed for chlorophyll formation, which is important for photosynthesis, i.e. the conversion of absorbed radiance into plant biomass. The objective of this study was to estimate leaf and canopy nitrogen contents by near and remote sensing observations and to link observations at leaf, plant and canopy level. A theoretical base is presented for scaling-up leaf optical properties to whole plants and crops, by linking different optical recording techniques at leaf, plant and canopy levels through the integration of vertical nitrogen distribution. Field data come from potato experiments in The Netherlands in 1997 and 1998, comprising two potato varieties: Eersteling and Bintje, receiving similar nitrogen treatments (0, 100, 200 and 300 kg N ha -1) in varying application schemes to create differences in canopy nitrogen status during the growing season. Ten standard destructive field samplings were performed to follow leaf area index and crop dry weight evolution. Samples were analysed for inorganic nitrogen and total nitrogen contents. At sampling dates, spectral measurements were taken both at leaf level and at canopy level. At leaf level, an exponential relation between SPAD-502 readings and leaf organic nitrogen contents with a high correlation factor of 0.91 was found. At canopy level, an exponential relation between canopy organic nitrogen contents and red edge position ( λrep, nm) derived from reflectance measurements was found with a good correlation of 0.82. Spectral measurements (SPAD-502) at leaf level of a few square mm were related to canopy reflectance measurements (CropScan™) of approximately 0.44 m 2. Statistical regression techniques were used to optimise theoretical vertical nitrogen profiles that allowed scaling-up leaf chlorophyll measurements

  18. XA readout chip characteristics and CdZnTe spectral measurements

    International Nuclear Information System (INIS)

    Barbier, L.M.; Birsa, F.; Odom, J.

    1999-01-01

    The authors report on the performance of a CdZnTe (CZT) array readout by an XA (X-ray imaging chip produced at the AMS foundry) application specific readout chip (ASIC). The array was designed and fabricated at NASA/Goddard Space Flight Center (GSFC) as a prototype for the Burst Arc-Second Imaging and Spectroscopy gamma-ray instrument. The XA ASIC was obtained from Integrated Detector and Electronics (IDE), in Norway. Performance characteristics and spectral data for 241 Am are presented both at room temperature and at -20 C. The measured noise (σ) was 2.5 keV at 60 keV at room temperature. This paper represents a progress report on work with the XA ASIC and CZT detectors. Work is continuing and in particular, larger arrays are planned for future NASA missions

  19. Results of neutron measurements in the spectral position of the Juelich FKS steel irradiation capsules

    International Nuclear Information System (INIS)

    Schneider, W.

    1986-10-01

    This is a report on the planning and results of neutron monitoring in the capsules of the Juelich steel irradiation for the research project on component safety (FKS). The table of results and their discussion is provided specifically for the spectral positions (for characterising the neutron spectrum) in each of the types of irradiation capsules used. The results are given for the reaction rates of the neutron measurement reactions used (activation or fission reactions), for the neutron flux densities and fluxes derived from them related to the actual or at least plausible neutron spectra and finally for the radiation damage (or exposure) of the irradiated material calculated from them, expressed as the atomic displacement figure (dpa) and its percentage in sections of the neutron spectrum. (orig.) [de

  20. Detection of crop water status in mature olive orchards using vegetation spectral measurements

    Science.gov (United States)

    Rallo, Giovanni; Ciraolo, Giuseppe; Farina, Giuseppe; Minacapilli, Mario; Provenzano, Giuseppe

    2013-04-01

    Leaf/stem water potentials are generally considered the most accurate indicators of crop water status (CWS) and they are quite often used for irrigation scheduling, even if costly and time-consuming. For this reason, in the last decade vegetation spectral measurements have been proposed, not only for environmental monitoring, but also in precision agriculture, to evaluate crop parameters and consequently for irrigation scheduling. Objective of the study was to assess the potential of hyperspectral reflectance (450-2400 nm) data to predict the crop water status (CWS) of a Mediterranean olive orchard. Different approaches were tested and particularly, (i) several standard broad- and narrow-band vegetation indices (VIs), (ii) specific VIs computed on the basis of some key wavelengths, predetermined by simple correlations and finally, (iii) using partial least squares (PLS) regression technique. To this aim, an intensive experimental campaign was carried out in 2010 and a total of 201 reflectance spectra, at leaf and canopy level, were collected with an ASD FieldSpec Pro (Analytical Spectral Devices, Inc.) handheld field spectroradiometer. CWS was contemporarily determined by measuring leaf and stem water potentials with the Scholander chamber. The results indicated that the considered standard vegetation indices were weakly correlated with CWS. On the other side, the prediction of CWS can be improved using VIs pointed to key-specific wavelengths, predetermined with a correlation analysis. The best prediction accuracy, however, can be achieved with models based on PLS regressions. The results confirmed the dependence of leaf/canopy optical features from CWS so that, for the examined crop, the proposed methodology can be considered a promising tool that could also be extended for operational applications using multispectral aerial sensors.

  1. Radionuclide, scintillation cocktail and chemical/color quench influence on discriminator setting in gross alpha/beta measurements by LSC

    International Nuclear Information System (INIS)

    Stojković, Ivana; Tenjović, Branislava; Nikolov, Jovana; Todorović, Nataša

    2015-01-01

    Gross alpha/beta measurements in drinking waters enable radiochemical composition analysis in environmental studies providing efficient screening method that can indicate whether water contains elevated levels of any radionuclide. Routine gross alpha/beta activity monitoring in drinking waters has been carried out for a few years in laboratory for low-level radioactivity measurements in Novi Sad according to ASTM method, performing measurements on liquid scintillation counter Quantulus 1220 which can simultaneously generate alpha/beta spectra of samples by Pulse Shape Analysis (PSA circuit). In this paper, PSA discriminator impact was investigated to ensure obtaining of accurate and reliable alpha/beta activities. One novelty of presented work is PSA parameter setup with two combinations of radionuclides ( 241 Am, 226 Ra and 90 Sr/ 90 Y) with varying activity concentrations. Performed experiments also make contribution to investigations on the manner in which chemical and color quench affect optimal PSA parameter setting and further on, their altogether influence on gross alpha/beta activity measurements. Nitromethane, 15.8 M nitric acid and water, as well as yellow and yellow-orange dye, were used as quenching agents in order to test PSA/interference factor behavior in the presence of quenchers with different quenching strengths. Variation of PSA setting in quenched samples with two different commercially available cocktails (Ultima Gold LLT and OptiPhase HiSafe 3) was also tested. Lastly, application i.e. assessment of obtained PSA-SQP(E) correlation on the obtained results of activity concentrations of few artesian well water samples and colored spiked samples, based on the measured SQP(E) value of samples, has been demonstrated. - Highlights: • Thorough study on influence of relevant factors on optimal PSA level in gross alpha/beta measurements in waters is presented. • Experiments were performed on liquid scintillation counter Quantulus 1220™ according

  2. Spectral encoding method for measuring the relative arrival time between x-ray/optical pulses

    International Nuclear Information System (INIS)

    Bionta, M. R.; Hartmann, N.; Weaver, M.; French, D.; Glownia, J. M.; Bostedt, C.; Chollet, M.; Ding, Y.; Fritz, D. M.; Fry, A. R.; Krzywinski, J.; Lemke, H. T.; Messerschmidt, M.; Schorb, S.; Zhu, D.; White, W. E.; Nicholson, D. J.; Cryan, J. P.; Baker, K.; Kane, D. J.

    2014-01-01

    The advent of few femtosecond x-ray light sources brings promise of x-ray/optical pump-probe experiments that can measure chemical and structural changes in the 10–100 fs time regime. Widely distributed timing systems used at x-ray Free-Electron Laser facilities are typically limited to above 50 fs fwhm jitter in active x-ray/optical synchronization. The approach of single-shot timing measurements is used to sort results in the event processing stage. This has seen wide use to accommodate the insufficient precision of active stabilization schemes. In this article, we review the current technique for “measure-and-sort” at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The relative arrival time between an x-ray pulse and an optical pulse is measured near the experimental interaction region as a spectrally encoded cross-correlation signal. The cross-correlation provides a time-stamp for filter-and-sort algorithms used for real-time sorting. Sub-10 fs rms resolution is common in this technique, placing timing precision at the same scale as the duration of the shortest achievable x-ray pulses

  3. Normal spectral emissivity measurement of molten copper using an electromagnetic levitator superimposed with a static magnetic field

    International Nuclear Information System (INIS)

    Kurosawa, Ryo; Inoue, Takamitsu; Baba, Yuya; Sugioka, Ken-ichi; Kubo, Masaki; Tsukada, Takao; Fukuyama, Hiroyuki

    2013-01-01

    The normal spectral emissivity of molten copper was determined in the wavelength range of 780–920 nm and in the temperature range of 1288–1678 K, by directly measuring the radiance emitted by an electromagnetically levitated molten copper droplet under a static magnetic field of 1.5 T. The spectrometer for radiance measurement was calibrated using the relation between the theoretical blackbody radiance from Planck's law and the light intensity of a quasi-blackbody radiation source measured using a spectrometer at a given temperature. As a result, the normal spectral emissivity of molten copper was determined as 0.075 ± 0.011 at a wavelength of 807 nm, and it was found that its temperature dependence is negligible in the entire measurement temperature range tested. In addition, the results of the normal spectral emissivity and its wavelength dependence were discussed, in comparison with those obtained using the Drude free-electron model. (paper)

  4. Measurement of the lepton {tau} spectral functions and applications to quantum chromodynamic; Mesure des fonctions spectrales du lepton {tau} et applications a la chromodynamique quantique

    Energy Technology Data Exchange (ETDEWEB)

    Hoecker, A [Paris-11 Univ., 91 - Orsay (France). Lab. de l' Accelerateur Lineaire; [Universite de Paris Sud, 91 - Orsay (France)

    1997-04-18

    This thesis presents measurements of the {tau} vector (V) and axial-vector (A) hadronic spectral functions and phenomenological studies in the framework of quantum chromodynamics (QCD). Using the hypothesis of conserved vector currents (CVC), the dominant two- and four-pion vector spectral functions are compared to the corresponding cross sections from e{sup +}e{sup -} annihilation. A combined fit of the pion form factor from {tau} decays and e{sup +}e{sup -} data is performed using different parametrizations. The mass and the width of the {rho}{sup {+-}}(770) and the {rho}{sup 0}(770) are separately determined in order to extract possible isospin violating effects. The mass and width differences are measured to be M{sub {rho}{sup {+-}}{sub (770)} - M{sub {rho}{sup 0}}{sub (770)}=(0.0{+-}1.0) MeV/c{sup 2} and {gamma}{sub {rho}{sup {+-}}{sub (770)} - {gamma}{sub {rho}{sup 0}}{sub (770)}=(0.1 {+-} 1.9) MeV/c{sup 2}. Several QCD chiral sum rules involving the difference (V - A) of the spectral functions are compared to their measurements. The Borel-transformed Das-Mathur-Okubo sum rule is used to measure the pion polarizability to be {alpha}{sub E}=(2.68{+-}0.91) x 10{sup -4} fm{sup 3}. The {tau} vector and axial-vector hadronic widths and certain spectral moments are exploited to measure {alpha}{sub s} and non-perturbative contributions at the {tau} mass scale. The best, and experimentally and theoretically most robust, determination of {alpha}{sub s}(M{sub {tau}}) is obtained from the inclusive (V + A) fit that yields {alpha}{sub s}(M{sub {tau}})= 0.348{+-}0.017 giving {alpha}{sub s}(M{sub Z})=0.1211 {+-} 0.0021 after the evolution to the mass of the Z boson. The approach of the Operator Product Expansion (OPE) is tested experimentally by means of an evolution of the {tau} hadronic width to masses smaller that the {tau} mass. Using the difference (V - A) of the spectral functions allows one to directly measure the dominant non-perturbative OPE dimension to be D=6

  5. An update on the analysis of the Princeton 19Ne beta asymmetry measurement

    Science.gov (United States)

    Combs, Dustin; Calaprice, Frank; Jones, Gordon; Pattie, Robert; Young, Albert

    2013-10-01

    We report on the progress of a new analysis of the 1994 19Ne beta asymmetry measurement conducted at Princeton University. In this experiment, a beam of 19Ne atoms were polarized with a Stern-Gerlach magnet and then entered a thin-walled mylar cell through a slit fabricated from a piece of micro channel plate. A pair of Si(Li) detectors at either end of the apparatus were aligned with the direction of spin polarization (one parallel and one anti-parallel to the spin of the 19Ne) and detected positrons from the decays. The difference in the rate in the two detectors was used to calculate the asymmetry. A new analysis procedure has been undertaken using the Monte Carlo package PENELOPE with the goal of determining the systematic uncertainty due to positrons scattering from the face of the detectors causing the incorrect reconstruction of the initial direction of the positron momentum. This was a leading cause of systematic uncertainty in the experiment in 1994.

  6. Measuring nuclear reaction cross sections to extract information on neutrinoless double beta decay

    Science.gov (United States)

    Cavallaro, M.; Cappuzzello, F.; Agodi, C.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Branchina, V.; Bussa, M. P.; Calabrese, S.; Calabretta, L.; Calanna, A.; Calvo, D.; Carbone, D.; Chávez Lomelí, E. R.; Coban, A.; Colonna, M.; D'Agostino, G.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; de Faria, P. N.; Ferraresi, C.; Ferreira, J. L.; Finocchiaro, P.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia, U.; Giraudo, G.; Greco, V.; Hacisalihoglu, A.; Kotila, J.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lavagno, A.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lo Presti, D.; Lubian, J.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Petrascu, H.; Pinna, F.; Reito, S.; Rifuggiato, D.; Rodrigues, M. R. D.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Sgouros, O.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Tudisco, S.; Vsevolodovna, R. I. M.; Wheadon, R. J.; Yildirin, A.; Zagatto, V. A. B.

    2018-02-01

    Neutrinoless double beta decay (0vββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0vββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0vββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0vββ.

  7. Measurement of gross alpha, gross beta, radon and radium activity concentrations in aqueous samples using liquid scintillation technique

    International Nuclear Information System (INIS)

    Zaini Hamzah; Ahmad Saat; Masitah Alias; Siti Afiqah Abdul Rahman; Mohamed Kasim; Abdul Kadir Ishak

    2011-01-01

    Recently, Malaysia has taken a positive step toward providing a better water quality by introducing more water quality parameters into its Water Quality Standard. With regard to the natural radionuclides that may present in the water, 3 parameters were introduced that is gross alpha, gross beta and radium which need to be measured and cannot exceed 0.1, 1.0 and 1.0 Bq/ L respectively. This study was conducted to develop a more practical method in measuring these parameters in aqueous environmental samples. Besides having a lot of former tin mining areas, some part of Malaysia is located on the granitic rock which also contributes to a certain extent the amount of natural radionuclides such as uranium and thorium. For all we know these two radionuclides are the origin of other radionuclides being produced from their decay series. The State of Kelantan was chosen as the study area, where the water samples were collected from various part of the Kelantan River. 25 liters of samples were collected, acidify to pH 2 and filtered before the analysis. Measurement of these parameters was done using liquid scintillation counter (LSC). The LSC was set up to the optimum discriminator level and counting was done using alpha-beta mode. The results show that gross alpha and beta can be measured using scintillation cocktail and radium and radon using extraction method. The results for gross alpha, gross beta, 222 Ra and 226 Ra are 0.39-6.42, 0.66-16.18, 0.40-4.65 and 0.05-0.56 Bq/ L. MDA for gross alpha, gross beta and radium is 0.03, 0.08 and 0.00035 Bq/ L respectively. (Author)

  8. The Significance of Serum beta2-Microglobulin Measurement in Various Renal Diseases

    Energy Technology Data Exchange (ETDEWEB)

    Koong, Sung Soo; Oh, Ha Yong; Han, Jin Suk; Lee, Jung Sang [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1985-03-15

    To evaluate change of serum beta{sub 2}-microglobulin concentration (sbeta{sub 2}-MG) and the usefulness of sbeta{sub 2}-MG and sbeta{sub 2}-MG/serum creatinine concentration (sCr) ratio in various renal diseases, sbeta{sub 2}-MG and sCr were measured in 25 normal controls and 90 patients of various renal diseases (16 cases of glomerulonephritis, 12 cases of acute renal failure, 8 cases of chronic renal failure, 24 cases of nephrotic syndrome, 15 cases of tubulointerstitial diseases and 15 cases of lupus nephritis) using Phadebas beta{sub 2}-Micro Test kits. The results were as follows; 1) In normal control, the mean value of sbeta{sub 2}-MG was 1.65+-0.41 mg/l and the mean value of sbeta{sub 2}-MG/sCr ratio was 0.14+-0.05. 2) In various renal diseases, the mean value of sbeta{sub 2}-MG was 6.74+-5.47 mg/l. The mean value of sbeta{sub 2}-MG/sCr ratio was 0.24+-0.11 and significantly elevated than that of normal contro1. (P<0.05). 3) The correlation between sbeta-2-MG and sCr in glomerular and tubulointerstitial disease was log sbeta{sub 2}-MG=0.90 log sCr-0.48 and its correlation coefficient was 0.78 (P<0.05). 4) In glomerular disease, the correlation between sbeta{sub 2}-MG and sCr was log sbeta{sub 2}-MG=0.89 log sCr-0.46 (r-0.76) and in tubulointerstitial disease, it was log sbeta{sub 2}-MG=0.95 1og sCr-0.59 (r-0.87). There was no significant difference between the two groups (p<0.05). 5) Among 32 cases of glomerular and tubulointerstitial disease patients, whose sCr was within normal range, 17 cases showed elevated sbeta{sub 2}-MG. The mean values of sbeta{sub 2}-MG/sCr ratio in these patients was 0.30+-0.14 and significantly elevated than that of normal control (p<0.05). 6) In 15 cases of lupus nephritis, 12 cases showed elevated sbeta{sub 2}-MG with normal sCr and 12 cases showed elevated sbeta{sub 2}-MG/sCr ratio. With above results, It was found that the sbeta{sub 2}-MG can be used as an index of glomerular filtration rate as in the case of sCr and thats

  9. Measurement of gross alpha and beta in air filter samples by using liquid scintillation counter

    International Nuclear Information System (INIS)

    Sudheendran, V.; Baburajan, A.; Gaikwad, R.H.; Ravi, P.M.; Tripathi, R.M.

    2015-01-01

    The determination of gross alpha and gross beta in particulate air filter samples was carried out by alpha, beta discrimination method using Liquid Scintillation Analyzer by setting the PSA value at 55 for 5 ml 0.1 HCl plus 15 ml of Ultima Gold AB cocktail by using 241 Am and 90 Sr/ 90 Y sources. The standardized method was compared with the gross alpha and gross beta activity determined by conventional method of direct counting with end window G.M. counter and ZnS (Ag). The minimum detectable activity of LSA method was found to be 9.3 mBq and 17.7 mBq for gross alpha and gross beta respectively for 6000 sec compared to the conventional method of 9.8 mBq and 189 mBq respectively at the same counting time. The result of analysis by both method indicate that the alpha, beta discrimination set up of LSA method is highly effective in the determination of low level alpha, beta activity in air filter samples. (author)

  10. Dual-peak dose measurement for radiochromic films by a newly developed spectral microdensitometer

    International Nuclear Information System (INIS)

    Lee, K.Y.; Fung, K.K.L.; Kwok, C.S.

    2005-01-01

    Radiochromic film (RCF) dosimetry is usually based on densitometric methods which use an analyzing light source of a fixed or a broad spectrum of wavelengths. These methods have not exploited the sensitivity of the dose response of the RCF otherwise attainable by using a light source with wavelengths peaked at the two absorption peaks in the absorption spectrum of the RCF. A new algorithm of dual-peak dose measurement for the RCF has been proposed in this paper to make use of these dual absorption peaks to achieve the maximum attainable sensitivity. This technique relies on the measurement of the transmittance of the RCF at the wavelength of the major and minor absorption peaks, respectively. The dual-peak dose measurement is accomplished with the aid of a novel spectral microdensitometer developed in our Institute. The microdensitometer utilizes a monochromator to provide a light source of which the wavelength can be matched precisely to the wavelength of the absorption peaks of the RCF. The doses obtained at these wavelengths are fed into a weighted objective function and an optimum dose is searched by minimizing the objective function to give the best estimate of the dose deposited on the film. An initial test shows that there is a good agreement between the estimated and actual dose deposited; and the maximum discrepancy was found to be less than 1%

  11. Spectral emissivity measurements of candidate materials for very high temperature reactors

    Energy Technology Data Exchange (ETDEWEB)

    Cao, G.; Weber, S.J.; Martin, S.O.; Anderson, M.H. [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Drive, Madison, WI (United States); Sridharan, K., E-mail: kumars@cae.wisc.edu [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Drive, Madison, WI (United States); Allen, T.R. [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Drive, Madison, WI (United States)

    2012-10-15

    Heat dissipation by radiation is an important consideration in VHTR components, particularly the reactor pressure vessel (RPV), because of the fourth power temperature dependence of radiated heat. Since emissivity is the material property that dictates the ability to radiate heat, measurements of emissivities of materials that are being specifically considered for the construction of VHTR become important. Emissivity is a surface phenomenon and therefore compositional, structural, and topographical changes that occur at the surfaces of these materials as a result of their interactions with the environment at high temperatures will alter their emissivities. With this background, an experimental system for the measurement of spectral emissivity has been designed and constructed. The system has been calibrated in conformance with U.S. DoE quality assurance standards using inert ceramic materials, boron nitride, silicon carbide, and aluminum oxide. The results of high temperature emissivity measurements of potential VHTR materials such as ferritic steels SA 508, T22, T91 and austenitic alloys IN 800H, Haynes 230, IN 617, and 316 stainless steel have been presented.

  12. Comparisons Between Model Predictions and Spectral Measurements of Charged and Neutral Particles on the Martian Surface

    Science.gov (United States)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F.; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan; hide

    2014-01-01

    Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Radiation Assessment Detector (RAD) on the Curiosity rover since August 2012. RAD is a particle detector that measures the energy spectrum of charged particles (10 to approx. 200 MeV/u) and high energy neutrons (approx 8 to 200 MeV). The data obtained on the surface of Mars for 300 sols are compared to the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used. For describing the daily column depth of atmosphere, daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station (REMS) are implemented into transport calculations. Particle flux at RAD after traversing varying depths of atmosphere depends on the slant angles, and the model accounts for shielding of the RAD "E" dosimetry detector by the rest of the instrument. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and suggest that future radiation environments on Mars can be predicted accurately. These contributions lend support to the understanding of radiation health risks to astronauts for the planning of various mission scenarios

  13. Measurement of the Spectral Absorption of Liquid Water in Melting Snow With an Imaging Spectrometer

    Science.gov (United States)

    Green, Robert O.; Dozier, Jeff

    1995-01-01

    Melting of the snowpack is a critical parameter that drives aspects of the hydrology in regions of the Earth where snow accumulates seasonally. New techniques for measurement of snow melt over regional scales offer the potential to improve monitoring and modeling of snow-driven hydrological processes. In this paper we present the results of measuring the spectral absorption of liquid water in a melting snowpack with the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). AVIRIS data were acquired over Mammoth Mountain, in east central California on 21 May 1994 at 18:35 UTC. The air temperature at 2926 m on Mammoth Mountain at site A was measured at 15-minute intervals during the day preceding the AVIRIS data acquisition. At this elevation. the air temperature did not drop below freezing the night of the May 20 and had risen to 6 degrees Celsius by the time of the overflight on May 21. These temperature conditions support the presence of melting snow at the surface as the AVIRIS data were acquired.

  14. Long-term uvb forecasting on the basis of spectral and broad-band measurements

    Science.gov (United States)

    Bérces, A.; Gáspár, S.; Kovács, G.; Rontó, G.

    2003-04-01

    The stratospheric ozone concentration has been investigated by several methods, e.g. determinations of the ozone layer using a network of ground based spectrophotometers, of the Dobson and the Brewer types. These data indicate significant decrease of the ozone layer superimposed by much larger seasonal changes at specific geographical locations. The stratospheric ozone plays an important role in the attenuation of the short-wavelength components of the solar spectrum, thus the consequence of the decreased ozone layer is an increased UVB level. Various pyranometers measuring the biological effect of environmental UV radiation have been constructed with spectral sensitivities close to the erythema action spectrum defined by the CIE. Using these erythemally weighted broad-band instruments to detect the tendency of UVB radiation controversial data have been found. To quantify the biological risk due to environmental UV radiation it is reasonable to weight the solar spectrum by the spectral sensitivity of the DNA damage taking into account the high DNA-sensitivity at the short wavelength range of the solar spectrum. Various biological dosimeters have been developed e.g. polycrystalline uracil thin layer. These are usually simple biological systems or components of them. Their UV sensitivity is a consequence of the DNA-damage. Biological dosimeters applied for long-term monitoring are promising tools for the assessment of the biological hazard. Simultaneous application of uracil dosimeters and Robertson-Berger meters can be useful to predict the increasing tendency of the biological UV exposure more precisely. The ratio of the biologically effective dose obtained by the uracil dosimeter (a predominately UVB effect) and by the Robertson-Berger meter (insensitive to changes below 300 nm) is a sensitive method for establishing changes in UVB irradiance due to changes in ozone layer.

  15. Double Beta Decay in Xenon-136. Measuring the Neutrino-Emitting Mode and Searching for Majoron-Emitting Modes

    Energy Technology Data Exchange (ETDEWEB)

    Herrin, Steven [Stanford Univ., CA (United States)

    2013-06-01

    Observations of neutrino flavor oscillations have demonstrated that neutrinos have mass. Since the discovery of these oscillations, much progress has been made at mea- suring the neutrino mass-squared differences and lepton mixing angles that character- ize them. However, the origin and absolute scale of neutrino masses remain unknown. Unique among fermions, neutrinos can be Majorana particles, which could provide an explanation for neutrino masses. Discovery of a hypothetical process known as neutrinoless double beta decay would show that neutrinos are Majorana particles and determine the mass scale for neutrinos. The Enriched Xenon Observatory (EXO) is a series of experiments searching for the neutrinoless double beta decay of 136Xe. The first experiment, EXO-200, began operation in 2011 and makes use of 200 kg of xenon enriched to 80.6% in 136Xe. The analysis presented here makes use of data from EXO-200 to obtain a more precise measurement of the half-life for the two-neutrino-emitting mode of double beta decay than previously reported. The analysis also sets limits on the half-lives for exotic, Majoron-emitting modes of neutrinoless double beta decay. Data from EXO-200 is also used to produce a measurement of the cosmic muon flux at the WIPP under- ground site where EXO-200 is located.

  16. Measurement of the $\\beta$-asymmetry parameter of $^{67}$Cu in search for tensor type currents in the weak interaction

    CERN Document Server

    Soti, G.; Breitenfeldt, M.; Finlay, P.; Herzog, P.; Knecht, A.; Köster, U.; Kraev, I.S.; Porobic, T.; Prashanth, P.N.; Towner, I.S.; Tramm, C.; Zákoucký, D.; Severijns, N.

    2014-01-01

    Precision measurements at low energy search for physics beyond the Standard Model in a way complementary to searches for new particles at colliders. In the weak sector the most general $\\beta$ decay Hamiltonian contains, besides vector and axial-vector terms, also scalar, tensor and pseudoscalar terms. Current limits on the scalar and tensor coupling constants from neutron and nuclear $\\beta$ decay are on the level of several percent. The goal of this paper is extracting new information on tensor coupling constants by measuring the $\\beta$-asymmetry parameter in the pure Gamow-Teller decay of $^{67}$Cu, thereby testing the V-A structure of the weak interaction. An iron sample foil into which the radioactive nuclei were implanted was cooled down to milliKelvin temperatures in a $^3$He-$^4$He dilution refrigerator. An external magnetic field of 0.1 T, in combination with the internal hyperfine magnetic field, oriented the nuclei. The anisotropic $\\beta$ radiation was observed with planar high purity germanium d...

  17. Measurement of the CP-Violating Phase beta_s in B0s -> J/Psi Phi Decays with the CDF II Detector

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T. [Helsinki Institute of Physics (Finland); et al.

    2012-04-01

    We present a measurement of the \\CP-violating parameter \\betas using approximately 6500 $\\BsJpsiPhi$ decays reconstructed with the CDF\\,II detector in a sample of $p\\bar p$ collisions at $\\sqrt{s}=1.96$ TeV corresponding to 5.2 fb$^{-1}$ integrated luminosity produced by the Tevatron Collider at Fermilab. We find the \\CP-violating phase to be within the range $\\betas \\in [0.02, 0.52] \\cup [1.08, 1.55]$ at 68% confidence level where the coverage property of the quoted interval is guaranteed using a frequentist statistical analysis. This result is in agreement with the standard model expectation at the level of about one Gaussian standard deviation. We consider the inclusion of a potential $S$-wave contribution to the $\\Bs\\to J/\\psi K^+K^-$ final state which is found to be negligible over the mass interval $1.009 < m(K^+K^-)<1.028 \\gevcc$. Assuming the standard model prediction for the \\CP-violating phase \\betas, we find the \\Bs decay width difference to be $\\deltaG = 0.075 \\pm 0.035\\,\\textrm{(stat)} \\pm 0.006\\,\\textrm{(syst)} \\ps$. We also present the most precise measurements of the \\Bs mean lifetime $\\tau(\\Bs) = 1.529 \\pm 0.025\\,\\textrm{(stat)} \\pm 0.012\\,\\textrm{(syst)}$ ps, the polarization fractions $|A_0(0)|^2 = 0.524 \\pm 0.013\\,\\textrm{(stat)} \\pm 0.015\\,\\textrm{(syst)}$ and $|A_{\\parallel}(0)|^2 = 0.231 \\pm 0.014\\,\\textrm{(stat)} \\pm 0.015\\,\\textrm{(syst)}$, as well as the strong phase $\\delta_{\\perp}= 2.95 \\pm 0.64\\,\\textrm{(stat)} \\pm 0.07\\,\\textrm{(syst)} \\textrm{rad}$. In addition, we report an alternative Bayesian analysis that gives results consistent with the frequentist approach.

