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Sample records for absolute radioactivity measurements

  1. Recent Progress in Liquid Scintillation Counting System for Absolute Radioactivity Measurement

    2011-01-01

    The triple to double coincidence ratio (TDCR) method is an absolute activity measurement method in liquid scintillation counting, especially developed for pure β- and EC-emitters activity standardization. Such a liquid scintillation counting system is now

  2. Measuring the absolute disintegration rate of a radioactive gas with a moveable endplate discharge counter (MEP) and theoretical calculation of wall effect

    A precision built moveable endplate Geiger-Mueller counter was used to measure the absolute disintegration rate of a beta-emitting radioactive gas. A Geiger-Mueller counter used for measuring gaseous radioactivity has 85Kr (beta energy, 0.67 MeV). The wall effect calculation is readily extendable to other beta energies

  3. Calibrated radioactive sources - absolute measurements using a 4π β-γ apparatus

    In this paper, the principle of the standardization of the radioisotopes by the 4π β - γ 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)

  4. Calculations of wall effect in proportional counter for absolute radioactivity measurements of gaseous radioisotopes

    Count loss by wall effect was calculated with EGS4 code. Calculated results agreed well with experimental results measured with pressure extrapolation method. In this calculation AE, AP and ECUT, PCUT are better to be set at lower values. Because EGS4 code is not so suited for very low energy of beta-ray, for those samples which emit beta-rays with lower energy than 14C, EGS4 is unsuited to be used for calculation of wall effect. (J.P.N.)

  5. Measurement of the absolute activity of alpha or beta emitters by measuring product nuclei (daughter) activity increase or by studing its radioactive decay

    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 UO2(NO3)2 6H2O 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)

  6. Measurement of the absolute \

    Aunion, Jose Luis Alcaraz; /Barcelona, IFAE

    2010-07-01

    This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 10{sup 20} protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 10{sup 20} POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the absolute CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.

  7. Absolute neutrino mass measurements

    Wolf, Joachim

    2011-10-01

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2β) searches, single β-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy. Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium β-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope (137Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R&D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2β decay and single β-decay.

  8. Measuring the absolute disintegration rate of a radioactive gas with a moveable endplate discharge counter (MEP) and theoretical calculation of wall effect

    Jaffey, A.H.; Gray, J.; Bentley, W.C.; Lerner, J.L.

    1987-09-01

    A precision built moveable endplate Geiger-Mueller counter was used to measure the absolute disintegration rate of a beta-emitting radioactive gas. A Geiger-Mueller counter used for measuring gaseous radioactivity has <100% counting efficiency owing to two factors: (1) ''end effect,'' due to decreased and distorted fields at the ends where wire-insulator joints are placed, and (2) ''wall effect,'' due to non-ionization by beta particles emitted near to and heading into the wall. The end effect was evaluated by making one end of the counter movable and measuring counting rates at a number of endplate positions. Much of the wall effect was calculated theoretically, based on known data for primary ionization of electrons as a function of energy and gas composition. Corrections were then made for the ''shakeoff'' effect in beta decay and for backscattering of electrons from the counter wall. Measurements and calculations were made for a sample of /sup 85/Kr (beta energy, 0.67 MeV). The wall effect calculation is readily extendable to other beta energies.

  9. Measuring radioactivity

    Research work at University College Dublin uses brown fucus seaweed as an indicator of contamination levels of iodine, caesium, ruthenium and plutonium. 20 sites around the Irish coast are regularly monitored, and the effect of discharges from the Sellafield reprocessing plant can thus be assessed. High resolution alpha spectroscopy is used to measure plutonium levels, which have been found to be considerably higher in the Irish Sea and along the Atlantic seaboard than those found along the Galician coast of Spain. This work now serves as a baseline against which the effects of fallout due to the Chernobyl fire can be measured

  10. Measurement of the absolute speed is possible?

    Sergey V. Shevchenko; Tokarevsky, Vladimir V.

    2016-01-01

    One of popular problems, which  are experimentally studied in physics in a long time, is the testing of the special relativity theory, first of all – measurements of isotropy and constancy of light speed; as well as attempts to determine so called “absolute speed”, i.e. the Earth speed in the absolute spacetime (absolute reference frame), if this spacetime (ARF) exists.  Corresponding experiments aimed at the measuring of proper speed of some reference frame in oth...

  11. Environmental radioactivity. Measurement and monitoring

    The contribution on environmental radioactivity covers the following issues: natural and artificial radioactivity; continuous monitoring of radioactivity; monitoring authorities and measurement; radioactivity in the living environment; radioactivity in food and feeding stuff; radioactivity of game meat and wild-growing mushrooms; radioactivity in mines; radioactivity in the research center Rossendorf.

  12. Absolute calibration in vivo measurement systems

    Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs

  13. Radioactivity and its measurement

    Mann, W B; Garfinkel, S B

    1980-01-01

    Begins with a description of the discovery of radioactivity and the historic research of such pioneers as the Curies and Rutherford. After a discussion of the interactions of &agr;, &bgr; and &ggr; rays with matter, the energetics of the different modes of nuclear disintegration are considered in relation to the Einstein mass-energy relationship as applied to radioactive transformations. Radiation detectors and radioactivity measurements are also discussed

  14. Absolute radioactivity measurements of sup 1 sup 5 sup 3 Sm, sup 1 sup 8 sup 8 Re, sup 8 sup 9 Sr and national comparisons

    Wang Jian Qing; Yao Yan Ling; Jia Xue Wen

    2003-01-01

    sup 1 sup 5 sup 3 Sm and sup 1 sup 8 sup 8 Re are short half-life nuclides and sup 8 sup 9 Sr is one of pure beta-decay nuclide, these nuclides have being applied to nuclear medicine. It's very important to carry out comparisons for radioactivity standardization of these nuclides. Several laboratories in China including our laboratory took part in the comparisons. The results from our laboratory are in good agreement with the mean values

  15. Precise Measurement of the Absolute Fluorescence Yield

    Ave, M.; Bohacova, M.; Daumiller, K.; Di Carlo, P.; di Giulio, C.; San Luis, P. Facal; Gonzales, D.; Hojvat, C.; Hörandel, J. R.; Hrabovsky, M.; Iarlori, M.; Keilhauer, B.; Klages, H.; Kleifges, M.; Kuehn, F.; Monasor, M.; Nozka, L.; Palatka, M.; Petrera, S.; Privitera, P.; Ridky, J.; Rizi, V.; D'Orfeuil, B. Rouille; Salamida, F.; Schovanek, P.; Smida, R.; Spinka, H.; Ulrich, A.; Verzi, V.; Williams, C.

    2011-09-01

    We present preliminary results of the absolute yield of fluorescence emission in atmospheric gases. Measurements were performed at the Fermilab Test Beam Facility with a variety of beam particles and gases. Absolute calibration of the fluorescence yield to 5% level was achieved by comparison with two known light sources--the Cherenkov light emitted by the beam particles, and a calibrated nitrogen laser. The uncertainty of the energy scale of current Ultra-High Energy Cosmic Rays experiments will be significantly improved by the AIRFLY measurement.

  16. ABSOLUTE MEASUREMENT OF THE GANIL BEAM ENERGY

    CASANDJIAN, JM; MITTIG, W; BEUNARD, R; GAUDARD, L; LEPINESZILY, A; VILLARI, ACC; AUGER, G; BIANCHI, L; CUNSOLO, A; FOTI, A; LICHTENTHALER, R; PLAGNOL, E; SCHUTZ, Y; SIEMSSEN, RH; WIELECZKO, JP

    1993-01-01

    The energy of the GANIL cyclotron beam was measured on-line during the Pb-208 + Pb-208 elastic scattering experiment ''Search for Color van der Waals Force in the Pb-208 + Pb-208 Mott scattering'' with an absolute precision of 7 x 10(-5) at approximately 1.0 GeV, which represents an improvement of o

  17. An absolute measure for a key currency

    Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

    It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no absolute general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an absolute measure for a key currency based on the strength of the periodicity. Moreover, we analyze the time evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.

  18. Measurement of absolute gravity acceleration in Firenze

    M. de Angelis

    2011-01-01

    Full Text Available This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy. In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0 μGal and (980 492 048.3 ± 3.0 μGal for the European Laboratory for Non-Linear Spectroscopy (LENS and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

  19. Determination of Corrections in the Absolute Measurement of 137Cs

    A method, of determining corrections in absolute measurements of 137Cs by 4π proportional counter is described. The correction for self-absorption of 137Cs beta particles from sources formed by vacuum deposition of CsCl on standard carrier films was determined. These samples, which had negligible self-absorption, were measured by 4π counter. The radioactive substance on the film was then dissolved, and by the addition of carrier was converted to a form similar to that of sources usually used for absolute measurement. The correction determined for self-absorption was higher than the value expected from comparison with other radionuclides having near Eβmax. The correction for internal conversion coefficient and gamma efficiency of the beta detector was determined with 137mBa samples. Barium was separated as BaSO4 precipitate and deposited on a standard carrier film used for absolute measurement with a layer thickness of about 1 mg/cm2. These samples were simultaneously measured by means of a 4π beta proportional counter and a Nal(Tl) scintillation counter. From corresponding counting rates in both counters, and from both known efficiencies, the value for a correction appropriate to one disintegration of 137mBa was calculated. The values measured were used further for computation of the internal conversion coefficient and the half-life of 137'mBa, which was ascertained to be 155 ± 3 s. (author)

  20. An All Fiber White Light Interferometric Absolute Temperature Measurement System

    Jeonggon Harrison Kim

    2008-01-01

    Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement system is presented using the previously proposed signal processing algorithm. Stability and absolute temperature measurement were demonstrated. These two tests demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe and 0.0005 fringe, resp...

  1. Absolute Distance Measurements with Tunable Semiconductor Laser

    Mikel, Břetislav; Číp, Ondřej; Lazar, Josef

    T118, - (2005), s. 41-44. ISSN 0031-8949 R&D Projects: GA AV ČR(CZ) IAB2065001 Keywords : tunable laser * absolute interferometer Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.661, year: 2004

  2. On The Absolute Measurement of Some Nuclear Material Samples

    A state with nuclear activities should establish a system capable of controlling all nuclear material (NM) under its authority. Continuous improvement of a measuring system is an essential mandate such controlling system. Measurements of NM using absolute methods could eliminate the dependency on NM standards, which are necessary for other relative or semi-absolute methods. In this work, an absolute method was used to estimate uranium contents in some NM samples. NM was measured by an absolute method through combination of experimental measurements and Monte Carlo calculations

  3. Low-level Radioactivity Measurements

    The low-level radioactivity measurements service performs measurements of alpha or beta emitters on various types of low-radioactivity samples (biological and environmental) from internal and external clients. to maintain and develop techniques concerning the measurement of low-level radioactivity of alpha and beta emitting radionuclides in environmental or biological samples; to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters and alpha-spectrometers); to support and advise the nuclear and non-nuclear industry on problems of radioactive contamination or low level radioactivity measurements; to maintain the quality assurance system according to the ISO17025 standard for which we obtained the Beltest accreditation in 1998; to assess the internal dose from occupational intakes of radionuclides for workers of the nuclear industry;

  4. Radioactivity measurements principles and practice

    Mann, W B; Spernol, A

    2012-01-01

    The authors have addressed the basic need for internationally consistent standards and methods demanded by the new and increasing use of radioactive materials, radiopharmaceuticals and labelled compounds. Particular emphasis is given to the basic and practical problems that may be encountered in measuring radioactivity. The text provides information and recommendations in the areas of radiation protection, focusing on quality control and the precautions necessary for the preparation and handling of radioactive substances. New information is also presented on the applications of both traditiona

  5. Neutronic measurements of radioactive waste

    This document presents the general matters involved in the radioactive waste management and the different non destructive assays of radioactivity. The neutronic measurements used in the characterization of waste drums containing emitters are described with more details, especially the active neutronic interrogation assays with prompt or delayed neutron detection: physical principle, signal processing and evaluation of the detection limit. (author)

  6. High-precision absolute coordinate measurement using frequency scanned interferometry

    We reported previously on measurements of absolute distance with frequency scanned interferometry (FSI) method [1, 2]. In this paper, we extend the FSI method into 2-dimensional and 3-dimensional high-precision absolute coordinate measurements using a single laser. Absolute position is determined by several related absolute distances measured simultaneously. The achieved precision on X and Y in 2- and in 3-dimensional measurements is confirmed to be below 1 μm, while the precision in Z (in 3D case) is found to be about 2 μm. The last one is limited by the accuracy of the available translational stage used in the tests. A much more powerful laser and a better real-time data acquirement system will be required in case of measurements of larger absolute distances

  7. Environmental radioactivity measurements in Switzerland

    The survey of the environmental radioactivity in Switzerland is the responsibility of the Swiss Federal Radioactivity Surveillance Commission KUeR. All laboratories specializing in environmental radioactivity measurements in Switzerland take part in the KUeR-sampling and measurement program. This program includes measurements of air, water, soil, grass, important food sources as well as the body radioactivity of human beings. Special environmental sampling and measurement programs are implemented in the vicinity of the operating Nuclear Power Stations (NPS) and those under construction. To confirm compliance with the licensing requirements the various activities include all measurements to assess any radiological consequences of NPS operation. Such requirements are drawn up for each power-station by the Nuclear Safety Division of the Swiss Federal Office of Energy (ASK) and the KUeR. (author)

  8. Absolute measurement of β activities and application to the determination of neutronic densities

    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 β sources became the central object of this work. In a first part, we will develop the methods of absolute determination for β activities. The use of a 4π 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.)

  9. Absolute measurements of fast neutrons using yttrium

    Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic recalibration. The total yttrium efficiency for detecting 2.45 MeV neutrons was determined to be fn∼4.1x10-4 with an uncertainty of about 0.27%. The yttrium detector was employed in the NX2 plasma focus experiments and showed the neutron yield of the order of 108 neutrons per discharge.

  10. Measuring the absolute magnetic field using high-Tc SQUID

    SQUID normally can only measure the change of magnetic field instead of the absolute value of magnetic field. Using a compensation method, a mobile SQUID, which could keep locked when moving in the earth's magnetic field, was developed. Using the mobile SQUID, it was possible to measure the absolute magnetic field. The absolute value of magnetic field could be calculated from the change of the compensation output when changing the direction of the SQUID in a magnetic field. Using this method and the mobile SQUID, we successfully measured the earth's magnetic field in our laboratory

  11. No-arbitrage conditions and absolutely continuous changes of measure

    Claudio Fontana

    2013-01-01

    We study the stability of several no-arbitrage conditions with respect to absolutely continuous, but not necessarily equivalent, changes of measure. We first consider models based on continuous semimartingales and show that no-arbitrage conditions weaker than NA and NFLVR are always stable. Then, in the context of general semimartingale models, we show that an absolutely continuous change of measure does never introduce arbitrages of the first kind as long as the change of measure density pro...

  12. Measurement of radioactivity in Norway

    A nation-wide network of 20 monitoring stations for continuous registration of radioactivity in the air has been established in Norway. Via the telecommunication network collected data are dayly automatically transmitted to the Norwegian Institute for Air Research (NILU). High radiation levels trigger an alarm for immediate transmission. The monitoring system and experiences in connection with its operation are described, and results from measurements in 1991 are presented. No unnormal radioactivity has been recorded in the period. 24 figs

  13. Absolute brightness temperature measurements at 2.1-mm wavelength

    Ulich, B. L.

    1974-01-01

    Absolute measurements of the brightness temperatures of the Sun, new Moon, Venus, Mars, Jupiter, Saturn, and Uranus, and of the flux density of DR21 at 2.1-mm wavelength are reported. Relative measurements at 3.5-mm wavelength are also preented which resolve the absolute calibration discrepancy between The University of Texas 16-ft radio telescope and the Aerospace Corporation 15-ft antenna. The use of the bright planets and DR21 as absolute calibration sources at millimeter wavelengths is discussed in the light of recent observations.

  14. Absolute Quantum Yield Measurement of Powder Samples

    Moreno, Luis A.

    2012-01-01

    Measurement of fluorescence quantum yield has become an important tool in the search for new solutions in the development, evaluation, quality control and research of illumination, AV equipment, organic EL material, films, filters and fluorescent probes for bio-industry.

  15. Absolute density measurements in the middle atmosphere

    M. Rapp

    Full Text Available In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting ‘ram-factor’ profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region.

    Key words. Middle atmosphere (composition and chemistry; pressure, density, and temperature; instruments and techniques

  16. Radioactivity

    This educative booklet give a general overview of radioactivity: history, structure of matter, radiations, radioactivity law, origin of radioactivity, radioactivity uses, radioprotection and measurement units. (J.S.)

  17. Measurement of radioactivity in steel

    Even after the control of scrap deliveries, there remains a small risk that the radioactive contaminated scrap passes the detecting devices. Therefore, the chemical laboratory takes a role to measure each heat for the absence of artificial radioactive nuclides with a gamma spectrometer equipped with NaI-detector. As the measurement must be performed in sequence with the steel production process, the allowable time for the measurement is quite limited. On the other hand, there could be still some possibility that background radiation might be present as the samples may contain some natural radioactivity. The task is how to differentiate the nature of radioactivity between naturally remaining radioactivity within safe limit and artificial nuclides present in the sample at a low level even though a very small amount of radioactivity could be detected in short time in both cases. We have set the alarm limit to 0.1 Bq/g for Co-60 as indicating nuclide. This limit is set more than 4 s (s = standard deviation) from the average background radiation. Therefore, false alarms are quite improbable. Strategy: The NaI gamma spectrometer performs a gross gamma measurement but it can not differentiate the nature of the nuclides present. If the alarm limit is hurt, the sample is measured on a high resolution gamma spectrometer with Ge-detector for identification of the gamma emitting nuclides. Calibration: Even though no appropriate international standards are adapted and no commercial measuring equipment is commercially available, the desired standard should contain Co-60 in the order of 1 to 100 Bq/g. The presence of other gamma emitting nuclides is desirable. In the Workshop we will present how to surmount this difficulty. (author)

  18. Absolute small-angle measurement based on optical feedback interferometry

    Jingang Zhong; Xianhua Zhang; Zhixiang Ju

    2008-01-01

    We present a simple but effective method for small-angle measurement based on optical feedback inter-ferometry (or laser self-mixing interferometry). The absolute zero angle can be defined at the biggest fringe amplitude point, so this method can also achieve absolute angle measurement. In order to verify the method, we construct an angle measurement system. The Fourier-transform method is used to analysis the interference signal. Rotation angles are experimentally measured with a resolution of 10-6 rad and a measurement range of approximately from -0.0007 to +0.0007 rad.

  19. Statistical aspects in radioactivity measurements

    This report contains a summary of basic concepts and formulae important for the treatment of errors and for calculating lower limits of detection in radioactivity measurements. Special attention has been paid to practical application and examples which are of interest for scientists working in this field. (orig./HP)

  20. Environmental radioactivity intercomparison measurements

    In the context of the North Cotentin radioecological group set up in 1997 by the Ministry of the Environment and the Ministry of the Secretariat d'Etat a la Sante, the Swiss Federal Office of Public health, a national organization of independent status with respect to nuclear energy, conducted a series of measurements in the north Cotentin in 1998. Some sites proposed by local association 'Angry mothers' were examined in particular. This association has now taken the initiative to organize a large scale international intercomparison, ' North Cotentin 2000', in the vicinity of local nuclear installations. Besides the scientific aspect of the intercomparison, a specific aim of this intercomparison consists in providing to the local population with a real opportunity for direct exchange with participating international teams. The primary concern of the workshop is the determination, by in situ gamma spectrometry, of both natural and artificial concentrations and resulting ambient dose rates at selected marine ( beach) and terrestrial sites. A particular aim of the workshop also is to test the capacity of mobile teams to produce reliable results in the field of low level measurements on trace of special radionuclides (I129, Sr90, H3, C14, and alpha emitters) from environmental samples, using both direct ( in situ) and differed ( laboratory methods). an overview of the results obtained will be prepared for the benefit of the public. (N.C.)

  1. Apparatus for measuring radioactive emissions

    Apparatus for measuring radioactive emissions from moving radioactive material comprises at least one radiation detector in a housing serving as a first radiation shield and in which at least one groove is formed to expose at least a portion of a receptor surface of the detector. The groove extends transverse to the direction of movement of the material over the detector. A second radiation shield may be located between at least a portion of the first shield and the detector. The material of the second shield is inherently less contaminated and emits secondary excitation radiation of lower energy than the first material. (author)

  2. On the Absolute Continuity of the Blackwell Measure

    Bárány, Balázs; Kolossváry, István

    2015-04-01

    In 1957, Blackwell expressed the entropy of hidden Markov chains using a measure which can be characterised as an invariant measure for an iterated function system with place-dependent weights. This measure, called the Blackwell measure, plays a central role in understanding the entropy rate and other important characteristics of fundamental models in information theory. We show that for a suitable set of parameter values the Blackwell measure is absolutely continuous for almost every parameter in the case of binary symmetric channels.

  3. A simplified method of absolute measurement for liquid scintillation counter

    A absolute measurement for simplified determining the activities of LS. sample is described. The total uncertainty of 2.0% and confidence level of 99.7% are given by the method, and as a example, three samples of 14C (n-hexadecane) are measured

  4. Mathematical Model for Absolute Magnetic Measuring Systems in Industrial Applications

    Fügenschuh, Armin; Fügenschuh, Marzena; Ludszuweit, Marina; Mojsic, Aleksandar; Sokół, Joanna

    2015-09-01

    Scales for measuring systems are either based on incremental or absolute measuring methods. Incremental scales need to initialize a measurement cycle at a reference point. From there, the position is computed by counting increments of a periodic graduation. Absolute methods do not need reference points, since the position can be read directly from the scale. The positions on the complete scales are encoded using two incremental tracks with different graduation. We present a new method for absolute measuring using only one track for position encoding up to micrometre range. Instead of the common perpendicular magnetic areas, we use a pattern of trapezoidal magnetic areas, to store more complex information. For positioning, we use the magnetic field where every position is characterized by a set of values measured by a hall sensor array. We implement a method for reconstruction of absolute positions from the set of unique measured values. We compare two patterns with respect to uniqueness, accuracy, stability and robustness of positioning. We discuss how stability and robustness are influenced by different errors during the measurement in real applications and how those errors can be compensated.

  5. Measurement of radioactivity in Norway

    A nation-wide network of 11 monotoring stations for continuous registration of radioactivity in the air has been established in Norway. Via the telecommunication network, collected data are dayly automatically transmitted to the Norwegian Institute for Air Research (NILU). High radiation levels trigger an alarn for immediate transmission. The monotoring system and experiences in connection with its operation are described, and results from measurements in 1988 are presented. 14 figs

  6. Testing and evaluation of thermal cameras for absolute temperature measurement

    Chrzanowski, Krzysztof; Fischer, Joachim; Matyszkiel, Robert

    2000-09-01

    The accuracy of temperature measurement is the most important criterion for the evaluation of thermal cameras used in applications requiring absolute temperature measurement. All the main international metrological organizations currently propose a parameter called uncertainty as a measure of measurement accuracy. We propose a set of parameters for the characterization of thermal measurement cameras. It is shown that if these parameters are known, then it is possible to determine the uncertainty of temperature measurement due to only the internal errors of these cameras. Values of this uncertainty can be used as an objective criterion for comparisons of different thermal measurement cameras.

  7. Absolute luminosity measurements with the LHCb detector at the LHC

    Aaij, R; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Arrabito, L; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Bailey, D S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Bediaga, I; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Brisbane, S; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Caicedo Carvajal, J M; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Charles, M; Charpentier, Ph; Chiapolini, N; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Constantin, F; Conti, G; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Almagne, B; D'Ambrosio, C; David, P; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Deissenroth, M; Del Buono, L; Deplano, C; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Eames, C; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; d'Enterria, D G; Esperante Pereira, D; Estève, L; Falabella, A; Fanchini, E; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hofmann, W; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koblitz, S; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kukulak, S; Kumar, R; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Luisier, J; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinez Santos, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Mclean, C; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M-N; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Musy, M; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nardulli, J; Nasteva, I; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Nies, S; Niess, V; Nikitin, N; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B; Palacios, J; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrella, A; Petrolini, A; Pie Valls, B; Pietrzyk, B; Pilar, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; du Pree, T; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schleich, S; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shao, B; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skottowe, H P; Skwarnicki, T; Smith, A C; Smith, N A; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Styles, N; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Topp-Joergensen, S; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urquijo, P; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Vervink, K; Viaud, B; Videau, I; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Voong, D; Vorobyev, A; Voss, H; Wacker, K; Wandernoth, S; Wang, J; Ward, D R; Webber, A D; Websdale, D; Whitehead, M; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wyllie, K; Xie, Y; Xing, F; Yang, Z; Young, R; Yushchenko, O; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zverev, E; Zvyagin, A

    2012-01-01

    Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ``van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5\\% in the absolute lumi...

  8. Beam energy absolute measurement using K-edge absorption spectrometers

    A method is presented of absolute energy measurement with an accuracy of triangle Ε ∼ 10-4Εo by direct measurement of the bend angle in a high-precision magnetic dipole using two opposite-direction short (about 2 mm long) high-field-intensity magnets (bar Β dipole much-lt Βshortmag) installed at each end and two K-edge absorption spectrometers. Using these spectrometers and the hard x-ray synchrotron radiation created by the short magnets, a bend angle of 4.5 arc deg for the CEBAF energy bandwidth can be measured with an accuracy of a few units of 10-6 rad, and the main sources of systematic errors are the absolute measurement of the field integral and the determination of the centroid of the synchrotron beam at a wavelength equal to the K-edge absorption of the chosen substance

  9. BMO solvability and absolute continuity of harmonic measure

    Hofmann, Steve; Le, Phi

    2016-01-01

    We show that for a uniformly elliptic divergence form operator $L$, defined in an open set $\\Omega$ with Ahlfors-David regular boundary, BMO-solvability implies scale invariant quantitative absolute continuity (the weak-$A_\\infty$ property) of elliptic-harmonic measure with respect to surface measure on $\\partial \\Omega$. We do not impose any connectivity hypothesis, qualitative or quantitative; in particular, we do not assume the Harnack Chain condition, even within individual connected comp...

  10. Spectrometry techniques for radioactivity measurements

    The energy of the radiation emission following the nuclear decay is unique and the characteristic of the radio nuclide which undergoes decay. Thus measurement of the energy of the radiation offers a method of identifying the radio nuclides. The prime requirement of the energy measurement is a suitable detector which shows response proportional to the energy of the radiation rather than the presence of the radiation. The response from such detectors are suitably processed and distributed with respect to the signal strength which is proportional to incident energy. This distribution is normally referred as energy spectrum and is recorded in the multichannel analyser. The measurement of energy and intensity of radiation from the spectrum is called radiation spectrometry. Thus the radiation spectrometry allows the identification and quantification of radioactive isotopes in variety of matrices. The radiation spectrometry has now become a popular radioanalytical technique in wide area of nuclear fuel cycle programs. The popular spectrometry techniques commonly used for the radioactivity measurement and analysis are Alpha spectrometry, Gamma ray spectrometry and Beta spectrometry

  11. Effects of natural radioactivity on food radioactivity measurement

    Since the accident of the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Company, groups and individuals including local governments, food manufacturers, distribution circles, retail circles, and citizens are eager to measure the radioactivity of food, in order to confirm the safety of food from the concerns about radioactive contamination. The measurement of radioactivity of food is done by quantitatively determining gamma rays due to radioactive cesium that was incorporated into the biosphere cycle after having been released into the environment. As for the radioactivity measurement of food using gamma-ray spectrometry with a potassium iodide scintillation detector, which is very commonly used, this paper describes the handling method of obtained data, the principle of erroneous detection of radioactive cesium and iodine interrupted by natural radionuclides, and countermeasures for it. Major natural radioactivity sources are uranium series and thorium series. This paper explains gamma rays, which are characteristic in the decay process of uranium series and often affect the measurement of radioactive cesium in food and water. (O.A.)

  12. Radioactivity measurements and control solutions

    In our department, in the last years, a new line of production has been developed devoted to the radioactivity measurements (portal monitor, gamma source detector, neutron monitor). Instruments of different design (hand-held, portals or steady-state) are intended for detection and locating of radioactive sources. Monitors are intended to detect radioactive and special nuclear materials in vehicles, pedestrians, luggage, as well as for illegal traffic prevention of radioactive sources. Monitors provide audio and visual alarm signals when radioactive and/or special nuclear materials are detected. Neutron dosimeters are designed for the determination of dose equivalent rate around neutron generators or sources. All devices can be recommended for use to officers of customs, border guard and emergency services, civil defense, fire brigades, police and military departments, nuclear research or power facilities. Incorporating micro controllers and new design, our products span almost all the spectra of radioactivity detection (gamma, beta, X and neutrons). No special knowledge is needed to operate these instruments as all service functions are performed automatically (self-tests, background updating and threshold calculation). The Portal monitor is intended to be a checkpoint in contamination control or in unauthorized traffic of radioactive materials. The portal monitor can be installed both in open, unprotected to environmental conditions areas or in enclosed areas. It may be used at pedestrian cross border points, at check points of Nuclear Power Plants, enterprises of nuclear industry, weapons manufacturing and storage plants, nuclear waste disposal and storage sites, at the entrances to steel plants, the post-offices and airports, the governmental offices, banks, private companies etc. The monitor provides audio alarming signals when radioactive and/or special nuclear materials are detected. The monitor consists in a portal frame, which sustains 5 detectors. Each

  13. An absolute measurement of #-v# of Cf252

    An absolute measurement of v of Cf252. An absolute determination of the average number of neutrons, #-v#, emitted in the spontaneous fission of Cf252 has been made by counting the fission neutrons in a large liquid scintillator. The detection efficiency of this counter was measured as a function of neutron energy. Well-collimated neutrons were scattered into the scintillator by an anthracene crystal, which detected the corresponding recoil protons. Pulse-shape discrimination was employed to eliminate γ-ray background. The detection efficiency for Cf252 fission neutrons was found to be 0.703 ± 0.007, giving a value of 3.78 ± 0.04 for the average number of prompt neutrons emitted per Cf252 fission. (author)

  14. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    Sannibale, F.; /LBL, Berkeley; Stupakov, G.V.; /SLAC; Zolotorev, M.S.; /LBL, Berkeley; Filippetto, D.; /INFN, Rome; Jagerhofer, L.; /Vienna, Tech. U.

    2009-12-09

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  15. Measurement of the absolute branching fraction of the Ds+- meson

    Abe, K; Dragic, J; Fujii, H; Gershon, T; Haba, J; Hazumi, M; Higuchi, T; Igarashi, Y; Itoh, R; Iwasaki, Y; Katayama, N; Kichimi, H; Krokovnyi, P P; Limosani, A; Nakamura, I; Nakao, M; Nakazawa, H; Nishida, S; Nozaki, T; Ozaki, H; Ronga, F J; Saitoh, S; Sakai, Y; Stamen, R; Sumisawa, K; Suzuki, S Y; Tajima, O; Takasaki, F; Tamai, K; Tanaka, M; Trabelsi, K; Tsuboyama, T; Tsukamoto, T; Uehara, S; Unno, Y; Uno, S; Ushiroda, Y; Yamauchi, M; Zhang, J; Hoshi, Y; Neichi, K; Aihara, H; Hastings, N C; Ishikawa, A; Itoh, K; Iwasaki, M; Kakuno, H; Kusaka, A; Nakahama, Y; Tanabe, K; Anipko, D; Arinstein, K; Aulchenko, V; Bedny, I; Bondar, A; Eidelman, S; Epifanov, D A; Gabyshev, N; Kuzmin, A; Poluektov, A; Root, N; Shwartz, B; Sidorov, V; Usov, Yu; Zhilich, V; Aoki, K; Enari, Y; Hara, K; Hayasaka, K; Hokuue, T; Iijima, T; Ikado, K; Inami, K; Kishimoto, N; Kozakai, Y; Kubota, T; Miyazaki, Y; Ohshima, T; Okabe, T; Sato, N; Senyo, K; Yoshino, S; Arakawa, T; Kawasaki, T; Miyata, H; Tamura, N; Watanabe, M; Asano, Y; Aso, T; Aushev, T; Bay, A; Hinz, L; Jacoby, C; Schietinger, T; Schneider, O; Villa, S; Wicht, J; Zürcher, D; Aziz, T; Banerjee, S; Gokhroo, G; Majumder, G; Bahinipati, S; Drutskoy, A; Goldenzweig, P; Kinoshita, K; Kulasiri, R; Sayeed, K; Schwartz, A J; Somov, A; Bakich, A M; Cole, S; McOnie, S; Parslow, N; Peak, L S; Stöck, H; Varvell, K E; Yabsley, B D; Balagura, V; Chistov, R; Danilov, M; Liventsev, D; Medvedeva, T; Mizuk, R; Pakhlov, P; Pakhlova, G; Tikhomirov, I; Uglov, T; Tian, Y BanX C; Barberio, E; Dalseno, J; Dowd, R; Moloney, G R; Sevior, M E; Taylor, G N; Tse, Y F; Urquijo, P; Barbero, M; Browder, T E; Guler, H; Jones, M; Li, J; Nishimura, K; Olsen, S L; Peters, M; Rorie, J; Sahoo, H; Uchida, K; Varner, G; Belous, K S; Shapkin, M; Sokolov, A; Bitenc, U; Bizjak, I; Fratina, S; Gorisek, A; Pestotnik, R; Staric, M; Zupanc, A; Blyth, S; Chen, A; Chen, W T; Go, A; Hou, S; Kuo, C C; Bozek, A; Kapusta, P; Lesiak, T; Matyja, A; Natkaniec, Z; Ostrowicz, W; Palka, H; Rózanska, M; Wiechczynski, J; Bracko, M; Korpar S; Brodzicka, J; Chang, M C; Kikuchi, N; Mikami, Y; Nagamine, T; Schonmeier, P; Yamaguchi, A; Yamamoto, H; Chang, P; Chao, Y; Chen, K F; Hou, W S; Hsiung, Y B; Lee, Y J; Lin, C Y; Lin, S W; Shen, Y T; Tsai, Y T; Ueno, K; Wang, C C; Wang, M Z; Wu, C H; Cheon, B G; Choi, J H; Ha, H; Kang, J S; Won, E; Choi, S K; Choi, Y; Choi, Y K; Kim, H O; Kim, J H; Park, C W; Park, K S; Chuvikov, A; Garmash, A; Marlow, D; Ziegler, T; Dash, M; Mohapatra, D; Piilonen, L E; Yusa, Y; Fujikawa, M; Hayashii, H; Imoto, A; Kataoka, S U; Miyabayashi, K; Noguchi, S; Krizan, P; Golob, B; Seidl, R; Grosse-Perdekamp, M; Hara, T; Heffernan, D; Miyake, H; Hasegawa, Y; Satoyama, N; Takada, N; Nitoh, O; Hoshina, K; Ishino, H; Khan, H R; Kibayashi, A; Mori, T; Ono, S; Watanabe, Y; Iwabuchi, M; Kim, Y J; Liu, Y; Sarangi, T R; Uchida, Y; Kang, J H; Kim, T H; Kwon, Y J; Kurihara, E; Kawai, H; Park, H; Kim, H J; Kim, S K; Lee, J; Lee, S E; Yang He Young; Kumar, R; Singh, J B; Soni, N; Lange, J S; Leder, G; MacNaughton, J; Mandl, F; Mitaroff, W A; Pernicka, M; Schwanda, C; Widhalm, L; Matsumoto, T; Nakagawa, T; Seki, T; Sumiyoshi, T; Yamamoto, S; Müller, J; Murakami, A; Sugiyama, A; Suzuki, S; Nagasaka, Y; Nakano, E; Sakaue, H; Teramoto, Y; Ogawa, A; Shibuya, H; Ogawa, S; Okuno, S; Sakamoto, H; Wang, C H; Schümann, J; Stanic, S; Xie, Q L; Yuan, Y; Zang, S L; Zhang, C C; Yamashita, Y; Zhang, L M; Zhang, Z P

    2006-01-01

    The Ds+- -> K+-K-+pi+- absolute branching fraction is measured using e+e- -> Ds*+- Ds1-+(2536) events collected by the Belle detector at the KEKB e+e- asymmetric energy collider. Using the ratio of yields when either the Ds1 or Ds* is fully reconstructed, we find Br(Ds+- -> K+-K-+pi+-)= (4.0+-0.4(stat)+-0.4(sys))%.

  16. Absolute Measurement of Quantum-Limited Interferometric Displacements

    Thiel, Valérian; Treps, Nicolas; Roslund, Jonathan

    2016-01-01

    A methodology is introduced that enables an absolute, quantum-limited measurement of sub-wavelength interferometric displacements. The technique utilizes a high-frequency optical path modulation within an interferometer operated in a homodyne configuration. All of the information necessary to fully characterize the resultant path displacement is contained within the relative strengths of the various harmonics of the phase modulation. The method, which is straightforward and readily implementable, allows a direct measurement of the theoretical Cram\\'er-Rao limit of detection without any assumptions on the nature of the light source.

  17. Strategy for the absolute neutron emission measurement on ITER

    Accuracy of 10% is demanded to the absolute fusion measurement on ITER. To achieve this accuracy, a functional combination of several types of neutron measurement subsystem, cross calibration among them, and in situ calibration are needed. Neutron transport calculation shows the suitable calibration source is a DT/DD neutron generator of source strength higher than 1010 n/s (neutron/second) for DT and 108 n/s for DD. It will take eight weeks at the minimum with this source to calibrate flux monitors, profile monitors, and the activation system.

  18. Absolute orientations from EBSD measurements - as easy as it seems?

    Kilian, Rüdiger; Bestmann, Michel; Heilbronner, Renée

    2016-04-01

    In structural geology, some problems can be addressed by inspecting the crystal orientation of grains in a rock. Deriving shear senses, kinematics of flow, information on deformation processes and recrystallization are some examples. Usually, oriented samples are taken in the field and, if inspected in an universal stage, the researcher has full control over the procedure and can make sure that the derived orientation is related to our geographic reference frame - that it is an absolute orientation. Nowadays, usage of electron backscatter diffraction (EBSD) has greatly improved the information in the derived data (fully crystal orientations, mappings, etc…), and the speed of data acquisition. However, this comes to the price of having to rely on the vendor supplied software and machine setup. Recent benchmarks and comparison of reference data revealed that for various EBSD setups around the world, the orientation data defaults to the wrong absolute orientation. The absolute orientation is not correctly derived - it commonly suffer a 180 degree rotation around the normal of the sample surface. In this contribution we will discuss the implications of such erroneous measurements and what kind of interpretations derived by orientation and texture data will be affected.

  19. Absolute and specific measures of research group excellence

    Mryglod, O; Holovatch, Yu; Berche, B

    2012-01-01

    A desirable goal of scientific management is to introduce, if it exists, a simple and reliable way to measure the scientific excellence of publicly-funded research institutions and universities to serve as a basis for their ranking and financing. While citation-based indicators and metrics are easily accessible, they are far from being universally accepted as way to automate or inform evaluation processes or to replace evaluations based on peer review. Here we consider absolute measurements of research excellence at an amalgamated, institutional level and specific measures of research excellence as performance per head. Using biology research institutions in the UK as a test case, we examine the correlations between peer-review-based and citation-based measures of research excellence on these two scales. We find that citation-based indicators are very highly correlated with peer-evaluated measures of group strength but are poorly correlated with group quality. Thus, and almost paradoxically, our analysis indi...

  20. Deflectometric systems for absolute flatness measurements at PTB

    Recently, two new scanning deflectometric flatness reference (DFR) measurement systems were installed at the Physikalisch-Technische Bundesanstalt. These instruments are aimed at measurements of the absolute flatness of optical surfaces with sub-nanometre uncertainties. System 1 is mainly designed for horizontal specimens with sizes up to 1 m and weights up to 120 kg. The other setup, i.e. system 2, is designed for vertical specimens. The two DFR systems use three different deflectometric procedures, which are based on scanning a pentaprism or the so-called double mirror unit (DMU) across the specimen. These 90° beam deflectors eliminate—to a great extent—residual guidance errors of the scanning stages, which is required to attain topography measurements with sub-nanometre uncertainty. The setups of the two new systems, the principles of the three different measurement modes, the alignment procedures, simulation results and first measurements are presented. (paper)

  1. On Absolute Measurements of β-Emitting Radionuclides

    4 π 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 Sr90 and Y90. 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 Bi210 (RaE) is described. A note is presented on the problem of foil absorption losses in scintillation absolute counting. (author)

  2. Absolute Measurement Fiber-optic Sensors in Large Structural Monitoring

    2003-01-01

    The security of civil engineering is an important task due to the economic, social and environmental significance. Compared with conventional sensors, the optical fiber sensors have their unique characteristics.Being durable, stable and insensitive to external perturbations,they are particular interesting for the long-term monitoring of civil structures.Focus is on absolute measurement optical fiber sensors, which are emerging from the monitoring large structural, including SOFO system, F-P optical fiber sensors, and fiber Bragg grating sensors. The principle, characteristic and application of these three kinds of optical fiber sensors are described together with their future prospects.

  3. High-precision absolute measurement of CEBAF beam mean energy

    The absolute measurement of the beam mean energy with an accuracy of one part in 104 or higher is an important demand of the CEBAF Hall A physics program. This accuracy may reduce the uncertainty in the d(e, e'p)p cross section δσ/σ to 1%. The need for such an accurately calibrated beam is not particular to CEBAF; at other electron facilities uncertainty in the incident energy has proven to be among the dominant sources of systematic error. The following methods for solving the problem were considered at both CEBAF and the Yerevan Physics Institute during 1990--1991: Backscattering of a plane electromagnetic wave by the relativistic electron beam. Calculations show that the intensity of the backscattered radiation in a bandwidth of 10-4 near the maximum frequency is about 1 photon per second at 4 GeV and 0.3 mA. Magnetic spectrometers performing as three- and four-magnet chicanes with appropriate detector systems. Such a system was used at SLAC for absolute measurement of the SLC beams energy, where a maximum accuracy of 5 x 10-4 was achieved. Calculations show that a similar accuracy can be achieved for the CEBAF beam in both proposed systems. Measurement of the vertical distribution of synchrotron radiation. Calculations indicate that precision of about 2.5 x 10-5 is achievable for CEBAF

  4. Measured and modelled absolute gravity changes in Greenland

    Nielsen, Jens Emil; Forsberg, René; Strykowski, Gabriel

    2014-01-01

    study ofGIA is important since it acts as an error source. GIA consists of three signals as seen by a gravimeter onthe surface of the Earth. These signals are investigated in this study. The ICE-5G ice history and recentlydeveloped ice models of present day changes are used to model the gravity change...... in Greenland. Theresult is compared with the initial measurements of absolute gravity (AG) change at selected GreenlandNetwork (GNET) sites.We find that observations are highly influenced by the direct attraction from the ice and ocean. Thisis especially evident in the measurements conducted at the...... GNET station near the Helheim Glacier.The effect of the direct attraction diminishes at sites that are more than one degree from the source.Here, the dominant signal is the effect of the elastic signal from present day ice mass changes. We findagreement between the measured and modelled gravity changes...

  5. Measurement of gamma radioactivity in steel

    The steel industry is being confronted increasingly with radioactive scrap from dismantled nuclear facilities. The clearance and release regulations that exist around the world differ very greatly and are difficult to implement. A 'radioactivity measurement' working group has therefore been set up at VDEh to clarify how radioactive measurements can be integrated into the day-to-day production routine. Operating results obtained at Thyssen Krupp Stahl AG with a gamma-ray spectrometer indicate a possibility for the simple detection of radioactive contamination. (orig.)

  6. Absolute measurement of neutron fluxes inside the reactor core

    The subject of this work is the development and study of two methods of neutron measurements in nuclear reactors, the new method of high neutron flux measurements and the Li6-semiconductor neutron spectrometer. This work is presented in four sections: Section I. The introduction explains the need for neutron measurements in reactors. A critical survey is given of the existing methods of high neutron flux measurement and methods of fast neutron spectrum determination. Section II. Theoretical basis of the work of semiconductor counters and their most important characteristics are given. Section III. The main point of this section is in presenting the basis of the new method which the author developed, i.e., the long-tube method, and the results obtained by it, with particular emphasis on absolute measurement of high neutron fluxes. Advantages and limitations of this method are discussed in details at the end of this section. Section IV. A comparison of the existing semiconductor neutron spectrometers is made and their advantages and shortcomings underlined. A critical analysis of the obtained results with the Li6-semiconductor spectrometer with plane geometry is given. A new type of Li6-semiconductor spectrometer is described, its characteristics experimentally determined, and a comparison of it with a classical Li6-spectrometer made (author)

  7. Absolute Thermal SST Measurements over the Deepwater Horizon Oil Spill

    Good, W. S.; Warden, R.; Kaptchen, P. F.; Finch, T.; Emery, W. J.

    2010-12-01

    Climate monitoring and natural disaster rapid assessment require baseline measurements that can be tracked over time to distinguish anthropogenic versus natural changes to the Earth system. Disasters like the Deepwater Horizon Oil Spill require constant monitoring to assess the potential environmental and economic impacts. Absolute calibration and validation of Earth-observing sensors is needed to allow for comparison of temporally separated data sets and provide accurate information to policy makers. The Ball Experimental Sea Surface Temperature (BESST) radiometer was designed and built by Ball Aerospace to provide a well calibrated measure of sea surface temperature (SST) from an unmanned aerial system (UAS). Currently, emissive skin SST observed by satellite infrared radiometers is validated by shipborne instruments that are expensive to deploy and can only take a few data samples along the ship track to overlap within a single satellite pixel. Implementation on a UAS will allow BESST to map the full footprint of a satellite pixel and perform averaging to remove any local variability due to the difference in footprint size of the instruments. It also enables the capability to study this sub-pixel variability to determine if smaller scale effects need to be accounted for in models to improve forecasting of ocean events. In addition to satellite sensor validation, BESST can distinguish meter scale variations in SST which could be used to remotely monitor and assess thermal pollution in rivers and coastal areas as well as study diurnal and seasonal changes to bodies of water that impact the ocean ecosystem. BESST was recently deployed on a conventional Twin Otter airplane for measurements over the Gulf of Mexico to access the thermal properties of the ocean surface being affected by the oil spill. Results of these measurements will be presented along with ancillary sensor data used to eliminate false signals including UV and Synthetic Aperture Radar (SAR

  8. The correction of vibration in frequency scanning interferometry based absolute distance measurement system for dynamic measurements

    Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Zhuang, Zhitao; Xu, Xinke; Gan, Yu

    2015-10-01

    Absolute distance measurement systems are of significant interest in the field of metrology, which could improve the manufacturing efficiency and accuracy of large assemblies in fields such as aircraft construction, automotive engineering, and the production of modern windmill blades. Frequency scanning interferometry demonstrates noticeable advantages as an absolute distance measurement system which has a high precision and doesn't depend on a cooperative target. In this paper , the influence of inevitable vibration in the frequency scanning interferometry based absolute distance measurement system is analyzed. The distance spectrum is broadened as the existence of Doppler effect caused by vibration, which will bring in a measurement error more than 103 times bigger than the changes of optical path difference. In order to decrease the influence of vibration, the changes of the optical path difference are monitored by a frequency stabilized laser, which runs parallel to the frequency scanning interferometry. The experiment has verified the effectiveness of this method.

  9. Measurement of environmental radioactivity. Ispra 1976

    In this report there are briefly described the measurements of environmental radioactivity performed during 1976 by the site survey group of the Protection Division of the Euratom Joint Research Centre - Ispra Establisment. Data are given on the concentrations of 90Sr, 137Cs and other radionuclides in precipitation, air, waters, herbage milk and radioactive effluents. The environmental contamination is mainly world-wide fall out

  10. Measurement of the absolute separation for atomic force microscopy measurements in the presence of adsorbed polymer

    McKee, C. T.; Mosse, W. K. J.; Ducker, W. A.

    2006-01-01

    We demonstrate that the absolute separation between an atomic force microscope (AFM) tip and a solid substrate can be measured in the presence of an irreversibly adsorbed polymer film. The separation is obtained from the analysis of a scattered evanescent wave that is generated at the surface of the solid. By comparing our scattering measurements to conventional AFM measurements, we also show an example where a conventional AFM measurement gives the incorrect force-distance profile. We valida...

  11. A proposal to measure absolute environmental sustainability in lifecycle assessment

    Bjørn, Anders; Margni, Manuele; Roy, Pierre-Olivier;

    2016-01-01

    sustainable are therefore increasingly important. Such absolute indicators exist, but suffer from shortcomings such as incomplete coverage of environmental issues, varying data quality and varying or insufficient spatial resolution. The purpose of this article is to demonstrate that life cycle assessment (LCA...... study evaluating emission scenarios for personal residential electricity consumption supplied by production from 45 US coal fired electricity plant. Median values of derived CFs are 0.16–0.19 ha year kg−1 for common acidifying compounds. CFs are generally highest in Northern Europe, Canada and Alaska...... supporting decisions aimed at simultaneously reducing environmental impacts efficiently and maintaining or achieving environmental sustainability. We have demonstrated that LCA indicators can be modified from being relative to being absolute indicators of environmental sustainability. Further research should...

  12. Radioactivity monitoring network: Measurements 1987

    Four papers are presented: radionuclide concentration measurement in aerosols, surface water and the wastes of the Vienna Central Clarification Plant respectively, and on tritium in Austrian lakes and rivers. (qui)

  13. Environmental radioactivity measurement intercomparison exercise 1990

    In a recent national intercomparison exercise, 49 laboratories involved in making environmental radioactivity measurements took part in the analysis of samples supplied by the National Physical Laboratory (NPL) in the United Kingdom. There were two sets of samples; one containing pure β-emitters and one containing β/γ-emitters. Two thirds of the participants measured the β/γ-emitter sample only, the remainder measured both. The results are presented. (author)

  14. Radioactivity measurements on live Bewick's Swans

    Measurements made on 46 live swans at Slimbridge using portable high resolution hyperpure germanium gamma ray spectrometry equipment are described. Laboratory measurements are also reported on two swans which died of natural causes or of flying accidents. The implications of the measured radioactivity levels are discussed in relation to the suggestion that they might have been affected by the Chernobyl accident on their migration. (UK)

  15. Portable laboratories for radioactivity measurements

    The portable radiometric laboratories LARA-10, LARA-GS, LARA-86 and ALARA-10 designed, developed and produced at the Boris Kidric Institute are described. Earlier models (LARA-1, LARA-1D, LARA-2 and LARA-5) are presented in brief. The basic characteristics of the devices and methods of measurements are given. All the instruments are battery operated and almost all can also use 220V/50Hz supply. They are a very suitable facility for radiological monitoring of soil, water, food, clothes etc., when working in field conditions (author)

  16. Measurement of environmental radioactivities, (1)

    The specific beta activities in rice and cigarette samples have been measured by a low background beta-spectrometer. The maximum energies of the beta-rays and the specific activities for cigarette samples were almost the same, independent of their species. On the other hand, specific activities for rice sample depended on the growing districts. The activities for rices and cigarettes were 27 -- 29 pCi per piece of cigarette and 0.50 -- 1.27 pCi per gram of rice, respectively. (author)

  17. Measurement of alpha emitters in radioactive waste

    The alpha emitters measurement in radioactive waste (10-2Ci/T) is essential for a good fissil materials management. This paper describes 3 classes of devices: device using a neutronic passive counting, device using a neutronic activation and detection of fission gamma, device using a neutronic activation and detection of prompt neutrons fission

  18. System for measuring radioactivity of labelled biopolymers

    A system is described for measuring radioactivity of labelled biopolymers, comprising: a set of containers adapted for receiving aqueous solutions of biological samples containing biopolymers which are subsequently precipitated in said containers on particles of diatomite in the presence of a coprecipitator, then filtered, dissolved, and mixed with a scintillator; radioactivity measuring means including a detection chamber to which is fed the mixture produced in said set of containers; an electric drive for moving said set of containers in a stepwise manner; means for proportional feeding of said coprecipitator and a suspension of diatomite in an acid solution to said containers which contain the biological sample for forming an acid precipitation of biopolymers; means for the removal of precipitated samples from said containers; precipitated biopolymer filtering means for successively filtering the precipitate, suspending the precipitate, dissolving the biopolymers mixed with said scintillator for feeding of the mixture to said detection chamber; a system of pipelines interconnecting said above-recited means; and said means for measuring radioactivity of labelled biopolymers including, a measuring cell arranged in a detection chamber and communicating with said means for filtering precipitated biopolymers through one pipeline of said system of pipelines; a program unit electrically connected to said electric drive, said means for acid precipatation of biopolymers, said means for the removal of precipitated samples from said containers, said filtering means, and said radioactivity measuring device; said program unit adapted to periodically switch on and off the above-recited means and check the sequence of the radioactivity measuring operations; and a control unit for controlling the initiation of the system and for selecting programs

  19. Nondestructive measurement of environmental radioactive strontium

    Saiba Shuntaro

    2014-03-01

    Full Text Available The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days, Cs-134 (2.1 years, Cs-137 (30 years, Sr-89 (51 days, and Sr-90 (29 years. We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.

