WorldWideScience
 
 
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.

1987-01-01

2

Calibrated radioactive sources - absolute measurements using a 4? ?-? apparatus  

International Nuclear Information System (INIS)

In this paper, the principle of the standardization of the radioisotopes by the 4? ? - ? 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)

1965-01-01

3

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

International Nuclear Information System (INIS)

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

1987-01-01

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)

2000-01-01

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)

[en] 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)

1981-01-01

6

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1987-09-01

7

Absolute measurement method of environment radon content  

International Nuclear Information System (INIS)

A portable environment radon content device with a 40 liter decay chamber based on the method of Thomas double filter radon content absolute measurement has been developed. The correctness of the method of Thomas double filter absolute measurement has been verified by the experiments to measure the sampling gas density of radon that the theoretical density has been known. In addition, the intrinsic uncertainty of this method is also determined in the experiments. The confidence of this device is about 95%, the sensitivity is better than 0.37 Bqm-3 and the intrinsic uncertainty is less than 10%. The results show that the selected measuring and structure parameters are reasonable and the experimental methods are acceptable. In this method, the influence on the measured values from the radioactive equilibrium of radon and its daughters, the ratio of combination daughters to the total daughters and the fraction of charged particles has been excluded in the theory and experimental methods. The formula of Thomas double filter absolute measuring radon is applicable to the cylinder decay chamber, and the applicability is also verified when the diameter of exit filter is much smaller than the diameter of inlet filter

1989-01-01

8

Absolute calibration in vivo measurement systems  

Energy Technology Data Exchange (ETDEWEB)

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.

Kruchten, D.A.; Hickman, D.P.

1991-02-01

9

Absolute cross-sections from X-? coincidence measurements  

International Nuclear Information System (INIS)

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

2009-01-11

10

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-01-11

11

Amoeba-absoluteness and projective measurability  

CERN Multimedia

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).

Brendle, J

1992-01-01

12

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

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

Wang Jian Qing; Yao Yan Ling; Jia Xue Wen

2003-01-01

13

Precision absolute positional measurement of laser beams.  

UK PubMed Central (United Kingdom)

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.

Fitzsimons ED; Bogenstahl J; Hough J; Killow CJ; Perreur-Lloyd M; Robertson DI; Ward H

2013-04-01

14

Absolute distance measurement with the MSTAR sensor  

Science.gov (United States)

The MSTAR sensor (Modulation Sideband Technology for Absolute Ranging) is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard intrferometers, and making it possible to measure distance with sub-nanometer accuracy. The sensor uses a single laser in conjugation with fast phase modulators and low-frequency detectors. We describe the design of the system - the principle of operation, the metrology source, beam-launching optics, and signal processing - and show results for target distance up to 1 meter. We then demonstrate how the system can be scaled to kilometer-scale distances.

Lay, Oliver P.; Dubovitsky, Serge; Peters, Robert D.; Burger, Johan; Ahn, Seh-Won; Steier, William H.; Fetterman, Harold R.; Chang, Yian

2003-11-01

15

Absolute Measurement of exp 152 Eu.  

Science.gov (United States)

A new method of the absolute measurement for exp 152 Eu was established based on the 4 pi beta - gamma spectroscopic anti-coincidence method. It is a coincidence counting method consisting of a 4 pi beta -counter and a Ge(Li) gamma -ray detector, in which...

H. Baba S. Baba S. Ichikawa T. Sekine I. Ishikawa

1981-01-01

16

Measurement of absolute gravity acceleration in Firenze  

Science.gov (United States)

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.

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

2011-01-01

17

MLU and IPSyn measuring absolute complexity  

Directory of Open Access Journals (Sweden)

Full Text Available This article compares the results of Mean Length of Utterance (MLU) and Index of Productive Syntax (IPSyn) with the structural complexity of spontaneous utterances produced by 30-month-old Finnish children in a semi-structured playing situation. The comparison was carried out in order to determine the aspects of structural complexity which can be detected with MLU and IPSyn. This research adopts the frameworks of absolute complexity together with a multidimensional view of utterance structure and, furthermore, applies it through Utterance Analysis (UA). The results of the comparison between the metrics and changes in structural complexity discovered by UA reveal that MLU and IPSyn do function as measures of structural complexity but only if used in close relation to each other. Because they focus on different aspects of utterances, the results of both metrics should be interpreted in relation to one another.DOI: http://dx.doi.org/10.5128/ERYa5.11

Lea Nieminen

2009-01-01

18

Absolute flow measurement with orthogonal internal calibration  

International Nuclear Information System (INIS)

Absolute flow measurement with orthogonal calibration was primarily designed for monitoring the percutaneous transluminal angioplasty. The method makes use of the well-known time-of-flight technique for time determinations and an original use of a marker catheter and two orthogonal projections for distance and diameter measurements. The first projection is used to measure the distance and the two orthogonal projections allow very accurate calibration of the vessel diameter. The accuracy of diameter measurements by the authors' methods was compared with that of the classic external calibration. The error of diameter measurement by external calibration can be as high as 24% (for a diameter of 3 mm), whereas with the authors' method this error was reduced to 7%. The authors' method is also independent of enlargement factor, pincushion distortion, and geometric location of the vessel. The accuracy of the method and the influence of the injection settings, distance between the markers, temporal sampling, field-of-view, and enlargement factor were tested with a flow phantom. An accuracy of 91.4% were achieved for a field-of-view of 25 cm and minimal enlargement, while for a 15-cm field-of-view of 25 cm and maximal enlargement the accuracy was improved up to 96.2%. The limiting factors of the authors' method are only the matrix size and the temporal sampling of digital subtraction angiography.

1987-12-04

19

Underground measurements of radioactivity  

Energy Technology Data Exchange (ETDEWEB)

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.

Laubenstein, M. E-mail: matthias.laubenstein@lngs.infn.it; Hult, M.; Gasparro, J.; Arnold, D.; Neumaier, S.; Heusser, G.; Koehler, M.; Povinec, P.; Reyss, J.-L.; Schwaiger, M.; Theodorsson, P

2004-09-01

20

Underground measurements of radioactivity  

International Nuclear Information System (INIS)

[en] 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

2004-01-01

 
 
 
 
21

Absolute decay width measurements in 16O  

International Nuclear Information System (INIS)

The reaction 126C(63Li, d)168O* at a 6Li bombarding energy of 42 MeV has been used to populate excited states in 16O. The deuteron ejectiles were measured using the high-resolution Munich Q3D spectrograph. A large-acceptance silicon-strip detector array was used to register the recoil and break-up products. This complete kinematic set-up has enabled absolute ?-decay widths to be measured with high-resolution in the 13.9 to 15.9 MeV excitation energy regime in 16O; many for the first time. This energy region spans the 14.4 MeV four-? breakup threshold. Monte-Carlo simulations of the detector geometry and break-up processes yield detection efficiencies for the two dominant decay modes of 40% and 37% for the ?+12C(g.s.) and a+12C(2+1) break-up channels respectively.

2012-09-18

22

Absolute activity measurements of pure beta emitters radionuclides using liquid scintillation detectors with three photomultipliers  

Energy Technology Data Exchange (ETDEWEB)

Liquid scintillation detectors are widely used for carrying out relative measurements of beta radioactivity in various fields. They can be used as well for absolute activity measurements, provided that an additional parameter physically related to the detector efficiency is available. In this paper, we present a method based on the use of three photomultipliers.

Vatin, R. (CEA Centre d' Etudes de Saclay, 91 - Gif-sur-Yvette (FR). Direction des Technologies Avancees)

1991-07-01

23

Radioactivity measurements principles and practice  

CERN Document Server

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

Mann, W B; Spernol, A

2012-01-01

24

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)

1956-01-01

25

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)

1997-01-01

26

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

1951-01-01

27

Measurement of the absolute luminosity with the ALEPH detector  

Energy Technology Data Exchange (ETDEWEB)

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.).

Decamp, D.; Deschizeaux, B.; Goy, C.; Lees, J.P.; Minard, M.N. (CNRS, 74 - Annecy-le-Vieux (France). Lab. de Physique des Particules); Alemany, R.; Crespo, J.M.; Delfino, M.; Fernandez, E.; Gaitan, V.; Garrido, Ll.; Mir, Ll.M.; Pacheco, A. (Universidad Autonoma de Barcelona (Spain). Lab. de Fisica de Altas Energias); Catanesi, M.G.; Creanza, D.; De Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Maggi, M.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G. (INFN, Bari (Italy) Bari Univ. (Italy). Dipt. di Fisica); Gao, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Lou, J.; Qiao, C.; Ruan, T.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhao, W. (Academia Sinica, Beijing, BJ (China). Inst. of High-Energy Physics); Atwood, W.B.; Bauerdick, L.A.T.; Bird, F.; Blucher, E.; Bonvicini, G.; Bossi, F.; Boudreau, J.; Brown, D.; Burnett, T.H.; Drevermann, H.; Forty, R.W.; Grab, C.; Hagelberg, R.; Haywood,; ALEPH Collaboration

1992-02-01

28

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.).

1992-01-01

29

Establishment and application of standard devices for radioactivity measurement  

International Nuclear Information System (INIS)

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

1991-01-01

30

Absolute measurements of fast neutrons using yttrium  

Energy Technology Data Exchange (ETDEWEB)

Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic recalibration. The total yttrium efficiency for detecting 2.45 MeV neutrons was determined to be f{sub n}{approx}4.1x10{sup -4} with an uncertainty of about 0.27%. The yttrium detector was employed in the NX2 plasma focus experiments and showed the neutron yield of the order of 10{sup 8} neutrons per discharge.

Roshan, M. V.; Springham, S. V.; Rawat, R. S.; Lee, P.; Krishnan, M. [National Institute of Education, Nanyang Technological University, Singapore, 637616 (Singapore)

2010-08-15

31

Detection of Absolute Motion through Measurement of Synchronization Offsets  

Directory of Open Access Journals (Sweden)

Full Text Available An absolute reference frame may be defined as the one which is stationary with respect to the center of mass of the Universe and in which speed of propagation of light is an isotropic constant. Any motion with respect to this frame may be referred as absolute motion. In this paper we examine the Sagnac effect of absolute motion in the context of clock synchronization through GPS satellites in common view mode. The e-synchronization of two clocks A and B amounts to introduction of time offsets such that the time taken by a light pulse to propagate between A and B will be measured to be the same in both directions. Synchronization of two clocks through a GPS satellite in common view mode is effectively equivalent to e-synchronization of these clocks and introduces an absolute synchronization mismatch proportional to the absolute velocity and length of the baseline. Measurement of this synchronization offset between the GPS synchronized clocks at the ends of a long baseline will enable the practical detection of absolute motion of earth. Here we propose a simple experiment for detection of absolute motion through measurement of absolute synchronization offsets between two timing laboratories maintaining UTC time.

Gurcharn Singh Sandhu

2012-01-01

32

Measuring the absolute magnetic field using high-Tc SQUID  

International Nuclear Information System (INIS)

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

2006-06-01

33

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.

1992-01-01

34

Measurement of radioactivity in Norway  

International Nuclear Information System (INIS)

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

1992-01-01

35

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 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.

2001-01-01

36

Absolute branching fraction measurements of exclusive D0 semileptonic decays.  

Science.gov (United States)

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 --> p-e+ve and improved measurements of the absolute branching fractions for D0 decays to K-e+ve, pi-e+ve, and K*-e+ve. PMID:16383893

Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Phillips, E A; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shibata, E I; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H

2005-10-24

37

Measurement of weak radioactivity  

CERN Multimedia

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

Theodorsson, P

1996-01-01

38

Absolute density measurements in the middle atmosphere  

Energy Technology Data Exchange (ETDEWEB)

In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ({proportional_to} 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. (orig.)

Rapp, M.; Luebken, F.J. [Leibniz Inst. of Atmospheric Physics, Kuehlungsborn (Germany); Gumbel, J. [Stockholm Univ. (Sweden). Dept. of Meteorology

2001-05-01

39

Absolute density measurements in the middle atmosphere  

Directory of Open Access Journals (Sweden)

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)

M. Rapp; J. Gumbel; F.-J. Lübken

0000-01-01

40

Absolute disintegration rate measurements of Ga-67  

Energy Technology Data Exchange (ETDEWEB)

The procedure for determining the {sup 67}Ga disintegration rate by means of a 4{pi}{beta}-{gamma} coincidence system is described. The main difficulty with this radionuclide is the presence of a meta-stable state with a half-life of 9.1 {mu}s and a total internal conversion coefficient of 0.89. This required several measurements using different electronic dead-times to correct for detection of delayed events. Gamma spectrometry measurements by a HPGe detector were also performed in order to check for impurities.

Attie, Marcia R.P.; Koskinas, Marina F.; Dias, Mauro S.; Fonseca, Katia A

1998-09-11

 
 
 
 
41

Measurements of Absolute Abundances in Solar Flares  

CERN Document Server

We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory (SDO). 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 $...

Warren, Harry P

2013-01-01

42

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).

1979-01-01

43

Absolute measurements with a 4 ?-counter  

International Nuclear Information System (INIS)

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

1959-01-01

44

Absolute flow measurements using pulsed Doppler US. Work in progress.  

UK PubMed Central (United Kingdom)

Quantitative flow measurements were assessed in both laboratory and canine models using pulsed Doppler ultrasonography (US). A hydrodynamic model consisting of a Harvard pulsatile pump, a water bath, tubing, and a variable resistance reservoir was used to obtain absolute volumetric flow measurements. Parameters including angle of incidence, size of tubing, stroke volume, stroke rate, sample volume, and transducer frequency were changed independently. The effect of varying these parameters on the determination of absolute flow was analyzed. Absolute flow measurements using duplex US were performed in the canine aorta and femoral artery with reference to the electromagnetic flow probe. These data are presented, along with methods to reduce error in flow measurements that can be directly applied to quantitative estimates of blood flow in humans.

Walter JP; McGahan JP; Lantz BM

1986-05-01

45

Notes on van der Meer Scan for Absolute Luminosity Measurement  

CERN Multimedia

An absolute luminosity can be measured in an accelerator by sweeping beams transversely across each other in the so called van der Meer scan. We prove that the method can be applied in the general case of arbitrary beam directions and a separation scan plane. A simple method to develop an image of the beam in its transverse plane from spatial distributions of interaction vertexes is also proposed. From the beam images one can determine their overlap and the absolute luminosity. This provides an alternative way of the luminosity measurement during van der Meer scan.

Balagura, Vladislav

2011-01-01

46

Notes on Van der Meer scan for absolute luminosity measurement  

International Nuclear Information System (INIS)

The absolute luminosity can be measured in an accelerator by sweeping beams transversely across each other in the so-called van der Meer scan. We prove that the method can be applied in the general case of arbitrary beam directions and a separation scan plane. A simple method to develop an image of the beam in its transverse plane from spatial distributions of interaction vertexes is also proposed. From the beam images one can determine their overlap and the absolute luminosity. This provides an alternative way of the luminosity measurement during van der Meer scan.

2011-10-21

47

Absolute branching fraction measurements of exclusive D+ semileptonic decays.  

Science.gov (United States)

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 K0e+ve, pi0e+ve, K*0e+ve, and p0e+ve, and the first observation and absolute branching fraction measurement of D+ --> omega e+ve. We also report the most precise tests to date of isospin invariance in semileptonic D0 and D+ decays. PMID:16383892

Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Weaver, K M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J

2005-10-24

48

Measurement of radioactivity in Norway  

International Nuclear Information System (INIS)

[en] A nation-wide network of seven monitoring stations for continuous registration of radioactivity in the air has been established in Norway. Via the telecommunication network, collected data are dayly automatically transmitted to the Norwegian Institute for Air Research (NILU). High radiation levels will trigger an alarm for immediate transmission. The monitoring system and field experiences in connection with its operation are described. NILU's directions in the event of radiation alarm are specified and radiation measurements for 1987 are presented

1988-01-01

49

Measurement of radioactivity in Norway  

International Nuclear Information System (INIS)

A nation-wide network of 11 monitoring stations for continous registration of radioactivity in the air has been established in Norway. Via the telecommunication network, collected data are dayly automatically transmitted to the Norwegian Institute for Air Research (NILU). High radiation levels trigger an alarm for immediate transmission. The monitoring system and experiences in connection with its operation are described. Results from measurements in 1989 are presented. 18 figs

1990-01-01

50

Measurement of radioactivity in Norway  

International Nuclear Information System (INIS)

[en] 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

1989-01-01

51

System for remote measurement of radioactivity  

International Nuclear Information System (INIS)

[en] 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)

1978-01-01

52

Absolute measurement of the spectral reflection factor using photon detectors  

International Nuclear Information System (INIS)

The absolute reflectometer was developed on the basis of the theory for the integrating sphere. To measure monochromatic flux in the equipment a photomultiplier EMI type 9558 AM with S-20 photocathode was used. The following investigations were carried out: 1.Determination of the dependence of the photocurrent from the supply voltage of the photomultiplier. 2. Finding out the fault of the measuring system, constituted by the photomultiplier and the measuring device, according to Clark's method

1986-01-01

53

Measurement of the (sup 235) U absolute activity.  

Science.gov (United States)

The absolute activity of (sup 235) U contained in a sample was measured utilizing a sum-coincidence circuit which selects only the alpha particles emitted simultaneously with the 143 KeV gamma radiations from the (sup 231) Th (product nucleus). The alpha ...

C. C. Bueno M. D. S. Santos

1993-01-01

54

Absolutely Continuous Invariant Measures for Nonuniformly Expanding Maps  

CERN Document Server

For a large class of nonuniformly expanding maps of $\\Bbb R^m$, with indifferent fixed points and unbounded distorsion and non necessarily Markovian, we construct an absolutely continuous invariant measure. We extend to our case techniques previously used for expanding maps on quasi-H\\"{o}lder spaces. We give general conditions and provide examples to which apply our result.

Hu, H; Hu, Huyi; Vaienti, Sandro

2005-01-01

55

Absolute luminosity measurements with the LHCb detector at the LHC  

CERN Document Server

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...

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

56

Measurement of the absolute thermopower at high temperatures  

International Nuclear Information System (INIS)

[en] This work describes the measurement, in the range of the high temperatures, of the absolute thermopower of thermoelectric materials and the technological resolutions of the problems encountered. The method defined is applied to the measurement of thermoelectric power of binary alloys Mo-Nb at different compositions. The results permit to define the two components of a new thermocouple whose thermoelectric power is similar to those of W-Re thermocouples but which is less sensitive to transmutations under irradiations

1980-07-04

57

Absolute measurement of neutron capture cross sections with BGO scintillators  

International Nuclear Information System (INIS)

[en] For the absolute measurement of capture cross sections by the linac time-of-flight method, a total absorption gamma-ray detector which is composed of 12 bricks of BGO scintillators (5 x 5 cm2, 7.5 cm thick) was prepared. At first, with the BGO scintillation detectors, determination of the capture detection efficiency and absolute measurement of neutron flux incident upon the sample were carried out. Then, the experimental results were applied to the cross section measurement for the 197Au(n,?)198Au and Sb(n,?) reactions in the energy region between 0.01 and 1.0 eV, by using the 10B(n,? ?) reaction as a well known standard reference cross section. Since the result of the 197Au(n,?)198Au cross section showed a good agreement with the existing measurements and the evaluated data ENDF/B-V, it was verified that the BGO detection system could be used for the absolute measurement of capture cross sections. Then, the detectors were applied to the Sb(n,?) cross section measurement, whose data were not always enough in quality and quantity. (author)

1991-01-01

58

Absolute phase measurement in fringe projection using multiple perspectives.  

UK PubMed Central (United Kingdom)

A technique for absolute phase measurement in fringe projection for shape measurement is presented. A standard fringe projection system is used, comprising a camera and a projector fixed relative to each other. The test object is moved to different orientations relative to the fringe projection system. Using the system calibration parameters, the technique identifies homologous surface areas imaged from different perspectives and resolves the 2? phase ambiguity between them simultaneously. The technique is also used to identify regions of the phase maps corresponding to discrete surfaces on the object. The methods described are suitable for automatic shape measurement with a lightweight fringe projection probe mounted to a coordinate measuring machine.

Huddart YR; Valera JD; Weston NJ; Moore AJ

2013-09-01

59

Absolute gravity acceleration measurement in atomic sensor laboratories  

Science.gov (United States)

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.

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

2012-03-01

60

Measurement of the absolute branching fraction for D0?K-?+  

International Nuclear Information System (INIS)

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

1993-01-01

 
 
 
 
61

Measurement of radioactivity of waste  

Energy Technology Data Exchange (ETDEWEB)

The practical performance of a number of nondestructive measuring methods developed by Japan's plant construction companies is examined through a simulation study and testing for actual wastes. Measurements are made of the 'matrix error', which is associated with the variation in the degree of gamma-ray shielding resulting from an uneven distribution of density and radioactivity of waste across its container (200L drum). Six nondestructive methods are evaluated in terms of the matrix error. The six are based on CT measurement, permeability correction, gross gamma-ray measurement, horizontal collimator measurement, double collimator measurement, and spectral correction, respectively. The computer simulation study shows that for almost all methods, observations are equivalent or superior to simulation results in terms of accuracy, indicating that the accuracy of analysis of miscellaneous solid waste can be evaluated properly through simulation. Testing for actual waste is conducted in order to determine the appropriateness of the proposed model and demonstrate its practical performance. Analysis is made to determine the measuring accuracy of each method and identify the causes of errors to permit evaluation of waste-filled drums. (N.K.).

Ohno, Hiroo (Chubu Electric Power Co. Inc., Nagoya (Japan)); Tsutsumi, Masayoshi; Sawayanagi, Masahiro

1990-07-01

62

Two methods for accounting radioactive equilibrium disturbance in K-Ar system when determining absolute age of rocks  

International Nuclear Information System (INIS)

The method of accounting radioactive equilibrium in the K-Ar system when determining absolute age of rocks is suggested. The method supposes the performance of preliminary procedure when a dispersive sample is treated in the autoclave at high temperatures and pressures (up to 40O deg C and 6 kbar). In this case radiogenous apgon is emanated. Then, the content of radiogenous argon in the sample is determined by the method of isotope dilution, and that of potassium - by the method of flame photometry. In the recent years the 40Ar/39Ar method is widely used. Samples are preliminarily subjected to neutron irradiation, part of potassium transforms into 39Ar isotope by (n, p)-transition. The task of determining K-Ar age is in this case reduced to mass spectrometric measurement of isotope ratio 40Ar/39Ar

1983-01-01

63

Two methods for accounting radioactive equilibrium disturbance in K-Ar system when determining absolute age of rocks  

Energy Technology Data Exchange (ETDEWEB)

The method of accounting radioactive equilibrium in the K-Ar system when determining absolute age of rocks is suggested. The method supposes the performance of preliminary procedure when a dispersive sample is treated in the autoclave at high temperatures and pressures (up to 40O deg C and 6 kbar). In this case radiogenous argon is emanated. Then, the content of radiogenous argon in the sample is determined by the method of isotope dilution, and that of potassium - by the method of flame photometry. In the recent years the /sup 40/Ar//sup 39/Ar method has been widely used. Samples are preliminarily subjected to neutron irradiation, part of potassium transforms into /sup 39/Ar isotope by (n, p)-transition. The task of determining K-Ar age is in this case reduced to mass spectrometric measurement of isotope ratio /sup 40/Ar//sup 39/Ar.

Amirkhanov, Kh.I.; Brandt, S.B.; Batyrmurzaev, M.R.; Omarova, M.R. (AN SSSR, Makhachkala. Fizicheskij Inst.)

1983-01-01

64

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

CERN Multimedia

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))%.

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

65

Precision Absolute Beam Current Measurement of Low Power Electron Beam  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-11-01

66

Oblique-incidence sounder measurements with absolute propagation delay timing  

Energy Technology Data Exchange (ETDEWEB)

Timing from the Global Position Satellite (GPS) system has been applied to HF oblique incidence sounder measurements to produce ionograms whose propagation delay time scale is absolutely calibrated. Such a calibration is useful for interpreting ionograms in terms of the electron density true-height profile for the ionosphere responsible for the propagation. Use of the time variations in the shape of the electron density profile, in conjunction with an HF propagation model, is expected to provide better near-term (1-24 hour) HF propagation forecasts than are available from current updating systems, which use only the MUF. Such a capability may provide the basis for HF frequency management techniques which are more efficient than current methods. Absolute timing and other techniques applicable to automatic extraction of the electron-density profile from an ionogram will be discussed.

Daehler, M.

1990-05-03

67

Absolute neutral helium density measurements in helicon source plasmas  

Science.gov (United States)

Laser induced fluorescence (LIF) measurements of the plasma opacity are used as a novel diagnostic to determine the absolute density of a metastable state of neutral helium atoms in a helicon plasma. The absorption scale length at a wavelength of 587.725 nm (vacuum) is determined from measurements of fluorescence intensity as a function of distance along the laser path. With a collisional-radiative model of the state populations, the absolute ground state neutral helium density is estimated from the metastable state density measurement. This work expands upon previous work through measurements of neutral density, temperature, and flow at different radial positions. The measured neutral density decreases by two orders of magnitude from the edge of the plasma to the axis of the plasma source. Furthermore, the measurements are extended to a case that the helicon source was operated in a static mode in which the helium gas was not continuously fed into the chamber. As a result, the on-axis measurements show 42% increase for the plasma density and 69% decrease for the neutral density, when compared to the traditionally active gas feeding of the helicon sources; yielding an ionization fraction of approximately 90%.