  18. Assessing the high frequency behavior of non-polarizable electrodes for spectral induced polarization measurements

    Science.gov (United States)

    Abdulsamad, Feras; Florsch, Nicolas; Schmutz, Myriam; Camerlynck, Christian

    2016-12-01

    During the last decades, the usage of spectral induced polarization (SIP) measurements in hydrogeology and detecting environmental problems has been extensively increased. However, the physical mechanisms which are responsible for the induced polarization response over the usual frequency range (typically 1 mHz to 10-20 kHz) require better understanding. The phase shift observed at high frequencies is sometimes attributed to the so-called Maxwell-Wagner polarization which takes place when charges cross an interface. However, SIP measurements of tap water show a phase shift at frequencies higher than 1 kHz, where no Maxwell-Wagner polarization may occur. In this paper, we enlighten the possible origin of this phase shift and deduce its likely relationship with the types of the measuring electrodes. SIP Laboratory measurements of tap water using different types of measuring electrodes (polarizable and non-polarizable electrodes) are carried out to detect the origin of the phase shift at high frequencies and the influence of the measuring electrodes types on the observed complex resistivity. Sodium chloride is used to change the conductivity of the medium in order to quantify the solution conductivity role. The results of these measurements are clearly showing the impact of the measuring electrodes type on the measured phase spectrum while the influence on the amplitude spectrum is negligible. The phenomenon appearing on the phase spectrum at high frequency (> 1 kHz) whatever the electrode type is, the phase shows an increase compared to the theoretical response, and the discrepancy (at least in absolute value) increases with frequency, but it is less severe when medium conductivity is larger. Additionally, the frequency corner is shifted upward in frequency. The dependence of this phenomenon on the conductivity and the measuring electrodes type (electrode-electrolyte interface) seems to be due to some dielectric effects (as an electrical double layer of small

  19. $\\beta$-decay and $\\beta$-delayed Neutron Emission Measurements at GSI-FRS Beyond N=126, for r-process Nucleosynthesis

    CERN Document Server

    Caballero-Folch, R; Cortès, G; Taín, J L; Agramunt, J; Algora, A; Ameil, F; Ayyad, Y; Benlliure, J; Bowry, M; Calviño, F; Cano-Ott, D; Davinson, T; Dillmann, I; Estrade, A; Evdokimov, A; Faestermann, T; Farinon, F; Galaviz, D; García-Ríos, A; Geissel, H; Gelletly, W; Gernhäuser, R; Gómez-Hornillos, M B; Guerrero, C; Heil, M; Hinke, C; Knöbel, R; Kojouharov, I; Kurcewicz, J; Kurz, N; Litvinov, Y; Maier, L; Marganiec, J; Marta, M; Martínez, T; Montes, F; Mukha, I; Napoli, D R; Nociforo, C; Paradela, C; Pietri, S; Podolyák, Zs; Prochazka, A; Rice, S; Riego, A; Rubio, B; Schaffner, H; Scheidenberger, C; Smith, K; Sokol, E; Steiger, K; Sun, B; Takechi, M; Testov, D; Weick, H; Wilson, E; Winfield, J S; Wood, R; Woods, P J; Yeremin, A

    2014-01-01

    New measurements of very exotic nuclei in the neutron-rich region beyond N=126 have been performed at the GSI facility with the fragment separator (FRS). The aim of the experiment is to determine half-lives and beta-delayed neutron emission branching ratios of isotopes of Hg, Tl and Pb in this region. This contribution summarizes final counting statistics for identification and for implantation, as well as the present status of the data analysis of the half-lives. In summary, isotopes of Pt, Au, Hg, Ti, Pb, Bi, Po, At, Rn and Fr were clearly identified and several of them (Hg208-211, Tl211-215, Pb214-218) were implanted with enough statistics to determine their half-lives. About half of them are expected to be neutron emitters, in such cases it will become possible to obtain the neutron emission probabilities, P-n.

  20. Simulation study of the aerosol information content in OMI spectral reflectance measurements

    Directory of Open Access Journals (Sweden)

    B. Veihelmann

    2007-06-01

    Full Text Available The Ozone Monitoring Instrument (OMI is an imaging UV-VIS solar backscatter spectrometer and is designed and used primarily to retrieve trace gases like O3 and NO2 from the measured Earth reflectance spectrum in the UV-visible (270–500 nm. However, also aerosols are an important science target of OMI. The multi-wavelength algorithm is used to retrieve aerosol parameters from OMI spectral reflectance measurements in up to 20 wavelength bands. A Principal Component Analysis (PCA is performed to quantify the information content of OMI reflectance measurements on aerosols and to assess the capability of the multi-wavelength algorithm to discern various aerosol types. This analysis is applied to synthetic reflectance measurements for desert dust, biomass burning aerosols, and weakly absorbing anthropogenic aerosol with a variety of aerosol optical thicknesses, aerosol layer altitudes, refractive indices and size distributions. The range of aerosol parameters considered covers the natural variability of tropospheric aerosols. This theoretical analysis is performed for a large number of scenarios with various geometries and surface albedo spectra for ocean, soil and vegetation. When the surface albedo spectrum is accurately known and clouds are absent, OMI reflectance measurements have 2 to 4 degrees of freedom that can be attributed to aerosol parameters. This information content depends on the observation geometry and the surface albedo spectrum. An additional wavelength band is evaluated, that comprises the O2-O2 absorption band at a wavelength of 477 nm. It is found that this wavelength band adds significantly more information than any other individual band.

  1. Impurity identifications, concentrations and particle fluxes from spectral measurements of the EXTRAP T2R plasma

    Science.gov (United States)

    Menmuir, S.; Kuldkepp, M.; Rachlew, E.

    2006-10-01

    An absolute intensity calibrated 0.5 m spectrometer with optical multi-channel analyser detector was used to observe the visible-UV radiation from the plasma in the EXTRAP T2R reversed field pinch experiment. Spectral lines were identified indicating the presence of oxygen, chromium, iron and molybdenum impurities in the hydrogen plasma. Certain regions of interest were examined in more detail and at different times in the plasma discharge. Impurity concentration calculations were made using the absolute intensities of lines of OIV and OV measured at 1-2 ms into the discharge generating estimates of the order of 0.2% of ne in the central region rising to 0.7% of ne at greater radii for OIV and 0.3% rising to 0.6% for OV. Edge electron temperatures of 0.5-5 eV at electron densities of 5-10×1011 cm-3 were calculated from the measured relative intensities of hydrogen Balmer lines. The absolute intensities of hydrogen lines and of multiplets of neutral chromium and molybdenum were used to determine particle fluxes (at 4-5 ms into the plasma) of the order 1×1016, 7×1013 and 3×1013 particles cm-2 s-1, respectively.

  2. Instrument for long-path spectral extinction measurements in air: application to sizing of airborne particles

    International Nuclear Information System (INIS)

    Paganini, Enrico; Trespidi, Franco; Ferri, Fabio

    2001-01-01

    A novel instrument that is capable of taking spectral extinction measurements over long optical paths (approximately 1-100 m) in the UV, visible, and IR ranges is described. The instrument is fully automated, and the extinction spectrum is acquired in almost real time (approximately 5-10 s) with a resolution of ∼3 nm. Its sensitivity and accuracy were estimated by tests carried out in a clean room that showed that, for optical paths between 50 and 100 m, the extinction coefficient can be detected at levels of ∼10 -5 m -1 . Tests carried out on calibrated latex particles showed that, when it was combined with an appropriate inversion method, the technique could be profitably applied to characterize airborne particulate distributions. By carrying out measurements over optical paths of ∼100 m, the instrument is also capable of detecting extinction coefficients that are due to aerosol concentrations well below the limits imposed by the European Economic Community for atmospheric pollution (150 μg/m3). Scaled over optical paths of ∼10 m, the limit imposed for particle emissions from industrial plants (10 mg/m3) can also be detected sensitively

  3. Airborne High Spectral Resolution Lidar Aerosol Measurements during MILAGRO and TEXAQS/GOMACCS

    Science.gov (United States)

    Ferrare, Richard; Hostetler, Chris; Hair, John; Cook Anthony; Harper, David; Burton, Sharon; Clayton, Marian; Clarke, Antony; Russell, Phil; Redemann, Jens

    2007-01-01

    Two1 field experiments conducted during 2006 provided opportunities to investigate the variability of aerosol properties near cities and the impacts of these aerosols on air quality and radiative transfer. The Megacity Initiative: Local and Global Research Observations (MILAGRO) /Megacity Aerosol Experiment in Mexico City (MAX-MEX)/Intercontinental Chemical Transport Experiment-B (INTEX-B) joint experiment conducted during March 2006 investigated the evolution and transport of pollution from Mexico City. The Texas Air Quality Study (TEXAQS)/Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) (http://www.al.noaa.gov/2006/) conducted during August and September 2006 investigated climate and air quality in the Houston/Gulf of Mexico region. During both missions, the new NASA Langley airborne High Spectral Resolution Lidar (HSRL) was deployed on the NASA Langley B200 King Air aircraft and measured profiles of aerosol extinction, backscattering, and depolarization to: 1) characterize the spatial and vertical distributions of aerosols, 2) quantify aerosol extinction and optical thickness contributed by various aerosol types, 3) investigate aerosol variability near clouds, 4) evaluate model simulations of aerosol transport, and 5) assess aerosol optical properties derived from a combination of surface, airborne, and satellite measurements.

  4. A differential spectral responsivity measurement system constructed for determining of the spectral responsivity of a single- and triple-junction photovoltaic cells

    Science.gov (United States)

    Sametoglu, Ferhat; Celikel, Oguz; Witt, Florian

    2017-10-01

    A differential spectral responsivity (DSR) measurement system has been designed and constructed at National Metrology Institute of Turkey (TUBITAK UME) to determine the spectral responsivity (SR) of a single- or a multi-junction photovoltaic device (solar cell). The DSR setup contains a broad band light bias source composed of a constructed Solar Simulator based on a 1000 W Xe-arc lamp owning a AM-1.5 filter and 250 W quartz-tungsten-halogen lamp, a designed and constructed LED-based Bias Light Sources, a DC voltage bias circuit, and a probe beam optical power tracking and correction circuit controlled with an ADuC847 microcontroller card together with an embedded C based software, designed and constructed in TUBITAK UME under this project. By using the constructed DSR measurement system, the SR calibration of solar cells, the monolitic triple-junction solar cell GaInP/GaInAs/Ge and its corresponding component cells have been performed within the EURAMET Joint Research Project SolCell.

  5. High spatial and spectral resolution measurements of Jupiter's auroral regions using Gemini-North-TEXES

    Science.gov (United States)

    Sinclair, J. A.; Orton, G. S.; Greathouse, T. K.; Lacy, J.; Giles, R.; Fletcher, L. N.; Vogt, M.; Irwin, P. G.

    2017-12-01

    Jupiter exhibits auroral emission at a multitude of wavelengths. Auroral emission at X-ray, ultraviolet and near-infrared wavelengths demonstrate the precipitation of ion and electrons in Jupiter's upper atmosphere, at altitudes exceeding 250 km above the 1-bar level. Enhanced mid-infrared emission of CH4, C2H2, C2H4 and further hydrocarbons is also observed coincident with Jupiter's auroral regions. Retrieval analyses of infrared spectra from IRTF-TEXES (Texas Echelon Cross Echelle Spectrograph on NASA's Infrared Telescope Facility) indicate strong heating at the 1-mbar level and evidence of ion-neutral chemistry, which enriches the abundances of unsaturated hydrocarbons (Sinclair et al., 2017b, doi:10.1002/2017GL073529, Sinclair et al., 2017c (under review)). The extent to which these phenomena in the stratosphere are correlated and coupled physically with the shorter-wavelength auroral emission originating from higher altitudes has been a challenge due to the limited spatial resolution available on the IRTF. Smaller-scale features observed in the near-infrared and ultraviolet emission, such as the main `oval', transient `swirls' and dusk-active regions within the main oval (e.g. Stallard et al., 2014, doi:10.1016/j/Icarus.2015.12.044, Nichols et al., 2017, doi: 10.1002/2017GL073029) are potentially being blurred in the mid-infrared by the diffraction-limited resolution (0.7") of IRTF's 3-metre primary aperture. However, on March 17-19th 2017, we obtained spectral measurements of H2 S(1), CH4, C2H2, C2H4 and C2H6 emission of Jupiter's high latitudes using TEXES on Gemini-North, which has a 8-metre primary aperture. This rare opportunity combines the superior spectral resolving power of TEXES and the high spatial resolution provided by Gemini-North's 8-metre aperture. We will perform a retrieval analyses to determine the 3D distributions of temperature, C2H2, C2H4 and C2H6. The morphology will be compared with near-contemporaneous measurements of H3+ emission from

  6. A teaser made simple: a didactic measurement of the spectral answer of a human-eye-calibrated lux meter

    International Nuclear Information System (INIS)

    Di Capua, R; Offi, F; Dell'Omo, M; Fontana, F

    2012-01-01

    A simple didactic experiment has been designed and realized, in order to illustrate to undergraduate students in scientific faculties some basic concepts lying behind the fundamentals of geometrical optics. The spectral response of a human-eye-calibrated lux meter was measured using a very trivial experimental arrangement. The white light of a halogen lamp was decomposed into its spectral components through a diffraction grating, so that collecting the radiation at different dispersion angles allowed one to measure the intensity as a function of wavelength. The experiment can be used to effectively illustrate the concepts of spectral distribution, the radiometry versus photometry conversion and photopic response, and the famous historical experience by Herschel on the ‘temperature of colours’. (paper)

  7. Improving documentation of a beta-blocker quality measure through an anesthesia information management system and real-time notification of documentation errors.

    Science.gov (United States)

    Nair, Bala G; Peterson, Gene N; Newman, Shu-Fang; Wu, Wei-Ying; Kolios-Morris, Vickie; Schwid, Howard A

    2012-06-01

    Continuation of perioperative beta-blockers for surgical patients who are receiving beta-blockers prior to arrival for surgery is an important quality measure (SCIP-Card-2). For this measure to be considered successful, name, date, and time of the perioperative beta-blocker must be documented. Alternately, if the beta-blocker is not given, the medical reason for not administering must be documented. Before the study was conducted, the institution lacked a highly reliable process to document the date and time of self-administration of beta-blockers prior to hospital admission. Because of this, compliance with the beta-blocker quality measure was poor (-65%). To improve this measure, the anesthesia care team was made responsible for documenting perioperative beta-blockade. Clear documentation guidelines were outlined, and an electronic Anesthesia Information Management System (AIMS) was configured to facilitate complete documentation of the beta-blocker quality measure. In addition, real-time electronic alerts were generated using Smart Anesthesia Messenger (SAM), an internally developed decision-support system, to notify users concerning incomplete beta-blocker documentation. Weekly compliance for perioperative beta-blocker documentation before the study was 65.8 +/- 16.6%, which served as the baseline value. When the anesthesia care team started documenting perioperative beta-blocker in AIMS, compliance was 60.5 +/- 8.6% (p = .677 as compared with baseline). Electronic alerts with SAM improved documentation compliance to 94.6 +/- 3.5% (p documentation and (2) enhance features in the electronic medical systems to alert the user concerning incomplete documentation.

  8. Calibration and validation of measures a total alpha beta counter in the tunisian mineral water

    International Nuclear Information System (INIS)

    Nasri, Sihem; Skhiri, Noura

    2009-01-01

    The risks due to contamination of mineral waters are essentially risk internal radiation following ingestion of radionuclides which brought us in this study to determine the global alpha and beta of the Tunisian mineral water. We used an alpha beta global counter. The results obtained by this technique have shown that alpha activity of these 10 waters are all lower than 50 mBq / l and are varied between 3.75 and 8.4 mBq / l and beta activity was found only 9 waters are also lower than 50 mBq / l (between 7.17 and 18.25) when only one is between 100 and 500 mBq / l (101.17).

  9. Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

    Energy Technology Data Exchange (ETDEWEB)

    Reynaldo, S. R. [Development Centre of Nuclear Technology, Posgraduate Course in Science and Technology of Radiations, Minerals and Materials / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Benavente C, J. A.; Da Silva, T. A., E-mail: sirr@cdtn.br [Development Centre of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the {sup 90}Sr/{sup 90}Y and {sup 85}Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the {sup 90}Sr/{sup 90}Y and -0.3% for the {sup 85}Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

  10. Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

    International Nuclear Information System (INIS)

    Reynaldo, S. R.; Benavente C, J. A.; Da Silva, T. A.

    2015-10-01

    Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the 90 Sr/ 90 Y and 85 Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the 90 Sr/ 90 Y and -0.3% for the 85 Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

  11. Combined High Spectral Resolution Lidar and Millimeter Wavelength Radar Measurement of Ice Crystal Precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Eloranta, Edwin [Univ. of Wisconsin, Madison, WI (United States)

    2016-10-28

    The goal of this research has been to improve measurements of snowfall using a combination of millimeter-wavelength radar and High Spectral Resolution Lidar (HSRL) Observations. Snowflakes are large compared to the 532nm HSRL wavelength and small compared to the 3.2 and 8.6 mm wavelength radars used in this study. This places the particles in the optical scattering regime of the HSRL, where extinction cross-section is proportional to the projected area of the particles, and in the Rayleigh regime for the radar, where the backscatter cross-section is proportional to the mass-squared of the particles. Forming a ratio of the radar measured cross-section to the HSRL measured cross section eliminates any dependence on the number of scattering particles, yielding a quantity proportional to the average mass-squared of the snowflakes over the average area of the flakes. Using simultaneous radar measurements of particle fall velocities, which are dependent particle mass and cross-sectional area it is possible to derive the average mass of the snow flakes, and with the radar measured fall velocities compute the snowfall rate. Since this retrieval requires the optical extinction cross-section we began by considering errors this quantity. The HSRL is particularly good at measuring the backscatter cross-section. In previous studies of snowfall in the high Arctic were able to estimate the extinction cross-section directly as a fixed ratio to the backscatter cross-section. Measurements acquired in the STORMVEX experiment in Colorado showed that this approach was not valid in mid-latitude snowfalls and that direct measurement of the extinction cross-section is required. Attempts to measure the extinction directly uncovered shortcomings in thermal regulation and mechanical stability of the newly deployed DOE HSRL systems. These problems were largely mitigated by modifications installed in both of the DOE systems. We also investigated other sources of error in the HSRL direct

  12. The Comparison between Spectral and Entropic Measures Following Fatigue in Erector Spinae Muscles

    Directory of Open Access Journals (Sweden)

    Saeed Talebian

    2016-03-01

    Full Text Available Background: Surface electromyography (sEMG of muscles is a non-invasive tool that can be helpful in the assessment of muscle function and some motor control evaluations. A loss of force, known as muscle fatigue is accompanied by changes in muscle electrical activity. One of the most commonly used surface EMG parameters which reflects paraspinal muscle fatigue during different tasks and positions is median frequency. Although it is widely known that the electromyography power spectrum shifts to lower frequencies during fatiguing contraction, an opinion exists that the validity of spectral shifts in assessment of fatigue is questionable. Some researchers have examined whether other quantities derived from sEMG signals are better indicators for muscle fatigue. Following cyclic flexion/extension and consequence fatigue, variation in sEMG signals may be complex for study. The aim of this study was to determine which of the median frequency (MF or entropic (ENTR is more sensitive for measuring muscular fatigue in erector spinae muscles during cyclic flexion/extension. Methods: Surface electromyography of erector spine muscles was recorded in 25 healthy subjects during cyclic dynamic contractions. The experimental session consisted of two parts: measurement of Maximal Voluntary Contraction (MVC, and performing the fatigue test. All subjects performed rhythmic flexion/extension with 50% MVC loading against B-200 Isostation, about 4-6 minutes. The MF and ENTR of the muscle activities were computed to assess muscular fatigue. Results: Paired sample t-tests showed that MF and ENTR changes after fatigue test were significant (P<0.001. Percentage changes of both MF and ENTR were reduced, this reduction for ENTR was more than 40% (P<0.001. Conclusion: It seems that the changes of ENTR in muscle activities have the ability to measure muscular fatigue and is more sensitive in comparison to MF.

  13. Retinal nerve fiber layer thickness in normals measured by spectral domain OCT.

    Science.gov (United States)

    Bendschneider, Delia; Tornow, Ralf P; Horn, Folkert K; Laemmer, Robert; Roessler, Christopher W; Juenemann, Anselm G; Kruse, Friedrich E; Mardin, Christian Y

    2010-09-01

    To determine normal values for peripapillary retinal nerve fiber layer thickness (RNFL) measured by spectral domain Optical Coherence Tomography (SOCT) in healthy white adults and to examine the relationship of RNFL with age, gender, and clinical variables. The peripapillary RNFL of 170 healthy patients (96 males and 74 females, age 20 to 78 y) was imaged with a high-resolution SOCT (Spectralis HRA+OCT, Heidelberg Engineering) in an observational cross-sectional study. RNFL thickness was measured around the optic nerve head using 16 automatically averaged, consecutive circular B-scans with 3.4-mm diameter. The automatically segmented RNFL thickness was divided into 32 segments (11.25 degrees each). One randomly selected eye per subject entered the study. Mean RNFL thickness in the study population was 97.2 ± 9.7 μm. Mean RNFL thickness was significantly negatively correlated with age (r = -0.214, P = 0.005), mean RNFL decrease per decade was 1.90 μm. As age dependency was different in different segments, age-correction of RNFL values was made for all segments separately. Age-adjusted RNFL thickness showed a significant correlation with axial length (r = -0.391, P = 0.001) and with refractive error (r = 0.396, P<0.001), but not with disc size (r = 0.124). Normal RNFL results with SOCT are comparable to those reported with time-domain OCT. In accordance with the literature on other devices, RNFL thickness measured with SOCT was significantly correlated with age and axial length. For creating a normative database of SOCT RNFL values have to be age adjusted.

  14. Using spectral methods to obtain particle size information from optical data: applications to measurements from CARES 2010

    Science.gov (United States)

    Atkinson, Dean B.; Pekour, Mikhail; Chand, Duli; Radney, James G.; Kolesar, Katheryn R.; Zhang, Qi; Setyan, Ari; O'Neill, Norman T.; Cappa, Christopher D.

    2018-04-01

    Multi-wavelength in situ aerosol extinction, absorption and scattering measurements made at two ground sites during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) are analyzed using a spectral deconvolution method that allows extraction of particle-size-related information, including the fraction of extinction produced by the fine-mode particles and the effective radius of the fine mode. The spectral deconvolution method is typically applied to analysis of remote sensing measurements. Here, its application to in situ measurements allows for comparison with more direct measurement methods and validation of the retrieval approach. Overall, the retrieved fine-mode fraction and effective radius compare well with other in situ measurements, including size distribution measurements and scattering and absorption measurements made separately for PM1 and PM10, although there were some periods during which the different methods yielded different results. One key contributor to differences between the results obtained is the alternative, spectrally based definitions of fine and coarse modes from the optical methods, relative to instruments that use a physically defined cut point. These results indicate that for campaigns where size, composition and multi-wavelength optical property measurements are made, comparison of the results can result in closure or can identify unusual circumstances. The comparison here also demonstrates that in situ multi-wavelength optical property measurements can be used to determine information about particle size distributions in situations where direct size distribution measurements are not available.

  15. Using spectral methods to obtain particle size information from optical data: applications to measurements from CARES 2010

    Directory of Open Access Journals (Sweden)

    D. B. Atkinson

    2018-04-01

    Full Text Available Multi-wavelength in situ aerosol extinction, absorption and scattering measurements made at two ground sites during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES are analyzed using a spectral deconvolution method that allows extraction of particle-size-related information, including the fraction of extinction produced by the fine-mode particles and the effective radius of the fine mode. The spectral deconvolution method is typically applied to analysis of remote sensing measurements. Here, its application to in situ measurements allows for comparison with more direct measurement methods and validation of the retrieval approach. Overall, the retrieved fine-mode fraction and effective radius compare well with other in situ measurements, including size distribution measurements and scattering and absorption measurements made separately for PM1 and PM10, although there were some periods during which the different methods yielded different results. One key contributor to differences between the results obtained is the alternative, spectrally based definitions of fine and coarse modes from the optical methods, relative to instruments that use a physically defined cut point. These results indicate that for campaigns where size, composition and multi-wavelength optical property measurements are made, comparison of the results can result in closure or can identify unusual circumstances. The comparison here also demonstrates that in situ multi-wavelength optical property measurements can be used to determine information about particle size distributions in situations where direct size distribution measurements are not available.

  16. Spectral stratigraphy

    Science.gov (United States)

    Lang, Harold R.

    1991-01-01

    A new approach to stratigraphic analysis is described which uses photogeologic and spectral interpretation of multispectral remote sensing data combined with topographic information to determine the attitude, thickness, and lithology of strata exposed at the surface. The new stratigraphic procedure is illustrated by examples in the literature. The published results demonstrate the potential of spectral stratigraphy for mapping strata, determining dip and strike, measuring and correlating stratigraphic sequences, defining lithofacies, mapping biofacies, and interpreting geological structures.

  17. Relationships Among Peripheral and Central Electrophysiological Measures of Spatial and Spectral Selectivity and Speech Perception in Cochlear Implant Users.

    Science.gov (United States)

    Scheperle, Rachel A; Abbas, Paul J

    2015-01-01

    The ability to perceive speech is related to the listener's ability to differentiate among frequencies (i.e., spectral resolution). Cochlear implant (CI) users exhibit variable speech-perception and spectral-resolution abilities, which can be attributed in part to the extent of electrode interactions at the periphery (i.e., spatial selectivity). However, electrophysiological measures of peripheral spatial selectivity have not been found to correlate with speech perception. The purpose of this study was to evaluate auditory processing at the periphery and cortex using both simple and spectrally complex stimuli to better understand the stages of neural processing underlying speech perception. The hypotheses were that (1) by more completely characterizing peripheral excitation patterns than in previous studies, significant correlations with measures of spectral selectivity and speech perception would be observed, (2) adding information about processing at a level central to the auditory nerve would account for additional variability in speech perception, and (3) responses elicited with spectrally complex stimuli would be more strongly correlated with speech perception than responses elicited with spectrally simple stimuli. Eleven adult CI users participated. Three experimental processor programs (MAPs) were created to vary the likelihood of electrode interactions within each participant. For each MAP, a subset of 7 of 22 intracochlear electrodes was activated: adjacent (MAP 1), every other (MAP 2), or every third (MAP 3). Peripheral spatial selectivity was assessed using the electrically evoked compound action potential (ECAP) to obtain channel-interaction functions for all activated electrodes (13 functions total). Central processing was assessed by eliciting the auditory change complex with both spatial (electrode pairs) and spectral (rippled noise) stimulus changes. Speech-perception measures included vowel discrimination and the Bamford-Kowal-Bench Speech

  18. Measurements of spectral responses for developing fiber-optic pH sensor

    Science.gov (United States)

    Yoo, Wook Jae; Heo, Ji Yeon; Jang, Kyoung Won; Seo, Jeong Ki; Moon, Jin Soo; Park, Jang-Yeon; Park, Byung Gi; Cho, Seunghyun; Lee, Bongsoo

    2011-01-01

    In this study, we have fabricated a fiber-optic pH sensor, which is composed of a light source, a pH-sensing probe, plastic optical fibers and a spectrometer, for determining the degree of infection by Helicobacter pylori in the stomach. As pH indicators, phenol red and m-cresol purple are used, and pH liquid solutions are prepared by mixing phenol red or m-cresol purple solutions and various kinds of pH buffer solutions. The light emitted by a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a reflected light is changed according to the color variations of the pH indicator in the pH-sensing probe. Therefore, we have measured the intensities and wavelength shifts of the reflected lights, which change according to the color variations of indicators at different pH values, by using a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of the modulated lights are obtained on the basis of the changes of the colors of indicators.

  19. Quantitative measurement of binocular color fusion limit for non-spectral colors.

    Science.gov (United States)

    Jung, Yong Ju; Sohn, Hosik; Lee, Seong-il; Ro, Yong Man; Park, Hyun Wook

    2011-04-11

    Human perception becomes difficult in the event of binocular color fusion when the color difference presented for the left and right eyes exceeds a certain threshold value, known as the binocular color fusion limit. This paper discusses the binocular color fusion limit for non-spectral colors within the color gamut of a conventional LCD 3DTV. We performed experiments to measure the color fusion limit for eight chromaticity points sampled from the CIE 1976 chromaticity diagram. A total of 2480 trials were recorded for a single observer. By analyzing the results, the color fusion limit was quantified by ellipses in the chromaticity diagram. The semi-minor axis of the ellipses ranges from 0.0415 to 0.0923 in terms of the Euclidean distance in the u'v´ chromaticity diagram and the semi-major axis ranges from 0.0640 to 0.1560. These eight ellipses are drawn on the chromaticity diagram. © 2011 Optical Society of America

  20. Spatial and spectral interpolation of ground-motion intensity measure observations

    Science.gov (United States)

    Worden, Charles; Thompson, Eric M.; Baker, Jack W.; Bradley, Brendon A.; Luco, Nicolas; Wilson, David

    2018-01-01

    Following a significant earthquake, ground‐motion observations are available for a limited set of locations and intensity measures (IMs). Typically, however, it is desirable to know the ground motions for additional IMs and at locations where observations are unavailable. Various interpolation methods are available, but because IMs or their logarithms are normally distributed, spatially correlated, and correlated with each other at a given location, it is possible to apply the conditional multivariate normal (MVN) distribution to the problem of estimating unobserved IMs. In this article, we review the MVN and its application to general estimation problems, and then apply the MVN to the specific problem of ground‐motion IM interpolation. In particular, we present (1) a formulation of the MVN for the simultaneous interpolation of IMs across space and IM type (most commonly, spectral response at different oscillator periods) and (2) the inclusion of uncertain observation data in the MVN formulation. These techniques, in combination with modern empirical ground‐motion models and correlation functions, provide a flexible framework for estimating a variety of IMs at arbitrary locations.

  1. Closed quotient and spectral measures of female adolescent singers in different singing styles.

    Science.gov (United States)

    Barlow, Christopher; Lovetri, Jeannette

    2010-05-01

    Although quantifiable assessment of the singing voice is now commonplace, research on young (child and adolescent) voices is still in its infancy. There is still insufficient data on young people's voices based on which, "norms" in behavior could be modeled, particularly for contemporary commercial music (CCM), such as musical theater (MT). The objective of this study was to assess if quantifiable differences in vocal production and acoustic output of young singers exist between "classical" and "MT" styles. The study was a prospective cohort study of 20 adolescent female singers aged 12-17 years training their voices using a system, which includes both "classical" and "MT" styles. The study examined laryngographically derived closed quotient (CQ), average vowel spectra (AVS) and long-term average spectra (LTAS) measures of the sung voices of singers in "classical" and "MT" styles. The spectral slope was shallower for the MT voice, and the mean CQ was significantly higher across the pitch range when singing in an MT style than in a "classical" style. The second to fifth harmonics were stronger in the MT style than in classical, with a significant difference between the two styles. The increase in relative intensity in the first five harmonics was disproportionately higher than the increase in CQ. Results, therefore, suggested that MT singing primarily uses change in resonance strategy rather than raised vocal tension to achieve the tonal changes associated with the genre. (c) 2010 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  2. Measurements of beam-ion confinement during tangential beam-driven instabilities in PBX [Princeton Beta Experiment

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Kaita, R.; Takahashi, H.; Gammel, G.; Hammett, G.W.; Kaye, S.

    1987-01-01

    During tangential injection of neutral beams into low density tokamak plasmas with β > 1% in the Princeton Beta Experiment (PBX), instabilities are observed that degrade the confinement of beam ions. Neutron, charge-exchange, and diamagnetic loop measurements are examined in order to identify the mechanism or mechanisms responsible for the beam-ion transport. The data suggest a resonant interaction between the instabilities and the parallel energetic beam ions. Evidence for some nonresonant transport also exists

  3. A solenoidal electron spectrometer for a precision measurement of the neutron {beta}-asymmetry with ultracold neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Plaster, B. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States)], E-mail: plaster@pa.uky.edu; Carr, R.; Filippone, B.W. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Harrison, D. [Physics Department, University of Winnipeg, Manitoba, Canada R3B 2E9 (Canada); Hsiao, J. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Ito, T.M. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Liu, J. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Martin, J.W. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Physics Department, University of Winnipeg, Manitoba, R3B 2E9 (Canada); Tipton, B.; Yuan, J. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

    2008-10-11

    We describe an electron spectrometer designed for a precision measurement of the neutron {beta}-asymmetry with spin-polarized ultracold neutrons. The spectrometer consists of a 1.0-T solenoidal field with two identical multiwire proportional chamber and plastic scintillator electron detector packages situated within 0.6-T field-expansion regions. Select results from performance studies of the spectrometer with calibration sources are reported.

