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. Radioactivity measurements of 177Lu, 111In and 123I by different absolute methods

    International Nuclear Information System (INIS)

    The activities of 177Lu, 111In and 123I solutions have been absolutely determined using three different measurement methods. 177Lu solution was standardized using the 4??(PC)–?(NaI) coincidence and 4??(LS)–?(NaI) live-timed anticoincidence methods. For the 111In and 123I solutions, besides these two mentioned methods, the coincidence sum-peak method was also applied. The measured activities results using these different methods are consistent within the evaluated experimental uncertainties demonstrating the equivalence of these methods. As an additional contribution to nuclear data, the half-lives have been determined using a well type IG12 ionization chamber. - Highlights: ? Lu-177, I-123 and In-111 have been absolutely standardized by different methods. ? Results between methods agreed within evaluated uncertainties. ? 3-Half-lives were also measured and compared with recent published results.

  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 ? X (or e) - ? coincidence method when K capture is followed by a ? 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. 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)

  5. 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)

  6. 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.

  7. Absolute neutrino mass measurements

    International Nuclear Information System (INIS)

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2?) searches, single ?-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium ?-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope (137Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2? decay and single ?-decay.

  8. Radioactive gas measuring device

    International Nuclear Information System (INIS)

    The radioactive gas measuring device comprises an introducing means for introducing radioactive gas, a sampling vessel, a measuring device for introducing and measuring radioactive gas, a gas bag for storing the radioactive gas after the measurement, an exhaustion device for exhausting the inside of the gas bag and containing the exhausted gas in a tank and a sensor for operating the exhaustion device upon reaching a predetermined value. The radioactive gas is stored in a gas bag after the measurement, and the pressure of the radioactive gas is kept stable, to improve the accuracy of the measurement. Further, when the amount of the stored radioactive gas is increased after the measurement, and the volume of the gas bag reaches a predetermined value, since the exhaustion device is operated by the sensor, the operation of the measuring device can be simplified. Then, the measurement for the radioactive gas can be conducted stably at high accuracy, thereby enabling to measure an absolute value of the impurity. The measurement for the impurity of the radioactive gas can be remarkably facilitated in the site of medical therapy. (N.H.)

  9. Active radiometric calorimeter for absolute calibration of radioactive sources

    International Nuclear Information System (INIS)

    This report describes the design and initial noise floor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise floor of approximately 2 nW. This low noise floor is achieved by using high temperature superconducting (HTS) transition edge sensor (TES) thermometers in a temperature-control feedback loop. This feedback loop will be used to provide absolute source calibrations based upon the electrical substitution method. Other unique features of the calorimeter are (a) its ability to change sources for calibration without disrupting the vacuum of the instrument, and (b) the ability to measure the emitted power of a source in addition to the total contained source power

  10. The class of absolute decomposable inequality measures

    OpenAIRE

    Bosmans, Kristof; Cowell, Frank

    2009-01-01

    We provide a parsimonious axiomatisation of the complete class of absolute nequality indices. Our approach uses only a weak form of decomposability and does not require a priori that the measures be differentiable.

  11. 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

  12. Amoeba-absoluteness and projective measurability

    CERN Document Server

    Brendle, J

    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-measurability. This answers a question of Haim Judah (private communication).

  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...

  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. Measurement of radioactivity

    International Nuclear Information System (INIS)

    The measurement of environmental radioactivity in Japan started from the time of the nuclear test at Bikini in 1954, and Science and Technology Agency has established ''Measuring Procedure of Radioactivity'' in 1957. This is total beta radiation measurement, and now the revised draught including nine points to be revised has been made. Since then, analyzing procedures were established for radioactive strontium, cesium-137, radioactive iodine, and radioactive cobalt, with NaI(Tl) scintillation spectrometers, for radioactive zirconium and instrumental analysis using Ge(Li) semiconductor detectors. Presently the tritium-analyzing procedure is under discussion. As the manuals for individual analyses have been instituted, the ''general manual'' for applying those has become to be required. The problems lie not in individual procedures but in the purpose of radioactivity measurement, monitoring method, and the evaluation of data obtained. The compilation of the manual started in 1973, but now temporarily stopped because of a new problem which is the opinion insisting that manual is to include the procedures for the estimation of population exposure dose based on the data obtained. (Wakatsuki, Y.)

  18. Absolute measurement of activity concentration of 87Kr by using internal gas proportional counting

    International Nuclear Information System (INIS)

    A internal gas proportional counting system for absolute measurement of gas radioactivity was established. The performances of the system, such as plateaus, back-ground, deadtime, end effect and wall effect were well tested. Then the activity concentration of 87Kr was measured absolutely to be 40.64(1 ± 0.9%) Bq/mL by this equipment. (authors)

  19. 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.

  20. 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 4? 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)

  1. 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.)

  2. 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 ?Gal and (980 492 048.3 ± 3.0 ?Gal 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.

  3. 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.

  4. 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.

  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. 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.)

  7. On Absolute Measurements of ?-Emitting Radionuclides

    International Nuclear Information System (INIS)

    4 ? 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)

  8. Absolute measurements of neutron induced reaction rates

    International Nuclear Information System (INIS)

    This paper describes techniques for the measurement of neutron-induced reaction rates on an absolute basis. Two main areas of application are discussed: determinations of threshold reactions used to monitor fast fluxes relevant to materials damage and neutron penetration. The accuracy required in these measurements is modest in view of other uncertainties, a standard error of +-10% normally being adequate; determinations of fission and capture rates in zero-power reactors which provide a basis for validation of data and calculation methods applied to the prediction of power reactor performance. Accuracies here are much more stringent, with +-1% on fission rates in the major heavy nuclides and +-0.7% in the capture rate in U-238 being target values based on neutron balance consid

  9. Absolute number concentration measurement of submicrometer particles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.H.B.

    1982-01-01

    Condensation nuclei in the atmosphere are known to be an important factor in the development of clouds, the occurrence of rainfall, and the formation of particulate air pollutions that can cause undesirable effects on man and his environment. Condensation nuclei are invisible and numerous, and their number concentration has become the characteristic of interest and has been widely studied since the development of the first condensation nuclei counter by Aitken in 1888. A conventional nuclei counter employs the so-called condensation technique which enables the minute nuclei to grow, in a supersaturated environment, to ..mu..m-sized droplets; the number concentration of the visible droplets is then measured. Since each nucleus grows to a droplet, the number concentration of droplets and nuclei remains the same. The number of droplets is measured by (1) direct observation with a microscope (direct counter), (2) counting from photographs of the droplets (photographic counter), (3) suitably calibrated light transmission (or scattering) measurement (relative photoelectric counter). Most of the widely-used counters are relative counters in which the instrument reading must be calibrated against a direct or photographic counter. A new condensation nuclei counter is described which is designed to have the following advantages over the widely-used counters: (a) It provides an absolute concentration measurement. (b) Even a small random fluctuation of nuclei concentration can immediately be detected.

  10. Elevation correction factor for absolute pressure measurements

    Science.gov (United States)

    Panek, Joseph W.; Sorrells, Mark R.

    1996-01-01

    With the arrival of highly accurate multi-port pressure measurement systems, conditions that previously did not affect overall system accuracy must now be scrutinized closely. Errors caused by elevation differences between pressure sensing elements and model pressure taps can be quantified and corrected. With multi-port pressure measurement systems, the sensing elements are connected to pressure taps that may be many feet away. The measurement system may be at a different elevation than the pressure taps due to laboratory space or test article constraints. This difference produces a pressure gradient that is inversely proportional to height within the interface tube. The pressure at the bottom of the tube will be higher than the pressure at the top due to the weight of the tube's column of air. Tubes with higher pressures will exhibit larger absolute errors due to the higher air density. The above effect is well documented but has generally been taken into account with large elevations only. With error analysis techniques, the loss in accuracy from elevation can be easily quantified. Correction factors can be applied to maintain the high accuracies of new pressure measurement systems.

  11. 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

  12. 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

  13. 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...

  14. 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

  15. 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)

  16. 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.)

  17. Measurement of the absolute luminosity with the ALEPH detector

    International Nuclear Information System (INIS)

    We report on the absolute luminosity measurement performed with the ALEPH detector at LEP. The systematic errors of the measurements in 1990 are estimated to be 0.6% (experimental) and 0.3% (theoretical). (orig.)

  18. 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

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

    Science.gov (United States)

    Kim, Jeonggon Harrison

    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, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.

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

    Directory of Open Access Journals (Sweden)

    Jeonggon Harrison Kim

    2008-11-01

    Full Text Available 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, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.

  1. 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)

  2. Accuracy of absolute gravity measurements when measuring crustal deformation

    Science.gov (United States)

    van Camp, M.; Williams, S. D.; Francis, O.; Camelbeeck, T.

    2004-12-01

    To observe secular land movements of the order of a few millimetres per year, a very precise instrument with long-term stability is required. This can be achieved using absolute gravimeters, which do not depend on a reference frame. Vertical land movements would modify the gravity at a rate of about -10 nms-2 (1 ? Gal) for 5 mm of uplift. Repeated absolute gravity (AG) measurements have now been performed at several sites for five or more years to constrain, for example, tectonic deformation and post-glacial rebound. It is often assumed that these time series contain only white noise. However, many geodetic data sets have now provided evidence for error sources that introduce large temporal correlations into the data. One common statistical model for many types of geophysical signal (which may contribute to the noise) maybe described as a power-law process. Accounting for the type of noise is very important when estimating gravity variations and their uncertainties. Moreover this can contribute to identify the noise source(s) affecting AG measurements We present an analysis of the error model using 10 years of AG data taken at the Proudman Oceanographic Laboratory (POL) and using 96 AG gravity measurements recorded over a period of 8 years at the Membach station (Belgium). A superconducting gravimeter (SG) is also continuously monitoring gravity variations at this site. The AG set-up white noise is estimated by comparison with the SG series. The coloured environmental noise is estimated using the Maximum Likelihood Estimation (MLE) technique to fit two types of stochastic model to the SG time series, power-law noise and first order Gauss Markov (FOGM) noise. The gravity rate of change and the associated uncertainties as a function of the noise structure are computed. Then we investigate the noise of AG values at frequencies higher than 1 cpd, where a white noise component usually dominates. Finally the POL and Membach experiments are applied to estimate the uncertainties of AG campaigns repeated once or twice a year to monitor crustal deformation. The results from repeated AG campaigns along a profile across the Ardenne and along the UK coastline are presented. Such repeated AG measurements should allow one to constrain gravity rate of change with an uncertainty of 1 nms-2 (or 0.5 mm) after 8 to 15 years. The conclusion is that long-term measurements using absolute gravimeters are appropriate for monitoring slow vertical tectonic deformation.

  3. Absolute Branching Fraction Measurements of Exclusive D^0 Semileptonic Decays

    OpenAIRE

    Coan, T. E.

    2005-01-01

    With the first data sample collected by the CLEO-c detector at the psi(3770) resonance we have studied four exclusive semileptonic decays of the D0 meson. Our results include the first observation and absolute branching fraction measurement for D0 --> rho- e+ nu_e and improved measurements of the absolute branching fractions for D0 decays to K- e+ nu_e, pi- e+ nu_e, and K*- e+ nu_e.

  4. Estimation of absolute error of measuring rock volume density

    International Nuclear Information System (INIS)

    Absolute error of measuring rock volume density in wells by gamma-gamma logging is estimated using computer calculations. The results of calculations have shown that the application of equipment for compensated gamma-gamma density logging (e.g. the RKS-1 radiometer) provides the measurement of rock volume density of an arbitrary mineral composition in the range of 2-2.8 g/cm3 with the absolute error not more than 0.05 g/cm3

  5. Absolute measurement methods for reflectance and fluorescence

    OpenAIRE

    Holopainen, Silja

    2009-01-01

    Reflectance and fluorescence are important properties when determining the colour and appearance of solid opaque material. They are also useful in several other industrial applications such as those in biochemical and medical industry and in remote sensing. In most industrial applications, the reflectance and / or fluorescence characteristics of samples are measured relative to a known reference standard. The uncertainty of the measurements is naturally dependent on the uncertainty of the ref...

  6. 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

  7. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    International Nuclear Information System (INIS)

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs

  8. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  9. 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

  10. The absolute measurement and analysis of 198Au activation

    International Nuclear Information System (INIS)

    198Au has a series of merits, such as the simple disintegration Chart, the single isotope constitute, the clear activation section, the high purity and the easy machining. Therefore, 198Au is used the first choice for the neutron flux absolute measurement. The activations absolute measurement for a set of 198Au samples which have been activated in reactor is finished through a suit of new type 4??-? coincidence measurement device which is designed by ourselves in lab. By compare, these measurement values and theory values accord in range of uncertainty, the most uncertainty is less than 1.2%. We can draw a conclusion that the activation absolute measurement of this set of 198Au samples is reliable. (authors)

  11. 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.

  12. 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

  13. 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.

  14. On the Absolute Continuity of the Blackwell Measure

    Science.gov (United States)

    Bárány, Balázs; Kolossváry, István

    2015-04-01

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

  15. 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

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

    Science.gov (United States)

    Fügenschuh, Armin; Fügenschuh, Marzena; Ludszuweit, Marina; Mojsic, Aleksandar; Sokó?, 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.

  17. Absolute Branching Fraction Measurements of Exclusive D^+ Semileptonic Decays

    OpenAIRE

    G. S. Huang

    2005-01-01

    Using data collected at the psi(3770) resonance with the CLEO-c detector at the Cornell e+e- storage ring, we present improved measurements of the absolute branching fractions of D+ decays to K0B e+ nu_e, pi0 e+ nu_e, K0B* e+ nu_e, and rho0 e+ nu_e, and the first observation and absolute branching fraction measurement of D+ --> omega e+ nu_e. We also report the most precise tests to date of isospin invariance in semileptonic D0 and D+ decays.

  18. 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.

  19. 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

  20. 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.)

  1. 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)

  2. 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)

  3. 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.

  4. Europe's Other Poverty Measures: Absolute Thresholds Underlying Social Assistance

    Science.gov (United States)

    Bavier, Richard

    2009-01-01

    The first thing many learn about international poverty measurement is that European nations apply a "relative" poverty threshold and that they also do a better job of reducing poverty. Unlike the European model, the "absolute" U.S. poverty threshold does not increase in real value when the nation's standard of living rises, even though it is…

  5. 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; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Brisbane, S; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Caicedo Carvajal, J M; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Charles, M; Charpentier, Ph; Chiapolini, N; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Constantin, F; Conti, G; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Almagne, B; D'Ambrosio, C; David, P; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Deissenroth, M; Del Buono, L; Deplano, C; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Eames, C; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; d'Enterria, D G; Esperante Pereira, D; Estève, L; Falabella, A; Fanchini, E; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hofmann, W; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koblitz, S; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kukulak, S; Kumar, R; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Luisier, J; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinez Santos, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Mclean, C; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M-N; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Musy, M; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nardulli, J; Nasteva, I; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Nies, S; Niess, V; Nikitin, N; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B; Palacios, J; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C

    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...

  6. 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...

  7. 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

  8. 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 1.3×10{sup ?3} at 633 nm and 900 nm, respectively.

  9. Absolute gravity acceleration measurement in atomic sensor laboratories

    Science.gov (United States)

    de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

    2012-03-01

    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 Florence University (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the measurement of forces with high spatial resolution are in progress. Both experiments require an independent knowledge on the local value of g. 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) ?Gal and ( 980 492 048.3 ± 3.0) ?Gal 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.

  10. Absolute measurement of square flats with Legendre polynomial fitting method

    Science.gov (United States)

    Gao, Bo; Li, Qiang; He, Yuhang; Chai, Liqun; Wei, Xiaohong

    2014-12-01

    Zernike Polynomial fitting method is an effective way to reconstruct absolute surface for three-flat test. However, the Zernike circle polynomials are not orthogonal over the circular area, hence they are not suitable for square flat. We present an absolute testing of a square flat with Legendre polynomial fitting method, which relies on calculating the coefficients of the Legendre terms by least-square fitting method. To obtain the three-dimensional surface data, one additional measurement that rotate the test flat through 90° should be introduced. The formulas are derived theoretically in detail, and validity has been proved by simulated experiment. Vertical profiles of the three surfaces are compared with the measurement results obtained by three-flat test. Good agreement validates our method.

  11. 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)

  12. Absolute and Relative Deprivation and the Measurement of Poverty

    OpenAIRE

    Duclos, Jean-Yves; Gregoire, Philippe

    2001-01-01

    This paper develops the link between poverty and inequality by focussing on a class of poverty indices (some of them well-known) which aggregate normative concerns for absolute and relative deprivation. The indices are distinguished by a parameter that captures the ethical sensitivity of poverty measurement to "exclusion" or "relative-deprivation" aversion. We also show how the indices can be readily used to predict the impact of growth on poverty. An illustration using LIS data finds that he...

  13. 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.

  14. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

    2008-09-29

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

  15. Absolute and relative deprivation and the measurement of poverty

    OpenAIRE

    Duclos, Jean-Yves

    2006-01-01

    This paper develops the link between poverty and inequality by focussing on a class of poverty indices (some of them well-known) which aggregate normative concerns for absolute and relative deprivation. The indices are distinguished by a parameter that captures the ethical sensitivity of poverty measurement to ``exclusion'' or ``relative-deprivation'' aversion. We also show how the indices can be readily used to predict the impact of growth on poverty. An illustration using LIS data finds tha...

  16. 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))%.

  17. 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.

  18. A quantitative PCR method for measuring absolute telomere length

    OpenAIRE

    Fenech Michael; O'Callaghan Nathan J

    2011-01-01

    Abstract We describe a simple and reproducible method to measure absolute telomere length (aTL) using quantitative real-time polymerase chain reaction (qPCR). This method is based on the Cawthon method for relative measurement of telomere length (TL) but modified by introducing an oligomer standard to measure aTL. The method describes the oligomer standards, the generation of the standard curve and the calculations required to calculate aTL from the qPCR data. The necessary controls and perfo...

