WorldWideScience

Sample records for absolute radioactivity measurements

  1. Absolute measurement of strontium-90 and yttrium-90 radioactivity

    International Nuclear Information System (INIS)

    Strontium-90 and yttrium-90 is one of the important fission products. At present it is applied widely in industry because its half life is longer and its fission yield is higher. The radioactivity of the nuclide is concerned by human, because strontium-90 and Yttrium-90 is extremely poisonous for living things. The purpose of present work is to provide the standardization of strontium-90 and yttrium-90 radioactivity for the isotopic application and for the reprocessing plant. Method of determing strontium-90 and yttrium-90 radioactivity is efficiency trace technique while cobalt-60 nuclide is used as tracer. The total uncertainty of measurement is about 1.4 percent

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

    International Nuclear Information System (INIS)

    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. Absolute measurements of radio-active bodies which disintegrate after neutron capture (1962)

    International Nuclear Information System (INIS)

    The calibration of radioactive bodies which disintegrate by neutron capture is rather delicate: we describe two calibration methods which we have used. - The 4 π X (or e) - γ coincidence method when K capture is followed by a γ disintegration; - Integral counting of all the X rays stopped in the detecting volume, for X-ray emitters of low energy disintegrating after neutron capture giving directly the fundamental level. (authors)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.)

  6. An improved gas counting system for absolute activity measurement of radioactive gases

    International Nuclear Information System (INIS)

    The calibration of gas monitoring instruments with beta emitting gases is an important procedure for increasing the reliability of the measurements for radiation protection. For example, gas standards of 3 H, 85 Kr and 133 Xe are frequently used for the calibration of gas effluent monitors of the nuclear power plants. The internal gas counting with proportional counters is the most frequently method for preparing gas standards. This method is based on a complex counting system composed of two length compensated proportional detectors, a gas handling system and two spectrometric counting channels. By virtue of their different lengths, the detectors permit compensation to be done for the end effect (non-uniform detection of ionizing events caused by beta particles which takes place near to the ends of the counters). To reduce the complexity and cost of the internal gas counting system, a proportional detector was manufactured with electric field corrections at the ends for canceling the end effect. As a result, a counting system was made using only one proportional detector and only one spectrometric counting channel . (authors)

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

    International Nuclear Information System (INIS)

    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)

  8. Measurement of the absolute \

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Absolute calibration in vivo measurement systems

    International Nuclear Information System (INIS)

    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

  11. Absolute cross-sections from X-{gamma} coincidence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lemasson, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Shrivastava, A. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Navin, A. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France)], E-mail: navin@ganil.fr; Rejmund, M. [GANIL, CEA/DSM - CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); Nanal, V. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Bhattacharyya, S. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India); Chatterjee, A.; Kailas, S.; Mahata, K.; Parkar, V.V. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Pillay, R.G. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Ramachandran, K.; Rout, P.C. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2009-01-11

    An activation technique using coincidences between characteristic X-rays and {gamma}-rays to obtain absolute cross-sections is described. This method is particularly useful in the case of nuclei that decay by electron capture. In addition to the reduction of possible contamination, an improved detection sensitivity is achieved as compared to inclusive measurements, thereby allowing the extraction of absolute fusion cross-sections in the nano-barn range. Results of this technique for {sup 6}Li+{sup 198}Pt system, at energies around the Coulomb barrier are described. Future applications with low intensity radioactive ion beams are also discussed.

  12. Absolute cross-sections from X-γ coincidence measurements

    International Nuclear Information System (INIS)

    An activation technique using coincidences between characteristic X-rays and γ-rays to obtain absolute cross-sections is described. This method is particularly useful in the case of nuclei that decay by electron capture. In addition to the reduction of possible contamination, an improved detection sensitivity is achieved as compared to inclusive measurements, thereby allowing the extraction of absolute fusion cross-sections in the nano-barn range. Results of this technique for 6Li+198Pt system, at energies around the Coulomb barrier are described. Future applications with low intensity radioactive ion beams are also discussed.

  13. Precision absolute positional measurement of laser beams

    OpenAIRE

    Fitzsimons, E.; Bogenstahl, J; Hough, J.; Killow, C; Perreur-Lloyd, M.; Robertson, D.; Ward, H.

    2013-01-01

    We describe an instrument which, coupled with a suitable coordinate measuring machine, facilitates the absolute measurement within the machine frame of the propagation direction of a millimeter-scale laser beam to an accuracy of around 4???m in position and 20???rad in angle.

  14. Amoeba-absoluteness and projective measurability

    OpenAIRE

    Brendle, Jörg

    1992-01-01

    We study the relationship between Amoeba forcing (the partial order which generically adds a measure one set of random reals) and projective measurability. Given a universe V of set theory and a forcing notion P in V we say that V is Sigma^1_n - P - absolute iff for every Sigma^1_n-sentence phi with parameters in V we have V models phi iff V^P models phi. We show that Sigma^1_4-Amoeba-absoluteness implies that forall a in omega^omega (omega_1^{L[a]} < omega_1^V), and hence Sigma^1_3-measurabi...

  15. Radioactivity and its measurement

    CERN Document Server

    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

  16. 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

    CERN Document Server

    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

  17. An absolute measure for a key currency

    Science.gov (United States)

    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 radioactive aerosols

    International Nuclear Information System (INIS)

    Radioactive nuclei or atoms released in the atmospheric environment may lead to the formation of radioactive aerosols which are widely used as a tracer for investigating atmospheric transport and diffusion. Aerosols collection methods are presented followed by radioactivity measurement including alpha-rays (proportional counters), beta-rays (gas-flow counters), and gamma radiations NaI scintillation and germanium semiconductor counters). For discriminating the nuclei, silicon semi-conductor or liquid scintillation counter are used. For particulate radius measurement, several methods such as impact, diffusion battery, and track detector counting are used. (S. Ohno)

  19. Absolute measurements of fission cross sections

    International Nuclear Information System (INIS)

    Absolute neutron fission cross sections measurements of 235U, 238U and 239Pu have been made at 13.9 and 14.6 MeV with a double 4π ionization chamber. The associated particle method with the time-of-flight technique was used. Our final values of sigma sub(nf)(235U), sigma sub(nf)(238U), sigma sub(nf)(239Pu), sigma sub(nf)(238U)/sigma sub(nf)(235U) and sigma sub(nf)(239Pu)/sigma sub(nf)(235U) are compared to previous data. A sigmasub(nf)(235U) absolute measurement has been made at 2.5 MeV using two references: the scattering cross section of 1H and the directional long counter. Preliminary results is compared to previous data. (author)

  20. Absolute measurement of the GANIL beam energy

    International Nuclear Information System (INIS)

    The energy of the GANIL cyclotron beam was measured on-line during the 208Pb+208Pb elastic scattering experiment 'Search for Color van der Waals Force in the 208Pb+208Pb Mott scattering' with an absolute precision of 7x10-5 at ∼1.0 GeV, which represents an improvement of one order of magnitude over previous absolute energy measurements. The energy was deduced from the time of flight between two beam-scanners, which only partially intercept the beam, situated on a straight line and separated by ∼48.0 m. It was found that the nomial beam energy was in good agreement with the present results. (orig.)

  1. Measurement of absolute gravity acceleration in Firenze

    Directory of Open Access Journals (Sweden)

    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.

  2. A Cryogenic Radiometer for Absolute Radiometric Measurements

    Science.gov (United States)

    Martin, J. E.; Fox, N. P.; Key, P. J.

    1985-01-01

    The adoption in 1979 of a new definition of the candela, which permitted a detector-based approach to the realization of the unit, has emphasized the importance of high-accuracy absolute radiation detectors. This paper describes a new electrical-substitution absolute radiometer operating at 5 K, based on a standard commercial helium cryostat, which has been developed at NPL for optical radiant-power measurements. The principal advantages of operating the radiometer at liquid helium temperatures are that the detector can be a large, highly absorbing cavity (absorptivity 99.998%) and that exact equivalence of electrical and radiant heating can be clearly demonstrated. It will be the primary absolute detector for a new realization of the candela at NPL and will provide the basis for the development of a wider range of radiometric and spectroradiometric standards. The use of the radiometer to measure the radiant power of an intensity-stabilized laser source at the milliwatt level with an uncertainty of 4 parts in 105 is also described, together with its application in the determination of the responsivity of transfer-standard detectors, such as silicon photodiodes.

  3. Absolute method of measuring magnetic susceptibility

    Science.gov (United States)

    Thorpe, A.; Senftle, F.E.

    1959-01-01

    An absolute method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.

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

    International Nuclear Information System (INIS)

    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)

  5. Absolute Measurement of Electron Cloud Density

    International Nuclear Information System (INIS)

    Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the expelled ions that are originated from the beam-background gas interaction, rather than by measuring electrons that reach the walls. The kinetic ion energy measured with a retarding field analyzer (RFA) maps the depressed beam space-charge potential and provides the dynamic electron cloud density. Clearing electrode current measurements give the static electron cloud background that complements and corroborates with the RFA measurements, providing an absolute measurement of electron cloud density during a 5 (micro)s duration beam pulse in a drift region of the magnetic transport section of the High-Current Experiment (HCX) at LBNL

  6. Development of NANA: A Fast-Scintillator, Coincidence Gamma-ray Array for Radioactive Source Characterisation and Absolute Activity Measurements at the UK National Physical Laboratory

    Science.gov (United States)

    Regan, P. H.; Shearman, R.; Judge, S. M.; Lorusso, G.; Main, P.; Bell, S.; Collins, S. M.; Ivanov, P.; Jerome, S. M.; Keightley, J. D.; Larijani, C.; Lotay, G.; Pearce, A. K.

    2015-06-01

    A multi-detector modular coincidence gamma-ray spectrometer is being designed and constructed for use at the UK's National Physical Laboratory (NPL) for use in direct measurement and metrological standardisation of nuclear decay activities. In its first generation, the NPL National Nuclear Array (NANA) will consist of twelve individual halide scintillation detectors placed in a high-efficiency geometry around a well-defined central point source position. This brief conference paper provides details of the measured detector module and coincidence energy and timing responses for the LaBr3(Ce) detectors which will be used in the NANA array. Preliminary GEANT4 simulations of the array's full energy peak efficiency and expected gamma-ray coincidence response are also presented.

  7. Airborne measurement of radioactivity

    International Nuclear Information System (INIS)

    The German Meteorological Service (Deutscher Wetterdienst, DWD) is responsible for the surveillance of radioactivity in the atmosphere. In case of an radioactive emergency radioactive plumes may be expected in heights up to the tropopause depending on the type of accident. For this reason aircraft measurements are necessary as a supplement to groundbased measuring sites, especially in case of non available details about the source of radioactive release and lack of details about the accident. The authors present an aircraft type Learjet 35A used for localizing radioactive contaminated air masses up to 10,000 m and the measurement of artificial radionuclides on aerosols. For this purpose the aircraft is equipped with an isokinetic high-volume sampler for collection of aerosols on filters outside the pressurized cabin and an onboard gamma spectrometry system with a high purity germanium detector to analyze the interchangeable contaminated filters during flight as well as a dose ratemeter and a GPS (Global Positioning System) for navigation. The collection of gaseous iodine is optional. The meteorological parameters temperature, atmospheric pressure, relative humidity, wind speed and wind direction are determined as well. Resulting data are transmitted by global VHF datalink from the plane to the DWD headquarter and used for verifying the prognosis. (orig.)

  8. Preparation of radioactive sources for radioactivity measurement

    International Nuclear Information System (INIS)

    The measurements of radioactivity and the analysis of radioactive solutions involve the preparation of solid sources. The quality of the sampling is of great importance to the quality of the results. In this monograph, the various steps are reviewed: - methods and accuracies of dilutions, - physico-chemical stability of solutions, - preparation of different source holders, - different methods for aliquote determination (volumenometry, microweighing) and associated uncertainties. Phenomena inherent to the measurement of such sources (absorption, retrodiffusion, auto-absorption) and corrections to be considered are studied too

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

    OpenAIRE

    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...

  10. Underground measurements of radioactivity

    International Nuclear Information System (INIS)

    The exceptional sensitivity of gamma-ray spectrometry in underground laboratories has increasing application because of the important science and technology that it allows to be studied. Early work focussed on rare fundamental phenomena, e.g. double beta decay, but a growing number of underground measurements is being performed in fields such as environmental monitoring, surveillance of nuclear activities, benchmarking of other physical techniques and materials selection for equipment which require materials with extremely low levels of radioactivity. This report describes the state of the art in underground gamma-ray spectrometry. Backgrounds of HPGe-detectors at various underground laboratories are presented and compared. Improved techniques and detectors are described and needs of deep underground facilities for higher sensitivity measurements are discussed

  11. On the absolute measure of Beta activities

    International Nuclear Information System (INIS)

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

  12. Absolute Distance Measurements with Tunable Semiconductor Laser

    Czech Academy of Sciences Publication Activity Database

    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

  13. Counting statistics in radioactivity measurements

    International Nuclear Information System (INIS)

    The application of statistical methods to radioactivity measurement problems is analyzed in several chapters devoted successively to: the statistical nature of radioactivity counts; the application to radioactive counting of two theoretical probability distributions, Poisson's distribution law and the Laplace-Gauss law; true counting laws; corrections related to the nature of the apparatus; statistical techniques in gamma spectrometry

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

    International Nuclear Information System (INIS)

    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.)

  15. Low-level Radioactivity Measurements

    International Nuclear Information System (INIS)

    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;

  16. Radioactivity measurements principles and practice

    CERN Document Server

    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

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

    OpenAIRE

    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...

  18. Neutronic measurements of radioactive waste

    International Nuclear Information System (INIS)

    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)

  19. Absolute Quantum Yield Measurement of Powder Samples

    OpenAIRE

    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.

  20. Absolute density measurements in the middle atmosphere

    Directory of Open Access Journals (Sweden)

    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

  1. Environmental radioactivity measurement. Ispra 1990

    International Nuclear Information System (INIS)

    In this report there are briefly described the measurements of environmental radioactivity performed during 1990 by the site survey group of the Radioprotection Division at the Joint Research Centre Ispra Establishment. Data are give on the concentrations of Sr-90, Cs-137, HTO and other radionuclides in precipitation, air, waters, herbage, milk and radioactive effluents. The environmental contamination is mainly a consequence of the nuclear accident of Chernobyl

  2. Low-level Radioactivity Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hurtgen, C

    2001-04-01

    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/ISO17025 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 2000 are reported.

  3. Low-level Radioactivity Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hurtgen, C

    2002-04-01

    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 advise the nuclear and non-nuclear industry on problems of radioactive contamination and low-level radioactivity measurements; (4) to maintain and improve the quality assurance system according to the ISO17025 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 2001 are reported.

  4. Low-level Radioactivity Measurements

    International Nuclear Information System (INIS)

    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 advise the nuclear and non-nuclear industry on problems of radioactive contamination and low-level radioactivity measurements; (4) to maintain and improve the quality assurance system according to the ISO17025 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 2001 are reported

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

  7. Measurements of the reactor neutron power in absolute units

    Science.gov (United States)

    Lebedev, G. V.

    2015-12-01

    The neutron power of the reactor of the Yenisei space nuclear power plant is measured in absolute units using the modernized method of correlation analysis during the ground-based tests of the Yenisei prototypes. Results of the experiments are given. The desired result is obtained in a series of experiments carried out at the stage of the plant preparation for tests. The acceptability of experimental data is confirmed by the results of measuring the reactor neutron power in absolute units at the nominal level by the thermal balance during the life cycle tests of the ground prototypes.

  8. Definition of correcting factors for absolute radon content measurement formula

    International Nuclear Information System (INIS)

    The absolute method of radio content measurement is based on thomas radon measurement formula. It was found in experiment that the systematic error existed in radon content measurement by means of thomas formula. By the analysis on the behaviour of radon daughter five factors including filter efficiency, detector construction factor, self-absorbance, energy spectrum factor, and gravity factor were introduced into the thomas formula, so that the systematic error was eliminated. The measuring methods of the five factors are given

  9. Measurement of radioactivity in steel

    International Nuclear Information System (INIS)

    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)

  10. Measurement of weak radioactivity

    CERN Document Server

    Theodorsson, P

    1996-01-01

    This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one

  11. Method for automatic absolute calibration of sodar measurement channels

    Science.gov (United States)

    Kamardin, A. P.; Odintsov, S. L.

    2015-11-01

    We discuss a method for continuous absolute calibration of "Volna-4M" meteorological acoustic radar (sodar) measurement channels. Accelerometers, placed on paraboloids of sodar antennas, are suggested to use for automatic calibration. Results of testing the module of continuous sodar calibration are presented.

  12. Absolute Poverty Measures for the Developing World, 1981-2004

    OpenAIRE

    Chen, Shaohua; Ravallion, Martin

    2007-01-01

    We report new estimates of measures of absolute poverty for the developing world for the period 1981–2004. A clear trend decline in the percentage of people who are absolutely poor is evident, although with uneven progress across regions. We find more mixed success in reducing the total number of poor. Indeed, the developing world outside China has seen little or no sustained progress in reducing the number of poor, with rising poverty counts in some regions, notably sub-Saharan Africa. There...

  13. Absolute gamma measurements by Ge-Li high resolution spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Garlea, I.; Miron, C.; Popa, F. (Institutul de Reactori Nucleari Energetici, Pitesti (Romania)); Fodor, G. (Institutul de Fizica si Inginerie Nucleara, Bucharest (Romania))

    1981-01-01

    The absolute efficiancy of a 100 cc Ge-Li crystal (Cannberra type) has been determined by means of two reference source sets delivered by CEA-Saclay and Radiochemical Centre Amersham-(U.K.) and /sup 152/Eu source offered by P.T.B.-B.R.D. The calibration measurements have been performed in the energy range 6O keV-1.4 MeV, for the crystal-source distances of 5 c and 50 cm. The error range has been obtained taking into account the incertitudes in knowing the absolute activities of sources and the disintegration intensities for the radiations used. The gamma peaks have been fitted by the SAMPO code. The absolute efficiency has been calculated by the same code.

  14. Radioactivity

    International Nuclear Information System (INIS)

    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.)

  15. Environmental radioactivity intercomparison measurements

    International Nuclear Information System (INIS)

    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.)

  16. Statistical aspects in radioactivity measurements

    International Nuclear Information System (INIS)

    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)

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

    CERN Document Server

    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; Bjrnstad, 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; Bchler-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 Surez, 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; Estve, L; Falabella, A; Fanchini, E; Frber, 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; Gbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gndara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugs, 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; Lefvre, R; Leflat, A; Lefranois, 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; Mrki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martn Snchez, 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; Mller, 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

    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...

  18. Apparatus for measuring radioactive emissions

    International Nuclear Information System (INIS)

    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)

  19. ABSOLUTE DISTANCE MEASUREMENTS USING TWO-MODE LASER TELEMETRY

    OpenAIRE

    Lintz, Michel; Courde, Clément; Brillet, Alain; Man, Catherine,

    2008-01-01

    A novel laser ranging method is described that uses a two-mode laser source, and detection of the phase of the return beam. The design eliminates the cyclic error usually associated with phase measurements and provides unambiguous, absolute distance determination. Measurements of an 8m path are obtained at a beat frequency of 13 GHz. We analyse the 1µm stability of the data obtained with this preliminary implementation, and expect that an improved version will allow accuracies well below 1 µm...

  20. Lens transmission measurement for an absolute radiation thermometer

    Energy Technology Data Exchange (ETDEWEB)

    Hao, X.; Yuan, Z.; Lu, X. [Division of Thermometry and Materials Evaluation, National Institute of Metrology, Beijing (China)

    2013-09-11

    The lens transmission for the National Institute of Metrology of China absolute radiation thermometer is measured by a hybrid method. The results of the lens transmission measurements are 99.002% and 86.792% for filter radiometers with center wavelengths 633 nm and 900 nm, respectively. These results, after correcting for diffraction factors and the size-of-source effect when the lens is incorporated within the radiometer, can be used for measurement of thermodynamic temperature. The expanded uncertainty of the lens transmission measurement system has been evaluated. It is 1.310{sup ?3} at 633 nm and 900 nm, respectively.

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

    International Nuclear Information System (INIS)

    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)

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

    CERN Document Server

    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))%.

  3. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    International Nuclear Information System (INIS)

    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.

  5. A null detecting system for absolute measurement of infrared radiation

    Science.gov (United States)

    Pradhan, M. M.; Garg, R. K.

    1983-11-01

    A pyroelectric radiometer is so designed that the output of the detector is null for equivalent radiation and electric powers. The sensing element is comprised of two poled crystal plates joined together such that the polarity of domains reverses across the junction. An auxiliary pyroelectric detector is used to provide in-phase electric signal for producing electric heating at the back electrode of the compound detector. The system has been used for absolute measurement of infrared radiation.

  6. Measurement of radioactivity in Norway

    International Nuclear Information System (INIS)

    A nation-wide network of seven 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 will trigger an alarm for immediate transmission. The monitoring system and field experiences in connection with its operation are described. NILU's directions in the event of radiation alarm are specified and radiation measurements for 1987 are presented

  7. Measurement of radioactivity in Norway

    International Nuclear Information System (INIS)

    A nation-wide network of 11 monitoring stations for continous 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. Results from measurements in 1989 are presented. 18 figs

  8. Measurement of radioactivity in Norway

    International Nuclear Information System (INIS)

    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

  9. Radioactivity and its measurement. 2. ed.

    International Nuclear Information System (INIS)

    The subject is covered in chapters, entitled: the discovery of radioactivity and early experiments into its nature; radioactive change and the theory of successive radioactive transformations; the interactions of α, β, and γ rays with matter; the neutrino and the neutron; the energetics of nuclear change; radiation detectors; electronic instrumentation; radioactivity measurements. (U.K.)

  10. System for remote measurement of radioactivity

    International Nuclear Information System (INIS)

    This invention relates to improvements in the detection and measurement of radioactivity and, more particularly, to apparatus and a method for measurement of radiation from a remote source of radioactivity using telephone equipment. (author)

  11. Absolute Measurement of Quantum-Limited Interferometric Displacements

    CERN Document Server

    Thiel, Valrian; 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.

  12. Establishment and application of standard devices for radioactivity measurement

    International Nuclear Information System (INIS)

    In order to establish the radioactivity measurement standards a 4πβ-γ coincidence apparatus and a 4πγ ionization chamber have been installed in the laboratory. The 4πβ-γ coincidence apparatus is for absolute measurement, and its uncertainty is ±(0.3∼5)%. The 4πγ ionization chamber is for working standard, and its uncertainty is ±(1∼5)%. The combination of these devices can meet the quality requirements controlled by National Verification System in the transfer of radioactivity values

  13. Absolute measurements of chlorine Cl+ cation single photoionization cross section

    International Nuclear Information System (INIS)

    The photoionization of Cl+ leading to Cl2+ was measured in the photon energy range of 19.5–28.0 eV. A spectrum with a photon energy resolution of 15 meV normalized to absolute cross-section measurements is presented. The measurements were carried out by merging a Cl+ ion beam with a photon beam of highly monochromatic synchrotron radiation at the Advanced Light Source at Lawrence Berkeley National Laboratory. The measured photoionization of Cl+ consists of several autoionization resonances surperimposed on the direct photoionization signal. Most of the prominent resonances are assigned to members of Rydberg series originating from the singlet ground state and from metastable triplet levels within the ground-state configuration of Cl+. The direct ionization cross section is no larger than 12 Mb. - Highlights: • The single photoionization absolute cross section of Cl+ ion was measured. • Numerous resonances were identified as belonging to Rydberg series. • A large population of the metastable Cl+(1D2) was identified. • Identified resulting Cl2+ state terms correspond to 2D5/2 and 2D3/2

  14. Deflectometric systems for absolute flatness measurements at PTB

    International Nuclear Information System (INIS)

    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)

  15. Absolute and specific measures of research group excellence

    CERN Document Server

    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...

  16. Radioactivity measurements and control solutions

    International Nuclear Information System (INIS)

    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 detector is an assembly consisting in a plastic scintillator, a photomultiplier and the associated electronics, all these components being mounted inside an aluminum cylindrical case. The specifications are: - Detects at least 1 Ci radioactivity spread all over the inspected body in a 20 Roentgen/h overall background; - Maximum detectable radioactivity, 10 Ci; - Acquisition time between 1 to 10 seconds. The Neutron Monitor is derived from the Bonner Spectrometer. The Bonner Spectrometer description is quite simple: A proportional counter filled with Helium 3 at a pressure value between 2 and 6 atmospheres is the detecting element. It is coated with a thick layer of hydrogen-rich material such as polyethylene. The output signal is measured by the current in the counter wire when it is biased to about +1000 volts. Our Neutron Monitor is a portable, battery powered monitor for dose equivalent rate measurements around reactors, accelerators and other neutron generating installations or sources. The instrument measures the neutron dose equivalent rate in units of Sv/h. It is important to note that we need to know the neutron energies to be measured so that the appropriate energy response correction factors are coded into the instrument driving calibrations. If these a priori data is not available the Neutron Monitor can only offer plain counts/second. The appropriate diameter for the polyethylene sphere was chosen to be 5 inches (127 mm). The instrument is equipped with a microprocessor and a 2 x 16 character display unit along with two push buttons. This simple setup configuration permits to choose the acquisition time base and the display mode (counts or Sv). Its specifications are: - Dose rate range,1 Sv/h to 100 mSv/h (neutron spectrum information is required before calibration); - Energy response, thermal range to 14 MeV; - Detector, He-3 proportional counter surrounded by 127 mm polyethylene sphere (SP9). The portable gamma source sniffer consists of a NaI(Tl) crystal, a photomultiplier and the associated electronics, all contained in an aluminum cylindrical case with a handle and a small 6 x 7 digits read-out. The associated electronics consists in a high voltage supply, a preamplifier, a discriminator and a microprocessor. The device is battery operated with a 12 hours autonomy. An acoustic signal proportional with the counting rate along with the counting rate value displayed on the display are available. The sniffer incorporates a micro controller which registers the counts, displays them and signals any preset threshold exceeding counting rate. The main features include: - Fault alarm probability, less than 10-3; - Non detecting probability, less than 10-2; - Portable device weighting 2 kg. (authors)

  17. Handbook of radioactivity measurements procedures. Second edition

    International Nuclear Information System (INIS)

    This report is concerned with the measurement of radioactivity in general, but specifically it deals with radioactive materials that have become available in the last three decades, from nuclear reactors and particle accelerators, for applications in medicine, scientific research, and industry. It is also concerned with low-level radioactivity measurements for the monitoring of radioactivity in environmental media, such as air and water, in connection with the control of radioactive effluents associated with the production of nuclear power or the use of radionuclides. Included in appendices are nuclear decay data for selected radionuclides and statistics of radioactive decay. An extensive bibliography is also included

  18. On Absolute Measurements of β-Emitting Radionuclides

    International Nuclear Information System (INIS)

    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)

  19. Recent advances in absolute distance measurements using femtosecond light pulses

    Science.gov (United States)

    Kim, Seung-Woo; Kim, Young-Jin; Hyun, Sangwon; Chun, Byung Jae; Jang, Yoon-Soo

    2015-02-01

    Absolute distance measurement (ADM) with high precision is required for various fields of precision engineering, which has long been implemented by means of time-of-flight measurement of a pulsed laser, intensity or frequency modulation of a continuous-wave laser, and cross-correlation of pseudo-random micro-wave signals. Recently, in response to increasing demands on the measurement precision and range beyond conventional limits, femtosecond pulse lasers began to draw attention as a new light source that permits realizing various advanced ADM principles such as synthetic radiofrequency wavelength generation, Fourier-transform-based dispersive analysis and multi-wavelength interferometry. In this talk, we present the state-of-the-art measurement principles and performance demonstrated by exploiting the unique temporal and spectral characteristics of femtosecond laser pulses for high-precision ADM applications.

  20. Absolute beam intensity measurements at the Intense Pulsed Neutron Source

    International Nuclear Information System (INIS)

    The three moderators at the Intense Pulsed Neutron Source are of cryogenic methane (CH4): one of liquid methane at 100 K, and two of solid methane at 30 K. These moderators produce intense beams of both cold and thermal neutrons. The moderators are each of a different physical configuration in order to tailor their performance for the fourteen instruments and test facilities that operate on the twelve neutron beams. IPNS has started a program to enhance the effectiveness of its target/moderator/reflector system. This program involves both Monte Carlo computer modeling of the system and measuring the characteristics of the neutron beams. The measurements reported here provide absolute spectra using foil activation techniques joined with time-of-flight measurements performed with thin beam monitor detectors installed at the neutron scattering instruments. We also outline a codified procedure which we believe will be useful at other pulsed neutron sources to perform equivalent measurements. (auth)

  1. An absolute scale for measuring the utility of money

    Science.gov (United States)

    Thomas, P. J.

    2010-07-01

    Measurement of the utility of money is essential in the insurance industry, for prioritising public spending schemes and for the evaluation of decisions on protection systems in high-hazard industries. Up to this time, however, there has been no universally agreed measure for the utility of money, with many utility functions being in common use. In this paper, we shall derive a single family of utility functions, which have risk-aversion as the only free parameter. The fact that they return a utility of zero at their low, reference datum, either the utility of no money or of one unit of money, irrespective of the value of risk-aversion used, qualifies them to be regarded as absolute scales for the utility of money. Evidence of validation for the concept will be offered based on inferential measurements of risk-aversion, using diverse measurement data.

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

    International Nuclear Information System (INIS)

    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 ??/? 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

  3. Effects of natural radioactivity on food radioactivity measurement

    International Nuclear Information System (INIS)

    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.)

  4. Absolute stress measurements at the rangely anticline, Northwestern Colorado

    Science.gov (United States)

    de la Cruz, R. V.; Raleigh, C.B.

    1972-01-01

    Five different methods of measuring absolute state of stress in rocks in situ were used at sites near Rangely, Colorado, and the results compared. For near-surface measurements, overcoring of the borehole-deformation gage is the most convenient and rapid means of obtaining reliable values for the magnitude and direction of the state of stress in rocks in situ. The magnitudes and directions of the principal stresses are compared to the geologic features of the different areas of measurement. The in situ stresses are consistent in orientation with the stress direction inferred from the earthquake focal-plane solutions and existing joint patterns but inconsistent with stress directions likely to have produced the Rangely anticline. ?? 1972.

  5. Estimation of absolute renal uptake with technetium-99m dimercaptosuccinic acid: direct comparison with the radioactivity of nephrectomy specimens

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Mariana da Cunha Lopes de; Ramos, Celso Dario; Brunetto, Sergio Quirino; Etchebehere, Elba Cristina Sa Camargo; Santos, Allan de Oliveira; Camargo, Edwaldo Eduardo [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Dept. of Radiology. Div. of Nuclear Medicine]. E-mail: mar.lima@terra.com.br; Lima, Marcelo Lopes e; Ferreira, Ubirajara; Netto Junior, Nelson Rodrigues [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Dept. of Surgery. Div. of Urology

    2008-07-01

    Context and objective: Studies using radionuclides are the most appropriate method for estimating renal function. Dimercaptosuccinic acid chelate labeled with technetium-99m ({sup 99m}Tc- DMSA) is the radiopharmaceutical of choice for high-resolution imaging of the renal cortex and estimation of the functional renal mass. The aim of this study was to evaluate a simplified method for determining the absolute renal uptake (ARU) of {sup 99m}Tc-DMSA prior to nephrectomy, using the radioactivity counts of nephrectomy specimens as the gold standard. Design and setting: Prospective study at the Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas. Methods: Seventeen patients (12 females; range 22-82 years old; mean age 50.8 years old) underwent nephrectomy for various reasons. Renal scintigraphy was performed three to four hours after intravenous administration of a mean dose of 188.7 MBq (5.1 mCi) of {sup 99m}Tc-DMSA, which was done six to 24 hours before surgery. The in vivo renal uptake of {sup 99m}Tc-DMSA was determined using the radioactivity of the syringe before the injection (measured using a dose calibrator) and the images of the syringe and kidneys, obtained from a scintillation camera. After surgery, the reference value for renal uptake of {sup 99m}Tc-DMSA was determined by measuring the radioactivity of the nephrectomy specimen using the same dose calibrator. Results: The ARU measurements were very similar to those obtained using the reference method, as determined by linear regression (r-squared = 0.96). Conclusion: ARU estimation using the proposed method before nephrectomy seems to be accurate and feasible for routine use. (author)

  6. Estimation of absolute renal uptake with technetium-99m dimercaptosuccinic acid: direct comparison with the radioactivity of nephrectomy specimens

    International Nuclear Information System (INIS)

    Context and objective: Studies using radionuclides are the most appropriate method for estimating renal function. Dimercaptosuccinic acid chelate labeled with technetium-99m (99mTc- DMSA) is the radiopharmaceutical of choice for high-resolution imaging of the renal cortex and estimation of the functional renal mass. The aim of this study was to evaluate a simplified method for determining the absolute renal uptake (ARU) of 99mTc-DMSA prior to nephrectomy, using the radioactivity counts of nephrectomy specimens as the gold standard. Design and setting: Prospective study at the Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas. Methods: Seventeen patients (12 females; range 22-82 years old; mean age 50.8 years old) underwent nephrectomy for various reasons. Renal scintigraphy was performed three to four hours after intravenous administration of a mean dose of 188.7 MBq (5.1 mCi) of 99mTc-DMSA, which was done six to 24 hours before surgery. The in vivo renal uptake of 99mTc-DMSA was determined using the radioactivity of the syringe before the injection (measured using a dose calibrator) and the images of the syringe and kidneys, obtained from a scintillation camera. After surgery, the reference value for renal uptake of 99mTc-DMSA was determined by measuring the radioactivity of the nephrectomy specimen using the same dose calibrator. Results: The ARU measurements were very similar to those obtained using the reference method, as determined by linear regression (r-squared = 0.96). Conclusion: ARU estimation using the proposed method before nephrectomy seems to be accurate and feasible for routine use. (author)

  7. Improvement of a cryogenic radiometer for XFEL absolute intensity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T., E-mail: takahiro-tanaka@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568 (Japan); Kato, M.; Kurosawa, T.; Morishita, Y.; Saito, N. [National Institute of Advanced Industrial Science and Technology (AIST), NMIJ, Tsukuba 305-8568 (Japan); Yabashi, M.; Tono, K.; Kudo, T.; Ishikawa, T. [SPring-8/RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Shiraiwa, S. [Rockgate Co., 1-11-12 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2011-12-11

    A cryogenic radiometer was improved for measurements of the absolute radiant power of x-ray Free Electron Laser, which provides intense radiation with an ultra-short pulse duration. Based on simulation results obtained by the Monte Carlo program EGS 5 code, a new cavity absorber of the cryogenic radiometer was developed. The simulation results show that the new cavity absorber achieves absorptance close to unity for hard x-rays up to photon energies of 40 keV. The excellent performance of the new cavity absorber, as well as the consistency between the new and the former cavity, was confirmed by calibrating two different types of silicon photodiodes. The calibration results agreed well within their relative expanded uncertainties. To confirm the performance of the new cavity absorber in the high radiant power region, the radiant powers obtained with the cryogenic radiometer and an x-ray beam monitor were also compared. A strong correlation between the two detectors was obtained. With the new cavity absorber, the absolute radiant power of XFEL for photon energies of up to 40 keV with low uncertainties is expected to be measured.