  4. Studies of. gamma. -ray irradiation effects on tris(. beta. -diketonato)iron(III) and cobalt(III) coordination compounds by means of Moessbauer spectroscopy and magnetic susceptibility measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Y.; Endo, K.; Sano, H. (Tokyo Metropolitan Univ. (Japan). Faculty of Science)

    1981-06-01

    Both absorption Moessbauer spectroscopy and magnetic susceptibility measurements on tris(..beta..-diketonato)iron(III) and cobalt(III) compounds indicate that ligands which have phenyl group as a substituent are more stable to ..gamma..-ray radiolysis, in accordance with previous results of emission Moessbauer spectroscopic studies of /sup 57/Co-labelled tris (..beta..-diketonato)cobalt(III) compounds.

  5. Comparison of SVM RBF-NN and DT for crop and weed identification based on spectral measurement over corn fields

    Science.gov (United States)

    It is important to find an appropriate pattern-recognition method for in-field plant identification based on spectral measurement in order to classify the crop and weeds accurately. In this study, the method of Support Vector Machine (SVM) was evaluated and compared with two other methods, Decision ...

  6. Prediction of late failure after medical abortion from serial beta-hCG measurements and ultrasonography

    DEFF Research Database (Denmark)

    Rørbye, C; Nørgaard, M; Nilas, Lisbeth

    2004-01-01

    BACKGROUND: Surgical treatment of failed medical abortion may be performed several weeks after initiation of the abortion. There are no recognized methods for early identification of these late failures. We assessed the prognostic values of beta-hCG and ultrasonography in predicting late failure ...

  7. Spectral contaminant identifier for off-axis integrated cavity output spectroscopy measurements of liquid water isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Brian Leen, J.; Berman, Elena S. F.; Gupta, Manish [Los Gatos Research, 67 East Evelyn Avenue, Suite 3, Mountain View, California 94041-1518 (United States); Liebson, Lindsay [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States)

    2012-04-15

    Developments in cavity-enhanced absorption spectrometry have made it possible to measure water isotopes using faster, more cost-effective field-deployable instrumentation. Several groups have attempted to extend this technology to measure water extracted from plants and found that other extracted organics absorb light at frequencies similar to that absorbed by the water isotopomers, leading to {delta}{sup 2}H and {delta}{sup 18}O measurement errors ({Delta}{delta}{sup 2}H and {Delta}{delta}{sup 18}O). In this note, the off-axis integrated cavity output spectroscopy (ICOS) spectra of stable isotopes in liquid water is analyzed to determine the presence of interfering absorbers that lead to erroneous isotope measurements. The baseline offset of the spectra is used to calculate a broadband spectral metric, m{sub BB}, and the mean subtracted fit residuals in two regions of interest are used to determine a narrowband metric, m{sub NB}. These metrics are used to correct for {Delta}{delta}{sup 2}H and {Delta}{delta}{sup 18}O. The method was tested on 14 instruments and {Delta}{delta}{sup 18}O was found to scale linearly with contaminant concentration for both narrowband (e.g., methanol) and broadband (e.g., ethanol) absorbers, while {Delta}{delta}{sup 2}H scaled linearly with narrowband and as a polynomial with broadband absorbers. Additionally, the isotope errors scaled logarithmically with m{sub NB}. Using the isotope error versus m{sub NB} and m{sub BB} curves, {Delta}{delta}{sup 2}H and {Delta}{delta}{sup 18}O resulting from methanol contamination were corrected to a maximum mean absolute error of 0.93 per mille and 0.25 per mille respectively, while {Delta}{delta}{sup 2}H and {Delta}{delta}{sup 18}O from ethanol contamination were corrected to a maximum mean absolute error of 1.22 per mille and 0.22 per mille . Large variation between instruments indicates that the sensitivities must be calibrated for each individual isotope analyzer. These results suggest that the

  8. The Ultimate Pile Bearing Capacity from Conventional and Spectral Analysis of Surface Wave (SASW) Measurements

    Science.gov (United States)

    Faizah Bawadi, Nor; Anuar, Shamilah; Rahim, Mustaqqim A.; Mansor, A. Faizal

    2018-03-01

    A conventional and seismic method for determining the ultimate pile bearing capacity was proposed and compared. The Spectral Analysis of Surface Wave (SASW) method is one of the non-destructive seismic techniques that do not require drilling and sampling of soils, was used in the determination of shear wave velocity (Vs) and damping (D) profile of soil. The soil strength was found to be directly proportional to the Vs and its value has been successfully applied to obtain shallow bearing capacity empirically. A method is proposed in this study to determine the pile bearing capacity using Vs and D measurements for the design of pile and also as an alternative method to verify the bearing capacity from the other conventional methods of evaluation. The objectives of this study are to determine Vs and D profile through frequency response data from SASW measurements and to compare pile bearing capacities obtained from the method carried out and conventional methods. All SASW test arrays were conducted near the borehole and location of conventional pile load tests. In obtaining skin and end bearing pile resistance, the Hardin and Drnevich equation has been used with reference strains obtained from the method proposed by Abbiss. Back analysis results of pile bearing capacities from SASW were found to be 18981 kN and 4947 kN compared to 18014 kN and 4633 kN of IPLT with differences of 5% and 6% for Damansara and Kuala Lumpur test sites, respectively. The results of this study indicate that the seismic method proposed in this study has the potential to be used in estimating the pile bearing capacity.

  9. Mass measurement project by determination of Q{sub {beta}} for neutron-rich nuclei; Projet de mesure des masses par determination des Q{sub {beta}} pour des noyaux tres riches en neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Pautrat, M; Lagrange, J M; Petizon, L [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Vanhorenbeeck, J; Duhamel, P [Brussels Univ. (Belgium). Inst. d` Astronomie et d` Astrophysique; Binon, F [Universite Libre de Bruxelles (Belgium)

    1994-12-31

    The aim of the project described hereafter is to collect new data on the exotic neutron rich nuclei of the Fe to Zn region, and in particular to determine their masses, for both nuclear physics and astrophysics purposes. These isotopes will be produced through projectile fragmentation at the GANIL facility and selected by the LISE3 spectrometer. Their half-lives will be measured as well as the energy of their main {gamma} rays; {gamma} - {gamma} coincidences will then allow to build a preliminary level scheme. The analysis of {beta} spectra and {beta} - {gamma} coincidences will finally provide the maximum {beta} decay energies of the studied nuclei leading to their masses. The difficulties arising from the low production rates, the {beta} detection, the data handling are discussed together with the solutions proposed to overcome them. (authors). 17 refs.

  10. Film thickness measurement based on nonlinear phase analysis using a Linnik microscopic white-light spectral interferometer.

    Science.gov (United States)

    Guo, Tong; Chen, Zhuo; Li, Minghui; Wu, Juhong; Fu, Xing; Hu, Xiaotang

    2018-04-20

    Based on white-light spectral interferometry and the Linnik microscopic interference configuration, the nonlinear phase components of the spectral interferometric signal were analyzed for film thickness measurement. The spectral interferometric signal was obtained using a Linnik microscopic white-light spectral interferometer, which includes the nonlinear phase components associated with the effective thickness, the nonlinear phase error caused by the double-objective lens, and the nonlinear phase of the thin film itself. To determine the influence of the effective thickness, a wavelength-correction method was proposed that converts the effective thickness into a constant value; the nonlinear phase caused by the effective thickness can then be determined and subtracted from the total nonlinear phase. A method for the extraction of the nonlinear phase error caused by the double-objective lens was also proposed. Accurate thickness measurement of a thin film can be achieved by fitting the nonlinear phase of the thin film after removal of the nonlinear phase caused by the effective thickness and by the nonlinear phase error caused by the double-objective lens. The experimental results demonstrated that both the wavelength-correction method and the extraction method for the nonlinear phase error caused by the double-objective lens improve the accuracy of film thickness measurements.

  11. Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules

    International Nuclear Information System (INIS)

    Rodríguez, J.A.; Fortes, M.; Alberte, C.; Vetter, M.; Andreu, J.

    2013-01-01

    Highlights: ► Spectral response equipment for measuring a-Si:H solar cells in a few seconds. ► Equipment based on 16 LEDs with simultaneous illumination of the solar cell. ► The current generated by each LED is analyzed by a Fast Fourier Transform. ► Cheap equipment without lock-in technology for the current measurement. ► Measurement error vs. conventional measurement less than 1% in J sc . - Abstract: An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2–4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.

  12. Measurement of $sin2\\beta$ from $B^{0}_{d} \\rightarrow J/\\Psi K^{0}_{S}$ with the LHCb detector

    CERN Document Server

    Mangiafave, N; Calvi, M; Matteuzzi, C

    2008-01-01

    The LHCb experiment will study CP violation and rare B meson decays at the LHC accelerator, in the CERN laboratories of Geneva. The CP violation in the $b$ quark mesons was observed for the first time measuring the $\\sin2\\beta$ parameter. In the first year of data taking at LHCb the $\\sin2\\beta$ measurement will be performed in the channel $B_d ^0 \\rightarrow J/\\psi K_S ^0$ (called golden channel). The comparison with results obtained in previous experiments will show possible systematic errors. Once the systematic errors will be understood, the possible discrepancies with the expected results will be the sign of a new physics beyond the Standard Model. $\\sin2\\beta$ is extracted from the asymmetry in the decay $B_d ^0 \\rightarrow J/\\psi(\\mu^+\\mu^-) K_S ^0 (\\pi^+\\pi^-)$ and its CP conjugated $\\overline{B}_d ^0 \\rightarrow J/\\psi(\\mu^-\\mu^+) K_S ^0(\\pi^-\\pi^+)$. To distinguish between $B_d ^0$ and $\\overline{B}_d$ flavour tagging algorithms are used. These introduce an additional parameter: the wrong tag fracti...

  13. Testing Left-Right extensions of the standard model of electroweak interactions with double-beta decay and LHC measurements

    Science.gov (United States)

    Civitarese, O.; Suhonen, J.; Zuber, K.

    2015-07-01

    The minimal extension of the standard model of electroweak interactions allows for massive neutrinos, a massive right-handed boson WR, and a left-right mixing angle ζ. While an estimate of the light (electron) neutrino can be extracted from the non-observation of the neutrinoless double beta decay, the limits on the mixing angle and the mass of the righthanded (RH) boson may be extracted from a combined analysis of the double beta decay measurements (GERDA, EXO-200 and KamLAND-Zen collaborations) and ATLAS data on the two-jets two-leptons signals following the excitation of a virtual RH boson mediated by a heavy-mass neutrino. In this work we shall compare results of both types of experiments, and show that the estimates are not in tension.

  14. Airborne spectral measurements of surface-atmosphere anisotropy during the SCAR-A, Kuwait oil fire, and TARFOX experiments

    Science.gov (United States)

    Soulen, Peter F.; King, Michael D.; Tsay, Si-Chee; Arnold, G. Thomas; Li, Jason Y.

    2000-04-01

    During the SCAR-A, Kuwait Oil Fire Smoke Experiment, and TARFOX deployments, angular distributions of spectral reflectance for various surfaces were measured using the scanning Cloud Absorption Radiometer (CAR) mounted on the nose of the University of Washington C-131A research aircraft. The CAR contains 13 narrowband spectral channels between 0.47 and 2.3 μm with a 190° scan aperture (5° before zenith to 5° past nadir) and 1° instantaneous field of view. The bidirectional reflectance is obtained by flying a clockwise circular orbit above the surface, resulting in a ground track approximately 3 km in diameter within about 2 min. Spectral bidirectional reflectances of four surfaces are presented: the Great Dismal Swamp in Virginia with overlying haze layer, the Saudi Arabian Desert and the Persian Gulf in the Middle East, and the Atlantic Ocean measured east of Richmond, Virginia. Although the CAR measurements are contaminated by atmospheric effects, results show distinct spectral characteristics for various types of surface-atmosphere systems, including hot spots, limb brightening and darkening, and Sun glint. In addition, the hemispherical albedo of each surface-atmosphere system is calculated directly by integrating over all high angular-resolution CAR measurements for each spectral channel. Comparing the nadir reflectance with the overall hemispherical albedo of each surface, we find that using nadir reflectances as a surrogate for hemispherical albedo can cause albedos to be underestimated by as much as 95% and overestimated by up to 160%, depending on the type of surface and solar zenith angle.

  15. Macular thickness and macular volume measurements using spectral domain optical coherence tomography in normal Nepalese eyes

    Directory of Open Access Journals (Sweden)

    Pokharel A

    2016-03-01

    Full Text Available Amrit Pokharel,1 Gauri Shankar Shrestha,2 Jyoti Baba Shrestha2 1Department of Ophthalmology, Kathmandu Medical College Teaching Hospital, 2B P Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Kathmandu, Nepal Purpose: To record the normative values for macular thickness and macular volume in normal Nepalese eyes. Methods: In all, 126 eyes of 63 emmetropic subjects (mean age: 21.17±6.76 years; range: 10–37 years were assessed for macular thickness and macular volume, using spectral domain-optical coherence tomography over 6×6 mm2 in the posterior pole. A fast macular thickness protocol was employed. Statistics such as the mean, median, standard deviation, percentiles, and range were used, while a P-value was set at 0.05 to test significance. Results: Average macular thickness and total macular volume were larger in males compared to females. With each year of increasing age, these variables decreased by 0.556 µm and 0.0156 mm3 for average macular thickness and total macular volume, respectively. The macular thickness was greatest in the inner superior section and lowest at the center of the fovea. The volume was greatest in the outer nasal section and thinnest in the fovea. The central subfield thickness (r=-0.243, P=0.055 and foveal volume (r=0.216, P=0.09 did not correlate with age. Conclusion: Males and females differ significantly with regard to macular thickness and macular volume measurements. Reports by other studies that the increase in axial length reduced thickness and volume, were negated by this study which found a positive correlation among axial length, thickness, and volume. Keywords: macular thickness, macular volume, optical coherence tomography, Nepal

  16. Prediction of late failure after medical abortion from serial beta-hCG measurements and ultrasonography

    DEFF Research Database (Denmark)

    Rørbye, C; Nørgaard, M; Nilas, Lisbeth

    2004-01-01

    on day 15 were greater among late failures than successes. Used as a predictive test, the positive predictive values of these variables were low. CONCLUSION: Neither beta-hCG nor endometrial thickness can be used clinically as diagnostic tests in predicting late failure after medical abortion.......BACKGROUND: Surgical treatment of failed medical abortion may be performed several weeks after initiation of the abortion. There are no recognized methods for early identification of these late failures. We assessed the prognostic values of beta-hCG and ultrasonography in predicting late failure...... thickness by ultrasonography was performed on day 15 after induction of medical abortion. Failures diagnosed after day 15 and within 15 weeks were identified and classified as late failures. All interventions in this group were due to bleeding problems. The predictive values of different absolute...

  17. Adaption of an array spectroradiometer for total ozone column retrieval using direct solar irradiance measurements in the UV spectral range

    Science.gov (United States)

    Zuber, Ralf; Sperfeld, Peter; Riechelmann, Stefan; Nevas, Saulius; Sildoja, Meelis; Seckmeyer, Gunther

    2018-04-01

    A compact array spectroradiometer that enables precise and robust measurements of solar UV spectral direct irradiance is presented. We show that this instrument can retrieve total ozone column (TOC) accurately. The internal stray light, which is often the limiting factor for measurements in the UV spectral range and increases the uncertainty for TOC analysis, is physically reduced so that no other stray-light reduction methods, such as mathematical corrections, are necessary. The instrument has been extensively characterised at the Physikalisch-Technische Bundesanstalt (PTB) in Germany. During an international total ozone measurement intercomparison at the Izaña Atmospheric Observatory in Tenerife, the high-quality applicability of the instrument was verified with measurements of the direct solar irradiance and subsequent TOC evaluations based on the spectral data measured between 12 and 30 September 2016. The results showed deviations of the TOC of less than 1.5 % from most other instruments in most situations and not exceeding 3 % from established TOC measurement systems such as Dobson or Brewer.

  18. Phase noise measurements with a cryogenic power-splitter to minimize the cross-spectral collapse effect

    Science.gov (United States)

    Hati, Archita; Nelson, Craig W.; Pappas, David P.; Howe, David A.

    2017-11-01

    The cross-spectrum noise measurement technique enables enhanced resolution of spectral measurements. However, it has disadvantages, namely, increased complexity, inability of making real-time measurements, and bias due to the "cross-spectral collapse" (CSC) effect. The CSC can occur when the spectral density of a random process under investigation approaches the thermal noise of the power splitter. This effect can severely bias results due to a differential measurement between the investigated noise and the anti-correlated (phase-inverted) noise of the power splitter. In this paper, we report an accurate measurement of the phase noise of a thermally limited electronic oscillator operating at room temperature (300 K) without significant CSC bias. We mitigated the problem by cooling the power splitter to liquid helium temperature (4 K). We quantify errors of greater than 1 dB that occur when the thermal noise of the oscillator at room temperature is measured with the power splitter at temperatures above 77 K.

  19. Different atmospheric parameters influence on spectral UV radiation (measurements and modelling)

    Energy Technology Data Exchange (ETDEWEB)

    Chubarova, N Y [Moscow State Univ. (Russian Federation). Meteorological Observatory; Krotkov, N A [Maryland Univ., MD (United States). JCESS/Meteorology Dept.; Geogdzhaev, I V; Bushnev, S V; Kondranin, T V [SUMGF/MIPT, Dolgoprudny (Russian Federation); Khattatov, V U [Central Aerological Observatory, Dolgoprudny (Russian Federation)

    1996-12-31

    The ultraviolet (UV) radiation plays a vital role in the biophysical processes despite its small portion in the total solar flux. UV radiation is subject to large variations at the Earth surface depending greatly on solar elevation, ozone and cloud amount, aerosols and surface albedo. The analysis of atmospheric parameters influence is based on the spectral archive data of three spectral instruments: NSF spectroradiometer (Barrow network) (NSF Polar Programs UV Spectroradiometer Network 1991-1992,1992), spectrophotometer (SUVS-M) of Central Aerological Observatory CAO, spectroradiometer of Meteorological Observatory of the Moscow State University (MO MSU) and model simulations based on delta-Eddington approximation

  20. Different atmospheric parameters influence on spectral UV radiation (measurements and modelling)

    Energy Technology Data Exchange (ETDEWEB)

    Chubarova, N.Y. [Moscow State Univ. (Russian Federation). Meteorological Observatory; Krotkov, N.A. [Maryland Univ., MD (United States). JCESS/Meteorology Dept.; Geogdzhaev, I.V.; Bushnev, S.V.; Kondranin, T.V. [SUMGF/MIPT, Dolgoprudny (Russian Federation); Khattatov, V.U. [Central Aerological Observatory, Dolgoprudny (Russian Federation)

    1995-12-31

    The ultraviolet (UV) radiation plays a vital role in the biophysical processes despite its small portion in the total solar flux. UV radiation is subject to large variations at the Earth surface depending greatly on solar elevation, ozone and cloud amount, aerosols and surface albedo. The analysis of atmospheric parameters influence is based on the spectral archive data of three spectral instruments: NSF spectroradiometer (Barrow network) (NSF Polar Programs UV Spectroradiometer Network 1991-1992,1992), spectrophotometer (SUVS-M) of Central Aerological Observatory CAO, spectroradiometer of Meteorological Observatory of the Moscow State University (MO MSU) and model simulations based on delta-Eddington approximation

  1. Carotenoid stoichiometry in the LH2 crystal: no spectral evidence for the presence of the second molecule in the alpha/beta-apoprotein dimer.

    Science.gov (United States)

    Gall, Andrew; Gardiner, Alastair T; Cogdell, Richard J; Robert, Bruno

    2006-07-10

    In this work we have investigated the carotenoid-protein interactions in LH2 complexes of Rhodopseudomonas acidophila both in "free in solution" mixed-micelles and in three-dimensional crystals by Raman spectroscopy in resonance with the carotenoid (Car) molecules. We show that the Car molecules when bound to their binding pockets show no significant differences when the complexes are "free in solution" or packed in crystalline arrays. Furthermore, there is no significant wavelength dependence in the Raman spectrum of the Car molecules of LH2. This indicates that there is only one Car configuration in LH2 and thus only one molecule per alpha/beta-heterodimer.

  2. Temporal measurement and analysis of high-resolution spectral signatures of plants and relationships to biophysical characteristics

    Science.gov (United States)

    Bostater, Charles R., Jr.; Rebbman, Jan; Hall, Carlton; Provancha, Mark; Vieglais, David

    1995-11-01

    Measurements of temporal reflectance signatures as a function of growing season for sand live oak (Quercus geminata), myrtle oak (Q. myrtifolia, and saw palmetto (Serenoa repens) were collected during a two year study period. Canopy level spectral reflectance signatures, as a function of 252 channels between 368 and 1115 nm, were collected using near nadir viewing geometry and a consistent sun illumination angle. Leaf level reflectance measurements were made in the laboratory using a halogen light source and an environmental optics chamber with a barium sulfate reflectance coating. Spectral measurements were related to several biophysical measurements utilizing optimal passive ambient correlation spectroscopy (OPACS) technique. Biophysical parameters included percent moisture, water potential (MPa), total chlorophyll, and total Kjeldahl nitrogen. Quantitative data processing techniques were used to determine optimal bands based on the utilization of a second order derivative or inflection estimator. An optical cleanup procedure was then employed that computes the double inflection ratio (DIR) spectra for all possible three band combinations normalized to the previously computed optimal bands. These results demonstrate a unique approach to the analysis of high spectral resolution reflectance signatures for estimation of several biophysical measures of plants at the leaf and canopy level from optimally selected bands or bandwidths.

  3. Measurement of the absolute activity of alpha or beta emitters by measuring product nuclei (daughter) activity increase or by studing its radioactive decay

    International Nuclear Information System (INIS)

    Campos, L.C. de.

    1981-01-01

    A new method for determining absolute activity of alpha or beta emitters by measuring daughter product radioactive decay is presented. The separation method of UX from hexahydrated uranyl nitrate UO 2 (NO 3 ) 2 6H 2 O based on its dissolution in ethyl ether is described and the accuracy of this method is shown. The factors which accuate on total efficiency of a Geiger Mueller detector for beta particles are determined. The possibility to determine the mass of precursor element by daughter nuclei activity is shown. The results are compared with the one obtained by direct measurement of the mass (or number of atoms) of precursor radioactive substance and with theoretical values calculated for isotopes in secular equilibrium. (Author) [pt

  4. Measurement of the activity of beta emitting gases using an ionisation chamber; Mesure de l'activite des gaz emetteurs beta au moyen d'une chambre d'ionisation

    Energy Technology Data Exchange (ETDEWEB)

    Lebouleux, P [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1962-07-01

    An ionization chamber was developed for measuring directly the activity of a {beta}-emitting gas whatever the gas may be. The following two parameters are defined and determined: p, the average specific ionization produced by a {beta} disintegration, and i, the average {beta} path in the chamber. It was shown, during the determination of i, that the {beta} particles are reflected on the walls of the ionization chamber when the latter are made of a high atomic number material. It was possible to eliminate this effect by constructing an electrode chamber made of graphite. With this chamber a direct measurement can be made of the activity of a gaseous {beta} emitter with a precision of about {+-}10%. Some applications are given of the graphite electrode chamber (calibration of the chambers built industrially and determination of the activation cross section of a gaseous emitter). It was possible to determine the activation cross section of {sup 134}Xe; a value of 0.18 {+-} 0.03 barn was found. (author) [French] Le but de l'etude est de realiser une chambre d'ionisation permettant d'effectuer une mesure directe de l'activite d'un gaz emetteur {beta} quel que soit l'emetteur considere. On definit et l'on determine les deux parametres suivants: p: ionisation specifique moyenne produite par une desintegration {beta}. La determination est effectuee par une methode graphique, i: moyenne des parcours des {beta} dans la chambre. La determination est effectuee experimentalement par introduction dans la chambre d'un gaz radioactif dont on peut calculer l'activite. On a mis en evidence, au cours de la determination de i, la reflexion des particules {beta} sur les parois des chambres d'ionisation lorsque celles-ci sont constituees d'un materiau de numero atomique eleve. La construction d'une chambre a electrodes de graphite nous a permis d'eliminer ce phenomene. Avec cette chambre, on effectue une mesure directe de l'activite d'un emetteur {beta} gazeux avec une precision de l

  5. High-Resolution Spectral Measurement of High Temperature CO2 and H2O.

    Science.gov (United States)

    1980-12-01

    a major constituent which critically controls the infrared radiative transfer in the telluric atmosphere. Their absorption bands are distributed over... movement to prevent cracking. Also, the continuous Q = s/) spectrum spectral coverage filament ceramic fiber, brand AB-312 manufactured by resolution the 3M

  6. Spectral Measurements of Cyg X-3: A Thermal Source Embedded in ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The attempts at unified model fitting to explain the spectral variations in Cyg ... observatory shows a rich discrete emission line spectrum, which also implies an origin ..... Bhat, P. N., Ramana Murthy, P. V., Vishwanath, P. R. 1988, JApA, 9, 155.

  7. Measurements of the spectral location of the structured target resonance for ultrarelativistic electrons

    NARCIS (Netherlands)

    Andersen, K.; Ketel, T.J.

    2014-01-01

    When an ultrarelativistic electron traverses two closely spaced foils, a radiation spectrum 'resonance' appears, arising from the photon formation length extending from one foil, across the gap and into the second foil. Several theoretical approaches yield quite different answers to the spectral

  8. Measuring evolution of a photon in an interferometer with spectrally resolved modes

    Czech Academy of Sciences Publication Activity Database

    Bula, M.; Bartkiewicz, K.; Černoch, Antonín; Javůrek, D.; Lemr, K.; Michálek, Václav; Soubusta, Jan

    2016-01-01

    Roč. 94, č. 5 (2016), 1-6, č. článku 052106. ISSN 2469-9926 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : Mach-Zehnder interferometer * spectrally resolved modes * photon Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.925, year: 2016

  9. DEVELOPMENT OF NEW HYPERSPECTRAL ANGLE INDEX FOR ESTIMATION OF SOIL MOISTURE USING IN SITU SPECTRAL MEASURMENTS

    Directory of Open Access Journals (Sweden)

    M. R. Mobasheri

    2013-10-01

    Full Text Available Near-surface soil moisture is one of the crucial variables in hydrological processes, which influences the exchange of water and energy fluxes at the land surface/atmosphere interface. Accurate estimate of the spatial and temporal variations of soil moisture is critical for numerous environmental studies. On the other hand, information of distributed soil moisture at large scale with reasonable spatial and temporal resolution is required for improving climatic and hydrologic modeling and prediction. The advent of hyperspectral imagery has allowed examination of continuous spectra not possible with isolated bands in multispectral imagery. In addition to high spectral resolution for individual band analyses, the contiguous narrow bands show characteristics of related absorption features, such as effects of strong absorptions on the band depths of adjacent absorptions. Our objective in this study was to develop a new spectral angle index to estimate soil moisture based on spectral region (350 and 2500 nm. In this paper, using spectral observations made by ASD Spectroradiometer for predicting soil moisture content, two soil indices were also investigated involving the Perpendicular Drought Index (PDI, NMDI (Normalized Multi-band Drought Index indices. Correlation and regression analysis showed a high relationship between PDI and the soil moisture percent (R2 = 0.9537 and NMDI (R2 = 0.9335. Furthermore, we also simulated these data according to the spectral range of some sensors such as MODIS, ASTER, ALI and ETM+. Indices relevant these sensors have high correlation with soil moisture data. Finally, we proposed a new angle index which shows significant relationship between new angle index and the soil moisture percentages (R2 = 0.9432.angle index relevant bands 3, 4, 5, 6, 7 MODIS also showing high accuracy in estimation of soil moisture (R2 = 0.719.

  10. THE MEASUREMENT, TREATMENT, AND IMPACT OF SPECTRAL COVARIANCE AND BAYESIAN PRIORS IN INTEGRAL -FIELD SPECTROSCOPY OF EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Greco, Johnny P. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ (United States); Brandt, Timothy D. [Institute for Advanced Study, Princeton, NJ (United States)

    2016-12-20

    The recovery of an exoplanet’s atmospheric parameters from its spectrum requires accurate knowledge of the spectral errors and covariances. Unfortunately, the complex image processing used in high-contrast integral-field spectrograph (IFS) observations generally produces spectral covariances that are poorly understood and often ignored. In this work, we show how to measure the spectral errors and covariances and include them self-consistently in parameter retrievals. By combining model exoplanet spectra with a realistic noise model generated from the Gemini Planet Imager (GPI) early science data, we show that ignoring spectral covariance in high-contrast IFS data can both bias inferred parameters and lead to unreliable confidence regions on those parameters. This problem is made worse by the common practice of scaling the χ {sup 2} per degree of freedom to unity; the input parameters then fall outside the 95% confidence regions in as many as ∼80% of noise realizations. The biases we observe can approach the typical levels of precision achieved in high-contrast spectroscopy. Accounting for realistic priors in fully Bayesian retrievals can also have a significant impact on the inferred parameters. Plausible priors on effective temperature and surface gravity can vary by an order of magnitude across the confidence regions appropriate for objects with weak age constraints; priors for objects with good age constraints are dominated by modeling uncertainties. Our methods are directly applicable to existing high-contrast IFSs including GPI and SPHERE, as well as upcoming instruments like CHARIS and, ultimately, WFIRST-AFTA.

  11. The double beta decay spectrum of 100Mo as measured with a TPC

    International Nuclear Information System (INIS)

    Elliott, S.R.; Moe, M.K.; Nelson, M.A.; Vient, M.A.

    1991-01-01

    A time projection chamber with 8.3 grams of enriched 100 MoO 3 as the central electrode has been operating approximately five months in an underground laboratory. A preliminary analysis of the two-electron sum energy spectrum, the spectrum of those same electrons taken singly, and the opening angle distribution yields a half life of 1.16 -0.08 +0.34 x10 19 y at the 68% confidence level for two-neutrino double beta decay of 100 Mo. (author)

  12. Laser spectroscopy and beta-NMR measurements of short-lived Mg isotopes

    CERN Document Server

    Kowalska, M

    2005-01-01

    The feasibility of studying the neutron-rich 29Mg, 31Mg and 33Mg isotopes has been demonstrated with the laser and beta-NMR spectroscopy setup at ISOLDE/CERN. The values of the magnetic moment and the nuclear spin of 31Mg are reported and reveal an intruder ground state. This proves the weakening of N=20 shell gap and places this nucleus inside the so called "island of inversion". The experimental setup and technique, as well as the results, are presented.

  13. Measuring Dirac CP-violating phase with intermediate energy beta beam facility

    Science.gov (United States)

    Bakhti, P.; Farzan, Y.

    2014-02-01

    Taking the established nonzero value of , we study the possibility of extracting the Dirac CP-violating phase by a beta beam facility with a boost factor . We compare the performance of different setups with different baselines, boost factors, and detector technologies. We find that an antineutrino beam from He decay with a baseline of km has a very promising CP-discovery potential using a 500 kton water Cherenkov detector. Fortunately this baseline corresponds to the distance between FermiLAB to Sanford underground research facility in South Dakota.

  14. Cloud phase identification of Arctic boundary-layer clouds from airborne spectral reflection measurements: test of three approaches

    Directory of Open Access Journals (Sweden)

    A. Ehrlich

    2008-12-01

    Full Text Available Arctic boundary-layer clouds were investigated with remote sensing and in situ instruments during the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR campaign in March and April 2007. The clouds formed in a cold air outbreak over the open Greenland Sea. Beside the predominant mixed-phase clouds pure liquid water and ice clouds were observed. Utilizing measurements of solar radiation reflected by the clouds three methods to retrieve the thermodynamic phase of the cloud are introduced and compared. Two ice indices IS and IP were obtained by analyzing the spectral pattern of the cloud top reflectance in the near infrared (1500–1800 nm wavelength spectral range which is characterized by ice and water absorption. While IS analyzes the spectral slope of the reflectance in this wavelength range, IS utilizes a principle component analysis (PCA of the spectral reflectance. A third ice index IA is based on the different side scattering of spherical liquid water particles and nonspherical ice crystals which was recorded in simultaneous measurements of spectral cloud albedo and reflectance.