  19. Precision Absolute Beam Current Measurement of Low Power Electron Beam

    International Nuclear Information System (INIS)

    Precise measurements of low power CW electron beam current for the Jefferson Lab Nuclear Physics program have been performed using a Tungsten calorimeter. This paper describes the rationale for the choice of the calorimeter technique, as well as the design and calibration of the device. The calorimeter is in use presently to provide a 1% absolute current measurement of CW electron beam with 50 to 500 nA of average beam current and 1-3 GeV beam energy. Results from these recent measurements will also be presented

  20. Precision Absolute Beam Current Measurement of Low Power Electron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M. M.; Bevins, M. E.; Degtiarenko, P.; Freyberger, A.; Krafft, G. A.

    2012-11-01

    Precise measurements of low power CW electron beam current for the Jefferson Lab Nuclear Physics program have been performed using a Tungsten calorimeter. This paper describes the rationale for the choice of the calorimeter technique, as well as the design and calibration of the device. The calorimeter is in use presently to provide a 1% absolute current measurement of CW electron beam with 50 to 500 nA of average beam current and 1-3 GeV beam energy. Results from these recent measurements will also be presented.

  1. Absolute measurements of photoionization cross-sections for ions

    International Nuclear Information System (INIS)

    A merged-beam set-up for absolute measurements of photoionization cross-sections of ions is described. The facility is capable of recording cross-sections as low as 10-19 cm2 and has been used to study a large number of singly- and multiply-charged, atomic and molecular, positive and negative ions. It is based on a synchrotron radiation beam line fitted with an undulator at the storage ring ASTRID and a low-energy (?2 keV) ion beam line. Photons in the energy range 15-200 eV are merged co-linearly with the target ions over a distance of 50 cm, and the absolute photoionization cross-section is determined from the resulting photoion yield with a typical accuracy of 10%. Different types of ion sources are available, thus permitting a large number of positive and negative, atomic and molecular, singly- and multiply-charged ions to be investigated. Emphasis is put on accurate determination of the absolute cross-sections, requiring calibration of photodiode and particle detectors together with measurements of the photon-ion overlap

  2. Absolute fluence measurement for a prototype neutron radiotherapy source

    International Nuclear Information System (INIS)

    An inexpensive recoil-proton counter telescope has been designed for absolute fluence measurements of a gas-target neutron source for radiation therapy. The detector has an absolute efficiency of 1.1times10-9 at 20 cm from an isotropic source and is useful for production rates of 109--1013 neutrons per second. The telescope consists of a thin hydrogenous irradiator foil and a surface-barrier detector to count recoil protons within a defined solid angle. The telescope provides n-? discrimination as well as discrimination against scattered neutrons. Initial tests of the counter telescope were performed using the DD reaction employed in development stages of the gas target. A clear separation of full-energy recoil protons from background and scattered neutron events was evident in the pulse-height spectra without the use of coincidence gating techniques

  3. Absolute Measurement of Quantum-Limited Interferometric Displacements

    CERN Document Server

    Thiel, Valérian; Treps, Nicolas; Roslund, Jonathan

    2016-01-01

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

  4. 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)

  5. 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

  6. 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

  7. 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.)

  8. 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.

  9. 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)

  10. 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.

  11. Measurements of Absolute Hadronic Branching Fractions of the ?_{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 ?_{c}^{+} baryon at the ?_{c}^{+}?[over ¯]_{c}^{-} production threshold, in the 30 years since the ?_{c}^{+} discovery. In total, 12 Cabibbo-favored ?_{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 ?_{c}^{+} decay modes, the branching fraction for ?_{c}^{+}?pK^{-}?^{+} 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

  12. 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

  13. 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)

  14. 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)

  15. Full field imaging based instantaneous hyperspectral absolute refractive index measurement

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S [ORNL; Boudreaux, Philip R [ORNL

    2012-01-01

    Multispectral refractometers typically measure refractive index (RI) at discrete monochromatic wavelengths via a serial process. We report on the demonstration of a white light full field imaging based refractometer capable of instantaneous multispectral measurement of absolute RI of clear liquid/gel samples across the entire visible light spectrum. The broad optical bandwidth refractometer is capable of hyperspectral measurement of RI in the range 1.30 1.70 between 400nm 700nm with a maximum error of 0.0036 units (0.24% of actual) at 414nm for a = 1.50 sample. We present system design and calibration method details as well as results from a system validation sample.

  16. 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.

  17. Measurement of Absolute Acoustic Strain by Non-Contact Technique

    Science.gov (United States)

    Jayaraman, Subash; Pedrick, Michael; Tittmann, Bernhard

    2006-03-01

    Some ultrasonic applications require non-contact techniques because the target material is not easily accessible. In such cases laser-based and air-coupled ultrasonic techniques play a major role but commonly significant transmission loss is known to occur especially at higher frequencies. Therefore, it becomes imperative to know the amount of absolute acoustic strain achieved for a given application. In this paper, we report on the use of laser-based techniques to measure absolute strain on the face of vibrating rods excited under various scenarios. These include contact and air-coupled excitation at frequencies at resonance, as well as a factor of 100 below and above the resonance. The limit of our out-of-plane displacement measurement appears to be about 5 nanometers. Strains as high as 10-6 have been obtained. The paper will describe the details of the ultrasonic techniques and some of the applications. The data are compared to theoretical and simulated strain calculations.

  18. 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.

  19. Heat amount measuring method for radioactive waste

    International Nuclear Information System (INIS)

    The present invention provides a device for easily and accurately measuring the amount of heat generated from high level radioactive wastes generated upon reprocessing of spent fuels. Namely, radioactive wastes are contained in a measuring vessel formed by using thick-walled iron plates. Air is circulated in the measuring vessel. The temperatures of charged air and discharged air are measured. Then the amount of heat dissipated from the radioactive wastes and the amount of heat dissipated from the iron plates due to absorption of ?-rays to the iron plates are obtained based on the temperature difference. Accordingly, the amount of heat generated from the radioactive wastes can be measured accurately. In addition, there is provided an effect that the amount of heat generated from radioactive wastes can be measured by simple procedures of charging radioactive wastes in the measuring vessel and driving air circulation fans. (I.S.)

  20. 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)

  1. 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)

  2. Measured and modelled absolute gravity changes in Greenland

    DEFF Research Database (Denmark)

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

    2014-01-01

    In glaciated areas, the Earth is responding to the ongoing changes of the ice sheets, a response knownas glacial isostatic adjustment (GIA). GIA can be investigated through observations of gravity change.For the ongoing assessment of the ice sheets mass balance, where satellite data are used, the...... study ofGIA is important since it acts as an error source. GIA consists of three signals as seen by a gravimeter onthe surface of the Earth. These signals are investigated in this study. The ICE-5G ice history and recentlydeveloped ice models of present day changes are used to model the gravity change...... in Greenland. Theresult is compared with the initial measurements of absolute gravity (AG) change at selected GreenlandNetwork (GNET) sites.We find that observations are highly influenced by the direct attraction from the ice and ocean. Thisis especially evident in the measurements conducted at the...

  3. 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.

  4. 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.)

  5. 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)

  6. 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.)

  7. 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)

  8. Absolute interferometric distance measurement using a FM-demodulation technique

    Science.gov (United States)

    Fischer, Edgar; Dalhoff, Ernst; Heim, Silke; Hofbauer, Ulrich; Tiziani, Hans J.

    1995-09-01

    We propose an interferometric method for measuring absolute distances larger than the wavelength. A laser diode is used as a light source. The principle of operation is based on multiple-wavelength interferometry that uses a modulated light source. This method uses the fact that the wavelength of light emitted by the laser diode can be varied by means of the injection current. The modulation of the injection current in combination with the optical heterodyne technique causes a high-frequency phase-modulated detector signal. The phase deviation of the signal is a measure of the optical path difference in the interferometer. By FM demodulation of the detector output with a phase-locked loop demodulator, the optical path difference can be determined directly without the classical ambiguity problem of interferometry. The measuring range in the experiments was limited to 50 mm by the maximum travel range of the used specimen translation stage. Because of the inherent light sensitivity of the method described, the rangefinder can be used for three-dimensional profile measurements on a wide variety of objects, even on diffuse scattering surfaces.

  9. Measured and modelled absolute gravity changes in Greenland

    DEFF Research Database (Denmark)

    Nielsen, Jens Emil; Forsberg, René

    2014-01-01

    In glaciated areas, the Earth is responding to the ongoing changes of the ice sheets, a response knownas glacial isostatic adjustment (GIA). GIA can be investigated through observations of gravity change.For the ongoing assessment of the ice sheets mass balance, where satellite data are used, the study ofGIA is important since it acts as an error source. GIA consists of three signals as seen by a gravimeter onthe surface of the Earth. These signals are investigated in this study. The ICE-5G ice history and recentlydeveloped ice models of present day changes are used to model the gravity change in Greenland. Theresult is compared with the initial measurements of absolute gravity (AG) change at selected GreenlandNetwork (GNET) sites.We find that observations are highly influenced by the direct attraction from the ice and ocean. Thisis especially evident in the measurements conducted at the GNET station near the Helheim Glacier.The effect of the direct attraction diminishes at sites that are more than one degreefrom the source.Here, the dominant signal is the effect of the elastic signal from present day ice mass changes. We findagreement between the measured and modelled gravity changes at all but one site. This agreement onlyholds when the direct attraction is considered. For one site, there is no agreement, indicating that someimprovements to the modelling results or the processing of the gravity data are needed. In addition, moreAG measurements are needed to strengthen the time series of gravity change.

  10. 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.

  11. 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

  12. 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

  13. 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}.

  14. Measuring the absolute quantum efficiency of luminescent materials

    International Nuclear Information System (INIS)

    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 (5x10-3 M in 0.1 N H2SO4), 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 ?6 mm2

  15. Different Kinds of DIF: A Distinction between Absolute and Relative Forms of Measurement Invariance and Bias

    Science.gov (United States)

    Borsboom, Denny; Mellenbergh, Gideon J.; Van Heerden, Jaap

    2002-01-01

    In this article, a distinction is made between absolute and relative measurement. Absolute measurement refers to the measurement of traits on a group-invariant scale, and relative measurement refers to the within-group measurement of traits, where the scale of measurement is expressed in terms of the within-group position on a trait. Relative…

  16. ATLAS ALFA—measuring absolute luminosity with scintillating fibres

    CERN Document Server

    Franz, S

    2009-01-01

    ALFA is a high-precision scintillating fibre tracking detector under construction for the absolute determination of the LHC luminosity at the ATLAS interaction point. This detector, mounted in so-called Roman Pots, will track protons elastically scattered under ?rad angles at IP1.In total there are four pairs of vertically arranged detector modules which approach the LHC beam axis to mm distance. Each detector module consists of ten layers of two times 64 scintillating fibres each (U and V planes). The fibres are coupled to 64 channels Multi-Anodes PhotoMultipliers Tubes read out by compact front-end electronics. Each detector module is complemented by so-called overlap detectors: Three layers of two times 30 scintillating fibres which will be used to measure the relative positioning of two vertically arranged main detectors. The total number of channels is about 15000. Conventional plastic scintillator tiles are mounted in front of the fibre detectors and will serve as trigger counter. The extremely restric...

  17. 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.

  18. 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)

  19. Model YZ-1 radioactive contamination measuring meter

    International Nuclear Information System (INIS)

    This paper introduces an instrument for measuring the radioactive contamination. Some home-made CMOS integrated circuits were adopted in the instrument. It provides a six-digit display. Its highest counting rate is 106/sec. It can work on AC or DC voltage and its working current is less than 72 mA. It is a protable instrument and can be used in laboratories to measure radioactivity of the samples

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

    DEFF Research Database (Denmark)

    Bjørn, Anders; Margni, Manuele; Roy, Pierre-Olivier; Bulle, Cécile; Hauschild, Michael Zwicky

    2016-01-01

    ) can potentially reduce or eliminate these shortcomings. We developed a generic mathematical framework for the use of carrying capacity as environmental sustainability reference in spatially resolved life cycle impact assessment models and applied this framework to the LCA impact category terrestrial...... sustainable are therefore increasingly important. Such absolute indicators exist, but suffer from shortcomings such as incomplete coverage of environmental issues, varying data quality and varying or insufficient spatial resolution. The purpose of this article is to demonstrate that life cycle assessment (LCA...... supporting decisions aimed at simultaneously reducing environmental impacts efficiently and maintaining or achieving environmental sustainability. We have demonstrated that LCA indicators can be modified from being relative to being absolute indicators of environmental sustainability. Further research should...

  1. 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)

  2. 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

  3. 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)

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

    Scientific Electronic Library Online (English)

    M., Talavera O.; M., López R.; E., de Carlos L.; S., Jiménez S.

    2007-10-01

    Full Text Available Una Trampa Magneto-Óptica (MOT) de Cs-133 se ha desarrollado en la División de Tiempo y Frecuencia del Centro Nacional de Metrología, CENAM, en Mexico. Esta MOT es parte de un patrón primario de frecuencia basado en átomos ultra fríos de Cs, llamado reloj CsF-1 que se encuentra en desarrollo en el C [...] ENAM. En esta MOT de Cs, se emplea la configuracion estándar (?+ - ?-) de 4 haces laser horizontales y 2 verticales de 1.9 cm de diametro con 5 mW de potencia cada uno. Se utiliza un láser DBR de 852 nm y 5 mW como láser maestro estabilizado por espectroscopia de saturación. El ancho de línea de emision del láser maestro es de 1 MHz. Para amplificar la luz del láser maestro, se emplea un laser esclavo de AlGaAs de 852 nm y 50 mW de potencia. Este láser esclavo es estabilizado por la técnica de inyección de luz. Se realiza un corrimiento de la luz al rojo de 12 MHz por un doble paso a través de dos Moduladores Acusto-Ópticos (AOMs). La parte óptica de la MOT del CENAM es muy robusta contra la vibracion mecánica, el ruido acústico 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 línea. En este trabajo se reportan los resultados de la caracterizacion de la MOT como una función de varios parámetros de operación tales como: intensidad y diámetro de los haces láser, corrimiento al rojo de la luz y el gradiente de campo magnético. También se reportan mediciones absolutas del número de átomos de Cs atrapados en la MOT. Se encontraron mas de 6 x 10(7) atomos de Cs atrapados, medidos con una incertidumbre que en ningún 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 Metrología, 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%.

  5. 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 4?? 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)

  6. 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)

  7. 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)

  8. 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)

  9. Radioactive Beam Measurements to Probe Stellar Explosions

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Michael Scott [ORNL

    2010-01-01

    Unique beams of unstable nuclei from the Holi eld Radioactive Ion Beam Facility at Oak Ridge National Laboratory are being used to measure the thermonuclear reactions that occur in novae, X-ray bursts, and supernovae. The astrophysical impact of these measurements is determined by synergistic nuclear data evaluations and element synthesis calculations. Results of recent measurements and explosion simulations are brie y described, along with future plans and software research tools for the community.

  10. 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)

  11. Radioactivity measurements on live Bewick's Swans

    International Nuclear Information System (INIS)

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

  12. 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

  13. 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.

  14. Nondestructive measurement of environmental radioactive strontium

    Science.gov (United States)

    Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Totsuka, Yumi; Murata, Jiro

    2014-03-01

    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.

  15. Nondestructive measurement of environmental radioactive strontium

    OpenAIRE

    Saiba Shuntaro; Okamiya Tomohiro; Tanaka Saki; Tanuma Ryosuke; Totsuka Yumi; Murata Jiro

    2014-01-01

    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 nee...

  16. 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

  17. 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)

  18. 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.)

  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. 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.

  1. A double fission chamber for absolute fission rate measurements in power reactor environments

    International Nuclear Information System (INIS)

    A prototype fission chamber has been extensively tested and several chambers assembled in preparation for the Fast Flux Test Facility - Reactor Characterization Program (FFTF - RCP). The major portion of our report concerns the chamber design and performance characteristics. The absolute efficiency of the device will not be explicitly discussed. In ruggedizing the chamber, great care has been taken not to significantly alter the absolute efficiency as compared to the more conventional NBS configuration. This configuration and the measurement of absolute fission rates have already been rigorously discussed in an earlier report. The FFTF characterization effort will be reported in a future paper after the measurements have been completed

  2. 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

  3. 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.

  4. Measurement of the absolute gas gain and gain variations study in straw-tube detectors

    International Nuclear Information System (INIS)

    We present the results of the absolute gas gain measurement of a straw drift-tube filled with a binary gaseous mixture Ar-CO2(90-10) at 2 bar absolute pressure. The measurement has been performed using an intense 1.3 GBq 137Cs-source producing the primary ionization current. The results, as a function of the high voltage and gas parameters, were fitted and parameterized with a Diethorn's formula

  5. 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.

  6. 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)

  7. 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.)

  8. 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.)

  9. 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

  10. 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

  11. 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) ECMpeak±1762MeV. 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) ECMpeak±1762MeV. 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

  12. An Absolute Index (Ab-index) to Measure a Researcher’s Useful Contributions and Productivity

    OpenAIRE

    Biswal, Akshaya Kumar

    2013-01-01

    Bibliographic analysis has been a very powerful tool in evaluating the effective contributions of a researcher and determining his/her future research potential. The lack of an absolute quantification of the author’s scientific contributions by the existing measurement system hampers the decision-making process. In this paper, a new metric system, Absolute index (Ab-index), has been proposed that allows a more objective comparison of the contributions of a researcher. The Ab-index takes into ...

  13. 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)

  14. 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

  15. 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.)

  16. Groundwater measurements by means of radioactive tracers

    Energy Technology Data Exchange (ETDEWEB)

    Drost, W.