  20. Radioactivity measurements as tool for physics dissemination

    In general people associate environmental radioactivity with the artificial radioactivity and knows very little about natural radioactivity. Thus there is a critical need to improve nuclear physics public education. From 2005 in Italy two programs were promoted from Ministry of Education and University and National Institute of Nuclear Physics (INFN) for scientific dissemination in the field of environmental radioactivity. High school students in many Italian regions were involved in particular in indoor radon measurements. With this program students acquired awareness about the risks of inhalation of radon and its progeny and at the same time contributed to carry out radon monitoring, participating to all the experimental phases, from detectors set-up to data analysis. In particular we report about the activities carried out at Catania University and INFN division regarding a survey in the eastern Sicily. The overall monitoring, spanned over a period of 5 years, was carried out using passive nuclear track detection technique, through CR-39 dosimeters. In total about 500 detectors were placed in dwellings and schools in 57 locations. The investigated area have shown medium-high indoor radon concentrations, higher than the Italian average (70 Bq/m3). From the evaluation of the participating teachers and students, this kind of activities represents a successful strategy to enhance dissemination of physics, in particular in radioactivity topics. (author)

  1. Measurement of environmental radioactivity in Toki district

    When the Institute of Plasma Physics, Nagoya University, expressed the hope to move into Toki district, the environmental problems accompanying the movement were discussed. The effect of the radioactivity leaking from the nuclear facility on human bodies must be far smaller than that of natural radiation, and for the purpose, the amount and fluctuation range of the natural radiation in the district must be known. The initial objectives of this cooperative research were to study on environmental radiation and to make a Geiger counter for the measurement. In 1981, a scintillation counter will be completed, and using a multi-channel pulse height analyzer, the nuclides which are the source of environmental radiation emission will be identified, and the tritium in natural water will be detected. Thus, the evaluation of environmental radiation can be carried out, and the situation before the movement of the research facility can be grasped. In this paper, the natural radioactivity in earth, atmosphere and water and cosmic ray, artificial radioactivity, and environmental radiation exposure dose are reported. Also, the manufacture of a GM counter measuring instrument and the measurements of cosmic ray background, typical earth samples and environmental radioactivity with the GM counter are reported. The related data are attached. (Kako, I.)

  2. Residual radioactivity measurements at Indus accelerator complex

    Indus-1 and Indus-2 are two Synchrotron Radiation Sources (SRS) operational at RRCAT, Indore. Indus-1 and Indus-2 are designed for maximum electron beam energy of 450 MeV and 2.5 GeV respectively. During shut down of these accelerators for maintenance purpose, residual radioactivity measurements were carried out. The residual radioactivity formation in various parts of the high energy electron accelerators is due to the beam loss taking place at these locations. The present paper describes the recent residual radioactivity measurements carried out at the electron accelerators of Indus Accelerator Complex and the radio-isotopes identified. The maximum dose rate due to induced activity obtained is 30 μSv/h, near dipole-5 of booster synchrotron after 12 h of cooling time. In case of Indus-1 and Indus-2 SRS the dose rate due to induced radioactivity is found to be of the order of 2 - 3 μSv/h. The radio isotopes identified at these beam loss locations are beta emitters that do not pose serious external hazard to the working personnel. However, precautions are to be observed while doing maintenance on activated components. The paper describes the measurements in detail with the results. (author)

  3. Radioactivity measurements in potassium enriched vegetation

    Measurements of radioactivity in food stuffs/vegetation is important because radiation dose to human population due to inhalation and ingestion (external and internal exposure) poses health hazard and contribute significantly to the total dose from natural sources. The radium and thorium isotopes always present in the body are measured in units of a millionth or a billionth of a gram, but when it comes to potassium we are talking about grams of material. The 2.5 g of potassium ingested each day contains 80 Becquerel (Bq) (or 2100 pCi) of 40K that quantity which produces 80 radioactive decays each second. The 140 g of potassium in a normal male contains about 4400 Bq (or 120,000 pCi) of 40K; that quantity produces a decay rate of about 4400 disintegrations per second. That means that 4400 radioactive 40K atoms decay and emit radiation in our bodies each second for as long as we live. Since potassium is found in the intracellular fluids, about 98 % of the potassium in the body is within cells. Thus at least 98 % of these disintegrations take place within body cells, and are potentially capable of altering the cell's DNA. Therefore, it is very essential to measure the activity concentration in the potassium enriched food stuffs. Knowledge of radioactivity present in potassium enriched food stuffs enables one to assess any possible radiological hazard to mankind by the use of such materials. In the light of the above mentioned facts, it is, therefore, fundamental to assess the radioactivity in commonly available potassium enriched foods. (author)

  4. The absolute gravity measurement by FG5 gravimeter at Great Wall Station, Antarctica

    2007-01-01

    Gravity measurement is of great importance to the height datum in Antarctica.The absolute gravity measurement was carried out at Great Wall Station, Antarctica, using FG5 absolute gravity instrument.The gravity data was processed with corrections of earth tide, ocean tide, polar motion and the atmospher, and the RMS is within +3 x 10 -s ms-2.The vertical and horizontal gravity gradients were measured using 2 LaCoaste & Romberg (LCR) gravimeters.The absolute gravity measurement provides the fundamental data for the validation and calibration of the satellite gravity projects such as CHAMP, GRACE and GOCE, and for the high accuracy geoid model.

  5. Study on the effect factor of the absolute fission rates measured by depleted uranium fission chamber

    The absolute fission rates was measured by the depleted uranium fission chamber. The efficiency of the fission fragments recorded in the fission chamber was analyzed. The factor influencing absolute fission rates was studied in the experiment, including the disturbing effect between detectors and the effect of the structural material of the fission chamber, etc

  6. Measurement and analysis of radioactive substances

    Here are gathered the abstracts presented to the 3. summer university of the year 2001 whose main themes were the destructive (5 conferences) and nondestructive (8 conferences) analyses applied to nuclear industry. The points of view of different organisms (as DSIN: Directorate for the Safety of Nuclear Installations, IPSN: Institute of Nuclear Protection and Safety, OPRI: Office of Protection against Ionizing Radiations, TUI: Institute for Transuranium Elements, COGEMA, EDF: Electric Utilities, ANDRA: French National Agency for Radioactive Waste Management, CRLC Val d'Aurelle, France) concerning the needs involved in nuclear facilities control, the methods of radionuclide speciation in use internationally, the measurements and analyses of radioactive substances are given too as well as some general concepts concerning 1)the laser-matter interaction 2)the ions production 3)the quality applied to the measurements and analyses 4)the standard in activity metrology. (O.M.)

  7. Error calculations statistics in radioactive measurements

    Basic approach and procedures frequently used in the practice of radioactive measurements.Statistical principles applied are part of Good radiopharmaceutical Practices and quality assurance.Concept of error, classification as systematic and random errors.Statistic fundamentals,probability theories, populations distributions, Bernoulli, Poisson,Gauss, t-test distribution,Ξ2 test, error propagation based on analysis of variance.Bibliography.z table,t-test table, Poisson index ,Ξ2 test

  8. Absolute Fluorescence Spectrum and Yield Measurements for a wide range of experimental conditions

    Monnier Ragaigne, D.; Gorodetzky, P.; Moretto, C; Blaksley, C.; Dagoret-Campagne, D.; Gonnin, A.; Miyamoto, H.; Monard, H.; Wicek, F.

    2013-01-01

    For the JEM-EUSO Collaboration The fluorescence yield is a key ingredient in cosmic ray energy determination. It is sensitive to pressure, temperature and humidity. Up to now the fluorescence yield of the brightest line at 337 nm has been measured in an absolute way in one set of conditions, whereas fluorescence yields at the other wavelengths have been relatively measured for different conditions. Thus, absolute calibration for all the lines is unclear. We will do all measurements at once...

  9. Cross-section measurements for radioactive samples

    The measurement of (n,p), (n,α) and (n,γ) cross sections for radioactive nuclei is of interest to both nuclear physics and astrophysics. For example, using these reactions, properties of levels in nuclei at high excitation energies, which are difficult or impossible to study using other reactions, can be investigated. Also, reaction rates for both big-bang and stellar nucleosynthesis can be obtained from these measurements. In the past, the large background associated with the sample activity limited these types of measurements to radioisotopes with very long half-lives. The advent of the low-energy, high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Examples of (n,p) measurements on samples with half lives as short as fifty-three days will be given. The nuclear physics and astrophysics to be learned from these data will be discussed. Additional difficulties are encountered when making (n,γ) rather than (n,p) or (n,α) measurements. However, with a properly-designed detector, and the high peak neutron intensities now available, (n,γ) measurements can be made for nuclei with half lives as short as several months. Progress on the Los Alamos (n,γ) cross-section measurement program for radioactive samples will be discussed. 39 refs., 7 figs

  10. National network of radioactivity measurement in environment

    This document constitutes the report of management for the year 2006 of the national network of measurement of radioactivity in environment, instituted by the article R.1333-11 of the Public Health code. According to the 5. of the decree of 27. june 2005, the Institute of radiation protection and nuclear safety (I.R.S.N.) has for mission to write every year a report of management of the national network of radioactivity measurement in environment. This report has for principal objectives: to do an evaluation on organisation and functioning of the piloting committee; to realize a synthesis on the different tasks lead by the working groups; as well as on the human and financial resources devoted to this project; to debrief on the development project of the national network information system. This report must allow to the network actors, as to the professional people and the public, to understand the functioning of the national network and the process implemented for the development of centralization, management and public diffusion tools, of the radioactivity data in environment. The year 2006 was marked by the opening of an Internet gate of the national network. (N.C.)

  11. Combining Near-Subject Absolute and Relative Measures of Longitudinal Hydration in Hemodialysis

    Chan, Cian; McIntyre, Christopher; Smith, David; Spanel, Patrik; Davies, Simon J.

    2009-01-01

    Background and objectives: The feasibility and additional value of combining bioimpedance analysis (BIA) with near-subject absolute measurement of total body water using deuterium dilution (TBWD) in determining longitudinal fluid status was investigated.

  12. Radioactivity measurement with a plastic scintillation vial

    Introduction: Liquid scintillation counting method is commonly used to measure radioactivity especially for beta emitters because of its high sensitivity. However, since the sample should be mixed with scintillation cocktail of organic liquid, there are problems that the sample could not be recovered and radioactive organic liquid waste is produced. The radioactive waste is usually burned with a specially designed incinerator, so that it needs costs and labor. To resolve the problems, I tried to develop a novel method to measure radioactivity using liquid scintillation counter without scintillation cocktail, and investigated the feasibility of the method. Method: A cylindrical plastic scintillator with well was installed in a counting vial, which is named 'ScintiVial' Sample contained in a 1500 μL microtube was put in the ScintiVial, and was measured with a liquid scintillation counter. Samples including 200-800 Bq of 32P in 25-1300 μL of solution and 900 Bq of 125I in 100 μL solution were measured using the ScintiVial. Results and Discussion: The counting efficiency for 25-1300 μL of 32P was 28-10%, and that for 100 μL of 125I was 3%. The counting efficiency was decreased with the increase of the sample volume. The pulse height distribution of the ScintiVial was similar to that of usual liquid scintillation of the nuclide in question. The microtube, commonly known as 'Eppendorf tube', for containing the sample is widely used for experiments of chemistry etc., and also used to contain most of labeled compounds. Using the ScintiVial made them possible that the sample on an experiment may be measured as it is and the sample may be recovered and reused. In addition, the method will not produce any radioactive organic liquid waste. Not producing the active organic liquid will eliminate the load for its incineration, and then CO2 with the incineration will not be generated. Therefore, the method will potentially assist the resolution of the environmental problem

  13. Absolute measurements of neutron cross sections. Progress report

    In the photoneutron laboratory, we have completed a major refurbishing of experimental facilities and begun work on measurements of the capture cross section in thorium and U-238. In the 14 MeV neutron experimental bay, work continues on the measurement of 14 MeV neutron induced reactions of interest as standards or because of their technological importance. First results have been obtained over the past year, and we are extending these measurements along the lines outlined in our proposal of a year ago

  14. Absolute dose measurement Gafchromic R EBT2 movies. Case Study of Kaposis sarcoma

    Because of its high spatial resolution, low energy dependence and good response over a wide energy range, EBT2 Gafchromic films are widely used in many applications in radiotherapy for measuring relative dose. Despite being the most common use can be used to measure absolute dose. This text is an example of using films as EBT2 for in vivo absolute dose in a Kaposis sarcoma.

  15. ABSOLUTE CONTINUITY FOR INTERACTING MEASURE-VALUED BRANCHING BROWNIAN MOTIONS

    ZHAOXUELEI

    1997-01-01

    The moments and absohite continuity of measure-valued branching Brownian motions with bounded interacting intensity are hivestigated. An estimate of higher order moments is obtained. The ahsolute continuity is verified in the one dimension case. This therehy verifies the conjecture of Méléard and Roelly in [5].

  16. Absolute Oxygenation Metabolism Measurements Using Magnetic Resonance Imaging

    An, Hongyu; Liu, Qingwei; Eldeniz, Cihat; Lin, Weili

    2011-01-01

    Cerebral oxygen metabolism plays a critical role in maintaining normal function of the brain. It is the primary energy source to sustain neuronal functions. Abnormalities in oxygen metabolism occur in various neuro-pathologic conditions such as ischemic stroke, cerebral trauma, cancer, Alzheimer’s disease and shock. Therefore, the ability to quantitatively measure tissue oxygenation and oxygen metabolism is essential to the understanding of pathophysiology and treatment of various diseases. T...

  17. Absolute measurements with a 4 π-counter

    Measurements on standardized p-emitters have been made in a 4 it proportional flow-counter. The counter efficiency is found to be near 100 %. Absorption curves have been determined with plastic foils and aluminium. A comparison is made between the self-absorption arising in different methods of source preparation which include precipitates and the use of wetting agents The most reliable results have been obtained with sources on aluminium foils, where the foil absorption is calculated from the absorption curves and the self-absorption is supposed to be negligible for isotopes with end point energy above 0.5 MeV. The β-emitters studied have energies ranging from 1.71 MeV (32P) to 0.167 MeV (35S). Most of them have been obtained from National Physical Laboratory and Atomic Energy Research Establishment, Harwell, England. The agreement between their calibration and our measurements is very good except in the case of Co 60

  18. Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

    Santos, Emilie M.M. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, Rotterdam (Netherlands); Department of Radiology, AMC, Amsterdam (Netherlands); Yoo, Albert J. [Texas Stroke Institute, Plano, TX (United States); Beenen, Ludo F.; Majoie, Charles B. [Department of Radiology, AMC, Amsterdam (Netherlands); Berkhemer, Olvert A. [Department of Radiology, AMC, Amsterdam (Netherlands); Department of Neurology, Erasmus MC, Rotterdam (Netherlands); Blanken, Mark D. den; Wismans, Carrie [AMC, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Niessen, Wiro J. [Erasmus MC - University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, Rotterdam (Netherlands); Delft University of Technology, Faculty of Applied Sciences, Delft (Netherlands); Marquering, Henk A. [Department of Radiology, AMC, Amsterdam (Netherlands); AMC, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Collaboration: on behalf of the MR CLEAN investigators

    2016-02-15

    Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert observers. For 132 consecutive patients with acute ischemic stroke, three experts and two trained observers determined thrombus density by placing three standardized regions of interest (ROIs) in the thrombus and corresponding contralateral arterial segment. Subsequently, absolute and relative thrombus densities were determined using either one or three ROIs. Intraclass correlation coefficient (ICC) was determined, and Bland-Altman analysis was performed to evaluate interobserver and intermethod agreement. Accuracy of the trained observer was evaluated with a reference expert observer using the same statistical analysis. The highest interobserver agreement was obtained for absolute thrombus measurements using three ROIs (ICCs ranging from 0.54 to 0.91). In general, interobserver agreement was lower for relative measurements, and for using one instead of three ROIs. Interobserver agreement of trained non-experts and experts was similar. Accuracy of the trained observer measurements was comparable to the expert interobserver agreement and was better for absolute measurements and with three ROIs. The agreement between the one ROI and three ROI methods was good. Absolute thrombus density measurement has superior interobserver agreement compared to relative density measurement. Interobserver variation is smaller when multiple ROIs are used. Trained non-expert observers can accurately and reproducibly assess absolute thrombus densities using three ROIs. (orig.)

  19. Observer variability of absolute and relative thrombus density measurements in patients with acute ischemic stroke

    Thrombus density may be a predictor for acute ischemic stroke treatment success. However, only limited data on observer variability for thrombus density measurements exist. This study assesses the variability and bias of four common thrombus density measurement methods by expert and non-expert observers. For 132 consecutive patients with acute ischemic stroke, three experts and two trained observers determined thrombus density by placing three standardized regions of interest (ROIs) in the thrombus and corresponding contralateral arterial segment. Subsequently, absolute and relative thrombus densities were determined using either one or three ROIs. Intraclass correlation coefficient (ICC) was determined, and Bland-Altman analysis was performed to evaluate interobserver and intermethod agreement. Accuracy of the trained observer was evaluated with a reference expert observer using the same statistical analysis. The highest interobserver agreement was obtained for absolute thrombus measurements using three ROIs (ICCs ranging from 0.54 to 0.91). In general, interobserver agreement was lower for relative measurements, and for using one instead of three ROIs. Interobserver agreement of trained non-experts and experts was similar. Accuracy of the trained observer measurements was comparable to the expert interobserver agreement and was better for absolute measurements and with three ROIs. The agreement between the one ROI and three ROI methods was good. Absolute thrombus density measurement has superior interobserver agreement compared to relative density measurement. Interobserver variation is smaller when multiple ROIs are used. Trained non-expert observers can accurately and reproducibly assess absolute thrombus densities using three ROIs. (orig.)

  20. Measurement of radioactivity in volcanic products

    Sato, Jun

    1988-10-01

    Radioactivity in volcanic products was measured for obtaining new knowledge about volcano. A distribution map of /sup 2//sup 2//sup 8/Ra//sup 2//sup 2//sup 6/Ra in the volcanic products of Japanese Islands volcanic front was prepared. From the map, it was understood that only Izu-Mariana Arc was different from other series of vocanos. Concerning Volcano Sakurajima, /sup 2//sup 2//sup 2/Rn//sup 2//sup 2//sup 0/Rn ratio in the pumice produced by the eruption was measured for studying its change with days after creation. Regarding the lava of Miyake Island, change of /sup 2//sup 1//sup 4/Bi with time was measured. 3 figures.

  1. Absolute Measurement of 14C Activity by Internal Proportional Counters

    14CO22 was obtained by decomposing carbonate with sulphuric acid heated to boiling point, after which it was mixed with CH4 in a reserve flask. Three brass internal proportional counters, differing only in length, were filled with this mixture. The counters were connected to the electronic equipment in the usual arrangement. The equipment dead time was determined by means of a modified two-source method, and the total volume of the equipment was obtained from the isothermic expansion of methane from a flask whose volume, together with that of the counters, had been determined by weighing a water filling. The wall effect was determined by measuring a 14CO2 + CH4 mixture at different pressures and by extrapolation to reciprocal pressure zero value; it was discovered that the wall-effect correction did not differ significantly from zero. The end effect was compensated for by using counters of different lengths so that the difference in plateau slope also did not differ significantly from zero. By the t-test power function it was estimated that the maximal error on a 0.01 significance level, caused by neglecting the wall-effect correction, amounted to ± 0.85% due to the end-effect correction (± 0.62% for the equipment used) having been neglected. The relation between wall, end and discrimination effects is discussed, and, in conclusion, the maximal errors from other sources are estimated; the total maximal error on a 0.01 significance level of the standard solution activity is computed as equal to ± 1.1%. (author)

  2. Absolute measurements of the thermal neutron flux by the foil activation method using the 4πβ-γ coincidence technique

    An analysis of the correction factors required for the β-γ coincidence method is presented together with a listing of the various formulae involved in the determination of radioactive sources. The detection system including the activation detectores are described and the results are shown for the absolute measurements of thermal neutron flux carried out in the core of the Argonaut Reactor, at Instituto de Engenharia Nuclear (IEN), Brazil. (Author)

  3. The Implications for Higher-Accuracy Absolute Measurements for NGS and its GRAV-D Project

    Childers, V. A.; Winester, D.; Roman, D. R.; Eckl, M. C.; Smith, D. A.

    2013-12-01

    Absolute and relative gravity measurements play an important role in the work of NOAA's National Geodetic Survey (NGS). When NGS decided to replace the US national vertical datum, the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project added a new dimension to the NGS gravity program. Airborne gravity collection would complement existing satellite and surface gravity data to allow the creation of a gravimetric geoid sufficiently accurate to form the basis of the new reference surface. To provide absolute gravity ties for the airborne surveys, initially new FG5 absolute measurements were made at existing absolute stations and relative measurements were used to transfer those measurements to excenters near the absolute mark and to the aircraft sensor height at the parking space. In 2011, NGS obtained a field-capable A10 absolute gravimeter from Micro-g LaCoste which became the basis of the support of the airborne surveys. Now A10 measurements are made at the aircraft location and transferred to sensor height. Absolute and relative gravity play other roles in GRAV-D. Comparison of surface data with new airborne collection will highlight surface surveys with bias or tilt errors and can provide enough information to repair or discard the data. We expect that areas of problem surface data may be re-measured. The GRAV-D project also plans to monitor the geoid in regions of rapid change and update the vertical datum when appropriate. Geoid change can result from glacial isostatic adjustment (GIA), tectonic change, and the massive drawdown of large scale aquifers. The NGS plan for monitoring these changes over time is still in its preliminary stages and is expected to rely primarily on the GRACE and GRACE Follow On satellite data in conjunction with models of GIA and tectonic change. We expect to make absolute measurements in areas of rapid change in order to verify model predictions. With the opportunities presented by rapid, highly accurate

  4. Precise measurements of the absolute γ-ray emission probabilities of 223Ra and decay progeny in equilibrium

    Precise measurements of the absolute γ-ray emission probabilities have been made of radiochemically pure solutions of 223Ra in equilibrium with its decay progeny, which had been previously standardised by 4π(liquid scintillation)-γ digital coincidence counting techniques. Two high-purity germanium γ-ray spectrometers were used which had been accurately calibrated using a suite of primary and secondary radioactive standards. Comparison of the activity concentration determined by the primary technique against γ-ray spectrometry measurements using the nuclear data evaluations of the Decay Data Evaluation Project exhibited a range of ~18% in the most intense γ-ray emissions (>1% probability) of the 223Ra decay series. Absolute γ-ray emission probabilities and standard uncertainties have been determined for the decay of 223Ra, 219Rn, 215Po, 211Pb, 211Bi and 207Tl in equilibrium. The standard uncertainties of the measured γ-ray emission probabilities quoted in this work show a significant improvement over previously reported γ-ray emission probabilities. Correlation coefficients for pairs of the measured γ-ray emission probabilities from the decays of the radionuclides 223Ra, 219Rn and 211Pb have been determined and are presented. The α-transition probabilities of the 223Ra have been deduced from P(γ+ce) balance using the γ-ray emission probabilities determined in this work with some agreement observed with the published experimental values of the α-emission probabilities. - Highlights: • Discrepancies found within currently published γ-ray emission probabilities. • Absolute γ-ray emission probabilities of decay series in equilibrium determined. • Significant improvement in precision of measured values. • Closer agreement between deduced and experimental α transition probabilities. • Correlation coefficients presented for γ-emissions of 223Ra, 219Rn and 211Pb

  5. Radioactivity measurements for some ophthalmic glasses

    The main aim of the present work is to implant the latest ICRP/IAEA recommendations related to exemption and clearness to the Ophthalmic Glass. As consumer product, glass lenses may contain trace quantities of uranium, thorium and potassium. Glass lenses under investigation were monitored for the detection of gamma rays and beta particles using radiation measuring devices. Using high purity germanium detector radioactivity concentration was estimated in Bq/kg. Activity concentration of 226 Ra, Th-232 and K-40 were determined using the energy gamma lines of 2l4Pb (352 keV), 212Pb (238 keV) and 1460 keV gamma line for 40K respectively .Experimental results showed that radioactivity concentration for radium -226 varies from 0.19 to 4.98 Bq/kg of radium-226, from to 0.18 to 2.83 Bq/kg for thorium -232 and from 0.8 to 1.13 Bq/kg for potassium. Implementing new ICRP recommendation of exemption and clearness indicated that several Ophthalmic Glass should not be in use

  6. Ethernet-based automation in radioactivity measurements

    The paper describes an integrated radioactivity measurements laboratory involved in a New York State program of monitoring environmental radioactivity and bioassay samples. The laboratory is set up as a comprehensive Ethernet network that integrates radiation detectors, electronics hardware components as well as software automation and communications. Two DEC VAXstations 3100 and 3200 are central to the system. The VAXstation 3100 runs the Canberra/Nuclear Data Genie data-acquisition program. The Acquisition Interface Modules interface the ADCs to the Ethernet. Using the DEC Pathworks, the VAXstation 3100 is also a server for the Ethernet-based network of several 486 and 386 PCs. A designated PC can display the Genie acquisition window, in addition to the main window at VAXstation 3100. Another PC collects data from several NaI detectors using the Oxford/Nucleus DMR-II program. The paper also describe the plans for the future upgrades such as installation of VAXstation 4000/90 as well as interfacing the proportional counters and surface barrier detectors to the network

  7. Measures of radioactivity: a tool for understanding statistical data analysis

    Montalbano, Vera; Quattrini, Sonia

    2012-01-01

    A learning path on radioactivity in the last class of high school is presented. An introduction to radioactivity and nuclear phenomenology is followed by measurements of natural radioactivity. Background and weak sources are monitored for days or weeks. The data are analyzed in order to understand the importance of statistical analysis in modern physics.

  8. Calibrating the absolute amplitude scale for air showers measured at LOFAR

    Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These pulses have been measured successfully in the past few years at the LOw-Frequency ARray (LOFAR) and are used to study the properties of cosmic rays. For a complete understanding of this phenomenon and the underlying physical processes, an absolute calibration of the detecting antenna system is needed. We present three approaches that were used to check and improve the antenna model of LOFAR and to provide an absolute calibration of the whole system for air shower measurements. Two methods are based on calibrated reference sources and one on a calibration approach using the diffuse radio emission of the Galaxy, optimized for short data-sets. An accuracy of 19% in amplitude is reached. The absolute calibration is also compared to predictions from air shower simulations. These results are used to set an absolute energy scale for air shower measurements and can be used as a basis for an absolute scale for the measurement of astronomical transients with LOFAR

  9. Calibrating the absolute amplitude scale for air showers measured at LOFAR

    Nelles, A.; Hörandel, J. R.; Karskens, T.; Krause, M.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Erdmann, M.; Falcke, H.; Haungs, A.; Hiller, R.; Huege, T.; Krause, R.; Link, K.; Norden, M. J.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; Schröder, F. G.; ter Veen, S.; Thoudam, S.; Trinh, T. N. G.; Weidenhaupt, K.; Wijnholds, S. J.; Anderson, J.; Bähren, L.; Bell, M. E.; Bentum, M. J.; Best, P.; Bonafede, A.; Bregman, J.; Brouw, W. N.; Brüggen, M.; Butcher, H. R.; Carbone, D.; Ciardi, B.; de Gasperin, F.; Duscha, S.; Eislöffel, J.; Fallows, R. A.; Frieswijk, W.; Garrett, M. A.; van Haarlem, M. P.; Heald, G.; Hoeft, M.; Horneffer, A.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Kohler, J.; Kondratiev, V. I.; Kuniyoshi, M.; Kuper, G.; van Leeuwen, J.; Maat, P.; McFadden, R.; McKay-Bukowski, D.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pandey, V. N.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Röttgering, H.; Schwarz, D.; Serylak, M.; Sluman, J.; Smirnov, O.; Tasse, C.; Toribio, M. C.; Vermeulen, R.; van Weeren, R. J.; Wijers, R. A. M. J.; Wucknitz, O.; Zarka, P.

    2015-11-01

    Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These pulses have been measured successfully in the past few years at the LOw-Frequency ARray (LOFAR) and are used to study the properties of cosmic rays. For a complete understanding of this phenomenon and the underlying physical processes, an absolute calibration of the detecting antenna system is needed. We present three approaches that were used to check and improve the antenna model of LOFAR and to provide an absolute calibration of the whole system for air shower measurements. Two methods are based on calibrated reference sources and one on a calibration approach using the diffuse radio emission of the Galaxy, optimized for short data-sets. An accuracy of 19% in amplitude is reached. The absolute calibration is also compared to predictions from air shower simulations. These results are used to set an absolute energy scale for air shower measurements and can be used as a basis for an absolute scale for the measurement of astronomical transients with LOFAR.

  10. Measurement of statistical evidence on an absolute scale following thermodynamic principles

    Vieland, V J; Hodge, S E; Seok, S -C

    2013-01-01

    Statistical analysis is used throughout biomedical research and elsewhere to assess strength of evidence. We have previously argued that typical outcome statistics (including p-values and maximum likelihood ratios) have poor measure-theoretic properties: they can erroneously indicate decreasing evidence as data supporting an hypothesis accumulate; and they are not amenable to calibration, necessary for meaningful comparison of evidence across different study designs, data types, and levels of analysis. We have also previously proposed that thermodynamic theory, which allowed for the first time derivation of an absolute measurement scale for temperature (T), could be used to derive an absolute scale for evidence (E). Here we present a novel thermodynamically-based framework in which measurement of E on an absolute scale, for which "one degree" always means the same thing, becomes possible for the first time. The new framework invites us to think about statistical analyses in terms of the flow of (evidential) i...

  11. Absolute measurement of the DT primary neutron yield on the National Ignition Facility

    Leeper R.J.; Bleuel D. L.; Frenje J.A.; Eckart M.J.; Hartouni E.; Kilkenny J.D.; Casey D.T.; Chandler G.A.; Cooper G.W.; Glebov V.Yu.; Hagmann C.; Johnson M. Gatu; Knauer J.P.; Knittel K.M.; Linden-Levy L.A.

    2013-01-01

    The measurement of the absolute neutron yield produced in inertial confinement fusion target experiments conducted on the National Ignition Facility (NIF) is essential in benchmarking progress towards the goal of achieving ignition on this facility. This paper describes three independent diagnostic techniques that have been developed to make accurate and precise DT neutron yield measurements on the NIF.

  12. Absolute measurement of the DT primary neutron yield on the National Ignition Facility

    Leeper R.J.

    2013-11-01

    Full Text Available The measurement of the absolute neutron yield produced in inertial confinement fusion target experiments conducted on the National Ignition Facility (NIF is essential in benchmarking progress towards the goal of achieving ignition on this facility. This paper describes three independent diagnostic techniques that have been developed to make accurate and precise DT neutron yield measurements on the NIF.

  13. Absolute measurement of the DT primary neutron yield on the National Ignition Facility

    The measurement of the absolute neutron yield produced in inertial confinement fusion target experiments conducted on the National Ignition Facility (NIF) is essential in benchmarking progress towards the goal of achieving ignition on this facility. This paper describes three independent diagnostic techniques that have been developed to make accurate and precise DT neutron yield measurements on the NIF. (authors)

  14. A technique for the absolute measurement of the W-value for X-rays in counting gases

    Vinagre, F.L.R. E-mail: fleonor@saturno.fis.uc.pt; Conde, C.A.N

    2000-08-11

    A technique was developed for the absolute measurement of the W-value (the mean energy for the production of an electron-ion pair) for low-energy X-rays in a wide range of gases at atmospheric pressures, with a standard uncertainty better than 1%. This technique is based on the absolute measurement of the primary ionization charge produced by X-ray photons from a constant intensity monoenergetic X-ray source, e.g. a long lifetime radioactive source. The ionization charge is calibrated by the number of X-ray photons absorbed in the gas, counted with a photon detector. For this purpose, a hybrid detector system was tested and its use in W-value measurements was investigated. The technique was applied to pure xenon at 825 Torr with 5.9 keV X-rays and a W-value of 21.61{sub -0.10}{sup +0.14} eV was obtained for a 68% confidence level. The required corrections and the different factors contributing to the accuracy of the results are discussed. The advantages and limitations of this technique are explored and future developments are discussed.

  15. Absolute frequency measurement of the 1S0 - 3P0 transition of 171Yb

    Pizzocaro, Marco; Rauf, Benjamin; Bregolin, Filippo; Milani, Gianmaria; Clivati, Cecilia; Costanzo, Giovanni A; Levi, Filippo; Calonico, Davide

    2016-01-01

    We report the absolute frequency measurement of the unperturbed transition 1S0 - 3P0 at 578 nm in 171Yb realized in an optical lattice frequency standard. The absolute frequency is measured 518 295 836 590 863.55(28) Hz relative to a cryogenic caesium fountain with a fractional uncertainty of 5.4x10-16 . This value is in agreement with the ytterbium frequency recommended as a secondary representation of the second in the International System of Units.

  16. First Absolutely Calibrated Localized Measurements of Ion Velocity in the MST in Locked and Rotating Plasmas

    Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; Munaretto, S.

    2015-11-01

    An Ion Doppler Spectrometer (IDS) is used on MST for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometer records data within 0.3 nm of the C+5 line of interest, and commercial calibration lamps do not produce lines in this narrow range . A novel optical system was designed to absolutely calibrate the IDS. The device uses an UV LED to produce a broad emission curve in the desired region. A Fabry-Perot etalon filters this light, cutting transmittance peaks into the pattern of the LED emission. An optical train of fused silica lenses focuses the light into the IDS with f/4. A holographic diffuser blurs the light cone to increase homogeneity. Using this light source, the absolute Doppler shift of ion emissions can be measured in MST plasmas. In combination with charge exchange recombination spectroscopy, localized ion velocities can now be measured. Previously, a time-averaged measurement along the chord bisecting the poloidal plane was used to calibrate the IDS; the quality of these central chord calibrations can be characterized with our absolute calibration. Calibration errors may also be quantified and minimized by optimizing the curve-fitting process. Preliminary measurements of toroidal velocity in locked and rotating plasmas will be shown. This work has been supported by the US DOE.

  17. Physical Measure and Absolute Continuity for One-Dimensional Center Direction

    Viana, Marcelo

    2010-01-01

    For a class of partially hyperbolic $C^k$, $k>1$ diffeomorphisms with circle center leaves we prove existence and finiteness of physical (or Sinai-Ruelle-Bowen) measures, whose basins cover a full Lebesgue measure subset of the ambient manifold. Our conditions contain an open and dense subset of all $C^k$ partially hyperbolic skew-products on compact circle bundles. Our arguments blend ideas from the theory of Gibbs states for diffeomorphisms with mostly contracting center direction together with recent progress in the theory of cocycles over hyperbolic systems that call into play geometric properties of invariant foliations such as absolute continuity. Recent results show that absolute continuity of the center foliation is often a rigid property among volume preserving systems. We prove that this is not at all the case in the dissipative setting, where absolute continuity can even be robust.

  18. Radioactivity measurements using storage phosphor technology

    Cheng, Y.T. [NeuTek, Darnestown, MD (United States); Hwang, J. [Advanced Technologies and Labs. International, Rockville, MD (United States); Hutchinson, M.R. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    1995-10-01

    We propose to apply a recently developed charged particle radiation imaging concept in bio-medical research for fast, cost-effective characterization of radionuclides in contaminated sites and environmental samples. This concept utilizes sensors with storage photostimulable phosphor (SPP) technology as radiation detectors. They exhibit high sensitivity for all types of radiation and the response is linear over a wide dynamic range (>10{sup 5}), essential for quantitative analysis. These new sensors have an Active area of up to 35 cm x 43 cm in size and a spatial resolution as fine as 50 {mu}m. They offer considerable promise as large area detectors for fast characterization of radionuclides with an added ability to locate and identify hot spots. Tests with SPP sensors have found that a single alpha particle effect can be observed and an alpha field of 100 dpm/100 cm{sup 2} or a beta activity of 0.1 dpm/mm{sup 2} or gamma radiation of few {mu}R/hr can all be measured in minutes. Radioactive isotopes can further be identified by energy discrimination which is accomplished by placing different thicknesses of filter material in front of the sensor plate. For areas with possible neutron contamination, the sensors can be coupled to a neutron to charged particle converter screen, such as dysprosium foil to detect neutrons. Our study has shown that this approach can detect a neutron flux of 1 n/cm{sup 2}s or lower, again with only minutes of exposure time. The utilization of these new sensors can significantly reduce the time and cost required for many site characterization and environmental monitoring tasks. The {open_quotes}exposure{close_quotes} time for mapping radioactivity in an environmental sample may be in terms of minutes and offer a positional resolution not obtainable with presently used counting equipment. The resultant digital image will lend itself to ready analysis.

  19. Measurement Technology on 200 Liters Barrels of Radioactive Waste

    BAI; Lei; SHAO; Jie-wen; LIU; Da-ming; LIU; Hong-bin; CHENG; Yi-mei; HE; Li-xia; ZHU; Li-qun

    2012-01-01

    <正>The measurement device on 200 liters barrel of radioactive waste is designed following the rule of orderly measurement automatically, by using the technology of non-destructive to measure the mass of radioactive waste produced from fuel cycle. Device objects as shown in Fig. 1, which consists of the

  20. Perfusion measurements with radioactively labelled microspheres

    The technique and the evaluation of the microsphere-method are comprehensively represented in theory and practice. Some changes and new concepts are discussed, besides the known foundations and techniques, that assure an essential methodic improvement resp. practical simplifications. Two new formulas are derived within the frame of the theoretical principles, by which the absolute flux of shorts can be calculated, i.e. on the one hand in the case of known and on the other hand in the case of unknown applied amount of indicator. The determination of the optimal indicator dose is defined and formulated mathematically with respect to the experimental conditions to be expected. The matrix method was designed for the analysis of complex gamma spectra. Hereby there is no selective error accumulation in the case of low energy radio nuclids contrary to the so far exclusively used stripping technique. The number of possible error quantities was reduced by one resp. two variables. The error of particular radio nuclid components is quantitatively computed as standard deviation by means of the theory of approximated systems of linear equations. The external measurement of distance was developed. This technique is less susceptible for errors as the aliquota i.e. whole body measurement technique. Additionally less measurement time is needed. A flexible computer program for a desk top computer was developped for the evaluation. The data from the gamma spectrometer are recorded on tipe and automatically read in by the computer. The manual input are limited to the weights of the organs and some control parameter. The output is made by a clearly arranged table by means of a lineprinter. (orig./MG)

  1. Absolute calibration of a wideband antenna and spectrometer for sky noise spectral index measurements

    Rogers, Alan E E

    2012-01-01

    A new method of absolute calibration of sky noise temperature using a three-position switched spectrometer, measurements of antenna and low noise amplifier impedance with a vector network analyzer, and ancillary measurements of the amplifier noise waves is described. The details of the method and its application to accurate wideband measurements of the spectral index of the sky noise are described and compared with other methods.

  2. Methods of measuring radioactivity in the environment

    A variety of sampling methods have been utilized to assess the amount of deposited activity, mainly from 137Cs, from the Chernobyl accident and from nuclear weapons tests. Starting with the Chernobyl accident in 1986 sampling of air and rain was used to determine the composition and amount of radioactive debris from this accident. The resulting deposition and its removal from urban areas was then studied through measurements on sewage sludge and water. The main part of the thesis considers methods of determining the amount of radiocesium in the ground through soil sampling. In connection with soil sampling a method of optimizing the sampling procedure has been developed and tested in the areas of Sweden with high amounts of 137Cs from the Chernobyl accident. This method was then used in a survey of the activity in soil in Scania (south Sweden) with fallout activity from nuclear weapons and Chernobyl. By comparing the results from this survey with deposition calculated from precipitation measurements it was found possible to predict the deposition pattern over Scania for both nuclear weapons and Chernobyl fallout. In addition, the vertical distribution of 137Cs has been modelled and the temporal variation of the depth distribution has been described. 65 refs

  3. Measurement of the absolute branching fraction of $D^{+}\\rightarrow\\bar K^0 e^{+}\

    Ablikim, M; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bettoni, D; Bian, J M; Bianchi, F; Boger, E; Boyko, I; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, H Y; Chen, J C; Chen, M L; Chen, S; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Cibinetto, G; Dai, H L; Dai, J P; Dbeyssi, A; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; De Mori, F; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Dou, Z L; Du, S X; Duan, P F; Fan, J Z; Fang, J; Fang, S S; Fang, X; Fang, Y; Farinelli, R; Fava, L; Fedorov, O; Feldbauer, F; Felici, G; Feng, C Q; Fioravanti, E; Fritsch, M; Fu, C D; Gao, Q; Gao, X L; Gao, X Y; Gao, Y; Gao, Z; Garzia, I; Goetzen, K; Gong, L; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, R P; Guo, Y; Guo, Y P; Haddadi, Z; Hafner, A; Han, S; Hao, X Q; Harris, F A; He, K L; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Hu, Y; Huang, G S; Huang, J S; Huang, X T; Huang, X Z; Huang, Y; Huang, Z L; Hussain, T; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L W; Jiang, X S; Jiang, X Y; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Ke, B C; Kiese, P; Kliemt, R; Kloss, B; Kolcu, O B; Kopf, B; Kornicer, M; Kupsc, A; Kühn, W; Lange, J S; Lara, M; Larin, P; Leng, C; Li, C; Li, Cheng; Li, D M; Li, F; Li, F Y; Li, G; Li, H B; Li, H J; Li, J C; Li, Jin; Li, K; Li, K; Li, Lei; Li, P R; Li, Q Y; Li, T; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, Y B; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; Liu, B; Liu, B J; Liu, C X; Liu, D; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, J Y; Liu, K; Liu, K Y; Liu, L D; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, H J; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lyu, X R; Ma, F C; Ma, H L; Ma, L L; Ma, M M; Ma, Q M; Ma, T; Ma, X N; Ma, X Y; Ma, Y M; Maas, F E; Maggiora, M; Mao, Y J; Mao, Z P; Marcello, S; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Mo, Y J; Morales, C Morales; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, S L; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Pan, Y; Patteri, P; Pelizaeus, M; Peng, H P; Peters, K; Pettersson, J; Ping, J L; Ping, R G; Poling, R; Prasad, V; Qi, H R; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Rosner, Ch; Ruan, X D; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Shi, M; Song, W M; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; Sun, X H; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, B L; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, W; Wang, W P; Wang, X F; Wang, Y; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Wang, Z Y; Weber, T; Wei, D H; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; Wu, L J; Wu, Z; Xia, L; Xia, L G; Xia, Y; Xiao, D; Xiao, H; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, J J; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H J; Yang, H X; Yang, L; Yang, Y X; Ye, M; Ye, M H; Yin, J H; Yu, B X; Yu, C X; Yu, J S; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zeng, Y; Zeng, Z; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J; Zhang, J J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, S Q; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y N; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhan, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, J Y; Zhao, J Z; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, W J; Zheng, Y H; Zhong, B; Zhou, L; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, S; Zhu, S H; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zotti, L; Zou, B S; Zou, J H

    2016-01-01

    By analyzing 2.93 fb$^{-1}$ data collected at the center-of-mass energy $\\sqrt s=3.773$ GeV with the BESIII detector, we measure the absolute branching fraction of the semileptonic decay $D^+\\rightarrow\\bar K^0 e^{+}\

  4. Measurements of the absolute branching fractions for $D_{s}^{+}\\rightarrow\\eta e^{+}\

    Ablikim, M; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bettoni, D; Bian, J M; Bianchi, F; Boger, E; Boyko, I; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, H Y; Chen, J C; Chen, M L; Chen, S; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Cibinetto, G; Dai, H L; Dai, J P; Dbeyssi, A; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; De Mori, F; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Dou, Z L; Du, S X; Duan, P F; Fan, J Z; Fang, J; Fang, S S; Fang, X; Fang, Y; Farinelli, R; Fava, L; Fedorov, O; Feldbauer, F; Felici, G; Feng, C Q; Fioravanti, E; Fritsch, M; Fu, C D; Gao, Q; Gao, X L; Gao, X Y; Gao, Y; Gao, Z; Garzia, I; Goetzen, K; Gong, L; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, R P; Guo, Y; Guo, Y P; Haddadi, Z; Hafner, A; Han, S; Hao, X Q; Harris, F A; He, K L; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Hu, Y; Huang, G S; Huang, J S; Huang, X T; Huang, X Z; Huang, Y; Huang, Z L; Hussain, T; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L W; Jiang, X S; Jiang, X Y; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Ke, B C; Kiese, P; Kliemt, R; Kloss, B; Kolcu, O B; Kopf, B; Kornicer, M; Kupsc, A; Kühn, W; Lange, J S; Lara, M; Larin, P; Leng, C; Li, C; Li, Cheng; Li, D M; Li, F; Li, F Y; Li, G; Li, H B; Li, H J; Li, J C; Li, Jin; Li, K; Li, K; Li, Lei; Li, P R; Li, Q Y; Li, T; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, Y B; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; Liu, B; Liu, B J; Liu, C X; Liu, D; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, J Y; Liu, K; Liu, K Y; Liu, L D; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, H J; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lyu, X R; Ma, F C; Ma, H L; Ma, L L; Ma, M M; Ma, Q M; Ma, T; Ma, X N; Ma, X Y; Ma, Y M; Maas, F E; Maggiora, M; Mao, Y J; Mao, Z P; Marcello, S; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Mo, Y J; Morales, C Morales; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, S L; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Pan, Y; Patteri, P; Pelizaeus, M; Peng, H P; Peters, K; Pettersson, J; Ping, J L; Ping, R G; Poling, R; Prasad, V; Qi, H R; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Rosner, Ch; Ruan, X D; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Shi, M; Song, W M; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; Sun, X H; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, B L; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, W; Wang, W P; Wang, X F; Wang, Y; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Wang, Z Y; Weber, T; Wei, D H; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; Wu, L J; Wu, Z; Xia, L; Xia, L G; Xia, Y; Xiao, D; Xiao, H; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, J J; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H J; Yang, H X; Yang, L; Yang, Y X; Ye, M; Ye, M H; Yin, J H; Yu, B X; Yu, C X; Yu, J S; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zeng, Y; Zeng, Z; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J; Zhang, J J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, S Q; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y N; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhan, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, J Y; Zhao, J Z; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, W J; Zheng, Y H; Zhong, B; Zhou, L; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, S; Zhu, S H; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zotti, L; Zou, B S; Zou, J H

    2016-01-01

    By analyzing 482 pb$^{-1}$ of $e^+e^-$ collision data collected at $\\sqrt s=4.009$ GeV with the BESIII detector at the BEPCII storage ring, we measure the absolute branching fractions for the semileptonic decays $D_{s}^{+}\\to\\eta e^{+}\

  5. Low geometry counter for the absolute measurement of the activity of alpha-emitting sources

    A low-geometry counter is described which allows the absolute determination of the activity for alpha-emitting sources. A Si implanted detector is used to obtain the spectrum of the sample. Two samples are measured with this counter and a 2 π gridded ion chamber. The results an their uncertainties for both instruments are discussed. (Author)

  6. Superharp: A wire scanner with absolute position readout for beam energy measurement at CEBAF

    Superharp is an upgrade CEBAF wire scanner with absolute position readout from shaft encoder. As high precision absolute beam position probe (Δx ∼ 10μm), three pairs of superharps are installed at the entrance, the mid-point, and the exit of Hall C arc beamline in beam switch yard, which will be tuned in dispersive mode as energy spectrometer performing 10-3 beam energy measurement. With dual sensor system: the direct current pickup and the bremsstrahlung detection electronics, beam profile can be obtained by superharp at wide beam current range from 1 μA to 100 μA

  7. Re-creating Gauss's method for non-electrical absolute measurements of magnetic fields and moments

    Van Baak, D. A.

    2013-10-01

    In 1832, Gauss made the first absolute measurements of magnetic fields and of magnetic moments in experiments that are straightforward and instructive to replicate. We show, using rare-earth permanent magnets and a variation of Gauss's technique, that the horizontal component of the ambient geomagnetic field, as well as the size of the magnetic moments of such magnets, can be found. The method shows the connection between the SI and cgs emu unit systems for these quantities and permits an absolute realization of the Ampere with considerable precision.

  8. Absolute phase retrieval for defocused fringe projection three-dimensional measurement

    Zheng, Dongliang; Da, Feipeng

    2014-02-01

    Defocused fringe projection three-dimensional technique based on pulse-width modulation (PWM) can generate high-quality sinusoidal fringe patterns. It only uses slightly defocused binary structured patterns which can eliminate the gamma problem (i.e. nonlinear response), and the phase error can be significantly reduced. However, when the projector is defocused, it is difficult to retrieve the absolute phase from the wrapped phase. A recently proposed phase coding method is efficient for absolute phase retrieval, but the gamma problem leads this method not so reliable. In this paper, we use the PWM technique to generate fringe patterns for the phase coding method. The gamma problem of the projector can be eliminated, and correct absolute phase can be retrieved. The proposed method only uses two grayscale values (0's and 255's), which can be used for real-time 3D shape measurement. Both simulation and experiment demonstrate the performance of the proposed method.

  9. Present status and prospects of ultralow level radioactivity measurements (3). Environmental radioactivity monitoring in Japan

    The environmental radioactivity survey in Japan is explained. There are two kinds of surveys such as monitoring around nuclear facilities and the environmental radioactivity survey. On monitoring around the nuclear facilities, its objects, monitoring at ordinary times and in an emergency, the measurement items, radioactive materials analysis, evaluation and open to the public of monitoring results and guarantee of monitoring quality are reported. On environmental radioactivity survey in wide area, its objects, environmental radioactivity survey, working organizations, fallout measurement, concentration of radon in foods, neutron dose, natural radionuclide and nuclides in relation to reprocessing plants are measured. The measurement results are opened on Web site; http://www.kankyo-hoshano.go.jp/ and http://www.search.kankyo-hoshano.go.jp/. (S.Y.)

  10. Measurement of Absolute Hadronic Branching Fractions of D_s Mesons

    Adam, N; Berkelman, K; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Weinberger, M; Athar, S B; Patel, R; Potlia, V; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Wiss, J; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Zweber, P; Dobbs, S; Metreveli, Z V; Seth, K K; Tomaradze, A G; Ernst, J; Severini, H; Dytman, S A; Love, W; Savinov, V; Aquines, O; Li, Z; López, A; Mehrabyan, S S; Méndez, H; Ramírez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Briere, R A; Brock, I; Chen, J; Ferguson, T; Tatishvili, G T; Vogel, H; Watkins, M E; Rosner, J L

    2006-01-01

    We report preliminary measurements of absolute hadronic branching fractions of Ds mesons determined using a double tag technique. These measurements are from 195 pb^{-1} of e+e- collisions recorded at center of mass energies near 4.17 GeV with the CLEO-c detector at CESR. We obtain absolute branching fractions for Ds+ decays to KS0 K+, K- K+ pi+, K- K+ pi+ pi-, pi+ pi+ pi-, pi+ eta, and pi+ etaprime. We discuss the problems inherent in measuring accurately the branching fraction for Ds+ to phi pi+, which is often used as a reference mode for measurement of other Ds+ branching fractions, and provide a measurement of a branching fraction that may be useful for this purpose.

  11. Radioactivity

    This pedagogical document presents the origin, effects and uses of radioactivity: where does radioactivity comes from, effects on the body, measurement, protection against radiations, uses in the medical field, in the electric power industry, in the food (ionization, radio-mutagenesis, irradiations) and other industries (radiography, gauges, detectors, irradiations, tracers), and in research activities (dating, preservation of cultural objects). The document ends with some examples of irradiation levels (examples of natural radioactivity, distribution of the various sources of exposure in France). (J.S.)

  12. Demonstrating the Error Budget for the Climate Absolute Radiance and Refractivity Observatory Through Solar Irradiance Measurements

    Thome, Kurtis; McCorkel, Joel; McAndrew, Brendan

    2016-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission addresses the need to observe highaccuracy, long-term climate change trends and to use decadal change observations as a method to determine the accuracy of climate change. A CLARREO objective is to improve the accuracy of SI-traceable, absolute calibration at infrared and reflected solar wavelengths to reach on-orbit accuracies required to allow climate change observations to survive data gaps and observe climate change at the limit of natural variability. Such an effort will also demonstrate National Institute of Standards and Technology (NIST) approaches for use in future spaceborne instruments. The current work describes the results of laboratory and field measurements with the Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) which is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO. SOLARIS allows testing and evaluation of calibration approaches, alternate design and/or implementation approaches and components for the CLARREO mission. SOLARIS also provides a test-bed for detector technologies, non-linearity determination and uncertainties, and application of future technology developments and suggested spacecraft instrument design modifications. Results of laboratory calibration measurements are provided to demonstrate key assumptions about instrument behavior that are needed to achieve CLARREO's climate measurement requirements. Absolute radiometric response is determined using laser-based calibration sources and applied to direct solar views for comparison with accepted solar irradiance models to demonstrate accuracy values giving confidence in the error budget for the CLARREO reflectance retrieval.