Houshmandyar, Saeid; Scime, Earl

2012-10-01

68

NPL support for environmental radioactivity measurements in the United Kingdom  

International Nuclear Information System (INIS)

Full text: The United Kingdom was one of the first nations to initiate a civil nuclear power programme in the 1950s, with the first commercial generation of electricity being achieved in 1957. As the civil nuclear programme grew in size, an ongoing programme of environmental monitoring was instituted by central government that placed the responsibility for monitoring radioactivity in the local environment and the measurement of discharges of radioactive gases and liquids with the site operator, the Environment Agency, the Environment and Heritage Service, the Food Standards Agency and the Scottish Environment Protection Agency (or their predecessors). This presentation will discuss the sources of radioactivity in the UK environment from the nuclear industry, natural and other sources, focussing on how these sources of radioactivity are monitored and what future trends may be, taking the Windscale fire of 1957, the Chernobyl accident and the Litvinenko incident of 2006 as examples of how unexpected events have been addressed in the UK. As the national metrology institute for the UK, the NPL is required to provide support to the National Measurement System infrastructure of the UK, including the measurement of radioactivity. The presentation will also describe the absolute standardisation of radioactivity at the NPL, and how this is disseminated to organisations measuring environmental radioactivity in the UK by means of directly traceable standards of radioactivity and through the provision of an ongoing series of proficiency test exercises. The outcomes of some recent proficiency tests will be discussed, with emphasis on how the general performance of laboratories participating in these proficiency tests has matured over the years since their inception in 1989. In addition, the data treatment of such proficiency tests will also be examined in order to illustrate that statutory regulatory bodies, laboratory accreditation organisations and customers are able to objectively determine and compare the performance of laboratories carrying out radioactivity measurement work in the UK

2009-01-01

69

Measurement of absolute lung density by Compton-scatter densitometry  

International Nuclear Information System (INIS)

[en] The non-invasive determination of absolute lung density would be of great importance if it could be used in the evaluation of patients with pulmonary edema. To obtain this measurement, we have developed a portable densitometer using CdTe room-temperature detectors, compact collimators made of tantalum tubes and a 153Gd source. System response in the density range of 0.1 to 1 g/cm3 is linear. Variations in the absorption paths of up to 8 cm of lucite do not produce significant changes on measured density values

1975-11-19

70

Environmental radioactivity. Measurement and monitoring; Umweltradioaktivitaet. Messung und Ueberwachung  

Energy Technology Data Exchange (ETDEWEB)

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

NONE

2009-11-15

71

Alpha absolute power measurement in panic disorder with agoraphobia patients.  

UK PubMed Central (United Kingdom)

BACKGROUND: Panic attacks are thought to be a result from a dysfunctional coordination of cortical and brainstem sensory information leading to heightened amygdala activity with subsequent neuroendocrine, autonomic and behavioral activation. Prefrontal areas may be responsible for inhibitory top-down control processes and alpha synchronization seems to reflect this modulation. The objective of this study was to measure frontal absolute alpha-power with qEEG in 24 subjects with panic disorder and agoraphobia (PDA) compared to 21 healthy controls. METHODS: qEEG data were acquired while participants watched a computer simulation, consisting of moments classified as "high anxiety"(HAM) and "low anxiety" (LAM). qEEG data were also acquired during two rest conditions, before and after the computer simulation display. RESULTS: We observed a higher absolute alpha-power in controls when compared to the PDA patients while watching the computer simulation. The main finding was an interaction between the moment and group factors on frontal cortex. Our findings suggest that the decreased alpha-power in the frontal cortex for the PDA group may reflect a state of high excitability. CONCLUSIONS: Our results suggest a possible deficiency in top-down control processes of anxiety reflected by a low absolute alpha-power in the PDA group while watching the computer simulation and they highlight that prefrontal regions and frontal region nearby the temporal area are recruited during the exposure to anxiogenic stimuli.

de Carvalho MR; Velasques BB; Freire RC; Cagy M; Marques JB; Teixeira S; Rangé BP; Piedade R; Ribeiro P; Nardi AE; Akiskal HS

2013-10-01

72

Absolute and specific measures of research group excellence  

CERN Multimedia

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

Mryglod, O; Holovatch, Yu; Berche, B

2012-01-01

73

Heterodyne interferometer for absolute amplitude vibration measurements with femtometer sensitivity.  

UK PubMed Central (United Kingdom)

A heterodyne interferometer for highly sensitive vibration measurements in the range 100kHz - 1.3GHz is presented. The interferometer measures absolute amplitude and phase. The signal processing of the setup is analyzed and described in detail to optimize noise suppression. A noise floor of 7.1fm/Hz1/2 at 21MHz was achieved experimentally where the bandwidth is the inverse of all time needed for filter settling and signal sampling. To demonstrate the interferometer, measurements up to 220MHz were performed on arrays of capacitive micromachined ultrasonic transducers (CMUTs). The measurements provided detailed information e.g. about the frequency response, vibration patterns and array uniformity. Such measurements are highly valuable in the design process of ultrasonic transducers.

Leirset E; Engan HE; Aksnes A

2013-08-01

74

Absolute measurement of CTR scattering and comparison with theoretical predictions  

Science.gov (United States)

Absolute intensity measurement of the CTR scattering from a Si(1 1 1) wafer of which the surface was mechanochemically treated was carried out by a technique of using an imaging plate detector in conjunction with a synchrotron radiation source [T. Shimura and J. Harada, J. Appl. Cryst. 26 (1993) 151]. Observation showed an excellent agreement with the prediction given by Kashihara et al. [Jpn. J. appl. Phys. 26 (1987) 1029] and Vlieg et al. [Surface Sci. 210 (1989) 301], suggesting that the approximation based on the kinematical diffraction theory is justified.

Shimura, T.; Harada, J.

1994-04-01

75

Absolute Measurement of Hadronic Branching Fractions of the Ds+ Meson  

International Nuclear Information System (INIS)

The branching fractions of Ds± meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb-1 of e+e- collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight Ds± decays with a double tag technique. In particular we determine the branching fraction B(Ds+?K-K+?+)=(5.50±0.23±0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K-K+?+ decay mode.

1485-01-00

76

Absolute measurement of hadronic branching fractions of the Ds+ meson.  

Science.gov (United States)

The branching fractions of D(s)(+/-) meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb(-1) of e(+)e(-) collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D(s)(+/-) decays with a double tag technique. In particular we determine the branching fraction B(D(s)(+)-->K(-)K(+}pi(+))=(5.50+/-0.23+/-0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K(-)K(+)pi(+) decay mode. PMID:18518186

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

2008-04-23

77

3D measurement of absolute radiation dose in grid therapy  

International Nuclear Information System (INIS)

Spatially fractionated radiotherapy through a grid is a concept which has a long history and was routinely used in orthovoltage radiation therapy in the middle of last century to minimize damage to the skin and subcutaneous tissue. With the advent of megavoltage radiotherapy and its skin sparing effects the use of grids in radiotherapy declined in the 1970s. However there has recently been a revival of the technique for use in palliative treatments with a single fraction of 10 to 20 Gy. In this work the absolute 3D dose distribution in a grid irradiation is measured for photons using a combination of film and gel dosimetry.

2004-01-01

78

Absolute luminosity measurement at LHCb with beam-gas imaging  

CERN Document Server

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). The technique has been used in 10 LHC fills during 2012 including and also provided a first luminosity measurement for proton-lead collisions. This talk presents the principles of the gas injection and the improvements reached with the increased pressure. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch. Those uncertainties are becoming the dominating factor because the uncertainty on the total beam current have been reduced.

Barschel, C

2013-01-01

79

Absolute branching fraction measurements for exclusive Ds semileptonic decays  

International Nuclear Information System (INIS)

We measure the absolute branching fractions of Ds semileptonic decays where the hadron in the final state is one of ?, ?, ?', KS0, K*0, and f0, using 2.8x105 e+e-?DsDs* decays collected in the CLEO-c detector at a center-of-mass energy close to 4170 MeV. We obtain B(Ds+??e+?e)=(2.29±0.37±0.11)%, B(Ds+??e+?e)=(2.48±0.29±0.13)%, B(Ds+??'e+?e)=(0.91±0.33±0.05)%, where the first uncertainties are statistical and the second are systematic. We also obtain B(Ds+?K0e+?e)=(0.37±0.10±0.02)%, and B(Ds+?K*0e+?e)=(0.18±0.07±0.01)%, which are the first measurements of Cabibbo suppressed exclusive Ds semileptonic decays, and, B(Ds+?f0e+?e)xB(f0??+?-)=(0.13±0.04±0.01)%. This is the first absolute product branching fraction determination for a semileptonic decay including a scalar meson in the final state.

2009-09-01

80

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.)

1983-01-01

 
 
 
 
81

Method and apparatus for making absolute range measurements  

Energy Technology Data Exchange (ETDEWEB)

This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through a screen at least partially opaque at the wavelength. The screen has an aperture sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector spaced some distance from the screen. The detector detects the central intensity of the beam as well as a set of intensities displaced from a center of the aperture. The distance from the source to the target can then be calculated based upon the known wavelength, aperture radius, and beam intensity.

Earl, Dennis D [Knoxville, TN; Allison, Stephen W [Knoxville, TN; Cates, Michael R [Oak Ridge, TN; Sanders, Alvin J [Knoxville, TN

2002-09-24

82

Absolute measurement of the critical scattering cross section in cobalt  

International Nuclear Information System (INIS)

[en] Small-angle neutron scattering techniques have been used to study the angular distribution of the critical scattering from cobalt above T/sub c/. These measurements have been put on an absolute scale by calibrating the critical scattering directly against the nuclear incoherent scattering from cobalt. In this way the interaction range r1, which appears in the classical and modified Ornstein--Zernike expressions for the asymptotic form of the spin pair correlation function and is related to the strength of the spin correlations, has been determined. We obtain r1/a = 0.46 +- 0.03 for the ratio of the interaction range to the nearest-neighbor distance in cobalt. This result is in good agreement with theoretical predictions. Lack of agreement among previous determinations of the ratio r1/a made in iron failed to provide a definitive comparison with theory

1975-12-09

83

Absolute measurement of neutron fluxes inside the reactor core  

International Nuclear Information System (INIS)

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

1964-01-01

84

Absolute measurements of the thermal neutron flux by the foil activation method using the 4??-? coincidence technique  

International Nuclear Information System (INIS)

[en] An analysis of the correction factors required for the ?-? 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)

1977-01-01

85

On measuring the absolute scale of baryon acoustic oscillations  

CERN Document Server

The baryon acoustic oscillation (BAO) feature in the distribution of galaxies provides a fundamental standard ruler which is widely used to constrain cosmological parameters. In most analyses, the comoving length of the ruler is inferred from a combination of CMB observations and theory. However, this inferred length may be biased by various non-standard effects in early universe physics; this can lead to biased inferences of cosmological parameters such as H_0, \\Omega_m and w, so it would be valuable to measure the absolute BAO length by combining a galaxy redshift survey and a suitable direct low-z distance measurement. One obstacle is that low-redshift BAO surveys mainly constrain the ratio r_S / D_V(z), where D_V is a dilation scale which is not directly observable by standard candles. Here, we find a new approximation D_V(z) \\simeq (3/4) D_L(4z/3) (1+ 4z/3)^{-1} (1 - 0.02455 z^3 + 0.0105 z^4) which connects D_V to the standard luminosity distance D_L at a somewhat higher redshift; this is shown to be ver...

Sutherland, Will

2012-01-01

86

An empirical reevaluation of absolute pitch: behavioral and electrophysiological measurements.  

UK PubMed Central (United Kingdom)

Here, we reevaluated the "two-component" model of absolute pitch (AP) by combining behavioral and electrophysiological measurements. This specific model postulates that AP is driven by a perceptual encoding ability (i.e., pitch memory) plus an associative memory component (i.e., pitch labeling). To test these predictions, during EEG measurements AP and non-AP (NAP) musicians were passively exposed to piano tones (first component of the model) and additionally instructed to judge whether combinations of tones and labels were conceptually associated or not (second component of the model). Auditory-evoked N1/P2 potentials did not reveal differences between the two groups, thus indicating that AP is not necessarily driven by a differential pitch encoding ability at the processing level of the auditory cortex. Otherwise, AP musicians performed the conceptual association task with an order of magnitude better accuracy and shorter RTs than NAP musicians did, this result clearly pointing to distinctive conceptual associations in AP possessors. Most notably, this behavioral superiority was reflected by an increased N400 effect and accompanied by a subsequent late positive component, the latter not being distinguishable in NAP musicians.

Elmer S; Sollberger S; Meyer M; Jäncke L

2013-10-01

87

Closing the gap between absolute and relative measures of localization, concentration or specialization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper solves one of the puzzles in the analysis of regional and industrial distributions of economic activity, the discrepancy between absolute and relative measures. It shows that the difference between an absolute and a relative Theil index of localization can be expressed in terms of absolut...

Bickenbach, Frank; Bode, Eckhardt; Krieger-Boden, Christiane

88

Global change and the measurement of absolute sea-level  

Energy Technology Data Exchange (ETDEWEB)

To quantify properly the long-term response of sea-level to climate change, land motions must be separated from the apparent or relative sea-level change recorded by conventional tide/sea-level gauges. Here we present a concept for global measurement of the true or ''absolute'' sea-level change, which combines recent advances in space-based geodetic techniques with plans for a global sea-level network under the World Climate Research Programme (WCRP). Data from initial feasibility tests show that land motion, due to global (plate tectonic), regional (glacial rebound), or local (fluid withdrawal) effects, can probably be measured to /plus minus/1cm (on a single measurement basis) by an innovative combination of Very Long Baseline Interferometry (VLBI) and Global Positioning System (GPS) techniques. By making repeated observations of position at a number of tide gauges using portable, economical GPS receivers in a differential mode relative to the fewer, more stable, but more expensive VLBI observatories, it will be possible to subtract land motion from the relative sea-level signal. Decadal to century scale trends at the 1-2mm y/sup /minus/1/ level will be resolvable in the sea-level and vertical land motion time series within about a decade. Detection of subsidence or uplift at specific gauges will allow correction for land motion or deletion of bad data when computing regional or global, i.e. eustatic, sea-level changes. If the predicted crustal motions are confirmed, we can also have more confidence in the use of historical tide/sea-level gauge records in retrospective studies of sea-level change related to climate variability on decadal or longer time scales.

Diamante, J.M.; Pyle, T.E.; Carter, W.E.; Scherer, W.

1987-01-01

89

Method and apparatus for making absolute range measurements  

Energy Technology Data Exchange (ETDEWEB)

This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through an object which causes it to be split (hereinafter referred to as a "beamsplitter"), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beamsplitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention.

Allison, Stephen W. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Key, William S. (Knoxville, TN); Sanders, Alvin J. (Knoxville, TN); Earl, Dennis D. (Knoxville, TN)

1999-01-01

90

ATLAS ALFA—measuring absolute luminosity with scintillating fibres  

CERN Document Server

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...

Franz, S

2009-01-01

91

Absolute measurement of the neutron emission rate with a manganese sulphate bath system  

International Nuclear Information System (INIS)

Recently, an absolute measurements of the neutron emission rates of neutron sources were carried out for 241Am - Be and 252Cf over a wide range of emission rates (2 x 105 ? 2 x 108 s-1). The measurements were done using a Manganese Sulphate Bath method, which is the principal method for the absolute determination of the neutron emission rates of radionuclide neutron sources. The efficiency of the system was determined by means of a 56Mn radioactive source of well-defined activity. Various corrections, including epithermal neutron capture, the (n, p) and the (n, ?) reactions, the leakage of neutrons, etc., were replaced by a direct calculation of the neutron capture probability for manganese nuclei. The neutron capture probability of the manganese nuclei was determined by using a careful MCNP (Monte Carlo N-Particle Transport Code System) calculation and was 0.102 ? 0.105 for the present status of the KRISS (Korea Research Institute of Standards and Science) Manganese Sulphate Bath system. The emission rates were determined with an uncertainty of

2005-01-01

92

Measurements of environmental radioactivity, Ispra 1988  

International Nuclear Information System (INIS)

In this report there are briefly described the measurements of environmental radioactivity performed during 1988 by the site survey group of the Radioprotection Division at the Joint Research Centre Ispra Establishment. Data are given on the concentrations of Sr-90, Cs-137, 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

1989-01-01

93

Accurate absolute measurement of trapped Cs atoms in a MOT  

Energy Technology Data Exchange (ETDEWEB)

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)

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

94

Accurate absolute measurement of trapped Cs atoms in a MOT  

International Nuclear Information System (INIS)

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 (?+ - ?-) 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 107 Cs atoms trapped in our MOT measured with an uncertainty no greater than 6.4%. (Author)

2007-01-01

95

Measurements of radioactivity in former thorium workers  

International Nuclear Information System (INIS)

In the studies of the possible health effects of occupational exposure to compounds of thorium, and of the metabolism of inhaled thorium, 100 men were selected randomly for physical examination from the morbidity study group of 558 men who had worked at a thorium refinery for one year or longer in occupations involving probable exposure to compounds of thorium. Measurements of radioactivity in vivo have now been made on 40 of the 100. Before these subjects visited the Center for Human Radiobiology, we investigated the radioactive content of six other men who were thought to have been exposed to radioactive dust and aerosols. The presence in these men of members of the thorium decay chain showed that we could expect to find radioactivity in at least some of the 100 subjects

1977-01-01

96

Direct mass measurements with radioactive beams  

International Nuclear Information System (INIS)

Atomic mass differences between radioactive isotopes have been measured directly with an isotope separator. The technique, its advantages and some recent improvements are described. Two measurements on isotopes of In and Br have been performed with the improved technique and the precision achieved was close to the 1 ppm level.

1990-01-01

97

Low-level radioactivity measurements in Argentina  

Energy Technology Data Exchange (ETDEWEB)

Low level measurements of environmental radioactivity are regularly performed at the Argentina AEC and at a joint institute for geological dating. Preoperation studies, operational monitoring, fallout and air monitoring, monitoring of milk and food, monitoring of Parana River samples, and measurements of external exposures are reviewed.

Rodriguez-Pasques, R.H.

1980-01-01

98

Environmental radioactivity measurements in the United Kingdom  

Energy Technology Data Exchange (ETDEWEB)

An account is given of current work in the field of radioactivity measurements in the marine and terrestrial environments of the United Kingdom. Reference is made to the increasing need for quality assurance and to the role of measurement standards and traceability. 20 references.

Christmas, P.

1984-01-01

99

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 ?-emitters and one containing ?/?-emitters. Two thirds of the participants measured the ?/?-emitter sample only, the remainder measured both. The results are presented. (author).

1991-01-01

100

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)

1987-01-01

 
 
 
 
101

Environmental radioactivity measurement intercomparison exercise 1990  

Energy Technology Data Exchange (ETDEWEB)

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 {beta}-emitters and one containing {beta}/{gamma}-emitters. Two thirds of the participants measured the {beta}/{gamma}-emitter sample only, the remainder measured both. The results are presented. (author).

Jerome, S.M. [National Physical Lab., Teddington (United Kingdom). Div. of Radiation Science and Acoustics

1991-05-01

102

Radioactive Beam Measurements to Probe Stellar Explosions  

International Nuclear Information System (INIS)

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.

2010-01-01

103

System for measuring radioactivity of labelled biopolymers  

Energy Technology Data Exchange (ETDEWEB)

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.

Gross, V.

1980-07-08

104

Flow measurement of blood radioactivity in animals  

Energy Technology Data Exchange (ETDEWEB)

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 /sup 14/C-urethane and (/sup 14/C)methyl-piperazinyl pyrazino benzoxazepine maleate.

Simonnet, F.; Azria, M.; Bourdinaud, M.; Simonnet, G.

1982-01-01

105

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.

1982-01-01

106

Accurate absolute measurement of trapped Cs atoms in a MOT  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish 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 CENAM. 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 (more) 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 (more) 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%.

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

2007-10-01

107

Apparatus for measuring a concentration of radioactivity  

International Nuclear Information System (INIS)

[en] Disclosed is an apparatus for measuring concentration of radioactivity in a fluid circulating in a cooling system or a disposal system, etc., of a nuclear power plant (e.g. coolant), the apparatus having a plurality of sampling tubes with different diameters depending on the intensities of radioactivity, and the sampling tubes having valves for switching from one fluid to another fluid. The sampling tubes are connected to the system to a discharge pipe, and are disposed in the proximity of a radiation detector adapted to issue a signal representative of radiation. The issued signal is supplied to a multichannel pulse height analyzer and a data processing system providing an indication of the concentrations of radioactivities for respective radionuclides

1978-01-01

108

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.)

1981-01-01

109

Measurements of natural radioactivity in phosphate fertilizers  

Energy Technology Data Exchange (ETDEWEB)

The natural radioactivity, mainly due to radium ({sup 226}Ra), in phosphate fertilizers used in north-western Greece has been measured by {gamma}-spectroscopy. Also radioactivity measurements were performed in soil samples and were compared to samples from undisturbed soils. {sup 226}Ra belongs to the {sup 238}U chain and is the precursor of radon gas ({sup 222}Rn). 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{sup -1} and the radon concentrations in warehouses were measured 540-3320 Bq m{sup -3}. The results are discussed from the radiation protection point of view.

Ioannides, K.G.; Mertzimekis, T.J.; Papachristodoulou, C.A. [Nuclear Physics Laboratory, The University of Ioannina, Ioannina (Greece); Tzialla, C.E. [Agricultural Research Station of Ioannina, Ioannina (Greece)

1997-02-17

110

[Working environment measurement of radioactive substances].  

UK PubMed Central (United Kingdom)

The control of the working environment is one of the most important duties in any working place to prevent occupational disease. In Japan, in the case of the controlled area using unsealed radioisotopes, the measurement of the concentration of airborne radioactive substances should be carried out under the regulations of the "Industrial Safety and Health Law" and the "Ordinance on Prevention of Ionizing Radiation Hazards". Many reports showed that the results of regular working environment measurements of radioactive substances were about background levels. Safe working environments are sufficiently guaranteed by a suitable estimation and handling under the strict regulation by the "Laws Concerning the Prevention from Radiation Hazards Due to Radioisotopes and Others". The regulation by "Ordinance on Prevention of Ionizing Radiation Hazards" would be relaxed in the field of education and research, which use very low quantities of radioactive substances, in ways such as estimation by calculation in place of the actual measurement, decrease of the number of monthly measurements, and measurement exemption for low levels of isotopes.

Kunugita N

2007-12-01

111

[Working environment measurement of radioactive substances].  

Science.gov (United States)

The control of the working environment is one of the most important duties in any working place to prevent occupational disease. In Japan, in the case of the controlled area using unsealed radioisotopes, the measurement of the concentration of airborne radioactive substances should be carried out under the regulations of the "Industrial Safety and Health Law" and the "Ordinance on Prevention of Ionizing Radiation Hazards". Many reports showed that the results of regular working environment measurements of radioactive substances were about background levels. Safe working environments are sufficiently guaranteed by a suitable estimation and handling under the strict regulation by the "Laws Concerning the Prevention from Radiation Hazards Due to Radioisotopes and Others". The regulation by "Ordinance on Prevention of Ionizing Radiation Hazards" would be relaxed in the field of education and research, which use very low quantities of radioactive substances, in ways such as estimation by calculation in place of the actual measurement, decrease of the number of monthly measurements, and measurement exemption for low levels of isotopes. PMID:18170964

Kunugita, Naoki

2007-12-01

112

Measurement of the absolute oscillator strength of the spectral line lambda=451. 966nm of gadolinium  

Energy Technology Data Exchange (ETDEWEB)

The absolute oscillator strength, f, was measured for the spectral line lambda=451.966 nm of gadolinium by means of the absorption method with the atomic beam acting as an absorbant. The absolute value of f which was obtained is f=0.28 +- 0.07.

Szynarowska, M.; Papaj, R. (Uniwersytet Jagiellonski, Krakow (Poland). Inst. Fizyki)

1982-03-01

113

Measuring the absolute decay probability of 82Sr by ion implantation  

Energy Technology Data Exchange (ETDEWEB)

We have developed a method of implanted ion counting in order to determine the absolute branching ratio of the 776.5 keV ?-ray transition in the decay sequence of 82Sr -> 82Rb -> 82Kr. A 215 MeV beam of 82Sr was produced at the Holifield Radioactive Ion Beam Facility and passed through an ionization chamber that counted and identified the ions before they were implanted into thin aluminum foils. Subsequent offline measurements using a Ge detector deduced the probability per decay of 82Rb for the 776.5 keV ?-ray in 82Kr to be 0.1493(38) in agreement with the accepted average value of 0.1508(16). This new technique measures directly the number of decaying nuclei in a given sample and significantly reduces the dependence on knowledge of the complete decay level scheme.

Gross, Carl J [ORNL; Rykaczewski, Krzysztof Piotr [ORNL; Stracener, Daniel W [ORNL; Wolinska-Cichocka, M [Oak Ridge Associated Universities (ORAU); Varner Jr, Robert L [ORNL; Miller, D [University of Tennessee, Knoxville (UTK); Jost, C [Oak Ridge National Laboratory (ORNL); Karny, M. [University of Warsaw; Korgul, A. [University of Warsaw; Liu, S [UNIRIB/Oak Ridge Associated Universities; Madurga, M [University of Tennessee, Knoxville (UTK)

2012-01-01

114

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.)

2001-01-01

115

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,?2 test, error propagation based on analysis of variance.Bibliography.z table,t-test table, Poisson index ,?2 test.

1994-07-01

116

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.)

2006-01-00

117

Cross section measurements on radioactive samples  

International Nuclear Information System (INIS)

[en] We have developed a system over the past few years at the Manuel Lujan, Jr. Neutron Scattering Center (LANSCE) for making (n,p) and (n,?) measurements on (mainly) radioactive nuclei. Measurements have included 7Be(n,p)7Li, 14N(n,p)14C, 17O(n,?)14C, 22Na(n,p)22Ne, 22Na(n,?)19F, 35Cl(n,p)35S and 36Cl(n,p)36S. The major basic physics motivation for these measurements has been the nuclear astrophysics to be learned. Currently, we are assembling a 4? detector of barium fluoride (BaF2) for making (n,?) measurements on radioactive nuclei with relatively short half lives. Once operational, this new detector should allow us to expand our measurements to many more nuclei, and to a broader range of nuclear physics and nuclear astrophysics issues addressed. Results of recent measurements are given and future plans are discussed. 38 refs., 2 figs

1990-01-01

118

High precision absolute laser power measurements using a magnetically suspended rotor  

Energy Technology Data Exchange (ETDEWEB)

Improvements to a torsion pendulum technique for making radiation pressure based measurements of laser power absolutely are presented. By replacing torsion fiber suspensions with magnetic suspensions, increases in sensitivity and reduced systematic drift are possible.