    1986-01-01

    Groundwater tracing by multi- and single-well techniques by means of well selected radioactive tracers, which have several advantages over conventional tracers, includes measurement of transport parameters of groundwater flow in saturated rock as well as moisture movement in the unsatured zone. Multi-well techniques give information on the spatial and temporal tracer distribution over a given distance, and tracer evolution at a given point is measured by single-well techniques. While field methods for the evaluation of groundwater flow by convection and of an aquifer's transmissivity are widely useful, the process of hydrodynamic dispersion in subsurface flow demands better understanding. (orig.).

  17. 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 ?L microtube was put in the ScintiVial, and was measured with a liquid scintillation counter. Samples including 200-800 Bq of 32P in 25-1300 ?L of solution and 900 Bq of 125I in 100 ?L solution were measured using the ScintiVial. Results and Discussion: The counting efficiency for 25-1300 ?L of 32P was 28-10%, and that for 100 ?L 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.

  18. 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

  19. 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.

  20. 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

  1. 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)

  2. 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.

  3. 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)

  4. 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...

  5. 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...

  6. 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

  7. 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.

  8. 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

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

    OpenAIRE

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

    2013-01-01

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

  10. 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)

  11. 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)

  12. 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)

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

    International Nuclear Information System (INIS)

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

  14. Measurement of absolute intensity of weak magnetic fields using rf biased SQUID

    International Nuclear Information System (INIS)

    A method to measure the absolute intensity of a weak magnetic field is described. A superconducting material was used as a sensor and the magnetization change was detected between the superconducting state and the normal state at the transition temperature. The magnetization change measured by a SQUID system was found to be proportional to the component of the absolute intensity of the magnetic field at the superconductor specimen parallel with the axis of the astatic pick up coils. A resolution of 10-5Oe was obtained. The practical limit of the resolution of this method is also discussed. (author)

  15. Direct frequency comb measurements of absolute optical frequencies and population transfer dynamics

    OpenAIRE

    Marian, Adela; Stowe, Matthew C.; Felinto, Daniel; Ye, * Jun

    2005-01-01

    A phase-stabilized femtosecond laser comb is directly used for high-resolution spectroscopy and absolute optical frequency measurements of one- and two-photon transitions in laser-cooled \\rb atoms. Absolute atomic transition frequencies, such as the 5S$_{1/2}$ F=2 \\ra 7S$_{1/2}$ F"=2 two-photon resonance measured at 788 794 768 921(44) kHz, are determined without \\textit{a priori} knowledge about their values. Detailed dynamics of population transfer driven by a sequence of ...

  16. Radioactive Measurements for KamLAND

    Science.gov (United States)

    Djurcic, Zelimir; Piepke, Andreas

    2000-11-01

    KamLAND will be the largest low-energy anti-neutrino detector ever built. It will study a wide range of science including particle physics, geophysics and astrophysics. Main objective of the project is to search for neutrino oscillations in disappearance mode by studying the flux and energy spectrum of anti-neutrinos produced by Japanese commercial nuclear reactors. The detector is exposed to low-energy anti-neutrinos coming from 16 commercial nuclear power stations, 150-200 km away from the experimental site. The extraordinary beseline and low anti-neutrino energies give us the possibility, for the first time, to access the large mixing angle solution of the solar neutrino problem in a terrestrial experiment and therefore provide a solar model independent test for neutrino oscillations. The quality of these measurements will depend on the extent to which the radioactive contamination, and hence the background, can be controlled. We expect the background to be dominated by the internal radioactivity of the scintillator. Goal of our project is to verify that the liquid scintillator has a purity level of 10-10 and 10-14 g/g in K and U/Th as required to carry out KamLAND's reactor neutrino program. We are working on a developement of a Neutron Activation Analysis to provide such test. Result and status of the project will be discussed.

  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. 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)

  19. 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 ? gridded ion chamber. The results an their uncertainties for both instruments are discussed. (Author)

  20. 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.

  1. 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.

  2. 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.)

  3. New absolute distance measurement technique with a self-mixing interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Guo Dongmei; Wang Ming [JiangSu Key Lab on opto-electronic Technology, School of Physical Science and Technology, Nanjing Normal University, 210097, Nanjing (China)

    2007-07-15

    A new compact self-aligned noncontact range finder is described. It uses the self-mixing effect inside a laser diode. Double modulation technique is proposed to improve the measurement accuracy. Wavelength modulation (WM) of the laser beam is obtained by modulating the injection current of the laser diode. Phase modulation (PM) of the laser beam is obtained by an electro-optic crystal (EOC) in the external cavity. Absolute distance of the external target is determined by Fourier analysis method. Experimental results show that an accuracy of {+-}0.3mm can be achieved for absolute distance ranging from 277mm to 477mm.

  4. 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

  5. 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)

  6. Absolute Wavelength Calibration of the IDSII Spectrometer for Impurity Ion Velocity Measurements in the MST

    Science.gov (United States)

    Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; MST Team

    2014-10-01

    The MST operates two Ion Doppler Spectrometers (IDS) for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometers record data within 0.3 nm of the line of interest, and commercial calibration lamps do not produce lines in this narrow range . Four calibration methods were investigated. First, emission along the chord bisecting the poloidal plane was measured as it should have no time-averaged Doppler shift. Second, a calibrated CCD spectrometer and the IDSII were used to observe the same plasma from opposing sides so as to measure opposite Doppler shifts. The unshifted line is located halfway between the two opposing measurements. Third, the two fibers of the IDSI were positioned to take absolute flow measurements using opposing views. Substituting the IDSII for one of the IDSI fibers, absolute measurements of flow from the IDSI were used to calibrate the IDSII. Finally, an optical system was designed to filter an ultraviolet LED, providing a known wavelength source within the spectral range covered by the IDSII. The optical train is composed of an air-gapped etalon and fused silica lenses. The quality of calibration for each of these methods is analyzed and their results compared. Preliminary impurity ion velocity measurements are shown. This work has been supported by the US DOE and the NSF.

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ave, M. [University of Chicago, Enrico Fermi Institute, 5640 S Ellis Ave., Chicago, IL 60637 (United States); Bohacova, M. [Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-18221 Praha 8 (Czech Republic)], E-mail: bohacova@fzu.cz; Buonomo, B. [Laboratori Nazionali di Frascati dell' INFN, INFN, Sezione di Frascati, Via Enrico Fermi 40, Frascati, Rome 00044 (Italy); Busca, N.; Cazon, L. [University of Chicago, Enrico Fermi Institute, 5640 S Ellis Ave., Chicago, IL 60637 (United States); Chemerisov, S.D.; Conde, M.E.; Crowell, R.A. [Argonne National Laboratory, Argonne, IL 60439 (United States); Di Carlo, P. [Dipartimento di Fisica dell' Universita de l' Aquila and INFN, Via Vetoio, I-67010 Coppito, Aquila (Italy); Di Giulio, C. [Dipartimento di Fisica dell' Universita di Roma Tor Vergata and Sezione INFN, Via della Ricerca Scientifica, I-00133 Rma (Italy); Doubrava, M. [Czech Technical University, Technicka 4, 16607 Praha 6 (Czech Republic); Esposito, A. [Laboratori Nazionali di Frascati dell' INFN, INFN, Sezione di Frascati, Via Enrico Fermi 40, Frascati, Rome 00044 (Italy); Facal, P. [Departmento de Fi' sica de Parti' culas, Campus Sur, Universidad, E-15782, Santiago de Compostela (Spain); Franchini, F.J. [Argonne National Laboratory, Argonne, IL 60439 (United States); Hoerandel, J.R. [Universitaet Karlsruhe (Thailand), Institut fuer Experimentelle Kernphysik (IEKP), Postfach 6980, D-76128 Karlsruhe (Germany); Hrabovsky, M. [Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-18221 Praha 8 (Czech Republic); Iarlori, M. [Dipartimento di Fisica dell' Universita de l' Aquila and INFN, Via Vetoio, I-67010 Coppito, Aquila (Italy); Kasprzyk, T.E. [Argonne National Laboratory, Argonne, IL 60439 (United States); Keilhauer, B. [Universitaet Karlsruhe (Thailand), Institut fuer Experimentelle Kernphysik (IEKP), Postfach 6980, D-76128 Karlsruhe (Germany)] (and others)

    2008-11-21

    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 Cherenkov 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.

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

    International Nuclear Information System (INIS)

    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 Cherenkov 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.

  10. 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.

  11. Radioactivity measurements applied to glaciers and lake sediments

    International Nuclear Information System (INIS)

    The behaviour of glaciers, polar ice-caps and lakes can be studied by means of natural and artificial radioactivity measurements conducted on snow (Alps, Arctic and Antarctic) and sediments samples. The nuclear decay of elements (210Pb and 238U filiation products) and nuclear events (atmospheric thermonuclear tests: 1954 and 1962-63; Chernobyl accident: 1986) allow an absolute dating of corresponding layers. These determinations need radiochemical separations (electro-plating, ion exchange filters), followed by ultra low level alpha and gamma spectrometries, or beta counting (137Cs, 90Sr). The high purity - N type - germanium detector (Compton-suppressed) allows the 210Pb analysis at 46.52 keV, enabling a direct comparison with 210Po alpha spectrometry. Typical applications concern primarily dating, and the determination of mean annual accumulation rates of glaciers, sedimentation rate and mixing time in lakes, with their associated spatio-temporal variations. These measurements give access to the global fallouts of radionuclides and to meteorological parameters: air to snow (or sediment) transfer, deposition processes and atmospheric circulation

  12. White-light scanning interferometer for absolute nano-scale gap thickness measurement

    OpenAIRE

    Xu, Zhiguang; Shilpiekandula, Vijay; Youcef-toumi, Kamal; Yoon, Soon Fatt

    2009-01-01

    A special configuration of white-light scanning interferometer is described for measuring the absolute air gap thickness between two planar plates brought into close proximity. The measured gap is not located in any interference arm of the interferometer, but acts as an amplitude-and-phase modulator of the light source. Compared with the common white-light interferometer our approach avoids the influence of the chromatic dispersion of the planar plates on the gap thickness quantification. It ...

  13. Production and trapping of carbon clusters for absolute mass measurements at ISOLTRAP

    CERN Document Server

    Scheidenberger, C; Herfurth, F; Kellerbauer, A G; Kluge, H J; Koizumi, M; Schwarz, S; Schweikhard, L

    2002-01-01

    Singly-charged carbon clusters C/sub n//sup +/ (n >or= 1) have been produced by laser-induced desorption and fragmentation of C/sub 60/ fullerenes and have been injected into and stored in the Penning trap system of the ISOLTRAP mass spectrometer at ISOLDE/CERN. The present study is the first step to extend the until now direct mass measurements at ISOLTRAP to absolute mass measurements by using clusters of /sup 12/C. (10 refs).

  14. Absolute equation of state measurements of iron using laser driven shocks

    International Nuclear Information System (INIS)

    First absolute equation of state measurements obtained for iron with laser driven shock waves are presented. The shock velocity and the free surface velocity of compressed iron have been simultaneously measured by using a VISAR diagnostic, and step targets. The pressure range 1-8 Mbar has been investigated, which is directly relevant to planetary physics. The experiments have been performed at the Laboratoire pour l'Utilisation des Lasers Intenses of the Ecole Polytechnique

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

    OpenAIRE

    Keihänen, Elina; Reinecke, Martin

    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...

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

    International Nuclear Information System (INIS)

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

  17. 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.

  18. Radioactivity measurements using storage phosphor technology

    International Nuclear Information System (INIS)

    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 (>105), 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 ?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 cm2 or a beta activity of 0.1 dpm/mm2 or gamma radiation of few ?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/cm2s 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 exposureclose quotes time for mapping radioactivity in an environmental sample may be in terms of minutes and offer a positional resolution not obtainable with presently used counting equipment. The resultant digital image will lend itself to ready analysis

  19. 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)

  20. A novel absolute measurement for the low-frequency figure correction of aspheric surfaces

    Science.gov (United States)

    Lin, Wei-Cheng; Chang, Shenq-Tsong; Ho, Cheng-Fang; Kuo, Ching-Hsiang; Chung, Chien-Kai; Hsu, Wei-Yao; Tseng, Shih-Feng; Sung, Cheng-Kuo

    2015-07-01

    This study proposes an absolute measurement method with a computer-generated hologram (CGHs) to assist the identification of manufacturing form error, and gravity and mounting resulted distortions for a 300 mm aspherical mirror. This method adopts the frequency of peaks and valleys of each Zernike coefficient grabbed by the measurement with various orientations of the mirror in horizontal optical-axis configuration. In addition, the rotational-symmetric aberration (spherical aberration) is calibrated with random ball test method. According to the measured absolute surface figure, a high accuracy aspherical surface with peak to valley (P-V) value of 1/8 wave @ 632.8 nm was fabricated after surface figure correction with the reconstructed error map.

  1. Measurement of absolute Al concentration in AlxGa1-xAs

    International Nuclear Information System (INIS)

    A technique has been developed to measure the absolute Al concentration x in AlxGa1-xAs. The technique involves simultaneous measurements of the 27Al(p,?)28Si resonant nuclear reaction and Rutherford backscattering (RBS), and comparisons with an AlAs reference sample. A detailed description of the experimental procedure is given. Samples analyzed in this study were prepared by LPE and MOVPE growth on GaAs substrates, with expitaxial layer thicknesses in the range 1-3 ?m and Al concentrations in the range 0.10< x<0.85. Measurements of x with an absolute error <0.02 were obtained. Factors limiting the precision obtainable with this technique are discussed. (orig.)

  2. 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].

  3. Proposal for absolute CEP measurement using 0-to-f self-referencing

    CERN Document Server

    Radnor, S B P; New, G H C

    2009-01-01

    We show how to adapt a 0-f self-referencing technique to provide a single shot absolute Carrier Envelope Phase (CEP) measurement by using the CEP reference provided by difference frequency generation (DFG) between the spectral wings of the fundamental pulse. Usually, the beat between the input pulse and the DFG signal then provides feedback with which to stabilize the CEP slip in a pulse train. However, with a simple extension we can get a single shot absolute CEP measurement. Success relies on having well characterized input pulses, and the use of accurate propagation models through the nonlinear crystal -- these enable us to construct a mapping between the experimental measurement and the CEP of the optical pulse.

  4. Methods of measuring radioactivity in the environment

    Science.gov (United States)

    Isaksson, Mats

    In this thesis a variety of sampling methods have been utilised to assess the amount of deposited activity, mainly of 137Cs, from the Chernobyl accident and from the 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, brought to southern Sweden by the weather systems. The resulting deposition and its removal from urban areas was than studied through measurements on sewage sludge and water. The main part of the thesis considers methods of determining the amount of radiocaesium in the ground through soil sampling. In connection with soil sampling a method of optimising the sampling procedure has been developed and tested in the areas of Sweden which have a comparatively high amount of 137Cs from the Chernobyl accident. This method was then used in a survey of the activity in soil in Lund and Skane, divided between nuclear weapons fallout and fallout from the Chernobyl accident. By comparing the results from this survey with deposition calculated from precipitation measurements it was found possible to predict the deposition pattern over Skane for both nuclear weapons fallout and fallout from the Chernobyl accident. In addition, the vertical distribution of 137Cs has been modelled and the temporal variation of the depth distribution has been described.

  5. 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

  6. 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.

  7. The measurement of the radioactive materials in food

    International Nuclear Information System (INIS)

    Since food contained radioactive materials released from Fukushima Daiichi nuclear power station accident initiated by Great East Japan earthquake disaster, new reference values of radioactive materials corresponding to 1 mSv/year was set up in April 2012 based on food hygiene law so as to ensure food safety and security for the people. As the request of development of continuous measurement of radioactive materials in food as it is with satisfying this criteria, continuous radioactive cesium measuring device had been developed for screening radioactive materials in food with measurement lower limit of 25 Bq/kg corresponding one fourth of new reference values. The device used CsI detector with CsI scintillator and Si photodiode (multi-pixel photo counter) combined. This article described outlines of the device, measurement examples (powdered food, powdered milk and tea leaves) and future perspective of device development (position sensitive detection of radioactive materials in complex shape food). (T. Tanaka)

  8. Infrastructure development of radiation measurement system for illicit radioactive materials

    International Nuclear Information System (INIS)

    On NORM (Naturally Occurring Radioactive Material) and export/import goods including the small radioactive material, it is also required for public that the level of the radiation safety and reassuring is raised to use the radiation measurement or the identification of radioactive material. Furthermore, it becomes in the age of which the necessity of radioactive material identification of the unidentified packing is strongly obtained in order to previously prevent nuclear-terrorism and dirty bomb. In NUSTEC, Infrastructure development of radiation measurement system for illicit use of radioactive materials is promoted using of the experience in measuring technique and gamma-ray spectrum measuring instrument (semiconductor detector, etc.) regulated at ISO22188 in the case of receiving a request from the government, local fire service and police. In this paper, improvement situation of the radioactive material detection equipment in our center is described. (author)

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

    Science.gov (United States)

    Mühlig, Christian; Kufert, Siegfried; Bublitz, Simon; Speck, Uwe

    2011-03-20

    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. PMID:21460979

  10. A system and methodologies for absolute QE measurements from the vacuum ultraviolet through the NIR

    CERN Document Server

    Jacquot, Blake C; Hoenk, Michael E; Greer, Frank; Jones, Todd J; Nikzad, Shouleh

    2011-01-01

    In this paper we present our system design and methodology for making absolute quantum efficiency (QE) measurements through the vacuum ultraviolet (VUV) and verify the system with delta-doped silicon CCDs. Delta-doped detectors provide an excellent platform to validate measurements through the VUV due to their enhanced UV response. The requirements for measuring QE through the VUV are more strenuous than measurements in the near UV and necessitate, among other things, the use of a vacuum monochromator, good dewar chamber vacuum to prevent on-chip condensation, and more stringent handling requirements.

  11. 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 ?m 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.

  12. 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)

  13. 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.