  13. Natural radioactivity measurements in Pahang State, Malaysia.

    Gabdo, Hamman Tukur; Ramli, Ahmad Termizi; Saleh, Muneer Aziz; Garba, Nuraddeen Nasiru; Sanusi, Mohamad

    2016-06-01

    This study was aimed at providing the baseline data of terrestrial gamma dose rates and natural radioactivity to assess the corresponding health risk in the ambient environment of the Pahang State. Terrestrial gamma radiation (TGR) from 640 locations was measured with the mean value found to be 176 ± 5 nGy h(-1). Ninety-eight soil samples were analysed using a high-purity germanium detector (HPGe), and the mean concentrations of the radionuclides (226)Ra, (232)Th and (40)K are 110 ± 3, 151 ± 5 and 542 ± 51 Bq kg(-1), respectively.(226)Ra and (232)Th concentrations were found to be three times the world average, while that of (40)K is quite higher than the world average value. The acid-intrusive geological formation has the highest mean concentrations for (226)Ra (215 ± 6 Bq kg(-1)), (232)Th (384 ± 12 Bq kg(-1)) and (40)K (1564 ± 153 Bq kg(-1)). The radium equivalent activities (Req) and the external hazard index (Hex) for the various soil types were also calculated. Some of the soil types were found to have values exceeding the internationally recommended levels of 370 Bq kg(-1) and the unity value, respectively. PMID:26999725

  14. Absolute Neutron Fluence Measurements at the NIST Center for Neutron Research

    Yue, A.; Dewey, M.; Gilliam, D.; Nico, J.; Anderson, E.; Snow, M.; Greene, G.; Laptev, A.

    2015-10-01

    Precise, absolute fluence measurements of cold and thermal neutron beams are of primary importance to beam-type determinations of the neutron lifetime, measurements of standard neutron cross sections, and the development of standards for neutron dosimetry. At the National Institute of Standards and Technology (NIST), a totally absorbing neutron detector based on absolute counting of the 10B(n,α1)7Li reaction 478 keV gamma ray has been used to perform fluence measurements with a precision of 0.06%. This detector has been used to improve the neutron fluence determination in the 2000 NIST beam neutron lifetime by a factor of five, significantly reducing the uncertainty in the lifetime result. Ongoing and possible future uses of the Alpha-Gamma device include 1) Calibration of the neutron fluence monitors that will be used in the upcoming NIST beam neutron lifetime measurement BL2; 2) The first direct, absolute measurement of the 6Li(n,t)4He neutron cross section at sub-thermal neutron energy; 3) Measurements of the 10B(n, γ)11B and 235U(n,f) neutron cross sections; 4) A re-calibration of the national neutron standard NBS-1. The apparatus, measurement technique, and applications will be discussed.

  15. Frequency-scanning interferometry for dynamic absolute distance measurement using Kalman filter.

    Tao, Long; Liu, Zhigang; Zhang, Weibo; Zhou, Yangli

    2014-12-15

    We propose a frequency-scanning interferometry using the Kalman filtering technique for dynamic absolute distance measurement. Frequency-scanning interferometry only uses a single tunable laser driven by a triangle waveform signal for forward and backward optical frequency scanning. The absolute distance and moving speed of a target can be estimated by the present input measurement of frequency-scanning interferometry and the previously calculated state based on the Kalman filter algorithm. This method not only compensates for movement errors in conventional frequency-scanning interferometry, but also achieves high-precision and low-complexity dynamic measurements. Experimental results of dynamic measurements under static state, vibration and one-dimensional movement are presented. PMID:25503050

  16. A novel method for the absolute fluorescence yield measurement by AIRFLY

    Ave, M

    2008-01-01

    One of the goals of the AIRFLY (AIR FLuorescence Yield) experiment is to measure the absolute fluorescence yield induced by electrons in air to better than 10% precision. We introduce a new technique for measurement of the absolute fluorescence yield of the 337 nm line that has the advantage of reducing the systematic uncertainty due to the detector calibration. The principle is to compare the measured fluorescence yield to a well known process - the Cerenkov emission. Preliminary measurements taken in the BFT (Beam Test Facility) in Frascati, Italy with 350 MeV electrons are presented. Beam tests in the Argonne Wakefield Accelerator at the Argonne National Laboratory, USA with 14 MeV electrons have also shown that this technique can be applied at lower energies.

  17. Polarized H- Jet Polarimeter For Absolute Proton Polarization Measurements in RHIC

    Status of the H-jet polarimeter development is reviewed. A number of design issues are discussed including vacuum system, integration into the RHIC storage ring, scattering chamber, and uniform vertical holding field magnet design. The absolute proton polarization of the atomic hydrogen-jet target will be measured to 3% accuracy by a Breit- systematic error contribution to the jet-target polarization measurements is also discussed

  18. Hilbertian sine as an absolute measure of Bayesian inference in ISR, homeland security, medicine, and defense

    Jannson, Tomasz; Wang, Wenjian; Hodelin, Juan; Forrester, Thomas; Romanov, Volodymyr; Kostrzewski, Andrew

    2016-05-01

    In this paper, Bayesian Binary Sensing (BBS) is discussed as an effective tool for Bayesian Inference (BI) evaluation in interdisciplinary areas such as ISR (and, C3I), Homeland Security, QC, medicine, defense, and many others. In particular, Hilbertian Sine (HS) as an absolute measure of BI, is introduced, while avoiding relativity of decision threshold identification, as in the case of traditional measures of BI, related to false positives and false negatives.

  19. Laser induced deflection (LID) method for absolute absorption measurements of optical materials and thin films

    Mühlig, Christian; Bublitz, Simon; Paa, Wolfgang

    2011-05-01

    We use optimized concepts to measure directly low absorption in optical materials and thin films at various laser wavelengths by the laser induced deflection (LID) technique. An independent absolute calibration, using electrical heaters, is applied to obtain absolute absorption data without the actual knowledge of the photo-thermal material properties. Verification of the absolute calibration is obtained by measuring different silicon samples at 633 nm where all laser light, apart from the measured reflection/scattering, is absorbed. Various experimental results for bulk materials and thin films are presented including measurements of fused silica and CaF2 at 193 nm, nonlinear crystals (LBO) for frequency conversion and AR coated fused silica for high power material processing at 1030 nm and Yb-doped silica raw materials for high power fiber lasers at 1550 nm. In particular for LBO the need of an independent calibration is demonstrated since thermal lens generation is dominated by stress-induced refractive index change which is in contrast to most of the common optical materials. The measured results are proven by numerical simulations and their influence on the measurement strategy and the obtained accuracy are shown.

  20. Absolute frequency measurements and hyperfine structures of the molecular iodine transitions at 578 nm

    Kobayashi, Takumi; Hosaka, Kazumoto; Inaba, Hajime; Okubo, Sho; Tanabe, Takehiko; Yasuda, Masami; Onae, Atsushi; Hong, Feng-Lei

    2016-01-01

    We report absolute frequency measurements of 81 hyperfine components of the rovibrational transitions of molecular iodine at 578 nm using the second harmonic generation of an 1156-nm external-cavity diode laser and a fiber-based optical frequency comb. The relative uncertainties of the measured absolute frequencies are typically $1.4\\times10^{-11}$. Accurate hyperfine constants of four rovibrational transitions are obtained by fitting the measured hyperfine splittings to a four-term effective Hamiltonian including the electric quadrupole, spin-rotation, tensor spin-spin, and scalar spin-spin interactions. The observed transitions can be good frequency references at 578 nm, and are especially useful for research using atomic ytterbium since the transitions are close to the $^{1}S_{0}-^{3}P_{0}$ clock transition of ytterbium.

  1. Measuring the absolute DT neutron yield using the Magnetic Recoil Spectrometer at OMEGA and the NIF

    A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  2. Measuring the absolute DT neutron yield using the Magnetic Recoil Spectrometer at OMEGA and the NIF

    Mackinnon, A; Casey, D; Frenje, J A; Johnson, M G; Seguin, F H; Li, C K; Petrasso, R D; Glebov, V Y; Katz, J; Knauer, J; Meyerhofer, D; Sangster, T; Bionta, R; Bleuel, D; Hachett, S P; Hartouni, E; Lepape, S; Mckernan, M; Moran, M; Yeamans, C

    2012-05-03

    A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  3. Absolute measurement of neutron source emission rate with manganese bath method

    The manganese bath method is one of the most widespread and exact method to measure neutron source emission rate (neutron source intensity) absolutely at present. Pouring some 56Mn solution with known activity into the bath, the system efficiency can be obtained from γ counts of 56Mn, which is measured by two NaI(Tl) detectors. From saturated counts of a 241Am-Be(α, n) neutron source in the bath, the source emission rate can be obtained. An standard 241Am-Be(α, n) source which is the transfer source of the CCRI(Ⅲ)-K9. AmBe international key comparison organized by the Comite Consultatif des Rayonnements Ionisants, was measured absolutely with the neutron source emission rate standard equipment (manganese bath method). The result is coincident with the average value of the comparison within the uncertainties, therefore the reliability of the standard equipment is verified. (authors)

  4. Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

    Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

    2016-06-01

    A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

  5. High-precision gravity measurements using absolute and relative gravimeters at Mount Etna (Sicily, Italy

    Ciro Del Negro

    2011-12-01

    Full Text Available Accurate detection of time gravity changes attributable to the dynamics of volcanoes requires high-precision gravity measurements. With the aim of improving the quality of data from the Mount Etna gravity network, we used both absolute and relative gravimeters in a hybrid method. In this report, some of the techniques for gravity surveys are reviewed, and the results related to each method are compared. We show how the total uncertainty estimated for the gravity measurements performed with this combined use of absolute and relative gravimeters is roughly comparable to that calculated when the measurements are acquired using only relative gravimeters (the traditional method. However, the data highlight how the hybrid approach improves the measurement capabilities for surveying the Mount Etna volcanic area. This approach enhances the accuracy of the data, and then of the four-dimensional surveying, which minimizes ambiguities inherent in the gravity measurements. As a case study, we refer to two gravity datasets acquired in 2005 and 2010 from the western part of the Etna volcano, which included five absolute and 13 relative stations of the Etna gravity network.

  6. Laser induced deflection technique for absolute thin film absorption measurement: optimized concepts and experimental results

    Using experimental results and numerical simulations, two measuring concepts of the laser induced deflection (LID) technique are introduced and optimized for absolute thin film absorption measurements from deep ultraviolet to IR wavelengths. For transparent optical coatings, a particular probe beam deflection direction allows the absorption measurement with virtually no influence of the substrate absorption, yielding improved accuracy compared to the common techniques of separating bulk and coating absorption. For high-reflection coatings, where substrate absorption contributions are negligible, a different probe beam deflection is chosen to achieve a better signal-to-noise ratio. Various experimental results for the two different measurement concepts are presented.

  7. Absolute Frequency Measurements of the D1 and D2 Transitions in Aatomic Li

    Sheets, Donal; Almaguer, Jose; Baron, Jacob; Elgee, Peter; Rowan, Michael; Stalnaker, Jason

    2014-05-01

    We present preliminary results from our measurements of the D1 and D2 transitions in Li. The data were obtained from a collimated atomic beam excited by light from an extended cavity diode laser. The frequency of the diode laser was stabilized to an optical frequency comb, providing absolute frequency measurement and control of the excitation laser frequency. These measurements will provide a stringent test of atomic structure calculations and yield information about the nuclear structure. We also discuss plans to extend the technique to other high-lying states in lithium. Funded by the NIST Precision Measurements Grant and NSF Award #1305591.

  8. Absolute reaction rate measurement with D-D neutron source in polyethylene spherical shell

    The absolute reaction rate distribution measurements in a polyethylene spherical shell with 38.6 cm outside diameter and 10 cm thickness were performed with D-D neutron source. By combining fission method and activation method, rich-uranium fission chamber, depleted-uranium fission chamber, 237Np fission chamber and 115In activation foils were placed at several positions on the equatorial line of the inner face of the shell, and the absolute reaction rates were obtained. The uncertainty of fission rates is 2.5%-4.3%, while the uncertainty of activation rates is about 6.3%. The reaction rates were calculated by MCNP and ENDF/B-VII. 0. The calculated results are lower than the measured results and 238U is typical. (authors)

  9. Absolutely continuous invariant measure of a map from grazing-impact oscillators

    In this paper we investigate a one-dimensional map with unbounded derivative. The map is the limit of the Nordmark map which is the normal form of a discrete time representation of impact oscillators near grazing, i.e. when the dissipation of the systems is large, the Nordmark map can be viewed as a perturbation of the one-dimensional map. We prove that the map has an ergodic absolutely continuous invariant probability measure in a region of parameter space by constructing an induced Markov map. - Highlights: • We investigate a one-dimensional map with unbounded derivative. • The map is the limit of the Nordmark map which is the normal form of the impact oscillators near grazing states. • We prove that the map has an ergodic absolutely continuous invariant probability measure by constructing an induced Markov map

  10. Hyperspectral interferometry for single-shot absolute measurement of two-dimensional optical path distributions

    We propose a method that we call hyperspectral interferometry (HSI) to resolve the 2π phase unwrapping problem in the analysis of interferograms recorded with a narrow-band light source. By using a broadband light source and a hyperspectral imaging system, a set of interferograms at different wave numbers are recorded simultaneously on a high resolution image sensor. These are then assembled to form a three-dimensional intensity distribution. By Fourier transformation along the wave number axis, an absolute optical path difference is obtained for each pixel independently of the other pixels in the field of view. As a result, interferograms with spatially distinct regions are analysed as easily as continuous ones. The approach is illustrated with a HSI system to measure 3D profiles of optically smooth or rough surfaces. Compared to existing profilometers able to measure absolute path differences, the single-shot nature of the approach provides greater immunity from environmental disturbance

  11. Absolute nuclear energy measurements using the γ-γ coincidence method

    I n this report a summary is first given of the principle of the γ-γ calibration method, stress being laid on the corrections required. After a description of the equipment used, the choice of the experimental conditions required for various isotopes is discussed (22Na, 46Sc, 60Co, 88Y) and the agreement between these results and those obtained by other absolute measurement methods is considered. (authors)

  12. Absolute Polarization Measurements at RHIC in the Coulomb Nuclear Interference Region

    Eyser, K. O.; Alekseev, I.; Bravar, A; Bunce, G.; Dhawan, S.; Gill, R; Haeberli, W.; Huang, H.; Jinnouchi, O.; Makdisi, Y.; Nakagawa, I.; Nass, A.; Okada, H.; Stephenson, E.; Svirida, D.

    2006-01-01

    The Relativistic Heavy Ion Collider at Brookhaven National Laboratory provides polarized proton beams for the investigation of the nucleon spin structure. For polarimetry, carbon-proton and proton-proton scattering is used in the Coulomb nuclear interference region at small momentum transfer ($-t$). Fast polarization measurements of each beam are carried out with carbon fiber targets at several times during an accelerator store. A polarized hydrogen gas jet target is needed for absolute norma...

  13. Absolute measurement of the ultrafast nonlinear electronic and rovibrational response in H$_2$ and D$_2$

    Wahlstrand, J K; Cheng, Y -H; Palastro, J P; Milchberg, H M

    2015-01-01

    The electronic, rotational, and vibrational components of the ultrafast optical nonlinearity in H$_2$ and D$_2$ are measured directly and absolutely at intensities up to the ionization threshold of $\\sim$10$^{14}$ W/cm$^2$. As the most basic nonlinear interactions of the simplest molecules exposed to high fields, these results constitute a benchmark for high field laser-matter theory and simulation.

  14. Absolute Frequency Measurement of Rubidium 5S-7S Two-Photon Transitions

    Morzynski, Piotr; Ablewski, Piotr; Gartman, Rafal; Gawlik, Wojciech; Maslowski, Piotr; Nagorny, Bartlomiej; Ozimek, Filip; Radzewicz, Czeslaw; Witkowski, Marcin; Ciurylo, Roman; Zawada, Michal

    2013-01-01

    We report the absolute frequency measurements of rubidium 5S-7S two-photon transitions with a cw laser digitally locked to an atomic transition and referenced to an optical frequency comb. The narrow, two-photon transition, 5S-7S (760 nm) insensitive to first order in a magnetic field, is a promising candidate for frequency reference. The performed tests yield the transition frequency with accuracy better than reported previously.

  15. Use of relative and absolute effect measures in reporting health inequalities: structured review

    Nicholas B. King; Harper, Sam; Young, Meredith E

    2012-01-01

    Objective To examine the frequency of reporting of absolute and relative effect measures in health inequalities research. Design Structured review of selected general medical and public health journals. Data sources 344 articles published during 2009 in American Journal of Epidemiology, American Journal of Public Health, BMJ, Epidemiology, International Journal of Epidemiology, JAMA, Journal of Epidemiology and Community Health, The Lancet, The New England Journal of Medicine, and Social Scie...

  16. Geometry of expanding absolutely continuous invariant measures and the liftability problem

    We consider a quite broad class of maps on compact manifolds of arbitrary dimension possibly admitting critical points, discontinuities and singularities. Under some mild nondegeneracy assumptions we show that f admits an induced Gibbs-Markov map with integrable inducing times if and only if it has an ergodic invariant probability measure which is absolutely continuous with respect to the Riemannian volume and has all Lyapunov exponents positive. (author)

  17. FFTF (FAST FLUX TEST FACILITY) REACTOR CHARACTERIZATION PROGRAM ABSOLUTE FISSION RATE MEASUREMENTS

    FULLER JL; GILLIAM DM; GRUNDL JA; RAWLINS JA; DAUGHTRY JW

    1981-05-01

    Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

  18. FFTF (Fast Flux Test Facility) Reactor Characterization Program: Absolute Fission-rate Measurements

    Fuller, J.L.; Gilliam, D.M.; Grundl, J.A.; Rawlins, J.A.; Daughtry, J.W.

    1981-05-01

    Absolute fission rate measurements using modified National Bureau of Standards fission chambers were performed in the Fast Flux Test Facility at two core locations for isotopic deposits of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. Monitor chamber results at a third location were analyzed to support other experiments involving passive dosimeter fission rate determinations.

  19. A luminescent molecular thermometer for long-term absolute temperature measurements at the nanoscale

    Brites, Carlos; Lima, Patricia; Silva, Nuno Joâo O.; Millán, Ángel; Amaral, Vitor S.; Palacio, Fernando; Carlos, Luis D.

    2010-01-01

    A unique Eu3+/Tb3+ luminescent self-referencing nanothermometer allowing absolute measurements in the 10–350 K temperature range and sub-micrometer spatial resolution is reported (see Figure). It has up to 4.9%·K−1 temperature sensitivity and high photostability for long-term use. The combination of molecular thermometry, superparamagnetism and luminescence in a nanometric host matrix provides multifunctionality opening the way for new exciting applications.

  20. Precise Measurement of the Absolute Yield of Fluorescence Photons in Atmospheric Gases

    Ave, M; Daumiller, K; Di Carlo, P; Di Giulio, C; Luis, P Facal San; Gonzales, D; Hojvat, C; Hörandel, J R; Hrabovský, M; Iarlori, M; Keilhauer, B; Klages, H; Kleifges, M; Kuehn, F; Monasor, M; Nožka, L; Palatka, M; Petrera, S; Privitera, P; Ridky, J; Rizi, V; d'Orfeuil, B Rouillé; Salamida, F; Schovánek, P; Šmida, R; Spinka, H; Ulrich, A; Verzi, V; Williams, C

    2011-01-01

    We have performed a measurement of the absolute yield of fluorescence photons at the Fermilab Test Beam. A systematic uncertainty at 5% level was achieved by the use of Cherenkov radiation as a reference calibration light source. A cross-check was performed by an independent calibration using a laser light source. A significant improvement on the energy scale uncertainty of Ultra-High Energy Cosmic Rays is expected.

  1. Identification of radionuclide in radioactivity measurement with imaging plate

    In this paper, we describe the application of Imaging Plate (IP) to in-situ detection and distribution measurement of extremely low level radioactivity, such as slightly contaminated floor surface, lab-wear and lab-shoes in a controlled area or the natural radioactivity on the surfaces of various materials, and identification methods of the nuclide species. (J.P.N.)

  2. Frequency comparison and absolute frequency measurement of I{sub 2}-stabilized lasers at 532 nm

    Nevsky, A.Yu. [Sektion Physik der Ludwig-Maximilians-Univ. Muenchen (Germany)]|[Max-Planck-Inst. fuer Quantenoptik, Garching (Germany)]|[Inst. of Laser Physics, Novosibirsk (Russian Federation); Holzwarth, R.; Reichert, J.; Udem, T.; Haensch, T.W.; Zanthier, J. von; Walther, H. [Sektion Physik der Ludwig-Maximilians-Univ. Muenchen (Germany)]|[Max-Planck-Inst. fuer Quantenoptik, Garching (Germany); Schnatz, H.; Riehle, F. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Pokasov, P.V.; Skvortsov, M.N.; Bagayev, S.N. [Inst. of Laser Physics, Novosibirsk (Russian Federation)

    2001-07-01

    We present a frequency comparison and an absolute frequency measurement of two independent I{sub 2}-stabilized frequency-doubled Nd:YAG lasers at 532 nm, one set up at the Institute of Laser Physics, Novosibirsk, Russia, the other at the Physikalisch-Technische Bundesanstalt, Braunschweig, Germany. The absolute frequency of the I{sub 2}-stabilized lasers was determined using a CH{sub 4}-stabilized He-Ne laser as a reference. This laser had been calibrated prior to the measurement by an atomic cesium fountain clock. The frequency chain linking phase-coherently the two frequencies made use of the frequency comb of a Kerr-lens mode-locked Ti:sapphire femtosecond laser where the comb mode separation was controlled by a local cesium atomic clock. A new value for the R(56)32-0:a{sub 10} component, recommended by the Comite International des Poids et Mesures (CIPM) for the realization of the metre, was obtained with reduced uncertainty. Absolute frequencies of the R(56)32-0 and P(54)32-0 iodine absorption lines together with the hyperfine line separations were measured.

  3. Radio frequency controlled synthetic wavelength sweep for absolute distance measurement by optical interferometry

    We present a new technique applied to the variable optical synthetic wavelength generation in optical interferometry. It consists of a chain of optical injection locking among three lasers: first a distributed-feedback laser is used as a master to injection lock an intensity-modulated laser that is directly modulated around 15 GHz by a radio frequency generator on a sideband. A second distributed-feedback laser is injection locked on another sideband of the intensity-modulated laser. The variable synthetic wavelength for absolute distance measurement is simply generated by sweeping the radio frequency over a range of several hundred megahertz, which corresponds to the locking range of the two slave lasers. In this condition, the uncertainty of the variable synthetic wavelength is equivalent to the radio frequency uncertainty. This latter has a relative accuracy of 10-7 or better, resulting in a resolution of ±25 μm for distances exceeding tens of meters. The radio frequency generator produces a linear frequency sweep of 1 ms duration (i.e., exactly equal to one absolute distance measurement acquisition time), with frequency steps of about 1 MHz. Finally, results of absolute distance measurements for ranges up to 10 m are presented

  4. Radio frequency controlled synthetic wavelength sweep for absolute distance measurement by optical interferometry.

    Le Floch, Sébastien; Salvadé, Yves; Mitouassiwou, Rostand; Favre, Patrick

    2008-06-01

    We present a new technique applied to the variable optical synthetic wavelength generation in optical interferometry. It consists of a chain of optical injection locking among three lasers: first a distributed-feedback laser is used as a master to injection lock an intensity-modulated laser that is directly modulated around 15 GHz by a radio frequency generator on a sideband. A second distributed-feedback laser is injection locked on another sideband of the intensity-modulated laser. The variable synthetic wavelength for absolute distance measurement is simply generated by sweeping the radio frequency over a range of several hundred megahertz, which corresponds to the locking range of the two slave lasers. In this condition, the uncertainty of the variable synthetic wavelength is equivalent to the radio frequency uncertainty. This latter has a relative accuracy of 10(-7) or better, resulting in a resolution of +/-25 microm for distances exceeding tens of meters. The radio frequency generator produces a linear frequency sweep of 1 ms duration (i.e., exactly equal to one absolute distance measurement acquisition time), with frequency steps of about 1 MHz. Finally, results of absolute distance measurements for ranges up to 10 m are presented. PMID:18516123

  5. A flowrate measurement method by counting of radioactive particles suspended in a liquid

    By external counting of fine #betta# emitting radioactive particles suspended in a liquid, the flowrate in a system of pipes can be measured. The study comprises three phases: 1. - The hydraulic validity of the method is demonstrated in laminar as well as in turbulent flow under certain conditions of particles size and density and of liquid viscosity. 2. - Radioactive labelling of microspheres of serumalbumin or ion exchange resins with indium 113m delivered by a generator Tin 113 → Indium 113m. 3. - Counting with a scintillation detector: a method of threshold overstepping is experimented with a mechanical or electronic simulator; the statistical study of particle superposition under the detector enables a correction for the resulting counting losses to be proposed. The method provides absolute measurements, but is particularly suitable to measure relative flowrates in a hydraulic network. It can be continuous and does not perturb the flow and the network. The accuracy of the method is analysed in details

  6. LHCb: A novel method for an absolute luminosity measurement at LHCb using beam-gas imaging

    Barschel, C

    2013-01-01

    A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used van der Meer scan method (VDM). This poster presents the principles of the Beam Gas Imaging method used to measure the beam overlap integral. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch.

  7. Results of radioactivity measurements on foodstuffs in Romania

    There are presented the results of gamma-spectrometric measurements performed between 1986-1995 on: milk and dairy products; meat and meat products; fish; wheat flour; fresh fruits and vegetables. The foodstuffs are sampled from some representative areas like: Bucharest, Bechet (affected by Kozloduj NPP, Bulgaria), Cernavoda, middle of Transylvania, Neamt. The radioactivity measurements are performed by high-resolution γ-ray spectrometry. There are identified and analysed mainly 134Cs, 137Cs, 40K and, sometimes, other radionuclides. There are pointed out: the constancy of natural radionuclides amounts; the drastic increasing in radioactive concentration in May 1986; the seasonal variation of radioactivity in some food items; the time - exponential diminution of radioactivity in 1991-1995; and the maximum permitted levels of radioactive contamination of foodstuffs following a nuclear accident. (author)

  8. Modelling and measurement of the absolute level of power radiated by antenna integrated THz UTC photodiodes.

    Natrella, Michele; Liu, Chin-Pang; Graham, Chris; van Dijk, Frederic; Liu, Huiyun; Renaud, Cyril C; Seeds, Alwyn J

    2016-05-30

    We determine the output impedance of uni-travelling carrier (UTC) photodiodes at frequencies up to 400 GHz by performing, for the first time, 3D full-wave modelling of detailed UTC photodiode structures. In addition, we demonstrate the importance of the UTC impedance evaluation, by using it in the prediction of the absolute power radiated by an antenna integrated UTC, over a broad frequency range and confirming the predictions by experimental measurements up to 185 GHz. This is done by means of 3D full-wave modelling and is only possible since the source (UTC) to antenna impedance match is properly taken into account. We also show that, when the UTC-to-antenna coupling efficiency is modelled using the classical junction-capacitance/series-resistance concept, calculated and measured levels of absolute radiated power are in substantial disagreement, and the maximum radiated power is overestimated by a factor of almost 7 dB. The ability to calculate the absolute emitted power correctly enables the radiated power to be maximised through optimisation of the UTC-to-antenna impedance match. PMID:27410104

  9. A Method for Measurement of Absolute Angular Position and Application in a Novel Electromagnetic Encoder System

    Zijian Zhang

    2015-01-01

    Full Text Available For the encoders, especially the sine-cosine magnetic ones, a new method to measure absolute angular position is proposed in the paper. In the method, the code disc of the encoder has only two circle tracks and each one was divided into N and (N-1 equal code cells. The cell angles, changing from 0° to 360° between any two neighboring code cells, are defined to represent any position on the code disc. The position value of the same point can be represented by different cell angle values of different tracks and the absolute angular position of the point can be obtained by the difference value between the cell angle value of the outer track and the inner one. To validate the correctness of the method theoretically, the derivation process of the method was provided. An electromagnetic encoder system was designed and the experimental platform was established to test the method. The experimental results indicate that the electromagnetic encoder can measure the absolute angular position. Besides, it shows that the method is easy to be realized in algorithm and can reduce computational complexity and decrease dimension of the encoder.

  10. Scanning Laser Polarimetry for Measurement of Retinal Nerve Fiber Layer in Absolute, Advanced and Early Glaucoma

    Jen-Chia Tsai

    2006-04-01

    Full Text Available Background: To detect differences in retinal nerve fiber layer (RNFL measurements inabsolute, advanced and early glaucoma with scanning laser polarimetry (TheNerve Fiber Analyzer GDx, and to assess the usefulness and limitations ofthis technique for longitudinal follow-up of glaucoma patients.Methods: This is a prospective, cross-sectional study. Twenty-one eyes of 21 patientswith absolute glaucoma, twenty-six eyes of 26 patients with advanced glaucomaand twenty-four eyes of 24 patients with early glaucoma were imagedusing scanning laser polarimetry. The twelve standard GDx measurementparameters were compared using ANOVA (analysis of variance and theTukey test.Results: No significant differences were demonstrated for any of the twelve GDxmeasurement parameters between absolute and advanced glaucoma cases.There were significant differences for some GDx parameters, including theGDx number (p < 0.0001 superior ratio (p < 0.0001, inferior ratio (p <0.0001, superior/nasal ratio (p < 0.0001, maximum modulation (p <0.0001, ellipse modulation (p < 0.0001 and inferior average (p = 0.001between early and advanced glaucoma, and, between early and absoluteglaucoma. Significant differences were demonstrated for the superior average(p = 0.01 parameter between early and absolute glaucoma, but notbetween early and advanced glaucoma.Conclusions: For follow-up of glaucoma progression, RNFL measurements using scanninglaser polarimetry are more useful in the early stage than in the advancedstage.

  11. Absolute X-ray emission cross section measurements of Fe K transitions

    Hell, Natalie; Brown, Gregory V.; Beiersdorfer, Peter; Boyce, Kevin R.; Grinberg, Victoria; Kelley, Richard L.; Kilbourne, Caroline; Leutenegger, Maurice A.; Porter, Frederick Scott; Wilms, Jörn

    2016-06-01

    We have measured the absolute X-ray emission cross sections of K-shell transitions in highly charged L- and K-shell Fe ions using the LLNL EBIT-I electron beam ion trap and the NASA GSFC EBIT Calorimeter Spectrometer (ECS). The cross sections are determined by using the ECS to simultaneously record the spectrum of the bound-bound K-shell transitions and the emission from radiative recombination from trapped Fe ions. The measured spectrum is then brought to an absolute scale by normalizing the measured flux in the radiative recombination features to their theoretical cross sections, which are well known. Once the spectrum is brought to an absolute scale, the cross sections of the K-shell transitions are determined. These measurements are made possible by the ECS, which consists of a 32 channel array, with 14 channels optimized for detecting high energy photons (hν > 10 keV) and 18 channels optimized for detecting low energy photons (hν collection area, relatively high energy resolution, and a large bandpass; all properties necessary for this measurement technique to be successful. These data will be used to benchmark cross sections in the atomic reference data bases underlying the plasma modeling codes used to analyze astrophysical spectra, especially those measured by the Soft X-ray Spectrometer calorimeter instrument recently launched on the Hitomi X-ray Observatory.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and supported by NASA grants to LLNL and NASA/GSFC and by ESA under contract No. 4000114313/15/NL/CB.

  12. Absolute silicon molar mass measurements, the Avogadro constant and the redefinition of the kilogram

    Vocke, R. D., Jr.; Rabb, S. A.; Turk, G. C.

    2014-10-01

    The results of an absolute silicon molar mass determination of two independent sets of samples from the highly 28Si-enriched crystal (AVO28) produced by the International Avogadro Coordination are presented and compared with results published by the Physikalisch-Technische Bundesanstalt (PTB, Germany), the National Research Council (NRC, Canada) and the National Metrology Institute of Japan (NMIJ, Japan). This study developed and describes significant changes to the published protocols for producing absolute silicon isotope ratios. The measurements were made at very high resolution on a multi-collector inductively coupled plasma mass spectrometer using tetramethylammonium hydroxide (TMAH) to dissolve and dilute all samples. The various changes in the measurement protocol and the use of TMAH resulted in significant improvements to the silicon isotope ratio precision over previously reported measurements and in particular, the robustness of the 29Si/30Si ratio of the AVO28 material. These new results suggest that a limited isotopic variability is present in the AVO28 material. The presence of this variability is at present singular and therefore its significance is not well understood. Fortunately, its magnitude is small enough so as to have an insignificant effect on the overall uncertainty of an Avogadro constant derived from the average molar mass of all four AVO28 silicon samples measured in this study. The NIST results confirm the AVO28 molar mass values reported by PTB and NMIJ and confirm that the virtual element-isotope dilution mass spectrometry approach to calibrated absolute isotope ratio measurements developed by PTB is capable of very high precision as well as accuracy. The Avogadro constant NA and derived Planck constant h based on these measurements, together with their associated standard uncertainties, are 6.02214076(19) × 1023 mol-1 and 6.62607017(21) × 10-34 Js, respectively.

  13. 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

    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.)

  14. Characterization of Fricke-gel layers for absolute dose measurements in radiotherapy

    Gambarini, G. [Dept. of Physics, ' Universita degli Studi' of Milan, via Celoria 16, I-20133 Milano (Italy); INFN Istituto Nazionale di Fisica Nucleare Section Milan, via Celoria 16, I-20133 Milano (Italy); Carrara, M. [Medical Physics Unit, Fondazione IRCCS Istituto Nazionale Tumori, Via Venezian 1, I-20133 Milano (Italy); Rrushi, B.; Guilizzoni, R. [Dept. of Physics, ' Universita degli Studi' of Milan, via Celoria 16, I-20133 Milano (Italy); Borroni, M.; Tomatis, S. [Medical Physics Unit, Fondazione IRCCS Istituto Nazionale Tumori, Via Venezian 1, I-20133 Milano (Italy); Pirola, L. [Dept. of Physics, ' Universita degli Studi' of Milan, via Celoria 16, I-20133 Milano (Italy); Battistoni, G. [INFN Istituto Nazionale di Fisica Nucleare Section Milan, via Celoria 16, I-20133 Milano (Italy)

    2011-07-01

    Fricke-gel layer dosimeters (FGLDs) have shown promising features for attaining absolute measurements of the spatial distribution of the absorbed dose in radiotherapy. Good precision of results (within 3%) is achieved by means of calibration of each single dosimeter before measurement. The calibration is performed irradiating the dosimeter at a uniform and precisely known dose, in order to get a calibration matrix that must be used, with pixel-to-pixel manipulation, to obtain the dose image. A study of the trend in time of dosimeter response after one or more exposures was carried out and calibration protocols were suitably established and verified. (authors)

  15. A Model for Converting Solid State Fermentation Growth Profiles Between Absolute and Relative Measurement Bases

    Viccini, Graciele; Mitchell, David A; Krieger, Nadia

    2003-01-01

    A mathematical model is developed for converting between the two measurement bases commonly used in the construction of growth profiles in solid-state fermentation, namely absolute mass ratio m(dry biomass)/m(initial dry matter) and relative mass ratio m(dry biomass)/m(dry matter). These are not equivalent, due to the loss of dry matter as CO2 during the fermentation. The model is equally applicable to any biomass component used in indirect measurements of growth, such as protein. Use of the ...

  16. Absolute Pulse Energy Measurements of Soft X-Rays at the Linac Coherent Light Source

    Tiedtke, K.; Sorokin, Andrey; Soufli, R.; Fernández-Perea, M.; Juha, L.; Heimann, P.(Universität Siegen, Siegen, Germany); Nagler, B.; Lee, H. J.; Mack, S; Cammarata, M.; O. Krupin; Messerschmidt, M.; Jastrow, U.; Holmes, M.; Rowen, M.

    2014-01-01

    This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short radiation generated in the soft x-ray regime of a free electron laser. We give a brief description of the detection principle for radiation measurements which was specifically adapted for this photon energy range. We present data characterizing the soft x-ray instrument at the Linac Coherent Light Source (LCLS) with respect to the radiant power output and transmission by usin...

  17. Wave cutoff method to measure absolute electron density in cold plasma

    A method for precise measurements of absolute electron density in plasma using wave cutoff is described. This method of measurement uses a network analyzer with radiating and detecting antenna A microwave signal of 10 kHZ-3 GHz frequency is introduced into the plasma from a radiating port of the network analyzer and propagates in the plasma. The transmitted wave is monitored at a distance from a radiating antenna using an antenna connected to the receiving port of the network analyzer. The transmitted wave decays rapidly at a cutoff plasma frequency, which is a direct measure of the absolute electron density. This cutoff method is free of many difficulties often encountered with a Langmuir probe, such as thin film deposition and plasma potential fluctuation. The cutoff probe can also measure the spatial distribution of the electron density. The measurement technique is analyzed theoretically and experimentally, demonstrated in density measurements of an inductively coupled radio-frequency plasma, and is compared with the double probe and a plasma oscillation methods

  18. Radioactivity Measurement of Short Life Nuclide 89Rb

    2008-01-01

    <正>The radioactivity of short life nuclide 89Rb produced by fast radiochemical separation was measured by the digital coincidence counting (DCC) system. In this experiment, there were a large quantity of impurities

  19. Radioactive contamination of edible mushrooms. Current measured values (State: 2013)

    The report includes the current measured values (2013) of the radioactive contamination of edible mushrooms in Southern Germany (Cs137 and K-40) and discusses the relation radio-cesium intake and radiation exposure now and and the future.

  20. Deduction of interfering nuclides in radioactive measurement of 87Kr

    The radioactivity of short-lived nuclide 87Kr is interfered by 85mKr and 125Xe when it is measured by internal gas proportional counting. It is difficult to separate interfering nuclides from the gas sample. In this work, a series of data were measured according to the characteristic that different nuclides have different half-life, the radioactivity of 87Kr is obtained by calculating coefficients of linear equations by the least square method. (authors)

  1. Absolute Position of Targets Measured Through a Chamber Window Using Lidar Metrology Systems

    Kubalak, David; Hadjimichael, Theodore; Ohl, Raymond; Slotwinski, Anthony; Telfer, Randal; Hayden, Joseph

    2012-01-01

    Lidar is a useful tool for taking metrology measurements without the need for physical contact with the parts under test. Lidar instruments are aimed at a target using azimuth and elevation stages, then focus a beam of coherent, frequency modulated laser energy onto the target, such as the surface of a mechanical structure. Energy from the reflected beam is mixed with an optical reference signal that travels in a fiber path internal to the instrument, and the range to the target is calculated based on the difference in the frequency of the returned and reference signals. In cases when the parts are in extreme environments, additional steps need to be taken to separate the operator and lidar from that environment. A model has been developed that accurately reduces the lidar data to an absolute position and accounts for the three media in the testbed air, fused silica, and vacuum but the approach can be adapted for any environment or material. The accuracy of laser metrology measurements depends upon knowing the parameters of the media through which the measurement beam travels. Under normal conditions, this means knowledge of the temperature, pressure, and humidity of the air in the measurement volume. In the past, chamber windows have been used to separate the measuring device from the extreme environment within the chamber and still permit optical measurement, but, so far, only relative changes have been diagnosed. The ability to make accurate measurements through a window presents a challenge as there are a number of factors to consider. In the case of the lidar, the window will increase the time-of-flight of the laser beam causing a ranging error, and refract the direction of the beam causing angular positioning errors. In addition, differences in pressure, temperature, and humidity on each side of the window will cause slight atmospheric index changes and induce deformation and a refractive index gradient within the window. Also, since the window is a

  2. A new Ultra Precision Interferometer for absolute length measurements down to cryogenic temperatures

    A new Ultra Precision Interferometer (UPI) was built at Physikalisch-Technische Bundesanstalt. As its precursor, the precision interferometer, it was designed for highly precise absolute length measurements of prismatic bodies, e.g. gauge blocks, under well-defined temperature conditions and pressure, making use of phase stepping imaging interferometry. The UPI enables a number of enhanced features, e.g. it is designed for a much better lateral resolution and better temperature stability. In addition to the original concept, the UPI is equipped with an external measurement pathway (EMP) in which a prismatic body can be placed alternatively. The temperature of the EMP can be controlled in a much wider range compared to the temperature of the interferometer's main chamber. An appropriate cryostat system, a precision temperature measurement system and improved imaging interferometry were established to permit absolute length measurements down to cryogenic temperature, demonstrated for the first time ever. Results of such measurements are important for studying thermal expansion of materials from room temperature towards less than 10 K. (paper)

  3. Radioactivity measuring system of labelled biopolymers

    System for determining the radioactivity of labelled biopolymers, comprising a bank of containers filled with aqueous solutions of biological samples containing biopolymers. This system features an electric drive to move the bank of containers step by step; a device for the acid precipitation of the biopolymers which sends determined amounts of co-precipitant and diatom suspension in an acid solution to the containers containing a biological sample; a system for taking precipitated samples from the containers; a system for filtering the precipitated biopolymers carrying out successive filterings; placing the deposit into suspension; dissolving the biopolymers and sending the labelled mixture labelled by the scintillation labeller to the detection chamber

  4. Camera-based speckle noise reduction for 3-D absolute shape measurements.

    Zhang, Hao; Kuschmierz, Robert; Czarske, Jürgen; Fischer, Andreas

    2016-05-30

    Simultaneous position and velocity measurements enable absolute 3-D shape measurements of fast rotating objects for instance for monitoring the cutting process in a lathe. Laser Doppler distance sensors enable simultaneous position and velocity measurements with a single sensor head by evaluating the scattered light signals. The superposition of several speckles with equal Doppler frequency but random phase on the photo detector results in an increased velocity and shape uncertainty, however. In this paper, we present a novel image evaluation method that overcomes the uncertainty limitations due to the speckle effect. For this purpose, the scattered light is detected with a camera instead of single photo detectors. Thus, the Doppler frequency from each speckle can be evaluated separately and the velocity uncertainty decreases with the square root of the number of camera lines. A reduction of the velocity uncertainty by the order of one magnitude is verified by the numerical simulations and experimental results, respectively. As a result, the measurement uncertainty of the absolute shape is not limited by the speckle effect anymore. PMID:27410133

  5. Absolute measurement of the 242Pu neutron-capture cross section

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Dance Collaboration

    2016-04-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n ,γ ) cross section was made over the incident neutron energy range from thermal to ≈6 keV, and the absolute scale of the (n ,γ ) cross section was set according to the known 239Pu(n ,f ) resonance at En ,R=7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the cross section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n ,γ ) cross section at the En ,R=2.68 eV resonance is within 2.4 % of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30 % lower than the evaluated data at En≈1 keV and are approximately 2 σ away from the previous measurement at En≈20 keV.

  6. Absolute measurement of $sup 235$U fission cross-section for 2200 m/sec neutrons

    Borcea, C.; Borza, A.; Buta, A.

    1973-12-31

    The results of an absolute fission cross-section measurement of /sup 235/ U are presented; the thermal neutrons were selected by the time-of-flight method. The principle of the method and the experimental apparatus are described. The method had the advantage of avoiding the use of an intermediate cross section in the neutron flux determination by choice of a B target thick enough to absorb all thermal neutrons. Target preparation, efficiency determination, corrections, etc., are reported. The value determined was 581.7 plus or minus 7.8 barns. (6 figures, 4 tables) (RWR)

  7. Absolute efficiency measurements with the {sup 10}B based Jalousie detector

    Modzel, G., E-mail: modzel@physi.uni-heidelberg [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); Henske, M. [CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8–10, 69123 Heidelberg (Germany); Houben, A. [Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen (Germany); Klein, M. [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8–10, 69123 Heidelberg (Germany); Köhli, M.; Lennert, P. [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); Meven, M. [Heinz Maier-Leibnitz Zentrum (MLZ), 85747 Garching (Germany); Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS), Outstation at MLZ, 85747 Garching (Germany); Schmidt, C.J. [CDT CASCADE Detector Technologies GmbH, Hans-Bunte-Str. 8–10, 69123 Heidelberg (Germany); GSI Detector Laboratory, Planckstr. 1, 64291 Darmstadt (Germany); Schmidt, U. [Physikalisches Institut, Universität Heidelberg, Neuenheimer Feld 226, 69120 Heidelberg (Germany); Schweika, W. [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS), 52425 Jülich (Germany); European Spallation Source ESS AB, SE-22100 Lund (Sweden)

    2014-04-11

    The {sup 10}B based Jalousie detector is a replacement for {sup 3}He counter tubes, which are nowadays less affordable for large area detectors due to the {sup 3}He crisis. In this paper we investigate and verify the performance of the new {sup 10}B based detector concept and its adoption for the POWTEX diffractometer, which is designed for the detection of thermal neutrons with predicted detection efficiencies of 75–50% for neutron energies of 10–100 meV, respectively. The predicted detection efficiency has been verified by absolute measurements using neutrons with a wavelength of 1.17 Å (59 meV)

  8. A Method for Measurement of Absolute Angular Position and Application in a Novel Electromagnetic Encoder System

    Zijian Zhang; Yangyang Dong; Fenglei Ni; Minghe Jin; Hong Liu

    2015-01-01

    For the encoders, especially the sine-cosine magnetic ones, a new method to measure absolute angular position is proposed in the paper. In the method, the code disc of the encoder has only two circle tracks and each one was divided into N and (N-1) equal code cells. The cell angles, changing from 0° to 360° between any two neighboring code cells, are defined to represent any position on the code disc. The position value of the same point can be represented by different cell angle values of di...

  9. Absolute Measurement of Hadronic Branching Fractions of the D_s^+ Meson

    Alexander, J; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A G; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; López, A; Méndez, H; Ramírez, J; Ge, J Y; Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Rademacker, J; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L

    2008-01-01

    The branching fractions of D_s meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 /pb of e+ e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D_s decays with a double tag technique. In particular we determine the branching fraction B(D_s -> K- K+ pi+) = (5.50 +- 0.23 +- 0.16)%, where the uncertainties are statistical and systematic respectively. We also provide partial branching fractions for kinematic subsets of the K- K+ pi+ decay mode.

  10. Absolute beam flux measurement at NDCX-I using gold-melting calorimetry technique

    We report on an alternative way to measure the absolute beam flux at the NDCX-I, LBNL linear accelerator. Up to date, the beam flux is determined from the analysis of the beam-induced optical emission from a ceramic scintilator (Al-Si). The new approach is based on calorimetric technique, where energy flux is deduced from the melting dynamics of a gold foil. We estimate an average 260 kW/cm2 beam flux over 5 (micro)s, which is consistent with values provided by the other methods. Described technique can be applied to various ion species and energies.

  11. Measurement of the absolute values of cross-sections in neutron photoproduction (1962)

    The absolute values of photoneutrons production cross-sections for the case of intermediate and heavy nuclei (lanthanium, cerium, tantalum, gold, lead and bismuth) are determined with an error of 15 per cent. The results obtained agree with theories in which the giant resonance is explained by the collective motion of the protons against the neutrons. The effect of the nuclear deformation on the shape of the giant resonance is seen in the case of Ta181, it will be possible to determine the quadrupole momenta of deformed nuclei with a good accuracy when we shall increase the statistics of measurements. (author)

  12. Common mistakes associated with absolute full energy peak efficiency measurements using high pure germanium detectors

    The present work focuses on the uncertainties associated with absolute full energy peak efficiency (AFEPE) when measurements of calibration point sources conducted at various distances from two high pure germanium detectors (HPGe) from Ortec and Eurisys. A set consists of 11 point sources from Amersham were used. The measurements were performed at different source to detector distances. All the spectra were unfolded and analyzed using Emc plus MCA card from Silena. Full energy peak efficiency for each energy was then calculated using the well-know formula. The first approach was to fit the experimental data using least square fitting. Following that, a comparison between the experimental and calculated results was performed. The scattering data due to measurements of the multi-energetic sources specially when measurements carried out at very close distances from the detector were plotted and discussed.(author)

  13. Improved Measurement of Absolute Hadronic Branching Fractions of the Ds+ Meson

    Onyisi, P U E; Cinabro, D; Smith, M J; Zhou, P; Naik, P; Rademacker, J; Edwards, K W; Briere, R A; Vogel, H; Rosner, J L; Alexander, J P; Cassel, D G; Das, S; Ehrlich, R; Gibbons, L; Gray, S W; Hartill, D L; Heltsley, B K; Kreinick, D L; Kuznetsov, V E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Sun, W M; Yelton, J; Rubin, P; Lowrey, N; Mehrabyan, S; Selen, M; Wiss, J; Libby, J; Kornicer, M; Mitchell, R E; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Hietala, J; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Xiao, T; Powell, A; Thomas, C; Wilkinson, G; Asner, D M; Tatishvili, G; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Napolitano, J; Ecklund, K M; Insler, J; Muramatsu, H; Pearson, L J; Thorndike, E H; Artuso, M; Blusk, S; Mountain, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M

    2013-01-01

    The branching fractions of Ds meson decays serve to normalize many measurements of processes involving charm quarks. Using 586 pb^-1 of e+ e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for 13 Ds decays in 16 reconstructed final states with a double tag technique. In particular we make a precise measurement of the branching fraction B(Ds -> K- K+ pi+) = (5.55 +- 0.14 +- 0.13)%, where the uncertainties are statistical and systematic respectively. We find a significantly reduced value of B(Ds -> pi+ pi0 eta') compared to the world average, and our results bring the inclusively and exclusively measured values of B(Ds -> eta' X)$ into agreement. We also search for CP-violating asymmetries in Ds decays and measure the cross-section of e+ e- -> Ds* Ds at Ecm = 4.17 GeV.

  14. Measurements of radioactive dust in high altitude air

    The radioactivities of airborne dust in samples were measured. The samples had been collected at high altitude by the Japan Air Self-Defense Force from April 2009 to March 2010. The data were obtained for the gross beta activity, gamma nuclide determination and radiochemical analysis. It was shown that there was no appreciable difference between the activity levels of this time and in the year before. Seasonal variations were not very pronounced. It is found that the radioactivity has been stable at a low level at high altitude. Radioactive gas (gaseous radioiodine) was not detected. (author)

  15. Measurements of radioactive dusts in high altitude air

    The radioactively of airborne dust in samples collected by aircraft of the Japan Air Self-Defense Force at high altitude during the period between April 2001 to March 2002 were measured. The data of the gross beta activity, gamma nuclide determination and radiochemical analysis show that there is no appreciable difference from the activity levels of the year before. Seasonal variations are becoming less pronounced and this shows that the low level radioactivity at high altitude is stable. Radioactive gas (gaseous radioiodine) was not detected. (author)

  16. Utilization of coincidence criteria in absolute length measurements by optical interferometry in vacuum and air

    Traceability of length measurements to the international system of units (SI) can be realized by using optical interferometry making use of well-known frequencies of monochromatic light sources mentioned in the Mise en Pratique for the realization of the metre. At some national metrology institutes, such as Physikalisch-Technische Bundesanstalt (PTB) in Germany, the absolute length of prismatic bodies (e.g. gauge blocks) is realized by so-called gauge-block interference comparators. At PTB, a number of such imaging phase-stepping interference comparators exist, including specialized vacuum interference comparators, each equipped with three highly stabilized laser light sources. The length of a material measure is expressed as a multiple of each wavelength. The large number of integer interference orders can be extracted by the method of exact fractions in which the coincidence of the lengths resulting from the different wavelengths is utilized as a criterion. The unambiguous extraction of the integer interference orders is an essential prerequisite for correct length measurements. This paper critically discusses coincidence criteria and their validity for three modes of absolute length measurements: 1) measurements under vacuum in which the wavelengths can be identified with the vacuum wavelengths, 2) measurements under air in which the air refractive index is obtained from environmental parameters using an empirical equation, and 3) measurements under air in which the air refractive index is obtained interferometrically by utilizing a vacuum cell placed along the measurement pathway. For case 3), which corresponds to PTB’s Kösters-Comparator for long gauge blocks, the unambiguous determination of integer interference orders related to the air refractive index could be improved by about a factor of ten when an ‘overall dispersion value,’ suggested in this paper, is used as coincidence criterion. (paper)

  17. First measurements of the absolute neutron spectrum using the magnetic recoil spectrometer at OMEGA (invited)

    A neutron spectrometer, called a magnetic recoil spectrometer (MRS), has been built and implemented at the OMEGA laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] for absolute measurements of the neutron spectrum in the range of 6-30 MeV, from which fuel areal density (ρR), ion temperature (Ti), and yield (Yn) can be determined. The results from the first MRS measurements of the absolute neutron spectrum are presented. In addition, measuring ρR at the National Ignition Facility (NIF) [G. H. Miller et al., Nucl. Fusion 44, S228 (2004)] will be essential for assessing implosion performance during all stages of development from surrogate implosions to cryogenic fizzles to ignited implosions. To accomplish this, we are also developing an MRS for the NIF. As much of the research and development and instrument optimization of the MRS at OMEGA are directly applicable to the MRS at the NIF, a description of the design and characterization of the MRS on the NIF is discussed as well.