Gillies, G.T.; Allison, S.W.

1985-01-01

119

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.

2011-01-01

120

Absolute measurement of anti. nu. for /sup 252/Cf  

Energy Technology Data Exchange (ETDEWEB)

Neutron yields were determined by measuring the activities produced in the INEL manganese bath. Of the three fission methods used, the neutron-fission coincidence method was found to be the most consistent and reliable. The value of /sup 252/Cf anti ..nu.. obtained by these measurements was 3.764. (RWR)

Smith, J.R.; Reeder, S.D.; Gehrke, R.J.

1980-01-01

 
 
 
 
121

Absolute measurement of ? emitters with a 4 ? counter  

International Nuclear Information System (INIS)

The object of this work is to investigate the conditions under which the activity of ?-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 ? counter have been examined successively: - comparison of 4 ?, 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 ? counter can be considered a very satisfactory calibration instrument. (author)

1959-01-01

122

Absolute measurement of beam energy by Compton scattering  

International Nuclear Information System (INIS)

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

1992-01-01

123

Reliable, absolute flux measurements of highly charged ion beams  

Energy Technology Data Exchange (ETDEWEB)

This paper analyzes flux measurements of highly charged ion beams with probes such as wires, flags, or Faraday cups which intercept the ion beam to collect its charge. Such flux measurements can be substantially in error due to currents from secondary- and Auger-electrons generated in large numbers by the highly charged ions impacting on a surface. Typical problems and error checks are illustrated with examples. (author).

Stockli, M.P.; Winecki, S. [Kansas State Univ., Manhattan, KS (United States). Dept. of Physics

1995-09-01

124

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)

2010-01-01

125

Measurement of absolute bone blood flow by positron emission tomography  

International Nuclear Information System (INIS)

A method of measuring bone blood flow has been developed using 18F sodium fluoride and positron emission tomography. The blood flow levels are in line with those obtained experimentally from microsphere embolisation. This investigative method could be applied to elucidate a number of clinical questions involving bone perfusion. (orig.).

1986-01-01

126

4? proportional counter for absolute measurement of ?-emitters  

International Nuclear Information System (INIS)

The 4? counter is commonly used to measure the activity of ? sources, the one we describe does not advance a new conception but the issue of several years of investigations. The apparatus presents good performances about the qualities commonly required in that kind of counter: detection efficiency, plateau and dead time. Moreover technical characteristics give a great flexibility in use, particularly a possibility of adaptation in a ?,? coincidence unit. (authors)

1967-01-01

127

Space resolved absolutely calibrated VUV spectroscopic measurements on CTX  

International Nuclear Information System (INIS)

Space resolved particle confinement times have been measured in two independent methods in CTX. The confinement time near the magnetic axis was found to be tau/sub p/ approx. 100 ?s and a factor of two lower for the outer flux surfaces. Attempts at sustainment so far have resulted in cold plasmas and additional impurities being injected with the flux. This problem is being specifically addressed in the electrode facility

1984-01-01

128

Measurement of absolute excitation cross sections near threshold  

International Nuclear Information System (INIS)

Though many electron impact excitation cross sections have been measured with fair degrees of accuracy, often to several hundred eV above threshold, cross section measurements within the first 10 or 20 eV above threshold, (often the most important energy region for modeling calculations and particularly so for modeling of low energy plasmas) are particularly difficult to make with any degree of accuracy using conventional techniques. Though one can to some extent guess the functional shape of a cross section in this energy region, this is not a particularly desirable procedure. For example, while optically forbidden triplet states often have a maximum cross section near threshold due to charge exchange processes, optically allowed states tend to increase monotonically from threshold. However, the actual magnitude of cross sections are often governed by the presence of negative ion resonances lying energetically just below or above the threshold for excitation. Recently, we hav employed a modified version of the so-called trapped electron method to measure for the first time the total (with respect to angle) individual excitation functions of the 3S, 1S, 3P and 1P states of He to about 4 or 5 eV above their respective thresholds with high resolution. 8 references

1983-01-01

129

Ultracold Atoms as a Target: Absolute Scattering Cross-Section Measurements  

CERN Multimedia

We report on a new experimental platform for the measurement of absolute scattering cross-sections. The target atoms are trapped in an optical dipole trap and are exposed to an incident particle beam. The exponential decay of the atom number directly yields the absolute total scattering cross-section. The technique can be applied to any atomic or molecular species that can be prepared in an optical dipole trap and provides a large variety of possible scattering scenarios.

Würtz, P; Vogler, A; Ott, H; 10.1088/1367-2630/12/6/065033

2010-01-01

130

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

UK PubMed Central (United Kingdom)

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

Kim JA; Kim JW; Kang CS; Jin J; Eom TB

2012-11-01

131

Absolute measurement of the activity of 222Rn using a proportional counter  

International Nuclear Information System (INIS)

A measuring set-up comprising a proportional counter of calculable 222Rn efficiency and quantifiable active volume (?V222Rn efficiency is determined by computer simulation of the measured ?-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the 222Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of 222Rn is obtained, which is independent of the unit of activity of 226Ra

2002-04-01

132

Quality control of environmental radioactivity measurements  

International Nuclear Information System (INIS)

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

1993-01-01

133

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.

1993-04-02

134

Radioactivity measurements of ytterbium-169 brachytherapy sources  

International Nuclear Information System (INIS)

[en] Ytterbium-169 is being considered as a new radiation source for brachytherapy applications. This radioisotope emits photons with energies ranging from 50 to 308 keV (average energy 93 keV) and decays with a half life of 32 days. For these reasons, it is believed to offer radiological and radiobiological advantages over some other isotopes currently in use. One impediment to widespread clinical use of this isotope is the determination of source strength in units of air kerma rate [cGy h-l]. The source strength can be measured directly with an ion chamber or calculated indirectly from the source radioactivity [Bq] with corrections for encapsulation. Our attempts to reconcile these two approaches have led to the development of a spectrometric technique for determining the radioactivity of ytterbium-169 brachytherapy seeds. A High Purity Germanium (HPGe) spectrometer is used to count the 307.7 keV photon emitted within a defined solid angle. The intrinsic photopeak efficiency of the detector was determined by Monte Carlo simulation followed by experimental verification with an activity-calibrated europium-152 source. Finally, the HPGe system has been used to calibrate a re-entrant ionisation chamber, allowing routine of Ytterbium source activity for clinical applications. Copyright (1998) Australasian Physical and Engineering Sciences in Medicine

1998-01-01

135

Measures of radioactivity: a tool for understanding statistical data analysis  

CERN Multimedia

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

Montalbano, Vera

2012-01-01

136

High accuracy, absolute, cryogenic refractive index measurements of infrared lens materials for JWST NIRCam using CHARMS  

CERN Document Server

The refractive optical design of the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam) uses three infrared materials in its lenses: LiF, BaF2, and ZnSe. In order to provide the instrument's optical designers with accurate, heretofore unavailable data for absolute refractive index based on actual cryogenic measurements, two prismatic samples of each material were measured using the cryogenic, high accuracy, refraction measuring system (CHARMS) at NASA's Goddard Space Flight Center (GSFC), densely covering the temperature range from 15 to 320 K and wavelength range from 0.4 to 5.6 microns. Data reduction methods are discussed and graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient for these three materials are presented for selected wavelengths and temperatures along with estimates of index uncertainty. Coefficients for temperature-dependent Sellmeier fits of measured index are also presented with an example of their usage to predict absolute index ...

Leviton, Douglas B; Kvamme, Todd

2008-01-01

137

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

2000-08-11

138

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2000-08-11

139

Absolute photoluminescence quantum efficiency measurement of light-emitting thin films.  

UK PubMed Central (United Kingdom)

We developed an integrated monochromatic excitation light source integrating sphere based detection system to accurately characterize the absolute photoluminescence quantum efficiency of commonly used polymer light emitting films without using a reference sample. Our methodology is similar to the method reported by de Mello et al. [Adv. Mater. 9, 230 (1997)] In this Note, we show that the absolute photoluminescence quantum efficiency might only be measured when an appropriate calibration of the spectral variation of the measurement system is done. This calibration is especially important when employing a short excitation wavelength (<400 nm) for common silicon-based detector.

Johnson AR; Lee SJ; Klein J; Kanicki J

2007-09-01

140

Comparative Test of Two Methods of Quantum Efficiency Absolute Measurement Based on Squeezed Vacuum Direct Detection  

CERN Document Server

We realize and test in experiment a method recently proposed for measuring absolute quantum efficiency of analog photodetectors. Similarly to the traditional (Klyshko) method of absolute calibration, the new one is based on the direct detection of two-mode squeezed vacuum at the output of a traveling wave OPA. However, in the new method one measures the difference-photocurrent variance rather than the correlation function of photocurrents (number of coincidences), which makes the technique applicable for high-gain OPA. In this work we test the new method versus the traditional one for the case of photon-counting detectors where both techniques are valid.

Agafonov, I N; Iskhakov, T Sh; Penin, A N; Rytikov, G O; Shumilkina, O A

2010-01-01

 
 
 
 
141

Radioactivity measurements using storage phosphor technology  

Energy Technology Data Exchange (ETDEWEB)

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.

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

142

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.

1995-01-01

143

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)

1980-01-01

144

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.)

2002-01-01

145

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)

1989-01-01

146

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2005-07-27

147

Measurement of the Absolute Differential Cross Section for np Elastic Scattering at 194 MeV  

CERN Document Server

A tagged medium-energy neutron beam has been used in a precise measurement of the absolute differential cross section for np back-scattering. The results resolve significant discrepancies within the np database concerning the angular dependence in this regime. The experiment has determined the absolute normalization with 1.5% uncertainty, suitable to verify constraints of supposedly comparable precision that arise from the rest of the database in partial wave analyses. The analysis procedures, especially those associated with evaluation of systematic errors in the experiment, are described in detail so that systematic uncertainties may be included in a reasonable way in subsequent partial wave analysis fits incorporating the present results.

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

2006-01-01

148

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

Directory of Open Access Journals (Sweden)

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.

ANDREI ANTOHE; BEATRICE NEACSU; ANA STOCHIOIU; AURELIAN LUCA; MARIA SAHAGIA

2011-01-01

149

Fast analysis of the radioactivity measurement data based on bluetooth  

International Nuclear Information System (INIS)

Introduced the method that the bluetooth technique imbeds the radioactivity measurement instrument, and realized remote monitor and radioactivity measurement data quickly analysis through the use of the wireless technique-bluetooth and the portable handhold PC. Give the system design, the device select and connect, the circumstance of the software programming and actual debug. (authors)

2006-01-01

150

Introducing an Absolute Cavity Pyrgeometer for Improving the Atmospheric Longwave Irradiance Measurement (Presentation)  

Energy Technology Data Exchange (ETDEWEB)

Advancing climate change research requires accurate and traceable measurement of the atmospheric longwave irradiance. Current measurement capabilities are limited to an estimated uncertainty of larger than +/- 4 W/m2 using the interim World Infrared Standard Group (WISG). WISG is traceable to the Systeme international d'unites (SI) through blackbody calibrations. An Absolute Cavity Pyrgeometer (ACP) is being developed to measure absolute outdoor longwave irradiance with traceability to SI using the temperature scale (ITS-90) and the sky as the reference source, instead of a blackbody. The ACP was designed by NREL and optically characterized by the National Institute of Standards and Technology (NIST). Under clear-sky and stable conditions, the responsivity of the ACP is determined by lowering the temperature of the cavity and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The absolute atmospheric longwave irradiance is then calculated with an uncertainty of +/- 3.96 W/m2 with traceability to SI. The measured irradiance by the ACP was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the WISG. A total of 408 readings was collected over three different clear nights. The calculated irradiance measured by the ACP was 1.5 W/m2 lower than that measured by the two pyrgeometers that are traceable to WISG. Further development and characterization of the ACP might contribute to the effort of improving the uncertainty and traceability of WISG to SI.

Reda, I.; Hansen, L.; Zeng, J.

2012-08-01

151

A novel method for the absolute fluorescence yield measurement by AIRFLY  

CERN Document Server

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

Ave, M

2008-01-01

152

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.

2008-11-21

153

Measurements of emittance and absolute spectral flux of the PETRA undulator at DESY Hamburg  

Energy Technology Data Exchange (ETDEWEB)

The first synchrotron radiation beamline using a 4 m-long undulator at the 12 GeV storage ring PETRA delivers hard X-ray photons usable up to 300 keV. The photon intensity is measured on an absolute scale in the energy range between 16 and 60 keV and compared with calculated intensities. The experimental set-up described is also used to measure the horizontal and vertical emittance of the source. (au) 7 refs.

Hahn, U.; Schulte-Schrepping, H.; Balewski, K.; Schneider, J.R. [Hamburger Synchrotronstrahlungslabor HASYLAB at Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Ilinski, P.; Lai, B.; Yun, W.; Legnini, D.; Gluskin, E. [Argonne National Lab., Advanced Photon Source, Argonne, Illinois (United States)

1997-01-01

154

Suppression of aliasing in multi-sensor scanning absolute profile measurement.  

Science.gov (United States)

The task of anti-aliasing in absolute profile measurement by multi-sensor scanning techniques is considered. Simulation results are presented which demonstrate that aliasing can be highly reduced by a suitable choice of the scanning steps. The simulation results were confirmed by results obtained for interferometric measurements (Nyquist frequency 1/646 microm(-1)) on a specifically designed chirp specimen with sinusoidal waves of amplitude 100 nm and wavelengths from 2.5 mm down to 19 microm. PMID:19550509

Wiegmann, Axel; Schulz, Michael; Elster, Clemens

2009-06-22

155

Absolute continuity of projected SRB measures of coupled Arnold cat map lattices  

CERN Document Server

We study a d-dimensional coupled map lattice consisting of hyperbolic toral automorphisms (Arnold cat maps) that are weakly coupled by an analytic coupling map. We construct the Sinai-Ruelle-Bowen measure for this system and study its marginals on the tori. We prove they are absolutely continuous with respect to the Lebesgue measure if and only if the coupling satisfies a nondegeneracy condition.

Bonetto, F; Lebowitz, J L

2003-01-01

156

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

CERN Multimedia

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).

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

2002-01-01

157

Absolute blood volume in hemodialysis patients: why is it relevant, and how to measure it?.  

UK PubMed Central (United Kingdom)

Intradialytic hypotension (IDH) is the most common complication during hemodialysis and is associated with significant morbidity. It occurs as a consequence of a reduction in blood volume during ultrafiltration. Today, devices for monitoring relative blood volume (i.e. the intradialytic blood volume as a fraction of the blood volume at the start of the dialysis treatment) are routinely available and have been used to analyze the relationship between changes in relative blood volume and the occurrence of IDH in an attempt to derive critical thresholds that, when observed, would help avoid hypotensive episodes during the treatment. However, the results have been unsatisfactory in many patients. Here we illustrate the importance of absolute blood volume in hemodialysis patients, summarize the acute physiologic mechanisms involved in the preservation of adequate circulation during ultrafiltration, and outline why hemodialysis patients are often particularly vulnerable to reductions in blood volume. We then discuss the shortcomings of relative blood volume measurements, make a case for the superiority of absolute blood volume measurements, and introduce the reader to a mathematical concept that allows relative blood volume devices to be used for the estimation of absolute blood volume. Finally, we discuss the implications of absolute blood volume beyond IDH and propose a paradigm shift in the approach to dry weight attainment.

Thijssen S; Kappel F; Kotanko P

2013-01-01

158

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

CERN Multimedia

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.

Radnor, S B P; New, G H C

2009-01-01

159

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-05-03

160

Measuring the absolute DT 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 (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

2012-01-01

 
 
 
 
161

Development of a detector (ALFA) to measure the absolute LHC luminosity at ATLAS  

CERN Multimedia

The ATLAS collaboration plans to determine the absolute luminosity of the CERN LHC at Interaction Point 1 by measuring the trajectory of protons elastically scattered at very small angles (μm). A scintillating fibre tracker system called ALFA (Absolute Luminosity For ATLAS) is proposed for this measurement. Detector modules will be placed above and below the LHC beam axis in roman pot units at a distance of 240 m on each side of the ATLAS interaction point. They allow the detectors to approach the beam axis to millimeter distance. Overlap detectors also based on the scintillating fibre technology, will measure the precise relative position of the two detector modules. Results obtained during beam tests at DESY and at CERN validate the detectors design and demonstrate the achievable resolution. We also report about radiation hardness studies of the scintillating fibres to estimate the lifetime of the ALFA system at different operating conditions of the LHC.

Mapelli, A; Ask, S; Barrillon, P; Blanchot, G; Blin, S; Braem, André; Cheiklali, C; de La Taille, C; Di Girolamo, B; Efthymiopoulos, I; Faustino, J; Fournier, D; Franz, S; Grafström, P; Gurriana, L; Haguenauer, M; Hedberg, V; Heller, M; Hoffmann, S; Iwanski, W; Joram, C; Kocnar, A; Lavigne, B; Lundberg, B; Maio, A; Maneira, M J P; Marques, C; Mjörnmark, U; Conde-Muíño, P; Puzo, P; Rijssenbeeck, M; Santos, J P; Saraiva, J G; Seguin-Moreau, N; Soares, S; Stenzel, H; Thioye, M; Valladolid-Gallego, E; Vorobel, V; 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications

2007-01-01

162

Temperature-dependent absolute refractive index measurements of synthetic fused silica  

Science.gov (United States)

Using the Cryogenic, High-Accuracy Refraction Measuring System (CHARMS) at NASA's Goddard Space Flight Center, we have measured the absolute refractive index of five specimens taken from a very large boule of Corning 7980 fused silica from temperatures ranging from 30 to 310 K at wavelengths from 0.4 to 2.6 microns with an absolute uncertainty of +/-1 ×10-5. Statistical variations in derived values of the thermo-optic coefficient (dn/dT) are at the +/-2 × 10-8/K level. Graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient are presented for selected wavelengths and temperatures along with estimates of uncertainty in index. Coefficients for temperature-dependent Sellmeier fits of measured refractive index are also presented to allow accurate interpolation of index to other wavelengths and temperatures. We compare our results to those from an independent investigation (which used an interferometric technique for measuring index changes as a function of temperature) whose samples were prepared from the same slugs of material from which our prisms were prepared in support of the Kepler mission. We also compare our results with sparse cryogenic index data from measurements of this material from the literature.

Leviton, Douglas B.; Frey, Bradley J.

2006-07-01

163

High-precision Absolute Distance Measurements over a Long Range Based on Two Optoelectronic Oscillators  

CERN Document Server

Absolute distance measurement (ADM) over a long range has been studied intensely over the last several decades, due to its important applications in large-scale manufacturing and outer space explorations [1-5]. Traditional absolute distance measurements utilize detection of time-of-flight information, detection of phase shift, or a combination of the two [6-17]. In this paper, we present a novel scheme for high-precision ADM over a long range based on frequency detection by using two optoelectronic oscillators (OEO) to convert distance information to frequency information. By taking advantage of accumulative magnification theory, the absolute error of the measured distance is magnified by about 2*10E5 times, which makes the precision of the measured distance significantly improved. In our experiments, the maximum error is 1.5 um at the emulated ~6 km distance, including the drift error of about 1 um in the air path due to the change in environmental conditions. In addition, the measurable distance using this ...

Yu, Jinlong; Miao, Wang; Zhu, Jigui; Sun, Bin; Wang, Wenrui; Hu, Hao

2012-01-01

164

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.

1983-01-01

165

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2011-03-20

166

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

CERN Multimedia

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.

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

2011-01-01

167

Calibration method based on direct radioactivity measurement for radioactive gas monitoring instruments  

International Nuclear Information System (INIS)

[en] A calibration method for radioactive gas monitoring instruments was studied. In the method, gaseous radioactivity standards were provided on the basis of the direct radioactivity measurement by the diffusion-in long proportional counter method (DLPC method). The radioactivity concentration of the gas mixture through a monitoring instrument was determined by sampling the known volume of the gas mixture into the proportional counter used for the DLPC method. Since oxygen in the gas mixture decreased the counting efficiency in a proportional counter, the influence on calibration was experimentally estimated. It was not serious and able to be easily corrected. By the present method, the relation between radioactivity concentration and ionization current was determined for a gas-flow ionization chamber with 1.5 l effective volume. It showed good agreement with the results in other works. (author)

1993-01-01

168

Temperature-dependent absolute refractive index measurements of synthetic fused silica  

CERN Document Server

Using the Cryogenic, High-Accuracy Refraction Measuring System (CHARMS) at NASA's Goddard Space Flight Center, we have measured the absolute refractive index of five specimens taken from a very large boule of Corning 7980 fused silica from temperatures ranging from 30 to 310 K at wavelengths from 0.4 to 2.6 microns with an absolute uncertainty of +/-1 x 10^-5. Statistical variations in derived values of the thermo-optic coefficient (dn/dT) are at the +/-2 x 10^-8/K level. Graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient are presented for selected wavelengths and temperatures along with estimates of uncertainty in index. Coefficients for temperature-dependent Sellmeier fits of measured refractive index are also presented to allow accurate interpolation of index to other wavelengths and temperatures. We compare our results to those from an independent investigation (which used an interferometric technique for measuring index changes as a function of temperatur...

Leviton, Douglas B

2008-01-01

169

Color-coding and phase-shift method for absolute phase measurement  

Science.gov (United States)

In this paper, a novel color-coding method for absolute phase measurement is proposed. A three steps phase-shift algorithm was adopted to calculate the relative phase (wrapped phase) because of the least need of images. Color strips were used to mark each 2? phase-change period and three neighboring colors as a group were used as codewords to identify the fringe orders. With the two parts, relative phase and fringe orders, the absolute phase can be obtained directly. We selected five colors (black, red, green, blue, and white) to test our algorithm, and nearly 60 different codewords were embedded in one image. The fringe orders and the relative phase are calculated simultaneously, and this algorithm can circumvent the phase unwrapping process. Moreover, errors will not diffuse, because the relative phase and fringe orders are uncorrelated. Besides, no need of unwrapping processing will lead to high speed in 3D profile measurement. In addition, large object can be measured with high precision using this method owe to enormous codewords can be embedded in one color image. One experiment with a small object and a big complex object was designed to test the algorithm for separate objects, and experimental results showed the validity of our algorithm for absolute phase measurement.

Chen, Xiangcheng; Lu, Chao; Ma, Mengchao; Mao, Xuesong; Mei, Tao

2013-07-01

170

Hyperspectral interferometry for single-shot absolute measurement of 3-D shape and displacement fields  

Directory of Open Access Journals (Sweden)

Full Text Available 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 broad-band light source and hyperspectral imaging system, a set of interferograms at different wavenumbers 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 wavenumber 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 3-D 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.

Huntley J.; Widjanarko T.; Ruiz P. D.

2010-01-01

171

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)

2009-01-01

172

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.

2008-01-01

173

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1981-05-01

174

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1981-05-01

175

Measurement of the absolute branching ratio of the K+??+?0(?) decay with the KLOE detector  

International Nuclear Information System (INIS)

We have measured the absolute branching ratio of the K+??+?0(?) decay, using ?20 million tagged K+ mesons collected with the KLOE detector at DA?NE, the Frascati ?-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+??+?0(?))=0.2065±0.0005stat±0.0008syst

2008-09-04

176

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

Energy Technology Data Exchange (ETDEWEB)

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.

Ave, M.; /Karlsruhe, Inst. Technol.; Bohacova, M.; /Chicago U., EFI; Daumiller, K.; /Karlsruhe, Inst. Technol.; Di Carlo, P.; /INFN, Aquila; Di Giulio, C.; /INFN, Rome; Luis, P.Facal San; /Chicago U., EFI; Gonzales, D.; /Karlsruhe U., EKP; Hojvat, C.; /Fermilab; Horandel, J.R.; /Nijmegen U., IMAPP; Hrabovsky, M.; /Palacky U.; Iarlori, M.; /INFN, Aquila /Karlsruhe, Inst. Technol.

2011-01-01

177

Frequency comparison and absolute frequency measurement of I2-stabilized lasers at 532 nm  

International Nuclear Information System (INIS)

We present a frequency comparison and an absolute frequency measurement of two independent I2-stabilized frequency-doubled Nd:YAG lasers at 532 nm, one set up at the Institute of Laser Physics, Novosibirsk, Russia, the other at the Physikalisch-Technische Bundesanstalt, Braunschweig, Germany. The absolute frequency of the I2-stabilized lasers was determined using a CH4-stabilized He-Ne laser as a reference. This laser had been calibrated prior to the measurement by an atomic cesium fountain clock. The frequency chain linking phase-coherently the two frequencies made use of the frequency comb of a Kerr-lens mode-locked Ti:sapphire femtosecond laser where the comb mode separation was controlled by a local cesium atomic clock. A new value for the R(56)32-0:a10 component, recommended by the Comite International des Poids et Mesures (CIPM) for the realization of the metre, was obtained with reduced uncertainty. Absolute frequencies of the R(56)32-0 and P(54)32-0 iodine absorption lines together with the hyperfine line separations were measured.

2001-01-01

178

Absolute measurement of oxygen edge structure in the quantum efficiency of X-ray CCDs  

Energy Technology Data Exchange (ETDEWEB)

As part of the program to calibrate X-ray CCD detectors for the AXAF mission we have performed high-spectral resolution, absolute measurements of CCD quantum efficiency using the synchrotron radiation and grating monochromator facilities of the FM radiometry laboratory at BESSY. We present here detailed measurements of the absolute quantum efficiency in the spectral region surrounding the oxygen K absorption edge for both front- and back-illuminated MIT Lincoln Laboratory CCDs. The absolute scale of the measurements is established by reference to an Electrical Substitution Radiometer. Near-edge absorption structure produces variations as large as 40% in the detection efficiency of the front-illuminated detectors. We find structure at energies immediately below the K absorption edge which we attribute to resonant absorption in the oxide layers of the CCD gate structure. The amplitude of edge structures in the back-illuminated devices is, as expected, much smaller. Finally, we demonstrate that edge structure can be reliably detected in CCD response using an electron impact source and a grating monochromator.