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

    International Nuclear Information System (INIS)

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

  15. 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

  16. 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 2? 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

  17. 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

  18. 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

  19. A measurement of the absolute flux of cosmic-ray electrons

    Science.gov (United States)

    Golden, R. L.; Mauger, B. G.; Badhwar, G. D.; Daniel, R. R.; Lacy, J. L.; Stephens, S. A.; Zipse, J. E.

    1984-01-01

    A balloon-borne superconducting magnet spectrometer was used to measure the absolute flux of cosmic-ray electrons. The instrument consisted of a gas Cerenkov detector, a momentum spectrometer, and a lead-scintillator shower counter. In order to determine electron flux in the interstellar medium, observed fluxes for energy loss in the atmosphere and the payload were corrected, taking into account solar modulation effects and bremsstrahlung energy losses. Fluxes were measured at an average atmospheric depth of 5.8 g/sq cm, and the solar modulation was 300 MeV. A cosmic-ray electron flux of 367 E to the exp(3.15 + or -0.2) per sq m/sr s GeV was obtained in the energy range 4.5-63.5 GeV. The uncertainty of the absolute (electron-positron) flux was 10 percent. A summary of the electron data is given in a table.

  20. 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)

  1. 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)

  2. Absolute energy measurement of heavy ion beams using a resonant time-of-flight system

    International Nuclear Information System (INIS)

    A resonant time-of-flight measurement system has been put into operation at the ATLAS facility for the determination of the energy of heavy ion beams. The system provides continuous, nondestructive monitoring of the beam energy. The system provides relative energy determination with a precision of ?E/E ? 10-4. Absolute energy is determined to an accuracy of 10-3. A variety of beam tests have been performed to study the properties of the system. (orig.)

  3. 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.

  4. 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.

  5. ABSOLUTE BUNCH LENGTH MEASUREMENTS AT THE ALS BY INCOHERENT SYNCHROTRON 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 tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented

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

    OpenAIRE

    AIRFLY Collaboration; Ave, M.; Bohá?ová, M.; Daumiller, K.; Di Carlo, P.; C. Di Giulio; Luis, P. Facal San; Gonzales, D.; Hojvat, C.; Hörandel, J. R.; Hrabovský, M.; Iarlori, M.; B. Keilhauer; Klages, H.; Kleifges, M.

    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.

  7. Absolute Bunch Length Measurements at the ALS by Incoherent Synchrotron Radiation Fluctuation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Filippetto, D.; /Frascati; Sannibale, F.; Zolotorev, Max Samuil; /LBL, Berkeley; Stupakov, G.V.; /SLAC

    2008-01-24

    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 tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented.

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

    CERN Document Server

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

    2015-01-01

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

  9. Precise measurement of the absolute yield of fluorescence photons in atmospheric gases

    Energy Technology Data Exchange (ETDEWEB)

    Ave, M. [Karlsruhe Institute of Technology, IK, Postfach 6980, D - 76021 Karlsruhe (Germany); Bohacova, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Daumiller, K. [Karlsruhe Institute of Technology, IK, Postfach 6980, D - 76021 Karlsruhe (Germany); Di Carlo, P. [Dipartimento di Fisica dell' Universita de l' Aquila and INFN, Via Vetoio, I-67010 Coppito, Aquila (Italy); Di Giulio, C. [Dipartimento di Fisica dell' Universita di Roma Tor Vergata and Sezione INFN, Via della Ricerca Scientifica, I-00133 Roma (Italy); Facal San Luis, Pedro, E-mail: facal@kicp.uchicago.edu [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Gonzales, D. [Karlsruhe Institute of Technology, IEKP, Postfach 3640, D - 76021 Karlsruhe (Germany); Hojvat, C. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Hoerandel, J.R. [IMAPP, Radboud University Nijmegen, 6500 GL Nijmegen (Netherlands); Hrabovsky, M. [Palacky University, RCATM, Olomuc (Czech Republic); Iarlori, M. [Dipartimento di Fisica dell' Universita de l' Aquila and INFN, Via Vetoio, I-67010 Coppito, Aquila (Italy); Keilhauer, B.; Klages, H. [Karlsruhe Institute of Technology, IK, Postfach 6980, D - 76021 Karlsruhe (Germany); Kleifges, M. [Karlsruhe Institute of Technology, IPE, Postfach 3640, D - 76021 Karlsruhe (Germany); Kuehn, F. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Monasor, M. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States); Nozka, L.; Palatka, M. [Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic)

    2011-03-15

    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.

  10. 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)

  11. Measurement of Absolute Arterial Cerebral Blood Volume in Human Brain Without Using a Contrast Agent

    OpenAIRE

    Hua, Jun; QIN, Qin; Pekar, James J.; Van Zijl, Peter C.M.

    2011-01-01

    Arterial cerebral blood volume (CBVa) is a vital indicator of tissue perfusion and vascular reactivity. We extended the recently developed inflow vascular-space-occupancy (iVASO) MRI technique, which uses spatially selective inversion to suppress the signal from blood flowing into a slice, with a control scan to measure absolute CBVa using CSF for signal normalization. Images were acquired at multiple blood nulling times to account for the heterogeneity of arterial transit times across the br...

  12. 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.

  13. 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

  14. 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

  15. Measurement of the Absolute np Scattering Differential Cross Section at 194 MeV

    CERN Document Server

    Sarsour, M; Planinic, M; Vigdor, S E; Allgower, C; Bergenwall, B; Blomgren, J; Hossbach, T; Jacobs, W W; Johansson, C; Klug, J; Klyachko, A V; Nadel-Turonski, P; Nilsson, L; Olsson, N; Pomp, S; Rapaport, J; Rinckel, T; Stephenson, E J; Tippawan, U; Wissink, S W; Zhou, Y

    2004-01-01

    We describe a double-scattering experiment with a novel tagged neutron beam to measure differential cross sections for np back-scattering to better than 2% absolute precision. The measurement focuses on angles and energies where the cross section magnitude and angle-dependence constrain the charged pion-nucleon coupling constant, but existing data show serious discrepancies among themselves and with energy-dependent partial wave analyses (PWA). The present results are in good accord with the PWA, but deviate systematically from other recent measurements.

  16. Radiative lifetimes, branching ratios and absolute transition probabilities of atomic uranium by delayed photoionization measurements

    Science.gov (United States)

    Mandal, P. K.; Das, R. C.; Seema, A. U.; Sahoo, A. C.; Shah, M. L.; Pulhani, A. K.; Manohar, K. G.; Dev, Vas

    2014-08-01

    Radiative lifetimes of ten even-parity energy levels of atomic uranium in the 15,500-19,000 cm-1 region and branching ratios of six transitions originating either from ground level (5L{6/o}) or from lowest metastable level (5K{5/o}) at 620.32 cm-1 are measured employing three-step delayed photoionization technique. The lifetimes of five energy levels and branching ratios of five transitions are measured for the first time. By combining the experimentally measured values of radiative lifetimes and branching ratios, we have determined the absolute transition probabilities of six transitions of uranium and compared with those previously reported in the literature.

  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. Measurement of the absolute energy scale of MINOS and background measurements in NEMO-3

    International Nuclear Information System (INIS)

    MINOS (Main Injector Neutrino Oscillation Search) is an experiment currently running in the US. A beam of neutrinos is created at Fermilab, Chicago, measured in the 1 kiloton 'Near Detector' and then travels 730 km to the 5 kiloton 'Far Detector' in the Soudan Mine, Minnesota. In the intervening time, it is hoped that some of these neutrinos will change from one flavor to another. If this is observed, it is strong evidence for neutrino oscillations, the parameters of which can be measured to 10%. The MINOS experiment is a large project with a huge number of technical issues. Many aspects of the experiment were tested several years before the main experiment itself began to run, by employing a scaled down version of the detectors, known as the Calibration Detector (CalDet). This was placed in a test-beam at CERN and extensively studied, the data from which is analyzed in this thesis. In this thesis, photomultiplier tube crosstalk is discussed, a phenomenon which generates false signals in the MINOS detectors. It is studied and an algorithm presented to enable its removal. Particle identification via various methods at CalDet is also described. Various pieces of hardware are available to assist with this, and a comparison is made to software techniques which are used at the larger MINOS detectors. A study of the CalDet beamline simulation is carried out and the discrepancies with data highlighted and explained. Finally, muon energy loss in CalDet is investigated. A comparison is made between published data and the observed data. NEMO-3 is an experiment that has been running for soe tie in the Frejus tunnel between France and italy. It is a 0??? experiment, hoping to show that the neutrino is a Majorana particle and set limits on its mass. This experiment, like every, has backgrounds. The dangerous background signals that arise from the radioactive decay of Uranium and Thorium are discussed in this thesis, specifically the measurement of the quantity of 208Tl and 214Bi in the source foils of the detector. This is achieved by using Monte Carlo simulations of the contaminants behavior in the detector, developing cuts on these events and applying them to the dataset.

  19. 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.)

  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. 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

  2. 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.

  3. 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

  4. International conventions for measuring radioactivity of building materials

    International Nuclear Information System (INIS)

    In buildings, whether civil or industrial, natural radioactivity always occurs at different degrees in the materials (main building materials, decorative materials). Concerns on radioactivity from building materials is unavoidable for human living and developing. As a member of WTO, China's measuring method of radioactivity for building materials, including radionuclides limitation for building materials, hazard evaluation system etc, should keep accordance with the international rules and conventions. (author)

  5. Measurement of the absolute cross section for multiphoton ionization of atomic hydrogen at 248 nm

    Energy Technology Data Exchange (ETDEWEB)

    Kyrala, G.A.; Nichols, T.D.

    1990-01-01

    We present measurements of the absolute rates for multiphoton ionization of the ground state from atomic hydrogen by a linearly polarized, subpicosecond KrF laser pulse at a wavelength of 248 nm. A laser crossed atomic beam technique is used. The irradiance was varied from 3{times}10{sup 12} w/cm{sup 2} to 2{times}10{sup 14} w/cm{sup 2} and three above threshold ionization peaks were observed. The measured rate for total electron production is less than predicted by the numerical and perturbation calculations, but significantly higher than calculated by the Reiss and Keldysh methods. 21 refs., 7 figs.

  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. Absolute photoionization cross-section measurements of the Kr I isoelectronic sequence

    International Nuclear Information System (INIS)

    Photoionization spectra have been recorded in the 4s, 4p, and 3d resonance regions for the Kr I isoelectronic sequence using both the dual laser produced plasma (DLP) technique (at DCU) to produce photoabsorption spectra, and the merged ion beam and synchrotron radiation technique (at ASTRID) to measure absolute photoionization cross sections. Profile parameters are compared for the 4s-np resonances of Rb+ and Sr2+. Many 4p?ns, md transitions are identified with the aid of Hartree-Fock calculations, and consistent quantum defects are observed for the various ns and md Rydberg series. Absolute single and double photoionization cross sections recorded in the 3d region for Rb+ and Sr2+ ions show preferential decay via double photoionization. This is only the second report to our knowledge where both the DLP technique and the merged-beam technique have been used simultaneously to record photoionization spectra, and the advantages of both techniques (i.e., better resolution in the case of DLP and values for absolute photoionization cross sections in the case of the merged-beam technique) are highlighted

  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. 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

  10. Progress towards absolute intensity measurements of emissions from high temperature thermographic phosphors

    International Nuclear Information System (INIS)

    Phosphor thermometry has been successfully used in a number of applications ranging from turbo-machinery, pyrolysis, supersonic and hypersonic studies in the past few decades. There are a number of issues related to high temperature, which include faster decays, decreasing emission intensity and increasing blackbody radiation. Although absolute lifetime decay values are readily available, there has been no known work presenting absolute intensity measurements throughout the phosphors operating temperature range. This additional information could help design engineers facilitate phosphor and instrument selection, optimise system setup, and help estimate the performance of the technique at higher temperatures, for any given optical setup. A number of well known high temperature thermographic phosphors were investigated including YAG:Tm, YAG:Tb and Y2O3:Eu from 20 oC in an excess of 1000 oC. Both 355 and 266 nm excitation wavelengths from a Q-switched Nd:YAG laser were used. The subsequent emissions were passed through a narrowband interference filter to isolate the peak emission wavelengths, and were collected using PMT. The methodology for an absolute measurement, which requires a sound understanding of the PMT, including solid angle, collection efficiency, dynode gain, calibration and electronic temporal response for intensity measurements is presented and discussed. The results clearly indicate a variation in phosphor intensity with an increasing temperature, which is considerably different amongst different phosphors under different excitation wavelengths. The combined standard uncertainty of measurement was estimated to be approximately ±10.7%. The existing system was able to monitor intensity values up to 900 oC for Mg3F2GeO4:Mn phosphors, 1100 oC for Y2O3:Eu, 1150 oC for YAG:Tb and up to 1400 oC for YAG:Tm thermographic phosphors. Y2O3:Eu using 266 nm excitation was found to exhibit the highest peak intensity per mJ of laser excitation from all the phosphors investigated at 20 oC. However, at high temperatures (900 oC+) YAG:Tm using 355 nm excitation was found to exhibit the highest peak intensity per mJ of an excitation energy. - Research highlights: ? A number of high temperature thermographic phosphors were investigated. ? Absolute measurement technique is used. ? Variation in intensity with increasing temperature of different phosphors is shown. ? Detected emissive power varied proportionally with the detectors collection area. ? Detected emissive power varied inversely proportional to the distance squared.

  11. Publication of measured values of radioactivity in food

    International Nuclear Information System (INIS)

    The radioactivity in food is recorded at 20 different measuring points in the Federal States, furthermore at one coordinating office of the Federal Government, and at a number of research institutes. Measurements are carried out permanently, particularly with regard to the relevant radionuclides such as Cesium 134 and Cesium 137. The measured values of the radioactive contamination in food are published by the Federal States for reasons of competence, and also by the Federal Government, in its summarizing reports ''Environmental radioactivity and radiation exposure.'' (orig./HSCH)

  12. 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 %.

  13. 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 ?-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)

  14. 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

  15. 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)

  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; Hänsch, 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. 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.

  18. Direct, Absolute, and In Situ Measurement of Fast Electron Transport via Cherenkov Emission

    International Nuclear Information System (INIS)

    We present direct measurements of the absolute energy distribution of relativistic electrons generated in intense, femtosecond laser interaction with a solid. Cherenkov emission radiated by these electrons in a novel prism target is spectrally dispersed to obtain yield and energy distribution of electrons simultaneously. A crucial advance is the observation of high density electron current as predicted by particle simulations and its transport as it happens inside the target. In addition, the strong sheath potential present at the rear side of the target is inferred from a comparison of the electron spectra derived from Cherenkov light observation with that from a magnet spectrometer.

  19. 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.; Di Giulio, C.; Luis, P. Facal San; Gonzales, D.; Hojvat, C.; Hörandel, 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_{s...

  20. 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)

  1. 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.

  2. 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.

  3. 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)

  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 Density Calibration Cell for Laser Induced Fluorescence Erosion Rate Measurements

    Science.gov (United States)

    Domonkos, Matthew T.; Stevens, Richard E.

    2001-01-01

    Flight qualification of ion thrusters typically requires testing on the order of 10,000 hours. Extensive knowledge of wear mechanisms and rates is necessary to establish design confidence prior to long duration tests. Consequently, real-time erosion rate measurements offer the potential both to reduce development costs and to enhance knowledge of the dependency of component wear on operating conditions. Several previous studies have used laser-induced fluorescence (LIF) to measure real-time, in situ erosion rates of ion thruster accelerator grids. Those studies provided only relative measurements of the erosion rate. In the present investigation, a molybdenum tube was resistively heated such that the evaporation rate yielded densities within the tube on the order of those expected from accelerator grid erosion. This work examines the suitability of the density cell as an absolute calibration source for LIF measurements, and the intrinsic error was evaluated.

  6. 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)

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

    Science.gov (United States)

    Schödel, R.

    2015-08-01

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

  8. 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.)

  9. Method of measuring radioactivity concentration in main steams

    International Nuclear Information System (INIS)

    Purpose: To determine the entire radioactivity dose rate and radioactivity dose rate of gamma-ray spectral peaks of C14, N16 at a certain position of reactor main steam pipes and the radioactivity concentration at a position other than above is calculated based thereon. Method: A radiation detector provided with a collimeter is disposed to main steam pipeways for guiding main steam pipes from the pressure vessel to the high pressure turbine in a nuclear reactor, and the output of the detector is connected to a data processing device. Radioactive doses for the respective nuclides are previously determined at a measuring position with standard C15 and N16 sources and a calibration curve is prepared. Radioactivity concentration for the respective nuclides are determined based on the total gamma ray dose rate from the main steams, the gamma-ray dose rate for C15, N16 and gamma-ray peaks for both of the nuclides. The total radioactivity concentration at the measuring position is calculated based on the thus determined values and the calibration curve. Further, the radioactivity concentration at the position other than the measured position can be determined based on the half-decay periods for both of the nuclides, the pipe length at the measured position/objective position and the main steam flow rate by calculation. (Kamimura, M.)

  10. Radioactivity measurements for the ERMES project at the STELLA facility

    Science.gov (United States)

    Laubenstein, M.; Plastino, W.; Aprili, P.; Balata, M.; Bella, F.; Gallese, B.; Ioannucci, L.; Nisi, S.

    2012-04-01

    STELLA (SubTErranean Low Level Assay) is the ultra low background facility of the Gran Sasso National Laboratories (L.N.G.S.) in Italy. It is mainly devoted to material screening and rare events physics due to its very low radioactive background. Nevertheless, also environmental samples are measured within the collaboration with the ERMES (Environmental Radioactivity Monitoring for Earth Sciences) project. After a short description of the facility some on-going applications within the ERMES project will be briefly presented. The usefulness of doing environmental radioactivity measurements in a deep underground laboratory will be shortly discussed.

  11. Radioactivity measurements for the ERMES project at the STELLA facility

    Directory of Open Access Journals (Sweden)

    Gallese B.