  18. First measurements of the absolute neutron spectrum using the Magnetic Recoil Spectrometer (MRS) at OMEGA

    A new type of neutron spectrometer, called a Magnetic Recoil Spectrometer (MRS), has been built and implemented at the OMEGA laser facility (T. R. Boehly. D. L. Brown, R. S. Craxton et al., Opt. Commun. 133, 495 (1997)) for absolute measurements of the neutron spectrum in the range 6 to 30 MeV, from which fuel areal density (ρR), ion temperature (Ti) and yield (Yn) can be determined. The results from the first MRS measurements of the absolute neutron spectrum are presented. In addition, measuring ρR at the National Ignition Facility (NIF) (G.H. Miller, E.I. Moses and C.R. Wuest, Nucl. Fusion 44, S228 (2004)) will be essential for assessing implosion performance during all stages of development from surrogate implosions to cryogenic fizzles and ignited implosions. To accomplish this, we are also developing an MRS for the NIF. As much of the R and D and instrument optimization of the MRS at OMEGA is directly applicable to the MRS at the NIF, a description of the MRS design on the NIF is discussed as well

  19. First measurements of the absolute neutron spectrum using the Magnetic Recoil Spectrometer (MRS) at OMEGA

    Frenje, J A; Casey, D T; Li, C K; Rygg, J R; Seguin, F H; Petrasso, R D; Glebov, V Y; Meyerhofer, D D; Sangster, T C; Hatchett, S; Haan, S; Cerjan, C; Landen, O; Moran, M; Song, P; Wilson, D C; Leeper, R J

    2008-05-12

    A new type of neutron spectrometer, called a Magnetic Recoil Spectrometer (MRS), has been built and implemented at the OMEGA laser facility [T. R. Boehly. D. L. Brown, R. S. Craxton et al., Opt. Commun. 133, 495 (1997)] for absolute measurements of the neutron spectrum in the range 6 to 30 MeV, from which fuel areal density ({rho}R), ion temperature (T{sub i}) and yield (Y{sub n}) can be determined. The results from the first MRS measurements of the absolute neutron spectrum are presented. In addition, measuring {rho}R at the National Ignition Facility (NIF) [G.H. Miller, E.I. Moses and C.R. Wuest, Nucl. Fusion 44, S228 (2004)] will be essential for assessing implosion performance during all stages of development from surrogate implosions to cryogenic fizzles and ignited implosions. To accomplish this, we are also developing an MRS for the NIF. As much of the R&D and instrument optimization of the MRS at OMEGA is directly applicable to the MRS at the NIF, a description of the MRS design on the NIF is discussed as well.

  20. First measurements of the absolute neutron spectrum using the magnetic recoil spectrometer at OMEGA (invited).

    Frenje, J A; Casey, D T; Li, C K; Rygg, J R; Séguin, F H; Petrasso, R D; Glebov, V Yu; Meyerhofer, D D; Sangster, T C; Hatchett, S; Haan, S; Cerjan, C; Landen, O; Moran, M; Song, P; Wilson, D C; Leeper, R J

    2008-10-01

    A neutron spectrometer, called a magnetic recoil spectrometer (MRS), has been built and implemented at the OMEGA laser facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] for absolute measurements of the neutron spectrum in the range of 6-30 MeV, from which fuel areal density (rhoR), ion temperature (T(i)), and yield (Y(n)) can be determined. The results from the first MRS measurements of the absolute neutron spectrum are presented. In addition, measuring rhoR at the National Ignition Facility (NIF) [G. H. Miller et al., Nucl. Fusion 44, S228 (2004)] will be essential for assessing implosion performance during all stages of development from surrogate implosions to cryogenic fizzles to ignited implosions. To accomplish this, we are also developing an MRS for the NIF. As much of the research and development and instrument optimization of the MRS at OMEGA are directly applicable to the MRS at the NIF, a description of the design and characterization of the MRS on the NIF is discussed as well. PMID:19044488

  1. Absolute fission rate measurement of 238U induced by 14 MeV neutrons penetrated composite material

    In order to prove the model calculation method and parameter, the 238U absolute fission rate in the case of 14 MeV neutrons penetrating through the special composite material was measured by minitype slab uranium fission chambers. The measuring spots are distributed in the surface of iron ball hull along the different position of equator. The calculated results are compared with the experiment results. The total error of measured 238U absolute fission rate is 6.1%. (author)

  2. Measurement of environmental radioactivity by imaging plate

    A photostimulable phosphor screen imaging technique has been developed to detect radioactive contamination on surface of Mugwort leaves due to JCO criticality accident. The imaging plate (IP) is well known to have many striking performances of two-dimensional radiation detection. IP has been extensively applied to surface contamination distribution studies since IP, is an integrated detection. Plant samples were collected in the surrounding areas of the uranium conversion facility of JCO Company Limited, Tokai, Ibaraki, Japan. The highest photo-stimulated luminescence density of IP of the nuclides was found in samples collected near the ventilation exhaust. The radionuclides detected in leaves by γ-ray spectroscopy were 131I, 133I, 140Ba, - 140La, and 137Cs and β-ray spectroscopy was 89Sr. In order to assess contamination, comparison has been made with leaves affected due to Chernobyl nuclear accident. (author)

  3. Measurement of total body radioactivity in man

    Techniques for the determination of whole-body radioactivity in man using uncollimated NaI(Tl) detectors have been studied. Geometrical effects and photon attenuation effects due to the different shapes of humans as well as due to varying in-vivo radioactivity distributions have been evaluated particularly for scanning-bed geometries and the chair geometry. Theoretically it is shown that the attenuation effects are generally dominating, for full-energy-peak pulse-range methods. For the application in radiation protection a cheap and simple chair-geometry unit has been constructed and used at various places distantly from the home-laboratory, for studies of body activity of Cs-137 in northern Sweden. High body activities were found particularly in reindeer-breeding Lapps. The elimination rate of Cs-137 in man was studied in the stationary whole-body counter in Lund as well as with the field-system. For the study of the performances at low and high photon energies clinical applications of methods for gastro-intestinal absorption of vitamin B12 (Co-57; 122 keV) and total body potassium determination (K-40; 1.46 MeV, K-42; 1.52 MeV) have been evaluated. Theoretical and experimental results as well as experiences of applications in radiation protection and medicine show that the scanning-bed geometry effectively evens out redistributional effects. For optimum results, however, scatter-energy pulse-ranges rather than full-energy-peak ranges should be used. (Auth.)

  4. Natural radioactivity measurements at the proposed nuclear power plant site

    Natural radioactivity measurement in the Philippines aims to establish baseline radioactivity levels in the environment of items essential to man. In this article, results of the environmental surveillance conducted in Bagac, Bataan from 1973 to 1974 are presented. Analyses were made on air parti-culates, sea and fresh water, grass, and soil samples for gross beta-gamma activities. Results obtained showed activity levels below the maximum permissible concentration recommended by the International Committee on Radiation Protection (ICRP)

  5. Superharp — A wire scanner with absolute position readout for beam energy measurement at CEBAF

    Yan, C.; Adderley, P.; Barker, D.; Beaufait, J.; Capek, K.; Carlini, R.; Dahlberg, J.; Feldl, E.; Jordan, K.; Kross, B.; Oren, W.; Wojcik, R.; VanDyke, J.

    1995-02-01

    The CEBAF superharp is an upgraded beam wire scanner which provides absolute beam position readout using a shaft encoder. Superharps allow for high precision measurements of the beam's profile and position ( Δx ˜ 10 μm). The Hall C endstation at CEBAF will use three pairs of superharps to perform beam energy measurements with 10 -3 accuracy. The three pairs are installed at the beginning, the mid-point and the end of the Hall C arc beamline. Using superharps in conjunction with a dual sensor system: the direct current pick-up and the bremsstrahlung detectors, beam profile measurements can be obtained over a wide beam current range of 1 ˜ 200 μA.

  6. ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC

    MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

    2007-06-25

    The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

  7. Absolute measurement of the relativistic magnetic dipole transition energy in heliumlike argon.

    Amaro, Pedro; Schlesser, Sophie; Guerra, Mauro; Le Bigot, Eric-Olivier; Isac, Jean-Michel; Travers, Pascal; Santos, José Paulo; Szabo, Csilla I; Gumberidze, Alexandre; Indelicato, Paul

    2012-07-27

    The 1s2s (3)S(1)→1s(2) (1)S(0) relativistic magnetic dipole transition in heliumlike argon, emitted by the plasma of an electron-cyclotron resonance ion source, has been measured using a double-flat crystal x-ray spectrometer. Such a spectrometer, used for the first time on a highly charged ion transition, provides absolute (reference-free) measurements in the x-ray domain. We find a transition energy of 3104.1605(77) eV (2.5 ppm accuracy). This value is the most accurate, reference-free measurement done for such a transition and is in good agreement with recent QED predictions. PMID:23006085

  8. Sonographic Measurement of Absolute and Relative Renal Length in Healthy Isfahani Adults

    A Hekmatnia

    2004-04-01

    Full Text Available Background: There is no information on renal size and its relation to age, sex and height in the area of Isfahan. The aim of this study was to define sonographically measured absolute renal lengths and their relations to height in normal Isfahani adults. Methods: 400 healthy Isfahani subjects aged 20 to 69 years with normal blood pressure, no history of renal disease in them or their first degree relatives and with normal sonographic appearance were chosen in 2002-2003. The study was cross-sectional. With real-time sonography, absolute renal length was measured. Results: Four hundred healthy adults (230 men and 170 women aged 20 to 69 years (39.6 ± 13.6 year were evaluated. The length of left kidney was longer than the right one (111 ± 9.8 mm vs. 109 ± 8.4 mm in right kidney; P < 0.01. Renal length was significantly greater in males compared to females (P < 0.01. Renal length decreased with age and the rate of decrease was accelerated at the age of 60 years and older. There was a significant correlation between kidney length and the subject's height (P < 0.01. Conclusion: The result of this study shows the normal values for renal length in Iranian males and females, which may be helpful in assessing the size of patients’ kidneys in different clinical settings. Keywords: Kidney size, Renal length, Ultrasonography, Normal values.

  9. Relative vs. absolute physiological measures as predictors of mountain bike cross-country race performance.

    Gregory, John; Johns, David P; Walls, Justin T

    2007-02-01

    The aims of this study were to document the effect terrain has on the physiological responses and work demands (power output) of riding a typical mountain bike cross-country course under race conditions. We were particularly interested in determining whether physiological measures relative to mass were better predictors of race performance than absolute measures. Eleven A-grade male cross-country mountain bike riders (VO2max 67.1 +/- 3.6 ml x kg(-1) x min(-1)) performed 2 tests: a laboratory-based maximum progressive exercise test, and a 15.5-km (six 2.58-km laps) mountain bike cross-country time trial. There were significant differences among the speed, cadence, and power output measured in each of 8 different terrain types found in the cross-country time trial course. The highest average speed was measured during the 10-15% downhill section (22.7 +/- 2.6 km x h(-1)), whereas the cadence was highest in the posttechnical flat sections (74.3 +/- 5.6 rpm) and lowest on the 15-20% downhill sections (6.4 +/- 12.1 rpm). The highest mean heart rate (HR) was obtained during the steepest (15-20% incline) section of the course (179 +/- 8 b x min(-1)), when the power output was greatest (419.8 +/- 39.7 W). However, HR remained elevated relative to power output in the downhill sections of the course. Physiological measures relative to total rider mass correlated more strongly to average course speed than did absolute measures (peak power relative to mass r = 0.93, p < 0.01, vs. peak power r = 0.64, p < 0.05; relative VO2max r = 0.80, p < 0.05, vs. VO2max r = 0.66, p < 0.05; power at anaerobic threshold relative to mass r = 0.78, p < 0.05, vs. power at anaerobic threshold r = 0.5, p < 0.05). This suggests that mountain bike cross-country training programs should focus upon improving relative physiological values rather than focusing upon maximizing absolute values to improve performance. PMID:17313256

  10. Measurements of absolute absorption cross sections of ozone in the 185- to 254-nm wavelength region and the temperature dependence

    Yoshino, K.; Esmond, J. R.; Freeman, D. E.; Parkinson, W. H.

    1993-01-01

    Laboratory measurements of the relative absorption cross sections of ozone at temperatures 195, 228, and 295 K have been made throughout the 185 to 254 nm wavelength region. The absolute absorption cross sections at the same temperatures have been measured at several discrete wavelengths in the 185 to 250 nm region. The absolute cross sections of ozone have been used to put the relative cross sections on a firm absolute basis throughout the 185 to 255 nm region. These recalibrated cross sections are slightly lower than those of Molina and Molina (1986), but the differences are within a few percent and would not be significant in atmospheric applications.

  11. Radiation Protection Research: Low-level Radioactivity Measurements

    Hurtgen, C

    2000-07-01

    The objectives of the research performed in the area of low-level radioactivity measurements are (1) to maintain and develop techniques for the measurement of low-level environmental and biological samples, (2) to measure these samples by means of low-background counters (liquid scintillators, proportional counters, ZnS counters, alpha spectrometry), (3) to support and advice the nuclear and non-nuclear industry in matters concerning radioactive contamination and/or low-level radioactivity measurements; (4) to maintain the quality assurance system according to the EN45001 standard; and (5) to assess the internal dose from occupational intakes of radionuclides of workers of the nuclear industry. Progress and achievements in these areas in 1999 are reported. Particular emphasis is SCK-CEN's contribution to the EULEP-EURADOS Action Group on 'Derivation of parameter values for application in the new model of the human respiratory tract for occupational exposure'.

  12. Measured radioactivity data acquisition and evaluation system (REA)

    In Germany, authorities in the Federal States are obliged to monitor the environment for radioactivity. Various institutions run radioactivity measurements for this purpose. The measured results are made available to the competent authorities in a variety of ways. Computer systems are now used for central collection and evaluation of these data. LfU has developed a concept to support by DP technologies also the procedures between the measurement site and the central authority. This facilitates data acquisition and speeds up data transmission. The REA concept will streamline procedures and improve data quality. (orig.)

  13. Measurements of radioactive dusts in high altitude air

    The radioactivities of the airborne dusts were measured in samples collected by aircrafts of the Japan Air Self-Defense Force in high altitude during the period between April 2000 and March 2001. From June 2000 the newly designed filters composed of electret filter and fibrous activated carbon filter were used to collect air suspended dust and radioactive gas at the same time. The data of the gross beta activities, gamma nuclide determination and radiochemical analysis show that there is no appreciable difference from the activity levels of the year before and seasonal variations are becoming not so clear, that shows the radioactivities in high altitude is stable in a low level. Radioactive gas (gaseous radioiodine) was not detected. (author)

  14. Absolute absorption cross-section measurements of ozone in the wavelength region 238-335 nm and the temperature dependence

    Yoshino, K.; Freeman, D. E.; Esmond, J. R.; Parkinson, W. H.

    1988-01-01

    The absolute absorption cross-section of ozone has been experimentally determined at the temperatures 195, 228, and 295 K at several discrete wavelengths in the 238-335-nm region. The present results for ozone at 295 K are found to be in agreement with those of Hearn (1961). Absolute cross-section measurements of ozone at 195 K have confirmed previous (Freeman et al., 1984) relative cross-section measurements throughout the 240-335-nm region.

  15. Application of the 4 pigammaMethod to the Absolute Standardization of Radioactive Sources of Positron Emitters

    We discuss the application of the method known as 4 pigammacountingto the standardization of positron emitters. Monte Carlo simulations are used to calculate the detection efficiency of positrons emitted by the nuclides 22Na and 18F. Two experimental setups are used, both based on a NaI(Tl) well detector. The results of the standardizations are in good agreement with those obtained by other methods. It is shown that the 4 pigammamethod can be successfully used for the absolute standardization of sources of positron emitters. (Author) 23 refs

  16. Precise measurement of the absolute fluorescence yield of the 337 nm band in atmospheric gases

    Ave, M.; Bohacova, M.; Curry, E.; Di Carlo, P.; Di Giulio, C.; Facal San Luis, P.; Gonzales, D.; Hojvat, C.; Hörandel, J.; Hrabovsky, M.; Iarlori, M.; Keilhauer, B.; Klages, H.; Kleifges, M.; Kuehn, F.; Li, S.; Monasor, M.; Nozka, L.; Palatka, M.; Petrera, S.; Privitera, P.; Ridky, J.; Rizi, V.; Rouille D'Orfeuil, B.; Salamida, F.; Schovanek, P.; Smida, R.; Spinka, H.; Ulrich, A.; Verzi, V.; Williams, C.

    2013-02-01

    A measurement of the absolute fluorescence yield of the 337 nm nitrogen band, relevant to ultra-high energy cosmic ray (UHECR) detectors, is reported. Two independent calibrations of the fluorescence emission induced by a 120 GeV proton beam were employed: Cherenkov light from the beam particle and calibrated light from a nitrogen laser. The fluorescence yield in air at a pressure of 1013 hPa and temperature of 293 K was found to be Y337=5.61±0.06stat±0.22syst photons/MeV. When compared to the fluorescence yield currently used by UHECR experiments, this measurement improves the uncertainty by a factor of three, and has a significant impact on the determination of the energy scale of the cosmic ray spectrum.

  17. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF.

    Casey, D T; Frenje, J A; Johnson, M Gatu; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Magoon, J; Meyerhofer, D D; Sangster, T C; Shoup, M; Ulreich, J; Ashabranner, R C; Bionta, R M; Carpenter, A C; Felker, B; Khater, H Y; LePape, S; MacKinnon, A; McKernan, M A; Moran, M; Rygg, J R; Yeoman, M F; Zacharias, R; Leeper, R J; Fletcher, K; Farrell, M; Jasion, D; Kilkenny, J; Paguio, R

    2013-04-01

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF. PMID:23635195

  18. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  19. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2013-04-15

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  20. Measurement of absolute reaction rates in Be,Pb and Fe spherical systems

    LiuRong; ChenYuan; 等

    1998-01-01

    The absolute reaction rates in Be,Pb and Fe have been measured by using the activation foil technique with different reaction energy thresholds.Thicknesses of Be,Pb and Fe spheres were 5.3,19.1 and 31.9cm.respectively,Eight kinds of activation folis were used for Fe,and four kinds each for Be and Pb,The total experimental er5ror was about 5-7%.The measured results were compared to the values calculated with the 1-D ANISN code and the ENDF/B-VI library data.The average ratio of the experimental to the calculational is less than 7% for Be and Pb,about 5-30% for Fe.

  1. Absolute alpha activity measurements of some plants growing in monazite bearing soils in Sri Lanka

    Mahawatte, P.; Hewamanna, R. (Colombo Univ. (Sri Lanka). Radioisotope Centre)

    1991-01-01

    Deposits of monazite bearing soils occur along the Southwest, West and East Coasts of Sri Lanka. High levels of gamma activity in some plant species growing in the West Coast have been reported. The high levels were due to the presence of the daughter nuclides of {sup 232}Th, most of which are alpha emitters. Absolute alpha activity measurements of ash samples of some plants growing in monazite bearing soils were carried out using the alpha sensitive polymeric nuclear track detector CR-39. The values ranged from 60-1900 mBq/g and were in good agreement with the values obtained from conventional scintillation counting method. The activity concentration of {sup 228}Th in the ash samples was also calculated by measuring the activity concentration of emanated thoron trapped inside a glass bottle with the use of a CR-39 track detector. (author).

  2. Absolute alpha activity measurements of some plants growing in monazite bearing soils in Sri Lanka

    Deposits of monazite bearing soils occur along the Southwest, West and East Coasts of Sri Lanka. High levels of gamma activity in some plant species growing in the West Coast have been reported. The high levels were due to the presence of the daughter nuclides of 232Th, most of which are alpha emitters. Absolute alpha activity measurements of ash samples of some plants growing in monazite bearing soils were carried out using the alpha sensitive polymeric nuclear track detector CR-39. The values ranged from 60-1900 mBq/g and were in good agreement with the values obtained from conventional scintillation counting method. The activity concentration of 228Th in the ash samples was also calculated by measuring the activity concentration of emanated thoron trapped inside a glass bottle with the use of a CR-39 track detector. (author)

  3. Precise measurement of the absolute fluorescence yield of the 337 nm band in atmospheric gases

    Ave, M; Curry, E; Di Carlo, P; Di Giulio, C; Luis, P Facal San; Gonzales, D; Hojvat, C; Hörandel, J; Hrabovsky, M; Iarlori, M; Keilhauer, B; Klages, H; Kleifges, M; Kuehn, F; Li, S; Monasor, M; Nozka, L; Palatka, M; Petrera, S; Privitera, P; Ridky, J; Rizi, V; D'Orfeuil, B Rouille; Salamida, F; Schovanek, P; Smida, R; Spinka, H; Ulrich, A; Verzi, V; Williams, C

    2012-01-01

    A measurement of the absolute fluorescence yield of the 337 nm nitrogen band, relevant to ultra-high energy cosmic ray (UHECR) detectors, is reported. Two independent calibrations of the fluorescence emission induced by a 120 GeV proton beam were employed: Cherenkov light from the beam particle and calibrated light from a nitrogen laser. The fluorescence yield in air at a pressure of 1013 hPa and temperature of 293 K was found to be $Y_{337} = 5.61\\pm 0.06_{stat} \\pm 0.21_{syst}$ photons/MeV. When compared to the fluorescence yield currently used by UHECR experiments, this measurement improves the uncertainty by a factor of three, and has a significant impact on the determination of the energy scale of the cosmic ray spectrum.

  4. Evaluation of the systematic shifts and absolute frequency measurement of a single Ca+ ion frequency standard

    Huang, Yao; Liu, Peiliang; Bian, Wu; Guan, Hua; Gao, Kelin

    2014-01-01

    This paper provides a detailed description of the 40Ca+ optical frequency standard uncertainty evaluation and the absolute frequency measurement of the clock transition, as a summary and supplement for the published papers of Yao Huang et al. (Phys Rev A 84:053841, 1) and Huang et al. (Phys Rev A 85:030503, 2). The calculation of systematic frequency shifts, expected for a single trapped Ca+ ion optical frequency standard with a "clock" transition at 729 nm is described. There are several possible causes of systematic frequency shifts that need to be considered. In general, the frequency was measured with an uncertainty of 10-15 level, and the overall systematic shift uncertainty was reduced to below a part in 10-15. Several frequency shifts were calculated for the Ca+ ion optical frequency standard, including the trap design, optical and electromagnetic fields geometry and laboratory conditions, including the temperature condition and the altitude of the Ca+ ion. And we measured the absolute frequency of the 729-nm clock transition at the 10-15 level. An fs comb is referenced to a hydrogen maser, which is calibrated to the SI-second through the Global Positioning System (GPS). Using the GPS satellites as a link, we can calculate the frequency difference of the two hydrogen masers with a long distance, one in WIPM (Wuhan) and the other in National Institute of Metrology (NIM, Beijing). The frequency difference of the hydrogen maser in NIM (Beijing) and the SI-second calculated by BIPM is published on the BIPM web site every 1 month, with a time interval of every 5 days. By analyzing the experimental data obtained within 32 days of a total averaging time of >2 × 106 s, the absolute frequency of the 40Ca+ 4 s 2 S 1/2-3 d 2D5/2 clock transition is measured as 411 042 129 776 393.0 (1.6) Hz with a fractional uncertainty of 3.9 × 10-15.

  5. A new method for the absolute radiance calibration for UV-vis measurements of scattered sunlight

    Wagner, T.; Beirle, S.; Dörner, S.; Penning de Vries, M.; Remmers, J.; Rozanov, A.; Shaiganfar, R.

    2015-10-01

    Absolute radiometric calibrations are important for measurements of the atmospheric spectral radiance. Such measurements can be used to determine actinic fluxes, the properties of aerosols and clouds, and the shortwave energy budget. Conventional calibration methods in the laboratory are based on calibrated light sources and reflectors and are expensive, time consuming and subject to relatively large uncertainties. Also, the calibrated instruments might change during transport from the laboratory to the measurement sites. Here we present a new calibration method for UV-vis instruments that measure the spectrally resolved sky radiance, for example zenith sky differential optical absorption spectroscopy (DOAS) instruments or multi-axis (MAX)-DOAS instruments. Our method is based on the comparison of the solar zenith angle dependence of the measured zenith sky radiance with radiative transfer simulations. For the application of our method, clear-sky measurements during periods with almost constant aerosol optical depth are needed. The radiative transfer simulations have to take polarisation into account. We show that the calibration results are almost independent from the knowledge of the aerosol optical properties and surface albedo, which causes a rather small uncertainty of about < 7 %. For wavelengths below about 330 nm it is essential that the ozone column density during the measurements be constant and known.

  6. Easy Absolute Values? Absolutely

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  7. Measurement methodology of natural radioactivity in the thermal establishments

    The thermal baths have been identified as an activity susceptible to expose to ionizing radiations the workers through the natural sources of radon and radon 220. The new regulation obliges these facilities to realize radioactivity measurements. The principal ways of exposure are radon and its daughters inhalation,, exposure to gamma radiation, ingestion of radioelements in thermal waters. I.R.S.N. proposes two methods of measurements of the natural radioactivity in application to the regulation relative to the protection of persons and workers. Some principles to reduce exposure to radon are reminded. (N.C.)

  8. A pulse-recording system for radioactivity measurements

    The NIST Radioactivity Group is developing a computer-based pulse-recording system to use for radioactivity measurements. The system consists of a dual ADC module and a plug-in board for an industry-standard-architecture personal computer. The host computer (or another computer) can be programmed to simulate many different logic systems (coincidence, anticoincidence, selective sampling, correlation counting, etc.), so that the pulse data from a given measurement can be analyzed using a wide range of timing parameters and types of logic

  9. Study on measurement of trace radioactivity, (2)

    The method was worked out so as to measure 59Fe, 60Co, 65Zn, 95Zr, and 144Ce successively from the same sample by ion-exchange separation. This method was also applicable to the measurement of 90Sr and 137Cs. It was confirmed that 131I in milk could be measured satisfactorily by the method of US Atomic Energy Commission, when raw milk before processing was preserved in good condition. 3H in natural water can be measured with a gas magnifying counter without isotope concentration when water is transformed into hydrogen gas. It was found that an external heater type reactor is desirable to transform 3H in water into methane gas so far as the repair is concerned. The present reactor needs some improvement, however, to get better yield as the best synthesizing yield for methane gas obtained so far was only 48.8%. (Kobatake, H.)

  10. Anticoincidence and differential measuring arrangement for radioactive substances

    For discontinuous measurement of radioactive substances in air, water, food, soil samples, and for potash determination, anticoincidence and differential measuring arrangements with large-area counters are used. By a number of measures, the background is effectively reduced. With anticoincidence measuring arrangements, low alpha and beta activities may also be detected. With differential measurements, substances are measured whose activities are not extremely low. Further applications are simultaneous alpha and alpha/beta measurements and the specific measurement of the man-made alpha component in air. (orig.)

  11. Measurement of absolute minority species concentration and temperature in a flame by the photothermal deflection spectroscopy technique.

    Li, Yunjing; Gupta, Rajendra

    2003-04-20

    It is experimentally demonstrated that absolute concentrations of minority species in flames can be measured by the photothermal deflection spectroscopy (PTDS) technique. In addition, the PTDS signal simultaneously yields the flame temperature the measurement point. Absolute concentration profiles of OH have been measured in a flat-flame burner with methane as fuel. The PTDS measurements agree well with those obtained independently by the absorption technique. The flame temperature measurements by PTDS are also in good agreement with those obtained by the Boltzmann distribution among the rotational levels of OH. PMID:12716166

  12. Measurement of the Absolute Branching Fraction of D0 to K- pi+

    Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, A.; /Bari U.; Eigen, G.; Ofte, I.; Stugu, B.; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Button-Shafer, J.; /LBL, Berkeley

    2007-04-25

    The authors measure the absolute branching fraction for D{sup 0} {yields} K{sup -} {pi}{sup +} using partial reconstruction of {bar B}{sup 0} {yields} D*{sup +}X{ell}{sup -}{bar {nu}}{sub {ell}} decays, in which only the charged lepton and the pion from the decay D*{sup +} {yields} D{sup 0}{pi}{sup +} are used. Based on a data sample of 230 million B{bar B} pairs collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC, they obtain {Beta}(D{sup 0} {yields} K{sup -}{pi}{sup +}) = (4.007 {+-} 0.037 {+-} 0.070)%, where the first error is statistical and the second error is systematic.

  13. Absolute Polarization Measurements at RHIC in the Coulomb Nuclear Interference Region

    The Relativistic Heavy Ion Collider at Brookhaven National Laboratory provides polarized proton beams for the investigation of the nucleon spin structure. For polarimetry, carbon-proton and proton-proton scattering is used in the Coulomb nuclear interference region at small momentum transfer (-t). Fast polarization measurements of each beam are carried out with carbon fiber targets at several times during an accelerator store. A polarized hydrogen gas jet target is needed for absolute normalization over multiple stores, while the target polarization is constantly monitored in a Breit-Rabi polarimeter. In 2005, the jet polarimeter has been used with both RHIC beams. We present results from the jet polarimeter including a detailed analysis of background contributions to asymmetries and to the beam polarization

  14. Conversion of far ultraviolet to visible radiation: absolute measurements of the conversion efficiency of tetraphenyl butadiene

    Vest, Robert E.; Coplan, Michael A.; Clark, Charles W.

    Far ultraviolet (FUV) scintillation of noble gases is used in dark matter and neutrino research and in neutron detection. Upon collisional excitation, noble gas atoms recombine into excimer molecules that decay by FUV emission. Direct detection of FUV is difficult. Another approach is to convert it to visible light using a wavelength-shifting medium. One such medium, tetraphenyl butadiene (TPB) can be vapor-deposited on substrates. Thus the quality of thin TPB films can be tightly controlled. We have measured the absolute efficiency of FUV-to-visible conversion by 1 μm-thick TPB films vs. FUV wavelengths between 130 and 300 nm, with 1 nm resolution. The energy efficiency of FUV to visible conversion varies between 1% and 5%. We make comparisons with other recent results. Work performed at the NIST SURF III Synchrotron Ultraviolet Radiation Facility,.

  15. Coincidence system for the absolute measurement of radionuclides activity using a liquid scintillator

    A system for the standartization of radioisotopes activity using liquid scintillator detector was developed. The system was set up at Nuclear Metrology Laboratory - L.M.N. (Nuclear Physics Division - IEA). The system performance was checked by absolute activity measurements for two radioisotopes, 60Co and 241Am. The activities were determined by the 4π(α, β-γ) coincidence method. An accuracy of the order of 99,8% was obtained. The results for 60Co were compared with those obtained by 4πβ-γ coincidence method using a proportional counter at L.M.N., while the results for 241Am were compared with those obtained through the linear extrapolation method using the same liquid scintillator. Compared to other systems, the advantages of this one are the simplicity and the short time spent in the sample preparation, and the negligible self-absorption. (Author)

  16. Absolute luminosity and proton-proton total cross section measurement for the ATLAS experiment at LHC

    The Large Hadron Collider (LHC) at CERN in Geneva will soon deliver collisions with an energy never reached in a particle accelerator. An energy in the center of mass of 10 and ultimately 14 TeV will allow to go beyond the borders of the physics known so far. ATLAS, the largest detector ever built, will hunt the Higgs boson and search for new physics beyond the Standard Model. Any physical process is described by a cross section that measures its probability to occur. The events resulting from a given process are registered by ATLAS. To determine their according cross section, one has to know the luminosity. For the ATLAS experiment, a relative measurement of the luminosity can be done using the response of several sub-detectors. However to calibrate these detectors, an absolute measurement has to be performed. The ALFA detector has been designed to measure the elastic scattering spectrum that will allow to determine the absolute luminosity and the proton-proton total cross section. This provides an accurate calibration tool at a percent level. These detectors, located 240 m away from the interaction point, are called roman pots, a mechanical system that allows to approach a scintillating fiber tracker a few millimeters to the beam center. The simulation of the measurement requires to use a charged particles transport program. This program has to be carefully chosen because the determination of the protons lost during their travel from the interaction point to the detector has a major impact on the acceptance computation. The systematical uncertainties affecting the luminosity and the total cross section measurements are also determined using the full simulation chain. The ALFA detector operates in a complex environment and consequently its design requires a great care. A large tests campaign has been performed on the front end electronics. The results and the corresponding data analysis have shown that all requirement where fulfilled. A test beam has been

  17. Absolute measurements of the fast neutron capture cross section of 115In

    The 115In(n,#betta#)/sup 116m1/In cross section has been absolutely determined at neutron energies of 23, 265 and 964 keV. These energies are the median neutron energies of the three photo-neutron sources. Sb-Be, Na-CD2 and Na-Be, utilized in this work. The measurements are independent of other cross section data except for corrections amounting to less than 10%. Independent determinations of the reaction rate, detector efficiency, neutron source strength, scalar flux and target masses were performed. Reaction rates were determined by beta counting of the /sup 116ml/In decay activity using a 4π gas flow proportional counter. Detector efficiency was measured using 4π#betta#-#betta# coincidence counting techniques and the foil absorber method of efficiency extrapolation for correction of complex decay scheme effects. Photoneutron source emission rates were determined by intercomparison with the NBS-II calibrated 252Cf spontaneous fission neutron source in the University of Michigan Manganese Bath. The normalized scalar flux was calculated from the neutron emission angular distribution results of the Monte Carlo computer program used to model neutron and gamma transport in the source. Target mass determinations were made with a microbalance. Correction factors were applied for competing reaction activities, neutron scattering from experiment components, room-return induced activities, spectral effects in the manganese bath and the neutron energy spectra of the photoneutron sources. Experimental cross section results were normalized to the source median energy using energy spectra d cross section shape data. The absolute cross sections obtained for the 115In(n,#betta#)/sup 116ml/In reaction were 588 +- 12, 196 +- 4 and 200 +- 3 millibarns at 23, 265 and 964 keV, respectively

  18. Croatian-Hungarian cooperation on the Danube river radioactivity measurements

    Danube river radioactivity measurements on the border profile Mohac-Batina have been performed since the beginning of 1978 with varying frequency of sampling. Thus, in the period before nuclear power plant Paks started to work joint croatian-hungarian sampling at the border profile was taking place four times a year; the obtained results of measured radioactivity levels were used to assess radioactivity background data. From the start of nuclear power plant Paks running until Chernobyl reactor accident (April 1986) sampling was performed six times a year. After the Chernobyl accident, samples have been taken every month. Since decreased Chernobyl reactor accident influence was estimated until present samples have been taken six times a year. On the Danube river border profile the concentration activity of gamma radionuclides has been determined in water samples (filtered water and suspended matter), and in fish, sediment and Danube river algae samples. (authors)

  19. Geometry Optimization Of Marinelli Sample In Environmental Radioactivity Measurement

    The problem of geometry optimization in environmental radioactivity determination has been studied by many scientists in the world. However, up to now, there have been not any published articles which studied optimum sample geometry in any given volumes. In this work, the simulation program MCNP was used to build the detection efficiency analytical formulas which can be used to calculate optimized geometries of Marinelli beaker in environmental radioactivity measurement. The geometry optimization was carried out with the sample volumes from 10 ml to 450 ml and the gamma-ray energy from 60 keV to 2 MeV. These optimized geometries give the highest detection efficiencies corresponding to given volumes. The goal of our study is to improve the limitation in low-level radioactivity measurement of environmental samples. (author)

  20. Measurements of radioactive dust in high altitude air

    The radioactivity in samples of airborne dust was measured. The samples had been collected at high altitude by the Japan Air Self-Defense Force. The data were obtained for the gross beta activity, gamma nuclide determination and radiochemical analysis. It was shown that there was no appreciable difference between the activity levels obtained in this time and in the year before. Seasonal variations were not very pronounced. It was found that the radioactivity at high altitude had been stable at a low level. Radioactive gases (gaseous radioiodine and xenon gas) were not detected. This report does not include the result on radionuclide measurements that Technical Research and Development Institute executed for examining the nuclear emergency situation at Fukushima Daiichi and Daini nuclear power plants after Tohoku Region Pacific Ocean Earthquake on March 11, 2011. (author)

  1. Improvement of a new portable monitor for measuring radioactivity levels

    Using a silicon photodiode as a sensor, the author has developed a new portable monitor for clinical use to measure irradiation from an inner organ through the body surface after the administration of radiopharmaceutical agent. The monitor can record the time course of radioactivity and can be assessed in the outpatient clinic. The total weight of this monitor is 660 g: the detector 70 g, the recorder 295 g, and the battery 295 g. In the present study, the monitor was utilized to measure and record the radioactivity in the bladder content of a patient who had been given Tc-99m methylene-diphosphonate for bone scintigraphy. The detector probe was placed on the abdomen over the bladder and fixed with adhesive tape. The recorder and battery were carried in a small backpack. The correlation between the radioactivity level in the urinary excretion and the count rate estimated by the monitor on the wall of urinary bladder was investigated. The average time to the first urinary excretion was made approximately 2 hr after the administration of radiopharmaceutical agent. The radioactivity count from the bladder reached the maximum level after approximately 2-3 hr, and subsequently decreased. The radioactivity in urine when excreted at 1 hr after administration was at 85% of that when excreted at 2 hr. In conclusion, the absorbed dosage in the bladder could be significantly reduced when the patients urinate at 1 hr after the administration of radiopharmaceutical agent. The newly developed portable monitor was adaptable to determine the radioactivity of inner organs directly from the outside of the body surface, and is effective in clinical management for excretion of clinical radioactive agents. (author)

  2. Measuring radioactive carbon with a liquid scintillator

    Petkov, T.

    1975-01-01

    Results are presented on the measurement of the soft beta emitter carbon-14 in a liquid scintillator by means of a single-channel scintillation spectrometer provided with a lucite light-guide. The scintillation solution had the composition: PPO-10 grams, POPOP-0.25 grams, naphthalene-100 grams, and dioxane-1 liter. The background count rate and counting efficiency were determined at a discrimination threshold of 2 V and an amplification of 54. Carbon-14 activities of 10 to 20 picocuries could be measured at 90% counting efficiency under the proper conditions. (SJR)

  3. A study on the absolute measurement of β-ray absorbed dose in the skin depth

    The absolute measurement of β ray absorbed dose in the skin depth located at the certain distance from the radiation source (90Sr + 90Y, 204TI, 147Pm) recommended by the International Standardization Organization is performed by using an extrapolation chamber in the range of several mGy/h. Since one of critical points in measuring of absorbed dose is to make the environment in chamber similar to tissue, a new approach to the measurement of absorbed dose is proposed. The attenuation difference is minimized by deciding a window thickness such as the attenuation effect in chamber window becomes similar to that in the skin depth. A-150 tissue equivalent plastic, whose structure and density is very similar to tissue, is used for back material. The back scattering effect of both media is measured using the proposed method to calibrate the difference in back scattering effect between back material and tissue. For the measurement of back scattering effect of each material, an ionization chamber, whose structure is very similar to the extrapolation chamber and back material is replaceable, is made. Based on the results, β ray absorbed dose in the skin depth of 70 μm was measured as follows : 0.759 μGy/s (±3.78% ) for 90Sr + 90Y, 0.173 μGy/s (±4.17%) for 204TI and 0.088 μGy/s (±7.70%) for 147Pm. In order to evaluate the reliability of the proposed method, the absorbed dose measured in this study is compared to that measured in PTB (Physikalisch Technische Bundesanstalt) for the same β ray source. Although the proposed method gives slightly higher value, the difference is within 1%. In conclusion, the proposed method seems to make the measuring environment closer to tissue, even though the calibration factor yielded by the proposed method has a little effect on evaluation of absorbed dose

  4. Measuring the absorbed radioactivity during a flight

    This paper presents the new system SIEVERT developed by the General Direction of the Civil Aviation (DGAC) to measure the radiations doses absorbed from cosmic radiation. The system is available on the Internet site: www.sievert-system.org. (A.L.B.)

  5. Krypton-85 and other airborne radioactivity measurements throughout Ireland

    In compliance with articles 35 and 36 of the EURATOM Treaty, the Radiological Protection Institute of Ireland (RPII) undertakes a comprehensive programme of radioactivity monitoring in the Irish terrestrial environment. Radioactivity is present in the terrestrial environment due to natural processes, the testing of nuclear weapons in the atmosphere, accidents such as the Chernobyl accident and the routine discharge of radionuclides from nuclear installations. The RPII monitors airborne radioactivity concentrations at ten stations throughout Ireland, of which, nine are equipped with low volume particulate samplers and one, in Dublin, with a high volume particulate sampler. The low volume particulate samples are assessed for total beta activity and high volume samples for gamma emitting radionuclides such as caesium-137 and beryllium-7. In addition, air sampled at the RPII laboratory in Dublin, is monitored for krypton-85, a radioactive noble gas, released into the environment primarily as a result of the reprocessing of nuclear fuel at installations such as Sellafield in the UK and La Hague in France. Since the inception of the krypton measurements in 1993 a trend of increasing atmospheric concentrations has been observed. The results of the krypton-85 monitoring, as well as the airborne radioactivity concentration measurements, will be presented and discussed in this paper. (author)

  6. Absolute measurement of the isotopic ratio of a water sample with very low deuterium content

    The presence of H3+ ions which are indistinguishable from HD+ ions presents the principal difficulty encountered in the measurement of isotopic ratios of water samples with very low deuterium contents using a mass spectrometer. Thus, when the sample contains no deuterium, the mass spectrometer does not indicate zero. By producing, in situ, from the sample to be measured, water vapor with an isotopic ratio very close to zero using a small distilling column, this difficulty is overcome. This column, its operating parameters, as well as the way in which the measurements are made are described. An arrangement is employed in which the isotopic ratios can be measured with a sensitivity better than 0.01 x 10-6. The method is applied to the determination of the isotopic ratios of three low deuterium content water samples. The results obtained permit one to assign to the sample with the lowest deuterium content an absolute value equal to 1.71 ± 0.03 ppm. This water sample is a primary standard from which is determined the isotopic ratio of a natural water sample which serves as the laboratory standard. (author)

  7. Absolute calibration method for laser megajoule neutron yield measurement by activation diagnostics.

    Landoas, Olivier; Glebov, Vladimir Yu; Rossé, Bertrand; Briat, Michelle; Disdier, Laurent; Sangster, Thomas C; Duffy, Tim; Marmouget, Jean Gabriel; Varignon, Cyril; Ledoux, Xavier; Caillaud, Tony; Thfoin, Isabelle; Bourgade, Jean-Luc

    2011-07-01

    The laser megajoule (LMJ) and the National Ignition Facility (NIF) plan to demonstrate thermonuclear ignition using inertial confinement fusion (ICF). The neutron yield is one of the most important parameters to characterize ICF experiment performance. For decades, the activation diagnostic was chosen as a reference at ICF facilities and is now planned to be the first nuclear diagnostic on LMJ, measuring both 2.45 MeV and 14.1 MeV neutron yields. Challenges for the activation diagnostic development are absolute calibration, accuracy, range requirement, and harsh environment. At this time, copper and zirconium material are identified for 14.1 MeV neutron yield measurement and indium material for 2.45 MeV neutrons. A series of calibrations were performed at Commissariat à l'Energie Atomique (CEA) on a Van de Graff facility to determine activation diagnostics efficiencies and to compare them with results from calculations. The CEA copper activation diagnostic was tested on the OMEGA facility during DT implosion. Experiments showed that CEA and Laboratory for Laser Energetics (LLE) diagnostics agree to better than 1% on the neutron yield measurement, with an independent calibration for each system. Also, experimental sensitivities are in good agreement with simulations and allow us to scale activation diagnostics for the LMJ measurement range. PMID:21806179

  8. Absolute production rate measurements of nitric oxide by an atmospheric pressure plasma jet (APPJ)

    Pipa, A V; Bindemann, T; Foest, R; Kindel, E; Roepcke, J; Weltmann, K-D [Leibniz-Institut fuer Plasmaforschung and Technologie e.V. (INP), Felix-Hausdorff Strasse 2, D-17489 Greifswald (Germany)], E-mail: foest@inp-greifswald.de

    2008-10-07

    Tunable diode laser absorption spectroscopy (TDLAS) has been applied to measure the absolute production rate of NO molecules in the gas phase of an atmospheric pressure plasma jet (APPJ) operating at rf (13.56 MHz) in argon with small (up to 1%) admixtures of air. The resulting NO production rates were found to be in the range (0.1-80) x 10{sup -3} sccm or (0.05-35) x 10{sup 18} molecules s{sup -1} depending on the experimental conditions. Maximum rates were obtained at 0.2% air. For TDLAS measurements the APPJ was arranged inside an astigmatic multi-pass cell of Herriott type with 100 m absorption length. The insertion into a closed volume differs slightly from the normal, open operation with the jet propagating freely into air. Therefore, the measuring results are compared with optical emission of the open jet to verify equivalent experimental conditions. The dependence of the optical emission of NO (237 nm) on power and gas mixture has been measured. The similar shape of the dependence of absorption and emission signals gives evidence that the comparability of experimental conditions is sufficiently satisfied. It is concluded that the NO production rate of the APPJ in ambient air can be characterized using TDLAS and provides reliable results in spite of differing experimental conditions due to the set-up.

  9. Radioactivity measurements of the HMI after the Chernobyl reactor accident

    The report explains the methods applied and the data measured by the HMI campaign. The material is presented so as to be of interest also to readers who in general are not concerned with aspects of radiation protection. The data measured refer to the local dose rate and to radioactivity in the environment (air, rain, surface waters, soil, food, mother's milk. Also, results of measurements of samples from Eastern Europe are given. (orig./HP)

  10. The impact of water temperature on the measurement of absolute dose

    Islam, Naveed Mehdi

    To standardize reference dosimetry in radiation therapy, Task Group 51 (TG 51) of American Association of Physicist's in Medicine (AAPM) recommends that dose calibration measurements be made in a water tank at a depth of 10 cm and at a reference geometry. Methodologies are provided for calculating various correction factors to be applied in calculating the absolute dose. However the protocol does not specify the water temperature to be used. In practice, the temperature of water during dosimetry may vary considerably between independent sessions and different centers. In this work the effect of water temperature on absolute dosimetry has been investigated. Density of water varies with temperature, which in turn may impact the beam attenuation and scatter properties. Furthermore, due to thermal expansion or contraction air volume inside the chamber may change. All of these effects can result in a change in the measurement. Dosimetric measurements were made using a Farmer type ion chamber on a Varian Linear Accelerator for 6 MV and 23 MV photon energies for temperatures ranging from 10 to 40 °C. A thermal insulation was designed for the water tank in order to maintain relatively stable temperature over the duration of the experiment. Dose measured at higher temperatures were found to be consistently higher by a very small magnitude. Although the differences in dose were less than the uncertainty in each measurement, a linear regression of the data suggests that the trend is statistically significant with p-values of 0.002 and 0.013 for 6 and 23 MV beams respectively. For a 10 degree difference in water phantom temperatures, which is a realistic deviation across clinics, the final calculated reference dose can differ by 0.24% or more. To address this effect, first a reference temperature (e.g.22 °C) can be set as the standard; subsequently a correction factor can be implemented for deviations from this reference. Such a correction factor is expected to be of similar

  11. Optical measurement of absolute flatness with the deflectometric measurement systems at PTB

    Highly accurate flatness measurements are needed for synchrotron optics, optical flats, or optical mirrors. Recently, two new scanning deflectometric flatness measurement systems have been installed at the Physikalisch-Technische Bundesanstalt (PTB). The two systems (one system for horizontal and the other for vertical specimens) can measure specimens with sizes up to one metre with an expected uncertainty in the sub-nanometre range. In addition to the classical deflectometric procedure, also the 'extended shear angle difference (ESAD)' and the 'exact autocollimation deflectometric scanning (EADS)' procedures are implemented. The lateral resolution of scanning deflectometric techniques is limited by the aperture of the angle measurement system, usually an autocollimator with typical apertures of a few millimetres. With the EADS procedure, the specimen is scanned with an angular null instrument which has the potential to improve the lateral resolution down to the sub-millimetre region. A new concept and design of an appropriate angular null instrument are presented and discussed.

  12. On the measurement of quadrupole moments of radioactive nuclei

    Electric quadrupole moments provide a direct insight on the single-particle structure or the collective nature of a nuclear state. This article presents a short review on some of the experimental methods available to measure quadrupole moments with emphasis on the reorientation technique in Coulomb excitation and its use in combination with radioactive ion beams.

  13. IAEA-MEL's AQCS programme for marine radioactivity measurements

    The main objectives of the IAEA-MEL's Analytical Quality Control Services (AQCS) for marine radioactivity measurements are discussed and future plans for the organization of intercomparison exercises and the production of certified reference materials are presented. The new developments should also include implementation of quality assurance programmes in Member States' laboratories, training in quality management and accreditation programmes. (author)

  14. A low noise highly integrated bolometer array for absolute measurement of VUV and soft x radiation

    A new low noise miniaturized multichannel bolometer module for absolute measurements in the VUV and soft x spectral ranges is described. Highly integrated four-channel modules (2x3.3x1.5 cm3) each comprising four independent ac-excited (50 kHz) metal resistor bolometer bridges were successfully tested on a large tokamak (Tore Supra in Cadarache) and on an electron synchrotron (BESSY in Berlin). The bolometer system features a linear response to the absorbed radiation power, a low detection limit (≤1.0x10-6 W cm-2 on Tore Supra with an integration time of τint=10x10-3 s) and a low NEP (≤10x10-9 W on BESSY). The thermal cross-talk between adjacent detectors is negligible (Br/ΔT -4 V degree C-1 is achieved. It can be operated at a maximum temperature of 150 degree C, at high magnetic fields (tested up to B=4.5 T in the laboratory) and survives high nuclear radiation doses. The system offers the possibility of detecting low-power VUV and soft x-radiation with sampling rates of up to 10 kHz on plasma machines and of absolutely calibrating VUV and soft x instruments. Effective suppression of electric, thermal and nuclear radiation interferences is characteristic of the bolometer system.Strain gauge effects, which could affect the behavior of the bolometers at high magnetic fields, are suppressed by the ac-excitation technique

  15. Methods for Measuring Sand Transport Using Radioactive Tracers

    Radioactive glass particles are sometimes used in the field for investigating the behaviour of sand and silt. Experiments have been performed in a flume with a rippled sand bed to compare the rate of movement of sand and glass particles of the same size and density. Several methods of measuring sand transport in the flume using radioactive tracers are described and compared. Two of these methods have been investigated in a series of tests; the first, usually termed the space integration method, involves the measurement of the spatial distribution of particles from a strip of the bed after various times; the second, referred to as the time integration method, requires the measurement of the passage of the tracer in time at a station downstream. These methods have been used to measure the velocity of several size fractions in a sand mixture. The practical difficulties of applying these methods to measurements in the field are briefly examined. (author)

  16. Measurement of nuclear cross sections using radioactive beams

    One of the main applications of the production and use of nuclear radioactive beams is the measurement of nuclear cross sections. In this work is used a 6 He nuclear radioactive beam (β emitting with half life 806.7 ms) for the study of the reaction 6 + 209 Bi which could have several products. This investigation was realized in collaboration with the personnel of the Nuclear Structure laboratory at the University of Notre Dame (U.S.A.) and the National institute of Nuclear Research and CONACyT by Mexico. (Author)

  17. Measurement of radioactivity in agricultural products (1995-96)

    Radioactivity levels and concentration of radionuclides in agricultural products like beans, sesame, potato, etc. were measured by using Low Level Beta/Alpha System and high resolution gamma-ray spectrometry system. The levels of radioactivity were found to be less than the Derivedc Intervention Level adopted by FAO/WHO Codex Alimentarius Commission in 1991 (IAEA BSS safety series No. 115-1). No artificial radionuclides such as fission products, activation products were not found whereas radionuclides found in the samples are only natural occurring radionuclide, K-40. (author)

  18. Advanced technologies for radioactive waste characterization and free release measurement

    Nuclear power generation, medicine and heavy industry are widely using radioactive materials and, as a result, are generating large amounts of radwaste that has to either be stored or free-released to the environment. Free-release procedures require precise detection of radionuclides that can remain in waste. The low activity of such nuclides can be on a level of natural background or even below. That requires the background influence to be removed. ENVINET has developed very low radioactivity materials which can be used to form a low background measuring chamber. The concrete composite based material has several advantages when compare with lead, which is usually used for such purposes. (author)

  19. Absolute and Relative Isotope Abundances Measured by Tunable Diode Laser Spectroscopy

    Tucker, George Franklin

    The potential for measuring absolute and relative isotope abundances by high resolution spectroscopy with tunable diode lasers as sources was studied. In order to achieve the sensitivity necessary to determine the absolute abundances of molecules containing long-lived radionuclides such as ('14)C an ('129)I, a resonant spectrophone based on the photoacoustic effect was used for detection. For safety, NH(,3) was used as a sample with air as a buffer gas when characterizing the performance of the TDL-spectrophone system. Frequency modulation of the TDL was employed. The optimum operating pressure was found to be 6.6 kPa(50 Torr). Substitution of Kr as a buffer gas yielded a fourfold increase in signal. It is estimated that with currently available TDLs a photoacoustic spectrometer should be capable of detecting ('14)CO(,2) and CH('129)I at the levels present in nuclear reactor containment gases. An isotope shift of CH(,3)('129) I relative to CH(,3)('127)I in the (nu)(,6) band of (0.0135 (+OR-) 0.0006) cm('-1) was measured by TDL linear absorption spectroscopy. To perform relative isotope abundance measurements a TDL was tuned over two adjacent, but well-resolved, rotation -vibration absorption lines, one of each isotopic species, while the transmitted radiation was monitored with a HgCdTe detector. The P(26) line of the (nu)(,1) band of N(,2)('18)O at 1225.3671 cm('-1) and the P(63) line of the (nu)(,1) band of N(,2)('16)O at 1225.4879 cm('-1) were chosen, for their line strength ratio is inversely proportional to the ratio of their natural abundances, and thereby yielded approximately equal absorbance for each isotopic species. A double-beam, single-detector spectrometer with wavelength modulation to minimize the effects of laser power and cell temperature fluctuations, has been adapted for use with a TDL. After samples of known ('18)O enrichment were used to calibrate the spectrometer, the (delta)('18)O of tropospheric N(,2)O was measured to be (8.05 (+OR-) 0

  20. Cryogenic Current Comparator for Absolute Measurement of the Dark Current of the Superconducting Cavities for Tesla

    Knaack, K; Wittenburg, K

    2003-01-01

    A newly high performance SQUID based measurement system for detecting dark currents, generated by superconducting cavities for TESLA is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the nA range with a small signal bandwidth of 70 kHz. To reach the maximum possible energy in the TESLA project is a strong motivation to push the gradients of the superconducting cavities closer to the physical limit of 50 MV/m. The field emission of electrons (the so called dark current) of the superconducting cavities at strong fields may limit the maximum gradient. The absolute measurement of the dark current in correlation with the gradient will give a proper value to compare and classify the cavities. This contribution describes a Cryogenic Current Comparator (CCC) as an excellent and useful tool for this purpose. The most important component of the CCC is a high performance DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted ...