Prigozhin, G.; Bautz, M.; Kissel, S. [Center for Space Research, Cambridge, MA (United States)] [and others

1996-12-31

179

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

CERN Document Server

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.

Barschel, C

2013-01-01

180

Measurement of the lithium 10p fine structure interval and absolute energy  

International Nuclear Information System (INIS)

We report a measurement of the fine structure interval of the 7Li 10p atomic state with a precision significantly better than previous measurements of fine structure intervals of Rydberg 7Li p states. Our result of 74.97(74) MHz provides an experimental value for the only n=10 fine structure interval which is yet to be calculated. We also report a measurement of the absolute energy of the 10p state and its quantum defect, which are, respectively, 42379.498(23)cm-1 and 0.04694(10). These results are in good agreement with recent calculations.

2010-01-01

 
 
 
 
181

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

CERN Document Server

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.

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

182

Absolute measurement of the responses of small lithium glass scintillators to gamma radiation  

International Nuclear Information System (INIS)

The absolute scintillation efficiency and intrinsic resolution of lithium glass scintillators for electron excitation have been determined over a range of electron energies, lithium concentrations and lithium enrichments. Measurements of these response characteristics form part of a study on the possible use of such glasses for the determination of tritium breeding in fusion reactor blanket experiments. The measurements were undertaken to establish a basis for extracting the information relating to tritium production reactions from the background signals induced within the glass scintillators by the neutron/gamma fields of a fusion reactor blanket. Criteria for the selection of glasses most suitable for tritium breeding measurements are discussed in tems of their observed responses

1987-01-01

183

Towards absolute activity measurements by ionisation chambers using the PENELOPE Monte-Carlo code  

International Nuclear Information System (INIS)

[en] The Monte-Carlo code PENELOPE for Ionisation Chamber Simulation Method has been applied for the calculation of ionisation-chamber (IC) calibration factors. Measuring only a few radionuclides well selected within the relevant energy range, and determining an adjustable parameter, commonly used radionuclides can be measured without any specific calibration. The simulation revealed a discontinuity in the IC response as a function of photon energy and its dependence on the chemical composition of the radioactive solution

2003-01-01

184

Towards absolute activity measurements by ionisation chambers using the PENELOPE Monte-Carlo code  

Energy Technology Data Exchange (ETDEWEB)

The Monte-Carlo code PENELOPE for Ionisation Chamber Simulation Method has been applied for the calculation of ionisation-chamber (IC) calibration factors. Measuring only a few radionuclides well selected within the relevant energy range, and determining an adjustable parameter, commonly used radionuclides can be measured without any specific calibration. The simulation revealed a discontinuity in the IC response as a function of photon energy and its dependence on the chemical composition of the radioactive solution.

Vismes, A. de; Amiot, M.N. E-mail: marie-noelle.amiot@cea.fr

2003-10-01

185

Radioactivity measurements for the ERMES project at the STELLA facility  

Directory of Open Access Journals (Sweden)

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.

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

2012-01-01

186

Measurement of metallothionein by radioactive silver saturation method  

International Nuclear Information System (INIS)

Radioactive silver saturation method has been developed for measurement of metallothionein in tissues of animal. The results show that the relative affinities of metals for metallothionein in 0.5M glycine buffer at pH 8.5 is Ag+ > Cu2+ > Cd2+ > Hg2+ > Zn2+, and measurement of metallothionein in liver of rats induced by zinc using radioactive silver satruation method is sensitive and valid.

1990-01-01

187

Absolute instrument spectral response measurements using angle-resolved parametric fluorescence.  

UK PubMed Central (United Kingdom)

The broadband parametric fluorescence from a nonlinear crystal can be used as a compact primary source instead of a blackbody for absolute measurements of instrument spectral efficiency. We describe such a setup for measuring the instrument spectral response function in the wavelength range from 450 to 1000 nm. We perform angle-resolved imaging spectroscopy of conical parametric fluorescence in a beta-barium borate crystal pumped by a 405-nm diode laser. The experimental angle-resolved spectra and the generation efficiency of parametric down-conversion agree with a plane-wave theoretical analysis.

Hsu FK; Lai CW

2013-07-01

188

Quasi-absolute measurement of aspheres with a combined diffractive optical element as reference  

International Nuclear Information System (INIS)

We have already reported a method for the quasi-absolute test of rotationally symmetric aspheres by means of combined diffractive optical elements (combo-DOEs).The combo-DOEs carry the information for the ideal shape of an aspheric surface under test as well as a spherical wave for the measurement at the cat's eye position. An experimental demonstration of the procedure is given. Measurements with two different designs of combo-DOEs have been conducted, and their relative advantages and disadvantages are discussed.

2006-12-01

189

Measurement of the absolute hohlraum-wall albedo under ignition foot drive conditions  

International Nuclear Information System (INIS)

We present measurements of the absolute albedos of hohlraums made from gold or from high-Z mixtures. The measurements are performed over the range of radiation temperatures (70-100 eV) expected during the foot of an indirect-drive temporally shaped ignition laser pulse, where accurate knowledge of the wall albedo (i.e., soft x-ray wall reemission) is most critical for determining capsule radiation symmetry. We find that the gold albedo agrees well with calculations using the supertransition array opacity model, potentially providing additional margin for inertial confinement fusion ignition.

2004-08-06

190

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

1976-08-23

191

Measurements of natural radioactivity inside Dandara temple  

International Nuclear Information System (INIS)

[en] The natural radioactivities inside Dandara temple are studied by using a NaI(Tl) scintillation spectrometer. The variation of these activities with location is investigated. Average values of the identified radionuclides inside the halls, sanctuary and crypt of the temple are examined. It is estimated that the mean value lies in the range 37.9-90.1 for 212Pb, 70.0-36.0 for 214Bi, 52.6-76.2 for 228 Ac, 1.6-5.9 for 208 Tl, while for 40K it is 169.3-286.6. (author)

1994-01-01

192

Measurements of natural radioactivity inside Dandara temple  

Energy Technology Data Exchange (ETDEWEB)

The natural radioactivities inside Dandara temple are studied by using a NaI(Tl) scintillation spectrometer. The variation of these activities with location is investigated. Average values of the identified radionuclides inside the halls, sanctuary and crypt of the temple are examined. It is estimated that the mean value lies in the range 37.9-90.1 for {sup 212}Pb, 70.0-36.0 for {sup 214}Bi, 52.6-76.2 for {sup 228} Ac, 1.6-5.9 for {sup 208} Tl, while for {sup 40}K it is 169.3-286.6. (author).

Ahmed, N.K.; Saied, M.H.; Abbady, A.; El-Kamel, A.H. [Assiut Univ. (Egypt). Dept. of Physics

1994-07-01

193

Measurement of the absolute oscillator strength of the spectral line lambda=451.966nm of gadolinium  

International Nuclear Information System (INIS)

The absolute oscillator strength, f, was measured for the spectral line lambda=451.966 nm of gadolinium by means of the absorption method with the atomic beam acting as an absorbant. The absolute value of f which was obtained is f=0.28 +- 0.07. (Auth.)

1982-01-01

194

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

Science.gov (United States)

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 %.

Tanaka, Takahiro; Kato, Masahiro; Kurosawa, Tadahiro; Saito, Norio; Kudo, Togo; Tono, Kensuke; Yabashi, Makina; Ishikawa, Tetsuya

2013-03-01

195

Measurements with radioactive beams at ATLAS  

International Nuclear Information System (INIS)

[en] 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

1998-01-01

196

Measurements with radioactive beams at ATLAS.  

Energy Technology Data Exchange (ETDEWEB)

Reactions of interest to nuclear astrophysics have been studied with radioactive beams at the ATLAS accelerator. Using a modified ISOL technique, beams of {sup 18}F (T{sub 1/2} = 110 min) and {sup 56}Ni (T{sub 1/2} = 6.1d) were produced and the reactions {sup 18}F(p,{alpha}){sup 15}O, {sup 18}F(p,{gamma}){sup 19}Ne, and {sup 56}Ni(d,p){sup 57}Ni have been investigated. The results indicate that the {sup 18}F(p,{gamma}) route is a small contributor to the breakout from the hot CNO cycle into the rp process, while the {sup 56}Ni(p,{gamma}){sup 57}Cu rate is about ten times larger than previously assumed.

Rehm, K. E.

1998-08-06

197

Natural radioactivity measurements in soil samples of central Kutahya (Turkey).  

UK PubMed Central (United Kingdom)

Measurement of the natural radioactivity of surface soils at 20 locations in central Kutahya has been made using gamma ray spectroscopy. Natural gamma ray radioactivity of the terrestrial nuclides in soil samples and the absorbed gamma ray dose rates of these radionuclides in the air have been calculated throughout different areas of central Kutahya. The average annual effective dose equivalent for a person living in central Kutahya was found to be approximately 57 microSv.

Sahin L; Cavas M

2008-01-01

198

Status of underground radioactivity measurements in Hades  

International Nuclear Information System (INIS)

[en] This paper describes the aim of the IRMM activities in the HADES laboratory, the equipment and the measurement program and gives examples of radiopurity measurements carried out in order to develop better low-level measurements.

2010-01-01

199

Measurement of total body radioactivity in man  

International Nuclear Information System (INIS)

[en] 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.)

1982-01-01

200

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

International Nuclear Information System (INIS)

[en] 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)

1962-01-01

 
 
 
 
201

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

International Nuclear Information System (INIS)

[en] 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.

2011-04-01

202

Measurement of the absolute branching fraction of D0-->K-pi+.  

Science.gov (United States)

We measure the absolute branching fraction for D(0)-->K(-)pi(+) using partial reconstruction of B(0)-->D(*+)Xl(-)nu(l) decays, in which only the charged lepton and the pion from the decay D(*+)-->D(0)pi(+) are used. Based on a data sample of 230 x 10(6) BB pairs collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, we obtain B(D(0)-->K(-)pi(+)) = (4.007+/-0.037+/-0.072)%, where the first uncertainty is statistical and the second is systematic. PMID:18352359

Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Eigen, G; Ofte, I; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo Sanchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schroeder, T; Steinke, M; Cottingham, W N; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Fisher, P H; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, G; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; Leruste, Ph; Malclès, J; Ocariz, J; Perez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F

2008-02-06

203

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

CERN Multimedia

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.

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

204

Absolute profile measurement of large moderately flat optical surfaces with high dynamic range.  

Science.gov (United States)

We present a novel procedure for absolute, highly-accurate profile measurement with high dynamic range for large, moderately flat optical surfaces. The profile is reconstructed from many sub-profiles measured by a small interferometer which is scanned along the specimen under test. Additional angular and lateral distance measurements are used to account for the tilt of the interferometer and its precise lateral location during the measurements. Accurate positioning of the interferometer is not required. The algorithm proposed for the analysis of the data allows systematic errors of the interferometer and height offsets of the scanning stage to be eliminated and it does not reduce the resolution. By utilizing a realistic simulation scenario we show that accuracies in the nanometer range can be reached. PMID:18679470

Wiegmann, A; Schulz, M; Elster, C

2008-08-01

205

Measurement of absolute flow rate in vessels using a stereoscopic DSA system. [Digital subtraction angiography  

Energy Technology Data Exchange (ETDEWEB)

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).

Fencil, L.E.; Doi, K.; Chua, K.G.; Hoffman, K.R. (Chicago Univ., IL (USA). Dept. of Radiology)

1989-06-01

206

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)

1989-01-01

207

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-06-25

208

Measurement of the absolute wavefront curvature radius in a heterodyne interferometer  

CERN Multimedia

We present an analytical derivation of the coupling parameter relating the angle between two interfering beams in a heterodyne interferometer to the differential phase-signals detected by a quadrant photo-diode. This technique, also referred to as Differential Wavefront Sensing (DWS), is commonly used in space-based gravitational wave detectors to determine the attitude of a test-mass in one of the interferometer arms from the quadrant diode signals. Successive approximations to the analytical expression are made to simplify the investigation of parameter dependencies. Motivated by our findings, we propose a new measurement method to accurately determine the absolute wave-front curvature of a single measurement beam. We also investigate the change in coupling parameter when the interferometer "test-mirror" is moved from its nominal position, an effect which mediates the coupling of mirror displacement noise into differential phase-measurements.

Hechenblaikner, Gerald

2010-01-01

209

Absolute measurements of the thermal conductivity of mixtures of alcohols with water  

Energy Technology Data Exchange (ETDEWEB)

New absolute measurements of the thermal conductivity of mixtures of methanol, ethanol, and propanol with water are presented. The measurements were performed in a tantalum-type transient hot-wire instrument at atmospheric pressure, in the temperature range 300-345 K. The overall uncertainty of the reported values is estimated to be less than {plus minus}0.5%, an estimate confirmed by measurements of the thermal conductivity of water. The mixtures with water studied have compositions of 25, 50, and 75%, by weight, of methanol and ethanol and 50%, by weight, of propanol. A recently proposed semiempirical scheme for the prediction of the thermal conductivity of pure liquids is extended to allow the prediction of the thermal conductivity of these mixtures from the pure components, as a function of both composition and temperature.

Assael, M.J.; Charitidou, E.; Wakeham, W.A. (Aristotle Univ., Thessaloniki (Greece))

1989-07-01

210

Absolute flatness measurements of silicon mirrors by a three-intersection method by near-infrared interferometry.  

UK PubMed Central (United Kingdom)

Absolute flatness of three silicon plane mirrors have been measured by a three-intersection method based on the three-flat method using a near-infrared interferometer. The interferometer was constructed using a near-infrared laser diode with a 1,310-nm wavelength light where the silicon plane mirror is transparent. The height differences at the coordinate values between the absolute line profiles by the three-intersection method have been evaluated. The height differences of the three flats were 4.5 nm or less. The three-intersection method using the near-infrared interferometer was useful for measuring the absolute flatness of the silicon plane mirrors.

Uchikoshi J; Hayashi Y; Ajari N; Kawai K; Arima K; Morita M

2013-06-01

211

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1985-01-01

212

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

Directory of Open Access Journals (Sweden)

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.

G. D?Agostino; S. Desogus; A. Germak; C. Origlia; D. Quagliotti; G. Berrino; G. Corrado; V. D?errico; G. Ricciardi

2008-01-01

213

Dose rate measurement inside a radioactive waste shipping container  

International Nuclear Information System (INIS)

After introduction of the radioactive waste container into the shipping container, a probe holder is introduced, through a hole, inside. The probe is connected with electric conductors to a measuring instrument outside. The probe can be rotated normally for a reliable and accurate dose rate measurement

1989-11-09

214

Radioactivity measurement using liquid scintillation counters  

International Nuclear Information System (INIS)

[en] The liquid scintillation counting of radioactive samples is presented to biologists and biochemists, under its adaptation to low energy ? detection (3H, 14C, 35S, 45Ca). The physical and chemical processes induced in liquid scintillation and the working principle of the auxiliary equipment associated to a liquid scintillation counter are discussed. The methods of counting corrections used for compensating the light fading phenomena or 'quenching' are exposed and the principal scintillating mixtures are given. The special case of ?- emitter counting using the Cerenkov effect (?->=300keV) inside water, without any scintillator is pointed out. The adequacy in the choice of the counters and auxiliary equipment, introduction of the samples into the mixtures, and provisions for the radioprotection in the laboratory are discussed[fr] On presente a l'intention des biologistes et biochimistes la technique de mesure des radioactivites a l'aide de compteurs a scintillation liquide, adaptee a la detection des rayonnements ? de faible energie (3H, 14C, 35S, 45Ca). On rappelle le mecanisme physico-chimique de la scintillation en milieu liquide et le principe de fonctionnement des dispositifs associes a un compteur a scintillation liquide. On expose les methodes de correction de comptage utilisees pour compenser les phenomenes d'affaiblissement lumineux ou quenching, dans les scintillateurs liquides, et on enumere les principaux melanges scintillants. On note le cas particulier de la mesure des emetteurs ?- par effet Cerenkov (?->=300keV) dans l'eau, sans melange scintillant. On donne quelques elements pour le choix des compteurs et accessoires, l'introduction des echantillons dans les melanges, la radioprotection au laboratoire

1977-01-01

215

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

UK PubMed Central (United Kingdom)

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.

Casey DT; Frenje JA; Johnson MG; Séguin FH; Li CK; Petrasso RD; Glebov VY; Katz J; Magoon J; Meyerhofer DD; Sangster TC; Shoup M; Ulreich J; Ashabranner RC; Bionta RM; Carpenter AC; Felker B; Khater HY; LePape S; MacKinnon A; McKernan MA; Moran M; Rygg JR; Yeoman MF; Zacharias R; Leeper RJ; Fletcher K; Farrell M; Jasion D; Kilkenny J; Paguio R

2013-04-01

216

Comb-calibrated frequency-modulated continuous-wave ladar for absolute distance measurements.  

Science.gov (United States)

We demonstrate a comb-calibrated frequency-modulated continuous-wave laser detection and ranging (FMCW ladar) system for absolute distance measurements. The FMCW ladar uses a compact external cavity laser that is swept quasi-sinusoidally over 1 THz at a 1 kHz rate. The system simultaneously records the heterodyne FMCW ladar signal and the instantaneous laser frequency at sweep rates up to 3400 THz/s, as measured against a free-running frequency comb (femtosecond fiber laser). Demodulation of the ladar signal against the instantaneous laser frequency yields the range to the target with 1 ms update rates, bandwidth-limited 130 ?m resolution and a ~100 nm accuracy that is directly linked to the counted repetition rate of the comb. The precision is <100 nm at the 1 ms update rate and reaches ~6 nm for a 100 ms average. PMID:23938965

Baumann, Esther; Giorgetta, Fabrizio R; Coddington, Ian; Sinclair, Laura C; Knabe, Kevin; Swann, William C; Newbury, Nathan R

2013-06-15

217

Absolute method of measurement of the fast neutron capture cross section by 238U  

International Nuclear Information System (INIS)

The absolute method of measurement of the neutron capture cross section by 238U and 197Au in the 15-480 keV energy range is presented. The method is based on utilization of a large liquid scintillation detector for detecting instantaneous ? rays of the capture events and nanosecond technique of time of flight at a pulsed electrostatic generator for determination of neutron energy and background discrimination. The method is realized on a fast and resonance neutron spectrometer on the basis of the PEI EG-1. Preliminary results of measurements of the fast neutron capture cross sections by 238U and 197Au are presented. The cross sections are normalized using the saturated resonance technique

1980-09-19

218

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

Science.gov (United States)

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.

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

2013-04-01

219

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

220

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$

2008-01-01

 
 
 
 
221

Absolute frequency measurements on the 2S --> 3S transition of lithium-6,7  

Energy Technology Data Exchange (ETDEWEB)

The frequencies of the 2S–3S two-photon transition for the stable lithium isotopes were measured by cavity-enhanced Doppler-free laser excitation that was controlled by a femtosecond frequency comb. The resulting values of 815 618 181.57(18) and 815 606 727.59(18) MHz, respectively, for 7Li and 6Li are in agreement with previous measurements but are more accurate by an order of magnitude. There is still a discrepancy of about 11.6 and 10.6MHz from the latest theoretical values. This is comparable to the uncertainty in the theoretical calculations, while uncertainty in our experimental values is more than a hundred-fold smaller. More accurate theoretical calculation of the transition frequencies would allow extraction of the absolute charge radii for these stable isotopes, which in turn could improve nuclear charge radii values for the unstable lithium isotopes.

Sanchez, R.; Zakova, Monika; Andejelkovic, Zoran; Bushaw, Bruce A.; Dasgupta, Kamalesh; Ewald, G.; Geppert, C. H.; Kluge, H. J.; Kramer, Jorg; Nothhelfer, Matthias; Tiedemann, Dirk; Winters, Danyal F.; Nortershauser, W.

2009-07-03

222

Measurement of the absolute neutron activity of a 252Cf source  

International Nuclear Information System (INIS)

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

1977-01-01

223

Absolute measurements of the high-frequency magnetic dynamics in high-{Tc} superconductors  

Energy Technology Data Exchange (ETDEWEB)

The authors review recent measurements of the high-frequency dynamic magnetic susceptibility in the high-T{sub c} superconducting systems La{sub 2{minus}x}Sr{sub x}CuO{sub 4} and YBa{sub 2}Cu{sub 3}O{sub 6+x}. Experiments were performed using the chopper spectrometers HET and MARI at the ISIS spallation source. The authors have placed their measurements on an absolute intensity scale, this allows systematic trends to be seen and comparisons with theory to be made. They find that the insulating S = 1/2 antiferromagnetic parent compounds show a dramatic renormalization in the spin wave intensity. The effect of doping on the response is to cause broadenings in wave vector and large redistributions of spectral weight in frequency.

Hayden, S.M. [Univ. of Bristol (United Kingdom). H.H. Wills Physics Lab.; Aeppli, G. [NEC Research Inst., Princeton, NJ (United States); Dai, P.; Mook, H.A. [Oak Ridge National Lab., TN (United States); Perring, T.G. [Rutherford Appleton Lab., Chilton (United Kingdom); Cheong, S.W. [Lucent Technologies, NJ (United States). Bell Labs.; Fisk, Z. [Florida State Univ., Tallahassee, FL (United States). Dept. of Physics; Dogan, F. [Univ. of Washington, Seattle, WA (United States). Dept. of Material Science and Engineering; Mason, T.E. [Univ. of Toronto, Ontario (Canada). Dept. of Physics

1997-08-07

224

Absolute measurements of the high-frequency magnetic dynamics in high-T{sub c} superconductors  

Energy Technology Data Exchange (ETDEWEB)

We review recent measurements of the high-frequency dynamic magnetic susceptibility in the high-T{sub c} superconducting systems La{sub 2-x}Sr{sub x}CuO{sub 4} and YBa{sub 2}Cu{sub 3}O{sub 6+x}. Experiments were performed using the chopper spectrometers HET and MARI at the ISIS spallation source. We have placed our measurements on an absolute intensity scale; this allows systematic trends to be seen and comparisons with theory to be made. We find that the insulating S= 1/2 antiferromagnetic parent compounds show a dramatic renormalization of the spin wave intensity. The effect of doping on the response is to cause broadenings in wave vector and large redistributions of spectral weight in the frequency spectrum. (orig.) 18 refs.

Hayden, S.M. [Bristol Univ. (United Kingdom). H.H. Wills Physics Lab.; Aeppli, G. [NEC Research Inst., Princeton, NJ (United States); Dai, P.; Mook, H.A. [Oak Ridge National Lab., TN (United States); Perring, T.G. [Rutherford Appleton Lab., Chilton (United Kingdom); Cheong, S.-W. [Bell Laboratories, Lucent Technologies, NJ 07974 (United States); Fisk, Z. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Dogan, F. [Department of Material Science and Engineering, University of Washington, Seattle, WA 98195 (United States); Mason, T.E. [Department of Physics, University of Toronto, Toronto M5S 1A7 (Canada)

1997-12-01

225

Absolute ultrasonic displacement amplitude measurements with a submersible electrostatic acoustic transducer  

Science.gov (United States)

An experimental technique for absolute measurement of ultrasonic wave particle displacement amplitudes in liquids is reported. The technique is capable of measurements over a frequency range of two decades with a sensitivity less than one angstrom. The technique utilizes a previously reported submersible electrostatic acoustic transducer (ESAT) featuring a conductive membrane stretched over a recessed electrode. An uncertainty analysis shows that the displacement amplitude of an ultrasonic plane wave incident on the ESAT can be experimentally determined to better than 2.3-4 percent, depending on frequency, in the frequency range of 0.5-15 MHz. Membranes with lower and more uniform areal densities can improve the accuracy and extend the operation to higher frequencies.

Yost, William T.; Cantrell, John H.

1992-09-01

226

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.

2006-01-01

227

Diffusion coefficient measurements with radioactive tracer technique  

International Nuclear Information System (INIS)

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

1985-01-01

228

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

International Nuclear Information System (INIS)

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

1988-01-01

229

Croatian-Hungarian cooperation on the Danube river radioactivity measurements  

International Nuclear Information System (INIS)

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

2003-01-01

230

Geometry Optimization Of Marinelli Sample In Environmental Radioactivity Measurement  

International Nuclear Information System (INIS)

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

2011-01-01

231

Marine radioactivity measurements with liquid scintillation spectrometers  

International Nuclear Information System (INIS)

Liquid Scintillation Spectrometry (LSS) has now become the most widespread method for quantitative analytical measurement of low levels of ?-emitting radionuclides like 3H and 14C. The high efficiency resulting from the latest development in LSS makes this technique not only appropriate but also enables direct measurement in environmental samples without excessive preparation. The introduction of several new cocktails based on solvents with a high flashpoint containing surfactants and having a high degree of aqueous sample compatibility has also contributed to the simplification of procedures

1999-01-01

232

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).

1991-01-01

233

Techniques for radioactivity measurement in water, suspensions and sediments  

International Nuclear Information System (INIS)

The measurements to determine the overall ?-radioactivity in surface water and sediment samples are intended as monitoring measurements to reveal long-term trends, as well as to detect uncontrolled release of radioactivity. The measurements to determine the overall ?-radioactivity in surface water and sediment samples are likewise a monitoring method to detect all radioecologically relevant nuclides in one process. This method can be applied under certain conditions as a means of controlling whether the dose limits set in section 45 of the Radiation Protection Ordinance are exceeded. Liquid scintillation spectrometry is usually applied to detect tritium within the framework of environmental monitoring. Gamma spectrometry using Ge(Li) detectors allows simultaneous determination of various radionuclide fractions in complex nuclide compositions. For this purpose, large-volume water samples have to be pre-treated because of their very low nuclide concentrations (50-100 l). Radioactivity release after incidents has to be controlled by direct measurement, using appropriate counting systems (ring dishes). Radionuclides are primarily adsorbed by suspended particles where they can be detected and measured with great sensitivity, just as in sediments. (orig./HP)

1983-01-01

234

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).