    2012-04-01

    Full Text Available STELLA (SubTErranean Low Level Assay is the ultra low background facility of the Gran Sasso National Laboratories (L.N.G.S. in Italy. It is mainly devoted to material screening and rare events physics due to its very low radioactive background. Nevertheless, also environmental samples are measured within the collaboration with the ERMES (Environmental Radioactivity Monitoring for Earth Sciences project. After a short description of the facility some on-going applications within the ERMES project will be briefly presented. The usefulness of doing environmental radioactivity measurements in a deep underground laboratory will be shortly discussed.

  12. PREMOS Absolute Radiometer Calibration and Implications to on-orbit Measurements of the Total Solar Irradiance

    Science.gov (United States)

    Fehlmann, A.; Kopp, G.; Schmutz, W. K.; Winkler, R.; Finsterle, W.; Fox, N.

    2011-12-01

    On orbit measurements starting in the late 1970's, have revealed the 11 year cycle of the Total Solar Irradiance (TSI). However, the absolute results from individual experiments differ although all instrument teams claim to measure an absolute value. Especially the data from the TIM/SORCE experiment confused the community as it measures 0.3 % lower than the other instruments, e.g. VIRGO/SOHO by PMOD/WRC, which clearly exceeds the uncertainty stated for the absolute characterization of the experiments. The PREMOS package on the PICARD platform launched in June 2010 is the latest space experiment by PMOD/WRC measuring the TSI. We have put great effort in the calibration and characterization of this instrument in order to resolve the inter-instrument differences. We performed calibrations at the National Physical Laboratory (NPL) in London and the Laboratory for Atmospheric and Space Physics (LASP) in Boulder against national SI standards for radiant power using a laser beam with a diameter being smaller than the aperture of the instrument. These measurements together with the World Radiometric Reference (WRR) calibration in Davos allowed to compare the WRR and the SI radiant power scale. We found that the WRR lies 0.18 % above the SI radiant power scale which explains a part of the VIRGO-TIM difference. The Total solar irradiance Radiometer Facility (TRF) at the LASP allows to generate a beam that over fills the apertures of our instruments, giving the presently best available representation of solar irradiance in a laboratory. These irradiance calibrations revealed a stray light contribution between 0.09 and 0.3 % to the measurements which had been underestimated in the characterization of our instruments. Using the irradiance calibrations, we found that the WRR lies 0.32 % above the TRF scale which in turn explains the full VIRGO-TIM difference. The first light PREMOS measurements in space confirmed our findings. If we use the WRR calibration, PREMOS yields a TSI value of 1365.5 ± 1.2 W/m2 (k=1) which is in excellent agreement with VIRGO (1365.4 W/m2). Else, applying the TRF calibration to PREMOS, we obtain a TSI value of 1360.9 ± 0.4 W/m2 (k=1) which is in excellent agreement with TIM (1361.3 W/m2).

  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. An absolute 3D measurement method using a 2D pattern based on digital moire

    Science.gov (United States)

    Liao, Jiarui

    With a remarkable evolution in the development of digital cameras, non-contact 3D measurement using computer vision has been rapidly developing in the past few decades. Excellent and well-accepted techniques include digital moire and stereo vision. An obvious drawback of digital moire is that it is not applicable to the measurement of significant discontinuities, which is common in this area of research. And in the process of measurement, error propagation is inevitable, especially under the condition of missing points. The reason for this shortcoming lies in its relative coding scheme. For stereo vision, it is based on triangulation which leads to an absolute measurement. However, correspondence searching and resolution limitation of measurement of lacking features are two of the major unsolved problems of stereo vision systems. Inspired by these two well-developed techniques, an absolute measuring method based on structured light is developed in this research, requiring only a camera and a projector. The philosophy behind the coding scheme is a hybrid of relativity to the center and absoluteness, or independence on every single point. The mathematical model of the system is described and theorems that relate to the guidance of designing such a system are introduced. Two important factors determine the accuracy of the 3D measurement: correspondence matching and calibration of the camera and the projector' parameters. For the correspondence matching, an image processing method is developed. Image subtraction, edge detection, grid permutation and establishment of sub-coordinate-systems are included in the algorithm. Aiming at the discontinuity measurement, discontinuous borders are marked out first by using a Gabor filter first. Epipolar geometry is then utilized in the process of searching out each corresponding points accurately on the image plane. Sub-pixel accuracy for correspondence matching can be achieved in this way. The second factor that affects the accuracy of the measurement system is concerned with the calibration of the whole system. A convenient calibration method for structured light systems is developed in this research. This calibration method significantly simplifies the calibration procedures, and experimental results are presented for the verification of this calibration method. And experiments verify accuracy of the whole measurement system. And its advantages over digital moire and stereo vision are presented and verified by experiments. However, this calibration method for structured light system is applicable to the existing methods that are based on the least squares minimization effort. The assumptions made for the calibration system are not suitable to the nonlinear stereo vision system. Moreover, the 2D planar pattern used in existing calibration methods cannot provide 3D information in the 3D space. To move it among different views will inadvertently introduce additional mechanical errors. An iterative calibration method is developed in order to solve the existing problems in the state-of-the-art calibration methods for stereo vision systems. It is the first time that an iterative calibration method is developed to solve the calibration of a two-camera system's calibration with iterations in the 3D space. Derivations are described for this iterative calibration algorithm using feedback control theory. Furthermore, the calibration target is designed and manufactured under specifications defined by the task has been created for. Experiments show the developed iterative calibration method based on feedback control can achieve convergent parameters. With the calibrated parameters, 3D measurement of the calibration target verifies the correctness and accuracy of this iterative calibration method. Hence, the contributions of this work are significant. An absolute 3D measurement system based on a 2D pattern using digital moire has been developed. At the same time, a novel calibration method for such a system has also been proposed and verified in this work. For investigation of calibration method on

  15. 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 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

  16. 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.

  17. Absolute wavelength measurement and fine structure determination in /sup 7/Li II

    Energy Technology Data Exchange (ETDEWEB)

    Riis, E.; Berry, H.G.; Poulsen, O.; Lee, S.A.; Tang, S.Y.

    1985-01-01

    The energy levels of two-electron atoms continue to provide rigorous tests of relativistic quantum theory, and of correlation effects within a multi-particle system. These interactions are determined perturbatively, with several approximations, and theoretical results often differ. It is critical to provide precise measurements of absolute wavelengths connecting these atomic energy levels to obtain a resolution of the precision of the different parts of such complex calculations. In this work, we report a high precision optical measurements in the 1s2s /sup 3/S - 1s2p /sup 3/P multiplet of Li II using fast-beam laser spectroscopy. A collinear interaction using both parallel and antiparallel laser and ion beams allows both for precise elimination of large Doppler shifts, and for a strong kinematic narrowing of the observed resonances, as compared with thermal beam experiments. The wavelengths of the observed resonance fluorescence radiation are determined by comparing them with simultaneously recorded saturated absorption profiles of molecular iodine hyperfine components. In turn, the absolute wavelengths of the iodine lines are obtained from precisely calibrated Fabry-Perot etalon fringes in a separate experiment. The final precision of the Li II wavelengths is 5 parts in 10/sup 9/, which is at a level of precision of 80 ppM of the QED corrections in the transition. 3 refs., 1 figs., 1 tab.

  18. Microfabricated Collector-Generator Electrode Sensor for Measuring Absolute pH and Oxygen Concentrations.

    Science.gov (United States)

    Dengler, Adam K; Wightman, R Mark; McCarty, Gregory S

    2015-10-20

    Fast-scan cyclic voltammetry (FSCV) has attracted attention for studying in vivo neurotransmission due to its subsecond temporal resolution, selectivity, and sensitivity. Traditional FSCV measurements use background subtraction to isolate changes in the local electrochemical environment, providing detailed information on fluctuations in the concentration of electroactive species. This background subtraction removes information about constant or slowly changing concentrations. However, determination of background concentrations is still important for understanding functioning brain tissue. For example, neural activity is known to consume oxygen and produce carbon dioxide which affects local levels of oxygen and pH. Here, we present a microfabricated microelectrode array which uses FSCV to detect the absolute levels of oxygen and pH in vitro. The sensor is a collector-generator electrode array with carbon microelectrodes spaced 5 ?m apart. In this work, a periodic potential step is applied at the generator producing transient local changes in the electrochemical environment. The collector electrode continuously performs FSCV enabling these induced changes in concentration to be recorded with the sensitivity and selectivity of FSCV. A negative potential step applied at the generator produces a transient local pH shift at the collector. The generator-induced pH signal is detected using FSCV at the collector and correlated to absolute solution pH by postcalibration of the anodic peak position. In addition, in oxygenated solutions a negative potential step at the generator produces hydrogen peroxide by reducing oxygen. Hydrogen peroxide is detected with FSCV at the collector electrode, and the magnitude of the oxidative peak is proportional to absolute oxygen concentrations. Oxygen interference on the pH signal is minimal and can be accounted for with a postcalibration. PMID:26375039

  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. 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

  1. 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...

  2. Absolute Gravity and Global Positioning System Measurements of Uplift in Quebec and Eastern Ontario, Canada

    Science.gov (United States)

    Henton, J. A.; Liard, J. O.; Craymer, M. R.; Gagnon, C. G.; Lapelle, E.

    2003-12-01

    The Nouveau Quebec-Labrador region was the site of one of the major ice domes of the Laurentide Ice Sheet and is currently experiencing postglacial rebound. Geodetic data provide a useful and accurate method of measuring the pattern and rates of contemporary uplift in this region. In order to monitor the temporal variations in gravitational potential resulting from regional glacial isostatic adjustment, a number of absolute gravity sites have been established in northern Quebec. These absolute-gravity field stations are co-located with sites of the Canadian Base Network (CBN). Initiated in 1994, the CBN is a network of pillar monuments with forced-centering plates for Global Positioning System (GPS) receiver antennae. Accurately positioned three-dimensionally with GPS, the CBN can serve as a monitoring network for deformation studies of the Canadian landmass. Issues such as mass redistribution or changes in density contrasts within the Earth may be better addressed by monitoring positional changes (i.e., primarily height changes) and integrating these observations with gravitational variations. The comparison of the temporal rate of change of gravity with the GPS height rate is thus highly desirable. Recent velocity estimates based on both the multiple-epoch GPS network surveys as well as the preliminary results from absolute-gravity trends indicate regional uplift. These preliminary results also exhibit general agreement among the uplift rates for GPS radial velocities, gravity trends, and predictions of vertical crustal motion from postglacial rebound models. Monitoring the temporal rate of change of gravity at key GPS sites is also an important step towards the maintenance of an integrated reference system. Co-located with the Canadian Geodetic Long Baseline Interferometry site at the Algonquin Radio Observatory (A.R.O.), the Canadian Active Control System's continuous GPS station at Algonquin Park, Ontario (ALGO) serves as an important reference site for many regional surveys, including this study. A.R.O. has thus been singled out as a key field station where a comparison of the temporal rate of change of gravity with the GPS radial position rate of change is highly desirable. Unfortunately to date, the uplift rate determined from the gravity trend at Algonquin Park appears much larger than the GPS-observed and model-predicted rates. With the gravity measurements taken at the stable base of the Algonquin Radio Observatory's 46m VLBI telescope, the cause of this apparently high uplift rate is unknown. Although the data will be further analyzed for possible instrumental offsets or biases, it is likely that the gravity trend is biased by variations in the local mass budget due to environmental or hydrological effects. To quantify these effects, we have begun more frequent ( ˜monthly) absolute gravity measurements. Additionally, pending further testing and evaluation, data from an autonomous, continuously-recording (but yet to be installed) gravimeter will be coupled with the absolute measurements to develop and test models of seasonal variations in the gravity field at A.R.O. due to groundwater effects.

  3. Trace elements and radioactivity measurements in Tunisia

    International Nuclear Information System (INIS)

    This work is a part of an undergoing activity at the radioanalytical laboratory at the National Center of Nuclear Science and Technology in Tunisia aiming at studying natural and man-made radioactivity and trace elements in environmental and industrial samples in the country. Several samples of environmental concern were analysed for radioactivity concentrations of 238U, 232Th, 40K and 137Cs. The environmental samples included clay soils and beach-sands from the north and the south of the country and the sahara in Tunisia, food products, and water samples and sediments from the Mediterranean sea. Technological products that may pose a radiological risk to the population included construction material such as cement, bricks and gravel, and phosphate products and by products such as phosphogypsum. The analytical methods employed were high-resolution gamma-spectrometry, instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Results from the techniques employed are compared in terms of their accuracy, uncertainty and feasibility of performance in developing countries. The objectives are three fold: 1. To determine the concentrations of radioelement in environmental and industrial samples. 2. To investigate the impact of industrial and human activities on environmental pollution. 3. To compare several analytical techniques in terms of accuracy, uncertainty and feasibility. From the result, we can conclude that exposure to NORM and artificial radiation from the samples analysed does not represent any major to human health

  4. Static Absolute Force Measurement for Preloaded Piezoelements Used for Active Lorentz Force Detuning System

    CERN Document Server

    Sekalski, S P; Sekalski, S P

    2004-01-01

    To reach high gradients in pulsed operation of superconducting (SC) cavities an active Lorentz force detuning compensation system is needed. For this system a piezoelement can be used as an actuator (other option is a magnetostrictive device). To guarantee the demanded lifetime of the active element, the proper preload force adjustment is necessary. To determine this parameter an absolute force sensor is needed which will be able to operate at cryogenic temperatures. Currently, there is no calibrated commercial available sensor, which will be able to measure the static force in such an environment. The authors propose to use a discovered phenomenon to estimate the preload force applied to the piezoelement. The principle of the proposed solution based on a shape of impedance curve, which changes with the value of applied force. Especially, the position of resonances are monitored. No need of specialized force sensor and measurement in-situ are additional advantages of proposed method.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-15

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

  6. 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 B–X transition R(80)8–4 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)

  7. 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.

  8. GENERAL: A diode laser spectrometer at 634 nm and absolute frequency measurements using optical frequency comb

    Science.gov (United States)

    Yi, Lin; Yuan, Jie; Qi, Xiang-Hui; Chen, Wen-Lan; Zhou, Da-Wei; Zhou, Tong; Zhou, Xiao-Ji; Chen, Xu-Zong

    2009-04-01

    This paper reports that two identical external-cavity-diode-laser (ECDL) based spectrometers are constructed at 634 nm referencing on the hyperfine B-X transition R(80)8-4 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.

  9. Measurement of absolute rates for multiphoton ionization of atomic hydrogen at 248 nm

    Energy Technology Data Exchange (ETDEWEB)

    Kyrala, G.A.; Nichols, T.D. (Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (US))

    1991-08-01

    We present measurements of absolute rates for multiphoton ionization of the ground state of atomic hydrogen by a linearly polarized, subpicosecond KrF laser at a wavelength of 248 nm. The irradiance was varied from 3{times}10{sup 12} to 2{times}10{sup 14} W/cm{sup 2}, and three above-threshold-ionization peaks were observed. The measured rate for total electron production was less than that predicted by Floquet theory (S.-I. Chu and J. Cooper, Phys. Rev. A 32, 2769 (1985)) and perturbation calculations (S. V. Khristenko and S. I. Vetchinkin, Opt. Specktrosk. 40, 417 (1976)), but significantly higher than calculated by the Reiss (Phys. Rev. A 22, 1786 (1980)) and Keldysh (Sov. Phys.---JETP 20, 1307 (1965)) methods using Volkov final states.

  10. 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)

  11. 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.

  12. Measurement of the absolute branching ratios for semileptonic K± decays with the KLOE detector

    International Nuclear Information System (INIS)

    Using a sample of over 600 million ? ? K+K- decays collected at the DA?NE e+e- collider, we have measured with the KLOE detector the absolute branching ratios for the charged kaon semileptonic decays, K± ? ?0e±?(?) and K± ? ?0?±?(?). The results, BR(Ke3) = 0.04965±0.00038stat±0.00037syst and BR(K?3) = 0.03233±0.00029stat±0.00026syst, are inclusive of radiation. Accounting for correlations, we derive the ratio ?(K?3)/?(Ke3) = 0.6511±0.0064. Using the semileptonic form factors measured in the same experiment, we obtain |Vus f+(0)| = 0.2141 ±0.0013$

  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. 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

  15. 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)

  16. 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.)

  17. 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.)

  18. 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…

  19. 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)

  20. 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)

  1. Radioactivity measurements for the ERMES project at the STELLA facility

    OpenAIRE

    Gallese B.; Bella F.; Balata M.; Aprili P.; Plastino W.; Laubenstein M.; Ioannucci L.; Nisi S.

    2012-01-01

    STELLA (SubTErranean Low Level Assay) is the ultra low background facility of the Gran Sasso National Laboratories (L.N.G.S.) in Italy. It is mainly devoted to material screening and rare events physics due to its very low radioactive background. Nevertheless, also environmental samples are measured within the collaboration with the ERMES (Environmental Radioactivity Monitoring for Earth Sciences) project. After a short description of the facility some on-going applications within the ERMES p...

  2. 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 4?(?, ?-?) coincidence method. An accuracy of the order of 99,8% was obtained. The results for 60Co were compared with those obtained by 4??-? 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-04-25

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

  4. 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.

  5. 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.

  6. Self-absorption-calibrated vacuum ultraviolet absorption spectroscopy for absolute oxygen atomic density measurement

    Science.gov (United States)

    Yang, Xiaoli; Sasaki, Koichi; Nagatsu, Masaaki

    2015-10-01

    Using a compact microwave plasma light source, a self-absorption-calibrated vacuum ultraviolet absorption spectroscopy (VUVAS) method was developed based on resonance escape factor theory and numerical analysis of the emission profile using Specair. After theoretical calibration of the self-absorption effect for two adjacent oxygen lines at 130.22?nm and 130.49?nm emitted from the light source, absolute oxygen atomic densities were measured for different N2/O2 gas mixture ratios in surface-wave plasmas. The oxygen atomic densities obtained for the two light probes were fairly close, supporting good reliability of the proposed self-absorption-calibrated VUVAS method. It is expected from the present results that the proposed method will extend the range of application of the VUVAS method in industrial plasma processing.