  1. Direct and absolute absorption measurements in optical materials and coatings by laser induced deflection (LID) technique

    Mühlig, Ch.

    2012-01-01

    Different strategies of the laser induced deflection (LID) technique for direct and absolute absorption measurements are presented. Besides selected strategies for bulk and coating absorption measurements, respectively, a new strategy is introduced allowing the transfer of the LID technique to very small samples and to significantly increase the sensitivity for materials with a very weak photo-thermal response. Additionally, an emphasis is placed on the importance of the calibration procedure. The electrical calibration of the LID setup is compared to two other approaches that use either doped samples or highly absorptive reference samples in combination with numerical simulations. Applying the LID technique, we report on the characterization of AR coated LBO crystals used in high power NIR/VIS laser applications. The comparison of different LBO crystals shows that there are significant differences in both, the AR coating and the LBO bulk absorption. These differences are much larger at 515 nm than at 1030 nm. Absorption spectroscopy measurements combining LID technique with a high power OPO laser system indicate that the coating process affects the LBO bulk absorption properties. Furthermore, the change of the absorption upon 1030 nm laser irradiation of a Nd:YVO4 laser crystal is investigated and compared to recent results. Finally, Ytterbium doped silica raw materials for high power fiber lasers are characterized with respect to the absorption induced attenuation at 1550 nm in order to compare these data with the total attenuation obtained for the subsequently manufactured laser active fibers.

  2. Absolute high-resolution Se+ photoionization cross-section measurements with Rydberg-series analysis

    Absolute single photoionization cross-section measurements for Se+ ions were performed at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory using the photo-ion merged-beams technique. Measurements were made at a photon energy resolution of 5.5 meV from 17.75 to 21.85 eV spanning the 4s24p34S3/2o ground-state ionization threshold and the 2P3/2o,2P1/2o,2D5/2o, and2D3/2o metastable state thresholds. Extensive analysis of the complex resonant structure in this region identified numerous Rydberg series of resonances and obtained the Se2+ 4s24p23P2 and 4s24p21S0 state energies. In addition, particular attention was given to removing significant effects in the measurements due to a small percentage of higher-order undulator radiation.

  3. Absolute measurement of the effective nonlinearities of KTP and BBO crystals by optical parametric amplification.

    Armstrong, D J; Alford, W J; Raymond, T D; Smith, A V

    1996-04-20

    Absolute magnitudes of the effective nonlinearity, deff, were measured for seven KTP and six BBO crystals. The d(eff), were derived from the parametric gain of an 800-nm signal wave in the sample crystals when they were pumped by the frequency-doubled, spatially filtered light from an injectionseeded, Q-switched Nd:YAG laser. The KTP crystals, all type II phase matched with propagation in the X-Z plane, had d(eff) values ranging from 1.97 to 3.50 pm/V. Measurements of gain as a function of phase velocity mismatch indicate that two of the KTP crystals clearly contain multiple ferroelectric domains. For five type I phase-matched BBO crystals, d(eff) ranged from 1.76 to 1.83 pm/V, and a single type II phase-matched BBO crystal had a d(eff) of 1.56 pm/V. The uncertainty in our measurements of d(eff) values is ±5% for KTP and ±10% for BBO. PMID:21085331

  4. Approximation by Absolutely Continuous Invariant Measures of Iterated Function Systems with Place-Dependent Probabilities

    Islam, Md Shafiqul; Chandler, Stephen

    2015-10-01

    Let S be the attractor (fractal) of a contractive iterated function system (IFS) with place-dependent probabilities. An IFS with place-dependent probabilities is a random map T = {τ1(x),τ2(x),…,τK(x); p1(x),p2(x),…,pK(x)}, where the probabilities p1(x),p2(x),…,pK(x) of switching from one transformation to another are functions of positions, that is, at each step, the random map T moves the point x to τk(x) with probability pk(x). If the random map T has a unique invariant measure μ, then the support of μ is the attractor S. For a bounded region X ⊆ ℝN, we prove the existence of a sequence {T0,n∗} of IFSs with place-dependent probabilities whose invariant measures {μn} are absolutely continuous with respect to Lebesgue measure. Moreover, if X is a compact metric space, we prove that μn converges weakly to μ as n →∞. We present examples with computations.

  5. ROKO-Database of the environmental radioactivity measurements in Slovenia

    ROKO is the acronym of the Environmental Radioactivity in Slovenian language Radioaktivnost v OKOlju. Computer database ROKO contains data of all measurements of the radioactivity in the environment in Slovenia. Data about radioactivity in the environment have been collected in Slovenia more or less regularly since 1961 on. Most results are gathered in the form of paper reports. Slovenian Nuclear Safety Administration (SNSA) has initiated the project of transfer of all those data into the electronic form and making it available for easy research. The database is designed so, that it contains all records, relevant for any kind of analyses and for the transfer to the international data systems. By the end of the summer 2005 a major part of data from previous years have already been transferred into the database and the user interface software is under development. It will allow the users to examine individual data records, to plot time history graphs or geographical contour plots. (author)

  6. Measurement and analysis of radioactive substances; Mesure et analyse de substances radioactives

    NONE

    2001-07-01

    Here are gathered the abstracts presented to the 3. summer university of the year 2001 whose main themes were the destructive (5 conferences) and nondestructive (8 conferences) analyses applied to nuclear industry. The points of view of different organisms (as DSIN: Directorate for the Safety of Nuclear Installations, IPSN: Institute of Nuclear Protection and Safety, OPRI: Office of Protection against Ionizing Radiations, TUI: Institute for Transuranium Elements, COGEMA, EDF: Electric Utilities, ANDRA: French National Agency for Radioactive Waste Management, CRLC Val d'Aurelle, France) concerning the needs involved in nuclear facilities control, the methods of radionuclide speciation in use internationally, the measurements and analyses of radioactive substances are given too as well as some general concepts concerning 1)the laser-matter interaction 2)the ions production 3)the quality applied to the measurements and analyses 4)the standard in activity metrology. (O.M.)

  7. Determining radioactive aerosol concentrations using a surface radioactive contamination measurement device

    For experiments with dispersed radioactive aerosols in a radon-aerosol chamber (RAC), it is desirable to know the activity of the radioactive aerosols applied in the RAC. A COLIBRI TTC survey metre with an SABG-151 probe (Canberra, USA) was purchased for this purpose. The probe is designed for surface contamination measurements, and it is intended to measure the activity of aerosols deposited on the filters during experiments in the RAC. Since the probe is calibrated in a different geometry, its response in the authors' experimental geometry was simulated by a Monte Carlo method. The authors present a Monte Carlo model using MCNPX and an experimental verification of this probe model. (authors)

  8. Radioactivity measurements in Egyptian Phosphate Mines and Their Significance As a Source of Hazardous Radioactive Waste

    Phosphate mines that may contain radioactive traces in the composition of their ores represent source of hazardous radioactive waste in the environment. Radioactivity measurements have been conducted in nine underground phosphate mines in the Egyptian Eastern Desert in order to estimate the occupational radiation exposure of mine workers in those mining sites. Measurements were carried out of airborne radon and its short- lived decay products (progeny) and thoron progeny, as well as radiation from mines walls, ceilings and floors. Conventional, well established techniques, methods and instrumentation were used to make these measurements. Comparison of experimental data and theoretical predictions showed partial agreement between these two sets of data. This result is partly attributed to the complex layout of these mines, which causes undesirable ventilation conditions, such as recirculation airflow patterns, which could not be adequately identified or quantified. The radiation data obtained were used to estimate the maximum Annual Dose (MAD), and other important occupational radiation exposure variables. These calculations indicate that in eight out of the nine mines surveyed, the MAD exceeded (by a factor of up to 7) the maximum recommended level by ICRP 60. Numbers of suggestions are made in order to reduce the MAD in the affected mines. This study could help in the estimation of the environmental impact of these mine operations on the environment

  9. Use of proportional gas scintillator in absolute measurements of alpha-gamma emitter activities

    The absolute activity of U-235 contained in a U3 O8 sample was measured utilizing a sum-coincidence circuit which selects only the alpha particles which are simultaneous with the 143 KeV and 186 KeV gamma radiations from the Th-231 (product nucleus). The alpha particles were detected by means of a new type of a gas scintillating chamber, in which the light emitted by excitation of the gas atoms, due to the passage of a charged incoming particle, has its intensity increased by the action of an applied electric field. The gamma radiations were detected by means of a NaI(Tl) 1'' x 11/2'' scintillation detector. The value obtained for the half-life of U-235 was compared with the data available from various observers which used different experimental techniques. It is shown tht the results, are in excellent agreement with the best international data available on the subject and that, therefore, the sum-coincidence technique constitutes an important method for such measurements. (Author)

  10. Gravity change from repeated absolute measurements in Estonia, Latvia and Lithuania 1994-2008

    Mäkinen, J.; Bilker-Koivula, M.; Falk, R.; Gitlein, O.; Kaminskis, J.; Lapushka, K.; Oja, T.; Paršeliunas, E.; Petroškevičius, P.; Timmen, L.

    2009-04-01

    Estonia, Latvia, and Lithuania belong to the margin of the Fennoscandian postglacial rebound (PGR) area. Vertical rates predicted by PGR models are in the range 0 to +3 mm/yr. Our first absolute gravity campaigns in the area were performed with the JILAg-5 gravimeter in 1994-1995 when three stations were measured in each country. All three stations in Lithuania were repeated with the JILAg-5 in 2002 and one of them (Vilnius) with the FG5#221 gravimeter in 2007. In Latvia one station (Riga) was remeasured with the FG5#101 and FG5#107 (D. Stizza, NIMA) in 1986 and with the FG5#221 in 2007. In Estonia two of the stations (Suurupi and Töravere) were remeasured with the FG5#220 in 2007 and with the FG5#221 in 2008, the third (Kuressaare) was only remeasured in 2008 with the FG5#221. This amounts to seven repeated stations with time spans of 8-13 years. In interpreting gravity change, special attention must be paid to subsurface water storage, as (due to inaccessibility of crystalline bedrock) many stations are on thick sediments, the repeat measurements were partly made in different seasons, and in some cases there is evidence of strong interannual variation in hydrology. We discuss the constraints to PGR implied by the observed gravity change and compare it with PGR models and with available observations of vertical motion.

  11. SQUID-based setup for the absolute measurement of the Earth’s magnetic field

    We present a configuration of LTS dc SQUID magnetometers that is suited for an absolute measurement of the vector components of the Earth’s magnetic field with a white noise level of about 6 fT Hz−1/2. Due to its periodic voltage–flux characteristic, a SQUID’s output voltage generally corresponds to a set of equidistant fluxes or magnetic field strengths. To resolve this ambiguity, we introduce a configuration of coplanar SQUIDs integrated on a single chip, which exhibit effective areas differing by several orders of magnitude. The set of possible magnetic field strengths matching the output voltages of these SQUIDs is thereby significantly reduced and especially unique for magnetic field strengths less than a certain threshold value of about 10 μT in our current implementation. The SQUIDs are realized with 0.8 μm cross-type Josephson junctions that withstand high background fields of up to 3.9 mT during cool down and operation. A first one-dimensional experimental implementation successfully measured the modulation of the magnetic field component perpendicular to the sensor surface with amplitudes exceeding 50 μT. The overall dynamic range of the SQUID magnetometer system achieves 190 dB. (paper)

  12. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between ∼6 and ∼13 GeV with an estimated uncertainty of ∼2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  13. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    Ackermann, M.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Ajello, M.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Allafort, A.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm; Baldini, L.; /INFN, Pisa; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Bechtol, K.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Bloom, E.D.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Bouvier, A.; /UC, Santa Cruz; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari Polytechnic /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Buehler, R.; /Stanford U., HEPL /SLAC /KIPAC, Menlo Park; Buson, S.; /INFN, Padua /Padua U. /CSIC, Catalunya /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Unlisted, US /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /ASDC, Frascati /Perugia U. /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Montpellier U. /ASDC, Frascati /Bari Polytechnic /INFN, Bari /Naval Research Lab, Wash., D.C. /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Montpellier U. /Bari Polytechnic /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Ecole Polytechnique /Hiroshima U. /Stanford U., HEPL /SLAC /KIPAC, Menlo Park /Bari Polytechnic /INFN, Bari /INFN, Bari /NASA, Goddard /INFN, Perugia /Perugia U.; /more authors..

    2012-09-20

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between {approx}6 and {approx}13 GeV with an estimated uncertainty of {approx}2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  14. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbielini, G; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B,; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Gehrels, N.; Hays, E.; McEnery, J. E.; Thompson, D. J.; Troja, E. J.

    2012-01-01

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron- plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between approx. 6 and approx. 13 GeV with an estimated uncertainty of approx. 2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  15. Absolute frequency measurement for the emission transitions of molecular iodine in the 982 - 985 nm range

    Matyugin, Yu A; Ignatovich, S M; Kuznetsov, Sergei A; Nesterenko, M I; Okhapkin, M V; Pivtsov, V S; Skvortsov, Mikhail N; Bagaev, Sergei N [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2012-03-31

    We report high-precision frequency measurements of the separate hyperfine structure (HFS) components of the emission B - X system transitions of {sup 127}I{sub 2} molecules in the 982 - 985 nm range. To resolve the HFS of the emission lines, advantage was taken of the method of three-level laser spectroscopy. The function of exciting radiation was fulfilled by the second harmonic of a cw Nd : YAG laser, and the probe radiation in the 968 - 998 nm range was generated by an external-cavity diode laser. The output Nd : YAG laser frequency was locked to an HFS component of the absorption transition and the probing laser radiation to the emission transition component. When both frequencies were locked to HFS components with a common upper level, the output diode laser frequency was precisely equal to the emission transition frequency. The output frequency of the thus stabilised diode laser was measured with the help of a femtosecond optical frequency synthesiser based on a Ti : sapphire laser. We present the results of the absolute frequency measurements of 20 HFS components belonging to six vibrational - rotational transitions of the B - X system of iodine [R56(32 - 48)a1, P58(32 - 48)a1, P85(33 - 48)a1, R87(33 - 48a1, R88(33 - 48)a10] and all 15 components of the R86(33 - 48) line. The relative measurement uncertainty is equal to 7 Multiplication-Sign 10{sup -10} and is determined by the frequency instability of the diode laser radiation.

  16. An accurate absolute-scale measurement of bremsstrahlung following absorption of incident X and γ rays

    The spectrum of bremsstrahlung due to photoelectrons ejected by incident photons of energy 59.5 keV was measured. The coincidence setup with two HP germanium detectors was applied, in which the target-detector recorded the energy of ejected photoelectron after it radiated a bremsstrahlung photon, and another (second) detector detected energy of radiated bremsstrahlung photon. A detailed analysis of the measurement was made taking into account various detector-to-detector cross-talk processes. As expected, the experimental method gave a clean spectrum, which can be reliably determined on absolute scale in the low- and mid-energy range. The condition for reliable measurement are that the asymmetry ratio (the ratio of number of incident photons which reached the target detector and the second detector) is higher than approximately 1000 to reduce reverse-Compton scattering, and solid angle is smaller than about 0.15 sr to reduce the influence of double-cross-talk processes. (We name a group of processes double-cross-talk processes in which incident radiation produces secondary radiation in target detector, the secondary radiation escapes it and reaches the second detector where it induces tertiary radiation, which reaches the target detector and is absorbed therein.) Almost any line source of photons can be used even if of a complex spectrum. Therefore, simultaneous measurements at several incident energies are possible in one experiment. Application of a very weak source is possible because of very high signal-to-background ratio and high efficiency of the applied experimental method. The simple theoretical model of bremsstrahlung radiation due to photoelectrons in infinity-thick target gives results in a good agreement with the experimental data. The bremsstrahlung cross-section calculated using the well-known semi-empirical thick-target formula gives also a good agreement with the experimental data. (author)

  17. Measurement of radioactivity levels and assessment of radioactivity hazards of soil samples in Karaman, Turkey

    In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the 238U series (226Ra, 214Pb and 214Bi), 232Th series (228Ac), 40K and fission product 137Cs are discussed. To evaluate the radiological hazard of radioactivity in samples, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose and the external (Hex) and internal hazard index (Hin) were calculated and presented in comparison with the data collected from different areas in the world and Turkey. (authors)

  18. A gridded ionization chamber for measurement of environmental radioactivity

    In order to detect low level alpha radioactivities in various natural materials, a single gridded ionization chamber was constructed. This chamber of the Frischgrid type has a very large source area of 200 cm2 and provides a resolution of about 79 keV for 5.48 MeV alpha particles of a Americium-241 source. It was attempted to eliminate the background pulses, by making use of cathode pulses. The resultant background counting rate was in the order of 3 counts per hour, which corresponds to a good figure of merit of about 106. As a preliminary measurement, radioactive contamination levels in a sample of aluminum have been measured. It was found that (0.014 +- 0.011) pCi of Radium-226 is contained in 1 gram of the sample. (author)

  19. Measures reducing incorporation of radioactive substances in emergency events

    In emergency events involving emission of radioactive nuclides, a major contribution to the radiation exposure of the population stems from incorporation of the substances. Based to a major part on literature studies, but also on own investigations, the authors show ways and means to influence the metabolic processes in connection with the radioactive substances taken in by the population through inhalation, through the skin, and ingestion of food and drinking water. The authors present a survey showing results achieved by measures reducing resorption and accelerating excretion. For evaluation of the the efficiency of the measures studied, a cost-benefit analysis has been made. Every interference in order to modify the resorptive or excretionary processes in man involve the risk of inducing a metabolic derangement. This is why the possibly resulting radiation injury is to be compared to the risks involved with treatment. (orig./MG)

  20. Design of automatic control and measurement software for radioactive aerosol continuity monitor

    The radioactive aerosol continuity measurement is very important for the development of nuclear industry, and it is the major method to measure and find out the leakage of radioactive material. Radioactive aerosol continuity monitor is the advanced method for the radioactive aerosol continuity measurement. With the development of nuclear industry and nuclear power station, it is necessary to design and automatic continuity measurement device. Because of this reason, the authors developed the first unit of radioactive aerosol continuity monitor and adopted the ministry appraisal. The design idea and method of automatic control and measurement for radioactive aerosol continuity monitor are discussed

  1. Our experience of blood flow measurements using radioactive tracers

    A critical study of blood flow measuring methods is proposed. After a review of the various diffusible and non-diffusible radioactive tracers and the corresponding detector systems, the principles which allow to measure blood flow from the data so obtained, are studied. There is a different principle of flow measurement for each type of tracer. The theory of flow measurement using non-diffusible tracers (human serum albumin labelled with 131I or sup(99m)Tc, 113In-labelled siderophiline) and its application to cardiac flow measurement are described first. Then the theory of flow measurement using diffusible tracers (133Xe, 85Kr) and its application to measurement of blood flow through tissues (muscles and kidney particularly) are described. A personal experience of this various flow measurements is reported. The results obtained, the difficulties encountered and the improvments proposed are developed

  2. Low-level radioactivity measurements in an ocean shellfish matrix

    Reference marine biological samples are necessary to test the performance of the analytical methods employed in surveying and monitoring radioactive materials in the sea. The measurement of artificial and natural radionuclide activity concentrations in ocean shellfish material by nondestructive ultra low-level γ-ray spectrometry in an underground laboratory is reported. The material analysed, a composite material made of Irish Sea and White Sea mussel and Japan Sea oyster, was prepared by the National Institute of Standards and Technology (NIST)

  3. Radon Natural Radioactivity Measurements for Evaluation of Primary Pollutants

    Fenjuan Wang; Zhenyi Zhang; Maria Pia Ancora; Xiaodong Deng; Hua Zhang

    2013-01-01

    Radon is naturally released from the soil into the surface layer of the atmosphere, and by monitoring the natural radioactivity data of radon and its shot-live decay products we can get valuable information about the dilution properties of the lower boundary layer. This paper explores the dispersion characteristics of the lower layer of the atmosphere in Lanzhou, China, and the close relationship with the patterns of primary pollutants’ concentrations. Measurements were conducted from July 20...

  4. The relation of the measurement physical quantities to radioactive logging

    According to the statistic error theory, the author discusses the vertical resolution because of the moving survey in the radioactive logging, and analyses its relation with the other measurement physical quantities, as the GR (Natural gamma-rays logging) being given. And the fitting process principle is described, especially Kalman fitting technology in modern control theory and adaptive Kalman fitting in the practical application. The examples of simulation are shown

  5. Radioactivity measurement in imported food and food related items

    The Philippine Nuclear Research Institute (PNRI), formerly Philippine Atomic Energy Commission (PAEC) undertook the radioactivity monitoring of imported food and food-related products after the Chernobyl Plant accident in April 1986. Food samples were analyzed for 137Cs and 134Cs by gamma spectral method of analysis. This report deals with the measurement process and gives the result of the activity covering the period June 1986 to December 1987. (Auth.). 9 tabs., 7 figs., 4 refs

  6. Measurements of radioactive dusts in high altitude air

    The radioactivities of the airborne dusts were measured in samples collected by an aircraft of the Japan Air Self-Defence Force in high altitude during the period between April 1997 and March 1998. The data of the gross beta activities show that there is no appreciable difference from the activity levels of the year before and seasonal variations are becoming not so clear. (author)

  7. Measurements of environmental radiations and radioactivities in Toki, (3)

    In this issue two reports are given from the 1983 IPP-Toki collaborational works of surveying environmental radiations and radioactivities over the Toki area. One of them is concerned with the TLD observations of radiation levels by a team of local school teachers, and the other shows the results of sample measurements due to gamma- and alpha- spectrometry by the IPP group. In addition, a map of background radiation levels in Japan is included for the reference use. (author)

  8. National network of environment radioactivity measurements. Press kit

    This document first presents the objectives, challenges, context, operation and actors of the French national network of environment radioactivity measurements. It discusses the reasons for these measurements, the way they are performed, who perform them and how they are transmitted to the national network. It describes the quality policy for these measurements, and how this network is at the service of authorities, experts and population. It outlines the originality of the French approach within the European Union, and how this network takes the population expectations and their evolution into account

  9. Precision mass measurements of radioactive nuclei at JYFLTRAP

    Rahaman, S; Eronen, T; Hager, U; Hakala, J; Jokinen, A; Kankainen, A; Moore, I D; Pentillä, H; Rinta-Antila, S; Rissanen, J; Saastamoinen, A; Sonoda, T; Weber, C; Äystö, J

    2007-01-01

    The Penning trap mass spectrometer JYFLTRAP was used to measure the atomic masses of radioactive nuclei with an uncertainty better than 10 keV. The atomic masses of the neutron-deficient nuclei around the N = Z line were measured to improve the understanding of the rp-process path and the SbSnTe cycle. Furthermore, the masses of the neutron-rich gallium (Z = 31) to palladium (Z = 46) nuclei have been measured. The physics impacts on the nuclear structure and the r-process paths are reviewed. A better understanding of the nuclear deformation is presented by studying the pairing energy around A = 100.

  10. Ultra low radioactivity measurements at Modane underground Laboratory

    We present in this paper the activities of the Laboratoire Souterrain de Modane, LSM, and in particular the activity related to Single-Event Rate Errors in semiconductors. The LSM is located in the middle of the Frejus tunnel under 1 800 m of rock. The rock coverage suppress the cosmic ray flux by about 2 millions with respect to the surface, thus, the LSM offers an excellent site for rare-event searches which would, if located on the surface, be overwhelmed by the cosmic-ray background. As semiconductor devices continue to be scaled down, the integrated circuits are sensitive to interactions with cosmic-ray particles on the surface (primarily atmospheric neutrons) or to interactions with alpha-particles produced in on-chip radioactive impurities disintegrations. The ultra-low background environment at LSM allows the measurement of extremely low radioactivity levels. The aim of the work presented in this paper is to assess the feasibility of the alpha-emission measurement in materials commonly used in integrated circuits, by means of ultra-low level gamma-spectrometry. An epoxy slab has been measured and the surface α-emission has been deduced from the radioactive impurities level. The result is compared to the value obtained with an a- gas proportional counter. (authors)

  11. Measurement of the thermal neutron capture cross section and the resonance integral of radioactive Hf182

    Vockenhuber, C.; Bichler, M.; Wallner, A.; Kutschera, W.; Dillmann, I.; Käppeler, F.

    2008-04-01

    The neutron capture cross sections of the radioactive isotope Hf182 (t1/2=8.9×106 yr) in the thermal and epithermal energy regions have been measured by activation at the TRIGA Mark-II reactor of the Atomic Institute of the Austrian Universities in Vienna, Austria, and subsequent γ-ray spectroscopy of Hf183. High values for the thermal (kT=25 meV) cross section σ0=133±10 b and for the resonance integral I0=5850±660 b were found. Additionally, the absolute intensities of the main γ-ray transitions in the decay of Hf182 have been considerably improved.

  12. Absolute measurement of the desintegration rate of 137 Cs by 4Π (BS) e--X coincidence method

    The method developed by the Nuclear Metrology Laboratory for the absolute measurement of the desintegration rate of 137Cs by 4Π(BS)e--X is described. The conversion electron are measured by a pair of surface barrier detectors with 200mm2 of active area and 1000μm of depletion depth. The X-rays are measured by two 50.8mm diameter and 1.0mm thick NaI (Tl) scintillation counters. (author)

  13. Absolute cerebral blood flow and blood volume measured by magnetic resonance imaging bolus tracking: comparison with positron emission tomography values

    Østergaard, Leif; Smith, D F; Vestergaard-Poulsen, Peter;

    1998-01-01

    blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small...... hypercapnic conditions. After dose normalization and introduction of an empirical constant phi Gd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral...

  14. Some triple-filament lead isotope ratio measurements and an absolute growth curve for single-stage leads

    Stacey, J.S.; Delevaux, M.E.; Ulrych, T.J.

    1969-01-01

    Triple-filament analyses of three standard lead samples are used to calibrate a mass spectrometer in an absolute sense. The bias we measure is 0.0155 percent per mass unit, and the precision (for 95% confidence limits) is ??0.13% or less for all ratios relative to 204Pb. Although its precision is not quite so good as that of the lead-tetramethyl method in the analysis of large samples, the triple-filament method is less complex and is an attractive alternative for smaller sample sizes down to 500 ??g. Triple-filament data are presented for six possibly single-stage lead ores and one feldspar. These new data for ores are combined with corrected tetramethyl data for stratiform lead deposits to compute absolute parameters for a universal single-stage lead isotope growth curve. Absolute isotopic ratios for primeval lead have been determined by Oversby and because all the previous data for both meteorites and lead ores were similarly fractionated, the absolute value of 238U 204Pb = 9.09 ?? 0.06 for stratiform leads is little different from the value 8.99 ?? 0.05 originally computed by Ostic, Russell and Stanton. Absolute values for lead isotope ratios for all interlaboratory standard samples presently available from the literature are tabulated. ?? 1969.

  15. Reduced Haemodynamic Response in the Ageing Visual Cortex Measured by Absolute fNIRS

    Ward, Laura McKernan; Aitchison, Ross Thomas; Tawse, Melisa; Simmers, Anita Jane; Shahani, Uma

    2015-01-01

    The effect of healthy ageing on visual cortical activation is still to be fully explored. This study aimed to elucidate whether the haemodynamic response (HDR) of the visual cortex altered as a result of ageing. Visually normal (healthy) participants were presented with a simple visual stimulus (reversing checkerboard). Full optometric screening was implemented to identify two age groups: younger adults (n = 12, mean age 21) and older adults (n = 13, mean age 71). Frequency-domain Multi-distance (FD-MD) functional Near-Infrared Spectroscopy (fNIRS) was used to measure absolute changes in oxygenated [HbO] and deoxygenated [HbR] haemoglobin concentrations in the occipital cortices. Utilising a slow event-related design, subjects viewed a full field reversing checkerboard with contrast and check size manipulations (15 and 30 minutes of arc, 50% and 100% contrast). Both groups showed the characteristic response of increased [HbO] and decreased [HbR] during stimulus presentation. However, older adults produced a more varied HDR and often had comparable levels of [HbO] and [HbR] during both stimulus presentation and baseline resting state. Younger adults had significantly greater concentrations of both [HbO] and [HbR] in every investigation regardless of the type of stimulus displayed (p<0.05). The average variance associated with this age-related effect for [HbO] was 88% and [HbR] 91%. Passive viewing of a visual stimulus, without any cognitive input, showed a marked age-related decline in the cortical HDR. Moreover, regardless of stimulus parameters such as check size, the HDR was characterised by age. In concurrence with present neuroimaging literature, we conclude that the visual HDR decreases as healthy ageing proceeds. PMID:25909849

  16. Reduced Haemodynamic Response in the Ageing Visual Cortex Measured by Absolute fNIRS.

    Laura McKernan Ward

    Full Text Available The effect of healthy ageing on visual cortical activation is still to be fully explored. This study aimed to elucidate whether the haemodynamic response (HDR of the visual cortex altered as a result of ageing. Visually normal (healthy participants were presented with a simple visual stimulus (reversing checkerboard. Full optometric screening was implemented to identify two age groups: younger adults (n = 12, mean age 21 and older adults (n = 13, mean age 71. Frequency-domain Multi-distance (FD-MD functional Near-Infrared Spectroscopy (fNIRS was used to measure absolute changes in oxygenated [HbO] and deoxygenated [HbR] haemoglobin concentrations in the occipital cortices. Utilising a slow event-related design, subjects viewed a full field reversing checkerboard with contrast and check size manipulations (15 and 30 minutes of arc, 50% and 100% contrast. Both groups showed the characteristic response of increased [HbO] and decreased [HbR] during stimulus presentation. However, older adults produced a more varied HDR and often had comparable levels of [HbO] and [HbR] during both stimulus presentation and baseline resting state. Younger adults had significantly greater concentrations of both [HbO] and [HbR] in every investigation regardless of the type of stimulus displayed (p<0.05. The average variance associated with this age-related effect for [HbO] was 88% and [HbR] 91%. Passive viewing of a visual stimulus, without any cognitive input, showed a marked age-related decline in the cortical HDR. Moreover, regardless of stimulus parameters such as check size, the HDR was characterised by age. In concurrence with present neuroimaging literature, we conclude that the visual HDR decreases as healthy ageing proceeds.

  17. Measurement of radioactivity in Norway. Annual report 1997

    The Norwegian Institute for Air Research (NILU) is managing a radioactivity monitoring network commissioned by the Norwegian Pollution Control Authority (Statens forurensningstilsyn). By 1997 the network consists of 28 stations throughout the country, especially tight in Finnmark.In addition there is a station in Russia (Verhetnetulomski). The 29 surveillance stations consist of: 12 ionic chamber instruments, 6 stationary gamma spectrometers for surveillance, 12 part-time gamma spectrometers designed for nutritional radioactivity measurements in co-operation with the Norwegian Food Control Authority (Naeringsmiddeltilsynet), LORAKON. The joint venture with LORAKON uses the gamma spectrometers at the stations for nutritional control for surveillance when they are not active in nutritional radioactivity measurements. The spectrometer detector is taken out of the lead tower and placed in windows at the laboratories. Then the spectrometer is connected to a telecommunication modem. The NILU computer is calling regularly whether the spectrometer is connected or not and uses it immediately when connected. The stations have not registered values that can not be attributed to natural variations in the radiation level or technical irregularities in 1997

  18. Hair radioactivity as a measure of exposure to radioisotopes

    Strain, W. H.; Pories, W. J.; Fratianne, R. B.; Flynn, A.

    1972-01-01

    Since many radioisotopes accumulate in hair, this tropism was investigated by comparing the radioactivity of shaved with plucked hair collected from rats at various time intervals up to 24 hrs after intravenous injection of the ecologically important radioisotopes, iodine-131, manganese-54, strontium-85, and zinc-65. The plucked hair includes the hair follicles where biochemical transformations are taking place. The data indicate a slight surge of each radioisotpe into the hair immediately after injection, a variation of content of each radionuclide in the hair, and a greater accumulation of radioactivity in plucked than in shaved hair. These results have application not only to hair as a measure of exposure to radioisotopes, but also to tissue damage and repair at the hair follicle.

  19. Gamma spectrometric system for measuring low and medium radioactive samples

    Measuring radioactive samples from environment and animal sub-products which usually have low radioactivity and a mixture of a radionuclides, requires the use of complex spectrometric systems. In our Department such a system was development, currently equipped with scintillation detector. All the electronic modules (High Voltage Supply, Pulse Amplifier, ADC) in the system are fully digitally controlled by the computer via a specialized interface and a special device driver, which is a resident program. The spectrum acquisition is performed in the background by the device driver. Spectrum processing (peak search, background subtraction, radionuclide identification, energy and efficiency calibration, activity and associated error calculation) is done by a special application which has a user friendly graphic interface and includes database and reporting facilities. The next year the system will be equipped with an automatic sample changer for large volume samples. We intend to provide the possibility to use also a HPGe detector. (authors)

  20. An overview on measurements of natural radioactivity in Malaysia

    Nisar Ahmad

    2015-01-01

    Full Text Available Humans are always exposed during their lives to ionizing radiation arising outside and within the earth. The exposure to these radiation occurs from natural sources such as radioactive elements in rocks and soil, internal exposure form radioactive elements through water, food and air and cosmic rays entering from outer space to earth's atmosphere. About 87% of the radiation dose received by human beings is due to natural radiation, it is essential to assess the radiation doses in order to control possible health effects from such natural sources. In this regard, a number of articles have been appeared for Malaysia in international research journals, which have been reviewed and complied in this article. Most of these articles are about the measurement of activity concentrations of primordial (238U, 232Th, 226Ra and 40K and anthropogenic (137Cs radionuclide's and gamma dose rate in environmental samples using HPGe and NaI (Tl survey meter.

  1. GEMS: Underwater spectrometer for long-term radioactivity measurements

    Sartini, Ludovica, E-mail: ludovica.sartini@ingv.i [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Genoa University, Genoa (Italy); Simeone, Francesco; Pani, Priscilla [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Lo Bue, Nadia; Marinaro, Giuditta [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Grubich, Andry; Lobko, Alexander [Institute for Nuclear Problems (INP), Belarus State University, Minsk (Belarus); Etiope, Giuseppe [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Capone, Antonio [' Sapienza' University and Istituto Nazionale di Fisica Nucleare (INFN), Sect.Roma, Roma (Italy); Favali, Paolo [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sect.Roma 2, Roma (Italy); Gasparoni, Francesco; Bruni, Federico [Tecnomare S.p.A., Venice (Italy)

    2011-01-21

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by {sup 40}K decays but it can detect other natural (e.g., {sup 238}U,{sup 232}Th) and anthropogenic radio-nuclides (e.g., {sup 137}Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.

  2. GEMS: Underwater spectrometer for long-term radioactivity measurements

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by 40K decays but it can detect other natural (e.g., 238U,232Th) and anthropogenic radio-nuclides (e.g., 137Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.

  3. Field Measurement of Sand Dune Bidirectional Reflectance Characteristics for Absolute Radiometric Calibration of Optical Remote Sensing Data.

    Coburn, C. A.; Logie, G.; Beaver, J.; Helder, D.

    2015-12-01

    The use of Pseudo Invariant Calibration Sites (PICS) for establishing the radiometric trending of optical remote sensing systems has a long history of successful implementation. Past studies have shown that the PICS method is useful for evaluating the trend of sensors over time or cross-calibration of sensors but was not considered until recently for deriving absolute calibration. Current interest in using this approach to establish absolute radiometric calibration stems from recent research that indicates that with empirically derived models of the surface properties and careful atmospheric characterisation Top of Atmosphere (TOA) reflectance values can be predicted and used for absolute sensor radiometric calibration. Critical to the continued development of this approach is the accurate characterization of the Bidirectional Reflectance Distribution Function (BRDF) of PICS sites. This paper presents the field data collected by a high-performance portable goniometer system in order to develop a BRDF model for the Algodones Dunes in California. These BRDF data are part of a larger study that is seeking to evaluate and quantify all aspects of this dune system (from regional effects to the micro scale optical properties of the sand) in order to provide an absolute radiometric calibration PICS. This paper presents the results of a dense temporal measurement sequence (several measurements per hour with high angular resolution), to yield detailed information on the nature of the surface reflectance properties. The BRDF data were collected covering typical view geometry of space borne sensors and will be used to close the loop on the calibration to create an absolute calibration target for optical satellite absolute radiometric calibration.

  4. Using relative and absolute measures for monitoring health inequalities: experiences from cross-national analyses on maternal and child health

    Huisman Martijn

    2007-10-01

    Full Text Available Abstract Background As reducing socio-economic inequalities in health is an important public health objective, monitoring of these inequalities is an important public health task. The specific inequality measure used can influence the conclusions drawn, and there is no consensus on which measure is most meaningful. The key issue raising most debate is whether to use relative or absolute inequality measures. Our paper aims to inform this debate and develop recommendations for monitoring health inequalities on the basis of empirical analyses for a broad range of developing countries. Methods Wealth-group specific data on under-5 mortality, immunisation coverage, antenatal and delivery care for 43 countries were obtained from the Demographic and Health Surveys. These data were used to describe the association between the overall level of these outcomes on the one hand, and relative and absolute poor-rich inequalities in these outcomes on the other. Results We demonstrate that the values that the absolute and relative inequality measures can take are bound by mathematical ceilings. Yet, even where these ceilings do not play a role, the magnitude of inequality is correlated with the overall level of the outcome. The observed tendencies are, however, not necessities. There are countries with low mortality levels and low relative inequalities. Also absolute inequalities showed variation at most overall levels. Conclusion Our study shows that both absolute and relative inequality measures can be meaningful for monitoring inequalities, provided that the overall level of the outcome is taken into account. Suggestions are given on how to do this. In addition, our paper presents data that can be used for benchmarking of inequalities in the field of maternal and child health in low and middle-income countries.

  5. Device and method for measuring radioactive particles in oil

    A device for wear measurement of machine parts labelled with radioactive material is improved in such a way that a filter may be installed in the oil flow transporting the wear particles containing the radioisotopes to the place of measurement. It is then possible to study the wear behavior of intricate internal-combustion engines. For this purpose either the total oil flow or only part of it is conducted through the filter. Design details are exhaustively presented. (10 sub-claims). (UWI) 891 HP

  6. Environmental radioactivity measurements at BNL following the Chernobyl accident

    Measurements are reported of the concentrations at Berkeley in Gloucestershire of radioactivity in the air, rainwater, tap water, soil, herbage and fresh vegetables for the period 29 April 1986 to 15 May 1986, following the Chernobyl Power Station accident. Data for up to 18 gamma emitting isotopes are reported, together with some limited actinide-in-air measurements. Deposition velocities are calculated and an assessment is presented of the sensitivity of the techniques employed. Some data are also included on the gaseous composition of the cloud and the isotope dependent dose rate from deposition. (author)

  7. Uncertainties of DS86 and prospects for residual radioactivity measurement.

    Shizuma, K; Hoshi, M; Hasai, H

    1999-12-01

    Residual radioactivity data of 152Eu, 60Co and 36Cl have been accumulated and it has been revealed in the thermal neutron region that a systematic discrepancy exists between the measured data and activation calculation based on the DS86 neutrons in Hiroshima. Recently 63Ni produced in copper samples by the fast neutron reaction 63Cu(n,p)63Ni has been of interest for evaluation of fast neutrons. Reevaluation of atomic-bomb neutrons and prospects based on residual activity measurements have been discussed. PMID:10805002

  8. Functional requirements document for measuring emissions of airborne radioactive materials

    This document states the functional requirements and procedures for systems making measurements of radioactive airborne emissions from facilities at the Hanford Site. The following issues are addressed in this document: Definition of the program objectives; Selection of the overall approach to collecting the samples; Sampling equipment design; Sampling equipment maintenance, and quality assurance issues. The intent of this document is to assist WHC in demonstrating a high quality of air emission measurements with verified system performance based on documented system design, testing, inspection, and maintenance

  9. A study of environmental radioactivity measurements for Cankiri, Turkey

    This study is the first to assess the level of background radiation for the Cankiri province of Turkey. Indoor air radon concentrations were determined using Columbia Resin-39 nuclear track detectors and the average 222Rn activity was found to be 44 Bq m-3(equivalent to an annual effective dose of 1.1 mSv). Measurements of gamma doses in outdoor air were performed using a portable plastic scintillation detector and the average gamma absorbed dose rate was found to be 8 μR h-1 (corresponding to an annual effective dose of 87.7 μSv). Radionuclide activity concentrations in soil samples were measured through gamma-ray spectrometry and the average activities were determined as 17.7, 22.3, 357 and 4.1 Bq kg-1 for the radionuclides 238U, 232Th, 40K and 137Cs, respectively. The average annual effective dose from the natural radioactivity sources 238U series, 232Th series and 40K) was calculated to be 44.4 μSv. Radioactivity levels of drinking water samples were carried out using a low-background proportional counter and the average gross alpha and beta activities were obtained as 0.25 and 0.26 Bq l-1, respectively (equivalent to an annual effective dose of 184 μSv). The average radon concentrations in indoor air and the average radionuclide activities in soil were found to be lower than most Turkish cities while higher levels of outdoor gamma dose rate and water radioactivity were observed. The results of this study showed that the region's background radioactivity level differs considerably from the reported data for Turkish cities. (authors)

  10. Lifetime measurements using radioactive ion beams at intermediate energies and the Doppler shift method

    Absolute transition probabilities are crucial quantities in nuclear structure physics. Therefore, it is important to establish Doppler shift (plunger) techniques also for the measurement of level lifetimes in radioactive ion beam experiments. After a first successful test of the Doppler Shift technique at intermediate energy (52MeV/u) with a stable 124Xe beam, a plunger has been built and used in two experiments, performed at the NSCL/MSU with the SEGA Ge-array and the S800 spectrometer. The aim of the first experiment was to investigate the plunger technique after a knock-out reaction using a radioactive 65Ge beam at 100 MeV/u for populating excited states in 64Ge. The second experiment aimed to measure the lifetimes of the first 2+ states in 110,114Pd with the plunger technique after Coulomb excitation at beam energies of 54 MeV/u. First results of both experiments will be presented and discussed. (orig.)

  11. National audit of radioactivity measurements in Nuclear Medicine Centres

    Routine activity measurements of radiopharmaceutical solutions in Nuclear Medicine Centres (NMC) are carried out with the help of radionuclide calibrators (RC). These solutions are either ingested or injected to the patient for diagnosis or therapy. However, for the realization of an optimized examination, the activity of these radiopharmaceuticals must be determined accurately before administering it to patients. The primary standards are maintained by Radiation Standards Section, Radiological Physics and Advisory Division. National audit programmes of Iodine -131 activity measurements with RCs are conducted biannually to establish traceability to national standards and to check the status of nuclear medicine practice followed at the NMC. The results of fifteenth audit of 131I activity measurements with RC are presented in this paper. Questionnaires were sent to two hundred and thirty three NMCs in-the country. One hundred and nine NMC's agreed for participation and accordingly, glass vials containing radioactive 131I solution of nominal activity of 100 MBq were procured from Board of Radiation and Isotope Technology, Mumbai. The radioactivity in each vial was determined with high pressure re-entrant gamma ionisation chamber (GIC), a secondary standard maintained by this laboratory. The sensitivity coefficient of GIC is traceable to the primary standard. The standardized radioactive solution of 131I in glass vial was sent to each participant. Measurements results were reported in the reporting form sent. This audit was conducted in four schedules in Jan 2013. One hundred and sixty six results were received from one hundred and nine participants as many participants took measurements on more than one isotope calibrator

  12. Absolute gravity measurements in Southeast Alaska and continuous gravity observation in Juneau by ISEA2 project

    Sato, T.; Kazama, T.; Miura, S.; Ohta, Y.; Okubo, S.; Fujimoto, H.; Kaufman, M.; Herreid, S. J.; Larsen, C. F.; Freymueller, J. T.

    2012-12-01

    It is known that Southeast Alaska (SE-AK) shows a large uplift rates exceeding 32 mm/year at the maximum mainly due to the three ice changes in ages, i.e. in the Large Glacier Maximum, the Little Ice Age and the present day. Comparisons between rates of change obtained from GPS and absolute gravimeter (AG) observations and the rates predicted by model computations based on independently estimated ice mass changes indicate the existence of a very thin lithosphere (on the order of 60 km) and a low viscousity upper mantle (on the order of 1.E18 Pa s) beneath SE-AK (Larsen et al., 2005; Sato et al, 2011; Sato et al., 2012). On the other hand, it is also known that there are very large oceanic tidal loading effects in SE-AK, i.e. exceeding 2.7 cm and 8 microGals for the M2 constituent of the vertical displacement and gravity, respectively (Sato et al., 2008; Inazu et al., 2009; Sun et al., 2010; Sato et al., 2012). These regional large loading and unloading effects provide good signals to study the viscoelastic structure beneath SE-AK. A joint observation project (ISEA2) between Japan and USA groups has restarted as a five years project beginning in 2012. In June 2012, we conducted the AG measurements at the 6 sites in SE-AK at where the AG measurements were conducted by the previous ISEA1 project (Sun et al., 2010). Continuous gravity observation started also on June 2012 with a portable super conducting gravimeter (iGrav) at the EGAN library of UAS. We will introduce the results for these observations and comparisons with the previous observations and model computations. It is noted that the precipitation during the period from the winter in 2011 to the spring in 2012 was very large compared with the usual amount. We evaluate this effect on our gravity observations with a hydrological model computation (Kazama and Okubo, 2009) using the observed precipitation data as an input data. The observation with the iGrav super conducting gravimeter shall give us a useful data

  13. Particle sizing of airborne radioactivity field measurements at Olympic Dam

    On July 1, 1991 the Australian Radiation Laboratory (ARL) commenced a two year project entitled - Particle sizing of airborne radioactivity, funded by a Mining and Quarrying Occupational Health and Safety Committee - grant (submission No. 9138). This study was set out to measure airborne radioactivity size distributions in an underground uranium mine, in order to provide better estimates of the health risks associated with inhalation of airborne radiation in the work place. These measurements included both active and passive measurement of radon gas, continuous and spot sample of radon daughter levels, as well as wire screen diffusion battery measurements of the radon daughter size distributions. The results of measurements at over 50 sites within the mine are reported, together with the calculated dose conversion factors derived from the older dosimetric models and from the new ICRP lung model using the computer code RADEP. The results showed that the ventilation is relatively uniform within the mine and the radon daughter concentrations are kept to less than 20% of the equilibrium concentration. The radon and radon daughter concentrations showed marked variability with both time and position within the mine. It is concluded that the present radiation protection methods and dose conversion factors used in Australia provide a good estimate of the radiation risk for the inhalation of radon progeny. 29 refs., 8 tabs., 9 figs

  14. Evaluation of the uncertainty of environmental measurements of radioactivity

    Results obtained by measurement of radioactivity have traditionally been associated with an expression of their uncertainty, based on the so-called counting statistics. This is calculated together with the actual result on the assumption that the number of counts observed has a Poisson distribution with equal mean and variance. Most of the nuclear scientific community has, therefore, assumed that it already complied with the latest ISO 17025 requirements. Counting statistics, however, express only the variability observed among repeated measurements of the same sample under the same counting conditions, which is equivalent to the term repeatability used in quantitative analysis. Many other sources of uncertainty need to be taken into account before a statement of the uncertainty of the actual result can be made. As the first link in the traceability chain calibration is always an important uncertainty component in any kind of measurement. For radioactivity measurements in particular counting geometry assumes the greatest importance, because it is often not possible to measure a standard and a control sample under exactly the same conditions. In the case of large samples there are additional uncertainty components associated with sample heterogeneity and its influence on self-absorption and counting efficiency. An uncertainty budget is prepared for existing data for 137Cs in Danish soil, which is shown to account adequately for all sources of uncertainty. (author)

  15. Design and construction of a cryogenic facility providing absolute measurements of radon 222 activity for developing a primary standard

    Radon 222 metrology is required to obtain higher accuracy in assessing human health risks from exposure to natural radiation. This paper describes the development of a cryogenic facility that allows absolute measurements of radon 222 in order to obtain a primary standard. The method selected is the condensation of a radon 222 sample on a geometrically defined cold surface with a constant, well known and adjustable temperature and facing an alpha particles detector. Counting of the alpha particles reaching the detector and the precisely known detection geometry provide an absolute measurement of the source activity. After describing the cryogenic facility, the measurement accuracy and precision are discussed and a comparison made with other measurement systems. The relative uncertainty is below 1 pc (1 σ). The facility can also be used to improve our knowledge of the nuclear properties of radon 222 and to produce secondary standards. (author)

  16. Design of a quasi-zero-stiffness based sensor system for the measurement of absolute vibration displacement of moving platforms

    Jing, Xingjian; Wang, Yu; Li, Quankun; Sun, Xiuting

    2016-09-01

    This study presents the analysis and design of a novel sensor system for measuring the absolute vibration displacement of moving platforms based on the concept of quasi-zero-stiffness (QZS). The sensor system is constructed using positive- and negative-stiffness springs, which make it possible to achieve an equivalent QZS and consequently to create a broadband vibration-free point for absolute vibration displacement measurement in moving platforms. Theoretical analysis is conducted for the analysis and design of the influence of structure parameters on system measurement performance. A prototype is designed which can avoid the drawback of instability in existing QZS systems with negative stiffness, and corresponding data-processing software is developed to fulfill time domain measurements. Both the simulation and experimental results verify the effectiveness of this novel sensor system.

  17. Measurement of the Absolute Proton and Helium Flux at the Top of the Atmosphere using IMAX

    Menn, W.; Hof, M.; Reimer, O.; Simon, M.; Barbier, L.M.; Christian, E.R.; Krombel, K.E.; Mitchell, J.W.; Ormes, J.F.; Streitmatter, R.E.; Davis, A.J.; Labrador, A.W.; Mewaldt, R.A.; Schindler, S.M.; Golden, R.L.; Stochaj, S.J.; Webber, W.R.; Rasmussen, Ib Lundgaard

    1996-01-01

    with ancillary scintillators, time-of-flight, and aerogel cherenkov detectors. High resolution drift chambers and MWPCs were used as the tracking devices. Using redundant detectors, an extensive examination of the instrument efficiency was carried out. We present the absolute spectra of protons and...