  8. AWID - an absolutely measuring stress cell using the compensation technique

    International Nuclear Information System (INIS)

    According to the measuring principle of the stress cell explained in this report, stresses can be measured without materials parameters of the cell influencing the measurements, so that calibration measurements are not required for this absolutely measuring cell. There is no temperature dependence either. The report discusses the functioning mode which is based on evaluation of a gap in the resistance of the cell which is induced when two sheets move apart from each other in the process of pumping hydraulic oil, at the point when external pressure is reached. Theoretical studies were supplemented by laboratory tests both in an autoclave and in a tube filled with salt rock grus, under a uniaxial press. The error observed with measurements in an oil-pressure autoclave was within the order of magnitude of the reading accuracy of the measuring equipment, i.e. it was less than 0.3% at 150 bar. This is to be taken as the error to be attributed to the cell. (orig.)

  9. Calibrated radioactive sources - absolute measurements using a 4{pi} {beta}-{gamma} apparatus; Sources etalons de radioactivite - mesures absolues au moyen d'un ensemble 4{pi} {beta}-{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, P.; Philis, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    In this paper, the principle of the standardization of the radioisotopes by the 4{pi} {beta} - {gamma} coincidence method is reminded. Some theoretical examples are given emphasizing on instrumental coincidences and their corrections. The experimental apparatus is described: one discusses the choice of the experimental conditions for the many isotopes measured. Results are given and discussed. In appendix we describe the preparation of the sources. (authors) [French] Dans ce rapport, nous rappelons d'abord le principe de la methode d'etalonnage 4{pi} {beta} - {gamma} en donnant quelques exemples theoriques et en insistant sur la correction des erreurs instrumentales. Une description critique de l'appareillage utilise est donnee. On discute le choix des conditions experimentales pour divers isotopes mesures et les resultats obtenus. En annexe, nous decrivons la fabrication des sources que nous mesurons.

  10. Measurement of Radioactivity in Some Croatian Regions

    International Nuclear Information System (INIS)

    Full text: After Government of Canada expressed its suspicion that Canadian soldiers who were included in UNPROFOR mission in Croatia were exposed to increased radioactivity and possible some chemical influences, a large action of measuring and sampling was undertaken. Canadian and Croatian experts were working together and a very large number of samples was collected. Measurements of alpha, beta and gamma radioactivity on terrain, as well as later analysis of samples showed no increased radioactivity or any other signs of radioactive contamination. The conclusion is that any possible diseases of Canadian soldiers can not originate from radiation or radioactive contamination in Croatia. (author)

  11. Radioactive waste measuring technique. Low level radioactive waste

    International Nuclear Information System (INIS)

    The operation of Rokkasho Low Level Radioactive Waste Burial Center was commenced in December 1992, and transport of homogeneous solidified body drums to this center was started. It is mandatory that low level radioactive waste drums are checked before bring-out to assure that they conform to the burial criteria of the nation. The items of this check are seven items. In these items, radioactivity measurement is explained below. 1. Radioactivity concentration measurement. The radio of the gamma-ray discharge nuclide is measured using a high purity Ge semiconductor detector, while the gross gamma-ray dose is measured simultaneously using a plastic scintillation detector. The radioactivity of the representative nuclide is calculated from the detected nuclide component ratio and the gross gamma-ray counting rate, and in addition, the radioactivity concentration is calculated from the involved total radioactivity and weight measured value included in the waste drum analysis data. Specification. Nuclide to be measured: Co-60, Cs-137, etc. Detection lower limit value: 3.7x10-1 Bq/g. 2. Surface contamination density and dose equivalent measurement. After the surface substance was sampled using a wiping material, measurement of this wiping material is taken using a radiation detector. For surface dose equivalent measurement, a radiation detector is directly mounted to a wiping material mounting arm, and the gamma-ray dose is measured simultaneously during wiping actions. Specification. Detection lower limit: 3.7x10-1 Bq/cm2. Surface dose rate: 10-3 mSv/h - 10 mSv/h. (author)

  12. Measuring absolute branching ratios of charmed baryons in B decays

    International Nuclear Information System (INIS)

    The B factories are expected to provide huge samples of single B decay events with little background by reconstructing one of the B mesons produced in Υ(4S) decays. This represents a new experimental paradigm: such samples will allow to make measurements of a quality previously thought unrealistic. As example we discuss how absolute branching ratios for exclusive as well as inclusive charm baryon decays can be extracted. One starts out by observing decays like B- →anti pX as a signature for B-→Λc anti pX etc. and then exploits various correlations of the flavour of the B meson with the baryon number of the (anti)proton and other observables like the charge of a lepton, baryon number of another baryon etc. An integrated luminosity of about 500 fb-1 as could be available by 2005 should be sufficient for the task. (orig.)

  13. Absolute measurement of undulator radiation in the extreme ultraviolet

    International Nuclear Information System (INIS)

    The spectral brightness of undulator radiation emitted by the model PMU-1 incorporated in the SOR-RING, the dedicated synchrotron radiation source in Tokyo, has been studied in the extreme ultraviolet region from 21.6 to 72.9 eV as a function of the electron energy #betta#, the field parameter K, and the angle of observation THETA in the absolute scale. A series of measurements covering the first and the second harmonic component of undulator radiation was compared with the fundamental formula lambdasub(n)=lambda0/2n#betta#2(1+K2/2+#betta#2THETA2), and the effects of finite emittance were studied. The brightness at the first peak was smaller than the theoretical value, while an enhanced second harmonic component was observed. (orig.)

  14. Absolute measurement of neutron fluxes inside the reactor core

    International Nuclear Information System (INIS)

    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)

  15. Radioactivity measurement and standardization in Thailand

    International Nuclear Information System (INIS)

    An absolute measurement method for disintegration rates of radioisotopes by 4? beta-gamma coincidence counting systems is described. Absolute activity of 60Co and 99Mo was determined by the counting systems of Japan and Thailand. Radon gas measurement and standardization were also performed. A radon chamber was constructed and employed for the comparative measurements by a pulse-counting ionization chamber and an environmental-level scintillation chamber. The background radon concentration of the radon chamber was also determined. (author)

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

    Science.gov (United States)

    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) information. Spatial variations and day-to-day changes in the visible oil concentration on the surface of the water were observed in performing these measurements. An assessment of the thermal imagery variation will be made based on the absolute calibration of the sensor to determine if the visible variation was due to properties of the reflected light or of the actual oil composition. Comparisons with satellite data (both SAR and thermal infrared images) and buoy data will also be included.

  17. Measurement of radioactivity in water samples

    International Nuclear Information System (INIS)

    Public concern about the levels of radioactivity release to the environment whether authorised discharges or resulting from nuclear accident, has increased in recent years. Consequently there is increasing pressure for reliable data on the distribution of radioactivity and the extent of its intrusion into food chains and water supplies. As a result a number of laboratories not experienced in radioactivity measurements have acquired nucleonic counting equipment. These notes explore the underlying basics and indicate sources of essential data and information which are required for a better understanding of radioactivity measurements. Particular attention is directed to the screening tests which are usually designated ''gross'' alpha and ''gross'' beta activity measurement. (author)

  18. Precise measurements of the absolute ?-ray emission probabilities of (223)Ra and decay progeny in equilibrium.

    Science.gov (United States)

    Collins, S M; Pearce, A K; Regan, P H; Keightley, J D

    2015-08-01

    Precise measurements of the absolute ?-ray emission probabilities have been made of radiochemically pure solutions of (223)Ra in equilibrium with its decay progeny, which had been previously standardised by 4?(liquid scintillation)-? digital coincidence counting techniques. Two high-purity germanium ?-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 ?-ray spectrometry measurements using the nuclear data evaluations of the Decay Data Evaluation Project exhibited a range of ~18% in the most intense ?-ray emissions (>1% probability) of the (223)Ra decay series. Absolute ?-ray emission probabilities and standard uncertainties have been determined for the decay of (223)Ra, (219)Rn, (215)Po, (211)Pb, (211)Bi and (207)Tl in equilibrium. The standard uncertainties of the measured ?-ray emission probabilities quoted in this work show a significant improvement over previously reported ?-ray emission probabilities. Correlation coefficients for pairs of the measured ?-ray emission probabilities from the decays of the radionuclides (223)Ra, (219)Rn and (211)Pb have been determined and are presented. The ?-transition probabilities of the (223)Ra have been deduced from P(?+ce) balance using the ?-ray emission probabilities determined in this work with some agreement observed with the published experimental values of the ?-emission probabilities. PMID:25933406

  19. Measuring the absolute quantum efficiency of luminescent materials

    Energy Technology Data Exchange (ETDEWEB)

    Rohwer, Lauren Shea [Sandia National Laboratories, P.O. Box 5800, MS-0892, Albuquerque, NM 87185-0892 (United States)]. E-mail: leshea@sandia.gov; Martin, James E. [Sandia National Laboratories, P.O. Box 5800, MS-0892, Albuquerque, NM 87185-0892 (United States)

    2005-11-15

    A measurement system and mathematical procedure are developed for determining the absolute quantum efficiency (QE), of luminescent materials. This technique, based on absorption of diffuse light within an integrating sphere, is applied to fluorescent laser dyes and conventional phosphor powders. The system described is tested for excitation in the near-UV and blue regions, but can be applied to higher energy excitation (UV), as well as lower energy excitation in the visible to near-IR, with the appropriate photodetectors and optical filters. The system was tested on both liquid and solid samples such as Coumarin 500 (CM500) dye in methanol and ethyl acetate; Rhodamine 6G in ethanol; and a variety of powder phosphors. The QE of quinine sulfate dihydrate solution (5x10{sup -3} M in 0.1 N H{sub 2}SO{sub 4}), a NIST fluorescence standard, was found to be in good agreement with the NIST value under 390 nm excitation. The accuracy of this measurement technique is acceptable for samples with absorption cross sections greater than {approx}6 mm{sup 2}.

  20. Measuring device for radioactive gas concentrations

    International Nuclear Information System (INIS)

    The invention has been aimed at a continuous or discontinuous measurement of radioactive gas concentrations. A covered electret and an oscillate opposite electrode are disposed at a radioactive gas. The opposite electrode is connected with the metallic back of the electret by an alternating voltage measuring device and has the function of a test electrode for the inductive evaluation of the electret

  1. Interpretation of the Arcade 2 Absolute Sky Brightness Measurement

    Science.gov (United States)

    Seiffert, M.; Fixsen, D. J.; Kogut, A.; Levin, S. M.; Limon, M.; Lubin, P. M.; Mirel, P.; Singal, J.; Villela, T.; Wollack, E.; Wuensche, C. A.

    2011-01-01

    We use absolutely calibrated data between 3 and 90 GHz from the 2006 balloon flight of the ARCADE 2 instrument, along with previous measurements at other frequencies to constrain models of extragalactic emission. Such emission is a combination of the cosmic microwave background (CMB) monopole, Galactic foreground emission, the integrated contribution of radio emission from external galaxies, any spectral distortions present in the CMB, and any other extragalactic source. After removal of estimates of foreground emission from our own Galaxy, and an estimated contribution of external galaxies, we present fits to a combination of the flat-spectrum CMB and potential spectral distortions in the CMB. We find 217 upper limits to CMB spectral distortions of u < 6x10(exp -4) and [Y(sub ff)] < 1x10(exp -4). We also find a significant detection of a residual signal beyond that, which can be explained by the CMB plus the integrated radio emission from galaxies estimated from existing surveys. This residual signal may be due to an underestimated galactic foreground contribution, an unaccounted for contribution of a background of radio sources, or some combination of both. The residual signal is consistent with emission in the form of a power law with amplitUde 18.4 +/- 2.1 K at 0.31 GHz and a spectral index of -2.57 +/- 0.05.

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

    Science.gov (United States)

    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.

  3. Accurate absolute measurement of trapped Cs atoms in a MOT

    Energy Technology Data Exchange (ETDEWEB)

    Talavera O, M.; Lopez R, M.; Carlos L, E. de [Division de Tiempo y Frecuencia, Centro Nacional de Metrologia, CENAM, km 4.5 Carretera a los Cues, El Marques, 76241 Queretaro (Mexico); Jimenez S, S. [Centro de Investigacion y Estudios Avanzados del lPN, Unidad Queretaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Queretaro (Mexico)

    2007-07-01

    A Cs-133 Magneto-Optical Trap (MOT) has been developed at the Time and Frequency Division of the Centro Nacional de Metrologia, CENAM, in Mexico. This MOT is part of a primary frequency standard based on ultra-cold Cs atoms, called CsF-1 clock, under development at CENAM. In this Cs MOT, we use the standard configuration ({sigma}{sup +} - {sigma}{sup -}) 4-horizontal 2-vertical laser beams 1.9 cm in diameter, with 5 mW each. We use a 852 nm, 5 mW, DBR laser as a master laser which is stabilized by saturation spectroscopy. Emission linewidth of the master laser is l MHz. In order to amplify the light of the master laser, a 50 mW, 852 nm AlGaAs laser is used as slave laser. This slave laser is stabilized by light injection technique. A 12 MHz red shift of the light is performed by two double passes through two Acusto-Optic Modulators (AOMs). The optical part of the CENAMs MOT is very robust against mechanical vibration, acoustic noise and temperature changes in our laboratory, because none of our diode lasers use an extended cavity to reduce the linewidth. In this paper, we report results of our MOT characterization as a function of several operation parameters such as the intensity of laser beams, the laser beam diameter, the red shift of light, and the gradient of the magnetic field. We also report accurate absolute measurement of the number of Cs atoms trapped in our Cs MOT. We found up to 6 x 10{sup 7} Cs atoms trapped in our MOT measured with an uncertainty no greater than 6.4%. (Author)

  4. Absolute measurement of the 125I desintegration rate

    International Nuclear Information System (INIS)

    The procedure followed by the Laboratorio de Metrologia Nuclear at the IPEN (Instituto de Pesquisas Energeticas e Nucleares), Sao Paulo - Brazil, for the absolute determination of the 125I desintegration rate by means of the X-(X,Π) Coincidence and Sum-Peak methods is described. The results were submitted to the BIPM (Bureau International des Poids et Mesures), France, for an International Comparison of this radionuclide. (author)

  5. Accurate absolute measurement of trapped Cs atoms in a MOT

    Scientific Electronic Library Online (English)

    M., Talavera O.; M., Lpez R.; E., de Carlos L.; S., Jimnez S.

    2007-10-01

    Full Text Available Una Trampa Magneto-ptica (MOT) de Cs-133 se ha desarrollado en la Divisin de Tiempo y Frecuencia del Centro Nacional de Metrologa, CENAM, en Mexico. Esta MOT es parte de un patrn primario de frecuencia basado en tomos ultra fros de Cs, llamado reloj CsF-1 que se encuentra en desarrollo en el C [...] ENAM. En esta MOT de Cs, se emplea la configuracion estndar (?+ - ?-) de 4 haces laser horizontales y 2 verticales de 1.9 cm de diametro con 5 mW de potencia cada uno. Se utiliza un lser DBR de 852 nm y 5 mW como lser maestro estabilizado por espectroscopia de saturacin. El ancho de lnea de emision del lser maestro es de 1 MHz. Para amplificar la luz del lser maestro, se emplea un laser esclavo de AlGaAs de 852 nm y 50 mW de potencia. Este lser esclavo es estabilizado por la tcnica de inyeccin de luz. Se realiza un corrimiento de la luz al rojo de 12 MHz por un doble paso a travs de dos Moduladores Acusto-pticos (AOMs). La parte ptica de la MOT del CENAM es muy robusta contra la vibracion mecnica, el ruido acstico y los cambios de temperatura en el laboratorio, debido a que ninguno de los diodos laser emplea una cavidad extendida para reducir el ancho de lnea. En este trabajo se reportan los resultados de la caracterizacion de la MOT como una funcin de varios parmetros de operacin tales como: intensidad y dimetro de los haces lser, corrimiento al rojo de la luz y el gradiente de campo magntico. Tambin se reportan mediciones absolutas del nmero de tomos de Cs atrapados en la MOT. Se encontraron mas de 6 x 10(7) atomos de Cs atrapados, medidos con una incertidumbre que en ningn caso es mayor a 6.4%. Abstract in english A Cs-133 Magneto-Optical Trap (MOT) has been developed at the Time and Frequency Division of the Centro Nacional de Metrologa, CENAM, in Mexico. This MOT is part of a primary frequency standard based on ultra-cold Cs atoms, called CsF-1 clock, under development at CENAM. In this Cs MOT, we use the [...] standard configuration (?+ - ?-) 4-horizontal 2-vertical laser beams 1.9 cm in diameter, with 5 mW each. We use a 852 nm, 5 mW, DBR laser as a master laser which is stabilized by saturation spectroscopy. Emission linewidth of the master laser is 1 MHz. In order to amplify the light of the master laser, a 50 mW, 852 nm AlGaAs laser is used as slave laser. This slave laser is stabilized by light injection technique. A 12 MHz red shift of the light is performed by two double passes through two Acusto-Optic Modulators (AOMs). The optical part of the CENAMs MOT is very robust against mechanical vibration, acoustic noise and temperature changes in our laboratory, because none of our diode lasers use an extended cavity to reduce the linewidth. In this paper, we report results of our MOT characterization as a function of several operation parameters such as the intensity of laser beams, the laser beam diameter, the red shift of light, and the gradient of the magnetic field. We also report accurate absolute measurement of the number of Cs atoms trapped in our Cs MOT. We found up to 6 x 10(7) Cs atoms trapped in our MOT measured with an uncertainty no greater than 6.4%.

  6. Measurements of natural radioactivity in phosphate fertilizers

    International Nuclear Information System (INIS)

    The natural radioactivity, mainly due to radium (226Ra), in phosphate fertilizers used in north-western Greece has been measured by ?-spectroscopy. Also radioactivity measurements were performed in soil samples and were compared to samples from undisturbed soils. 226Ra belongs to the 238U chain and is the precursor of radon gas (222Rn). The radon concentrations in warehouses, where large quantities of fertilizers are kept, were measured with CR-39 SSNTDs. The radium concentrations in the fertilizers ranged from 0 to 4584 Bq kg-1 and the radon concentrations in warehouses were measured 540-3320 Bq m-3. The results are discussed from the radiation protection point of view

  7. Absolute activity measurement of 198Au and 116In neutron activation detectors

    International Nuclear Information System (INIS)

    The absolute measurement of activity of Au- and In-activation detectors by the 4πβ proportional flow counter with methane filling has been presented. All correction factors, necessary for absolute measurements have been quoted. The particularly attention is paid to self-absorption coefficient, since it is significant, and amounts from 0.4 to 0.98. (author)

  8. Measurement of environmental radioactivity. Ispra 1976

    International Nuclear Information System (INIS)

    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

  9. National and international traceability in radioactivity measurements

    International Nuclear Information System (INIS)

    The quality of radioactivity measurements in this period of rapidly expanding production and use of radioactive materials and their transfer to the biosphere has come under increasing scrutiny from government regulatory agencies and the public alike. This paper reviews the history and present status of measurements assurance, or traceability, programmes developed in the United States of America to ensure the quality of such measurements. It also briefly describes intercomparative measurements carried out with other national laboratories either directly or through the Bureau International des Poids et Mesures and the International Atomic Energy Agency for the purpose of establishing traceability in the international field. It is concluded that in the USA it is logistically impossible, except in a few special cases, for the National Bureau of Standards to provide other than programmes that will give implicit quality assurance for radioactivity measurements. (author)

  10. Absolute continuity of autophage measures on finite-dimensional vector spaces

    International Nuclear Information System (INIS)

    We consider a class of measures called autophage which was introduced and studied by Szekely for measures on the real line. We show that the autophage measures on finite-dimensional vector spaces over real or Qp are infinitely divisible without idempotent factors and are absolutely continuous with bounded continuous density. We also show that certain semistable measures on such vector spaces are absolutely continuous. (author)

  11. Radioactivity monitoring network: Measurements 1987

    International Nuclear Information System (INIS)

    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)

  12. NKS 1999 intercomparison of measurements of radioactivity

    International Nuclear Information System (INIS)

    34 laboratories have returned radioactivity measurements on six different environmental samples. The samples were analysed for their content of gamma emitters, Sr-90, transuranics and Tc-99. The samples materials are described and the results presented. Some scatter was observed in measurements of Cs-137 in low-level samples such as dry milk, meat and hay. The scatter was less pronounced for sediments and seaweed material that had higher levels of radioactivity. In general, the most of the results were consistent with a few laboratories reporting outlying values. An exception was seawater where no clear agreement could be found for the activity of Cs-137. (au)

  13. Environmental radioactivity measurement intercomparison exercise 1990

    International Nuclear Information System (INIS)

    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. Study on measurement of radioactive contamination

    International Nuclear Information System (INIS)

    The complexity in analysis of results measuring the level of radioactive contamination with β- particles, relative to personnel working in the field of radiation safety because of different units of measurements (β/ s,. cpm ,μSv/h,β/ (min cm2)). This paper show the particle study to standardize the units of measurement specified calibration process to determine the factor of conversion in a unit β/(mincm2) that allows a normalized unit. (Author)

  15. Portable laboratories for radioactivity measurements

    International Nuclear Information System (INIS)

    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. System for measuring radioactivity of labelled biopolymers

    International Nuclear Information System (INIS)

    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

  17. Nondestructive measurement of environmental radioactive strontium

    Directory of Open Access Journals (Sweden)

    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.

  18. Flow measurement of blood radioactivity in animals

    International Nuclear Information System (INIS)

    In order to permit flow measurement of blood radioactivity in an animal after establishing extracorporeal circulation, counting cells were constructed of various plastic scintillator materials. The cell was placed in a liquid scintillation spectrometer replacing the sample vial. Stable and reproducible counting rates were obtained only with cells made of blue Altustipe plastic. The counting efficiency was 1.8%. Using this detection system, continuous records were produced of blood radioactivity in miniature pigs after administration of 14C-urethane and [14C]methyl-piperazinyl pyrazino benzoxazepine maleate

  19. Absolute beam emittance measurements at RHIC using ionization profile monitors

    Energy Technology Data Exchange (ETDEWEB)

    Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Connolly, R [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Liu, C. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Summers, T. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-08-15

    In the past, comparisons between emittance measurements obtained using ionization profile monitors, Vernier scans (using as input the measured rates from the zero degree counters, or ZDCs), the polarimeters and the Schottky detectors evidenced significant variations of up to 100%. In this report we present studies of the RHIC ionization profile monitors (IPMs). After identifying and correcting for two systematic instrumental errors in the beam size measurements, we present experimental results showing that the remaining dominant error in beam emittance measurements at RHIC using the IPMs was imprecise knowledge of the local beta functions. After removal of the systematic errors and implementation of measured beta functions, precise emittance measurements result. Also, consistency between the emittances measured by the IPMs and those derived from the ZDCs was demonstrated.

  20. Absolute β Counting and its Application for the Standardization of Radioactive Neutron Sources

    International Nuclear Information System (INIS)

    The emission rate of the Canadian neutron standard, a Ra-Be (,α n) source, has been determined by two methods. Both involve the standardization of radioactive nuclides. By the first method, the neutrons were moderated in a manganese sulphate solution surrounding the source. A calculable number of thermal neutrons is captured in the manganese of the bath and produces radioactive Mn56. From its resulting activity the neutron emission rate is found. High specific activity Mn56 solution, prepared by using the Szilard-Chalmer s process, was standardized by 4 π β counting (proportional) and compared with the activated solution of the bath. The second method which does not seem to have been used previously, makes use of the F19 (α, n) Na22 reaction in a specially prepared Po-F source. Since fluorine is monoisotopic the neutron output can be calculated from the yield of the resulting radioactive Na22 because for each neutron a Na22 nucleus is produced. Na22 is a positron emitter and discrimination against γ-rays from Po210 and from the reaction could be achieved by detecting the two annihilation quanta in coincidence. Comparison was made with a standardized Na22 source. Standardization was carried out using the 4 π β-γ coincidence technique; details on its application to Na22 will be described. (author)

  1. Technological Basis and Scientific Returns for Absolutely Accurate Measurements

    Science.gov (United States)

    Dykema, J. A.; Anderson, J.

    2011-12-01

    The 2006 NRC Decadal Survey fostered a new appreciation for societal objectives as a driving motivation for Earth science. Many high-priority societal objectives are dependent on predictions of weather and climate. These predictions are based on numerical models, which derive from approximate representations of well-founded physics and chemistry on space and timescales appropriate to global and regional prediction. These laws of chemistry and physics in turn have a well-defined quantitative relationship with physical measurement units, provided these measurement units are linked to international measurement standards that are the foundation of contemporary measurement science and standards for engineering and commerce. Without this linkage, measurements have an ambiguous relationship to scientific principles that introduces avoidable uncertainty in analyses, predictions, and improved understanding of the Earth system. Since the improvement of climate and weather prediction is fundamentally dependent on the improvement of the representation of physical processes, measurement systems that reduce the ambiguity between physical truth and observations represent an essential component of a national strategy for understanding and living with the Earth system. This paper examines the technological basis and potential science returns of sensors that make measurements that are quantitatively tied on-orbit to international measurement standards, and thus testable to systematic errors. This measurement strategy provides several distinct benefits. First, because of the quantitative relationship between these international measurement standards and fundamental physical constants, measurements of this type accurately capture the true physical and chemical behavior of the climate system and are not subject to adjustment due to excluded measurement physics or instrumental artifacts. In addition, such measurements can be reproduced by scientists anywhere in the world, at any time, by appeal to the scientific literature and protocols supported by the international community of measurement scientists. This link to the international measurement community provides an established link to a rigorous body of knowledge for the assessment of measurement uncertainty, which is crucial to societal objectives of a quantitative nature. Finally, because enhanced quantitative weather and climate prediction directly serve decision support structures that embody critical societal objectives, the credibility of these predictions is paramount. Since the foundation of credibility of any scientific theory is the underlying observational evidence, the link between these measurements and internationally recognized measurement standards is a critical component in the portfolio of Earth observing systems. Clearly measurements that are unerringly compatible with fundamental physical and chemical relationships offer distinct advantages for supporting improved prediction.

  2. Radioactivity measurements as tool for physics dissemination

    International Nuclear Information System (INIS)

    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)

  3. Measurement of environmental radioactivity in Toki district

    International Nuclear Information System (INIS)

    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.)

  4. A method of absolute measurement of radon daughters concentration in air

    International Nuclear Information System (INIS)

    A method of absolute measurement of radon daughters concentration in air by means of the liquid scintillation technique is described. The method, thanks to its high accuracy, is very convenient for calibration of portable radon daughters monitors. (author). 3 refs

  5. Uncertainty vade-mecum in radioactivity measurement

    International Nuclear Information System (INIS)

    This article reviews the tools available to assign realistic uncertainties in the field of radioactivity measurements following the prescriptions of the Guide to the Expression of Uncertainty in Measurement. A presentation of different distributions that can be encountered in the analysis of radioactivity measurements is listed, and explained using simple but pertinent examples. Two different methods, a simplified coincidence method and γ counting, are considered, for each of which a detailed uncertainty budget is given. This leads into the characteristics function and the law of propagation of errors that can be used in the evaluation of the total uncertainty. The treatment of correlations, which occur when using the same set of sources and the same decay period for both methods, is also detailed. Subsequently, the analysis of the results of a comparison of activity measurements made by various national laboratories is presented with special care regarding the treatment of correlations that may arise. (author)

  6. Uncertainty vade-mecum in radioactivity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ratel, G. [Bureau International des Poids et Mesures, 92 - Sevres (France)

    2007-08-15

    This article reviews the tools available to assign realistic uncertainties in the field of radioactivity measurements following the prescriptions of the Guide to the Expression of Uncertainty in Measurement. A presentation of different distributions that can be encountered in the analysis of radioactivity measurements is listed, and explained using simple but pertinent examples. Two different methods, a simplified coincidence method and {gamma} counting, are considered, for each of which a detailed uncertainty budget is given. This leads into the characteristics function and the law of propagation of errors that can be used in the evaluation of the total uncertainty. The treatment of correlations, which occur when using the same set of sources and the same decay period for both methods, is also detailed. Subsequently, the analysis of the results of a comparison of activity measurements made by various national laboratories is presented with special care regarding the treatment of correlations that may arise. (author)

  7. Environmental radioactivity measurements after the Chernobyl accidents

    International Nuclear Information System (INIS)

    The measurements of the environmental radioactivity performed by the Radiation Protection Division of the CCR Ispra and by the Healt Physics Service of the CRE Saluggia ENEA on samples collected in the North-Western Italy after the Chernobyl accident are here reported. The general structure of the environmental laboratories; the choice of the samples and their collection are discussed in order to plan the actions and to make the measurements comparable

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

    International Nuclear Information System (INIS)

    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.

  9. Why the Bradley aberration cannot be used to measure absolute speeds. A comment

    OpenAIRE

    Kassner, Klaus

    2002-01-01

    In a recent article in this journal [G. Sardin, Measure of the absolute speed through the Bradley aberration of light beams on a three-axis frame, Europhys. Lett. 53 (2001) 310], Sardin proposed to use the Bradley aberration of light for the construction of a speedometer capable of measuring absolute speeds. The purpose of this comment is to show that the device would not work.

  10. Absolute measurement of beam energy by Compton scattering

    International Nuclear Information System (INIS)

    We propose that the energy of a relativistic electron beam can be measured by observing the Compton radiation it scatters from a resonating cavity. The radiation is to be observed at the frequency at which the intensity does not depend upon the phase of the beam relative to the rf. The measurement will give δE/E to within 10-4 in about 10 seconds for a 1 mA beam. The number of photons can be significantly increased, and the measuring time decreased proportionately, by use of an rf wiggler in place of the cavity

  11. Absolute measurements of neutron cross sections. Progress report

    International Nuclear Information System (INIS)

    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

  12. Absolute measurement of β emitters with a 4 π counter

    International Nuclear Information System (INIS)

    The object of this work is to investigate the conditions under which the activity of β-emitting radionuclides may be measured with a maximum of precision, and as a result to study the relevant corrections. The various problems relating to activity measurements with a 4 π counter have been examined successively: - comparison of 4 π, GM and proportional counters; - study of the preparation of sources; - corrections on the counting of sources; - self-absorption; - correction for absorption. The precision obtained on these measurements varies from 1.2 to 3 per cent, with the result that the 4 π counter can be considered a very satisfactory calibration instrument. (author)

  13. Radioactivity measurements in potassium enriched vegetation

    International Nuclear Information System (INIS)

    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)

  14. Absolute measurements of neutron cross sections. Progress report

    International Nuclear Information System (INIS)

    The measurement of the Cr(n,x)52V cross section at 14.6 MeV is discussed. Included in the discussion are sample preparation, counting systems, and calibration techniques. Future projects are also discussed. 13 refs., 2 figs., 3 tabs

  15. Absolute beam energy measurements in e+e- storage rings

    International Nuclear Information System (INIS)

    The CERN Large Electron Positron collider (LEP) was dedicated to the measurement of the mass Mz and the width ?z of the Z0 resonance during the LEP1 phase which terminated in September 1995. The Storage Ring operated in Energy Scan mode during the 1993 and 1995 physics runs by choosing the beam energy Ebeam to correspond to a center-of-mass (CM) energy at the interaction points (IPs) ECMpeak1762MeV. After a short review of the techniques usually adopted to set and control the beam energy, this paper describes in more detail two methods adopted at LEP for precise beam energy determination that are essential to reduce the contribution to the systematic error on Mz and ?z. The positron beam momentum was initially determined at the 20-GeV injection energy by measuring the speed of a less relativistic proton beam circulating on the same orbit, taking advantage of the unique opportunity to inject two beams into the LEP at short time intervals. The positron energy at the Z0 peak was in this case derived by extrapolation. Once transverse polarization became reproducible, the Resonant Depolarization (RD) technique was implemented at the Z0 operating energies, providing a ?2x10-5 instantaneous accuracy. RD Beam Energy Calibration has been adopted during the LEP Energy Scan campaigns as well as in Accelerator Physics runs for accurate measurement of machruns for accurate measurement of machine parameters. copyright 1997 American Institute of PhysicsThe CERN Large Electron Positron collider (LEP) was dedicated to the measurement of the mass Mz and the width ?z of the Z0 resonance during the LEP1 phase which terminated in September 1995. The Storage Ring operated in Energy Scan mode during the 1993 and 1995 physics runs by choosing the beam energy Ebeam to correspond to a center-of-mass (CM) energy at the interaction points (IPs) ECMpeak1762MeV. After a short review of the techniques usually adopted to set and control the beam energy, this paper describes in more detail two methods adopted at LEP for precise beam energy determination that are essential to reduce the contribution to the systematic error on Mz and ?z. The positron beam momentum was initially determined at the 20-GeV injection energy by measuring the speed of a less relativistic proton beam circulating on the same orbit, taking advantage of the unique opportunity to inject two beams into the LEP at short time intervals. The positron energy at the Z0 peak was in this case derived by extrapolation. Once transverse polarization became reproducible, the Resonant Depolarization (RD) technique was implemented at the Z0 operating energies, providing a ?2x10-5 instantaneous accuracy. RD Beam Energy Calibration has been adopted during the LEP Energy Scan campaigns as well as in Accelerator Physics runs for accurate measurement of mac

  16. Measurement and analysis of radioactive substances

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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.)

  18. Methods applied for measuring radioactive environmental isotopes

    International Nuclear Information System (INIS)

    Hydrologic applications of the radioactive environmental isotopes 3H, 14C and 85Kr require measuring methods, whose detection limits range 1 to 2 magnitudes below the concentrations of these radionuclides in recently generated groundwater. The study gives a survey about the corresponding analytic methods, which are applicable today at the GSF Institute for Radiohydrometry. In addition some information about the detection of 39Ar is provided. (orig.)