  7. 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)

  8. 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)

  9. 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

  10. 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 4? gas flow proportional counter. Detector efficiency was measured using 4?#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

  11. Quartz crystal microbalance measurements of absolute laser photodeposition rates: Application to 257-nm deposition from W(CO)6

    International Nuclear Information System (INIS)

    A quartz crystal microbalance has been used to measure absolute rates of laser-induced photochemical deposition processes in real time. A cw UV laser (257 nm) focused at normal incidence onto the microbalance crystal surface is used to induce deposition by photodecomposition of an organometallic vapor. An equation is derived to obtain the absolute mass of the deposit. The method is demonstrated for photodeposition from W(CO)6

  12. A study on the absolute measurement of ?-ray absorbed dose in the skin depth

    International Nuclear Information System (INIS)

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

  13. 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'.

  14. 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)

  15. 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)

  16. 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

  17. 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.

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

    International Nuclear Information System (INIS)

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

  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. A measurement of the absolute neutron beam polarization produced by an optically pumped 3He neutron spin filter

    International Nuclear Information System (INIS)

    The capability of performing accurate absolute measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with an absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically pumped polarized 3He spin filter and a relative transmission measurement technique. 3He was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method

  1. A measurement of the absolute neutron beam polarization produced by an optically pumped sup 3 He neutron spin filter

    CERN Document Server

    Rich, D R; Crawford, B E; Delheij, P P J; Espy, M A; Haseyama, T; Jones, G; Keith, C D; Knudson, J; Leuschner, M B; Masaike, A; Masuda, Y; Matsuda, Y; Penttilae, S I; Pomeroy, V R; Smith, D A; Snow, W M; Szymanski, J J; Stephenson, S L; Thompson, A K; Yuan, V

    2002-01-01

    The capability of performing accurate absolute measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with an absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically pumped polarized sup 3 He spin filter and a relative transmission measurement technique. sup 3 He was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method.

  2. 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

  3. 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.

  4. 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

  5. Measurements of 7Be radioactivity concentrations in high altitude air

    International Nuclear Information System (INIS)

    Preliminary measurements of the 7Be radioactivity concentrations in high altitude air were made between April 1984 and March 1985 in order to check the possibility of use for the analysis of the measured gross beta concentrations. Airborne dusts were collected with a filter type air sampler attached to the F-4EJ aircraft. The measurement of the 7Be radioactivity in the filters was made by gamma-ray spectrometry with a Ge(Li) detector. The results ranging from 0.03 to 5 pCi/m3 are in approximate agreement with the calculated values using the equation derived by B. Peters. Comparing the results of 7Be with the gross beta activity concentrations, it is shown that observations of 7Be is helpful in the study of environmental radioactivity as a tracer for air circulation. (author)

  6. 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.

  7. 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

  8. Absolute Measurement of the Cosmic Infrared Background Using Ganymede as an Occulter

    Science.gov (United States)

    Tsumura, Kohji; Surace, Jason; Arai, Toshiaki; Arimatsu, Ko; Egami, Eiichi; Enya, Keigo; Kotani, Takayuki; Matsuura, Shuji; Shirahata, Mai; Usui, Fumihiko; Wada, Takehiko

    2012-12-01

    The Cosmic Infrared Background (CIB) as an integrated history of the early universe is important for the study of the Dark Ages, and it may include the light from the first stars at z~10. However, previous CIB measurements suffer from residual contamination from the strong foreground emission (e.g. the zodiacal light). We propose to observe Ganymede eclipsed in the shadow of Jupiter at 3.6 microns to detect the absolute CIB intensity without any zodiacal light subtraction error. The zodiacal light originates inside the orbit of Jupiter; since Ganymede in eclipse shields all light beyond the Jovian orbit, it should be detected as a 'dark spot' if the strong CIB implied by previous observations exists. The intensity deficit of this dark spot relative to the surrounding sky directly measures the strength of the CIB, free from any assumptions about the zodiacal light. A previous DDT program demonstrated the efficacy of the major observational components of this program, including the severity of the Jovian straylight. The new observations are required to further refine the measurements to reach the required S/N.

  9. 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)

  10. 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 ...

  11. Measurement of radioactive iodine at the time of emergency

    International Nuclear Information System (INIS)

    This manual is published to prescribe on a rapid measuring method for radioactive iodine when it is released accidentally into the atmosphere from nuclear facilities, that is, to obtain the data necessary for taking measures and evaluation at the time of emergency. It is described on the assumption that samples of measuring objects have been collected in the field in principle. The iodine isotopes released accidentally into the atmosphere are not limited to one kind, but normally contain the mixture of a few kinds. The method also can not select radioactive iodine only among radioactive nuclides, so that all the radioactive nuclides are sensed as 131I, thus the quantity of 131I is estimated always in excess. The measuring instrument is a conventional ?-scintillation survey meter with a NaI(Tl) scintillator. The manual comprises 6 chapters including introduction, measurement criteria, dust in air, drinking water, milk, and vegetables. At the end of the manual, further explanations on ?-scintillation survey meter, measured results of various environmental samples, and measurement of 131I in thyroid gland are described for reference. (Wakatsuki, Y.)

  12. 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.)

  13. Measurement of the Absolute Branching Fractions for $D^-_s\\!\\rightarrow\\!\\ell^-\\bar{\

    Energy Technology Data Exchange (ETDEWEB)

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, David Nathan; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U.; /more authors..

    2010-10-27

    The absolute branching fractions for the decays D{sub s}{sup -} {yields} {ell}{sup -}{bar {nu}}{sub {ell}} ({ell} = e, {mu}, or {tau}) are measured using a data sample corresponding to an integrated luminosity of 521 fb{sup -1} collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. The number of D{sub s}{sup -} mesons is determined by reconstructing the recoiling system DKX{gamma} in events of the type e{sup +}e{sup -}DKXD*{sub s}{sup -}, where D*{sub s}{sup -} {yields} D{sub s}{sup -}{gamma} and X represents additional pions from fragmentation. The D{sub s}{sup -} {yields} {ell}{sup 0}{nu}{sub {ell}} events are detected by full or partial reconstruction of the recoiling system DKX{gamma}{ell}. The branching fraction measurements are combined to determine the D{sub s}{sup -} decay constant f{sub D{sub s}} = (258.6 {+-} 6.4 {+-} 7.5) MeV, where the first uncertainty is statistical and the second is systematic.

  14. 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.

  15. From direct to absolute mass measurements a study of the accuracy of ISOLTRAP

    CERN Document Server

    Kellerbauer, A G; Bollen, G; Herfurth, F; Kluge, H J; Kuckein, M; Sauvan, E; Scheidenberger, C; Schweikhard, L; 10.1140/epjd/e2002-00222-0

    2003-01-01

    For a detailed study of the accuracy of the Penning trap mass spectrometer ISOLTRAP all expected sources of uncertainty were investigated with respect to their contributions to the uncertainty of the final result. In the course of these investigations, cross-reference measurements with singly charged carbon clusters $^{12}$C$^{+}_{n}$ were carried out. The carbon cluster ions were produced by use of laser-induced desorption, fragmentation, and ionization of C$_{60}$ fullerenes and injected into and stored in the Penning trap system. The comparison of the cyclotron frequencies of different carbon clusters has provided detailed insight into the residual systematic uncertainty of \\acro{ISOLTRAP} and yielded a value of $8 \\cdot 10^{-9}$. This also represents the current limit of mass accuracy of the apparatus. Since the unified atomic mass unit is defined as 1/12 of the mass of the $^{12}$C atom, it will be possible to carry out absolute mass measurements with \\acro{ISOLTRAP} in the future.\\\\[1\\baselineskip] PACS...

  16. 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)

  17. Gps, Superconducting and Absolute Gravimeters Measurements To Evaluate Crustal Deformations In Membach, Belgium.

    Science.gov (United States)

    van Camp, M.; Warnant, R.; Francis, O.

    We report on the results of 6 years of data from the absolute (AG) and superconducting gravimeters (SG) located at the Membach Station, eastern Belgium. By using the AG FG5, we were able to estimate the instrumental drift of the SG. SG gravity signal, corrected for Earth tides, ocean loading and atmospheric effects, polar motion and drift tracks changes in gravity observed by the AG at the µGal level. We distinguish two effects: a seasonal-like terms due to the uncorrected atmospheric loading effects and to hydrology variations. The second effect, which is the most interesting result, is the detection of a very low geophysical trend in gravity of -0.9 µGal/year at the Membach station. The SG drift stability, the rainfall effects, and the origin of the possible low trend are discussed. In particular, we compare those gravimetric measurements with continuous GPS measurements made since 1997 at 3 km from the station. The possible deformations could be linked to active faults in the Ardenne and/or bordering the Roer Graben, or linked to the possible Eifel plume.

  18. 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.)

  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. 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)

  1. 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)

  2. 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)

  3. (n, ?) measurements on radioactive isotopes with DANCE

    International Nuclear Information System (INIS)

    The Detector for Advanced Neutron Capture Experiments (DANCE) at the Los Alamos National Laboratory (LANL) is designed as a high efficiency, highly segmented 4? BaF2 detector for calorimetrically detecting gamma rays following a neutron capture. Coupled with the neutron spallation source at the Los Alamos Neutron Science Center (LANSCE), DANCE measurements on unstable isotopes in the energy range between 10 meV and 500 keV will provide many of the missing key reactions that are needed to understand the nucleosynthesis of the heavy elements and will also provide vital information for the design of future reactor concepts

  4. Measurement of residual radioactivity in the facility being decommissioned

    International Nuclear Information System (INIS)

    After decommissioned, the site of a nuclear facility is necessary not to be contaminated with any radioactivity for site radioactive-free release. Major nuclides deposited on components, building floors, sites etc. are found to be 60Co, 137Cs and etc. Because the latter nuclides usually accompany 60Co, the detection nuclide characterizing contamination can be determined to be 60Co. The termination survey for the site release must be carried out on the condition that the residual radioactivity is a very low level, and the site is a very large area. In addition there is possibility that the detection of 60Co is disturbed by the background level due to 40K and other natural radioactivities. Therefore, the basis of the measuring system consists of several NaI detectors and electronic circuits mounted on a vehicle in order to enhance the efficiencies of detection and of measuring operation. Further, the position of measuring points will be determined by an auto-positioning apparatus. Our development program of the measuring system is going on and will be outlined in the presentation. (author)

  5. 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)

  6. Shielding for measuring radioactive-rays

    International Nuclear Information System (INIS)

    In FBR type reactors, a neutron flux detector is accommodated in a detector guide tube, which is inserted to the vicinity of a primary coolant pipeline passing through a wall for measuring delayed neutrons coming from the primary coolant circuit pipeline extended from a reactor container to an intermediate heat exchanger. There are disposed lead shieldings at the periphery of the neutron flux detector, boron carbide shieldings at the periphery of the lead shieldings and the primary coolant circuit pipeline for shielding neutrons from other than the primary cooling circuit pipeline. Upon disposing these shieldings, positional deviations were caused by installation errors between each of guide tubes and with respect to pipelines depending on the position of a penetrating sleeve. However, the errors could not be absorbed since the lead shieldings had a block structure. This problem can be solved by forming a space between neutron moderators and lead shieldings for absorbing installation errors upon fixing the detector guide tube. (N.H.)

  7. Frequency comparisons and absolute frequency measurements of 171Yb+ single-ion optical frequency standards

    CERN Document Server

    Peik, E; Schnatz, H; Schneider, T; Tamm, C; Karshenboim, S G; Tamm, Chr.

    2005-01-01

    We describe experiments with an optical frequency standard based on a laser cooled $^{171}$Yb$^+$ ion confined in a radiofrequency Paul trap. The electric-quadrupole transition from the $^2S_{1/2}(F=0)$ ground state to the $^2D_{3/2}(F=2)$ state at the wavelength of 436 nm is used as the reference transition. In order to compare two $^{171}$Yb$^+$ standards, separate frequency servo systems are employed to stabilize two probe laser frequencies to the reference transition line centers of two independently stored ions. The experimental results indicate a relative instability (Allan standard deviation) of the optical frequency difference between the two systems of $\\sigma_y(1000 {\\rm s})=5\\cdot 10^{-16}$ only, so that shifts in the sub-hertz range can be resolved. Shifts of several hertz are observed if a stationary electric field gradient is superimposed on the radiofrequency trap field. The absolute optical transition frequency of Yb$^+$ at 688 THz was measured with a cesium atomic clock at two times separated...

  8. 6 Years of Absolute and Superconducting Gravimeter Measurements in Membach, Belgium

    Science.gov (United States)

    Van Camp, M.; Francis, O.

    2001-12-01

    We report on the results of 6 years of data from the absolute (AG) and superconducting gravimeters (SG) located at the Membach Station, eastern Belgium. By using the AG FG5, we were able to estimate the instrumental drift of the SG. SG gravity signal, corrected for Earth tides, ocean loading and atmospheric effects, polar motion and drift tracks changes in gravity observed by the AG at the ? Gal level. We distinguish two effects: a seasonal-like terms due to the uncorrected atmospheric loading effects and to hydrology variations. The second effect, which is the most interesting result, is the detection of a very low geophysical trend in gravity of -0.3 ? Gal/year at the Membach station. If this trend is confirmed, assuming that the observed gravity change is only due to a vertical motion of the station, we can interpret that the Membach station is going up by 1 mm/year. The SG drift stability, the rainfall effects, and the origin of the possible low trend are discussed. In particular, the present deformations can be linked to active faults in the Ardenne and/or bordering the Roer Graben, or linked to the possible Eifel plume. In order to confirm this uplift and to estimate its wavelength, we are performing semi-annual AG measurements since 1999 along an 8 stations profile across the Ardenne and the Roer Graben.

  9. Study of a 4??-? coincidence system for absolute radionuclide activity measurement using plastic scintillators

    International Nuclear Information System (INIS)

    The present work was intended to study a coincidence system 4?(PS)?-? for absolute activity measurement using plastic scintillators in 4? geometry. Along with experiments on the coincidence system, simulations were also performed applying the Monte Carlo Method, by means of codes PENELOPE and ESQUEMA. These simulations were performed in order to calculate the extrapolation curve of the coincidence system 4?(PS)?-? and compare it to experimental data. A new geometry was proposed to the coincidence system adding up a second photomultiplier tube to the previous system for improving light collection from the plastic scintillator, as this system presented limitations in the minimum detected energy due to the presence of electronic noise and low gain. The results show that an improvement in the signal-to-noise ratio was obtained, as well as in the minimum detected energy. Moreover, there was an increase in the detection efficiency. With these modifications, it is now possible to calibrate radionuclides which emit low energy electrons or X-rays, increasing the number of radionuclides that can be standardized with this type of system.(author)

  10. 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

  11. Comparison of absolute spectral irradiance responsivity measurement techniques using wavelength-tunable lasers

    International Nuclear Information System (INIS)

    Independent methods for measuring the absolute spectral irradiance responsivity of detectors have been compared between the calibration facilities at two national metrology institutes, the Helsinki University of Technology (TKK), Finland, and the National Institute of Standards and Technology (NIST). The emphasis is on the comparison of two different techniques for generating a uniform irradiance at a reference plane using wavelength-tunable lasers. At TKK's Laser Scanning Facility (LSF) the irradiance is generated by raster scanning a single collimated laser beam, while at the NIST facility for Spectral Irradiance and Radiance Responsivity Calibrations with Uniform Sources (SIRCUS), lasers are introduced into integrating spheres to generate a uniform irradiance at a reference plane. The laser-based irradiance responsivity results are compared to a traditional lamp-monochromator-based irradiance responsivity calibration obtained at the NIST Spectral Comparator Facility (SCF). A narrowband filter radiometer with a24 nm bandwidth and an effective band-center wavelength of 801 nm was used as the artifact. The results of the comparison between the different facilities, reported for the first time in the near-infrared wavelength range, demonstrate agreement at the uncertainty level of less than 0.1%. This result has significant implications in radiation thermometry and in photometry as well as in radiometry

  12. Prediction of absolute concentrations of elements from SR XRF scan measurements of natural wet sediments

    International Nuclear Information System (INIS)

    We report a method to predict absolute concentrations of elements in natural wet sediments (cores) from their SR XRF scan measurements. This prediction is problematic because: (i) relationship between fluorescent intensity and element concentrations is strongly biased by variability of pore water content in thick samples; (ii) thickness and mass of fluorescent layers are likewise variable; and (iii) spectral responses are perturbed by interference of elements. It is suggested to overcome these difficulties using an adapted algorithm of fundamental parameters. The mathematical model based on this algorithm accounts for two events of photon/matter interaction. Element concentrations are estimated using reference samples and the internal standard procedure, both with correction of interference effects. The pore water content is inferred from its correlation with the Rayleigh (coherent)/Compton (incoherent) scatter intensity ratio. Sediment density is found from water content by a reliable sedimentological law. Normalization to Compton scattering accounts for the irradiated mass of wet sediment controlled by porosity and sampling-related core disturbance. The mathematical model also includes these scattering variations related to lithology, water content, and density of samples. The new method was applied to SR XRF scans of cores from Lake Baikal and Lake Teletskoye to predict concentrations of 20 elements (K-Ba, REE, Th, U). Tests against ICP-MS and conventional SR XRF (with traditional pretreatment of samples) show good agreement and stability of SR XRF scanning. Neglect of the disturbing effects may cause errors up to 30-150%

  13. Long distance absolute laser ranging at the nanometer precision level: the two-mode interference measurement in the Iliade rangemeter

    OpenAIRE

    Phung, Ha,; Courde, Clément; Brillet, Alain; Alexandre, Christophe; Lintz, Michel

    2013-01-01

    Some measurement schemes have been proposed and realized for the absolute measurement of long distances with an accuracy better than 10 nm. Published measurement setups use one or even two laser frequency combs. But significant engineering will be required to space qualify such a system. Simple methods, less technology-demanding would be valuable in the perspective of embedded instrumentation. We have designed and implemented a two-mode interference measurement scheme that allows sub-nanomete...