  18. Fundamentals of absolute measurements of the absorved dose of quantum and electron radiation up to 50 MeV

    Absorbed dose measurements are dealt with considering the existing or missing secondary electron balance. At present, calorimeters, ionization chambers and chemical dosimeters are particularly suitable for absolute measurements of absorbed doses and for ensuring the accuracy needed for standard procedures. The above-mentioned methods are briefly discussed together with the requirements to be met in applying them. Intermediate solutions for electron and quantum energies exceeding 3 MeV are outlined. (author)

  19. Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139 (United States); Glebov, V. Yu.; Katz, J.; Knauer, J. P.; Meyerhofer, D. D.; Sangster, T. C. [Laboratory for Laser Energetics, UR, Rochester, New York 14623 (United States); Bionta, R. M.; Bleuel, D. L.; Doeppner, T.; Glenzer, S.; Hartouni, E.; Hatchett, S. P.; Le Pape, S.; Ma, T.; MacKinnon, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2012-10-15

    A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  20. Measuring the absolute deuterium–tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF

    A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  1. Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF.

    Casey, D T; Frenje, J A; Gatu Johnson, M; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Knauer, J P; Meyerhofer, D D; Sangster, T C; Bionta, R M; Bleuel, D L; Döppner, T; Glenzer, S; Hartouni, E; Hatchett, S P; Le Pape, S; Ma, T; MacKinnon, A; McKernan, M A; Moran, M; Moses, E; Park, H-S; Ralph, J; Remington, B A; Smalyuk, V; Yeamans, C B; Kline, J; Kyrala, G; Chandler, G A; Leeper, R J; Ruiz, C L; Cooper, G W; Nelson, A J; Fletcher, K; Kilkenny, J; Farrell, M; Jasion, D; Paguio, R

    2012-10-01

    A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF. PMID:23126915

  2. Absolute distance measurement by dual-comb interferometry with multi-channel digital lock-in phase detection

    We present a dual-comb-based heterodyne multi-wavelength absolute interferometer capable of long distance measurements. The phase information of the various comb modes is extracted in parallel by a multi-channel digital lock-in phase detection scheme. Several synthetic wavelengths of the same order are constructed and the corresponding phases are averaged to deduce the absolute lengths with significantly reduced uncertainty. Comparison experiments with an incremental HeNe reference interferometer show a combined relative measurement uncertainty of 5.3 × 10−7 at a measurement distance of 20 m. Combining the advantage of synthetic wavelength interferometry and dual-comb interferometry, our compact and simple approach provides sufficient precision for many industrial applications. (paper)

  3. Radioactivity

    Tables are presented of trends in annual emissions of radioactive gaseous effluents at sites of civil establishments in the U.K. Trends in the discharge to surface and coastal water sites in the U.K. and trends in the radioactivity of solid wastes dumped in the N.E. Atlantic and in the volume and activity level of wastes disposed at sites in the U.K. are presented. Tables of radioactivity in samples of fish and shellfish at selected sites are presented. Radioactivity from global fallout and the annual mean ratio of 90Sr to calcium, and concentrations of 137Cs in milk are given. Trends in estimated collective doses from the consumption of fish and shellfish in the U.K. and Europe are presented. (U.K.)

  4. Direct measurements of neutron capture on radioactive isotopes

    Couture, A

    2009-01-01

    We simulated the response of a 4p calorimetric g-detector array to decays of radioactive isotopes on the s-process path. The GEANT 3.21 simulation package was used. The main table contains estimates on the maximum sample size and required neutron flux based on the latest available neutron capture cross section at 30 keV. The results are intended to be used to estimate the feasibility of neutron capture measurements with 4p arrays using the time of flight technique.

  5. The observatories for the radioactivity. results of measures

    This IPSN's report on the monitoring of the radioactivity in France provides many graphs and tables of measures results recorded during the year 2000. The graphs show the activity levels (Bq or Bq fraction, per mass or volume unit) of many radionuclides in selected indicators and for levels upper than the detection limits. The metrology and the selected samples are presented. These samples are different for the three types of observatories: atmospheric, coast and terrestrial observatories. A chronological account of the results from 1959 to 2000 is also provided for the Cesium 137 and the beryllium 7 in the aerosols. (A.L.B.)

  6. Absolute brightness temperature measurements at 3.5-mm wavelength. [of sun, Venus, Jupiter and Saturn

    Ulich, B. L.; Rhodes, P. J.; Davis, J. H.; Hollis, J. M.

    1980-01-01

    Careful observations have been made at 86.1 GHz to derive the absolute brightness temperatures of the sun (7914 + or - 192 K), Venus (357.5 + or - 13.1 K), Jupiter (179.4 + or - 4.7 K), and Saturn (153.4 + or - 4.8 K) with a standard error of about three percent. This is a significant improvement in accuracy over previous results at millimeter wavelengths. A stable transmitter and novel superheterodyne receiver were constructed and used to determine the effective collecting area of the Millimeter Wave Observatory (MWO) 4.9-m antenna relative to a previously calibrated standard gain horn. The thermal scale was set by calibrating the radiometer with carefully constructed and tested hot and cold loads. The brightness temperatures may be used to establish an absolute calibration scale and to determine the antenna aperture and beam efficiencies of other radio telescopes at 3.5-mm wavelength.

  7. Precise measurement of the absolute fluorescence yield of nitrogen in air. Consequences on the detection of ultra-high energy cosmic rays

    The study of the energy spectrum of ultra-high energy cosmic rays (E > 1020 eV) requires to determine the energy with much more precision than what is currently achieved. The shower of particles created in the atmosphere can be detected either by sampling particle on the ground, or by detecting the fluorescence induced by the excitation of nitrogen by shower electrons. At present, the measurement of the fluorescence is the simplest and the most reliable method, since it does not call upon hadronic physics laws at extreme energies, a field still inaccessible to accelerators. The precise knowledge of the conversion factor between deposited energy and the number of fluorescence photons produced (the yield) is thus essential. Up to now, it has been determined with an accuracy of 15 % only. This main goal of this work is to measure this yield to better than 5 per cent. To do this, 1 MeV electrons from a radioactive source excite nitrogen of the air. The accuracy has been reached thanks to the implementation of a new method for the absolute calibration of the photomultipliers detecting the photons, to better than 2 per cent. The fluorescence yield, measured and normalized to 0.85 MeV, 760 mmHg and 15 Celsius degrees, is (4.23 ± 0.20) photons per meter, or (20.46 ± 0.98) photons per deposited MeV. In addition, and for the first time, the absolute fluorescence spectrum of nitrogen excited by a source has been measured with an optical grating spectrometer. (author)

  8. Measurements of environmental radiations and radioactivities in Toki, 4

    This is a series of reports concerning the achievements of an IPP-Toki collaborational work on the environmental survey of radiations and radioactivities in Toki Area, where the new IPP experimental site is to be constructed. A School Teachers' Group of Science has been organized in Toki and been active in good cooperation with the Environmental Measurement Working Group (formerly, Site and Facilities Team) of IPP to perform various kinds of measurement over the area. In this fourth issue of the series are contained several articles mainly discussing the results obtained in 1984 ∼ 85 period, including the following topics: 1) Method of In-Situ γ-Spectrometry with a Portable Ge-Detector, 2) Observed Radioactivities in Various Parts of Toki, 3) Method of Environmental Tritium Measurement, 4) Observed Tritium Concentrations in River Waters in Toki, 5) Summary of Radiation Dose Rates Observed in Toki 1982 ∼ 84, 6) 1985 TLD Observations in Toki, 7) Reports of Visits to Several Facilities in Japan. (author)

  9. Measurement of indoor radon and natural/fall out radioactivity

    Indoor radon and natural radioactivity measurement surveys were carried out in various parts of the Punjab, Khyber Pakhtoonkha, FATA, Azad Jammu and Kashmir and Gilgit Baltistan using CR-39 based radon detectors. The annual effective dose, mean effective dose and exhalation rate were calculated for the general public. Indoor radon activity concentrations in the surveyed houses ranged from 12 +- 5 to 169 +- 9 Bq m/sup -3/ with an overall average value of 57 +- 30 Bq m/sup -3/ which is more than the world average of 40 Bq m/sup -3/. The indoor radon levels were maximum in winter and minimum during summer season and were within the recommended limits. Besides indoor radon and natural radioactivity measurements, uranium contents were determined in samples of drinking water collected from natural springs of Hatian Bala using fission track technique. Except in a few cases, the measured uranium concentration was found within the safe limit of 30 gL/sup -1/. (Orig./A.B.)

  10. Simultaneous pO2 and HbO2 measurement to determine absolute HbO2 concentration for in vivo near infrared spectroscopy

    Macnab, Andrew J.; Gagnon, Roy; Gagnon, Faith; Minchinton, Andrew I.; Fryer, Karen H.

    2003-01-01

    Purpose: Near infrared spectroscopy (NIRS) monitors absolute changes in concentration of chromophores from an unquantified baseline. A change in oxygenation is required to obtain information. Clinically, knowing initial chromophore concentration is desirable. We sought absolute initial concentrations by combining NIRS measurements with simultaneous Eppendorf histograph measurement (absolute values of tissue partial pressure of oxygen (pO2)). Methods: There were 22 trials on 9 occasions in 2 a...

  11. System for absolute measurement of electrolytic conductivity in aqueous solutions based on van der Pauw's theory

    Based on an innovative application of van der Pauw's theory, a system was developed for the absolute measurement of electrolytic conductivity in aqueous solutions. An electrolytic conductivity meter was designed that uses a four-electrode system with an axial–radial two-dimensional adjustment structure coupled to an ac voltage excitation source and signal collecting circuit. The measurement accuracy, resolution and repeatability of the measurement system were examined through a series of experiments. Moreover, the measurement system and a high-precision electrolytic conductivity meter were compared using some actual water samples. (paper)

  12. Trace radioactive measurement in foodstuffs using high purity germanium detector

    Trace radioactivity in food has been seriously considered sources of potential harm after the accidental radioactive releases in the last decades which led to contamination of the food chain. Countermeasures are being used to reduce the radiological health risk to the population and to ensure that public safety and international commitments are met. Investigation of radioactive traces in foods was carried out by gamma-ray spectrometry. The radionuclides being measured were fission products 137Cs and 134Cs and naturally occurring 40Κ. Gamma-ray measurements were performed using a hybrid gamma-ray counting system with coaxial p-type Tennelec High Purity Germanium (HPGe) detector with relative efficiency of 18.4%. Channels were calibrated to energies using a standard check source with 137Cs and 60Co present. Self-shielding within samples was taken into account by comparing directly with reference standards of similar matrix and geometry. Efficiencies of radionuclides of interests were accounted in calculating the activity concentrations in the samples. Efficiency calibration curve was generated using an in-house validated program called FINDPEAK, a least-square method that fits a polynomial up to sixth-order of equation. Lower Limits of Detection (LLD) obtained for both 137Cs and 134Cs ranges from 1-6 Bq/Kg depending on the sample matrix. In the last five years, there have been no foodstuffs analyzed exceeded the local and international regulatory limit of 1000Bq/Kg for the summed activities of 137Cs and 134Cs. (author)

  13. Measurement of absolute gamma ray emission probability of 1001 keV from the decay of 234mPa

    In the direct γ-ray spectrometric measurements of 238U content, 1001 keV γ-ray of 234mPa is commonly used in recent years. 234mPa is the second daughter of 238U and rapidly reaches secular equilibrium with the parent nucleus. This clean peak is well resolved by high purity Ge detectors and gives more accurate indication of uranium content without requiring any self attenuation correction. Several measurements of the absolute emission probability of the 1001 keV γ-ray of 234mPa have resulted in doubts concerning the old recommended value 0.59±0.01 % obtained by a radiochemical method. Therefore, this old value is now absolute and a newly value of 0.835±0.004 % is recommended. In this study the γ-ray spectrometric measurements were carried out using the powdered U3O8 and the certified uranium samples. A new experimental value o 0.861±0.015 % for the absolute γ-ray emission probability for the 1001 keV gamma-ray of the 234mPa has been obtained. The present measured values agrees good with the most experimental results appeared in the literature and is close to the newly recommended values of 0.835±0.004 % and 0.837±0.012 % for the 1001 keV γ-ray of 234mPa

  14. HML's whole body counter: measuring highly radioactive persons.

    Kramer, Gary H; Capello, Kevin; Chiang, Albert; Hauck, Barry M

    2009-12-01

    The National Internal Radiation Assessment Section's Human Monitoring Laboratory (HML) has the responsibility to measure persons who may become internally contaminated following an accidental or intentional release of radioactivity. In preparation for measuring individuals who may be highly internally contaminated, the HML has reconfigured and recalibrated its whole body counter for this event. The calibration was performed using Monte Carlo simulations and validated by experimental measurements. An equation was developed that related the counting efficiency as a function of photon energy and phantom-to-detector distance. The equation could predict efficiencies to within 10% or better. Dead time problems, as a result of high internal activities, have been minimized by having a variety of counting positions. Six example nuclides have been used (Co, Co, Y, Ba, Cs, and Am) to show what is achievable and what is not. PMID:19901599

  15. The measurement of the radioactive aerosol diameter by position sensitive semiconductor detectors, 1

    The measurement of the diameter of radioactive aerosol, in particular plutonium aerosol, is very important for the internal dose estimation. Determination of the diameter of radioactive aerosol is performed by using position sensitive semiconductor detector (PSD). The filter paper with the radioactive aerosols is contacted to the PSD which is connected to the data processor so that the diameter of the aerosol is calculated from the measured radioactivity. This investigation was performed in cooperation with Rikkyo University. (author)

  16. A Proposed Method for Measurement of Absolute Air Fluorescence Yield based on High Resolution Optical Emission Spectroscopy

    Gika, V; Maltezos, S

    2016-01-01

    In this work, we present a method for absolute measurement of air fluorescence yield based on high resolution optical emission spectroscopy. The absolute measurement of the air fluorescence yield is feasible using the Cherenkov light, emitted by an electron beam simultaneously with the fluorescence light, as a "standard candle". The separation of these two radiations can be accomplished exploiting the "dark" spectral regions of the emission band systems of the molecular spectrum of nitrogen. In these "dark" regions the net Cherenkov light can be recorded experimentally and be compared with the calculated one. The instrumentation for obtaining the nitrogen molecular spectra in high resolution and the noninvasive method for monitoring the rotational temperature of the emission process are also described. For the experimental evaluation of the molecular spectra analysis we used DC normal glow discharges in air performed in an appropriate spectral lamp considered as an air-fluorescence light emulator. The propose...

  17. Measurement of radioactive soil contamination from the air

    In-situ gamma spectrometry can be used to determine the qualitative and quantitative deposition of radioactive materials on the ground surface. By applying the in-situ spectrometry method using either a helicopter or an airplane, large areas can be scanned in a short period of time. In this report the results of in-situ gamma spectroscopic measurements taken from a helicopter are described. Measurements were carried out using a single point source, a field of 36 point sources, and using the present ground contamination due to fall-out from the Chernobyl accident and atom bombs. The results of these measurements were used to determine calibration factors, which were in agreement with a calibration obtained using more simple (and less expensive) laboratory measurements in combination with flux calculations. Detection limits for the measurement of surface contamination were determined. At a height of 50 meters above the surface and using a measurement time of 2 minutes, the minimally detectable surface contamination was 1.1 kBqm-2 for a Cs-137 contamination and 2.1 kBqm-2 for I-131 contamination. Fall-out determinations based on measurements taken at a height of 50 meters were in agreement with determinations taken at a height of 1 meter, and with the results obtained measuring soil samples. The in-situ gamma spectroscopy, using helicopter or airplane, is a fast and powerful method for mapping surface contamination. (author). 13 refs.; 18 figs.; 13 tabs

  18. Measurement of radioactive aeroions mobility in atmospheric air

    Paper describes a technique to measure mobility of 218Po radon daughter ions in gas. Technique is based on aspiration technique to record aeroions grounded on ion precipitation from radon containing gas flow to the surface of semiconducting detector within electrostatic field of a plane condenser with subsequent recording of 218Po α-radiation. For ∼ 1 s ions one determined dependence of mobility on air absolute humidity. Within 3.4-13.6 g/m3 humidity variation range the mentioned dependence is shown to be negligible one. The average value of 218Po mobility according to the experiment results constituted 1.05 ± 0.05 cm2/(s W)

  19. Integration of Quantitative Positron Emission Tomography Absolute Myocardial Blood Flow Measurements in the Clinical Management of Coronary Artery Disease.

    Gewirtz, Henry; Dilsizian, Vasken

    2016-05-31

    In the >40 years since planar myocardial imaging with(43)K-potassium was introduced into clinical research and management of patients with coronary artery disease (CAD), diagnosis and treatment have undergone profound scientific and technological changes. One such innovation is the current state-of-the-art hardware and software for positron emission tomography myocardial perfusion imaging, which has advanced it from a strictly research-oriented modality to a clinically valuable tool. This review traces the evolving role of quantitative positron emission tomography measurements of myocardial blood flow in the evaluation and management of patients with CAD. It presents methodology, currently or soon to be available, that offers a paradigm shift in CAD management. Heretofore, radionuclide myocardial perfusion imaging has been primarily qualitative or at best semiquantitative in nature, assessing regional perfusion in relative terms. Thus, unlike so many facets of modern cardiovascular practice and CAD management, which depend, for example, on absolute values of key parameters such as arterial and left ventricular pressures, serum lipoprotein, and other biomarker levels, the absolute levels of rest and maximal myocardial blood flow have yet to be incorporated into routine clinical practice even in most positron emission tomography centers where the potential to do so exists. Accordingly, this review focuses on potential value added for improving clinical CAD practice by measuring the absolute level of rest and maximal myocardial blood flow. Physiological principles and imaging fundamentals necessary to understand how positron emission tomography makes robust, quantitative measurements of myocardial blood flow possible are highlighted. PMID:27245647

  20. Dose rate measurements around consignments of radioactive material

    The International Atomic Energy Agency's (IAEA) Regulations for the Safe Transport of Radioactive Material require compliance with various radiation protection control measures and also require the competent authority to arrange for periodic assessments of the radiation doses to workers and to members of the public. It is a two-fold approach of controls and assessments. Periodic reviews of the radiological impact arising from the transport of radioactive materials by road, rail, sea and air, have been undertaken by NRPB on behalf of the UK Competent Authority. Dose assessments were made using estimated exposure times together with measured and extrapolated dose rates from 'near-field' regions close to consignments, 'mid-field' regions occupied by transiently exposed persons and 'far-field' regions occupied by members of the public. The results show that annual doses to workers and public are generally small fractions of dose limits. The exception is a small group of driver/handlers involved with packages for medical and industrial use. Compliance with the Regulations has ensured that a sufficient degree of control exists. Originally, most packages were small compared with the distances to exposed persons. Point source geometry was therefore used. More recently, it has been estimated that only a minority of all consignments of radioactive material is of sufficiently small dimensions for point source geometry to continue to apply. Instead, initial despatches of radionuclide packages can consist of consignments of several cubic metres in size, and only at tertiary despatch level would point source geometry prevail. However, for all physically large loads, the measured dose rates do not decline as rapidly as point source geometry would suggest based on the Tl value. Development of the methodology adopted by the IAEA Regulations over some 40 years has introduced parameters to compensate in part for these levels of dose rate, and, together with operational improvements

  1. Absolute measurements of the alpha-gamma emitters activities by a sum-coincidence method

    The absolute activity of U-235 contained in a UO2 sample, using a sum-coincidence circuit which selected only the alpha particles which were simultaneous with the well known 184 Kev gamma radiation from Th-231. The alpha particles were detected by ZnS(Ag) scintillator specially designed to show its maximun efficiency for U-235 alpha particles, whereas the gamma radiation was detected by NaI(Tl) scintillation detector. The values obtained for the half-life of U-235 was compared with data from various observers using different experimental techniques. (Author)

  2. Absolute measurements of the fast neutron flux in the reactor RA

    The absolute neutron flux in the vertical VK-5 hole of the reactor RA was determined by using the 27Al (n, alpha) 24Na reaction, and by counting the 24Na - 2.5 MeV gamma line photopeak activity. A method for the determination of σeff as a mean value between the two large limiting cases of neutron spectra is used. The flux at the power level of 5 MW was found to be (2.5±0.9)·1012n/cm2sec (author)

  3. IAEA's ALMERA network: Supporting the quality of environmental radioactivity measurements.

    Osvath, I; Tarjan, S; Pitois, A; Groening, M; Osborn, D

    2016-03-01

    The International Atomic Energy Agency coordinates and provides methodological and analytical quality support to the network of Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA), comprising 150 laboratories in 84 countries. Annual proficiency tests (PTs) are organized for the network laboratories using sets of different samples typically encountered in environmental and food monitoring laboratories. The PT system is designed to respond to the needs of the network for rapid response and reliable measurement results, and to metrological principles and international standards and guides. Comparison of performance of ALMERA and non-ALMERA laboratories in PTs indicates that the "PT - method development - training - PT" strategy adopted for capability building is beneficial to the network. PMID:26810873

  4. Radioactivity measurement of environmental level by using imaging plate

    We are studying a measuring system of environmental level radioactivity by using IP. On γ ray measurement, many lead blocks are used for the natural radiation shielding. Sometimes, weak contaminations which can not detected by usually used detector such as GM survey meter bother us. By contacting IP on lead blocks for about 12 hs, contaminations on them are easily found out and we can decontaminate the small spots by shaving. This method will be applied for the decontamination of the valuables with no serious destructions. We are developing activity concentration evaluation system of mechanical wastes which have been set in irradiation room by contacting IPs or a piece of IP on them. (author)

  5. ISEA (International geodetic project in SouthEastern Alaska) for rapid uplifting caused by glacial retreat: (3) Absolute gravity measurements

    Sun, W.; Miura, S.; Sato, T.; Kaufman, A. M.; Cross, R.; Freymueller, J. T.; Schiel, A.

    2006-12-01

    The southeast Alaska is undergoing a rapid ice-melting and land uplift due to the effect of global warming in the last three hundred years. The corresponding crustal deformation caused by the post-glacial rebound has been clearly detected by modern geodetic techniques, e.g., GPS and tidal gauge measurements (Larsen et al., 2004; Sato et al., 2005). The geodetic deformation provides us useful information in evaluating ice-melting rate, effect of global warming, and even the viscosity beneath the crust. For this purpose, however, integrated geodetic observation, especially including gravity measurement, is considered very important (Miura et al., a separate presentation at the same AGU conference; Wahr et al., 1995). Therefore, to detect the crutal deformation caused by the post-glacial rebound and to study the viscoelastic structure of the earth in the southeast Alaska, a joint team of Japanese and U.S. researchers has begun a three year project of GPS, earth tide, and absolute gravity measurements. In this presentation, results of the absolute gravity observation carried out between June 3 and June 18, 2006 are reported. During the 2006 observation campaign, a network of absolute gravity was for the first time established which is composed of five sites about 100 km around of Juneau: Bartlett Cove at Gustavus, Russell Island, Hains Fairground at Hains, UAS Egan Library at Juneau and Mendenhall Glacier Visitors Center at Juneau, Alaska. Absolute gravity data were acquired at the five sites using a Micro-LaCoste absolute gravimeter, serial number 111. A typical occupation recorded a set of 100 single measurements every half hour. At each site data were collected over a 48~62 hour period. Due to the bad ocean model in this area, ocean loading correction seems not efficient because large tidal residuals remain in the observed results. To carry out an accurate tidal correction, on site tidal observation was also performed. Detail discussions on tidal observation and

  6. Quality assurance for radioactive measurement in nuclear medicine

    The field of nuclear medicine continues to grow around the world, owing in part to a number of successful programmes carried out by the IAEA to enhance the use of nuclear medicine techniques in Member States. The implementation of quality assurance (QA) programmes to ensure the safe application of radiopharmaceuticals has, however, been variable in many Member States. One possible reason is the lack of a unified set of principles regarding the establishment of such programmes. This publication addresses the issue of QA programmes for radioactivity measurement in nuclear medicine. A group of experts consulted by the IAEA recommended in 2002 that unified principles concerning QA and quality control (QC) procedures for the measurement of radioactivity in nuclear medicine be developed because of its importance in controlling the safety and effectiveness of the use of radiopharmaceuticals. This publication is the result of advice provided to the IAEA by experts in the fields of radionuclide metrology, medical physics and radiopharmacy. This report can be considered to be a more detailed and updated version of IAEA-TECDOC-602, Quality Control of Nuclear Medicine Instruments, published in 1991. Advances in the field of nuclear instrumentation since that report was published, particularly in imaging, and the increased emphasis on QA and QC prompted the need for an update. Moreover, it was realized that the activity measurement and imaging aspects had each become so specialized as to be better treated in separate publications. The present report focuses on the factors affecting radioactivity measurement and the implementation of QA and QC programmes to ensure accurate and consistent results. The IAEA has developed a safety standard on The Management System for Facilities and Activities (IAEA Safety Standards Series No. GS-R-3), which replaces the IAEA publications on QA issued as Safety Series No. 50-C/SG-Q (1996). In GS-R-3, the management system is described as a set of

  7. Changing methodology for measuring airborne radioactive discharges from nuclear facilities

    The US Environmental Protection Agency (USEPA) requires that measurements of airborne radioactive discharges from nuclear facilities be performed following outdated methods contained in the American National Standards Institute (ANSI) N13.1-1969 Guide to Sampling Airborne Radioactive Materials in Nuclear Facilities. Improved methods are being introduced via two paths. First, the ANSI standard is being revised, and second, EPA's equivalency granting process is being used to implement new technology on a case-by-case or broad basis. The ANSI standard is being revised by a working group under the auspices of the Health Physics Society Standards Committee. The revised standard includes updated methods based on current technology and a performance-based approach to design. The performance-based standard will present new challenges, especially in the area of performance validation. Progress in revising the standard is discussed. The US Department of Energy recently received approval from the USEPA for an alternate approach to complying with air-sampling regulations. The alternate approach is similar to the revised ANSI standard. New design tools include new types of sample extraction probes and a model for estimating line-losses for particles and radioiodine. Wind tunnel tests are being performed on various sample extraction probes for use at small stacks. The data show that single-point sampling probes are superior to ANSI-Nl3.1-1969 style multiple-point sample extraction probes

  8. Natural radioactivity measurements in some Indian building materials

    The present work deals with the radioactivity measurements of some Indian building materials using gamma ray spectrometry. The activity concentration obtained for 226Ra, 232Th and 40K ranged from 8.3 to 88.47, 8.45 to 95.29 and 23.43 to 155.46 Bq kg-1, with the mean values of 42.57, 34.85 and 63.25 Bq kg-1 respectively. To assess the radiological hazard of the natural radioactivity in the samples, the radium equivalent activity the absorbed dose rate and the external hazard index were also calculated. The study yields an annual effective dose equivalent in the range of 0.6 to 11.73 x 10-5 Sv with a mean value of 5.77 x 10-5 Sv. The results suggest that the use of such building materials in the construction of domestic dwellings or workplaces in India is unlikely to give rise to any significant radiation exposure to the occupants. The uranium calculated using fission track registration technique and the values ranged from 0.69 to 2.28 ppm. (author)

  9. Measurement of environmental radioactivity in Toki district, (2)

    Three and a half years have elapsed since the start of this joint research. At first, cosmic ray was measured with a Geiger counter made by ourselves, then strong radioactivity was found in soils and stones. In order to observe the natural environment in which we live from the viewpoint of radiation, the measuring instrument having better sensitivity and on which the effect of background is small was sought for. The main subject of this report is the progress during this period, accordingly, the circuit composition of a NaI scintillation counter, thermo-luminescent dosimeter and ionization chamber measurement are described. When the Tokitsu Elementary School was reconstructed from wooden structure to concrete structure, the exposure dose in the teacher's room doubled. One summer day, mutual comparison was carried out among the measurement with a Geiger counter, a NaI scintillator and a TLD using an ionization chamber as the reference. The features of various measuring instruments were clarified, and utilizing these results, the effect of the combined measurement can be obtained. (Kako, I.)

  10. Absolute nuclear material assay

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  11. Absolute nuclear material assay

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  12. Radioactivity measurements of sewerage in 4 hospitals from Chongqing,China

    ZHAO Xian-ying; SHU Wei-qun; CAO Jia; LIU Yi-min

    2007-01-01

    @@ Monitoring of any release of radioactive materials to the environment is necessary for the environmental protection. Measurement of medical radioactive elements in the hospital sewerage is very important too. However, few study of radioactivity in hospital sewerage has been carried out or reported.

  13. Radioactive versus capacitance techniques for measuring soil water

    A field study was conducted to compared a capacitance probe and a neutron probe for use in measuring the soil water changes and the absolute values of soil water. The study was conducted using three plots each receiving different amounts of water by a surface drip irrigation system. The 50 mm PVC access tubes were installed using a machine to auger the holes. One hole was dug using a 50 mm bulk density probe and the remaining two holes were dug using a 54 mm soil sampling tube. The two probes were calibrated to this site. The capacitance probe measured both absorption and desorption of the soil water in the semi-dry site as well as the neutron probe. The capacitance probe gave slightly higher soil water values in the semi-dry plot than the neutron probe. However, both instruments tracked the changes reasonably well. In the wet site, both probes underpredicted the actual water content, but still tracked the changes. In the dry site, which had a poorly install access tube, the capacitance probe did not accurately predict the water content or changes, while the neutron probe did. The capacitance technique will provide acceptable soil water measurements if the access tube is properly installed and appropriate calibration used. (author). 4 refs, 4 figs, 1 tab

  14. Intercomparisons for the agreement of radioactivity measurement laboratories in environment

    Four tests having for object the evaluation of ability of laboratories that solicit a ministerial agreement for the radioactivity measurement in environment are detailed: Water matrix, soil matrix, aerosol on filter matrix and biological matrix. For the first one test, water matrix, the categories of measures concerned are the gamma emitters radionuclides (gamma energy inferior to 100 keV), the level of activities is very low (sample: water). The second one, soil matrix, the categories of measures concerned are the uranium radioisotopes, thorium radioisotopes, radium 226 and daughter products, radium 228 and daughter products (sample: lake sediment). The third one test, aerosol on filter matrix, the categories of measures concerned are the global beta activity, the beta-gamma emitters radionuclides ( gamma energy superior to 100 keV, strontium 90 on yttrium 90 rate. For the fourth and last one test, on biological matrix the categories of measures concerned are the tritium and the strontium 90 on yttrium 90 rate (sample whole milk). The agreements are delivered by The I.R.S.N. ( Institute of radiation protection and nuclear safety). (N.C.)

  15. A measurement to analyze the relative change in the Absolute Parity of Power Purchase: An application to the European Union

    Feijoo, Santiago Rodriguez; Caro, Alejandro Rodriguez; Correa, Carlos Gonzalez

    2003-01-01

    In the present paper an index to measure the changes in the Absolute Purchasing Power Parity. in the short term of a group of territories that conform an unique market, using the information of the Harmonized Index of Consumer Prices and the Exchange Rates. This measurement is utilized to study the change in relative prices of the countries of the European Union for the period 1991-2002, and the fulfillment of the theory of the Relative Purchasing Power Parity, taking as a reference the Absol...

  16. Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb:YAG

    Chenais, Sébastien; Forget, Sébastien; Druon, Frédéric; Balembois, François; Georges, Patrick

    2004-01-01

    We report direct and absolute temperature measurements in a diode-end-pumped Yb:YAG crystal, using a calibrated infrared camera, with a 60-$\\mu$m spatial resolution. The heat transfer coefficient has been measured, for the first time to our knowledge, with four different types of thermal contact (H = 0.25, 0.28, 0.9 and 2.0 for bare contact, graphite layer, indium foil and heat sink grease respectively). The dynamics of thermal effects is also presented.

  17. Cross-Section Measurements with the Radioactive Isotope Accelerator (RIA)

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed

  18. Cross-Section Measurements with the Radioactive Isotope Accelerator (ria)

    Stoyer, M. A.; Moody, K. J.; Wild, J. F.; Patin, J. B.; Shaughnessy, D. A.; Stoyer, N. J.; Harris, L. J.

    2003-10-01

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  19. Cross-Section Measurements with the Radioactive Isotope Accelerator (RIA)

    Stoyer, M A; Moody, K J; Wild, J F; Patin, J B; Shaughnessy, D A; Stoyer, N J; Harris, L J

    2002-11-19

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  20. Advances in Radioactive-Isotope Science from Mass Measurements

    Lunney, David

    Mass is a fundamental property that is indispensable for the study of nuclear structure, for applications in stellar nucleosynthesis and neutron-star composition, as well as studies of atomic and weak-interaction physics. We briefly review the mass-measurement programs at radioactive-beam facilities worldwide and examine the wealth of new mass data, compare the strengths of the different installations and reflect on the multitude of physics results. The series of ENAM meetings from 1995 to 2008 saw the rise and subsequent dominance of Penning traps in the field of mass spectrometry, which has continued through the new era of the ARIS meetings. As for the ARIS 2011 conference, we attempt a nomination for "Penning trap of the year."

  1. Measurement of the cross-sections of radioactive Ba isotopes

    The radioactive Ba isotopes are produced in the interaction of 60 MeV/u 18O with 232Th. Ba is separated from thorium and complex reaction product mixture by BaCl2 precipitation and purified. 133Ba is used as the tracer to determine chemical yield of Ba. The Ba fraction is measured by off-line gamma-ray spectroscopy. The formation cross-sections of the individual Ba isotope is calculated from the intensities of gamma-ray peaks of each Ba isotope as well as relative nuclear data. The results show the n-deficient Ba isotopes still have higher formation cross-sections under the conditions of intermediate energy projectile and thick targets

  2. Measurement of cosmogenic radioactive products in xenon and copper

    Piastra, Francesco

    2016-02-01

    Rare events searches, such as direct dark matter detection or neutrinoless double beta decay (0vββ) observation, using liquid xenon as target and detection medium require ultralow background to fully exploit the physics potential. Cosmogenic activation of the detector components, and even more importantly, of the xenon itself might have undesired impact on the background and the final sensitivity of the experiment. Since no measurement of cosmogenic activation of xenon was present in literature so far, we performed such a measurement exposing of a natural xenon sample to the cosmic radiation at the Jungfraujoch research station at an altitude of 3470 m above sea level for 245 days. This study was complemented with a ultra pure copper sample that was activated together with the xenon. We directly observed, with gamma-ray spectrometry, the production of 7Be, 101Rh, 125Sb, 126I and 127Xe in xenon, out of which only 125 Sb could potentially lead to a background relevant for multi-ton scale direct dark matter search. The production rates for five out of eight radioactive isotopes in copper are in good agreement with the only dedicated measurement present in literature. The production rates measured for both samples were compared with the predictions obtained with commonly used software packages. The latter showed a systematic under-estimation, especially for xenon.

  3. Measurements of whole-body radioactivity in the UK population

    A national survey of whole-body radioactivity was undertaken. A mobile whole-body counter visited collaborating Medical Physics Departments and Hospitals in England and Wales. Data were also obtained from an installed whole-body counter at the West Cumberland Hospital, Whitehaven, and from a control site at Addenbrooke's Hospital, Cambridge. 1657 volunteer members of the public were measured, including 162 children. 36% of volunteers had been measured in a similar survey 2 years earlier, and showed between a two and five fold reduction in body radiocaesium. No radiocaesium was detected in 54% of people measured. Measurements showed a progressive fall over the course of the study, reaching a baseline of 0.3 Bq137Cs/gK. In 1989, the additional radiation dose incurred from radiocaesium varied from a maximum of 4.1 μSv in Cumbria to 1.5 μSv in the South East, compared with the average annual radiation dose of 2500 μSv due to all other causes. No other gamma-emitting radionuclides were found. Results are consistent with Chernobyl as the source of the radiocaesium detected. (author)

  4. Method based on chirp decomposition for dispersion mismatch compensation in precision absolute distance measurement using swept-wavelength interferometry.

    Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Hu, Tao; Zhuang, Zhitao; Xu, Xinke; Gan, Yu

    2015-12-14

    We establish a theoretical model of dispersion mismatch in absolute distance measurements using swept-wavelength interferometry (SWI) and propose a novel dispersion mismatch compensation method called chirp decomposition. This method separates the dispersion coefficient and distance under test, which ensures dispersion mismatch compensation without introducing additional random errors. In the measurement of a target located at 3.9 m, a measurement resolution of 45.9 μm is obtained, which is close to the theoretical resolution, and a standard deviation of 0.74 μm is obtained, which is better than the traditional method. The measurement results are compared to a single-frequency laser interferometer. The target moves from 1 m to 3.7 m, and the measurement precision using the new method is less than 0.81 μm. PMID:26698959

  5. Absolute frequency measurement of the neutral 40Ca optical frequency standard at 657 nm based on microkelvin atoms

    Wilpers, G.; Oates, C. W.; Diddams, S. A.; Bartels, A.; Fortier, T. M.; Oskay, W. H.; Bergquist, J. C.; Jefferts, S. R.; Heavner, T. P.; Parker, T. E.; Hollberg, L.

    2007-04-01

    We report an absolute frequency measurement of the optical clock transition at 657 nm in 40Ca with a relative uncertainty of 7.5 × 10-15, one of the most accurate frequency measurements of a neutral atom optical transition to date. The frequency (455 986 240 494 135.8 ± 3.4) Hz was measured by stabilizing a diode laser system to a spectroscopic signal derived from an ensemble of 106 atoms cooled in two stages to a temperature of 10 µK. The measurement used a femtosecond-laser-based frequency comb to compare the Ca transition frequency with that of the single-ion 199Hg+ optical frequency standard at NIST. The Hg+ frequency was simultaneously calibrated relative to the NIST Cs fountain via the NIST time scale to yield an absolute value for the Ca transition frequency. The relative fractional instability between the two optical standards was 2 × 10-15 for 10 s of averaging time and 2 × 10-16 for 2000 s.

  6. Absolute measurements of total peroxy nitrate mixing ratios by thermal dissociation blue diode laser cavity ring-down spectroscopy.

    Paul, Dipayan; Osthoff, Hans D

    2010-08-01

    Peroxycarboxylic nitric anhydrides (PANs) have long been recognized as important trace gas constituents of the troposphere. Here, we describe a blue diode laser thermal dissociation cavity ring-down spectrometer for rapid and absolute measurements of total peroxyacyl nitrate (SigmaPAN) abundances at ambient concentration levels. The PANs are thermally dissociated and detected as NO2, whose mixing ratios are quantified by optical absorption at 405 nm relative to a reference channel kept at ambient temperature. The effective NO2 absorption cross-section at the diode laser emission wavelength was measured to be 6.1 x 10(-19) cm2 molecule(-1), in excellent agreement with a prediction based on a projection of a high-resolution literature absorption spectrum onto the laser line width. The performance, i.e., accuracy and precision of measurement and matrix effects, of the new 405 nm thermal dissociation cavity ring-down spectrometer was evaluated and compared to that of a 532 nm thermal dissociation cavity ring-down spectrometer using laboratory-generated air samples. The new 405 nm spectrometer was considerably more sensitive and compact than the previously constructed version. The key advantage of laser thermal dissociation cavity ring-down spectroscopy is that the measurement can be considered absolute and does not need to rely on external calibration. PMID:20698583

  7. Radioactivity measurement in Austria 1992 and 1993. Data and evaluation

    The Federal Ministry of Health and Consumer Protection is responsible for the large scale surveillance of radioactive contaminations of the Austrian territory. For this purpose on one hand an on-line measurement system has been set up, using gamma dose rate measuring devices situated in 336 locations. On the other hand, various media e.g. aerosols, precipitation, surface water and foodstuffs are being collected. Their radionuclide content is analysed in several laboratories. Additional special projects have been set up to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. The report covers the results of this surveillance for the years 1992 and 1993. The evaluation of these measurements and of other data concerning the average exposure of the Austrian population for the year 1993 is summarized in the following figure. It can be seen that the main contributions to the radiation dose are due to natural exposure pathways, among which the inhalation of indoor radon is of main importance. (Compared to the data in earlier reports due to a new evaluation of the radon risk by ICRP this dose contribution is significantly lower.) In comparison, the component due to the consequences of the Chernobyl reactor accident in 1986 onto Austrian territory during 1992 and 1993 was marginal. (author)

  8. The measurement of radioactive microspheres in biological samples

    Measurements of the distribution of radioactive microspheres are used in investigations of regional coronary blood flow, but the size and shape of the heart varies for different test animals, and the organ is frequently divided into smaller pieces for studies of regional perfusion. Errors are introduced by variations in the distribution of the radioactive source and the amount of Compton scatter in different samples. A technique has therefore been developed to allow the counting of these tissue samples in their original form, and correction factors have been derived to inter-relate the various counting geometries thus encountered. Dogs were injected with microspheres labelled with 141Ce, 51Cr or 85Sr. The tissue samples did not require remodelling to fit a standard container, and allowance was made for the inhomogeneous distribution in the blood samples. The activities in the centrifuged blood samples were correlated with those from the tissue samples by a calibration procedure involving comparisons of the counts from samples of microspheres embedded in sachets of gelatine, and similar samples mixed with blood and then centrifuged. The calibration data have indicated that 51Cr behaves anomalously, and its use as a label for microspheres may introduce unwarranted errors. A plane cylindrical 10 x 20 cm NaI detector was used, and a 'worst case' correction of 20% was found to be necessary for geometry effects. The accuracy of this method of correlating different geometries was tested by remodelling the same tissue sample into different sizes and comparing the results, and the validity of the technique was supported by agreement of the final results with previously published data. (U.K.)

  9. Measurements of neutron cross sections of radioactive waste nuclides

    Katoh, Toshio [Gifu College of Medical Technology, Seki, Gifu (Japan); Harada, Hideo; Nakamura, Shoji; Tanase, Masakazu; Hatsukawa, Yuichi

    1998-01-01

    Accurate nuclear reaction cross sections of radioactive fission products and transuranic elements are required for research on nuclear transmutation methods in nuclear waste management. Important fission products in the nuclear waste management are {sup 137}Cs, {sup 135}Cs, {sup 90}Sr, {sup 99}Tc and {sup 129}I because of their large fission yields and long half-lives. The present authors have measured the neutron capture cross sections and resonance integrals of {sup 137}Cs, {sup 90}Sr and {sup 99}Tc. The purpose of this study is to measure the neutron capture cross sections and resonance integrals of nuclides, {sup 129}I and {sup 135}Cs accurately. Preliminary experiments were performed by using Rikkyo University Reactor and JRR-3 reactor at Japan Atomic Energy Research Institute (JAERI). Then, it was decided to measure the cross section and resonance integral of {sup 135}Cs by using the JRR-3 Reactor because this measurement required a high flux reactor. On the other hand, those of {sup 129}I were measured at the Rikkyo Reactor because the product nuclides, {sup 130}I and {sup 130m}I, have short half-lives and this reactor is suitable for the study of short lived nuclide. In this report, the measurements of the cross section and resonance integral of {sup 135}Cs are described. To obtain reliable values of the cross section and resonance integral of {sup 135}Cs(n, {gamma}){sup 136}Cs reaction, a quadrupole mass spectrometer was used for the mass analysis of nuclide in the sample. A progress report on the cross section of {sup 134}Cs, a neighbour of {sup 135}Cs, is included in this report. A report on {sup 129}I will be presented in the Report on the Joint-Use of Rikkyo University Reactor. (author)

  10. Absolute optical extinction measurements of single nano-objects by spatial modulation spectroscopy using a white lamp.

    Billaud, Pierre; Marhaba, Salem; Grillet, Nadia; Cottancin, Emmanuel; Bonnet, Christophe; Lermé, Jean; Vialle, Jean-Louis; Broyer, Michel; Pellarin, Michel

    2010-04-01

    This article describes a high sensitivity spectrophotometer designed to detect the overall extinction of light by a single nanoparticle (NP) in the 10(-4)-10(-5) relative range, using a transmission measurement configuration. We focus here on the simple and low cost scheme where a white lamp is used as a light source, permitting easy and broadband extinction measurements (300-900 nm). Using a microscope, in a confocal geometry, an increased sensitivity is reached thanks to a modulation of the NP position under the light spot combined with lock-in detection. Moreover, it is shown that this technique gives access to the absolute extinction cross-sections of the single NP provided that the incident electromagnetic field distribution experienced by the NP is accurately characterized. In this respect, an experimental procedure to characterize the light spot profile in the focal plane, using a reference NP as a probe, is also laid out. The validity of this approach is discussed and confirmed by comparing experimental intensity distributions to theoretical calculations taking into account the vector character of the tightly focused beam. The calibration procedure permitting to obtain the absolute extinction cross-section of the probed NP is then fully described. Finally, the force of the present technique is illustrated through selected examples concerning spherical and slightly elongated gold and silver NPs. Absolute extinction measurements are found to be in good consistency with the NP size and shape independently obtained from transmission electron microscopy, showing that spatial modulation spectroscopy is a powerful tool to get an optical fingerprint of the NP. PMID:20441319

  11. Present status and prospects of ultralow level radioactivity measurements (2). Underground laboratory and recent topics emerged from ultralow level radioactivity measurements

    The present status of ultralow level radioactivity measurements in underground laboratories in Japan and Europe, and some researches using ultralow level radioactivity measurement technologies are stated. The background radiation originating cosmic ray is not excluded on the ground, but it decreased in the underground laboratory. Anticoincidence of underground measurement, countermeasure of radon, shielding materials, background of Ge measurement in Ogoya and other underground laboratories in Japan are reported. There are many underground laboratories for ultralow level radioactivity measurements in Europe, and a group of Collaboration of European Low-level underground LAboRatories (CELLAR) was organized. Some examples of ultralow level background of gamma ray measurements such as 152Eu, atomic bomb induced nuclide, natural induced radioactive nuclide by environmental neutron, measurement of 22Na, 108mAg and 110mAg, new evaluation method using 108mAg, high resolution analysis of change of 7Be and 210Pb in air, and nuclide in meteorite are reported. The sensitivity increasing method of low level radioactivity measurement and radioactive contamination of reagents are described. (S.Y.)

  12. Measurement of the absolute νμ-CCQE cross section at the SciBooNE experiment

    This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 1020 protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 1020 POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the absolute CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.

  13. Measurement of the absolute vμ-CCQE cross section at the SciBooNE experiment

    Aunion, Jose Luis Alcaraz [Autonomous Univ. of Barcelona (Spain)

    2010-07-01

    This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 1020 protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 1020 POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the absolute CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.

  14. Absolute Beam Energy Measurement using Elastic ep Scattering at Thomas Jefferson National Accelerator Facility

    Deur, Alexandre

    1999-10-01

    The Jefferson Lab beam energy measurement in Hall A using the elastic ep scattering will be described. This new, non-magnetic, energy measurement method allows a ( triangle E/E=10-4 ) precision. First-order corrections are canceled by the measurements of the electron and proton scattering angles for two symmetric kinematics. The measurement principle will be presented as well as the device and measurement results. Comparison with independent magnetic energy measurements of the same accuracy will be shown. This project is the result of a collaboration between the LPC: université Blaise Pascal/in2p3), Saclay and Jefferson Lab.

  15. Measurement of natural radioactivity of the leaf Nefza (Oued belif)

    Nefza region, specifically Oued Belif, has a unique geological diversity in Tunisia. That's why it was chosen to be a study of natural radioactivity. The results were encouraging and have allowed us to draw conclusions about the origin of the high natural radioactivity found in certain rocks.

  16. Results of radioactivity measurements in France during 1983

    Various marine and continental sampling networks for the environmental monitoring of radioactivity of liquid waste discharges from French nuclear establishments have been set up by the Departement de Protection Sanitaire (DPS) since 1983. Measurements carried out on marine biological indicators: seaweeds, molluscs and fish caught all along the French shore, show that man-made radionuclide levels are locally higher both in the Channel near the release outlet of La Hague fuel reprocessing plant and in the influence area of the Rhone river waters in the Mediterranean sea. At the stations with the highest levels, the sanitary incidence of man-made radionuclides remains low, since it corresponds to a fraction in the range of 10-5 of the dose limit recommended by the International Commission on Radiological Protection. Continental measurements, especially those carried out on the crops from the agricultural area irrigated by the Compagnie Nationale d'Amenagement de la Region du Bas-Rhone et du Languedoc, corroborate the lack of transfers of radionuclides conveyed by the Rhone water to the agricultural produces of this region

  17. Functional requirements document for measuring emissions of airborne radioactive materials

    This document states the general functional requirements for systems and procedures for measuring emissions of airborne radioactive materials from facilities administered by the Westinghouse Hanford Company (WHC). The following issues are addressed in this document: lg-bullet definition of the program objectives lg-bullet selection of the overall approach to collecting the samples lg-bullet sampling equipment design lg-bullet sampling equipment maintenance and quality assurance issues. The following issues are not addressed in this document: lg-bullet air sampling in work areas or containments lg-bullet selection of specific on-line sample monitoring instrumentation lg-bullet analyzing collected samples lg-bullet reporting and interpreting results. The document provides equipment design guidance that is performance based rather than prescriptive. Locations from which samples are obtained should exhibit mixing of the contaminants with the airstream and acceptable air flow characteristics. Sample collection equipment and effluent and sample flow elements should meet defined performance standards. Quality control and assurance requirements specific to sample collection, equipment inspection, and calibration are presented. Key sample collection performance requirements are summarized in Section 5.4. The intent of this document is to assist WHC in demonstrating a high quality of air emission measurements with verified system performance based on documented system design, testing, inspection, and maintenance

  18. Contribution to the measurement of absolute activity of electron capture decaying nuclides. Determination of the fluorescence yield of some elements

    The object of this work is the study of techniques of measurement of the absolute activity of electron capture nuclides. Two methods have been specially studied. Determination of the number of X rays emitted from the K shell due to the reorganization of atomic electrons following electron capture. This measurement was made with a high pressure (5 kg/cm2) 4π proportional counter. The absorption in the source and the backing were also studied. To determine the absolute activity it is necessary to know the fluorescence yield and the different capture probabilities PL and PK. When the electron capture is followed by γ emission (within the resolution time of the coincidence circuit) the activity was determined through the X-γ coincidence method. In such a case it is not necessary to know the fluorescence yield and the capture probabilities. Various corrections - dead time, chance coincidences - were also studied. This method minimizes the decay scheme corrections. By applying these two methods to the following nuclides: Cr51, Mn54 and Zn65, the corresponding fluorescence yields have been determined: vanadium ωK = 0.191 ±0.002, chromium ωK = 0.262 ± 0.002 and copper ωK = 0.390 ± 0.004. (author)

  19. Absolute measurement of gauge block without wringing using tandem low-coherence interferometry

    A novel method of gauge block measurement without wringing onto a glass platen is proposed. By using tandem low-coherence interferometry to perform remote measurements, wringing is rendered unnecessary. To measure its length, a gauge block for measurement without wringing is set several millimeters above a glass platen that is positioned on a triangle interferometer such that the distances between the surfaces of the block and the reflection surface of the platen can be measured from opposite directions. By using tandem low-coherence interferometry with a He–Ne laser as a reference length standard, gauge blocks with nominal lengths of 5, 10 and 75 mm have been measured remotely with an expanded uncertainty of about 86 nm. (paper)

  20. Measurents of natural radioactivity in an underground hydroelectric power plant

    In underground working places, especially when ventilation is not properly regulated, large amounts of natural radioactivity can be found. This can give rise to potential exposures of non-negligible magnitude. Direct measurements of gamma radiation and radon were carried out during excavation works for the construction of an hydroelectric plant in the north of Italy. After the construction of the plant, in order to reduce radon concentrations and to improve ventilation effectiveness, the main entry gate was motorized and automated. Then, in order to find the optimal speed for the fans located in the galleries and in the power plant, radon and airflow velocity were measured. Correlation data between airflow and radon concentrations were found. An automatic regulation system has been set up using air velocity detectors and slightly modifying the software for the control and regulation of the power plant. Measurements must be made in order to identify radon sources and evaluate quantitative contributions as a function of ventilation. Underground hydroelectric plants are provided with entry galleries as well as secondary galleries from which radon coming out from the soil and the walls can exhale in quantities that depend on the contents of 226Ra in the rocks and in the building materials. Other radon sources are the water coming out from the walls of the galleries and the water in the deep well located at the bottom of the power plant. Geological studies and mathematical models are useful means for the analysis of the relative contributions of the main sources as well as for the prediction of the effects deriving from modifications of the hydroelectric plant ventilation system or resulting from other important structural changes. (author)

  1. Application of γ spectrometry sourceless efficiency method in measuring radioactive rare earth residues in Jiangsu province

    Background: The radioactivity levels of rare earth residues in Jiangsu province are not well known, and there are no explicit laws on their regulation. Purpose: By analyzing the radioactive nuclides in rare earth residues of Jiangsu province, we plan to propose some suggestions on volume reduction. Methods: HPGe γ spectrometry sourceless efficiency calibration method is playing an important role in the radioactive analysis because of its high accuracy and efficiency. It can be used without standard radioactive source and is easy to be measured on the spot. The reliability of method was verified by using IAEA reference materials. Results: The results show that in the rare earth residues the radioactive equilibrium of uranium and thorium decay series has been broken, and the radioactive levels in different samples have obvious difference. Conclusions: Based on the results, this paper investigates and analyses the radioactive residues of rare earth smelting and separation plants in Jiangsu Province, and puts forward some suggestions on volume reduction. (authors)

  2. Time, absolute.

    Mughal, Muhammad Aurang Zeb

    2009-01-01

    The concept of absolute time is a hypothetical model from the laws of classical physics postulated by Isaac Newton in the Principia in 1687. Although the Newtonian model of absolute time has since been opposed and rejected in light of more recent scholarship, it still provides a way to study science with reference to time and understand the phenomena of time within the scientific tradition. According to this model, it is assumed that time runs at the same rate for all the observers in the uni...