  19. Error calculations statistics in radioactive measurements

    International Nuclear Information System (INIS)

    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

  20. Method for the absolute measurement of photon energies

    Energy Technology Data Exchange (ETDEWEB)

    Likhachev, V.P.; Arruda Neto, J.D.T.; Deppman, A.; Cruz, M.T.F.; Carvalho, W.R.; Gavrikov, V.B.; Martins, M.N.; Mesa, J. [Universidade de Sao Paulo, SP (Brazil). Inst. de Fisica. Lab. do Acelerador Linear; Margarian, A. [Yerevan Institute of Nuclear Physics (Armenia)

    2001-07-01

    We present a Monte Carlo study of the Compton scattering of high energy photons on atomic electrons of a {sup 27} Al target. The calculation was done in order to estimate the potentiality of using this reaction for high precision measurements of photon energies. A computer code was developed, based on relativistic reaction kinematics in impulse approximation, accounting for the final atom kinetic energy and the internal motion of the atomic electrons. The code includes the rescattering of the emitted electron in the target material, and allows to study the influence of several geometrical parameters of the system on the accuracy with which the initial photon energy is determined. The results of the simulations show that, for high intensity photon beams, the energy of the photons can be determined with a relative accuracy of 10{sup -3}. (author)

  1. Absolute measurement of F2-laser power at 157 nm

    International Nuclear Information System (INIS)

    We report a comparison of laser power measurements at the F2-laser wavelength oaf nm made at two facilities of the Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute. At the PTB laboratory at the electron storage ring BESSY II in Berlin, the scale for laser power was directly traced to a cryogenic radiometer operating at 157 nm, whereas at the PTB laser radiometry facility in Braunschweig the calibration of transfer detectors was performed with a newly developed standard for laser power at 157 nm, which is traceable in several steps to a cryogenic radiometer operating at 633 nm. The comparison was performed under vacuum conditions with laser pulse energies of?10 ?J, however with different average powers because different primary standard radiometers were used. The relative deviation for the responsivity of the transfer detector was 4.8% and thus within the combined standard uncertainty

  2. An optical absolute position measurement method using a phase-encoded single track binary code

    Science.gov (United States)

    Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan; Bong Eom, Tae

    2012-11-01

    We present a new absolute position measurement method using a single track binary code where an absolute position code is encoded by changing the phase of one binary state representation. It can be decoded efficiently using structural property of the binary code, and its sub-division is possible by detecting the relative positions of the binary state representation used for the absolute position encoding. Therefore, the absolute position encoding does not interfere with the sub-division process and so any pseudo-random sequence can be used as the absolute position code. Because the proposed method does not require additional sensing part for the sub-division, it can be realized with a simple configuration and efficient data processing. To verify and evaluate the proposed method, an absolute position measurement system was setup using a binary code scale, a microscopic imaging system, and a CCD camera. In the comparison results with a laser interferometer, the measurement system shows the resolution of less than 50 nm and the nonlinearity error of less than ±60 nm after compensation.

  3. Cross-section measurements for radioactive samples

    International Nuclear Information System (INIS)

    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

  4. High-precision absolute distance and vibration measurement with frequency scanned interferometry

    International Nuclear Information System (INIS)

    We report high-precision absolute distance and vibration measurements performed with frequency scanned interferometry using a pair of single-mode optical fibers. Absolute distance was determined by counting the interference fringes produced while scanning the laser frequency. A high-finesse Fabry-Perot interferometer was used to determine frequency changes during scanning. Two multiple-distance-measurement analysis techniques were developed to improve distance precision and to extract the amplitude and frequency of vibrations. Under laboratory conditions, measurement precision of ∼50 nm was achieved for absolute distances ranging from 0.1 to 0.7 m by use of the first multiple-distance-measurement technique. The second analysis technique has the capability to measure vibration frequencies ranging from 0.1 to 100 Hz with an amplitude as small as a few nanometers without a priori knowledge

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

    International Nuclear Information System (INIS)

    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)

  6. National network of radioactivity measurement in environment

    International Nuclear Information System (INIS)

    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.)

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

    Science.gov (United States)

    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 absolute gravimetry, we expect that GRAV-D may be affected in a number of ways. 1) Areas requiring re-measurement as a result of poor quality data or temporal change could be measured with such a new meter. With a meter capable of field measurement with observation times that are very short, surveys previously conducted only with the relative meters could be performed with the absolute meter with no loss of time and a significant increase in accuracy. 2) Regions of rapid change due to hydrological change associated with aquifers could be measured and re-measured rather quickly. Such accuracy may provide more accurate snapshots of the aquifers over time. 3) NGS conducts absolute gravity comparisons at its Table Mountain facility for validating the performance of absolute meters through their co-located operation at gravity piers. An increase in accuracy of an order of magnitude may change the entire nature of absolute meter performance evaluation.

  8. Radioactivity measurement with a plastic scintillation vial

    International Nuclear Information System (INIS)

    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 caused by CO2. One of the methods without scintillation cocktail is using a solid scintillator (ReadyCap, Beckman). However, the method needs to dry up the sample, so it requires certain time to dry up and is not applicable for volatile compounds. Also the sample could not be recovered and the solid waste would be produced. Another method is the Cherenkov counting. The method is applicable for the nuclides emitting beta rays with energy more than 260 keV, if water is used for the medium of Cherenkov effect. To detect lower energies, Takiue et al. proposed a method using a high-refractive transparent ceramic. The method, however, needs to dry up the sample. In contrast, using the ScintiVial, one does not need to dry up the sample. More than ten times use of the ScintiVial may be less expensive than the whole c.ost of liquid scintillation counting, which includes 10-mL cocktail, counting vial, and the cost for incineration. Conclusion: The ScintiVial method to measure radioactivity using a liquid scintillation counter was developed. The counting efficiency for 32P was 28-10% and that for 125I was 3%. This method is quite simple, is less expensive, and do not produce any radioactive organic liquid waste. Furthermore the sample can be recovered.

  9. Dynamic frequency-domain interferometer for absolute distance measurements with high resolution

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Jidong; Liu, Shenggang; Ma, Heli; Tao, Tianjiong; Wang, Xiang; Liu, Cangli; Tan, Hua [Laboratory for Shock Waves and Detonation Physics Research, Institute of Fluid Physics, P. O. Box 919-102, Mianyang, Sichuan 621900 (China)

    2014-11-15

    A unique dynamic frequency-domain interferometer for absolute distance measurement has been developed recently. This paper presents the working principle of the new interferometric system, which uses a photonic crystal fiber to transmit the wide-spectrum light beams and a high-speed streak camera or frame camera to record the interference stripes. Preliminary measurements of harmonic vibrations of a speaker, driven by a radio, and the changes in the tip clearance of a rotating gear wheel show that this new type of interferometer has the ability to perform absolute distance measurements both with high time- and distance-resolution.

  10. Correlation method for measuring absolute power of zero-power reactors

    International Nuclear Information System (INIS)

    Principles of designing devices for measuring absolute power of reactors by the correlation method are considered. A model of the analog-to-digital device, realizing the correlation method for measuring absolute power of zero-power reactors and ways of its gaugeing using harmonic and noise signals are described. The results of device testing at the critical facility are given. The correlation method is shown to be applicable for efficiency of the neutron detectors of 2.3x10-5 order, when the frequency method is not applicable. The conclusion is made that the data obtained agree well with the results of measurements carried out by the frequency method

  11. Three-Counter System for Absolute Measurement of Source Activity by the Coincidence Method

    International Nuclear Information System (INIS)

    With the new method of absolute measurements proposed in the paper, it is possible to dispense with the nuclear constants needed for absolute measurements by the beta-gamma coincidence method in the case of isotopes with decay schemes including a beta branching and a partial gamma conversion, After an explanation of the principle involved, the paper describes how the method was applied to measurement of two dense sources (203Hg and 141C), together with the experimental results obtained, and compares activity Values obtained for one and the same sample with different methods. (author)

  12. Measurement time interval based on FPGA in NIM-3 absolute gravimeter

    Science.gov (United States)

    Wu, Shuqing; Li, Chunjian; Su, Duowu; Feng, Jinyang; Xu, Jinyi

    2015-02-01

    In order to perform gravity measurement with compact and portable instrument at several ten mGal accuracy level, a digital fringe signal processing method was proposed for the measurement time interval in a ballistic free-fall absolute gravimeter. This method based on the theory of digital phase-shift which was used in the SOPC system on a FPGA DE2 Electric Board and NIOS-II processor produced by Altera company. This method has been successfully used for the measurement of interference fringe numbers and time interval in NIM-3 ballistic free-fall absolute gravimeter.

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

    Science.gov (United States)

    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.

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

    CERN Document Server

    Nelles, A; 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; Bruüggen, 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

    2015-01-01

    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 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 35% 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 astronomic...

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

    International Nuclear Information System (INIS)

    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)

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

    CERN Document Server

    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...

  17. Absolute spectral responsivity measurements of solar cells by a hybrid optical technique.

    Science.gov (United States)

    Hamadani, Behrang H; Roller, John; Dougherty, Brian; Persaud, Fiona; Yoon, Howard W

    2013-07-20

    An irradiance mode, absolute differential spectral response measurement system for solar cells is presented. The system is based on combining the monochromator-based approach of determining the power mode spectral responsivity of cells with an LED-based measurement to construct a curve representing the light-overfilled absolute spectral response of the entire cell. This curve can be used to predict the short-circuit current (I(sc)) of the cell under the AM 1.5 standard reference spectrum. The measurement system is SI-traceable via detectors with primary calibrations linked to the NIST absolute cryogenic radiometer. An uncertainty analysis of the methodology places the relative uncertainty of the calculated I(sc) at better than ±0.8%. PMID:23872765

  18. Absolute determination of 75Se for international comparison of activity measurements

    International Nuclear Information System (INIS)

    An international intercomparison of absolute activity measurements of a solution of Se-75, organized by the Bureau International des Poids et Mesures, France, in 1992, has been carried out. The methodology and results are presented. Source preparation, experimental techniques and measurement system are described. (author). 2 refs

  19. 2? absolute measurement research for ?-electroplating source covering ZnS(Ag)

    International Nuclear Information System (INIS)

    2? absolute measurement can be completed after the quantitative deposit (5 +- 1) mg/cm2 with ZnS(Ag) on surface of the alpha electroplating source. The measuring efficiency is 100%. This method is suitable for both of electroplating ordinary sample and electroplating standard (of reference) source

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    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)

  2. High-precision Absolute Distance Measurement using Dual-Laser Frequency Scanned Interferometry Under Realistic Conditions

    CERN Document Server

    Yang, H J; Riles, Keith; Yang, Hai-Jun

    2006-01-01

    In this paper, we report on new high-precision absolute distance measurements performed with frequency scanned interferometry using a pair of single-mode optical fibers. Absolute distances were determined by counting the interference fringes produced while scanning the frequencies of the two chopped lasers. High-finesse Fabry-Perot interferometers were used to determine frequency changes during scanning. Dual lasers with oppositely scanning directions, combined with a multi-distance-measurement technique previously reported, were used to cancel drift errors and to suppress vibration effects and interference fringe uncertainties. Under realistic conditions, a precision about 0.2 microns was achieved for a distance of 0.41 meters.

  3. Absolute rate measurements of two-photon process of gases, liquids, and solids

    International Nuclear Information System (INIS)

    Due to rapid improvements in high-power laser performance, two-photon absorption processes have become a very useful tool for studying the molecular structures of various gases, liquids and solids. However, measurements of absolute two-photon absorption cross sections were more or less ignored previously because of their small size. In this work, we obtained not only the two-photon absorption spectra, but also measurements of their absolute cross sections for various gases, liquids, and solids. 8 refs., 1 fig., 1 tab

  4. Radioactivity measurements for air-dust samples around Fukushima prefecture

    International Nuclear Information System (INIS)

    A large amount of radioactive materials were released in the environment by the accident at the Fukushima Daiichi Nuclear Power Station. To investigate pollution status and behavior of radioactive materials in the environment, it is essential to monitor amounts of these radioactive materials in the environment at several places for long term. We have been collecting air-dust using high volume air sampler at Fukushima city (Fukushima Pref.), Marumori town (Miyagi Pref.) and Hitachi city (Ibaraki Pref.) since the accident. We identified the radioactivities of 134Cs and 137Cs in filters using HPGe detector. The activity ratio of 134Cs/137Cs was mostly constant, on the other hand, the absolute activity of 134Cs and 137Cs varied with sample collection date by about ten times. In this report, we discuss the relationship between the time variation of the radioactivity concentrations and meteorological phenomenon. (author)

  5. g(21+) factor measurement with radioactive beams

    International Nuclear Information System (INIS)

    The g factor studies in the short lived nuclear states provide valuable information on various structural properties observed at high spins in nuclei. The importance of transient magnetic field method in measuring the g factor of such short lived states in stable nuclei has been well recognised. The fast development of physics of unstable nuclei produced as radioactive ion beams over the last one decade has put an increased demand for g factor measurement in these short lived exotic nuclei. Their special means of production require some new methods of measuring g factor in them. In this pursuit, a new technique, the high velocity transient magnetic field (HVTF) has emerged as a promising technique and has been tested successfully in some realistic cases. There are some issues in the techniques which need to be looked at before it can be applied at wider level. (author)

  6. Quality control of environmental radioactivity measurements

    International Nuclear Information System (INIS)

    Quality control of measured data from an environmental monitoring network is of great importance to assure that further dose assessments and measures are based on reliable data. The demand for a fast data flow requires a clear concept and predefined criteria. Even if data have passed technical check procedures, according to daily experience, some of them will still be inconsistent with others in a radioecological sense. A model of interdependencies for six well established fast detection methods for radioactivity in the air and on the ground is presented and the checks for consistency are discussed. In a further step it is shown how data from stations with an incomplete set of instrumentation can be interpreted on the basis of the model results. An expert system written in PROLOG and presently running as a demo version has been developed on the basis of this model in cooperation with DORNIER. (author)

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

    International Nuclear Information System (INIS)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1956-07-01

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

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

    CERN Document Server

    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^{+}\

  10. Why the Bradley aberration cannot be used to measure absolute speeds. A comment

    Science.gov (United States)

    Kassner, K.

    2002-05-01

    In a recent article in this journal (Sardin G., Europhys. Lett., 53 (2001) 310), Sardin proposed to use the Bradley aberration of light for the construction of a speedometer capable of measuring absolute speeds. The purpose of this comment is to show that the device would not work.

  11. DESIGN AND USE OF A HIGH-ACCURACY NON-CONTACT ABSOLUTE THICKNESS MEASUREMENT MACHINE

    Energy Technology Data Exchange (ETDEWEB)

    Nederbragt, W; Hibbard, R; Kroll, J; Kelly, D

    2005-07-27

    Many commercial metrology systems exist for making accurate surface form and roughness measurements of nominally planar parts. However, few metrology systems exist for making accurate absolute thickness measurements. At Lawrence Livermore National Laboratory there is an increasing need for absolute thickness measurements of mesoscale parts ranging in size from 1 mm to 25 mm in diameter and 2 {micro}m to 500 {micro}m thickness. The samples of interest in this case are nominally planar parts that require absolute thickness to be known to an accuracy of better than one micrometer. An Absolute Thickness Measurement Machine (ATMM) has been designed and constructed to fulfill this requirement (see Figure 1). This article describes the design of the ATMM and the theory behind its operation including a detailed error budget. Other issues discussed involve errors associated with the sensors (non-linearity, and sensor resolution), development of the stepped thickness reference, thermal effects, and future upgrades. This research represents one of many issues involving meso-scale metrology currently under development at Lawrence Livermore National Laboratory.

  12. A method for the absolute differential calibration of the time scale for precise timing measurements

    Energy Technology Data Exchange (ETDEWEB)

    Becvar, F.; Cizek, J.; Prochazka, I. [Karlova Univ., Prague (Czech Republic). Fakulta Matematicko-Fyzikalni

    2001-07-01

    A method for precise calibration of time scale in timing measurements is described thanks to sensitivity of this method and its ability to determine independently absolute widths of individual time channels even very small local deviations from linearity of time scale can be detected and quantitatively characterized. (orig.)

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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

  15. Measurement of Absolute Hadronic Branching Fractions of D_s Mesons

    CERN Document Server

    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.

  16. Radioactivity measurements for some ophthalmic glasses

    International Nuclear Information System (INIS)

    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

  17. Ethernet-based automation in radioactivity measurements

    International Nuclear Information System (INIS)

    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

  18. Demonstrating the error budget for the Climate Absolute Radiance and Refractivity Observatory through solar irradiance measurements

    Science.gov (United States)

    Thome, Kurtis; McCorkel, Joel; McAndrew, Brendan

    2015-09-01

    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 testbed 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.

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

    Science.gov (United States)

    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.

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

    CERN Document Server

    Montalbano, Vera

    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.

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

    Science.gov (United States)

    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.

  2. Reprocessing of GPS and Repeated Absolute Gravity Measurements Realized in the Tatra Mountain

    Science.gov (United States)

    Mojzes, M.; Papco, J.; Mikolaj, M.

    2012-04-01

    Long time series of position and gravity were monitored for determination of vertical velocities in the Tatra Mountain. All results were combined and compared to the present trend of global loading effects in the locality of the Tatra Mountain. The GPS measurements started in 1998 at 11 sites in the frame of CERGOP-2/Environmental Project and were reprocessed by standard procedure using Bernese software 5.0. Repeated absolute gravity measurements started in 2003 at 3 sites and were processed by standard Micro-g software. These results are compared to influence of the local environmental signals. The measurements were organized by Slovak University of Technology in Bratislava with cooperation of Warsaw University of Technology. The paper presents results of combination process GPS and absolute gravity measurements for the determination of the vertical movements.

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

    CERN Document Server

    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.

  4. Marine environmental radioactivity measurement programme in India

    International Nuclear Information System (INIS)

    Coastal marine Environmental Radioactivity Measurement Programme in India assumes significance in view of massive expansion of nuclear power plants in the Asia Pacific region and to establish benchmark of specific radionuclides in coastal marine environment. In the present study Marine Environmental Surveillance was carried out along the east and west coast of India. Fallout out 137Cs and naturally occurring 226Ra, 228Ra were assessed by in house developed in-situ pre-concentration method using copper ferrocyanide and manganese di-oxide coated filter cartridges. 137Cs activity concentration mapped for Indian coastal region varied from 0.30 to 1.25 Bq m-3 and these were compared with 137Cs levels of Asia Pacific Region. The marine surveillance data also indicates no input from any source including operation of nuclear power plant in east and west coast of India. (author)

  5. Measurement of Radioactivity in the Human Body

    International Nuclear Information System (INIS)

    A body counter with a steel room and a 4-inch-diameter by 4-inch thick Nal scintillation counter has been in operation since February 1958. It is used to control the internal contamination in people working with radioactive materials. Measurements have also been made on the natural activity in the human body. The average cesium-137/potassium ratio in a group of Swedish males was in May 1959 73 μμc per gram of body potassium and in June 1960 55 μμc per gram of body potassium. The cessation of the nuclear bomb tests has caused a decrease in the cesium level in people. This gives some information of how cesium is entering the biosphere

  6. Luminosity Measurement Method for the LHC: Event Selection and Absolute Luminosity Determination

    OpenAIRE

    Krasny, M. W.; Chwastowski, J.; Cyz, A.; Słowikowski, K.

    2011-01-01

    Absolute normalisation of the LHC measurements with O(1%) precision and their relative normalisation, for the data collected at variable centre-of-mass energies, or for variable beam particle species, with O(0.1%) precision is crucial for the LHC experimental programme but presently beyond the reach for the general purpose LHC detectors. This paper is the third in the series of papers presenting the measurement method capable to achieve such a goal.

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

    Science.gov (United States)

    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.

  8. Absolute measurement of the nitrogen fluorescence yield in air between 300 and 430 nm

    CERN Document Server

    Lefeuvre, G; Gorodetzky, P; Patzak, T; Salin, P

    2007-01-01

    The nitrogen fluorescence induced in air is used to detect ultra-high energy cosmic rays and to measure their energy. The precise knowledge of the absolute fluorescence yield is the key quantity to improve the accuracy on the cosmic ray energy. The total yield has been measured in dry air using a 90Sr source and a [300-430 nm] filter. The fluorescence yield in air is 4.23 $\\pm$ 0.20 photons per meter when normalized to 760 mmHg, 15 degrees C and with an electron energy of 0.85 MeV. This result is consistent with previous experiments made at various energies, but with an accuracy improved by a factor of about 3. For the first time, the absolute continuous spectrum of nitrogen excited by 90Sr electrons has also been measured with a spectrometer. Details of this experiment are given in one of the author's PhD thesis [32].

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

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

    2016-04-01

    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.

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

    International Nuclear Information System (INIS)

    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)

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

    CERN Document Server

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Radioactivity measurements using storage phosphor technology

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Perfusion measurements with radioactively labelled microspheres

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.

  17. A novel absolute displacement measurement technology based on wavenumber resolved low coherence interferometry

    Science.gov (United States)

    Zhao, Keqiang; Xie, Fang; Ma, Sen; Wang, Yunzhi; Chen, Liang

    2015-12-01

    This paper proposed a novel absolute displacement measurement technology which is based on the wavenumber spectrum of low coherence interferometry. The signal from a Michelson interferometer, which is derived from a broadband light source, is dispersed by a bulk dispersing grating. The interferometric signal of each wavelength is detected by a linear array charge coupled device (CCD). By transforming the wavelength spectrum of the signal into wavenumber spectrum, absolute displacement can be measured precisely by measuring the wavenumber difference between two neighboring peaks of the wavenumber spectrum. Unlike the normal low coherence interferometric measurement systems (LCIMS) which have to scan the optical path difference (OPD) of the interferometer in order to demodulate the measurand, there is no need of scanning action during the measurement procedure, which not only simplifies the measurement system but also improves the measurement speed greatly. A fiber Bragg grating (FBG) is employed to produce a feedback signal which is used to stabilize the Michelson interferometer so as to obtain high measurement precision. A step height with the calibrated value of 50 μm that is configurated with two gauge blocks is measured by the system. The measurement resolution is 6.03 nm and the standard deviation of 10 times measurement results is 6.8 nm.

  18. Absolute measurements of electron impact excitation cross-sections of atoms using cavity ringdown spectroscopy

    International Nuclear Information System (INIS)

    A new method of using cavity ringdown spectroscopy (CRDS) technique to measure apparent electron impact excitation cross-sections (EIECS) for different energy levels of an atom is described. The method involves measurements of absolute population densities of the energy levels in concern using the high sensitivity CRDS, leading to an analytical expression of EIECS as a function of the population densities. Determination of EIECS in this method does not require an external calibration. The proposed method is validated by determining EIECS of the metastable levels of Hg (6s6p 3P0) and Ne (2p53s 3P2), and the results are in good agreement with the cross-sections reported in the literature. The population densities in both cases were extracted from the published data. This method exhibits promising potential for absolute measurements of EIECS of metastable energy levels. - Highlights: • Cavity ringdown spectroscopy for electron impact excitation cross-sections. • Measurements of absolute population densities of the energy levels. • An analytical expression of electron impact excitation cross-section. • The method is validated by two cases (the metastable Hg and the metastable Ne atoms)

  19. Measurement of absolute neutron flux in LWSCR based on the nuclear track method

    International Nuclear Information System (INIS)

    Highlights: ► Up to now the spectral parameters of thermal neutrons are measured with activation foils that are not always reliable in low flux systems. ► We applied a solid state nuclear track detector to measure the absolute neutron flux in the light water sub-critical reactor (LWSCR). ► Experiments concerning fission track detecting were performed and were investigated using the Monte Carlo code MCNP. ► The neutron fluxes obtained in experiment are in fairly good agreement with the results obtained by MCNP. - Abstract: In the present paper, a solid state nuclear track detector is applied to measure the absolute neutron flux in the light water sub-critical reactor (LWSCR) in Nuclear Science and Technology Research Institute (NSTRI). Up to now, the spectral parameters of thermal neutrons have been measured with activation foils that are not always reliable in low flux systems. The method investigated here is the irradiation method. Experiments concerning fission track detecting were performed. The experiment including neutron flux calculation method has also been investigated using the Monte Carlo code MCNP. The analysis shows that the values of neutron flux obtained by experiment are in fairly good agreement with the results obtained by MCNP. Thus, this method may be able to predict the absolute value of neutron flux at LWSCR and other similar reactors.

  20. Methods of measuring radioactivity in the environment

    International Nuclear Information System (INIS)

    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

  1. Alpha radioactivity measurements in tobacco leaves

    International Nuclear Information System (INIS)

    Smoking is hazardous to your health, warning labels such as this appear on every pack of cigarettes sold in the country. The link between cigarette smoke and cancer has long been established. Smokers are ten times at greater risk of developing lung cancer than that of non-smokers. Tobacco plants were grown using different types of chemical fertilizers in different amounts just before the plantation is done in some cases while after an interval of one month in other cases. The alpha radioactivity of the leaves of these plants was measured using plastic track detectors LR-115 Type-II manufactured by Kodak. Measurement of track densities (track cm-2 day) shows a variation from 15.2 track cm-2 day-1 to 38.6 track cm-2 day-1 on the upper face and 20.7 track cm-2 day-1 to 45.4 track cm-2 day-1 at the bottom face for the plants in which fertilizers were added to soil just before the plantation while it varied from 6.9 track cm-2 day-1 to 35.8 track cm-2 day-1 and 17.9 to 41.3 track cm-2day-1 respectively on the upper and bottom faces for those plants in which fertilizers were added at a later stage. These variations are on higher side as compared to the plants grown without any use of fertilizer has been established. (author)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  4. Absolute Triply Differential (e,2e ) Cross Section Measurements for H with Comparison to Theory

    International Nuclear Information System (INIS)

    Absolute triply differential (e,2e ) cross section measurements are presented for H (for incident energies, E0 , of 15.6 and 17.6eV) for equal energy sharing and the ?12=? configuration. Results of distorted partial wave calculations agree with the measurements; those of convergent close coupling calculations agree with the relative angular distributions, but are lower than experiment by factors of from 2 to 7. Relative experimental results for H for E0=14.6 eV show a qualitative change in shape, which agrees with theory. Implications of the absolute experimental results for the range of validity of the Wannier threshold law are discussed. copyright 1997 The American Physical Society

  5. Absolute distance measurement by dual-comb nonlinear asynchronous optical sampling.

    Science.gov (United States)

    Zhang, Hongyuan; Wei, Haoyun; Wu, Xuejian; Yang, Honglei; Li, Yan

    2014-03-24

    A dual-comb nonlinear asynchronous optical sampling method is proposed to simplify determination of the time interval and extend the non-ambiguity range in absolute length measurements. Type II second harmonic generation facilitates curve fitting in determining the time interval between adjacent pulses. Meanwhile, the non-ambiguity range is extended by adjusting the repetition rate of the signal laser. The performance of the proposed method is compared with a heterodyne interferometer. Results show that the system achieves a maximum residual of 100.6 nm and an uncertainty of 1.48 ?m in a 0.5 ms acquisition time. With longer acquisition time, the uncertainty can be reduced to 166.6 nm for 50 ms and 82.9 nm for 500 ms. Moreover, the extension of the non-ambiguity range is demonstrated by measuring an absolute distance beyond the inherent range determined by the fixed repetition rate. PMID:24664008

  6. High-precision absolute distance measurement using dual-laser frequency scanned interferometry under realistic conditions

    International Nuclear Information System (INIS)

    In this paper, we report on new high-precision absolute distance measurements performed with frequency scanned interferometry using a pair of single-mode optical fibers. Absolute distances were determined by counting the interference fringes produced while scanning the frequencies of the two chopped lasers. High-finesse Fabry-Perot interferometers were used to determine frequency changes during scanning. Dual lasers with oppositely scanning directions, combined with a multi-distance-measurement technique previously reported, were used to cancel drift errors and to suppress vibration effects and interference fringe uncertainties. Under realistic conditions, a precision about 0.2?m was achieved for a distance of 0.41m. With a precision that exceeds requirements, the frequency scanned interferometry is a promising high-precision optical alignment technique for International Linear Collider silicon tracker detector

  7. Measurement of the absolute branching fraction for D0→K-π+

    International Nuclear Information System (INIS)

    Using 1.79 fb-1 of data recorded by the CLEO II detector we have measured the absolute branching fraction for D0→K-π+. The angular correlation between the π+ emitted in the decay D*+→D0π+, and the jet direction in e+e-→c bar c events, is used to determine the total number of inclusive D0 mesons produced from this source. The subsequent reconstruction of the decay chain D*+→D0π+,D0→K-π+ allows a measurement of the absolute D0→K-π+ branching fraction. Correcting for decay radiation in the final state, we find scrB(D0→K-π+)=[3.95±0.08(stat)±0.17(syst)]%

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

    OpenAIRE

    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.

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

    CERN Document Server

    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.

  10. Comment on 'Simultaneous gravity and gradient measurements from a recoil-compensated absolute gravimeter'

    CERN Document Server

    Nagornyi, V D

    2011-01-01

    The article (Niebauer et al. 2011 Metrologia 48 154-163) reports on the important innovations enhancing the ability of absolute gravimeter to measure vertical gravity gradient along with the gravity acceleration. This comment suggests experiments to further assess the improvements and the results obtained with the modified instrument, considers some limitations of non-linear models in metrology and ways to overcome them, and discusses possible applications of the described instrument.

  11. Comment on "Measurement of the speed-of-light perturbation of free-fall absolute gravimeters"

    CERN Document Server

    Nagornyi, V D

    2014-01-01

    The paper (Rothleitner et al. 2014 Metrologia 51, L9) reports on the measurement of the speed-of-light perturbation in absolute gravimeters. The conclusion that the perturbation reaches only 2/3 of the commonly accepted value violates the fundamental limitation on the maximum speed of information transfer. The conclusion was deluded by unaccounted parasitic perturbations, some of which are obvious from the report.

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    CERN Document Server

    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.

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

    International Nuclear Information System (INIS)

    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 ?m 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    CERN Multimedia

    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.

  18. Efficiency of Measurements of Radioactivity in Relation to Sample Preparation and Measuring Arrangement

    International Nuclear Information System (INIS)

    Different methods for measuring radioactivity routinely in biological tracer studies are compared in terms of their absolute sensitivities. The data were obtained by measurement of samples prepared from standard solutions of various radioactive nuclides (3T, 35S, 131I, 204Tl, 147Pm, 32P). The nature and method of preparation of the sample depend on chemical and physical properties of the elements in question and on the 6-energy of their radioactive isotopes as well as on the type of measuring apparatus to be used. The following devices used in routine work are compared in this paper: Geiger-Müller counter tubes with end windows of different thickness (mass per unit area), liquid sampling jacketed G-M tubes, gas flow counters, low background counters (Omniguard, Tracerlab), liquid scintillation spectrometers (Tricarb, Packard), gas analysis counters (Frieseke and Hoepfner), large window G-M counters (Kiefer-Maushart) and scanners for paper chromatograms (Packard). Lower limits of detection for the various radioactive nuclides are estimated from data on background and sensitivity of the various devices. In deriving these limits the time for measuring the samples is considered not to exceed 20 min. Furthermore, both sample and background counting rates are considered to be measured for identical times and are therefore subject to similar statistical errors. The detection limits then represent amounts of radioactivity which can be detected to a stated degree of statistical significance as compared with random variations in background. From the results thus achieved it is obvious that the total yield of sample measurements - i.e. the ratio of impulse rate detected by the tube to the rate of transmutations in this sample - is influenced by very differing components depending on preparation. Self-absorption will affect especially results obtained from solid samples containing emitters with low β-energy. The counting of liquids in jacketed tubes is limited by the thickness of the tube glass wall. For 14C and 3H measurements, optimal efficiency will be obtained with gas analysis counters and liquid scintillation sets, the latter being superior on account of simpler procedures and more reliable results. (author)

  19. METHODS FOR THE REALIZATION OF RADIOACTIVE STANDARDS AND FOR THE ENVIRONMENTAL RADIOACTIVITY MEASUREMENT

    Directory of Open Access Journals (Sweden)

    ANDREI ANTOHE

    2011-06-01

    Full Text Available The radionuclide metrology assures: the realization, the conservation and the transmission of the activity standards, in various fields of measurement, environmental radioactivity characterization being included. The Radionuclide Metrology Laboratory (RML, IFIN-HH, usually prepares radioactivity standards (reference materials, consisting from: standard solutions, point and large area alpha and beta standard sources, and gamma volume standard sources used for the measurement of environmental samples and for the calibration of surface contamination monitors.The most important measurement methods used in the environmental radioactivity measurements, developed in IFIN-HH, are: gross alpha and gross beta measurements and gamma-ray spectrometry measurements. The choice of the adequate method depends on several factors, such as: type of emitted radiation, existence of a single or mixture of radionuclides, physical shape of the matrix.The authors describe the methods for the realization of standard sources used for the calibration of equipment used in such monitoring and methods for the environmental radioactivity measurement.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Absolute measurements of light impurities line radiation using MLM-based spectrometers on CASTOR tokamak

    International Nuclear Information System (INIS)

    A multilayer mirror (MLM) based single channel spectrometer was built and is operated at the CASTOR tokamak as a monitor of impurities. The spectrometer covers two wavelength ranges, namely 14 to 24 A with a spectral resolution of 0.5 to 1.0 A and 31 to 45 A with a spectral resolution of 1.2 to 1.5 A, depending on the mirror used. The main spectrometer elements, ie. the MLMs, filters and the detector were calibrated absolutely in both wave ranges. Absolute intensities of the spectral lines of He-like and H-like oxygen and carbon ions were measured with a time resolution of 0.1 ms at the small-scale CASTOR tokamak in several regimes of the Ohmic discharge. (author) 2 tabs., 9 figs., 8 refs

  2. Silicon microcantilevers with different actuation-readout schemes for absolute pressure measurement

    International Nuclear Information System (INIS)

    Silicon resonant microcantilevers for the measurement of the absolute pressure have been fabricated through micromachining processes. The first release is based on vertical resonant actuation and detection, both externally implemented, respectively through a piezoelectric actuator and an optical lever. The variation in resonance response was investigated as a function of pressure (10-1 to 105 Pa), both in terms of resonance frequency and quality factor. We demonstrated the feasibility of a miniaturized absolute pressure sensor working over a six decades range. The second release is based on lateral resonating microcantilevers in which a significative upgrade is represented by the miniaturization and integration of the actuator and the sensing directly on chip providing a more compact and potentially interesting solution for industrial vacuum applications. Actuation is performed with an electrostatic modulated force, while detection relies on a capacitive readout. Preliminary experiments are encouraging for the replication of the results obtained with the first version

  3. Silicon microcantilevers with different actuation-readout schemes for absolute pressure measurement

    Energy Technology Data Exchange (ETDEWEB)

    Bianco, S; Cocuzza, M; Ferrante, I; Giuri, E; Pirri, C F; Ricci, A; Scaltrito, L [Xlab - Materials and Microsystems Laboratory - Polytechnic of Turin, Latemar Unit Lungo Piazza D' Armi 6, 10034 Chivasso (Turin) (Italy); Bich, D; Merialdo, A; Schina, P [Olivetti I-Jet, Loc. Le Vieux, 11020 Arnad (Aosta) (Italy); Correale, R [Varian S.p.A., Via Fratelli Varian 54, 10040 Leini (Turin) Italy (Italy)], E-mail: matteo.cocuzza@infm.polito.it

    2008-03-01

    Silicon resonant microcantilevers for the measurement of the absolute pressure have been fabricated through micromachining processes. The first release is based on vertical resonant actuation and detection, both externally implemented, respectively through a piezoelectric actuator and an optical lever. The variation in resonance response was investigated as a function of pressure (10{sup -1} to 10{sup 5} Pa), both in terms of resonance frequency and quality factor. We demonstrated the feasibility of a miniaturized absolute pressure sensor working over a six decades range. The second release is based on lateral resonating microcantilevers in which a significative upgrade is represented by the miniaturization and integration of the actuator and the sensing directly on chip providing a more compact and potentially interesting solution for industrial vacuum applications. Actuation is performed with an electrostatic modulated force, while detection relies on a capacitive readout. Preliminary experiments are encouraging for the replication of the results obtained with the first version.