  14. 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)

  15. Development of Nondestructive Measuring Technique of Environmental Radioactive Strontium

    Science.gov (United States)

    Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Yoshida, Tatsuru; Murata, Jiro

    The Fukushima first nuclear power plant accident was triggered by the Japanese big earthquake in 2011. The main radioactivity concerned after the accident are I-131 (half-life 8.0 days), Cs-134 (2.1 years) and 137 (30 years), Sr-89 (51 days) and 90 (29 years). We are aiming to establish a new detection technique which enables us to realize quantitative evaluation of the strontium radioactivity by means of nondestructive measurement without chemical separation processing, which is concerned to be included inside foods, environmental water and soil around us, in order to prevent us from undesired internal exposure to the radiation.

  16. 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)

  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. 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

  19. Absolute Absorption Cross Section Measurements of Schumann-Runge Continuum of O2 at 90 K and 295 K

    International Nuclear Information System (INIS)

    Full text: Laboratory measurements of the absorption cross section of the Schumann-Runge continuum of O2 at the temperatures 90 K and 295 K have been made in the wavelength region 130 nm - 175 nm. The absolute absorption cross sections at the same temperatures have been measured at several discrete wavelengths through the region. The absolute cross sections of the O2 continuum have been used to put relative cross sections on a firm absolute basis throughout the region 130 nm - 175 nm. These recalibrated cross sections are available as numerical compilations. In the course of these experiment, we discovered that when using the stainless steel absorption cell the O2 gas temperature was not 78 K but was 90 K, because of thermal conduction through the inner tube

  20. Radioactivity measurements for the thin layer activation technique

    International Nuclear Information System (INIS)

    Thin layer activation (TLA) is one of the promising techniques employing radiotracers at low levels of radioactivity for material performance studies such as wear and corrosion. The principle of TLA is the creation of an appropriate radionuclide in a given material to a well defined depth of a selected area. This activation is realised by exposure of the component to a charged particle beam using, e.g., a cyclotron facility. If the material is subjected to mechanical or chemical degradation, any loss of the activated material will result in a loss in radioactivity of the activated component. The sensitivity of TLA technique is high due to the capability of low level radioactivity measurement performed by ? spectrometry. The sensitivity of TLA is below 0.1 ?m thickness loss or 1 ng mass loss. In the present paper, some applications of TLA in ongoing research at the Institute for Health and Consumer Protection of the European Commission are presented

  1. 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)

  2. 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.)

  3. 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.)

  4. 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.

  5. 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.)

  6. 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)

  7. 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.)

  8. 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)

  9. 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

  10. 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)

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

    OpenAIRE

    Huisman Martijn; Kunst Anton E; Houweling Tanja AJ; Mackenbach Johan P

    2007-01-01

    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...

  12. Use of parallel plate avalanche detectors for absolute photofission cross section measurement on 238U and 232Th

    International Nuclear Information System (INIS)

    This paper is a digest of a series of studies on parallel plate avalanche detectors, built with the purpose of measuring absolute photofission cross section on 238U and 232Th. Besides a few theoretical recallings, we describe the experimental configuration, and point out the various problems met during its elaboration, and their respective solutions

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Remote measurements of radioactivity distribution with BROKK robotic system - 16147

    International Nuclear Information System (INIS)

    Robotic system for the remote measurement of radioactivity in the reactor areas was developed. The BROKK robotic system replaces hand-held radiation measuring tools. The system consists of a collimated gamma detector, a standard gamma detector, color CCD video camera and searchlights, all mounted on a robotic platform (BROKK). The signals from the detectors are coupled with the video signals and are transferred to an operator's console via a radio channel or a cable. Operator works at a safe position. The video image of the object with imposed exposure dose rate from the detectors generates an image on the monitor screen, and the images are recorded for subsequent analysis. Preliminary work has started for the decommissioning of a research reactor at the RRC 'Kurchatov Institute'. Results of the remote radioactivity measurements with new system during radiation inspection waste storage of this reactor are presented and discussed. (authors)

  19. Radioactive targets for neutron-induced cross section measurements

    International Nuclear Information System (INIS)

    Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,?) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 ? gamma array made up of 160 BaF2 detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to ?500 keV). The high granularity and high detection efficiency of DANCE, combined with the high TOF-neutron flux available at the Lujan Center provides a versatile tool for measuring many important cross section data using radioactive and isotopically enriched targets of about 1 milligram. Another powerful instrument is the Lead-slowing down spectrometer (LSDS), which will enable the measurement of neutron-induced fission cross-section of U-235m and other short-lived actinides in a energy range from 1-200 keV with sample sizes down to 10 nanograms. Due to the short half-life of the U-235m isomer (T1/2 = 26 minutes), the samples must be rapidly and repeatedly extracted from its 239Pu parent. Since 239Pu is itself highly fissile, the separation must not only be rapid, but must also be of very high purity (the Pu must be removed from the U with a decontamination factor >1012). Once extracted and purified, the 235mU isomer would be electrodeposited on solar cells as a fission detector and placed within the LSDS for direct (n,f) cross section measurements. The production of radioactive targets of a few milligrams will be described as well as the containment for safe handling of these targets at the Lujan Center at LANSCE. To avoid any contamination, the targets are electrochemically fixed onto thin Ti foils and two foils are placed back to back to contain the radioactive material within. This target sandwich is placed in a cylinder made of aluminum with thin translucent windows made of Kapton. Actinides targets, such as 234,235,236,238U, 237Np, and 239Pu are prepared by electrodeposition or molecular plating techniques. Target thicknesses of 1-2 mg/cm2 with sizes of 1 cm2 or more have been made. Other targets will be fabricated from separation of irradiated isotopically enriched targets, such as 155Eu from 154Sm,171Tm from 170Er, and 147Pm from 146Nd, which has been irradiated in the high flux reactor at ILL, Grenoble. A radioactive sample isotope separator (RSIS) is in the process of being commissioned for the preparation of other radioactive targets. A brief summary of these experiments and the radioactive target preparation technique will be given.

  20. 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.

  1. Measurement of the absolute flux from Vega in the K band (2.2 ?m)

    International Nuclear Information System (INIS)

    A method is described for determining absolute stellar flux in the infrared, based on a direct comparison between a star and a furnace at a known temperature. Observations have been made of Vega in the K band (2.2 ?m) using the Tenerife flux collector. The absolute flux from this star at the Earth, reduced to the wavelength 2.20 ?m, is found to be 0.375 x 10-9 W m-2 ?m-1 with an uncertainty of 8 per cent. (author)

  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. 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.)

  4. 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.)

  5. 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.

  6. 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 ?). The facility can also be used to improve our knowledge of the nuclear properties of radon 222 and to produce secondary standards. (author)

  7. 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.

  8. 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

  9. 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)

  10. DANCE device for measurement of (n, ?) reactions on radioactive species

    International Nuclear Information System (INIS)

    DANCE (Device for Advanced Neutron Capture Experiments) is a 4? 162 element BaF2 array under development at Los Alamos National Laboratory. It is designed to provide high granularity, fast timing and high photon detection efficiency. It will be located at the Los Alamos Neutron Scattering Center where neutrons are produced using 800 MeV proton induced spallation reactions on heavy element production targets. Using the pulsed high neutron fluence available at this facility combined with time of flight techniques it will be possible to make neutron capture measurements in the neutron energy range from eV to 100's keV on rate and radioactive target material at the milligram and below level. These measurements will provide critically needed data for the interpretation of the astrophysical s-process 'branching point' nuclei as well as information for reactions needed in understanding transmutation processes of radioactive species. (author)

  11. 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)

  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. Surveillance and control of containment by means of radioactive measurements

    International Nuclear Information System (INIS)

    In this paper, the radioactive measurements participating in the surveillance and control of the reactor containment as well as the possible procedures or operating rules related to, especially the ultimate procedures which could be implemented in case of a beyond of design accident, are presented. However, an overall view of the plant radiation monitoring system installed on the French plants is first given. If necessary, difference between 900 MW and 1300 MW units are emphasized

  14. 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.

  15. 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)

  16. 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

  17. Absolute measurement of the neutron sensitivity of a ZP1320 geiger-Mueller counter using the associated-particle technique

    International Nuclear Information System (INIS)

    Because of their low neutron sensitivity Geiger-Mueller counters are often used in mixed-field dosimetry to determine the photon dose fraction. The associated-particle technique has been used to determine absolutely the neutron sensitivity of an energy-compensated ZP 1320 Geiger-Mueller counter at 3 MeV. The measurement is consistent with previous measurements using this type of counter. (author)

  18. 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

  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. 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

  1. 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

  2. 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)

  3. 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)

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-15

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

  6. Measuring the absolute deuterium–tritium 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.

  7. 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)

  8. Measurements and evaluation of absolute emission probabilities for soft photons of 153Gd, 155Eu and 169Yb

    International Nuclear Information System (INIS)

    Absolute emission probabilities of Kx- and ?-rays in the energy region 40-200 keV have been obtained for 153Gd and 155Eu using measurements of emission rates by Ge, Ge(Li) and Si(Li)-detectors and of activities by a 4??-? coincidence system. The main results of our measurements and evaluation of decay data of 153Gd and 155Eu were published in 1992 and 1994. Here new experimental data concerning soft photon radiation which were obtained with a new Si(Li) spectrometer calibrated on the basis of a generalized energy response functions are presented. For the 14.06 keV ?-ray in the decay of 153Gd a value of (0.029 ± 0.003) photons per 100 disintegrations has been measured. For 155Eu the absolute emission probabilities of Kx- and 26.5, 45.3, 58.0, 60.0 ?-rays have been measured using the Si(Li) (formerly only a Ge-detector was used). A re-evaluated value of the 153Gd half-life is reported. For 169Yb the evaluation of decay data has been carried out taking into account the results of the latest measurements of absolute emission probabilities of ?-rays with energies 63.12, 109.80, 130.52 and 197.96 keV. (author)

  9. 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

  10. Hair radioactivity as a measure of exposure to radioisotopes

    Science.gov (United States)

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

    1972-01-01

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

  11. 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.

  12. 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)

  13. 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)

  14. 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)

  15. 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)

  16. 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

  17. 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...

  18. A measurement of the absolute neutron beam polarization produced by an optically-pumped $^{3}He$ spin filter

    CERN Document Server

    Rich, D R; Crawford, B E; Delheij, P P J; Espy, M A; Haseyama, T; Jones, G; Keith, C D; Knudson, J N; Leuschner, M B; Masaike, A; Masuda, Y; Matsuda, Y; Penttilä, S; Pomeroy, V R; Smith, D A; Snow, W M; Stephenson, S L; Thompson, A K; Yuan, V

    2002-01-01

    The capability of performing accurate measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically-pumped polarized 3He spin filter and a relative transmission measurement technique. 3He was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method.

  19. 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)

  20. 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

  1. 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

  2. The research of a method of absolute measurement for laser-driven high pressure equation of state

    CERN Document Server

    Huang Xiu Guang; Gu Yuan; Wu Jian; He Ju Hua; Luo Ping Qing; Ma Min Xun

    2002-01-01

    Numerical simulations of the whole physical process of aluminum flyer-vacuum-target directly driven by high power laser were presented. Simulation results showed that a symmetric impact will be realized between the flyer and the target and there is a wide stable area of shock wave propagation in the target if the parameters of flyer-vacuum-target and the conditions of laser match. And the absolute measurement of equation of state (EOS) may be approached if the structure parameters of flyer both-side-step-target are chosen reasonably. At the same time, the experimental researches of absolute measurement for EOS were conducted, and the experimental results are in accord with the simulation results on the whole

  3. 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)

  4. 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

  5. Resolution limit of the white-light interferometric sensor for absolute position measurement based on central fringe maximum identification

    International Nuclear Information System (INIS)

    In this paper a simple theoretical analysis together with an experimental verification of the analysis that provides an estimation of the resolution limit of the white-light interferometric sensor for absolute position measurement based on central fringe maximum identification is presented. The resolution better than 10 pm is obtained in the white-light interferometric sensing system where the signal-to-noise ratio was greater than 80 dB. (paper)

  6. 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; Müller, 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}.

  7. 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)

  8. 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

  9. Chiral Cavity Ring-Down Absolute Measurement of Optical Rotation in Gases and Liquids with Signal Reversals

    Science.gov (United States)

    Bougas, Lykourgos; Katsoprinakis, G. E.; Rakitzis, T. P.

    2013-06-01

    We demonstrate the absolute measurement of optical rotation using a four-mirror cavity-ring-down polarimetric setup. A four-mirror bow-tie cavity allows counter-propagating laser beams, for which symmetry is broken with a longitudinal magnetic field acting upon an intracavity magneto-optic window (producing a Faraday rotation ?_{{F}}). A chiral sample is introduced in one arm of the cavity, producing a chiral rotation ?_{_{{C}}}. The different symmetry of the two rotations produces a total rotation of (?_{{F}} + ?_{_{{C}}}) for one laser beam, and (?_{{F}} + ?_{_{{C}}}) for the counter-propagating beam. These rotations produce a polarization beating in the cavity ring-down, of frequency ?_{_{{CW}}} and ?_{_{{CCW}}} for the clockwise and counter-clockwise beams, respectively. Analysis of the difference (?_{_{{CW}}}-?_{_{{CCW}}}) yields the chiral rotation angle ± ?_{_{{C}}}, where the sign of the angle is determined by the sign of the applied magnetic field. Therefore, subtracting the signals using +{B} and D{B} yields 2?_{_{{C}}}, allowing the absolute determination of ?_{_{{C}}}, without needing to remove the sample [1]. We demonstrate these absolute optical rotation measurements for chiral gases (?-pinene) and chiral liquids. This work is a proof-of-principle demonstration of the experimental setup proposed for the measurement of parity non-conserving optical rotation in atomic systems [1]. [1] L. Bougas, G. E. Katsoprinakis, W. von Klitzing, J. Sapirstein, and T. P. Rakitzis, Phys. Rev. Lett {108}, 210801 (2012).

  10. 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...

  11. Absolute measurements of the 235U and 238U fission cross-sections in the 252Cf fission neutron spectrum

    International Nuclear Information System (INIS)

    Absolute measurements have been made of the fission cross-sections of 235U and 238U in the 252Cf fission neutron spectrum, using the method of coincidences between fission events in a target made of the isotope studied, and the associated fission fragments of californium. A detailed description of the measurement method is provided, covering the reasons for choosing the geometrical conditions of the experiment, the calculations made for that purpose, the preparation of targets, the detection apparatus and sources of errors. 235U and 238U fission cross-sections in the 252Cf fission neutron spectrum are calculated from differential fission cross-section measurements. (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. 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)

  14. 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

  15. 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 ?eff 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)

  16. 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.

  17. 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

  18. 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.)

  19. 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 %

  20. 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

  1. 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

  2. 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.

  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. 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...

  5. 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...

  6. The Comparison of Absolute Dose due to Differences of Measurement Condition and Calibration Protocols for Photon Beams

    International Nuclear Information System (INIS)

    The absolute absorbed dose can be determined according to the measurement conditions; measurement material, detector, energy and calibration protocols. The purpose of this study is to compare the absolute absorbed dose due to the differences of measurement condition and calibration protocols for photon beams. Dosimetric measurements were performed with a farmer type PTW and NEL ionization chambers in water, solid water, and polystyrene phantoms using 6 MV photon beams from Siemens linear accelerator. Measurements were made along the central axis of field size for constant target to surface distance of 100 cm for water, solid water and polystyrene phantom. Theoretical absorbed dose intercomparisons between TG21 and IAEA protocol were performed for various measurement combinations on phantom, ion chamber, and electrometer. There were no significant differences of absorbed dose value between TG2l and IAEA protocol. The differences between two protocols are within 1% while the average value of IAEA protocol was 0.5% smaller than TG2l protocol. For the purpose of comparison, all the relative absorbed dose were normalized to NEL ion chamber with Keithley electrometer and water phantom, The average differences are within 1%, but individual discrepancies are in the range of -2.5% to 1.2% depending upon the choice of measurement combination. The largest discrepancy of -2.5% was observed when NEL ion chamber with Keithley electrometer is used in solid water phantom. The main cause for this discrepancy is due to the use of same parameters of stopping power, absorption coefficient, etc. as used in water phantom. It should be mentioned that the solid water phantom is not recommended for absolute dose calibration as the alternative of water, since absorbed dose show some dependency on phantom material other than water. In conclusion, the trend of variation was not much dependent on calibration protocol. However, It shows that absorbed dose could be affected by phantom material other than water.

  7. Measurement of absolute gamma-ray emission probabilities from decay of 138Xe

    International Nuclear Information System (INIS)

    The fission gaseous 138Xe products play an important role in the research of nuclear-reaction products and radioisotope applications. Therefore, precise data for emission probabilities of gamma-ray from decay of 138Xe are highly desired. However, a high precision is not achievable with a sufficient accuracy due to the limitations of the usual experimental techniques. In this paper, after the homogeneous sources of 138Xe–138Cs were prepared, the activity of 138Xe was obtained by the decay relationship between 138Xe and 138Cs using a HPGe detector. The full-energy peak efficiencies of gamma-ray for 138Xe and 138Cs were accurately calibrated using many activity standard sources and self-absorption was corrected. As a result, the absolute emission probabilities of the 258.4, 434.6 and 1768.3 keV gamma-ray from decay of 138Xe were determined to be 34.9(10)%, 22.2(6)% and 18.8(5)%, respectively. - Highlights: • The activity of 138Xe was obtained by the decay relationship between 138Xe and 138Cs. • The full-energy peak efficiencies of gamma-ray for 138Xe and 138Cs were accurately calibrated. • The absolute gamma-ray probabilities from decay of 138Xe were determined

  8. 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.)