1987-01-01

235

Atmospheric xenon radioactive isotopes sampling and measurement  

International Nuclear Information System (INIS)

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

2001-01-01

236

Absolute measurement of thermal neutron fluence and its application for fission track dating  

International Nuclear Information System (INIS)

[en] The absolute measurements of thermal neutron fluence for fission track dating have been developed after the proceeding results of Honda et al. (1987). The 2,200 m/sec activation cross section of 197Au (98.8 barn) is corrected to 87.4 barn (?a) by the three factors of the neutron temperature, Maxwellian distribution of thermal neutrons and non 1/v correction factor for the above absolute measurement. The calibrated factor (Bth) of standard glasses (SRM613, SRM962a, CN-1 and CN-2) and zeta-a (?a) values for fission track dating are determined on the basis of these experimental results. The values of Bth, (7.47 ± 0.29) x 109 for SRM613, (7.43 ± 0.34) x 109 for SRM962a, (2.50 ± 0.06) x 109 for CN-1 and (2.74 ± 0.06) x 109 for CN-2 closely agree with those reported previously by Honda et al. (1987). Further, the ?a values of 392.3 ± 16.5 for SRM962a and SRM613, 131.4 ± 3.1 for CN-1 and 144.1 ± 3.3 for CN-2 calculated from Bth, effective thermal neutron fission cross-section ?f (497.4 barn), isotopic abundance ratio 235U/239U, I (7.2527 x 10-3) and spontaneous fission decay constant of 238U, ?f (6.85 x 10-17a-7) show close agreement with ?b values (392.5 ± 10.0, 131.6 ± 3.3, 140.1 ± 3.5) derived from the absolute age of Fish Canyon Tuff (27.9 ± 0.7 Ma) respectively. The fission track dating of zircons separated from Oligocene-Miocene tuff distributed in Eastern Hokkaido have been carried out by the external detector method using ?a. The obtained ages are 28.6 ± 0.7 Ma (1 - 2) and 23.3 ± 0.7 Ma (3 - 2). These results agree well with the geologic age supported from Ashoro Fossil Fauna, K-Ar ages of volcanic rocks and stratigraphy in this area. (author)

1988-01-01

237

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

238

Absolute density measurement of SD radicals in a molecular beam at the quantum-noise-limit  

CERN Multimedia

The absolute density of SD radicals in a molecular beam has been measured down to $(1.1\\pm0.1)\\times10^5$ cm$^{-3}$ in a modestly specified apparatus that uses a cross-correlated combination of cavity ring-down and laser-induced fluorescence detection. Such a density corresponds to $215\\pm21$ molecules in the probe volume at any given time. The quantum-noise-limited noise-equivalent absorption sensitivity of the apparatus was found to be $(3.5\\pm0.3)\\times10^{-11}$ cm$^{-1}$ Hz$^{-1/2}$ based on a 200 s acquisition time at 10 Hz, therefore competing favourably with more sophisticated techniques.

Mizouri, Arin; Eardley, Jack S; Nahler, N Hendrik; Wrede, Eckart; Carty, David

2013-01-01

239

Heterodyne measurements of electron cyclotron emission from Alcator A and absolute submillimeter receiver calibration  

International Nuclear Information System (INIS)

Electron cyclotron emission (ECE) from thermal plasmas in the Alcator A tokamak for harmonics from 2nd through 5th and up to the 7th harmonic for nonthermal plasmas have been observed in the frequency range of 400--800 GHz using a sensitive, low-noise submillimeter heterodyne receiver. The sensitivity of the receiver (approx.10-20 W Hz-1) allowed for the measurement of 4th and 5th harmonic ECE from thermal plasmas with T/sub e/roughly-equal800 eV. The receiver was absolutely calibrated and its field of view was experimentally determined. A careful analysis has been made to relate the receiver calibration to the plasma-emitting volume, taking into account radiation coherence time, wall reflections, polarization scrambling, window losses, and aperture restrictions

1981-01-01

240

Simple on-line method of measuring the absolute ionization efficiency of an ion source  

International Nuclear Information System (INIS)

We report a new method of measuring the absolute ionization efficiency of an ion source, which is independent of gas flow rate fed to an ionizer and of detection efficiency of the resulting ions. The method is based on the fact that when a pulsed alternate potential is applied between the ionizer and an electrode set outside near its exit hole, ions stored inside the ionizer while the potential is repulsive for the ions are flushed out as soon as it becomes attractive. It is shown that when the duty factor and repetition rate of the applied potential are properly chosen, the magnitude of this bunching effect can simply be expressed only by the ionization efficiency. Since its magnitude can quickly be evaluated, for example, by observing the time dependence of the bunched ion current in an oscilloscope, it provides a simple and reliable way for on-line diagnostics of the source. (author)

1994-01-01

 
 
 
 
241

Absolute measurement of thermal neutron flux by using natural copper foil  

International Nuclear Information System (INIS)

Up to the present, gold foil has been regarded as the best detector in thermal neutron flux measurements, since its absorption cross section is very large and induced isotope 198Au has a simple decay schema. In this paper, it is shown that the copper foil has the great advantage over most other elements including gold in reactor physics experiments. With the use of natural copper, no complicated correction for perturbation and decreasing of neutron field is necessary for determining absolute value of thermal neutron flux in wide range of reactor power, and more accurate result can be obtained by means of gamma-gamma coincidence technique instead of beta-gamma coincidence method. (author).

1992-01-01

242

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)

1979-01-01

243

Absolute Polarization Measurements at RHIC in the Coulomb Nuclear Interference Region  

CERN Document Server

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.

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

244

Measurement of natural radioactivity in construction materials with silicon detectors  

International Nuclear Information System (INIS)

The results of radioactive contamination measurements of the construction materials most commonly used in the process of building the apparatus for low-level counting are discussed. They were obtained using an apparatus for low-level counting with four semiconductor detectors. (author).

1981-01-01

245

Measuring system for radioactivity of labelled biopolymers  

International Nuclear Information System (INIS)

The apparatus incorporates a steel container for samples of biological biopolymers in conjunction with a co-precipitator, filtration unit and scintillator. An electrical drive is employed for stepwise movements of the system. A control unit is included for regulation of the degree of radio activity. The various reagents are contained in separate vessels. A vacuum pump is employed for the filtration process. The measuring cylinder is a hollow unit made of polyfluoroethylene with end surfaces of film of the same material. Carbon dioxide under presure is used as a control medium. (G.C.)

1977-01-01

246

(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.

2005-01-01

247

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

CERN Document Server

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.

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

248

Absolute differential cross section measurements for charge transfer scattering of keV energy ions with atomic oxygen  

Energy Technology Data Exchange (ETDEWEB)

Absolute differential cross section (DCS) measurements for charge transfer of H{sup +} with atomic oxygen have been performed using a recently developed atomic oxygen target apparatus. We report measurements in the energy range 500-5000 eV over a range of 0-3.5{degrees} in laboratory scattering angle. DCS curves are integrated and compared with total cross section measurements.

Seiglaff, D.R.; Lindsay, B.G.; Smith, K.A.; Stebbings, R.F.

1993-05-01

249

Absolute differential cross section measurements for charge transfer scattering of keV energy ions with atomic oxygen  

International Nuclear Information System (INIS)

Absolute differential cross section (DCS) measurements for charge transfer of H+ with atomic oxygen have been performed using a recently developed atomic oxygen target apparatus. We report measurements in the energy range 500-5000 eV over a range of 0-3.5 degrees in laboratory scattering angle. DCS curves are integrated and compared with total cross section measurements.

1993-01-01

250

Radioactive Aerosol Size Distribution Measured in Nuclear Workplaces  

International Nuclear Information System (INIS)

Inhalation is the main route for internal exposure of workers to radioactive aerosols in the nuclear industry.Aerosol's size distribution and in particular its activity median aerodynamic diameter (AMAD)is important for determining the fractional deposition of inhaled particles in the respiratory tract and the resulting doses. Respiratory tract models have been published by the International Commission on radiological Protection (ICRP).The former model has recommended a default AMAD of 1 micron for the calculation of dose coefficients for workers in the nuclear industry [1].The recent model recommends a 5 microns default diameter for occupational exposure which is considered to be more representative of workplace aerosols [2]. Several researches on radioactive aerosol's size distribution in nuclear workplaces has supported this recommendation [3,4].This paper presents the results of radioactive aerosols size distribution measurements taken at several workplaces of the uranium production process.

2002-05-22

251

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

Energy Technology Data Exchange (ETDEWEB)

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.)

NONE

2001-07-01

252

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

International Nuclear Information System (INIS)

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

1991-01-01

253

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

Energy Technology Data Exchange (ETDEWEB)

A new low noise miniaturized multichannel bolometer module for absolute measurements in the VUV and soft x spectral ranges is described. Highly integrated four-channel modules (2{times}3.3{times}1.5 cm{sup 3}) each comprising four independent ac-excited (50 kHz) metal resistor bolometer bridges were successfully tested on a large tokamak (Tore Supra in Cadarache) and on an electron synchrotron (BESSY in Berlin). The bolometer system features a linear response to the absorbed radiation power, a low detection limit ({le}1.0{times}10{sup {minus}6} W cm{sup {minus}2} on Tore Supra with an integration time of {tau}{sub int}=10{times}10{sup {minus}3} s) and a low NEP ({le}10{times}10{sup {minus}9} W on BESSY). The thermal cross-talk between adjacent detectors is negligible ({lt}0.003) and a low thermal drift {Delta}{ital U}{sub Br}/{Delta}{ital T} {lt} 10{sup {minus}4} V {degree}C{sup {minus}1} is achieved. It can be operated at a maximum temperature of 150 {degree}C, at high magnetic fields (tested up to {ital B}=4.5 T in the laboratory) and survives high nuclear radiation doses. The system offers the possibility of detecting low-power VUV and soft x-radiation with sampling rates of up to 10 kHz on plasma machines and of absolutely calibrating VUV and soft x instruments. Effective suppression of electric, thermal and nuclear radiation interferences is characteristic of the bolometer system.Strain gauge effects, which could affect the behavior of the bolometers at high magnetic fields, are suppressed by the ac-excitation technique.

Mast, K.F.; Vallet, J.C.; Andelfinger, C.; Betzler, P.; Kraus, H.; Schramm, G. (Max-Planck-Institut fuer Plasmaphysik, EURATOM-IPP Association, D-8046 Garching, West Germany (FR))

1991-03-01

254

An automatic viscosimeter for measuring the rheology of radioactive substances  

International Nuclear Information System (INIS)

[en] This paper describes an automatic capillary viscosimeter that was developed to measure the rheological characteristics of radio-active slurries. The system is designed for use in a glove box and uses disposable modules in the active cell. The data acquisition and monitoring equipment, which is computer controlled, is stationed outside the active area. Once set up the system can measure a full rheogram in a few minutes and correlate the results to a given rheological model. (author)

1992-01-01

255

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.).

1983-11-03

256

Measurement of the radioactivity of the channel DTD before Chernobyl  

International Nuclear Information System (INIS)

[en] The activity concentration of long loved fission and corrosion products and natural radionuclides has been measured in a selected part of the Danube-Tisa-Danube channel system which is not receiving liquid effluents from nuclear power plants. The comparison with the activities measured in the river danube did not show statistically significant differences. The results obtained describe the reference level of radioactivity for the evaluation of the contamination of the system caused by the Chernobyl accident. (author)

1987-01-01

257

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.

1999-01-01

258

Absolute angle measurement using the earth-field-referenced hall effect sensors.  

UK PubMed Central (United Kingdom)

A miniaturized absolute angle sensor utilizing Hall generators referenced to the Earth's ambient magnetic field has been developed. The sensor has three-dimensional angular sensitivity which allows the output to be self-normalized resulting in high immunity to both B-field and temperature induced errors. The individual Hall generator elements were operated with a final sensitivity of 4.07 V G-1. The Earth's field, magnitude 0.486 G with a surface declination angle of 58.2 degrees (San Diego, California), was used as the excitation/reference field. Bandwidth limiting, low-noise design, and active/passive thermal compensation techniques were employed resulting in a sensor bandwidth of DC to 100 Hz with a maximum signal-to-noise ratio of 44.5 dB. The maximum angular resolution of the sensor was measured to be +/- 0.27 degrees. Temperature induced error was measured to be less than 2% from 25 degrees C to 40 degrees C. The measurement of shoulder joint rotation was used as the test case application for the sensor with excellent agreement between theoretical and experimental performance.

Kolen PT; Rhode JP; Francis PR

1993-03-01

259

Absolute angle measurement using the earth-field-referenced hall effect sensors.  

Science.gov (United States)

A miniaturized absolute angle sensor utilizing Hall generators referenced to the Earth's ambient magnetic field has been developed. The sensor has three-dimensional angular sensitivity which allows the output to be self-normalized resulting in high immunity to both B-field and temperature induced errors. The individual Hall generator elements were operated with a final sensitivity of 4.07 V G-1. The Earth's field, magnitude 0.486 G with a surface declination angle of 58.2 degrees (San Diego, California), was used as the excitation/reference field. Bandwidth limiting, low-noise design, and active/passive thermal compensation techniques were employed resulting in a sensor bandwidth of DC to 100 Hz with a maximum signal-to-noise ratio of 44.5 dB. The maximum angular resolution of the sensor was measured to be +/- 0.27 degrees. Temperature induced error was measured to be less than 2% from 25 degrees C to 40 degrees C. The measurement of shoulder joint rotation was used as the test case application for the sensor with excellent agreement between theoretical and experimental performance. PMID:8468339

Kolen, P T; Rhode, J P; Francis, P R

1993-03-01

260

Absolute frequency measurement of the In+ clock transition with a mode-locked laser.  

UK PubMed Central (United Kingdom)

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 HeNe laser at 3.39 microm, which was calibrated against an atomic cesium fountain clock. A frequency gap of 37 THz at the fourth harmonic of the HeNe standard was bridged by a frequency comb generated by a mode-locked femtosecond laser. The frequency of the In(+) clock transition was found to be 1,267,402,452,899.92 (0.23) kHz, the accuracy being limited by the uncertainty of the HeNe laser reference. This result represents an improvement in accuracy of more than 2 orders of magnitude over previous measurements of the line and now stands as what is to our knowledge the most accurate measurement of an optical transition in a single ion.s.

von Zanthier J; Becker T; Eichenseer M; Nevsky AY; Schwedes C; Peik E; Walther H; Holzwarth R; Reichert J; Udem T; Hänsch TW; Pokasov PV; Skvortsov MN; Bagayev SN

2000-12-01

 
 
 
 
261

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

CERN Multimedia

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 femtosecond laser. The frequency of the In$^{+}$ clock transition was found to be $1 267 402 452 899.92 (0.23)$ kHz, the accuracy being limited by the uncertainty of the He-Ne laser reference. This represents an improvement in accuracy of more than 2 orders of magnitude on previous measurements of the line and now stands as the most accurate measurement of an optical transition in a single ion.

Von Zanthier, J; Eichenseer, M; Nevsky, A Y; Schwedes, C; Peik, E; Walther, H; Holzwarth, R; Reichert, J; Udem, T; Hänsch, T W; Pokasov, P V; Skvortsov, M N; Bagayev, S N; Becker, Th.; Schwedes, Ch.; Udem, Th.

2000-01-01

262

Absolute frequency measurement of the In+ clock transition with a mode-locked laser.  

Science.gov (United States)

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 HeNe laser at 3.39 microm, which was calibrated against an atomic cesium fountain clock. A frequency gap of 37 THz at the fourth harmonic of the HeNe standard was bridged by a frequency comb generated by a mode-locked femtosecond laser. The frequency of the In(+) clock transition was found to be 1,267,402,452,899.92 (0.23) kHz, the accuracy being limited by the uncertainty of the HeNe laser reference. This result represents an improvement in accuracy of more than 2 orders of magnitude over previous measurements of the line and now stands as what is to our knowledge the most accurate measurement of an optical transition in a single ion.s. PMID:18066328

von Zanthier, J; Becker, T; Eichenseer, M; Nevsky, A Y; Schwedes, C; Peik, E; Walther, H; Holzwarth, R; Reichert, J; Udem, T; Hänsch, T W; Pokasov, P V; Skvortsov, M N; Bagayev, S N

2000-12-01

263

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

UK PubMed Central (United Kingdom)

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.

Armstrong DJ; Alford WJ; Raymond TD; Smith AV

1996-04-01

264

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

Energy Technology Data Exchange (ETDEWEB)

Absolute magnitudes of the effective nonlinearity, {ital d}{sub eff}, were measured for seven KTP and six BBO crystals. The {ital d}{sub eff}{close_quote}s 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 injection-seeded, {ital Q}-switched Nd:YAG laser. The KTP crystals, all type II phase matched with propagation in the {ital X}{endash}{ital Z} plane, had {ital d}{sub 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, {ital d}{sub eff} ranged from 1.76 to 1.83 pm/V, and a single type II phase-matched BBO crystal had a {ital d}{sub eff} of 1.56 pm/V. The uncertainty in our measurements of {ital d}{sub eff} values is {plus_minus}5{percent} for KTP and {plus_minus}10{percent} for BBO. {copyright} {ital 1996 Optical Society of America.}

Armstrong, D.J.; Alford, W.J.; Raymond, T.D.; Smith, A.V. [Department of Lasers, Optics, and Remote Sensing, Sandia National Laboratories, Albuquerque, New Mexico 87185-1423 (United States)

1996-04-01

265

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

CERN Multimedia

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 ...

Knaack, K; Wittenburg, K

2003-01-01

266

New measurement techniques of environmental radioactivity. Methods of surveying marine radioactivity  

International Nuclear Information System (INIS)

Measurements of radioactivity have been carried out in solution or suspension in sea-water, bottom sediments and specific marine organisms. The general approach to radionuclide measurement in seawater and bottom sediments has been concentration by coprecipitation, adsorption, ion exchange or solvent extraction. These methods employed are based primarily on shipboard collection of samples followed by land-based laboratory analyses and are too time-consuming. For rapid measurement, in situ measurement of seawater or seabed gamma-ray has developed. A gamma-ray detecting probe containing the NaI(Tl) scintillation or germanium detector is enclosed in a sealed cylinder. The measurements are made by suspending the probe in a 200-300 liter tank and passing seawater through the tank by means of ship deck pumping system, towing the probe across the seafloor, hanging down the probe to the seabed, or loading the probe on a remotely operated undersea vehicle. In situ measurement of gamma-ray in the marine environment has some application to a mineral exploration and to monitoring of sea areas which may become contaminated as the result of accidents or contamination incidents. This article reviews several gamma-ray detecting probes and describes the recent studies at JAERI on the development of a small electric-cooled Ge gamma-ray detector and a marine environmental radioactivity investigation system for in situ measurement of gamma-ray. (J.P.N.).

1994-01-01

267

Evaluation of uncertainty and detection limits in radioactivity measurements  

International Nuclear Information System (INIS)

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

2008-10-01

268

Measurements of environmental radiations and radioactivities in Toki, 4  

International Nuclear Information System (INIS)

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

1986-01-01

269

Balance method of wear measurement in I. C. engine components using radioactive isotopes  

Energy Technology Data Exchange (ETDEWEB)

Application of isotopes to the measurement of wear in machine elements provides high sensitivity, makes continuous wear control feasible and shortens testing time considerably. However, in order to make the method very accurate for measurement of absolute values representing wear in I.C. engine components, knowledge of the wear particles' mass balance is required, including data on the radioactivity of the oil, oil filter and exhaust gases. Based on analysis of the theoretical model of wear mass distribution between the engine's lubricating and exhaust systems, it has been demonstrated that the relative coefficients of mass distribution Usub(oo) (oil), Usub(of) (filter), and Usub(os) (exhaust gases) are non-linear functions of time, despite the assumed steady course of wear. This proves that when these measurements are based only on the radioactivity of the oil or of the oil and oil filter, the accuracy of the measurement method is decreased, even in the case of comparative research. Theoretical considerations were confirmed by means of experiments using a specially constructed test stand, the results of which were presented in the form of real characteristics of the mass distribution of piston ring wear in the engine, and of wear on other engine components. Also, for the first time, the extent of what is referred to as direct emission of wear particle mass, msub(sb), into the exhaust system was determined.

Niewczas, A.; Makala, A.

1984-04-01

270

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

UK PubMed Central (United Kingdom)

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

Kim JA; Kim JW; Kang CS; Jin J; Eom TB

2013-05-01

271

Investigating 2010 Northern Cascadia ETS Processes With Absolute Gravity & Deformation Measurements Near Port Renfrew, British Columbia  

Science.gov (United States)

The monitoring of subduction zone Episodic Tremor and Slip (ETS) has been carried out primarily using seismic data for tremor and continuous Global Positioning System (GPS) and strain- or tilt-meter observations for transient slip. The regularity of ETS episodes in the forearc of the northern Cascadia Subduction Zone has recently allowed us to schedule a series of absolute gravity (AG) measurements to augment these other data and thereby help in understanding the physical processes involved in the generation of ETS. High-precision AG observations are sensitive to vertical motion of the observation site as well as mass redistribution during transient deformation. For the 2010 ETS event in the northern Cascadia, AG observations were carried out at Port Renfrew, British Columbia. The Port Renfrew region was targeted since it has typically had large (~7mm) vertical displacements measured at a nearby GPS site. Additionally this region has experienced large strains during past ETS episodes. The closest PBO borehole strainmeter to Port Renfrew, B004 (Sekiu, WA), typically experiences ETS shear strain transients exceeding 100 nanostrain. In this contribution, we focus on the analysis of the multiple epoch series of AG observations at Port Renfrew during the 2010 ETS event. The ratio of the change of surface gravity (?g) to vertical displacement (?h) during the ETS event will also be examined. This ratio provides unique constraints on processes involved in generating observed gravity signals and will help us explore the mechanism of ETS.

Henton, J. A.; Dragert, H.; Wang, K.; Kao, H.; Lambert, A.

2010-12-01

272

In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope  

CERN Document Server

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

,

2011-01-01

273

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

International Nuclear Information System (INIS)

[en] We present a configuration of LTS dc SQUID magnetometers that is suited for an absolute measurement of the vector components of the Earth’s magnetic field with a white noise level of about 6 fT Hz?1/2. Due to its periodic voltage–flux characteristic, a SQUID’s output voltage generally corresponds to a set of equidistant fluxes or magnetic field strengths. To resolve this ambiguity, we introduce a configuration of coplanar SQUIDs integrated on a single chip, which exhibit effective areas differing by several orders of magnitude. The set of possible magnetic field strengths matching the output voltages of these SQUIDs is thereby significantly reduced and especially unique for magnetic field strengths less than a certain threshold value of about 10 ?T in our current implementation. The SQUIDs are realized with 0.8 ?m cross-type Josephson junctions that withstand high background fields of up to 3.9 mT during cool down and operation. A first one-dimensional experimental implementation successfully measured the modulation of the magnetic field component perpendicular to the sensor surface with amplitudes exceeding 50 ?T. The overall dynamic range of the SQUID magnetometer system achieves 190 dB. (paper)

2013-01-01

274

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

Science.gov (United States)

We present a configuration of LTS dc SQUID magnetometers that is suited for an absolute measurement of the vector components of the Earth’s magnetic field with a white noise level of about 6 fT Hz-1/2. Due to its periodic voltage-flux characteristic, a SQUID’s output voltage generally corresponds to a set of equidistant fluxes or magnetic field strengths. To resolve this ambiguity, we introduce a configuration of coplanar SQUIDs integrated on a single chip, which exhibit effective areas differing by several orders of magnitude. The set of possible magnetic field strengths matching the output voltages of these SQUIDs is thereby significantly reduced and especially unique for magnetic field strengths less than a certain threshold value of about 10 ?T in our current implementation. The SQUIDs are realized with 0.8 ?m cross-type Josephson junctions that withstand high background fields of up to 3.9 mT during cool down and operation. A first one-dimensional experimental implementation successfully measured the modulation of the magnetic field component perpendicular to the sensor surface with amplitudes exceeding 50 ?T. The overall dynamic range of the SQUID magnetometer system achieves 190 dB.

Schönau, T.; Schmelz, M.; Zakosarenko, V.; Stolz, R.; Meyer, M.; Anders, S.; Fritzsch, L.; Meyer, H.-G.

2013-03-01

275

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-03-31

276

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

International Nuclear Information System (INIS)

We report high-precision frequency measurements of the separate hyperfine structure (HFS) components of the emission B - X system transitions of 127I2 molecules in the 982 - 985 nm range. To resolve the HFS of the emission lines, advantage was taken of the method of three-level laser spectroscopy. The function of exciting radiation was fulfilled by the second harmonic of a cw Nd : YAG laser, and the probe radiation in the 968 - 998 nm range was generated by an external-cavity diode laser. The output Nd : YAG laser frequency was locked to an HFS component of the absorption transition and the probing laser radiation to the emission transition component. When both frequencies were locked to HFS components with a common upper level, the output diode laser frequency was precisely equal to the emission transition frequency. The output frequency of the thus stabilised diode laser was measured with the help of a femtosecond optical frequency synthesiser based on a Ti : sapphire laser. We present the results of the absolute frequency measurements of 20 HFS components belonging to six vibrational - rotational transitions of the B - X system of iodine [R56(32 - 48)a1, P58(32 - 48)a1, P85(33 - 48)a1, R87(33 - 48a1, R88(33 - 48)a10] and all 15 components of the R86(33 - 48) line. The relative measurement uncertainty is equal to 7×10-10 and is determined by the frequency instability of the diode laser radiation.

2012-03-31

277

Improved Absolute Frequency Measurement of the 171Yb Optical Lattice Clock towards a Candidate for the Redefinition of the Second  

Science.gov (United States)

We demonstrate an improved absolute frequency measurement of the 1S0--3P0 clock transition at 578 nm in 171Yb atoms in a one-dimensional optical lattice. The clock laser linewidth is reduced to ?2 Hz by phase-locking the laser to an ultrastable neodymium-doped yttrium aluminum garnet (Nd:YAG) laser at 1064 nm through an optical frequency comb with an intracavity electrooptic modulator to achieve a high servo bandwidth. The absolute frequency is determined as 518 295 836 590 863.1(2.0) Hz relative to the SI second, and will be reported to the International Committee for Weights and Measures.