  4. Corrosion measuring apparatus for radioactive components

    International Nuclear Information System (INIS)

    Disclosed is a remotely manipulatable probe and apparatus for positioning a corrosion thickness sensing transducer over selected areas of the surface of a radioactive component submerged in a pool of water for radiation shielding

  5. Absolute distance measurement system using a femtosecond laser as a modulator

    International Nuclear Information System (INIS)

    The generation of broadband microwave frequency comb from a femtosecond pulse train by direct photodetection opens the possibility for high-accuracy length measurements of long distances. We demonstrate a relatively simple realization of this measurement principle: an electronic distance measurement system based on a time-of-flight approach, driven by a femtosecond fibre laser source as a modulator. By the evaluation of the phase shifts of two distinct comb frequencies, a coarse and a fine measurement of the absolute distance can be performed. The range of the measurement system is demonstrated up to a length of 100 m. The experimental comparison of the femtosecond laser system with a conventional reference counting interferometer shows a precision better than ±10 µm at 100 m, corresponding to a relative measurement uncertainty of 1 × 10−7 L. The limiting factors for the measurement uncertainty of the system are theoretically investigated and shown to be of the same order of magnitude

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1951-01-15

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

  7. Radioactivity

    International Nuclear Information System (INIS)

    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.)

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

    Science.gov (United States)

    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 dispersive media, the effect of both phase and group indices have to be considered. Taking all these factors into account, a method was developed to measure targets through multiple regions of different materials and produce results that are absolute measurements of target position in three-dimensional space, rather than simply relative position. The environment in which the lidar measurements are taken must be broken down into separate regions of interest and each region solved for separately. In this case, there were three regions of interest: air, fused silica, and vacuum. The angular position of the target inside the chamber is solved using only phase index and phase velocity, while the ranging effects due to travel from air to glass to vacuum/air are solved with group index and group velocity. When all parameters are solved simultaneously, an absolute knowledge of the position of each target within an environmental chamber can be derived. Novel features of this innovation include measuring absolute position of targets through multiple dispersive and non-dispersive media, deconstruction of lidar raw data from a commercial off-the-shelf unit into reworkable parameters, and use of group velocities to reduce range data. Measurement of structures within a vacuum chamber or other harsh environment, such as a furnace, may now be measured as easily as if they were in an ambient laboratory. This analysis permits transformation of the raw data into absolute spatial units (e.g., mm). This technique has also been extended to laser tracker, theodolite, and cathetometer measurements through refractive media.

  9. Absolute measurements of radiation sources spectral brightness and detectors quantum efficiency

    Science.gov (United States)

    Penin, Alexander N.; Klyshko, David N.

    1991-12-01

    In this paper we present schemes of experimental setups for the radiation spectral brightness measurements in the range of 0.6 - 5 (mu) for N varying from 10-1 to 102 (if, for example, (lambda) equals 1 (mu) , this range of N corresponds to the brightness temperature range from 6 (DOT) 103 to 106 K), and for photomultipliers quantum efficiency measurements in the range of 0.4 - 5 (mu) with a dynamical range 10 - 1012 photon/sec and accuracy not worse than 1%. The new measurement methods are based on the utilization of the parametric light scattering phenomenon which is a spontaneous decay of laser pump photons in correlated photon pairs in crystals with quadratic nonlinear susceptibility. The first of two methods allows measurement of the radiation spectral brightness N in absolute units ('photons per mode') in visible and infrared range. The quantity N is related to the energetic brightness spectral density B through the equation B equals (hc2/(lambda) 5)N, where h is the Plank constant, c - the light velocity, (lambda) - the wavelength. The method is absolute and does not require any reference source or detector of radiation. Quantum noise of a parametric down-convertor, caused by the zero vacuum fluctuations with an effective brightness Nvac equals 1 photon per mode, is the reference in this case. The second method concerns the quantum efficiency of photodetectors determination, and it is based on the connection between the statistics of photocurrent and the radiation which causes it. The parametric scattering is a unique source of rather intensive and directed radiation flow consisting of photon pairs. Such a flow can be used to determine the absolute quantum efficiency of photodetectors.

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

    International Nuclear Information System (INIS)

    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

  11. Absolute radiant power measurement of the X-ray free-electron laser at SACLA

    International Nuclear Information System (INIS)

    The Japanese hard X-ray free-electron laser (XFEL), SACLA (SPring-8 Angstrom Compact free-electron LAser), reached laser amplification at 10 keV photon energy in June 2011. SACLA can provide XFELs with its wavelength of shorter than 0.1 nm. Since the radiant power is a fundamental parameter of the XFEL beam which strongly influences nonlinear effects, its measurement in absolute terms is of significant importance. In the present study, the absolute radiant power of the XFEL was measured using a cryogenic radiometer at the BL3 in SACLA. The radiant power as a function of a silicon attenuator thickness was also measured to estimate the contribution of the higher harmonics. The radiant power in the range between 8 ?W and 1005 ?W was measured in the photon energies of 4.4 keV, 5.8 keV, 9.6 keV, 13.6 keV and 16.8 keV. The contribution of the higher harmonics is negligible except for the photon energy of 4.4 keV. The third harmonics component in the photon energy of 4.4 keV is about 1 %.

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

    CERN Document Server

    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.

  13. Absolute measurement of a standard thermal-neutron flux using gold-detector activation

    International Nuclear Information System (INIS)

    The density of neutrons in a standard stacking is determined between the zero-energy and the cut-off energy of 1 mm thick cadmium unit using a gold detector. Its absolute activity is measured using a 4 π β counter calibrated for 4 π β,γ coincidence by counting strongly active sources. The correction factor F due to the disintegration process for the gold is determined experimentally. Φ0 = N0ECdV0 = 6495 ± 1.5 per cent n/cm2/s. (author)

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

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

    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 rather than absolute changes in CBF and CMRO2 adequately characterise the flow-metabolism response to neural activity. The coupling parameter n is important in terms of its effect on the BOLD response, and as potential insight into the flow-metabolism relationship in both normal and pathological brain function. In 10 healthy human subjects, BOLD and CBF responses were measured to test the effect of baseline perfusion (modulated by a hypercapnia challenge) on the coupling parameter n during graded visual stimulation. A dual-echo pulsed arterial spin labelling (PASL) sequence provided absolute quantification of CBF in baseline and active states as well as relative BOLD signal changes, which were used to estimate CMRO2 responses to the graded visual stimulus. The absolute CBF response to the visual stimuli were constant across different baseline CBF levels, meaning the fractional CBF responses were reduced at the hyperperfused baseline state. For the graded visual stimuli, values of n were significantly reduced during hypercapnia induced hyperperfusion. Assuming the evoked neural responses to the visual stimuli are the same for both baseline CBF states, this result has implications for fMRI studies that aim to measure neurovascular coupling using relative changes in CBF. The coupling parameter n is sensitive to baseline CBF, which would confound its interpretation in fMRI studies where there may be significant differences in baseline perfusion between groups. The absolute change in CBF, as opposed to the change relative to baseline, may more closely match the underlying increase in neural activity in response to a stimulus. PMID:26477657

  16. Absolute frequency measurement of the In$^{+}$ clock transition with a mode-locked laser

    OpenAIRE

    von Zanthier, J.; Becker, Th.; Eichenseer, M.; Nevsky, A. Yu.; Schwedes, Ch.; E. PEIK; Walther, H.; Holzwarth, R; Reichert, J.; Udem, Th; Hnsch, T.W.; Pokasov, P. V.; Skvortsov, M. N.; Bagayev, S. N.

    2000-01-01

    The absolute frequency of the In$^{+}$ $5s^{2 1}S_{0}$ - $5s5p^{3}P_{0}$ clock transition at 237 nm was measured with an accuracy of 1.8 parts in $10^{13}$. Using a phase-coherent frequency chain, we compared the $^{1}S_{0}$ - $^{3}P_{0}$ transition with a methane-stabilized He-Ne laser at 3.39 $\\mu$m which was calibrated against an atomic cesium fountain clock. A frequency gap of 37 THz at the fourth harmonic of the He-Ne standard was bridged by a frequency comb generated by a mode-locked fe...

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

    OpenAIRE

    AIRFLY Collaboration; Ave, M.; Bohacova, M.; Curry, E; Di Carlo, P.; C. Di Giulio; Luis, P. Facal San; Gonzales, D.; Hojvat, C.; Hrandel, J.; Hrabovsky, M.; Iarlori, M.; B. Keilhauer; Klages, H.; Kleifges, M.

    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....

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

    OpenAIRE

    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...

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

    International Nuclear Information System (INIS)

    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.

  20. Measurement of the absolute number of electrons in the KUTI prototype storage ring

    International Nuclear Information System (INIS)

    Experimental results are reported on determining the electron energy from the spectrum of the synchrotron radiation (SR). The SR spectrum was measured over a single compression cycle, as well as over many cycles, and the resulting energies were used to deduce the absolute number of electrons in the ring. Three types of photoreceivers measured the SR intensity: 1) a germanium photodiode at wavelength lambda = 1.6 μm; 2) a cooled photoresistor at lambda = 2.4 μm; 3) a photomultiplier with a set of narrow-band filters at wavelengths lambda = 0.63 and 0.41 μm. The dependence of the angular distribution of the SR on the number of electrons must be allowed for in measurements at visible wavelengths. The maximum number of electrons in the ring was found to be 8 x 1012. Measurements carried out using different photoreceivers were in agreement to within 20%

  1. Measurement of the absolute number of electrons in the KUTI prototype storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Dolbilov, G.V.; Sarantsev, V.P.; Sumbaev, A.P.; Tyutyunnikov, S.I.; Shalyapin, V.N.

    1985-07-01

    Experimental results are reported on determining the electron energy from the spectrum of the synchrotron radiation (SR). The SR spectrum was measured over a single compression cycle, as well as over many cycles, and the resulting energies were used to deduce the absolute number of electrons in the ring. Three types of photoreceivers measured the SR intensity: 1) a germanium photodiode at wavelength lambda = 1.6 ..mu..m; 2) a cooled photoresistor at lambda = 2.4 ..mu..m; 3) a photomultiplier with a set of narrow-band filters at wavelengths lambda = 0.63 and 0.41 ..mu..m. The dependence of the angular distribution of the SR on the number of electrons must be allowed for in measurements at visible wavelengths. The maximum number of electrons in the ring was found to be 8 x 10/sup 12/. Measurements carried out using different photoreceivers were in agreement to within 20%.

  2. Measurements of absolute hadronic branching fractions of $\\Lambda_{c}^{+}$ baryon

    CERN Document Server

    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 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; Eren, E E; 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, 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, Y; 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; Kuehn, W; Kupsc, A; 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, J C; Li, Jin; Li, K; Li, Lei; Li, P R; Li, Q Y; Li, T; Li, W D; Li, W G; Li, X L; Li, X M; Li, X N; Li, X Q; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; Liu, B J; Liu, C X; Liu, D; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; 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, 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; 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; Santoro, V; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Song, W M; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; 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, S G; Wang, W; Wang, W P; Wang, X F; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Weber, T; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; 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, 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 J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y N; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhang, 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

    2015-01-01

    Using $567\\rm{pb}^{-1}$ of $e^+e^-$ collisions recorded at $\\sqrt{s}=4.599\\rm{GeV}$ with the BESIII detector, we report first measurements of absolute hadronic branching fractions of Cabibbo-favored decays of the $\\Lambda_{c}^{+}$ baryon with a double-tag technique. A global least-square fitter is utilized to improve the measured precision. Among the measurements for twelve $\\Lambda_{c}^{+}$ decay modes, the branching fraction for $\\Lambda_{c}^{+} \\rightarrow pK^-\\pi^+$ is determined to be $(5.84\\pm0.27\\pm0.23)\\%$, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other eleven Cabbibo-favored hadronic decay modes are significantly improved.

  3. Absolute position measurement in a gas time projection chamber via transverse diffusion of drift charge

    Science.gov (United States)

    Lewis, P. M.; Vahsen, S. E.; Seong, I. S.; Hedges, M. T.; Jaegle, I.; Thorpe, T. N.

    2015-07-01

    Time Projection Chambers (TPCs) with charge readout via micro pattern gaseous detectors can provide detailed measurements of charge density distributions. We here report on measurements of alpha particle tracks, using a TPC where the drift charge is amplified with Gas Electron Multipliers and detected with a pixel ASIC. We find that by measuring the 3-D topology of drift charge and fitting for its transverse diffusion, we obtain the absolute position of tracks in the drift direction. For example, we obtain a precision of ~1 cm for 0.8 cm-long alpha track segments. To our knowledge this is the first demonstration of such a measurement in a gas TPC. This technique has several attractive features: it does not require knowledge of the initial specific ionization, is robust against bias from diffuse charge below detection threshold, and is also robust against high charge densities that saturate the detector response.

  4. Absolute Position Measurement in a Gas Time Projection Chamber via Transverse Diffusion of Drift Charge

    CERN Document Server

    Lewis, P M; Hedges, M T; Jaegle, I; Seong, I S; Thorpe, T N

    2014-01-01

    Time Projection Chambers (TPCs) with charge readout via micro pattern gaseous detectors can provide detailed measurements of charge density distributions. We here report on measurements of alpha particle tracks, using a TPC where the drift charge is amplified with Gas Electron Multipliers and detected with a pixel ASIC. We find that by measuring the 3-D topology of drift charge and fitting for its transverse diffusion, we obtain the absolute position of tracks in the drift direction. For example, we obtain a precision of 1~cm for 1~cm-long alpha track segments. To our knowledge this is the first demonstration of such a measurement in a gas TPC. This technique has several attractive features: it does not require knowledge of the initial specific ionization, is robust against bias from diffuse charge below detection threshold, and is also robust against high charge densities that saturate the detector response.

  5. Absolute position measurement in a gas time projection chamber via transverse diffusion of drift charge

    International Nuclear Information System (INIS)

    Time Projection Chambers (TPCs) with charge readout via micro pattern gaseous detectors can provide detailed measurements of charge density distributions. We here report on measurements of alpha particle tracks, using a TPC where the drift charge is amplified with Gas Electron Multipliers and detected with a pixel ASIC. We find that by measuring the 3-D topology of drift charge and fitting for its transverse diffusion, we obtain the absolute position of tracks in the drift direction. For example, we obtain a precision of ~1 cm for 0.8 cm-long alpha track segments. To our knowledge this is the first demonstration of such a measurement in a gas TPC. This technique has several attractive features: it does not require knowledge of the initial specific ionization, is robust against bias from diffuse charge below detection threshold, and is also robust against high charge densities that saturate the detector response

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

    CERN Document Server

    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.

  7. Measurement of absolute flow rate in vessels using a stereoscopic DSA system

    International Nuclear Information System (INIS)

    We used a stereoscopic digital subtraction angiography (DSA) system to measure absolute blood flow rates in vessels. The magnification factor and the three-dimensional orientation of a selected vessel are obtained from automated analysis of stereoscopic DSA images. The cross-sectional area of the vessel is determined from the vessel diameter, which is measured with an iterative deconvolution technique. The time required for fluid to flow through a selected segment of a vessel is determined from the automated analysis of contrast medium 'time-density' curves. The effectiveness of these combined techniques was demonstrated in measurement of rates of both continuous and pulsatile flow in a vessel phantom, with the actual flow rate calibrated volumetrically or by an electromagnetic flowmeter. We have obtained accuracies in measured flow rates of approximately 5% and 18% for continuous and pulsatile flow respectively. (author)

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

    International Nuclear Information System (INIS)

    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)

  9. Absolute measurement of the nitrogen fluorescence yield in air between 300 and 430 nm

    International Nuclear Information System (INIS)

    The nitrogen fluorescence induced in air is used to detect ultra-high-energy cosmic rays (UHECR) and to measure their energy. The precise knowledge of the absolute fluorescence yield is the key quantity to improve the accuracy on the cosmic ray energy. The total yield has been measured in dry air using a 90Sr source and a [300-430 nm] filter. The fluorescence yield in air is 4.23±0.21 photons/m when normalized to 760 mmHg, 15 oC and with an electron energy of 0.85 MeV. This result is consistent with previous experiments made at various energies, but with an accuracy improved by a factor of about 3. For the first time, the absolute continuous spectrum of nitrogen excited by 90Sr electrons has also been measured with a spectrometer. Details of this experiment are given in one of the author's Ph. D. thesis [G. Lefeuvre, Ph. D. Thesis, Paris 7 University, 2006 (Ref: APC-26-06) .

  10. Feasibility studies of high-pressure 4? proportional counter for absolute activity measurement

    International Nuclear Information System (INIS)

    A high-pressure proportional counter system is constructed. The high pressure 4?? counter system constructed is made of aluminum and is divided into two 2? counters. The gas pressure is controlled with a pressure regulator and very fine leak valves to keep the balance of a stable pressure and constant flow rate. Investigation of characteristics of th counter shows that there is an almost linear relation between voltage and pressure. The linearlity of gas gain of this counter to the electron energies is measured with different gas pressures. Quite good linear gas multiplication is obtained at 0.9 MPa. Another investigation is made of application of to activity measurement of 109Cd. When the gas pressure is over 0.5 MPa, the proportion of collected conversion electrons to absolute activity comes to a constant value of 96 %. This is quite good agreement with the decay data of 96.4 % conversion electron emission rate. The study indicated many excellent features for activity measurement. Especially the efficiency variation technique is good for automatic data acquisition with a programmable high voltage supplier. Moreover, since it is possible to obtain absolute activity with only one sample, it will be quite useful for limited samples experiments. (N.K.)

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

    International Nuclear Information System (INIS)

    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

  12. Results of radioactivity measurements on foodstuffs in Romania

    International Nuclear Information System (INIS)

    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)

  13. Absolute calibration of in vivo measurement systems using magnetic resonance imaging and Monte Carlo computations

    International Nuclear Information System (INIS)

    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. This method uses magnetic resonance imaging (MRI) to determine the anatomical makeup of an individual. A new MRI technique is also employed that is capable of resolving the fat and water content of the human tissue. This anatomical and biochemical information is used to model a mathematical phantom. Monte Carlo methods are then used to simulate the transport of radiation throughout the phantom. By modeling the detection equipment of the in vivo measurement system into the code, calibration factors are generated that are specific to the individual. Furthermore, this method eliminates the need for surrogate human structures in the calibration process. A demonstration of the proposed method is being performed using a fat/water matrix

  14. Superharp - a wire scanner with absolute position readout for beam energy measurement at CEBAF

    International Nuclear Information System (INIS)

    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 similar 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 similar 200 μA. (orig.)

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

    Science.gov (United States)

    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

  16. Glacial mass balance determination in the accumulation zone by in situ measurements of Chernobyl radioactivity

    International Nuclear Information System (INIS)

    Radioactive fallout from atmospheric thermo-nuclear tests conducted in 1954 and 1962-1963, and more recently from the Chernobyl accident on 26 April 1986, provide markers, or well-known levels, in the snow layers of the north hemisphere glacier accumulation zones. The design and operation of the in situ measurement of gamma rays from cesium-137 (662 KeV) in ice bore-holes allows rapid detection in the field of the Chernobyl radioactive layer of snow. The validity of this detection method is much enhanced due to the 29.5 year half-life of cesium-137. These measurements indicate the absolute dating of snow layers deposited since May 1986; they give the spatio-temporal variations of glacial mass balance, as well as fallout amounts of radio-isotopes

  17. The new IMGC-02 transportable absolute gravimeter: measurement apparatus and applications in geophysics and volcanology

    Directory of Open Access Journals (Sweden)

    V. D’errico

    2008-06-01

    Full Text Available The research carried out at the Istituto Nazionale di Ricerca Metrologica (formerly Istituto di Metrologia «G. Colonnetti» aiming to develop a transportable ballistic absolute gravimeter ended with a new version of the instrument, called the IMGC-02. It uses laser interferometry to measure the symmetrical free rising and falling motion of a test mass in the gravity field. Providing the same accuracy achieved with previous versions, the instrumental improvements mainly concern size, weight, data processing algorithms and operational simplicity. An uncertainty of 9 ?Gal (1 ?Gal=1×10–8 m·s?2 can be achieved within a single observation session, lasting about 12 h, while the time series of several observation sessions show a reproducibility of 4 ?Gal. At this level, gravity measurements provide useful information in Geophysics and Volcanology. A wide set of dynamic phenomena, i.e. seismicity and volcanic activity, can produce temporal gravity changes, often quite small, with an amplitude ranging from a few to hundreds of microgals. Therefore the IMGC absolute gravimeter has been employed since 1986 in surveying the Italian active volcanoes. A brief history of the gravimeter and the description of the new apparatus, together with the main results of ongoing applications in Geophysics and Volcanology are presented.

  18. A novel electrochemical approach for prolonged measurement of absolute levels of extracellular dopamine in brain slices.

    Science.gov (United States)

    Burrell, Mark H; Atcherley, Christopher W; Heien, Michael L; Lipski, Janusz

    2015-11-18

    Tonic dopamine (DA) levels influence the activity of dopaminergic neurons and the dynamics of fast dopaminergic transmission. Although carbon fiber microelectrodes and fast-scan cyclic voltammetry (FSCV) have been extensively used to quantify stimulus-induced release and uptake of DA in vivo and in vitro, this technique relies on background subtraction and thus cannot provide information about absolute extracellular concentrations. It is also generally not suitable for prolonged (>90 s) recordings due to drift of the background current. A recently reported, modified FSCV approach called fast-scan controlled-adsorption voltammetry (FSCAV) has been used to assess tonic DA levels in solution and in the anesthetized mouse brain. Here we describe a novel extension of FSCAV to investigate pharmacologically induced, slowly occurring changes in tonic (background) extracellular DA concentration, and phasic (stimulated) DA release in brain slices. FSCAV was used to measure adsorption dynamics and changes in DA concentration (for up to 1.5 h, sampling interval 30 s, detection threshold < 10 nM) evoked by drugs affecting DA release and uptake (amphetamine, l-DOPA, pargyline, cocaine, Ro4-1284) in submerged striatal slices obtained from rats. We also show that combined FSCAV-FSCV recordings can be used for concurrent study of stimulated release and changes in tonic DA concentration. Our results demonstrate that FSCAV can be effectively used in brain slices to measure prolonged changes in extracellular level of endogenous DA expressed as absolute values, complementing studies conducted in vivo with microdialysis. PMID:26322962

  19. Absolute choline concentration measured by quantitative proton MR spectroscopy correlates with cell density in meningioma

    International Nuclear Information System (INIS)

    This study was aimed to investigate the relationship between quantitative proton magnetic resonance spectroscopy (1H-MRS) and pathological changes in meningioma. Twenty-two meningioma cases underwent single voxel 1H-MRS (point-resolved spectroscopy sequence, repetition time/echo time = 2,000 ms/68, 136, 272 ms). Absolute choline (Cho) concentration was calculated using tissue water as the internal reference and corrected according to intra-voxel cystic/necrotic parts. Pathological specimens were stained with MIB-1 antibody to measure cell density and proliferation index. Correlation analysis was performed between absolute Cho concentration and cell density and MIB-1 labeled proliferation index. Average Cho concentration of all meningiomas before correction was 2.95 ± 0.86 mmol/kg wet weight. It was increased to 3.23 ± 1.15 mmol/kg wet weight after correction. Average cell density of all meningiomas was 333 ± 119 cells/HPF, and average proliferation index was 2.93 ± 5.72%. A linear, positive correlation between cell density and Cho concentration was observed (r = 0.650, P = 0.001). After correction of Cho concentration, the correlation became more significant (r = 0.737, P < 0.001). However, no significant correlation between Cho concentration and proliferation index was found. There seemed to be a positive correlation trend after correction of Cho concentration but did not reach significant level. Absolute Cho concentration, especially Cho concentration corrected according to intra-voxel cystic/necrotic parts, reflects cell density of meningioma. (orig.)

  20. Absolute choline concentration measured by quantitative proton MR spectroscopy correlates with cell density in meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Qiang [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan)]|[West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China); Shibata, Yasushi; Kawamura, Hiraku; Matsumura, Akira [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan); Isobe, Tomonori [Kitasato University, Department of Medical Technology, School of Allied Health Sciences, Minato, Tokyo (Japan); Anno, Izumi [University of Tsukuba, Department of Radiology, Institute of Clinical Medicine, Tsukuba, Ibaraki (Japan); Gong, Qi-Yong [West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China)]|[University of Liverpool, Division of Medical Imaging, Faculty of Medicine, Liverpool (United Kingdom)

    2009-01-15

    This study was aimed to investigate the relationship between quantitative proton magnetic resonance spectroscopy (1H-MRS) and pathological changes in meningioma. Twenty-two meningioma cases underwent single voxel 1H-MRS (point-resolved spectroscopy sequence, repetition time/echo time = 2,000 ms/68, 136, 272 ms). Absolute choline (Cho) concentration was calculated using tissue water as the internal reference and corrected according to intra-voxel cystic/necrotic parts. Pathological specimens were stained with MIB-1 antibody to measure cell density and proliferation index. Correlation analysis was performed between absolute Cho concentration and cell density and MIB-1 labeled proliferation index. Average Cho concentration of all meningiomas before correction was 2.95 {+-} 0.86 mmol/kg wet weight. It was increased to 3.23 {+-} 1.15 mmol/kg wet weight after correction. Average cell density of all meningiomas was 333 {+-} 119 cells/HPF, and average proliferation index was 2.93 {+-} 5.72%. A linear, positive correlation between cell density and Cho concentration was observed (r = 0.650, P = 0.001). After correction of Cho concentration, the correlation became more significant (r = 0.737, P < 0.001). However, no significant correlation between Cho concentration and proliferation index was found. There seemed to be a positive correlation trend after correction of Cho concentration but did not reach significant level. Absolute Cho concentration, especially Cho concentration corrected according to intra-voxel cystic/necrotic parts, reflects cell density of meningioma. (orig.)

  1. Radioactivity. Nuclear radiation and measured variables; Radioaktivitaet. Strahlenarten und Messgroessen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-03-15

    The leaflet of the German Atomforum e.V. on radioactivity describes the different radiations: alpha, beta, gamma and neutron radiation. The discussed measuring variables are Becquerel (activity) and Sievert (radiation doses). Radiation sources and radiation effects are shortly described.

  2. Analysis, Design and Testing of a Novel Quasi-Zero-Stiffness based Sensor System for Measurement of Absolute Vibration Motion

    OpenAIRE

    Wang, Yu; Jing, Xingjian

    2015-01-01

    This study presents the analysis and design of a novel quasi-zero-stiffness (QZS) based vibration sensor system for measuring absolute displacement of vibrating platforms/objects. The sensor system is constructed by using positive and negative-stiffness springs, which makes it possible to achieve an equivalent QZS and consequently to create a broadband vibration-free point for absolute displacement measurement in vibrating platforms. Theoretic analysis is conducted for the analysis and design...

  3. Measurements of absolute total cross sections for electron scattering from triatomic polar molecules: SO2 and H2S

    International Nuclear Information System (INIS)

    Absolute total electron-scattering cross sections (TCSs) have been measured in the energy range from 0.5 to 370 eV for SO2 and from 6 to 370 eV for H2S molecules. Measurements have been carried out using modified electron spectrometer working in a linear transmission mode. The present results are compared to published experimental TCS data. Some aspects important for achieving accurate absolute total cross sections in an electron transmission experiment are discussed

  4. Measurement of gross α and gross β radioactivity in water

    International Nuclear Information System (INIS)

    Nuclear energy brings human tremendous interest and potential nuclear threat as well. As one of the simplest radioanalytical procedures, gross α and gross β radioactivity measurement has been widely applied in the field of environmental monitoring and industrial applications. This paper introduced the common methods that used for measuring gross α and gross β radioactivity in water and compared their advantages and disadvantages briefly. (authors)

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

    International Nuclear Information System (INIS)

    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)

  6. Absolute activity measurement of {sup 152}Eu sources with a single detector

    Energy Technology Data Exchange (ETDEWEB)

    Nemes, T. [Faculty of Engineering, University of Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad (Serbia); Mrda, D. [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad (Serbia); Bikit, I., E-mail: bikit@df.uns.ac.rs [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad (Serbia)

    2011-08-21

    We investigated the possibility of absolute source activity measurements by a single gamma spectrometer. The measurements were performed for three (point, cylinder and Marinelly shaped) calibrated {sup 152}Eu sources. Making use of data on peak, sum-peak and total spectrum area in the single spectrum, we developed the activity determination method based on the dominant gamma cascades in the {sup 152}Eu decay. We have shown that spectral data of {sup 152}Eu point and Marinelli shaped source can yield activity information with uncertainty below 10%. - Highlights: > Peak, sum-peak and total spectrum area in single spectrum were used for activity determination. > For the {sup 152}Eu source the activity was determined from the dominant gamma cascades in the decay. > The activity of point and Marinelly shaped sources was determined with uncertainty of less than 10%.

  7. Measurement of the absolute neutron activity of a 252Cf source

    International Nuclear Information System (INIS)

    A method for measuring the absolute neutron activity of a large 252Cf source has been developed. The neutron counting assembly is composed of eight BF3 counters mounted in a large tank filled with water which is used as a moderator. The detection efficiency is determined using a low activity 252Cf source. The mehod is based on the identification of every fission event, followed by the counting of the fission neutrons detected by the BF3 counters during a time interval equal to the maximum neutron lifetime in the moderator. The efficiency is thus obtained relative to the average number of prompt neutrons emitted per 252Cf spontaneous fission which is commonly used as a standard. A systematic analysis of the different sources of error is presented. The measurement accuracy is estimated to be better than 1%

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

    International Nuclear Information System (INIS)

    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)

  9. ArtDeco: A beam deconvolution code for absolute CMB measurements

    CERN Document Server

    Keihänen, Elina

    2012-01-01

    We present a method for beam deconvolution for cosmic microwave background (CMB) anisotropy measurements. The code takes as input the time-ordered data, along with the corresponding detector pointings and known beam shapes, and produces as output the harmonic a_Tlm, a_Elm, and a_Blm coefficients of the observed sky. From these one can further construct temperature and Q and U polarisation maps. The method is applicable to absolute CMB measurements with wide sky coverage, and is independent of the scanning strategy. We test the code with extensive simulations, mimicking the resolution and data volume of Planck 30GHz and 70GHz channels, but with exaggerated beam asymmetry. We apply it to multipoles up to l=1700 and examine the results in both pixel space and harmonic space. We also test the method also in presence of white noise.

  10. A diode laser spectrometer at 634 nm and absolute frequency measurements using optical frequency comb

    International Nuclear Information System (INIS)

    This paper reports that two identical external-cavity-diode-laser (ECDL) based spectrometers are constructed at 634 nm referencing on the hyperfine BX transition R(80)84 of 127I2. The lasers are stabilized on the Doppler-free absorption signals using the third-harmonic detection technique. The instability of the stabilized laser is measured to be 2.8 10?12 (after 1000 s) by counting the beat note between the two lasers. The absolute optical frequency of the transition is, for the first time, determined to be 472851936189.5 kHz by using an optical frequency comb referenced on the microwave caesium atomic clock. The uncertainty of the measurement is less than 4.9 kHz. (general)

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

    CERN Document Server

    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.

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

    International Nuclear Information System (INIS)

    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.

  13. Absolute-scale measurement of Compton backscattering in germanium at 105.3 KeV

    International Nuclear Information System (INIS)

    The differential cross section d2σ/dEdΩ was measured at incident photon energy of 105.3 keV in germanium (Z = 32). The experimental method used in the present experiment was introduced by the present authors previously. In the measurements, one detector serves as target and detector of ejected electrons, and another detector as detector of Compton-scattered photons. 155Eu was used as the source of photons. It gives a complex multi-line spectrum. We found that fast (multiple) cascades influence little the data of the 105.3 keV crossover transition. The calculations of other non-single Compton detector-to-detector scattering processes were made. As an improvement to our previous calculations, we have taken into account the finite dimensions of the cylindrical active volume of the detectors. Accordingly, the calculation of the detector efficiency was also improved. The absolute scale of the experimental Compton-scattering cross section was determined by cross talk between the two detectors via characteristic Kα and Kβ x-rays of germanium with accuracy better than few percents. The values of the experimental cross section d2σ/dEdΩ have been compared with corresponding values calculated by the impulse approximation with Hartree-Fock (HF) and hydrogen-like wave functions. The impulse approximation with HF wave functions gives excellent agreement to the experimental cross section, while the impulse approximation with hydrogen like wave functions give fairly agreement. The accurate absolute-scale values of Compton-scattering cross section from the present measurement and those from our previous measurements clearly show that HF wave functions are much better than the hydrogen-like wave functions in the description of Compton scattering data. (author)

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

    Science.gov (United States)

    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.