  3. Absolute distance measurement in a combined-dispersive interferometer using a femtosecond pulse laser

    In this paper, a ranging system using dispersive interferometry is developed with a femtosecond pulse laser, aiming to eliminate the measurement dead zones by using a greatly unbalanced Mach–Zehnder interferometer. The distance can be measured by the frequency of the spectral modulation. We indicate that the integer number of the pulse-to-pulse length can be determined by changing the repetition frequency. In the short distance measurement, the results show an agreement within 1.5 μm compared with an incremental He-Ne laser in the 1 m measurement range. We do large-scale experiments on a long optical rail using a typical Michelson interferometer, and an agreement well within 25 μm is obtained in a range up to 75 m, corresponding to a relative precision of 3.3  ×  10−7. Additionally, we experimentally optimize the system set-up to minimize the measurement uncertainty. (paper)

  4. Results of radioactivity measurements in French coastal waters during 1985

    Various sampling networks for the environmental monitoring of levels from radioactive waste releases from french nuclear plants have been set up by the Departement de Protection Sanitaire (DPS) since 1983. In 1985, various marine and freshwater biological indicators were collected regularly on the Channel, Atlantic and Mediterranean shores and at the level of the lower Rhone river. As in the previous years, the results showed the prevailing effects of the releases from the LA HAGUE reprocessing plant on the Channel and of the Rhone waters on the Mediterranean sea. Measurements at the level of the lower Rhone showed a clear labelling of the Rhone river waters by 106Ru. The monitoring of ruthenium levels in various biological indicators from the Mediterranean shore supplied a good representation of the marine areas affected by the Rhone river. At the stations with the highest levels, the sanitary consequence of man-made radionuclides remained low, representing a fraction in the range of 10-5 of the dose limit recommended by the International Commission on Radiological Protection

  5. Measurement of intrinsic radioactivity in a GSO crystal

    Wang, S C; Fujiwara, M

    2002-01-01

    Scintillating crystal detectors offer potential advantages in low-energy low-background experiments for particle physics and astrophysics. The GSO crystal is an interesting detector to explore in future neutrino physics experiments. The contributions to background due to the various channels of intrinsic radio isotopes from the sup 2 sup 3 sup 2 Th and sup 2 sup 3 sup 8 U series are identified and studied with time-correlation analysis and detailed fits to the spectral shape. Good agreement is achieved between measured and simulated spectra, indicating that background suppression factors to the 10 sup - sup 2 -10 sup - sup 3 level are possible. The procedures can be adopted for background understanding and suppression in other low-count-rate experiments where the dominant source of background is from internal radioactivity. Based on 1656 h of data taking, limits on the double beta decay half-life for the various channels in sup 1 sup 6 sup 0 Gd are derived. The limits for the neutrinoless and the Majoron mode...

  6. Measurement of intrinsic radioactivity in a GSO crystal

    Scintillating crystal detectors offer potential advantages in low-energy low-background experiments for particle physics and astrophysics. The GSO crystal is an interesting detector to explore in future neutrino physics experiments. The contributions to background due to the various channels of intrinsic radio isotopes from the 232Th and 238U series are identified and studied with time-correlation analysis and detailed fits to the spectral shape. Good agreement is achieved between measured and simulated spectra, indicating that background suppression factors to the 10-2-10-3 level are possible. The procedures can be adopted for background understanding and suppression in other low-count-rate experiments where the dominant source of background is from internal radioactivity. Based on 1656 h of data taking, limits on the double beta decay half-life for the various channels in 160Gd are derived. The limits for the neutrinoless and the Majoron modes are T((1)/(2))0νββ>2.0(0.8)x1020 yr and T((1)/(2))χββ>3.0(1.9)x1019 yr, respectively, at 68(90)% confidence level

  7. Preparation of radioactive ''mixed'' waste samples for measurement of RCRA [Resource Conservation and Recovery Act] organic compounds

    A radioactive ''mixed'' waste typically contains alpha-, beta-, or gamma-emitting radionuclides and varying quantities of semivolatile or volatile organic species, some or all of which may be named specifically by the Resource Conservation and Recovery Act (RCRA). Because there are no acceptable means available currently for disposing of these mixed wastes, they are presently stored above-ground in sealed drums. For this reason, analytical procedures which can determine RCRA organics in radioactive waste are necessary for deciding the proper approach for disposal. An important goal of this work is the development of methods for preparing mixed waste samples in a manner which allows the RCRA organics to be measured in conventional organic analysis laboratories without special precautions. Analytical procedures developed for handling mixed waste samples must satisfy not only the usual constraints present in any trace-level organic chemical determination, but also those needed to insure the protection of the operator from radioactive contamination. Consequently, procedures should be designed to use the least amount of radioactive sample commensurate with achieving acceptable sensitivity with the RCRA analytical methods. Furthermore, the unusual laboratory glassware which would normally be used should be replaced with disposable materials wherever possible, in order to reduce the ''clean-up'' time required, and thereby reduce the operator's exposure to radioactivity. Actual sample handling should be reduced to the absolute minimum. Finally, the final isolate must exhibit a sufficiently low level of alpha, beta, or gamma activity to permit detailed characterization in a conventional organic analysis laboratory. 4 refs., 5 tabs

  8. Measurements of radioactivity in Austria 1998, data and assessment

    In Austria an extensive program is realized for the purpose of large scale surveillance on radioactivity. On the one hand an Early Radiation Warning System with 336 gamma dose rate monitors and several partly nuclide specific air contamination monitors is operated by the Federal Chancellery. The data are automatically communicated to various authorities in real-time. On the other hand the radionuclide content of various media such as air, precipitation, surface water, foodstuffs etc. is monitored by periodic sampling and analysis in laboratories. In addition to this routine program special projects are carried out for investigation of specific media and to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. The inspection of the nuclear installations by the authorities concerning emissions and immissions is set up of two parts: inspection of the quality of the internal control by the operator and independent surveillance by examination of samples taken by the authority. In 1998 the average annual radiation exposure of the Austrian population amounted to about 4.6 mSv effective dose. The contributions dominating by far originate from natural and medical sources of radiation. In comparison with these, contributions from all other sources of radiation are extremely small. The average annual effective dose caused by natural radiation amounts to approximately 3.2 mSv. The inhalation of the radioactive noble gas radon and its short lived progeny in the mean contributes more than half to this exposure. Mainly because of different radon values considerable variations in natural radiation exposure do occur. There are regions with particular geological conditions where exposure levels by far exceed the average dose due to high radon values. Artificial radiation exposure is predominantly caused by the use of radioactive substances and of ionizing radiation in medical applications, in particular by X-ray diagnostics

  9. KLOE measurements of KL lifetime and absolute branching ratio of K+ → π+π-π+

    We are presently finalizing a new determination of the KL lifetime using the whole KLOE data set, consisting of more than 109 φ → KSKL decays (the previous KLOE measurement is reported in PLB 626, 2005). The KL lifetime will be extracted from the proper time distribution of KL → 3π0 decays, tagged by KS → π+π- decays on the opposite hemisphere of the apparatus. The measurement of the BR for the decay K+ → 3 charged pions completes the KLOE program of precise and fully inclusive measurements of the kaon dominant BR's. We are currently finalizing this measurement, which is based on the analysis of φ → K+K- events in which one of the two kaons undergoes a two-body decay, either μ ν or π π0 (tagging kaon). Given a tag, the opposite charged kaon decaying to 3 charged pions is easily and unambiguously identified. (author)

  10. Absolute measurements of anti ν (252Cf) using the manganese bath method

    By the manganese bath method and defined solid angle counting the fission rate anti ν (Cf-252) was measured. The corrections for neutrons losses due to leakage and absorption in the source itself and its surroundings were measured experimentally. The corrections for absorption fast neutrons on S and O was calculated by Monte-Carlo method. The obtained value of anti ν (Cf- 252) is 3.758+-0.015

  11. The absolute CBF response to activation is preserved during elevated perfusion: Implications for neurovascular coupling measures

    Whittaker, Joseph R.; Driver, Ian D.; Bright, Molly G.; Murphy, Kevin

    2016-01-01

    Functional magnetic resonance imaging (fMRI) techniques in which the blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) response to a neural stimulus are measured, can be used to estimate the fractional increase in the cerebral metabolic rate of oxygen consumption (CMRO2) that accompanies evoked neural activity. A measure of neurovascular coupling is obtained from the ratio of fractional CBF and CMRO2 responses, defined as n, with the implicit assumption that relative rath...

  12. Absolute polarimetry at RHIC

    Okada, H.; Alekseev, I.; Bravar, A; Bunce, G.; Dhawan, S.; Eyser, K. O.; Gill, R; Haeberli, W.; Huang, H.; Jinnouchi, O.; Makdisi, Y.; Nakagawa, I.; Nass, A.; Saito, N; Stephenson, E.

    2007-01-01

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy of $\\Delta P_{beam}/P_{beam} < 5%$. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detector...

  13. Determination of the absolute excited state density of a sodium target by means of beam deflection measurements

    The average deflection of a laser excited, divergent sodium beam with a broad velocity distribution is measured by means of a Langmuir-Taylor detector and exploited for determining the absolute density of the excited state in the interaction area. Simulations of the excitation and deflection process point out that the knowledge of the velocity distribution of the sodium atoms plays a crucial part in obtaining reliable information from deflection measurements. From the comparison of simulated and experimental results we find that in our set-up typically 30% of the sodium atoms are in the excited state when both ground state levels are pumped with an intensity of 35 mW cm-2 from an electro-optically modulated CW laser beam; the corresponding excited state density is 1.5 x 109 cm-3. (Author)

  14. Method for the absolute measurement of the total pair production cross section near threshold using a source of variable energy

    A method for the absolute measurement of the total pair production cross section in germanium near threshold is presented, using a source of photons of variable energy. This source is constituted by Compton scattered photons in lead. The incident beam is produced by the collimation of an intense source of 60Co (8 Ci). By continuous variation of the scattering angle one obtains a continuous variation of the energy of the photons impinging on the target. Measurements are presented for energies ranging between 1240 and 1263 keV and between 1180 and 1207 keV by steps of 2.8 keV. The results are compared with the predictions of different theories (Born approximation, exact calculation without and with screening effects). (Auth.)

  15. Measurement and Monte Carlo Calculation of Waste Drum Filled With Radioactive Aqueous Solution

    XU; Li-jun; ZHANG; Wei-dong; YE; Hong-sheng; LIN; Min; CHEN; Xi-lin; GUO; Xiao-qing

    2012-01-01

    <正>Theoretically the best calibrating source of gamma scan system (SGS) is a waste drum filled with uniform distribution of medium and radioactive nuclides. However, in reality, waste drums usually full of solid substance, which are difficult to be prepared in a completely uniformly distributed state. To reduce measurement uncertainty of the radioactivity of waste drums prepared using the method of shell source, a waste drum filled with radioactive aqueous solution was prepared. Besides, its radioactivity was measured by a SGS device and calculated using Monte Carlo method to verify the exact geometric model, which

  16. Establishment of a force balanced piston gauge for very low gauge and absolute pressure measurements at NPL, India

    National Physical Laboratory, the National Metrology Institute (NMI) of India is maintaining Primary standards of pressure that cover several decades of pressure, starting from 3.0E-06 Pa to 1.0 GPa. Among which a recent addition is a Force Balanced Piston Gauge, the non-rotating piston type, having better resolution and zero stability compared to any other primary pressure standards commercially available in the range 1.0 Pa to 15.0 kPa (abs and gauge). The characterization of this FPG is done against Ultrasonic Interferometer Manometer (UIM), the National Primary pressure standard, working in the range 1.0 Pa to 130.0 kPa (abs and diff) and Air Piston Gauge (APG), a Transfer Pressure Standard, working in the range 6.5 kPa to 360 kPa (abs and gauge), in their overlapping pressure regions covering both absolute and gauge pressures. As NPL being one of the signatories to the CIPM MRA, the Calibration and Measurement Capabilities (CMC) of both the reference standards (UIM and APG), are Peer reviewed and notified in the Key Comparison Data Base (KCDB) of BIPM. The estimated mean effective area of the Piston Cylinder assembly of this FPG against UIM (980.457 mm2) and APG (980.463 mm2) are well within 4 ppm and 10 ppm agreement respectively, with the manufacturer's reported value (980.453 mm2). The expanded uncertainty of this FPG, Q(0.012 Pa, 0.0025% of reading), evaluated against UIM as reference standard, is well within the reported value of the manufacturer, Q(0.008 Pa, 0.003% of reading) at k = 2. The results of the characterization along with experimental setup and measurement conditions (for gauge and absolute pressure measurements), uncertainty budget preparation and evaluation of measurement uncertainty are discussed in detail in this paper.

  17. Establishment of a force balanced piston gauge for very low gauge and absolute pressure measurements at NPL, India

    Vijayakumar, D. Arun; Prakash, Om; Sharma, R. K.

    2012-11-01

    National Physical Laboratory, the National Metrology Institute (NMI) of India is maintaining Primary standards of pressure that cover several decades of pressure, starting from 3.0E-06 Pa to 1.0 GPa. Among which a recent addition is a Force Balanced Piston Gauge, the non-rotating piston type, having better resolution and zero stability compared to any other primary pressure standards commercially available in the range 1.0 Pa to 15.0 kPa (abs and gauge). The characterization of this FPG is done against Ultrasonic Interferometer Manometer (UIM), the National Primary pressure standard, working in the range 1.0 Pa to 130.0 kPa (abs and diff) and Air Piston Gauge (APG), a Transfer Pressure Standard, working in the range 6.5 kPa to 360 kPa (abs and gauge), in their overlapping pressure regions covering both absolute and gauge pressures. As NPL being one of the signatories to the CIPM MRA, the Calibration and Measurement Capabilities (CMC) of both the reference standards (UIM & APG), are Peer reviewed and notified in the Key Comparison Data Base (KCDB) of BIPM. The estimated mean effective area of the Piston Cylinder assembly of this FPG against UIM (980.457 mm2) and APG (980.463 mm2) are well within 4 ppm and 10 ppm agreement respectively, with the manufacturer's reported value (980.453 mm2). The expanded uncertainty of this FPG, Q(0.012 Pa, 0.0025% of reading), evaluated against UIM as reference standard, is well within the reported value of the manufacturer, Q(0.008 Pa, 0.003% of reading) at k = 2. The results of the characterization along with experimental setup & measurement conditions (for gauge and absolute pressure measurements), uncertainty budget preparation and evaluation of measurement uncertainty are discussed in detail in this paper.

  18. TU-A-12A-09: Absolute Blood Flow Measurement in a Cardiac Phantom Using Low Dose CT

    Ziemer, B; Hubbard, L; Lipinski, J; Molloi, S [University of California, Irvine, CA (United States)

    2014-06-15

    Purpose: To investigate a first pass analysis technique to measure absolute flow from low dose CT images in a cardiac phantom. This technique can be combined with a myocardial mass assignment to yield absolute perfusion using only two volume scans and reduce the radiation dose to the patient. Methods: A four-chamber cardiac phantom and perfusion chamber were constructed from poly-acrylic and connected with tubing to approximate anatomical features. The system was connected to a pulsatile pump, input/output reservoirs and power contrast injector. Flow was varied in the range of 1-2.67 mL/s with the pump operating at 60 beats/min. The system was imaged once a second for 14 seconds with a 320-row scanner (Toshiba Medical Systems) using a contrast-enhanced, prospective-gated cardiac perfusion protocol. Flow was calculated by the following steps: subsequent images of the perfusion volume were subtracted to find the contrast entering the volume; this was normalized by an upstream, known volume region to convert Hounsfield (HU) values to concentration; this was divided by the subtracted images time difference. The technique requires a relatively stable input contrast concentration and no contrast can leave the perfusion volume before the flow measurement is completed. Results: The flow calculated from the images showed an excellent correlation with the known rates. The data was fit to a linear function with slope 1.03, intercept 0.02 and an R{sup 2} value of 0.99. The average root mean square (RMS) error was 0.15 mL/s and the average standard deviation was 0.14 mL/s. The flow rate was stable within 7.7% across the full scan and served to validate model assumptions. Conclusion: Accurate, absolute flow rates were measured from CT images using a conservation of mass model. Measurements can be made using two volume scans which can substantially reduce the radiation dose compared with current dynamic perfusion techniques.

  19. TU-A-12A-09: Absolute Blood Flow Measurement in a Cardiac Phantom Using Low Dose CT

    Purpose: To investigate a first pass analysis technique to measure absolute flow from low dose CT images in a cardiac phantom. This technique can be combined with a myocardial mass assignment to yield absolute perfusion using only two volume scans and reduce the radiation dose to the patient. Methods: A four-chamber cardiac phantom and perfusion chamber were constructed from poly-acrylic and connected with tubing to approximate anatomical features. The system was connected to a pulsatile pump, input/output reservoirs and power contrast injector. Flow was varied in the range of 1-2.67 mL/s with the pump operating at 60 beats/min. The system was imaged once a second for 14 seconds with a 320-row scanner (Toshiba Medical Systems) using a contrast-enhanced, prospective-gated cardiac perfusion protocol. Flow was calculated by the following steps: subsequent images of the perfusion volume were subtracted to find the contrast entering the volume; this was normalized by an upstream, known volume region to convert Hounsfield (HU) values to concentration; this was divided by the subtracted images time difference. The technique requires a relatively stable input contrast concentration and no contrast can leave the perfusion volume before the flow measurement is completed. Results: The flow calculated from the images showed an excellent correlation with the known rates. The data was fit to a linear function with slope 1.03, intercept 0.02 and an R2 value of 0.99. The average root mean square (RMS) error was 0.15 mL/s and the average standard deviation was 0.14 mL/s. The flow rate was stable within 7.7% across the full scan and served to validate model assumptions. Conclusion: Accurate, absolute flow rates were measured from CT images using a conservation of mass model. Measurements can be made using two volume scans which can substantially reduce the radiation dose compared with current dynamic perfusion techniques

  20. Absolute Thickness Measurements on Coatings Without Prior Knowledge of Material Properties Using Terahertz Energy

    Roth, Don J.; Cosgriff, Laura M.; Harder, Bryan; Zhu, Dongming; Martin, Richard E.

    2013-01-01

    This study investigates the applicability of a novel noncontact single-sided terahertz electromagnetic measurement method for measuring thickness in dielectric coating systems having either dielectric or conductive substrate materials. The method does not require knowledge of the velocity of terahertz waves in the coating material. The dielectric coatings ranged from approximately 300 to 1400 m in thickness. First, the terahertz method was validated on a bulk dielectric sample to determine its ability to precisely measure thickness and density variation. Then, the method was studied on simulated coating systems. One simulated coating consisted of layered thin paper samples of varying thicknesses on a ceramic substrate. Another simulated coating system consisted of adhesive-backed Teflon adhered to conducting and dielectric substrates. Alumina samples that were coated with a ceramic adhesive layer were also investigated. Finally, the method was studied for thickness measurement of actual thermal barrier coatings (TBC) on ceramic substrates. The unique aspects and limitations of this method for thickness measurements are discussed.

  1. Research on temperature measurement technology for graphite-cone-absorption-cavity absolute calorimeter

    Wei, Ji Feng; Lu, Fei; Sun, Li Qun; Zhang, Kai; Hu, Xiao Yang; Zhou, Shan; Xu, De

    2015-02-01

    The nonlinear effect of materials and sensors in high-energy laser calorimeters is especially obvious—due to the steep temperature gradients of their absorbers. Significant measurement errors occur when traditional integral temperature sensors and methods are utilized. In an effort to remedy this, a method is proposed in this paper in which an absorption cavity is divided into many parts and multiple discrete thermocouple sensors are used to measure the temperature rise of the absorbers. The temperature distribution in the absorbers is theoretically analyzed, numerically simulated, and verified through experimentation. Energy measurement results are compared according to the temperature distribution for different layouts of thermocouples. A high-accuracy calorimeter is developed by setting and optimizing thermocouple layout, as well as correcting various elements such as the specific heat of graphite and responsivity of thermocouples. The calorimeter employing this measurement method is calibrated against a standard energy meter, resulting in correction coefficient of 1.027 and relative standard deviation of the correction coefficient of only 0.8%. Theoretical analysis, numerical simulation, and experimental verification all prove that the proposed method successfully improves measurement accuracy.

  2. A new method for the absolute radiance calibration for UV/vis measurements of scattered sun light

    Wagner, T.; Beirle, S.; Dörner, S.; Penning de Vries, M.; Remmers, J.; Rozanov, A.; Shaiganfar, R.

    2015-05-01

    Absolute radiometric calibrations are important for measurements of the atmospheric spectral radiance. Such measurements can be used to determine actinic fluxes, the properties of aerosols and clouds and the short wave energy budget. Conventional calibration methods in the laboratory are based on calibrated light sources and reflectors and are expensive, time consuming and subject to relatively large uncertainties. Also, the calibrated instruments might change during transport from the laboratory to the measurement sites. Here we present a new calibration method for UV/vis instruments that measure the spectrally resolved sky radiance, like for example zenith sky Differential Optical Absorption Spectroscopy (DOAS-) instruments or Multi-AXis (MAX-) DOAS instruments. Our method is based on the comparison of the solar zenith angle dependence of the measured zenith sky radiance with radiative transfer simulations. For the application of our method clear sky measurements during periods with almost constant aerosol optical depth are needed. The radiative transfer simulations have to take polarisation into account. We show that the calibration results are almost independent from the knowledge of the aerosol optical properties and surface albedo, which causes a rather small uncertainty of about <7%. For wavelengths below about 330 nm it is essential that the ozone column density during the measurements is constant and known.

  3. A new method for the absolute radiance calibration for UV/vis measurements of scattered sun light

    T. Wagner

    2015-05-01

    Full Text Available Absolute radiometric calibrations are important for measurements of the atmospheric spectral radiance. Such measurements can be used to determine actinic fluxes, the properties of aerosols and clouds and the short wave energy budget. Conventional calibration methods in the laboratory are based on calibrated light sources and reflectors and are expensive, time consuming and subject to relatively large uncertainties. Also, the calibrated instruments might change during transport from the laboratory to the measurement sites. Here we present a new calibration method for UV/vis instruments that measure the spectrally resolved sky radiance, like for example zenith sky Differential Optical Absorption Spectroscopy (DOAS- instruments or Multi-AXis (MAX- DOAS instruments. Our method is based on the comparison of the solar zenith angle dependence of the measured zenith sky radiance with radiative transfer simulations. For the application of our method clear sky measurements during periods with almost constant aerosol optical depth are needed. The radiative transfer simulations have to take polarisation into account. We show that the calibration results are almost independent from the knowledge of the aerosol optical properties and surface albedo, which causes a rather small uncertainty of about <7%. For wavelengths below about 330 nm it is essential that the ozone column density during the measurements is constant and known.

  4. Laser-excitation technique for the measurement of absolute transition probabilities of weak atomic lines

    Kwong, H. S.; Smith, P. L.; Parkinson, W. H.

    1982-01-01

    A new technique is presented for the measurement of transition probabilities for weak allowed, intersystem, and forbidden lines. The method exploits the fact that oscillator strength is proportional to the number of stimulated absorptions and emissions produced by a narrow-band laser pulse of known energy which is in resonance with an atomic transition. The method is tested for a particular transition of Mg I with a known oscillator strength value and of appropriate magnitude. The number densities are measured using a Mach-Zehnder interferometer and the hook method for the lower level population and by measuring an absorption-equivalent width for the other. The apparatus consisted of a high-power tunable laser and a magnesium oven to produce excited Mg vapor, and a laser-plasma background continuum. The results are in good agreement with theoretical and other experimental data.

  5. Measurement of radioactive nuclides from geological samples and radiation hazards due to environmental radon

    The naturally occurring radio nuclides present in the environment may result in external and internal doses received by a population exposed to them directly and via the ingestion/inhalation pathways. Human beings are exposed to low levels of ionizing radiation from natural sources during their daily lives. The basic component of our life support system is considered to be in the soil, water, plants and air. These environmental components contain measurable amount of radioactivity. Radon and its progeny are radioactive and is the major contributor to environmental radioactivity. Radon is formed from the decay of radium which in turn is formed from uranium. The gaseous radioactive isotope of radon, from natural sources has a significant share in the total quantum of natural sources exposure to human beings. Gamma radiations are spontaneously emitted by naturally occurring radioactive material like 226Ra, 232Th and 40K, ever since their existence on earth. Natural radioactive materials under certain conditions can reach hazardous radiological levels. So, it becomes necessary to study the natural radioactivity in different materials to assess the dose for the population in order to know the health risks and future changes in the environmental radioactivity due to human activities. The present study deals with the measurement of radioactivity in some naturally occurring radioactive materials (NORMs). (author)

  6. Measurement of absolute diffraction efficiency of a variable line spaced grating using reflectivity beamline

    First and second order diffraction efficiency of a variable line spacing grating of average 1200 lines/mm density is measured at the reflectivity beam line of Indus-1. This grating is blazed at 3.2 deg. and has a blaze wavelength of 10 nm. The measurement has been carried out in the spectral range of 4.5 nm to 80 nm at 3o grazing angle of incidence. The maximum diffraction efficiency of the first order at ∼10 nm has been found to be ∼ 23% and for the second order it is ∼13%.

  7. Measurement of absolute diffraction efficiency of a variable line spaced grating using reflectivity beamline

    Kumar, M.; Modi, M. H.; Singhal, H.; Chakera, J. A.; Gupta, R. K.; Naik, P. A.; Lodha, G. S.; Gupta, P. D. [Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

    2012-06-05

    First and second order diffraction efficiency of a variable line spacing grating of average 1200 lines/mm density is measured at the reflectivity beam line of Indus-1. This grating is blazed at 3.2 deg. and has a blaze wavelength of 10 nm. The measurement has been carried out in the spectral range of 4.5 nm to 80 nm at 3o grazing angle of incidence. The maximum diffraction efficiency of the first order at {approx}10 nm has been found to be {approx} 23% and for the second order it is {approx}13%.

  8. Absolute measurement of 115In capture cross section at 144 and 565 keV

    The cross section of 115In(n, γ) 116mIn reaction are measured at 144 keV and 565 keV neutron energy by activation technique. The neutron fluence is measured by using H2 and CH4 filled proportional counter. A 4πβ counter is used to determine the β activities of 116mIn. The efficiency of the β detector is determined by 4πβ-γ coincidence techniques. A Monte-Carlo program is used to calculate the effect for neutron scattering from target, sample and holder. The results are compared with others

  9. Absolute frequency measurement of the magnesium intercombination transition $^1S_0 \\to ^3P_1$

    Friebe, Jan; Pape, André; Riedmann, Matthias; Moldenhauer, Karsten; Mehlstäubler, Tanja; Rehbein, Nils; Lisdat, Christian; Rasel, Ernst M.; Ertmer, Wolfgang; Schnatz, Harald; Lipphardt, Burghard; Grosche, Gesine

    2007-01-01

    We report on a frequency measurement of the $(3s^2)^1S_0\\to(3s3p)^3P_1$ clock transition of $^{24}$Mg on a thermal atomic beam. The intercombination transition has been referenced to a portable primary Cs frequency standard with the help of a femtosecond fiber laser frequency comb. The achieved uncertainty is $2.5\\times10^{-12}$ which corresponds to an increase in accuracy of six orders of magnitude compared to previous results. The measured frequency value permits the calculation of several ...

  10. Absolute high spectral resolution measurements of surface solar radiation for detection of water vapour continuum absorption.

    Gardiner, T D; Coleman, M; Browning, H; Tallis, L; Ptashnik, I V; Shine, K P

    2012-06-13

    Solar-pointing Fourier transform infrared (FTIR) spectroscopy offers the capability to measure both the fine scale and broadband spectral structure of atmospheric transmission simultaneously across wide spectral regions. It is therefore suited to the study of both water vapour monomer and continuum absorption behaviours. However, in order to properly address this issue, it is necessary to radiatively calibrate the FTIR instrument response. A solar-pointing high-resolution FTIR spectrometer was deployed as part of the 'Continuum Absorption by Visible and Infrared radiation and its Atmospheric Relevance' (CAVIAR) consortium project. This paper describes the radiative calibration process using an ultra-high-temperature blackbody and the consideration of the related influence factors. The result is a radiatively calibrated measurement of the solar irradiation at the ground across the IR region from 2000 to 10 000 cm(-1) with an uncertainty of between 3.3 and 5.9 per cent. This measurement is shown to be in good general agreement with a radiative-transfer model. The results from the CAVIAR field measurements are being used in ongoing studies of atmospheric absorbers, in particular the water vapour continuum. PMID:22547234

  11. Absolute pulse energy measurements of soft x-rays at the Linac Coherent Light Source

    Tiedtke, K.; Sorokin, A. A.; Jastrow, U.; Juranić, P.; Kreis, S.; Gerken, N.; Richter, M.; Arp, U.; Feng, Y.; Nordlund, D.; Soufli, R.; Fernández-Perea, M.; Juha, Libor; Heimann, P.; Nagler, B.; Lee, H.J.; Mack, S.; Cammarata, M.; Krupin, O.; Messerschmidt, M.; Holmes, M.; Rowen, M.; Schlotter, W.; Moeller, S.; Turner, J.J.

    2014-01-01

    Roč. 22, č. 18 (2014), s. 21214-21226. ISSN 1094-4087 R&D Projects: GA MŠk(CZ) LG13029 Institutional support: RVO:68378271 Keywords : soft x-ray * free electron laser * LCLS * instrumentation * measurement * metrology Subject RIV: BH - Optics , Masers, Laser s Impact factor: 3.488, year: 2014

  12. Local variation in absolute water content of human and rabbit eye lenses measured by Raman microspectroscopy

    Huizinga, Alex; Bot, Annet C.C.; Mul, de Frits F.M.; Vrensen, Gijs F.J.M.; Greve, Jan

    1989-01-01

    Raman spectra were obtained from fresh, fixed and sliced rabbit lenses and from human lens slices. For all lenses and lens slices the ratio R, defined as the Raman intensity at 3390 cm−1 divided by the Raman intensity at 2935 cm−1, was measured at different locations along the visual and equatorial

  13. Absolute activity measurement and gamma-ray emission probability for decay of I-126

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of 126 I, its importance lies mainly in fast neutron dosimetry as well as in the production of 125 I where 126 I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of 126 I have been measured. This radionuclide was obtained by means of the 127 I(n, 2n)126 I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of 126 I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The βbranch measurement was carried out in a 4 π(PC)β-γ coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-γ coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)

  14. Development and application of a detector for absolute measurement of neutron fluence rate in MeV region

    The development and performance of the DTS (Dual Thin Scintillator) for the absolute measurement of the neutron fluence rate between 1 and 15 MeV is decribed. The DTS detector consists of a pair of organic scintillators in a dual configuration, where the incident produces a proton-recoil which is detected in a 2Π geometry therefore avoiding the effect of the escape of protons. Thin scintillators are used resulting in small multiple scattering corrections. The theoretical caluclations of detector efficiency and proton-recoil spectrum were performed by means of a Monte Carlos code - CARLO DTS. The calculated efficiency was compared to the experimental one at two neutron energies namely 2.446 MeV and 14.04 MeV applying the Time Correlated Associated Particle technique. The theoretical and experimental efficiencies agreed within the experimental uncertainties of 1.44% and 0.77%, respectively. The performance of the DTS has been verified in an absolute 235U(n,f) cross section measurement between 1 and 6 MeV neutron energy. The cross section results were compared to those obtained replacing the DTS detector by the NBS (National Bureau of Standards, USA) Black Neutron Detector. The agreement was excellent in the overlapping energy interval of the two experiments (between 1 and 3 MeV), within the estimated uncertainly in the range of 1,0 to 1,7%. The agreement with the most recent evaluation from the ENDF/B-VI was excellent in almost all the energy range between 1 and 6 MeV. The 235U(n,f) cross section, average over the 252Cf fission neutron spectrum has been evaluated. The result including the cross section values of the present work was 1220 mb, in excellent agreement with the average value among the most recent measurements, 1227 +- 12 mb, and with the value 1213 mb, using the ENDF/B-VI data. (author)

  15. Measurement of the Absolute Branching Fraction of D_s^+ --> tau^+ nu_tau Decay

    Ecklund, K M; Savinov, V; López, A; Méndez, H; Ramírez, J; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Rademacker, J; Asner, D M; Edwards, K W; Naik, P; Reed, J; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A G; Libby, J; Powell, A; Wilkinson, G

    2007-01-01

    Using a sample of tagged D_s decays collected near the D^*_s D_s peak production energy with the CLEO-c detector, we study the leptonic decay D^+_s to tau^+ nu_tau via the decay channel tau^+ to e^+ nu_e bar{nu}_tau. We measure B(D^+_s to tau^+ nu_tau) = (6.17 +- 0.71 +- 0.34) %. Combining with our measurements of D^+_s to mu^+ nu_mu and D^+_s to tau^+ nu_tau (via tau^+ to pi^+ bar{nu}_tau), we determine f_{D_s} = 274 +- 10 +- 5 MeV.

  16. Absolute measurement of thermal noise in a resonant short-range force experiment

    Yan, H.; Housworth, E. A.; Meyer, H. O.; Visser, G.; Weisman, E.; Long, J. C.

    2014-10-01

    Planar, double-torsional oscillators are especially suitable for short-range macroscopic force search experiments, since they can be operated at the limit of instrumental thermal noise. As a study of this limit, we report a measurement of the noise kinetic energy of a polycrystalline tungsten oscillator in thermal equilibrium at room temperature. The fluctuations of the oscillator in a high-Q torsional mode with a resonance frequency near 1 kHz are detected with capacitive transducers coupled to a sensitive differential amplifier. The electronic processing is calibrated by means of a known electrostatic force and input from a finite-element model. The measured average kinetic energy, Eexp = (2.0 ± 0.3) × 10-21 J, is in agreement with the expected value of 1/2{{k}B}T.

  17. Flux depression and the absolute measurement of the thermal neutron flux density

    The thermal neutron flux depression in a diffusing medium by an absorbing foil has been treated in numerous papers. The results are re-examined in an attempt to find a uniform and physically meaningful representation of the 'activation correction'. This quantity can be split up into a combination of probabilities. Thus, it is possible to determine the activation correction for any moderator and foil material. Measurements confirm the utility of the concepts introduced

  18. Flux depression and the absolute measurement of the thermal neutron flux density

    The thermal neutron flux depression in a diffusing medium by an absorbing foil has been treated in numerous papers. The results are re-examined in an attempt to find a uniform and physically meaningful representation of the 'activation correction'. This quantity can be split up into a combination of probabilities. Thus, it is possible to determine the activation correction for any moderator and foil material. Measurements confirm the utility of the concepts introduced. (orig.)

  19. Absolute frequency measurement of the magnesium intercombination transition $^1S_0 \\to ^3P_1$

    Friebe, Jan; Riedmann, Matthias; Moldenhauer, Karsten; Mehlstäubler, Tanja; Rehbein, Nils; Lisdat, Christian; Rasel, Ernst M; Ertmer, Wolfgang; Schnatz, Harald; Lipphardt, Burghard; Grosche, Gesine

    2007-01-01

    We report on a frequency measurement of the $(3s^2)^1S_0\\to(3s3p)^3P_1$ clock transition of $^{24}$Mg on a thermal atomic beam. The intercombination transition has been referenced to a portable primary Cs frequency standard with the help of a femtosecond fiber laser frequency comb. The achieved uncertainty is $2.5\\times10^{-12}$ which corresponds to an increase in accuracy of six orders of magnitude compared to previous results. The measured frequency value permits the calculation of several other optical transitions from $^1S_0$ to the $^3P_J$-level system for $^{24}$Mg, $^{25}$Mg and $^{26}$Mg. We describe in detail the components of our optical frequency standard like the stabilized spectroscopy laser, the atomic beam apparatus used for Ramsey-Bord\\'e interferometry and the frequency comb generator and discuss the uncertainty contributions to our measurement including the first and second order Doppler effect. An upper limit of $3\\times10^{-13}$ in one second for the short term instability of our optical f...

  20. Measurements and calculations of doses from radioactive particles

    Three Mile Island (TMI) and Tchernobyl reactor accidents have revealed the importance of the skin exposure to beta radiation produced by small high activity sources, named 'hot particles'. In nuclear power reactors, they may arise as small fragments of irradiated fuel or material which have been neutron activated by passing through the reactor co. In recent years, skin exposure to hot particles has been subject to different limitation criteria, formulated by AIEA, ICRP, NCRP working groups. The present work is the contribution of CEA Grenoble to a contract of the Commission of the European communities in cooperation with several laboratories: University of Birmingham, University of Toulouse and University of Montpellier with the main goal to check experiments and calculations of tissue dose from 60Co radioactive particles. This report is split up into two parts: hot particle dosimetry close to a 60Co spherical sample with an approximately 200 μm diameter, using a PTW extrapolation chamber model 233991; dose calculations from two codes: the Varskin Mod 2 computer code and the Hot 25 S2 Monte Carlo algorithm. The two codes lead to similar results; nevertheless there is a large discrepancy (of about 2) between calculations and PTW measurements which are higher by a factor of 1.9. At a 70 μm skin depth and for 1 cm2 irradiated area, the total (β + γ) tissue dose rate delivered by a spherical ( φ = 200 μm) 60Co source, in contact with skin, is of the order of 6.1 10-2 nGy s-1 Bq-1. (author)

  1. Measurement of radioactive nuclides in the `Mayak` region

    Myasoedov, B.F. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Novikov, A.P. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    1997-03-01

    The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

  2. Measurements of Natural Radioactivity in Submicron Aerosols in Mexico City.

    Gaffney, J. S.; Marley, N. A.; Sterling, K.; Sturchio, N. C.

    2003-12-01

    Natural radionuclides can be useful in evaluating the transport of ozone and aerosols in the troposphere. Beryllium-7, which is produced by cosmic ray interactions in the upper troposphere and lower stratosphere and becomes adsorbed on fine aerosols, can be a useful indicator of upper air transport into a region. Lead-210 is produced by the decay of radon-222 out-gassed into the lower atmosphere from ground-based uranium deposits. Potassium-40, found in soils, can act as a measure of wind-blown dust and also comes from burning of wood and other biomass that is enriched in this natural radioisotope. Thus, both lead-210 and potassium-40 can aid in identification of aerosols sourced in the lower atmosphere. As part of our continuing interest in the lifetimes and sources of aerosols and their radiative effects, we report here measurements of fine aerosol radioactivity in Mexico City, one of the largest megacities in the world. Samples were collected on quartz fiber filters by using cascade impactors (Sierra type, Anderson Instruments) and high-volume air samplers from the rooftop of the main laboratory of El Centro Nacional de Investigacion y Capacitacion Ambiental (CENICA). By using stage 4 of the impactor and timers, we were able to collect integrated samples of sizes > 1 micrometer and < 1 micrometer over 12-hr time periods daily for approximately one month in April 2003. Samples were counted at the University of Illinois at Chicago by using state-of-the-art gamma counting (beryllium-7, 477.6 keV; potassium-40, 1460.8 keV; lead-210, 46.5 keV). The beryllium-7 data indicate one possible upper-air transport event during April 2003. As expected, the lead-210 data indicate very little soil contribution to the fine aerosol. The potassium-40 data showed an increase in fine aerosol potassium during Holy Week that might be attributed to local combustion of biomass fuels. The data will be presented and discussed in light of future data analysis and comparison with other

  3. Regularity of absolutely continuous invariant measures for piecewise expanding unimodal maps

    Contreras, Fabián; Dolgopyat, Dmitry

    2016-09-01

    Let f:[0,1]\\to [0,1] be a piecewise expanding unimodal map of class C  k+1, with k≥slant 1 , and μ =ρ \\text{d}x the (unique) SRB measure associated to it. We study the regularity of ρ. In particular, points N where ρ is not differentiable has zero Hausdorff dimension, but is uncountable if the critical orbit of f is dense. This improves on a work of Szewc (1984). We also obtain results about higher orders of differentiability of ρ in the sense of Whitney.

  4. New design of a microcalorimeter for measuring absolute heat capacity from 300 to 550 K

    Highlights: • A microcalorimeter (Cadd ∼ 6 μJ K−1) having a Si:N/SiO2 membrane was designed. • Concentric heater and sensor leads are useful for achieving better heat confinement. • Fabrication in one side of the membrane makes the process easy and cost-effective. • The lumped-τ2 model incorporating radiation effects was used to measure accurate Cp. • Measurement errors were confirmed to be less than 3% from 300 to 550 K. - Abstract: We report development of a new type of a microcalorimeter based on an amorphous membrane composed of Si:N and SiO2 layers, which holds an isothermal Au film of a disc shape and concentric Pt leads as a heater and a thermal sensor. Two-dimensional thermal simulation was used to confirm that the layout of the isothermal platform and metallic leads result in nearly perfect isothermal conditions at temperatures from 20 to 600 K. Moreover, by placing the insulating SiO2 layer between the isothermal film and metallic leads, we could locate all electrical and thermal components in the top side of the membrane, allowing the micro-fabrication easy and cost-effective. The micro-fabrication method produces a total of 49 devices in a four inch Si wafer and can be also applied in a larger wafer size. Heat capacity value of the isothermal platform was found to be as small as ∼6 μJ K−1 at room temperature. Upon applying the lumped-τ2 model in the measurement scheme, we found that specific heat of an Al2O3 single crystal (NIST standard, ∼0.2 mg) was consistent with the literature value within ∼3% at temperatures between 300 and 550 K. Our results show that the circular layout of the isothermal platform with better heat confinement is useful for increasing the accuracy of measured heat capacity if the other parameters such as thickness and thermal conductivity of each layer in the membrane are fixed

  5. New design of a microcalorimeter for measuring absolute heat capacity from 300 to 550 K

    Lee, Woong-Jhae; Kim, Hyung Joon; Kim, Jae Wook; Nam, Dong Hak; Choi, Ki-Young [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, Kee Hoon, E-mail: khkim@phya.snu.ac.kr [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of); Institute of Applied Physics, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2015-03-10

    Highlights: • A microcalorimeter (C{sub add} ∼ 6 μJ K{sup −1}) having a Si:N/SiO{sub 2} membrane was designed. • Concentric heater and sensor leads are useful for achieving better heat confinement. • Fabrication in one side of the membrane makes the process easy and cost-effective. • The lumped-τ{sub 2} model incorporating radiation effects was used to measure accurate C{sub p}. • Measurement errors were confirmed to be less than 3% from 300 to 550 K. - Abstract: We report development of a new type of a microcalorimeter based on an amorphous membrane composed of Si:N and SiO{sub 2} layers, which holds an isothermal Au film of a disc shape and concentric Pt leads as a heater and a thermal sensor. Two-dimensional thermal simulation was used to confirm that the layout of the isothermal platform and metallic leads result in nearly perfect isothermal conditions at temperatures from 20 to 600 K. Moreover, by placing the insulating SiO{sub 2} layer between the isothermal film and metallic leads, we could locate all electrical and thermal components in the top side of the membrane, allowing the micro-fabrication easy and cost-effective. The micro-fabrication method produces a total of 49 devices in a four inch Si wafer and can be also applied in a larger wafer size. Heat capacity value of the isothermal platform was found to be as small as ∼6 μJ K{sup −1} at room temperature. Upon applying the lumped-τ{sub 2} model in the measurement scheme, we found that specific heat of an Al{sub 2}O{sub 3} single crystal (NIST standard, ∼0.2 mg) was consistent with the literature value within ∼3% at temperatures between 300 and 550 K. Our results show that the circular layout of the isothermal platform with better heat confinement is useful for increasing the accuracy of measured heat capacity if the other parameters such as thickness and thermal conductivity of each layer in the membrane are fixed.

  6. Measuring the Absolute Height and Profile of the Mesospheric Sodium Layer using a Continuous Wave Laser

    Butler, D J; Redfern, R M; Ageorges, N; Fews, H

    2003-01-01

    We have developed and tested a novel method, based on LIDAR, of measuring the height and profile of the mesospheric sodium layer using a continuous wave laser. It is more efficient than classical LIDAR as the laser is on for 50% of the time, and so can in principle be used during laser guide star adaptive optics observations. It also has significant advantages over direct imaging techniques because it does not require a second telescope, is almost independent of the atmospheric conditions, and avoids triangulation problems in determining the height. In the long term, regular monitoring using this method would allow a valuable database of sodium layer profiles, heights, and return flux measurements to be built up which would enable observatory staff astronomers to schedule observations optimally. In this paper we describe the original experiment carried out using the ALFA laser guide star system at Calar Alto Observatory in Spain. We validate the method by comparing the LIDAR results with those obtained from s...

  7. Absolute activity measurement and gamma-ray emission probability for decay of I-126

    Fonseca, K A

    1997-01-01

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of sup 1 sup 2 sup 6 I, its importance lies mainly in fast neutron dosimetry as well as in the production of sup 1 sup 2 sup 5 I where sup 1 sup 2 sup 6 I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of sup 1 sup 2 sup 6 I have been measured. This radionuclide was obtained by means of the sup 1 sup 2 sup 7 I(n, 2n) sup 1 sup 2 sup 6 I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of sup 1 sup 2 sup 6 I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The beta branch measurement was carried out in a 4 pi(PC)beta-gamma coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch ...

  8. Absolute beginners

    Costa, Carlos Casimiro da; Costa, Jacinta Casimiro da

    2012-01-01

    Tomorrow, I m recovering my Thursday child as an absolute beginner , Transporting you to the essential touch of surface skin and space, Only for you, i do not regret, looking for education in a materia set. My love is your love , my materiality is you making things, The legacy of our ethnography, craftsmen s old and disappear, make me strong hard feelings, Recovering experiences and knowledge sprinkled in powder of stone, wood and metal ( ) reflecting in your dirty face the ...

  9. Radioactivity Measurement in the Detergent Products by Gamma Spectrometry

    Our study focuses on the evaluation of the level of radioactivity in the detergents. We have determined the specific activities of gamma emitting radionuclides belonging to the natural families of uranium, thorium and potassium using gamma spectrometry. The activities of radionuclides (235U, 238U, 226Ra, 232Th, 40K) and their descendants are below the minimum detectable activity for dishwasher products, soaps, bleaches and shampoos, whereas they are found to levels considered very low (between 0,2 and 13 Bq/kg on average) in the products washes linens. These values are always lower than those of raw materials, what is explained by the conservation of radioactive material throughout the manufacturing process. The effective dose due to external exposure estimated below the regulatory standard recommended (<1 mSv / year), allows us to show that detergent products are not contaminated by radioactivity, are healthy and do not have harmful radiological impact on the consumer.

  10. Absolute linearity measurements on a PV HgCdTe detector in the infrared

    Theocharous, Evangelos

    2012-04-01

    The linearity-of-response characteristics of a photovoltaic (PV) HgCdTe detector were investigated at a number of wavelengths in the infrared, using the NPL linearity of detector response characterization facility. The measurements were performed with the test detector operating under conditions identical to those in which the detectors will be used in typical infrared radiometric applications. The deviation from linearity in the generated photocurrent was shown to be strongly dependent on the area of the detector being illuminated. Plots of the linearity factor versus generated photocurrent for different illuminated wavelengths were shown to overlap. The linearity factor was shown to be a function of the photon irradiance of the illuminating beam. This behaviour was similar to that exhibited by photoconductive (PC) HgCdTe detectors, indicating that Auger recombination was the dominant source of the deviation from linearity observed in the test detector.

  11. Measurement of natural and 137Cs radioactivity concentrations at Izmit Bay (Marmara Sea), Turkey

    Öksüz, I.; Güray, R. T.; Özkan, N.; Yalçin, C.; Ergül, H. A.; Aksan, S.

    2016-03-01

    In order to determine the radioactivity level at Izmit Bay Marmara Sea, marine sediment samples were collected from five different locations. The radioactivity concentrations of naturally occurring 238U, 232Th and 40K isotopes and also that of an artificial isotope 137Cs were measured by using gamma-ray spectroscopy. Preliminary results show that the radioactivity concentrations of 238U and 232Th isotopes are lower than the average worldwide values while the radioactivity concentrations of the 40K are higher than the average worldwide value. A small amount of 137Cs contamination, which might be caused by the Chernobyl accident, was also detected.

  12. Measurement of radioactivity in building materials in Serbia

    This work presents a comprehensive study of natural radioactivity in 720 building materials imported in Serbia in 2012. Radioactivity concentrations of 226Ra, 232Th and 40K in the studied samples range from -1, respectively. The maximum values of 226Ra and 232Th activity concentrations were found in zirconium mineral, while the highest 40K activity concentration was in the feldspar. Based on the obtained radionuclide concentrations, radium equivalent activity, air absorbed dose rate, annual effective dose, external and internal hazard indices, gamma and alpha index due to radon inhalation were evaluated to assess the potential radiological hazard associated with these building materials. (author)

  13. Measurement of radioactive contamination in the foodstuffs by gamma spectrometry

    The Chernobyl nuclear reactor accident in 1986, resulted in the increase of radioactive contamination at a global level. To avoid undesirable exposure to public, Pakistan like other countries imposed radioactive contamination levels on food items. Various imported/to be exported and locally purchased food items for human consumption have been analysed for gamma emitting radionuclides. Amongst the food items, special attention was focussed on the imported dry milk. In addition to naturally occurring K-40 radionuclide, small amounts of Cs-137 and Cs-134 fission products have been detected in some of the samples. The concentrations of these two fission radionuclides are presented and compared with the relevant limits. (author)

  14. Absolute surface energy determination

    Metois, J. J.; Muller, P.

    2007-01-01

    Experimental determination of absolute surface energies remains a challenge. We propose a simple method based on two independent measurements on 3D and 2D equilibrium shapes completed by the analysis of the thermal fluctuation of an isolated step. Using then basic equations (Wulff' theorem, Gibbs-Thomson equation, thermodynamics fluctuation of an isolated step) allows us to extract the absolute surface free energy of a singular face. The so-proposed method can be applied when (i) all orientat...

  15. Stochastic Optimization for Portfolio Selection Problem with Mean Absolute Negative Deviation Measure

    Anton A. Kamil

    2009-01-01

    Full Text Available Problem statement: The most important character within optimization problem is the uncertainty of the future returns. Approach: To handle such problems, we utilized probabilistic methods alongside with optimization techniques. We developed single stage and two stage stochastic programming with recourse. The models were developed for risk adverse investors and the objective of the stochastic programming models is to minimize the maximum downside semi deviation. We used the so-called “Here-and-Now” approach where the decision-maker makes decision “now” before observing the actual outcome for the stochastic parameter. Results: We compared the optimal portfolios between the single stage and two stage models with the incorporation of the deviation measure. The models were applied to the optimal selection of stocks listed in Bursa Malaysia and the return of the optimal portfolio was compared between the two stochastic models. Conclusion: The results showed that the two stage model outperforms the single stage model in the optimal and in-sample analysis.

  16. USBM [United States Bureau of Mines] borehole deformation gage absolute stress measurement test procedure: Final draft

    The technique described herein for determining the magnitudes and directions of the in situ principal stresses utilizes the stress relief in a small volume of rock when it is physically isolated from the surrounding rock mass. Measurements of deformation are related to stress magnitudes through an understanding of the constitutive behavior of the rock. The behaviors of the non-salt strata around the ESF are expected to conform approximately to that of uniform homogeneous linear-elastic materials having either isotropic or transverse isotropic properties, for which constitutive relations are developed. The constitutive behavior of the salt strata is not well understood and so the overcoring technique yields information of only very limited use. For this reason the overcoring technique will not be used in the salt strata. The technique has also limited application in rocks containing joints spaced less than 8 in. (0.2 m) apart, unless a large number of test can be performed to obtain, a good statistical average. However, such unfavorably discontinuous rocks are not expected as a norm at the Deaf Smith County site. 7 refs., 22 figs., 4 tabs

  17. Measuring absolute frequencies beyond the GPS limit via long-haul optical frequency dissemination

    Clivati, C; Livi, L; Poggiali, F; de Cumis, M Siciliani; Mancini, M; Pagano, G; Frittelli, M; Mura, A; Costanzo, G A; Levi, F; Calonico, D; Fallani, L; Catani, J; Inguscio, M

    2015-01-01

    Global Positioning System (GPS) dissemination of frequency standards is ubiquitous at present, providing the most widespread time and frequency reference for the majority of industrial and research applications worldwide. On the other hand, the ultimate limits of the GPS presently curb further advances in high-precision, scientific and industrial applications relying on this dissemination scheme. Here, we demonstrate that these limits can be reliably overcome even in laboratories without a local atomic clock by replacing the GPS with a 642-km-long optical fiber link to a remote primary caesium frequency standard. Through this configuration we stably address the $^1$S$_0$---$^3$P$_0$ clock transition in an ultracold gas of $^{173}$Yb, with a precision that exceeds the possibilities of a GPS-based measurement, dismissing the need for a local clock infrastructure to perform high-precision tasks beyond GPS limit. We also report an improvement of two orders of magnitude in the accuracy on the transition frequency ...