    Radiative transfer simulations show that IS, IP and IA range between 5 to 80, 0 to 8 and 1 to 1.25 respectively with lowest values indicating pure liquid water clouds and highest values pure ice clouds. The spectral slope ice index IS and the PCA ice index IP are found to be strongly sensitive to the effective diameter of the ice crystals present in the cloud. Therefore, the identification of mixed-phase clouds requires a priori knowledge of the ice crystal dimension. The reflectance-albedo ice index IA is mainly dominated by the uppermost cloud layer (τ<1.5. Therefore, typical boundary-layer mixed-phase clouds with a liquid cloud top layer will

  15. Improving Our Ability to Assess Land Management and Disturbance by Linking Traditional Ecosystem Measurements with UAV Spectral Analysis

    Science.gov (United States)

    Sutter, L., Jr.; Barron-Gafford, G.; Smith, W. K.; Minor, R. L.; Raub, H.; Jimenez, J. R.; Wolsiffer, S. K.; Escobedo, E. B.; Smith, J.

    2017-12-01

    Drylands are dynamic landscapes of mixed plant functional types that vary in their response to abiotic and biotic drivers of change. Within these regions, woody plant-herbaceous relationships have generally been viewed as negative: woody plants within these ecosystems have been shown to negatively impact herbaceous growth by taking advantage of both deeper stored water and intercepting near surface moisture after precipitation events. There has been a long-invested effort to eliminate woody plants in many areas of the world, and analyzing and assessing land management decisions has historically required high monetary and time inputs. Unfortunately, both management practices and disturbances from fire can leave a very heterogeneous landscape, making assessment of their impacts difficult to assess. This study has attempted to address the effectiveness of two commonly used treatments within woody plant invaded areas, fire and herbicide application, by linking plant physiological measurements with the emerging technology of unmanned aerial vehicle (UAV) spectral analysis. Taking advantage of a USDA-ARS sponsored herbicide treatment in 2016 and the accidental Sawmill Fire of 2017, both within the Santa Rita Experimental Range (SRER) of Southern Arizona, USA, we linked spectral data collected via UAV with ground-based photosynthetic measurements. Given the high repeatability, and both spatial and spectral resolution of low-flying UAV measurements, we found that there are a variety of spectral indices that can be derived and accurately linked with traditional ecological measurements. Results and techniques from this study can be immediately applied to land management plans as well as be improved for other ecological parameters, such as those obtained from long-term study sites containing eddy covariance towers.

  16. Potential of remote sensing of cirrus optical thickness by airborne spectral radiance measurements at different sideward viewing angles

    Science.gov (United States)

    Wolf, Kevin; Ehrlich, André; Hüneke, Tilman; Pfeilsticker, Klaus; Werner, Frank; Wirth, Martin; Wendisch, Manfred

    2017-03-01

    Spectral radiance measurements collected in nadir and sideward viewing directions by two airborne passive solar remote sensing instruments, the Spectral Modular Airborne Radiation measurement sysTem (SMART) and the Differential Optical Absorption Spectrometer (mini-DOAS), are used to compare the remote sensing results of cirrus optical thickness τ. The comparison is based on a sensitivity study using radiative transfer simulations (RTS) and on data obtained during three airborne field campaigns: the North Atlantic Rainfall VALidation (NARVAL) mission, the Mid-Latitude Cirrus Experiment (ML-CIRRUS) and the Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems (ACRIDICON) campaign. Radiative transfer simulations are used to quantify the sensitivity of measured upward radiance I with respect to τ, ice crystal effective radius reff, viewing angle of the sensor θV, spectral surface albedo α, and ice crystal shape. From the calculations it is concluded that sideward viewing measurements are generally better suited than radiance data from the nadir direction to retrieve τ of optically thin cirrus, especially at wavelengths larger than λ = 900 nm. Using sideward instead of nadir-directed spectral radiance measurements significantly improves the sensitivity and accuracy in retrieving τ, in particular for optically thin cirrus of τ ≤ 2. The comparison of retrievals of τ based on nadir and sideward viewing radiance measurements from SMART, mini-DOAS and independent estimates of τ from an additional active remote sensing instrument, the Water Vapor Lidar Experiment in Space (WALES), shows general agreement within the range of measurement uncertainties. For the selected example a mean τ of 0.54 ± 0.2 is derived from SMART, and 0.49 ± 0.2 by mini-DOAS nadir channels, while WALES obtained a mean value of τ = 0.32 ± 0.02 at 532 nm wavelength, respectively. The mean of τ derived from the sideward viewing mini

  17. Measurement of Moments and Radii of Light Nuclei by Collinear Fast-Beam Laser Spectroscopy and $\\beta$-NMR Spectroscopy

    CERN Multimedia

    Marinova, K P

    2002-01-01

    Nuclear Moments and radii of light unstable isotopes are investigated by applying different high-sensitivity and high-resolution techniques based on collinear fast-beam laser spectroscopy. A study of nuclear structure in the sd shell is performed on neon isotopes in the extended chain of $^{17-28}$Ne, in particular on the proton-halo candidate $^{17}$Ne. Measurements of hyperfine structure and isotope shift have become possible by introducing an ultra-sensitive non-optical detection method which is based on optical pumping, state-selective collisional ionization and $\\beta$-activity counting. The small effect of nuclear radii on the optical isotope shifts of light elements requires very accurate measurements. The errors are dominated by uncertainties of the Doppler shifts which are conventionally determined from precisely measured acceleration voltages. These uncertainties are removed by measuring the beam energy with simultaneous excitation of two optical lines in parallel / antiparallel beam configuration. ...

  18. Measurement of beta decay periods for Fe-Ni neutrons rich isotopes

    International Nuclear Information System (INIS)

    Czajkowski, S.

    1992-01-01

    Thermal fission of 239 Pu was used to produce 68,69 Co and 68 Fe isotopes, the lightest ones ever observed in thermal fission, at the ILL high-flux reactor, in Grenoble. Separated with the Lohengrin recoil spectrometer, then identified by means of a Δ E-E ionization chamber, fragments were implanted in a set of Si-detectors, where β-particles were detected too. The fission yields were determined, and the beta-decay half-lives were extracted from delayed coincidence analysis between ion implantation and the subsequent beta detection: They were found to be 0.27±0.05s, 0.18±0.10s, and 0.10±0.06s respectively for 69 Co, 68 Co, and 68 Fe. This method was adapted to a new experimental configuration: 65 Fe isotopes were produced from 86 Kr projectile fragmentation at 500 MeV/u on a Be target. Selected ions were separated with the fragment separator FRS at GSI (Darmstadt), tuned in the monoenergetic mode. Fragments were identified by ΔE-ToF, slowed down, and then implanted in two rows of PIN-diodes that provided an additional range selection. The half-life were determined from the analysis of the decay chain Fe-Co-Ni: it was found 0.4±0.2s. Production rates obtained with the two methods are compared at the end of this work

  19. Bayesian Nonparametric Measurement of Factor Betas and Clustering with Application to Hedge Fund Returns

    Directory of Open Access Journals (Sweden)

    Urbi Garay

    2016-03-01

    Full Text Available We define a dynamic and self-adjusting mixture of Gaussian Graphical Models to cluster financial returns, and provide a new method for extraction of nonparametric estimates of dynamic alphas (excess return and betas (to a choice set of explanatory factors in a multivariate setting. This approach, as well as the outputs, has a dynamic, nonstationary and nonparametric form, which circumvents the problem of model risk and parametric assumptions that the Kalman filter and other widely used approaches rely on. The by-product of clusters, used for shrinkage and information borrowing, can be of use to determine relationships around specific events. This approach exhibits a smaller Root Mean Squared Error than traditionally used benchmarks in financial settings, which we illustrate through simulation. As an illustration, we use hedge fund index data, and find that our estimated alphas are, on average, 0.13% per month higher (1.6% per year than alphas estimated through Ordinary Least Squares. The approach exhibits fast adaptation to abrupt changes in the parameters, as seen in our estimated alphas and betas, which exhibit high volatility, especially in periods which can be identified as times of stressful market events, a reflection of the dynamic positioning of hedge fund portfolio managers.

  20. Soil spectral measurements in the field: problems and solutions in light of the GEO-CARDEL project

    Science.gov (United States)

    Dor, E. Ben; Granot, Amihai

    2017-09-01

    The GEO-CRADEL project aims to establish several knowhow for GEO applications. One of them is food security in which soil spectroscopy plays a major role. To that end we had developed a new assembly for measuring surface reflectance in the field. This was done in order to fill the gap between laboratory and field soil spectral measurements. This device, named SoilPRO (SP) can be connected to any field spectrometer fiber's tip and used to measure representative and undisturbed surfaces of different soil types. The SoilPRO's performance was evaluated against laboratory measurements under optimal conditions and demonstrated high performance in the field. As the SP measurement is not dependent on main factors such as the sun's radiation, atmospheric variations, operator stability or measurement geometry, and it does not disturb the surface being measured, its measurement can be used with laboratory soil spectral data (SSL). To that end the SSL that is generated under the GEO-CARDEL project is now can be used for agro- application in the field.

  1. THE IMPACT OF ACCURATE EXTINCTION MEASUREMENTS FOR X-RAY SPECTRAL MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Randall K. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Valencic, Lynne A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Corrales, Lia, E-mail: lynne.a.valencic@nasa.gov [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37-241, Cambridge, MA 02139 (United States)

    2016-02-20

    Interstellar extinction includes both absorption and scattering of photons from interstellar gas and dust grains, and it has the effect of altering a source's spectrum and its total observed intensity. However, while multiple absorption models exist, there are no useful scattering models in standard X-ray spectrum fitting tools, such as XSPEC. Nonetheless, X-ray halos, created by scattering from dust grains, are detected around even moderately absorbed sources, and the impact on an observed source spectrum can be significant, if modest, compared to direct absorption. By convolving the scattering cross section with dust models, we have created a spectral model as a function of energy, type of dust, and extraction region that can be used with models of direct absorption. This will ensure that the extinction model is consistent and enable direct connections to be made between a source's X-ray spectral fits and its UV/optical extinction.

  2. First direct observation of bound-state beta-decay: Measurements of branching and lifetime of 207Tl81+ fragments

    International Nuclear Information System (INIS)

    Boutin, D.

    2005-08-01

    The first experimental observation of bound-state beta-decay showed, that due solely to the electron stripping, a stable nuclide, e.g. 163 Dy, became unstable. Also a drastic modification of the half-life of bare 187 Re, from 4.12(2) x 10 10 years down to 32.9(20) years, could be observed. It was mainly due to the possibility for the mother nuclide to decay into a previously inaccessible nuclear level of the daughter nuclide. It was proposed to study a nuclide where this decay mode was competing with continuum-state beta-decay, in order to measure their respective branchings. The ratio β b /β c could also be evaluated for the first time. 207 Tl was chosen due to its high atomic number, and Q-value of about 1.4 MeV, small enough to enhance the β b probability and large enough to allow the use of time-resolved Schottky Mass Spectrometry (SMS) to study the evolution of mother and bound-state beta-decay daughter ions. The decay properties of the ground state and isomeric state of 207 Tl 81+ have been investigated at the GSI accelerator facility in two separate experiments. For the first time β-decay where the electron could go either to a bound state (atomic orbitals) and lead to 207 Pb 81+ as a daughter nuclide, or to a continuum state and lead to 207 Pb 82+ , has been observed. The respective branchings of these two processes could be measured as well. The deduced total nuclear half-life of 255(17) s for 207 Tl 81+ , was slightly modified with respect to the half-life of the neutral atom of 286(2) s. It was nevertheless in very good agreement with calculations based on the assumption that the beta-decay was following an allowed type of transition. The branching β b /β c =0.192(20), was also in very good agreement with the same calculations. The application of stochastic precooling allowed to observe in addition the 1348 keV short-lived isomeric state of 207 Tl. The half-life of this isomeric state was measured as 1.47(32) s, which shows a small deviation

  3. Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.A., E-mail: jose.rodriguez@tsolar.eu [Dept. Technology, Development and Innovation, T-Solar Global S.A., Parque Tecnologico de Galicia, Avda. de Vigo 5, E-32900 San Cibrao das Vinas (Ourense) (Spain); Fortes, M. [Departamento de Electronica e Computacion, Universidade de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Alberte, C.; Vetter, M.; Andreu, J. [Dept. Technology, Development and Innovation, T-Solar Global S.A., Parque Tecnologico de Galicia, Avda. de Vigo 5, E-32900 San Cibrao das Vinas (Ourense) (Spain)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer Spectral response equipment for measuring a-Si:H solar cells in a few seconds. Black-Right-Pointing-Pointer Equipment based on 16 LEDs with simultaneous illumination of the solar cell. Black-Right-Pointing-Pointer The current generated by each LED is analyzed by a Fast Fourier Transform. Black-Right-Pointing-Pointer Cheap equipment without lock-in technology for the current measurement. Black-Right-Pointing-Pointer Measurement error vs. conventional measurement less than 1% in J{sub sc}. - Abstract: An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2-4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.

  4. The LPCTrap experiment: measurement of the {beta}-{nu} angular correlation in {sup 6}He{sup +} decay using a transparent Paul trap

    Energy Technology Data Exchange (ETDEWEB)

    Velten, Ph., E-mail: velten@lpccaen.in2p3.fr; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D.; Thomas, J. C. [Universite de Caen, LPC Caen, ENSICAEN (France)

    2011-07-15

    The LPCTrap experiment is devoted to the precise measurement of the {beta}-{nu} angular correlation parameter, a{sub {beta}{nu}}, in the pure Gamow-Teller decay of {sup 6}He{sup +}. This experiment is motivated by the search of the presence of tensor type contributions in the weak interaction. The radioactive source is confined in a transparent Paul trap installed at LIRAT, the low energy beam line of the SPIRAL facility. The {beta}-{nu} correlation is studied by measuring the time of flight of the recoil ions detected in coincidence with the {beta} particles. During the last experiment, a total of 4 Multiplication-Sign 10{sup 6} coincidence events have been recorded which would enable to determine the coefficient with a statistical uncertainty of 0.5%. The status of the analysis is presented in this contribution.

  5. Beam Based Measurements of Field Multipoles in the RHIC Low Beta Insertions and Extrapolation of the Method to the LHC

    CERN Document Server

    Koutchouk, Jean-Pierre; Ptitsyn, V I

    2001-01-01

    The multipolar content of the dipoles and quadrupoles is known to limit the stability of the beam dynamics in super-conducting machines like RHIC and even more in LHC. The low-beta quadrupoles are thus equipped with correcting coils up to the dodecapole order. The correction is planned to rely on magnetic measurements. We show that a relatively simple method allows an accurate measurement of the multipolar field aberrations using the beam. The principle is to displace the beam in the non-linear fields by local closed orbit bumps and to measure the variation of sensitive beam observable. The resolution and robustness of the method are found appropriate. Experimentation at RHIC showed clearly the presence of normal and skew sextupolar field components in addition to a skew quadrupolar component in the interaction regions. Higher-order components up to decapole order appear as well.

  6. Trending in Probability of Collision Measurements via a Bayesian Zero-Inflated Beta Mixed Model

    Science.gov (United States)

    Vallejo, Jonathon; Hejduk, Matt; Stamey, James

    2015-01-01

    We investigate the performance of a generalized linear mixed model in predicting the Probabilities of Collision (Pc) for conjunction events. Specifically, we apply this model to the log(sub 10) transformation of these probabilities and argue that this transformation yields values that can be considered bounded in practice. Additionally, this bounded random variable, after scaling, is zero-inflated. Consequently, we model these values using the zero-inflated Beta distribution, and utilize the Bayesian paradigm and the mixed model framework to borrow information from past and current events. This provides a natural way to model the data and provides a basis for answering questions of interest, such as what is the likelihood of observing a probability of collision equal to the effective value of zero on a subsequent observation.

  7. Reduction of beta-interference in gamma-spectrometric measurements of neutron-irradiated geological material

    International Nuclear Information System (INIS)

    Garmann, L.B.

    1986-01-01

    The analytical technique for INAA, when applied to geological materials, is improved by introducing an electromagnetic field between sample and detector. This field lowers the bremsstrahlung background intensity in the gamma-spectrum by reducing the number of beta-particles reaching the detector. Thus precision, accuracy and lower detection limit are improved. The technique was used on alkalisyenite and on meteoritic material, rocks containing high quantities of sodium and iron, respectively. After neutron irradiation, the induced nuclides sup(24)Na and sup(59)Fe are responsible for high bremsstrahlung interference, which under normal analyitical conditions would mask any x-ray or gamma-ray peaks of interest. The technique is easily applied to multielement analysis of geological and biological materials. It can be combined with sophisticated spectrum-treating techniques such as spectrum stripping and spectrum smoothing, or coincidence-anticoincidence circuits. (author)

  8. [The radial velocity measurement accuracy of different spectral type low resolution stellar spectra at different signal-to-noise ratio].

    Science.gov (United States)

    Wang, Feng-Fei; Luo, A-Li; Zhao, Yong-Heng

    2014-02-01

    The radial velocity of the star is very important for the study of the dynamics structure and chemistry evolution of the Milky Way, is also an useful tool for looking for variable or special objects. In the present work, we focus on calculating the radial velocity of different spectral types of low-resolution stellar spectra by adopting a template matching method, so as to provide effective and reliable reference to the different aspects of scientific research We choose high signal-to-noise ratio (SNR) spectra of different spectral type stellar from the Sloan Digital Sky Survey (SDSS), and add different noise to simulate the stellar spectra with different SNR. Then we obtain theradial velocity measurement accuracy of different spectral type stellar spectra at different SNR by employing a template matching method. Meanwhile, the radial velocity measurement accuracy of white dwarf stars is analyzed as well. We concluded that the accuracy of radial velocity measurements of early-type stars is much higher than late-type ones. For example, the 1-sigma standard error of radial velocity measurements of A-type stars is 5-8 times as large as K-type and M-type stars. We discuss the reason and suggest that the very narrow lines of late-type stars ensure the accuracy of measurement of radial velocities, while the early-type stars with very wide Balmer lines, such as A-type stars, become sensitive to noise and obtain low accuracy of radial velocities. For the spectra of white dwarfs stars, the standard error of radial velocity measurement could be over 50 km x s(-1) because of their extremely wide Balmer lines. The above conclusion will provide a good reference for stellar scientific study.

  9. Remote measurement of water color in coastal waters. [spectral radiance data used to obtain quantitative values for chlorophyll and turbidity

    Science.gov (United States)

    Weldon, J. W.

    1973-01-01

    An investigation was conducted to develop procedure to obtain quantitative values for chlorophyll and turbidity in coastal waters by observing the changes in spectral radiance of the backscattered spectrum. The technique under consideration consists of Examining Exotech model 20-D spectral radiometer data and determining which radiance ratios best correlated with chlorophyll and turbidity measurements as obtained from analyses of water samples and sechi visibility readings. Preliminary results indicate that there is a correlation between backscattered light and chlorophyll concentration and secchi visibility. The tests were conducted with the spectrometer mounted in a light aircraft over the Mississippi Sound at altitudes of 2.5K, 2.8K and 10K feet.

  10. Extraction of optical parameters of thin films from spectral measurements for design and optical performance of multilayer structures

    International Nuclear Information System (INIS)

    Muellerova, J.; Jurecka, S.; Kucerova, A.

    2003-01-01

    Optical parameters of a-Si:H and indium tin oxide (ITO) thin films deposited on glass substrates are determined from spectral measurements of reflectance and/or transmittance. It is shown how important the exact knowledge of optical parameters as well as thicknesses of the layers for the design and the optical performance of multilayer structures is. The model of the p-i-n based a:Si-H solar cell with ITO as transparent conductive oxide layer is used for illustrating. The modeling of the solar cell integral reflectance in the spectral region of (650-830) nm is used as a criterion to reverse engineering of a multilayer structure with suppressed reflectance losses. The reflectance of a solar cell is modelled and the simulation of the varying optical parameters of individual layers including their thicknesses is discussed. Besides this,the advantage of using an antireflective layer under ITO is discussed (Authors)

  11. Modelling of hand phantoms and optimisation of dose measurements in inhomogeneous beta-photon radiation fields using the MCNP code

    International Nuclear Information System (INIS)

    Becker, Frank; Blunck, Christoph; Hegenbart, Lars; Heide, Bernd; Leone, Debora; Nagels, Sven; Schimmelpfeng, Jutta; Urban, Manfred

    2008-01-01

    Inhomogeneous beta-photon radiation fields make a reliable dose difficult to determine. Routine monitoring with dosemeters does not guarantee any accurate determination of the local skin dose. In general, correction factors are used to correct for the measured dose and the maximum exposure. However, strong underestimations of the maximum exposure are possible, depending on the individual handling and the reliability of dose measurements. Simulations provide the possibility to track the points of highest exposure and the origin of the highest dose. In this connection, simulations are performed with MCNPX. In order to investigate the local skin dose, two hand phantoms are used, a model based on geometrical elements and a voxel hand. A typical case of radio synoviorthesis, handling of a syringe filled with 90 Y, is simulated. Another simulation focuses on the selective internal radio therapy, revealing the origin of the main dose component in the mixed beta-photon radiation field of a 90 Y vial in an opened transport container. (author)

  12. Broadband cavity-enhanced absorption spectroscopy in the ultraviolet spectral region for measurements of nitrogen dioxide and formaldehyde

    Science.gov (United States)

    Washenfelder, R. A.; Attwood, A. R.; Flores, J. M.; Zarzana, K. J.; Rudich, Y.; Brown, S. S.

    2016-01-01

    Formaldehyde (CH2O) is the most abundant aldehyde in the atmosphere, and it strongly affects photochemistry through its photolysis. We describe simultaneous measurements of CH2O and nitrogen dioxide (NO2) using broadband cavity-enhanced absorption spectroscopy in the ultraviolet spectral region. The light source consists of a continuous-wave diode laser focused into a Xenon bulb to produce a plasma that emits high-intensity, broadband light. The plasma discharge is optically filtered and coupled into a 1 m optical cavity. The reflectivity of the cavity mirrors is 0.99930 ± 0.00003 (1- reflectivity = 700 ppm loss) at 338 nm, as determined from the known Rayleigh scattering of He and zero air. This mirror reflectivity corresponds to an effective path length of 1.43 km within the 1 m cell. We measure the cavity output over the 315-350 nm spectral region using a grating monochromator and charge-coupled device array detector. We use published reference spectra with spectral fitting software to simultaneously retrieve CH2O and NO2 concentrations. Independent measurements of NO2 standard additions by broadband cavity-enhanced absorption spectroscopy and cavity ring-down spectroscopy agree within 2 % (slope for linear fit = 1.02 ± 0.03 with r2 = 0.998). Standard additions of CH2O measured by broadband cavity-enhanced absorption spectroscopy and calculated based on flow dilution are also well correlated, with r2 = 0.9998. During constant mixed additions of NO2 and CH2O, the 30 s measurement precisions (1σ) of the current configuration were 140 and 210 pptv, respectively. The current 1 min detection limit for extinction measurements at 315-350 nm provides sufficient sensitivity for measurement of trace gases in laboratory experiments and ground-based field experiments. Additionally, the instrument provides highly accurate, spectroscopically based trace gas detection that may complement higher precision techniques based on non-absolute detection methods. In addition to

  13. Computerized Assessment of Communication for Cognitive Stimulation for People with Cognitive Decline Using Spectral-Distortion Measures and Phylogenetic Inference

    Science.gov (United States)

    Pham, Tuan D.; Oyama-Higa, Mayumi; Truong, Cong-Thang; Okamoto, Kazushi; Futaba, Terufumi; Kanemoto, Shigeru; Sugiyama, Masahide; Lampe, Lisa

    2015-01-01

    Therapeutic communication and interpersonal relationships in care homes can help people to improve their mental wellbeing. Assessment of the efficacy of these dynamic and complex processes are necessary for psychosocial planning and management. This paper presents a pilot application of photoplethysmography in synchronized physiological measurements of communications between the care-giver and people with dementia. Signal-based evaluations of the therapy can be carried out using the measures of spectral distortion and the inference of phylogenetic trees. The proposed computational models can be of assistance and cost-effectiveness in caring for and monitoring people with cognitive decline. PMID:25803586

  14. Computerized assessment of communication for cognitive stimulation for people with cognitive decline using spectral-distortion measures and phylogenetic inference.

    Directory of Open Access Journals (Sweden)

    Tuan D Pham

    Full Text Available Therapeutic communication and interpersonal relationships in care homes can help people to improve their mental wellbeing. Assessment of the efficacy of these dynamic and complex processes are necessary for psychosocial planning and management. This paper presents a pilot application of photoplethysmography in synchronized physiological measurements of communications between the care-giver and people with dementia. Signal-based evaluations of the therapy can be carried out using the measures of spectral distortion and the inference of phylogenetic trees. The proposed computational models can be of assistance and cost-effectiveness in caring for and monitoring people with cognitive decline.

  15. Spectral evolution of energetic neutral atom emissions at the heliospheric poles as measured by IBEX during its first three years

    Energy Technology Data Exchange (ETDEWEB)

    Dayeh, M. A.; Allegrini, F.; Desai, M. I.; Ebert, R. W.; Fuselier, S. A.; Livadiotis, G.; McComas, D. J.; Schwadron, N. A. [Southwest Research Institute, San Antonio, TX 78228 (United States); DeMajistre, R. [Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723 (United States); Janzen, P.; Reisenfeld, D. [University of Montana, Missoula, MT 59812 (United States); Siewert, M., E-mail: maldayeh@swri.edu [Institut für Astronomie der Universität Bonn, Abteilung f. Astrophysik und Extraterrestrische Forschung, Auf dem Hügel 71, D-53121 Bonn (Germany)

    2014-12-10

    The Interstellar Boundary Explorer (IBEX) mission continues to measure energetic neutral atom (ENA) emissions produced by charge exchange between solar wind (SW) protons and interstellar neutrals at the edge of our heliosphere. Using the first 3 yr of IBEX-Hi ENA measurements (2009-2011), we examined the spectral evolution of ∼0.5-6 keV ENAs at the polar regions (above 60°). We found the following: (1) pixels with a characteristic 'ankle' spectra (lower spectral index at higher energies) increase by ∼5% in 2010 and ∼10% in 2011 compared to 2009. (2) The averaged spectral index in 2011 is smaller than that of 2009. (3) The slope of the ENA spectrum above ∼1.7 keV is more variable than the slope below ∼1.7 keV. The lower spectral index at higher energies of the spectrum does not appear to be caused by an increase of the ENA production at these energies, but rather from a consistent decrease at lower energies. (4) The decrease in polar ENA fluxes does not correlate significantly with the averaged SW dynamic pressure, back-traced in time to 1 AU along the flow streamlines (originating between 10° and 30° for slow SW, and 60° and 80° for fast SW), assuming these are the respective conditions of ENA progenitors back in time. These results provide insights into the complexity of relating the slow and fast SW contributions to polar ENAs and shed light on how the solar output and the resulting change in the global heliospheric structure possibly affect the heliosheath (HS) populations.

  16. Measurement of the spectral shift of the 3d→4p transitions in Ar+, Cl+ and S+ by means of collinear fast-beam laser spectroscopy

    International Nuclear Information System (INIS)

    Eichhorn, A.

    1981-01-01

    The spectral shift of the 3d→4p transitions in Ar + ( 36 Ar + and 40 Ar + ) Cl + ( 35 Cl + and 37 Cl + ) and S + ( 32 S + + 34 S + ) were measured by means of collinear fast-beam laser spectroscopy. Since the volume effect is neglectible only the normal and specific mass effect give contributions to the spectral shift. (BEF)

  17. THE RADIO-2 mm SPECTRAL INDEX OF THE CRAB NEBULA MEASURED WITH GISMO

    International Nuclear Information System (INIS)

    Arendt, R. G.; George, J. V.; Staguhn, J. G.; Benford, D. J.; Fixsen, D. J.; Maher, S. F.; Moseley, S. H.; Sharp, E.; Wollack, E. J.; Devlin, M. J.; Dicker, S. R.; Korngut, P. M.; Irwin, K. D.; Jhabvala, C. A.; Miller, T. M.; Kovacs, A.; Mason, B. S.; Navarro, S.; Sievers, A.; Sievers, J. L.

    2011-01-01

    We present results of 2 mm observations of the Crab Nebula, obtained using the Goddard-IRAM Superconducting 2 Millimeter Observer (GISMO) bolometer camera on the IRAM 30 m telescope. Additional 3.3 mm observations with the MUSTANG bolometer array on the Green Bank Telescope are also presented. The integrated 2 mm flux density of the Crab Nebula provides no evidence for the emergence of a second synchrotron component that has been proposed. It is consistent with the radio power-law spectrum, extrapolated up to a break frequency of log (ν b [GHz]) = 2.84 ± 0.29 or ν b = 695 +651 -336 GHz. The Crab Nebula is well resolved by the ∼16.''7 beam (FWHM) of GISMO. Comparison to radio data at comparable spatial resolution enables us to confirm significant spatial variation of the spectral index between 21 cm and 2 mm. The main effect is a spectral flattening in the inner region of the Crab Nebula, correlated with the toroidal structure at the center of the nebula that is prominent in the near-IR through X-ray regime.

  18. Measurements and analysis of the noise spectral density of YBCO films

    International Nuclear Information System (INIS)

    Taoufik, A.; Bghour, M.; Labrag, A.; Bouaaddi, A.; Abaragh, A.; Ramzi, A.; Senoussi, S.; Tirbiyine, A.

    2006-01-01

    We studied the voltage noise spectral density S V (f,T,H) dependence on frequency f, temperature T and applied magnetic field H in YBa 2 Cu 3 O 7-δ films. The voltage noise spectral density S V (f) as a function of frequency exhibits 1/f behavior according to a Lorentzian shape A [(1+πf/f 0 ) B ] C , where A, f 0 , B, C constants which are determined and compared for many values of H. The influence of temperature and magnetic field is clearly observed as a function of temperature, S V (T) is found to vanish at T g , the temperature of vortex glass transition, according to a (T-T g ) x law. We interpreted those results by the formation of a large distribution of glass vortex domains. Approaching T g , these domains grow in size and lifetime, while at T g those parameters diverge. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  19. Structural evolution in the isothermal crystallization process of the molten nylon 10/10 traced by time-resolved infrared spectral measurements and synchrotron SAXS/WAXD measurements

    International Nuclear Information System (INIS)

    Tashiro, Kohji; Nishiyama, Asami; Tsuji, Sawako; Hashida, Tomoko; Hanesaka, Makoto; Takeda, Shinichi; Weiyu, Cao; Reddy, Kummetha Raghunatha; Masunaga, Hiroyasu; Sasaki, Sono; Takata, Masaki; Ito, Kazuki

    2009-01-01

    The structural evolution in the isothermal crystallization process of nylon 10/10 from the melt has been clarified concretely on the basis of the time-resolved infrared spectral measurement as well as the synchrotron wide-angle and small-angle X-ray scattering measurements. Immediately after the temperature jump from the melt to the crystallization point, the isolated domains consisting of the hydrogen-bonded random coils were formed in the melt, as revealed by Guinier plot of SAXS data and the infrared spectral data. With the passage of time these domains approached each other with stronger correlation as analyzed by Debye-Bueche equation. These domains transformed finally to the stacked crystalline lamellae, in which the conformationally-regularized methylene segments of the CO sides were connected each other by stronger intermolecular hydrogen bonds to form the crystal lattice.