  15. Optical parameters Determination for absolute luminosity and total cross section measurements in ATLAS

    CERN Document Server

    Cavalier, Sophie

    ALFA (Absolute Luminosity For ATLAS) aims at measuring the absolute luminosity for the ATLAS experiment with an incertitude down to 2-3 \\% and the total elastic cross section. The luminosity is related to the number of events, the highest the luminosity, the highest the number of events. This is, then, an important quantity for colliders like LHC (Large Hadron Collider). LHC is made of two beams circulating in two different beam pipes and colliding at four interaction points where the four physics experiments are located (ATLAS, CMS, ALICE, LHCb). ALFA detectors inserted into Roman Pots (RPs), have been placed around ATLAS at 240 m distance from the collision point (IP1) after six quadrupoles magnets and two dipoles defining the ALFA beam line which is part of the LHC ring.The detectors are made of scintillating optics fibers to catch elastic protons generated at IP1. These protons are tracked through the LHC magnets beam line which needs to be optimized in terms of optics parameters. We call high β optics, ...

  16. Testing of an absolute measuring flat jack according to the compensation method (AWID)

    International Nuclear Information System (INIS)

    A measurement principle for a flat jack is being introduced by means of which stress measurements may be carried out without requiring any material parameters of the flat jack for the measurements. No calibration measurements are needed for this absolute measuring flat jack. A temperature dependence does not exist. A leap in the electrical resistance of the flat jack, which is brought about by two metal sheets separating when being pumped up with hydraulic oil at reaching of external pressure, is evaluated. Besides theoretical considerations on the mode of operation of the flat jack, laboratory tests were performed in an autoclave as well as in a tube filled with salt grit under a uniaxial press. The error which arose during measurements in the oil pressure autoclave was due to the magnitude of the reading accuracy of the measuring devices, i.e., it was smaller than 0.3% at 150 bars. This is to be considered as the error which may be assigned to the flat jack. Finally an arrangement of six flat jacks is treated for determining stress tensors in the heated area of the Temperature Test Field (TV 6) in the Asse salt mine. 5 refs.; 15 figs

  17. The radioactivity measurement of Turkish lignites

    International Nuclear Information System (INIS)

    This is a study on the radioactivity of Turkish lignites in which the γ spectrometric technique has been used for the determination of activity levels of naturally occurring radionuclides 238U, 232Th, 40K, 226Ra and fallout radionuclides 137Cs and 134Cs in lignites taken from 12 different parts of Turkey by the Mineral Research and Exploration Institute of Turkey. Concentrations of 238U, 232Th, 226Ra, 40K, 137Cs and 134Cs were found up to 52, 37, 207, 163 Bq kg-1, LLD, ND, respectively. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. Measurements with radioactive beams at ATLAS

    International Nuclear Information System (INIS)

    Reactions of interest to nuclear astrophysics have been studied with radioactive beams at the ATLAS accelerator. Using a modified ISOL technique, beams of 18F (T1/2 = 110 min) and 56Ni (T1/2 = 6.1d) were produced and the reactions 18F(p,?)15O, 18F(p,?)19Ne, and 56Ni(d,p)57Ni have been investigated. The results indicate that the 18F(p,?) route is a small contributor to the breakout from the hot CNO cycle into the rp process, while the 56Ni(p,?)57Cu rate is about ten times larger than previously assumed

  19. Radioactivity measuring system of labelled biopolymers

    International Nuclear Information System (INIS)

    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

  20. Preliminary results of absolute and high-precision gravity measurements at the Nevada Test Site and vicinity, Nevada

    International Nuclear Information System (INIS)

    Absolute gravity measurements were made at 4 sites in southern Nevada using the absolute gravity free-fall apparatus. Three of the sites are located on the Nevada Test Site at Mercury, Yucca Pass, and in northern Jackass Flats. The fourth site is at Kyle Canyon ranger station near Charleston Park where observed gravity is 216.19 mGal lower than at Mercury. Although there is an uncertainty of about 0.02 mGal in the absolute measured values, their gravity differences are considered accurate to about 0.03 mGal. Therefore, the absolute measurements should provide local control for the calibration of gravity meters between Mercury and Kyle Canyon ranger station to about 1 to 2 parts in 10,000. The average gravity differences between Mercury and Kyle Canyon obtained using LaCoste and Romberg gravity meters is 216.13 mGal, 0.06 mGal lower, or 3 parts in 10,000 lower than using the absolute gravity meter. Because of the discrepancy between the comparison of the absolute and relative gravity meters, more absolute and relative gravity control in southern Nevada, as well as the Mt. Hamilton area where the LaCoste and Romberg instruments were calibrated, is needed. Multiple gravity meter ties were also made between each of the four absolute stations to nearby base stations located on bedrock. These stations were established to help monitor possible real changes in gravity at the absolute sites that could result from seasonal variations in the depth to the water table or other local mass changes. 8 refs., 16 figs., 7 tabs

  1. Easy Absolute Values? Absolutely

    Science.gov (United States)

    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

  2. Spectroscopic determination of electrical conductivity in an MHD duct from absolute intensity measurements

    Science.gov (United States)

    Wang, S. Y.; Smith, J. M.

    1977-01-01

    Measurements of the electrical conductivity in the NASA Lewis cesium seeded, H2-O2 MHD duct made by applying a voltage across the channel from one end electrode to the other, measuring the current, and using the inner electrodes as probes to monitor the voltage distribution along the channel were found to be in good agreement with theory except at low combustion pressures and/or high ratios of seed/oxygen mass flows. To corroborate these measurements and to analyze the possibility of nonuniform seed injection as a cause of the above deviations, a spectroscopic investigation of the plasma conductivity was undertaken. Radial profiles of emission coefficient were obtained from measured transverse profiles of the absolute integrated intensity by Abel inversion. Radial profiles of electrical conductivity were then obtained under two different assumptions. In the first the Cs seed fraction is assumed uniform and equal to the measured flow rate at the time when the temperature and conductivity were obtained. In the second method the local temperature and pressure are taken to be those given by a one-dimensional channel calculation including heat transfer and friction. The results of the two methods are compared to the previously measured conductivity.

  3. Study on influences of experimental factors on energy and absolute activity measurements of alpha-emitters

    International Nuclear Information System (INIS)

    This work presents firstly a review of the fundamental results and conclusions obtained through alpha-spectrometry and alpha-counting, and the influence of energy straggling, energy loss, self-absorption and backscattering, on the determination of the energy and the absolute activity of alpha samples. Is is shown that the techniques of source fabrication and the methods of measurements play a capital influence on the obtained results. Moreover, measurements made by us, with a silicon surface barrier detector, show that the peak-asymmetry and peak-shift of an alpha-spectrum increases with the angle of emission, and that the magnitude of this effect depends on the thickness and homogeneity of the sample, as well as on the geometry of the measuring system. Through an analysis of the angular distribution of the emitted particles, the degree of isotropy of some thin Am sup(241) sources was measured and the influence of source backing and the geometry was analysed. We can conclude that, in general, there is a larger precision in measurements made under very small solid angles around the normal to the sample, and we enphasize the necessary cares required on the production of the source and on the set up of the measuring system. (author)

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

    Science.gov (United States)

    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

  5. Measurements of low radioactive contaminations in lead using bolometric detectors

    International Nuclear Information System (INIS)

    Bolometric detectors made with samples of crystalline and polycrystalline lead have been operated to measure their internal radioactivity due to 210Pb. It has been found that contaminations of hundreds of becquerels per kilogram are present in commercial low radioactivity lead and that these contaminations can be reduced by an order of magnitude by crystallisation. A low activity of a few hundreds of millibecquerels per kilogram still persists in specially prepared low radioactivity lead. No evidence for contamination is on the contrary found in a 2000 year old lead sample from a sunk Roman ship, at a level of less than 20 millibecquerel per kilogram. (orig.)

  6. Measurements of radioactive dusts in high altitude air

    International Nuclear Information System (INIS)

    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)

  7. Measurement of the absolute differential cross section of proton-proton elastic scattering at small angles

    CERN Document Server

    Mchedlishvili, D; Dymov, S; Bagdasarian, Z; Barsov, S; Gebel, R; Gou, B; Hartmann, M; Kacharava, A; Keshelashvili, I; Khoukaz, A; Kulessa, P; Kulikov, A; Lehrach, A; Lomidze, N; Lorentz, B; Maier, R; Macharashvili, G; Merzliakov, S; Mikirtychyants, S; Nioradze, M; Ohm, H; Prasuhn, D; Rathmann, F; Serdyuk, V; Schroer, D; Shmakova, V; Stassen, R; Stein, H J; Stockhorst, H; Strakovsky, I I; Ströher, H; Tabidze, M; Täschner, A; Trusov, S; Tsirkov, D; Uzikov, Yu; Valdau, Yu; Wilkin, C; Workman, R L; Wüstner, P

    2015-01-01

    The differential cross section for proton-proton elastic scattering has been measured at a beam energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12-16 degrees to 25-30 degrees, depending on the energy. Absolute normalisations of typically 3% were achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon a partial wave analysis. After extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations.

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

    CERN Document Server

    Eyser, K O; 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; Wise, T; Wood, J; Zelenski, A

    2007-01-01

    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 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.

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

    International Nuclear Information System (INIS)

    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)

  10. Absolute height measurement of specular surfaces with modified active fringe reflection photogrammetry

    Science.gov (United States)

    Ren, Hongyu; Jiang, Xiangqian; Gao, Feng; Zhang, Zonghua

    2014-07-01

    Deflectometric methods have been studied for more than a decade for slope measurement of specular freeform surfaces through utilization of the deformation of a sample pattern after reflection from a tested sample surface. Usually, these approaches require two-directional fringe patterns to be projected on a LCD screen or ground glass and require slope integration, which leads to some complexity for the whole measuring process. This paper proposes a new mathematical measurement model for measuring topography information of freeform specular surfaces, which integrates a virtual reference specular surface into the method of active fringe reflection photogrammetry and presents a straight-forward relation between height of the tested surface and phase signals. This method only requires one direction of horizontal or vertical sinusoidal fringe patterns to be projected from a LCD screen, resulting in a significant reduction in capture time over established methods. Assuming the whole system has been precalibrated during the measurement process, the fringe patterns are captured separately via the virtual reference and detected freeform surfaces by a CCD camera. The reference phase can be solved according to the spatial geometric relation between the LCD screen and the CCD camera. The captured phases can be unwrapped with a heterodyne technique and optimum frequency selection method. Based on this calculated unwrapped-phase and that proposed mathematical model, absolute height of the inspected surface can be computed. Simulated and experimental results show that this methodology can conveniently calculate topography information for freeform and structured specular surfaces without integration and reconstruction processes.

  11. Absolute distance measurement by dual-comb interferometry with adjustable synthetic wavelength

    International Nuclear Information System (INIS)

    Absolute distances were measured using two femtosecond lasers of different pulse repetition rates by revisiting the dual-comb interferometric method proposed by Coddington et al (2009 Nature Photon. 3 351–6). The apparatus built for experiments was designed to eliminate the dead zones in the measurement range by separating the measurement pulses from the reference pulses using orthogonal polarization. In addition, the pulse repetition rate of the signal laser was made tunable in order to extend the non-ambiguity range (NAR) by adaptively adjusting the synthetic wavelength in consideration of the de facto measurement stability in the air. Actual tests performed in the open air proved that a target distance of 69.3 m is measured without interruptions at a 200 µs update rate in the presence of a ∼170 µm drift of the optical path length caused by the fluctuation of the refractive index of air. The proposed hardware system design for effective NAR extension will facilitate the use of dual-comb interferometry for various terrestrial applications. (paper)

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

    International Nuclear Information System (INIS)

    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 preformed at each major step in the detector development. During these periods, the detector has been investigated under all aspects. The tracks reconstruction algorithm, the methods to extract the detection efficiency or the cross talk level are just a part of all the parameters that have to be determined. All these tests have confirmed the technical choices made so far and allowed to launch the serial production of the eight detectors that will be install in 2011 for the luminosity measurement. (author)

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

    International Nuclear Information System (INIS)

    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

  14. Measurement of total body radioactivity in man

    International Nuclear Information System (INIS)

    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.)

  15. Solar-cell radiance standard for absolute electroluminescence measurements and open-circuit voltage mapping of silicon solar modules

    Science.gov (United States)

    Mochizuki, Toshimitsu; Kim, Changsu; Yoshita, Masahiro; Mitchell, Jonathon; Lin, Zhu; Chen, Shaoqiang; Takato, Hidetaka; Kanemitsu, Yoshihiko; Akiyama, Hidefumi

    2016-01-01

    In this work, we propose and demonstrate a durable and distributable Lambertian light-emitter secondary standard using the electroluminescence (EL) of a Si solar cell. This standard is useful for calibration of the absolute sensitivity of an EL-imaging infrared camera used to acquire quick on-site measurements of the absolute EL efficiencies of individual Si solar cells in modules and arrays. The developed method enables the realization of quantitative open-circuit voltage mapping.

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  18. Absolute measurement of radiation losses of a tokamak in the region of ultrasoft X-radiation

    International Nuclear Information System (INIS)

    In this work experiments were performed to investigate the question to which extent spectroscopic measurements in the ultrasoft X-ray region (lambda=1-10nm) are a useful technique for diagnosing the relatively cool edge region (Tsub(e)approx.=100-200 eV) of fusion-oriented plasmas. Object of these measurements was the plasma centre of a small tokamak where the plasma parameters are comparable to those in the edge region mentioned above. The measurements were done with a Bragg-spectrometer using either TAP (2d=2.59 nm) or lead stearate (2d=10.04 nm) as analyzer crystal. This allowed to cover the whole spectrum between 0.5 and 9 nm with one instrument. Using a photon-counting detector the spectrometer/detector system was absolutely calibrated by measuring the transmission of its different components by means of monochromatic X-ray radiation. For the investigated tokamak plasma intense line spectra in the region 1.4 nm =4.4 nm have been observed, where the former was caused by the high ionization stages of oxygen (OVII and OVIII), whereas the latter could be explained by Ar- to Na-like ions of the metallic impurities Fe, Cr, and Ni. (orig./HT)

  19. A new method for the absolute measurement of piezoelectric coefficients on thin polymer films

    Science.gov (United States)

    Guillot; Jarzynski

    2000-08-01

    A new quasistatic method to measure piezoelectric coefficients on thin polymer films is presented. This method is based on a combined experimental/analytical approach, where small polymer samples (6 mm x 3 mm x 110 microm) are encapsulated in a soft silicone rubber and an electric field is applied across their thickness (3-direction). Strains are measured optically along three perpendicular directions using a laser Doppler vibrometer, and the experimental measurements are used in a Rayleigh-Ritz energy minimization procedure implemented symbolically in MATHCAD, which yields the absolute piezoelectric coefficients d(3ii). These measured coefficients are material properties of the polymer and do not depend on the specific boundary conditions of the problem. The validity of the method is established using the ATILA finite element code. Experimental values of d(311), d(322), and d(333) obtained for polyvinylidene fluoride (PVDF) at room temperature, in the frequency range 500-2000 Hz, are presented and compared with existing data; excellent agreement is found. The extension of the method to the determination of electrostrictive coefficients on soft polyurethane materials is introduced. PMID:10955625

  20. Measurements of Absolute Hadronic Branching Fractions of the Λ_{c}^{+} Baryon.

    Science.gov (United States)

    Ablikim, M; Achasov, M N; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Baldini Ferroli, R; 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 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; Eren, E E; 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, 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, Y; 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; Kuehn, W; Kupsc, A; 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, 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 M; Li, X N; Li, X Q; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; 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, 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; Mitchell, R E; Mo, X H; Mo, Y J; Morales Morales, C; 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; Santoro, V; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Song, W M; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; 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, S G; Wang, W; Wang, W P; Wang, X F; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Weber, T; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; 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, 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 J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y N; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhang, 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

    2016-02-01

    We report the first measurement of absolute hadronic branching fractions of Λ_{c}^{+} baryon at the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold, in the 30 years since the Λ_{c}^{+} discovery. In total, 12 Cabibbo-favored Λ_{c}^{+} hadronic decay modes are analyzed with a double-tag technique, based on a sample of 567  pb^{-1} of e^{+}e^{-} collisions at sqrt[s]=4.599  GeV recorded with the BESIII detector. A global least-squares fitter is utilized to improve the measured precision. Among the measurements for twelve Λ_{c}^{+} decay modes, the branching fraction for Λ_{c}^{+}→pK^{-}π^{+} is determined to be (5.84±0.27±0.23)%, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other 11 Cabibbo-favored hadronic decay modes are significantly improved. PMID:26894702

  1. A portable system for measuring the absolute geographic location of distant objects

    Science.gov (United States)

    Kuscer, Lovro; Diaci, Janez

    2010-10-01

    This contribution presents the development of a lightweight, man-portable system for measuring the absolute geographic location of distant objects. The system is built entirely from COTS (Commercial Of-The-Shelf) components that are controlled using custom software and hardware solutions. It consists of a laser rangefinder, an electronic compass and inclinometer, an optical incremental encoder, a GPS receiver, a CMOS camera, an LCOS viewfinder and an FPGA module that serves as a system controller. With the use of the FPGA, low power consumption and high processing power was achieved. The user interface comprises the viewfinder and a multidirectional button. While performing measurements, the live image of the target, sensor data and calculated coordinates are displayed in the viewfinder. The measuring system also features an SD card slot for data storage and WLAN connectivity to transfer the acquired data to a geographic information system. The contribution also presents the results of field tests used to verify the system operation and Monte Carlo simulations employed to evaluate its measuring characteristics.

  2. Absolute distance measurement by spectrally resolved interferometry based on a femtosecond pulse laser

    Science.gov (United States)

    Xu, Yan; Zhou, Weihu; Liu, Deming; Ding, Lei

    2012-08-01

    A spectrally resolved interferometry ranging method based on the optical frequency comb of a femtosecond pulse laser was presented. The approach utilized a frequency stabilized Ti:sapphire femtosecond pulse laser to provide a phase-locked summation of discrete quasi-monochromatic light modes of consecutive frequencies, which is seen as an optical comb in the frequency domain. In this method all modes interference signals of the optical frequency comb obtained by the femtosecond light pulses traveling along different optical path between the reference and measurement arms were utilized to measure absolute distance. A Fabry-Perot Etalon was used to filter smaller frequency modes from the broad-bandwidth femtosecond laser pulse produced. The actual measured light spectrum of the femtosecond laser source was used as the input data, the whole process of the spectrally resolved interferometry ranging method was simulated through MATLAB. The simulation results indicate that the spectrally resolved interferometry ranging method could satisfy the demand of the small scale measurement with a nonambiguity range of 5.75 mm and an associated resolution of nanometer level.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Landoas, Olivier; Rosse, Bertrand; Briat, Michelle; Marmouget, Jean Gabriel; Varignon, Cyril; Ledoux, Xavier; Caillaud, Tony; Thfoin, Isabelle; Bourgade, Jean-Luc [CEA, DAM, DIF, F-91297 Arpajon (France); Glebov, Vladimir Yu; Sangster, Thomas C.; Duffy, Tim [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Disdier, Laurent [CEA, LIST, F-91191 Gif-sur-Yvette (France)

    2011-07-15

    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 a 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.

  5. New method for absolute measurement of neutron flux in reactors operated at high power levels

    International Nuclear Information System (INIS)

    The objective of this thesis is to develop and study two methods of neutron measurements in nuclear reactors - new methods for measuring fast neutron fluxes, and Li6 semiconductor neutron spectrometer. It contains four chapters: Chapter I, Introduction covers the explanation of the need for neutron measurements in the reactor, and critical consideration of the existing methods for fast neutron flux measurements as well as methods for measuring the fast neutron spectra. Chapter II describes theoretical basis of semiconductor counters operation and their most important properties. Chapter III includes the description of the method developed by the author, long-tube method, and the results obtained by applying this method with the special emphasis on absolute measurements of fast neutron flux. Advantages and limitations of this method are discussed at the end of this chapter. Chapter IV contains intercomparison of the existing semiconductor spectrometers and emphasis of their positive and negative properties. A critical analysis of the results obtained by Li6 spectrometer with flat geometry in included. A new type of Li6 semiconductor spectrometer is described. Its properties are experimentally determined and it was compared to the classical Li6 spectrometer. Most of the experiments were done in the Physics Laboratory and at RA and RB reactors in the 'Boris Kidric' Institute of Nuclear Sciences in Vinca, and some at reactor in McMaster University, Hamilton, Canada. Experiments concerned with registering particles scattering were done at the Lockheed research reactor during fall 1963 in Belgrade. Neutron fluxes and spectra were measured by semiconductor counters improved and adapted for neutronic measurements by the author

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

    International Nuclear Information System (INIS)

    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.

  7. Absolute wind measurements in the lower thermosphere of Venus using infrared heterodyne spectroscopy

    International Nuclear Information System (INIS)

    The first absolute wind velocities above the cloud-tops were obtained during four planetary phases spanning 82 percent of a synodic period. Bean-integrated Doppler displacements in the non-thermal emission core of (12)C(16)O2 10.33 microns R(8) (obtained at sub-Doppler resolution), sampled the line of sight projection of the lower thermospheric wind field (100 to 120 km). A field-usable Lamb-dip laser stabilization system, developed for spectrometer absolute frequency calibration to less than +/- 0.1 MHz, allowed S/N-limited line of sight velocity resolution at the 1 m/s level. The spectrometer's diffraction-limited beam and 1-2 arc-second seeing, provided the spatial resolution necessary for circulation model discrimination. Qualitative analysis of beam-integrated winds definitively established a dominant subsolar-antisolar circulation in the lower thermosphere. A retrograde zonal component was also suggested. Beam-integrated winds were modelled with a 100 x 100 grid over the beam, incorporating beam spatial rolloff and across-the-beam gradients in non-thermal emission intensity, line of sight projection geometry, and horizontal wind velocity. Horizontal wind velocity was derived from a 2-parameter model wind field comprised of subsolar-antisolar and zonal components. Best-fit models indicated a dominant subsolar-antisolar flow with 120 m/s cross-terminator winds and a retrograde zonal component with a 25 m/s equatorial velocity. Detection of a significant zonal component indicates upper thermospheric super-rotation may be coupled to, hence pumped by, cloud level super-rotation. Early heterodyne mesospheric wind measurements were re-examined based on laser stability test results

  8. Measurement of absolute differential cross sections for vibrational excitation of O2 by electron impact

    International Nuclear Information System (INIS)

    New measurements of absolute differential cross sections (DCSs) for vibrational excitation of O2, with improved sensitivity and resolution, are presented. The 90o DCSs are given as a function of energy up to 16 eV for elastic scattering and vibrational excitation of up to ν = 7. A weak continuous, probably non-resonant, background scattering is found in the ν = 1 cross section in addition to the well known sharp 2Πg resonances dominating vibrational excitation in the energy range up to 2.5 eV. The sharp 2Πg resonances interfere coherently with the background scattering both in the ν = 1 and in the elastic channels. New absolute values for the energy-integrated DCSs for 2Πg resonances are given. They exhibit oscillatory Franck-Condon factors in the ν - 4-7 exit channels. The broad resonance peaking at 9 eV, dominating vibrational DCSs at higher energies, causes excitation of high vibrational levels (up to the dissociation limit) of the X3Σg- ground state, but not of the a1Δg and b1Σg+ electronically excited states, supporting its assignment as the 4Σu- resonance, the selectivity being caused by spin selection rules. The excitation of high ν's indicates a relatively narrow autodetachment width for this resonance. The angular dependence at 9 eV is, however, not a simple pσ wave as would be expected for a simple σu* shape resonance. Preliminary experiments with a free jet cooled sample, concerned with rotational broadening of the 2Πg resonance, are reported. (author)

  9. The Cosmological Impact of AGN Outflows: Measuring Absolute Abundances and Kinetic Luminosities

    Science.gov (United States)

    Arav, Nahum

    2009-07-01

    AGN outflows are increasingly invoked as a major contributor to the formation and evolution of supermassive black holes, their host galaxies, the surrounding IGM, and cluster cooling flows. Our HST/COS proposal will determine reliable absolute chemical abundances in six AGN outflows, which influences several of the processes mentioned above. To date there is only one such determination, done by our team on Mrk 279 using 16 HST/STIS orbits and 100 ksec of FUSE time. The advent of COS and its high sensitivity allows us to choose among fainter objects at redshifts high enough to preclude the need for FUSE. This will allow us to determine the absolute abundances for six AGN {all fainter than Mrk 279} using only 40 HST COS orbits. This will put abundances studies in AGN on a firm footing, an elusive goal for the past four decades. In addition, prior FUSE observations of four of these targets indicate that it is probable that the COS observations will detect troughs from excited levels of C III. These will allow us to measure the distances of the outflows and thereby determine their kinetic luminosity, a major goal in AGN feedback research. We will use our state of the art column density extraction methods and velocity-dependent photoionization models to determine the abundances and kinetic luminosity. Previous AGN outflow projects suffered from the constraints of deciding what science we could do using ONE of the handful of bright targets that were observable. With COS we can choose the best sample for our experiment. As an added bonus, most of the spectral range of our targets has not been observed previously, greatly increasing the discovery phase space.

  10. Radiation Protection Research: Low-level Radioactivity Measurements

    Energy Technology Data Exchange (ETDEWEB)

    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'.

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

    Science.gov (United States)

    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-) 0.17)('o)/oo relative to a laboratory standard, or approximately 42('o)/oo relative to standard mean ocean water. After 190 days at 24(DEGREES)C no oxygen isotope exchange was observed between N(,2)('16)O and H(,2)('18)O.

  12. Absolute cross sections measurement for the 12C + 12C system at astrophysically relevant energies

    International Nuclear Information System (INIS)

    The 12C + 12C fusion reaction has been studied in the center-of-mass energy range of 2.25 to 6.01 MeV. Through the detection of gamma rays from the first excited states of the residual nuclei 20Ne, 23Na and 23Mg, absolute cross sections for the 12C(12C,-bar α), 12C(12C,-bar p) and 12C(12C,-bar n) reactions have been obtained. In this new measurement, the energy dependence of the S-factor is found to increase as the energy decreases below 3 MeV in the center of mass. This tendency was observed in previous measurements by Mazarakis et al., and has since then become a subject of controversy. In this work, where the cross sections are measured at even lower energies, we confirm the rise in the S-factor toward the energy region relevant for star evolution and nucleosynthesis calculations (Ec.m.=1-3 MeV)

  13. Luminosity measurement method for the LHC: Event selection and absolute luminosity determination

    Energy Technology Data Exchange (ETDEWEB)

    Krasny, M.W., E-mail: krasny@lpnhep.in2p3.fr [LPNHE, Pierre and Marie Curie University, CNRS-IN2P3, Tour 33, RdC, 4, pl. Jussieu, 75005 Paris (France); Chwastowski, J. [Institute of Teleinformatics, Faculty of Physics, Mathematics and Computer Science, Cracow University of Technology, ul. Warszawska 24, 31-115 Kraków (Poland); Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Cyz, A.; Słowikowski, K. [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland)

    2013-11-21

    In our earlier papers Krasny et al. [1,2] have proposed a new luminosity measurement method which uses lepton pairs produced in peripheral collisions of the LHC beam particles, and identified the requirements for a new, specialized luminosity detector which is indispensable for their efficient on-line selection. In this paper we use the base-line detector model, with no precise timing capabilities, to evaluate the statistical and systematic accuracy of the method. We propose the complete event selection procedure and demonstrate that it allows to collect a sufficiently large sample of e{sup +}e{sup −} pairs to achieve a better than 1% statistical accuracy of the luminosity measurement over less than one-month-long running time intervals. We argue that the absolute luminosity measurement systematic errors can be kept below 1%. The proposed method can be directly applied to the LHC running periods for which the machine instantaneous luminosity does not exceed the L=10{sup 33}s{sup −1}cm{sup −2} value. Two ways extending the method to the large pile-up periods corresponding to higher instantaneous luminosities are proposed.

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

    CERN Document Server

    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 ...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  18. Measurements of radioactive dusts in high altitude air

    International Nuclear Information System (INIS)

    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)

  19. Heat generation amount measuring device for radioactive waste containing vessel

    International Nuclear Information System (INIS)

    The present invention provides a device for measuring heat fluxes on the entire surface of a radioactive waste containing vessel in a short period of time and determining the entire heat generation amount. If a rotational driving means is operated in a state where the radioactive waste containing vessel is loaded thereon, positions of contact of heat flux meters arranged in a row are changed in a circumferential direction, the heat fluxes on the entire surface of radioactive waste containing vessel are measured and the entire heat generation amount of the waste containing vessel is calculated. Since a plurality of the heat flux meters are positioned separately, elastic contact with the radioactive waste containing vessel is kept relative to the unevenness on the outer surface of the radioactive waste containing vessel. If the heat flux meters are moved integrally while being loaded on a moving means, contact or noncontact state of the heat flux meters relative to the radioactive waste containing vessel is set rapidly. (I.S.)

  20. Device for radioactivity measurement of liquid samples

    International Nuclear Information System (INIS)

    The device for low activity gamma measurements comprises an automatic changer for sample transfer from a conveyor to a measuring chamber. The conveyor includes a horizontal table were are regularly distributed sample holders. A lift allows a vertical motion of a plate for the exposition in front of a detector

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    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)

  5. Absolute-scale measurement of compton backscattering in germanium at 105.3 keV

    International Nuclear Information System (INIS)

    The differential cross section d2σ/dE dΩ was measured at an incident photon energy of 105.3 keV in germanium on absolute scale. The measurements were made using two high purity Ge detectors that operated in a coincidence mode. One detector served as the target and detector of ejected electrons, and another as the detector of Compton-scattered photons. It was found that fast (multiple) cascades have little influence on the data of the 105.3 keV crossover transition. An improved determination of the detector efficiency was made. The calculated values of the cross-section d2σ/dE dΩ using the impulse approximation (IA) with Hartree-Fock (HF) wave functions are in excellent agreement with the experimental cross-sections, while the IA with hydrogen like (HL) wave functions give fair agreement. A comparison of the calculated values of the cross-sections obtained with HF and HL wave functions for each subshell in germanium gives new values for effective charges, which improve agreement between the results of IA with HL and experimental values. (author)

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

    International Nuclear Information System (INIS)

    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)

  7. Diffusion coefficient measurements with radioactive tracer technique

    International Nuclear Information System (INIS)

    A measuring cell and a new method were developed to study chloride ion diffusion through thin layers and to measure diffusion coefficient. β-radiation of the tracer was detected making use of Cherenkov radiation. The chamber developed is suitable for diffusion test with any β-decay nuclide with a maximum energy higher than the Cherenkov threshold referring to water. The results obtained were checked by GM counting. The method was used for testing paint films and coating systems. The diffusion developed in the layer was computer simulated and the results were compared to measured data. (author)

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

    International Nuclear Information System (INIS)

    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.)

  9. Note: Nonlinearity error compensated absolute planar position measurement using a two-dimensional phase-encoded binary grating

    Science.gov (United States)

    Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan; Eom, Tae Bong

    2013-05-01

    This Note presents a new absolute planar position measurement method using a two-dimensional phase-encoded binary grating and a sub-division process where nonlinearity error is compensated inherently. Two orthogonally accumulated intensity profiles of the image of the binary grating are analyzed separately to obtain the absolute position values in each axis. The nonlinearity error caused by the non-ideal sinusoidal signals in the intensity profile is compensated by modifying the configuration of the absolute position binary code and shift-averaging the intensity profile. Using an experimental setup, we measured a circular trajectory of 100 nm radius, and compared the measurement result with that of a laser interferometer. Applying the proposed compensation method, the nonlinearity error was reduced to less than 15 nm.

  10. Absolute coverage measurement of adsorbed CO and D2 on platinum

    International Nuclear Information System (INIS)

    Nuclear microanalysis, in conjunction with MeV 4He scattering, LEED, and Auger spectroscopy, is being applied to investigate the adsorption behaviour of various gases on monocrystalline platinum surfaces. Using an anodized Ta2O5 film of known thickness as the primary standard, we have calibrated the 16O(d,p1)17O reaction for analysing the surface coverage of oxygen in our UHV system with an absolute accuracy of +- 2%. Suitable secondary standards for calibrating the 12C(d,p)13C and D(3He,p)4He reactions have been prepared by cooling a clean metal target to 20 K and condensing on it a fairly thick (approx. 100 nm) film of either CO2 or D2O ice. The 16O(d,p1)17O reaction plus the Ta2O5 standard is then used to determine the absolute number of CO2 or D2O molecules (and hence the number of C or D atoms) in the frozen film to +- 3%. For saturation coverage of the Pt(100) surface with CO molecules at 185 K, preliminary values of (0.85 +- 0.06) x 1015O atoms cm-2 and (0.89 +- 0.04) x 1015 C atoms cm-2 have been obtained. Similar measurements on Pt(111) gave a saturation CO coverage corresponding to (0.69 +- 0.05)x 1015O atoms cm-2 and (0.79 +- 0.03) x 1015 C atoms cm-2. In both cases, the 16O(d,p1)17O analysis gives a slightly smaller value than the 12C(d, p)13C result. In another series of runs, the D(3He,p)4He reaction has been used to measure the surface coverage of hydrogen on Pt(111). A 10 min exposure to 1.3 x 10-4 Pa of molecular D2 gas at 185 K produces a deuterium coverage of (1.10 +- 0.05) x 1015 atoms cm-2. (orig.)

  11. Anticoincidence and differential measuring arrangement for radioactive substances

    International Nuclear Information System (INIS)

    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.)

  12. A pulse-recording system for radioactivity measurements

    International Nuclear Information System (INIS)

    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

  13. Measurement methodology of natural radioactivity in the thermal establishments

    International Nuclear Information System (INIS)

    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.)

  14. A pulse-recording system for radioactivity measurements

    CERN Document Server

    Lucas, L L

    1998-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Measuring radioactive carbon with a liquid scintillator

    Energy Technology Data Exchange (ETDEWEB)

    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)

  17. Geometry Optimization Of Marinelli Sample In Environmental Radioactivity Measurement

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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. Airborne measurement of radioactivity by learjet 35A

    International Nuclear Information System (INIS)

    In case of a radioactive emergency radioactive plumes may be expected in heights up to the tropopause. For this reason aircraft measurements are necessary as a supplement to ground-based measuring sites. The authors present an aircraft type learjet 35A used for localizing and analyzing radioactive contaminated air masses up to 12,000 m. The aircraft is equipped with an isokinetic high-volume sampler to collect aerosols on filters outside the pressurized cabin and an onboard gamma spectrometry system with a high purity germanium detector to analyze the filters during flight as well as a dose ratemeter, a radon daughter monitor and equipment to collect gaseous iodine and noble gases. The meteorological parameters temperature, atmospheric pressure, relative humidity, wind speed and wind direction are determined as well. Resulting data are transmitted from the plane to the headquarter of the German Meteorological Service (Deutscher Wetterdienst, DWD) and used for verifying the prognosis. (orig.)