Yasuda, Masami; Inaba, Hajime; Kohno, Takuya; Tanabe, Takehiko; Nakajima, Yoshiaki; Hosaka, Kazumoto; Akamatsu, Daisuke; Onae, Atsushi; Suzuyama, Tomonari; Amemiya, Masaki; Hong, Feng-Lei

2012-10-01

278

Detection unit in equipment for measuring radioactive aerosols  

International Nuclear Information System (INIS)

The detection unit patented consists of two detectors mounted on opposite sides of the element for the collection of aerosols, with the advantage of a membrane ultrafilter. At least one of the detectors simultaneously measures alpha and beta radiation, the second detector measures either both types of radiation or only one of them. After amplification, the signals of both detectors are processed by pulse-height or pulse-shape discriminators. The outputs of the two discriminators are connected to a common input of the evaluation element. Using the pseudocoincidence method a 4 ? geometry will be achieved, the background due to natural alpha-radioactive aerosols will be reduced and sensitivity to artificial radioactive aerosols will be increased. (A.K.)

1982-01-01

279

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

International Nuclear Information System (INIS)

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

1985-01-01

280

Radioactivity measurement in imported food and food related items  

International Nuclear Information System (INIS)

[en] 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

1989-01-01

 
 
 
 
281

Measurement of natural radioactivity levels in soil in Tripoli  

International Nuclear Information System (INIS)

[en] The active concentration of radionuclides in surface soil around Tripoli metropolitan area have been measured using gamma-ray spectrometry. The average radioactivity concentrations of 238U, 232Th and 40K are 10.5, 9.5 and 270 Bq kg-1 respectively. The average outdoor terrestrial absorbed dose rate in air from gamma-radiation 1 m above the ground surface 23 nGy h-1. (Author)

1997-01-01

282

Measurement of natural radioactivity from soil samples of Sind (Pakistan)  

International Nuclear Information System (INIS)

Natural radioactivity has been measured from the soil samples collected from the Sind province of Pakistan. The measured activities of 226Ra, 232Th and 40K were found in the range of 18-47, 24-69 and 254-769 Bq kg-1, respectively. The calculated values of the absorbed dose rate in air and the annual effective dose were in the range of 33-87 nGy kg-1 and 0.16-0.43 mSv, respectively. The measured results of activity were found compatible with the worldwide findings. (authors)

2011-01-01

283

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

2004-01-01

284

Absolute measurement of dielectronic recombination for C3+ in a known external field  

International Nuclear Information System (INIS)

An absolute measurement of the rate coefficient for dielectronic recombination (DR) of C3+, via the 2s-2p core excitation, in an external electric field of 11.4±0.9(1?) Vcm-1 is presented. An inclined-beam arrangement is used and the stabilizing photons at ?155 nm are detected in delayed coincidence with the recombined ions. The full width at half maximum of the electron energy spread in the ion rest frame is 1.74±0.22(1?) eV. The measured DR rate, at a mean electron energy of 8.26±0.07(1?) eV, is (2.76±0.75)x10-10 cm3s-1. The uncertainty quoted for the DR rate is the total uncertainty, systematic and statistical, at the 1? level. In comparing the present results to theory, a semiempirical formula is used to determine which recombined ion states are ionized by the 4.65 kVcm-1 fields in the final-charge-state analyzer and not detected. For the present results, any DR of the incident electrons into n levels greater than 44 is assumed to be field ionized in the final-charge-state analyzer. A more precise treatment of field ionization, which includes the lifetime of the C2+ ions before they are ionized and the time evolution and rotation of the fields experienced by the recombined ions, is needed before a definitive comparison between experiment and theory can be made. Our DR measurement, within the limits of that approach, agrees reasonably well with an intermediate coupling calculation that uses an isolated resonance, single-configuration approximation, but does not agree with pure LS-coupling calculations. copyright 1996 The American Physical Society

1996-01-01

285

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

International Nuclear Information System (INIS)

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

1976-06-28

286

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)

2007-01-01

287

Absolute distance measurement with micrometer accuracy using a Michelson interferometer and the iterative synthetic wavelength principle.  

UK PubMed Central (United Kingdom)

We present a novel system that can measure absolute distances of up to 300 mm with an uncertainty of the order of one micrometer, within a timeframe of 40 seconds. The proposed system uses a Michelson interferometer, a tunable laser, a wavelength meter and a computer for analysis. The principle of synthetic wave creation is used in a novel way in that the system employs an initial low precision estimate of the distance, obtained using a triangulation, or time-of-flight, laser system, or similar, and then iterates through a sequence of progressively smaller synthetic wavelengths until it reaches micrometer uncertainties in the determination of the distance. A further novel feature of the system is its use of Fourier transform phase analysis techniques to achieve sub-wavelength accuracy. This method has the major advantages of being relatively simple to realize, offering demonstrated high relative precisions better than 5 × 10(-5). Finally, the fact that this device does not require a continuous line-of-sight to the target as is the case with other configurations offers significant advantages.

Alzahrani K; Burton D; Lilley F; Gdeisat M; Bezombes F; Qudeisat M

2012-02-01

288

ELENA MCP detector: absolute efficiency measurement for low energy neutral atoms  

Science.gov (United States)

MicroChannel plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission to Mercury to be launched in 2014. ELENA is a TOF sensor, based on a novel concept ultra-sonic oscillating shutter (Start section)which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop section. It is aimed to detect neutral atoms in the range 10 eV - 5 keV, within 70° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface, via solar wind-induced ion sputtering (100 eV) as well as Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (EMCP detection efficiency in the range 10eV-1keV. Outcomes from such measurements are here discussed.

Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

2012-04-01

289

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)

1983-01-00

290

Measurements of environmental radiations and radioactivities in Toki, 6  

International Nuclear Information System (INIS)

The booklet carries five reports. The first one, titled 'A Study on Nuclear Fusion Environmental Safety in the Nagoya University, Institute of plasma physics', deals with the design and development of a radiation monitoring system and a tritium monitoring system. The second work, titled 'Measurement of Environmental Radiations', consists of two parts: 'A report on TLD Measurement of Environmental Radiations in the Toki Area' and 'TLD Measurement in Toki Area (1982-1988)'. Measurements of environmental radiations made at various points throughout the area are presented. The third study addresses 'Radioactivity in Rain Associated with Chernobyl Nuclear Reactor Accident'. Rain is collected on the roof of the Institute of Plasma Physics, and gamma ray measurements are made with a germanium detector. The concentrations of radioactive fallout substances are analyzed. Then, the relations of the concentrations with the spatial dose rate is investigated. The fourth report, titled 'Measurements of Environmental Tritium Concentration in the Toki Area', deals with measurements made at various points throughout the area are listed. The fifth and last report briefly outlines some features of the Kyoto University Plasma Physics Laboratory and the Osaka University Institute of Laser Engineering. (N.K.)

1989-01-01

291

Measurements of environmental radiations and radioactivities in Toki, 5  

International Nuclear Information System (INIS)

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

1989-01-01

292

Measuring the Absolute Activity of a 58Co Source with a Coincidence Device  

International Nuclear Information System (INIS)

[en] Knowledge of the absolute activity of 58Co sources is of great value for determining the fast-neutron flux in a reactor. The authors measure this activity from ?+-? de-'excitation with a coincidence device: ?+-signal obtained from the rapid coincidence (resolving time 6 ns) of annihilation gammas is made to coincide (resolving time 0.6 ?s) with the signal for 810-keV gammas. By this method it is easily possible to measure activity in a range extending from several 104 to several 106 disintegrations per second. Under the best conditions, which are obtained at several 105 disintegrations/s, an accuracy of 1% is reached: Intercalibrations carried out between 1963 and 1965 showed good agreement between different laboratories. (author)[fr] La connaissance de l'activité absolue de sources de 58Co est d'un grand intérêt pour la détermination de flux de neutrons rapides dans un réacteur. Les auteurs effectuent la mesure de cette activité par la voie de désexcitation ?+-? au moyen d'un dispositif à coïncidences: un signal ?+-, obtenu par la mise en coïncidence rapide (temps de résolution 6 ns) des ? d'annihilation est mis en coïncidence (temps de résolution 0,6 ?s) avec le signal des y de 810 keV. La gamme des activités mesurables aisément par cette méthode s'étend de quelque 104 à quelque 106 désint./s. Dans les meilleures conditions, réalisées pour quelque 105 désint. /s, la précision atteinte est de l'ordre de 1%. Un bon accord a été obtenu lors de comparaisons interlaboratoires effectuées de 1963 a1965. (author)

1967-01-01

293

Natural radioactivity measurements in building materials used in Samsun, Turkey  

International Nuclear Information System (INIS)

[en] In this study, radioactivity levels of 35 different samples of 11 commonly used building materials in Samsun were measured by using a gamma spectrometry system. The analysis carried out with the high purity Germanium gamma spectrometry system. Radioactivity concentrations of 226Ra, 232Th and 40K range from 6 to 54 Bq kg-1, 5 to 88 Bq kg-1 and 6 to 1070 Bq kg-1, respectively. From these results, radium equivalent activities, gamma indexes, absorbed dose rates and annual effective doses were calculated for all samples. Obtained results were compared with the available data, and it was concluded that all the investigated materials did not have radiological risk. (authors)

2013-01-01

294

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.

2011-01-01

295

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

Energy Technology Data Exchange (ETDEWEB)

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

Dewald, A.; Melon, B.; Pissulla, T.; Rother, W.; Fransen, C.; Moeller, O.; Zell, K.O.; Jolie, J. [IKP, Univ. zu Koeln (Germany); Petkov, P. [Bulg. Acad. of Science, INRNE, Solfia (Bulgaria); Starosta, K.; Przemyslaw, A.; Miller, D.; Chester, A.; Vaman, C.; Voss, P.; Gade, A.; Glasmacher, T.; Stolz, A.; Bazin, D.; Weisshaar, D. [NSCL, MSU, East Lansing (United States)

2007-07-01

296

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

International Nuclear Information System (INIS)

[en] 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

1988-01-01

297

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

CERN Document Server

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.

Shendrik, Roman

2013-01-01

298

Measurements of astrophysical reaction rates for radioactive samples  

Energy Technology Data Exchange (ETDEWEB)

Reaction rates for both big-bang and stellar nucleosynthesis can be obtained from the measurement of (n,p) and (n,..gamma..) cross sections for radioactive nuclei. In the past, large backgrounds associated with the sample activity limited these types of measurements to radioisotopes with very long half lives. The advent of the low-energy, high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Results of (n,p) measurements on samples with half lives as short as fifty-three days will be given. The astrophysics to be learned from these data will be discussed. Additional difficulties are encountered when making (n,..gamma..) rather than (n,p) measurements. However, with a properly designed detector, and with the high peak neutron intensities now available, (n,..gamma..) measurements can be made for nuclei with half lives as short as several weeks. Progress on the Los Alamos (n,..gamma..) cross-section measurement program for radioactive samples will be discussed. 25 refs., 3 figs., 1 tab.

Koehler, P.E.; O' Brien, H.A.; Bowman, C.D.

1987-01-01

299

Functional requirements document for measuring emissions of airborne radioactive materials  

International Nuclear Information System (INIS)

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

1994-01-01

300

Radioactivity measurement of ?-nuclides by small solid angle method  

International Nuclear Information System (INIS)

Counting under a precise small solid angle is one of the oldest methods developed for the radioactivities measurement of ?-nuclides. The principle of solid angle counting is very simple and the accuracy is much better. The advantages of an equipment developed by the authors, in which a large area Au-Si surface barrier detector (450 mm2) is used, are introduced. Some comparisons on measurement results have been obtained with the gridded ionization chamber, and a national comparison result of 241Am which deviated from the average result is less than 0.2% are presented in detail

1998-01-01

 
 
 
 
301

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

International Nuclear Information System (INIS)

[en] 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)[fr] La principale difficulte rencontree dans la mesure des rapports isotopiques en deuterium des eaux tres pauvres avec un spectrometre de masse, provient de la presence des ions H3+ qui ne sont pas separes des ions HD+ . Il en resulte que l'indication du spectrometre de masse, quand l'echantillon ne contient pas de deuterium, n'est pas zero. On resout cette difficulte en produisant in situ, a partir de l'echantillon a mesurer, de la vapeur d'eau de rapport isotopique tres sensiblement egal a 0, au moyen d'une petite colonne a distiller. L'article decrit cette colonne, ses parametres de fonctionnement ainsi que la facon dont sont effectuees les mesures. Un dispositif de mesure des rapports isotopiques dont la sensibilite est meilleure que 0.01 x 10-6 est utilise. La methode est appliquee pour determiner ]es rapports isotopiques de trois eaux pauvres. Les resultats obtenus permettent d'attribuer a la plus pauvre d'entre elles une teneur absolue en deuterium egale a 1.71 ± 0.03 ppm. Cette eau pauvre constitue un etalon primaire a partir duquel on determine le rapport isotopique d'une eau naturelle servant de standard de laboratoire. (auteur)

1968-01-01

302

Particle sizing of airborne radioactivity field measurements at Olympic Dam  

International Nuclear Information System (INIS)

[en] 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

1993-01-01

303

Particle sizing of airborne radioactivity field measurements at Olympic Dam  

Energy Technology Data Exchange (ETDEWEB)

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.

Solomon, S.B.; Wilkis, M.; O`Brein, R.; Ganakas, G.

1993-12-01

304

Weak Interaction Measurements with Optically Trapped Radioactive Atoms  

Energy Technology Data Exchange (ETDEWEB)

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project is to apply the latest in magneto-optical and pure magnetic trapping technology to concentrate, cool, confine, and polarize radioactive atoms for precise electroweak interaction measurements. In particular, the authors have concentrated their efforts on the trapping of {sup 82}Rb for a parity-violating, beta-asymmetry measurement. Progress has been made in successfully trapping of up to 6 million {sup 82}Rb(t{sub 1/2}=75s) atoms in a magneto-optical trap coupled to a mass separator. This represents a two order of magnitude improvement in the number trapped radioactive atoms over all previous work. They have also measured the atomic hyperfine structure of {sup 82}Rb and demonstrated the MOT-to-MOT transfer and accumulation of atoms in a second trap. Finally, they have constructed and tested a time-orbiting-potential magnetic trap that will serve as a rotating beacon of spin-polarized nuclei and a beta-telescope detection system. Prototype experiments are now underway with the initial goal of making a 1% measurements of the beta-asymmetry parameter A which would match the world's best measurements.

Vieira, D.J.; Crane, S.G.; Guckert, R.; Zhao, X.; Brice, S.J.; Goldschmidt, A.; Hime, A.; Tupa, D.

1999-07-16

305

Weak Interaction Measurements with Optically Trapped Radioactive Atoms  

International Nuclear Information System (INIS)

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project is to apply the latest in magneto-optical and pure magnetic trapping technology to concentrate, cool, confine, and polarize radioactive atoms for precise electroweak interaction measurements. In particular, the authors have concentrated their efforts on the trapping of 82Rb for a parity-violating, beta-asymmetry measurement. Progress has been made in successfully trapping of up to 6 million 82Rb(t1/2=75s) atoms in a magneto-optical trap coupled to a mass separator. This represents a two order of magnitude improvement in the number trapped radioactive atoms over all previous work. They have also measured the atomic hyperfine structure of 82Rb and demonstrated the MOT-to-MOT transfer and accumulation of atoms in a second trap. Finally, they have constructed and tested a time-orbiting-potential magnetic trap that will serve as a rotating beacon of spin-polarized nuclei and a beta-telescope detection system. Prototype experiments are now underway with the initial goal of making a 1% measurements of the beta-asymmetry parameter A which would match the world's best measurements

1999-01-01

306

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)

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.

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

2007-01-01

307

Absolute measurement of dielectronic recombination for C{sup 3+} in a known external field  

Energy Technology Data Exchange (ETDEWEB)

An absolute measurement of the rate coefficient for dielectronic recombination (DR) of C{sup 3+}, via the 2{ital s}-2{ital p} core excitation, in an external electric field of 11.4{plus_minus}0.9(1{sigma}) Vcm{sup {minus}1} is presented. An inclined-beam arrangement is used and the stabilizing photons at {approximately}155 nm are detected in delayed coincidence with the recombined ions. The full width at half maximum of the electron energy spread in the ion rest frame is 1.74{plus_minus}0.22(1{sigma}) eV. The measured DR rate, at a mean electron energy of 8.26{plus_minus}0.07(1{sigma}) eV, is (2.76{plus_minus}0.75){times}10{sup {minus}10} cm{sup 3}s{sup {minus}1}. The uncertainty quoted for the DR rate is the total uncertainty, systematic and statistical, at the 1{sigma} level. In comparing the present results to theory, a semiempirical formula is used to determine which recombined ion states are ionized by the 4.65 kVcm{sup {minus}1} fields in the final-charge-state analyzer and not detected. For the present results, any DR of the incident electrons into {ital n} levels greater than 44 is assumed to be field ionized in the final-charge-state analyzer. A more precise treatment of field ionization, which includes the lifetime of the C{sup 2+} ions before they are ionized and the time evolution and rotation of the fields experienced by the recombined ions, is needed before a definitive comparison between experiment and theory can be made. Our DR measurement, within the limits of that approach, agrees reasonably well with an intermediate coupling calculation that uses an isolated resonance, single-configuration approximation, but does not agree with pure {ital LS}-coupling calculations. {copyright} {ital 1996 The American Physical Society.}

Savin, D.W.; Gardner, L.D.; Reisenfeld, D.B.; Young, A.R.; Kohl, J.L. [Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States)

1996-01-01

308

Measurement of the absolute flux from VEGA in the K band /2.2 microns/  

Science.gov (United States)

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 microns) using the Tenerife flux collector. The absolute flux from this star at the earth, reduced to the wavelength 2.20 microns, is found to be 0.375 x 10 to the -9th W/sq m-micron with an uncertainty of 8 per cent.

Selby, M. J.; Blackwell, D. E.; Petford, A. D.; Shallis, M. J.

1980-10-01

309

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).

1980-01-01

310

Measurement of the relative 235U concentration and the absolute 235U content of individual HTGR fuel particles  

International Nuclear Information System (INIS)

[en] The absolute 235U content and the relative 235U 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 235U 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

1976-01-01

311

Absolute wave-number measurements in 130Te2: reference lines spanning the 420.9-464.6-nm region  

International Nuclear Information System (INIS)

We have measured the absolute wave numbers of 39 transitions of 130Te2 spanning the spectral region of 420.9-464.6 nm to an accuracy of better than 2 parts in 109 by use of saturation spectroscopy and Fabry-Perot interferometry. These measurements provide a set of convenient and accurate transfer standards for laser wavelength calibration spanning the entire Stilbene-420 dye-tuning curve.

2005-01-01

312

Absolute measurement of the neutron sensitivity of a ZP1320 Geiger-Mueller counter using the associated-particle technique  

Energy Technology Data Exchange (ETDEWEB)

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 ZP1320 Geiger-Mueller counter at 3 MeV. The measurement is consistent with previous measurements using this type of counter.

Jones, D.T.; Bartle, C.M.; Hough, J.H.; McMurray, W.R.

1982-11-01

313

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

Energy Technology Data Exchange (ETDEWEB)

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 ZP1320 Geiger-Mueller counter at 3 MeV. The measurement is consistent with previous measurements using this type of counter.

Jones, D.T.; Bartle, C.M.; Hough, J.H.; McMurray, W.R.

1982-11-01

314

Absolute measurement of the neutron sensitivity of a ZP1320 Geiger-Mueller counter using the associated-particle technique  

Energy Technology Data Exchange (ETDEWEB)

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.

Jones, D.T.L. (Karl Bremer Hospital, Bellville (South Africa)); Bartle, C.M. (Cape Town Univ. (South Africa). Dept. of Physics); Hough, J.H. (Stellenbosch Univ. (South Africa). Dept. of Physics); McMurray, W.R. (Southern Universities Nuclear Inst., Faure (South Africa))

1982-11-01

315

PH-EP Seminar a novel method for measuring the absolute luminosity at the LHC  

CERN Multimedia

A novel method for determining the absolute luminosity in a colliding-beam experiment at circular accelerators is discussed. It uses vertex reconstruction of beam-gas interaction to determine the beam shapes and beams overlap. This method could be applied (for example) at the main LHC experiments without modification of their detectors.

CERN. Geneva; CERN. Geneva

2005-01-01

316

Measurement of the absolute sensitivity of a high-sensitivity microchannel plate  

Science.gov (United States)

We have developed a tapered microchannel plate with a large open-area ratio (90%). The absolute detection efficiency of the tapered-MCP for xenon ions exceeded that of a normal MCP roughly in proportion to the open-area ratio.

Matoba, Shiro; Takahashi, Ryota; Io, Chiro; Koizumi, Tetsuo; Shiromaru, Haruo

2012-11-01

317

Absolute Wind Measurements in the Lower Thermosphere of Venus Using Infrared Heterodyne Spectroscopy.  

Science.gov (United States)

The first absolute wind velocities above the Venusian cloud-tops were obtained using NASA/Goddard infrared heterodyne spectrometers at the NASA Infrared Telescope Facility (IRTF) and the McMath Solar Telescope. Beam-integrated Doppler displacements in the...

J. J. Goldstein

1990-01-01

318

The radioactivity measurements in soil, coal and water in south Marmara region of Turkey  

Energy Technology Data Exchange (ETDEWEB)

Radioactivity levels were determined in soil, coal and water samples collected from various locations in the south Marmara region of Turkey. The activities in samples were determined using TENNELEC LB 1000-PW detector. The absolute {beta} activities were observed to vary in the range 0.83 {+-} 0.06-0.50 {+-} 0.05 for soil in units of Bq g{sup -1}, and 1.284 {+-} 0.02-0.079 {+-} 0.002 for coal samples in units of Bq g{sup -1} and 0.74 {+-} 0.05-0.06 {+-} 0.02 for water in units of Bq l(-1) . In addition, gamma spectra of soil and coal samples which have highest level of {beta} activities were measured by using HpGe detector. U-235, Pb-214, Cs-134, Cs-137, Bi-214 and K-40 were detected in soil samples. U-235, Pb-214, Cs-134 and Bi-214 were detected in coal samples. The radioactivity levels in water samples were compared with WHO and ITS recommended levels and the literature values.

Yalcin, S.; Gurler, O. [Kastamonu University, Kastamonu (Turkey). Faculty of Education

2007-02-15

319

The radioactivity measurements in soil, coal and water in south Marmara region of Turkey  

International Nuclear Information System (INIS)

[en] Radioactivity levels were determined in soil, coal and water samples collected from various locations in the south Marmara region of Turkey. The activities in samples were determined using TENNELEC LB 1000-PW detector. The absolute beta activities were observed to vary in the range 0.83+/-0.06-0.50+/-0.05 for soil in units of Bqg-1, and 1.284+/-0.02-0.079+/-0.002 for coal samples in units of Bqg-1 and 0.74+/-0.05-0.06+/-0.02 for water in units of Bql-1. In addition, gamma spectra of soil and coal samples which have highest level of beta activities were measured by using HpGe detector. 235U, 214Pb, 134Cs, 137Cs, 214Bi and 40K were detected in soil samples. 235U, 214Pb, 134Cs and 214Bi were detected in coal samples. The radioactivity levels in water samples were compared with WHO and ITS recommended levels and the literature values

2007-01-01

320

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.)

2001-01-01

 
 
 
 
321

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 %.

1988-01-01

322

Measurement of indoor radon and natural/fall out radioactivity  

International Nuclear Information System (INIS)

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

2012-01-01

323

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.)

1984-01-00

324

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.)

1985-01-00

325

Measurement of the Radioactive Aerosol Diameter by Position Sensitive Detectors, 3.  

Science.gov (United States)

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 the position sensitive detectors. Posit...

H. Murakami A. Nakamoto M. Kanamori A. Seki

1981-01-01

326

Measurement of the Radioactive Aerosol Diameter by Position Sensitive Semiconductor Detectors, 1.  

Science.gov (United States)

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 detect...

K. Nakata M. Kanamori

1979-01-01

327

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

Science.gov (United States)

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.

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

2012-10-01

328

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

UK PubMed Central (United Kingdom)

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.

Casey DT; Frenje JA; Gatu Johnson M; Séguin FH; Li CK; Petrasso RD; Glebov VY; Katz J; Knauer JP; Meyerhofer DD; Sangster TC; Bionta RM; Bleuel DL; Döppner T; Glenzer S; Hartouni E; Hatchett SP; Le Pape S; Ma T; MacKinnon A; McKernan MA; Moran M; Moses E; Park HS; Ralph J; Remington BA; Smalyuk V; Yeamans CB; Kline J; Kyrala G; Chandler GA; Leeper RJ; Ruiz CL; Cooper GW; Nelson AJ; Fletcher K; Kilkenny J; Farrell M; Jasion D; Paguio R

2012-10-01

329

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)

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.)

Dinis de Almeida, P.M

1999-07-01

330

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)

2010-01-01

331

Interlaboratory comparisons in Scotland of airborne radioactivity measurements  

International Nuclear Information System (INIS)

In the context of the EU-sponsored project 'European Calibration and Cooperation of Mobile and Airborne Gamma-Spectrometry, the '2nd International Training in Airborne Radiation Measurement' took place in Scotland between May 21 and June 5, 2002. The Federal Radiation Protection Authority (BfA) and the Federal Border Guard (BGS) were among the 10 participating European institutions. Large-area and nuclide-specifiic environmental radioactivity measurements were carried out in a terrain with different soil contamination levels north west of the Sellafield reprocessing plant, and the data recorded by the teams were compared. The measuring campaign was to promote international cooperation in aero-gamma spectrometry in the context of disaster prevention. The tasks, preparations and results of the training are described and evaluated. (orig.)

2003-01-01

332

Radioactive waste reality as revealed by neutron measurements  

Energy Technology Data Exchange (ETDEWEB)

To comprehend certain aspects of the contents of a radioactive waste container is not a trivial matter, especially if one is not allowed to open the container and peer inside. One of the suite of tools available to a practioner in the art of nondestructive assay is based upon neutron measurements. Neutrons, both naturally occuring and induced, are penertrating radiations that can be detected external to the waste container. The practioner should be skilled in applying the proper technique(s) to selected waste types. Available techniques include active and passive neutron measurements, each with their own strengths and weaknesses. The waste material itself can compromise the assay results by occluding a portion of the mass of fissile material present, or by multiplying the number of neutrons produced by a spontaneously fissioning mass. This paper will discuss the difficult, but albeit necessary marriage, between radiioactive waste types and alternative neutron measurement techniques.