  20. Statistical comparison of spectral and biochemical measurements on an example of Norway spruce stands in the Ore Mountains, Czech Republic

    Directory of Open Access Journals (Sweden)

    Markéta Potůčková

    2016-07-01

    Full Text Available The physiological status of vegetation and changes thereto can be monitored by means of biochemical analysis of collected samples as well as by means of spectroscopic measurements either on the leaf level, using field (or laboratory spectroradiometers or on the canopy level, applying hyperspectral airborne or spaceborne image data. The presented study focuses on the statistical comparison and ascertainment of relations between three datasets collected from selected Norway spruce forest stands in the Ore Mountains, Czechia. The data sets comprise i photosynthetic pigments (chlorophylls, carotenoids and water content of 495 samples collected from 55 trees from three different vertical levels and the first three needle age classes, ii the spectral reflectance of the same samples measured with an ASD Field Spec 4 Wide-Res spectroradiometer equipped with a plant contact probe, iii an airborne hyperspecral image acquired with an Apex sensor. The datasets cover two localities in the Ore Mountains that were affected differently by acid deposits in the 1970s and 1980s. A one-way analysis of variance (ANOVA, Tukey’s honest significance test, hot spot analysis and linear regression were applied either on the original measurements (the content of leaf compounds and reflectance spectra or derived values, i.e., selected spectral indices. The results revealed a generally low correlation between the photosynthetic pigments, water content and spectral measurement. The results of the ANOVA showed significant differences between sites (model areas only in the case of the leaf compound dataset. Differences between the stands on various levels of significance exist in all three datasets and are explained in detail. The study also proved that the vertical gradient of the biochemical and biophysical parameters in the canopy play a role when the optical properties of the forest stands are modelled.

  1. A correlational method to concurrently measure envelope and temporal fine structure weights: effects of age, cochlear pathology, and spectral shaping.

    Science.gov (United States)

    Fogerty, Daniel; Humes, Larry E

    2012-09-01

    The speech signal may be divided into spectral frequency-bands, each band containing temporal properties of the envelope and fine structure. This study measured the perceptual weights for the envelope and fine structure in each of three frequency bands for sentence materials in young normal-hearing listeners, older normal-hearing listeners, aided older hearing-impaired listeners, and spectrally matched young normal-hearing listeners. The availability of each acoustic property was independently varied through noisy signal extraction. Thus, the full speech stimulus was presented with noise used to mask six different auditory channels. Perceptual weights were determined by correlating a listener's performance with the signal-to-noise ratio of each acoustic property on a trial-by-trial basis. Results demonstrate that temporal fine structure perceptual weights remain stable across the four listener groups. However, a different weighting typography was observed across the listener groups for envelope cues. Results suggest that spectral shaping used to preserve the audibility of the speech stimulus may alter the allocation of perceptual resources. The relative perceptual weighting of envelope cues may also change with age. Concurrent testing of sentences repeated once on a previous day demonstrated that weighting strategies for all listener groups can change, suggesting an initial stabilization period or susceptibility to auditory training.

  2. Ability of spectral domain optical coherence tomography peripapillary retinal nerve fiber layer thickness measurements to identify early glaucoma

    Directory of Open Access Journals (Sweden)

    Tarannum Mansoori

    2011-01-01

    Full Text Available Purpose : To evaluate the ability of spectral domain optical coherence tomography (OCT peripapillary retinal nerve fiber layer thickness (RNFLT parameters to distinguish normal eyes from those with early glaucoma in Asian Indian eyes. Design : Observational cross-sectional study. Materials and Methods : One hundred and seventy eight eyes (83 glaucoma patients and 95 age matched healthy subjects of subjects more than 40 years of age were included in the study. All subjects underwent RNFLT measurement with spectral OCT/ scanning laser ophthalmoscope (SLO after dilatation. Sensitivity, specificity and area under the receiving operating characteristic curve (AROC were calculated for various OCT peripapillary RNFL parameters. Results: The mean RNFLT in healthy subjects and patients with early glaucoma were 105.7 ± 5.1 μm and 90.7 ± 7.5 μm, respectively. The largest AROC was found for 12 o′clock- hour (0.98, average (0.96 and superior quadrant RNFLT (0.9. When target specificity was set at ≥ 90% and ≥ 80%, the parameters with highest sensitivity were 12 o′clock -hour (91.6%, average RNFLT (85.3% and 12 o′ clock- hour (96.8 %, average RNFLT (94.7% respectively. Conclusion : Our study showed good ability of spectral OCT/ SLO to differentiate normal eyes from patients with early glaucoma and hence it may serve as an useful adjunct for early diagnosis of glaucoma.

  3. Wavelength selection for portable noninvasive blood component measurement system based on spectral difference coefficient and dynamic spectrum

    Science.gov (United States)

    Feng, Ximeng; Li, Gang; Yu, Haixia; Wang, Shaohui; Yi, Xiaoqing; Lin, Ling

    2018-03-01

    Noninvasive blood component analysis by spectroscopy has been a hotspot in biomedical engineering in recent years. Dynamic spectrum provides an excellent idea for noninvasive blood component measurement, but studies have been limited to the application of broadband light sources and high-resolution spectroscopy instruments. In order to remove redundant information, a more effective wavelength selection method has been presented in this paper. In contrast to many common wavelength selection methods, this method is based on sensing mechanism which has a clear mechanism and can effectively avoid the noise from acquisition system. The spectral difference coefficient was theoretically proved to have a guiding significance for wavelength selection. After theoretical analysis, the multi-band spectral difference coefficient-wavelength selection method combining with the dynamic spectrum was proposed. An experimental analysis based on clinical trial data from 200 volunteers has been conducted to illustrate the effectiveness of this method. The extreme learning machine was used to develop the calibration models between the dynamic spectrum data and hemoglobin concentration. The experiment result shows that the prediction precision of hemoglobin concentration using multi-band spectral difference coefficient-wavelength selection method is higher compared with other methods.

  4. Precision measurements of the $^{60}$Co $\\beta$-asymmetry parameter in search for tensor currents in weak interactions

    CERN Document Server

    Wauters, F; Zákoucký, D; Beck, M; Breitenfeldt, M; De Leebeeck, V; Golovko, V V; Kozlov, V Yu; Phalet, T; Roccia, S; Soti, G; Tandecki, M; Towner, I S; Traykov, E; Van Gorp, S; Severijns, N

    2010-01-01

    The $\\beta$-asymmetry parameter $\\widetilde{A}$ for the Gamow-Teller decay of $^{60}$Co was measured by polarizing the radioactive nuclei with the brute force low-temperature nuclear-orientation method. The $^{60}$Co activity was cooled down to milliKelvin temperatures in a $^3$He-$^4$He dilution refrigerator in an external 13 T magnetic field. The $\\beta$ particles were observed by a 500 ${\\mu}m$ thick Si PIN diode operating at a temperature of about 10 K in a magnetic field of 0.6 T. Extensive GEANT4 Monte-Carlo simulations were performed to gain control over the systematic effects. Our result, $\\widetilde{A} = -1.014(12)_{stat}(16)_{syst}$, is in agreement with the Standard-Model value of $-0.987(9)$, which includes recoil-order corrections that were addressed for the first time for this isotope. Further, it enables limits to be placed on possible tensor-type charged weak currents as well as other physics beyond the Standard Model.

  5. EPR and TL-based beta dosimetry measurements in various tooth components contaminated by 90Sr

    International Nuclear Information System (INIS)

    Veronese, I.; Fattibene, P.; Cantone, M.C.; De Coste, V.; Giussani, A.; Onori, S.; Shishkina, E.A.

    2008-01-01

    Thermoluminescence-based beta dosimetry, previously proposed for the estimate of the internal contamination in teeth, and EPR has been used in this paper to investigate the homogeneity of 90 Sr contamination and of dose within nine teeth of one person born in the year of the onset of waterborne radioactive releases of the Mayak plutonium facility. A large deviation of dose and activity distributions in both enamel and radical dentine of the various teeth was observed. Average dose was 27±7Gy in enamel and 0.90±0.31Gy in radical dentine. Average 90 Sr concentration was 52±8Bq/g in enamel and 5±2Bq/g in radical dentine. The observed deviation around the mean value of dose and 90 Sr concentration can be explained due to the specific mineral evolution of each tooth at the time of Sr intake. In the same donor, a negative correlation was also observed between radical dentine and enamel for the 90 Sr specific activity as well for the dose. Similar analyses performed on one massive molar belonging to a second donor revealed absence of correlation between dose and 90 Sr concentration in the same tissue, indicating a dose contribution from 90 Sr present in neighbouring tissue compartments. Systematic differences in cumulated dose and activity levels between the lingual and the buccal parts of crown dentine and of enamel were also observed

  6. Nuclear techniques and cross-correlation methods for spectral analysis in two-phase flow measurements in mineral pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Luis E.B.; Salgado, Cesar M., E-mail: brandaos@ien.gov.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Divisao de Radiofarmacos; Sicilliano, Umberto C.C.S., E-mail: umberto.cassara@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Metalurgia

    2013-07-01

    In mineral industry is common to use water to transport pellets inside pipes. In these units, the correct measurement of flow (both solid and liquid phase) is important to guarantee a safe operation. Cross correlation flow meters are devices specially suited to be used in dual-phase flow and they are based on measure the transit time due the disturbances registered between two points, in our case gamma attenuation from radioactive sources. The emphasis of this work is the application of gamma transmission and scattering technique associated with spectral analysis methods to measure the flow of solid phase in a liquid fluid in side the pipe. The detectors and the sources are out side of the tube and are positioned 10.0 cm distant one from the other. The photons of transmission/scattering gamma radiation were registered, and across-correlation method was applied to measure the flow and spectral analysis was used to study the flow profile inside the pipe. (author)

  7. Specalyzer—an interactive online tool to analyze spectral reflectance measurements

    Directory of Open Access Journals (Sweden)

    Alexander Koc

    2018-06-01

    Full Text Available Low-cost phenotyping using proximal sensors is increasingly becoming popular in plant breeding. As these techniques generate a large amount of data, analysis pipelines that do not require expertise in computer programming can benefit a broader user base. In this work, a new online tool Specalyzer is presented that allows interactive analysis of the spectral reflectance data generated by proximal spectroradiometers. Specalyzer can be operated from any web browser allowing data uploading, analysis, interactive plots and exporting by point and click using a simple graphical user interface. Specalyzer is evaluated with case study data from a winter wheat fertilizer trial with two fertilizer treatments. Specalyzer can be accessed online at http://www.specalyzer.org.

  8. Measurement of the proton recoil spectrum in neutron beta decay with the spectrometer aSPECT. Study of systematic effects

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, Gertrud Emilie

    2012-01-24

    Free neutron decay, n{yields}pe anti {nu}{sub e}, is the simplest nuclear beta decay, well described as a purely left-handed, vector minus axial-vector interaction within the framework of the Standard Model (SM) of elementary particles and fields. Due to its highly precise theoretical description, neutron beta decay data can be used to test certain extensions to the SM. Possible extensions require, e.g., new symmetry concepts like left-right symmetry, new particles, leptoquarks, supersymmetry, or the like. Precision measurements of observables in neutron beta decay address important open questions of particle physics and cosmology, and are generally complementary to direct searches for new physics beyond the SM in high-energy physics. In this doctoral thesis, a measurement of the proton recoil spectrum with the neutron decay spectrometer aSPECT is described. From the proton spectrum the antineutrinoelectron angular correlation coefficient a can be derived. In our first beam time at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich, Germany (2005-2006), background instabilities due to particle trapping and the electronic noise level of the proton detector prevented us from presenting a new value for a. In the latest beam time at the Institut Laue-Langevin (ILL) in Grenoble, France (2007-2008), the trapped particle background has been reduced sufficiently and the electronic noise problem has essentially been solved. For the first time, a silicon drift detector was used. As a result of the data analysis, we identified and fixed a problem in the detector electronics which caused a significant systematic error. The target figure of the latest beam time was a new value for a with a total relative error well below the present literature value of 4 %. A statistical accuracy of about 1.4% was reached, but we could only set upper limits on the correction of the problem in the detector electronics, which are too high to determine a meaningful result. The present

  9. Measurement of the proton recoil spectrum in neutron beta decay with the spectrometer aSPECT. Study of systematic effects

    International Nuclear Information System (INIS)

    Konrad, Gertrud Emilie

    2012-01-01

    Free neutron decay, n→pe anti ν e , is the simplest nuclear beta decay, well described as a purely left-handed, vector minus axial-vector interaction within the framework of the Standard Model (SM) of elementary particles and fields. Due to its highly precise theoretical description, neutron beta decay data can be used to test certain extensions to the SM. Possible extensions require, e.g., new symmetry concepts like left-right symmetry, new particles, leptoquarks, supersymmetry, or the like. Precision measurements of observables in neutron beta decay address important open questions of particle physics and cosmology, and are generally complementary to direct searches for new physics beyond the SM in high-energy physics. In this doctoral thesis, a measurement of the proton recoil spectrum with the neutron decay spectrometer aSPECT is described. From the proton spectrum the antineutrinoelectron angular correlation coefficient a can be derived. In our first beam time at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich, Germany (2005-2006), background instabilities due to particle trapping and the electronic noise level of the proton detector prevented us from presenting a new value for a. In the latest beam time at the Institut Laue-Langevin (ILL) in Grenoble, France (2007-2008), the trapped particle background has been reduced sufficiently and the electronic noise problem has essentially been solved. For the first time, a silicon drift detector was used. As a result of the data analysis, we identified and fixed a problem in the detector electronics which caused a significant systematic error. The target figure of the latest beam time was a new value for a with a total relative error well below the present literature value of 4 %. A statistical accuracy of about 1.4% was reached, but we could only set upper limits on the correction of the problem in the detector electronics, which are too high to determine a meaningful result. The present doctoral

  10. Development of new index for forest fire risk using satellite images in Indonesia through the direct spectral measurements of soil

    Science.gov (United States)

    Hashimoto, A.; Akita, M.; Takahashi, Y.; Suzuki, H.; Hasegawa, Y.; Ogino, Y.; Naruse, N.; Takahashi, Y.

    2016-12-01

    In recent years, the smoke caused by the forest fires in Indonesia has become a serious problem. Most of the land in Indonesia is covered with peat moss, which occurs the expanding of fires due to the burning itself. Thus, the surface soil water, reflecting the amount of precipitation in the area, can become the indication of the risk of fires. This study aims to develop a new index reflecting the risk of forest fires in Indonesia using satellite remote sensing through the direct spectral measurements of peat moss soil.We have prepared the peat moss in 7 steps of soil water content measured at an accuracy of ±15 percent (Field pro, WD-3). We obtained spectra between 400nm and 1050nm (Source: halogen lamp, spectroscope: self-made space time, spectral analysis kit) from the peat moss.The obtained spectra show the difference from the previous spectral measurement for the soil in various water content. There are the features, especially, in the wavelength range of ultraviolet (400-450nm) and infrared (530-800nm) as shown in the figure; the more the soil water increases, the lower the reflectance becomes. We have developed a new index using the New deep blue band (433 453nm and NIR band 845 885nm of Landsat 8. The resulting satellite images calculated by our original index appears to reflect the risk of forest fires rather than well-known indices such as Normalized Difference Water Index and Normalized difference Soil Index.In conclusion, we have created a new index that highly reflects to the degree of soil water of a peat soil in Indonesia.

  11. Study on the mechanism of human blood glucose concentration measuring using mid-infrared spectral analysis technology

    Science.gov (United States)

    Li, Xiang

    2016-10-01

    All forms of diabetes increase the risk of long-term complications. Blood glucose monitoring is of great importance for controlling diabetes procedure, preventing the complications and improving the patient's life quality. At present, the clinical blood glucose concentration measurement is invasive and could be replaced by noninvasive spectroscopy analytical techniques. The mid-infrared spectral region contains strong characteristic and well-defined absorption bands. Therefore, mid-infrared provides an opportunity for monitoring blood glucose invasively with only a few discrete bonds. Although the blood glucose concentration measurement using mid-infrared spectroscopy has a lot of advantages, the disadvantage is also obvious. The absorption in this infrared region is fundamental molecular group vibration. Absorption intensity is very strong, especially for biological molecules. In this paper, it figures out that the osmosis rate of glucose has a certain relationship with the blood glucose concentration. Therefore, blood glucose concentration could be measured indirectly by measuring the glucose exudate in epidermis layer. Human oral glucose tolerance tests were carried out to verify the correlation of glucose exudation in shallow layer of epidermis layer and blood glucose concentration. As it has been explained above, the mid-infrared spectral region contains well-defined absorption bands, the intensity of absorption peak around 1123 cm-1 was selected to measure the glucose and that around 1170 cm-1 was selected as reference. Ratio of absorption peak intensity was recorded for each set of measurement. The effect and importance of the cleaning the finger to be measured before spectrum measuring are discussed and also verified by experiment.

  12. A spectral approach to compute the mean performance measures of the queue with low-order BMAP input

    Directory of Open Access Journals (Sweden)

    Ho Woo Lee

    2003-01-01

    Full Text Available This paper targets engineers and practitioners who want a simple procedure to compute the mean performance measures of the Batch Markovian Arrival process (BMAP/G/1 queueing system when the parameter matrices order is very low. We develop a set of system equations and derive the vector generating function of the queue length. Starting from the generating function, we propose a spectral approach that can be understandable to those who have basic knowledge of M/G/1 queues and eigenvalue algebra.

  13. Spectral-domain low-coherence interferometry for phase-sensitive measurement of Faraday rotation at multiple depths.

    Science.gov (United States)

    Yeh, Yi-Jou; Black, Adam J; Akkin, Taner

    2013-10-10

    We describe a method for differential phase measurement of Faraday rotation from multiple depth locations simultaneously. A polarization-maintaining fiber-based spectral-domain interferometer that utilizes a low-coherent light source and a single camera is developed. Light decorrelated by the orthogonal channels of the fiber is launched on a sample as two oppositely polarized circular states. These states reflect from sample surfaces and interfere with the corresponding states of the reference arm. A custom spectrometer, which is designed to simplify camera alignment, separates the orthogonal channels and records the interference-related oscillations on both spectra. Inverse Fourier transform of the spectral oscillations in k-space yields complex depth profiles, whose amplitudes and phase difference are related to reflectivity and Faraday rotation within the sample, respectively. Information along a full depth profile is produced at the camera speed without performing an axial scan for a multisurface sample. System sensitivity for the Faraday rotation measurement is 0.86 min of arc. Verdet constants of clear liquids and turbid media are measured at 687 nm.

  14. Validation of a spectral correction procedure for sun and sky reflections in above-water reflectance measurements.

    Science.gov (United States)

    Groetsch, Philipp M M; Gege, Peter; Simis, Stefan G H; Eleveld, Marieke A; Peters, Steef W M

    2017-08-07

    A three-component reflectance model (3C) is applied to above-water radiometric measurements to derive remote-sensing reflectance Rrs (λ). 3C provides a spectrally resolved offset Δ(λ) to correct for residual sun and sky radiance (Rayleigh- and aerosol-scattered) reflections on the water surface that were not represented by sky radiance measurements. 3C is validated with a data set of matching above- and below-water radiometric measurements collected in the Baltic Sea, and compared against a scalar offset correction Δ. Correction with Δ(λ) instead of Δ consistently reduced the (mean normalized root-mean-square) deviation between Rrs (λ) and reference reflectances to comparable levels for clear (Δ: 14.3 ± 2.5 %, Δ(λ): 8.2 ± 1.7 %), partly clouded (Δ: 15.4 ± 2.1 %, Δ(λ): 6.5 ± 1.4 %), and completely overcast (Δ: 10.8 ± 1.7 %, Δ(λ): 6.3 ± 1.8 %) sky conditions. The improvement was most pronounced under inhomogeneous sky conditions when measurements of sky radiance tend to be less representative of surface-reflected radiance. Accounting for both sun glint and sky reflections also relaxes constraints on measurement geometry, which was demonstrated based on a semi-continuous daytime data set recorded in a eutrophic freshwater lake in the Netherlands. Rrs (λ) that were derived throughout the day varied spectrally by less than 2 % relative standard deviation. Implications on measurement protocols are discussed. An open source software library for processing reflectance measurements was developed and is made publicly available.

  15. Effect of altitude on solar UVR and spectral and spatial variations of UV irradiances measured inWagrain, Austria in winter

    DEFF Research Database (Denmark)

    Baczynska, Katarzyna A; Pearson, Andy J; O'Hagan, John B

    2013-01-01

    Ultraviolet radiation spectral irradiance was measured at different altitudes on horizontal and tilted planes in different azimuth directions on cloudless days in Austria, in March 2010, within the Impact of Climatic and Environmental factors on Personal Ultraviolet Radiation Exposure project...

  16. A study on radiation safety measures for the use of high-energy beta-ray sources in medical fields

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Woo; Yang, Jeong Seon; Kim, Hyeon Jo [Cheju National Univ., Cheju (Korea, Republic of)

    2000-12-15

    The scope of this study consists of : an investigation of the current application status of medical radioisotopes, Sr-90, Ho-166, Re-188, which emit beta-rays of energy greater than 1.5 Mev, analyses of the environments under which the above isotopes are used, estimation of personal radiation doses by using the MCNP-4C computer code for the situations in which high radiation doses might be probable, review of the USA's regulations related to safe use of the radioisotopes, investigation of past over-expose cases reported in the internet, analysis of the current domestic regulations, suggestion of safety measures necessary for the use of the radioisotopes.

  17. 90Sr- 90Y and 89Sr beta radioactivity measurement in milk samples using a proportional counter

    International Nuclear Information System (INIS)

    Mananes, A.; Perez Santos, C.; Martinez Churiaque, F.

    1987-01-01

    A thin window glas flow proportional counter is used to measure the 90 Sr- 90 Y and 89 Sr beta radioactivity in milk samples. A chemical procedure is used to separate strontium-yttrium from the other radionuclides present in milk. A calculation of the total efficiency of the system is performed which includes an empirical estimation of the backscattering factor. The calibration of the whole process allows the determination of the 90 Sr activity within 10% relative error in spite of uncertainties in the recovery yields of strontium and yttrium. No 89 Sr activity has been detected, and the mean value obtained for the 90 Sr activity in nine milk samples of Cantabria is 0.115 Bq/1 with a minimum detectable activity of 0.0105 Bq. (author) 18 refs

  18. Summary report of consultants' meeting on high-precision beta-intensity measurements and evaluations for specific PET radioisotopes

    International Nuclear Information System (INIS)

    Capote Noy, R.; Nicols, A.L.

    2009-12-01

    A summary is given of a Consultants' Meeting on 'High-precision beta-intensity measurements and evaluations for specific PET radioisotopes'. Participants assessed and reviewed the decay data for close to 50 positron-emitting radionuclides. Technical discussions are described in this report, along with the detailed recommendations and a priority list for future work. Direct positron and X-ray measurements are required to resolve a significant number of outstanding issues associated with the radionuclides reviewed. The following new measurements are recommended: gamma-ray emission probability for Cu-64, positron and Xray emission probabilities for Ni-57, Cu-62, Ga-66, As-72, Se-73, Rb-81,82m, Sr-83, Y-86 and Tc-94m. The following immediate evaluations were also recommended: Br-76 and I-120g.. Participants assessed and reviewed the decay data for close to 50 positron-emitting radionuclides. Technical discussions are described in this report, along with the detailed recommendations and a priority list for future work. Direct positron and X-ray measurements are required to resolve a significant number of outstanding issues associated with the radionuclides reviewed. The following new measurements are recommended: gamma-ray emission probability for Cu-64, positron and Xray emission probabilities for Ni-57, Cu-62, Ga-66, As-72, Se-73, Rb-81,82m, Sr-83, Y-86 and Tc-94m. The following immediate evaluations were also recommended: Br-76 and I-120g. (author)

  19. Retrieval of aerosol mass load (PM10 from MERIS/Envisat top of atmosphere spectral reflectance measurements over Germany

    Directory of Open Access Journals (Sweden)

    M. Vountas

    2011-03-01

    Full Text Available Results of a new methodology for retrievals of surface particulate matter concentration (PM10 from satellite reflectance measurements over Germany are presented in this paper. The retrieval derives effective radii from Ångström-α exponents and benefits from the fitting of a smooth spectral slope from seven MERIS spectrometer channels. Comparisons with ground measurements from the air quality surveillance show standard deviations of 33.9% with −18.9% bias over Hamburg. Over rural sites a standard deviation of 17.9% (bias 12.9% is reached. We discuss critically limitations and potential applications of the retrieval. Additionally, we talk about the aspects at comparing of retrieved particulate matter with ground station measurements.

  20. Hydrogen Atom Collision Processes in Cool Stellar Atmospheres: Effects on Spectral Line Strengths and Measured Chemical Abundances in Old Stars

    International Nuclear Information System (INIS)

    Barklem, Paul S

    2012-01-01

    The precise measurement of the chemical composition of stars is a fundamental problem relevant to many areas of astrophysics. State-of-the-art approaches attempt to unite accurate descriptions of microphysics, non-local thermodynamic equilibrium (non-LTE) line formation and 3D hydrodynamical model atmospheres. In this paper I review progress in understanding inelastic collisions of hydrogen atoms with other species and their influence on spectral line formation and derived abundances in stellar atmospheres. These collisions are a major source of uncertainty in non-LTE modelling of spectral lines and abundance determinations, especially for old, metal-poor stars, which are unique tracers of the early evolution of our galaxy. Full quantum scattering calculations of direct excitation processes X(nl) + H ↔ X(n'l') + H and charge transfer processes X(nl) + H ↔ X + + H − have been done for Li, Na and Mg [1,2,3] based on detailed quantum chemical data, e.g. [4]. Rate coefficients have been calculated and applied to non-LTE modelling of spectral lines in stellar atmospheres [5,6,7,8,9]. In all cases we find that charge transfer processes from the first excited S-state are very important, and the processes affect measured abundances for Li, Na and Mg in some stars by as much as 60%. Effects vary with stellar parameters (e.g. temperature, luminosity, metal content) and so these processes are important not only for accurate absolute abundances, but also for relative abundances among dissimilar stars.

  1. A measurement of the 2 neutrino double beta decay rate of Te-130 in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kogler, Laura K. [Univ. of California, Berkeley, CA (United States)

    2011-11-30

    CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2vββ). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO2 crystals arranged in a tower and operated at a temperature of 10 mK. Events depositing energy in the detectors, such as radioactive decays or impinging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors. The experiment included 4 enriched crystals, 2 enriched with 130Te and 2 with 128Te, in order to aid in the measurement of the 2vββ rate. The enriched crystals contained a total of 350 g 130Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130- enriched crystals. Residual backgrounds in the subtracted spectrum were fit using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2vββ half-life was measured to be T2v1/2 = [9.81± 0.96(stat)± 0.49(syst)] x1020 y.

  2. A 4{pi} Anticoincidence Arrangement for Measurements of Beta-Ray Emitting Isotopes; Montage a Anticoiencidence 4{pi} pour la Mesure des Radioisotopes Emetteurs Beta; 4{pi} sistema schetchikov antisovpadenij dlya izmerenij beta-izluchayushchikh izotopov; Aparato de Recuento 4{pi} en Anticoincidencia para Medir Emisores Beta

    Energy Technology Data Exchange (ETDEWEB)

    Srdoc, D. [Institute ' ' Ruder Boskovic' ' , Zagreb, Yugoslavia (Croatia)

    1965-10-15

    A 4{pi} anticoincidence, low-background counting system consisting of two specially designed parallel plate counters and a bridge anticoincidence circuit is described. Each counter is of a flat, mica window ''pancake'' type. The diameter of the counters is much larger than the gap between the plates. Good counting properties are obtained in spite of the unusual counter geometry, owing to the flexibility of the counter shape design when a neon-halogen mixture is used. The counters are so arranged that both windows face the sample, leaving a narrow slit for the sample holder. The sample is spread on a thin metalized plastic film. The pulses from both counters due to beta-particles coming from the sample are recorded, giving a 4{pi} counting geometry. The pulses due to cosmic particles triggering both counters simultaneously cancel out in a simple bridge anticoincidence arrangement, thus eliminating the need for an electronic circuit. Furthermore, the parallel plate counters used here for beta-particle counting possess a markedly reduced sensitivity to gamma-rays near the threshold voltage, resulting in a further lowering of the background. Sources of beta-particles of higher energies, as well as gamma-ray sources, can also be measured by the described system, because in the proposed geometry there is no possibility of triggering both counters simultaneously, as is the case with the conventional guard-counter arrangements. (author) [French] Le memoire decrit un ensemble de mesure a anticolhcidence 4{pi}, ayant un faible bruit de fond, compose de deux compteurs speciaux a plateaux paralleles relies par un pont d'anticofncidence. Ces deux compteurs sont de type circulaire plat a fenetre de mica. Le diametre du compteur est tres superieur a l'espace entre les plaques. Malgre sa geometrie inusitee, l'appareil a des proprietes de comptage satisfaisantes en raison de la souplesse que lui conferent ses caracteristiques lorsqu'on utilise un melange halogene-neon. Les

  3. High spectral resolution measurements of a solar flare hard X-ray burst

    International Nuclear Information System (INIS)

    Lin, R.P.; Schwartz, R.A.; NASA, Goddard Space Flight Center, Greenbelt, MD)

    1987-01-01

    Observations are reported of an intense solar flare hard X-ray burst on June 27, 1980, made with a balloon-borne array of liquid nitrogen-cooled Ge detector which provided unprecedented spectral resolution (no more than 1 keV FWHM). The hard X-ray spectra throughout the impulsive phase burst fitted well to a double power-law form, and emission from an isothermal 0.1-1 billion K plasma can be specifically excluded. The temporal variations of the spectrum indicate that the hard X-ray burst is made up of two superposed components: individual spikes lasting about 3-15 sec, which have a hard spectrum and a break energy of 30-65 keV; and a slowly varying component characterized by a soft spectrum with a constant low-energy slope and a break energy which increases from 25 kev to at least 100 keV through the event. The double power-law shape indicates that DC electric field acceleration, similar to that occurring in the earth's auroral zone, may be the source of the energetic electrons which produce the hard X-ray emission. 39 references

  4. Analysis of global water vapour trends from satellite measurements in the visible spectral range

    Directory of Open Access Journals (Sweden)

    S. Mieruch

    2008-02-01

    Full Text Available Global water vapour total column amounts have been retrieved from spectral data provided by the Global Ozone Monitoring Experiment (GOME flying on ERS-2, which was launched in April 1995, and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY onboard ENVISAT launched in March 2002. For this purpose the Air Mass Corrected Differential Optical Absorption Spectroscopy (AMC-DOAS approach has been used. The combination of the data from both instruments provides us with a long-term global data set spanning more than 11 years with the potential of extension up to 2020 by GOME-2 data on MetOp.

    Using linear and non-linear methods from time series analysis and standard statistics the trends of H2O columns and their errors have been calculated. In this study, factors affecting the trend such as the length of the time series, the magnitude of the variability of the noise, and the autocorrelation of the noise are investigated. Special emphasis has been placed on the calculation of the statistical significance of the observed trends, which reveal significant local changes from −5% per year to +5% per year. These significant trends are distributed over the whole globe. Increasing trends have been calculated for Greenland, East Europe, Siberia and Oceania, whereas decreasing trends have been observed for the northwest USA, Central America, Amazonia, Central Africa and the Arabian Peninsular.