  20. Measuring the absorbed radioactivity during a flight

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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. Absolute femtosecond measurements of Auger recombination dynamics in lead sulfide quantum dots

    OpenAIRE

    Jonas D.M.; Hill R.J.; Baranov D.; Spencer A.P.; Tiwari V; Peters W.K.; Cho B.

    2013-01-01

    Multiphoton excitation of hot carriers generates multiexcitons that are probed as a function of the absolute number of photons absorbed. Standard assumptions of Auger recombination analyses fail for an average of 2 excitations.

  3. Absolute femtosecond measurements of Auger recombination dynamics in lead sulfide quantum dots

    Directory of Open Access Journals (Sweden)

    Jonas D.M.

    2013-03-01

    Full Text Available Multiphoton excitation of hot carriers generates multiexcitons that are probed as a function of the absolute number of photons absorbed. Standard assumptions of Auger recombination analyses fail for an average of 2 excitations.

  4. ARCADE 2 Measurement of the Absolute Sky Brightness at 3-90 GHz

    Science.gov (United States)

    Fixsen, D. J.; Kogut, A.; Levin, S.; Limon, M.; Mirel, P.; Seiffert, M.; Singal, J.; Wollack, E.; Villela, T.; Wuensche, C. A.

    2011-01-01

    The ARCADE 2 instrument has measured the absolute temperature of the sky at frequencies 3, 8, 10, 30, and 90 GHz, uSing an open-aperture cryogenic instrument observing al balloon altitudes with no emissive windows between the beam-forming optics and the sky. An external blackbody calibrator provides an in situ reference. Systematic errors were greatly reduced by using differential radiometers and cooling all critical components to physical temperatures approximating the cosmic microwave background (CMB) temperature. A linear model is used to compare the output of each radiometer to a set of thermometers on the instrument. Small correction. are made for the residual emission from the flight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE 2 data alone show an excess radio rise of 54 +/- 6 mK at 3.3 GHz in addition to a CMB temperature of 2.731 +/- 0.004 K. Combining the ARCADE 2 data with data from the literature shows an excess power-law spectrum of T = 24.1 +/- 2.1 (K)(v/v(sub o)(exp -2.599+/-0.036 from 22 MHz to 10 GHz (v(sub 0) = 310 MHz) in addition to a CMB temperature of 2.725 +/- 0.001 K.

  5. Absolute measurements of 235U and 239Pu fission cross sections with photoneutron sources

    International Nuclear Information System (INIS)

    The fission cross sections of 235U and 239Pu for Na-Be, La-Be, Na-D, and Ga-D photoneutrons have been measured absolutely (i.e., without significant dependence on other cross section data). The neutron flux at the targets was calculated from the experimental geometry and by using a manganese bath to compare the photoneutron source yield with the standard source NBS-II. Fission counts were accumulated with the source positioned symmetrically between two identical foils and detectors in an experiment package suspended in a low-albedo laboratory. Fission fragments passing through limited solid angle apertures were recorded on polyester track-etch films. The masses of the foil deposits were determined by microbalance weighings and confirmed by thermal fission and alpha counting. After making a correction for the calculated energy distribution of the source neutrons, values of 1.471, 1.271, 1.161, and 1.210 barns were obtained for the 235U fission cross section at neutrons energies of 140, 265, 770, and 964 keV, respectively. Corresponding values of 1.465, 1.490, 1.678, and 1.644 barns were derived for 239Pu. Present uncertainties are about 2.0 percent for the 235U values and 2.5 percent for the 239Pu results

  6. Absolute measurements of the fast neutron capture cross-section of In115

    International Nuclear Information System (INIS)

    The In115(n,?)In/sup 116ml/ cross section has been absolutely determined at neutron energies of 23, 265, 770, and 964 keV. These energies are the median neutron energies of the four photoneutron sources, Sb-Be, Na-D2C, La-Be and Na-Be, utilized in this work. 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 In/sup 116ml/ decay activity using a 4? gas flow proportional counter. The detector efficiency was measured using 4??-? coincidence counting techniques. A correction factor for non-ideal detector behavior and the complex decay scheme effects was performed using the foil absorber method of efficiency extrapolation. Photoneutron source emission rates were determined by intercomparison with a Cf252 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. 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. The neutron energy spectra were also determined with the Monte Carlo program. The experimental cross section results were normalized to the source median energy using the energy spectra and cross section shape data

  7. C2O(X tilde 3Σ-): Absolute reaction rates measured by laser induced fluorescence

    International Nuclear Information System (INIS)

    Absolute rate constants are reported for reactions of C2O(X tilde 3Σ-) under pseudo-first-order decay conditions. C2O is generated by laser photodissociation of C3O2 at 266 nm, and detected by dye-laser induced fluorescence on the A tilde 3PIsub(i)-X tilde 3Σ- transition. Rate constants of (433 +- 12), (3.30 +- 0.12) and (1.12 +- 0.05) x 10-13 cm3 molecule-1s-1 are reported for reactions with NO, O2 and isobutene. The NO value is approximate due to an apparent dark reaction between NO and C3O2. Upper limits of 1 x 10-14 cm3 molecule-1s-1 are reported for reactions with H2, CO2, C2H2 and C2H4. The C2O + C3O2 reaction does not follow pseudo-first-order decay kinetics. Two explanations are proposed to explain this observation. Results are compared with previous relative rate measurements and are discussed in terms of their relevance to combustion chemistry. (orig.)

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

    International Nuclear Information System (INIS)

    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)

  9. Atmospheric xenon radioactive isotopes sampling and measurement

    International Nuclear Information System (INIS)

    The Comprehensive Test Ban Treaty (CTBT) organisation plans to implement a world wide monitoring network in order to check the compliance with the treaty. According to the requirements, the CEA-DAM is developing a device which automatically extracts xenon from the air and makes in situ measurements of the activities of four xenon radioisotopes which are fission products emitted by any nuclear test. The limit of detection for 133Xe is 0.6 m βq/m3. (authors)

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

    International Nuclear Information System (INIS)

    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)

  11. Measurements and Monte Carlo calculations to determine the absolute detector response of radiochromic film for brachytherapy dosimetry

    International Nuclear Information System (INIS)

    GafChromic (MD-55-2) radiochromic film has become increasingly popular for medical applications and has proven to be useful for brachytherapy dosimetry. To measure the absolute dose near a brachytherapy source, the response of the proposed detector in the measurement conditions relative to the response of the detector in calibration conditions must be known. MD-55-2 radiochromic film has been exposed in four different photon beams, a 30 and 40 kVp tungsten anode x-ray beam, a 75 kVp orthovoltage therapy beam, and a 60Co teletherapy beam to measure the relative detector response. These measurements were combined with coupled photon/electron Monte Carlo transport calculations to determine the absolute detector response. The Los Alamos National Laboratory Monte Carlo transport code MCNP4B2 was used. The measured relative response of this batch of MD-55-2 film varies from 8.79 mOD/Gy, measured for the 60Co beam, by as much as 42% for the low-energy x-ray beams. However, the absolute detector response varies from 4.32 mOD/Gy for the 60Co beam by, at most, only 6.3%. In this work we demonstrate that the absolute detector response of MD-55-2 radiochromic film is a constant and independent of beam quality. Further, this work shows that MCNP4B2 accurately simulates the energy response and geometry artifacts of the radiochromic film

  12. Methods for Measuring Sand Transport Using Radioactive Tracers

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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. Radionuclide absolute left ventricular volumes during upright exercise: Validation in normal subjects by simultaneous hemodynamic measurements

    International Nuclear Information System (INIS)

    A nongeometric radionuclide technique for the determination of absolute left ventricular volumes was validated during exercise in nine normal subjects. Simultaneous reference stroke volume and cardiac output measurements were obtained by the Fick method. The reference left ventricular volumes were calculated by combining the Fick stroke volume and the isotopic ejection fraction. Data were collected at rest in the supine and upright positions and during 600 upright exercise, at three levels of increasing severity. At rest, from supine to upright position, the reference end-diastolic volume decreased significantly from 182+-24 ml to 154+-21 ml (mean +-SD,P<0.005); during upright exercise of low intensity, end diastolic volume increased to 176+-24 ml (P<0.05); at maximal exercise, end-diastolic volume was not different from the resting value in upright position. The end-systolic volume gradually decreased at rest from 67+-11 ml in the supine position to 54+-8 ml in the upright position (P<0.05) and to 32+-7 ml at maximal exercise (P<0.005). Compared with these reference data, the scintigraphic measurements were significantly lower on average by 23% for stroke volume, 21% for cardiac output, 22% for end-diastolic volume, and 23% for end-systolic volume. The overall changes in stroke volume (P<0.05) and end-systolic volume (P<0.001) occurring at rest during exercise were correctly detected by the scintigraphic method but the smaller changes in end-diastolic volume (less than 15%) were not (P<0.15) because they were within the range of the precision of the technique. If subtle changes in left ventricular volume are to be quantitated, attempts should be made to reduce the random variability of the scintigraphic method. (orig.)

  15. Standardisation of 125Sb and 154Eu, and measurement of absolute gamma-ray emission probabilities

    International Nuclear Information System (INIS)

    A method has been devised to separate 125Sb from its short-lived daughter 125mTe. This technique was based on the repeated use of columns of anion exchange resin and supplemented by chemical procedures chosen to avoid any steps involving evaporation, which in initial trials gave severe problems due to the volatility of the antimony. Standardisation by 4πβ-γ coincidence counting was carried out within a few days of the separation, allowing for the daughter which grows in at about 0.25% per day. Beta counting efficiencies, as measured by the ratio of coincidence to gamma count rates, of up to 90% and 95% respectively were obtained for the two gamma-ray energy windows used. The ingrowth was monitored over a period of one month by gamma-ray spectrometry, using the weak 109 keV gamma-ray of 125mTe, to check the original separation. Samples of 154Eu were produced by neutron irradiation of high purity 153Eu, which was obtained by passing inactive europium through the NPL isotope separator. A solution of the 154Eu was standardised by coincidence counting, again using two gamma-ray energy windows, to give efficiencies of 96% and 98%. Absolute gamma-ray emission probabilities were measured for both nuclides using a germanium spectrometer calibrated with a range of nuclides of known activities and gamma-ray emissions. Sources were positioned 55 cm from the detector to ensure that real summing effects were negligible. (orig.)

  16. Absolute and relative path measures in a discrete system by using two analytical methods

    Science.gov (United States)

    Inoue, A.; Singh, R.; Fernandes, G. A.

    2008-06-01

    This paper analytically examines two vibration paths rank ordering methods and critically investigates several path identification issues. One method is the indirect interfacial path force estimation procedure that is employed in the well known experimental transfer path analysis. The other method is path disconnect scheme that has been historically utilized in industry to empirically find a dominant or defective path. In this article we utilize simplified, but pedagogical, discrete vibratory systems to clarify the underlying principles of both methods and to assess the path rank orders. Our analysis is limited to a linear time-invariant system (with only translating motions) under harmonic excitation and three distinct parallel paths (with or without masses) are considered. Alternate formulations of the interfacial path forces, based on direct and indirect methods, are derived. The indirect, yet exact, interfacial (path) force expressions could be used to estimate time-averaged dissipated power and Lagrangian energy spectra in various sub-systems. Estimations using only the driving point frequency response functions are emphasized, since they would ease the experimental burden. Next, the path disconnect method is analytically formulated and related to the path connect scheme (assuming one path at a time). This analysis reveals some useful relations among the path measures and the way a particular path could be connected or disconnected. A laboratory experiment validates the simplified massless path model, which yields asymptotic trends. Finally, all of the path rank orders are quantified and compared using many absolute and relative measures (based on interfacial force, receiver motion and sub-system energy relationships). Direction for future work is briefly discussed.

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

  19. Measurement of nuclear cross sections using radioactive beams

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

  2. Recent developments at Saclay for measuring absolute cross sections of reactions between heavy ions by in-beam gamma techniques

    International Nuclear Information System (INIS)

    The potentiality of the in-beam gamma techniques to measure absolute cross sections in the fusion-evaporation domain is discussed. These techniques have been used (with Ge(Li) detectors) for more than one decade, but in view of the considerable progress which has been achieved in the last years, it seems worth while to reconsider to day their merits and limitations

  3. Absolute measurement and international intercomparison of 0.1-0.8 MeV monoenergetic neutron fluence rate

    International Nuclear Information System (INIS)

    The methods for absolute measurement of 0.1-18MeV monoenergetic neutron fluence rate are described. Which include proton recoil telescope, semicoducetor telescope, hydrogen filled proportional counter and associated particale method. A long counter used as secondary recent international intercomparison of neutron fluence rate organized by BIPM, and the results were given

  4. Absolute light yield measurements on SrF$_{2}$ and BaF$_{2}$ doped with rare earth ions

    CERN Document Server

    Shendrik, Roman

    2013-01-01

    Results of absolute light output measurements on strontium and barium fluoride doped with PrF$_3$ and CeF$_3$ are presented and compared with scintillators having well-known light output (NaI-Tl, CsI-Tl, BGO). For pure SrF$_2$ crystal we obtain a value of about 28600 photons/MeV.

  5. Absolute Light Yield Measurements on SrF_2 and BaF_2 Doped With Rare Earth Ions

    Science.gov (United States)

    Shendrik, Roman; Radzhabov, Evgeny

    2014-02-01

    Results of absolute light output measurements on strontium and barium fluoride doped with PrF$_3$ and CeF$_3$ are presented and compared with scintillators having well-known light output (NaI-Tl, CsI-Tl, BGO). For pure SrF$_2$ crystal we obtain a value of about 28600 photons/MeV.

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  9. Measuring technique and facility for detecting radioactively irradiated organic substances

    International Nuclear Information System (INIS)

    Organic substances exposed to radioactive radiation, especially food and luxury food, are detected by measuring the intensity of chemoluminescence at a given, raised temperature and comparing it with the intensity of chemoluminescence of unirradiated samples. The measurements are carried out preferably at a temperature of 400C to 600C and between the 1st and 60th minute after starting heat-up. (orig.)

  10. Use of Statistics for Data Evaluation in Environmental Radioactivity Measurements

    International Nuclear Information System (INIS)

    Counting statistics will give a correction on environmental radioactivity measurement result. Statistics provides formulas to determine standard deviation (SB) and minimum detectable concentration (MDC) according to the Poisson distribution. Both formulas depend on the background count rate, counting time, counting efficiency, gamma intensity, and sample size. A long time background counting results in relatively low SB and MDC that can present relatively accurate measurement results. (author)

  11. Measurement of distribution of low-level internal radioactivity

    International Nuclear Information System (INIS)

    A new technique for measuring distribution of a small amount of radioactivity in the human body is described. The distribution is obtained by analysing the difference in gamma-ray pulse height distributions measured around the body, which contains information for not only unscattered, but also scattered rays within the body, by use of the response function method. The analysis is performed by the least squares method with the condition that the radioactivity is greater than or equal to zero. Basic experiments involving the measurement of two-dimensional radioactivity distribution in a homogeneous acrylate block (40 cmW x 20 cmH x 50 cmL) containing two 137Cs point sources (0.8 and 1.0 μCi) were made using gamma-ray counts measured by twenty 2'' φ x 2'' H NaI(Tl) scintillators arranged on a circle, and the response functions calculated by the Monte Carlo technique or obtained by measurements. The distribution on a 10 x 5 mesh division was successfully analysed using both 20 unscattered rays data and 100 scattered rays data, for a measuring time of 10 min. The mesh size was 4 cm x 4 cm, which was about one-half that possible when analysing only unscattered rays. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    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

  14. Evaluation of uncertainty and detection limits in radioactivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, M. [Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Escuela Tecnica Superior de Ingenieria de Bilbao, Alda. Urquijo, s/n, 48013 Bilbao (Spain); Idoeta, R. [Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Escuela Tecnica Superior de Ingenieria de Bilbao, Alda. Urquijo, s/n, 48013 Bilbao (Spain)], E-mail: raquel.idoeta@ehu.es; Legarda, F. [Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, Escuela Tecnica Superior de Ingenieria de Bilbao, Alda. Urquijo, s/n, 48013 Bilbao (Spain)

    2008-10-01

    The uncertainty associated with the assessment of the radioactive content of any sample depends on the net counting rate registered during the measuring process and on the different weighting factors needed to transform this counting rate into activity, activity per unit mass or activity concentration. This work analyses the standard uncertainties in these weighting factors as well as their contribution to the uncertainty in the activity reported for three typical determinations for environmental radioactivity measurements in the laboratory. It also studies the corresponding characteristic limits and their dependence on the standard uncertainty related to those weighting factors, offering an analysis of the effectiveness of the simplified characteristic limits as evaluated by various measuring software and laboratories.

  15. Evaluation of uncertainty and detection limits in radioactivity measurements

    International Nuclear Information System (INIS)

    The uncertainty associated with the assessment of the radioactive content of any sample depends on the net counting rate registered during the measuring process and on the different weighting factors needed to transform this counting rate into activity, activity per unit mass or activity concentration. This work analyses the standard uncertainties in these weighting factors as well as their contribution to the uncertainty in the activity reported for three typical determinations for environmental radioactivity measurements in the laboratory. It also studies the corresponding characteristic limits and their dependence on the standard uncertainty related to those weighting factors, offering an analysis of the effectiveness of the simplified characteristic limits as evaluated by various measuring software and laboratories

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

    International Nuclear Information System (INIS)

    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)

  17. Measurement of the relative /sup 235/U concentration and the absolute /sup 235/U content of individual HTGR fuel particles

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, R.W.

    1976-07-01

    The absolute /sup 235/U content and the relative /sup 235/U concentration of 77 individual TRISO-coated HTGR fuel particles were measured using delayed-neutron activation analysis. The particles were from batches A611 and A601. The measurements, which were done to determine the variation in kernel /sup 235/U concentration with kernel diameter, revealed no significant size-dependent variation in the kernel uranium concentration. The absolute measurement technique and its applicability to the construction of assay machine calibration standards are discussed. With the present irradiation facility, the technique was found to be too time consuming to be used to measure the large number of particles needed for a calibration standard individually.

  18. Analysis, Design and Testing of a Novel Quasi-Zero-Stiffness based Sensor System for Measurement of Absolute Vibration Motion

    CERN Document Server

    Wang, Yu

    2015-01-01

    This study presents the analysis and design of a novel quasi-zero-stiffness (QZS) based vibration sensor system for measuring absolute displacement of vibrating platforms/objects. The sensor system is constructed by using positive and negative-stiffness springs, which makes it possible to achieve an equivalent QZS and consequently to create a broadband vibration-free point for absolute displacement measurement in vibrating platforms. Theoretic 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 the corresponding data-processing software is developed to fulfill time domain and frequency domain measurements simultaneously. Both simulation and experiment results verify the effectiveness of this novel sensor system.

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

    Science.gov (United States)

    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 to evaluate the seasonal gravity changes including the hydrological effects. References: Inazu et al., 2009, J. Oceanography, Vol.65, 335-347. Kazama and Okubo, 2009, J. Geophys. Res., 114, B08402. Larsen et al., 2005, EPSL, Vol.237, 548-560. Sato et al., 2008, J. Geodyn., Vol.46, 78-89. Sato et al., 2011, Tectonophysics, Vol.511,79-88. Sato et al., 2012, J. Geophys. Res., 117, B01401. Sun et al., 2010, J. Geophys. Res., 115, B12406.

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

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    Agar, O; Boztosun, I; Korkmaz, M E; Özmen, S F

    2014-12-01

    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 (238)U series ((226)Ra, (214)Pb and (214)Bi), (232)Th series ((228)Ac), (40)K and fission product (137)Cs 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. PMID:24587487

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

    International Nuclear Information System (INIS)

    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)

  3. Measurements of the Temperature of Plasmas in MHD Ducts and Combustion Chambers by Recording Absolute Spectral Line Intensities

    International Nuclear Information System (INIS)

    This work has been carried out under a collaboration agreement between the Institute of Nuclear Research, Swierk, Poland, and CEN de Saclay, France. The author discusses the theory of measuring the temperature of plasmas in combustion chambers and MHD ducts by recording the absolute intensities (AI) of spectral lines. The accuracy of the method and its suitability for measuring the temperature of plasmas in MHD ducts is analysed. The paper describes the experimental set-up, which consists of a combustion chamber and an MHD duct, and presents a schematic diagram for temperature measurements by the absolute line intensity method. The paper also describes how the accuracy of the method is checked by determining the normalized coefficient of emission of the recorded Na15890 Å and Na1 5896 Å line values. A schematic diagram is also given for measuring the surface temperature of electrodes in an MHD duct through the plasma by means of an optical pyrometer. The author presents the results of plasma temperature measurements made by the absolute line intensity method and the results of electrode surface temperature measurements for different regimes of combustion chamber operation. (author)

  4. Validation of radioactivity measurements under the Safe Drinking Water Act

    International Nuclear Information System (INIS)

    Radioactivity measurements are made under the Safe Drinking Water Act to obtain information on the potential radiological hazard of water and to institute regulatory action when water quality does not meet requirements. Measurements must be both precise and accurate if these goals are to be met. Regulations issued under the act require that analyses be performed by approved (certified) laboratories, which must carry out quality assurance programs. This paper briefly describes the certification requirements and discusses the components of an effective quality assurance program. The Environmental Protection Agency has established procedures for the certification of laboratories making radioactivity measurements of drinking water. These procedures recommend minimum laboratory qualifications for personnel, facilities, equipment, and procedures; proficiency testing by analysis of samples provided by the Agency; and operation of a quality assurance program. A major function of a quality assurance program is to provide the Laboratory Director an ongoing flow of information on laboratory analytical performance. A properly designed and conducted program provides this information in a timely manner, indicates areas where discrepancies exist, and often suggests ways of correcting the discrepancies. Pertinent aspects of radioactivity measurements for drinking water are discussed, including how analyses of blanks, blind duplicates, and reference samples contribute needed information, and evaluations by control charts and statistical analyses. Examples of the usefulness of quality control in correcting both procedural and background problems are given. (author)

  5. Specialized and technical advancement of the BFS radioactivity measurement network

    International Nuclear Information System (INIS)

    After a short report on the general structural development of the BfS radioactivity measurement network, some specialized and technical advancements are presented which aim at qualitative improvements of the measuring results and at an acceleration of the data transfer in case of a nuclear event: In an intensive operation phase the measuring data are collected from the measuring posts and offered to decision makers in a cadence of 10 minutes now instead of 2 hours before. In the surroundings of nuclear plants the BfS radioactivity measurement network cooperates with the nuclear plant remote monitoring systems of the Laender with the effect that both networks complement each other. To ensure the comparability of the measured data of different measuring posts, criteria for the choice, documentation and evaluation of the site locations have been defined and correspondingly the posts have been evaluated. The properties of the gamma dose rate probes have been examined and a procedure for periodic examination of the environmental conditions close to the measuring posts has been developed and introduced. The development of a new generation of data collecting units enables different organisations to directly access the data from the measuring posts and furthermore these new data loggers provide improved techniques of data evaluation. (orig.)

  6. Measures of treatment and disposal of radioactive wastes

    International Nuclear Information System (INIS)

    The fundamental policy of the countermeasures to radioactive wastes in Japan is determined based on the results of deliberation of the Expert Committee on Radioactive Waste Countermeasures, the Atomic Energy Commission. As to the high level wastes from reprocessing process, the results of deliberation were summarized in the Committee report of December, 1980, ''Promotion of research and development related to the treatment and disposal of high level radioactive wastes''. As to the low level wastes generated by the operation of nuclear power plants, there is the Committee report of June, 1982, ''On low level radioactive wastes''. In June, 1982, the long term plan of atomic energy development and utilization was revised on the basis of these reports. In order to promote the storage of low level wastes outside plant sites, the meeting for its examination was organized by the Science and Technology Agency, and the report was presented in July, 1983. By the instruction of the Atomic Energy Commission, the Expert Committee started anew the examination on the land disposal of low level and extremely low level wastes and the measures against high level and TRU wastes in December, 1983. The progress of these deliberations is reported. (Kako, I.)

  7. Our experience of blood flow measurements using radioactive tracers

    International Nuclear Information System (INIS)

    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

  8. Renewal of centralized radioactivity measurement system for radiation control

    International Nuclear Information System (INIS)

    The centralized radioactivity measurement system has been used to carry out intensively measurements of a large number and variety of samples that are necessary for the control of radioactivity in the facilities of the JAERI Tokai Establishment and its environment. The operation of the system started in 1981, and presently the system processes more than 20,000 samples a year. However, the computers of the system have aged so much that the manufacturer's support and stable operation are no longer sure. Therefore, we renewed and restructured the computer system in 2003. A client-server system was adopted in the new system. The information of samples can be registered through the intranet. The clients can also confirm the progress of processing of their samples and browse the analytical results from their own computers. The renewed system can provide some convenience functions to the clients. (author)

  9. Measures reducing incorporation of radioactive substances in emergency events

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

    Yang, Ruitao; Pollinger, Florian; Meiners-Hagen, Karl; Krystek, Michael; Tan, Jiubin; Bosse, Harald

    2015-08-01

    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.

  11. Measuring the absolute deuteriumtritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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

  13. Radioactive contamination of edible mushrooms. Current measured values (State: 2014)

    International Nuclear Information System (INIS)

    The report on the radioactive contamination of different wild edible mushrooms in southern Germany summarizes the actual situation in 2014 in comparison with the data since 2005. The mushrooms were fund in the regions contaminated as a consequence of the reactor accident in Chernobyl 1986. The data for Cs-137 and K-40 contamination of a large amount of wild edible mushrooms are tabulated for different sampling sites. Measured data of the years 2004 to 2013 are included.

  14. Measuring the activity of a radioactive source in the classroom

    International Nuclear Information System (INIS)

    A standard NaI(Tl) detector can be used in classroom experiments to measure radioactive source activities, once the detector peak efficiencies and geometric acceptances are known. Tables of peak efficiencies for 5.1cm x 5.1cm and 7.6cm x 7.6cm NaI(Tl) detectors, computed using the GEANT3 Monte Carlo code, are supplied. A Monte Carlo method to compute the geometric acceptance in a general way is also presented

  15. Radioactivity measurement in imported food and food related items

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 ?-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)

  17. Traceability of measurements of radioactivity and of amount of substance

    Science.gov (United States)

    De Bievre P; Reher

    2000-07-01

    Comparability of measurement results in space and time are highly desirable to observe whether differences are real, whether concordance of results is real and whether trends over time of the quantity measured, are significant. The metrological way to achieve this, is to make results 'traceable' to a common 'stated reference' (definition in the Vocabulaire International de Metrologie-VIM). This 'stated reference' should be (the value of) the relevant SI unit wherever and whenever possible. The latest traceability concepts for results of measurements of radioactivity and amount of substance are presented and critically compared for their similarity. Transparent and simple pictures of traceability chains are given, respecting the VIM definition. PMID:10879832

  18. National network of environment radioactivity measurements. Press kit

    International Nuclear Information System (INIS)

    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

  19. Traceability of measurements of radioactivity and of amount of substance

    International Nuclear Information System (INIS)

    Comparability of measurement results in space and time are highly desirable to observe whether differences are real, whether concordance of results is real and whether trends over time of the quantity measured, are significant.The metrological way to achieve this, is to make results 'traceable' to a common 'stated reference' (definition in the Vocabulaire International de Metrologie - VIM). This 'stated reference' should be (the value of) the relevant SI unit wherever and whenever possible. The latest traceability concepts for results of measurements of radioactivity and amount of substance are presented and critically compared for their similarity. Transparent and simple pictures of traceability chains are given, respecting the VIM definition

  20. Measurement of snow at a remote site: natural radioactivity technique

    International Nuclear Information System (INIS)

    The use of natural gamma radiation from the soil as a basis for snow water equivalent measurements at remote sites has been under investigation by the National Weather Service since 1970. Results to date indicate that measurements with about five percent error in the five to forty centimeter water equivalent range can be obtained in periods uncomplicated by precipitation or considerable change in soil moisture. Periods of active melt can be subject to serious errors. A new natural radioactivity method is also proposed. The use of highly penetrating cosmic radiation appears to have excellent potential for point snow water equivalent measurement in extremely deep snow

  1. Broad band and absolute measurement of transient dynamic normal velocity of surface

    Science.gov (United States)

    Kim, Byoung-Geuk; Enoki, Manabu; Kishi, Teruo

    1998-02-01

    Broad band direct sensing of the transient dynamic normal velocity of an object surface and evaluating its absolute value were realized by using a sensor fabricated with a piezoelectric polyvinylidene fluoride film and a polyvinyl chloride (PVC) back load and a PVC wear plate. The transient output signal from the sensor obtained by a test employing a well-defined steplike force, at the epicenter of a steel plate, showed very good agreement with the dynamic normal velocity calculated by using a Green's function and a simulated source function. The output was proportional to the dynamic normal velocity of the surface, and the frequency-dependent sensitivity for the velocity was flat within a deviation of ±3.8 dB for the average in the frequency range up to 2 MHz. The transient dynamic normal velocity of the surface could be absolutely determined by using a sensor calibrated by theoretical one.

  2. Measuring Absolute RNA Copy Numbers at High Temporal Resolution Reveals Transcriptome Kinetics in Development.

    Science.gov (United States)

    Owens, Nick D L; Blitz, Ira L; Lane, Maura A; Patrushev, Ilya; Overton, John D; Gilchrist, Michael J; Cho, Ken W Y; Khokha, Mustafa K

    2016-01-26

    Transcript regulation is essential for cell function, and misregulation can lead to disease. Despite technologies to survey the transcriptome, we lack a comprehensive understanding of transcript kinetics, which limits quantitative biology. This is an acute challenge in embryonic development, where rapid changes in gene expression dictate cell fate decisions. By ultra-high-frequency sampling of Xenopus embryos and absolute normalization of sequence reads, we present smooth gene expression trajectories in absolute transcript numbers. During a developmental period approximating the first 8 weeks of human gestation, transcript kinetics vary by eight orders of magnitude. Ordering genes by expression dynamics, we find that "temporal synexpression" predicts common gene function. Remarkably, a single parameter, the characteristic timescale, can classify transcript kinetics globally and distinguish genes regulating development from those involved in cellular metabolism. Overall, our analysis provides unprecedented insight into the reorganization of maternal and embryonic transcripts and redefines our ability to perform quantitative biology. PMID:26774488

  3. Measurement of absolute copy number variation reveals association with essential hypertension

    OpenAIRE

    Marques, Francine Z; Prestes, Priscilla R; Pinheiro, Leonardo B; Scurrah, Katrina; Emslie, Kerry R; Tomaszewski, Maciej; Stephen B. Harrap; Charchar, Fadi J.

    2014-01-01

    Background The role of copy number variation (CNV) has been poorly explored in essential hypertension in part due to technical difficulties in accurately assessing absolute numbers of DNA copies. Droplet digital PCR (ddPCR) provides a powerful new approach to CNV quantitation. The aim of our study was to investigate whether CNVs located in regions previously associated with blood pressure (BP) variation in genome-wide association studies (GWAS) were associated with essential hypertension by t...

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

    OpenAIRE

    Wilpers, Guido; Oates, Chris; Diddams, Scott A.; Bartels, Albrecht; Fortier, Tara M.; Oskay, Windell; Bergquist, James C.; Jefferts, Steven; Heavner, Tom; Parker, Thomas; Hollberg, Leo

    2007-01-01

    We report an absolute frequency measurement of the optical clock transition at 657 nm in 40Ca with a relative uncertainty of 7.5 x 10-15 , one of the most accurate frequency measurements of a neutral atom optical transition to date. The frequency (455986240494135.8 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 flK. The measurement used a femtosecond-laser-based frequency co...

  5. Airborne Measurement of Radioactivity by Learjet 35 A

    International Nuclear Information System (INIS)

    Full text: The Deutscher Wetterdienst (DWD, German Meteorological Service) is responsible for surveillance of radioactivity in the atmosphere. In case of an accident, radioactive plumes may be expected in high heights up to the tropopause, however it depends on the type of accident. For this reason, aircraft measurements are necessary as a supplement to ground-based measuring sites, especially in case of non available details about the source of radioactive release and lack of details about the accident. The authors present an aircraft, type Learjet 35 A, used for localising radioactive contaminated air masses up to 33,000 feet (10,000 m) and the measurement of artificial radionuclides on aerosols. For this purpose the jet is equipped with an isokinetic high-volume sampler for collection of aerosols on filters outside the pressurised cabin and an onboard gamma spectrometry system with a high purity germanium detector to analyse the interchangeable, contaminated filters during flight, as well as a dose ratemeter, a radon daughter monitor and for navigation a GPS (Global Positioning System). The collection of gaseous iodine is optional. The meteorological parameters temperature, relative humidity, wind speed and wind direction are determined as well. Resulting data are transmitted by global VHF datalink (Very High Frequency) from the plane to the DWD headquarter and used for verifying the prognosis. In case of emergency the plane has to be airborne not later than 10 hours after alert. Homebase of the Learjet is a German military airbase, 100 km northwest of Hamburg. Six backup Learjets are available. The Learjet's service ceiling is 41,000 feet (12,330 m), cruising speed 800 km/hr, max. flying time 5 hrs. Originally developed to be operated in Germany, the Learjet can reach every destination in Europe within 3 hours. (author)

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

    International Nuclear Information System (INIS)

    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)

  7. Measurements of environmental radiations and radioactivities in Toki, 5

    International Nuclear Information System (INIS)

    The booklet carries six reports. The first report, titled 'Measurements of Environmental Radiation in 1986 and 1987', consists of two parts: 'A report of TLD Measurement of Environmental Radiations in the Toki Area' and 'Measurement of Environmental Radiations at the Higashiyama and Toki Sites'. Measurements of environmental radiations made at various points throughout the area are presented. The second report, titled 'Environmental Tritium Measurements in Toki Area', presents measurements of environmental tritium made at various points in the Toki area. The third study addresses the 'Radioactivity in Rain Associated with Chernobyl Nuclear Reactor Accident'. Rain is collected on the roof of the Institute of Plasma Physics, and gamma ray measurements are made with a germanium detector. The concentrations of radioactive fallout substances are analyzed. Then, the relations of the concentrations with the spatial dose rate is investigated. The fourth work deals with the 'Concept and Mutual Relation of Radiation-Related Quantities'. The fifth report outlines a 'System for Radiation Monitoring around Accelerator'. The sixth report describes some features of the National Lab. for High Energy Physics (KEK). (N.K.)