  18. Characteristics and Measurement of Radioactivity and Radiation Levels. Annex I of Technical Volume 4

    This annex provides background information on the quantities and units used in radiation protection and an introduction to the characteristics of radioactive material. Discussed are also their dispersion and deposition in the terrestrial environment and their measurement as well as the assessment of the resulting exposure due to ionizing radiation emitted by radioactive material

  19. MDA trend research on radioactive xenon measurement by HPGe γ spectrometer

    Monitoring radioactive Xenon concentration in air is effective way to screen nuclear event in CTBT verification regime. This article introduces the theory and process of radioactive Xenon measurement by HPGe gamma spectrometer and researches MDA trend of Xenon isotope base on background data. (authors)

  20. Development of Radioactive Inventory Evaluation System using 3D Shape and Multiple Radiation Measurement

    The increase of the operating NPPs and the superannuation of the equipment in NPPs cause a large amount of the metal radioactive waste. Presently the metal radioactive wastes are stored in the temporary storage facility in NPPs because of the delay of the construction of the final disposal facility. The radioactive level of general metal radioactive wastes is low, and the radioactive level can be lowered by the simple decontamination process. If the radioactive wastes are disposed as the industry waste, the disposal cost is diminished largely. For the disposal of the radioactive wastes as the industrial wastes, the radioactive level of the target wastes are evaluated. It is difficult to know the position of the source term for most of the metal radioactive and the source term is distributed non-homogeneously. And the self-shielding effect of the metal material makes the evaluation more difficult. In this study, the radioactive inventory evaluation system for the metal radioactive waste is developed. For the correction of the uncertainty of the position and the non-homogeneity of the source term, the 3D shape and multiple radiation measurement are used. The existing gamma-ray measurement system for the metal radioactive waste cannot reflect the position and the distribution of the source term and the effect of self-shielding. This evaluation system suggested in this system can calculate the reasonable value regarding to the position and the distribution of the source term and the effect of self-shielding. By the calculation of the partial inventory of the target metal waste, the advantage in the application of the clearance criteria can be obtained

  1. The lessons learnt from a series of radioactivity measurement intercomparison exercises

    Over the past decade, the National Physical Laboratory (NPL) has run a number of intercomparison exercises, aimed at those laboratories making measurements of radioactivity at environmental levels. The need for such intercomparisons were initially driven by the Chernobyl accident and it's aftermath. Immediately after the accident, many measurements were made of radioactivity in the UK environment, but the lack at that time of a coordinated programme of measurements, feeding into a dissemination centre did nothing to improve public confidence in such measurements. This situation was remedied by the Department of the Environment (DoE) in the years following Chernobyl. In the longer term this perceived (and in most cases, undeserved) lack of public confidence in 'official' data led many laboratories in the UK, with no statutory need to measure radioactivity, to equip themselves to be able to make measurements of radioactivity in food and other environmental materials

  2. Low level air radioactivity measurements in Prague, Czech Republic

    Rulík, P.; Malá, H.; Bečková, V.; Hölgye, Z.; Schlesingerová, E.; Světlík, Ivo; Škrkal, J.

    2009-01-01

    Roč. 67, - (2009), s. 969-973. ISSN 0969-8043 Institutional research plan: CEZ:AV0Z10480505 Keywords : atmospheric radionuclides * monitoring * low level activities Subject RIV: DL - Nuclear Waste, Radioactive Pollution ; Quality Impact factor: 1.094, year: 2009

  3. Measures to prevent breaches in the security of radioactive materials

    The objective of this paper, which is the result of the co-operation between the Swedish Board of Customs, the Swedish Radiation Protection Institute, the Security Police and the Swedish Nuclear Power Inspectorate, is to give an idea of the national prevention system as to illicit trafficking of nuclear materials and other radioactive sources. (author)

  4. Application of the permeation to the production of low radioactive calibrated gas flows. Low radioactive tritium measurement

    The permeation of compounds (HT, HTO, 131ICH3, and 129ICH3) through organic membranes in view of producing low radioactive calibrated gas flows has been studied. This process of which the diffusion is the main stage enables respecting certain conditions (choice of the membrane, temperature, partial pressure differential) our aims to be reached with a good accuracy. In order to measure radioactivity of tritiated standard gases, a detector was built. This detector is an Oeschger type proportional counter with a total volume of 17.4 dm3 and an useful volume of 3.9 dm3. In the conditions of operation, the background is of 1.7.10-6 I s-1 cm-3. The counter coupled with a feed-rack enables various samples to be measured and it is possible in the best conditions to detect some 10-11 μCi cm-3 NTP

  5. Measuring Radioactivity from Fukushima Daiichi in New Mexico

    On March 11, 2011, the Fukushima Daiichi nuclear power plant was damaged by the tsunami that followed the 'Great East Japan Earthquake,' and the reactor subsequently leaked radioactive material. In response, LANL augmented the routine ambient (AIRNET) and stack (Rad-NESHAP) measurements with three high-volume samplers: No.167 at the Old White Rock Fire Station; No.173 at the TA-49 gate, and No.211 at the Los Alamos Medical Center. Previous accidents, such as the Three-Mile-Island accident in 1979 and the Chernobyl accident in 1986, indicated that the most likely releases were (a) the noble gases: krypton and xenon; and (b) the volatile elements: cesium, tellurium, and iodine. At the latitude of Fukushima, the predominant winds across the Pacific Ocean are from west to east, and models predicted that the plume would arrive in the western US on about March 18. By this time the shorter-lived isotopes would have decayed. Therefore, the expected radionuclides were xenon-133, cesium-134, cesium-136, cesium-137, tellurium-132, iodine-131, and iodine-132. As expected, cesium-134, cesium-136, cesium-137, tellurium-132, iodine-131, and iodine-132 were all detected by all three high-volume samplers during March 17-21. The concentrations peaked during the March 24-28 period. After this, concentrations of all nuclides declined. In general, the concentrations were consistent with those measured by the EPA RadNet system and many other monitoring systems throughout the world. At the time of writing, preliminary results from the AIRNET and Rad-NESHAP systems are being reported. More detailed results are described in LA-UR-11-10304 and will be reported in full in the annual environmental report for 2011. All previous releases from nuclear reactors have been dominated by noble gases, primarily krypton and xenon, which are not measured by the high-volume samplers or the AIRNET system. However, in sufficient concentrations these and other fission products would be detected by NEWNET

  6. International intercomparison for radioactivity measurements of environmental samples during past decade

    During the period 1985-1994 our laboratory participated in a series of international intercomparison activities of radioactivity measurements sponsored respectively by WHO IRC, IAEA AOCS and IAEA MEL, with 20 samples measured in total. This paper describes the intercomparison activities concerned during past decade, methods of analysis and measurement, and measurement results. Some problems involved in measurements was discussed. (author)

  7. Absolute measurements of the electronic transition moments of seven band systems of the C2 molecule. Ph.D. Thesis - York Univ., Toronto

    Cooper, D. M.

    1979-01-01

    Electronic transition moments of seven C2 singlet and triplet band systems in the 0.2-1.2 micron spectral region were measured. The measurements were made in emission behind incident shock waves in C2H2-argon mixtures. Narrow bandpass radiometers were used to obtain absolute measurements of shock-excited C2 radiation from which absolute electronic transition moments are derived by a synthetic spectrum analysis. New results are reported for the Ballik-Ramsay, Phillips, Swan, Deslandres-d'Azambuja, Fox-Herzberg, Mulliken, and Freymark systems.

  8. Systematic Uncertainties in the Spectroscopic Measurements of Neutron-Star Masses and Radii from Thermonuclear X-ray Bursts. III. Absolute Flux Calibration

    Guver, Tolga; Ozel, Feryal; Marshall, Herman; Psaltis, Dimitrios; Guainazzi, Matteo; Diaz-Trigo, Maria

    2015-01-01

    Many techniques for measuring neutron star radii rely on absolute flux measurements in the X-rays. As a result, one of the fundamental uncertainties in these spectroscopic measurements arises from the absolute flux calibrations of the detectors being used. Using the stable X-ray burster, GS 1826-238, and its simultaneous observations by Chandra HETG/ACIS-S and RXTE/PCA as well as by XMM-Newton EPIC-pn and RXTE/PCA, we quantify the degree of uncertainty in the flux calibration by assessing the...

  9. Absolute Summ

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  10. Measures to radioactive contamination connected with nuclear power generation

    The problems on the environmental radioactivity due to nuclear power generation must be dealt with not only as the local problems in the regions around nuclear power plants but also as the environmental acitivity problems in global scale. Human security and protection are maintained by the regulation of releasing radioactive materials to the environment from all the facilities, not limited to nuclear power plants and nuclear fuel reprocessing plants, and the safety control of environmental activity. The fundamental concept of the regulation and control of environmental activity and each system taken in U.K., U.S. and Japan are described first. Next, the present status of releasing radioactivity into the air and water in the world is explained in detail and the minute data are shown for the release into water. The underground and deep ocean disposals of solid wastes are described with calculation formulae obtained so far. Since the information on the aspect of exposure of human body to natural radiation is important for comparison when the influence of artificial activity is evaluated, the survey of the natural radiation and the conditions of activity due to nuclear tests and the peaceful uses of atomic energy are described, respectively. In Japan, the special committee on environmental safety investigated the possibility of materializing the numerical guide to ''as low as practicable'', and submitted the report showing ''target dose'' in light water reactor nuclear power plants to the Atomic Energy Comission of Japan, in which the dose for whole body exposure is proposed as 5 m rem/year and that for thyroid gland exposure due to radioactive iodine as 15 m rem/year. (Wakatsuki, Y.)

  11. The 1993 Intercomparison of the Measurement of In Vivo Radioactivity

    Kramer, G.H.; Loesch, R.M.; Olsen, P.C

    1999-07-01

    The Canadian National Calibration Reference Centre for In-Vivo Monitoring and the United States Department of Energy collaborated to offer an international intercomparison programme to whole-body counting facilities in 1993. The Human Monitoring Laboratory fabricated a phantom shell corresponding to a reference four-year-old child and Battelle Pacific Northwest National Laboratory filled the shell with radioactive tissue substitute polyurethane to simulate a uniform natural radioactivity and fission product distribution in soft tissues ({sup 40}K, {sup 88}Y, {sup 137}Cs). Participants were not informed of the radioactive content and were asked to determine the identity and amount of the radionuclides in the energy range 200-2000 keV. Although all nuclides were identified correctly, most participantsreported activities for {sup 88}Y and {sup 137}Cs only. Each facility was asked to make an estimate of the 'worst case' precision and estimate their minimum detectable activity. The programme had 35 participants from 18 countries for a total of 43 counting systems. The programme began in April 1993 and ended on 1 August 1995. The intercomparison has shown that all whole-body counters are phantom-size dependent and that size-dependent calibration factors should be used. The scanning bed geometry is less size-dependent than the other geometries when only the standard (man-sized) calibration factors are used; however, when applied, size correction factors remove this geometrical advantage and all configurations perform equally well. (author)

  12. Use of airborne radiometric measurements for monitoring environmental radioactive contamination

    The technique of airborne gamma spectrometry has many advantages over conventional ground based monitoring methods in the mounting of a time constrained response to an accident involving a release of radioactive material into the environment. The paper reviews the basis and background of the method, with an emphasis on the role that detector and nucleonics development plays in determining capabilities. The main features of detector response are briefly discussed, including nuclide specificity, circles of investigation and sensitivity. Identification of distributed and point sources of radioactivity is potentially of interest and leads to differing survey requirements. The relative merits and limitations of calibration methods are also reviewed. Practical examples of the use of aerial methods in the United Kingdom are given, including surveys conducted by the Scottish Universities Research and Reactor Centre using fixed wing and rotary wing aircraft in Scotland and west Cumbria in the aftermath of the Chernobyl accident. The results clearly show the potential of aerial methods for guiding ground based work in the recovery phase of an accident involving release of radioactivity to the environment. Further needs include baseline studies, technical developments and improved knowledge of nuclide mobility and transfer factors. (author). 25 refs, 1 fig., 2 tabs

  13. The 1993 Intercomparison of the Measurement of In Vivo Radioactivity

    The Canadian National Calibration Reference Centre for In-Vivo Monitoring and the United States Department of Energy collaborated to offer an international intercomparison programme to whole-body counting facilities in 1993. The Human Monitoring Laboratory fabricated a phantom shell corresponding to a reference four-year-old child and Battelle Pacific Northwest National Laboratory filled the shell with radioactive tissue substitute polyurethane to simulate a uniform natural radioactivity and fission product distribution in soft tissues (40K, 88Y, 137Cs). Participants were not informed of the radioactive content and were asked to determine the identity and amount of the radionuclides in the energy range 200-2000 keV. Although all nuclides were identified correctly, most participants reported activities for 88Y and 137Cs only. Each facility was asked to make an estimate of the 'worst case' precision and estimate their minimum detectable activity. The programme had 35 participants from 18 countries for a total of 43 counting systems. The programme began in April 1993 and ended on 1 August 1995. The intercomparison has shown that all whole-body counters are phantom-size dependent and that size-dependent calibration factors should be used. The scanning bed geometry is less size-dependent than the other geometries when only the standard (man-sized) calibration factors are used; however, when applied, size correction factors remove this geometrical advantage and all configurations perform equally well. (author)

  14. Natural Radioactivity Measurements and Radiation Dose Estimation in Some Sedimentary Rock Samples in Turkey

    Akkurt, I.; K. Günoğlu

    2014-01-01

    The natural radioactivity existed since creation of the universe due to the long life time of some radionuclides. This natural radioactivity is caused by γ-radiation originating from the uranium and thorium series and 40K. In this study, the gamma radiation has been measured to determine natural radioactivity of 238U, 232Th, and 40K in collected sedimentary rock samples in different places of Turkey. The measurements have been performed using γ-ray spectrometer containing NaI(Tl) detector and...

  15. Measurement of radioactivity in the environment - Soil - Part 1: General guidelines and definitions

    This part of ISO 18589 specifies the general requirements to carry out radionuclides tests on soil sample, including sampling. This part of ISO 18589 is addressed to people responsible for determining the radioactivity present in soils for the purpose of radiation protection. This may concern soils from gardens and farmland, urban or industrial sites, as well as soil not affected by human activities. This part of ISO 18589 is applicable to all laboratories regardless of the number of personnel or the extent of the scope of testing activities. When a laboratory does not undertake one or more of the activities covered by this part of ISO 18589, such as planning, sampling or testing, the requirements of those clauses do not apply. This part of ISO 18589 is to be used in conjunction with other parts of ISO 18589 that outline the setting up of programmes and sampling techniques, methods of general processing of samples in the laboratory and also methods for measuring the radioactivity in soil. Its purpose is the following: - define the main terms relating to soils, sampling, radioactivity and its measurement; - describe the origins of the radioactivity in soils; - define the main objectives of the study of radioactivity in soil samples; - present the principles of studies of soil radioactivity; - identify the analytical and procedural requirements when measuring radioactivity in soil. This part of ISO 18589 is applicable if radionuclide measurements for the purpose of radiation protection are to be made in the following cases: - initial characterization of radioactivity in the environment; - routine surveillance of the impact of nuclear installations or of the evolution of the general territory; - investigations of accident and incident situations; - planning and surveillance of remedial action; - decommissioning of installations or clearance of materials. This part of ISO 18589 is not intended to cover scientific investigations of soil radioactivity and therefore does

  16. A critical review of measures to reduce radioactive doses from drinking water and consumption of freshwater foodstuffs

    Smith, Jim; Voitsekhovitch, O.; Hakanson, L.; Hilton, J.

    2001-01-01

    Following a radioactive fallout event, there are a number of possible intervention measures to reduce radioactive doses to the public via the surface water pathway. We have critically reviewed the options available to decision-makers in the event of radioactive contamination of surface waters. We believe that the most effective and viable measures to reduce radioactivity in drinking water are those which operate at the water treatment and distribution stage. Intervention measures to reduce co...

  17. Exact method for determining subsurface radioactivity depth profiles from gamma spectroscopy measurements

    Van Siclen, Clinton DeW

    2011-01-01

    Subsurface radioactivity may be due to transport of radionuclides from a contaminated surface into the solid volume, as occurs for radioactive fallout deposited on soil, or from fast neutron activation of a solid volume, as occurs in concrete blocks used for radiation shielding. For purposes including fate and transport studies of radionuclides in the environment, decommissioning and decontamination of radiation facilities, and nuclear forensics, an in situ, nondestructive method for ascertaining the subsurface distribution of radioactivity is desired. The method developed here obtains a polynomial expression for the radioactivity depth profile, using a small set of gamma-ray count rates measured by a collimated detector directed towards the surface at a variety of angles with respect to the surface normal. To demonstrate its capabilities, this polynomial method is applied to the simple case where the radioactivity is maximal at the surface and decreases exponentially with depth below the surface, and to the ...

  18. Absolute sensitivity calibration of vacuum and extreme ultraviolet spectrometer systems and Z(eff) measurement based on bremsstrahlung continuum in HL-2A tokamak.

    Zhou, Hangyu; Cui, Zhengying; Morita, Shigeru; Fu, Bingzhong; Goto, Motoshi; Sun, Ping; Dong, Chunfeng; Gao, Yadong; Xu, Yuan; Lu, Ping; Yang, Qingwei; Duan, Xuru

    2012-10-01

    A grazing-incidence flat-field extreme ultraviolet (EUV) spectrometer has been newly developed in HL-2A tokamak. Typical spectral lines are observed from intrinsic impurities of carbon, oxygen, iron, and extrinsic impurity of helium in the wavelength range of 20 Å-500 Å. Bremsstrahlung continuum is measured at different electron densities of HL-2A discharges to calibrate absolute sensitivity of the EUV spectrometer system and to measure effective ionic charge, Z(eff). The sensitivity of a vacuum ultraviolet (VUV) spectrometer system is also absolutely calibrated in overlapped wavelength range of 300 Å-500 Å by comparing the intensity between VUV and EUV line emissions. PMID:23126850

  19. Measurement of radioactivity induced by GeV-protons and spallation neutrons using AGS accelerator

    Measurement of radioactivity induced by high-energy protons with energy of 2.83 and 24 GeV and spallation neutrons produced by bombarding a mercury target with the high-energy protons were performed by using the AGS (Alternative Gradient Synchrotron) accelerator at Brookhaven National Laboratory. The samples of boron, carbon, aluminum, iron, copper, niobium, mercury-oxide, lead, bismuth, acrylic resin, SS-316, Inconel-625 and Inconel-718 were irradiated around the mercury target. After the irradiation, the radioactivity of each sample was measured by using HPGe detectors at the cooling time between 2 h and 200 d. In the processing of the measured γ-ray spectra, more than 90 radioactive nucleus were identified, and the radioactivity production data were obtained. This report gives the experimental procedure, the data processing and the experimental results. (author)

  20. Experimental ship fire measurements with simulated radioactive cargo

    Results from a series of eight test fires ranging in size from 2.2 to 18.8 MW conducted aboard the Coast Guard fire test ship Mayo Lykes at Mobile, Alabama are presented and discussed. Tests aboard the break bulk type cargo ship consisted of heptane spray fires simulating engine room and galley fires, wood crib fires simulating cargo hold fires, and pool fires staged for comparison to land based regulatory fire results. Primary instrumentation for the tests consisted of two pipe calorimeters that simulated a typical package shape for radioactive materials packages

  1. Comparison of a citation-based indicator and peer review for absolute and specific measures of research-group excellence

    Mryglod, O; Holovatch, Yu; Berche, B

    2013-01-01

    Many different measures are used to assess academic research excellence and these are subject to ongoing discussion and debate within the scientometric, university-management and policy-making communities internationally. One topic of continued importance is the extent to which citation-based indicators compare with peer-review-based evaluation. Here we analyse the correlations between values of a particular citation-based impact indicator and peer-review scores in several academic disciplines, from natural to social sciences and humanities. We perform the comparison for research groups rather than for individuals. We make comparisons on two levels. At an absolute level, we compare total impact and overall strength of the group as a whole. At a specific level, we compare academic impact and quality, normalised by the size of the group. We find very high correlations at the former level for some disciplines and poor correlations at the latter level for all disciplines. This means that, although the citation-ba...

  2. Study of a 4πβ-γ coincidence system for absolute radionuclide activity measurement using plastic scintillators

    The present work was intended to study a coincidence system 4π(PS)β-γ for absolute activity measurement using plastic scintillators in 4π geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4π(PS)β-γ and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author)

  3. Radioactive fallout in the South Pacific: a history Part 2: radioactivity measurements in the Pacific islands

    This report summarises results of the environmental radioactivity monitoring programme maintained in the Pacific islands by the National Radiation Laboratory (NRL) since 1961. Monitoring was commenced during the nuclear weapons tests at Christmas Island, then extended to a greater number of sites during the French atmospheric tests at Mururoa during 1966-1974 and maintained at that level until 1985 when the network was scaled down to its pres the monitoring of the French tests as the largest local source of short-lived fallout. These pacific monitoring operations during the period of 1960 to 1990 are reviewed which brings together and summarises the extensive compilation of data comprising 70 NRL report published during the period. An attempt is also made to correct the original data for decay between sampling and analysis. The average effective dose commitment for the South Pacific island population due to the entire history of atmospheric weapons tests is estimated to be 1.1 milli sievert.(author). 17 refs., 23 figs., tabs., ills

  4. Comparative measurements of plant radioactivity in the Agrobotanical Garden and experimental fields

    Attila T. SZABO

    1986-08-01

    Full Text Available In order to demonstrate the usefulness of the Garden's Catalogue in unforeseen situations, the radioactivity of some plant species cultivated on different plots of the Agrobotanical Garden has been measured in May 1986. Comparative measurements have been carried out on species harvested from the experimental fields Sapca-Verde (Cluj-Napoca and from a collection trip in Tulcea county (Tulcea, Babadag, too. A monocanal energy spectrometer NK-350 (Gamma has been used for measurements; impulses per minute have been registered and plant radioactivity expressed in Becquerel (Bq units has been calculated. The highest values have been measured in the Agrobotanical Garden (alt. s.m. 475 m, incl. about 200 , exp. NE. Small-leaved low stature plants of Cyperaceae and Poaceae family have been much more radioactive than large-leaved Brassicaceae. In 28th May 1986 plants were generally more radioactive at basis as on top; older stems were 4-6 times more radioactive than top leaves or regrowth after harvest. Washing in running water (100 gr fresh weight in 50 l water for 5 minutes reduced the radioactivity levels measured in different species with about 30%.

  5. Rapid measurement of 89,90Sr radioactivity in rinse water.

    Masashi, Takada; Hiroko, Enomoto; Toshikazu, Suzuki

    2013-03-01

    Rapid measurement of radioactivity from Sr in aqueous solutions is performed using a technique combining a strontium rad disk and a picobeta spectrometer. Identification of Sr radionuclides is accomplished in as little as 90 min in a radiation-tainted solution that contains more highly radioactive cesium. It is possible to perform triage by assessing skin exposure doses in this short time. This simple technique could be used in mobile laboratories. Sr having 1 Bq radioactivities are measured in 10 kBq Cs in aqueous solution. The radioactivity contained in rinse water used to decontaminate the feet of workers who stepped into highly contaminated water in the basement of the turbine building of Unit 3 at the Fukushima Daiichi nuclear power station was measured. The amount of Sr radioactivity in rinse water using the authors' rapid measurement technique (0.29 Bq mL) and a traditional method agree well, with 3.6% difference. Based on this agreement, this technique is confirmed to be useful for rapid measurement of Sr radioactivities. PMID:23361426

  6. PC based system for absolute neutron flux-spectrum measurements. Final report for the period 1 April 1994 - 15 December 1997

    When measuring absolute neutron flux-spectra, thin detector foils are irradiated in a neutron field. The absolute activity of isotopes generated by activation or fission reactions (fission products) is then measured, using an efficiency calibrated high resolution gamma-ray spectroscopy system, and the absolute reaction rates for their production is determined. Finally the flux-spectrum is determined based upon the reaction rate values. A general method to obtain flux-spectra from the reaction rate is the unfolding method. The above process involves computations of photopeak area, reaction rate, flux perturbation corrections and flux-spectrum. The PC's are well suited for the data processing system outlined above. Using available interfaces, the PC's can be involved even in the data acquisition. Graphical facilities allow decision upon the data processing flow

  7. Measures to ensure safety of radioactive materials in India

    In India, the use of ionizing radiation sources in industry, medicine, agriculture and research registered a significant increase during recent years. The basis of legislative control of the use of radiation in India is the Atomic Energy Act from 1962, which empowers the central Government to provide control over radioactive substances. Exercising these powers, the central Government has promulgated several radiation safety rules, which specify the requirements of licensing, the duties and responsibilities of radiation safety officers, powers of inspection, etc. Later in 1983, by the Act, the Atomic Energy Regulatory Board (AERB) was constituted by the central Government to exercise regulatory and safety functions. The report describes the existing system of regulatory control of radiation sources in India and in particular, refers to the regulatory documents prepared by the AERB, the type approval of radiation equipment, the regulatory consent for every person handling radioactive sources, and the inspection activities and enforcement of regulatory actions. The report also explains how management of disused sources is carried out in India, including the handling of accidents and emergency activities. (author)

  8. Correlation between measured gas leaks and possible loss of contents from radioactive materials packagings

    For a radioactive materials package, correlations between possible aperture size (the opening or fault induced by environmental testing) and radioactive material sizes are useful to confirm test evidence when that evidence demonstrates no loss or very small loss of radioactive material through specific seals and joints at measured leak rates. For the smaller leak rates that were actually measured following severe tests of containment vessel seals, such as 10-5 atm cm3/s, the approximated fault or aperture (crack height in the seal) is molecular and sub-particulate in size. Containment was predicted and was achieved. In the case of well designed seals and joints for the contianment of radioactive materials, very large leak rates (such as 10-2 to 10-4 atm cm3/s air or helium) may be associated with a fault or aperture (crack height in the seal) that is still smaller than the particulate size of the solid-form radioactive material being contained. In a specific case, containment was predicted and was achieved. This indicates that large post-accident-test gas leak rates in radioactive materials packagings, when associated with a well-designed seal and joint, may be supportive of the adequate containment of radioactive materials

  9. Measurement of radioactivity in the atmosphere and pollution nearby an atomic centre

    The French Atomic Energy Commission (CEA) is particularly interested in studies on atmospheric radioactivity by reason of the necessity to control the atmosphere nearby nuclear plants as uranium mines, nuclear reactors and hot laboratories or radioactive materials treatment plants. Thus, the CEA developed different apparatus to control and monitor the atmosphere nearby its sites. These air monitors are essentially of two types: the first one, called 'Babar', monitors smokes, fogs and dusts, the second type is an ionization chamber and measures the concentration of radioactive gas in the air. The functioning and sensitivity of these two systems are discussed. (M.P.)

  10. Concept and measures of radioactive liquid effluents 'near-zero release' in inland nuclear power plants

    The radioactive liquid effluents of inland NPPs are discharged into inland surface water. In order to better protect the public and environment, the Chinese national standards, GB 6249-2011 and GB 14587-2011, put forward more stringent requirements on release concentrations of inland NPPs than that of coastal NPPs. It means in fact a target of 'near-zero release' of radioactive liquid effluents for inland NPPs. This paper sets forth the concept of 'near-zero release' of radioactive liquid effluents for inland NPPs, and also describes measures that should be taken to achieve this target. (authors)

  11. Measurement Of Radioactivity Levels And Assessment Of Radioactivity Hazards Of Soil Samples İn Karaman, Turkey

    Ağar, O.; Boztosun, I.; Korkmaz, M E; Özmen, S. F.

    2014-01-01

    In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the 238U series (226Ra, 214Pb and 214Bi), 232Th series (228Ac), 40K and fission product 137Cs are discussed. To evaluate the radiological ...

  12. Automated station for the measurement of the total beta radioactivity in the air

    An automatic station for measuring the beta total radioactivity of air has been designed. The station consists in an intake section with a capacity of 384 cubic metres of air a day and a glass fibre ribbon filter and in a detection section with three shielded Geiger counters, a plastic beta detector and a NaI (Tl) crystal detector. This stage is linked to the counting section that processes the data and outputs the values of the radioactivity minimum, mean and maximum. The minimum radioactivity measurable is almost 0.015 pC; for such a radioactivity the relative error is 45%. For the mean values the relative error amounts to almost 10%. This station is therefore particularly reliable for its high sensitivity and for the little relative error

  13. Possibility of gas flow measurements using ionization produced by radioactive sources. Performance obtained using continuous and pulsed ionization

    Two methods for measuring gas flow have been studied, based on the ionization of the fluid by a radioactive source. In the first one, called the continuous method, use is made of the relationship between the flow and the ionic density at a point situated down-stream from the ionizing source. In the second method, called 'pulsed', the time for a burst of ions to pass between two points in the circuit is measured. An attempt has been made to predict and to justify theoretically the experimental results, and to determine to what extent these methods can provide absolute measurements or measurements requiring a calibration using known gas flows. These methods are characterized by the absence of moving parts or of parts under reduced pressure and can yield results with an accuracy of between a few per cent to a few tenths of a per cent. The information, provided in either analog or digital form, can be adapted for use in servo-mechanisms or automatic systems. Two applications of an industrial type are described; they concern gas-flow measurements in a railway braking circuit, and in tubes of 20 and 30 cm diameter. (author)

  14. The measurement of natural radioactivity and the impact on humans

    Faanhof, A.

    2000-02-01

    Naturally occurring radioactive materials (NORM) are quite common in the South African mining and mineral processing industry, even so that uranium is produced as a by-product at certain gold mines. Other major industries associated with NORMs are the coal, copper and heavy mineral sectors. Legislation in South Africa addresses the allowed yearly radiation dose to registered radiation workers and the general public, and adheres to the most common internationally accepted standards of 20 mSvSv/a. This imposes severe constraints on the radioanalytical laboratory to offer an affordable routine service due to the required sensitivity to analyse these NORMs and the variety of matrices involved. Evaluation of the available radioanalytical infrastructure, the yearly intake and the generally accepted dose conversion factors allow the laboratory to provide proper service designs to enable meaningful radiological hazard evaluation.

  15. Radioactivity measurement in Austria 1994 and 1995. Data and evaluation

    This report presents results of the radiation surveillance in Austria in the years 1994 and 1995, performed by the former Federal Ministry of Health and Consumer Protection, based on the Austrian Radiation Protection Act. In particular data of large scale monitoring concerning radioactive contaminations and of nuclear research reactor emission and immission control are given. By revision of the Federal Ministry Act the competence for these tasks has been turned over to the General Directorate VI of the Federal Chancellery. For the purpose of large scale surveillance on one hand an Early Radiation Warning System comprised of 336 gamma dose rate monitors is operated by the Federal Chancellery. The data are automatically communicated to various authorities in real-time. On the other hand the radionuclide content of various media such as air, precipitation, surface water, foodstuffs etc. is monitored via periodic sampling and analysis in the laboratory. In addition to this routine program special projects are carried out for investigation of specific media and to improve the knowledge of the time dependence respectively of regional aspects of the contamination situation. In the years 1994 and 1995 the average annual radiation exposure of the Austrian population amounted to about 4.6 mSv effective dose. The contributions dominating by far originate from natural and medical sources of radiation. Contributions of all other sources of radiation are extremely small in comparison with these. The average annual effective dose caused by natural radiation amounts to approximately 3.2 mSv. The inhalation of the radioactive noble gas radon and its short lived progeny in the mean contributes more than half to this exposure, but considerable variations occur. There are regions with particular geological conditions where the exposure due to radon by far exceeds all other exposures. (author)

  16. Measures Against-Illicit Trafficking of Nuclear Materials and Other Radioactive Sources

    Since the early nineties, illicit trafficking (IT) of nuclear materials and radioactive sources appeared as a new trend which raised the concern of the international community due to the grave consequences that would merge if these materials or radioactive sources fell into the hands of terrorist groups. However, by the end of the last century illicit trafficking of nuclear materials and radioactive sources lost its considerable salience, in spite of seizure of considerable amounts of 2'3'5U (76% enrichment) in Bulgaria (May 1999) and also 235U (30% enrichment) in Georgia (April 2000). Nevertheless, IT should be always considered as a continued and viable threat to the international community. Awareness of the problem should be developed and maintained among concerned circles as the first step towards combating illicit trafficking of nuclear materials and radioactive sources. Illicit trafficking of nuclear and radioactive materials needs serious consideration and proper attention by the governmental law enforcement authorities. Measures to combat with IT of nuclear material or radioactive sources should be effective in recovery, of stolen, removed or lost nuclear materials or radioactive sources due to the failure of the physical protection system or the State System Accounting and Control (SSAC) system which are normally applied for protecting these materials against illegal actions. Measures such as use of modern and efficient radiation monitoring equipment at the borders inspection points, is an important step in preventing the illicit trafficking of nuclear and radioactive materials across the borders. Also providing radiological training to specific personnel and workers in this field will minimize the consequences of a radiological attack in case of its occurrence. There is a real need to start to enter into cooperative agreements to strengthen borders security under the umbrella of IAEA to faster as an international cooperation in the illicit trafficking of

  17. International measures needed to protect metal recycling facilities from radioactive materials

    . The government of every country that licences the use of radioactive material should institute a program to determine both the location of every known source and the effectiveness of current controls over that source. (ii) Control of orphaned material. Each government should institute a program for the safe removal and control of orphaned radioactive sources and material without penalty to the individual that has unintentionally received it. (iii) Transportation rules. International agreements should be developed that allow discovered radioactive material to be easily yet safely transported to either its point of origin or to a facility for its safe disposal. (iv) Registry of events. An international mechanism should be developed for the documentation and reporting of radiation related incidents and the discovery of potentially orphaned radioactive sources and material. (v) Universal measurements. There are several highly technical ways to describe radioactivity. None of these can be easily understood by the individuals who may encounter this material. The international community should agree on how radioactivity will be measured and qualified in a manner that is easily understood by all individuals. (vi) Technology sharing. As new, user-friendly technology is being advanced, the international community should keep track of such advances, share this information, as well as fund the development of technology that will accurately and consistently identify radioactive material that could be found in all forms of metal or containers. (author)

  18. Surveillance of radioactivity by the German Meteorological Service. Automatic nuclide specific measurements

    The DWD (Deutscher Wetterdienst, German Meteorological Service) is charged by law with the surveillance of radioactivity in the atmosphere. In the frame of the ''Integrated Measuring and Information System for the Surveillance of Radioactivity in the Environment'' (IMIS) the measuring tasks of DWD are well described. Since 2009 it was aimed for the automatic measurement of aerosol-bound radionuclides, gaseous Iodine-131 and deposited radionuclides at the 48 measuring sites of DWD. To guarantee the continuous operation of germanium detectors it was necessary to install electrically cooled systems instead of systems cooled by liquid nitrogen. The technical details and the experiences are described.

  19. Solubility of krypton, xenon and radon in polycarbonates. Application for measurement of their radioactive isotopes

    Bisphenol-A polycarbonates have a high absorption ability for noble gases that can be employed for sampling and measurement of radioactive isotopes of these gases. In this report the solubility of krypton, xenon and radon in the specified polycarbonates is determined by measurement of 85Kr, 133Xe and 222Rn absorbed in polycarbonate specimens. The found solubility is used to develop a general methodology for measurement of radioactive noble gases in air and water. The methodology is tested in pilot measurements of 133Xe in air under real conditions. The results demonstrate sufficient potential for practical applications.

  20. Two-dimensional measurement of natural radioactivity of some Archean and Proterozoic rocks from South Africa

    Tsuchiya, Noriyoshi/Hareyama, Mihoko

    2001-01-01

    The imaging plate is employed as a radiation sensor for obtaining two-dimensional radiation images of natural radioactivity. We used it to evaluate the autoradiography of several types of Archean and Proterozoic granitoids and ultramafic rocks from South Africa for obtaining the distribution of radiation emitters. The semiquantitative dose of natural radioactivity, represented by PSL value in the imaging plate measuring system (the intensity of photostimulated luminescence per unit area), is ...

  1. Portable scintillation gamma-spectrometer for field measurement of radioactivity in extensive objects

    The portable scintillated gamma-spectrometer for field measurement of radioactivity in the volume objects was designed. The crystal CdWO4 that has weak dependence of light yield from temperature in combination with PMT was applied as the gamma-rays detector. The design of the device provides the possibility for measuring radioactivity of the extensive objects in 4π-geometry without background measurements. In this case the value of the efficiency needed for specific activity calculation in close approximation depends only from crystal geometry and density of measuring object and may be set as the device parameter without efficiency calibration procedure during the operation. The spectrometer does not have an auxiliary radio-active source and connecting cables in the composition. The smartphone operated under Windows Mobile is used as the control module. Bluetooth connection provides data exchange between smartphone and measurement head.

  2. Calibration of a gamma spectrometer for natural radioactivity measurement. Experimental measurements and Monte Carlo modelling

    The thesis proceeded in the context of dating by thermoluminescence. This method requires laboratory measurements of the natural radioactivity. For that purpose, we have been using a germanium spectrometer. To refine the calibration of this one, we modelled it by using a Monte-Carlo computer code: Geant4. We developed a geometrical model which takes into account the presence of inactive zones and zones of poor charge-collection within the germanium crystal. The parameters of the model were adjusted by comparison with experimental results obtained with a source of 137Cs. It appeared that the form of the inactive zones is less simple than is presented in the specialized literature. This model was widened to the case of a more complex source, with cascade effect and angular correlations between photons: the 60Co. Lastly, applied to extended sources, it gave correct results and allowed us to validate the simulation of matrix effect. (author)

  3. Preventive measures for radioactive contamination in iron and steel used as construction materials

    At the end of July 1992, Atomic Energy Council (AEC) received tips-off from Taipei local residents, saying some buildings in Taipei had their rebar been contaminated by radioactive materials. Regarding causes and sources of those radioactively contaminated rebar, views from every aspects were pointing toward that scraps mixed with radioactive source smelting in the steel mill as the most possible reason. After investigating houses and constructors, AEC found that most contaminated buildings were constructed during the period of 1982 and 1984. For protection of public rights, AEC then actively undertook nation-wide survey of more than forty thousand buildings constructed between 1982 and 1984. Thermal Luminescent Dosimeters (TLD) and house by house surveying were major methods to investigate houses contamination. Finally, it was found that radiation contaminated houses are concentrated in Taipei City, Taipei County, Tauoyen County, Keelung County. According to data collected up to December 31, 1999, there were 180 cases, with a total of 1601 contaminated housing units. Based on information data of dose assessment, distribution of annual dose are as the following: higher than 15 mSv -143 housing units (9.21%), 5-15 mSv -117 housing units (7.53%), less than 5 mSv -1293 housing units (83.26%). Except actively conducting remodeling of contaminated houses and granting compensation to house owners, AEC has established following measures to prevent rebars from being radioactively contaminated. (1) Radiation detection training of iron and steel detectors (2) Strengthening controls over radioactive sources (3) Enforcing examination of radioactive levels for imported rebars (4) Requesting domestic steel companies establish radiation detection capability (5) Promoting installation of portal type radiation detectors for steel companies having smelting furnace (6) Enforcing no-radioactive contamination certificate system. The radiation detection training of iron and steel

  4. In-Situ Gamma Spectrometry Measurement of Environmental Radioactivity in Israel

    In-situ, high-resolution gamma spectrometry is a well-established, nondestructive, rapid and efficient method for detection, identification and quantitative determination of radioactivity in the environment, mainly in soils. Measurements were performed in the soils, along selected areas of southern and northern Israel, for the determination of background radiation levels and soil distributions of natural radionuclides and Chernobyl fallout. An independent analytical method was applied to substantiate the in-situ measurements by collecting soil samples from the site and measuring them in the laboratory. Soil sampling was performed also for obtaining information on radioactivity depth distribution and on the uniformity of superficial concentration of top-soil radioactivity. Exposure rate measurement from gamma radiation at the same site were also performed

  5. Screening measurement by simple dose-rate-meter for the waste water including radioactive cesium

    Decontamination work for taking off the radioactive materials is still performed in Fukushima prefecture. A waste fluid including radioactive materials comes out in decontamination work. The waste water quality standard of such waste fluid is indicated by the guideline issued by the Ministry of the Environment in Japan. We tried to measure concentration of radioactive cesium in the water by putting simple dose-rate meter in a waterproof case. As a result, we could get a correlation of the measure of the simple dose-rate meter (μ Sv/h) and the concentration of the radioactive cesium in the water (Bq/L). Our system can measure the concentration of the radioactive cesium in the water by 10.3 Bq/L to 1140 Bq/L. It's enough to measure the waste water quality standard of the guideline because the detection lower limit is about 10.3 Bq/L. From these, the screening measurement of the treated waste water that is come out from a decontamination site became possible. (author)

  6. IAEA reference materials for quality assurance of marine radioactivity measurements

    The IAEA's Marine Environment Laboratory has been assisting laboratories in Analytical Quality Control Services (AQCS) for the analysis of radionuclides in the marine environment since the early seventies. AQCS through world-wide and regional intercomparison exercises and the provision of reference methods and reference materials (RM) have been recognized as an important component of quality assurance/quality control. A total of 43 intercomparison exercises were organized and 37 RM were produced for marine radioactivity studies. All important marine matrices were covered, e.g., seawater, marine sediments of different chemical compositions, fish, shellfish and seaplants. RM were prepared from samples collected at contaminated sites (e.g., the Irish Sea, the Baltic Sea, the Arabian Sea, Mururoa and Bikini Atolls, etc.) as well as from sites affected only by global fallout (e.g., the Pacific Ocean). Available RM are listed in the IAEA biennial catalogue and can be purchased at a minimal price. An overview of prepared RM for radionuclides in marine matrices is presented and discussed in more detail. (author)

  7. Measurement of mean transit time with radioactive tracers

    The purpose of this work was to validate the use of moment to computer transit time in radioactive tracer studies. In tracer dilution studies, input and output functions usually can be described by means of exponential and gamma-variate functions. The authors demonstrated mathematically that computation of transit time with use of the first moments of these modeling functions is equivalent to the use of impulse response functions. They used a test object that would emulate the transit time of pulmonary blood flow in a medium-size dog to validate the computation of transit time with the first moment. A bolus of 185 MBq (5 mCi) of Tc-99m pertechnetate was injected. The quality of the bolus injection was modified by changing the size of the bolus. The transit time obtained from the first moments of the tracer-dilution curves was in agreement with the first moments of the modeling mathematical functions. Transit time is radionuclide studies can be computed from either the first moment of the tracer-dilution curve or of the modeling mathematical functions. Derivation of the impulse response function is not necessary

  8. Study on residual radioactivity measurement method for site release of nuclear facilities. In-situ radioactivity measurement test with the use of portable Ge semiconductor detector (Contract research)

    Nuclear facility sites after decommissioning are allowed to be released from nuclear safety regulations after confirming that sites have been decontaminated to acceptable levels. In-situ measurement with the use of a portable pure-germanium semiconductor detector (Ge detector) is a suitable technology for confirmatory survey. A method to conservatively evaluate residual radioactivity on the sites was proposed in this study. In the evaluation method concept, the radionuclide (Cs-137, etc.), which are in reality distributed across the area of interest, is assumed to be the single point source located at the furthest position on the ground surface of the area from the Ge detector. Based on this assumption, the detectable minimum time of the interest radionuclide was predicted by the calculation. If radiation from the point source is not detected for longer than the predicted detectable time, it can be proven that the radioactivity remaining in the interest area is lower than the radioactivity corresponding to the assumed point source. Results of the field test in JAEA site indicated that the proposed evaluation method was reasonable for the conservative evaluation of residual radioactivity. (author)

  9. Validation of a Monte Carlo model for a GMX detector used for measurements of environmental radioactivity

    In an Environmental Radioactivity Laboratory, samples from several products are analyzed, in order to determine the amount of radioactive products they contain. A usual method is the gamma activity measurement of these samples, which typically requires the use of High Purity Germanium Detectors (HPGe). GMX (n-type) detectors can be found among this group of detectors. They have a high efficiency for low energy emissions. As any detector, it must be calibrated, in energy, efficiency and resolution (FWHM). To do this calibration, a gamma standard solution is used, whose composition and activity are certified by a reference laboratory. This source contains several radionuclides, providing a wide energy spectrum. The simulation of the detection process with MCNP5, a code based on the Monte Carlo method, is a useful tool in an Environmental Radioactivity Laboratory, since it can reproduce the experimental conditions of the essay, without manipulating radioactive sources, and consequently reducing radioactive wastes. On the other hand, the simulation of the detector calibration permits to analyze the influence of different variables on detector efficiency. In this paper, the simulation of the calibration of the GMX detector used in the Environmental Radioactivity Laboratory of the Polytechnic University of Valencia (UPV) is presented. Results obtained with this simulation are compared with laboratory measurements, in order to validate the model. (author)

  10. Radioactive measurement technology of two-surface source based on LRAD inside pipes

    Background: The development of measuring technologies of radioactive contamination becomes more and more important. Long Range Alpha Detector (LRAD) can effectively solve some problems such as the short ranges of alpha particles, weak penetration ability and so on. LRAD also has advantages that the alpha radioactivity of interior surface of irregular pipes or just irregular surface can be measured nondestructively and precisely. Purpose: This paper attempts to obtain the measured value of multi-point sources and large contamination areas in pipes. And the comparative experiments of impact factors of two different radioactive surface sources (different nuclides and radioactivities) have been done. Methods: In the experiment, a new domestic LRAD is utilized to measure the alpha activity of interior surface of steel pipes. Here, the inner diameter of pipes is 78 mm and there are two kinds of pipes: straight pipe and U-bend pipe. The radioactive sources include 241Am (3 772.2 Bq) and 239Pu (224.4 Bq). The distance between different sources takes values of o cm, 10 cm, 20 cm and 40 cm, respectively, and the distance between the whole mixed radioactive source and detector increases by step of 20 cm. Results: When the relative distance of the two surface sources is 10 cm, the detection efficiency of LRAD is higher than that of relative distance of 0 cm, 20 cm and 40 cm, which matches the result of theoretical analysis. When 241Am is closer to the detector than 239Pu, measuring results are much higher than those of the opposite situation. And in the same position, when the two sources are put together, the measured results are lower than those of the sum of each single source. Conclusion: Based on the experimental results, a self-developed new LRAD measurement system has been used to measure two non-point sources in pipes. (authors)

  11. LOWRAD 96. Methods and applications of low-level radioactivity measurements. Proceedings

    Fietz, J. [ed.] [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany)

    1997-03-01

    The newest developments in the field of low-level radioactivity measurements and new applications for existing and low-level measuring facilities are presented. The contributions mostly were devoted to basic physical aspects and applications of low-level counting. Papers on chemical separation and preparation techniques and on low-level radiation dose determinations were also presented. (DG)

  12. Design project of the device for measuring the radioactivity of wires

    This report includes the detailed design description and engineering drawings of the device and equipment for measuring the radioactivity of a wire. The wire is irradiated in the reactor core. The activity of the wire proportional to the neutron flux enables determining the neutron flux distribution. Activity is measured by GM counter

  13. Measuring and analyzing on natural radioactive nuclide uranium concentration in mineral water from market

    Using the Laser-fluorescence analyzing technology and adopting the standard mix method, the measuring and analyzing on mineral water was made. Seventeen samples of mineral water were chosen. The LMA-3 type laser trace analysis instrument was employed. The measuring result showed that the uranium content of the mineral water belongs in normal radioactive background level

  14. Glossary concerning the measuring instructions for the envrionmental control of radioactive materials and external radiation

    The glossary is covering the technical terms used in the measuring instructions for radioactivity control published by the Federal Ministry for Environment, Nature Protection and Reactor Safety. The glossary includes definitions for the technical terms; the measuring units are explained and commented. The glossary is aimed to be used by journalists and scientific personnel.

  15. Result of measuring inner radioactive contamination of people due to the Chernobyl accident

    A survey of results of about 140 measurements of internal radioactive contamination of Dutch people in consequence of the Chernobylsk accident is presented. The measurements were performed with total body counters by the Dutch Institute for Radiopathology and Radiation Protection (IRS) and the Radiologic Department TNO (RD-TNO). 4 figs.; 3 tabs

  16. LOWRAD 96. Methods and applications of low-level radioactivity measurements. Proceedings

    The newest developments in the field of low-level radioactivity measurements and new applications for existing and low-level measuring facilities are presented. The contributions mostly were devoted to basic physical aspects and applications of low-level counting. Papers on chemical separation and preparation techniques and on low-level radiation dose determinations were also presented. (DG)

  17. Absolute measurement of the subcriticality based on the third order neutron correlation in consideration of the finite nature of neutron counts data

    We have studied a measurement of subcriticality by using the neutron correlation method. Furuhashi proposed an absolute measurement of subcriticality by using the third order neutron correlation factor X in addition to the second order neutron correlation factor Y. In actual experiments, the number of neutron counts data is not infinity so that we take the effect of the finite nature of the neutron counts data into account. We derived new formulas in consideration of the number of data and verified them. (author)

  18. Measuring, and identifying predictors of, women's perceptions of three types of breast cancer risk: population risk, absolute risk and comparative risk

    Apicella, C.; Peacock, S.J.; Andrews, L.; Tucker, K.; Daly, M B; Hopper, J L

    2009-01-01

    Although a key function of cancer genetics services is to provide risk information, to date there has been little consistency in the way in which breast cancer risk perception has been measured. The aims of the study were to measure estimates of (i) population risk, (ii) absolute risk and (iii) comparative risk of developing breast cancer for Ashkenazi Jewish women, and to determine predictors of breast cancer risk perception. Of 152 women, 107 (70%) completed all questions. The mean (s.d.) e...

  19. Measuring manual for radioactivity monitoring in the environment and for nuclear facility effluent monitoring

    The measuring specifications in this manual have been compiled paying attention to the tasks and duties defined in the Preventive Radiation Protection Act (StrlSchVG) for monitoring environmental radioactivity and radioactivity levels in the off-plant environment of nuclear facilities. Existing measuring instructions set up some time ago have been updated according to recent developments in science and engineering. The competent monitoring stations of the Lands will thus have a guide for performing their radioactivity monitoring tasks on a standardized basis and by standardized techniques. The manual is published as a loose-leaf edition in order to allow for easy updating of the material in response to future developments in analytics and measuring engineering. (orig./BBR)

  20. Measurement of the Absolute Magnitude and Time Courses of Mitochondrial Membrane Potential in Primary and Clonal Pancreatic Beta-Cells.

    Gerencser, Akos A; Mookerjee, Shona A; Jastroch, Martin; Brand, Martin D

    2016-01-01

    The aim of this study was to simplify, improve and validate quantitative measurement of the mitochondrial membrane potential (ΔψM) in pancreatic β-cells. This built on our previously introduced calculation of the absolute magnitude of ΔψM in intact cells, using time-lapse imaging of the non-quench mode fluorescence of tetramethylrhodamine methyl ester and a bis-oxonol plasma membrane potential (ΔψP) indicator. ΔψM is a central mediator of glucose-stimulated insulin secretion in pancreatic β-cells. ΔψM is at the crossroads of cellular energy production and demand, therefore precise assay of its magnitude is a valuable tool to study how these processes interplay in insulin secretion. Dispersed islet cell cultures allowed cell type-specific, single-cell observations of cell-to-cell heterogeneity of ΔψM and ΔψP. Glucose addition caused hyperpolarization of ΔψM and depolarization of ΔψP. The hyperpolarization was a monophasic step increase, even in cells where the ΔψP depolarization was biphasic. The biphasic response of ΔψP was associated with a larger hyperpolarization of ΔψM than the monophasic response. Analysis of the relationships between ΔψP and ΔψM revealed that primary dispersed β-cells responded to glucose heterogeneously, driven by variable activation of energy metabolism. Sensitivity analysis of the calibration was consistent with β-cells having substantial cell-to-cell variations in amounts of mitochondria, and this was predicted not to impair the accuracy of determinations of relative changes in ΔψM and ΔψP. Finally, we demonstrate a significant problem with using an alternative ΔψM probe, rhodamine 123. In glucose-stimulated and oligomycin-inhibited β-cells the principles of the rhodamine 123 assay were breached, resulting in misleading conclusions. PMID:27404273