  5. RECEIVER OPERATING CHARACTERISTICS MEASURE FOR THE RECOGNITION OF STUTTERING DYSFLUENCIES USING LINE SPECTRAL FREQUENCIES

    Directory of Open Access Journals (Sweden)

    Nahrul Khair Alang Rashid

    2017-05-01

    Full Text Available Stuttering is a motor-speech disorder, having common features with other motor control disorders such as dystonia, Parkinson’s disease and Tourette’s syndrome. Stuttering results from complex interactions between factors such as motor, language, emotional and genetic. This study used Line Spectral Frequency (LSF for the feature extraction, while using three classifiers for the identification purpose, Multilayer Perceptron (MLP, Recurrent Neural Network (RNN and Radial Basis Function (RBF. The UCLASS (University College London Archive of Stuttered Speech release 1 was used as database in this research. These recordings were from people of ages 12y11m to 19y5m, who were referred to clinics in London for assessment of their stuttering. The performance metrics used for interpreting the results are sensitivity, accuracy, precision and misclassification rate. Only M1 and M2 had below 100% sensitivity for RBF. The sensitivity of M1 was found to be between 40 & 60%, therefore categorized as moderate, while that of M2 falls between 60 & 80%, classed as substantial. Overall, RBF outperforms the two other classifiers, MLP and RNN for all the performance metrics considered.

  6. Standard Test Methods for Measurement of Electrical Performance and Spectral Response of Nonconcentrator Multijunction Photovoltaic Cells and Modules

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 These test methods provide special techniques needed to determine the electrical performance and spectral response of two-terminal, multijunction photovoltaic (PV) devices, both cell and modules. 1.2 These test methods are modifications and extensions of the procedures for single-junction devices defined by Test Methods E948, E1021, and E1036. 1.3 These test methods do not include temperature and irradiance corrections for spectral response and current-voltage (I-V) measurements. Procedures for such corrections are available in Test Methods E948, E1021, and E1036. 1.4 These test methods may be applied to cells and modules intended for concentrator applications. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and ...

  7. Comparison of peripapillary choroidal thickness measurements via spectral domain optical coherence tomography with and without enhanced depth imaging.

    Science.gov (United States)

    Ayyildiz, Onder; Kucukevcilioglu, Murat; Ozge, Gokhan; Koylu, Mehmet Talay; Ozgonul, Cem; Gokce, Gokcen; Mumcuoglu, Tarkan; Durukan, Ali Hakan; Mutlu, Fatih Mehmet

    2016-05-01

    To compare peripapillary choroidal thickness (PP-CT) measurements using a spectral domain optical coherence tomography (SD-OCT) device with and without enhanced depth imaging (EDI). Sixty healthy subjects aged from 18 to 40 years were included in this study. PP-CTs were measured in the right eyes by manual segmentation via SD-OCT both with and without EDI. The intraclass correlation coefficient (ICC) for each technique and comparison of PP-CT measurements between two techniques were evaluated. The correlation between retinal nerve fiber layer (RNFL) thickness and PP-CT was also explored on images of SD-OCT without EDI. The PP-CT measurements of 55 subjects were evaluated. The ICC was 0.999 (95% CI: 0.998-1.0, p  0.05). Additionally, there was no correlation between RNFL thickness and PP-CT (r = -0.109; p = 0.335). The PP-CT measurements via SD-OCT without EDI were consistent with the measurements via SD-OCT with EDI. Ophthalmologists who do not have access to EDI technology can use images of SD-OCT without EDI to measure the peripapillary choroid for research purposes. However, thicker peripapillary choroids cannot be measured using this technique and require further modifications or newer technologies, such as SD-OCT with EDI.

  8. Realized Beta GARCH: A Multivariate GARCH Model with Realized Measures of Volatility and CoVolatility

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri

    We introduce a multivariate GARCH model that utilizes and models realized measures of volatility and covolatility. The realized measures extract information contained in high-frequency data that is particularly beneficial during periods with variation in volatility and covolatility. Applying the ...

  9. Diagnostic method for measuring plasma-induced voltages on the PBX-M [Princeton Beta Experiment-Modified] stabilizing shell

    International Nuclear Information System (INIS)

    Kugel, H.W.; Okabayashi, M.; Schweitzer, S.

    1990-07-01

    The Princeton Beta Experiment-Modified (PBX-M) has a close-fitting conducting, passive plate, stabilizing shell which nearly surrounds highly indented, bean-shaped plasmas. The proximity of this electrically isolated shell to a large fraction of the plasma surface allows measurements similar to previous work on other tokamaks using floating probes and limiters. Measurements were performed to characterize the plasma-induced voltages on the PBX-M passive plate stabilizing shell during high-β plasmas. Voltage differences were measured between the respective passive plate toroidal and poloidal gaps, the respective passive plates and the vessel, and an outer poloidal graphite limiter and its passive plate. The calibration and qualification testing procedures are discussed. The initial measurements found that the largest voltages were observed at plasma start-up and at the plasma current disruption and exhibited characteristics depending on operating conditions. The highest voltages observed have been at disruption and were less than 2 kV. 9 refs., 5 figs

  10. Peripapillary Retinal Nerve Fiber Measurement with Spectral-Domain Optical Coherence Tomography in Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    Simon K. Law

    2017-12-01

    Full Text Available Purpose: To evaluate the relationship between the peripapillary retinal nerve fiber layer (RNFL measurements with Spectral-domain Optical Coherence Tomography (OCT and Age-related macular degeneration (AMD. Methods: Patients >60 years of age without glaucoma or record of intraocular pressure >21 mmHg and no systemic or intraocular diseases or treatment or surgical intervention that affected the RNFL underwent OCT measurement of the RNFL. The severity of AMD was staged with the Clinical Age-Related Maculopathy Staging System. The relationship between RNFL measurements and AMD stages of one eye per patient was analyzed. Results: Eighty-six eyes (46 patients with AMD and no glaucoma or other exclusion criteria received OCT RNFL measurements. Nine eyes (10.5% were excluded because of distorted peripapillary anatomy from exudative AMD (7 eyes or failure of the RNFL segmentation algorithm (2 eyes. Mean age ± S.D. of the 43 patients analyzed was 81.2 ± 7.3 years. The mean stage ± S.D. of AMD of the 77 eyes was 3.77 ± 1.05. Higher stages of AMD were statistically significantly associated with lower average RNFL and inferior sector RNFL (p = 0.049, 0 0015, respectively. The association of inferior sector RNFL and AMD stage remained statistically significant after adjusting for age. Conclusions: Spectral domain OCT is generally useful in measuring the peripapillary RNFL in eyes with different stages of AMD. Higher stage of AMD is associated with thinner peripapillary RNFL, which may masquerade as early glaucomatous damage.

  11. Measurement of the internal bremsstrahlung spectrum of a 89Sr beta emitter in the 1–100 keV photon energy regime

    International Nuclear Information System (INIS)

    Singh, Amrit; Dhaliwal, A.S.

    2015-01-01

    The internal bremsstrahlung (IB) spectrum of 89 Sr, which is a unique first forbidden beta emitter, is studied in the 1–100 keV photon energy regime. The IB spectrum is experimentally measured using a Si(Li) detector, which is efficient in this photon energy regime, and is compared with the IB distributions that are predicted by the Knipp, Uhlenbeck and Bloch (KUB), Nilsson, and Lewis and Ford theories. In the soft energy regime up to 15 keV, the measured results are in agreement with all the aforementioned theories. However, from 16–30 keV, the experimental results are in agreement with the Lewis and Ford theory, which applies to forbidden transitions, and at higher photon energies, the Nilsson theory best describes the measured results. The differences among the different theories also increase with the photon energy. The effect of the electrostatic Coulomb field on the IB process for beta emitters with different end-point energies is investigated by comparing the ratio of the IB probabilities predicted using the KUB and Nilsson theories for 35 S and 89 Sr, i.e., soft and hard beta emitters, respectively. The Coulomb effect is shown to be significant in the high photon energy regime and for beta emitters with low end-point energies. - Highlights: • Internal bremsstrahlung spectrum of 89 Sr, a unique first forbidden beta emitter, is studied. • The measurements are taken in the photon energy regions of 1–100 keV with Si(Li) detector. • The measured results are deviating from Lewis and Ford theory and are close to the Nilsson theory. • The effect of Coulomb field on the IB process for different end point energy sources is investigated. • Effect of Coulomb field is more for low energy beta emitter towards the high energy end

  12. Measurement of Resistive Wall Mode stability in rotating high beta plasmas

    International Nuclear Information System (INIS)

    Reimerdes, H.; Bialek, J.; Garofalo, A.M.; Navratil, G.A.; Chance, M.S.; Menard, J.E.; Okabayashi, M.; Takahashi, H.; Chu, M.S.; Gohil, P.; Jackson, G.L.; Jensen, T.H.; La Haye, R.J.; Scoville, J.T.; Strait, E.J.; Jayakumar, R.J.; Liu, Y.Q.

    2005-01-01

    Toroidal plasma rotation in the order of a few percent of the Alfven velocity can stabilize the resistive wall mode and extend the operating regime of tokamaks from the conventional, ideal MHD no-wall limit up to the ideal MHD ideal wall limit. The stabilizing effect has been measured passively by measuring the critical plasma rotation required for stability and actively by probing the plasma with externally applied resonant magnetic fields. These measurements are compared to predictions of rotational stabilization of the sound wave damping and of the kinetic damping model using the MARS code. (author)

  13. Using a Combination of Spectral and Textural Data to Measure Water-Holding Capacity in Fresh Chicken Breast Fillets

    Directory of Open Access Journals (Sweden)

    Beibei Jia

    2018-02-01

    Full Text Available The aim here was to explore the potential of visible and near-infrared (Vis/NIR hyperspectral imaging (400–1000 nm to classify fresh chicken breast fillets into different water-holding capacity (WHC groups. Initially, the extracted spectra and image textural features, as well as the mixed data of the two, were used to develop partial least square-discriminant analysis (PLS-DA classification models. Smoothing, a first derivative process, and principle component analysis (PCA were carried out sequentially on the mean spectra of all samples to deal with baseline offsets and identify outlier data. Six samples located outside the confidence ellipses of 95% confidence level in the score plot were defined as outliers. A PLS-DA model based on the outlier-free spectra provided a correct classification rate (CCR value of 78% in the prediction set. Then, seven optimal wavelengths selected using a successive projections algorithm (SPA were used to develop a simplified PLS-DA model that obtained a slightly reduced CCR with a value of 73%. Moreover, the gray-level co-occurrence matrix (GLCM was implemented on the first principle component image (with 98.13% of variance of the hyperspectral image to extract textural features (contrast, correlation, energy, and homogeneity. The CCR of the model developed using textural variables was less optimistic with a value of 59%. Compared to results of models based on spectral or textural data individually, the performance of the model based on the mixed data of optimal spectral and textural features was the best with an improved CCR of 86%. The results showed that the spectral and textural data of hyperspectral images together can be integrated in order to measure and classify the WHC of fresh chicken breast fillets.

  14. Spectrally resolved measurements of the terahertz beam profile generated from a two-color air plasma

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Zalkovskij, Maksim; Strikwerda, Andrew

    2014-01-01

    Using a THz camera and THz bandpass filters, we measure the frequency - resolved beam profile emitted from a two - color air plasma. We observe a frequency - independent emission angle from the plasma .......Using a THz camera and THz bandpass filters, we measure the frequency - resolved beam profile emitted from a two - color air plasma. We observe a frequency - independent emission angle from the plasma ....

  15. Ozone, spectral irradiance and aerosol measurements with the Brewer spectro radiometer

    International Nuclear Information System (INIS)

    Marenco, F.; Di Sarra, A.

    2001-01-01

    In this technical report a detailed description of the Brewer spectro radiometer, a widespread instrument for ozone and ultraviolet radiation, is given. The methodologies used to measure these quantities and for instrument calibration are described in detail. Finally a new methodology, developed by ENEA to derive the aerosol optical depth from the Brewer routine total ozone measurements, is described. This methodology is based on Langley extrapolation, on the determination of the transmissivity of the Brewer neutral density filters, and on a statistically significant number of half days of measurements obtained in could-free conditions. Results of this method, obtained with the Brewer of the ENEA station for climate observations Roberto Sarao, located in the island of Lampedusa, are reported. These results confirm the validity of the method, thanks to independent measurements taken in 1999 with a Multi filter Rotating Shadow band Radiometer. This methodology allows researchers to obtain an aerosol climatology from ozone measurements obtained at several sites world-wide [it

  16. Evaluating the Effects of Fire on Semi-Arid Savanna Ecosystem Productivity Using Integrated Spectral and Gas Exchange Measurements

    Science.gov (United States)

    Raub, H. D.; Jimenez, J. R.; Gallery, R. E.; Sutter, L., Jr.; Barron-Gafford, G.; Smith, W. K.

    2017-12-01

    Drylands account for 40% of the land surface and have been identified as increasingly important in driving interannual variability of the land carbon sink. Yet, understanding of dryland seasonal ecosystem productivity dynamics - termed Gross Primary Productivity (GPP) - is limited due to complex interactions between vegetation health, seasonal drought dynamics, a paucity of long-term measurements across these under-studied regions, and unanticipated disturbances from varying fire regimes. For instance, fire disturbance has been found to either greatly reduce post-fire GPP through vegetation mortality or enhance post-fire GPP though increased resource availability (e.g., water, light, nutrients, etc.). Here, we explore post-fire ecosystem recovery by evaluating seasonal GPP dynamics for two Ameriflux eddy covariance flux tower sites within the Santa Rita Experimental Range of southeastern Arizona: 1) the US-SRG savanna site dominated by a mix of grass and woody mesquite vegetation that was burned in May 2017, and 2) the US-SRM savanna site dominated by similar vegetation but unburned for the full measurement record. For each site, we collected leaf-level spectral and gas exchange measurements, as well as leaf-level chemistry and soil chemistry to characterize differences in nutrient availability and microbial activity throughout the 2017 growing season. From spectral data, we derived and evaluated multiple common vegetation metrics, including normalized difference vegetation index (NDVI), photochemical reflectivity index (PRI), near-infrared reflectance (NIRv), and MERIS terrestrial chlorophyll index (MTCI). Early results suggest rates of photosynthesis were enhanced at the burned site, with productivity increasing immediately following the onset of monsoonal precipitation; whereas initial photosynthesis at the unburned site remained relatively low following first monsoonal rains. MTCI values for burned vegetation appear to track higher levels of leaf-level nitrogen

  17. Heterogeneity in pre-monsoon aerosol types over the Arabian Sea deduced from ship-borne measurements of spectral AODs

    Directory of Open Access Journals (Sweden)

    D. G. Kaskaoutis

    2010-05-01

    Full Text Available Ship-borne sunphotometer measurements obtained in the Arabian Sea (AS in the pre-monsoon season (18 April–10 May 2006 during a cruise campaign (ICARB have been used to retrieve the Aerosol Optical Depth (AOD; τ and the Ångström wavelength exponent (α. The continents surrounding the AS produce natural and anthropogenic aerosols that have distinctive influences on α and its spectral distribution. The α values were estimated by means of the least-squares method over the spectral bands 340–1020 nm and 340–870 nm. The spectral distribution of AOD in logarithmic co-ordinates could be fit using a 2nd order polynomial with higher accuracy in the wavelength band 340–1020 nm than in the 340–870 nm band. A polynomial fit analytically parameterizes the observed wavelength dependencies of AOD with least errors in spectral variation of α and yields accurate estimates of the coefficients (a1 and a2. The coarse-mode (positive curvature in the lnτλ vs. lnλ aerosols are mainly depicted in the Northern part of the AS closely associated with the nearby arid areas while fine-mode aerosols are mainly observed over the far and coastal AS regions. In the study period the mean AOD at 500 nm is 0.25±0.11 and the α340-1020 is 0.90±0.19. The α340-870 exhibits similar values (0.92±0.18, while significant differences revealed for the constant terms of the polynomial fit (a1 and a2 proportionally to the wavelength band used for their determination. Observed day-to-day variability in the aerosol load and optical properties are direct consequence of the local winds and air-mass trajectories along with the position of the ship.

  18. Systematic measurement of beta-decay half-lives of short-lived isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, T.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Iida, T.; Takahashi, A.; Kasugai, Y.; Ikeda, Y.

    1997-03-01

    We have measured the half-lives of short-lived isotopes for past decade and deduced the half-lives of 6 isotopes further. These results demonstrated that most of the literature values shorter than 10 min systematically deviated from our measurement ones. The cause seems to be that a large number of the previous half-life studies were performed with scintillation counters before 1970 and they had a difficulty in distinguishing the interest {gamma}-ray from the contamination and correcting for pile-up and dead-time losses. Moreover, the deviated data found to be quoted for evaluation. (author)

  19. Speculative Betas

    OpenAIRE

    Harrison Hong; David Sraer

    2012-01-01

    We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

  20. Identifying Subalpine Fir (Abies lasiocarpa Attacked by the Balsam Woolly Adelgid (Adelges piceae Using Spectral Measurements of the Foliage

    Directory of Open Access Journals (Sweden)

    Stephen P. Cook

    2010-01-01

    Full Text Available Balsam woolly adelgid is an invasive pest of firs in the United States. Aerial surveys are conducted for detection of adelgid infestations but other remotely sensed data may also be useful. Our objective was to determine if high spectral resolution, branch-level data can be used to distinguish infested from noninfested trees. Stepwise discriminant analysis yielded a three-variable model (the red-green index and two narrow-bands (one at 670 nm and the other at 1912 nm that classified infested versus non-infested trees with 94% accuracy compared with the 83% accuracy obtained with a single-variable model. The response of trees in narrow spectral bands was integrated across wavebands to simulate measurements from the multispectral SPOT5-HRVIR sensor. Stepwise discriminant analysis again yielded a three-variable model (simple ratio, the SPOT5-HRVIR band in the SWIR region and NDVI with similar accuracy (93% at discriminating infested from non-infested trees compared with the 83% accuracy obtained with a single-variable model.

  1. Estimation of atmospheric columnar organic matter (OM) mass concentration from remote sensing measurements of aerosol spectral refractive indices

    Science.gov (United States)

    Zhang, Ying; Li, Zhengqiang; Sun, Yele; Lv, Yang; Xie, Yisong

    2018-04-01

    Aerosols have adverse effects on human health and air quality, changing Earth's energy balance and lead to climate change. The components of aerosol are important because of the different spectral characteristics. Based on the low hygroscopic and high scattering properties of organic matter (OM) in fine modal atmospheric aerosols, we develop an inversion algorithm using remote sensing to obtain aerosol components including black carbon (BC), organic matter (OM), ammonium nitrate-like (AN), dust-like (DU) components and aerosol water content (AW). In the algorithm, the microphysical characteristics (i.e. volume distribution and complex refractive index) of particulates are preliminarily separated to fine and coarse modes, and then aerosol components are retrieved using bimodal parameters. We execute the algorithm using remote sensing measurements of sun-sky radiometer at AERONET site (Beijing RADI) in a period from October of 2014 to January of 2015. The results show a reasonable distribution of aerosol components and a good fit for spectral feature calculations. The mean OM mass concentration in atmospheric column is account for 14.93% of the total and 56.34% of dry and fine-mode aerosol, being a fairly good correlation (R = 0.56) with the in situ observations near the surface layer.

  2. Spectral and Broad Band Ultraviolet Measurements in Valencia (Spain): A Preliminary Comparison

    International Nuclear Information System (INIS)

    Tena, F.; Marin, M.J.; Martinez-Lozano, J.A.; Utrillas, M.P.; Gomez, J.L.

    2000-01-01

    The Solar Radiation Group of the University of Valencia, in collaboration with the National Institute of Meteorology (INM), recently began a database of erythemal UV irradiance measurements. Such measurements are obtained by a YES UVB-1 pyranometer (280-330 nm) that measures continuously, integrates the values and stores them in a database. The measured values are being compared with those obtained by the integration of the data registered by an Optronic OL 754 spectroradiometer (250-800 nm) considering clear days and different solar zenith angles. For the present study only the data corresponding to the summer (1999) are being considered because these are the days of the year with the higher erythemal values and also the season when people enjoy sunbathing. The results are used to deduce the ultraviolet index (UVI) related to the erythemal doses and the sunburn time. (author)

  3. Spectral and Broad Band Ultraviolet Measurements in Valencia (Spain): A Preliminary Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Tena, F.; Marin, M.J.; Martinez-Lozano, J.A.; Utrillas, M.P.; Gomez, J.L

    2000-07-01

    The Solar Radiation Group of the University of Valencia, in collaboration with the National Institute of Meteorology (INM), recently began a database of erythemal UV irradiance measurements. Such measurements are obtained by a YES UVB-1 pyranometer (280-330 nm) that measures continuously, integrates the values and stores them in a database. The measured values are being compared with those obtained by the integration of the data registered by an Optronic OL 754 spectroradiometer (250-800 nm) considering clear days and different solar zenith angles. For the present study only the data corresponding to the summer (1999) are being considered because these are the days of the year with the higher erythemal values and also the season when people enjoy sunbathing. The results are used to deduce the ultraviolet index (UVI) related to the erythemal doses and the sunburn time. (author)

  4. Measured and numerically partitioned phytoplankton spectral absorption coefficients in inland waters

    NARCIS (Netherlands)

    Zhang, Y.; Liu, M.; Van Dijk, M.A.; Zhu, G.; Gong, Z.; Li, Y.M.; Qin, B.

    2009-01-01

    Total particulate, tripton and phytoplankton absorption coefficients were measured for eutrophic (Lake Taihu), meso-eutrophic (Lake Tianmuhu) and mesotrophic waters (the Three Gorges Reservoir) in China using the quantitative filter technique. Meanwhile, tripton and phytoplankton absorption

  5. Synthesis, spectral, crystallography and thermal investigations of novel Schiff base complexes of manganese (III) derived from heterocyclic beta-diketone with aromatic and aliphatic diamine.

    Science.gov (United States)

    Surati, Kiran R; Thaker, B T

    2010-01-01

    The Schiff base tetradentate ligands N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(1)), N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-ethane-1,2-diamine (H(2)L(2)), N,N-bis-(3,5-dimethyl-1-p-tolyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(3)) and N,N-bis-(3,5-dimethyl-1-p-sulfonyl-1H-pyrazol-4-ylmethylene)-benzene-1,2-diamine (H(2)L(4)) were prepared from the reaction between 5-oxo-3-methyl-1-p-tolyl-1H-pyrazole-4-carbaldehyde or 4-(4-formyl-5-oxo-3-methyl-pyrazol-1-yl)-benzenesulfonic acid and o-phenylenediamine or ethylenediamine. And these are characterized by elemental analysis, FT-IR, (1)H NMR and GC-MS. The corresponding Schiff base complexes of Mn(III) were prepared by condensation of [Mn(3)(mu(3)-O)(OAc)(6)(H(2)O)(3)].3H(2)O with ligands H(2)L(1), H(2)L(2), H(2)L(3) and H(2)L(4). All these complexes have been characterized by elemental analysis, magnetic susceptibility, X-ray crystallography, conductometry measurement, FT-IR, electronic spectra and mass (FAB) spectrometry. Thermal behaviour of the complexes has been studied by TGA, DTA and DSC. Electronic spectra and magnetic susceptibility measurements indicate octahedral stereochemistry of manganese (III) complexes, while non-electrolytic behaviour complexes indicate the absence of counter ion. Copyright 2009. Published by Elsevier B.V.

  6. Observation of B(0)(s)-->Psi(2S)Phi and measurement of the ratio of branching fractions Beta(B(0)(s)-->Psi(2S)Phi)/Beta(B(0)(s)-->J/PsiPhi).

    Science.gov (United States)

    Abulencia, A; Acosta, D; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Bachacou, H; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Haim, E Ben; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chapman, J; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Chu, P H; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Cresciolo, F; Cruz, A; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cyr, D; Daronco, S; D'Auria, S; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'orso, M; Paoli, F Delli; Demers, S; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Dionisi, C; Dittmann, J R; Dituro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Ebina, K; Efron, J; Ehlers, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Flores-Castillo, L R; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Sciveres, M Garcia; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Ginsburg, C; Giokaris, N; Giolo, K; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Gotra, Y; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, S R; Hahn, K; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hatakeyama, K; Hauser, J; Hays, C; Heijboer, A; Heinemann, B; Heinrich, J; Herndon, M; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Kang, J; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kobayashi, H; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kuhlmann, S E; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Martin, A; Martin, V; Martínez, M; Maruyama, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; von der Mey, M; Miao, T; Miladinovic, N; Miles, J; Miller, R; Miller, J S; Mills, C; Milnik, M; Miquel, R; Mitra, A; Mitselmakher, G; Miyamoto, A; Moggi, N; Mohr, B; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Naganoma, J; Nahn, S; Nakano, I; Napier, A; Naumov, D; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Ogawa, T; Oh, S H; Oh, Y D; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Paoletti, R; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Rakitin, A; Rappoccio, S; Ratnikov, F; Reisert, B; Rekovic, V; van Remortel, N; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robertson, W J; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Rott, C; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sanchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfiligoi, I; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Skiba, A; Slaughter, A J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spezziga, M; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Denis, R St; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sumorok, K; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tanimoto, N; Tecchio, M; Teng, P K; Terashi, K; Tether, S; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Tönnesmann, M; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vaiciulis, A; Vallecorsa, S; Varganov, A; Vataga, E; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wallny, R; Walter, T; Wan, Z; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zetti, F; Zhang, X; Zhou, J; Zucchelli, S

    2006-06-16

    We report the first observation of B(0)(s)-->Psi(2S)Phi decay in p(p_) collisions at square root of 8=1.96 TeV using 360 pb(-1) of data collected by the CDF II detector at the Fermilab Tevatron. We observe 20.2 +/- 5.0 and 12.3 +/- 4.1 B(0)(s)-->Psi(2S)Phi candidates, in Psi(2S)-->mu(+)mu(-) and Phi(2S)-->J/Phipi(+)pi(-) decay modes, respectively. We present a measurement of the relative branching fraction Beta(B(0)(s)-->Psi(2S)Phi)/Beta(B(0)(s)-->J/PsiPhi)=0.52 +/- 0.13(stat) +/- 0.04(syst) +/- 0.06(BR) using the Psi(2S)-->mu(+)mu(-) decay mode.

  7. Calibrated radioactive sources - absolute measurements using a 4{pi} {beta}-{gamma} apparatus; Sources etalons de radioactivite - mesures absolues au moyen d'un ensemble 4{pi} {beta}-{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, P; Philis, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    In this paper, the principle of the standardization of the radioisotopes by the 4{pi} {beta} - {gamma} coincidence method is reminded. Some theoretical examples are given emphasizing on instrumental coincidences and their corrections. The experimental apparatus is described: one discusses the choice of the experimental conditions for the many isotopes measured. Results are given and discussed. In appendix we describe the preparation of the sources. (authors) [French] Dans ce rapport, nous rappelons d'abord le principe de la methode d'etalonnage 4{pi} {beta} - {gamma} en donnant quelques exemples theoriques et en insistant sur la correction des erreurs instrumentales. Une description critique de l'appareillage utilise est donnee. On discute le choix des conditions experimentales pour divers isotopes mesures et les resultats obtenus. En annexe, nous decrivons la fabrication des sources que nous mesurons.

  8. X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility.

    Science.gov (United States)

    Reverdin, Charles; Thais, Frédéric; Loisel, Guillaume; Busquet, M; Bastiani-Ceccotti, S; Blenski, T; Caillaud, T; Ducret, J E; Foelsner, W; Gilles, D; Gilleron, F; Pain, J C; Poirier, M; Serres, F; Silvert, V; Soullie, G; Turck-Chieze, S; Villette, B

    2012-10-01

    An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution ∼ 50. It has been used at the LULI-2000 laser facility at École Polytechnique (France) to measure the Δn = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

  9. X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility

    International Nuclear Information System (INIS)

    Reverdin, Charles; Caillaud, T.; Gilleron, F.; Pain, J. C.; Silvert, V.; Soullie, G.; Villette, B.; Thais, Frédéric; Loisel, Guillaume; Blenski, T.; Poirier, M.; Busquet, M.; Bastiani-Ceccotti, S.; Serres, F.; Ducret, J. E.; Foelsner, W.; Gilles, D.; Turck-Chieze, S.

    2012-01-01

    An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution ∼ 50. It has been used at the LULI-2000 laser facility at École Polytechnique (France) to measure the Δn = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

  10. X-ray grating spectrometer for opacity measurements in the 50 eV to 250 eV spectral range at the LULI 2000 laser facility

    Energy Technology Data Exchange (ETDEWEB)

    Reverdin, Charles; Caillaud, T.; Gilleron, F.; Pain, J. C.; Silvert, V.; Soullie, G.; Villette, B. [CEA, DAM, DIF, 91297 Arpajon (France); Thais, Frederic; Loisel, Guillaume; Blenski, T.; Poirier, M. [CEA, DSM, IRAMIS, Service Photons, Atomes et Molecules, 91191 Gif-sur-Yvette (France); Busquet, M. [ARTEP Inc, Ellicott City, Maryland 21042 (United States); Bastiani-Ceccotti, S.; Serres, F. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, route de Saclay, 91128 Palaiseau (France); Ducret, J. E. [CELIA, UMR5107, CEA, CNRS, Universite de Bordeaux, 33400 Talence (France); Foelsner, W. [Max Planck Instituet fuer Quantum Optik, 85748 Garching (Germany); Gilles, D.; Turck-Chieze, S. [CEA, DSM, IRFU, Service d' astrophysique, 91191 Gif-sur-Yvette (France)

    2012-10-15

    An x-ray grating spectrometer was built in order to measure opacities in the 50 eV to 250 eV spectral range with an average spectral resolution {approx} 50. It has been used at the LULI-2000 laser facility at Ecole Polytechnique (France) to measure the {Delta}n = 0, n = 3 transitions of several elements with neighboring atomic number: Cr, Fe, Ni, and Cu in the same experimental conditions. Hence a spectrometer with a wide spectral range is required. This spectrometer features one line of sight looking through a heated sample at backlighter emission. It is outfitted with one toroidal condensing mirror and several flat mirrors cutting off higher energy photons. The spectral dispersion is obtained with a flatfield grating. Detection consists of a streak camera sensitive to soft x-ray radiation. Some experimental results showing the performance of this spectrometer are presented.

  11. Development of a combination detector system for simultaneous measurement of Alpha and Beta/Gamma radioactivity

    International Nuclear Information System (INIS)

    Thakur, Vaishali M.; Ashokkumar, P.; Rekha, A.K.; Jain, Amit; Rath, D.P.; Chaudhury, Probal; Chaudhari, L.M.