Schultz, F.J. [Oak Ridge National Lab., TN (United States)

1995-12-31

333

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

International Nuclear Information System (INIS)

[en] 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)

1979-01-01

334

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

CERN Multimedia

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.

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

335

A system and methodologies for absolute quantum efficiency measurements from the vacuum ultraviolet through the near infrared.  

UK PubMed Central (United Kingdom)

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.

Jacquot BC; Monacos SP; Hoenk ME; Greer F; Jones TJ; Nikzad S

2011-04-01

336

A system and methodologies for absolute quantum efficiency measurements from the vacuum ultraviolet through the near infrared.  

Science.gov (United States)

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. PMID:21528990

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

2011-04-01

337

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

1986-01-01

338

Interlaboratory tests for low-level radioactivity measurements in France  

International Nuclear Information System (INIS)

In the framework of French national metrological coordination, the Laboratoire de Metrologie des Rayonnements Ionisants (LMRI) organizes every year an interlaboratory test program. The participation in these programs is on a voluntary basis and the results are presented in a nameless way. These tests concern radioactivity, neutron and dosimetry measurements. In this paper, a review of interlaboratory tests for low-level radioactivity measurements proposed by LMRI is given from 1975 to 1986. Every year, three types of tests are proposed: activity tests, multigamma tests, radioanalysis tests. For the last ten years, the number of results has been respectively 90 for activity tests, 570 for multigamma tests and 400 for radioanalysis tests. The user's interest has increased, while the quality of results has improved. The deviations from LMRI's reference values are less than 3% for a restricted number of laboratories, and range between 3 and 10% for the majority of the others. The most urgent tests are for mixtures of 90Sr and activation and fission products in various matrices such as milk, grass, cereals, and sediments. 16 refs., 3 figs., 3 tabs.

1988-01-01

339

Interlaboratory tests for low-level radioactivity measurements in France  

Energy Technology Data Exchange (ETDEWEB)

In the framework of French national metrological coordination, the Laboratoire de Metrologie des Rayonnements Ionisants (LMRI) organizes every year an interlaboratory test program. The participation in these programs is on a voluntary basis and the results are presented in a nameless way. These tests concern radioactivity, neutron and dosimetry measurements. In this paper, a review of interlaboratory tests for low-level radioactivity measurements proposed by LMRI is given from 1975 to 1986. Every year, three types of tests are proposed: activity tests, multigamma tests, radioanalysis tests. For the last ten years, the number of results has been respectively 90 for activity tests, 570 for multigamma tests and 400 for radioanalysis tests. The user's interest has increased, while the quality of results has improved. The deviations from LMRI's reference values are less than 3% for a restricted number of laboratories, and range between 3 and 10% for the majority of the others. The most urgent tests are for mixtures of {sup 90}Sr and activation and fission products in various matrices such as milk, grass, cereals, and sediments. 16 refs., 3 figs., 3 tabs.

Despres, M. (DAMRI/Laboratoire de Metrologie des Rayonnements Ionisants, Gif sur Yvette (France))

1988-01-01

340

Photodetachment of He- near the 1s threshold: Absolute cross-section measurements and postcollision interactions  

International Nuclear Information System (INIS)

[en] Inner-shell photodetachment of He- is studied near the He- 1s2s2p 4Po?He 2s2p 3Po threshold. The spectrum over this region shows significant suppression of He+ signal production due to postcollision interaction (PCI) effects. The observed shape and absolute cross section are in general agreement with theoretical predictions when corrections for semiclassical PCI effects are included

2006-01-01

 
 
 
 
341

Low level radioactivity measurement in support of the CTBTO  

International Nuclear Information System (INIS)

Radioactivity measurements, together with three other technologies: seismic, hydroacoustic and infrasound, are able to detect, identify and locate nuclear explosions down to 1 kt. Eighty stations worldwide, with a sensitivity of 10-30 ?Bq/m3 for 140Ba and 1 mBq/m m3 for 133Xe, have been or will be established in order to provide an estimated 90% detection probability within 10 days after a nuclear explosion. The equipment for manual stations - the high volume samplers, high sensitivity HPGe detectors and auxiliary measurement systems, as well as the automatic stations are described. The problems and results of atmospheric transport, site location as well as equipment and station operation are discussed

2000-07-15

342

Standardisation of 125I using seven techniques for radioactivity measurement  

Science.gov (United States)

Seven methods of radioactivity measurement were used to standardise an 125I solution within the frame of an international key comparison organised by BIPM: photon photon coincidence counting with two NaI detectors, photon sum-peak counting in a NaI well detector and in a 4? CsI(Tl) sandwich spectrometer, total emission counting in a windowless 4? CsI(Tl) sandwich spectrometer, electron-X,? coincidence counting and electron-X,? sum counting in a pressurised proportional counter inside a NaI well detector and liquid scintillation counting with the CIEMAT/NIST method. The solid sources were prepared by quantitative drop deposition with addition of AgNO3. The measurement methods, the results and the applied corrections are described and discussed.

Pommé, S.; Altzitzoglou, T.; van Ammel, R.; Sibbens, G.

2005-06-01

343

Radioactive tracer measuring methods and its applications on environmental technique  

International Nuclear Information System (INIS)

[en] 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.)

1975-01-01

344

Standardisation of 125I using seven techniques for radioactivity measurement  

International Nuclear Information System (INIS)

Seven methods of radioactivity measurement were used to standardise an 125I solution within the frame of an international key comparison organised by BIPM: photon-photon coincidence counting with two NaI detectors, photon sum-peak counting in a NaI well detector and in a 4? CsI(Tl) sandwich spectrometer, total emission counting in a windowless 4? CsI(Tl) sandwich spectrometer, electron-X,? coincidence counting and electron-X,? sum counting in a pressurised proportional counter inside a NaI well detector and liquid scintillation counting with the CIEMAT/NIST method. The solid sources were prepared by quantitative drop deposition with addition of AgNO3. The measurement methods, the results and the applied corrections are described and discussed.

2005-06-01

345

Measurements and interpretation of indoor aerosol radioactivity by a microcomputer system  

Energy Technology Data Exchange (ETDEWEB)

Airborne radioactivity is closely related to the aerosol concentration, which determines the radioactivity attachment. The radioactivity hazard assessment in situations where there is mixed ventilation and aerosol concentrations also requires sensitive methods for radioactivity detection. In the present study a continuously operating cassette system with a low pressure capillary impaction (Raunemaa et al., 1984) is applied to the radioactivity control. The observed radioactivity variations indoors are interpreted on the basis of particle concentration measurements as well as radon daughter attachment modelling (Raunemaa and Hautojaervi, 1984; Olin et al., 1985).

Raunemaa, T.; Olin, M.; Hannikainen, M.; Kulmala, M.; Hautojaervi, A.

1986-06-01

346

Measurements and interpretation of indoor aerosol radioactivity by a microcomputer system  

International Nuclear Information System (INIS)

[en] Airborne radioactivity is closely related to the aerosol concentration, which determines the radioactivity attachment. The radioactivity hazard assessment in situations where there is mixed ventilation and aerosol concentrations also requires sensitive methods for radioactivity detection. In the present study a continuously operating cassette system with a low pressure capillary impaction (Raunemaa et al., 1984) is applied to the radioactivity control. The observed radioactivity variations indoors are interpreted on the basis of particle concentration measurements as well as radon daughter attachment modelling (Raunemaa and Hautojaervi, 1984; Olin et al., 1985). (author)

1986-01-01

347

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

Science.gov (United States)

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).

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

2013-06-01

348

Studies of radioactivity produced by the Hiroshima atomic bomb, 2; Measurements of fallout radioactivity  

Energy Technology Data Exchange (ETDEWEB)

Three studies of fallout measurements were reviewed for the discussion of possible radioactivity intake from the Hiroshima atomic bomb. The first study discussed correlations between enriched {sup 234}U and {sup 137}Cs specific activities from the measurement of soil samples collected in the 'black rain' area. The second study measured {sup 137}Cs activity on the rock and roof tile samples collected in the hypocenter area immediately after the explosion. Some of the rock and roof tile samples collected near the hypocenter had a small but detectable amount of {sup 137}Cs activity. However, it has been determined that {sup 137}Cs exposure, for example, was negligible compared with DS86 dose estimates, since these activity levels were low. The third study detected {sup 90}Sr activity in some of the specimens of human bones exhumed on Ninoshima Island. This study compared the difference in activity between the bone head and shaft, with higher activities obtained in the bone head. This fact suggests a short intake period for this activity, however, the levels of {sup 90}Sr contamination were too low to allow a discussion of the exposure risks. (author).

Hasai, Hiromi (Hiroshima Univ., Higashi-Hiroshima (Japan). Faculty of Engineering); Hoshi, Masaharu; Yokoro, Kenjiro

1991-03-01

349

The measurement of the radioactive aerosol diameter by position sensitive semiconductor detectors, 2  

International Nuclear Information System (INIS)

Determination of the diameter of radioactive aerosol is performed by using checkerboad type position sensitive semiconductor detectors (PSD). The filter paper with the radioactive aerosols is contacted to the PSD in order to calculate the diameter of the aerosol from the measured radioactivity. (author)

1979-01-01

350

Predicted versus absolute values in the application of exhaled nitric oxide measurements.  

UK PubMed Central (United Kingdom)

BACKGROUND: Constitutional factors such as age, sex and height, and acquired factors such as atopy and smoking, influence exhaled nitric oxide (F(E)NO) levels. The utility of predicted values based on reference equations which account for these factors has not been evaluated. AIM: To compare the performance characteristics of absolute versus % predicted values for F(E)NO as predictors of diagnosed asthma and steroid response. METHODS: We compared the sensitivities, specificities and likelihood ratios using F(E)NO (% predicted) with absolute values for F(E)NO (ppb) in 52 steroid-naive subjects with non-specific respiratory symptoms. The reference equations of Olin et al. (Chest, 2007) and Dressel et al. (Resp. Med., 2008) were used to derive predicted values. Receiver operating curve analyses were performed and the areas under the curve (AUC) were calculated for two outcomes: diagnosed asthma (yes/no), and steroid response after fluticasone for 4 weeks (defined as ? 12% increase in FEV(1); increase in mean morning PEF ? 15%; reduction in symptoms ? 1 point; increase in PC(20)AMP of ? 2 doubling doses). RESULTS: The AUCs for diagnosed asthma were: F(E)NO (absolute) 0.770; F(E)NO (% pred.): 0.758 (Olin) and 0.775 (Dressel) (NS). The AUCs for F(E)NO (abs.) and F(E)NO (% pred.) with respect to the four indices of steroid response were likewise not significantly different. CONCLUSION: Correcting F(E)NO for combinations of age, sex, height, smoking and atopy using reference equations did not enhance the performance characteristics of F(E)NO as a predictor of either the diagnosis of asthma or steroid responsiveness in patients with chronic airways-related symptoms.

Leon de la Barra S; Smith AD; Cowan JO; Peter Herbison G; Robin Taylor D

2011-11-01

351

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).

1982-01-01

352

Measurements of single and double spin asymmetry in proton-proton elastic scattering. Using RHIC polarized proton beam absolute polarimeter  

International Nuclear Information System (INIS)

Novel information on nucleon spin structure has been reported one after another from RHIC spin program. In this paper, an overview of the absolute polarimeter, which is referred to by all results of the experiment groups, is presented. Experiment of the precise measurement of spin asymmetry of proton-proton elastic scattering, which supports the principle of the polarimeter, is also presented. In addition, recent experimental information of the spin dependence of nuclear force in the region where momentum transfer is too small to apply perturbative QCD is reported. The absolute polarimeter is designed for two objectives. The first is to supply the polarization officially to the experiment groups of PHENIX and STAR. The second is to study the origin of single and double spin asymmetry AN and ANN. The RHIC accelerator is reviewed with an illustration from the viewpoint of polarized neutron beam. Set up of the absolute polarimeter and event identification of elastic scattering are illustrated. Back ground is discussed briefly. Result of AN is presented. Finally measurements of beam polarization and ANN are discussed. (S. Funahashi)

2010-01-01

353

Evaluation of representation of measuring points in atmospheric radioactivity monitoring  

International Nuclear Information System (INIS)

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

1979-03-14

354

Measurement of the abrasion of radioactive teeth by dentifrices  

International Nuclear Information System (INIS)

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

1990-01-01

355

Measurement of the abrasion of radioactive teeth by dentifrices  

Energy Technology Data Exchange (ETDEWEB)

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

Hiyoshi, Katsunori; Murai, Syouji (Industrial Research Inst. of Kanagawa Prefecture, Yokohama (Japan)); Hayashi, Ken; Hirai, Taichirou

1990-05-01

356

Proton Radioactivity Measurements at HRIBF: Ho, Lu, and Tm Isotopes  

Energy Technology Data Exchange (ETDEWEB)

Two new isotopes, {sup 145}Tm and {sup 140}Ho and three isomers in previously known isotopes, {sup 141m}Ho, {sup 150m}Lu and {sup 151m}Lu have been discovered and studied via their decay by proton emission. These proton emitters were produced at the Holifield Radioactive Ion Beam Facility (HRIBF) by heavy-ion fusion-evaporation reactions, separated in A/Q with a recoil mass spectrometer (RMS), and detected in a double-sided silicon strip detector (DSSD). The decay energy and half-life was measured for each new emitter. An analysis in terms of a spherical shell model is applied to the Tm and Lu nuclei, but Ho is considerably deformed and requires a collective model interpretation.

Akovali, Y.; Batchelder, J.C.; Bingham, C.R.; Davinson, T.; Ginter, T.N.; Gross, C.J.; Grzywacz, R.; Hamilton, J.H.; Janas, Z.; Karny, M.; Kim, S.H.; MacDonald, B.D.; Mas, J.F.; McConnell, J.W.; Piechaczek, A.; Ressler, J.J.; Rykaczewski, K.; Slinger, R.C.; Szerypo, J.; Toth, K.S.; Weintraub, W.; Woods, P.J.; Yu, C.-H.; Zganjar, E.F.

1998-11-13

357

A fast signal subspace approach for the determination of absolute levels from phased microphone array measurements  

Science.gov (United States)

Phased microphone arrays are used in a variety of applications for the estimation of acoustic source location and spectra. The popular conventional delay-and-sum beamforming methods used with such arrays suffer from inaccurate estimations of absolute source levels and in some cases also from low resolution. Deconvolution approaches such as DAMAS have better performance, but require high computational effort. A fast beamforming method is proposed that can be used in conjunction with a phased microphone array in applications with focus on the correct quantitative estimation of acoustic source spectra. This method bases on an eigenvalue decomposition of the cross spectral matrix of microphone signals and uses the eigenvalues from the signal subspace to estimate absolute source levels. The theoretical basis of the method is discussed together with an assessment of the quality of the estimation. Experimental tests using a loudspeaker setup and an airfoil trailing edge noise setup in an aeroacoustic wind tunnel show that the proposed method is robust and leads to reliable quantitative results.

Sarradj, Ennes

2010-04-01

358

Radioactivity measurements with liquid scintillator counters. 3. ed.  

International Nuclear Information System (INIS)

[en] This book is aimed at biologist initiation to radiation detection by liquid scintillators. Some basic notions on radioactivity are first recalled. Radiation absorption, and fluorescence and scintillation phenomena are studied. The different electronic elements, which are the counter constituents, and their operation principles are described, together with the controls. The user has to operate on an instrument before its use. Quenching correction methods are described. They are necessary when, with the introduction of the radioactive sample, substances which modify the scintillation yield are introduced. The operation of these corrections needs measurements and calculus: the use of computers is presented. The principal types of biological origin samples introduced in the scintillator, on which radioactivity measurement may be needed, are presented. At last some notions of radiation protection are given[fr] Il s'agit d'un manuel destine a des biologistes qui desirent s'initier a la detection des rayonnements par scintillation en milieu liquide et aux problemes qu'elle souleve. Dans un premier temps, quelques notions fondamentales sur la radioactivite sont rappelees: expliquer pourquoi certains isotopes sont instables et donc radioactifs, et preciser l'origine des differents rayonnements. L'absorption du rayonnement, les phenomenes de fluorescence et de scintillation, sont etudies dans un chapitre consacre au mecanisme physico-chimique de la scintillation en milieu liquide. Les differents elements electroniques et le principe de fonctionnement qui constituent un compteur sont decrits ainsi que les reglages que l'utilisateur doit effectuer sur un appareil avant de l'utiliser pour des mesures de radioactivite. Les methodes de corrections de quenching sont decrites. La mise en oeuvre de ces corrections necessite des mesures et des calculs, parfois effectues a l'aide de calculateurs ou d'ordinateurs. Nous examinons evidemment l'utilisation de ces dispositifs. Les echantillons doivent subir une preparation avant d'etre introduits dans des milieux scintillants de composition appropriee. Nous examinons les principaux types d'echantillons d'origine biologique sur lesquels on peut etre amene a mesurer une radioactivite. Quelques notions de radioprotection sont rappelees

1986-01-01

359

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

2009-01-01

360

Measurements of whole-body radioactivity in the UK population  

International Nuclear Information System (INIS)

[en] 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)

1992-01-01

 
 
 
 
361

Gas-phase NMR measurements, absolute shielding scales, and magnetic dipole moments of 29Si and 73Ge nuclei.  

UK PubMed Central (United Kingdom)

New gas-phase NMR measurements of the shielding constants of 29Si, 73Ge, and 1H nuclei in SiH4 and GeH4 are reported. The results, extrapolated to zero density, provide accurate isolated molecule values, best suited for comparison with theoretical calculations. Using the recent ab initio results for these molecules and the measured chemical shifts, we determine the absolute shielding scales for 29Si and 73Ge. This allows us to provide new values of the nuclear magnetic dipole moments for these two nuclei; in addition, we examine the dipole moments of 13C and 119Sn.

Makulski W; Jackowski K; Antusek A; Jaszu?ski M

2006-10-01

362

Gas-phase NMR measurements, absolute shielding scales, and magnetic dipole moments of 29Si and 73Ge nuclei.  

Science.gov (United States)

New gas-phase NMR measurements of the shielding constants of 29Si, 73Ge, and 1H nuclei in SiH4 and GeH4 are reported. The results, extrapolated to zero density, provide accurate isolated molecule values, best suited for comparison with theoretical calculations. Using the recent ab initio results for these molecules and the measured chemical shifts, we determine the absolute shielding scales for 29Si and 73Ge. This allows us to provide new values of the nuclear magnetic dipole moments for these two nuclei; in addition, we examine the dipole moments of 13C and 119Sn. PMID:17020257

Makulski, W; Jackowski, K; Antusek, A; Jaszu?ski, M

2006-10-12

363

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

CERN Document Server

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.

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

2004-01-01

364

Band oscillator strengths of the (2, 1)-(12, 1) Schumann-Runge bands of O 2 from absolute absorption cross-section measurements at room temperature  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The absolute absorption cross sections of the (2, 1)-(12, 1) Schumann-Runge bands of O 2 at room temperature have been obtained from measurements of the total absolute absorption cross sections arising from transitions from the ground-state level with v?=0 and 1 by subtraction of the v?=0 contributi...

Yoshino, K; Esmond, JR; Cheung, ASC; Freeman, DE; Parkinson, WH

365

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

Energy Technology Data Exchange (ETDEWEB)

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.

Al-Khawaja, I.M.; Lahiri, Avijit; Raftery, E.B.

1988-07-01

366

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

Energy Technology Data Exchange (ETDEWEB)

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

Goldstein, J.J.

1990-05-01

367

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

International Nuclear Information System (INIS)

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

1990-01-01

368

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

1994-01-01

369

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

UK PubMed Central (United Kingdom)

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.

Nesterenko AV; Nesterenko VB

2009-11-01

370

Measurements of neutron cross sections of radioactive waste nuclides  

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-01-01

371

Development of sampling methodic of radioactive materials and measurements in performing radioactive inspection of APS  

International Nuclear Information System (INIS)

This report describes sampling methods and methods of determination of radioactive contamination which are needed in reactor decommissioning. The decommissioning of the Armenian Power Plant is and inspection techniques is discussed.

1993-01-01

372

Characterization and absolute QE measurements of delta-doped N-channel and P-channel CCDs  

Science.gov (United States)

In this paper we present the methodology for making absolute quantum efficiency (QE) measurements from the vacuum ultraviolet (VUV) through the near infrared (NIR) on 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, and good camera vacuum to prevent chip condensation, and more stringent handling requirements. The system used for these measurements was originally designed for deep UV characterization of CCDs for the WF/PC instrument on Hubble and later for Cassini CCDs.

Jacquot, Blake C.; Monacos, Steve P.; Jones, Todd J.; Blacksberg, Jordana; Hoenk, Michael E.; Nikzad, Shouleh

2010-07-01

373

SAXS/WAXS Capability and Absolute Intensity Measurement Study at the SAXS Beamline of the Siam Photon Laboratory  

Science.gov (United States)

A Small Angle X-ray Scattering (SAXS) beamline has been constructed at the Siam Photon Laboratory of the Synchrotron Light Research Institute (SLRI), Thailand. The beamline was commissioned and opened for users in March 2011. In order to maximize the photon flux, a Double Multilayer Monochromator was adopted to monochromatize synchrotron x-rays within the energy range of 6-9 keV. The experimental station is equipped with a CCD detector for SAXS measurements and an Image Plate for wide angle x-ray scattering (WAXS) measurements. Apparatus for in-situ measurements have been developed to enable studies of nano structural changes during temperature and tensile variation. Capability for scattering measurements in absolute unit has been investigated. This work reports the current status of the beamline and results from dispersed Au nanoparticles measurements.

Phinjaroenphan, Rarm; Soontaranon, Siriwat; Chirawatkul, Prae; Chaiprapa, Jitrin; Busayaporn, Wutthikrai; Pongampai, Surachai; Lapboonreung, Supanan; Rugmai, Supagorn

2013-03-01

374

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

2004-01-01

375

Radioactivity  

Energy Technology Data Exchange (ETDEWEB)

This bulletin supplements UK radioactivity data published in Chapter 4 of the Digest of Envirnomental Protection and Water Statistics No 11 1988 (HMSO 1989). The data are presented in three sections: (a) annual emissions (gaseous liquid and solid) by site, and trends in volume; (b) annual concentrations, particularly of drinking water, strontium 90 and caesium 137; (c) estimation of collective doses from fish and shellfish consumption in the U.K. and Europe, and summary of committed dose equivalents to a one-year old infant from milk consumption in the U.K. (UK).

1989-04-01

376

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

International Nuclear Information System (INIS)

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

2009-01-01

377

Functional requirements document for measuring emissions of airborne radioactive materials  

International Nuclear Information System (INIS)

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

1994-01-01

378

Results of radioactivity measurements in France during 1983  

International Nuclear Information System (INIS)

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

1985-01-01

379

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

CERN Document Server

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).

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

380

Studies of the absolute measurement of low-level natural environmental radiation using the normal-pressure ionization chamber  

International Nuclear Information System (INIS)

The characteristics and the measurement results of a normal-pressure dry-air ionization chamber of 21-liter cylindrical type with 0.5 cm-thick walls are given. A specially designed electrometer is capable of measuring current to within +- 0.5% accuracy. Alpha contamination, which is an important factor affecting the accuracy of the environmental measurements, is precisely evaluated. The uncertainty of the absolute measurement of the environmental radiation dose in free air is found to be +- 5.2%, of which +-2.2% is from inherent factors and +- 3.0% is from common factors. The fluctuation of the ionization current is also quantitatively evaluated as a function of the charge integration time. The precision for 10-min integration time is estimated to be +- 2.4% (2sigma) at 6 ?rads/h

1978-04-28

 
 
 
 
381

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

Energy Technology Data Exchange (ETDEWEB)

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.

Maurer, A.H.; Siegel, J.A.; Denenberg, B.S.; Carabello, B.A.; Gash, A.K.; Spann, J.F.; Malmud, L.S.

1983-03-01

382

Measurements of N(4S) absolute density in a 2.45 GHz surface wave discharge by optical emission spectroscopy  

Science.gov (United States)

We have generated a N2 flowing discharge sustained by surface waves employing a 2.45 GHz high frequency source. The N2 dissociation was studied in the discharge and post-discharge regions by optical emission spectroscopy (OES) as a function of the experimental parameters: discharge power (30-160 W) and absolute pressure (1-20 Torr), at 0.5 Slm-1 flow rate. The N(2p3 4S0) absolute density was measured in the discharge by actinometry. We have introduced the effect of the N2(X1 ?g+) vibrational temperature in the actinometry equation. Such a consideration was made based on the work of Catherinot and Sy (1979 Phys. Rev. A 20 1511) which presents a profound discussion about the quenching mechanism of the N(3p 4S0) by N2(X1 ?g+, v) states. The 811.5 nm Ar and 821.6 nm N lines, from 2p9 ? 1s5 and 3p 4P0 ? 3s 4P transitions have been utilized here. Both are easily observed in the surface wave discharge. Further, the NO chemical titration was carried out in the late post-discharge furnishing the N(2p3 4S0) absolute density in that region. The extinction point of the 580.4 nm band of the N2 1st positive system was measured. The density values obtained by actinometry are validated by comparison with those measured in the post-discharge region. The two sets of data, function of pressure and discharge power, may be related by the mass conservation equation. The work provides the experimental N(2p3 4S0) absolute density values as a function of power and pressure only by application of OES techniques. Moreover, we demonstrate here that the N(3p 4P0) state is quenched by N2(X1 ?g+, v >= 2) molecules forming N2(b 1?u, v = 0) and N(4S) states, in agreement with Catherinot and Sy.

Levaton, J.; Ricard, A.; Henriques, J.; Silva, H. R. T.; Amorim, J.