  8. Measurements of radioactive and xenobiotic substances in the biosphere in the Netherlands 1983

    International Nuclear Information System (INIS)

    In this annual report the results and conclusions are given of measurements of radioactive and xenobiotic substances in the biosphere of the Netherlands. The measurements are coordinated by the Coordinating Committee for the Monitoring of Radioactive and Xenobiotic Substances (CCRX)

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

    CERN Document Server

    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...

  10. Instituting the CEA rapid transmission network for environmental radioactivity measurement

    International Nuclear Information System (INIS)

    The radiological impact of the Chernobyl accident has been followed at CEA sites using measuring stations installed for monitoring the local environments. This has shown a need for respecification and improved coordination of the measurements in order to provide coherent radiological coverage of the CEA sites and by extension a potential contribution to national surveillance. The structure of the new measurement chain is based on the three stages of the evolution of an accident: real-time measurement of airborne activity, deferred spectrometric measurements of air, water and ground deposition activity and monitoring of significant links in the food chain. Radiological protection recommendations allow derivation of the levels of radioactivity which the equipment and methods must be able to detect. A rapid information transmission system allows the measurements to be collected together for the purposes of analysis and interpretation to the benefit of CEA central and site managements and of the public authorities

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

    International Nuclear Information System (INIS)

    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.)

  12. Measurement of radioactivity in Norway. Annual report 1997

    International Nuclear Information System (INIS)

    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

  13. Measurement of the absolute branching ratio of the K+ -> pi+ pi0 (gamma) decay with the KLOE detector

    CERN Document Server

    Ambrosino, F; Antonelli, M; Archilli, F; Bacci, C; Beltrame, P; Bencivenni, G; Bertolucci, S; Bini, C; Bloise, C; Bocchetta, S; Bossi, F; Branchini, P; Campana, P; Capon, G; Capussela, T; Ceradini, F; Cesario, F; Chi, S; Chiefari, G; Ciambrone, P; Crucianelli, F; De Lucia, E; De Santis, A; De Simone, P; De Zorzi, G; Denig, A; Di Domenico, A; Di Donato, C; Di Micco, B; Doria, A; Dreucci, M; Felici, G; Ferrari, A; Ferrer, M L; Fiore, S; Forti, C; Franzini, P; Gatti, C; Gauzzi, P; Giovannella, S; Gorini, E; Graziani, E; Kluge, W; Kulikov, V; Lacava, F; Lanfranchi, G; Lee-Franzini, J; Leone, D; Martemyanov, M; Martini, M; Massarotti, P; Mei, W; Meola, S; Miscetti, S; Moulson, M; Mller, S; Murtas, F; Napolitano, M; Nguyen, F; Palutan, M; Pasqualucci, E; Passeri, A; Patera, V; Perfetto, F; Primavera, M; Santangelo, P; Saracino, G; Sciascia, B; Sciubba, A; Sibidanov, A; Spadaro, T; Testa, M; Tortora, L; Valente, P; Venanzoni, G; Versaci, R; Xu, G

    2008-01-01

    We have measured the absolute branching ratio of the K+ -> pi+ pi0 (gamma) decay, using about 20 million tagged K+ mesons collected with the KLOE detector at DAFNE, the Frascati phi-factory. Signal counts are obtained from the fit of the distribution of the momentum of the charged decay particle in the kaon rest frame. The result, inclusive of final-state radiation, is BR(K+ -> pi+ pi0 (gamma))=0.2065+/-0.0005_{stat}+/- 0.0008_{syst}.

  14. Environmental radioactivity measurements in the autonomous community of Aragon

    International Nuclear Information System (INIS)

    To know the level of environmental radioactivity in the Autonomous Community of Aragon thermoluminescent dosimeters used to measure the cumulative dose over a period of time in each of its 33 counties. The project, funded by the Government of Aragon and La Caixa to carry a map of environmental radioactivity with the collaboration of Secondary Schools and public schools for the renovation and shipment of dosimeters. The selection of the different locations was carried out taking into account the points of interest in the project reflected Marna, by ENUSA and the CSN, on natural gamma radiation. The work program began in 2009 and to date working with 43 centers distributed throughout the community tried to cover a wide surface area of Aragon. (Author)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.

  17. Measurement of environmental radioactivity in Taegu area: pt. 8

    International Nuclear Information System (INIS)

    Since July 1956, the survey of environmental radioactivity has continuously been carried out as a fall-out program. This report concerns radioactivity in Air-borne dust. Fall-out, and Rain-out measured in Taegu area (N.lat. 35sup(0)53', E.long. 128sup(0)37') during the period of 2 years from January 1, 1977 to December 31, 1978. This report includes special survey results from the 22th, 23th, and 24th nuclear explosion tests carried out in the Lop Nor (N.lat. 40sup(0), E.long. 90sup(0)), China. The results of these measurements are as follows; The annual average values of radioactivity of the Air-borne dust collected by the air sample in this period were (2.95+-0.02)p?Ci/cc(6 hr.), and (0.08+-0.01)p?Ci/cc(12hr.). The maximum radioactivities in this period of investigation were (19.61+-0.58)p?Ci/cc(6 hr.:Feb. 11,'77), and (0.52+-0.20)p?Ci/cc (120hr. Jun. 13,'77). The annual average values of radioactivity of the Fall-out collected by gummed papers in this period were (0.23+-0.02) mCi/km2-10d. (6hr.), and (0.13+-0.02) mCi/km2-10d. (120hr.). While the maxium values of radioactivities during the period were (2.31+-0.21) mCi/km2-10d. (6hr.: Oct. 1 11, '77), and (1.63+-0.20) mCi/kmsup(2)-10d. (120hr. : Oct. 1 11, '77). The annual average value of radioactivities in the Rain-out collected at fixed time daily were (0.84+-0.19)x10sup(-8)?Ci/cc (6hr.), and (0.58+-0.12)x10sup(-8)?Ci/cc(120hr.), and the maximum values of the radioactivities during the period were (8.93+-1.02)x10sup(-8)?Ci/cc (6hr.:6approximately7,'77), and (7.55+-1.00)x10sup(-8)?Ci/cc(120hr.: Oct. 6approximately7,'77). The results of the environmental radioactivities caused by these three time-nuclear explosion tests (22th, 23th, and 24th) were much smaller than those of the former tests (1st through 21st). According to the above data obtained, we have found that the maximum permissible concentrations(M.P.C.approximately10sup(-7)?Ci/cc for water, 4x10sup(-13)?Ci/cc for air) are not reached both in water and in air. (Author)

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

    International Nuclear Information System (INIS)

    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

  19. Environmental radioactivity measurements at BNL following the Chernobyl accident

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

    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

  1. Absolutely calibrated, time-resolved measurements of soft x rays using transmission grating spectrometers at the Nike Laser Facility

    International Nuclear Information System (INIS)

    Accurate simulation of pellet implosions for direct drive inertial confinement fusion requires benchmarking the codes with experimental data. The Naval Research Laboratory (NRL) has begun to measure the absolute intensity of radiation from laser irradiated targets to provide critical information for the radiatively preheated pellet designs developed by the Nike laser group. Two main diagnostics for this effort are two spectrometers incorporating three detection systems. While both spectrometers use 2500 lines/mm transmission gratings, one instrument is coupled to a soft x-ray streak camera and the other is coupled to both an absolutely calibrated Si photodiode array and a charge coupled device (CCD) camera. Absolute calibration of spectrometer components has been undertaken at the National Synchrotron Light Source at Brookhaven National Laboratories. Currently, the system has been used to measure the spatially integrated soft x-ray flux as a function of target material, laser power, and laser spot size. A comparison between measured and calculated flux for Au and CH targets shows reasonable agreement to one-dimensional modeling for two laser power densities

  2. National audit of radioactivity measurements in Nuclear Medicine Centres

    International Nuclear Information System (INIS)

    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

  3. Radioactive Sources in Medicine: Impact of Additional Security Measures

    International Nuclear Information System (INIS)

    For many years, medical centers and hospitals have utilized appropriate security measures to prevent theft or unauthorized use of radioactive materials. Recent anxiety about orphan sources and terrorism has heightened concern about diversion of radioactive sources for purposes of constructing a radiological dispersion device. Some medical centers and hospitals may have responded by conducting threat assessments and incorporating additional measures into their security plans, but uniform recommendations or regulations have not been promulgated by regulatory agencies. The International Atomic Energy Agency drafted interim guidance for the purpose of assisting member states in deciding what security measures should be taken for various radioactive sources. The recommendations are aimed at regulators, but suppliers and users also may find the recommendations to be helpful. The purpose of this paper is to describe threat assessments and additional security actions that were taken by one large and one medium-sized medical center and the impact these measures had on operations. Both medical centers possess blood bank irradiators, low-dose-rate therapy sources, and Mo-99/Tc-99m generators that are common to many health care organizations. Other medical devices that were evaluated include high-dose-rate after loaders, intravascular brachytherapy sources, a Co-60 stereotactic surgery unit, and self-shielded irradiators used in biomedical research. This paper will discuss the impact additional security has had on practices that utilize these sources, cost of various security alternatives, and the importance of a security culture in assuring the integrity of security measures without negatively impacting beneficial use of these sources. (Author) 10 refs

  4. Absolute frequency measurement of the 40Ca+ S1/2 - D5/2 clock transition

    OpenAIRE

    Chwalla, M.; Benhelm, J.; Kim, K.; Kirchmair, G.; Monz, T.; Riebe, M.; Schindler, P.; Villar, A.S.; Haensel, W.; Roos, C. F.; Blatt, R.; Abgrall, M.; G. Santarelli; Rovera, G. D.; Laurent, Ph.

    2008-01-01

    We report on the first absolute transition frequency measurement at the 10^{-15} level with a single, laser-cooled 40Ca+ ion in a linear Paul trap. For this measurement, a frequency comb is referenced to the transportable Cs atomic fountain clock of LNE-SYRTE and is used to measure the S1/2-D5/2 electric-quadrupole transition frequency. After the correction of systematic shifts, the clock transition frequency f_Ca+ = 411 042 129 776 393.2 (1.0) Hz is obtained, which corresponds to a fractiona...

  5. Evaluation of the uncertainty of environmental measurements of radioactivity

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

  8. Nanoscale range finding of subsurface structures by measuring the absolute phase lag of thermal wave

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jaehun; Kim, Kyeongtae; Hwang, Gwangseok; Kwon, Ohmyoung [Department of Mechanical Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Joon Sik [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Park, Seung Ho [Department of Mechanical and System Design Engineering, Hongik University, Seoul 121-791 (Korea, Republic of); Choi, Young Ki [School of Mechanical Engineering, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

    2010-05-15

    The need for a subsurface imaging technique to locate and characterize subsurface defects in multidimensional micro- and nanoengineered devices has been growing rapidly. We show that a subsurface heater can be located accurately using the phase lag of a thermal wave. We deduce that the absolute phase lag is composed of four components. Among the four components, we isolate the component directly related to the position and the structure of the periodic heat source. We demonstrate that the position of the heater can be estimated accurately from the isolated phase lag component.

  9. Nanoscale range finding of subsurface structures by measuring the absolute phase lag of thermal wave.

    Science.gov (United States)

    Chung, Jaehun; Kim, Kyeongtae; Hwang, Gwangseok; Kwon, Ohmyoung; Lee, Joon Sik; Park, Seung Ho; Choi, Young Ki

    2010-05-01

    The need for a subsurface imaging technique to locate and characterize subsurface defects in multidimensional micro- and nanoengineered devices has been growing rapidly. We show that a subsurface heater can be located accurately using the phase lag of a thermal wave. We deduce that the absolute phase lag is composed of four components. Among the four components, we isolate the component directly related to the position and the structure of the periodic heat source. We demonstrate that the position of the heater can be estimated accurately from the isolated phase lag component. PMID:20515139

  10. Absolute left ventricular volume by a non-invasive esophageal transmission measurement

    International Nuclear Information System (INIS)

    A new method for determining absolute left ventricular volumes during routine clinical gated blood pool imaging is presented. The technique is geometry independent and is the first of its kind to correct for tissue attenuation by utilizing an in vivo point source. An orally administered gelatin capsule containing Tc-99m is used for this purpose. Serial images are obtained as the capsule transits the esophagus. The transmission factor is then determined by dividing the capsule count rate in the region of the left ventricle by the capsule counts recorded in air prior to administration. Thus, experimentally determined transmission factors are directly determined for each patient

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

    International Nuclear Information System (INIS)

    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)

  12. Nanoscale range finding of subsurface structures by measuring the absolute phase lag of thermal wave

    International Nuclear Information System (INIS)

    The need for a subsurface imaging technique to locate and characterize subsurface defects in multidimensional micro- and nanoengineered devices has been growing rapidly. We show that a subsurface heater can be located accurately using the phase lag of a thermal wave. We deduce that the absolute phase lag is composed of four components. Among the four components, we isolate the component directly related to the position and the structure of the periodic heat source. We demonstrate that the position of the heater can be estimated accurately from the isolated phase lag component.

  13. Establishing radioactivity measurement capabilities for nuclear medicine in Member States

    International Nuclear Information System (INIS)

    Full text: The International Atomic Energy Agency (IAEA), in response to a growing need for measurement quality assurance for radionuclides used in nuclear medicine, particularly in developing countries, is establishing a new radioactivity standardization programme in the Dosimetry and Medical Radiation Physics Section. The short-term (3-5 years) goals of this project are to: 1) Develop capabilities within the IAEA to prepare and distribute calibrated solution sources of medically relevant radionuclides, traceable to international standards, to Member States for use in calibrating instrumentation. Traceability will be established through comparisons with primary National Measurement Laboratories, as well as with the International Reference System for activity measurements of the BIPM. Ultimately, the goal will be for the Agency to be able to distribute standard sources of the most relevant radionuclides to Member States that require them as part of a secondary standards radioactivity laboratory network. The laboratories in the network will then provide calibration and auditing services to nuclear medicine clinics on a national or regional basis. Formation of the laboratory network is ongoing. 2) Assist Member States in the development of quality assurance networks for nuclear medicine clinics in their countries. This could be accomplished through Technical Cooperation projects at the national and regional levels and will take the form of personnel training and consultations to develop appropriate quality assurance and audit systems, and in some cases, donation of appropriate instrumentation. Further, a Coordinated Research Project has recently been approved to develop a uniform code of practice for clinical radioactivity measurements. Formation of the research group will begin in early 2004. (author)

  14. Measurement of the absorption length and absolute quantum efficiency of TMAE and TEA from threshold to 120 nm

    International Nuclear Information System (INIS)

    The absorption length and absolute photoionization quantum efficiency of TMAE (tetrakis-dimethylamino-ethylene) and TEA (triethylamine) vapors have been measured in a wavelength interval from 120 to 280 nm. Both of these materials can serve as a photosensitive agent for ultraviolet photon detectors used in high energy and nuclear physics experiments and for medical imaging. The absorption length and absolute quantum efficiency are important parameters in the design of these detectors. We find that the quantum efficiency for TMAE has a peak of 58% at 146 nm and rises again toward shorter wavelengths. The TEA quantum efficiency reaches a peak of 33% at 153 nm and has a plateau of 17% below 135 nm. We fail to observe a second peak in TEA around 136 nm as has been previously reported. (orig.)

  15. Identification and elimination of half-synthetic wavelength error for multi-wavelength long absolute distance measurement

    International Nuclear Information System (INIS)

    A multi-wavelength absolute distance measurement method based on synchronous occurrence and phase measurement of coarse and refined synthetic wavelength is proposed to remove the effect of vibration on the measurement distance. The phase value of refined synthetic wavelength is monitored to see if half-synthetic wavelength error occurs by judging whether it is near to 2π or 0. If yes, a new suitable refined synthetic wavelength is generated to re-measure the distance with phase near π. A measuring system has been built with a He–Ne laser source and three acousto-optic frequency shifters for implementation of this method. A comparative measurement has been performed using a counting laser interferometer at a distance of 20 m. Actual measurements indicate that half-synthetic wavelength error has been identified and eliminated with uncertainty of smaller than 60 µm under laboratory conditions

  16. Contribution to the development of an absolute quantification method in single photon emission tomography of the brain; Tomographie d'emission monophonique cerebrale: contribution a la mise en oeuvre d'une methode de quantification absolue de la concentration radioactive

    Energy Technology Data Exchange (ETDEWEB)

    Dinis de Almeida, P.M

    1999-07-01

    The recent development of single photon emission tomography (SPECT) mainly focussed on the use of transmission measurements and iterative algorithms to allow a correction of attenuation. These new tools can be associated to correction methods for the diffused and the spatial resolution effects, in order to quantify in an absolute way the in-vivo radioactive concentration. The aim of this work is to propose an absolute quantification method for the SPECT imaging of small brain structures. This method is based on the use of transmission measurements to correct the attenuation. The diffuse photons have been subtracted from the measurements of the events gathered in a Compton window. The effects of spatial resolution have been taken into account using a deconvolution algorithm. The potential radiation dose received by a patient during a transmission examination has been evaluated using anthropomorphic phantoms and convenient dosemeters. A preliminary evaluation of the proposed quantification method has been done using an anthropomorphic phantom of head. Then, in vivo acquisitions have been obtained for the baboon. The radioactive concentration values fixed in the striata and obtained in similar conditions with SPECT and with positon emission tomography (PET) have been compared. The measurements performed on anthropomorphic phantom show that radiation doses linked with transmission measurements do not limit their clinical use. The attenuation is a particularly penalizing phenomenon in SPECT of the brain and its correction can be done using an attenuation map and an iterative algorithm. The corrections of the attenuation, of the diffused effect and of the spatial resolution have improved the preciseness of the measurements of radioactive concentrations in the striata of the phantom. The in-vivo measurements performed on the baboon have shown that the radioactivity values fixed in the striata can be measured by SPECT with uncertainties comparable to those obtained with PET. (J.S.)

  17. Absolute nuclear material assay

    Science.gov (United States)

    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.

  18. Absolute nuclear material assay

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    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.

  19. Absolute measurement at 1 THz of the optical coupling of a FIR conical antenna with a Josephson detector

    Energy Technology Data Exchange (ETDEWEB)

    Henaux, J.C.; Vernet, G.

    1983-05-01

    The first absolute measurement of the optical coupling of a FIR antenna with a Josephson detector is presented. A study was conducted of a wide band FIR coupling system made of a conical antenna (discone) and a focussing paraboloid mirror. The calculated efficiency is (6.8 + or - 0.3) x 0.01 for the optimum choice of parameters at 1 THz. The best measurements using a HCN laser at 891 GHz are in agreement while the average achieved coupling is (2.3 + or - 0.4) x 0.01 reflecting the experimental difficulties.

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

    OpenAIRE

    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...

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

    CERN Document Server

    Chenais, S; Druon, F; Balembois, F; Georges, P; Chenais, Sebastien; Forget, Sebastien; Druon, Frederic; Balembois, Francois; 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.

  2. Measurements of the absolute value of the penetration depth in high-$ T_c$ superconductors using a tunnel diode resonator

    OpenAIRE

    Prozorov, R.; Giannetta, R. W.; Carrington, A.; Fournier, P.; Greene, R. L.; Hinks, D. G.; Banks, A. R.

    2000-01-01

    A method is presented to measure the absolute value of the London penetration depth, $\\lambda$, from the frequency shift of a resonator. The technique involves coating a high-$T_c$ superconductor (HTSC) with film of low - Tc material of known thickness and penetration depth. The method is applied to measure London penetration depth in YBa2Cu3O{7-\\delta} (YBCO) Bi2Sr2CaCu2O{8+\\delta} (BSCCO) and Pr{1.85}Ce{0.15}CuO{4-\\delta}$ (PCCO). For YBCO and BSCCO, the values of $\\lambda (0)$ are in agree...

  3. The observatories for the radioactivity. results of measures

    International Nuclear Information System (INIS)

    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.)

  4. Direct measurements of neutron capture on radioactive isotopes

    CERN Document Server

    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. Standard cartridges used in gamma spectrometry measurements of radioactive halogens

    International Nuclear Information System (INIS)

    Activated charcoal cartridges are used to trap radioactive halogens contained in gaseous effluents of nuclear facilities. Two types of standard cartridges, with barium 133 or europium 152 are available. One of the models simulates a volumic distribution, and the other a surface distribution of the radionuclides inside the cartridge. They are characterized in terms of activity with an uncertainty lower than 5 %. The standard cartridges utilization conditions are specified and the main measurement error causes are analyzed. The proper routine use of these standards should allow us to get results with an accuracy better than 10 %

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

    OpenAIRE

    Sartini, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Simeone, F.; Sapienza UniversityandIstitutoNazionalediFisicaNucleare(INFN),Sect.Roma,Roma,Italy; Pani, P.; Sapienza UniversityandIstitutoNazionalediFisicaNucleare(INFN),Sect.Roma,Roma,Italy; Lo Bue, N.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Marinaro, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Grubich, A.; Institute forNuclearProblems(INP),BelarusStateUniversity,Minsk,Belarus; Lobko, A.; Institute forNuclearProblems(INP),BelarusStateUniversity,Minsk,Belarus; Etiope, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Capone, A.; Sapienza UniversityandIstitutoNazionalediFisicaNucleare(INFN),Sect.Roma,Roma,Italy; Favali, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Gasparoni, F.; Tecnomare S.p.A.; Bruni, F.; Tecnomare S.p.A.

    2011-01-01

    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 a...

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

    OpenAIRE

    L.Sartini; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia

    2010-01-01

    GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework of the KM3NeT Design Study (DS) EC project. The spectrometer is sensitive to gamma rays produced by 40K decays and it is also able to detect other natural (e.g., 238U, 232Th) and anthropogenic radionuclides (e.g. 137Cs). The decay of 40K, contained in sea salt, particulate and sediments, is one of the main sources of photon background...

  8. Aerial measurements of radioactivity and meteorological parameters in real time

    International Nuclear Information System (INIS)

    The aircrafts operating in the case of nuclear accidents have to be equipped with all necessary instruments for radioactivity, aerosol and gas sampling, chemical characterization and additional avionic for exact flight path recordings. In close cooperation with NIR, AERODATA, FAG and FhG-IFU will provide the research aircraft Beechcraft King Air 200 and/or Hawker Siddeley 125. Impactors and denuders are to be installed on the aircraft for particle and gaseous measurements. The aircraft should be made available in stand-by operation

  9. Environmental radioactivity measurements Using a compton suppression spectrometer

    International Nuclear Information System (INIS)

    The natural and artificial radioactivities of some environmental samples such as soil and vegetables have been studied through gamma-ray spectroscopy with a new constructed compton suppression spectrometer (CSS). The spectrometer consists of a 10% p-type HPGe detector as a main detector, an annular NE-102 A plastic scintillator as a guard detector, and a fast-slow coincidence system employing standard electronic modules for anti-compton operation. This study shows that CSS is a powerful tool for measuring the low level activities of environmental samples

  10. Absolute wind measurements in the lower thermosphere of Venus using infrared heterodyne spectroscopy

    International Nuclear Information System (INIS)

    The first absolute wind velocities above the Venusian cloud-tops were obtained using NASA/Goddard infrared heterodyne spectrometers at the NASA Infrared Telescope Facility (IRTF) and the McMath Solar Telescope. Beam-integrated Doppler displacements in the non-thermal emission core of (12)C(16)O2 10.33 micron R(8) sampled the line of sight projection of the lower thermospheric wind field (100 to 120 km). A field-usable Lamb-dip laser stabilization system, developed for spectrometer absolute frequency calibration to less than + or - 0.1 MHz, allowed S/N-limited line of sight velocity resolution at the 1 m/s level. The spectrometer's diffraction-limited beam (1.7 arc-second HPBW at McMath, 0.9 arc-second HPBW at IRTF), and 1 to 2 arc-second seeing, provided the spatial resolution necessary for circulation model discrimination. Qualitative analysis of beam-integrated winds provided definitive evidence of a dominant subsolar-antisolar circulation in the lower thermosphere. Beam-integrated winds were modelled with a 100x100 grid over the beam, incorporating beam spatial rolloff and across-the-beam gradients in non-thermal emission intensity, line of sight projection geometry, and horizontal wind velocity. Horizontal wind velocity was derived from a 2-parameter model wind field comprised of subsolar-antisolar and zonal components. Best-fit models indicated a dominant subsolar-antisolar flow with 120 m/s cross-terminator winds and a retrograde zonal component with a 25 m/s equatorial velocity. A review of all dynamical indicators above the cloud-tops allowed development of an integrated and self-consistent picture of circulation in the 70 to 200 km range

  11. The Measurement of Size Distribution of Indoor Natural Radioactive Aerosols by Imaging Plate Technique

    Science.gov (United States)

    Iida, Takao; Rahman, Naureen Mahbub; Matsui, Akihiro; Yamazawa, Hiromi; Moriizumi, Jun

    2008-08-01

    The indoor radioactive aerosols of radon decay products are considered as a main radioactive contaminant in human environment. In this study, the particle size distribution was measured with low pressure cascade impactor and imaging plate. The temporal and spatial variations of indoor radioactive aerosols were measured at eight indoor sites of Nagoya, Japan. Effective doses were assessed using ICRP 66 and UNSCEAR 2000 approaches.

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

    Science.gov (United States)

    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

  13. Measurements of radioactive and xenobiotic substances in the biosphere in The Netherlands 1985

    International Nuclear Information System (INIS)

    In this annual report the results and conclusions are given of radioactive and xenobiotic substances in the biosphere of the Netherlands. The measurements are coordinated by the Coordination Committee for the Monitoring of Radioactive and Xenobiotic substances. (Auth.)

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

    International Nuclear Information System (INIS)

    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 40?. 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)

  15. Measurement of radioactive aeroions mobility in atmospheric air

    International Nuclear Information System (INIS)

    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)

  16. Measurement of radioactive soil contamination from the air

    International Nuclear Information System (INIS)

    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

  17. Radioactivity measurements in ceramics industries: results and comments

    International Nuclear Information System (INIS)

    As part of the NORM evaluation programme launched by the Spanish Nuclear Safety Council, a radiological study of the ceramics industry was carried out by the Environmental Radioactivity Laboratory of the Universidad Politecnica de Valencia. The study covered three types of plant: zircon sand milling, ceramic frit production and ceramic tile production, all of which use zircon as a raw material. In accordance with European Directive 96/29/Euratom, these types of plant are of radiological interest because of the presence of 238U and to a lesser extent 232Th, together with their progeny. The first step in the study was to collect information on materials and processes used in the different types of factory, after which a radiological characterization of the materials, including dust from the indoor environment, was performed. Gamma spectrometry analysis was carried out using a Ge(HP) detector. The second step was to identify the areas in which radioactive materials and workers were present. Direct measurements were carried out in different factory areas, which were radiologically characterized using a portable radiation monitor and thermoluminescent dosimeters. Finally, the external and internal radiation doses received by workers were estimated, on the basis of the aforementioned measurements. (author)

  18. Quality assurance for radioactive measurement in nuclear medicine

    International Nuclear Information System (INIS)

    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 interrelated or interacting elements for establishing policies and objectives and enabling the objectives to be achieved in a safe and efficient way. The management system is designed to fulfil requirements that integrate elements related to safety, health, the environment, security, quality and economics. Safety is the fundamental principle upon which the management system is based. It is also recognized in GS-R-3 that QC and QA are important components of the management system. While QC is a means of applying controls to ensure that the product or service consistently meets specifications, QA is an interdisciplinary management tool that provides a means for ensuring that all work is adequately planned, correctly performed and assessed. A QA programme is designed primarily to ensure the quality of a product for a customer and may be appropriate to control the activities in radioactivity measurement in nuclear medicine. However, it would be more effective if these QA controls were integrated into a single management system. There are numerous processes that review and assess financial and technical performance, the achievement of goals and the effectiveness of an organization's processes. It is necessary to integrate the results of all assessment activities to focus decision making on the needs of the business strategy. It is important to understand how assessments enable managers to achieve higher standards of performance. The principles in this publication are based on those described in IAEA Safety Standards Series No. GS-R-3 and in the General Requirements for the Competence of Testing and Calibration Laboratories (ISO/IEC 17025:1999), which set requirements that testing and calibration laboratories must meet to demonstrate that they have a management system in place and are technically competent. The present report provides information specific to implementing these standards at both the end user (clinic) and the secondary standards radioactivity laboratory levels. If adopted to their greatest extent, the principles herein will provide the user with al l th

  19. Gravity Change in Finland 1962-2010 from the Comparison of Legacy Relative Measurements with New Absolute Measurements Using the A10-020 Gravimeter

    Science.gov (United States)

    Raja-Halli, A.; Makinen, J.; Sekowski, M.; Krynski, J. S.; Kuokkanen, J.; Naranen, J.; Ruotsalainen, H. E. O.; Virtanen, H.; Bilker-Koivula, M.

    2014-12-01

    The gravity change associated with the Fennoscandian Postglacial Rebound (PGR) has been studied for 50 years now, with both relative and absolute gravity measurements. High-precision relative gravity measurements on the specially designed Fennoscandian Land Uplift Gravity Lines began in 1966. First absolute-gravity measurements with laboratory-type instruments were made in 1976. Here we report on a new regionally dense dataset: the comparison of legacy relative measurements in the Finnish First Order Gravity Net (FOGN) with absolute-gravity measurements with the A10-020 gravimeter. The FOGN was first measured in 1962 using a Worden Master gravimeter, and re-surveyed in 1988 using two LaCoste&Romberg model G gravimeters. It was re-measured in 2009-2010 using the A10-020 free-fall gravimeter of the Institute of Geodesy and Cartography. The FOGN covers the whole country and consists of 50 outdoor stations in public buildings, typically on church steps. About 30 stations from 1962 were still intact in 2009/10, and at some additional stations there is a history of local relative ties to replacement sites now occupied with the A10-020. The vertical PGR rates at the sites are up to 1 cm/yr, and thus the total gravity change in the 47 years can amount to 80 microgals. Since the legacy measurements are relative, only the differences of gravity change are estimable, and consequently the expected maximum signal is less, about 60 microgals. We compare the observed gravity change in the FOGN with estimates of vertical motion from continuous GNSS, from repeated precise leveling and from tide gauges, and with gravity change predicted from PGR models. At seven locations the gravity change estimated from the FOGN can also be compared with time series of absolute-gravity measurements with laboratory-type instruments.

  20. Radioactive tracer measuring methods and its applications on environmental technique

    International Nuclear Information System (INIS)

    A new tracer technique for measuring reairing of recipients during discharge of biological and chemical wastes. The new technique makes possible a selective determination of oxygen originating from the atmosphere. Kr-85 have been used as gas tracer and Br-82 as tracer for measuring dilution. 2. Methods for labelling sewege with radioactive tracers have been developed. The methods may be used to study the function and effectiveness of treatment of sewage from municipolities and industries. 3. Water transport in the ground in connection with leaching from municipal dumps or sludge stocks have been studied with tracer techniques. The investigation showed that the transport of water through garbage stocks was much faster than was earlier presumed. (K.K.)

  1. Diagnostic measures and therapeutic possibilities in incorporations of radioactive substances

    International Nuclear Information System (INIS)

    In the interest of better understanding the diagnostic measures to be taken in cases of incorporation, the exposure pathways of an incorporation are outlined and their physical and chemical mechanisms described. Attention is drawn to the need for interdisciplinary cooperation with health physics. Therapeutic possibilities are indicated for both first aid measures and further treatment by the authorized physician. These efforts are intended to reduce the absorption of the radionuclide from the gastro-intestinal tract, prevent the ascension of activity from a wound deposit to the transfer compartiment, and impede depostions of the radioactive substance in some organs. In-house experience accumulated in the treatment of incorporation accidents associated with transuranium isotopes is described on the basis of some case reports. (orig.)