  9. 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 2? or 0. If yes, a new suitable refined synthetic wavelength is generated to re-measure the distance with phase near ?. 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

  10. 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.

  11. Absolute nuclear material assay

    Science.gov (United States)

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

    2012-05-15

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

  12. 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.

  13. 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)

  14. 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.)

  15. Measurements of radioactive and xenobiotic substances in the biosphere in The Netherlands 1984

    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.)

  16. 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.

  17. 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...

  18. 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.

  19. Measurement of absolute left ventricular volume by radionuclide angiography: a technical review

    International Nuclear Information System (INIS)

    Absolute left ventricular volumes have important clinical implications in the evaluation of cardiac performance. Several invasive and noninvasive techniques have been reported, none of which can be considered ideal for this purpose. Contrast angiography, echocardiography and radionuclide ventriculography are open to criticism. Different radioisotopic approaches are described with emphasis on the importance of accurate separation of left ventricular activity, the selection of background activity, and the correction for photon attenuation by body tissues. Improper use of statistics and validation techniques have obscured the value of these techniques. In the absence of a 'gold standard' there should be a 'radioisotopic' left ventricular volume with established independent characteristics, repeatability and reproducibility by which new approaches can be judged. (author)

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

    International Nuclear Information System (INIS)

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

  1. 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)

  2. Considerations on measurements of radioactivity in biological samples

    International Nuclear Information System (INIS)

    Radioactivity in biological samples and particularly in foodstuffs can be measured with several procedures, depending on the type of sample and radiation. In case of a radioactive fallout like the one from Chernobyl 1986, contamination in biological samples varies with time, being high immediately after the accident and decreasing successively with time. During the first stage, accurate measurements of gamma-emission should be made with high-resolution instruments, like HPGe-detectors coupled to multichannel analyzers in order to be able to assess the fallout's composition and separate the different nuclides. Even portable GM-counters and NaI(Tl)-detectors can be used, but they provide very limited information and the resolution of NaI(Tl) is too poor to make them suitable for other than survey purposes. In this case, they can be used for monitoring the activity in a certain area, or scanning a large amount of samples. After some months, when the activity has decayed and only a few nuclides are still active, the most important parameter is not resolution any longer, but sensitivity, since the content of radionuclides has decreased. At this stage NaI(Tl)-detectors assume greater importance and their sensitivity can permit the detection of low activity levels in relatively short time. The laboratory procedures for sample handling and preparation is also very important: established routines concentrated upon reducing the risk of contamination and minimizing sources of error must be used

  3. Measurement of absolute CO number densities in CH3F/O2 plasmas by optical emission self-actinometry

    International Nuclear Information System (INIS)

    CH3F/O2 inductively coupled plasmas at 10 mTorr were investigated using optical emission spectroscopy. A ‘self-actinometry’ method was developed to measure the absolute number density of CO that formed in reactions following dissociation of CH3F and O2 in the plasma. In this method, small amounts of CO were added to the plasma, leading to small increases in the CO emission intensity. By carefully accounting for small perturbations to the plasma electron density and/or electron energy distribution, and by showing that very little of the CO added to the plasma was decomposed by electron impact or other reactions, it was possible to derive absolute number densities for the CO content of the plasma. With equal fractions (0.50) of CH3F and O2 in the feed gas, the CO mole fraction as a function of plasma power saturated at a value of 0.20–0.25. As O2 in the feed gas was varied at a constant power of 100 W, the CO mole fraction went through a maximum of about 0.25 near an O2 feed gas fraction of 0.5. The relative CO number densities determined by ‘standard’ actinometry followed the same functional dependence as the absolute mole fractions determined by self-actinometry, aided by the fact that electron temperature did not change appreciably with power or feed gas composition. (paper)

  4. Measurements of absolute M-subshell X-ray production cross sections of Th by electron impact

    International Nuclear Information System (INIS)

    Highlights: • The M X-ray production cross sections of Th were measured by electron impact. • The M-subshell ionization cross sections of Th were determined from 3 to 38 keV. • Theoretical ionization cross-sections are in agreement with our experimental results. - Abstract: Measurements of absolute M-subshell X-ray production cross sections for element Th were made by electron impact for energies ranging from the ionization threshold up to 38 keV. Experimental data were obtained by measuring the X-ray intensity emitted from ultrathin Th films deposited onto self-supporting C backing films. The measurements were conducted with an electron microprobe using high-resolution wavelength dispersive spectrometers. Recorded intensities were converted into absolute X-ray production cross sections by means of atomic data and estimation of the number of primary electrons, target thickness, and detector efficiency. Our experimental X-ray production cross sections, the first to be reported for the M subshells of Th, are compared with X-ray production cross sections calculated with the mean of ionization cross sections obtained from the distorted-wave Born approximation. The M? X-ray production cross section calculated is in excellent agreement with the measurements, allowing future use for standardless quantification in electron probe microanalysis

  5. 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

  6. 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)

  7. 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.)

  8. 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.)

  9. Measurement of absolute radical densities in a plasma using modulated-beam line-of-sight threshold ionization mass spectrometry

    International Nuclear Information System (INIS)

    Using modulated beam line-of-sight threshold ionization mass spectrometry (LOS-TIMS) we measured absolute O, O2, and Ar densities, and the average neutral-gas temperature in an O2/Ar electrical discharge as a function of pressure in the plasma chamber and the mole fraction of Ar in O2; the pressure and mole fraction range was 25-200 mTorr and 0-0.90, respectively. Although LOS-TIMS is a versatile tool for measuring absolute radical densities, it requires careful vacuum design and calibration to account for various sources of error such as the contribution to the quadrupole mass spectrometer (QMS) ion current from the background gases, the ion mass-to-charge ratio dependent sensitivity of the various QMS components, and space-charge limitations in the QMS ionizer. In addition, collisions within the molecular beam extracted from the discharge must be taken into account particularly for higher plasma chamber pressures (>75 mTorr). In our measurements, these effects are carefully considered and the consequences of ignoring them are discussed. The O atom density increases with pressure and O2 mole fraction in the feed gas and is in the range of 2.1x1018-2.6x1019 m-3. At low pressures, our measurements show that the O2 translational temperature is higher than that for Ar

  10. 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)

  11. 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 the information (including measurement procedures) necessary to carry out most tasks associated with routine radioactivity measurement, including maintaining the necessary documentation. The primary audience for this report includes radiopharmacists, nuclear medicine technologists, medical physicists, technicians in secondary standards radioactivity laboratories and managers responsible for the operation of such facilities

  12. 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.

  13. 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

  14. 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

  15. 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

    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).

  16. Quality assurance of radioactivity measurements for soil samples in the investigation of national environmental natural radioactivity level

    International Nuclear Information System (INIS)

    The author summarizes the work of quality assurance of radioactivity measurements for soil samples in the investigation of national environmental natural radioactivity level. Examination of analytical methods of soil sample and inspection survey of analytical results for 29 provinces, municipalities, autonomy regions and cities of Wuhan and Baotou were introduced. The results of examination and inspection survey were given, and some technique problems involved were also discussed

  17. 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.

  18. 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 %.

  19. 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)

  20. Effect of self-vibration on accuracy of free-fall absolute gravity measurement with laser interferometer

    Science.gov (United States)

    Feng, Jin-yang; Wu, Shu-qing; Li, Chun-jian; Su, Duo-wu; Yu, Mei

    2015-02-01

    A free-fall absolute gravimeter was used to measure the gravity acceleration of a corner-cube released in high vacuum, and the gravity acceleration was determined by fitting the free-falling trajectories obtained through optical interferometry. During the measurement, the self-vibration of an absolute gravimeter caused ground vibration and the change in optical path length due to vibration of vacuum-air interface, which resulted in a measurement error. Numerical simulation was run by introducing vibration disturbance to the trajectories of free-fall. The effect of disturbance under different instrumental self-vibration conditions was analyzed. Simulation results indicated that the deviation of calculated gravity acceleration from the preset value and residuals amplitude after fitting depended on the amplitude and initial phase of the vibration disturbance. The deviation value and fitting residuals amplitude increased with the increasing of amplitude and there was a one-to-one correspondence between the two. The deviation of calculated gravity acceleration decreases by properly setting the initial phase difference of vibration disturbance with respect to the interference fringe signal.

  1. 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

  2. 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.

  3. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-11-19

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

  5. Measuring and evaluation of ambient radioactivity due to mining activities

    International Nuclear Information System (INIS)

    Systematic measuring, examination and evaluation of ambient radioactivity due to mining activities in the Laender Saxonia, Thuringia and Sachsen-Anhalt is placed under the responsibility of the Federal Government pursuant to paragraph 11, para. 8 German act on Preventive Radiation Protection (StrVG). The purpose of this Federal obligation is to examine the special radiological situation in these federal states which results from coal and ore mining activities, and in particular from uranium ore mining since the end of the second world war. The field and laboratory tests are exclusively performed by local firms specializing in the subject. The final evaluation of data is done by the BfS. The data are stored in the A.LAS.KA database (cadastre of long-standing pollution or contamination). (orig./DG)

  6. Age classification of water sediments. Measurement of isotope radioactivity

    International Nuclear Information System (INIS)

    The aim of this study was to find out whether measurement of radioactivity of environmental isotopes can serve to make statements on the age of individual samples of water sediment. As a precondition, the sediment must originate form suspended matter that deposited more or less uniformly at least over certain time intervals (time windows). Samples exhibiting chaotically changing sedimentation and erosion can still not be dated at the present stage. Conclusions from measurements on environmental isotopes: The individual samples are compared with reference samples of suspended matter of the O-38?m size fraction with respect to radioactivity concentration. Then they are classified roughly in four age groups: largely new sediments (sedimentation approximately since the last high water); sediments largely dating back to around 1986; sediments largely dating back to the Nineteen Sixties, and sediments older than 1955 (including the botton ground). In addition, the class of new sediments can again be subdivided into four more finely distinguished age classes by means of beryllium-7(7Be). The samples may also contain admixtures from all other age classes. Twentyeight out of the total of 52 single samples from the Rhine, Weser, and Erft were classified as new sediment and proved capable of subclassification. The other samples exhibited no uniform sedimentation. Older fractions were predominant in this age spectrum. These fractions were again classified roughly in three age classes. The 14 samples of the oldest class contain large fractions of uncontaminated botton ground. This and other similar procedures could be used for the following practical applications: The age classes can be taken into account in the valuation of chemical parameters and can thus facilitate water quality assessment, depending on the exact problem under study; sediments of apredefined age can be extracted from several individual samples taken from selected sites and analysed to clarify the initial issue of past hazardous incidents and emission and deposition situations; age calssification may also help improve sampling strategies and techniques. (orig.)

  7. 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 ?Sv in Cumbria to 1.5 ?Sv in the South East, compared with the average annual radiation dose of 2500 ?Sv 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)

  8. Application of a graded screen array for size measurements of radioactive aerosols in accelerator rooms

    Energy Technology Data Exchange (ETDEWEB)

    Osada, N.; Kanda, H. [Kyoto Univ. (Japan). Graduate School of Engineering; Oki, Y.; Yamasaki, K.; Shibata, S. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    2011-07-01

    A rapid measurement method for aerosol particle size is required to clarify the formation mechanism of freshly-formed radioactive aerosols in accelerator rooms. A graded screen array (GSA) method only requires brief sampling. Therefore, the GSA method is suitable for the measurement of radioactive aerosols in the accelerator rooms. In this work, a conventional GSA was applied to measure the particle size distribution of an aerosol. An influence of the radioactive gas on the GSA measurement was found. The adsorption of radioactive gases resulted in a discrepancy between the results of the GSA method and those of the diffusion battery method. An improved GSA method was developed to measure the radioactive aerosol formed in the accelerator room. The adsorption was measured by the improved GSA, and the influence of the radioactive gas was eliminated. The result of the improved GSA showed fair agreement with that of the diffusion battery system. (orig.)

  9. Time-of-flight system with a movable ion detector for absolute measurement of cyclotron beam energy

    International Nuclear Information System (INIS)

    A time-of-flight system for determining the absolute energy of ion beams has been developed for the azimuthally varying field (AVF) cyclotron at Japan Atomic Energy Agency (JAEA). Ion detectors, a microchannel-plate detector and a plastic scintillation detector, were applied to the system in order to achieve high time resolution measurement of the flight time and to cover a wide range of beam intensity in combination with a beam attenuator. The change of the flight length, performed by moving the plastic scintillation detector with flexible bellows, allows determination of the mean beam energy only from the relative measurement of the flight time and the flight length without knowing their absolute values. A maximum movable distance of 2 m yields the difference in the time of flight from 16 to 94 ns for the energy range of ion beams accelerated by the JAEA AVF cyclotron. The time-of-flight system even with the 2 m change in the flight length achieves accurate energy determination of the order of 0.1%, since the relative measurement has an advantage of elimination of the uncertainties in determination of the time zero and the length zero. The time-of-flight measurement with the relative measurement also allows estimation of the beam energy spread without conventional expensive systems such as a magnetic spectrometer. By comparing the widths of the time-of-flight spectra of ions accumulated at different flight lengths, we have estimated the energy spread. In order to reduce the labor process of the coincidence detection of ions in the time-of-flight measurement, we have also accomplished a simple estimation method for mean beam energy determination with a beam bunch, naturally modulated with the acceleration RF of the cyclotron. The mean beam energy has been obtained from the shift of the beam bunch centroids at different flight lengths in the time-of-flight spectrum

  10. 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)

  11. Radioactivity

    International Nuclear Information System (INIS)

    Large amounts of radioactivity can be released in nuclear accidents and nuclear explosions. Important events since the atomic bombs of 1945 are listed more or less in chronological order, including the nuclear weapons tests after World War II and the accidents recorded in nuclear facilities. (DG)

  12. 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

  13. 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)

  14. 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 Observation—QA4EO".

  15. 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

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

    International Nuclear Information System (INIS)

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

  17. Radioactivity measurements in some building materials in Khartoum state

    International Nuclear Information System (INIS)

    In this work various samples of building materials like red brick, cement as new building materials and soft sand,coarse sand, lime,red clay, mud brick as conventional materials, from different areas in Khartoum state were measured to determine the radioactivity concentration. Activity concentration of (226Ra), (232Ra), (40k), and (137Cs) in these sample were measured. Measurements were done using gamma ray spectrometry system with high purity germanium (HPGe) detector of the radiation protection and environmental monitoring department of sudan atomic energy commission. The analysis was performed using GAN Aas software program. The specific activity of (226Ra) and (232th) were compared with different values of other countries and found to be in a lower range. The radium equivalent activities Raeg for these samples were calculated. Results were found to be from 78.62 to 18.38 Bq/kg. The criteria formula was applied to the samples; all results are less than one, which indicates that the annual dose from each sample is less than 1.5 mGy. to estimate the level of gamma radiation hazard associated with natural radionuclides in these building materials,the representative level index were calculated for each material. Results obtained ranging from 0.6 to 0.136. The activity concentrations fro the above nuclides shows lower values for the conventional building materials. The radium equivalent, criteria formula and the level index values shows lower values for the conventional materials than the new one. (Author)

  18. 14. Protective measures for activities in Chernobyl's radioactively contaminated territories.

    Science.gov (United States)

    Nesterenko, Alexey V; Nesterenko, Vassily B

    2009-11-01

    Owing to internally absorbed radionuclides, radiation levels for individuals living in the contaminated territories of Belarus, Ukraine, and Russia have been increasing steadily since 1994. Special protective measures in connection with agriculture, forestry, hunting, and fishing are necessary to protect the health of people in all the radioactively contaminated territories. Among the measures that have proven to be effective in reducing levels of incorporated radionuclides in meat production are food additives with ferrocyanides, zeolites, and mineral salts. Significant decreases in radionuclide levels in crops are achieved using lime/Ca as an antagonist of Sr-90, K fertilizers as antagonists of Cs-137, and phosphoric fertilizers that form a hard, soluble phosphate with Sr-90. Disk tillage and replowing of hayfields incorporating applications of organic and mineral fertilizers reduces the levels of Cs-137 and Sr-90 three- to fivefold in herbage grown in mineral soils. Among food technologies to reduce radionuclide content are cleaning cereal seeds, processing potatoes into starch, processing carbohydrate-containing products into sugars, and processing milk into cream and butter. There are several simple cooking techniques that decrease radionuclides in foodstuffs. Belarus has effectively used some forestry operations to create "a live partition wall," to regulate the redistribution of radionuclides into ecosystems. All such protective measures will be necessary in many European territories for many generations. PMID:20002058

  19. Radioactive effluent measurements at the Army Pulse Radiation Facility

    International Nuclear Information System (INIS)

    Staff from the Pacific Northwest Laboratory (PNL) performed measurements of the radioactive effluents emitted by the Army Pulse Radiation Facility (APRF). These measurements were performed by collecting the cooling air that passed by the APRF reactor as it operated, passing the air through filters to collect the particulates and iodines, and collecting samples of the air to be analyzed for noble gases. The reactor operated for four test runs, including two pulses and two steady state runs. After each reactor run, the filters were counted using gamma spectrometry to identify the nuclides and to determine the activity of nuclides deposited on the filters. The study provided radionuclide release fraction data that can be used to estimate the airborne emissions resulting from APRF operations. The release fraction for particulate fission products and radioiodines, as derived from these measurements, was found to be 8.9 x 10-6 for reactor pulses and 4.3 x 10-6 for steady state operation. These values compare to a theoretical value of 1.5 x 10-5

  20. Measurement of absolute thermal neutron flux density in the core of miniature neutron source reactor

    International Nuclear Information System (INIS)

    In the miniature neutron source reactor (MNSR) reactivity and neutron flux are related. A xenon poison method is proposed for measurement of thermal neutron flux density. The principle measurement condition and procedures are discussed. The precision of the method is better than that of gold foil activation method