    2018-01-01

    Analysis of various samples for α and β/γ radioactivity is carried out in radiological laboratories. Using independent α and β/γ counting systems such measurements are done separately for same sample. In order to address the requirement of simultaneous measurement of α and β/γ activity content of radioactive samples, a counting system using combination of two detectors has been developed. Activity deposited on a 2 mm deep 30 mm diameter aluminum planchette was counted under the detector combination consisting of a ZnS(Ag) and plastic scintillator for α and β/γ respectively. The design and fabrication of the combination detector, development of electronics associated with the system, its characterization and application are presented here

  12. Precision of high definition spectral-domain optical coherence tomography for measuring central corneal thickness.

    Science.gov (United States)

    Correa-Pérez, María E; López-Miguel, Alberto; Miranda-Anta, Silvia; Iglesias-Cortiñas, Darío; Alió, Jorge L; Maldonado, Miguel J

    2012-04-06

    This study was intended to assess the reliability of central corneal thickness (CCT) measurements using Cirrus high-definition optical coherence tomography (HD-OCT) in healthy subjects and its accuracy compared with ultrasonic pachymetry. Seventy-seven consecutive subjects were recruited for evaluating repeatability, and agreement between two examiners. To analyze repeatability, one examiner measured 77 eyes four times in succession. To study agreement between two observers, a second independently trained examiner obtained another CCT measurement. We also measured eyes in a subgroup of 20 patients using standard ultrasonic pachymetry. Within-subject standard deviation (S(w)), coefficient of variation (CV), limits of agreement (LoA), and intraclass correlation coefficient (ICC) data were obtained. For repeatability, the S(w) and precision (1.96 × S(w)) were 4.86 and 9.52 μm, respectively. Intraobserver CV was 0.89% and the ICC was 0.98 (95% confidence interval [CI], 0.97-0.99). For agreement between two examiners, the S(w) and precision were 7.58 and 14.85 μm, respectively; the CV was 1.40%. The mean difference between observers was -0.13 μm (95% CI, -1.85 to 1.58; P = 0.87). The width of the LoA was 29.64 μm. Median difference between Cirrus HD-OCT and ultrasound CCT measurements was -4.5 μm (interquartile range, -7.0-0.0; P = 0.04). Cirrus HD-OCT provides repeatable CCT measurements, good agreement between two independently trained examiners, and its systematic bias compared to ultrasonic pachymetry is clinically negligible. Therefore, research laboratories and eye clinics using Cirrus HD-OCT as a diagnostic imaging method, can also benefit from a reliable noncontact pachymeter when counseling patients with glaucoma and those undergoing corneal and refractive surgeries.

  13. A measurement of deuterium neutral by the Balmer-series in the STP-2 high beta screw pinch tokamak

    International Nuclear Information System (INIS)

    Yamaguchi, S.; Hirano, K.

    1980-06-01

    The Balmer-alpha and beta are measured with a calibrated spectrograph in STP-2 screw pinch tokamak operated under the maximum toroidal field being 9.2 kG, peak plasma current 30 kA and filling pressure 5 mtorr. The electron temperature and density profiles are obtained by ruby laser Thomson scattering. It is shown that electron temperature is about 10 eV and density is of the order of 10 14 /cm 3 . A non-cylindrical symmetric Abel-inversion technique is used to deduce the emission coefficient profiles from that of the line intensity of the Balmer's. In the present parameter range the neutral deuterium density is almost equal to the population density of the ground state, so that it is obtainable from measured intensities of D sub(α) and D sub(β) which give the population densities of the upper levels i = 3 and 4. The Collisional Radiative (CR) model is applied to the rate equations to estimate the ground state population density. It is found that at 4 μsec from the start of the discharge the deuterium neutral density may be approximately 2 x 10 12 /cm 3 at the center of plasma and 2 x 10 14 /cm 3 at the periphery. These values may contain an error of about factor two. Time history of neutral deuterium density is consistent with the increase of plasma density. (author)

  14. The inference of vector magnetic fields from polarization measurements with limited spectral resolution

    Science.gov (United States)

    Lites, B. W.; Skumanich, A.

    1985-01-01

    A method is presented for recovery of the vector magnetic field and thermodynamic parameters from polarization measurement of photospheric line profiles measured with filtergraphs. The method includes magneto-optic effects and may be utilized on data sampled at arbitrary wavelengths within the line profile. The accuracy of this method is explored through inversion of synthetic Stokes profiles subjected to varying levels of random noise, instrumental wave-length resolution, and line profile sampling. The level of error introduced by the systematic effect of profile sampling over a finite fraction of the 5 minute oscillation cycle is also investigated. The results presented here are intended to guide instrumental design and observational procedure.

  15. Elaboration of Co-60 sources on gilding vyns, with beta efficiencies 80 % or better and its activity measure by the coincidences method

    International Nuclear Information System (INIS)

    Cortes P, A.; Tejera R, A.; Becerril V, A.; Ortiz C, A.

    1991-12-01

    The measuring technique of radioactive activity by the coincidences method 4 π β - γ it requires of the elaboration of radioactive sources on thin supports in order to flows the biggest percentage of beta particles, those of the order of the 80 % or but. In this work a procedure for the elaboration of this type of sources, with gilding Vyns is reported. (Author)

  16. Design and Construction of a Vertex Chamber and Measurement of the Average Beta-Hadron Lifetime

    Science.gov (United States)

    Nelson, Harry Norman

    Four parameters describe the mixing of the three quark generations in the Standard Model of the weak charged current interaction. These four parameters are experimental inputs to the model. A measurement of the mean lifetime of hadrons containing b-quarks, or B-Hadrons, constrains the magnitudes of two of these parameters. Measurement of the B-Hadron lifetime requires a device that can measure the locations of the stable particles that result from B-Hadron decay. This device must function reliably in an inaccessible location, and survive high radiation levels. We describe the design and construction of such a device, a gaseous drift chamber. Tubes of 6.9 mm diameter, having aluminized mylar walls of 100 μm thickness are utilized in this Vertex Chamber. It achieves a spatial resolution of 45 mum, and a resolution in extrapolation to the B-Hadron decay location of 87 mum. Its inner layer is 4.6 cm from e^+e ^- colliding beams. The Vertex Chamber is situated within the MAC detector at PEP. We have analyzed both the 94 pb ^{-1} of integrated luminosity accumulated at sqrt{s} = 29 GeV with the Vertex Chamber in place as well as the 210 pb^{-1} accumulated previously. We require a lepton with large momentum transverse to the event thrust axis to obtain a sample of events enriched in B-Hadron decays. The distribution of signed impact parameters of all tracks in these events is used to measure the B-Hadron flight distance, and hence lifetime. The trimmed mean signed impact parameters are 130 +/- 19 μm for data accumulated with the Vertex Chamber, and 162 +/- 25 μm for previous data. Together these indicate an average B-Hadron lifetime of tau_{b} = (1.37_sp{-0.19}{+0.22} stat. +/- 0.11 sys.) times (1 +/- 0.15 sys.) psec. We separate additive and multiplicative systematic errors because the second does not degrade the statistical significance of the difference of the result from 0. If b-c dominates b-quark decay the corresponding weak mixing matrix element mid V_ {cb

  17. Evaluation of spectral correction techniques for fluorescence measurements on pigmented lesions in vivo

    NARCIS (Netherlands)

    Sterenborg, H. J.; Saarnak, A. E.; Frank, R.; Motamedi, M.

    1996-01-01

    Recently, the use of optical spectroscopy for non-invasive diagnosis of malignant melanoma has been suggested. The reliability of such optical measurements can be seriously compromised by spatial variations in the optical properties of the tissue that are not related to malignancy. In the present

  18. Measuring the iron spectral opacity in solar conditions using a double ablation front scheme

    Energy Technology Data Exchange (ETDEWEB)

    Colaitis, A. [Centre Lasers Intenses et Applications, Talence (France); CEA/DRF/IRFU/DAp, CEA Saclay (France); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Ducret, J. E. [Centre Lasers Intenses et Applications, Talence (France); CEA/DRF/IRFU/DAp, CEA Saclay (France); Turck-Chieze, S [CEA/DRF/IRFU/DAp, CEA Saclay (France); Pennec, M L [CEA/DRF/IRFU/DAp, CEA Saclay (France); CEA/DIF, Arpajon (France); Blancard, C [CEA/DIF, Arpajon (France)

    2018-01-22

    We propose a new method to achieve hydrodynamic conditions relevant for the investigation of the radiation transport properties of the plasma at the base of the solar convection zone. The method is designed in the framework of opacity measurements with high-power lasers and exploits the temporal and spatial stability of hydrodynamic parameters in counter-propagating Double Ablation Front (DAF) structures.

  19. The issue of gamma spectral system sourceless object calibration software using in radioactive environment measurement

    International Nuclear Information System (INIS)

    Shen Ming; Zhu Yuelong; Zhao Yanzi

    2009-01-01

    The paper introduces the characteristic, based method of HPGe detector LabSOCS (Laboratory Sourceless Object Calibration Software). Compared measured efficiency and LabSOCS efficiency for different point sources, and the tolerance is about 6% at middle and high energy range. For cylinder samples of dirt, animal ash and plant ash, the results of verification is 7%-10%. (authors)

  20. Choroidal thickness changes after dynamic exercise as measured by spectral-domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Nihat Sayin

    2015-01-01

    Full Text Available Purpose: To measure the choroidal thickness (CT after dynamic exercise by using enhanced depth imaging optical coherence tomography (EDI-OCT. Materials and Methods: A total of 19 healthy participants performed 10 min of low-impact, moderate-intensity exercise (i.e., riding a bicycle ergometer and were examined with EDI-OCT. Each participant was scanned before exercise and afterward at 5 min and 15 min. CT measurement was taken at the fovea and 1000 μ away from the fovea in the nasal, temporal, superior, and inferior regions. Retinal thickness, intraocular pressure, ocular perfusion pressure (OPP, heart rate, and mean blood pressure (mBP were also measured. Results: A significant increase occurred in OPP and mBP at 5 min and 15 min following exercise (P ˂ 0.05. The mean subfoveal CT at baseline was 344.00 ± 64.71 μm compared to 370.63 ± 66.87 μm at 5 min and 345.31 ± 63.58 μm at 15 min after exercise. CT measurements at all locations significantly increased at 5 min following exercise compared to the baseline (P ˂ 0.001, while measurements at 15 min following exercise did not significant differ compared to the baseline (P ˃ 0.05. There was no significant difference in retinal thickness at any location before and at 5 min and 15 min following exercise (P ˃ 0.05. Conclusion: Findings revealed that dynamic exercise causes a significant increase in CT for at least 5 min following exercise.

  1. Pet measurements of postsynaptic muscarinic and beta adrenergic receptors in the heart

    International Nuclear Information System (INIS)

    Syrota, A.

    1991-01-01

    There is ample evidence from both experimental and clinical studies that changes in β-adrenergic and muscarinic receptor density can be associated with such cardiac diseases as congestive heart failure, myocardial ischemia and infarction, cardiomyopathy, diabetes, or thyroid-induced muscle disease. Changes in B-adrenergic density also have been shown in the denervated transplanted heart. These alterations of cardiac receptors have been demonstrated in vitro on homogenates from samples collected mainly during surgery or post mortem. Recent developments of Positron Emission Tomography (PET) techniques and of radioligands suitable for cardiac receptor binding studies in vivo have made possible both the imaging and the measurement of receptor density. From these studies, important information is now available concerning physiologic and pathologic conditions, as well as alterations induced by treatment. For the investigation of myocardial B-adrenergic receptors we have used [ 11 C] CGP 12177, a potent hydrophilic antagonist of the 3-adrenergic receptor. The quantification of myocardial muscarinic receptors in vivo has been obtained with [ 11 C] MQNB, a nonmetabolized hydrophilic antagonist of the muscarinic receptor. Receptor density and affinity have been measured by a kinetic, nonequilibrium approach in an experimental protocol that provides sufficient data to determine values for all parameters from a single experiment

  2. High-resolution measurements and multichannel quantum defect analysis of spectral line shapes of autoionizing Rydberg series

    International Nuclear Information System (INIS)

    Ueda, Kiyoshi

    1997-01-01

    Spectral line shapes for autoionizing Rydberg series are briefly reviewed within the framework of multichannel quantum defect theory (MQDT). Recent high-resolution measurements and MQDT analysis for the spectra line shapes are reviewed for the mp 5 ( 2 P 1/2 )ns ' and nd ' J=1 odd spectra of the Ar, Kr, and Xe atoms (m=3,4,5 for Ar, Kr, and Xe) and the 3p 5 ( 2 P 1/2 )nd ' J=2 and 3 odd spectra of Ar*3p 5 4p excited atoms. Some results are also discussed for the Ca 4p( 2 P 1/2,3/2 )ns and nd J=1 odd spectrum and the Ba 5d( 2 P 5/2 )nd J=1 odd spectrum

  3. Spectral flux of the p-7Li(C Q-M neutron source measured by proton recoil telescope

    Directory of Open Access Journals (Sweden)

    Simakov S.P.

    2010-10-01

    Full Text Available The cyclotron-based fast neutron source at NPI produces mono-energetic neutron fields up to 35 MeV neutron energy using the p + 7Li(carbon backing reactions. To be applied for activation cross-section measurements, not only the intensity of neutron peak, but also the contribution of low-energy continuum in the spectra must be well determined. Simulations of the spectral flux from present source at a position of irradiated samples were performed using CYRIC TOF-data validated in the present work against LA150h by calculations with the transport Monte Carlo code MCNPX. Simulated spectra were tested by absolute measurements using a proton-recoil telescope technique. The recoil-proton spectrometer consisted of a shielded scattering chamber with polyethylene and carbon radiators and the ΔE1-ΔE2-E telescope of silicon-surface detectors located to the neutron beam axis at 45° in the laboratory system. Si-detectors were handled by usual data acquisition system. Dead-time – and pulse-overlap losses of events were determined from the count rate of pulse generator registered during duty cycle of accelerator operation. The proton beam charge and data were taken in the list mode for later replay and analysis. The calculations for 7Li(p,n and 12C(p,n reactions reasonably reproduce CYRIC TOF neutron source spectra. The influence of neutron source set-up (proton beam dimensions, 7Li-foil, carbon stopper, cooling medium, target support/chamber and the geometry-arrangement of irradiated sample on the spectral flux is discussed in details.

  4. White source gamma-ray production spectral measurement facilities in the USA

    International Nuclear Information System (INIS)

    Larson, D.C.; Dickens, J.K.; Nelson, R.O.; Wender, S.A.

    1991-01-01

    The two primary neutron sources for measuring gamma-ray production (GRP) cross sections for basic and applied work in the USA are the Oak Ridge Electron Linear Accelerator (ORELA) located at the Oak Ridge National Laboratory (ORNL) and the Weapons Neutron Research (WNR) facility located at the Los Alamos National Laboratory (LANL). ORELA is based on a 180-MeV electron linear accelerator, while the WNR facility uses the Los Alamos Meson Physics Facility 800 MeV proton beam to produce neutrons. The facilities collectively cover the neutron-energy range from thermal to over 700 MeV. The paper describes the present capabilities for GRP measurements at each facility. 18 refs

  5. Measurements of soft X-ray power and spectral features on Angara-5-1

    International Nuclear Information System (INIS)

    Branitskij, A.V.; Olejnik, G.M.

    1996-01-01

    In many tasks related to high temperature plasmas and ICF is it important to investigate the power and spectrum features of radiation with nanosecond resolution. Measurement methods and signal processing methods are presented. The methods were applied in experiments at the ''Angara-5-1'' facility in the 0.1-2 keV band. The time resolution was 0.5 ns. (author). 1 tab., 2 figs., 8 refs

  6. Measurements of soft X-ray power and spectral features on Angara-5-1

    Energy Technology Data Exchange (ETDEWEB)

    Branitskij, A V; Olejnik, G M [Troitsk Inst. of Innovative and Fusion Research (Russian Federation)

    1997-12-31

    In many tasks related to high temperature plasmas and ICF is it important to investigate the power and spectrum features of radiation with nanosecond resolution. Measurement methods and signal processing methods are presented. The methods were applied in experiments at the ``Angara-5-1`` facility in the 0.1-2 keV band. The time resolution was 0.5 ns. (author). 1 tab., 2 figs., 8 refs.

  7. Spectral broadening measurement of the lower hybrid waves during long pulse operation in Tore Supra

    Science.gov (United States)

    Berger-By, G.; Decampy, J.; Antar, G. Y.; Goniche, M.; Ekedahl, A.; Delpech, L.; Leroux, F.; Tore Supra Team

    2014-02-01

    On many tokamaks (C-Mod, EAST, FTU, JET, HT-7, TS), a decrease in current drive efficiency of the Lower Hybrid (LH) waves is observed in high electron density plasmas. The cause of this behaviour is believed to be: Parametric Instabilities (PI) and Scattering from Density Fluctuations (SDF). For the ITER LH system, our knowledge must be improved to avoid such effects and to maintain the LH current drive efficiency at high density. The ITPA IOS group coordinates this effort [1] and all experimental data are essential to validate the numerical codes in progress. Usually the broadening of the LH wave frequency spectrum is measured by a probe located in the plasma edge. For this study, the frequency spectrum of a reflected power signal from the LH antenna was used. In addition, the spectrum measurements are compared with the density fluctuations observed on RF probes located at the antenna mouth. Several plasma currents (0.6 to 1.4 MA) and densities up to 5.2 × 1019 m-3 have been realised on Tore Supra (TS) long pulses and with high injected RF power, up to 5.4 MW-30s. This allowed using a spectrum analyser to make several measurements during the plasma pulse. The side lobe amplitude, shifted by 20-30MHz with respect to the main peak, grows with increasing density. Furthermore, for an increase of plasma current at the same density, the spectra broaden and become asymmetric. Some parametric dependencies are shown in this paper.

  8. Comparison of calculated and measured spectral response and intrinsic efficiency for a boron-loaded plastic neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Kamykowski, E.A. (Grumman Corporate Research Center, Bethpage, NY (United States))

    1992-07-15

    Boron-loaded scintillators offer the potential for neutron spectrometers with a simplified, peak-shaped response. The Monte Carlo code, MCNP, has been used to calculate the detector characteristics of a scintillator made of a boron-loaded plastic, BC454, for neutrons between 1 and 7 MeV. Comparisons with measurements are made of spectral response for neutron energies between 4 and 6 MeV and of intrinsic efficiencies for neutrons up to 7 MeV. In order to compare the calculated spectra with measured data, enhancements to MCNP were introduced to generate tallies of light output spectra for recoil events terminating in a final capture by {sup 10}B. The comparison of measured and calculated spectra shows agreement in response shape, full width at half maximum, and recoil energy deposition. Intrinsic efficiencies measured to 7 MeV are also in agreement with the MCNP calculations. These results validate the code predictions and affirm the value of MCNP as a useful tool for development of sensor concepts based on boron-loaded plastics. (orig.).

  9. In-beam PET measurement of $^{7}Li^{3+}$ irradiation induced $\\beta^+}$-activity

    CERN Document Server

    Priegnitz, M; Parodi, K; Sommerer, F; Fiedler, F; Enghardt, W

    2008-01-01

    At present positron emission tomography (PET) is the only feasible method of an in situ and non-invasive monitoring of patient irradiation with ions. At the experimental carbon ion treatment facility of the Gesellschaft für Schwerionenforschung (GSI) Darmstadt an in-beam PET scanner has been integrated into the treatment site and lead to a considerable quality improvement of the therapy. Since ions other than carbon are expected to come into operation in future patient treatment facilities, it is highly desirable to extend in-beam PET also to other therapeutic relevant ions, e.g. 7Li. Therefore, by means of the in-beam PET scanner at GSI the β+-activity induced by 7Li3+ ions has been investigated for the first time. Targets of PMMA, water, graphite and polyethylene were irradiated with monoenergetic, pencil-like beams of 7Li3+ with energies between 129.1 A MeV and 205.3 A MeV and intensities ranging from 3.0 × 107 to 1.9 × 108 ions s−1. This paper presents the measured β+-activity profiles as well as d...

  10. Spectral broadening measurement of the lower hybrid waves during long pulse operation in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Berger-By, G.; Decampy, J.; Goniche, M.; Ekedahl, A.; Delpech, L.; Leroux, F. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Antar, G. Y. [American University of Beirut, Riad el-Solh, Beirut 1107-2020 (Lebanon); Collaboration: Tore Supra Team

    2014-02-12

    On many tokamaks (C-Mod, EAST, FTU, JET, HT-7, TS), a decrease in current drive efficiency of the Lower Hybrid (LH) waves is observed in high electron density plasmas. The cause of this behaviour is believed to be: Parametric Instabilities (PI) and Scattering from Density Fluctuations (SDF). For the ITER LH system, our knowledge must be improved to avoid such effects and to maintain the LH current drive efficiency at high density. The ITPA IOS group coordinates this effort [1] and all experimental data are essential to validate the numerical codes in progress. Usually the broadening of the LH wave frequency spectrum is measured by a probe located in the plasma edge. For this study, the frequency spectrum of a reflected power signal from the LH antenna was used. In addition, the spectrum measurements are compared with the density fluctuations observed on RF probes located at the antenna mouth. Several plasma currents (0.6 to 1.4 MA) and densities up to 5.2 × 10{sup 19} m−3 have been realised on Tore Supra (TS) long pulses and with high injected RF power, up to 5.4 MW-30s. This allowed using a spectrum analyser to make several measurements during the plasma pulse. The side lobe amplitude, shifted by 20-30MHz with respect to the main peak, grows with increasing density. Furthermore, for an increase of plasma current at the same density, the spectra broaden and become asymmetric. Some parametric dependencies are shown in this paper.

  11. Spectral measurements of howardites in support of the interpretation of the Dawn VIR spectra at Vesta

    Science.gov (United States)

    De Angelis, S.; Ammannito, E.; Di Iorio, T.; De Sanctis, M.; Mittlefehldt, D.

    2014-07-01

    The howardites, eucrites, and diogenites constitute a suite of meteorite lithologies (HED) known to be related to asteroid Vesta [1]. Howardites are physical mixtures of eucrites and diogenites. Howardites are divided in two subtypes: regolithic howardites are actually linked to the true regolith, while fragmental howardites are simple polymict breccias [2]. Mapping of Vesta's surface, as obtained with data from Visible and Infrared mapping Spectrometer (VIR) on Dawn [3,4], showed that it is mainly howarditic, with few regions of diogenite-rich and eucrite-rich terrains [5, 6]. In order to map quantitatively the distribution of lithologic types on Vesta, we are carrying on a study of a set of well-characterized howardites [7]. Spectra were measured on sample powders sieved to 75 μ m in the laboratories of the Istituto di Astrofisica e Planetologia Spaziali (IAPS-INAF) in Rome (Italy) and Brown University, in Providence (USA). Here we report about the measurements done at IAPS-INAF. The spectra of 33 samples have been acquired with the S.LAB setup, consisting in the FieldSpec Pro spectrometer (range 0.35-2.5 μ m, spatial resolution 0.5 cm^2) coupled with a goniometer (incidence i=30°, emission e=0°) [8]. Some representative spectra of the measured howardites are shown in the figure. The spectra are characterized by the two broad Fe^{2+} absorption bands near 1 and 2 μ m (BI and BII) indicative of pyroxenes. Band parameters relative to BI and BII have been calculated using the algorithm developed to process VIR spectra [4]. This enables us to compare laboratory data directly with the VIR results. Other weaker absorptions also characterize some spectra: the 0.5 μ m feature (Mn^{2+} or Cr^{3+}) and the 1.2 μ m feature possibly due to Fe^{2+} in plagioclases. The PRA04401 sample is characterized by a pyroxene-carbonaceous matter mixture [7].

  12. Beta decay rates of nuclei with 65

    Indian Academy of Sciences (India)

    of spectral averaging theory for two-body nuclear Hamiltonian in a large nuclear shell ... Beta decay rates; supernova evolution; spectral distribution method. ... level density formula, Wigner's treatment of spectral fluctuations using matrix en-.

  13. Evaluation of time domain and spectral domain optical coherence tomography in the measurement of diabetic macular edema.

    Science.gov (United States)

    Forooghian, Farzin; Cukras, Catherine; Meyerle, Catherine B; Chew, Emily Y; Wong, Wai T

    2008-10-01

    To evaluate macular thickness and volume measurements and their intrasession repeatability in two optical coherence tomography (OCT) systems: the Stratus OCT, a time domain system, and the Cirrus HD-OCT, a spectral domain system (both by Carl Zeiss Meditec, Inc., Dublin, CA), in the context of diabetic macular edema (DME). Thirty-three eyes of 33 diabetic patients with clinically significant macular edema (CSME) were scanned in a single session by a single operator on both OCT systems. Macular thickness measurements of nine standard macular subfields and total macular volume were obtained and analyzed. Bland-Altman plots were constructed to assess agreement in macular measurements. Intraclass correlation coefficients (ICCs), coefficients of repeatability (CR(W)), and coefficients of variation (CV(W)) were used to assess intrasession repeatability. Macular thickness in nine retinal subfields and macular volume were significantly higher in the Cirrus HD-OCT system compared with the Stratus OCT system. Subfield thickness and total volume measurements, respectively, were 30 to 55 microm and 3.2 mm(3) greater for the Cirrus HD-OCT system compared with the Stratus OCT system. Both Stratus OCT and Cirrus HD-OCT systems demonstrated high intrasession repeatability, with overlapping ranges for CR(W), CV(W), and ICC. Repeatability measures (CR(W) and CV(W)) differed significantly between systems in only one of nine subfields (outer temporal subfield). Absolute measures of macular thickness and volume in patients with DME differed significantly in magnitude between the Stratus OCT and Cirrus HD-OCT systems. However, both OCT systems demonstrated high intrasessional repeatability. Although the two systems may not be used interchangeably, they appear equally reliable in generating macular measurements for clinical practice and research.

  14. Simultaneous measurement of Aspartate, NAA, and NAAG using HERMES spectral editing at 3 Tesla.

    Science.gov (United States)

    Chan, Kimberly L; Saleh, Muhammad G; Oeltzschner, Georg; Barker, Peter B; Edden, Richard A E

    2017-07-15

    It has previously been shown that the HERMES method ('Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy') can be used to simultaneously edit pairs of metabolites (such as N-acetyl-aspartate (NAA) and N-acetyl aspartyl glutamate (NAAG), or glutathione and GABA). In this study, HERMES is extended for the simultaneous editing of three overlapping signals, and illustrated for the example of NAA, NAAG and Aspartate (Asp). Density-matrix simulations were performed in order to optimize the HERMES sequence. The method was tested in NAA and Asp phantoms, and applied to the centrum semiovale of the nine healthy control subjects that were scanned at 3T. Both simulations and phantom experiments showed similar metabolite multiplet patterns with good segregation of all three metabolites. In vivo measurements show consistent relative signal intensities and multiplet patterns with concentrations in agreement with literature values. Simulations indicate co-editing of glutathione, glutamine, and glutamate, but their signals do not significantly overlap with the detected aspartyl resonances. This study demonstrates that a four-step Hadamard-encoded editing scheme can be used to simultaneously edit three otherwise overlapping metabolites, and can measure NAA, NAAG, and Asp in vivo in the brain at 3T with minimal crosstalk. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Branching Ratios and Spectral Functions of $\\tau$ Decays final ALEPH measurements and physics implications

    CERN Document Server

    Schael, S.; Bruneliere, R.; De Bonis, I.; Decamp, D.; Goy, C.; Jezequel, S.; Lees, J.-P.; Martin, F.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Trocme, B.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Martinez, M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; De Filippis, N.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Barklow, T.; Buchmuller, O.; Cattaneo, M.; Clerbaux, B.; Drevermann, H.; Forty, R.W.; Frank, M.; Gianotti, F.; Hansen, J.B.; Harvey, J.; Hutchcroft, D.E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Teubert, F.; Valassi, A.; Videau, I.; Badaud, F.; Dessagne, S.; Falvard, A.; Fayolle, D.; Gay, P.; Jousset, J.; Michel, B.; Monteil, S.; Pallin, D.; Pascolo, J.M.; Perret, P.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Kraan, A.C.; Nilsson, B.S.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.-C.; Machefert, F.; Rouge, A.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bossi, F.; Capon, G.; Cerutti, F.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, G.P.; Passalacqua, L.; Kennedy, J.; Lynch, J.G.; Negus, P.; O'Shea, V.; Thompson, A.S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E.E.; Putzer, A.; Stenzel, H.; Tittel, K.; Wunsch, M.; Phys., Kirchhoff Inst.; Beuselinck, R.; Cameron, W.; Davies, G.; Dornan, P.J.; Girone, M.; Marinelli, N.; Nowell, J.; Rutherford, S.A.; Sedgbeer, J.K.; Thompson, J.C.; White, R.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C.K.; Clarke, D.P.; Ellis, G.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Pearson, M.R.; Robertson, N.A.; Smizanska, M.; van der Aa, O.; Delaere, C.; Leibenguth, G.; Lemaitre, V.; Blumenschein, U.; Holldorfer, F.; Jakobs, K.; Kayser, F.; Muller, A.-S.; Renk, B.; Sander, H.-G.; Schmeling, S.; Wachsmuth, H.; Zeitnitz, C.; Ziegler, T.; Bonissent, A.; Coyle, P.; Curtil, C.; Ealet, A.; Fouchez, D.; Payre, P.; Tilquin, A.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Manner, W.; Moser, H.-G.; Settles, R.; Villegas, M.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Hocker, Andreas; Jacholkowska, A.; Serin, L.; Veillet, J.-J.; Yuan, C.Z.; Zhang, Z.Q.; Azzurri, P.; Bagliesi, Giuseppe; Boccali, T.; Foa, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciaba, A.; Sguazzoni, G.; Spagnolo, P.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Awunor, O.; Blair, G.A.; Cowan, G.; Garcia-Bellido, A.; Green, M.G.; Medcalf, T.; Misiejuk, A.; Strong, J.A.; Teixeira-Dias, P.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Ward, J.J.; Bloch-Devaux, Brigitte; Boumediene, D.; Colas, P.; Fabbro, B.; Lancon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Tuchming, B.; Vallage, G.; Litke, A.M.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Hodgson, P.N.; Lehto, M.; Thompson, L.F.; Bohrer, A.; Brandt, S.; Grupen, C.; Hess, J.; Ngac, A.; Prange, G.; Borean, C.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S.R.; Berkelman, Karl; Cranmer, K.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P.A., III; Nielsen, J.; Pan, Y.B.; von Wimmersperg-Toeller, J.H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.; Dissertori, G.

    2005-01-01

    The full LEP-1 data set collected with the ALEPH detector at the $Z$ pole during 1991-1995 is analysed in order to measure the $\\tau$ decay branching fractions. The analysis follows the global method used in the published study based on 1991-1993 data, but several improvements are introduced, especially concerning the treatment of photons and $\\pi^0$'s. Extensive systematic studies are performed, in order to match the large statistics of the data sample corresponding to over 300\\,000 measured and identified $\\tau$ decays. Branching fractions are obtained for the two leptonic channels and eleven hadronic channels defined by their respective numbers of charged particles and $\\pi^0$'s. Using previously published ALEPH results on final states with charged and neutral kaons, corrections are applied to the hadronic channels to derive branching ratios for exclusive final states without kaons. Thus the analyses of the full LEP-1 ALEPH data are combined to yield a complete description of $\\tau$ decays, encompassing 22...