  2. Determination of intake radioactivity by ?(HPGe)-?(HPGe) coincidence measurement

    International Nuclear Information System (INIS)

    It is important to estimate internal exposure dose from intake radioactivity measured by human counter. The previous paper described application of the ?-? coincidence method to human counter using two large HPGe detectors and showed equation to calculate activity without determination of ?-ray detection efficiency. This paper showed the results of further experiments using absorbers based on the previous fundamental experiments. When absorption of ?-rays in human body was simulated by depth of water on the source, the activities obtained for various depth agreed with true activity within 10%. Furthermore, a moving source like a human in X-ray CT apparatus was measured to simulate whole body counting and the result showed usefulness of this method for human counter. (author)

  3. Considerations on marine gross radioactivity measurements between 1982-1990

    International Nuclear Information System (INIS)

    This paper includes working details concerning gross alpha and beta measurements of components of the marine environment compared with oceanic fish. There are also included processing, interpretations and discussions on the results with specifications of the observations on this type of radioactivity. The alpha level is below the lower detection limit (LDL) for all samples except the green alga Bryopsis plumosa. The beta level is below LDL for water (salt), beach sand, molluscs-shell. The averages for algae, 84 Bq kg-1 f.w. molluscs - soft part, 118 Bq kg-1 f.w. marine fish, 113 Bq kg-1 f.w. oceanic fish. Bryopsis plumosa is in exception, with values of 103 Bq kg-1 f.w. The measurements in 1986 have not registered spectacular values of the activity of the medium-and long live radionuclides in the Romanian area of the Black Sea. (author) 1 fig., 2 tabs., 26 refs

  4. Absolute left ventricular volume from gated blood pool imaging with use of esophageal transmission measurement

    International Nuclear Information System (INIS)

    A new method for determining absolute left ventricular (LV) volume from equilibrium gated blood pool images was validated in 36 patients by comparing gated blood pool (GBP) imaging with contrast ventriculography (CV) using both Simpson's rule (SR) and area-length (AL) calculations. The technique is geometry-independent and is the first to correct for tissue attenuation with use of an in vivo point source. An orally administered capsule containing 1 to 2 mCi of technetium-99m (Tc-99m) sulfur colloid is used for this purpose. Left ventricular volumes are determined by dividing attenuation and background-corrected count rates obtained from semiautomated LV regions of interest by the count rate per milliliter from a blood sample. The correlation between GBP and CV (SR) was 0.96 (CV [SR] . 0.99 GBP + 1.32 ml; standard error of the estimate [SEE] . 21.2 ml) for diastole and 0.97 (CV [SR] . 0.93 GBP - 0.03 ml; SEE . 11.9 ml) for systole. The correlation between GBP and CV (AL) was 0.92 (CV [AL] . 0.90 GBP + 16.72 ml; SEE . 27.8 ml) for diastole and 0.95 (CV [AL] . 0.87 GBP + 4.56 ml; SEE . 14.4 ml) for systole. The method is noninvasive and can be performed easily as part of routine gated blood pool imaging and analysis

  5. Measurements of the Absolute Branching Fractions of B^\\pm --> K^\\pm X_{c\\bar c}

    CERN Document Server

    Aubert, B; Abrams, G S; Adye, T; Ahmed, M; Ahmed, S; Alam, M S; Albert, J; Aleksan, Roy; Allen, M T; Allison, J; Allmendinger, T; Altenburg, D; Andreassen, R; Andreotti, M; Angelini, C; Anulli, F; Arnaud, N; Aston, D; Azzolini, V; Baak, M; Back, J J; Baldini-Ferroli, R; Band, H R; Banerjee, S; Barate, R; Bard, D J; Barlow, N R; Barlow, R J; Barrett, M; Bartoldus, R; Batignani, G; Battaglia, M; Bauer, J M; Beck, T W; Behera, P K; Bellini, F; Benayoun, M; Benelli, G; Berger, N; Bernard, D; Berryhill, J W; Best, D; Bettarini, S; Bettoni, D; Bevan, A J; Bhimji, W; Bhuyan, B; Bianchi, F; Biasini, M; Biesiada, J; Blanc, F; Blaylock, G; Blinov, A E; Blinov, V E; Bloom, P; Bomben, M; Bondioli, M; Bonneaud, G R; Bosisio, L; Boutigny, D; Bowerman, D A; Boyarski, A M; Boyd, J T; Bozzi, C; Brandenburg, G; Brandt, T; Brau, J E; Breon, A B; Briand, H; Brose, J; Brown, C L; Brown, C M; Brown, D; Brown, D N; Bruinsma, M; Brunet, S; Bucci, F; Buchanan, C; Buchmüller, O L; Bugg, W; Bukin, A D; Bula, R; Bulten, H; Burchat, P R; Burke, J P; Button-Shafer, J; Buzzo, A; Bóna, M; Cahn, R N; Calabrese, R; Calcaterra, A; Calderini, G; Campagnari, C; Capra, R; Carpinelli, M; Cartaro, C; Cavallo, N; Cavoto, G; Cenci, R; Chai, X; Chaisanguanthum, K S; Chao, M; Charles, E; Charles, M J; Chauveau, J; Chavez, C A; Chen, A; Chen, C; Chen, E; Chen, J C; Chen, S; Chen, X; Cheng, B; Cheng, C H; Chevalier, N; Cibinetto, G; Clark, P J; Claus, R; Cochran, J; Coleman, J P; Contri, R; Convery, M R; Cormack, C M; Cossutti, F; Cottingham, W N; Couderc, F; Covarelli, R; Cowan, G; Cowan, R; Crawley, H B; Cremaldi, L; Cristinziani, M; Cunha, A; Curry, S; Côte, D; D'Orazio, A; Dahmes, B; Dallapiccola, C; Danielson, N; Dasu, S; Datta, M; Dauncey, P D; David, P; Davier, M; Davis, C L; Day, C T; De Groot, N; De Nardo, Gallieno; De Sangro, R; Del Buono, L; Del Re, D; Della Ricca, G; Di Lodovico, F; Di Marco, E; Dickopp, M; Dingfelder, J C; Dittongo, S; Dong, D; Dorfan, J; Druzhinin, V P; Dubitzky, R S; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Dvoretskii, A; Eckhart, E A; Eckmann, R; Edgar, C L; Edwards, A J; Egede, U; Eichenbaum, A M; Eigen, G; Eisner, A M; Elmer, P; Emery, S; Ernst, J A; Eschenburg, V; Eschrich, I; Eyges, V; Fabozzi, F; Faccini, R; Fan, S; Feltresi, E; Ferrarotto, F; Ferroni, F; Field, R C; Finocchiaro, G; Flacco, C J; Flack, R L; Flächer, H U; Flood, K T; Ford, K E; Ford, W T; Forster, I J; Forti, F; Fortin, D; Foulkes, S D; Franek, B; Frey, R; Fritsch, M; Fry, J R; Fulsom, B G; Gabathuler, E; Gaidot, A; Gaillard, J R; Galeazzi, F; Gallo, F; Gamba, D; Gamet, R; Gan, K K; Ganzhur, S F; Gary, J W; Gaspero, M; Gatto, C; George, K A; Gill, M S; Giorgi, M A; Giroux, X; Gladney, L; Glanzman, T; Godang, R; Goetzen, K; Golubev, V B; Gopal, G P; Gowdy, S J; Gradl, W; Graham, M; Grancagnolo, S; Graugès-Pous, E; Graziani, G; Green, M G; Grenier, P; Gritsan, A V; Grosdidier, G; Groysman, Y; Guo, Q H; Hadavand, H K; Hadig, T; Haire, M; Halyo, V; Hamano, K; Hamel de Monchenault, G; Hamon, O; Harrison, P F; Harrison, T J; Hart, A J; Hartfiel, B L; Hast, C; Hauke, A; Hawkes, C M; Hearty, C; Held, T; Hertzbach, S S; Heusch, C A; Hill, E J; Hirschauer, J F; Hitlin, D G; Hodgkinson, M C; Hollar, J J; Hong, T M; Honscheid, K; Hopkins, D A; Hrynóva, T; Hufnagel, D; Hulsbergen, W D; Hutchcroft, D E; Höcker, A; Igonkina, O; Innes, W R; Izen, J M; Jackson, P D; Jackson, P S; Jacobsen, R G; Jawahery, A; Jessop, C P; John, M J J; Johnson, J R; Judd, D; Kadel, R W; Kadyk, J; Kagan, H; Karyotakis, Yu; Kass, R; Kelly, M P; Kelsey, M H; Kerth, L T; Khan, A; Kim, H; Kim, P; Kirkby, D; Kitayama, I; Klose, V; Knecht, N S; Koch, H; Kocian, M L; Koeneke, K; Kofler, R; Kolomensky, Yu G; Koptchev, V B; Kovalskyi, D; Kowalewski, R V; Kozanecki, Witold; Kravchenko, E A; Kreisel, A; Krishnamurthy, M; Kroeger, R; Kroseberg, J; Kukartsev, G; Kutter, P E; Kyberd, P; La Vaissière, C de; Lacker, H M; Lae, C K; Lafferty, G D; Lanceri, L; Lange, D J; Langenegger, U; Lankford, A J; Latham, T E; Lau, Y P; Lazzaro, A; Le Diberder, F R; Lees, J P; Legendre, M; Leith, D W G S; Lepeltier, V; Leruste, P; Lewandowski, B; Li Gioi, L; Li, H; Li, X; Libby, J; Lista, L; Liu, R; Lo Vetere, M; LoSecco, J M; Lockman, W S; Lombardo, V; London, G W; Long, O; Lou, X C; Lu, M; Luitz, S; Lund, P; Luppi, E; Lusiani, A; Lutz, A M; Lynch, G; Lynch, H L; Lü, C; Lüth, V; MacFarlane, D B; Macri, M; Mader, W F; Majewski, S A; Malcles, J; Mallik, U; Mancinelli, G; Mandelkern, M A; Marchiori, G; Margoni, M; Marks, J; Marsiske, H; Martínez-Vidal, F; Mattison, T S; Mayer, B; Mazur, M A; Mazzoni, M A; McKenna, J A; McMahon, T R; Meadows, B T; Mellado, B; Menges, W; Messner, R; Meyer, W T; Mihályi, A; Minamora, J S; Mir, L M; Mohanty, G B; Mohapatra, A K; Mommsen, R K; Monge, M R; Monorchio, D; Moore, T B; Morandin, M; Morgan, S E; Morganti, M; Morganti, S; Morii, M; Muheim, F; Müller, D R; Naisbit, M T; Narsky, I; Nash, J A; Nauenberg, U; Neal, H; Negrini, M; Neri, N; Nesom, G; Nicholson, H; Nikolich, M B; Nogowski, R; O'Grady, C P; Ocariz, J; Oddone, P J; Ofte, I; Olaiya, E O; Olivas, A; Olsen, J; Onuchin, A P; Orimoto, T J; Otto, S; Oyanguren, A; Ozcan, V E; Paar, H P; Pacetti, S; Palano, A; Palombo, F; Pan, Y; Panduro-Vazquez, W; Panetta, J; Panvini, R S; Paoloni, E; Paolucci, P; Pappagallo, M; Parry, R J; Passaggio, S; Patel, P M; Patrignani, C; Patteri, P; Payne, D J; Pelizaeus, M; Perazzo, A; Perl, M; Peruzzi, I M; Peters, K; Petersen, B A; Petersen, T C; Petzold, A; Piatenko, T; Piccolo, D; Piccolo, M; Piemontese, L; Pierini, M; Pioppi, M; Piredda, G; Plaszczynski, S; Playfer, S; Poireau, V; Polci, F; Pompili, A; Porter, F C; Posocco, M; Potter, C T; Prell, S; Prepost, R; Pripstein, M; Pulliam, T; Purohit, M V; Qi, N D; Rahatlou, S; Rahimi, A M; Rama, M; Ratcliff, B N; Raven, G; Reidy, J; Ricciardi, S; Richman, J D; Ritchie, J L; Rizzo, G; Roat, C; Roberts, D A; Robertson, S H; Robutti, E; Rodier, S; Roe, N A; Ronan, M T; Roney, J M; Rong, G; Roodman, A; Roos, L; Rosenberg, E I; Rotondo, M; Roudeau, P; Rubin, A E; Ruddick, W O; Ryd, A; Röthel, W; Sacco, R; Saeed, M A; Safai-Tehrani, F; Saleem, M; Salnikov, A A; Salvatore, F; Samuel, A; Sanders, D A; Santroni, A; Saremi, S; Satpathy, A; Schalk, T; Schenk, S; Schindler, R H; Schofield, K C; Schott, G; Schrenk, S; Schröder, T; Schröder, H; Schubert, J; Schubert, K R; Schumm, B A; Schune, M H; Schwiening, J; Schwierz, R; Schwitters, R F; Sciacca, C; Sciolla, G; Seiden, A; Sekula, S J; Serednyakov, S I; Sharma, V; Shen, B C; Simani, M C; Simi, G; Simonetto, F; Sinev, N B; Skovpen, Yu I; Smith, A J S; Smith, J G; Snoek, H L; Snyder, A; Sobie, R J; Soffer, A; Sokoloff, M D; Solodov, E P; Spaan, B; Spanier, S M; Spitznagel, M; Spradlin, P; Steinke, M; Stelzer, J; Stocchi, A; Stoker, D P; Stroili, R; Strom, D; Strube, J; Stugu, B; Stängle, H; Su, D; Sullivan, M K; Summers, D J; Sundermann, J E; Suzuki, K; Swain, S K; Tan, P; Taras, P; Taylor, F; Telnov, A V; Teodorescu, L; Ter-Antonian, R; Therin, G; Thiebaux, C; Thompson, J M; Tisserand, V; Toki, W H; Torrence, E; Tosi, S; Touramanis, C; Ulmer, K A; Uwer, U; Van Bakel, N; Vasileiadis, G; Vasseur, G; Vavra, J; Verderi, M; Verkerke, W; Viaud, B; Vitale, L; Voci, C; Voena, C; Wagner, G; Wagner, S R; Wagoner, D E; Waldi, R; Walsh, J; Wang, K; Wang, P; Wappler, F R; Watson, A T; Weaver, M; Weidemann, A W; Weinstein, A J R; Wenzel, W A; Wilden, L; Williams, D C; Williams, J C; Willocq, S; Wilson, F F; Wilson, J R; Wilson, M G; Wilson, R J; Wisniewski, W J; Wittgen, M; Won, E; Wong, Q K; Wormser, G; Wright, D H; Wright, D M; Wu, J; Wu, S L; Xie, Y; Yamamoto, R K; Yarritu, A K; Ye, S; Yi, J; Yi, K; Young, C C; Yu, Z; Yumiceva, F X; Yushkov, A N; Yéche, C; Zain, S B; Zallo, A; Zeng, Q; Zghiche, A; Zhang, J; Zhang, L; Zhao, H W; Zhu, Y S; Ziegler, V; Zito, M; Çuhadar-Dönszelmann, T

    2006-01-01

    We study the two-body decays of B^\\pm mesons to K^\\pm and a charmonium state, X_{c\\bar c}, in a sample of 210.5 fb^{-1} of data from the BaBar experiment. We perform measurements of absolute branching fractions BR(B^\\pm --> K^\\pm X_{c\\bar c}) using a missing mass technique, and report several new or improved results. In particular, the upper limit BR(B^\\pm --> K^\\pm X(3872)) J/\\psi\\pi^+\\pi^-)>4.2% will help in understanding the nature of the recently discovered X(3872).

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

    International Nuclear Information System (INIS)

    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.

  7. Absolute optical oscillator strengths for the electronic excitation of atoms at high resolution: Experimental methods and measurements for helium

    International Nuclear Information System (INIS)

    An alternative method is described for the measurement of absolute optical oscillator strengths (cross sections) for electronic excitation of free atoms and molecules throughout the discrete region of the valence-shell spectrum at high energy resolution (full width at half maximum of 0.048 eV). The technique, utilizing the virtual-photon field of a fast electron inelastically scattered at negligible momentum transfer, avoids many of the difficulties associated with the various direct optical techniques that have traditionally been used for absolute optical oscillator strength measurements. The method is also free of the bandwidth (line saturation) effects that can seriously limit the accuracy of photoabsorption cross-section measurements for discrete transitions of narrow linewidth obtained using the Beer-Lambert law [I0/I=exp(nl?p)]. Since the line-saturation effects are not widely appreciated and are only usually considered in the context of peak heights, a detailed analysis of this problem is presented, with consideration of the integrated cross section (oscillator strength) over the profile of each discrete peak

  8. A Novel Portable Absolute Transient Hot-Wire Instrument for the Measurement of the Thermal Conductivity of Solids

    Science.gov (United States)

    Assael, Marc J.; Antoniadis, Konstantinos D.; Metaxa, Ifigeneia N.; Mylona, Sofia K.; Assael, John-Alexander M.; Wu, Jiangtao; Hu, Miaomiao

    2015-11-01

    A new portable absolute Transient Hot-Wire instrument for measuring the thermal conductivity of solids over a range of 0.2 { W}{\\cdot }m^{-1}{\\cdot }{K}^{-1} to 4 { W}{\\cdot }m^{-1}{\\cdot }{K}^{-1} is presented. The new instrument is characterized by three novelties: (a) an innovative two-wires sensor which provides robustness and portability, while at the same time employs a soft silicone layer to eliminate the effect of the contact resistance between the wires and the sample, (b) a newly designed compact portable printed electronic board employing an FPGA architecture CPU to the control output voltage and data processing—the new board replaces the traditional, large in size Wheatstone-type bridge system required to perform the experimental measurements, and (c) a cutting-edge software suite, developed for the mesh describing the structure of the sensor, and utilizing the Finite Elements Method to model the heat flow. The estimation of thermal conductivity is modeled as a minimization problem and is solved using Bayesian Optimization. Our revolutionizing proposed methodology exhibits radical speedups of up to × 120, compared to previous approaches, and considerably reduces the number of simulations performed, achieving convergence only in a few minutes. The new instrument was successfully employed to measure, at room temperature, the thermal conductivity of two thermal conductivity reference materials, Pyroceram 9606 and Pyrex 7740, and two possible candidate glassy solids, PMMA and BK7, with an absolute low uncertainty of 2 %.

  9. Absolute measurement of ?eff based on Rossi-? experiments and two-region model in IPEN/MB-01 research reactor

    International Nuclear Information System (INIS)

    A new method for absolute measurement of the effective delayed neutron fraction, ?eff, based on Rossi-? experiments and the Two-Region Model was developed at the IPEN/MB-01 Research Reactor facility. In contrast with other techniques like the Slope Method, Nelson-Number Method and 252Cf-Source Method, the main advantage of this new methodology is to obtain the effective delayed neutron parameters in a purely experimental way, eliminating all parameters that are difficult to measure or calculate. In this way, Rossi-alpha experiments for validation of this method were performed at the IPEN/MB-01 facility, and adopting the present approach, ?eff was measured with a 1.46% uncertainty. In addition, the prompt neutron generation time, LAMBDA and other parameters, was also obtained in an absolute experimental way. In general, the final results agree well with values from frequency analysis experiments. The theory-experiment comparison reveals that JENDL-3.3 shows deviation for ?eff lower than 1% which meets the desired accuracy for the theoretical determination of this parameter. This work supports the reduction of the 235U thermal yield as proposed by Okajima and Sakurai. (author)

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

    International Nuclear Information System (INIS)

    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.)

  11. Environmental radioactivity monitoring in Lower Saxonia in 1991 and 1992. Joint report of the Lower Saxonian environmental radioactivity measuring stations

    International Nuclear Information System (INIS)

    The updated joint report of the lower Saxonian measuring stations for environmental radioactivity is for the years 1991 and 1992 and serves the purpose of providing information to interested citizens regarding the results of measurements. Technical terms are explained in the annex. Monitoring for environmental radioactivity (including foodstuffs and drinking water) has been carried through in Germany since the beginning of the 60s, when environmental radioactivity increased globally because of nuclear testing at that time. Measurements are executed by institutions of the federal government and laender on behalt of the federal government. Furthermore, measurements are regularly carried through in the surroundings of nuclear installations. Results are collected and evaluated by the federal authorities and regularly published by the Federal minister for environment, nature protection and reactor safety in the government's annual reports on ''Environmental radioactivity and radiation exposure''. Experiences with transfrontier radioactive contamination in the wake of the Chernobyl reactor accident prompted the federal government to intensify and reorganize environmental radioactivity monitoring. For this, the precautionary radiation protection law (StrVG) of 1986 provides the legal basis. (orig./HP)

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

    Science.gov (United States)

    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.

  13. Turbidimetry: Measurement of X- or γ-absorption or measurement of natural radioactivity?

    International Nuclear Information System (INIS)

    Turbidity may be measured by radioactive means on the basis of the two following methods: (a) measurement of X- or γ-absorption in a nuclear gauge, corresponding to a measurement of the density of the medium; (b) in-situ measurement of the natural radioactivity of the sediment in suspension. The authors used the two methods simultaneously: by constructing a prototype γ-absorption measuring gauge (241Am) whose characteristics are described and by seeking to determine the true precision of such an apparatus (limit of precision approximately 1. 5 g/l ± 500 mg); carrying out in-situ measurements of natural radioactivity of sediment in suspension, in particular in estuaries (limit for the Loire approximately 0.7 g/l ± 250 mg). The advantages and disadvantages of each of these two methods are critically analysed. It would appear, in particular: that the natural radioactivity gauge is much less sensitive to local salinity and is a valuable tool in estuaries, of which there are many in Europe, of variable salinity and of generally high turbidity; that being robuster and simpler, it is less sensitive to different parameters (electronic drifts, geometric variations, etc.). On the other hand, it must be calibrated for each site and periodically on the same site. Further, it can only be used in a clayey medium. Particulars are given for the use of each of these instruments. (author)

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

    International Nuclear Information System (INIS)

    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

  15. Natural radioactivity measurements in some Indian building materials

    International Nuclear Information System (INIS)

    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)

  16. Environmental radioactivity measurements in Kastamonu region of northern Turkey.

    Science.gov (United States)

    Kam, Erol; Bozkurt, Ahmet

    2007-04-01

    Located in the north-western part of Turkey, the province of Kastamonu has lately been receiving national attention because of its cultural and touristic attractions. This study assesses the environmental radioactivity levels of the region through measurements of indoor radon concentrations and indoor/outdoor gamma absorbed dose in air and radionuclide activities in surface soil and drinking water. The indoor (222)Rn activity concentration was found to be 98.4 Bq/m(3) equivalent to an annual effective dose of 2.48 mSv. The indoor and outdoor gamma absorbed doses were measured as 54.81 and 48.03 nGy/h, respectively, corresponding to a total gamma radiation level (of terrestrial and cosmic origin) of 0.33 mSv/y. The activity concentrations in the soil samples collected from the study area were determined as 32.93, 27.17, 431.43 Bq/kg for the natural radionuclides (238)U, (232)Th and (40)K, respectively, and 8.02 Bq/kg for the fission product (137)Cs. These natural radioactivity sources result in a terrestrial gamma level of 60 microSv/y. The water samples collected from the region carry an average of 0.0089 Bq/l of gross alpha and 0.271 Bq/l of gross beta activities which together cause an annual effective dose of 1.83 microSv. The measurement results obtained in this study indicate that the region has a background radiation level that is within the natural limits and shows no significant departure from the other parts of the country. PMID:17207627

  17. absolute measurement of α-activity in solution by inner scintillation method of ZnS(Ag)

    International Nuclear Information System (INIS)

    The method of increasing the measurement efficiency can be reached by mixing the samples directly with ZnS(Ag), which allows carriers to be used in two circles and prepares the double sliced samples. This becomes 4π absolute measuring method of α-total activity in solution. A simulating measurement for the Pu-240 tracer solution got a good result: the accuracy is -0.1% and the precision is +- 0.21%. The method takes advantage of common instruments, combining the improvement of preparing the radiochemical sample method. The correctness of factors of the whole method are checked by experiments: the 4π detecting efficiency is 99.9% and the total uncertainty is +- 0.7%

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

    International Nuclear Information System (INIS)

    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.)

  19. The NIST radioactivity measurement assurance program for the radiopharmaceutical industry

    International Nuclear Information System (INIS)

    The National Institute of Standards and Technology (NIST) maintains a program for the establishment and dissemination of activity measurement standards in nuclear medicine. These standards are disseminated through Standard Reference Materials (SRMs), Calibration Services, radionuclide calibrator settings, and the NIST Radioactivity Measurement Assurance Program (NRMAP, formerly the NEI/NIST MAP). The MAP for the radiopharmaceutical industry is described here. Consolidated results show that, for over 3600 comparisons, 96% of the participants' results differed from that of NIST by less than 10%, with 98% being less than 20%. Individual radionuclide results are presented from 214 to 439 comparisons, per radionuclide, for 67Ga, 90Y, 99mTc, 99Mo, 111In, 125I, 131I, and 201Tl. The percentage of participants results within 10% of NIST ranges from 88% to 98%. - Research highlights: ? NIST has maintained an MAP for the radiopharmaceutical industry since 1975. ? Participants measure sources with known, but blinded, activity and submit results. ? The schedule is chosen by a steering committee made up of participants and NIST. ? Participants submit calibrated sources for measurement by NIST during open months. ? Results are presented for over 3600 measurements of distributed sources.

  20. Evaluation of representation of measuring points in atmospheric radioactivity monitoring

    International Nuclear Information System (INIS)

    The radioactive concentrations of 222Rn, 220Rn, and their daughter nuclides in the air depend on geology, topography, the state of ground surface, weather, atmospheric temperature and wind velocity. Because of the dependence on these factors, it was studied that how wide area measuring points can represent, and the results are reported. It was confirmed that the basic measuring point for 222Rn concentration was able to represent the whole area in the Nagoya University by the measurement from October, 1972, to February, 1973, and the whole area in Nagoya City from October, 1976, to February, 1977. The survey area was expanded this time to the region with 30 km radius from the Nagoya University as the center, and the concentration of 222Rn daughter nuclides was obtained by filter method. This method is to count the number of 2 particles of 222Rn daughter nuclides gathered on millipore filters RA, utilizing a scintillation counter. The experimental monitoring was conducted simultaneously with the Government Industrial Research Institute Nagoya (GIRI). The temporal variation of the ratio of 222Rn daughter concentration measured at GIRI to that measured at the basic point in the Nagoya University during three months is shown. As the other observed results, the simultaneous measurements of 222Rn daughter concentration carried out at the basic point and at the location J (about 15 km south from the basic point) and the correlation between 222Rn daughter concentration measured at the basic point and that measured at the location J are presented. A criterion for classification was tried using the concentration level and the variation pattern, to clarify the representative characteristics of the locations, and the actual classification of measuring locations according to the criterion is shown. (Nakai, Y.)

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

    International Nuclear Information System (INIS)

    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) 4? 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 ? emission (within the resolution time of the coincidence circuit) the activity was determined through the X-? 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 ?K = 0.191 0.002, chromium ?K = 0.262 0.002 and copper ?K = 0.390 0.004. (author)

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

    International Nuclear Information System (INIS)

    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)

  3. Measurement of the abrasion of radioactive teeth by dentifrices

    International Nuclear Information System (INIS)

    The purpose of this study is to assess the dentifrice abrasivity of both commercially available products and test products. The assessment of abrasivity was carried out by the measurement of 32P released from tooth by using radioactive dentifrice abrasion (RDA) method. In dentine, RDA values, which show in polishing ability for dentine, were 65-100 with dentifrices with normal cleaning power and 106-182 with those with high cleaning power, respectively. On the other hand, REA values which slow the polishing ability for enamel were 12-405 with both market products and test products. The difference of the REA values according to the dentrifrices appears to be largely influenced by the difference of polishing agents of each dentifrice. It is concluded that RDA method is useful for assessing of dentifrice abrasivity. However, particular attention should be given to the abrasion of dentine. (author)

  4. Radioactivity measurement in spring waters of Cantabria, Spain

    International Nuclear Information System (INIS)

    A study of the radioactivity existing in a high number of springs located in Cantabria, Northern Spain, was made. The spring analyzed in three sampling campaign's, And alpha and beta total activities and 226Ra and 222Rn concentrations were determined for each sample. The measuring techniques employed were gamma spectrometry with Ge detector, counting with gas flow proportional counter, and counting with ZnS(Ag) scintillating detector. Results show that springs with high radon water concentration have high values respect to the national mean. The springs with the highest radium and radon levels have thermal waters and are located on two deep fault, those have historic seismicity and seismical and geomorphological evidences of recent tectonic activity

  5. Framework for preparing and performing absolute radiometric measurements using electrooptical instruments for the earth observations

    Science.gov (United States)

    Panfilov, A. S.; Gavrilov, V. R.; Sapritsky, V. I.

    2014-12-01

    The complex of measurements necessary for high-quality radiometric measurements of the Earth to be performed using space electrooptical instruments, including hyperspectrometric instruments, has been considered. This complex was developed in order to maintain the uniformity of measurements according to Russian legislation. In addition to organizational measures, it is necessary to determine the interrelation between radiometric data and geophysical parameters received using these data and to solve the methodological problems of the Earth observation instrument (EOI) radiometric calibration and in-orbit verification of EOI radiometric characteristics. The considered approaches are largely close to the statements of the international document "Quality Assurance Framework for Earth ObservationQA4EO".

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

    International Nuclear Information System (INIS)

    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)

  7. Measurement of cosmogenic radioactive products in xenon and copper

    Science.gov (United States)

    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.

  8. Precision absolute measurement and alignment of laser beam direction and position.

    Science.gov (United States)

    Schütze, Daniel; Müller, Vitali; Heinzel, Gerhard

    2014-10-01

    For the construction of high-precision optical assemblies, direction and position measurement and control of the involved laser beams are essential. While optical components such as beamsplitters and mirrors can be positioned and oriented accurately using coordinate measuring machines (CMMs), the position and direction control of laser beams is a much more intriguing task since the beams cannot be physically contacted. We present an easy-to-implement method to both align and measure the direction and position of a laser beam using a CMM in conjunction with a position-sensitive quadrant photodiode. By comparing our results to calibrated angular and positional measurements we can conclude that with the proposed method, a laser beam can be both measured and aligned to the desired direction and position with 10 μrad angular and 3 μm positional accuracy. PMID:25322238

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

    Science.gov (United States)

    Wu, Hanzhong; Zhang, Fumin; Meng, Fei; Liu, Tingyang; Li, Jianshuang; Pan, Liang; Qu, Xinghua

    2016-01-01

    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 MachZehnder 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 ?m 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 ?m 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.

  10. A cryogenic current comparator for the absolute measurement of nA beams

    International Nuclear Information System (INIS)

    A new type of beam transformer, based on the principle of a Cryogenic Current Comparator (CCC), was built to measure extracted ion beams from the SIS, the heavy ion synchroton at GSI. A current resolution of 0.006-0.065 nA/√(Hz), depending on the frequency range, could be achieved allowing us to measure ion beams with intensities greater than 109 particles per second with high accuracy. Numerous investigations were carried out to study the zero drift of the system which shows a strong exponential slope with two time constants. In addition, the influence of external magnetic fields was measured. Furthermore the microphonic sensitivity of the system was studied by measuring noise spectra of the detector's vibration and the output signal. Measurements with neon and argon beams will be presented and compared with signals emitted from Secondary Emission Monitors (SEM). Another measuring function of the CCC-detector aims at the analysis of the beam's time structure to get information about beam spill fluctuations. With an extended bandwidth (0-20 kHz) of the detector system it is now possible to compare simulations of extracted beams from synchrotons with measurements of the CCC

  11. Time, absolute.

    OpenAIRE

    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...

  12. MTF-insensitive algorithm for absolute diameter measurements of coronary arteries

    International Nuclear Information System (INIS)

    The authors are investigating a new algorithm for the determination of coronary artery dimensions that has a low sensitivity to the modulation transfer function of the imaging system. This algorithm uses the first zero crossing frequency of the Fourier transform of the vessel profile to indicate the vessel size. Measurements of vessel phantoms imaged with blurring aperture sizes extending from 20% to 80% of the vessel diameter have shown a 10%-25% improvement in measurement accuracy over standard videodensitometric and edge detection techniques. Preliminary in vivo measurements of stenosed coronary arteries in a dog model indicate a similar improvement in accuracy

  13. Plasma oscillation method for measurements of absolute electron density in plasma

    International Nuclear Information System (INIS)

    A new and simple method for precise measurements of electron density in a plasma with use of plasma oscillations is described. A weak electron beam is injected from a hot filament and excites electron waves oscillating at the plasma frequency ?p, whose sharp spectrum, obtained using a detector, gives the electron density. This plasma oscillation method is free of many difficulties often encountered with a Langmuir probe, such as thin film deposition, plasma potential fluctuation, and magnetic fields. The measurement technique is theoretically analyzed and experimentally demonstrated in the density measurements of an inductively coupled rf plasma, together with a comparison with the Langmuir probe method. (author)

  14. Determination of critical assembly absolute power using post-irradiation activation measurement of week-lived fission products

    International Nuclear Information System (INIS)

    The work presents a detailed comparison of calculated and experimentally determined net peak areas of longer-living fission products after 100 h irradiation on a reactor with power of ∼630 W and several days cooling. Specifically the nuclides studied are 140Ba, 103Ru, 131I, 141Ce, 95Zr. The good agreement between the calculated and measured net peak areas, which is better than in determination using short lived 92Sr, is reported. The experiment was conducted on the VVER-1000 mock-up installed on the LR-0 reactor. The Monte Carlo approach has been used for calculations. The influence of different data libraries on results of calculation is discussed as well. - Highlights: • Measured and calculated net peak areas of selected longer living isotopes. • Determination of absolute reactor power. • Discrepancies between calculation and experiment. • Effect of data libraries on calculational results

  15. Radio frequency cavity analysis, measurement, and calibration of absolute Dee voltage for K-500 superconducting cyclotron at VECC, Kolkata

    Energy Technology Data Exchange (ETDEWEB)

    Som, Sumit; Seth, Sudeshna; Mandal, Aditya; Paul, Saikat; Duttagupta, Anjan [Variable Energy Cyclotron Centre, Kolkata (India)

    2013-02-15

    Variable Energy Cyclotron Centre has commissioned a K-500 superconducting cyclotron for various types of nuclear physics experiments. The 3-phase radio-frequency system of superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and {+-}0.2{sup 0}, respectively. The analysis of the RF cavity has been carried out using 3D Computer Simulation Technology (CST) Microwave Studio code and various RF parameters and accelerating voltages ('Dee' voltage) are calculated from simulation. During the RF system commissioning, measurement of different RF parameters has been done and absolute Dee voltage has been calibrated using a CdTe X-ray detector along with its accessories and known X-ray source. The present paper discusses about the measured data and the simulation result.

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

    International Nuclear Information System (INIS)

    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)

  17. Experimental and numerical study of the degradation of radioactive measurements in the filters of airborne radioactive surveillance systems

    International Nuclear Information System (INIS)

    The measurement of radioactivity in the filters of airborne radioactive surveillance systems is a major metrology difficulty due to the fact that the absorption of a radiation in the filter media and the mass of aerosols accumulated distort the nuclear counting response. This thesis focuses on the determination of correction factors for the radioactivity loss in the survey filters. In a first step, radioactive filters representing the atmospheric samples have been prepared using the nuclear test bench ICARE. The experimental study on reference filters provided a database to determine correction factors for various filtration conditions. The second part proposes a new numerical method developed to determine the correction factors. It consists of coupling GeoDict for particles filtration simulations and MCNPX simulations for a transport in matter. The good agreement obtained by comparing the numerical and experimental correction factors has permitted to validate the numerical model

  18. Absolute measurement of γ-ray emitter radioelements by spectrometry (1963)

    International Nuclear Information System (INIS)

    The proposed apparatus is composed of a lead collimator and a thallium sodium iodide activated scintillation detector. The geometrical solid angle is determined by the collimator, but the real solid angle is larger owing to the γ-ray filtration in the inner sides. The filtration coefficient to apply for obtention of the counting rate corresponding to the geometrical solid angle has been calculated and measured experimentally. γ-rays are scattered in the shielding of the scintillator what as a consequence to increase the counting rate. The scattering coefficient to apply for obtaining the real counting rate has been measured experimentally. The device efficiency for different γ-ray energies has been calculated and measured experimentally. A certain quantity of γ-ray emitter radioelements have been measured. The accuracy is 4 per cent. (author)

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

    International Nuclear Information System (INIS)

    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

  20. Practice and experience in traceability of radioactivity measurements of environmental samples

    International Nuclear Information System (INIS)

    This paper discusses some aspects on radioactivity measurement traceability and summarizes the work on quality assurance of radioactivity measurements of environmental samples in the laboratory, including transfer of standards, preparation of reference materials, and calibration of efficiency for volumse surces with Ge(Li) spectrometer. Some practical activitis regarding intercomparison of radioactivity measurements and other traceabillity-related activities are also described. Some sugestions relating to performing quality assurance are made