2006-08-01

383

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

International Nuclear Information System (INIS)

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

1987-01-01

384

Results of radioactivity measurements in French coastal waters during 1985  

International Nuclear Information System (INIS)

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

1986-01-01

385

Measurement of intrinsic radioactivity in a GSO crystal  

CERN Multimedia

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

Wang, S C; Fujiwara, M

2002-01-01

386

Measurements of radioactive and xenobiotic substances in the biosphere in the Netherlands 1982  

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). (Auth.)

1982-01-00

387

International guidance on the establishment of quality assurance programmes for radioactivity measurement in nuclear medicine  

International Nuclear Information System (INIS)

A new guidance document for the implementation of quality assurance (QA) programmes for nuclear medicine radioactivity measurement, produced by the International Atomic Energy Agency, is described. The proposed programme is based on the principles of ISO 17025 and will enable laboratories, particularly in developing countries, to provide consistent, safe and effective radioactivity measurement services to the nuclear medicine community.

388

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)

1965-01-01

389

Absolute K-shell emission line brightness measurements of laser-irradiated targets at the National Ignition Facility (NIF)  

Science.gov (United States)

X-ray K-shell-emission-line sources generated with under-dense laser-irradiated targets, including Ge and Zn pre-pulsed foils, Ge-doped silica aerogel, Kr gas targets, and a stainless-steel-lined cavity, were developed for radiographic and imaging applications on the NIF. Tailored laser pulses delivering up to 750 kJ of 3w light on target with peak laser power ranging from 14 to 150 TW were used to optimize laser-to-x-ray conversion efficiency (CE) for the various targets. The time-integrated, K-shell emission line brightness was measured using an absolutely calibrated, elliptically curved Bragg crystal spectrometer, measuring x rays between 6 and 16 keV. Absolute x-ray yields up to ˜10 kJ/sr for the He? plus satellite emission from the mid-Z elements and corresponding CE up to 2.5% into He? and ˜6% into 6.4-16 keV emission are reported and compared with simulated spectra.

Barrios, M. A.; Regan, S. P.; Fournier, K. B.; May, M.; Colvin, J.; Olson, R.; Kane, J.; Widmann, K.; Bradley, D.; Collins, G. W.

2012-10-01

390

The measurement of the radioactive aerosol diameter by position sensitive detectors, 3  

International Nuclear Information System (INIS)

[en] 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 the position sensitive detectors. Position sensitive semiconductor detectors and Scintillation detectors with IIT tube are used as the position sensitive detector. 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. (author)

1981-01-01

391

Standard Cartridges Used in Gamma Spectrometry Measurements of Radioactive Halogens.  

Science.gov (United States)

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, ...

M. C. Lepy M. Etcheverry J. Morel B. Chauvenet

1988-01-01

392

Low energy ? counts at the radioactivity measurement laboratory of Grenoble  

International Nuclear Information System (INIS)

[en] Radioelements emitting ? low energy are very useful in biology specially in labelled compounds. The counting method with liquid scintillator is very often used. The radioactivity measurement laboratory of Grenoble uses for these measures a Tricarb-Packard. The samples to be counted are: tritiated water which is measured with a dioxane scintillator; animals textures which is measured with a dioxane scintillator; animals textures which contain 14C: these samples are dissolved in hyamine 10 X, then melted with a toluene scintillator, solid samples containing 14C or 45Ca (plant ashes); these samples are measured by suspension in scintillating mixtures. Gaseous samples 14CO2 are also counted, the gas is retained by hyamine, then mixed with a liquid scintillator. Counting of double labelled samples are also made 45Ca + 32P and 14C + 32P. The quenching corrections are made by internal standardization method, by channels ratio method or better by external standardization method. (author)[fr] Les emetteurs ? de faible energie (C14, H3, Ca45) sont tres utilises en biologie sous forme de molecules marquees. La methode de comptage par scintillateur liquide est celle qui est la plus employee. Le LMR de Grenoble effectue la mesure de ces emetteurs avec un appareil Tricarb-Packard. Les comptages portent sur des ehantillons d'eau titree comptee avec un scintillateur au dioxane; des echantillons de tissus animaux contenant du C14 sont dissous par de l'hyamine puis melange a un scintillateur au toluene. Des echantillons solides (cendres de vegetaux) contenant du C14 ou du Ca45 sont comptes sous forme de gels scintillants; des echantillons gazeux de 14CO2, le gaz est retenu par de l'hyamine puis melange au scintillateur liquide. Enfin des comptages d'echantillons doublement marques CO45 + P32 et C14 + P32 sont effectues. Les diverses corrections de quenching sont faites par la technique du standard interne, du rapport des canaux ou mieux du standard externe. (auteur)

1966-01-01

393

Ordinance on measures for the preparation of radioactive waste repositories (Ordinance on preparatory measures)  

International Nuclear Information System (INIS)

This Ordinance specifies the special licensing procedure provided for under Section 10(2) of the Federal Order of 6 October 1978 concerning the Atomic Energy Act whereby the Federal Council must grant permission before preparations for the construction of radioactive waste repositories may be undertaken. The Ordinance defines the preparatory measures, which include maps and plans of the area, a geological report, etc. It repeals the Ordinance of 24 October 1979 on the same subject. (NEA).

1978-10-06

394

Decontamination and radioactivity measurement on building surfaces related to dismantling of Japan power demonstration reactor (JPDR)  

Energy Technology Data Exchange (ETDEWEB)

In the final stage of dismantling activities for decommissioning a nuclear power plant, building structures have to be demolished to release the site for unrestricted use. Since building structures are generally made from massive reinforced concrete materials, it is not a rational way to treat all concrete materials arising from its demolition as radioactive waste. Segregation of radioactive parts from building structures is therefore indispensable. The rational procedures were studied for demolition of building structures by treating arising waste as non-radioactive materials, based on the concept established by Nuclear Safety Commission, then these were implemented in the following way by the JPDR dismantling demonstration project. Areas of the JPDR facilities are categorized into two groups : possibly contaminated areas, and possibly non-contaminated areas, based on the document of the reactor operation. Radioactivity on the building surfaces was then measured to confirm that the qualitative categorization is reasonable. After that, building surfaces were decontaminated in such a way that the contaminated layers were removed with enough margin to separate radioactive parts from non-radioactive building structures. Thought it might be possible to demolish the building structures by treating arising waste as non-radioactive materials, confirmation survey for radioactivity was conducted to show that there is no artificial radioactive nuclides produced by operation in the facility. This report describes the procedures studied on measurement of radioactivity and decontamination, and the results of its implementation in the JPDR dismantling demonstration project. (author)

Hatakeyama, Mutsuo; Tachibana, Mitsuo; Yanagihara, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-12-01

395

Absolute depth-dose-rate measurements for an 192Ir HDR brachytherapy source in water using MOSFET detectors  

International Nuclear Information System (INIS)

[en] Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an 192Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are presented and special attention is paid to the calibration of the R and K type detectors, and to the determination of appropriate correction factors for the sensitivity variation with the increase of the threshold voltage and the energy dependence. The experimental results are compared with Monte Carlo simulated dose rate distributions. The experimental results show a good agreement with the Monte Carlo simulations: the discrepancy between experimental and Monte Carlo results being within 5% for 82% of the points and within 10% for 95% of the points. Moreover, all points except two are found to lie within the experimental uncertainties, confirming thereby the quality of the results obtained

2006-01-01

396

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

Science.gov (United States)

Variable Energy Cyclotron Centre has commissioned a K-500 superconducting cyclotron for various types of nuclear physics experiments. The 3-phase radio-frequency system of superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and ±0.2(0), respectively. The analysis of the RF cavity has been carried out using 3D Computer Simulation Technology (CST) Microwave Studio code and various RF parameters and accelerating voltages ("Dee" voltage) are calculated from simulation. During the RF system commissioning, measurement of different RF parameters has been done and absolute Dee voltage has been calibrated using a CdTe X-ray detector along with its accessories and known X-ray source. The present paper discusses about the measured data and the simulation result. PMID:23464200

Som, Sumit; Seth, Sudeshna; Mandal, Aditya; Paul, Saikat; Duttagupta, Anjan

2013-02-01

397

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-02-15

398

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

Science.gov (United States)

Variable Energy Cyclotron Centre has commissioned a K-500 superconducting cyclotron for various types of nuclear physics experiments. The 3-phase radio-frequency system of superconducting cyclotron has been developed in the frequency range 9-27 MHz with amplitude and phase stability of 100 ppm and +/-0.20, respectively. The analysis of the RF cavity has been carried out using 3D Computer Simulation Technology (CST) Microwave Studio code and various RF parameters and accelerating voltages (``Dee'' voltage) are calculated from simulation. During the RF system commissioning, measurement of different RF parameters has been done and absolute Dee voltage has been calibrated using a CdTe X-ray detector along with its accessories and known X-ray source. The present paper discusses about the measured data and the simulation result.

Som, Sumit; Seth, Sudeshna; Mandal, Aditya; Paul, Saikat; Duttagupta, Anjan

2013-02-01

399

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

UK PubMed Central (United Kingdom)

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

Som S; Seth S; Mandal A; Paul S; Duttagupta A

2013-02-01

400

Absolute frequency measurements on the 2S{yields}3S transition of lithium-6,7  

Energy Technology Data Exchange (ETDEWEB)

The frequencies of the 2S-3S two-photon transition for the stable lithium isotopes were measured by cavity-enhanced Doppler-free laser excitation that was controlled by a femtosecond frequency comb. The resulting values of 815 618 181.57(18) and 815 606 727.59(18) MHz, respectively, for {sup 7}Li and {sup 6}Li are in agreement with previous measurements but are more accurate by an order of magnitude. There is still a discrepancy of about 11.6 and 10.6 MHz from the latest theoretical values. This is comparable to the uncertainty in the theoretical calculations, while uncertainty in our experimental values is more than a hundred-fold smaller. More accurate theoretical calculation of the transition frequencies would allow extraction of the absolute charge radii for these stable isotopes, which in turn could improve nuclear charge radii values for the unstable lithium isotopes.

Sanchez, Rodolfo; Ewald, Guido; Geppert, Christopher; Kluge, H-Juergen; Winters, Danyal F A; Noertershaeuser, Wilfried [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Zakova, Monika; Andjelkovic, Zoran; Kraemer, Joerg; Nothhelfer, Matthias; Tiedemann, Dirk [Institut fuer Kernchemie, Johannes Gutenberg-Universitaet Mainz, Fritz-Strassman-Weg 2, D-55128 Mainz (Germany); Bushaw, Bruce A [Chemical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Dasgupta, Kamalesh [Bhabha Atomic Research Center, Mumbai 400085 (India)], E-mail: R.Sanchez@gsi.de

2009-07-15

 
 
 
 
401

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

International Nuclear Information System (INIS)

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

2012-11-05

402

Subkilohertz absolute-frequency measurement of the 467-nm electric octupole transition in 171Yb+  

International Nuclear Information System (INIS)

The 2S1/2(F=0)?2F7/2(F=3,mF=0) transition at 467 nm in a single trapped, laser-cooled ion of 171Yb+ has been measured to be fYb+=642 121 496 771.26(23) kHz using a femtosecond laser frequency comb generator. The measurement is limited by measurement statistics and by the ac Stark shift, both related to the 4.5 kHz linewidth of the probe laser at the time. The systematic shifts of the transition, including ac Stark, second-order Zeeman, quadrupole, and blackbody shifts, have been evaluated.

2003-01-01

403

Measurement and Calculation of Absolute Single and Multiple Charge Exchange Cross Sections for Feg+ Ions Impacting H2O  

International Nuclear Information System (INIS)

Charge exchange (CE) plays a fundamental role in the collisions of solar- and stellar-wind ions with lunar and planetary exospheres, comets, and circumstellar clouds. Reported herein are absolute cross sections for single, double, triple, and quadruple CE of Feq+ (q = 5-13) ions with H2O at a collision energy of 7q keV. One measured value of the pentuple CE is also given for Fe9+ ions. An electron cyclotron resonance ion source is used to provide currents of the highly charged Fe ions. Absolute data are derived from knowledge of the target gas pressure, target path length, and incident and charge-exchanged ion currents. Experimental cross sections are compared with new results of the n-electron classical trajectory Monte Carlo approximation. The radiative and non-radiative cascades following electron transfers are approximated using scaled hydrogenic transition probabilities and scaled Auger rates. Also given are estimates of cross sections for single capture, and multiple capture followed by autoionization, as derived from the extended overbarrier model. These estimates are based on new theoretical calculations of the vertical ionization potentials of H2O up to H2O10+.

2010-09-01

404

Calibration of the Odyssey Photosynthetic Irradiance Recorder for Absolute Irradiance Measures  

Science.gov (United States)

Researchers are increasingly interested in measuring hotosynthetically active radiation (PAR) because of its importance in determining the structure and function of lotic ecosystems. The Odyssey Photosynthetic Irradiance Recorder is an affordable PAR meter gaining popularity am...

405

Calibration of new measuring systems to detect emissions of radioactive noble gases  

International Nuclear Information System (INIS)

This report describes the calibration of different systems for the integral measurement of radioactive noble gases and the calibration of a measuring chamber for the detection of individual nuclides of radioactive noble gases in the gaseous effluent of nuclear power plants. For these measuring chambers the calibration factors for Kr-85 and Xe-133 are given as well as the detection limits to be obtained with these measuring systems for several radioactive noble gases present in the gaseous effluent at the stack of nuclear power plants. Calibration factors for Kr-85 and Xe-133 and the detection limits of this measuring method for the detections of individual nuclides of radioactive noble gases in air samples are defined taken wirh a high pressure compressor in pressure flasks an measured on a Ge(Li)-semiconductor spectrometer (pressure flask measuring method). A measuring equipment is described and calibrated which allows simultaneous measurement of activity concentration of radioactive noble gases and radioactive aerosols with a sensitivity of 2 x 10-7 Ci/m3 for radioactive gases and 1 x 10-9 Ci/m3 for radioactive particulates at a background radiation of 1 R/h. This paper is an additional report to our STH-Bericht 3/76, 'Calibration of measuring equipment for monitoring of gaseous effluents from nuclear power plants', which specifies a procedure for the calibration of measuring chambers for monitoring of gaseous radioactive effluents from nuclear power plants /1/. The calibration system used here makes it possible to simultaneously calibrate several noble gas measuring devices. (orig.)

1977-01-01

406

Measurement of radioactive nuclides in the `Mayak` region  

Energy Technology Data Exchange (ETDEWEB)

The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

Myasoedov, B.F. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Novikov, A.P. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

1997-03-01

407

Measurement of radioactive nuclides in the 'Mayak' region  

International Nuclear Information System (INIS)

The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.).

1997-01-01

408

Development and application of a detector for absolute measurement of neutron fluence rate in MeV region  

International Nuclear Information System (INIS)

The development and performance of the DTS (Dual Thin Scintillator) for the absolute measurement of the neutron fluence rate between 1 and 15 MeV is decribed. The DTS detector consists of a pair of organic scintillators in a dual configuration, where the incident produces a proton-recoil which is detected in a 2? geometry therefore avoiding the effect of the escape of protons. Thin scintillators are used resulting in small multiple scattering corrections. The theoretical caluclations of detector efficiency and proton-recoil spectrum were performed by means of a Monte Carlos code - CARLO DTS. The calculated efficiency was compared to the experimental one at two neutron energies namely 2.446 MeV and 14.04 MeV applying the Time Correlated Associated Particle technique. The theoretical and experimental efficiencies agreed within the experimental uncertainties of 1.44% and 0.77%, respectively. The performance of the DTS has been verified in an absolute 235U(n,f) cross section measurement between 1 and 6 MeV neutron energy. The cross section results were compared to those obtained replacing the DTS detector by the NBS (National Bureau of Standards, USA) Black Neutron Detector. The agreement was excellent in the overlapping energy interval of the two experiments (between 1 and 3 MeV), within the estimated uncertainly in the range of 1,0 to 1,7%. The agreement with the most recent evaluation from the ENDF/B-VI was excellent in almost all the energy range between 1 and 6 MeV. The 235U(n,f) cross section, average over the 252Cf fission neutron spectrum has been evaluated. The result including the cross section values of the present work was 1220 mb, in excellent agreement with the average value among the most recent measurements, 1227 +- 12 mb, and with the value 1213 mb, using the ENDF/B-VI data. (author)

1988-01-01

409

Improvements to the measurement of absolute cortical blood flow and its application to multi-head cameras: a feasibility study  

International Nuclear Information System (INIS)

Full text:A program is described that performs Patlak graphical analysis of the brain uptake curve from the bolus phase of an ECD or HMPAO study. The aortic arch curve is used as the input function (Matsuda, EJNM 1992). This yields the unidirectional uptake coefficient that is related to absolute cortical blood flow (aCBF) in mil I O Og/min and transport of the agent into the neurons. The absolute nature of this measure has the potential to detect global cerebral microvascular or neuronal pathology that is not possible with the SPECT scan. Measuring aCBF with multiple camera heads permits its evaluation beyond the obligatory anterior view that primarily reflects frontal aCBF. Additional program features include correction for contamination of the aortic-arch (input) curve by activity from underlying vessels, better evaluation of the aortic-arch to brain delay, and subtraction of residual activity from a previous injection. We have ana lysed 17 patients at random (aged 40 to 90) who presented for HMPAO brain scans on a 3-head camera. Non aortic arch activity in the input curve underestimated aCBF by as much as 15%. aCBF was relatively unaffected by small changes in the aortic arch ROI or the bolus delay. Measured aCBF ranged from 10% above to 32% below the age-corrected normal value. The aCBF from the LPO and RPO views were at most II % below the ANT value. When a reliable age-dependence for aCBF in the normal aged population has been established, this technique can be evaluated for the detection of changes in aCBF in early dementia.

2009-01-01

410

Measurement of absolute diffraction efficiency of a variable line spaced grating using reflectivity beamline  

Energy Technology Data Exchange (ETDEWEB)

First and second order diffraction efficiency of a variable line spacing grating of average 1200 lines/mm density is measured at the reflectivity beam line of Indus-1. This grating is blazed at 3.2 deg. and has a blaze wavelength of 10 nm. The measurement has been carried out in the spectral range of 4.5 nm to 80 nm at 3o grazing angle of incidence. The maximum diffraction efficiency of the first order at {approx}10 nm has been found to be {approx} 23% and for the second order it is {approx}13%.

Kumar, M.; Modi, M. H.; Singhal, H.; Chakera, J. A.; Gupta, R. K.; Naik, P. A.; Lodha, G. S.; Gupta, P. D. [Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2012-06-05

411

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Photoionization spectra have been recorded in the 4s, 4p and 3d resonance regions for the Kr Iisoelectronic sequence using both the dual laser produced plasma technique (at DCU) to produce photoabsorption spectra, and the merged ion beam and synchrotron radiation technique (at ASTRID) to measure abs...

Kilbane, Deirdre; Folkmann, F.; Banahan, Caroline; Scully, S.; Kjeldsen, H.; van Kampen, Paul; Mansfield, M.W.D.

412

Simultaneous measurement of gamma rays and radon emission (SIMGRAE) for solid samples radioactivity assessment  

International Nuclear Information System (INIS)

A gamma/radon high-sensitivity radioactivity counter has been built in the frame of a research and development aimed at assessing the effect of construction materials on the annual radioactive dose absorbed by individuals. The counter features simultaneous gamma measurement (by high-resolution germanium spectroscopy) and radon evaluation through electrostatic collection and alpha spectroscopy of radon daughters.

2006-01-01

413

Measurement of the absolute branching fraction of Ds+ --> tau+ nutau decay.  

Science.gov (United States)

Using a sample of tagged D(s)(+) decays collected near the D(s)(*+/-)D(s)(-/+) peak production energy in e(+)e(-) collisions with the CLEO-c detector, we study the leptonic decay D(s)(+)-->tau(+)nu(tau) via the decay channel tau(+)-->e(+)nu(e)nu(tau). We measure B(D(s)(+)-->tau(+)nu(tau))=(6.17+/-0.71+/-0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D(s)(+)-->mu(+)nu(mu) and D(s)(+)-->tau(+)nu(tau) (via tau(+)-->pi(+)nu(tau)), we determine f(D(s))=(274+/-10+/-5) MeV. PMID:18518183

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

2008-04-21

414

Measurement of the Absolute Branching Fraction of D_s^+ --> tau^+ nu_tau Decay  

CERN Multimedia

Using a sample of tagged D_s decays collected near the D^*_s D_s peak production energy with the CLEO-c detector, we study the leptonic decay D^+_s to tau^+ nu_tau via the decay channel tau^+ to e^+ nu_e bar{nu}_tau. We measure B(D^+_s to tau^+ nu_tau) = (6.17 +- 0.71 +- 0.34) %. Combining with our measurements of D^+_s to mu^+ nu_mu and D^+_s to tau^+ nu_tau (via tau^+ to pi^+ bar{nu}_tau), we determine f_{D_s} = 274 +- 10 +- 5 MeV.

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

2007-01-01

415

Measuring the absolute non-gravitational acceleration of a spacecraft: goals, devices, methods, performances  

CERN Document Server

Space provides unique opportunities to test gravitation. By using an interplanetary spacecraft as a test mass, it is possible to test General Relativity at the Solar System distance scale. This requires to compute accurately the trajectory of the spacecraft, a process which relies on radio tracking and is limited by the uncertainty on the spacecraft non-gravitational acceleration. The Gravity Advanced Package (GAP) is designed to measure the non-gravitational acceleration without bias. It is composed of an electrostatic accelerometer supplemented by a rotating stage. This article presents the instrument and its performances, and describes the method to make unbiased measurements. Finally, it addresses briefly the improvement brought by the instrument as far as orbit reconstruction is concerned.

Lenoir, Benjamin; Reynaud, Serge

2011-01-01

416

Direct measurement of the 4He(?,p0) absolute cross section  

International Nuclear Information System (INIS)

A direct measurement of the 4He(?,p0) reaction was performed using 34 MeV end-point bremsstrahlung photons. Photoprotons were simultaneously detected at nine angles. The magnitude of the deduced cross section is at variance with the results from recent experiments but is in perfect agreement with the previously recommended values. Consequently, as yet no definite conclusion can be drawn about the validity of charge symmetry of the nuclear force.

1993-01-01

417

Absolute measurement of photon-flux using a multi-electrode ion chamber  

Energy Technology Data Exchange (ETDEWEB)

We measured photon flux using a multi-electrode ion chamber. These results were compared with photoemission measurements of photo-diode and Au. The experiment was carried out for photon energy of 487, 571, 688, 868 and 1078 eV at the soft-X ray beamline, BL23SU in the SPring-8. The ion chamber was supplied with Ar gas. A fitting calculation with consideration of secondary ionization by ejected electrons has reproduced plotting curves of experimental ion currents against gas density in the pressure region of 10{sup -2} to 10{sup 2} Pa. These results were from 2.07x10{sup 10} to 3.13x10{sup ll} photons/s as increasing with photon energy under the storage ring current of 100 mA. Although analytical results under 571 eV were consistent with those from measurement using a photo-diode within statistical error, the discrepancies between both results were larger as increasing the photon energy over 571 eV. The photon flux obtained at 1078 eV by using the photo-diode showed 33% smaller value comparing to that obtained from the ion chamber. (author)

Sano, Mutsumi [Japan Synchrotron Radiation Research Institute, Mikazuki, Hyogo (Japan); Yoshigoe, Akitaka; Teraoka, Yuden [Japan Atomic Energy Research Inst., Kansai Research Establishment, Synchrotron Radiation Research Center, Mikazuki, Hyogo (Japan); Saito, Norio; Suzuki, Isao H. [Electrotechnical Laboratory, Tsukuba, Ibaraki (Japan)

2001-02-01

418

Absolute frequency measurement of the magnesium intercombination transition $^1S_0 \\to ^3P_1$  

CERN Multimedia

We report on a frequency measurement of the $(3s^2)^1S_0\\to(3s3p)^3P_1$ clock transition of $^{24}$Mg on a thermal atomic beam. The intercombination transition has been referenced to a portable primary Cs frequency standard with the help of a femtosecond fiber laser frequency comb. The achieved uncertainty is $2.5\\times10^{-12}$ which corresponds to an increase in accuracy of six orders of magnitude compared to previous results. The measured frequency value permits the calculation of several other optical transitions from $^1S_0$ to the $^3P_J$-level system for $^{24}$Mg, $^{25}$Mg and $^{26}$Mg. We describe in detail the components of our optical frequency standard like the stabilized spectroscopy laser, the atomic beam apparatus used for Ramsey-Bord\\'e interferometry and the frequency comb generator and discuss the uncertainty contributions to our measurement including the first and second order Doppler effect. An upper limit of $3\\times10^{-13}$ in one second for the short term instability of our optical f...

Friebe, Jan; Riedmann, Matthias; Moldenhauer, Karsten; Mehlstäubler, Tanja; Rehbein, Nils; Lisdat, Christian; Rasel, Ernst M; Ertmer, Wolfgang; Schnatz, Harald; Lipphardt, Burghard; Grosche, Gesine

2007-01-01

419

Measurement and comparison of absolute value of soft X-ray natural circular dichroism of serine and alanine  

International Nuclear Information System (INIS)

Soft X-ray natural circular dichroism (SXNCD) spectra of serine (Ser) and alanine (Ala) thin films, were measured in absolute value with the focus at the oxygen 1s ? ?* transition of COO-. In the case of L-Ser, a positive and negative SXNCD peaks were observed around 531.5 and 532.5 eV, respectively. In the case of L-Ala, a negative SXNCD peak was observed around 532.8 eV. The SXNCD intensity of L-Ala was about ten times as large as that of L-Ser. Those differences would reflect the chiral environment of the core hole oxygen atoms of COO-.

2009-01-01

420

Measures to prevent breaches in the security of radioactive materials  

International Nuclear Information System (INIS)

The objective of this paper, which is the result of the co-operation between the Swedish Board of Customs, the Swedish Radiation Protection Institute, the Security Police and the Swedish Nuclear Power Inspectorate, is to give an idea of the national prevention system as to illicit trafficking of nuclear materials and other radioactive sources. (author)

1998-01-01