  16. Measurements of the Spectral Light Emission from Decaying High Pressure Helium Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stevefelt, J; Johansson, J

    1971-04-15

    The rate of electron density decay has been determined in a helium pulsed discharge plasma at pressures ranging from 100 to 600 Torr, primarily during the early afterglow where the electron density is from 1019 to 2 x 1017/m3. Measurements of the electrical conductivity and the absolute intensity of the light emission were made. The effective recombination rate coefficient was found to increase faster than linearly with gas pressure. The total photon emission rate was significantly lower than the effective recombination rate. Below 400 Torr pressure the afterglow was dominated by He-bands, which were related to the recombination of He{sub 2+} and He{sub 3+} ions. At higher pressures the appearance of intense lines originating from the atomic n = 3 and 23 P states is proposed to result from the He{sub 4+} recombination. Absorption measurements of the atomic metastable concentration gave evidence for recombination directly into the 23 S state. The concentration of molecular metastables was surprisingly low. The light emission had a Techi dependence, with 0 < chi < 0.35 for the intense atomic lines and 0.78 < chi < 1.10 for the molecular bands

  17. The BAT AGN Spectroscopic Survey (BASS) DR1-Spectral Measurements, Derived Quantities, and AGN Demographics

    Science.gov (United States)

    Koss, Michael; BASS Team

    2018-01-01

    We present the first catalog and data release of the Swift-BAT AGN Spectroscopic Survey (BASS). We analyze optical spectra of the majority of AGN (77%, 641/836) detected based on their 14-195 keV emission in the 70-month Swift BAT all-sky catalog. This includes redshift determination, absorption and emission line measurements, and black hole mass and accretion rate estimates for the majority of obscured and un-obscured AGN (74%, 473/641) with 340 measured for the first time. With ~90% of sources at z10^21.9 cm^-2. Seyfert 1.9 show a range of column densities. Compared to narrow line AGN in the SDSS, the X-ray selected AGN have a larger fraction of dusty host galaxies suggesting these types of AGN are missed in optical surveys. Using the most sensitive [OIII]/Hbeta and [NII]/Halpha emission line diagnostic, about half of the sources are classified as Seyferts, ~15% reside in dusty galaxies that lack an Hbeta detection, but for which the line upper limits imply either a Seyfert or LINER, ~15% are in galaxies with weak or no emission lines despite high quality spectra, and a few percent each are LINERS, composite galaxies, HII regions, or in known beamed AGN.

  18. Measurements of the Spectral Light Emission from Decaying High Pressure Helium Plasmas

    International Nuclear Information System (INIS)

    Stevefelt, J.; Johansson, J.

    1971-04-01

    The rate of electron density decay has been determined in a helium pulsed discharge plasma at pressures ranging from 100 to 600 Torr, primarily during the early afterglow where the electron density is from 10 19 to 2 x 10 17 /m 3 . Measurements of the electrical conductivity and the absolute intensity of the light emission were made. The effective recombination rate coefficient was found to increase faster than linearly with gas pressure. The total photon emission rate was significantly lower than the effective recombination rate. Below 400 Torr pressure the afterglow was dominated by He-bands, which were related to the recombination of He 2 + and He 3 + ions. At higher pressures the appearance of intense lines originating from the atomic n = 3 and 2 3 P states is proposed to result from the He 4 + recombination. Absorption measurements of the atomic metastable concentration gave evidence for recombination directly into the 2 3 S state. The concentration of molecular metastables was surprisingly low. The light emission had a T e χ dependence, with 0 < χ < 0.35 for the intense atomic lines and 0.78 < χ < 1.10 for the molecular bands

  19. A Measurement of the CP Parameter sine two beta Using Fully Reconstructed B to ccbar Decays at the BABAR Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Charles, Eric A

    2003-04-22

    This dissertation presents a measurement of the time-dependent CP-violating asymmetries in the neutral B-meson system performed with data collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample used consists of 29.7 fb{sup -1} collected at the {Upsilon}(4S) resonance and 3.9 fb{sup -1} collected off-resonance. We analyze three samples of fully-reconstructed B-meson decays: a sample of decays to CP eigenstates in the modes J/{psi} K{sub s}{sup 0}, {psi}(2S) K{sub s}{sup 0}, {chi}{sub cl} K{sub s}{sup 0}, and J/{psi} K*{sup 0} (822 events); as well as both charged (14304 events) and neutral (10457 events) B decays to flavor-eigenstates including D{sup (*)} and {pi}/{rho}/{alpha}{sub 1}. In all cases, the proper decay time difference between the reconstructed B-meson and the recoiling B-meson is determined by measuring the separation of the two decay vertices. Furthermore, the flavor of the recoiling B-meson is tagged using a neural network algorithm. We use the flavor-eigenstate samples to calibrate both the vertexing and tagging performance. We measure the amplitude of the CP asymmetry, sin2{beta} = 0.61 {+-} 0.14(stat) {+-} 0.06(syst). These results indicate the existence of indirect CP violation in the B-meson system.

  20. Review of personal monitoring techniques for the measurement of absorbed dose from external beta and low energy photon radiation

    DEFF Research Database (Denmark)

    Christensen, Poul

    1986-01-01

    The techniques available at present for personal monitoring of doses from external beta and low energy photon radiation are reviewed. The performance of currently used dosimetry systems is compared with that recommended internationally, and developments for improving the actual performance...

  1. Development of methodology for detection of long lived alpha emitters in air based on simultaneous alpha and beta activity measurement

    International Nuclear Information System (INIS)

    Kaushik, Vivek; Rath, D.P.; Vinayagami, Bhakti; Ashokkumar, P.; Umashankar, C.; Gopalakrishnan, R.K.; Kulkarni, M.S.

    2018-01-01

    Interference of the radon and thoron progeny co-deposited on the filtration media is the long-standing problem related to prompt analyses in continuous air sampling or monitoring of any potential suspect radionuclides. The solutions to this problem have been quite diverse, and included, for example, simple gross-alpha counting, the use of beta-to-alpha ratios, and the use of alpha spectrum analyses. The techniques based on beta to alpha disintegration ratios make use of the naturally occurring alpha to beta disintegration ratios and departures therefrom. This ratio is found empirically to be relatively constant. With the help of the solution of differential equation, which govern the deposition of radionuclide on filter paper, one can easily estimate theoretically the behavior of the radon progeny alpha to beta disintegration (or count) rate ratio

  2. Measuring the spectral emissivity of thermal protection materials during atmospheric reentry simulation

    Science.gov (United States)

    Marble, Elizabeth

    1996-01-01

    Hypersonic spacecraft reentering the earth's atmosphere encounter extreme heat due to atmospheric friction. Thermal Protection System (TPS) materials shield the craft from this searing heat, which can reach temperatures of 2900 F. Various thermophysical and optical properties of TPS materials are tested at the Johnson Space Center Atmospheric Reentry Materials and Structures Evaluation Facility, which has the capability to simulate critical environmental conditions associated with entry into the earth's atmosphere. Emissivity is an optical property that determines how well a material will reradiate incident heat back into the atmosphere upon reentry, thus protecting the spacecraft from the intense frictional heat. This report describes a method of measuring TPS emissivities using the SR5000 Scanning Spectroradiometer, and includes system characteristics, sample data, and operational procedures developed for arc-jet applications.

  3. The spectral and chemical measurement of pollutants on snow near South Pole, Antarctica

    Science.gov (United States)

    Casey, K. A.; Kaspari, S. D.; Skiles, S. M.; Kreutz, K.; Handley, M. J.

    2017-06-01

    Remote sensing of light-absorbing particles (LAPs), or dark colored impurities, such as black carbon (BC) and dust on snow, is a key remaining challenge in cryospheric surface characterization and application to snow, ice, and climate models. We present a quantitative data set of in situ snow reflectance, measured and modeled albedo, and BC and trace element concentrations from clean to heavily fossil fuel emission contaminated snow near South Pole, Antarctica. Over 380 snow reflectance spectra (350-2500 nm) and 28 surface snow samples were collected at seven distinct sites in the austral summer season of 2014-2015. Snow samples were analyzed for BC concentration via a single particle soot photometer and for trace element concentration via an inductively coupled plasma mass spectrometer. Snow impurity concentrations ranged from 0.14 to 7000 part per billion (ppb) BC, 9.5 to 1200 ppb sulfur, 0.19 to 660 ppb iron, 0.013 to 1.9 ppb chromium, 0.13 to 120 ppb copper, 0.63 to 6.3 ppb zinc, 0.45 to 82 parts per trillion (ppt) arsenic, 0.0028 to 6.1 ppb cadmium, 0.062 to 22 ppb barium, and 0.0044 to 6.2 ppb lead. Broadband visible to shortwave infrared albedo ranged from 0.85 in pristine snow to 0.62 in contaminated snow. LAP radiative forcing, the enhanced surface absorption due to BC and trace elements, spanned from snow to 70 W m-2 for snow with high BC and trace element content. Measured snow reflectance differed from modeled snow albedo due to specific impurity-dependent absorption features, which we recommend be further studied and improved in snow albedo models.

  4. Measurement of position dependence of spectral distribution in primary X-ray beam of CT system using compton spectroscopy

    International Nuclear Information System (INIS)

    Matsumoto, Masao; Maeda, Koji; Maeda, Koji

    2005-01-01

    Our purpose is to acquire the diagnostic x-ray spectra of the CT system easily under clinical conditions by Compton scatter spectroscopy using a high resolution Schottky CdTe detector recently developed and to estimate the quality and quantity of these spectra compared the relative exposure measured using an ionization chamber with curves measured by the reconstructed spectra. Although the spectral broadening and the fluctuation were slightly shown, the errors of the relative exposure were under 10%. Though the experimental arrangement of this method is so easy and reconstructed algorithm is simple, these results suggested that this method is little influenced by the variation of dose rates or property of the incident x rays. We therefore propose that the Compton scatter spectroscopy with the newly developed Schottky CdTe detector is suitable for measuring the diagnostic x-ray spectra of the CT system under the clinical conditions and useful for quality assurance and quality control of the clinical x-ray CT system. (author)

  5. Dual-energy approach to contrast-enhanced mammography using the balanced filter method: spectral optimization and preliminary phantom measurement.

    Science.gov (United States)

    Saito, Masatoshi

    2007-11-01

    Dual-energy contrast agent-enhanced mammography is a technique of demonstrating breast cancers obscured by a cluttered background resulting from the contrast between soft tissues in the breast. The technique has usually been implemented by exploiting two exposures to different x-ray tube voltages. In this article, another dual-energy approach using the balanced filter method without switching the tube voltages is described. For the spectral optimization of dual-energy mammography using the balanced filters, we applied a theoretical framework reported by Lemacks et al. [Med. Phys. 29, 1739-1751 (2002)] to calculate the signal-to-noise ratio (SNR) in an iodinated contrast agent subtraction image. This permits the selection of beam parameters such as tube voltage and balanced filter material, and the optimization of the latter's thickness with respect to some critical quantity-in this case, mean glandular dose. For an imaging system with a 0.1 mm thick CsI:T1 scintillator, we predict that the optimal tube voltage would be 45 kVp for a tungsten anode using zirconium, iodine, and neodymium balanced filters. A mean glandular dose of 1.0 mGy is required to obtain an SNR of 5 in order to detect 1.0 mg/cm2 iodine in the resulting clutter-free image of a 5 cm thick breast composed of 50% adipose and 50% glandular tissue. In addition to spectral optimization, we carried out phantom measurements to demonstrate the present dual-energy approach for obtaining a clutter-free image, which preferentially shows iodine, of a breast phantom comprising three major components-acrylic spheres, olive oil, and an iodinated contrast agent. The detection of iodine details on the cluttered background originating from the contrast between acrylic spheres and olive oil is analogous to the task of distinguishing contrast agents in a mixture of glandular and adipose tissues.

  6. Dual-energy approach to contrast-enhanced mammography using the balanced filter method: Spectral optimization and preliminary phantom measurement

    International Nuclear Information System (INIS)

    Saito, Masatoshi

    2007-01-01

    Dual-energy contrast agent-enhanced mammography is a technique of demonstrating breast cancers obscured by a cluttered background resulting from the contrast between soft tissues in the breast. The technique has usually been implemented by exploiting two exposures to different x-ray tube voltages. In this article, another dual-energy approach using the balanced filter method without switching the tube voltages is described. For the spectral optimization of dual-energy mammography using the balanced filters, we applied a theoretical framework reported by Lemacks et al. [Med. Phys. 29, 1739-1751 (2002)] to calculate the signal-to-noise ratio (SNR) in an iodinated contrast agent subtraction image. This permits the selection of beam parameters such as tube voltage and balanced filter material, and the optimization of the latter's thickness with respect to some critical quantity--in this case, mean glandular dose. For an imaging system with a 0.1 mm thick CsI:Tl scintillator, we predict that the optimal tube voltage would be 45 kVp for a tungsten anode using zirconium, iodine, and neodymium balanced filters. A mean glandular dose of 1.0 mGy is required to obtain an SNR of 5 in order to detect 1.0 mg/cm 2 iodine in the resulting clutter-free image of a 5 cm thick breast composed of 50% adipose and 50% glandular tissue. In addition to spectral optimization, we carried out phantom measurements to demonstrate the present dual-energy approach for obtaining a clutter-free image, which preferentially shows iodine, of a breast phantom comprising three major components - acrylic spheres, olive oil, and an iodinated contrast agent. The detection of iodine details on the cluttered background originating from the contrast between acrylic spheres and olive oil is analogous to the task of distinguishing contrast agents in a mixture of glandular and adipose tissues

  7. Understanding the aerosol information content in multi-spectral reflectance measurements using a synergetic retrieval algorithm

    Directory of Open Access Journals (Sweden)

    D. Martynenko

    2010-11-01

    Full Text Available An information content analysis for multi-wavelength SYNergetic AErosol Retrieval algorithm SYNAER was performed to quantify the number of independent pieces of information that can be retrieved. In particular, the capability of SYNAER to discern various aerosol types is assessed. This information content depends on the aerosol optical depth, the surface albedo spectrum and the observation geometry. The theoretical analysis is performed for a large number of scenarios with various geometries and surface albedo spectra for ocean, soil and vegetation. When the surface albedo spectrum and its accuracy is known under cloud-free conditions, reflectance measurements used in SYNAER is able to provide for 2–4° of freedom that can be attributed to retrieval parameters: aerosol optical depth, aerosol type and surface albedo.

    The focus of this work is placed on an information content analysis with emphasis to the aerosol type classification. This analysis is applied to synthetic reflectance measurements for 40 predefined aerosol mixtures of different basic components, given by sea salt, mineral dust, biomass burning and diesel aerosols, water soluble and water insoluble aerosols. The range of aerosol parameters considered through the 40 mixtures covers the natural variability of tropospheric aerosols. After the information content analysis performed in Holzer-Popp et al. (2008 there was a necessity to compare derived degrees of freedom with retrieved aerosol optical depth for different aerosol types, which is the main focus of this paper.

    The principle component analysis was used to determine the correspondence between degrees of freedom for signal in the retrieval and derived aerosol types. The main results of the analysis indicate correspondence between the major groups of the aerosol types, which are: water soluble aerosol, soot, mineral dust and sea salt and degrees of freedom in the algorithm and show the ability of the SYNAER to

  8. The measurement and calculation of the kinetic parameter {beta}{sub eff}/{Lambda} of a small high-temperature like, critical system

    Energy Technology Data Exchange (ETDEWEB)

    Wallerbos, E.J.M.; Hoogenboom, J.E. [Interfaculty Reactor Inst., Delft Univ. of Technology, Delft (Netherlands)

    1998-01-01

    This paper demonstrates that it is well possible to determine the kinetic parameter {beta}{sub eff}/{Lambda} in a neutronically very slow system by means of noise measurements in the critical state. The advantages of this technique are that it can be conducted in a critical reactor directly, and that no special measurement equipment is needed. The comparison to calculated values for four configurations, which differ in the amount of moderation in the core region, shows a satisfactory agreement. (author)

  9. Methods and results of reconstruction of 131I concentration in milk from total beta-activity measurements in Belarus after Chernobyl

    International Nuclear Information System (INIS)

    Savkin, Mikhail; Shinkarev, Sergey; Titov, Alexey

    2008-01-01

    Full text: During the first few weeks following the Chernobyl accident a large scale monitoring of radioactive contamination of foodstuffs locally produced was carried out in the most contaminated areas of Belarus. Due to a lack of spectrometric instruments, radiometric devices (DP-100) were used for beta activity measurements mostly of milk and milk products. Because the intake of 131 I with milk was the main contributor of the thyroid dose for the Belarus population, it is very important to reconstruct levels of 131 I in milk for Belarus settlements. The purpose of the paper is to present the methods and results of assessing the 13I concentration in milk based on historical records of total-beta activity measurements carried out in April-June 1986 in Belarus. The results of reconstruction of the 131 I concentration in milk will be used in on-going epidemiologic studies of a cohort of Belarus children. About 20,000 total-beta activity measurements were used in the analysis; for about 50% of those, the measurement result exceeded the minimum detectable activity. Estimates of 131 I concentration in milk at the date of sampling and of time-integrated milk concentrations were reconstructed for 482 settlements in Gomel Oblast and for 100 settlements in Mogilev Oblast, the most contaminated areas in Belarus, where at least one milk measurement was available. The assessment of the 131 I concentrations in milk involved: 1) An analysis of the calibration coefficients of the detectors for radionuclides available in milk (the main radionuclides were 131 I, 132 4Cs, 137 Cs, 89 Sr, 90 Sr); and 2) An assessment of the relative activity distribution of those radionuclides in milk. Only measurements made before 21 May 1986 were considered to be reliable, as the measurements conducted late May and in June were found to be unreliable because of the decrease in 131 I concentrations and the growing influence of other radionuclides with longer half-lives. Analysis of multiple

  10. Inelastic neutron scattering and spectral measurements of advanced cold moderator materials

    International Nuclear Information System (INIS)

    Conrad, H.; Prager, M.; Nuenighoff, K.; Pohl, C.; Kuhs, W.F.

    2004-01-01

    Inelastic neutron scattering with emphasis on energetically low lying modes as well as cold neutron leakage measurements have been performed on four prospective advanced cold moderator materials. Employing the time-of-flight instrument SV29 at the Juelich FRJ-2 reactor, spectra have been obtained from synthetic methane clathrate, tetrahydro-furane (THF) clathrate, 1,3,5-trimethyl-benzene (mesitylene) and light water ice at several temperatures between 2 K and 70 K. Clearly separated excitations at energy transfers of ±1 meV, +2 meV and +3 meV have been observed with synthetic methane clathrate. In mesitylene a wealth of low lying excitations have been observed. In the quenched phase we found lines at 4.7, 7.2, 9.6, 13.6, 15.4, 18.4, 19.0, 23.0, 29.5 and 34.3 meV, respectively. In the annealed phase, we observed significant shifts with the majority of lines. The lowest lying lines now are located at 7.0, 8.5 and 10.5 meV, respectively. In hexagonal ice at T=2 K up to now unreported low lying energy levels were found at energy transfers of 1.8 meV and 2.8 meV. An additional line at about 10 meV could be detected in THF clathrate. Mesitylene, synthetic methane clathrate and water ice, all at T=20 K, have been tested as moderators at the Juelich spallation mock-up JESSICA. The expected gain in neutron leakage current at energies around 2 meV as compared to conventional liquid hydrogen moderators has been observed for methane clathrate and mesitylene. (orig.)

  11. Comparison of choroidal thickness measurements between spectral-domain OCT and swept-source OCT in normal and diseased eyes

    Directory of Open Access Journals (Sweden)

    Zafar S

    2016-11-01

    Full Text Available Sidra Zafar,1 MA Rehman Siddiqui,2,3 Rida Shahzad1 1Medical College, Aga Khan University Hospital, 2Department of Ophthalmology, Shahzad Eye Hospital, 3South City Hospital, Karachi, Pakistan Purpose: Sub-foveal choroidal thickness (SFCT is affected in many ocular diseases. The aim of this study was to compare SFCT measurements between Topcon 3D 2000 spectral-domain optical coherence tomography (SD-OCT and Topcon swept-source OCT (SS-OCT, with different laser wavelengths, in normal and diseased populations. Materials and methods: This was a prospective, cross-sectional, noninterventional study including 27 normal volunteers and 27 participants with retinal disease. OCT scans were performed sequentially and under standardized conditions using both SD-OCT and SS-OCT. The OCT scans were evaluated by two independent graders. Paired t-tests and intraclass correlation coefficients (ICCs were used to assess the statistically significant difference between SFCT measurements as measured by the two devices. Results: Mean SFCT measurements for all 54 participants were 264.9±103.1 µm using SD-OCT (range: 47–470 µm and 278.5±110.5 µm using SS-OCT (range: 56–502 µm, with an inter-device ICC of 0.850. Greater variability was noted in the diseased eyes. Inter-device ICCs were 0.870 (95% CI; 0.760–0.924 and 0.840 (95% CI; 0.654–0.930 for normal and diseased eyes, respectively. However, the difference was not statistically significant (P=0.132. Conclusion: Both machines reliably measure SFCT. Larger studies are needed to confirm these findings. Keywords: choroidal imaging, diseased, normal, SD-OCT, SS-OCT

  12. Searches for massive neutrinos in nuclear beta decay

    International Nuclear Information System (INIS)

    Jaros, J.A.

    1992-10-01

    The status of searches for massive neutrinos in nuclear beta decay is reviewed. The claim by an ITEP group that the electron antineutrino mass > 17eV has been disputed by all the subsequent experiments. Current measurements of the tritium beta spectrum limit m bar νe < 10 eV. The status of the 17 keV neutrino is reviewed. The strong null results from INS Tokyo and Argonne, and deficiencies in the experiments which reported positive effects, make it unreasonable to ascribe the spectral distortions seen by Simpson, Hime, and others to a 17keV neutrino. Several new ideas on how to search for massive neutrinos in nuclear beta decay are discussed

  13. Do different spectral domain OCT hardwares measure the same? Comparison of retinal thickness using third-party software

    DEFF Research Database (Denmark)

    Sander, Birgit; Ahmad Al-Abiji, Hajer; Kofod, Mads

    2015-01-01

    Purpose Spectral-domain optical coherence tomographies (OCTs) from different companies do not give identical retinal thicknesses. The purpose of this study was to evaluate if differences in thickness when using a spectral domain Cirrus OCT or a Heidelberg Spectralis are due to hardware difference...

  14. Fine structure and spectral index measurements in natural uranium - graphite lattices; Mesures fines dans des reseaux a graphite

    Energy Technology Data Exchange (ETDEWEB)

    Cogne, F; Journet, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The experiments described in this report have been carried out for the most part in the critical facility MARIUS, and a few during the start up of the EDF-1 power reactor. The first part deals with the fine structure measurements made in various lattices and with their analysis. Integration over the neutron spectrum of the mono-kinetic disadvantage factor derived by the A.B.H method yields results in good agreement with the experiments. The second part deals with spectral indexes measurements (Pu/U, In/Mn) made at room temperature in MARIUS. Comparison are made of experiments with calculations using various thermalization models. Experiments carried out at higher temperatures in EDF-1 are also described. (authors) [French] Les mesures decrites dans ce rapport ont ete faites pour la plupart dans l'empilement critique MARIUS sur des reseaux a graphite-uranium naturel. Une premiere partie traite des mesures de structure fine faites dans differents reseaux et de leur interpretation. On montre en particulier qu'une integration sur le spectre d'un calcul monocinetique type A.B.H. rend bien compte des experiences. Dans une deuxieme partie, on donne les resultats de mesures d'indices de spectre Pu/U et In/Mn faites sur des reseaux froids a MARIUS et leur comparaison avec les differents modeles de calculs de thermalisation. On donne egalement les resultats de quelques mesures en temperature effectuees lors du demarrage du reacteur EDF-1. (auteurs)

  15. STRUCTURAL PHASE TRANSITION OF ALIPHATIC NYLONS VIEWED FROM THE WAXD/SAXS AND VIBRATIONAL SPECTRAL MEASUREMENTS AND MOLECULAR DYNAMICS CALCULATION

    Institute of Scientific and Technical Information of China (English)

    Kohji Tashiro

    2007-01-01

    The crystalline phase transition of aliphatic nylon 10/10 has been investigated on the basis of the simultaneous measurement of wide-angle and small-angle X-ray scatterings, the infrared spectral measurement and the molecular dynamics calculation. An interpretation of infrared spectra taken for a series of nylon samples and the corresponding model compounds was successfully made, allowing us to assign the infrared bands of the planar-zigzag methylene segments reasonably. As a result the methylene segmental parts of molecular chains were found to experience an order-to-disorder transition in the Brill transition region, where the intermolecular hydrogen bonds are kept alive although the bond strength becomes weaker at higher temperature. The small-angle X-ray scattering data revealed a slight change in lamellar stacking mode in the transition region. The crystal structure has been found to change more remarkably in the temperature region immediately below the melting point, where the conformationally disordered chains experienced drastic rotational and translational motions without any constraints by hydrogen bonds, and the lamellar thickness increased largely along the chain axis. These experimental results were reasonably reproduced by the molecular dynamics calculation performed at the various temperatures.

  16. Impacts of age and sex on retinal layer thicknesses measured by spectral domain optical coherence tomography with Spectralis.

    Science.gov (United States)

    Nieves-Moreno, María; Martínez-de-la-Casa, José M; Morales-Fernández, Laura; Sánchez-Jean, Rubén; Sáenz-Francés, Federico; García-Feijoó, Julián

    2018-01-01

    To examine differences in individual retinal layer thicknesses measured by spectral domain optical coherence tomography (SD-OCT) (Spectralis®) produced with age and according to sex. Cross-sectional, observational study. The study was conducted in 297 eyes of 297 healthy subjects aged 18 to 87 years. In one randomly selected eye of each participant the volume and mean thicknesses of the different macular layers were measured by SD-OCT using the instrument's macular segmentation software. Volume and mean thickness of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigmentary epithelium (RPE) and photoreceptor layer (PR). Retinal thickness was reduced by 0.24 μm for every one year of age. Age adjusted linear regression analysis revealed mean GCL, IPL, ONL and PR thickness reductions and a mean OPL thickness increase with age. Women had significantly lower mean GCL, IPL, INL, ONL and PR thicknesses and volumes and a significantly greater mRNFL volume than men. The thickness of most retinal layers varies both with age and according to sex. Longitudinal studies are needed to determine the rate of layer thinning produced with age.

  17. Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range

    Energy Technology Data Exchange (ETDEWEB)

    Canada, J.; Maj, A. [Departamento de Termodinamica Aplicada, Universidad Politecnica de Valencia, Camino de Vera, s/n. 46022 Valencia (Spain); Utrillas, M.P.; Martinez-Lozano, J.A.; Pedros, R.; Gomez-Amo, J.L. [Departamento de Fisica de la Tierra y Termodinamica, Facultat de Fisica, Universitat de Valencia, 46100 Burjassot (Valencia) (Spain)

    2007-10-15

    An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectro radiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330-1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth. (author)

  18. Examining the Spectral Separability of Prosopis glandulosa from Co-Existent Species Using Field Spectral Measurement and Guided Regularized Random Forest

    Directory of Open Access Journals (Sweden)

    Nyasha Mureriwa

    2016-02-01

    Full Text Available The invasive taxa of Prosopis is rated the world’s top 100 unwanted species, and a lack of spatial data about the invasion dynamics has made the current control and monitoring methods unsuccessful. This study thus tests the use of in situ spectroscopy data with a newly-developed algorithm, guided regularized random forest (GRRF, to spectrally discriminate Prosopis from coexistent acacia species (Acacia karroo, Acacia mellifera and Ziziphus mucronata in the arid environment of South Africa. Results show that GRRF was able to reduce the high dimensionality of the spectroscopy data and select key wavelengths (n = 11 for discriminating amongst the species. These wavelengths are located at 356.3 nm, 468.5 nm, 531.1 nm, 665.2 nm, 1262.3 nm, 1354.1 nm, 1361.7 nm, 1376.9 nm, 1407.1 nm, 1410.9 nm and 1414.6 nm. The use of these selected wavelengths increases the overall classification accuracy from 79.19% and a Kappa value of 0.7201 when using all wavelengths to 88.59% and a Kappa of 0.8524 when the selected wavelengths were used. Based on our relatively high accuracies and ease of use, it is worth considering the GRRF method for reducing the high dimensionality of spectroscopy data. However, this assertion should receive considerable additional testing and comparison before it is accepted as a substitute for reliable high dimensionality reduction.

  19. Radiometric Normalization of Temporal Images Combining Automatic Detection of Pseudo-Invariant Features from the Distance and Similarity Spectral Measures, Density Scatterplot Analysis, and Robust Regression

    Directory of Open Access Journals (Sweden)

    Ana Paula Ferreira de Carvalho

    2013-05-01

    Full Text Available Radiometric precision is difficult to maintain in orbital images due to several factors (atmospheric conditions, Earth-sun distance, detector calibration, illumination, and viewing angles. These unwanted effects must be removed for radiometric consistency among temporal images, leaving only land-leaving radiances, for optimum change detection. A variety of relative radiometric correction techniques were developed for the correction or rectification of images, of the same area, through use of reference targets whose reflectance do not change significantly with time, i.e., pseudo-invariant features (PIFs. This paper proposes a new technique for radiometric normalization, which uses three sequential methods for an accurate PIFs selection: spectral measures of temporal data (spectral distance and similarity, density scatter plot analysis (ridge method, and robust regression. The spectral measures used are the spectral angle (Spectral Angle Mapper, SAM, spectral correlation (Spectral Correlation Mapper, SCM, and Euclidean distance. The spectral measures between the spectra at times t1 and t2 and are calculated for each pixel. After classification using threshold values, it is possible to define points with the same spectral behavior, including PIFs. The distance and similarity measures are complementary and can be calculated together. The ridge method uses a density plot generated from images acquired on different dates for the selection of PIFs. In a density plot, the invariant pixels, together, form a high-density ridge, while variant pixels (clouds and land cover changes are spread, having low density, facilitating its exclusion. Finally, the selected PIFs are subjected to a robust regression (M-estimate between pairs of temporal bands for the detection and elimination of outliers, and to obtain the optimal linear equation for a given set of target points. The robust regression is insensitive to outliers, i.e., observation that appears to deviate

  20. First direct observation of bound-state beta-decay. Measurements of branching and lifetime of {sup 207}Tl{sup 81+} fragments

    Energy Technology Data Exchange (ETDEWEB)

    Boutin, D.

    2005-08-01

    The first experimental observation of bound-state beta-decay showed, that due solely to the electron stripping, a stable nuclide, e.g. {sup 163}Dy, became unstable. Also a drastic modification of the half-life of bare {sup 187}Re, from 4.12(2) x 10{sup 10} years down to 32.9(20) years, could be observed. It was mainly due to the possibility for the mother nuclide to decay into a previously inaccessible nuclear level of the daughter nuclide. It was proposed to study a nuclide where this decay mode was competing with continuum-state beta-decay, in order to measure their respective branchings. The ratio {beta}{sub b}/{beta}{sub c} could also be evaluated for the first time. {sup 207}Tl was chosen due to its high atomic number, and Q-value of about 1.4 MeV, small enough to enhance the {beta}{sub b} probability and large enough to allow the use of time-resolved Schottky Mass Spectrometry (SMS) to study the evolution of mother and bound-state beta-decay daughter ions. The decay properties of the ground state and isomeric state of {sup 207}Tl{sup 81+} have been investigated at the GSI accelerator facility in two separate experiments. For the first time {beta}-decay where the electron could go either to a bound state (atomic orbitals) and lead to {sup 207}Pb{sup 81+} as a daughter nuclide, or to a continuum state and lead to {sup 207}Pb{sup 82+}, has been observed. The respective branchings of these two processes could be measured as well. The deduced total nuclear half-life of 255(17) s for {sup 207}Tl{sup 81+}, was slightly modified with respect to the half-life of the neutral atom of 286(2) s. It was nevertheless in very good agreement with calculations based on the assumption that the beta-decay was following an allowed type of transition. The branching {beta}{sub b}/{beta}{sub c}=0.192(20), was also in very good agreement with the same calculations. The application of stochastic precooling allowed to observe in addition the 1348 keV short-lived isomeric state of {sup